Indian Patents. 227342:A NOVEL METHOD FOR INTRODUCTION OF FLUORINE IN MONOMERS AND POLYMERS AND MONOMERS AND POLYMERS THEREOF

Title of Invention	A NOVEL METHOD FOR INTRODUCTION OF FLUORINE IN MONOMERS AND POLYMERS AND MONOMERS AND POLYMERS THEREOF
Abstract	A process for introduction of Fluorine in vinylic monomers, polymers like polyesters and acrylic copolymers by using tetra fluoro propanioc acid. Further the use of the fluotinated acrylic copolymers and polymers as surfactant, additives and in anti-corrosive highly durable coatings.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION [See section 10; rule 13] "A novel method for introduction of fluorine in monomers and polymers and monomers and polymers thereof (a) MALSHE VINOD CHINTAMANI (b) 1, Staff Quarters, UDCT Campus, Matunga Mumbai - 400 019, Maharashtra, India (c) Indian National The following specification describes the nature of the invention and the manner in which it is to be performed: Technical field: The present invention relates to a process for introduction of Fluorine in vinylic monomers, polyesters and acrylic copolymers by using tetra fluoro propanoic acid, a commercial chemical. Particularly, the present invention relates to fluorinated acrylic copolymers as surfactant additives which are used in anti-corrosive highly durable coatings. •Background and Prior art: Fluoropolymers are used in functional coating applications due to their unique properties like low coefficient of friction, low surface tension, oil and water repellency, nonadhesive nature and antifouling properties along with the added advantages like their outstanding thermal and chemical stability in extreme conditions. Because of their small size, fluorine atoms can shield a fluorinated carbon atom without any steric stress. As fluorine is difficult to polarize, it results in low intermolecular force and hence fluoropolymers have low surface tension. This is especially advantageous for their applications in surface coatings for imparting corrosion protection properties. Oxygen and water are two essential ingredients for initiating corrosion and water acts as an electrolyte in atmospheric corrosion. Liquid water especially is the most efficient corrosion medium due to its electrical conductive nature, ability to dissolve other corrosive components in the atmosphere like O2, SO2, etc and ionic species. Polymers act as barriers in the protective coatings. However polar groups like hydroxyl, ester, amide etc., in conventional polymers result in molecular interaction with moisture leading to increased surface condensed water. By minimizing such interactions, wetting of the surface can be reduced and protective life of the coatings can be extended. Most of the polymers have critical surface tension less than that of water (72X105 N/cm) and hence are poorly wetted by water. Fluoropolymers are known to have very low critical surface tension due to the small bond polarization of C-F bond. Hence fluoropolymers hinder water reaching the metallic surface in two ways: fluorinated polymers are not wetted by water and secondly the molecular absorption of water into these polymers is relatively small, about 2 15% of the conventional films. Introduction of fluorine in a polymeric molecule, thus leads to all round improvements in the polymer properties. Both surface fluorination and bulk fluorination are used for imparting hydrophobicity. The former approach involves addition of fluoro-component to the composition which is allowed to migrate to the surface and then crosslinked thus anchoring in the matrix. Their ability to migrate to the air interface during drying gives a low surface energy which results in dramatic change in the properties. There are varieties of effects that can be achieved by such surface migration like leveling, easy-clean non stick surface, moisture resistance, biological resistance, etc. Fluorocarbons are the most highly surface-active group of coating additives. Fluorosurfactants aid in wetting and flow because they decrease surface and interfacial tension. Fluorosurfactants are leveling aids because they minimize surface tension gradients between the resin and solvent that resists leveling. Fluorochemical agents function quite effectively and unlike silicones do not usually affect other properties such as water sensitivity. They are generally used at very low levels (0.05-0.10%). To improve the interaction between the solid substrate and the liquid film, it is of prime importance to ensure good wetting of the surface. Flow and leveling agents are chemical compounds that increase a coating's mobility after application, thus enabling the process of leveling. They reduce the surface tension of the wet coating and, more importantly, maintain a uniform surface tension over the entire surface area. Leveling agents influence the surface forces thereby limiting or preventing flow defects such as pinholes, fisheyes, crawling, edge crawling, sagging etc. The wetting of the substrate and leveling of the liquid film depends on the surface tension of the coating. Dupont has developed a series of fluorosurfactants and fluoro-intermediates under the trade name of Zonyl®. Zonyl® (FSP and FSO) surfactants are recommended in coatings for improvement of flow and wetting. They also reduce surface defects such as craters, pinholes, orange peels, fish eyes and edge crawling. 3 United States Patent No. 6,221,429 discloses a process for making and applying a coating powder having controlled gloss properties. The method comprises blending a mixture of a resin consisting of 60-90 wt % of a fluorine-based terpolymer, having a melting point less than 150° C, and 40-10 wt % of a compatible thermoplastic acrylic resin mixed with the terpolymer to provide a product. The coating powder is then applied to a substrate surface and baked. US 5,827,608 discloses a method of forming a thermoplastic layer on a flexible substrate having two major opposing surfaces which comprises a thermoplastic powder having a melt flow index of at least 0.008 grams/10 minutes and comprises a (meth)acrylate polymer and a fluoropolymer, the weight ratio of the (meth)acrylate polymer to the fluoropolymer ranges from 1:1 to 99:1. US 5,599,873 discloses a fluorinated coating powder for galvanized steel. The fluorinated powder coating product consists of a resin component admixed with a pigment. The resin component consists of from 60-90 wt% of a vinylidene fluoride copolymer. US 5,439,896 discloses a thermosetting powder coating composition comprising a mixture of fluorine containing copolymer and a curing agent. The fluorine containing copolymer is present in 40 to 98 parts and is selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoropropylene, and pentafluoropropylene having at least one crosslinkable reactive group selected from the group consisting of carboxyl, glycidyl, amide, and isocyanates. The copolymer has a fluorine content of at least 10% by weight, an intrinsic viscosity which is determined at 30° C in tetrahydrofuran of 0.05 to 2 dl/g, a glass transition temperature of 35-120° C, and a weight loss by heating at 105° C for three hours which does not exceed 2%. US 5,229,460 discloses a process for preparing a thermoplastic polymer based powder. The process comprises mixing a poly(vinylidene fluoride) polymer with a compatible acrylic polymer with units derived from acrylates or methacrylates; heating the mixture to obtain a molten mixture; and slow cooling the molten mixture to ambient temperature, 4 without quenching or subjecting the mixture that is cooled to ambient temperature to a subsequent annealing step, to obtain a solid mass having a degree of crystallinity of at least 85%. US 5,177,150 discloses a coating powder composition comprising a resin component, a thermoplastic acrylic resin, and a pigment component. The resin component comprises from about 50-90 wt% vinylidene fluoride/hexafluoropropylene copolymer resin. US 5,147,934 discloses a thermosetting powdery coating composition comprising a fluorine containing copolymer and a blocked isocyanates compound. The fluorine containing copolymer is present in 40-98 parts and is a monomeric moiety derived from a fluorolefin compound having hydroxyl groups as the crosslinkable reactive groups of which the content of fluorine is at least 10% by weight. US 5,093,427 discloses a process for producing a vinylidene fluoride hexafluoropropylene copolymer by the emulsion polymerization of vinylidene fluoride and hexafluoropropylene in a stirred aqueous reaction medium. The process comprises charging to a reactor: water, vinylidene fluoride, an initiator to start the polymerization, and a water-soluble surfactant capable of emulsifying both the initiator and the reaction mass during the polymerization. Additional amounts of vinylidene fluoride and initiator are fed to continue polymerization of the vinylidene fluoride until from about 50% to about 90%) of the total weight of vinylidene fluoride utilized in the process has been added to the reaction medium. To the reaction medium is then added 1-20% hexafluoropropylene by weight, based upon the combined weight of the hexafluoropropylene and the total weight of vinylidene fluoride for further polymerization, and the balance of the vinylidene fluoride which is utilized in the process. US 5,030,394 discloses a process for preparing pigmented PVDF-based powder coating products. The process comprises mixing PVDF resin with at least one compatible 5 thermoplastic PMMA resin, a minor amount of a low molecular weight acrylic polymer as a flow improver, and a minor amount of at least one pigment. US4581412 describes a fluoride resin coating composition curable at room temperature and capable of providing coating with an improved transparency and gloss. Fluorine containing copolymer comprises vinylidene fluoride and a minor amount of a vinyl monomer. US 4,690,968 discloses a fluoro olefin copolymer having an inherent viscosity from 0.05 to 2.0 dl/g and composed of (I) 10 to 70 mole % of monomeric units derived from a fluoro olefin, (II) 5 to 60 mole % of monomeric units derived from a vinyl carboxylate, (III) 5 to 70 mole % of monomeric units derived from a vinyl ether, and (IV) 0 to 30 mole % of monomeric units derived from a hydroxyl-containing vinyl ether. US 4,916,188 describes a coating powder composition containing a thermosetting polymeric binder. The thermosetting polymeric binder comprises a hydroxyl functional fluorocarbon copolymer of copolymerized monomers comprising hydroxy alkyl vinyl ether and fluoro olefin. The fluorocarbon copolymer contains between 1% and 30% mole percent hydroxy alkyl vinyl ether and is produced by copolymerizing the monomers in the absence of water. EP1422269 describes addition thermoplastic fluorocarbon having hydroxy functional group to the coating powder which enhances corrosion resistance, flexibility and adhesion. GB1408882 describes a corrosion-retardant finish consisting spraying a primer composition onto the corrosion-retardant finish in which the primer composition consists essentially of polytetrafluoroethylene or a copolymer of tetrafluoroethylene and hexafluoropropylene in a weight ratio of 95/5 to 50/50 and phosphoric acid and chromic acid and baking the primer at about 150°C - 260°C; further spraying on a powder coating of a perfluorocarbon copolymer of polytetrafluoroethylene, a copolymer of 6 tetrafluoroethylene and hexafluoropropylene or a copolymer of tetrafluoroethylene/perfluoropropylvinyl ether and baking the powder coating at about 200°C - 350°C to form a coalesced layer of the perfluorocarbon polymer about 0.5-30.0 mils in thickness. A coating composition for providing non- stick cookware comprising (a) at least one polymer of one or more ethylenically unsaturated monomers fully substituted with fluorine or a combination of fluorine and chlorine (b) at least one polymer of one or more ethyleneically un- saturated monomers other than those defined in (a) which polymer depolymerizes below the decomposition temperature of (a), (c) a compound of Co, Fe, Bi, Ce or Mn which decomposes at 100-500° C to give an oxide or hydroxide and (d) a liquid carrier is disclosed in GB1510022. In the present invention, we have used a simple and non-hazardous approach of introducing fluorine on the main chain. Monomers containing 8-10 % fluorine by weight were synthesized by one or two step processes. Ethylene glycol mono tetra fluoro propionate was used as a raw material to prepare fluorinated acrylic monomers. Tetra fluoro propanoic acid was used for blocking the excessive hydroxyl groups in a polyester polymer. Tetra fluoro propanoic acid was also used for preparation of acrylic monomers by reacting it with glycidyl methacrylate or acrylate. A novel series of water insoluble copolymers containing various % of fluorine content were synthesized. Polymeric fluoro surfactants based on hydroxyl terminated acrylic copolymer of HEMA, MMA, BA and EHA and tetrafluoro propanoic acid, Fluorinated acrylic copolymers containing 3 to 5 % fluorine were investigated for their efficacy as surfactants for their wetting and leveling properties. Higher fluorine containing resins (4 to 10 %) were used as clear coatings on curing with butylated melamine-formaldehyde resin and tested for their optical, mechanical and corrosion protective ability. No pigment has been used for assessment of anticorrosion property to accelerate the process. 7 Summary of the invention: A process for preparation of fluorinated acrylic copolymer comprising preparing Fluorinated acidic compound, tetrafluoropropionic acid by ion-exchanging sodium salt of aqueous sodium tetrafluoro propanate or hydrolyzing sodium tetrafluoro propanate with sulfuric acid; synthesizing Acrylic copolymers by solution polymerization technique using free radical initiator such as Azoisobutyronitrile (AIBN), 2-dodecyl mercaptan (DM) as a chain transfer agent and 50% solution of the acrylic monomers in solvent; and esterifying acrylic copolymer with tetrafluoro propanoic acid in the presence of esterification catalyst, p-toluene sulphonic acid (PTSA) at 1% concentration based on weight of acid and hydroxyl components at 120°C using cyclohexanone as an azeotropic solvent. The acrylic monomers are selected from methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA), etc. The solvents in solution polymerization technique are selected from cyclohexanone, tetrahydrofuran, diethyl ether, propanoic acid, etc. The quantity of said acrylic monomer is in the range of 60-65% containing 10-15 mole % of hydroxy containing acrylate. The quantity of tetrafluoro propanoic acid is in the range of 50-60-mole % of the hydroxy acrylic monomer. Fluorinated acrylic copolymers prepared by the above mentioned process and having fluorine content of said copolymer is 4 to 11 %. Fluorinated acrylic copolymers is used as an additive in coatings; fluorinated surfactant and functions as a wetting, leveling agent; in coatings as a base coat to impart hydrophobic surface; in antigraffiti paint; used in electrodeposition coating in water-dispersible form; etc. A process for preparing fluoropolymers comprising adding 50 % solution of monomer in cyclohexanone in a three necked round bottom flask fitted with a water condenser and a teflon stirrer; adding 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent to the above solution; carrying out the reaction at 75 °C 8 using water condenser; adding 100 % moles of tetrafluoro propionic acid on hydroxy ethyl acrylate along with 1 % p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component and carrying out esterification reaction at 120°C using cyclohexanone as an azeotropic solvent. Fluoropolymers prepared by the above mentioned process and having fluorine content of said fluoropolymers is 2 to 25 %.The fluoropolymers are polyester, alkyd or any other type of resins. The fluoropolymers is polyesters modified with tetra fluoro propanoic acid. The fluoropolymers is used in powder coatings with high gloss, flow properties and protection properties. A process for the preparation of fluorine containing monomers comprising esterifying glycol or hydroxyl acrylate monomer with a fluoropropionic acid using P-toluene sulphonic acid catalyst. Detailed Description: Fluorinated component i.e. tetrafluoro propanoic acid (TFPA) ([756-09-2]) was obtained by acidifying aqueous sodium tetrafluoro propionate ( [22898-01-7], M.P. 152°C), with sulfuric acid. TFPA was extracted with diethyl ether and separated by distillation. The product was a pale colored clear liquid. The purity of the acid was determined by acid value (B.P. was 133°C, Acid value of TFPA was found to be 380mg of KOH per gm compound. % purity was 98.9%). Alternatively TFPA was also obtained by ion-exchanging the aqueous solution of tetrafluoro sodium propionate with a strong acid cation exchange resin, Indion 130 (M/s. Ion Exchange Ltd., Mumbai). Acrylic monomers like methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA) obtained from the local suppliers were polymerized with azoisobutyronitrile (AIBN) and 2-dodecyl mercaptan (DM) as a free radical initiator and a chain transfer agent respectively. Solvents like cyclohexanone, tetrahydrofuran were used as diluents for the reaction. 9 Acrylic copolymers were synthesized by solution polymerization technique using free radical initiator, AIBN, 2-dodecyl mercaptan as a chain transfer agent and cyclohexanone as a solvent. 50% solution of the monomer in cyclohexanone was used for polymerization. In a three-necked round bottom flask fitted with water condenser, thermometer pocket and a Teflon stirrer, required quantity of acrylic monomers were charged along with the solvent, initiator and chain-terminating agent. The polymerization was carried out at 75°C using water bath. Acrylic monomers are selected from methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA), etc. Solvents are selected from cyclohexanone, tetrahydrofuran, diethyl ether and propanoic acid. Preferred solvent is cyclohexanone. In the second stage, the required quantity of tetrafluoro propanoic acid (depending upon the desired extent of fluorination ) was added along with the esterification catalyst, p-toluene sulphonic acid (PTSA) at 1% concentration based on weight of acid and hydroxyl components. Esterification was carried out at 120°C using cyclohexanone as an azeotropic solvent. The reaction was monitored by water of condensation. Similarly the esterification was also carried out using propanoic acid. The generalized structure of the resins is represented in Figure No. 1. For coating application high molecular weight and high fluorine containing copolymers were synthesized. Polyester polymers were synthesized using high hydroxyl content monomers such as glycerol, pentaerythritol with other dibasic acids such as phthalicanhydride, isophthalic acid and the other di and tri basic acids used in manufacture of polyester resins used for the manufacture of coatings and polyester polyols. In these syntheses, tetrafluoropropanoic acid was used as a monobasic acid for adding fluorine to the molecule to the desired extent. The concentration of acrylic monomer used is in the range of 50-90% in a solvent. 10 The quantity of acrylic monomer used is in the range of 30-65% containing 10-15 molt % of hydroxy containing acrylate The quantity of tetrafluoro propanoic acid used is in the range of 50-60 mole % of th The quantity of free radical initiator used is in the range of 0.1 to 10% of the total monomers. Alternatively the monomers were polymerized without any initiators using thermal polymerization. The quantity of propanoic acid used is in the same range as tetraflouropropanoic acid fo comparison. Various acrylic copolymers were synthesized which are quoted in Table I Table 1 : Composition of Various Acrylic Copolymers (used for clear coatings) Resins Monomers Esterification -OHvalue % Solids Mn Mw / Mn MMA HEMA BA Acid % Mole MHBT-24 50 20 30 TFPA 40 51.1 62.1 6536 2.004 MHBP-24 50 20 30 PA 40 50.3 53.2 6445 1.752 MHBT-26 50 20 30 TFPA 60 26.1 51.5 6625 1.949 MHBP-26 50 20 30 PA 60 43.8 53.1 6640 1.818 MHBT-275 50 20 30 TFPA 75 16.3 54.6 6691 1.818 MHBP-275 50 20 30 PA 75 21.3 47.6 5784 1.725 MHBT-34 50 30 20 TFPA 40 58.7 54 4746 1.925 MHBP-34 50 30 20 PA 40 69.5 54.4 6180 1.849 MHBT-36 50 30 20 TFPA 60 36.6 56.2 6670 1.980 MHBP-36 50 30 20 PA 60 45.7 50.8 6500 1.864 MHBT-375 50 30 20 TFPA 75 20.3 56.4 6666 1.978 11 MHBP-375 50 30 20 PA 75 33.9 52.5 6296 2.074 Solvent: cyclohexanone; AIBN: 3%; dodecyl Mercaptan: 7.2%; TFPA: 2.2,3,3 tetrafluoro propanoic acid ; PA: Propanoic acid, Temperature: 75°C ( 1st stage) and 120°C (2nd stage) $ : based on moles of HEMA;- mg of KOH per gm resin Fluorine content of the acrylic coplymers are given in table 2 Table 2 : Fluorine Content of copolymers Resin % Fluorine content Theoretical Experimental MHBT-24 4.48 4.1 MHBT-26 6.28 6.1 MHBT-275 7.77 7.47 MHBT-34 6.16 6.06 MHBT-36 8.78 8.68 MHBT-375 10.59 9.98 The products were analyzed for their hydroxyl value, molecular weight and molecular weight distribution by gel permeation chromatography (GPC). The products were characterized by IR. Fluoride content of the resins was found by the following method; Known weight of the resin was mixed with the excess anhydrous sodium carbonate and heated at 800°C for 8hrs in the furnace. On cooling the incinerated product was dissolved in water and liquor ammonia was added to make the solution more basic and to avoid formation of gel-like solution. The content was then heated to boiling for 15 minutes. The content was cooled and calcium chloride (about 10% of the weight of the monomers) was added to convert sodium fluoride to calcium fluoride. The solution was filtered to separate the solid calcium fluoride. The product was incinerated at 750 C in the furnace for 4 hrs and weighed after cooling. From the amount of calcium fluoride formed fluorine 12 content was calculated after correcting for the solubility of calcium fluoride in aqueous solution (Solubility of CaF2 in water is 16mg / lit corresponding to lOmg / lit as fluoride). The theoretical fluorine content was calculated from the composition of the copolymer. The contact angle is the angle formed between the plane tangent to the surfaces of the solid and the liquid at the wetting perimeter. The advancing contact angle was measured using a Kruss G-10 contact angle measuring system under ambient conditions. For comparison contact angles of commercial surfactants Span-20, Span-80 and Brij-30 were measured under similar conditions. Testing of resins The resins were tested for their mechanical, optical properties as per ASTM standards . For testing the properties of coatings like corrosion protection, scratch hardness and falling weight impact resistance, mild steel panels of 15cm X 7.5cm were used. The panels were abraded with emery paper followed by cleaning with the solvent. The resins were cured with stoichiometric quantity of butylated melamine formaldehyde resin at 135°C for 15minutes. Since nonfluorinated resins showed nonwetting behaviour, 0.1% (w/w) of commercial urethane-based wetting agent WD 1070 (K-Tech India (P) Ltd., Thane) dissolved in methyl ethyl ketone was mixed with the resin solution for all the composition before applying on the panels by leveling technique. The solid content of the resin solution was maintained at 30% by diluting with cyclohexanone. Other properties like gloss, flexibility, Crosshatch adhesion; pencil harness and solvent resistance were tested on aluminium panels. All the fluorinated resins were dark colored as compared to their nonfluorinated counterparts. Dry film thickness of the coatings (DFT) was measured by using magnetic DFT meter. Pencil hardness of the coatings was determined using standard pencils of hardness of 6B to 5A. Impact resistance was measured by using falling weight impact tester having a load of lKg. Flexibility of the coatings was tested on a conical mandrel of 3 8-3 mm diameter size and the panels were inspected for cracks or delamination after bending. Adhesion was determined by using cross-hatch adhesion test. Specular gloss of the coatings was measured by using Gardner Glossometer at an angle of 45°. The solvent resistance of the coatings was determined for methyl ethyl 13 ketone and xylene rubs and the panels were inspected for loss of gloss or other impairment. For corrosion testing, the panels were exposed in humidity chamber, which was essentially salt spray chamber except for the salt solution replaced by deionised water. Humidity inside the cabinet was 84% RH at 30° C The panels were checked for corrosion by visual inspection regularly. Mechanical properties of the coatings comprising acrylic copolymers such as MHBT-2<: mhbp-24 mhbt-26 mhbp-26 mhbt-275 mhbp-275 mhbt-34 mhbp-3 mhbt-36 mhbp-36 mhbt-375 and mhbp-375 were tested given in table> Table 3 : Mechanical Properties of Coatings Properties FilmThickness (ASTM Dl 186-93) 00 Pencil hardness (ASTM D3363-74) Flexibility(conicalmandrel)(ASTMD522-93a) Scratchhardness(gm)(ASTMD2197-98) Crosshatchadhesion(ASTM D3359-83) Impact resistance (ASTM D2794-84) Resins Direct(0.6Kg.m) Indirect (Kg.m) MHBT-24 75-100 2H Passes 700 Good Passes 0.55 MHBP-24 75-100 2H Passes 1100 Good Passes 0.55 MHBT-26 100-150 2H Passes 700R Good Passes 0.55 MHBP-26 100-150 2H Passes MOOR Good Passes 0.55 MHBT-275 75-100 2H Passes 600R Good Passes 0.55 MHBP-275 75-100 2H Passes 1000R Good Passes >0.60 MHBT-34 100-150 2H Passes 500R Good Passes 0.55 MHBP-34 100-150 2H Passes 1200R Good Passes 0.55 MHBT-36 100-150 2H Passes 500R Good Passes 0.55 MHBP-36 75-100 2H Passes 1000 Good Passes 0.55 MHBT-375 75-100 2H Passes 300R Good Passes >0.60 MHBP-375 75-100 2H Passes 1100 Good Passes >0.60 R: Failed in the reverse travel of the test panel; * Good - the him was intact 14 The properties of all the clear coatings are given above, it can be seen that the falling weight impact and flexibility were not affected by introduction of fluorine. All the films showed good pencil hardness but some fluorinated films showed less scratch hardness. Optical, Chemical and Protective properties of the coatings comprising acrylic copolymers such as MHBT-24, MHBP-24, MHBT-26, MHBP-26, MHBT-275, MHBP-275, MHBT-34, MHBP-34, MHBT-36, MHBP-36, MHBT-375 and MHBP-375 were tested and given in table 4. Table 4: Optical, Chemical and Protective Properties of Coatings Properties Gloss@45u(ASTMD523-67) Solvent resistance (ASTM D5402-93) Corrosion test" (hrs) Resins 1 Xylene rub test MEK rub test MHBT-24 52 100 100 41 MHBP-24 59 100 100+ 21 MHBT-26 63 100 70 41 MHBP-26 50 100 100 21 MHBT-275 47 100 100 54 MHBP-275 56 100 100 21 MHBT-34 54 100 100 44 MHBP-34 58 100 100+ 21 MHBT-36 58 100 70 44 MHBP-36 58 100 100 21 MHBT-375 58 100 100 54 MHBP-375 45 100 100 21 #- Exposed to deionised water in humidity chamber at 84%RH and 30 L The properties of all the clear coatings are given above, it can be seen that properties like adhesion, gloss were more or less the same. MEK and xylene rub tests showed loss of gloss for both types of resins. The coatings showed good gloss. However the most 15 noticeable difference was observed in case of their corrosion protective ability. Fluorinated films showed better corrosion protection against corrosion than their nonfluorinated analogs. Addition of fluorine in a range 4 to 10% showed improvement of the protective properties significantly. Air-drying alkyd coatings cured on these fluorinated coatings could be peeled off from the surface thus making them suitable in anti-graffiti paints. Fluorinated polymers with lower molecular weight and lower fluorine content were prepared for use a surfactants by increasing the quantity of the initiator and reducing the quantity of TFPA for esterification of the hydroxyl groups. The prepolymers used here were also having a lower hydroxyl value. Fluoropolymer was prepared by adding 50 % solution of monomer in cyclohexanone in a three necked round bottom flask fitted with a water condenser and a teflon stirrer; adding 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent to the above solution; carrying out the reaction at 75°C using water condenser; adding 100% moles of tetrafluoro propionic acid on hydroxy ethyl acrylate along with 1 % , p-toluene sulphonic acid (PTS A) catalyst concentration based on weight of acid and hydroxy component, carrying out esterification reaction at 120°C using cyclohexanone as an azeotropic solvent and achieving the fluorine content of the resins obtained was 5.1%. To improve some of the flow properties other monomers such as ethyl acrylate is also used. Composition of fluoropolymers are given in Table 5 which were used as fluorosurfactants. The fluorine content of the fluoropolymers are given in Table 6. Molecular weight and polydispersity of the corresponding polymeric surfactants are given in table 7. Table 5 : Composition of polymeric fluorosurfactants Surfactant HEMA (m) MMA (m) EHA (m) BA(m) TFPA (m) Hydroxyl value* PS-8 0.077 0.154 - 0.078 0.054 25.3 16 PS-10 0.062 0.154 - 0.062 0.025 51.1 PS-13 0.046 0.154 0.033 - 0.019 44.1 PS-14 0.046 0.154 - 0.047 0.019 43.5 mg of KOH / g of sample Table 6 : Fluorine content of fluorosurfactants Surfactant % Fluorine Theoretical Experimental PS-8 5.18 5.15 PS-10 4.55 4.3 PS-13 4.27 3.65 PS-14 4.27 3.75 Table 7 : Molecular weight and polydispersity of polymeric surfactants Table 8: Reduction in Contact angle at 1 wt% of various surfactants on an aluminium panel Surfactant HLB values Reduction in Contact angle (°) PS-8 8.1 10 PS-10* 8.1 8 PS-13* 8.1 10 17 PS-14* 8.3 8 Span-20 8.6 6 Brij-30 9.7 4 Span-80 4.3 6 *Theoretical values calculated using following formulae; 20XMH HLB = MH + M Where MH •' weight of hydrophilic part M : weight of hydrophobic part The above results show decrease in contact angle of fluorinated surfactants and commercial surfactants. As can be seen at 1% concentration the decrease in contact angle is maximum for fluorinated surfactants, thus making them more effective. The effect of addition of these fluorinated polymeric surfactants on the wetting and flow properties of epoxy resins such as liquid and solid epoxy, alkyd resin based paint and powder coating were studied. Alkyd Paint Formulation Ingredients Wt(g) Ti02 30 Alkyd Resin (60% solid) 55 Drier (Co & Pb) 0.26 + 0.69 SMO 0.7 Solvent (Xylene: Butanol) 13 Fluorosurfactant 0.01 Total 100 For evaluating the performance of the polymeric surfactant in alkyd paint; the white paint was formulated with the above formulation. Polymeric fluorosurfactants were incorporated in the standard formula for paint (Soya bean oil alkyd based system 18 containing TiO2 as a primary pigment, PVC was 17%, 60% solids and viscosity 60sec on Ford cup B-4) at 100ppm level and the paint was applied on the mild steel panels by brush. The gloss of the panels was measured at 45°, 60° angle of incidence (ISO 2813) using BYK Glossometer. Gloss of Alkyd Paint Surfactant Gloss values @45u @60° PS 8 62 79 PS10 61 81 PS13 61 80 PS14 59 82 Blank 57 75 Gloss of the paint containing fluorosurfactant was consistantly more than the blank. Further prepared polymeric fluorosurfactants have better flow, wetting than the blank. Powder Coating Formulations Ingredients Hybrid System (PN80) (g) Polyester Resin 25.0 GT 7004 25.0 Carbon Black 1.25 BaS04 47.5 Surfactant 0.25 Benzoin 0.5 Flow additive (Acrylic based) 0.5 Total 100 The aluminium panels were coated using a above powder coating formulation and the gloss was measured and compared with blank (without polymeric surfactants). Gloss of 19 the powder coatings containing polymeric fluorosurfactants was better than that of blank as shown below Gloss of powder coating Surfactant Gloss values @45u @60u PS 8 46 66 PS10 47 66 PS13 45 63 PS14 48 62 Blank 45 62 Liquid epoxy system The aluminium panels were abraded with emery paper and then cleaned with acetone. Polymeric fluorosurfactants were mixed with epoxy resin by stirring at room temperature. The required amount of hardener triethylene tetramine was subsequently added, mixed thoroughly, and applied on aluminium panels. The samples were cured at room temperature for 15 minutes and post-cured for 5 minutes at 60° C. Their properties such as flow and wetting were compared with those of epoxy resins without polymeric fluorosurfactants (blank). Results show that the epoxy resins containing fluorosurfactant showed better flow and wetting than the blank and the films ha a high gloss and were free of cratering, so common with solvent less epoxy coatings. Epoxy polyester hybrid system Polymeric fluorosurfactants were mixed with epoxy, polyester, solvent (xylene and phenol in 4: 6 ratio) mixture and then applied on aluminium panels. The samples were cured at 190° C for 20minutes. Similarly panels without any surfactant were prepared. Their properties such as flow and wetting were compared with those of epoxy polyester hybrid system without polymeric flurorosurfactants (blank). Results show that hybrid 20 system containing prepared polymeric surfactants exhibited better flow and wetting than the blank. Figure No. 1 : Molecular Structure Of Fluorinated Acrylic Copolymers Structure of polyesters with fluorine containing side chains Where G represents a glycerin molecule, Pe represents a polyhydric alcohol such as penta erythritol or trimethylol propane or sorbitol, P represents a dibasic acid such as phthalic anhydride and F represents a tetrafluoro propanoic acid and FA represents a saturated or unsaturated fatty acid. Preparation of fluorine containing monomers. 1 g mole of ethylene glycol was esterified with one gram mole of TFPA using 1% p-tsa as a catalyst. The water of reaction was removed by addition of an entrainer such as toluene. The product was purified by fractionation to remove the unreacted ethylene glycol and diester of TFPA of ethlyne glycol. The pure monoester of TFPA of ethylene glycol was reader with one gram mole of acrylic acid or one gram mole of methacrylic acid using p-tsa as a catalyst. The water of reaction was removed by using xylene or 21 toluene as an entrainer. The monomer could be conveniently self polymerized or copolymerized using conventional acrylic monomers. The properties of the products could be adjusted with the combination of other monomers. The preparation could also be carried out using one mole of hydroxy methyl acrylate and one mole of tetrafluoropropionic acid using p-tsa as a catalyst and xylene as an entrainer. It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. Introducing the fluorine molecule by esterification of pendent hydroxyl groups in polyesters, epoxies, urethanes, phenolics, vinyls, and any other resins would be achieved by tetra fluoro propanoic acid or its higher homologues of odd number of carbon atoms produced in the manufacture of the chemical. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be falling within the scope of the invention. The following examples are for the purpose of illustration of the invention only and are not intended in any way to limit the scope of the invention. For the sake of pointing out improvement by the new technique, a comparative study has been included with propanoic acid. Example 1 Fluorinated component i.e. tetrafluoro propanoic acid (TFPA) was obtained by acidifying aqueous (quantity) sodium tetrafluoro propionate (B.P. 152°C), with equimolar proportion of sulfuric acid. TFPA was extracted with 3 times the volume diethyl ether of TFPA and separated by distillation. The product was a pale colored clear liquid. The purity of the acid was 98.9%. Acid value of TFPA was found to be 380mg of KOH per gm compound. 22 Example 2 Tetrafluoro propanoic acid TFPA was obtained by ion-exchanging the 5% solution of tetrafluoro sodium propionate with a strong acid cation exchange resin Indion 130 resin. Example 3 50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 40% moles of tetrafluoro propionic acid were added along with p-toluene sulphonic acid (PTSA) catalyst 1% concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 4.1%. Example 4 50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75 °C using water. 60% moles of tetrafluoro propionic acid was added along with , p-toluene sulphonic acid (PTSA) catalyst 1% concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 6.1%. 23 Example 5 50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 75% moles of tetrafluoro propionic acid was added along with , p-toluene sulphonic acid (PTSA) catalyst 1% concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 7.47%. Example 6 50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 40% moles of tetrafluoro propionic acid was added along with , l% p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 6.06%. Example 7 50% solution of monomer [50% mole methacrylate (MMA), 30% mole 2-hydroxy ethyl methacrylate (HEMA) and 20% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 60% moles of tetrafluoro 24 propionic acid was added along with, 1% p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 8.68%. Example 8 50% solution of monomer [50% mole methacrylate (MMA), 30% mole 2-hydroxy ethyl methacrylate (HEMA) and 20% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 75% moles of tetrafluoro propionic acid was added along with 1% , p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 9.98%. Example 9 50% solution of monomer [50% mole methacrylate (MMA), 10% mole 2-hydroxy ethyl methacrylate (HEMA) and 40% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water condensor. 100% moles of tetrafluoro propionic acid was added on hydroxy ethyl acrylate along with 1% , p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120°C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 5.1%. Advantages of the present invention : 25 • An easy non hazardous and low cost procedure of introducing fluorine atoms in polymers. An easily available chemical, sodium tetrafluoro propionate was acidified with a mineral acid or ion exchanged to get an intermediate, tetrafluoro propanoic acid by extraction. • A novel series of polymeric fluorosurfactants with water insoluble properties were prepared by the esterification of hydroxy containing acrylate copolymer with tetrafluoro propanoic acid. Introduction of fluorine in the range of 4 to 10% was found to enhance corrosion protection ability of coatings. Alkyds cured on these fluorinated surfaces could be easily peeled off. Hence such coatings can be used as antigraffiti paints. • Prepared polymeric fluorosurfactants with 3 to 5% fluorine were found to give better flow, leveling and wettability in epoxy coating, alkyd paints and powder coating. Gloss and flow of powder coatings were found to be improved by these fluorosurfactants. 26 We claim: 1. A process for preparation of fluorinated acrylic copolymer comprising preparing Fluorinated acidic compound, tetrafluoropropionic acid, by ion-exchanging sodium salt of aqueous sodium tetrafluoro propanate or hydrolyzing sodium tetrafluoro propanate with sulfuric acid; synthesizing Acrylic copolymers by solution polymerization technique using free radical initiator such as Azoisobutyronitrile (AIBN), 2-dodecyl mercaptan (DM) as a chain transfer agent and 50% solution of the acrylic monomers in solvent; and esterifying acrylic copolymer with tetrafluoro propanoic acid in the presence of esterification catalyst, p-toluene sulphonic acid (PTSA) at 1% concentration based on weight of acid and hydroxyl components at 120°C using cyclohexanone as an azeotropic solvent. 2. The process as claimed in claim 1, wherein said acrylic monomers are selected from methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA), etc. 3. The process as claimed in claim 1, wherein said solvents in solution polymerization technique are selected from cyclohexanone, tetrahydrofuran, diethyl ether, propanoic acid, etc. 4. The process as claimed in claims 1 and 2, wherein quantity of said acrylic monomer is in the range of 60-65% containing 10-15 mole % of hydroxy containing acrylate. 5. The process as claimed in claim 1, wherein quantity of tetrafluoro propanoic acid is in the range of 50-60-mole % of the hydroxy acrylic monomer. 6. Fluorinated acrylic copolymers prepared by the process as claimed in claims 1 to 5. 7. Fluorinated acrylic copolymers as claimed in claim 6, wherein fluorine content of said copolymer is 4 to 11 %. 8. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used as an additive in coatings. 27 9. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used as fluorinated surfactant and functions as a wetting, leveling agent. 10. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used in coatings as a base coat to impart hydrophobic surface. 11. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used in antigraffiti paint. 12. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used in electrodeposition coating in water-dispersible form. 13. A process for preparing fluoropolymers comprising adding 50 % solution of monomer in cyclohexanone in a three necked round bottom flask fitted with a water condenser and a teflon stirrer; adding 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent to the above solution; carrying out the reaction at 75°C using water condenser; adding 100 % moles of tetrafluoro propionic acid on hydroxy ethyl acrylate along with 1 % p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component and carrying out esterification reaction at 120°C using cyclohexanone as an azeotropic solvent. 14. Fluoropolymers prepared by the process as claimed in claim 13. 15. The Fluoropolymers as claimed in claim 14, wherein fluorine content of said fluoropolymers is 2 to 25 %. 16. The fluoropolymers as claimed in claims 14 to 15 wherein said fluoropolymers are polyester, alkyd or any other type of resins. 17. The fluoropolymers as claimed claims 14 to 16, wherein said polymer is polyesters modified with tetra fluoro propanoic acid. 18. The fluoropolymers as claimed in claims 14 to 17, wherein said polymer is used in powder coatings with high gloss, flow properties and protection properties. 19. A process for the preparation of fluorine containing monomers comprising esterifying glycol or hydroxyl acrylate monomer with a fluoropropionic acid using P-toluene sulphonic acid catalyst. 28 20. A process for preparing fluorinated acrylic copolymers, copolymers thereof and their application as substantially described herein with reference to foregoing examples 1 to 10. 21. A process for preparing fluoropolymers, polymers thereof, and their application as substantially described herein with reference to foregoing example 10. 29 Abstract A process for introduction of Fluorine in vinylic monomers, polymers like polyesters and acrylic copolymers by using tetra fluoro propanoic acid. Further the use of the fluorinated acrylic copolymers and polymers as surfactant, additives and in anti-corrosive highly durable coatings. 3 0 NOV 2004

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
[See section 10; rule 13]
"A novel method for introduction of fluorine in monomers and polymers and monomers and polymers thereof
(a) MALSHE VINOD CHINTAMANI
(b) 1, Staff Quarters, UDCT Campus, Matunga Mumbai - 400 019, Maharashtra, India
(c) Indian National

The following specification describes the nature of the invention and the manner in which it is to be performed:

Technical field:
The present invention relates to a process for introduction of Fluorine in vinylic monomers, polyesters and acrylic copolymers by using tetra fluoro propanoic acid, a commercial chemical. Particularly, the present invention relates to fluorinated acrylic copolymers as surfactant additives which are used in anti-corrosive highly durable coatings.
•Background and Prior art:
Fluoropolymers are used in functional coating applications due to their unique properties like low coefficient of friction, low surface tension, oil and water repellency, nonadhesive nature and antifouling properties along with the added advantages like their outstanding thermal and chemical stability in extreme conditions. Because of their small size, fluorine atoms can shield a fluorinated carbon atom without any steric stress. As fluorine is difficult to polarize, it results in low intermolecular force and hence fluoropolymers have low surface tension. This is especially advantageous for their applications in surface coatings for imparting corrosion protection properties. Oxygen and water are two essential ingredients for initiating corrosion and water acts as an electrolyte in atmospheric corrosion. Liquid water especially is the most efficient corrosion medium due to its electrical conductive nature, ability to dissolve other corrosive components in the atmosphere like O2, SO2, etc and ionic species. Polymers act as barriers in the protective coatings. However polar groups like hydroxyl, ester, amide etc., in conventional polymers result in molecular interaction with moisture leading to increased surface condensed water. By minimizing such interactions, wetting of the surface can be reduced and protective life of the coatings can be extended. Most of the polymers have critical surface tension less than that of water (72X105 N/cm) and hence are poorly wetted by water. Fluoropolymers are known to have very low critical surface tension due to the small bond polarization of C-F bond. Hence fluoropolymers hinder water reaching the metallic surface in two ways: fluorinated polymers are not wetted by water and secondly the molecular absorption of water into these polymers is relatively small, about
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15% of the conventional films. Introduction of fluorine in a polymeric molecule, thus leads to all round improvements in the polymer properties.
Both surface fluorination and bulk fluorination are used for imparting hydrophobicity. The former approach involves addition of fluoro-component to the composition which is allowed to migrate to the surface and then crosslinked thus anchoring in the matrix. Their ability to migrate to the air interface during drying gives a low surface energy which results in dramatic change in the properties. There are varieties of effects that can be achieved by such surface migration like leveling, easy-clean non stick surface, moisture resistance, biological resistance, etc. Fluorocarbons are the most highly surface-active group of coating additives. Fluorosurfactants aid in wetting and flow because they decrease surface and interfacial tension. Fluorosurfactants are leveling aids because they minimize surface tension gradients between the resin and solvent that resists leveling. Fluorochemical agents function quite effectively and unlike silicones do not usually affect other properties such as water sensitivity. They are generally used at very low levels (0.05-0.10%).
To improve the interaction between the solid substrate and the liquid film, it is of prime importance to ensure good wetting of the surface. Flow and leveling agents are chemical compounds that increase a coating's mobility after application, thus enabling the process of leveling. They reduce the surface tension of the wet coating and, more importantly, maintain a uniform surface tension over the entire surface area. Leveling agents influence the surface forces thereby limiting or preventing flow defects such as pinholes, fisheyes, crawling, edge crawling, sagging etc. The wetting of the substrate and leveling of the liquid film depends on the surface tension of the coating.
Dupont has developed a series of fluorosurfactants and fluoro-intermediates under the trade name of Zonyl®. Zonyl® (FSP and FSO) surfactants are recommended in coatings for improvement of flow and wetting. They also reduce surface defects such as craters, pinholes, orange peels, fish eyes and edge crawling.
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United States Patent No. 6,221,429 discloses a process for making and applying a coating powder having controlled gloss properties. The method comprises blending a mixture of a resin consisting of 60-90 wt % of a fluorine-based terpolymer, having a melting point less than 150° C, and 40-10 wt % of a compatible thermoplastic acrylic resin mixed with the terpolymer to provide a product. The coating powder is then applied to a substrate surface and baked.
US 5,827,608 discloses a method of forming a thermoplastic layer on a flexible substrate having two major opposing surfaces which comprises a thermoplastic powder having a melt flow index of at least 0.008 grams/10 minutes and comprises a (meth)acrylate polymer and a fluoropolymer, the weight ratio of the (meth)acrylate polymer to the fluoropolymer ranges from 1:1 to 99:1.
US 5,599,873 discloses a fluorinated coating powder for galvanized steel. The fluorinated powder coating product consists of a resin component admixed with a pigment. The resin component consists of from 60-90 wt% of a vinylidene fluoride copolymer.
US 5,439,896 discloses a thermosetting powder coating composition comprising a mixture of fluorine containing copolymer and a curing agent. The fluorine containing copolymer is present in 40 to 98 parts and is selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoropropylene, and pentafluoropropylene having at least one crosslinkable reactive group selected from the group consisting of carboxyl, glycidyl, amide, and isocyanates. The copolymer has a fluorine content of at least 10% by weight, an intrinsic viscosity which is determined at 30° C in tetrahydrofuran of 0.05 to 2 dl/g, a glass transition temperature of 35-120° C, and a weight loss by heating at 105° C for three hours which does not exceed 2%.
US 5,229,460 discloses a process for preparing a thermoplastic polymer based powder. The process comprises mixing a poly(vinylidene fluoride) polymer with a compatible acrylic polymer with units derived from acrylates or methacrylates; heating the mixture to obtain a molten mixture; and slow cooling the molten mixture to ambient temperature,
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without quenching or subjecting the mixture that is cooled to ambient temperature to a subsequent annealing step, to obtain a solid mass having a degree of crystallinity of at least 85%.
US 5,177,150 discloses a coating powder composition comprising a resin component, a thermoplastic acrylic resin, and a pigment component. The resin component comprises from about 50-90 wt% vinylidene fluoride/hexafluoropropylene copolymer resin.
US 5,147,934 discloses a thermosetting powdery coating composition comprising a fluorine containing copolymer and a blocked isocyanates compound. The fluorine containing copolymer is present in 40-98 parts and is a monomeric moiety derived from a fluorolefin compound having hydroxyl groups as the crosslinkable reactive groups of which the content of fluorine is at least 10% by weight.
US 5,093,427 discloses a process for producing a vinylidene fluoride hexafluoropropylene copolymer by the emulsion polymerization of vinylidene fluoride and hexafluoropropylene in a stirred aqueous reaction medium. The process comprises charging to a reactor: water, vinylidene fluoride, an initiator to start the polymerization, and a water-soluble surfactant capable of emulsifying both the initiator and the reaction mass during the polymerization. Additional amounts of vinylidene fluoride and initiator are fed to continue polymerization of the vinylidene fluoride until from about 50% to about 90%) of the total weight of vinylidene fluoride utilized in the process has been added to the reaction medium. To the reaction medium is then added 1-20% hexafluoropropylene by weight, based upon the combined weight of the hexafluoropropylene and the total weight of vinylidene fluoride for further polymerization, and the balance of the vinylidene fluoride which is utilized in the process.
US 5,030,394 discloses a process for preparing pigmented PVDF-based powder coating products. The process comprises mixing PVDF resin with at least one compatible
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thermoplastic PMMA resin, a minor amount of a low molecular weight acrylic polymer as a flow improver, and a minor amount of at least one pigment.
US4581412 describes a fluoride resin coating composition curable at room temperature and capable of providing coating with an improved transparency and gloss. Fluorine containing copolymer comprises vinylidene fluoride and a minor amount of a vinyl monomer.
US 4,690,968 discloses a fluoro olefin copolymer having an inherent viscosity from 0.05 to 2.0 dl/g and composed of (I) 10 to 70 mole % of monomeric units derived from a fluoro olefin, (II) 5 to 60 mole % of monomeric units derived from a vinyl carboxylate, (III) 5 to 70 mole % of monomeric units derived from a vinyl ether, and (IV) 0 to 30 mole % of monomeric units derived from a hydroxyl-containing vinyl ether.
US 4,916,188 describes a coating powder composition containing a thermosetting polymeric binder. The thermosetting polymeric binder comprises a hydroxyl functional fluorocarbon copolymer of copolymerized monomers comprising hydroxy alkyl vinyl ether and fluoro olefin. The fluorocarbon copolymer contains between 1% and 30% mole percent hydroxy alkyl vinyl ether and is produced by copolymerizing the monomers in the absence of water.
EP1422269 describes addition thermoplastic fluorocarbon having hydroxy functional group to the coating powder which enhances corrosion resistance, flexibility and adhesion.
GB1408882 describes a corrosion-retardant finish consisting spraying a primer composition onto the corrosion-retardant finish in which the primer composition consists essentially of polytetrafluoroethylene or a copolymer of tetrafluoroethylene and hexafluoropropylene in a weight ratio of 95/5 to 50/50 and phosphoric acid and chromic acid and baking the primer at about 150°C - 260°C; further spraying on a powder coating of a perfluorocarbon copolymer of polytetrafluoroethylene, a copolymer of
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tetrafluoroethylene and hexafluoropropylene or a copolymer of tetrafluoroethylene/perfluoropropylvinyl ether and baking the powder coating at about 200°C - 350°C to form a coalesced layer of the perfluorocarbon polymer about 0.5-30.0 mils in thickness.
A coating composition for providing non- stick cookware comprising (a) at least one polymer of one or more ethylenically unsaturated monomers fully substituted with fluorine or a combination of fluorine and chlorine (b) at least one polymer of one or more ethyleneically un- saturated monomers other than those defined in (a) which polymer depolymerizes below the decomposition temperature of (a), (c) a compound of Co, Fe, Bi, Ce or Mn which decomposes at 100-500° C to give an oxide or hydroxide and (d) a liquid carrier is disclosed in GB1510022.
In the present invention, we have used a simple and non-hazardous approach of introducing fluorine on the main chain. Monomers containing 8-10 % fluorine by weight were synthesized by one or two step processes. Ethylene glycol mono tetra fluoro propionate was used as a raw material to prepare fluorinated acrylic monomers. Tetra fluoro propanoic acid was used for blocking the excessive hydroxyl groups in a polyester polymer. Tetra fluoro propanoic acid was also used for preparation of acrylic monomers by reacting it with glycidyl methacrylate or acrylate. A novel series of water insoluble copolymers containing various % of fluorine content were synthesized. Polymeric fluoro surfactants based on hydroxyl terminated acrylic copolymer of HEMA, MMA, BA and EHA and tetrafluoro propanoic acid, Fluorinated acrylic copolymers containing 3 to 5 % fluorine were investigated for their efficacy as surfactants for their wetting and leveling properties. Higher fluorine containing resins (4 to 10 %) were used as clear coatings on curing with butylated melamine-formaldehyde resin and tested for their optical, mechanical and corrosion protective ability. No pigment has been used for assessment of anticorrosion property to accelerate the process.
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Summary of the invention:
A process for preparation of fluorinated acrylic copolymer comprising preparing Fluorinated acidic compound, tetrafluoropropionic acid by ion-exchanging sodium salt of aqueous sodium tetrafluoro propanate or hydrolyzing sodium tetrafluoro propanate with sulfuric acid; synthesizing Acrylic copolymers by solution polymerization technique using free radical initiator such as Azoisobutyronitrile (AIBN), 2-dodecyl mercaptan (DM) as a chain transfer agent and 50% solution of the acrylic monomers in solvent; and esterifying acrylic copolymer with tetrafluoro propanoic acid in the presence of esterification catalyst, p-toluene sulphonic acid (PTSA) at 1% concentration based on weight of acid and hydroxyl components at 120°C using cyclohexanone as an azeotropic solvent.
The acrylic monomers are selected from methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA), etc. The solvents in solution polymerization technique are selected from cyclohexanone, tetrahydrofuran, diethyl ether, propanoic acid, etc. The quantity of said acrylic monomer is in the range of 60-65% containing 10-15 mole % of hydroxy containing acrylate. The quantity of tetrafluoro propanoic acid is in the range of 50-60-mole % of the hydroxy acrylic monomer.
Fluorinated acrylic copolymers prepared by the above mentioned process and having fluorine content of said copolymer is 4 to 11 %. Fluorinated acrylic copolymers is used as an additive in coatings; fluorinated surfactant and functions as a wetting, leveling agent; in coatings as a base coat to impart hydrophobic surface; in antigraffiti paint; used in electrodeposition coating in water-dispersible form; etc.
A process for preparing fluoropolymers comprising adding 50 % solution of monomer in cyclohexanone in a three necked round bottom flask fitted with a water condenser and a teflon stirrer; adding 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent to the above solution; carrying out the reaction at 75 °C
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using water condenser; adding 100 % moles of tetrafluoro propionic acid on hydroxy ethyl acrylate along with 1 % p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component and carrying out esterification reaction at 120°C using cyclohexanone as an azeotropic solvent.
Fluoropolymers prepared by the above mentioned process and having fluorine content of said fluoropolymers is 2 to 25 %.The fluoropolymers are polyester, alkyd or any other type of resins. The fluoropolymers is polyesters modified with tetra fluoro propanoic acid. The fluoropolymers is used in powder coatings with high gloss, flow properties and protection properties.
A process for the preparation of fluorine containing monomers comprising esterifying glycol or hydroxyl acrylate monomer with a fluoropropionic acid using P-toluene sulphonic acid catalyst.
Detailed Description:
Fluorinated component i.e. tetrafluoro propanoic acid (TFPA) ([756-09-2]) was obtained by acidifying aqueous sodium tetrafluoro propionate ( [22898-01-7], M.P. 152°C), with sulfuric acid. TFPA was extracted with diethyl ether and separated by distillation. The product was a pale colored clear liquid. The purity of the acid was determined by acid value (B.P. was 133°C, Acid value of TFPA was found to be 380mg of KOH per gm compound. % purity was 98.9%). Alternatively TFPA was also obtained by ion-exchanging the aqueous solution of tetrafluoro sodium propionate with a strong acid cation exchange resin, Indion 130 (M/s. Ion Exchange Ltd., Mumbai). Acrylic monomers like methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA) obtained from the local suppliers were polymerized with azoisobutyronitrile (AIBN) and 2-dodecyl mercaptan (DM) as a free radical initiator and a chain transfer agent respectively. Solvents like cyclohexanone, tetrahydrofuran were used as diluents for the reaction.
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Acrylic copolymers were synthesized by solution polymerization technique using free radical initiator, AIBN, 2-dodecyl mercaptan as a chain transfer agent and cyclohexanone as a solvent. 50% solution of the monomer in cyclohexanone was used for polymerization. In a three-necked round bottom flask fitted with water condenser, thermometer pocket and a Teflon stirrer, required quantity of acrylic monomers were charged along with the solvent, initiator and chain-terminating agent. The polymerization was carried out at 75°C using water bath.
Acrylic monomers are selected from methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA), etc.
Solvents are selected from cyclohexanone, tetrahydrofuran, diethyl ether and propanoic acid. Preferred solvent is cyclohexanone.
In the second stage, the required quantity of tetrafluoro propanoic acid (depending upon the desired extent of fluorination ) was added along with the esterification catalyst, p-toluene sulphonic acid (PTSA) at 1% concentration based on weight of acid and hydroxyl components. Esterification was carried out at 120°C using cyclohexanone as an azeotropic solvent. The reaction was monitored by water of condensation. Similarly the esterification was also carried out using propanoic acid. The generalized structure of the resins is represented in Figure No. 1. For coating application high molecular weight and high fluorine containing copolymers were synthesized.
Polyester polymers were synthesized using high hydroxyl content monomers such as glycerol, pentaerythritol with other dibasic acids such as phthalicanhydride, isophthalic acid and the other di and tri basic acids used in manufacture of polyester resins used for the manufacture of coatings and polyester polyols. In these syntheses, tetrafluoropropanoic acid was used as a monobasic acid for adding fluorine to the molecule to the desired extent.
The concentration of acrylic monomer used is in the range of 50-90% in a solvent.
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The quantity of acrylic monomer used is in the range of 30-65% containing 10-15 molt % of hydroxy containing acrylate
The quantity of tetrafluoro propanoic acid used is in the range of 50-60 mole % of th The quantity of free radical initiator used is in the range of 0.1 to 10% of the total monomers. Alternatively the monomers were polymerized without any initiators using thermal polymerization.
The quantity of propanoic acid used is in the same range as tetraflouropropanoic acid fo comparison.
Various acrylic copolymers were synthesized which are quoted in Table I
Table 1 : Composition of Various Acrylic Copolymers (used for clear coatings)

Resins Monomers Esterification -OHvalue % Solids Mn Mw / Mn
MMA HEMA BA Acid % Mole
MHBT-24 50 20 30 TFPA 40 51.1 62.1 6536 2.004
MHBP-24 50 20 30 PA 40 50.3 53.2 6445 1.752
MHBT-26 50 20 30 TFPA 60 26.1 51.5 6625 1.949
MHBP-26 50 20 30 PA 60 43.8 53.1 6640 1.818
MHBT-275 50 20 30 TFPA 75 16.3 54.6 6691 1.818
MHBP-275 50 20 30 PA 75 21.3 47.6 5784 1.725
MHBT-34 50 30 20 TFPA 40 58.7 54 4746 1.925
MHBP-34 50 30 20 PA 40 69.5 54.4 6180 1.849
MHBT-36 50 30 20 TFPA 60 36.6 56.2 6670 1.980
MHBP-36 50 30 20 PA 60 45.7 50.8 6500 1.864
MHBT-375 50 30 20 TFPA 75 20.3 56.4 6666 1.978
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MHBP-375 50 30 20 PA 75 33.9 52.5 6296 2.074
Solvent: cyclohexanone; AIBN: 3%; dodecyl Mercaptan: 7.2%; TFPA: 2.2,3,3 tetrafluoro propanoic acid ; PA: Propanoic acid, Temperature: 75°C ( 1st stage) and 120°C (2nd stage) $ : based on moles of HEMA;*- mg of KOH per gm resin Fluorine content of the acrylic coplymers are given in table 2
Table 2 : Fluorine Content of copolymers

Resin % Fluorine content
Theoretical Experimental
MHBT-24 4.48 4.1
MHBT-26 6.28 6.1
MHBT-275 7.77 7.47
MHBT-34 6.16 6.06
MHBT-36 8.78 8.68
MHBT-375 10.59 9.98
The products were analyzed for their hydroxyl value, molecular weight and molecular weight distribution by gel permeation chromatography (GPC). The products were characterized by IR.
Fluoride content of the resins was found by the following method;
Known weight of the resin was mixed with the excess anhydrous sodium carbonate and heated at 800°C for 8hrs in the furnace. On cooling the incinerated product was dissolved in water and liquor ammonia was added to make the solution more basic and to avoid formation of gel-like solution. The content was then heated to boiling for 15 minutes. The content was cooled and calcium chloride (about 10% of the weight of the monomers) was added to convert sodium fluoride to calcium fluoride. The solution was filtered to separate the solid calcium fluoride. The product was incinerated at 750 C in the furnace for 4 hrs and weighed after cooling. From the amount of calcium fluoride formed fluorine
12

content was calculated after correcting for the solubility of calcium fluoride in aqueous solution (Solubility of CaF2 in water is 16mg / lit corresponding to lOmg / lit as fluoride). The theoretical fluorine content was calculated from the composition of the copolymer.
The contact angle is the angle formed between the plane tangent to the surfaces of the solid and the liquid at the wetting perimeter. The advancing contact angle was measured using a Kruss G-10 contact angle measuring system under ambient conditions. For comparison contact angles of commercial surfactants Span-20, Span-80 and Brij-30 were measured under similar conditions.
Testing of resins
The resins were tested for their mechanical, optical properties as per ASTM standards . For testing the properties of coatings like corrosion protection, scratch hardness and falling weight impact resistance, mild steel panels of 15cm X 7.5cm were used. The panels were abraded with emery paper followed by cleaning with the solvent. The resins were cured with stoichiometric quantity of butylated melamine formaldehyde resin at 135°C for 15minutes. Since nonfluorinated resins showed nonwetting behaviour, 0.1% (w/w) of commercial urethane-based wetting agent WD 1070 (K-Tech India (P) Ltd., Thane) dissolved in methyl ethyl ketone was mixed with the resin solution for all the composition before applying on the panels by leveling technique. The solid content of the resin solution was maintained at 30% by diluting with cyclohexanone. Other properties like gloss, flexibility, Crosshatch adhesion; pencil harness and solvent resistance were tested on aluminium panels. All the fluorinated resins were dark colored as compared to their nonfluorinated counterparts. Dry film thickness of the coatings (DFT) was measured by using magnetic DFT meter. Pencil hardness of the coatings was determined using standard pencils of hardness of 6B to 5A. Impact resistance was measured by using falling weight impact tester having a load of lKg. Flexibility of the coatings was tested on a conical mandrel of 3 8-3 mm diameter size and the panels were inspected for cracks or delamination after bending. Adhesion was determined by using cross-hatch adhesion test. Specular gloss of the coatings was measured by using Gardner Glossometer at an angle of 45°. The solvent resistance of the coatings was determined for methyl ethyl
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ketone and xylene rubs and the panels were inspected for loss of gloss or other impairment. For corrosion testing, the panels were exposed in humidity chamber, which was essentially salt spray chamber except for the salt solution replaced by deionised water. Humidity inside the cabinet was 84% RH at 30° C The panels were checked for corrosion by visual inspection regularly.
Mechanical properties of the coatings comprising acrylic copolymers such as MHBT-2<: mhbp-24 mhbt-26 mhbp-26 mhbt-275 mhbp-275 mhbt-34 mhbp-3 mhbt-36 mhbp-36 mhbt-375 and mhbp-375 were tested given in table> Table 3 : Mechanical Properties of Coatings

Properties FilmThickness (ASTM Dl 186-93) 00 Pencil hardness (ASTM D3363-74) Flexibility(conicalmandrel)(ASTMD522-93a) Scratchhardness(gm)(ASTMD2197-98) Crosshatchadhesion*(ASTM D3359-83) Impact resistance (ASTM D2794-84)
Resins Direct(0.6Kg.m) Indirect (Kg.m)
MHBT-24 75-100 2H Passes 700 Good Passes 0.55
MHBP-24 75-100 2H Passes 1100 Good Passes 0.55
MHBT-26 100-150 2H Passes 700R Good Passes 0.55
MHBP-26 100-150 2H Passes MOOR Good Passes 0.55
MHBT-275 75-100 2H Passes 600R Good Passes 0.55
MHBP-275 75-100 2H Passes 1000R Good Passes >0.60
MHBT-34 100-150 2H Passes 500R Good Passes 0.55
MHBP-34 100-150 2H Passes 1200R Good Passes 0.55
MHBT-36 100-150 2H Passes 500R Good Passes 0.55
MHBP-36 75-100 2H Passes 1000 Good Passes 0.55
MHBT-375 75-100 2H Passes 300R Good Passes >0.60
MHBP-375 75-100 2H Passes 1100 Good Passes >0.60
R: Failed in the reverse travel of the test panel; * Good - the him was intact
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The properties of all the clear coatings are given above, it can be seen that the falling weight impact and flexibility were not affected by introduction of fluorine. All the films showed good pencil hardness but some fluorinated films showed less scratch hardness.
Optical, Chemical and Protective properties of the coatings comprising acrylic copolymers such as MHBT-24, MHBP-24, MHBT-26, MHBP-26, MHBT-275, MHBP-275, MHBT-34, MHBP-34, MHBT-36, MHBP-36, MHBT-375 and MHBP-375 were tested and given in table 4.
Table 4: Optical, Chemical and Protective Properties of Coatings

Properties Gloss@45u(ASTMD523-67) Solvent resistance (ASTM D5402-93) Corrosion test" (hrs)
Resins 1 Xylene rub test MEK rub test
MHBT-24 52 100 100 41
MHBP-24 59 100 100+ 21
MHBT-26 63 100 70 41
MHBP-26 50 100 100 21
MHBT-275 47 100 100 54
MHBP-275 56 100 100 21
MHBT-34 54 100 100 44
MHBP-34 58 100 100+ 21
MHBT-36 58 100 70 44
MHBP-36 58 100 100 21
MHBT-375 58 100 100 54
MHBP-375 45 100 100 21
#- Exposed to deionised water in humidity chamber at 84%RH and 30 L
The properties of all the clear coatings are given above, it can be seen that properties like adhesion, gloss were more or less the same. MEK and xylene rub tests showed loss of gloss for both types of resins. The coatings showed good gloss. However the most
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noticeable difference was observed in case of their corrosion protective ability. Fluorinated films showed better corrosion protection against corrosion than their nonfluorinated analogs. Addition of fluorine in a range 4 to 10% showed improvement of the protective properties significantly. Air-drying alkyd coatings cured on these fluorinated coatings could be peeled off from the surface thus making them suitable in anti-graffiti paints.
Fluorinated polymers with lower molecular weight and lower fluorine content were prepared for use a surfactants by increasing the quantity of the initiator and reducing the quantity of TFPA for esterification of the hydroxyl groups. The prepolymers used here were also having a lower hydroxyl value.
Fluoropolymer was prepared by adding 50 % solution of monomer in cyclohexanone in a three necked round bottom flask fitted with a water condenser and a teflon stirrer; adding 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent to the above solution; carrying out the reaction at 75°C using water condenser; adding 100% moles of tetrafluoro propionic acid on hydroxy ethyl acrylate along with 1 % , p-toluene sulphonic acid (PTS A) catalyst concentration based on weight of acid and hydroxy component, carrying out esterification reaction at 120°C using cyclohexanone as an azeotropic solvent and achieving the fluorine content of the resins obtained was 5.1%.
To improve some of the flow properties other monomers such as ethyl acrylate is also
used.
Composition of fluoropolymers are given in Table 5 which were used as
fluorosurfactants. The fluorine content of the fluoropolymers are given in Table 6.
Molecular weight and polydispersity of the corresponding polymeric surfactants are
given in table 7.
Table 5 : Composition of polymeric fluorosurfactants

Surfactant HEMA (m) MMA (m) EHA (m) BA(m) TFPA (m) Hydroxyl value*
PS-8 0.077 0.154 - 0.078 0.054 25.3
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PS-10 0.062 0.154 - 0.062 0.025 51.1
PS-13 0.046 0.154 0.033 - 0.019 44.1
PS-14 0.046 0.154 - 0.047 0.019 43.5
*mg of KOH / g of sample
Table 6 : Fluorine content of fluorosurfactants

Surfactant % Fluorine
Theoretical Experimental
PS-8 5.18 5.15
PS-10 4.55 4.3
PS-13 4.27 3.65
PS-14 4.27 3.75
Table 7 : Molecular weight and polydispersity of polymeric surfactants
Table 8: Reduction in Contact angle at 1 wt% of various surfactants on an aluminium panel

Surfactant HLB values Reduction in Contact angle (°)
PS-8* 8.1 10
PS-10* 8.1 8
PS-13* 8.1 10
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PS-14* 8.3 8
Span-20 8.6 6
Brij-30 9.7 4
Span-80 4.3 6
*Theoretical values calculated using following formulae;
20XMH
HLB =
MH + M
Where MH •' weight of hydrophilic part M : weight of hydrophobic part
The above results show decrease in contact angle of fluorinated surfactants and commercial surfactants. As can be seen at 1% concentration the decrease in contact angle is maximum for fluorinated surfactants, thus making them more effective. The effect of addition of these fluorinated polymeric surfactants on the wetting and flow properties of epoxy resins such as liquid and solid epoxy, alkyd resin based paint and powder coating were studied.
Alkyd Paint Formulation

Ingredients Wt(g)
Ti02 30
Alkyd Resin (60% solid) 55
Drier (Co & Pb) 0.26 + 0.69
SMO 0.7
Solvent (Xylene: Butanol) 13
Fluorosurfactant 0.01
Total 100
For evaluating the performance of the polymeric surfactant in alkyd paint; the white paint was formulated with the above formulation. Polymeric fluorosurfactants were incorporated in the standard formula for paint (Soya bean oil alkyd based system
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containing TiO2 as a primary pigment, PVC was 17%, 60% solids and viscosity 60sec on Ford cup B-4) at 100ppm level and the paint was applied on the mild steel panels by brush. The gloss of the panels was measured at 45°, 60° angle of incidence (ISO 2813) using BYK Glossometer.
Gloss of Alkyd Paint

Surfactant Gloss values
@45u @60°
PS 8 62 79
PS10 61 81
PS13 61 80
PS14 59 82
Blank 57 75
Gloss of the paint containing fluorosurfactant was consistantly more than the blank. Further prepared polymeric fluorosurfactants have better flow, wetting than the blank.
Powder Coating Formulations

Ingredients Hybrid System (PN80) (g)
Polyester Resin 25.0
GT 7004 25.0
Carbon Black 1.25
BaS04 47.5
Surfactant 0.25
Benzoin 0.5
Flow additive (Acrylic based) 0.5
Total 100
The aluminium panels were coated using a above powder coating formulation and the gloss was measured and compared with blank (without polymeric surfactants). Gloss of
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the powder coatings containing polymeric fluorosurfactants was better than that of blank as shown below
Gloss of powder coating

Surfactant Gloss values
@45u @60u
PS 8 46 66
PS10 47 66
PS13 45 63
PS14 48 62
Blank 45 62
Liquid epoxy system
The aluminium panels were abraded with emery paper and then cleaned with acetone. Polymeric fluorosurfactants were mixed with epoxy resin by stirring at room temperature. The required amount of hardener triethylene tetramine was subsequently added, mixed thoroughly, and applied on aluminium panels. The samples were cured at room temperature for 15 minutes and post-cured for 5 minutes at 60° C. Their properties such as flow and wetting were compared with those of epoxy resins without polymeric fluorosurfactants (blank). Results show that the epoxy resins containing fluorosurfactant showed better flow and wetting than the blank and the films ha a high gloss and were free of cratering, so common with solvent less epoxy coatings.
Epoxy polyester hybrid system
Polymeric fluorosurfactants were mixed with epoxy, polyester, solvent (xylene and phenol in 4: 6 ratio) mixture and then applied on aluminium panels. The samples were cured at 190° C for 20minutes. Similarly panels without any surfactant were prepared. Their properties such as flow and wetting were compared with those of epoxy polyester hybrid system without polymeric flurorosurfactants (blank). Results show that hybrid
20

system containing prepared polymeric surfactants exhibited better flow and wetting than the blank.
Figure No. 1 : Molecular Structure Of Fluorinated Acrylic Copolymers

Structure of polyesters with fluorine containing side chains

Where G represents a glycerin molecule, Pe represents a polyhydric alcohol such as penta
erythritol or trimethylol propane or sorbitol, P represents a dibasic acid such as phthalic
anhydride and F represents a tetrafluoro propanoic acid and FA represents a saturated or
unsaturated fatty acid.
Preparation of fluorine containing monomers.
1 g mole of ethylene glycol was esterified with one gram mole of TFPA using 1% p-tsa
as a catalyst. The water of reaction was removed by addition of an entrainer such as
toluene. The product was purified by fractionation to remove the unreacted ethylene
glycol and diester of TFPA of ethlyne glycol. The pure monoester of TFPA of ethylene
glycol was reader with one gram mole of acrylic acid or one gram mole of methacrylic
acid using p-tsa as a catalyst. The water of reaction was removed by using xylene or
21

toluene as an entrainer. The monomer could be conveniently self polymerized or copolymerized using conventional acrylic monomers. The properties of the products could be adjusted with the combination of other monomers.
The preparation could also be carried out using one mole of hydroxy methyl acrylate and one mole of tetrafluoropropionic acid using p-tsa as a catalyst and xylene as an entrainer. It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. Introducing the fluorine molecule by esterification of pendent hydroxyl groups in polyesters, epoxies, urethanes, phenolics, vinyls, and any other resins would be achieved by tetra fluoro propanoic acid or its higher homologues of odd number of carbon atoms produced in the manufacture of the chemical. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be falling within the scope of the invention.
The following examples are for the purpose of illustration of the invention only and are not intended in any way to limit the scope of the invention. For the sake of pointing out improvement by the new technique, a comparative study has been included with propanoic acid.
Example 1
Fluorinated component i.e. tetrafluoro propanoic acid (TFPA) was obtained by acidifying aqueous (quantity) sodium tetrafluoro propionate (B.P. 152°C), with equimolar proportion of sulfuric acid. TFPA was extracted with 3 times the volume diethyl ether of TFPA and separated by distillation. The product was a pale colored clear liquid. The purity of the acid was 98.9%. Acid value of TFPA was found to be 380mg of KOH per gm compound.
22

Example 2
Tetrafluoro propanoic acid TFPA was obtained by ion-exchanging the 5% solution of tetrafluoro sodium propionate with a strong acid cation exchange resin Indion 130 resin.
Example 3
50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 40% moles of tetrafluoro propionic acid were added along with p-toluene sulphonic acid (PTSA) catalyst 1% concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 4.1%.
Example 4
50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75 °C using water. 60% moles of tetrafluoro propionic acid was added along with , p-toluene sulphonic acid (PTSA) catalyst 1% concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 6.1%.
23

Example 5
50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 75% moles of tetrafluoro propionic acid was added along with , p-toluene sulphonic acid (PTSA) catalyst 1% concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 7.47%.
Example 6
50% solution of monomer [50% mole methacrylate (MMA), 20% mole 2-hydroxy ethyl methacrylate (HEMA) and 30% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 40% moles of tetrafluoro propionic acid was added along with , l% p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 6.06%.
Example 7
50% solution of monomer [50% mole methacrylate (MMA), 30% mole 2-hydroxy ethyl methacrylate (HEMA) and 20% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 60% moles of tetrafluoro
24

propionic acid was added along with, 1% p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 8.68%.
Example 8
50% solution of monomer [50% mole methacrylate (MMA), 30% mole 2-hydroxy ethyl methacrylate (HEMA) and 20% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water. 75% moles of tetrafluoro propionic acid was added along with 1% , p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120 °C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 9.98%.
Example 9
50% solution of monomer [50% mole methacrylate (MMA), 10% mole 2-hydroxy ethyl methacrylate (HEMA) and 40% mole butyl acrylate (BA)] in cyclohexanone was added in a three necked round bottom flask fitted with a water condenser and a teflon stirrer. 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent were added. The reaction was carried out at 75°C using water condensor. 100% moles of tetrafluoro propionic acid was added on hydroxy ethyl acrylate along with 1% , p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component. The reaction (esterification) was carried out at 120°C using cyclohexanone as an azeotropic solvent. The fluorine content of the resins obtained was 5.1%.
Advantages of the present invention :
25

• An easy non hazardous and low cost procedure of introducing fluorine atoms in polymers. An easily available chemical, sodium tetrafluoro propionate was acidified with a mineral acid or ion exchanged to get an intermediate, tetrafluoro propanoic acid by extraction.
• A novel series of polymeric fluorosurfactants with water insoluble properties were prepared by the esterification of hydroxy containing acrylate copolymer with tetrafluoro propanoic acid. Introduction of fluorine in the range of 4 to 10% was found to enhance corrosion protection ability of coatings. Alkyds cured on these fluorinated surfaces could be easily peeled off. Hence such coatings can be used as antigraffiti paints.
• Prepared polymeric fluorosurfactants with 3 to 5% fluorine were found to give better flow, leveling and wettability in epoxy coating, alkyd paints and powder coating. Gloss and flow of powder coatings were found to be improved by these fluorosurfactants.
26

We claim:
1. A process for preparation of fluorinated acrylic copolymer comprising preparing Fluorinated acidic compound, tetrafluoropropionic acid, by ion-exchanging sodium salt of aqueous sodium tetrafluoro propanate or hydrolyzing sodium tetrafluoro propanate with sulfuric acid; synthesizing Acrylic copolymers by solution polymerization technique using free radical initiator such as Azoisobutyronitrile (AIBN), 2-dodecyl mercaptan (DM) as a chain transfer agent and 50% solution of the acrylic monomers in solvent; and esterifying acrylic copolymer with tetrafluoro propanoic acid in the presence of esterification catalyst, p-toluene sulphonic acid (PTSA) at 1% concentration based on weight of acid and hydroxyl components at 120°C using cyclohexanone as an azeotropic solvent.
2. The process as claimed in claim 1, wherein said acrylic monomers are selected from methyl methacrylate (MMA), butyl acrylate (BA), 2-ethyl hexyl acrylate, 2-hydroxy ethyl methacrylate (HEMA), etc.
3. The process as claimed in claim 1, wherein said solvents in solution polymerization technique are selected from cyclohexanone, tetrahydrofuran, diethyl ether, propanoic acid, etc.
4. The process as claimed in claims 1 and 2, wherein quantity of said acrylic monomer is in the range of 60-65% containing 10-15 mole % of hydroxy containing acrylate.
5. The process as claimed in claim 1, wherein quantity of tetrafluoro propanoic acid is in the range of 50-60-mole % of the hydroxy acrylic monomer.
6. Fluorinated acrylic copolymers prepared by the process as claimed in claims 1 to 5.
7. Fluorinated acrylic copolymers as claimed in claim 6, wherein fluorine content of said copolymer is 4 to 11 %.
8. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used as an additive in coatings.
27

9. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used as fluorinated surfactant and functions as a wetting, leveling agent.
10. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used in coatings as a base coat to impart hydrophobic surface.
11. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used in antigraffiti paint.
12. Fluorinated acrylic copolymers as claimed in claims 6 to 7, wherein said copolymer is used in electrodeposition coating in water-dispersible form.
13. A process for preparing fluoropolymers comprising adding 50 % solution of monomer in cyclohexanone in a three necked round bottom flask fitted with a water condenser and a teflon stirrer; adding 3% initiator Azoisobutyronitrile (AIBN) and 7 % 2-dodecyl mercaptan chain transfer agent to the above solution; carrying out the reaction at 75°C using water condenser; adding 100 % moles of tetrafluoro propionic acid on hydroxy ethyl acrylate along with 1 % p-toluene sulphonic acid (PTSA) catalyst concentration based on weight of acid and hydroxy component and carrying out esterification reaction at 120°C using cyclohexanone as an azeotropic solvent.
14. Fluoropolymers prepared by the process as claimed in claim 13.
15. The Fluoropolymers as claimed in claim 14, wherein fluorine content of said fluoropolymers is 2 to 25 %.
16. The fluoropolymers as claimed in claims 14 to 15 wherein said fluoropolymers are polyester, alkyd or any other type of resins.
17. The fluoropolymers as claimed claims 14 to 16, wherein said polymer is polyesters modified with tetra fluoro propanoic acid.
18. The fluoropolymers as claimed in claims 14 to 17, wherein said polymer is used in powder coatings with high gloss, flow properties and protection properties.
19. A process for the preparation of fluorine containing monomers comprising esterifying glycol or hydroxyl acrylate monomer with a fluoropropionic acid using P-toluene sulphonic acid catalyst.
28

20. A process for preparing fluorinated acrylic copolymers, copolymers thereof and their application as substantially described herein with reference to foregoing examples 1 to 10.
21. A process for preparing fluoropolymers, polymers thereof, and their application as substantially described herein with reference to foregoing example 10.
29

Abstract
A process for introduction of Fluorine in vinylic monomers, polymers like polyesters and acrylic copolymers by using tetra fluoro propanoic acid. Further the use of the fluorinated acrylic copolymers and polymers as surfactant, additives and in anti-corrosive highly durable coatings.
3 0 NOV 2004

Documents:

1280-MUM-2004-ABSTRACT(23-07-2008).pdf

1280-mum-2004-abstract.doc

1280-mum-2004-abstract.pdf

1280-mum-2004-cancelled pages(29-9-2008).pdf

1280-MUM-2004-CLAIMS(23-07-2008).pdf

1280-MUM-2004-CLAIMS(AMENDED)-(29-9-2008).pdf

1280-mum-2004-claims(granted)-(29-9-2008).doc

1280-mum-2004-claims(granted)-(29-9-2008).pdf

1280-mum-2004-claims.doc

1280-mum-2004-claims.pdf

1280-mum-2004-correspondance-received-060906.pdf

1280-mum-2004-correspondance-received-091204.pdf

1280-mum-2004-correspondance-received.pdf

1280-MUM-2004-CORRESPONDENCE(23-07-2008).pdf

1280-MUM-2004-CORRESPONDENCE(29-9-2008).pdf

1280-mum-2004-correspondence(ipo)-(21-11-2008).pdf

1280-mum-2004-description (complete).pdf

1280-MUM-2004-DESCRIPTION(COMPLETE)-(23-07-2008).pdf

1280-MUM-2004-FORM 1(23-07-2008).pdf

1280-mum-2004-form 1(30-11-2004).pdf

1280-mum-2004-form 18(7-9-2006).pdf

1280-mum-2004-form 2(granted)-(29-9-2008).doc

1280-mum-2004-form 2(granted)-(29-9-2008).pdf

1280-MUM-2004-FORM 2(TITLE PAGE)-(23-07-2008).pdf

1280-MUM-2004-FORM 26(08-05-2003).pdf

1280-mum-2004-form 26(15-5-2003).pdf

1280-MUM-2004-FORM 3(23-07-2008).pdf

1280-mum-2004-form 3(23-7-2008).pdf

1280-mum-2004-form 3(30-11-2004).pdf

1280-mum-2004-form-1.pdf

1280-mum-2004-form-18.pdf

1280-mum-2004-form-2.doc

1280-mum-2004-form-2.pdf

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Patent Number

227342

Indian Patent Application Number

1280/MUM/2004

PG Journal Number

10/2009

Publication Date

06-Mar-2009

Grant Date

07-Jan-2009

Date of Filing

30-Nov-2004

Name of Patentee

MALSHE VINOD CHINTAMANI

Applicant Address

1, STAFF QUARTERS, UDCT CAMPUS, MATUNGA, MUNBAI - 400 019

Inventors:

#	Inventor's Name	Inventor's Address
1	MALSHE VINOD CHINTAMANI	1, STAFF QUARTERS, UDCT CAMPUS, MATUNGA, MUNBAI - 400 019
2	SANJAY NIVEDITA SHISHUPAL	1, STAFF QUARTERS, UDCT CAMPUS, MATUNGA, MUNBAI - 400 019
3	ELANGO SUBRAMANYAM	1, STAFF QUARTERS, UDCT CAMPUS, MATUNGA, MUNBAI - 400 019

PCT International Classification Number

C08F32/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA