Title of Invention

"A PROCESS FOR PREPARATION OF SILICONE MODIFIED SOYA ALKYD CO-POLYMER AND PRODUCTS THEREOF"

Abstract

This invention relates to an improved process for preparation of silicone modified soya alkyd copolymer by reacting a mixture of 250 to 310 soya oil, 50 to 80 Pentaerythritol, 0.6 to 1.8 calcium phthalate and 280 to 360 xylene in parts by weight quantity, agitating at temperature between 200 to 250°C under an inert atmosphere for two hours; adding gradually 110 to 150 by weight quantity in parts phthalic anhydride to the reacting mixture of said step (i) followed by refluxation, reducing the temperature to 150°C, adding 175 to 225 by wt. quantity silicone resin so that acid value of the reaction mixture is 11 to 12g of KOH/g of resin after cooling.

Full Text

FIELD OF THE INVENTION The present invention relates to the process for preparation of silicone modified soya alkyd co-polymer and to the products thereof. In particular this invention relates to a process for preparation of a coating material, and the products thereof, more particularly it relates to process for preparation of silicone soya alkyd copolymer and to the products thereof, which inturn may kind application in exterior paints requiring long life, especially for the superstructure of ships etc. PRIOR ART OF THE INVENTION The superstructures of ships are generally exposed to the highly corroding environment, which in-turn may initiate the corrosion preferably oxidation process on the exposed surfaces of the superstructures ships. This process of oxidation once initiated results in the deterioration of the such superstructure. This deterioration process requires for the application of a coating on the surface of superstructures, which can withstand the corrosive attack of the deteriorating environment, that is, should be capable of giving better corrosion protection performance. The known such coatings are generally based on soya alkyd composition. In addition to being the corrosion resistant, such coatings are also required to be impermeable to water vapors, if not completely impermeable, at least th& permeability should be minimum. The impermeability to water vapours, enhances the corrosion resistance of the suit-face of the material wherever such coating is applied. Yet another requirement of such coating materials is that, it should be capable of quick drying. As, otherwise the coating may absorb moisture and effect the surface of the structure wheresoever such coat ing has been applied. Still another requirement of such coating ma t er i a 1 s , is that, these should have superior mechanical properties. which in-turn can facilitate the coating to with mitand greater mechanical abuses. For such requirements, generally a binder is required to be mixed in the coating composition. Still further a requirement of such coating materials for such applications, as stated herein above, is that such materials should have superior resistance to weathering besides having above stated requirements. The known such coating materials of known compositions generally, have good adhesion properties but poor exterior durabi1ity. Further the exterior paints are also exposed to a variety of environmental conditions which may include exposure to ultraviolet radiations in the sunlight. This exposure of paints to the ultraviolet radiations are also responsible for degradation of the polymeric composit ion and eventually the paint coating. Presently known exterior paints used for application as coating materials on the ships or superstructures are based on linseed oil alkyd and provides the service life merely of about twelve months, particularly in Indian tropical conditions, and hence having the disadvantage of requirement of frequent painting. Alkyds, which are particularly oil modified polyesters, as known in the prior art, have been widely used in the past world over for making paints for exterior app1ication is . The linseed oil based alkyds, as stated herein above as well. were the only choice for formulation of these paint1? in the early years. The disadvantages of known such linseed oil based alkyds are that they have inadequate durability rind rapid yellowing effect due to the presence of excessi ve unsaturation in the oil. T o o v e r c o m e these part i c u 1 a r d i s a d v a n t a g e s , s o y a oil based alkyds were developed for formulating the exter ior paints. The soya oil based alkyds known in the prior art have advantage of producing the non-yellowing coatings and having the improved durability due to reduction of unsaturation. Continuous research had been conducted tofurther improve the weathering property and other properties as described herein above, of the soya oil based alkyds;, by- modifying them with other resins having good weather- resistance . / However, the information on their synthesis and characterisation and physico-chemical characteristics' of such soya oil based alkyds is scarce.' The known methods of preparation of such known soya oil based alkyds are generally based on the soya fatty acid and require arrangements for good agitation and nitrogen purg ing. The known such processes of synthesis of soya, oil based alkyds are continued generally, till the acid number drops to 7-9 mg of potassium hydroxide per gram of the resin. The main disadvantage of such known processes of synthesis of soya oil based alkyds is that the main reactant is soya fatty acid and not the soya oil, which in turn makes the process lengthier by one step, which further results in increase in the cost of the process making it uneconomical and time consuming. OBJECTS OF THE INVENTION The primary object of the present invention is to propose an improved process for preparation of silicone modified soya alkyd copolymer and to the products thereof, which in turn have improved weathering characteristics, which further make the producs of the present invention suitable for use as the exterior paints. A further object of the present invention is to propose an improved process for preparation of silicoie modified soya alkyd copolymer, which comprises reaction of soya oil instead of soya fatty acid, which inturn eliminates one step, hence making the process of the present invention time saving and more economical. Yet another object of the present invention is to propose an improved process for preparation of silicone modified soya alkyd copolymer and products thereof having higher tensile strength and percent elongation. Still another object of the present invention is to propose a process for the preparation of silicone modified soya alkyd copolymer and products thereof having improved drying characteristics. Further an object of the invention is to is to propose a process for the preparation of silicone modified soya alkyd copolymer and products thereof, which in turn possess superior colour and glass retention properties. Still further an object of this invention is to propose an improved process for obtaining silicone modified soya alkyd copolymer and products thereof having improved resistance to erosion/corrosion. Yet another an object of this invention is to propose an improved process for the preparation of silicone modified soya alkyd copolymer with low water permeation characteristics. BRIEF DESCRIPTION OF THE INVENTION According to this invention there is provided An improved process for preparation of silicone modified soya alkyd copolymer by: i) reacting a mixture of 250 to 310 soya oil, 50 to 80 Pentaerythritol, 0.6 to 1.8 calcium phthalate and 280 to 360 xylene in parts by weight quantity, agitating at temperature between 200 to 250°C under an inert atmosphere for two hours; ii) adding gradually 110 to 150 by weight quantity in parts phthalic anhydride to the reacting mixture of said step (i) followed by refluxation; iii) reducing the temperature to 150°C, adding 175 to 225 by wt. quantity silicone resin so that acid value of the reaction mixture is 11 to 12g of KOH/g of resin after cooling. In accordance to the presently disclosed invention, an improved process for preparation of silicone modified soya alkyd copolymer, particularly an improved process for preparation of silicone soya alkyd copolymer and the products thereof are disclosed and described herein. The process of the present invention is carried out in following steps: a) the mixture of soya oil, pentaerythritol, xylene and calcium naphthanate is allowed to react at the temperature of 200 to 250°C with agitation under an inert atmosphere. b) to the monoglyceride obtained in the above step, phthalic anhydride is added gradually and the reaction mixture is refluxed further. c) the temperature of reaction mixture of 'step two is brought dawn upta about 150 C and to this reaction mixture the weighted quantities of si 1 icon e resin and xylene are added followed by re f lu:-:at ion . d) the synthesised silicone modified soya alkycl copolyrner is characterised for drying properties 1t tensile strength percent elongation, water vapour: i permeation, resistance to UV-radiat ion, gloss and colour retention properties. The silicone modified soya alkyd copolymer prepared in accordance to the process of this invention, as described herein above, has demonstrated higher tensile strength and percent elongation, lower water vapor permeation, improved drying chracteristics improved resistance to ultraviolet radiation, superior resistance to weathering, improved colour retention and reduced loss of gloss as compared to the linseed oil alkyd and also to the soya alkyd resins prepared using soya fatty acid. DETAILED DESCRIPTION OF THE INVENTION Accordingly the present invention makes a disclosure of an improved process for preparation of silicone modified soya alkyd copolymer and of the products thereof, as described herein above and below. The process of the present invention is characterised by three steps, which are conducted in same and one reaction vessel . In accordance to the process of this invention the weighted quantities of soya oil, pentaerythrito 1 and xylene are taken, alonguiith calcium naphthanate, in a three neck flask fitted with Dean and Stark assembly, and having the provision of nitrogen purging and agitation. 36. This reaction mixture is heated slowly to the temperature, preferably -between 200 to 230ºC, more preferably between 225 to 235 C with constant agitation. The heated reaction mixture is refluxed at the preferable temperature of 225 to 235°C preferably for aboul; two hours. 37. The reaction mixture is further re fluxed with phthalic anhydride, which is added gradually to the same reaction vessel. This step is monitored by acid value and viscosity determination at the periodic intervals. 38. The reaction temperature is brought down upto about 1500C, when the acid value of 11 to 12 g of KDH/g of resin is achieved . 39. On achieving the acid value of 11 to 12 g of KDH/g and attaining the reaction temperature the weighed quantity of silicone resin and adequate quantity of xylene are added to this reaction mixture in the same reaction vessel. This reaction is continued by reluxing the reacting mixture at about 150 C temperature till an acid value of 6-7 mg of KOH/g of resin is achieved. 40. In accordance to the preferred invention soya ail is taken between 250 to 310, preferably between 2.75 l;o 30O, pentaerythritol is taken between 50 to 00, preferably between 60 to 70, phthalic anhydride between 110 to 150 preferably between 120 to 135, silicone resin between 175 to 225, preferably 190 to 205, calcium phth'alate between 0.6 to 1.8, preferably 0.8 to 1.2 and total xylene, that is in step 1 and step 3, is taken between 280 to 36O, preferably between 310 to 340. All reactions are taken in parts by- weight quantity, as stated herein above. 41. It is understood f 17001 the foregoing description that the process disclosed herein above, definitely has over-come the drawbacks of such known, processes, particular reduction of number of reaction steps, reaction time and elimination of soya fatty acid, still the products produced have improved properties as stated herein above. 42. The process of the present invention is completed in three steps, which in turn are carried out in the single reaction vessel. 43. It is further understood from the foregoing description that the present invention ha?; made disclosure of an improved, convenient, simple process comprising of on« step less than known such processes, time saving and economical process and hence of economical product still having improved characteristics. 44. The foregoing process was performed by using following spec i fic chemical composition: a) Soya Oil = 288.0 parts by weight; b) Pentaerythritol = 66.O c) Phthatic anhydride = 126.0 " d) Silicons resin / = 197.O " e) Calcium naphthanate = l.O " " " f ) ! (combined for first and third steps) = 320.0 " 45. The foregoing process of this invention is explained in specific details by the following description. (A) The weighed amounts of ingredient (a), (b) and (e) are taken in a three necked flask fitted with Dean and Stark assembly. The reaction mixture is herated slowly to 230 C with agitation and nitrogen purge. The reaction is completed in approximate 1 y two hours which is indicated by solubility of 0.5 1 ml of reaction mixture in 10 ml, of ethyl alcohol . (EO The temperature of the reaction mixture is lowered to 160 C followed by addition of 27.0 q of xylene which is followed by addition of weighed amount of phthalic anhydride in small lots. (C) The mixture is heated to 24O+5°C and reflux ing is continued to allow the reaction and to remove water produced as a result of this reaction. The reaction is continued till the acid value is dropped to 1.1-12 mg of KOH/Q of resin. (D) The temperature of reaction mixture is brought down to 130+5 C and silicone resin is added gradually to the flask followed by 213 g of xylene. The reaction mixture is refluxed at this temperature, till it attained an acid value of 6-7 mg of KOH/Q of resin. The material is cooled and diluted to 70 percent solid content. (E) Silicons modified soya alkyd copolymer thus produced having yield of one litre is examined for relevant characteristics and found to have desired characteristics, as stated herein above. The specific characteristics of the silicone modified saya alkyd copolymer are compared with soya alkyd r by known such methods in the table-1. Table -1 : Comparison of Characteristics of Soya Alkyd resin and silicons modified soya alkyd copalymer. (Table Removed) 46. The foregoing example and the data of the silicons modified soya alkyd copolymer synthesized in accordance to the process of the present invention is not intended to limit the scape of the present invention. I CLAIM; 1. An improved process for preparation of silicone modified soya alkyd copolymer by: i) reacting a mixture of 250 to 310 soya oil, 50 to 80 Pentaerythritol, 0.6 to 1.8 calcium phthalate and 280 to 360 xylene in parts by weight quantity, agitating at temperature between 200 to 250°C under an inert atmosphere for two hours; ii) adding gradually 110 to 150 by weight quantity in parts phthalic anhydride to the reacting mixture of said step (i) followed by refluxation; iii) reducing the temperature to 150°C, adding 175 to 225 by wt. quantity silicone resin so that acid value of the reaction mixture is 11 to 12g of KOH/g of resin after cooling. 2. A process as claimed in claim 1, wherein the said process is conducted in a single reaction vessel. 3. A process as claimed in claim 1, wherein said reaction mixture of step (i) is heated to a temperature of 225° to 235°C. 4. A process as claimed in preceding claims, wherein the said reaction mixture is refluxed at 150°C temperature till an acid value of 6-7 mg of KOH/g of resin is achieved after addition of weighed quantities of said silicone resin and xylene. 5. A process as claimed in preceding claims, wherein the said soya oil is taken preferably between 275 to 300, pentaerythritol is taken preferably between 60 to 70, phthalic anhydride preferably between 120 to 135, silicone resin preferably 190 to 205, calcium phthalate preferably 0.8 to 1.2 and total xylene, that is in step 1 and step 3, is taken preferably between 310 to 340 in parts by weight quantity. 6. A process as claimed in preceding claims, wherein said chemical composition of said reactants is specifically: a) Soya Oil = 288.0 parts by weight b) Pentaerythritol = 66.0 parts by weight c) Phthatic anhydride = 126.0 parts by weight d) Silicone resin = 199.0 parts by weight e) Calcium napthanate = 1.0 parts by weight f) Xylene (combined for first and third steps) = 320.0 parts by weight 7. A process for preparation of silicone modified soya alkyd copolymer substantially as herein described in the foregoing description with the help of example.

Documents:

400-del-1997-abstract.pdf

400-del-1997-claims.pdf

400-del-1997-correspondence-others.pdf

400-del-1997-correspondence-po.pdf

400-del-1997-description (complete).pdf

400-del-1997-form-1.pdf

400-del-1997-form-19.pdf

400-del-1997-form-2.pdf

400-del-1997-form-3.pdf

400-del-1997-gpa.pdf