Title of Invention

POLYESTER RESIN HAVING IMPROVED FRICTIONAL PROPERTIES

Abstract

An improved process for the continuous production of a high molecular weight polyester resin of IV of about 0.5dl/g to about 1 dl/g from low molecular weight crystalline prepolymer of IV of about 0.1 dl/g to about 0.4 dl/g with the improved frictional properties comprising adding anti-stiction additive at any stage during melt polymerization steps of (a), (b), (c) or (d) but before the particle former process. Low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 with improved frictional property and uniform hemispherical shape, uniform particle size, uniform crystallinity prepared by the above process. High molecular weight polyester resin with an IV from about 0.5dl/g to about 1 dl/g with improved frictional property and accepted haze prepared by the above process is also disclosed. The high molecular weight polyester resin with improved frictional property with accepted haze prepared by the process is used for the production of preforms, beverage container, bottles, sheets and film with low coefficient of friction and improved slip performance.

Full Text

FORM 2 THE PATENT ACT 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See section 10 and rule13) 1. TITLE OF THE INVENTION: Polyester resin having improved frictional properties 2 APPLICANT (a) NAME : Reliance Industries Limited (b)NATIONALITY: Indian company incorporated under the Companies Act 1956 (c) ADDRESS : Reliance Technology Center, B-4 MIDC Industrial Area, Patalganga- 410220, Dist- Raigad , Maharashtra, India 3. INVENTORS (a) Name : Nadkarni Vikas Madhusudan (b) Nationality: Indian (c) Address : A18 Garden Estate, Off D P Road, Aundh, Pune -411007, Maharashtra, India. (a) Name : Ayodhya, Srinivasacharya Ramacharya (b) Nationality: Indian (c) Address : Flat No: 7, Phoenix Co-op Housing Society, Plot No. 23, Sector 9A, Vashi, Navi Mumbai - 400 703, Maharashtra, India. (a) Name : Wadekar, Shreeram Ashok (b)Nationality : Indian (c) Address : 204, Mohandeep Co-op Housing Society Ltd., Almeida Road, Chandanwadi, Panchpakhadi, Thane (West)-400 601, Maharashtra, India a)Name : Limaye Chetan Vijay (b)Nationality : Indian (c) Address : FlatNo.3,PratikPooja Co-op Hsg. Soc. Amar Chowk Makhmalabad Naka Panchawati Nashik- 422003 Maharashtra, India 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed: FIELD OF THE INVENTION: This invention relates to an improved process for continuous production of high molecular weight polyester resin having IV up to 1dl/g produced from low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 dl/g comprising anti-stiction additive for lowering coefficient of friction (COF) in the moulded articles. Particularly, this invention relates to an improved process for continuous production of high molecular weight polyester resin comprising about 0.002 % to about 0.3 % of precipitated silica having an average particle size of 0.5 to 50 microns to improve the frictional properties of polyester articles. This invention also relates to high molecular weight polyester resin having IV up to 1dl/g produced comprising anti-stiction additive for lowering coefficient of friction (COF). This invention also relates to use of high molecular weight polyester resin comprising anti-stiction additive for the productions of films, sheets and beverage containers such as bottles with improved frictional properties. BACKGROUND OF THE INVENTION: PET homopolymers and copolymers are widely used in carbonated soft drink (CSD) bottles. These bottles are being produced by injection stretch blow moulding process with high-speed blow moulding machines. One major problem faced while transporting or handling the CSD containers at different stages is that due to the high friction encountered between surfaces of the containers, their aesthetic value as well as physical properties get affected. This excessive friction can lead to process or filling line interruptions that are economically undesirable. 2 The problem occurs after the polyester polymer has been moulded into performs or various types of stretch blow moulded containers. The containers are sometimes conveyed directly into a palletizing station and then shipped to a filling plant or they are conveyed to a labeling and filling line contained within the same plant. The problem can also occur during the shipment of closely packed blown containers from one site to another. Problem is more severe when container sidewalls are smooth and thus more friction occurs between the containers during handling or transportation. During the production of injection-moulded preforms, preforms are packed in a large box, which contains more than 500 preforms. Preforms have a tendency to stick on top of one another thus reducing their packing efficiency in the box. As a result, less quantity of the preforms are kept in the box than the optimum capacity thus increases transportation cost for the preform manufacturer. The high level of friction between the preforms results in the damage of the surface of the preforms and thus increasing the rejection rate. Higher sticking tendency causes problems in the feeder of the stretch blow-moulding machine and thus reduces the productivity of the machine than the optimum. CSD bottles are usually produced with 2 or 2.5L volume using injection stretch blow moulding machine. If the bottle sidewalls are smooth, the surface area that comes in the contact with two adjacent bottles increases. Since PET inherently has high coefficient of friction (COF), containers become entangled and tip over or just stop moving in the conveying line after blowing or filling. Such interruption obviously causes undesirable loss of productivity and increases maintenance of the filling or conveying process. This problem also arises during the shipment of bottle from one site to another. Such type of friction or tip over causes unwanted scratches thus deteriorating the appearance of bottles. A high coefficient of friction (COF) prevents adjacent containers on a multiple-row conveying line from moving (turning or slipping) during conveying. When the 3 conveying line changes direction, sometimes as much as 90 degrees, the containers may become entangled and either stay upright and stop the feed or tip over and stop the line. In either event, someone has to monitor continuously these problematic areas to keep the line moving. A container having low coefficient of friction is useful for reducing or eliminating the process down time and also eliminates or reduces the need for someone to constantly monitor the process. A container having low coefficient of friction is also useful to reduce or eliminate the frictional forces between two adjacent bottles which are responsible for scratches while the shipment of containers from one site to other. This helps in maintaining the appearance of bottle in terms of clarity / gloss. The sticking tendency of the preforms or bottles may arise due to the static electricity and / or rough surfaces. However, the exact reason for sticking is still unknown. Generally, two major and distinct process steps are involved in the production of high molecular weight polyesters. These two steps include: melt polymerization and solid-state polymerization (SSP). In the conventional polymerization process for producing high IV polyester, base polymer having IV of about 0.4 dl/g to about 0.65 dl/g is produced by melt polymerization process. These base chips usually are cylindrical or circular shape. Base polyester is amorphous in nature. Base polyester resin is then subjected for solid-state polymerization after crystallizing it in a crystallizer so as to avoid sintering or lump formation in the SSP reactor. Using SSP process, depending on the application, different IV resin can be produced. Conventional polymerization processes of polyester are disclosed in patents US 3,405,098, US 3,544,525, US 4,245,253, US 4,238,593, and US 5,408,035. In this conventional polymerization process, the use of additives such as siliceous compounds, barium sulphate, calcium carbonate and many others for improving frictional properties of finished articles such as preforms, containers 4 are disclosed in patents US 3,968,183, US 5,830,544, US 6,323,271 and also in the patent applications US 2002009564, 20030039783 and US 20030055207. Another polymerization process which is different than conventional polymerization process is disclosed in US 5,510,454, 5,532,333, 5,540,868, 5,714,262, 5,830,982, and 6,451,966 which are incorporated herein as reference in their entirety. In this polymerization process, a crystalline hemispherical prepolymer having IV of about 0,1 dl/g to about 0.4 dl/g is formed using particle former process. The base polyester chips produced with this process are crystalline in nature. Particle former process is disclosed in US 5,510,454. These crystalline prepolymer chips can then be used as a precursor for solid-state polymerization for increasing the IV from about 0.5 dl/g to about 1 dl/g. Polymerization process for the production of high molecular weight PET from the low molecular weight crystalline prepolymer is disclosed in patents US 5,510,454, US 5,532,333, US 5,540,868, US 5,714,262, US 5,830,982, and US 6,451,966. However, none of these patents discloses the composition for the production of polyester resin having anti-stiction additive for the improvement of frictional properties of finished articles such as preforms and containers. OBJECTS OF THE INVENTION : An object of the invention is to provide an improved process for the continuous production of low molecular weight crystalline polyester prepolymer having IV of 0.1 dl/g to 0.4 dl/g with improved frictional properties comprising among other things, anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate. Another object of the invention is to provide improved process for the production of high molecular weight polyester resins having IV of 0.5 dl/g to 1 dl/g from the low molecular weight crystalline polyester prepolymer having IV of 0.1 to 0.4 dl/g 5 with improved frictional properties comprising, among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diolthe anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate. Yet another object of the invention is to provide improved process for the production of high molecular weight polyester resins having IV of 0.5 dl/g to 1 dl/g from the low molecular weight crystalline polyester prepolymer having IV of 0.1 to 0.4 dl/g comprising anti-stiction additive, which is suitable for the production of moulded articles and films with improved slip performance, preferably beverage containers with low co-efficient of friction Yet another object of the invention is to provide improved process for the production of polyethylene terephthalate (PET) resin comprising anti-stiction additive, which is used for producing preforms, bottles, sheets and film with accepted haze. Yet another object of the invention is to provide low molecular weight crystalline polyester prepolymer having IV of 0.1 dl/g to 0.4 dl/g comprising among other things, anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate, or magnesium carbonate. Yet another object of the invention is to provide high molecular weight polyester resins having IV of 0.5 dl/g to 1 dl/g from the low molecular weight crystalline polyester prepolymer having IV of 0.1 to 0.4 dl/g comprising, among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid, 6 naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diol and anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate. Yet another object of the invention is to provide the high molecular weight polyester resins having IV of 0.5 dl/g to 1 dl/g from the low molecular weight crystalline polyester prepolymer having IV of 0.1 to 0.4 dl/g comprising anti-stiction additive, which is suitable for the production of moulded articles and films with improved slip performance, preferably beverage containers with low coefficient of friction (COF) and accepted haze. Yet another object of the invention is to provide polyethylene terephthalate (PET) resin comprising anti-stiction additive, which is used for producing preforms, bottles, sheets and film with accepted haze. DETAILED DESCRIPTION OF THE INVENTION : According to the invention there is provided improved process for the production of high molecular weight polyester resin comprising anti-stiction additive for the improvement in the slip performance of polyester article. According to the invention there is provided improved process for the continuous production of high molecular weight polyester resin having IV of about 0.5 dl/g to about 1 dl/g with low co-efficient of friction and accepted haze produced from low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 dl/g using particle former process. 7 According to the present invention there is provided improved process for the continuous production of a high molecular weight polyester resin of IV of about 0.5dl/g to about 1 dl/g from low molecular weight crystalline prepolymer of IV of about 0.1 dl/g to about 0.4 dl/g with the improved frictional properties, suitable for the production of preforms, beverage containers and films, the process comprising ; a. adding among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diol; b. esterifying the mixture of step (a) at temperature in the range of 250 to 290°C; c. removing excess or unreacted polyol or water produced from the step (b); d. polymerizing the esterified mixture at temperature in the range at 260°C - 300°C to obtain low molecular weight polyester prepolymer having IV of about 0.1 to about 0.4 dl/g; e. adding anti-stiction additive at any stage during melt polymerization steps of (a), (b), (c) or (d) but before the particle former process; f. producing a hemispherical, crystalline prepolymer of polyesters by a particle former process at temperature in the range of 110 to 160°C and g. polymerizing crystalline and hemispherical prepolymer by solid- state polymerization to produce high molecular weight polyester resin containing silica additive having IV of about 0.5dl/g to about 1 dl/g. The term "polyester" is used herein means polyethylene terephthalate (PET), and is intended to cover all polymeric and co-polymeric forms of polyethylene terephthalate or any other polyester. 8 Particle former process is disclosed in US 5,510,454 and incorporated herein as a reference in its entirety. Low molecular PET having IV of about 0.1 dl/g to about 0.4 dl/g was prepared according to the procedure disclosed in US 5,510,454 and incorporated herein as a reference in its entirety. Preferably, the anti-stiction additive is selected from fumed silica, colloidal silica, precipitated silica or silica beads, etc. Further the anti-stiction additive is also selected from other inorganic substances such as barium sulphate, calcium carbonate or magnesium carbonate, etc. Preferably, anti-stiction additive is precipitated silica having particle size of about 0.5 to about 50 microns, more preferably about 0.5 to about 15 micron, most preferably about 5 to about 10 micron. The anti-stiction additive is added in the range of about 0.002% to about 0.2% by weight of polyester. Preferably silica additive is added as a powder or as slurry prepared by mixing silica in ethylene glycol at any stage of melt polymerization such as estenfication reactor, oligomer line and column reactor particularly oligomer line. A static mixer is put after every injection nozzle for adding any suitable additive, co monomer for better dispersion. Preferably the anti-stiction additive is added in the estenfication reactor, oligomer line or column reactor, more preferably in the oligomer line The term "polyol" is intended to cover alcohol having two or more hydroxyl group known to those skilled in the art. According to the invention there is provided low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 with improved frictional property and uniform hemispherical shape, uniform particle size, uniform crystallinity prepared by the above process. Preferably , prepolymer with improved frictional property comprises among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic 9 acid, naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diol and anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate in the range of about 0.002% to 0.2% by weight of polyester. According to the invention there is provided high molecular weight polyester resin with an IV from about 0.5dl/g to about 1 dl/g with improved frictional property and accepted haze prepared by the above process. Preferably high molecular weight polyester resin with improved frictional property having IV about 0.5 dl/g to about 1 dl/g produced from low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 dl/g, comprising among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diol and anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or calcium - magnesium carbonate in the range of about 0.002% to 0.2% by weight of polyester. Preferably high molecular weight polyester resin with improved frictional property and accepted haze also comprises any suitable additives such as reheat additives, nucleating agents, antioxidants or UV stabilizers for the improvement of any performance of polyester article. Preferably high molecular weight polyester resin with improved frictional property and accepted haze prepared by the above process is used for the production of 10 preforms, beverage container, bottles, sheets and film with low coefficient of friction and improved slip performance. According to the invention there is provided high molecular weight polyester resin having IV of about 0.5 dl/g to about 1 dl/g with low co-efficient of friction and accepted haze produced from low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 dl/g by the above process. According to the invention there is provided polyethylene terephthalate with low coefficient friction and accepted haze comprising among other thing, pure terephthalic acid, monoethylene glycol and anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate in the range of about 0.002% to 0.2% by weight of polyester. PET prepared by the above process may or may not contain reheat additives, nucleating agents, antioxidants, UV stabilizers, or any suitable additives that are well known in the art. The polyester resin comprising anti-stiction additive, prepared by the above mentioned process is used for producing preforms, beverage container, bottles, sheets and film with low coefficient of friction and improved slip performance. The haze level of preform and bottle prepared according to the invention is found to be acceptable level and proportional to the amount of silica material added to the resin. Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. 11 Example 1: PET prepolymer having IV of 0.245 dl/g was prepared by melt-phase polymerization process. Purified terephthalic acid and monoethylene glycol (MEG) were charged in 1:2 ratio in reactor. 2 wt % Isophthalic acid and 1.5 wt % diethylene glycol (DEG) were added in the reactor. Esterification reaction was carried out at 280°C. About 200 ppm silica was added in the oligomer. The oligomer obtained was further polymerized at 290°C to raise the IV up to 0.245 dl/g. About 290ppm of antimony was added as a catalyst and 10 ppm P was added as a thermal stabilizer. A static mixer is put after every injection nozzle for adding any suitable additive, co monomer for better dispersion. The low IV prepolymer melt was then passed through the 1.5 mm diameter orifice to form droplets on a continuous moving steel belt of particle former. These droplets were then crystallized on the particle former maintained at a temperature between 110 to 160°C and then collected for carrying out solid-state polymerization. Example 2 Comparative PET prepolymer having IV of 0.245 dl/g was prepared by melt-phase polymerization process. Purified terephthalic acid and monoethylene glycol (MEG) were charged in 1:2 ratio in reactor. 2 wt % Isophthalic acid and 1.5 wt % diethylene glycol (DEG) were added in the reactor. Esterification reaction was carried out at 280°C. The oligomer obtained was further polymerized at 290°C to raise the IV up to 0.245 dl/g. About 290ppm of antimony was added as a catalyst and 10 ppm P was added as a thermal stabilizer. A static mixer is put after every injection nozzle for adding any suitable additive, co monomer for better dispersion. The low IV prepolymer melt was then passed through the 1.5 mm diameter orifice to form droplets on a continuous moving steel belt of particle former. These droplets were then crystallized on the particle former maintained at 12 a temperature between 110 to 160°C and then collected for carrying out solid-state polymerization. This prepolymer was considered as " Control". Example 3: Solid state polymerization Crystalline prepolymer having IV of 0.245 dl/g obtained in the example 1 to 2, was solid-state polymerized under inert atmosphere to raise the IV up to 1 dl/g. During SSP process, the material was passed through fluid bed heater at a temperature 236°C at least for 5 minutes; further passing through crystallizer maintained at 224°C; passing through a reactor of stage 1 maintained at 234°C, by maintaining g/s ratio 0.6 with atleast two hours residence time and further through a reactor of stage 2 maintained at 223°C temperature for atleast 23 hours by maintaining g/s ratio 0.5. The properties of hemispherical shaped low molecular crystalline PET having with and without silica additive prepared according to Example 1 and 2 are given in the table 1. TABLE 1 : Properties of hemispherical shaped low molecular crystalline prepolymer with or without anti-stiction additive Resin IV (dl/g) Additive level (ppm) carboxylendgroups(meq / kg) Tm peak CO Delta Hm (J/g) PET - Control {Preparedaccording to Example 2) 0.245 0 140.8 256.0 48.0 13 PET with precipitated silica (prepared 0.245 200 , 136.7 257.5 48.8 according to Example 1) Tm peak temperature was obtained using differential scanning calorimetry. Heating rate was 10°C/min. According to table 1, the stiction additive does not have any adverse effect on particle former operation, melting point as well as crystallinity of prepolymer. This is extremely important for trouble free run of solid-state polymerization (SSP) process. IV of low molecular weight PET was increased by solid-state polymerization process at a temperature of about 180°C to 240°C. Preferred solid-state polymerization temperature was about 210°C to about 230°C. Properties of high IV PET resin are given in the table 2. TABLE 2 : IV of PET resin with or without additive Resin Additive level (ppm) IV (dl / g) PET - Control (prepared according to Example 2and 3) 0 0.825 PET with precipitated silica(prepared according to Example 1and 3) 200 0.805 14 Arburg injection moulding machine was used to produce PET performs with and without silica additive. Preform properties are given in the table 3. TABLE 3 : Preform properties with or without anti-stiction additive Resin silica (ppm) L* a* B* %Haze PET - Control(prepared according to Example2 and 3) 0 66.9 0.54 5.49 11.4 PET with precipitated silica(prepared according to Example1 and 3) 200 66.2 0.54 5.97 9.7 According to Table 3, the clarity of the bottle (as seen from the haze value) was improved with the addition of silica additive. No impact on color properties of the preforms was observed. Bottles for the evaluation of color, haze and frictional properties were produced on SIDEL SB-01 machine. Bottle properties are given in the table 4. 15 TABLE 4 : Properties of bottles Resin Silica (ppm) L* a* b* %Haze Static coefficient of friction Dynamiccoefficient of friction PET-Control(preparedaccording toExample 2and 3) 0 95.06 0.04 0.64 3.22 0.268 0.170 PET with precipitatedsilica(preparedaccording toExample 1and 3) 200 94.93 0.06 0.94 3.37 0.156 0.070 According to table 4, substantial reduction was observed in the frictional properties of the bottles. Clarity of the bottle was comparable for Control as well as anti-stiction additive. 16 we claim 1 An improved process for the continuous production of a high molecular weight polyester resin of IV of about 0.5dl/g to about 1 dl/g from low molecular weight crystalline prepolymer of IV of about 0.1 dl/g to about 0.4 dl/g with the improved frictional properties, the process comprising; a. adding among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diol; b. esterifying the mixture of step (a) at temperature in the range of 250 to 290°C; c. removing excess or unreacted polyol or water produced from the step (b); d. polymerizing the esterified mixture at temperature in the range at 260°C - 300°C to obtain low molecular weight polyester prepolymer having IV of about 0.1 to about 0.4 dl/g; e. adding anti-stiction additive at any stage during melt polymerization steps of (a), (b), (c) or (d) but before the particle former process; f. producing a hemispherical, crystalline prepolymer of polyesters by a particle former process at temperature in the range of 110 to 160°C and g. polymerizing crystalline and hemispherical prepolymer by solid- state polymerization to produce high molecular weight polyester resin containing silica additive having IV of about 0.5dl/g to about 1 dl/g. 17 2. Process as claimed in claim 1, wherein the anti-stiction additive is selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate. 3. Process as cliamed in claim 1, wherein the antistiction additive is precipitated silica having particle size of about 0.5 to about 50 microns. 4. Process as claimed in claim 1, wherein the anti-stiction additive is added in the range of about 0.002% to 0.2% by weight of polyester. 5. Low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 with improved frictional property and uniform hemispherical shape, uniform particle size, uniform crystallinity prepared by the process as cliamed in claim 1. 6. Prepolymer with improved frictional property as claimed in claim 5, wherein prepolymer comprises among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diol and anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate in the range of about 0.002% to 0.2% by weight of polyester. 7. High molecular weight polyester resin with an IV from about 0.5dl/g to about 1 dl/g with improved frictional property and accepted haze prepared by the process as claimed in claim 1. 8. High molecular weight polyester resin with improved frictional property as claimed in claim 7, wherein the resin having IV about 0.5 dl/g to about 1 dl/g produced from low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 dl/g, comprising among other things, at least one dicarboxylic acid selected from terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid or 4,4'-biphenyl dicarboxylic acid or 18 monoesters thereof or diesters thereof and at least one polyol selected from monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylenes glycol or 1,4-cyclohexane diol and anti-stiction additive selected from fumed silica, colloidal silica, precipitated silica, silica beads, barium sulphate, calcium carbonate or magnesium carbonate in the range of about 0.002% to 0.2% by weight of polyester 9. Use of high molecular weight polyester resin with improved frictional property with accepted haze as cliamed in claim 7 prepared by the process as cliamed in claim 1 for the production of preforms, beverage container, bottles, sheets and film with low coefficient of friction and improved slip performance. Dated this the 8 day of June 2006 19 ABSTRACT An improved process for the continuous production of a high molecular weight polyester resin of IV of about 0.5dl/g to about 1 dl/g from low molecular weight crystalline prepolymer of IV of about 0.1 dl/g to about 0.4 dl/g with the improved frictional properties comprising adding anti-stiction additive at any stage during melt polymerization steps of (a), (b), (c) or (d) but before the particle former process. Low molecular weight crystalline prepolymer having IV of about 0.1 dl/g to about 0.4 with improved frictional property and uniform hemispherical shape, uniform particle size, uniform crystallinity prepared by the above process. High molecular weight polyester resin with an IV from about 0.5dl/g to about 1 dl/g with improved frictional property and accepted haze prepared by the above process is also disclosed. The high molecular weight polyester resin with improved frictional property with accepted haze prepared by the process is used for the production of preforms, beverage container, bottles, sheets and film with low coefficient of friction and improved slip performance. 20 -9 JUN 2006

Documents:

988-mum-2005-form-2 (provisional).doc

989-mum-2005-abstract(22-6-2009).pdf

989-MUM-2005-ABSTRACT(23-1-2009).pdf

989-mum-2005-abstract.doc

989-mum-2005-abstract.pdf

989-MUM-2005-CANCELLED PAGES(9-6-2006).pdf

989-mum-2005-claims(22-6-2009).pdf

989-MUM-2005-CLAIMS(23-1-2009).pdf

989-mum-2005-claims.doc

989-mum-2005-claims.pdf

989-mum-2005-correspondence 1(9-6-2006).pdf

989-mum-2005-correspondence 2(12-11-2009).pdf

989-MUM-2005-CORRESPONDENCE(16-9-2008).pdf

989-MUM-2005-CORRESPONDENCE(23-1-2009).pdf

989-MUM-2005-CORRESPONDENCE(5-2-2009).pdf

989-MUM-2005-CORRESPONDENCE(7-4-2011).pdf

989-mum-2005-correspondence(ipo)-(17-7-2009).pdf

989-MUM-2005-CORRESPONDENCE-(20-12-2010).pdf

989-mum-2005-correspondence-received.pdf

989-mum-2005-description (complete).pdf

989-MUM-2005-DESCRIPTION(COMPLETE)-(23-1-2009).pdf

989-mum-2005-description(granted)-(22-6-2009).pdf

989-mum-2005-description(provisional)-(22-8-2005).pdf

989-MUM-2005-FORM 1(22-8-2005).pdf

989-mum-2005-form 13(16-9-2008).pdf

989-mum-2005-form 2(23-1-2009).pdf

989-mum-2005-form 2(granted)-(22-6-2009).pdf

989-mum-2005-form 2(provisional)-(22-8-2005).pdf

989-mum-2005-form 2(title page)-(22-6-2009).pdf

989-MUM-2005-FORM 2(TITLE PAGE)-(23-1-2009).pdf

989-mum-2005-form 2(title page)-(provisional)-(22-8-2005).pdf

989-MUM-2005-FORM 26(16-9-2008).pdf

989-MUM-2005-FORM 26(7-4-2011).pdf

989-MUM-2005-FORM 3(23-1-2009).pdf

989-MUM-2005-FORM 5(9-6-2006).pdf

989-MUM-2005-FORM 8(5-2-2009).pdf

989-mum-2005-form-1.pdf

989-mum-2005-form-2.doc

989-mum-2005-form-2.pdf

989-mum-2005-form-3.pdf

989-mum-2005-form-5.pdf

989-mum-2005-specification(amanded)-(23-1-2009).pdf