Title of Invention	NOVEL AQUEOUS POLYURETHANE ACRYLIC HYBRID RESIN DISPERSION
Abstract	The novel invention describes aqueous polyurethane-acrylic hybrid resin dispersion, which comprises, b) forming carboxy containing, water dispersible , isocyanate terminated polyurethane prepolymer, c) neutralizing prepolymer by addition tertiary amines, d) adding vinyl monomers which includes polyethylenically unsaturated monomers to this neutralize prepolymer, e) dispersing the prepolymer/monomer mixture in water f) adding an oil soluble free radial initiator and then chain-extender to this aqueous dispersion, and g) polymerizing this vinyl monomer by free radical polymerization.

Title of Invention

NOVEL AQUEOUS POLYURETHANE ACRYLIC HYBRID RESIN DISPERSION

Abstract

The novel invention describes aqueous polyurethane-acrylic hybrid resin dispersion, which comprises, b) forming carboxy containing, water dispersible , isocyanate terminated polyurethane prepolymer, c) neutralizing prepolymer by addition tertiary amines, d) adding vinyl monomers which includes polyethylenically unsaturated monomers to this neutralize prepolymer, e) dispersing the prepolymer/monomer mixture in water f) adding an oil soluble free radial initiator and then chain-extender to this aqueous dispersion, and g) polymerizing this vinyl monomer by free radical polymerization.

Full Text	FORM 2 THE PATENT ACT 197 0 (39 of 1970) The Patents Rules, 2003 COMPLETE SPECIFICATION See Section 10, and rule 13) TITLE OF INVENTION NOVEL AQUEOUS POLYURETHANE-ACRYLIC HYBRID RESIN DISPERSION APPLICANT(S) a) Name b) Nationality c) Address GOODLASS NEROLAC PAINTS LIMITED INDIAN Company NEROLAC HOUSE, GANPATRAO KADAM MARG, LOWER PAREL, MUMBAI - 400 013 PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - Novel Aqueous Polyurethane - Acrylic Hybrid Resin Dispersion Introduction: Stringent laws relating to health, safety, & environmental protection are restricting the use of conventional solvent-based Polyurethane. Aqueous based Polyurethane and Polyurethane Hybrid dispersions consequently have become an important substitute for the conventional solvent-based polymers. Described herein is Polyurethane - Acrylic hybrid resin dispersion with high film hardness, and better weatherability as compared to Polyurethane Dispersions, which often suffer from poor exterior durability & poor pH stability. Acrylics on the otherhand are used in exterior coatings because of their versatile chemistry, which allows formulation of coatings with excellent durability & film hardness. Also acrylic emulsions are lower in cost in comparison with Polyurethane dispersions alone. However, acrylic emulsions have poor mechanical properties. Also, good film formation of coatings based on acrylic emulsions requires use of film forming aids which are organic co solvents contributing to the Volatile Organic Content (VOC) of coatings. Hence the main objective of preparing this novel Polyurethane / Acrylic hybrid dispersions is to combine Acrylics and Polyurethane to come up with coatings which can provide benefits inherent in both types of polymers without significant contribution from their disadvantages. Described herein is Polyurethane - Acrylic hybrid resin dispersion that is formed by reaction of a carboxyl containing, water dispersible, isocyanate terminated polyurethane prepolymer & polyethylenically unsaturated monomer to form 2 prepolymer - monomer mixture. This monomer is then polymerized by free radical polymerization in presence of Polyurethane dispersions using catalysts like peroxides, persulphates etc. DESCRIPTION: BACKGROUND OF THE INVENTION: 1. Field of invention: This novel invention relates to aqueous polyurethane acrylic hybrid resin dispersion, which can be used for coatings on wood, metal, ABS, masonry, leather, paper, fabric etc. 2. Description Of The Background Art: Over the past decade the use of conventional solvent based polyurethane (PU) is becoming restricted by stringent laws relating to health, safety, and environmental protection. Hence coating systems based on aqueous polyurethane dispersions have grown in importance across a fairly broad range of applications because of their beneficial properties and low VOC content. Coatings based on Polyurethane dispersion have properties like adhesion to variety of substrates, abrasion resistance, flexibility and toughness. But Polyurethane dispersion has limited outdoor durability and high cost. Here is the comparison of properties of both Polyurethane and Acrylics. Sr Properties Acrylic Polyurethane 12 Yellowing Outdoor resistance Very less Better More Limited 3 pH stability Better Poor 4 Compatibility with other ingredients Better Limited 5 Cost Low High 6 Thermoplasticity More Less 7 Film formation Slightly inferior Better 8 Mechanical properties Slightly inferior Poor Excellent Better 9 Chemical resistance 3 To get both cost & performance benefits, physical blends of acrylic emulsions and aqueous polyurethane dispersions can be made. These physically blended dispersions can provide enhanced properties as compared to all acrylics and cost benefits as compared to polyurethane, but there are some limitations to these blended systems. Many polyurethane / acrylic dispersions are incompatible, resulting in unstable blends which may phase separate, gel or discolour upon storage. Furthermore, the homogeneity of the polyurethane/ acrylic hybrid blends is questionable, both in wet state and most importantly in the final dried coating. There are two chemical processes for generating an aqueous based Polyurethane dispersion. 1) Use of external emulsifiers with some organic co solvents 2) Use of ionic compounds as internal emulsifiers in the polymer. Like most organic polymers, Polyurethane is not easily converted into a stable aqueous phase without the aid of emulsifiers, because of its hydrophobic character. These dispersions are prepared by using ionic compounds like dihydroxy alkanoic acid. This addition of acid containing diols has following advantages: The ionic content is a major factor for controlling the particle size of the dispersion. Low ionic content (acid number) dispersion must be neutralizing to 120 % to achieve a stable dispersion during production. Increasing acid number widens the processing window, allows lower neutralizing amine level, and allows lower pH of the dispersion. Hence Polyurethane/ Acrylic hybrid coatings are prepared by adding ionic compounds as internal emulsifiers to get better stability for the dispersion. 4 Currently available formulations have disadvantages like poor outdoor durability, poor chemical resistance. Also these formulations are not cost effective. The aim of the present invention is to develop Polyurethane / Acrylic hybrid resin dispersion with better outdoor durability & to overcome other disadvantages of prior art. The design of base acrylics is the primary determinant of coating performance. The properties of the hybrid coating are largely derived from the properties of the acrylic part of the dispersion. Monomers are selected according to desired final film properties. Hence this novel Polyurethane/ Acrylic dispersion has been developed based on polyester polyol / polyether polyol having molecular weight ranging from 700 -4000, low molecular weight polyols (di or tri functional) and dihydroxy alkanoic acid with diisocyanate in presence of catalyst and solvent will give Polyurethane prepolymer. This prepolymer on neutralization with tertiary amine & then monomer addition, dispersion with water, initiator addition & chain extension process will give final Polyurethane / Acrylic hybrid dispersion. SUMMARY OF INVENTION: Aqueous Polyurethane and Polyurethane hybrid consequently has become an important substitute for the conventional solvent-based polymers. The novelty of the disclosed invention lies in use of polyester polyols / polyetherpolyol with molecular weight ranging from 700 - 4000, low molecular weight polyols (difunctionl or trifunctional), dihydroxy alkanoic acid as a polyol to produce Polyurethane/ Aery lie Hybrid resin dispersion which gives better hardness as well as better flexibility to the coatings and also gives excellent adhesion on wood, plastic, masonry, leather, paper, fabric etc. 5 In this case ethylenically unsaturated monomers are polymerized by means of free radical polymerization in presence of preformed polyurethane dispersion. Each dispersion particle is stabilized by hydrophilic moieties of polyurethane, usually anionic groups in the polyurethane backbone. The resulting Polyurethane / Acrylic hybrid resin dispersion comprises acrylic and urethane polymer chains which are intimately mixed at the molecular level within each dispersion particle. DETAILED DESCRIPTION OF INVENTION : The present invention describes Polyurethane /Acrylic dispersion made by the following process, which comprises a) forming carboxy containing, water dispersible, isocyanate terminated polyurethane prepolymer, b) neutralizing prepolymer by addition tertiary amines, c) adding vinyl monomers which includes polyethylenically unsaturated monomer to this neutralize prepolymer, d) dispersing the prepolymer/ monomer mixture in water, e) adding an oil soluble free radical initiator and then chain - extender to this aqueous dispersion, and polymerizing this vinyl monomer by free radical polymerization in presence of polyurethane dispersion. The novelty of the disclosed invention lies in use of polyester polyol/ polyether polyol with molecular weight ranging from 700 - 4000, low molecular weight polyols (difunctional or trifunctional) like 1,4- cyclohexane dimethanol (CHDM), trimethylol propane (TMP), dihydroxy alkanoic acid like dimethylol propionic acid as a polyol to produce Polyurethane/Acrylic Hybrid resin dispersion for coatings which has excellent adhesion on wood, concrete, plastic etc. The polyester or polyether diol can be obtained by reacting atleast one polyhydric alcohol and atleast one polycarboxylic acid or polycarboxylic anhydride. Examples of polyhydric alcohols include 1,6 hexanediol, ethylene glycol, propylene glycol, 6 diethylene glycol, neopentyl glycol, 1,4-butanediol, and cyclohexane dimethanol. Polycarboxylic acids used are succinic acid, glutaric acid, adipic acid, and phthalic acid or phthalic anhydride, isophthalic acid. The carboxylic acid containing diols like 2,2-dimethylolpropionic acid, 2,2- dimethylol-butyric acid, 2,2- dimethylolvaleric acid etc are used to react with diisocyanate. This will form a prepolymer of polyurethane having free carboxylic group. The stable urethane - acrylic hybrid polymer dispersion, wherein the isocyanate monomer is selected from the group consisting of 1,4- tetramethylene diisocyanate' 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl- 1,6-diisocynatohexane, 1,10-decamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, bis (4-isocynatocyclohexyl) methane, l-isocynato-3-isocynatomethyl-3,5,5-trimethyl-cyclohexane, m- and p-phenylene diisocyanate, 2,6- and 2,4-tolune diisocyanate, xylene diisocyanate,4-chloro- 1,3-phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 4,4'-methylene diphenyl diisoisocyanate, 1,5-naphthylene diisocyanate, 1,5-tetrahydronaphthylene diisocyanate, polymethylene polyphenylisocyanates, 1,12-dodecyl diisocyanate, norbornane diisocyanate, 2-methyl-l,5-pentane diisocyanate, isophorone diisocyanate and mixtures thereof. NCO : OH ratio is kept at 1:1 to 1:4 to control molecular weight of isocyanate terminated prepolymer (7000 - 12000 Mw typical). Addition of low molecular weight polyols like trimethylol propane will give controlled branching, which improves strength and chemical resistance properties. Addition of low molecular weight polyols like trimethylol ethane, 1,4-cyclohexane dimethanol will give excellent hardness with some flexibility & high Tg relative to linear aliphatic glycol. Also it will give low temperature reactivity during resin 7 synthesis & curing. This low molecular weight polyol addition will give good hydrolytic stability to dispersion. The polymeric polyols are reacted with stoichiometric excess of the organic polyisocyanate to form carboxylated polyurethane in presence or absence of solvents at the temperature of 50 to 90° C. The solvents used here are required to adjust viscosity of prepolymer. These solvents are dioxane, acetone, methyl ethyl ketone, N- methylpyrrolidone, tetrahydrofuran, and N- vinyl acetate etc. If desired, a catalyst may be used to assist prepolymer formation. The catalyst used can be dibutyltin dilaurate (DBTDL). For neutralization of prepolymer, tertiary amine used are trimethylamine, triethyl amine, di-methyl ethanolamine, tri-n-propylamine, triethanolamine, tributylamine, ammonia, hydrazine etc. These amines are added in an amount sufficient to render the prepolymer water dispersible i.e. an amount sufficient to neutralize carboxylic groups present in the prepolymer. This amine is added at about 65 to 100 % amine equivalent per equivalent of carboxy functionality. This tertiary amine, which is added to the prepolymer before the dispersion of prepolymer in water to ensure compatibility of organic & aqueous phases. To this neutralized prepolymer ethylenically unsaturated monomers are added like methylmethacrylate, butyl acrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, styrene, methylmethacrylate etc. The carboxylate groups on carboxylated polyurethane impart water dispersibility to polyurethane, i.e. colloidal stabilization in water. This neutralized prepolymer of polyurethane is then emulsified in water to get proper dispersion. 8 The polymer/monomer mixture can be added to the water under stirring or alternatively, water may be stirred into the polymer / monomer mixture. To this dispersion formed, add free radical initiator and solvent mixture. The molecular weight of the final acrylic polymer is crucial for effective hybridization. Lower molecular weights and low polydispersity (Mw/Mn - close or equal to 1) are favoured. Then chain extension of NCO terminated emulsified prepolymer, water may contain polyamines as chain extending. Chain extending agents used are piperazine, piperazine hexahydrate, diethylene triamine, triethylene tetramine, and ethylene diamine etc. The quantity of chain extender employed should be approximately equivalent to the free isocyanate groups in the prepolymer preferably being in the range of 0.7:1 to 1.3 :1. Then, by thermal decomposition of free radical initiator, polymerization of monomers is carried out within the miscells of polyurethane dispersion at temperature ranging from 60 - 90° C. The advantage of this method of preparation is that monomers and initiator can be added together at room temperature and that their stabilization in polyurethane dispersion does not require any additional emulsifiers. The charge density of polyurethane micelles is sufficiently great to ensure the polymerization of monomers within the micelles without emulsifiers - by virtue of their stability alone. The stability of polyurethane/ Acrylic hybrid micelles is retained for a long period even after polymerization has come to an end, without further addition of stabilizer. Diluting the chain extender with portions of the dispersion medium makes possible to separate the by - products formed during prepolymer mixing in water. 9 The polymer dispersions obtained have 20 to 60 wt % solids & may be employed as coating compositions and can be applied to wood, glass, plastics, leather, paper, fabric etc. by any conventional method of application like brushing, spraying, dipping. These dispersions can be used as air-drying coatings or it can be used as stoving coatings. The novelty of this Polyurethane / Acryhc hybrid resin dispersion lies in incoporation of Polyester Polyol with molecular weight 700 - 4000 & Polyol (difunctional or trifunctional) with low molecular weight which gives good flexibility with better hardness, good chemical resistance, excellent stability of the dispersion within a wide range of pH, good freeze thaw stability, cost benefit and achieved in simple synthesis route, without chemical crosslinking, with low organic solvent content. Dispersion characteristics - Prepared with less quantity of solvents. - No external surfactants required. - LowVOC. - Low viscosity. - Good shelf stability (1 year). - Better coating toughness. - Better coating flexibility. - Excellent adhesion on substrates like wood, masonry, plastics, leather, paper, fabric etc. - Excellent gloss retention 10 EXAMPLES - The following examples constitute some dispersion formulation based on the experimental work. This is not an exhaustive list of the compositions tested; comparative composition number 8 is an example of the prior state of art dispersion formulation. Abbreviations: NV: Non-Volatile Content Sec: seconds Hrs: hours Gms: grams NCO content: isocyanate content DETA : diethyl triamine PREPARATION OF POLYURETHANE/ ACRYLIC HYBRID DISPERSIONS Example 1 A 4 neck round bottom flask equipped with agitator, condenser, addition funnel, thermometer, nitrogen purge, and water bath is taken. To this flask charge 61.8 gms of Polyester polyol/ Polyether polyol (OH value 85 - 125), 0.61 gms of trimethylolpropane, 9.27 gms of 2,2-dimethylolpropionic acid, 0.017 gms of dibutyltin dilaurate, 50.0 gms of N-methylpyrrolidone, 30.0 gms of acetone. Heat these contents of flask to 75° C under nitrogen purging for 30 minutes. When temperature reaches to 75° C start adding 114.7 gms of isophorone diisocyanate drop wise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 6.9 gms of triethylamine to this 11 prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl acrylate, 100.0 gms of methylmethacrylate & 20.0 gms of styrene. Add this monomer mixture to neutralized prepolymer slowly under stirring. Add 474.50 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20 - 30 minutes. Prepare mixture of 2 gms of (2,2-azobisisobutyronitrile) & 10.0 gms N-methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 13.4 gms of ethylenediamine & 26.8 gms of deionized water. Add this solution to the dispersion quickly & stir this for 10 - 15 minutes. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 75° C till complete conversion of monomers takes place. Example 2 A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 64.13 gms of Polyester polyol (OH value 85 - 125), 6.83 gms of trimethylolethane, 11.46 gms of 2,2-dimethylolpropionic acid, 0.017 gms of dibutyltin dilaurate, 60.0 gms of N-methylpyrrolidone, 20.0 gms of acetone. Heat these contents of flask at 70° C under nitrogen purging. When temperature reaches to 70° C start adding 108.24 gms of methylene bis(4-cyclohexylisocyanate) drop wise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 70 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 40° C. Add 7.77 gms of triethylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 40.0 gms of butyl acrylate & 160.0 gms of methylmethacrylate. Add this monomer mixture to neutralized prepolymer slowly under stirring. Add 467.73 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20 - 30 minutes. Prepare mixture of 2.0 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 9.32 gms of 12 diethyltriamine & 32.5 gms of deionized water. Add this solution to the dispersion quickly & stir this for 10 - 15 minutes. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place. Example 3 A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 73.0 gms of Polyester polyol/ polyether polyol (OH value 85 - 125), 8.56 gms of 1,4 cyclohexane dimethanol, 11.42 gms of 2,2-dimethylolpropionic acid, 0.015 gms of dibutyltin dilaurate. 64.5 gms of N-Methylpyrrolidone, 17.0 gms of acetone. 97.17 gms of isophorone diisocyanate to the flask. Heat these contents of flask to 75° C. The temperature of reaction mixture is maintained to 75° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 8.6 gms of triemylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl acrylate & 120.0 gms of methylmethacrylate. Add this monomer mixture to polyurethane polymer slowly under stirring within 15 - 20 minutes. Add 476.78 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20- 30 minutes. Prepare mixture of 2.5 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above mixture within 10 minutes. Make solution of 9.84 gms ethylenediamine & 20.6 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place. Example 4 A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 90.8 gms of Polyester polyol/ Polyether polyol (OH value 85 - 125), 3.29 gms of Trimethylolpropane, 13.1 gms of 2.2'-dimethylolpropionic acid, 0.015 gms of 13 dibutyltin dilaurate. 80.0 gms of N-Methylpyrrolidone, 12.0 gms of Acetone. Heat these contents of flask to 75° C under nitrogen purging. When temperature reaches to 75° C start adding 85.38 gms of methylene bis(4-cyclohexylisocyanate) dropwise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 8.7 gms of dimethyl ethanol amine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 79.0 gms of methyl methacrylate & 111.0 gms of butyl acrylate and 2.0 gms of methacrylic acid. Add this monomer mixture to neutralized prepolymer slowly under stirring within 15 - 20 minutes. Add 465.55 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 30 minutes. Prepare mixture of 2.5 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 7.33 gms of ethylenediamine & 29.33 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place. Example 5 A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 77.01 gms of Polyester polyol / Polyether polyol (OH value 85 - 125), 10.25 gms of 1,4 chyclohexane dimethanol, 12.033 gms of 2,2'-dimethylol propionic acid, 0.017 gms of dibutyltin dilaurate. 64.5 gms of N-methylpyrrolidone, 17.59 gms of acetone. Heat these contents of flask at 75° C under nitrogen purging. When temperature reaches to 75° C start adding 95.06 gms of methylene bis(4-cyclohexylisocyanate) dropwise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 7.7 gms of triethylamine to this 14 prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl aery late & 120.0 gms of methylmethacrylate. Add this monomer mixture to neutralized prepolymer slowly under stirring within 15 - 20 minutes. Add 486.98 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20-30 minutes. Prepare mixture of 2 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 5.62 gms of EDA & 11.24 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 75° C till complete conversion of monomers takes place. Example 6 A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 80.2 gms of Polyester polyol/ Polyether polyol (OH value 85 - 125), 0.015 gms of dibtyltin dilaurate, 94.42 gms of methylene bis(4-cyclohexylisocyanate), 17.0 gms of acetone. Heat these contents of flask to 70° C under nitrogen purging. Then raise the temperature to 85° C add 14.45 gms of 2,2'-dimethylol propionicacid and 64.5 gms of N-Methylpyrrolidone to the contents of the flask. The temperature of reaction mixture is maintained at 85 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 40° C. Add 10.9 gms of triethylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 100.0 gms of butyl acrylate & 100.0 gms of methylmethacrylate. Add this monomer mixture to prepolymer slowly under stirring within 15 - 20 minutes. Add 472.51 gms of deionized water to this Polyurethane polymer / monomer mixture slowly under high speed stirring within 20-30minutes. Prepare mixture of 2 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 10.21 gms of ethylenediamine & 30.0 gms of deionized water. Add this solution to the prepolymer slowly within 15 15 min. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place. Example 7 A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 99.85 gms of Polyester polyol / Polyetherpolyol (OH value 85 - 125), 2.57 gms of 1,4 cyclohexane dimethanol, 9.72 gms of 2,2'-dimethylol propionicacid, 0.017 gms of dibutyltin dilaurate, 55.5 gms of N-Methylpyrrolidone, 24.5 gms of acetone. Heat these contents of flask to 75° C under nitrogen purging. When temperature reaches to 75° C start adding 80.81 gms of methylene bis(4-cyclohexylisocyanate) dropwise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 85 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50 - 55° C. Add 7.33 gms of triethylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl acrylate & 120.0 gms of methylmethacrylate. Add this monomer mixture to neutralized prepolymer slowly under stirring within 15 - 20 minutes. Add 476.70 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20-30 minutes. Prepare mixture of 2 gms of (2,2-azobisisobutyronitrile) & 20.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 7.0 gms of ethylenediamine & 14.0 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place. Example 8 A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 145.64 gms of Polyester polyol / polyether polyol (OH value 85 - 125), 17.15 gms of 1,4- 16 cyclohexane dimethanol, 22.78 gms of 2,2'-dimethylol propionic acid, 0.03 gms of dibutyltin dilaurate, 129.6 gms of N-Methylpyrrolidone, 33.39 gms of acetone. Heat these contents of flask to 75° C under nitrogen purging for 30 minutes. When temperature reaches to 75° C start adding 193.86 gms of isophorone diisocyanate drop wise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80 ° C. The resulting prepolymer is cooled to 50 -55° C. It is taken under high-speed stirrer. Add 18.03 gms of triethylamine to this prepolymer under vigorous stirring. Make solution of 20.63 gms of ethylenediamine & 418.92 gms of deionized water. Add this solution to the dispersion slowly. After complete addition of ethylenediamine solution, stir this dispersion for 10 - 15 minutes. TESTING OF THE PHISICO-CHEMICAL PROPERTIES OF THE NOVEL DISPERSION: Wood coatings were prepared in lab, using this novel Polyurethane/ Acrylic hybrid resin dispersion to evaluate its physico - chemical properties. Preparation of coating formulation : The wood coating using Polyurethane / Acrylic dispersion was formulated as per the following recipe. Ingredients wt % 1) Polyurethane/ Acrylic : 97.35 hybrid resin dispersion 2) Polysiloxane in Polyglycol : 0.25 (defoamer) 3) Levelling agents 0.2 4) Silicone based surfactant : 0.2 5) Aqueous wax emulsion : 1.5 6) Associative PU thickner : 0.5 Total 100.00 17 OUTLINE OF TESTING METHODS: 1) DETERMINATION OF VISCOSITY ON FLOW CUP B4: (ASTM - D - 1200) 2) NON - VOLATILE CONTENT: (IS -197-1969) 3) DETERMINATION OF DRYING TIME: (IS -197) 4) CROSSCUT ADHESION OF FILM: (ASTM - D - 3363) 5) WATER RESISTANCE: (IS 101) 6) PENCIL HARDNESS: (ASTM - D - 3363) 7) STABILITY: (IS 101) 8) CHEMICAL RESISTANCE:(ASTM D 1308) 9) FREEZE THAW STABILITY: (ASTM D 2243-82) 10) GLOSS : (ASTM D 523) 11) CHEMICAL RUB METHOD : (ASTM D 4752) 12) UV EXPOSURE : (IS 101) APPLICATION METHOD: 1) The final coating is thinned with water if required to adjust viscosity up to 25 - 30 sec on Ford cup B4 @ 30° C & applied by brush on wood, plastic, concrete, masonry, leather, fabric etc. Or 2) The paint is thinned with water if required to adjust viscosity up to 15 - 20 sec on Ford cup B4 @ 30° C & applied by spraying on wood, plastic, concrete. Wood panel preparation system: 1) Water based Wood sealer 2) Water based Wood filler 3) Polyurethane / acrylic resin dispersion. The film applied on wood & concrete is air dried for 24 hrs. Testing of wood panels is done after 72 hrs. curing. 18 Observations: From the above test results it is observed that PU / Acrylic Hybrid resin dispersion has better properties than Polyurethane dispersion w.r.t. 1) Stability. 2) Freeze thaw stability. 3) Gloss & hardness. 4) UV resistance than PU dispersion described in example 8. BRIEF DESCRIPTION OF DIAGRAM CH3 -CI COON 1 HO^R^OH + Q=C=N«**N=C=Q + HOCH2-C-CH2OM catalyst, heat, coivwit 0=C=N -H—J-^WAW}—NHCeNw— M=C=Q 9 -«\|—Uw,fJMCCJ^nivMHCQNH *NHCONH- COO" X Fig : Synthesis of water borne polyurethane dispersion by the isocyanate prepolymer process 20 CONCLUSIONS: Polyurethane/ Acrylic hybrid resin dispersion formed by this invention when compared with other similar resin (example) shows good performance properties like i) Better gloss & hardness. ii) Excellent dispersion stability. iii) Excellent freeze/thaw stability. iv) Good adhesion on glass, wood and plastics, leather, masonry, paper, fabric. v) Better weather resistance vi) Cost effective. FLOW CHART: PU PREPOLYMER l_ j NEUTRALIZATION , ZTZZZ" DISPERSION IN WATER "ZZ^ZZZI"" CHAIN EXTENSION ~ ~T FREE RADICAL POLYMERIZATION ] \| i ! FINAL DISPERSION I ADDITIVES .-"3X11" , ! WOOD FINISH GLOSSY \| 21 WE CLAIMS: 1) We claim a Polyurethane/ Acrylic hybrid resin dispersion comprising carboxyl containing isocyanate terminated polyurethane prepolymer which is neutralized with tertiary amine, its mixture with polyethylenically unsaturated monomer dispersed in water, the said mixture after chain extension is then polymerized with the help of free radical initiator. 2) A Polyurethane/ Acrylic hybrid resin dispersion as claimed in claim 1, comprising the following ingredients. a) 3 to 25 % by weight of a polyester/ polyether polyol having molecular weight ranging from 700 - 4000. b) 0 to 3 % by weight of dihydroxyalkanoic acid. c) 2 to 20 % by weight of polyisocyanate component. d) 0 to 0.5 % of catalyst like dibutyl tin dilaurate. e) 0 - 20 % by weight of a organic solvent. f) 0.2 to 3 % by weight of neutralizing component. g) 0.2 to 2 % by weight of chain extender. h) 5 to 30 % by weight of monomer component, i) 0.01 to 2 % by weight of a free radical initiator component, j) 30 to 70 % by weight, preferably 50 % by weight of water as dispersion medium. 3) Polyurethane/ Acrylic hybrid resin dispersion as claimed in claim 1, wherein the polyester/ polyether polyol component is 3 to 25% by weight having a molecular weight ranging from 700 to 4000 obtainable by reacting atleast one polycarboxylic acid and/or polycarboxylic anhydride with atleast one polyhydric alcohol. 4) Polyurethane/ Acrylic hybrid resin dispersion as claimed in claim 1, wherein polyhydric alcohols are selected singly or in combination from a group comprising 1,6 hexanediol, ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, and / or cyclohexanedimethanol. Polycarboxylic acids used are succinic acid, glutaric acid, adipic acid, and phthalic acid or phthalic anhydride, isophthalic acid, 0 to 2 % by weight of low molecular mass polyols (di or tri functional) like 1,4-cyclohexane dimethanol (CHDM), trimethylolpropane (TMP) trimethylol ethane (TME), 0 to 3 % by weight of dihydroxyalkanoic acid like 2,2 dimethylolproppionic acid, 2,2-dimethylol-butyric acid, 2,2-dimethylolvaleric acid etc. 5) A hybrid resin dispersion as claimed in claim 1, wherein polyisocyanate components are selected from one or more polyisocyanates like 1,4-tetramethylene diisocyanate 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-diisocynatohexane, 1,10-decamethylenediisocyanate, 1,4-cyclohexylene diisocyanate, bis (4-isocynatocyclohexyl) methane, l-isocynato-3- 22 isocynatomethyl-3,5,5-trimethyl-cyclohexane, m- and p-phenylene diisocyanate, 2,6- and 2,4-tolune diisocyanate, xylene diisocyanate, 4- chloro- 1,3-phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 4,4'- methylene diphenylisocyanate, 1,5-naphthylene diisocyanate, 1,5- tetrahydronaphthylene diisocyanate, polymethylene polyphenylisocyanates, 1,12-dodecyl diisocyanate, norbornane diisocyanate, 2- methyl-l,5-pentane diisocyanate having two or more aliphatic and / or aromaticisocyanate groups. 6) A hybrid resin dispersion as claimed in claim 1, wherein the solvent component consists of at least one polyisocyanate - inert organic solvent comprising of high boiling & hydrophilic compounds like dioxane, acetone, methyl ethyl ketone, N-methylpyrrolidone, tetrahydrofuran, and N-vinyl acetate. The solvent component may remain therein or may be removed in part or in whole by distillation. 7) A hybrid resin dispersion as claimed in claim 1, wherein 0 - 0.5 % catalyst like dibutyltin dilaurate (DBTDL) is used. 8) A hybrid resin dispersion as claimed in claim 1, wherein the neutralizing component comprises at least one tertiary amine like trimethylamine, triethyl amine, di-methyl ethanolamine, tri-n-propylamine, triethanolamine, tributylamine, ammonia, hydrazine etc. 9) A hybrid resin dispersion as claimed in claim 1, wherein the chain extender is selected from one or more polyamines like piperazine, piperazine hexahydrate, diethylene triamine, triethylene tetramine, and ethylene diamine having two or more functionalities. 10) A hybrid resin dispersion as claimed in claim 1, wherein the monomer component comprises one or more monomers like methylmethacrylate, butyl acrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, styrene, methylmethacrylate etc. having one or more free radically polymerizable double bonds. 11) A hybrid resin dispersion as claimed in claim 1, wherein free radical initiator components are selected from azonitrile initiators, (2,2-azobisisobutyronitrile) and peroxyesters, (t- amyl peroxy-2-ethylhexanoate). 12) A hybrid resin dispersion as claimed in claim 1, which comprises of 30 to 70% by weight preferably 50% by weight of water as dispersion media. 13) A hybrid resin dispersion as claimed in claim 1, wherein the dispersion of claim 1 comprises forming an isocyanate terminated polyurethane prepolymer by 23 reaction of polyester/ polyether polyol & an acid containing diol reacting with isocyanate in the ratio ranging from 1:1 to 1:3 in presence or absence of catalyst & solvent at temperature from 50 to 120° C, preferably from 70 to 90° C. 14) A process of making hybrid resin dispersion with high film hardness reacting the following components. a) 3 to 35% by weight of a polyester/ polyether polyol components having molecular weight ranging from 700-4000. b) 0 to 3 % by weight of dihydroxyalkanoic acid. c) 2 to 20% by weight of polyisocyanate component. d) 0-20% by weight of a solvent component. e) 0 to 0.5% of catalyst like dibutyltin dilaurate. f) 0.2 to 3% by weight of a neutralizing component. g) 0.2 to 2% by weight of a chain extender component, h) 5% to 30% by weight of a monomer component. i) 0.01 to 2% by weight of a free radical initiator component, j) 30 to 70% by weight, preferably 50% by weight of water. 15) The process as claimed in claim 14 wherein the polyester/ polyether polyol component having molecular weight ranging from 700 - 4000 is obtained by reacting at least one polyhydric alcohol and at least one polycarboxylic acid and / or polycarboxylic anhyride with polyhydroxy alcohol. 16) A process as claimed in claim 14 wherein the Polyisocyanate components are selected from one or more polyioscyanates like 1,4-tetramethylene diisocyante 1,6-hexamefhylene diisocyanate, 2,2,4-trimethyl-l,6-diisocynatohexane/ 1,10-decamethylenediisocyanate, 1,4-cyclohexylene diisocyanate, bis(4-isocynatocyclohexyl)methane, l-isocynato-3- isocynatomethyl-3,5,5-trimethyl-cyclohexane, m-and p-phenylene diisocyanate, 2,6- and 2,4-tolune diisocyanate, xylene diisocyanate, 4-chloro-l,3-phenyle diisocyanate, 4,4'-biphenylene diisocyanate,4,4'-methylene diphenylisocyanate,l,5-naphthylene diisocyante, 1,5-tetrahydronaphthlene diisocyanate, polymethylene polyphenylisocyanates, 1,12-dodecyl diisocyanate, norbornane diisocyanate, 2-methyl-l, 5-pentane diisocyanate, having two or more aliphatic and/or aromatic isocyanate groups. 17) A process as claimed in claim 14 wherein the solvent component consists of at least one polyisocyanate-inert organic solvent comprising of high boiling & hydrophilic compounds like dioxane, acetone, methyl ethyl ketone, N-methylpyrrolidone, tetrahydrofuran, and N/ vinyl acetate, The solvent component may remain therein or may be removed in part or in whole by distillation. 24 18) A process as claimed in claim 14 wherein the neutralizing component comprises at least one tertiary amine like trimethylamine, triethyl amine, di methyl ethanolamine, tri-n-propylamine, triethanolamine, tributylamine, ammonia, hydrazine etc. 19) A process as claimed in claim 14 wherein 0 - 0.5 % catalyst like dibutyltin dilaurate (DBTDL) is used. 20) A process as claimed in claim 14 wherein the process is carried out at temperature ranging from 25-40°C and ethylenically unsaturated monomers:prepolymer ratio varies from 1:0.5 to 1:1.5. 21) A process as claimed in claim 14 wherein the chain extender component comprises one or more polyamines like piperazine, piperazine hexahydrate, diethylene triamine, triethylene tetramine, and ethylene diamine having two or more functionalities 22) A process as claimed in claim 14 wherein the monomer component comprises one or more monomers like methylmethacrylate, butyl acrylate, methyl aery late, ethyl acrylate, ethyl methacrylate, styrene, methylmethacrylate etc. having one or more free radically polymerizable double bonds. 23) A process as claimed in claim 14 wherein the free radical initiator component which comprises of azonitrile initiators, (2,2-azobisisobutyronitrile) and peroxyesters, (-amyl peroxy-2-ethylhexanoate). 24) A process as claimed in claim 14 wherein the process of making dispersion of claim 1 is carried out at temperature ranging from 50 to 120°C. Dated this 7th day of November, 2005. HARISHCHANDRA MEGHRAJ BHARUKA MANAGING DIRECTOR GOODLASS NEROLAC PAINTS LIMITED 25 ABSTRACT The novel invention describes aqueous polyurethane - acrylic hybrid resin dispersion, which comprises, b) forming carboxy containing, water dispersible, isocyanate terminated polyurethane prepolymer, c) neutralizing prepolymer by addition tertiary amines, d) adding vinyl monomers which includes polyethylenically unsaturated monomer to this neutralize prepolymer, e) dispersing the prepolymer/ monomer mixture in water, f) adding an oil soluble free radical initiator and then chain - extender to this aqueous dispersion, and g) polymerizing this vinyl monomer by free radical polymerization. To, The Controller of Patent, The Patent Office, Mumbai 26

Full Text

FORM 2
THE PATENT ACT 197 0 (39 of 1970)
The Patents Rules, 2003 COMPLETE SPECIFICATION See Section 10, and rule 13)
TITLE OF INVENTION
NOVEL AQUEOUS POLYURETHANE-ACRYLIC HYBRID RESIN DISPERSION

APPLICANT(S)
a) Name
b) Nationality
c) Address

GOODLASS NEROLAC PAINTS LIMITED
INDIAN Company
NEROLAC HOUSE, GANPATRAO KADAM MARG,
LOWER PAREL,
MUMBAI - 400 013

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed : -

Novel Aqueous Polyurethane - Acrylic Hybrid Resin Dispersion
Introduction:
Stringent laws relating to health, safety, & environmental protection are restricting the use of conventional solvent-based Polyurethane. Aqueous based Polyurethane and Polyurethane Hybrid dispersions consequently have become an important substitute for the conventional solvent-based polymers.
Described herein is Polyurethane - Acrylic hybrid resin dispersion with high film hardness, and better weatherability as compared to Polyurethane Dispersions, which often suffer from poor exterior durability & poor pH stability.
Acrylics on the otherhand are used in exterior coatings because of their versatile chemistry, which allows formulation of coatings with excellent durability & film hardness. Also acrylic emulsions are lower in cost in comparison with Polyurethane dispersions alone.
However, acrylic emulsions have poor mechanical properties. Also, good film formation of coatings based on acrylic emulsions requires use of film forming aids which are organic co solvents contributing to the Volatile Organic Content (VOC) of coatings.
Hence the main objective of preparing this novel Polyurethane / Acrylic hybrid dispersions is to combine Acrylics and Polyurethane to come up with coatings which can provide benefits inherent in both types of polymers without significant contribution from their disadvantages.
Described herein is Polyurethane - Acrylic hybrid resin dispersion that is formed by reaction of a carboxyl containing, water dispersible, isocyanate terminated polyurethane prepolymer & polyethylenically unsaturated monomer to form
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prepolymer - monomer mixture. This monomer is then polymerized by free radical polymerization in presence of Polyurethane dispersions using catalysts like peroxides, persulphates etc.
DESCRIPTION:
BACKGROUND OF THE INVENTION: 1. Field of invention:
This novel invention relates to aqueous polyurethane acrylic hybrid resin dispersion, which can be used for coatings on wood, metal, ABS, masonry, leather, paper, fabric etc.
2. Description Of The Background Art:
Over the past decade the use of conventional solvent based polyurethane (PU) is
becoming restricted by stringent laws relating to health, safety, and environmental
protection. Hence coating systems based on aqueous polyurethane dispersions have
grown in importance across a fairly broad range of applications because of their
beneficial properties and low VOC content.
Coatings based on Polyurethane dispersion have properties like adhesion to variety
of substrates, abrasion resistance, flexibility and toughness. But Polyurethane
dispersion has limited outdoor durability and high cost.
Here is the comparison of properties of both Polyurethane and Acrylics.

Sr Properties Acrylic Polyurethane
12 Yellowing Outdoor resistance Very less Better More Limited
3 pH stability Better Poor
4 Compatibility with other ingredients Better Limited
5 Cost Low High
6 Thermoplasticity More Less
7 Film formation Slightly inferior Better
8 Mechanical properties Slightly inferior Poor Excellent Better
9 Chemical resistance
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To get both cost & performance benefits, physical blends of acrylic emulsions and aqueous polyurethane dispersions can be made. These physically blended dispersions can provide enhanced properties as compared to all acrylics and cost benefits as compared to polyurethane, but there are some limitations to these blended systems. Many polyurethane / acrylic dispersions are incompatible, resulting in unstable blends which may phase separate, gel or discolour upon storage. Furthermore, the homogeneity of the polyurethane/ acrylic hybrid blends is questionable, both in wet state and most importantly in the final dried coating.
There are two chemical processes for generating an aqueous based Polyurethane dispersion.
1) Use of external emulsifiers with some organic co solvents
2) Use of ionic compounds as internal emulsifiers in the polymer.
Like most organic polymers, Polyurethane is not easily converted into a stable aqueous phase without the aid of emulsifiers, because of its hydrophobic character.
These dispersions are prepared by using ionic compounds like dihydroxy alkanoic acid. This addition of acid containing diols has following advantages:
The ionic content is a major factor for controlling the particle size of the
dispersion.
Low ionic content (acid number) dispersion must be neutralizing to 120 % to
achieve a stable dispersion during production.
Increasing acid number widens the processing window, allows lower
neutralizing amine level, and allows lower pH of the dispersion.
Hence Polyurethane/ Acrylic hybrid coatings are prepared by adding ionic compounds as internal emulsifiers to get better stability for the dispersion.
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Currently available formulations have disadvantages like poor outdoor durability, poor chemical resistance. Also these formulations are not cost effective.
The aim of the present invention is to develop Polyurethane / Acrylic hybrid resin
dispersion with better outdoor durability & to overcome other disadvantages of
prior art.
The design of base acrylics is the primary determinant of coating performance. The
properties of the hybrid coating are largely derived from the properties of the acrylic
part of the dispersion. Monomers are selected according to desired final film
properties.
Hence this novel Polyurethane/ Acrylic dispersion has been developed based on polyester polyol / polyether polyol having molecular weight ranging from 700 -4000, low molecular weight polyols (di or tri functional) and dihydroxy alkanoic acid with diisocyanate in presence of catalyst and solvent will give Polyurethane prepolymer.
This prepolymer on neutralization with tertiary amine & then monomer addition, dispersion with water, initiator addition & chain extension process will give final Polyurethane / Acrylic hybrid dispersion.
SUMMARY OF INVENTION:
Aqueous Polyurethane and Polyurethane hybrid consequently has become an important substitute for the conventional solvent-based polymers.
The novelty of the disclosed invention lies in use of polyester polyols / polyetherpolyol with molecular weight ranging from 700 - 4000, low molecular weight polyols (difunctionl or trifunctional), dihydroxy alkanoic acid as a polyol to produce Polyurethane/ Aery lie Hybrid resin dispersion which gives better hardness as well as better flexibility to the coatings and also gives excellent adhesion on wood,
plastic, masonry, leather, paper, fabric etc.
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In this case ethylenically unsaturated monomers are polymerized by means of free radical polymerization in presence of preformed polyurethane dispersion. Each dispersion particle is stabilized by hydrophilic moieties of polyurethane, usually anionic groups in the polyurethane backbone. The resulting Polyurethane / Acrylic hybrid resin dispersion comprises acrylic and urethane polymer chains which are intimately mixed at the molecular level within each dispersion particle.
DETAILED DESCRIPTION OF INVENTION :
The present invention describes Polyurethane /Acrylic dispersion made by the following process, which comprises
a) forming carboxy containing, water dispersible, isocyanate terminated polyurethane prepolymer,
b) neutralizing prepolymer by addition tertiary amines,
c) adding vinyl monomers which includes polyethylenically unsaturated monomer to this neutralize prepolymer,
d) dispersing the prepolymer/ monomer mixture in water,
e) adding an oil soluble free radical initiator and then chain - extender to this aqueous dispersion, and polymerizing this vinyl monomer by free radical polymerization in presence of polyurethane dispersion.
The novelty of the disclosed invention lies in use of polyester polyol/ polyether polyol with molecular weight ranging from 700 - 4000, low molecular weight polyols (difunctional or trifunctional) like 1,4- cyclohexane dimethanol (CHDM), trimethylol propane (TMP), dihydroxy alkanoic acid like dimethylol propionic acid as a polyol to produce Polyurethane/Acrylic Hybrid resin dispersion for coatings which has excellent adhesion on wood, concrete, plastic etc.
The polyester or polyether diol can be obtained by reacting atleast one polyhydric
alcohol and atleast one polycarboxylic acid or polycarboxylic anhydride. Examples
of polyhydric alcohols include 1,6 hexanediol, ethylene glycol, propylene glycol,
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diethylene glycol, neopentyl glycol, 1,4-butanediol, and cyclohexane dimethanol.
Polycarboxylic acids used are succinic acid, glutaric acid, adipic acid, and phthalic
acid or phthalic anhydride, isophthalic acid.
The carboxylic acid containing diols like 2,2-dimethylolpropionic acid, 2,2-
dimethylol-butyric acid, 2,2- dimethylolvaleric acid etc are used to react with
diisocyanate. This will form a prepolymer of polyurethane having free carboxylic
group.
The stable urethane - acrylic hybrid polymer dispersion, wherein the isocyanate monomer is selected from the group consisting of 1,4- tetramethylene diisocyanate' 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl- 1,6-diisocynatohexane, 1,10-decamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, bis (4-isocynatocyclohexyl) methane, l-isocynato-3-isocynatomethyl-3,5,5-trimethyl-cyclohexane, m- and p-phenylene diisocyanate, 2,6- and 2,4-tolune diisocyanate, xylene diisocyanate,4-chloro- 1,3-phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 4,4'-methylene diphenyl diisoisocyanate, 1,5-naphthylene diisocyanate, 1,5-tetrahydronaphthylene diisocyanate, polymethylene polyphenylisocyanates, 1,12-dodecyl diisocyanate, norbornane diisocyanate, 2-methyl-l,5-pentane diisocyanate, isophorone diisocyanate and mixtures thereof.
NCO : OH ratio is kept at 1:1 to 1:4 to control molecular weight of isocyanate terminated prepolymer (7000 - 12000 Mw typical).
Addition of low molecular weight polyols like trimethylol propane will give controlled branching, which improves strength and chemical resistance properties.
Addition of low molecular weight polyols like trimethylol ethane, 1,4-cyclohexane dimethanol will give excellent hardness with some flexibility & high Tg relative to linear aliphatic glycol. Also it will give low temperature reactivity during resin
7

synthesis & curing. This low molecular weight polyol addition will give good hydrolytic stability to dispersion.
The polymeric polyols are reacted with stoichiometric excess of the organic polyisocyanate to form carboxylated polyurethane in presence or absence of solvents at the temperature of 50 to 90° C. The solvents used here are required to adjust viscosity of prepolymer. These solvents are dioxane, acetone, methyl ethyl ketone, N- methylpyrrolidone, tetrahydrofuran, and N- vinyl acetate etc.
If desired, a catalyst may be used to assist prepolymer formation. The catalyst used can be dibutyltin dilaurate (DBTDL).
For neutralization of prepolymer, tertiary amine used are trimethylamine, triethyl amine, di-methyl ethanolamine, tri-n-propylamine, triethanolamine, tributylamine, ammonia, hydrazine etc. These amines are added in an amount sufficient to render the prepolymer water dispersible i.e. an amount sufficient to neutralize carboxylic groups present in the prepolymer. This amine is added at about 65 to 100 % amine equivalent per equivalent of carboxy functionality. This tertiary amine, which is added to the prepolymer before the dispersion of prepolymer in water to ensure compatibility of organic & aqueous phases.
To this neutralized prepolymer ethylenically unsaturated monomers are added like methylmethacrylate, butyl acrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, styrene, methylmethacrylate etc.
The carboxylate groups on carboxylated polyurethane impart water dispersibility to polyurethane, i.e. colloidal stabilization in water. This neutralized prepolymer of polyurethane is then emulsified in water to get proper dispersion.
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The polymer/monomer mixture can be added to the water under stirring or alternatively, water may be stirred into the polymer / monomer mixture.
To this dispersion formed, add free radical initiator and solvent mixture. The molecular weight of the final acrylic polymer is crucial for effective hybridization. Lower molecular weights and low polydispersity (Mw/Mn - close or equal to 1) are favoured.
Then chain extension of NCO terminated emulsified prepolymer, water may contain polyamines as chain extending. Chain extending agents used are piperazine, piperazine hexahydrate, diethylene triamine, triethylene tetramine, and ethylene diamine etc.
The quantity of chain extender employed should be approximately equivalent to the free isocyanate groups in the prepolymer preferably being in the range of 0.7:1 to 1.3 :1. Then, by thermal decomposition of free radical initiator, polymerization of monomers is carried out within the miscells of polyurethane dispersion at temperature ranging from 60 - 90° C.
The advantage of this method of preparation is that monomers and initiator can be added together at room temperature and that their stabilization in polyurethane dispersion does not require any additional emulsifiers. The charge density of polyurethane micelles is sufficiently great to ensure the polymerization of monomers within the micelles without emulsifiers - by virtue of their stability alone. The stability of polyurethane/ Acrylic hybrid micelles is retained for a long period even after polymerization has come to an end, without further addition of stabilizer.
Diluting the chain extender with portions of the dispersion medium makes possible to separate the by - products formed during prepolymer mixing in water.
9

The polymer dispersions obtained have 20 to 60 wt % solids & may be employed as coating compositions and can be applied to wood, glass, plastics, leather, paper, fabric etc. by any conventional method of application like brushing, spraying, dipping. These dispersions can be used as air-drying coatings or it can be used as stoving coatings.
The novelty of this Polyurethane / Acryhc hybrid resin dispersion lies in incoporation of Polyester Polyol with molecular weight 700 - 4000 & Polyol (difunctional or trifunctional) with low molecular weight which gives good flexibility with better hardness, good chemical resistance, excellent stability of the dispersion within a wide range of pH, good freeze thaw stability, cost benefit and achieved in simple synthesis route, without chemical crosslinking, with low organic solvent content.
Dispersion characteristics
- Prepared with less quantity of solvents.
- No external surfactants required.
- LowVOC.
- Low viscosity.
- Good shelf stability (1 year).
- Better coating toughness.
- Better coating flexibility.
- Excellent adhesion on substrates like wood, masonry, plastics, leather, paper, fabric etc.
- Excellent gloss retention
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EXAMPLES -
The following examples constitute some dispersion formulation based on the experimental work. This is not an exhaustive list of the compositions tested; comparative composition number 8 is an example of the prior state of art dispersion formulation.
Abbreviations:
NV: Non-Volatile Content
Sec: seconds
Hrs: hours
Gms: grams
NCO content: isocyanate content
DETA : diethyl triamine
PREPARATION OF POLYURETHANE/ ACRYLIC HYBRID DISPERSIONS
Example 1
A 4 neck round bottom flask equipped with agitator, condenser, addition funnel, thermometer, nitrogen purge, and water bath is taken. To this flask charge 61.8 gms of Polyester polyol/ Polyether polyol (OH value 85 - 125), 0.61 gms of trimethylolpropane, 9.27 gms of 2,2-dimethylolpropionic acid, 0.017 gms of dibutyltin dilaurate, 50.0 gms of N-methylpyrrolidone, 30.0 gms of acetone. Heat these contents of flask to 75° C under nitrogen purging for 30 minutes. When temperature reaches to 75° C start adding 114.7 gms of isophorone diisocyanate drop wise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 6.9 gms of triethylamine to this
11

prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl acrylate, 100.0 gms of methylmethacrylate & 20.0 gms of styrene. Add this monomer mixture to neutralized prepolymer slowly under stirring. Add 474.50 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20 - 30 minutes. Prepare mixture of 2 gms of (2,2-azobisisobutyronitrile) & 10.0 gms N-methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 13.4 gms of ethylenediamine & 26.8 gms of deionized water. Add this solution to the dispersion quickly & stir this for 10 - 15 minutes. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 75° C till complete conversion of monomers takes place.
Example 2
A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 64.13 gms of Polyester polyol (OH value 85 - 125), 6.83 gms of trimethylolethane, 11.46 gms of 2,2-dimethylolpropionic acid, 0.017 gms of dibutyltin dilaurate, 60.0 gms of N-methylpyrrolidone, 20.0 gms of acetone. Heat these contents of flask at 70° C under nitrogen purging. When temperature reaches to 70° C start adding 108.24 gms of methylene bis(4-cyclohexylisocyanate) drop wise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 70 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 40° C. Add 7.77 gms of triethylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 40.0 gms of butyl acrylate & 160.0 gms of methylmethacrylate. Add this monomer mixture to neutralized prepolymer slowly under stirring. Add 467.73 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20 - 30 minutes. Prepare mixture of 2.0 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 9.32 gms of
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diethyltriamine & 32.5 gms of deionized water. Add this solution to the dispersion quickly & stir this for 10 - 15 minutes. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place.
Example 3
A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 73.0 gms of Polyester polyol/ polyether polyol (OH value 85 - 125), 8.56 gms of 1,4 cyclohexane dimethanol, 11.42 gms of 2,2-dimethylolpropionic acid, 0.015 gms of dibutyltin dilaurate. 64.5 gms of N-Methylpyrrolidone, 17.0 gms of acetone. 97.17 gms of isophorone diisocyanate to the flask. Heat these contents of flask to 75° C. The temperature of reaction mixture is maintained to 75° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 8.6 gms of triemylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl acrylate & 120.0 gms of methylmethacrylate. Add this monomer mixture to polyurethane polymer slowly under stirring within 15 - 20 minutes. Add 476.78 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20- 30 minutes. Prepare mixture of 2.5 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above mixture within 10 minutes. Make solution of 9.84 gms ethylenediamine & 20.6 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place.
Example 4
A 4 neck round bottom flask equipped with agitator, condenser, thermometer,
addition funnel, nitrogen purge, and water bath is taken. To this flask charge 90.8
gms of Polyester polyol/ Polyether polyol (OH value 85 - 125), 3.29 gms of
Trimethylolpropane, 13.1 gms of 2.2'-dimethylolpropionic acid, 0.015 gms of
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dibutyltin dilaurate. 80.0 gms of N-Methylpyrrolidone, 12.0 gms of Acetone. Heat these contents of flask to 75° C under nitrogen purging. When temperature reaches to 75° C start adding 85.38 gms of methylene bis(4-cyclohexylisocyanate) dropwise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 8.7 gms of dimethyl ethanol amine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 79.0 gms of methyl methacrylate & 111.0 gms of butyl acrylate and 2.0 gms of methacrylic acid. Add this monomer mixture to neutralized prepolymer slowly under stirring within 15 - 20 minutes. Add 465.55 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 30 minutes. Prepare mixture of 2.5 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 7.33 gms of ethylenediamine & 29.33 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place.
Example 5
A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 77.01 gms of Polyester polyol / Polyether polyol (OH value 85 - 125), 10.25 gms of 1,4 chyclohexane dimethanol, 12.033 gms of 2,2'-dimethylol propionic acid, 0.017 gms of dibutyltin dilaurate. 64.5 gms of N-methylpyrrolidone, 17.59 gms of acetone. Heat these contents of flask at 75° C under nitrogen purging. When temperature reaches to 75° C start adding 95.06 gms of methylene bis(4-cyclohexylisocyanate) dropwise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50° C. Add 7.7 gms of triethylamine to this
14

prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl aery late & 120.0 gms of methylmethacrylate. Add this monomer mixture to neutralized prepolymer slowly under stirring within 15 - 20 minutes. Add 486.98 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20-30 minutes. Prepare mixture of 2 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 5.62 gms of EDA & 11.24 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 75° C till complete conversion of monomers takes place.
Example 6
A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 80.2 gms of Polyester polyol/ Polyether polyol (OH value 85 - 125), 0.015 gms of dibtyltin dilaurate, 94.42 gms of methylene bis(4-cyclohexylisocyanate), 17.0 gms of acetone. Heat these contents of flask to 70° C under nitrogen purging. Then raise the temperature to 85° C add 14.45 gms of 2,2'-dimethylol propionicacid and 64.5 gms of N-Methylpyrrolidone to the contents of the flask. The temperature of reaction mixture is maintained at 85 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 40° C. Add 10.9 gms of triethylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 100.0 gms of butyl acrylate & 100.0 gms of methylmethacrylate. Add this monomer mixture to prepolymer slowly under stirring within 15 - 20 minutes. Add 472.51 gms of deionized water to this Polyurethane polymer / monomer mixture slowly under high speed stirring within 20-30minutes. Prepare mixture of 2 gms of (2,2'-azobisisobutyronitrile) & 10.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 10.21 gms of ethylenediamine & 30.0 gms of deionized water. Add this solution to the prepolymer slowly within 15
15

min. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place.
Example 7
A 4 neck round bottom flask equipped with agitator, condenser, thermometer, addition funnel, nitrogen purge, and water bath is taken. To this flask charge 99.85 gms of Polyester polyol / Polyetherpolyol (OH value 85 - 125), 2.57 gms of 1,4 cyclohexane dimethanol, 9.72 gms of 2,2'-dimethylol propionicacid, 0.017 gms of dibutyltin dilaurate, 55.5 gms of N-Methylpyrrolidone, 24.5 gms of acetone. Heat these contents of flask to 75° C under nitrogen purging. When temperature reaches to 75° C start adding 80.81 gms of methylene bis(4-cyclohexylisocyanate) dropwise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 85 ° C until required isocyanate content is achieved. The resulting prepolymer is cooled to 50 - 55° C. Add 7.33 gms of triethylamine to this prepolymer under vigorous stirring. Prepare mixture of monomers i.e. 80.0 gms of butyl acrylate & 120.0 gms of methylmethacrylate. Add this monomer mixture to neutralized prepolymer slowly under stirring within 15 - 20 minutes. Add 476.70 gms of deionized water to this prepolymer / monomer mixture slowly under high speed stirring within 20-30 minutes. Prepare mixture of 2 gms of (2,2-azobisisobutyronitrile) & 20.0 gms N-Methylpyrrolidone. Add this mixture to the above dispersion within 10 minutes. Make solution of 7.0 gms of ethylenediamine & 14.0 gms of deionized water. Add this solution to the dispersion quickly. Carry out free radical polymerization of monomers in presence of Polyurethane dispersion at 70° C till complete conversion of monomers takes place.
Example 8
A 4 neck round bottom flask equipped with agitator, condenser, thermometer,
addition funnel, nitrogen purge, and water bath is taken. To this flask charge 145.64
gms of Polyester polyol / polyether polyol (OH value 85 - 125), 17.15 gms of 1,4-
16

cyclohexane dimethanol, 22.78 gms of 2,2'-dimethylol propionic acid, 0.03 gms of dibutyltin dilaurate, 129.6 gms of N-Methylpyrrolidone, 33.39 gms of acetone. Heat these contents of flask to 75° C under nitrogen purging for 30 minutes. When temperature reaches to 75° C start adding 193.86 gms of isophorone diisocyanate drop wise to the contents of the flask within 30 - 40 minutes. The temperature of reaction mixture is maintained at 80 ° C. The resulting prepolymer is cooled to 50 -55° C. It is taken under high-speed stirrer. Add 18.03 gms of triethylamine to this prepolymer under vigorous stirring. Make solution of 20.63 gms of ethylenediamine & 418.92 gms of deionized water. Add this solution to the dispersion slowly. After complete addition of ethylenediamine solution, stir this dispersion for 10 - 15 minutes.
TESTING OF THE PHISICO-CHEMICAL PROPERTIES OF THE NOVEL DISPERSION:
Wood coatings were prepared in lab, using this novel Polyurethane/ Acrylic hybrid
resin dispersion to evaluate its physico - chemical properties.
Preparation of coating formulation :
The wood coating using Polyurethane / Acrylic dispersion was formulated as per
the following recipe.
Ingredients wt %
1) Polyurethane/ Acrylic : 97.35 hybrid resin dispersion
2) Polysiloxane in Polyglycol : 0.25 (defoamer)
3) Levelling agents 0.2
4) Silicone based surfactant : 0.2
5) Aqueous wax emulsion : 1.5
6) Associative PU thickner : 0.5

Total

100.00
17

OUTLINE OF TESTING METHODS:
1) DETERMINATION OF VISCOSITY ON FLOW CUP B4: (ASTM - D - 1200)
2) NON - VOLATILE CONTENT: (IS -197-1969)
3) DETERMINATION OF DRYING TIME: (IS -197)
4) CROSSCUT ADHESION OF FILM: (ASTM - D - 3363)
5) WATER RESISTANCE: (IS 101)
6) PENCIL HARDNESS: (ASTM - D - 3363)
7) STABILITY: (IS 101)
8) CHEMICAL RESISTANCE:(ASTM D 1308)
9) FREEZE THAW STABILITY: (ASTM D 2243-82)

10) GLOSS : (ASTM D 523)
11) CHEMICAL RUB METHOD : (ASTM D 4752)
12) UV EXPOSURE : (IS 101)
APPLICATION METHOD:
1) The final coating is thinned with water if required to adjust viscosity up to 25
- 30 sec on Ford cup B4 @ 30° C & applied by brush on wood, plastic, concrete,
masonry, leather, fabric etc.
Or
2) The paint is thinned with water if required to adjust viscosity up to 15 - 20
sec on Ford cup B4 @ 30° C & applied by spraying on wood, plastic, concrete.
Wood panel preparation system:
1) Water based Wood sealer
2) Water based Wood filler
3) Polyurethane / acrylic resin dispersion.
The film applied on wood & concrete is air dried for 24 hrs. Testing of wood panels is done after 72 hrs. curing.
18

Observations:
From the above test results it is observed that PU / Acrylic Hybrid resin dispersion has better properties than Polyurethane dispersion w.r.t. 1) Stability.
2) Freeze thaw stability.
3) Gloss & hardness.
4) UV resistance than PU dispersion described in example 8.
BRIEF DESCRIPTION OF DIAGRAM

CH3 -CI COON
1
HO^R^OH + Q=C=N«***N=C=Q + HOCH2-C-CH2OM
catalyst, heat, coivwit

0=C=N -H—J-^WAW}—NHCeNw— M=C=Q

9
-«|*—Uw,fJMCCJ^nivMHCQNH *NHCONH-
COO" X
Fig : Synthesis of water borne polyurethane dispersion by the isocyanate prepolymer process
20

CONCLUSIONS:
Polyurethane/ Acrylic hybrid resin dispersion formed by this invention when compared with other similar resin (example) shows good performance properties like
i) Better gloss & hardness.
ii) Excellent dispersion stability.
iii) Excellent freeze/thaw stability.
iv) Good adhesion on glass, wood and plastics, leather, masonry, paper, fabric.
v) Better weather resistance
vi) Cost effective.
FLOW CHART:
PU PREPOLYMER
l_ j
NEUTRALIZATION
, ZTZZZ"
DISPERSION IN WATER
"ZZ^ZZZI""
CHAIN EXTENSION
~ ~T
FREE RADICAL POLYMERIZATION ]
| i !
FINAL DISPERSION
I ADDITIVES
.-"3X11" ,
! WOOD FINISH GLOSSY |
21

WE CLAIMS:
1) We claim a Polyurethane/ Acrylic hybrid resin dispersion comprising carboxyl containing isocyanate terminated polyurethane prepolymer which is neutralized with tertiary amine, its mixture with polyethylenically unsaturated monomer dispersed in water, the said mixture after chain extension is then polymerized with the help of free radical initiator.
2) A Polyurethane/ Acrylic hybrid resin dispersion as claimed in claim 1, comprising the following ingredients.

a) 3 to 25 % by weight of a polyester/ polyether polyol having molecular weight ranging from 700 - 4000.
b) 0 to 3 % by weight of dihydroxyalkanoic acid.

c) 2 to 20 % by weight of polyisocyanate component.
d) 0 to 0.5 % of catalyst like dibutyl tin dilaurate.
e) 0 - 20 % by weight of a organic solvent.
f) 0.2 to 3 % by weight of neutralizing component.
g) 0.2 to 2 % by weight of chain extender.
h) 5 to 30 % by weight of monomer component, i) 0.01 to 2 % by weight of a free radical initiator component, j) 30 to 70 % by weight, preferably 50 % by weight of water as dispersion medium.
3) Polyurethane/ Acrylic hybrid resin dispersion as claimed in claim 1, wherein the polyester/ polyether polyol component is 3 to 25% by weight having a molecular weight ranging from 700 to 4000 obtainable by reacting atleast one polycarboxylic acid and/or polycarboxylic anhydride with atleast one polyhydric alcohol.
4) Polyurethane/ Acrylic hybrid resin dispersion as claimed in claim 1, wherein polyhydric alcohols are selected singly or in combination from a group comprising 1,6 hexanediol, ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, and / or cyclohexanedimethanol. Polycarboxylic acids used are succinic acid, glutaric acid, adipic acid, and phthalic acid or phthalic anhydride, isophthalic acid, 0 to 2 % by weight of low molecular mass polyols (di or tri functional) like 1,4-cyclohexane dimethanol (CHDM), trimethylolpropane (TMP) trimethylol ethane (TME), 0 to 3 % by weight of dihydroxyalkanoic acid like 2,2 dimethylolproppionic acid, 2,2-dimethylol-butyric acid, 2,2-dimethylolvaleric acid etc.
5) A hybrid resin dispersion as claimed in claim 1, wherein polyisocyanate components are selected from one or more polyisocyanates like 1,4-tetramethylene diisocyanate 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-diisocynatohexane, 1,10-decamethylenediisocyanate, 1,4-cyclohexylene diisocyanate, bis (4-isocynatocyclohexyl) methane, l-isocynato-3-
22

isocynatomethyl-3,5,5-trimethyl-cyclohexane, m- and p-phenylene
diisocyanate, 2,6- and 2,4-tolune diisocyanate, xylene diisocyanate, 4- chloro-
1,3-phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 4,4'- methylene
diphenylisocyanate, 1,5-naphthylene diisocyanate, 1,5-
tetrahydronaphthylene diisocyanate, polymethylene polyphenylisocyanates, 1,12-dodecyl diisocyanate, norbornane diisocyanate, 2- methyl-l,5-pentane diisocyanate having two or more aliphatic and / or aromaticisocyanate groups.
6) A hybrid resin dispersion as claimed in claim 1, wherein the solvent component consists of at least one polyisocyanate - inert organic solvent comprising of high boiling & hydrophilic compounds like dioxane, acetone, methyl ethyl ketone, N-methylpyrrolidone, tetrahydrofuran, and N-vinyl acetate. The solvent component may remain therein or may be removed in part or in whole by distillation.
7) A hybrid resin dispersion as claimed in claim 1, wherein 0 - 0.5 % catalyst like dibutyltin dilaurate (DBTDL) is used.
8) A hybrid resin dispersion as claimed in claim 1, wherein the neutralizing component comprises at least one tertiary amine like trimethylamine, triethyl amine, di-methyl ethanolamine, tri-n-propylamine, triethanolamine, tributylamine, ammonia, hydrazine etc.
9) A hybrid resin dispersion as claimed in claim 1, wherein the chain extender is selected from one or more polyamines like piperazine, piperazine hexahydrate, diethylene triamine, triethylene tetramine, and ethylene diamine having two or more functionalities.
10) A hybrid resin dispersion as claimed in claim 1, wherein the monomer component comprises one or more monomers like methylmethacrylate, butyl acrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, styrene, methylmethacrylate etc. having one or more free radically polymerizable double bonds.
11) A hybrid resin dispersion as claimed in claim 1, wherein free radical initiator components are selected from azonitrile initiators, (2,2-azobisisobutyronitrile) and peroxyesters, (t- amyl peroxy-2-ethylhexanoate).
12) A hybrid resin dispersion as claimed in claim 1, which comprises of 30 to 70%
by weight preferably 50% by weight of water as dispersion media.
13) A hybrid resin dispersion as claimed in claim 1, wherein the dispersion of claim
1 comprises forming an isocyanate terminated polyurethane prepolymer by
23

reaction of polyester/ polyether polyol & an acid containing diol reacting with isocyanate in the ratio ranging from 1:1 to 1:3 in presence or absence of catalyst & solvent at temperature from 50 to 120° C, preferably from 70 to 90° C.
14) A process of making hybrid resin dispersion with high film hardness reacting
the following components.
a) 3 to 35% by weight of a polyester/ polyether polyol components having molecular weight ranging from 700-4000.
b) 0 to 3 % by weight of dihydroxyalkanoic acid.
c) 2 to 20% by weight of polyisocyanate component.
d) 0-20% by weight of a solvent component.
e) 0 to 0.5% of catalyst like dibutyltin dilaurate.
f) 0.2 to 3% by weight of a neutralizing component.
g) 0.2 to 2% by weight of a chain extender component,
h) 5% to 30% by weight of a monomer component.
i) 0.01 to 2% by weight of a free radical initiator component, j) 30 to 70% by weight, preferably 50% by weight of water.
15) The process as claimed in claim 14 wherein the polyester/ polyether polyol
component having molecular weight ranging from 700 - 4000 is obtained by
reacting at least one polyhydric alcohol and at least one polycarboxylic acid
and / or polycarboxylic anhyride with polyhydroxy alcohol.
16) A process as claimed in claim 14 wherein the Polyisocyanate components are selected from one or more polyioscyanates like 1,4-tetramethylene diisocyante 1,6-hexamefhylene diisocyanate, 2,2,4-trimethyl-l,6-diisocynatohexane/ 1,10-decamethylenediisocyanate, 1,4-cyclohexylene diisocyanate, bis(4-isocynatocyclohexyl)methane, l-isocynato-3- isocynatomethyl-3,5,5-trimethyl-cyclohexane, m-and p-phenylene diisocyanate, 2,6- and 2,4-tolune diisocyanate, xylene diisocyanate, 4-chloro-l,3-phenyle diisocyanate, 4,4'-biphenylene diisocyanate,4,4'-methylene diphenylisocyanate,l,5-naphthylene diisocyante, 1,5-tetrahydronaphthlene diisocyanate, polymethylene polyphenylisocyanates, 1,12-dodecyl diisocyanate, norbornane diisocyanate, 2-methyl-l, 5-pentane diisocyanate, having two or more aliphatic and/or aromatic isocyanate groups.
17) A process as claimed in claim 14 wherein the solvent component consists of at least one polyisocyanate-inert organic solvent comprising of high boiling & hydrophilic compounds like dioxane, acetone, methyl ethyl ketone, N-methylpyrrolidone, tetrahydrofuran, and N/ vinyl acetate, The solvent component may remain therein or may be removed in part or in whole by distillation.
24

18) A process as claimed in claim 14 wherein the neutralizing component
comprises at least one tertiary amine like trimethylamine, triethyl amine, di
methyl ethanolamine, tri-n-propylamine, triethanolamine, tributylamine,
ammonia, hydrazine etc.
19) A process as claimed in claim 14 wherein 0 - 0.5 % catalyst like dibutyltin dilaurate (DBTDL) is used.
20) A process as claimed in claim 14 wherein the process is carried out at temperature ranging from 25-40°C and ethylenically unsaturated monomers:prepolymer ratio varies from 1:0.5 to 1:1.5.
21) A process as claimed in claim 14 wherein the chain extender component comprises one or more polyamines like piperazine, piperazine hexahydrate, diethylene triamine, triethylene tetramine, and ethylene diamine having two or more functionalities
22) A process as claimed in claim 14 wherein the monomer component comprises one or more monomers like methylmethacrylate, butyl acrylate, methyl aery late, ethyl acrylate, ethyl methacrylate, styrene, methylmethacrylate etc. having one or more free radically polymerizable double bonds.
23) A process as claimed in claim 14 wherein the free radical initiator component which comprises of azonitrile initiators, (2,2-azobisisobutyronitrile) and peroxyesters, (-amyl peroxy-2-ethylhexanoate).
24) A process as claimed in claim 14 wherein the process of making dispersion of claim 1 is carried out at temperature ranging from 50 to 120°C.
Dated this 7th day of November, 2005.

HARISHCHANDRA MEGHRAJ BHARUKA MANAGING DIRECTOR GOODLASS NEROLAC PAINTS LIMITED
25

ABSTRACT
The novel invention describes aqueous polyurethane - acrylic hybrid resin dispersion, which comprises,
b) forming carboxy containing, water dispersible, isocyanate terminated polyurethane prepolymer,
c) neutralizing prepolymer by addition tertiary amines,
d) adding vinyl monomers which includes polyethylenically unsaturated monomer to this neutralize prepolymer,
e) dispersing the prepolymer/ monomer mixture in water,
f) adding an oil soluble free radical initiator and then chain - extender to this aqueous dispersion, and
g) polymerizing this vinyl monomer by free radical polymerization.
To,
The Controller of Patent,
The Patent Office,
Mumbai
26

Documents:

1497-MUM-2005-ABSTRACT(2-9-2009).pdf

1497-mum-2005-abstract(granted)-(26-3-2010).pdf

1497-mum-2005-abstract.doc

1497-mum-2005-abstract.pdf

1497-MUM-2005-CANCELLED PAGES(2-9-2009).pdf

1497-MUM-2005-CLAIMS(2-9-2009).pdf

1497-mum-2005-claims(granted)-(26-3-2010).pdf

1497-mum-2005-claims.doc

1497-mum-2005-claims.pdf

1497-MUM-2005-CORRESPONDENCE(19-11-2009).pdf

1497-mum-2005-correspondence(2-9-2009).pdf

1497-mum-2005-correspondence(ipo)-(26-3-2010).pdf

1497-mum-2005-correspondence-received-100806.pdf

1497-mum-2005-correspondence-received.pdf

1497-mum-2005-description (complete).pdf

1497-MUM-2005-DESCRIPTION(COMPLETE)-(2-9-2009).pdf

1497-mum-2005-description(granted)-(26-3-2010).pdf

1497-MUM-2005-DRAWING(2-9-2009).pdf

1497-mum-2005-drawing(granted)-(26-3-2010).pdf

1497-MUM-2005-FORM 1(2-9-2009).pdf

1497-mum-2005-form 13(11-8-2006).pdf

1497-mum-2005-form 13(2-9-2009).pdf

1497-mum-2005-form 18(23-8-2007).pdf

1497-mum-2005-form 2(granted)-(26-3-2010).pdf

1497-MUM-2005-FORM 2(TITLE PAGE)-(2-9-2009).pdf

1497-mum-2005-form 2(title page)-(granted)-(26-3-2010).pdf

1497-MUM-2005-FORM 26(2-9-2009).pdf

1497-MUM-2005-FORM 26(23-07-2008).pdf

1497-MUM-2005-FORM 26(23-08-2007).pdf

1497-mum-2005-form-1.pdf

1497-mum-2005-form-13.pdf

1497-mum-2005-form-2.doc

1497-mum-2005-form-2.pdf

1497-mum-2005-form-26.pdf

1497-mum-2005-form-3.pdf

1497-MUM-2005-REPLY TO FIRST EXAMINATION REPORT(2-9-2009).pdf

1497-mum-2005-specification(amanded)-(2-9-2009).pdf

1497-MUM-2005-THE PATENTAS RULE 2003.pdf

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Patent Number

239611

Indian Patent Application Number

1497/MUM/2005

PG Journal Number

14/2010

Publication Date

02-Apr-2010

Grant Date

26-Mar-2010

Date of Filing

02-Dec-2005

Name of Patentee

KANSAI NEROLAC PAINTS LTD.

Applicant Address

NEROLAC HOUSE, GANPATRAO KADAM MARG, LOWER PAREL, MUMBAI-400 013

Inventors:

#	Inventor's Name	Inventor's Address
1	VINAYAK MAHADEV NATU	506, AMBER-LOK-LRACHANA, AMAR NAGAR, MULUND (EAST), MUMBAI-400 082
2	PRADEEP KRISHNAJI KHISMATRAO	SHREE SADGURU SADAN PLOT NO. D-18, SECTOR-12 KHARGHAR NAVI MUMBAI-410 210
3	MRUNAL MILIND VAIDYA	21/203, TUSIDHAM AMRAPALI CHS, GHODUNDER ROAD, THANE-400 607

PCT International Classification Number

C07C3/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA