Polyester resin as well as preparation method and application thereof

Abstract

The invention relates to polyester resin as well as a preparation method and application thereof. The polyester resin is prepared from the following raw materials: polybasic acid, polyhydric alcohol, an unsaturated monomer and a grafting modified monomer, the polybasic acid is selected from one or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1, 4-cyclohexanedicarboxylic acid and hexahydrophthalic anhydride; the polyhydric alcohol is selected from one or more of neopentyl glycol, 1, 2-propylene glycol, 2-methyl-1, 3-propylene glycol, 2-butyl-2-ethyl-1, 3-propylene glycol, 2, 2, 4-trimethyl-1, 3-pentanediol, 1, 4-cyclohexanedimethanol, 1, 6-hexanediol and trimethylolpropane, and the polyhydric alcohol is selected from one or more of neopentyl glycol, 1, 2-propylene glycol, 2-methyl-1, 3-propylene glycol, 2-butyl-2-ethyl-1, 3-propylene glycol, 2, 2, 4-trimethyl-1, 3-pentanediol, 1, 4-cyclohexanedimethanol, 1, 6-hexanediol and trimethylolpropane. The polyester resin disclosed by the invention has excellent compatibility with acrylic resin.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a polyester resin and a preparation method and application thereof. Background Art

[0002] In the field of polymer materials, the method of mixing different polymers to improve material performance has been widely adopted, and it was also used earlier in coatings. However, the structure of coating resins is diverse and complex, and the compatibility problem between the two resins cannot be ignored. Among them, acrylic resin and polyester resin are the more commonly used types of coatings. Acrylic resin has the advantages of good gloss, weather resistance, chemical resistance and high stability, but it has the disadvantages of not being too high in solid content, not being easy to take into account hardness and elasticity, and not being full of the coating film. Polyester resin coatings have the advantages of high gloss, good fullness, good flexibility, good light and color retention. If the advantages of the two can be combined, a resin coating with better performance can be obtained. However, due to the characteristics of their structures, the main chain polarity of the two is too different, and the compatibility problem is a factor that needs to be considered.

[0003] The compatibility problem between polyester resin and acrylic resin is generally improved by grafting, copolymerization, adjusting the dissolution process, etc. CN107814945A is a saturated polyester-acrylic resin graft copolymer containing carboxyl functional groups, and its preparation method and application, which synthesizes an acrylic prepolymer and a polyester prepolymer containing carboxyl groups separately, and then melt copolymerizes the two to synthesize a polyester-acrylic resin copolymer containing carboxyl groups, thereby achieving the purpose of compatibility between acrylic resin and polyester resin, and the carboxyl group provides a curing reaction group for subsequent applications, but its synthesis process is complicated, and the final acid value of the resin is too high, and there will be certain defects in storage stability; CN113651930A is a preparation method and application of a polyester-modified acrylic secondary dispersion, which is to introduce a terminal double bond through glycidyl methacrylate, and then copolymerize with an unsaturated monomer, and then continue to react with a hydrophilic acrylic monomer after copolymerization, and then add water and a neutralizer to obtain a polyester-modified acrylic secondary dispersion. This method also has cumbersome steps, and involves an aqueous emulsion, and has high requirements for equipment.

[0004] Therefore, a method for improving the compatibility of acrylic resin and polyester resin with simple process and strong controllability is urgently needed to be developed. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a polyester resin that can be miscible with most acrylic resin coatings on the market in any proportion and a preparation method thereof.

[0007] Solutions for solving problems

[0008] In one aspect, the present invention provides a polyester resin, wherein the raw materials for preparing the polyester resin include polyacid, polyol, unsaturated monomer, and graft-modified monomer;

[0009] Wherein, the polyacid is selected from one or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride;

[0010] The polyol is selected from one or more of neopentyl glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2-butyl-2-ethyl-1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol and trimethylolpropane;

[0011] The unsaturated monomer is selected from one or more of maleic anhydride, itaconic acid, and fumaric acid;

[0012] The graft modification monomer is selected from one or more of ethyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, ethyl methacrylate, n-butyl methacrylate, n-pentyl methacrylate, and n-hexyl methacrylate.

[0013] Preferably, the polyacid is selected from two or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride;

[0014] The polyol is selected from two or more of neopentyl glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2-butyl-2-ethyl-1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol and trimethylolpropane.

[0015] Preferably, the molar ratio of the polyol to the polyacid is (1-2.5):1, preferably (1.5-2):1.

[0016] Preferably, the molar amount of the unsaturated monomer accounts for 10 to 30% of the molar amount of the polyacid, preferably 12 to 30%.

[0017] Preferably, the molar amount of the graft-modified monomer accounts for 10 to 30% of the molar amount of the polyacid, preferably 12 to 30%.

[0018] In one aspect, the present invention provides a method for preparing the polyester resin described in any one of the above, the preparation method comprising:

[0019] (1) adding a polyacid, a polyol and a catalyst into a reactor, heating the reaction system to perform an esterification reaction, and obtaining an intermediate product 1;

[0020] (2) After the esterification reaction is completed, an unsaturated monomer and an auxiliary agent are added to the reaction system to react to obtain an intermediate product 2;

[0021] (3) After the reaction of step (2) is completed, the intermediate product 2 is subjected to a condensation polymerization reaction to obtain an intermediate product 3;

[0022] (4) reacting the intermediate product 3 with a graft-modified monomer in the presence of a solvent and an initiator to obtain the polyester resin.

[0023] Preferably, in step (1), the catalyst is selected from one or more of tetrabutyl titanate, zinc acetate, and germanium oxide.

[0024] Preferably, the amount of the catalyst used is 0.005-0.05% of the molar amount of the polyacid.

[0025] Preferably, the temperature of the esterification reaction is controlled to be 220-240°C.

[0026] Preferably, the acid value of the intermediate product 1 is controlled to be less than 3 mgKOH / g.

[0027] Preferably, in step (2), the auxiliary agent is selected from 2,6-di-tert-butyl-p-methylphenol and / or trimethyl phosphate.

[0028] Preferably, the dosage of the auxiliary agent is 0.005-0.5% of the molar amount of the polyacid.

[0029] Preferably, the reaction temperature of step (2) is controlled to be 200-220° C., and the reaction time is 20-40 min.

[0030] Preferably, the polycondensation reaction temperature in step (3) is 220-240°C.

[0031] Preferably, the intermediate product 3 has an acid value of less than 1 mgKOH / g and a hydroxyl value of 8 to 20 mgKOH / g.

[0032] Preferably, in step (4), the solvent is selected from one or more of cyclohexanone, dibasic acid ester, 150# solvent oil, toluene and xylene.

[0033] Preferably, the initiator is selected from azobisisobutyronitrile and / or benzoyl peroxide.

[0034] Preferably, the amount of the initiator used is 1-5% of the molar amount of the polyacid.

[0035] Preferably, the initiator is added to the reaction system in a dropwise manner, and the duration of the dropwise addition is controlled to be less than 2 hours.

[0036] Preferably, the reaction time in step (4) is controlled to be 3 to 8 hours.

[0037] In one aspect, the present invention provides a composition comprising the polyester resin described in any one of the above items or the polyester resin obtained by any one of the above methods and an acrylic resin.

[0038] In one aspect, the present invention provides use of any of the above polyester resins or the polyester resin obtained by any of the above methods in preparing polyester-acrylic resin copolymer dyes.

[0039] Effects of the Invention

[0040] The present invention obtains a polyester resin with high compatibility with acrylic resin by specifically selecting raw materials for preparing polyester resin and the content thereof. Specifically, the present invention selects alcohols and acids with long carbon chains or side chains to reduce the ester bonds with strong polarity on the main chain. Meanwhile, the introduction of non-polar side chains also reduces the polarity of the polyester resin itself to a certain extent. Furthermore, the present invention further increases a large number of side chains by grafting, thereby ultimately promoting the compatibility of the polyester resin with the acrylic resin and improving the comprehensive performance of the acrylic resin. The polyester resin prepared by the present invention can be compatible with the acrylic resin in any proportion, has a wider application range, and expands the application range of the acrylic resin. The present invention also has the advantages of low price of raw materials for preparation, low cost, and the like. DETAILED DESCRIPTION

[0041] In order to make the technical solutions and beneficial effects of the present invention more obvious and easy to understand, the following is a detailed description by listing specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the enlightenment of the present invention or by combining the features of the present invention with other prior arts falls within the protection scope of the present invention. Unless otherwise defined, the technical and scientific terms used herein have the same meaning as those in the technical field to which this application belongs.

[0042] If no specific techniques or conditions are specified in the following examples, they are generally carried out according to conventional techniques or conditions described in the literature in the art, or according to the product instructions and the conditions recommended by the manufacturer.

[0043] Unless otherwise indicated, various starting materials, materials and reagents were either commercially available or synthesized according to known methods.

[0044] In one aspect, the present invention provides a polyester resin, wherein the raw materials for preparing the polyester resin include polyacid, polyol, unsaturated monomer, and graft-modified monomer;

[0045] Wherein, the polyacid is selected from one or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride;

[0046] The polyol is selected from one or more of neopentyl glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2-butyl-2-ethyl-1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol and trimethylolpropane;

[0047] The unsaturated monomer is selected from one or more of maleic anhydride, itaconic acid, and fumaric acid;

[0048] The graft modification monomer is selected from one or more of ethyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, ethyl methacrylate, n-butyl methacrylate, n-pentyl methacrylate, and n-hexyl methacrylate.

[0049] In one embodiment, the polyacid is selected from two or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride;

[0050] The polyol is selected from two or more of neopentyl glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2-butyl-2-ethyl-1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol and trimethylolpropane.

[0051] In one embodiment, the polyacid is selected from three or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride;

[0052] The polyol is selected from three or more of neopentyl glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2-butyl-2-ethyl-1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol and trimethylolpropane.

[0053] In one embodiment, the molar ratio of the polyol to the polyacid is (1-2.5):1, for example, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, etc.

[0054] In one embodiment, the molar ratio of the polyol to the polyacid is (1.5-2):1.

[0055] In one embodiment, the molar amount of the unsaturated monomer is 10-30% of the molar amount of the polyacid, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc.

[0056] In one embodiment, the molar amount of the unsaturated monomer accounts for 12-30% of the molar amount of the polyacid.

[0057] In one embodiment, the molar amount of the unsaturated monomer accounts for 15-30% of the molar amount of the polyacid.

[0058] In one embodiment, the molar amount of the grafted modified monomer is 10-30% of the molar amount of the polyacid, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, etc.

[0059] In one embodiment, the molar amount of the graft-modified monomer accounts for 12 to 30% of the molar amount of the polyacid.

[0060] In one embodiment, the molar amount of the graft-modified monomer accounts for 15-30% of the molar amount of the polyacid.

[0061] The present invention obtains a main chain polyester resin with low polarity by selecting specific polyols and polyacids for polymerization. At the same time, the non-polar groups on the side chains also reduce the polarity of the polyester resin to a certain extent. Furthermore, the number of side chains is further increased by grafting, thereby achieving good compatibility with acrylic acid.

[0062] In one aspect, the present invention provides a method for preparing the polyester resin described in any one of the above, the preparation method comprising:

[0063] (1) adding a polyacid, a polyol and a catalyst into a reactor, heating the reaction system to perform an esterification reaction, and obtaining an intermediate product 1;

[0064] (2) After the esterification reaction is completed, an unsaturated monomer and an auxiliary agent are added to the reaction system to react to obtain an intermediate product 2;

[0065] (3) After the reaction of step (2) is completed, the intermediate product 2 is subjected to a condensation polymerization reaction to obtain an intermediate product 3;

[0066] (4) reacting the intermediate product 3 with a graft-modified monomer in the presence of a solvent and an initiator to obtain the polyester resin.

[0067] In one embodiment, in step (1), the catalyst is selected from one or more of tetrabutyl titanate, zinc acetate, and germanium oxide.

[0068] In one embodiment, the amount of the catalyst used is 0.005 to 0.05% of the molar amount of the polyacid.

[0069] In one embodiment, the amount of the catalyst used is 0.01-0.05% of the molar amount of the polyacid, for example, 0.02%, 0.03%, 0.04%, 0.05%.

[0070] In one embodiment, the temperature of the esterification reaction is controlled to be 220-240°C, for example, 221°C, 222°C, 223°C, 224°C, 225°C, 226°C, 227°C, 228°C, 229°C, 230°C, 231°C, 232°C, 234°C, 235°C, 236°C, 237°C, 238°C, 239°C, and 240°C.

[0071] In one embodiment, the acid value of the intermediate product 1 is controlled to be less than 3 mgKOH / g.

[0072] In one embodiment, in step (2), the auxiliary agent is selected from 2,6-di-tert-butyl-p-methylphenol and / or trimethyl phosphate.

[0073] In one embodiment, the amount of the auxiliary agent is 0.005-0.5% of the molar amount of the polyacid.

[0074] In one embodiment, the amount of the auxiliary agent is 0.05-0.5% of the molar amount of the polyacid, for example, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, 0.3%, 0.32%, 0.34%, 0.36%, 0.38%, 0.40%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, etc.

[0075] In one embodiment, the reaction temperature of step (2) is controlled to be 200-220°C (e.g., 201°C, 202°C, 203°C, 204°C, 205°C, 206°C, 207°C, 208°C, 209°C, 210°C, 211°C, 212°C, 214°C, 215°C, 216°C, 217°C, 218°C, 219°C, 220°C), and the reaction time is 20-40 min (e.g., 22 min, 24 min, 26 min, 28 min, 30 min, 32 min, 34 min, 36 min, 38 min, 40 min, etc.).

[0076] In one embodiment, the polycondensation reaction temperature in step (3) is 220-240°C, for example, 221°C, 222°C, 223°C, 224°C, 225°C, 226°C, 227°C, 228°C, 229°C, 230°C, 231°C, 232°C, 234°C, 235°C, 236°C, 237°C, 238°C, 239°C, 240°C.

[0077] In one embodiment, the polycondensation reaction in step (3) is carried out under negative pressure.

[0078] In one embodiment, the reaction of step (1) and step (2) is carried out under normal pressure.

[0079] In one embodiment, the intermediate product 3 has an acid value of less than 1 mgKOH / g and a hydroxyl value of 8 to 20 mgKOH / g (e.g., 8 mgKOH / g, 9 mgKOH / g, 10 mgKOH / g, 11 mgKOH / g, 12 mgKOH / g, 13 mgKOH / g, 14 mgKOH / g, 15 mgKOH / g, 16 mgKOH / g, 17 mgKOH / g, 18 mgKOH / g, 19 mgKOH / g, 20 mgKOH / g, etc.).

[0080] In one embodiment, in step (4), the solvent is selected from one or more of cyclohexanone, dibasic acid ester, 150# solvent oil, toluene and xylene.

[0081] In one embodiment, the initiator is selected from azobisisobutyronitrile and / or benzoyl peroxide.

[0082] In one embodiment, the amount of the initiator is 1-5% of the molar amount of the polyacid, for example, 1.1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5%, etc.

[0083] In one embodiment, the amount of the initiator is 1 to 3% of the molar amount of the polyacid.

[0084] In one embodiment, the initiator is added to the reaction system in a dropwise manner, and the duration of the dropwise addition is controlled to be less than 2 hours.

[0085] In one embodiment, the reaction time in step (4) is controlled to be 3 to 8 hours, for example, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, etc.

[0086] In one embodiment, the reaction temperature of step (4) is determined according to the selected initiator. In a preferred embodiment, the initiator is azobisisobutyronitrile, and the reaction temperature is 73-82°C, preferably 75-78°C. In another preferred embodiment, the initiator is benzoyl peroxide, and the reaction temperature is 82-91°C, preferably 85-88°C.

[0087] The polyester resin provided by the present invention can significantly improve the compatibility with acrylic resin, significantly improve the storage stability and shelf life of the polyester-acrylic resin copolymer dye, has good storage stability uniformity, is not prone to adverse phenomena such as turbidity and stratification, and has a simple preparation process, easy operation, low cost, and has a wider application prospect.

[0088] In one aspect, the present invention provides a composition comprising the polyester resin described in any one of the above items or the polyester resin obtained by any one of the above methods and an acrylic resin.

[0089] In one aspect, the present invention provides use of any of the above polyester resins or the polyester resin obtained by any of the above methods in preparing polyester-acrylic resin copolymer dyes.

[0090] The present invention is further described below in conjunction with specific examples and comparative examples. If no specific techniques or conditions are specified in the following examples, the conventional techniques or conditions described in the literature in the art, or the conditions recommended by the product instructions and the manufacturer are generally used. Unless otherwise specified, various starting materials, materials and reagents are commercially available or synthesized according to known methods.

[0091] Example 1

[0092] Add 432.76g dimer acid, 156.04g sebacic acid, 177.13g 1,4-cyclohexanedicarboxylic acid, 241.07g neopentyl glycol, 70.45g 1,2-propylene glycol, 222.55g 2-butyl-2-ethyl-1,3-propylene glycol, 0.13g tetrabutyl titanate, 0.13g zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, stir at a speed of 60-100r / min, and judge that the esterification reaction is completed when the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0093] Then add 50.97g of fumaric acid, 0.13g of trimethyl phosphate, and 0.65g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0094] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 230°C at a rate of 1°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0095] The amount of xylene solvent required for dissolving the obtained polyester at 40wt% is calculated, and 80wt% of xylene is used for dissolution. After complete dissolution, a constant temperature of 76°C is maintained. 80.35g of n-pentyl methacrylate and 8.45g of azobisisobutyronitrile are dissolved in the remaining 20wt% of xylene. The solution is placed in a constant pressure dropping funnel for titration. The solution is titrated within 2h, and then stirring is maintained to continue the reaction for 5h to obtain the final target polyester solution.

[0096] Example 2

[0097] Add 412.08g dimer acid, 169.19g dodecanedioic acid, 151.01g hexahydrophthalic anhydride, 183.64g neopentyl glycol, 193.37g 2,2,4-trimethyl-1,3-pentanediol, 190.70g 1,4-cyclohexanedimethanol, 0.13g tetrabutyl titanate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, stir at 60-100r / min, and judge that the esterification reaction is over when the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0098] Then add 60.03g of maleic anhydride, 0.13g of trimethyl phosphate, and 0.65g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0099] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 230°C at a rate of 1°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0100] The amount of xylene solvent required for dissolving the obtained polyester at 40wt%, 80wt% of xylene is used for dissolution, and a constant temperature of 87°C is maintained after complete dissolution. 87.06g of n-butyl methacrylate and 14.83g of benzoyl peroxide are dissolved in the remaining 20wt% of xylene, and the solution is placed in a constant pressure dropping funnel for titration. The solution is titrated within 2h, and then the reaction is continued with stirring for 5h to obtain the final target polyester solution.

[0101] Example 3

[0102] Add 451.85g dimer acid, 139.65g sebacic acid, 138.70g 1,4-cyclohexanedicarboxylic acid, 165.94g 2-methyl-1,3-propanediol, 108.79g 1,6-hexanediol, 295.07g 2-butyl-2-ethyl-1,3-propanediol, 0.13g tetrabutyl titanate, 0.13g zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 240°C at 1°C / min, start stirring at above 150°C, stir at 60-100r / min, and judge that the esterification reaction is over when the amount of esterified by-products exceeds 90% of the theory and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0103] Then add 89.83g of itaconic acid, 0.26g of trimethyl phosphate, and 1.3g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0104] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was maintained at 220°C. The polycondensation was performed until the hydroxyl value of the sample was 8-20 mgKOH / g, which was the reaction end point.

[0105] The amount of solvent toluene required for dissolving the obtained polyester at 40wt% is calculated, and 80wt% of toluene is used for dissolution. After complete dissolution, a constant temperature of 76°C is maintained. 53.93g of n-pentyl methacrylate, 58.78g of n-hexyl methacrylate and 11.34g of azobisisobutyronitrile are dissolved in the remaining 20wt% of toluene. The solution is placed in a constant pressure dropping funnel for titration. The solution is titrated within 2h, and then stirring is maintained to continue the reaction for 5h to obtain the final target polyester solution.

[0106] Example 4

[0107] Add 523.04g dimer acid, 68.14g adipic acid, 160.55g 1,4-cyclohexanedicarboxylic acid, 138.39g neopentyl glycol, 39.92g 2-methyl-1,3-propanediol, 157.02g 1,6-hexanediol, 212.94g 2-butyl-2-ethyl-1,3-propanediol, and 0.26g tetrabutyl titanate into a 2L reactor, esterify at normal pressure, gradually heat to 235°C at 1°C / min, start stirring at above 150°C, and stir at a speed of 60-100r / min. When the amount of esterified byproducts exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C, the esterification reaction is determined to be complete, sample and determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0108] Then add 27.43g of maleic anhydride, 0.26g of trimethyl phosphate, and 0.65g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0109] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 240°C at a rate of 1°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0110] The obtained polyester is dissolved at 40wt% and the required dibasic acid ester and 150# solvent oil are used in a mixed solvent of 1:1 by mass. 80wt% of the mixed solvent is used for dissolution. After complete dissolution, a constant temperature of 87°C is maintained. 39.78g of n-pentyl acrylate and 6.78g of benzoyl peroxide are dissolved in the remaining 20wt% mixed solvent. The solution is placed in a constant pressure dropping funnel for titration. The dropping is completed within 2h, and then the stirring is maintained to continue the reaction for 5h to obtain the final target polyester solution.

[0111] Example 5

[0112] Add 319.28g dimer acid, 287.81g sebacic acid, 131.63g hexahydrophthalic anhydride, 69.3g 1,2-propylene glycol, 114.91g 2-methyl-1,3-propylene glycol, 364.86g 2-butyl-2-ethyl-1,3-propylene glycol, 12.22g trimethylolpropane, 0.1g tetrabutyl titanate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, stir at 60-100r / min, and judge that the esterification reaction is over when the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0113] Then add 49.55g of fumaric acid, 0.1g of trimethyl phosphate, and 0.3g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0114] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 235°C at a rate of 1°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0115] The amount of solvent cyclohexanone required for dissolving the obtained polyester at 40wt%, 80wt% of cyclohexanone is used for dissolution, and a constant temperature of 87°C is maintained after complete dissolution. 21.89g of n-butyl acrylate, 40.01g of n-hexyl acrylate and 10.34g of benzoyl peroxide are dissolved in the remaining 20wt% of cyclohexanone, and the solution is placed in a constant pressure dropping funnel for titration. The dropping is completed within 2h, and then the reaction is continued with stirring for 5h to obtain the final target polyester solution.

[0116] Example 6

[0117] Add 214.72g of sebacic acid, 104.43g of adipic acid, 304.66g of 1,4-cyclohexanedicarboxylic acid, 250.63g of neopentyl glycol, 108.43g of 2-methyl-1,3-propanediol, 142.18g of 1,6-hexanediol, 175.94g of 2,2,4-trimethyl-1,3-pentanediol, 0.1g of tetrabutyl titanate, and 0.1g of zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 225°C at 1°C / min, start stirring at above 150°C, and stir at a speed of 60-100r / min. When the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C, the esterification reaction is determined to be complete, sample and measure the acid value of the esterified product to be less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0118] Then add 69.40g of maleic anhydride, 0.2g of trimethyl phosphate, and 0.6g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0119] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 225°C at a rate of 0.5°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0120] The amount of solvent toluene required for dissolving the obtained polyester at 40wt% is calculated, and 80wt% of toluene is used for dissolution. After complete dissolution, a constant temperature of 76°C is maintained. 60.39g of n-pentyl acrylate, 48.20g of n-hexyl methacrylate and 11.62g of azobisisobutyronitrile are dissolved in the remaining 20wt% of toluene. The solution is placed in a constant pressure dropping funnel for titration. The solution is titrated within 2h, and then the reaction is continued with stirring for 5h to obtain the final target polyester solution.

[0121] Comparative Example 1

[0122] Add 432.76g dimer acid, 156.04g sebacic acid, 177.13g 1,4-cyclohexanedicarboxylic acid, 241.07g neopentyl glycol, 70.45g 1,2-propylene glycol, 222.55g 2-butyl-2-ethyl-1,3-propylene glycol, 0.13g tetrabutyl titanate, 0.13g zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, stir at a speed of 60-100r / min, and judge that the esterification reaction is completed when the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0123] Then add 26.87g of fumaric acid, 0.13g of trimethyl phosphate, and 0.65g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0124] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 230°C at a rate of 1°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0125] The amount of solvent xylene required for dissolving the obtained polyester at 40wt%, 80wt% of xylene was used for dissolution, and a constant temperature of 76°C was maintained after complete dissolution. 36.16g of n-pentyl methacrylate and 3.80g of azobisisobutyronitrile were dissolved in the remaining 20wt% of xylene, and the solution was placed in a constant pressure dropping funnel for titration. The solution was titrated within 2h, and then the stirring was maintained to continue the reaction for 5h to obtain the final target polyester solution.

[0126] Comparative Example 2

[0127] Add 432.76g dimer acid, 156.04g sebacic acid, 177.13g 1,4-cyclohexanedicarboxylic acid, 241.07g neopentyl glycol, 70.45g 1,2-propylene glycol, 222.55g 2-butyl-2-ethyl-1,3-propylene glycol, 0.13g tetrabutyl titanate, 0.13g zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, stir at a speed of 60-100r / min, and judge that the esterification reaction is completed when the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0128] Then add 92.54 g of fumaric acid, 0.13 g of trimethyl phosphate, and 0.65 g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100 r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0129] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 230°C at a rate of 1°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0130] The amount of xylene solvent required for dissolving the obtained polyester at 40wt%, 80wt% of xylene was used for dissolution, and a constant temperature of 76°C was maintained after complete dissolution. 124.55g of n-pentyl methacrylate and 13.09g of azobisisobutyronitrile were dissolved in the remaining 20wt% of xylene, and the solution was placed in a constant pressure dropping funnel for titration. The solution was titrated within 2h, and then the stirring was maintained to continue the reaction for 5h to obtain the final target polyester solution.

[0131] Comparative Example 3

[0132] Add 432.76g dimer acid, 156.04g sebacic acid, 177.13g 1,4-cyclohexanedicarboxylic acid, 241.07g neopentyl glycol, 70.45g 1,2-propylene glycol, 222.55g 2-butyl-2-ethyl-1,3-propylene glycol, 0.13g tetrabutyl titanate, 0.13g zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, stir at a speed of 60-100r / min, and judge that the esterification reaction is completed when the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0133] Then add 104.48g of fumaric acid, 0.13g of trimethyl phosphate, and 0.65g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0134] The polycondensation reaction was started, and the polycondensation temperature was gradually increased to 230°C at a rate of 1°C / min. The polycondensation reaction process was unstable and prone to cross-linking, and the target hydroxyl value range could not be reached. Therefore, no subsequent grafting experiment was performed.

[0135] Comparative Example 4

[0136] Add 432.76g dimer acid, 156.04g sebacic acid, 177.13g 1,4-cyclohexanedicarboxylic acid, 241.07g neopentyl glycol, 70.45g 1,2-propylene glycol, 222.55g 2-butyl-2-ethyl-1,3-propylene glycol, 0.13g tetrabutyl titanate, 0.13g zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, stir at a speed of 60-100r / min, and judge that the esterification reaction is completed when the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C. Take a sample to determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0137] Then, 0.13 g of trimethyl phosphate was added to the reaction system, and the reaction system was gradually evacuated to 200 Pa. At the same time, the polycondensation temperature was gradually increased to 230° C. at a rate of 1° C. / min. The polycondensation was performed until the hydroxyl value of the sample was 8-20 mgKOH / g, which was the reaction end point.

[0138] The obtained polyester was dissolved in xylene at a solid content of 40 wt %, to obtain the final target polyester solution.

[0139] Comparative Example 5

[0140] Add 223.37g terephthalic acid, 223.37g isophthalic acid, 261.99g adipic acid, 168.05 neopentyl glycol, 122.77g 1,2-propylene glycol, 300.45g ethylene glycol, 0.13g tetrabutyl titanate, and 0.13g zinc acetate into a 2L reactor, esterify at normal pressure, gradually heat to 230°C at 1°C / min, start stirring at above 150°C, and stir at a speed of 60-100r / min. When the amount of esterified by-products exceeds 90% of the theoretical amount and the tower top temperature drops below 96°C, the esterification reaction is determined to be complete, sample and determine that the acid value of the esterified product is less than 3mgKOH / g, and cool down to 180°C while maintaining an inert gas atmosphere;

[0141] Then add 104.04 g of fumaric acid, 0.13 g of trimethyl phosphate, and 0.65 g of 2,6-di-tert-butyl-p-methylphenol into the reaction system, continue the reaction at normal pressure, control the stirring speed at 60-100 r / min, and gradually increase the temperature to 220°C at 1°C / min until the reaction is completed;

[0142] The reaction system was gradually evacuated to 200 Pa, and the polycondensation temperature was gradually increased to 230°C at a rate of 1°C / min. The polycondensation was terminated when the hydroxyl value of the sample was 8-20 mgKOH / g.

[0143] The amount of xylene solvent required for dissolving the obtained polyester according to 40wt% solid content is calculated, and 80wt% of xylene is used for dissolution. After complete dissolution, a constant temperature of 76°C is maintained. 140.03g of n-pentyl methacrylate and 14.72g of azobisisobutyronitrile are dissolved in the remaining 20wt% of xylene. The solution is placed in a constant pressure dropping funnel for titration. The dropping is completed within 2h, and then stirring is maintained to continue the reaction for 5h to obtain the final target polyester solution.

[0144] Test Case

[0145] The polyester resins prepared in the above Examples 1 to 6 and Comparative Examples 1 to 5 were evaluated for performance:

[0146] The acid value and hydroxyl value of the polyester resin esterified samples and final samples prepared in the above 1 to 6 and comparative examples 1 to 5 were measured. The measurement results are shown in Table 1 below:

[0147] Table 1

[0148]

[0149] Compatibility evaluation was performed on four acrylic resins (Neocryel B-723, Neocryl B-731, Neocryl B-736, UracronCY463) and the polyester resin prepared by the present invention:

[0150] The corresponding polyester resins in the examples and comparative examples were dissolved with the above four acrylic resins at a solid content of 40 wt%, and mixed at a mass ratio of acrylic resin solution / polyester resin solution of 90% / 10%, 50% / 50%, and 10% / 90%, and the state and stability as well as the state of the mixed sample after 10 days were observed.

[0151] The test results are detailed in Tables 2-4, wherein Table 2 is the test results obtained by mixing the acrylic resin solution / polyester resin solution at a mass ratio of 90% / 10%, Table 3 is the test results obtained by mixing the acrylic resin solution / polyester resin solution at a mass ratio of 50% / 50%, and Table 4 is the test results obtained by mixing the acrylic resin solution / polyester resin solution at a mass ratio of 10% / 90%. In Tables 2-4, ○ indicates a stable, clear and uniform state, and × indicates an abnormal state, turbidity, or stratification:

[0152] Table 2

[0153]

[0154] Table 3

[0155]

[0156]

[0157] Table 4

[0158]

[0159] The above results show that the present invention improves the compatibility of polyester resin and coating acrylic resin by modifying the polyester structure. After the polyester resin of the present invention is mixed with the acrylic resin, the comprehensive performance of the acrylic resin is improved, and the application range of the coating is expanded; the polyester resin synthesized by the present invention can be miscible with the coating acrylic resin solution in any proportion, so that the subsequent coating formula is flexible and changeable; the synthesis process of the present invention is simple and controllable, and the raw material price is low and the practicability is strong.

[0160] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments only express several implementations of the present invention and do not limit the scope of protection of the patent of the present invention.

Claims

1. A polyester resin, characterized in that The raw materials for preparing the polyester resin include polyacid, polyol, unsaturated monomer and graft-modified monomer; Wherein, the polyacid is selected from one or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride; The polyol is selected from one or more of neopentyl glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2-butyl-2-ethyl-1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol and trimethylolpropane; The unsaturated monomer is selected from one or more of maleic anhydride, itaconic acid, and fumaric acid; The graft modification monomer is selected from one or more of ethyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, ethyl methacrylate, n-butyl methacrylate, n-pentyl methacrylate, and n-hexyl methacrylate.

2. The polyester resin according to claim 1, characterized in that The polyacid is selected from two or more of dimer acid, sebacic acid, adipic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid, and hexahydrophthalic anhydride; The polyol is selected from two or more of neopentyl glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 2-butyl-2-ethyl-1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol and trimethylolpropane.

3. The polyester resin according to claim 1, characterized in that The molar ratio of the polyol to the polyacid is (1-2.5):1, preferably (1.5-2):

1.

4. The polyester resin according to claim 1, characterized in that The molar amount of the unsaturated monomer accounts for 10 to 30% of the molar amount of the polyacid, preferably 12 to 30%.

5. The polyester resin according to claim 1, characterized in that The molar amount of the graft-modified monomer accounts for 10 to 30% of the molar amount of the polyacid, preferably 12 to 30%.

6. A method for preparing a polyester resin according to any one of claims 1 to 5, characterized in that: The preparation method comprises: (1) adding a polyacid, a polyol and a catalyst into a reactor, heating the reaction system to perform an esterification reaction, and obtaining an intermediate product 1; (2) After the esterification reaction is completed, an unsaturated monomer and an auxiliary agent are added to the reaction system to react to obtain an intermediate product 2; (3) After the reaction of step (2) is completed, the intermediate product 2 is subjected to a condensation polymerization reaction to obtain an intermediate product 3; (4) reacting the intermediate product 3 with a graft-modified monomer in the presence of a solvent and an initiator to obtain the polyester resin.

7. The preparation method according to claim 6, characterized in that: In step (1), the catalyst is selected from one or more of tetrabutyl titanate, zinc acetate, and germanium oxide; Preferably, the amount of the catalyst is 0.005 to 0.05% of the molar amount of the polyacid; Preferably, the temperature of the esterification reaction is controlled to be 220-240°C; Preferably, the acid value of the intermediate product 1 is controlled to be less than 3 mgKOH / g; Preferably, in step (2), the auxiliary agent is selected from 2,6-di-tert-butyl-p-methylphenol and / or trimethyl phosphate; Preferably, the amount of the auxiliary agent is 0.005 to 0.5% of the molar amount of the polyacid; Preferably, the reaction temperature of step (2) is controlled to be 200-220° C., and the reaction time is 20-40 min.

8. The preparation method according to claim 6, characterized in that: The polycondensation reaction temperature in step (3) is 220-240°C; Preferably, the acid value of the intermediate product 3 is less than 1 mgKOH / g, and the hydroxyl value is 8 to 20 mgKOH / g; Preferably, in step (4), the solvent is selected from one or more of cyclohexanone, dibasic acid ester, 150# solvent oil, toluene and xylene; Preferably, the initiator is selected from azobisisobutyronitrile and / or benzoyl peroxide; Preferably, the amount of the initiator is 1 to 5% of the molar amount of the polyacid; Preferably, the initiator is added to the reaction system in a dropwise manner, and the duration of the dropwise addition is controlled to be less than 2 hours; Preferably, the reaction time in step (4) is controlled to be 3 to 8 hours.

9. A composition, characterized in that The composition comprises the polyester resin according to any one of claims 1 to 5 or the polyester resin obtained by the method according to any one of claims 6 to 8 and an acrylic resin.

10. Use of the polyester resin according to any one of claims 1 to 5 or the polyester resin obtained by the method according to any one of claims 6 to 8 in the preparation of polyester-acrylic resin copolymer dyes.

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