Method for preparing acrylic polymer containing polyester particles

Abstract

The present invention relates to the technical field of acrylic acids. Disclosed is a method for preparing an acrylic polymer containing polyester particles. The method comprises the following steps: S100. synthesizing an intermediate M; and S200. synthesizing an acrylic polymer solution, wherein the intermediate M is an intermediate containing an unsaturated a C=C double bond. Step S100 comprises: S110. putting a dihydric alcohol and a dibasic acid into a reactor; S120. introducing a protective gas into the reactor; S130. heating the mixture to 200ºC-250ºC to implement an esterification dehydration reaction; S140. upon detecting that an acid value reaches 100-150 mgKOH / g, cooling the resulting reaction solution to 120ºC-160ºC; S150. stopping inputting the protective gas; S160. adding a catalyst and a polymerization inhibitor; and S170. introducing air, adding glycidyl methacrylate in portions, maintaining the mixture at 90ºC-105ºC, and then adding a solvent to obtain an intermediate M. A coating made of the acrylic polymer containing polyester particles of the present invention exhibits high gloss and hardness while maintaining good flexibility. The preparation method is simple and easy to promote.

Description

Method for preparing an acrylic polymer containing polyester microparticles TECHNICAL FIELD

[0001] The present application belongs to the technical field of acrylic acid, and particularly relates to a method for preparing an acrylic polymer containing polyester microparticles. BACKGROUND

[0002] The existing acrylic polymer has the problem of high gloss and hardness but poor flexibility when prepared into paint.

[0003] After searching, the Chinese invention patent: a method for preparing a solution containing self-extinguishing acrylic polymer microparticles (application number 201911224571.2, publication date 2022.09.09) includes the following steps: a mixture of a first initiator and a first monomer is added to a reactor, heated and dropped, and a polymer M1 is obtained; glycidyl methacrylate is added to the polymer M1, a catalyst is added, and the reaction is heated to perform ring opening reaction of epoxy and carboxyl, and a polymer M2 is obtained; the mixture of the second initiator and the second monomer is added to the polymer M2, and the solution containing self-extinguishing acrylic polymer microparticles is obtained. The reaction temperature after adding glycidyl methacrylate is 110-135℃, under this condition, glycidyl methacrylate is easy to self-polymerize, which affects the stability of the resin performance. The final synthesized polymer is used to make a low gloss paint.

[0004] The Chinese invention patent: a method for preparing a gel containing self-extinguishing acrylic polymer microparticles (application number 202311131073.X, publication date 2023.11.07) uses a poor solvent for synthesis and preparation, and the final polymer is a gel. The final synthesized polymer is also used to make a low gloss paint.

[0005] SUMMARY

[0006] The present application aims to solve the problem of high gloss and hardness but poor flexibility of the existing acrylic polymer. A solution of acrylic polymer containing polyester microparticles is prepared using good solvents, and the paint prepared therefrom has high gloss, high hardness and good flexibility.

[0007] To achieve the above-mentioned purpose, the technical scheme provided by the present application is as follows:

[0008] The present application provides a method for preparing an acrylic polymer containing polyester microparticles, and the method steps are as follows:

[0009] S100, synthesis of intermediate M;

[0010] S200, synthesis of acrylic polymer solution;

[0011] The intermediate M is an intermediate containing unsaturated C=C double bonds.

[0012] Preferably, the step S100 comprises

[0013] S110, feeding dihydric alcohol and diacid into the reactor;

[0014] S120, feeding protective gas into the reactor;

[0015] S130, heating to 200-250°C to perform esterification and dehydration reaction;

[0016] S140, detecting acid value and reducing temperature to 120-160°C after the acid value is 100-150 mgKOH / g;

[0017] S150, stopping feeding of the protective gas;

[0018] S160, adding catalyst and polymerization inhibitor;

[0019] S170, feeding air and glycidyl methacrylate in batches, and adding solvent after holding at 90-105°C to obtain the intermediate M, and feeding the glycidyl methacrylate in batches. In order to ensure that the glycidyl methacrylate can be repeatedly mixed with the whole mixture to further reduce self-polymerization of the glycidyl methacrylate and ensure that the non-volatile fraction NV of the intermediate M is 50%, the glycidyl methacrylate is added in batches.

[0020] In the step S170, the esterification reaction of the dihydric alcohol and the diacid in the step S110 is performed, and the ratio of the dihydric alcohol and the diacid is controlled to retain relatively high acid value (carboxyl group) after the reaction, and then the acid value reacts with the epoxy group on the glycidyl methacrylate under the action of the catalyst to obtain the intermediate M. The solvent is added to dilute the intermediate M to control the non-volatile fraction NV of the intermediate M to be 50%, and the intermediate M retains the double bond on the glycidyl methacrylate and participates in the subsequent free radical reaction in the step S230 to obtain the polyester microparticle-containing acrylic acid solution.

[0021] Preferably, the step S200 comprises

[0022] S210, feeding solvent into the reactor, the solvent added in the step S210 is used as a base material to effectively dissolve the reactants of the acrylic monomer mixture and the intermediate M in the subsequent step S230; and the solvent added in the steps S230 and S250 is used to dissolve the initiator to ensure the reaction effect;

[0023] S220, feeding protective gas into the reactor;

[0024] S230, dropping the acrylic monomer mixture, the intermediate M, the initiator and the solvent;

[0025] S240, holding temperature 90-140℃;

[0026] S250, adding initiator and solvent;

[0027] S260, holding temperature 90-120℃, to obtain an acrylic acid solution containing polyester microparticles.

[0028] Preferably, the dihydric alcohol in step S110 is one or more of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol; and the dihydric acid is one or more of phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid.

[0029] Preferably, the solvent is one or more of toluene, xylene, butyl acetate, propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate.

[0030] Preferably, the catalyst in step S160 is at least one of triphenylphosphine, ethyl triphenylphosphonium iodide, tetrabutylphosphonium chloride, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, triethylamine, triethanolamine, tetrabutylammonium bromide, triethylbenzylammonium chloride, chromium trichloride, and the polymerization inhibitor is one or more of p-hydroxyanisole, methylhydroquinone, 2,6-di-tert-butyl-p-cresol.

[0031] Preferably, the initiator in step S230 is one or more of azobis isovaleronitrile, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, benzoyl peroxide, tert-butyl peroxybenzoate, 3,5,5-trimethylhexyl tert-butyl peroxide; and the acrylic monomer mixture is one or more of styrene, methyl methacrylate, isooctyl acrylate, n-butyl methacrylate, hydroxyethyl methacrylate, acrylic acid, methacrylic acid, cyclohexyl methacrylate, butyl acrylate, ethyl methacrylate, ethyl acrylate, methyl acrylate, isooctyl methacrylate, lauryl methacrylate, isobutyl acrylate, tert-butyl acrylate, tert-butyl methacrylate, hydroxypropyl methacrylate, and hydroxypropyl acrylate.

[0032] Preferably, the non-volatile fraction NV of the M intermediate obtained in step S100 is 50%, and the non-volatile fraction NV of the acrylic acid polymer containing polyester microparticles obtained in step S200 is 50%.

[0033] Preferably, the mass of the catalyst added in step S160 is 8‰-18‰ of the sum of the mass of the dihydric alcohol and the diacid, and the mass of the polymerization inhibitor is 0.5‰-2‰ of the sum of the mass of the dihydric alcohol and the diacid; the mass ratio of the mass of the acrylic monomer mixture, the intermediate M, and the initiator added in step S230 is 30-40: 15-25: 1-4.

[0034] Preferably, the amount of the initiator added in step S250 is 8‰-55‰ of the sum of the mass of the acrylic monomer mixture and the intermediate M; the holding time in step S240 is 1-4 hours, and the holding time in step S260 is 4-12 hours.

[0035] The initiator and the solvent added in step S230 and the initiator and the solvent added in step S250 can be the same or different, and the solvents are both for diluting the initiator before being added.

[0036] Preferably, in step 110, the mass ratio of the dihydric alcohol and the diacid is configured such that, after the dihydric alcohol is completely reacted, the acid value of the mixed solution is 110-160 mgKOH / g, so that the glycidyl methacrylate grafted therewith in the subsequent reaction process can be well reacted, and the self-polymerization of the glycidyl methacrylate is reduced; and the mass of the glycidyl methacrylate added in step S170 is configured to reduce the acid value reaction in step S140 to 20-40 mgKOH / g.

[0037] Preferably, in step S210, the mass percentage of the solvent added is 25-35%;

[0038] In step S230, the mass percentage of the acrylic monomer mixture added is 30-40%, the mass percentage of the intermediate M is 15-25%, the mass percentage of the initiator is 1-4%, and the mass percentage of the solvent is 8-10%; when the mass percentage of the intermediate M is greater than 25%, the final product is prone to gelation, and thus the flexibility of the final paint film, and when the mass percentage of the intermediate M is less than 15%, it is difficult to form enough polyester microparticles, and the performance of the polymer is difficult to meet the demand;

[0039] In step S250, the mass percentage of the initiator added is 0.2-0.6%, and the mass percentage of the solvent is 5-10%;

[0040] The mass percentage above is the proportion of the mass percentage of the entire step S200.

[0041] Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects:

[0042] The application discloses a preparation method of an acrylic polymer containing polyester microparticles, and the method steps are as follows: S100, synthesizing an intermediate M; S200, synthesizing an acrylic polymer solution; the intermediate M is an intermediate containing unsaturated C=C double bonds. In the application, after glycidyl methacrylate is added multiple times after esterification and dehydration reactions are performed by adding dihydric alcohols and diacids, the intermediate M is added into a mixture of a good solvent and acrylic monomers, the polyester microparticles obtained through the reaction can be effectively stretched in the polymer due to the presence of the good solvent, and the polyester microparticles are more uniformly distributed, the prepared coating film has good leveling performance, and the polyester microparticles increase the flexible groups of the polymer, so that the flexibility of the prepared coating film is improved. In the step S100, the glycidyl methacrylate is added multiple times, so that the glycidyl methacrylate can be fully mixed and reacted each time, and the self-polymerization of the glycidyl methacrylate caused by excessive addition of the glycidyl methacrylate at one time is effectively prevented, and the intermediate M is smoothly formed. BRIEF DESCRIPTION OF DRAWINGS

[0043] Fig. 1 is a method flowchart of the step S100 of the application;

[0044] Fig. 2 is a method flowchart of the step S200 of the application. DETAILED DESCRIPTION

[0045] In order to enable personnel in the art to better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts should fall within the scope of protection of the present application.

[0046] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0047] Embodiment 1

[0048] With reference to Figs. 1 and 2, the preparation method of the acrylic polymer containing polyester microparticles in the embodiment is as follows:

[0049] S100, synthesizing an intermediate M;

[0050] S200, synthesizing an acrylic polymer solution;

[0051] The intermediate M is an intermediate containing unsaturated C=C double bonds.

[0052] The step S100 comprises

[0053] S110, input dihydric alcohol and diacid into the reactor, the mass ratio of dihydric alcohol and diacid is configured to be 110-160 mgKOH / g when the dihydric alcohol is completely reacted, and in the embodiment, 23 parts of 1, 4-butanediol, 22 parts of ethylene glycol, 74 parts of diethylene glycol, and 240 parts of adipic acid are used;

[0054] S120, input protective gas into the reactor, and in the embodiment, nitrogen is used;

[0055] S130, heated to 200-250°C, and in the embodiment, the temperature is raised to 215°C for 4 hours to perform esterification and dehydration reaction;

[0056] S140, after the acid value is detected to be 100-150 mgKOH / g, the temperature is lowered to 120-160°C, and in the embodiment, the temperature is lowered to 135°C when the solid acid value is 135 mgKOH / g;

[0057] S150, stop inputting protective gas;

[0058] S160, add catalyst and polymerization inhibitor, and in the embodiment, 3 parts of triphenylphosphine and 0.5 parts of p-hydroxyanisole are used;

[0059] S170, input air, and add glycidyl methacrylate in batches, and after heat preservation, add solvent to obtain intermediate M, and in the embodiment, 80 parts of glycidyl methacrylate are added in three batches for 1.5 hours; 400 parts of propylene glycol methyl ether acetate are added after heat preservation at 105°C for 8 hours to obtain M intermediate, the non-volatile part NV is 50%, and the solid acid value is 48 mgKOH / g.

[0060] The step S200 comprises

[0061] S210, input solvent into the reactor, and in the embodiment, 150 parts of butyl acetate are used;

[0062] S220, input protective gas into the reactor, and in the embodiment, nitrogen is used;

[0063] S230, drop acrylate monomer mixture, intermediate M, initiator, and solvent, and in the embodiment, 135 parts of methyl methacrylate, 24 parts of isooctyl acrylate, 10 parts of isobutyl methacrylate, 11 parts of methacrylic acid, 45 parts of hydroxyethyl methacrylate, 110 parts of M intermediate, 18 parts of azobis isovaleronitrile, and 50 parts of butyl acetate are used, and the drop time is 3 hours;

[0064] S240, heat preservation temperature is 90-140°C, and in the embodiment, heat preservation is performed at 97°C for 2 hours;

[0065] S250, adding initiator and solvent, preferably azobisisovaleronitrile 3 parts and propylene glycol methyl ether acetate 38 parts in the embodiment;

[0066] S260, keeping temperature at 90-120℃, preferably 97℃ for 6 hours in the embodiment, to obtain polyester microparticle-containing acrylic acid solution.

[0067] The non-volatile portion NV of the intermediate M obtained in step S100 is 50%, the non-volatile portion NV of the polyester microparticle-containing acrylic acid polymer obtained in step S200 is 50%, and the solid acid value is 28 mgKOH / g.

[0068] The intermediate M used in the embodiment is a polyester microparticle with flexible groups and unsaturated bonds, which can undergo free radical reaction with acrylic acid monomers to obtain the target product. All good solvents are used, so that the polyester microparticle can effectively stretch in the polymer, thereby significantly improving the leveling property of the polymer after being prepared into a coating film, and then improving the gloss of the paint film. The addition of polyester microparticles increases the flexible groups of the polymer, thereby improving the flexibility of the paint film.

[0069] Embodiment 2

[0070] The preparation method of the polyester microparticle-containing acrylic acid polymer of the present application comprises the following steps:

[0071] S100, synthesizing intermediate M;

[0072] S200, synthesizing acrylic acid polymer solution;

[0073] The intermediate M is an intermediate containing unsaturated C=C double bonds.

[0074] Preferably, the step S100 comprises

[0075] S110, feeding dihydric alcohol and dihydric acid into the reactor, preferably 1,4-butanediol 23 parts, ethylene glycol 22 parts, diethylene glycol 74 parts, and adipic acid 240 parts in the embodiment;

[0076] S120, introducing protective gas into the reactor, preferably nitrogen in the embodiment;

[0077] S130, heating to 200-250℃, preferably heating to 215℃ for 4 hours in the embodiment, to perform esterification and dehydration reaction;

[0078] S140, after the acid value reaction reaches 100-150 mgKOH / g, cooling to 120-160℃, preferably cooling to 135℃ when the solid acid value reaches 135 mgKOH / g in the embodiment;

[0079] S150, stopping inputting protective gas;

[0080] S160, adding catalyst, polymerization inhibitor, preferably tetrabutylphosphonium chloride 3 parts and p-hydroxyanisole 0.5 parts in the embodiment;

[0081] S170, passing air, adding glycidyl methacrylate in batches, and adding solvent after heat preservation to obtain intermediate M. In the embodiment, glycidyl methacrylate 80 parts is added in 3 batches for 1.5 hours; 400 parts of propylene glycol methyl ether acetate is added after heat preservation at 100℃ for 6 hours to obtain intermediate M, non-volatile part NV=50%, solid acid value 48 mgKOH / g.

[0082] Preferably, the step S200 comprises

[0083] S210, putting solvent into the reactor, preferably butyl acetate 150 parts in the embodiment;

[0084] S220, passing protective gas into the reactor, preferably nitrogen in the embodiment;

[0085] S230, dropping acrylic monomer mixture, intermediate M, initiator and solvent, preferably methyl methacrylate 127.5 parts, isooctyl acrylate 24 parts, isobutyl methacrylate 10 parts, methacrylic acid 11 parts, hydroxyethyl methacrylate 45 parts, intermediate M prepared in S100 125 parts, tert-butyl peroxy-2-ethylhexanoate 18 parts, butyl acetate 50 parts in the embodiment, dropping time 3 hours;

[0086] S240, heat preservation temperature 90-140℃, preferably 110℃ for 2 hours in the embodiment;

[0087] S250, supplementing initiator and solvent, preferably supplementing tert-butyl peroxy-2-ethylhexanoate 3 parts and propylene glycol methyl ether acetate 30.5 parts in the embodiment;

[0088] S260, heat preservation temperature 90-120℃, to obtain acrylic acid solution containing polyester microparticles, preferably 110℃ for 6 hours in the embodiment, to obtain acrylic polymer containing polyester microparticles, non-volatile part NV=50%, solid acid value 28 mgKOH / g.

[0089] Embodiment 3

[0090] A method for preparing an acrylic polymer containing polyester microparticles according to the present application, the method steps are as follows:

[0091] S100, synthesizing intermediate M;

[0092] S200, synthesizing acrylic polymer solution;

[0093] The intermediate M is an intermediate containing unsaturated C=C double bond.

[0094] Preferably, the step S100 comprises

[0095] S110, put dihydric alcohol and diacid into the reactor, in this embodiment, 30 parts of 1,6-hexanediol, 20 parts of neopentyl glycol, 50 parts of diethylene glycol, and 250 parts of sebacic acid;

[0096] S120, introduce protective gas into the reactor, in this embodiment, nitrogen is preferred;

[0097] S130, heat to 200-250°C, in this embodiment, the temperature is preferably raised to 215°C in 4 hours, and esterification and dehydration are performed;

[0098] S140, after the acid value is detected to be 100-150 mgKOH / g, reduce the temperature to 120-160°C, in this embodiment, the temperature is preferably reduced to 135°C when the solid acid value is 125 mgKOH / g;

[0099] S150, stop inputting the protective gas;

[0100] S160, add catalyst and polymerization inhibitor, in this embodiment, 6 parts of triphenylphosphine and 0.5 parts of p-hydroxyanisole are preferred, the purpose of adding the catalyst is to accelerate the reaction of glycidyl methacrylate with the remaining carboxyl groups in the previous product, and the polymerization inhibitor is added to prevent the tendency of self-polymerization of the product;

[0101] S170, introduce air, add glycidyl methacrylate in portions, and then add solvent to obtain intermediate M, in this embodiment, 85 parts of glycidyl methacrylate are preferably added in 4 portions in 2 hours; 400 parts of butyl acetate are added after being kept at 110°C for 10 hours to obtain the M intermediate, the non-volatile part NV is 50%, and the solid acid value is 40 mgKOH / g.

[0102] Preferably, the step S200 comprises

[0103] S210, put solvent into the reactor, in this embodiment, 150 parts of butyl acetate are preferred;

[0104] S220, introduce protective gas into the reactor, in this embodiment, nitrogen is preferred;

[0105] S230, drop acrylate monomer mixture, intermediate M, initiator, and solvent, in this embodiment, 113 parts of methyl methacrylate, 24 parts of isooctyl acrylate, 10 parts of isobutyl methacrylate, 11 parts of methacrylic acid, 45 parts of hydroxyethyl methacrylate, 139 parts of the M intermediate prepared in S100, 18 parts of tert-butyl peroxy-2-ethylhexanoate, and 50 parts of butyl acetate are preferred, and the dropping time is 4 hours;

[0106] S240, holding temperature 90-140°C, preferably 105°C for 2 hours in this example;

[0107] S250, adding initiator and solvent, preferably adding 3 parts of t-butyl peroxy 2-ethylhexanoate and 31 parts of propylene glycol methyl ether acetate, the initiator is added to eliminate unreacted monomers in the residual system;

[0108] S260, holding temperature 90-120°C, to obtain an acrylic acid solution containing polyester microparticles, preferably holding at 105°C for 5 hours, to obtain an acrylic acid polymer containing polyester microparticles with non-volatile content NV=50%, solid acid value 25 mg KOH / g.

[0109] Comparative Example 1: Acrylic resin ESB-1254B produced by DOW Chemical, with non-volatile content 51-53%, viscosity Z2-Z4 (25°C) Gardner, acid value 2.5-5.0 mg KOH / g.

[0110] Comparative Example 2: Polyester resin ESC-2238 produced by DOW Chemical, with non-volatile content 59-61%, viscosity T-V (25°C) Gardner, acid value less than 10 mg KOH / g. The formulation and process of Comparative Example 2 are as follows:

[0111] Production process:

[0112] S1. Add A material to the reaction kettle, pass nitrogen, and start heating;

[0113] S2. Heat to about 160°C to start dehydrating;

[0114] S3. Heat to 230°C for another 4 hours, add B material to reflux the solvent;

[0115] S4. Keep the temperature at 230°C until the viscosity reaches T-U (diluted to 60% non-volatile content with xylene), AV (solid): <12, cool to below 140°C and add C material to dilute.

[0116] Comparative Example 3

[0117] This comparative example prepared a solution containing self-extinguishing acrylic polymer microparticles, the intermediate of step S1 did not contain polyester microparticles, and the amount of glycidyl methacrylate added was 10 parts, which was less. The specific steps are as follows:

[0118] S1, synthesis of intermediate containing unsaturated C=C double bond:

[0119] Into a reactor was placed 360 parts of xylene; nitrogen was bubbled to start stirring; the temperature was raised to 110°C; a mixed solution (including 172.5 parts of styrene, 66 parts of isobutyl methacrylate, 22.5 parts of isooctyl acrylate, 63 parts of hydroxyethyl methacrylate, 19.5 parts of methacrylic acid, 18 parts of t-butyl peroxy-2-ethylhexanoate, 100 parts of xylene) was added dropwise over 3 hours; the temperature was maintained at 110°C for 1 hour; 1.5 parts of t-butyl peroxy-2-ethylhexanoate and 12 parts of xylene were added; the temperature was maintained at 110°C for 4 hours; the temperature was raised to 135°C; nitrogen was turned off; 3 parts of triphenylphosphine and 0.5 parts of p-hydroxyanisole were added; air was bubbled; 10 parts of glycidyl methacrylate was added; after the temperature was maintained at 135°C for 4 hours, M intermediate was obtained;

[0120] S2, synthesis of a solution containing target polymer microparticles:

[0121] Into a reactor was placed 360 parts of xylene; nitrogen was bubbled to start stirring; the temperature was raised to 110°C; a mixed solution (including 172.5 parts of styrene, 66 parts of isobutyl methacrylate, 22.5 parts of isooctyl acrylate, 63 parts of hydroxyethyl methacrylate, 19.5 parts of methacrylic acid, 18 parts of t-butyl peroxy-2-ethylhexanoate, 100 parts of xylene) was added dropwise over 3 hours; the temperature was maintained at 110°C for 1 hour; 1.5 parts of t-butyl peroxy-2-ethylhexanoate and 12 parts of xylene were added; the temperature was maintained at 110°C for 4 hours; the temperature was raised to 135°C; nitrogen was turned off; 3 parts of triphenylphosphine and 0.5 parts of p-hydroxyanisole were added; air was bubbled; 10 parts of glycidyl methacrylate was added; after the temperature was maintained at 135°C for 4 hours, M intermediate was obtained;

[0122] Comparative Example 4

[0123] This comparative example prepared a method for preparing a gel containing self- extinguishing acrylic polymer microparticles, including the following steps:

[0124] S1, synthesis of an intermediate containing unsaturated C=C double bonds:

[0125] Into a reactor was placed 360 parts of xylene; nitrogen was bubbled to start stirring; the temperature was raised to 110°C; a mixed solution (including 172.5 parts of styrene, 66 parts of isobutyl methacrylate, 22.5 parts of isooctyl acrylate, 63 parts of hydroxyethyl methacrylate, 19.5 parts of methacrylic acid, 18 parts of t-butyl peroxy-2-ethylhexanoate, 100 parts of xylene) was added dropwise over 3 hours; the temperature was maintained at 110°C for 1 hour; 1.5 parts of t-butyl peroxy-2-ethylhexanoate and 12 parts of xylene were added; the temperature was maintained at 110°C for 4 hours; the temperature was raised to 135°C; nitrogen was turned off; 3 parts of triphenylphosphine and 0.5 parts of p-hydroxyanisole were added; air was bubbled; 10 parts of glycidyl methacrylate was added; after the temperature was maintained at 135°C for 4 hours, M intermediate was obtained;

[0126] S2, synthesis of the colloidal substance containing target polymer microparticles:

[0127] Into a reaction kettle were put 110 parts of propylene glycol methyl ether acetate and 210 parts of isobutyl isobutyrate; nitrogen was passed to start stirring; the temperature was raised to 110°C; the M intermediate mixed solution (including 250 parts of methyl methacrylate, 80 parts of hydroxyethyl methacrylate, 40 parts of isooctyl acrylate, 13 parts of isobutyl methacrylate, 17 parts of methacrylic acid, 180 parts of the M intermediate prepared in S1, 24 parts of t-butyl peroxy-2-ethylhexanoate, 50 parts of propylene glycol methyl ether acetate, and 50 parts of isobutyl isobutyrate) was added dropwise, and the dropping was completed in 3 hours; the temperature was kept at 110°C for 1 hour; 3 parts of t-butyl peroxy-2-ethylhexanoate and 15 parts of propylene glycol methyl ether acetate were added; the temperature was kept at 110°C for 5 hours, to obtain a colloidal substance containing self-extinguishing acrylic polymer microparticles, with a solid content of 50%, a liquid acid value of 15.5 mgKOH / g, and a solid hydroxyl value of 77 mgKOH / g.

[0128] The performance tests of Examples 1-3 and Comparative Examples 1-4 were carried out, and the specific process and results are as follows:

[0129] The polymers obtained from Examples 1-3 and Comparative Examples 1-4 were respectively prepared into coatings, and the coating formula was as follows: 60 parts of polymer (diluted to NV=50% with xylene), 20 parts of black paste, 20 parts of butyl acetate, 0.3 parts of silicone leveling agent (BYK-331), and 10 parts of curing agent (N-3390).

[0130] The above coating formula was prepared into varnish, which was sprayed on tinplate, baked at 80°C for 30 min, and then placed for 7 days to detect the film performance. The gloss was GB / T9754-2007, the pencil hardness was GB / T6739-2006, and the flexibility was GB / T1731-2020. The test results are as follows:

[0131] From the test results of the above examples and comparative examples, it can be seen that the greater the gloss value, the higher the gloss; the pencil hardness increases from F, H, 2H, 3H in turn; the lower the flexibility value, the better the flexibility. The gloss of examples 1-3 is maintained above 90, the hardness is maintained at 2H and above, and the flexibility is stable within 1. Comparative example 1 is a conventional acrylic resin, although the gloss is above 90, but due to the influence of the structure and molecular weight of the acrylic resin itself, the flexibility is poor and the hardness is not high. Comparative example 2 is a conventional polyester resin, the gloss and flexibility are acceptable, but the hardness is low. Comparative example 3 is a modified acrylic resin, the gloss is low, and the hardness and flexibility are not very high. Comparative example 4 is a modified acrylic resin using a poor solvent, the hardness is high, but the gloss is very low, and the flexibility is also poor. Therefore, the acrylic polymer containing polyester microparticles of the present application not only has high gloss and hardness after being made into paint, but also significantly improves the flexibility.

[0132] The above examples only express certain embodiments of the present application, which are described in more detail and in more detail, but should not be construed as limiting the scope of the present patent; it should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application; therefore, the scope of protection of the present patent should be subject to the appended claims.

Claims

1. A process for the preparation of a polyester-containing microparticle-containing acrylic polymer, characterized by: The method steps are as follows: S100, synthesis of intermediate M; S200, synthesis of acrylic polymer solution; The intermediate M is an intermediate containing unsaturated C=C double bond; the step S100 comprises S110, feeding dihydric alcohol and diacid into the reactor; S120, feeding protective gas into the reactor; S130, heating to 200-250℃ to perform esterification and dehydration reaction; S140, detecting acid value and reducing temperature to 120-160℃ after the acid value is 100-150 mgKOH / g; S150, stopping feeding protective gas; S160, adding catalyst and polymerization inhibitor; S170, feeding air and adding glycidyl methacrylate in batches, and then adding solvent to obtain intermediate M after holding at 90-105℃; The step S200 comprises S210, feeding solvent into the reactor; S220, feeding protective gas into the reactor; S230, dropping acrylic monomer mixture, intermediate M, initiator and solvent; S240, holding at 90-140℃; S250, adding initiator and solvent; S260, holding at 90-120℃ to obtain acrylic solution containing polyester microparticles.

2. The method of preparing an acrylic polymer containing polyester microparticles according to claim 1, characterized by: The dihydric alcohol in the step S110 is one or more of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, neopentyl glycol, and 1,4-cyclohexanedimethanol; and the diacid is one or more of phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid.

3. The method for preparing an acrylic polymer containing polyester microparticles according to claim 1, characterized in that: The solvent is one or more of toluene, xylene, butyl acetate, propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, and ethylene glycol butyl ether acetate.

4. The method for preparing an acrylic polymer containing polyester microparticles according to claim 1, characterized in that: The catalyst in the step S160 is at least one of triphenylphosphine, ethyl triphenylphosphonium iodide, tetrabutylphosphonium chloride, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, triethylamine, triethanolamine, tetrabutylammonium bromide, triethylbenzylammonium chloride, and chromium trichloride, and the polymerization inhibitor is one or more of p-hydroxyanisole, methylhydroquinone, and 2,6-di-tert-butyl-p-cresol.

5. The method for preparing an acrylic polymer containing polyester microparticles according to claim 2, characterized in that: The initiator in the step S230 is one or more of azobisisovaleronitrile, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, benzoyl peroxide, tert-butyl peroxybenzoate, 3,5,5-trimethylhexyl tert-butyl peroxide; and the acrylic monomer mixture is one or more of styrene, methyl methacrylate, propylene isooctyl ester, methyl methacrylate n-butyl ester, hydroxyethyl methacrylate, acrylic acid, methacrylic acid, cyclohexyl methacrylate, butyl acrylate, ethyl methacrylate, ethyl acrylate, methyl acrylate, methacrylate isooctyl ester, methacrylate lauryl ester, isobutyl acrylate, tert-butyl acrylate, tert-butyl methacrylate, hydroxypropyl methacrylate and hydroxypropyl acrylate.

6. The method of claim 2, wherein the polyester microparticle-containing acrylic polymer is prepared by the steps of: (a) preparing a polyester microparticle-containing acrylic polymer by the method of claim 1; (b) adding a solvent to the polyester microparticle-containing acrylic polymer; and (c) drying the polyester microparticle-containing acrylic polymer. The non-volatile content NV of the intermediate M obtained in the step S100 is 50%, and the non-volatile content NV of the polyester microparticle-containing acrylic polymer obtained in the step S200 is 50%.

7. The method for preparing an acrylic polymer containing polyester microparticles according to claim 2, characterized in that: In the step S160, the mass of the catalyst is 8‰-18‰ of the sum of the masses of the dihydric alcohol and the diacid, and the mass of the polymerization inhibitor is 0.5‰-2‰ of the sum of the masses of the dihydric alcohol and the diacid; and in the step S230, the mass ratio of the acrylic monomer mixture, the intermediate M and the initiator is 30-40:15-25:1-4.

8. The method for preparing an acrylic polymer containing polyester microparticles according to claim 2, characterized in that: In the step S250, the amount of the added initiator is 8‰-55‰ of the sum of the masses of the acrylic monomer mixture and the intermediate M; the holding time in the step S240 is 1-4 hours, and the holding time in the step S260 is 4-12 hours.

9. The method for preparing an acrylic polymer containing polyester microparticles according to claim 2, characterized in that: In the step 110, the mass ratio of the dihydric alcohol and the diacid is configured such that, after the dihydric alcohol is completely reacted, the acid value of the mixed solution is 110-160 mgKOH / g; and in the step S170, the mass of the added glycidyl methacrylate is configured to reduce the acid value in the step S140 to 20-40 mgKOH / g.

10. The method according to claim 2, characterized in that: In the step S210, the mass percentage of the added solvent is 25-35%; In the step S230, the mass percentage of the added acrylic monomer mixture is 30-40%, the mass percentage of the intermediate M is 15-25%, the mass percentage of the initiator is 1-4%, and the mass percentage of the solvent is 8-10%; In the step S250, the mass percentage of the added initiator is 0.2-0.6%, and the mass percentage of the solvent is 5-10%; The mass percentage is the percentage of the mass of the entire step S200.

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