阅读说明：本技术 一种高亮涂料及其制备方法 (High-brightness coating and preparation method thereof ) 是由 费邦忠 胡先海 查全达 王平 于 2021-09-15 设计创作，主要内容包括：本发明公开了一种高亮涂料及其制备方法,属于涂料技术领域。且该涂料包括以下重量份的原料：改性聚酯树脂40-60份、填料15-30份、色料8-16份、三缩水甘油异氰尿酸酯1.5-3份、促进剂4-7份。且本发明利用对苯二甲酸和全氟己基二元醇的聚合反应,形成了羧基型含氟聚酯,首先该聚酯中含有含氟支链,使得聚酯链中的酯基被含氟支链包围起来,进而提高聚酯的耐水性能和耐酸碱性；同时利用了羧基型含氟聚酯和二元胺单体的缩聚反应,使聚酯的分子链接入了硅氧烷支链,利用硅氧烷支链良好的柔软性、相容性,进而提高了改性聚酯树脂与填料、色料、促进剂的相容性。(The invention discloses a high-brightness coating and a preparation method thereof, and belongs to the technical field of coatings. The coating comprises the following raw materials in parts by weight: 40-60 parts of modified polyester resin, 15-30 parts of filler, 8-16 parts of pigment, 1.5-3 parts of triglycidyl isocyanurate and 4-7 parts of accelerator. The carboxyl fluorine-containing polyester is formed by utilizing the polymerization reaction of terephthalic acid and perfluorohexyl dihydric alcohol, and firstly, the polyester contains a fluorine-containing branched chain, so that ester groups in a polyester chain are surrounded by the fluorine-containing branched chain, and the water resistance and the acid and alkali resistance of the polyester are further improved; meanwhile, the polycondensation reaction of the carboxyl fluorine-containing polyester and diamine monomers is utilized, so that the siloxane branched chain is connected to the molecular chain of the polyester, and the good flexibility and compatibility of the siloxane branched chain are utilized, so that the compatibility of the modified polyester resin with the filler, the pigment and the accelerator is improved.)

1. A high-brightness paint is characterized in that: the feed comprises the following raw materials in parts by weight: 40-60 parts of modified polyester resin, 15-30 parts of filler, 8-16 parts of pigment, 1.5-3 parts of triglycidyl isocyanurate and 4-7 parts of accelerator;

the modified polyester resin is prepared by the following steps:

s1, adding terephthalic acid, perfluorohexyl diol and p-toluenesulfonic acid into a reaction kettle, heating to 215 ℃ under the protection of nitrogen, reacting for 5 hours, cooling, reducing pressure, taking out a reactant, washing, decompressing, steaming and drying to obtain carboxyl fluorine-containing polyester;

and S2, stirring the mixture of the carboxyl fluorine-containing polyester, EDC and NHS, water and DMF for 1h at 50 ℃ in a nitrogen atmosphere, then adding a diamine monomer, heating to 76 ℃ in the nitrogen atmosphere, stirring for reacting for 6h, cooling to room temperature, precipitating, filtering, washing, and carrying out reduced pressure rotary evaporation to obtain the modified polyester resin.

2. A high brightness coating according to claim 1, characterized in that: in step S1, the molar ratio of terephthalic acid to perfluorohexyl glycol is: 2-2.3: 1.

3. a high brightness coating according to claim 1, characterized in that: in step S2, the dosage ratio of the carboxyl fluorine-containing polyester, the diamine monomer, the mixture of EDC and NHS, water and DMF is 100 mg: 110-150 mg: 5-10 mg: 2-4 mg: 80-150 mL.

4. A high brightness coating according to claim 1, characterized in that: the diamine monomer is prepared by the following steps:

dissolving the organic silicon modified aniline derivative in dichloromethane, adding trifluoroacetic acid, reacting at room temperature for 12h, carrying out reduced pressure distillation to obtain a residue, dissolving with water, adjusting the pH value of the solution to 11.5, then extracting, combining organic phases, drying with anhydrous magnesium sulfate, filtering, concentrating, and carrying out vacuum drying to obtain a diamine monomer.

5. A highlighting coating according to claim 4, wherein: the dosage ratio of the organic silicon modified aniline derivative to the dichloromethane to the trifluoroacetic acid is 1-1.2 mmol: 10-30 mL: 1-2 mL.

6. A highlighting coating according to claim 4, wherein: the organic silicon modified aniline derivative is prepared by the following steps:

c1, aniline derivatives, (Boc)₂Mixing O, triethylamine and dichloromethane, stirring and reacting for 36 hours at room temperature in a nitrogen atmosphere, and carrying out aftertreatment to obtain an intermediate 1;

c2, stirring the intermediate 1 and glacial acetic acid uniformly, adding 3-glycidyl ether oxypropyl trimethoxy silane and triethylamine under the protection of nitrogen, heating to 143 ℃, reacting for 5h, and performing rotary evaporation to obtain the organic silicon modified aniline derivative.

7. A highlighting coating according to claim 6, wherein: aniline derivative in step C1, (Boc)₂The dosage ratio of O, triethylamine and dichloromethane is 0.01 mol: 0.02-0.023 mol: 0.02 mol: 50-100 mL; in the step C2, the mol ratio of the intermediate 1, the 3-glycidyl ether oxy propyl trimethoxy silane and the triethylamine is 1: 1.1-1.3: 1.3-1.5.

8. A method for preparing a high-brightness paint according to claim 1, characterized in that:

the modified polyester resin, the filler, the pigment, the triglycidyl isocyanurate and the accelerator are uniformly mixed, and the high-brightness coating is obtained through extrusion, tabletting, crushing and screening.

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to a high-brightness coating and a preparation method thereof.

Background

The polyester resin coating is a coating which takes polyester resin as a main film forming substance and is formed by polycondensing polyalcohol and polybasic acid. Polyester resin coatings are often classified into unsaturated polyester coatings, saturated polyester coatings, and terephthalic acid polyester coatings. Among them, a saturated polyester resin coating is generally used, which is a film formed by crosslinking and curing a polyester resin containing a terminal hydroxyl functional group as a base material with a resin such as isocyanate, amino resin, or the like. The formed coating film has the characteristics of high glossiness, good fullness, high hardness, good flexibility, good wear resistance and heat resistance, and good gloss retention and color retention. Therefore, the method is widely applied to the fields of metal, automobiles, outdoor decoration and the like. However, polyester coating has a large amount of ester groups, which results in poor water resistance and influences the application range of the coating.

Therefore, the invention provides a high-brightness coating and a preparation method thereof.

Disclosure of Invention

The invention aims to provide a high-brightness coating and a preparation method thereof.

The technical problems to be solved by the invention are as follows: the existing saturated polyester coating has poor water resistance.

The purpose of the invention can be realized by the following technical scheme:

a high-brightness coating comprises the following raw materials in parts by weight: 40-60 parts of modified polyester resin, 15-30 parts of filler, 8-16 parts of pigment, 1.5-3 parts of triglycidyl isocyanurate and 4-7 parts of accelerator.

Furthermore, the accelerator is one or a mixture of several of a leveling agent, a degassing agent and a brightener in any ratio.

Further, the modified polyester resin is prepared by the following steps:

s1, adding terephthalic acid, perfluorohexyl dihydric alcohol and p-toluenesulfonic acid into a reaction kettle, heating to 215 ℃ under the protection of nitrogen, stirring, dehydrating, esterifying for 5 hours, cooling, reducing pressure, taking out a reactant, washing the reactant with ethyl acetate for 2-3 times, taking an organic layer, reducing pressure, performing rotary evaporation, and drying at 50 ℃ to obtain the carboxyl fluorine-containing polyester, wherein the molar ratio of the terephthalic acid to the perfluorohexyl dihydric alcohol is controlled as follows: 2-2.3: 1, so as to produce carboxyl fluorine-containing polyester, wherein the adding mass of the p-toluenesulfonic acid is 1.5 to 4 percent of that of the terephthalic acid;

the structural formula of the carboxyl fluorine-containing polyester is shown as follows:

s2, stirring carboxyl fluorine-containing polyester, a mixture of EDC and NHS, water and DMF for 1h at 50 ℃ in nitrogen atmosphere, then adding diamine monomer, heating to 76 ℃ in nitrogen atmosphere, stirring for reaction for 6h, cooling to room temperature, precipitating with ethanol, filtering, washing with ethyl acetate for 2-3 times, and carrying out reduced pressure rotary evaporation to obtain the modified polyester resin, wherein the dosage ratio of the carboxyl fluorine-containing polyester to the diamine monomer to the mixture of EDC and NHS to the mixture of water and DMF is 100 mg: 110-150 mg: 5-10 mg: 2-4 mg: 80-150mL, wherein the mass ratio of EDC to NHS in the mixture of EDC and NHS is 1: 1-1.3.

In the above reaction, the molecular chain of the carboxyl type fluorine-containing polyester is extended by the polycondensation reaction of the carboxyl type fluorine-containing polyester and the diamine monomer, so that the molecular chain is connected with the structure of the diamine monomer.

Further, the perfluorohexyl glycol is prepared by the following steps:

s11, adding perfluorohexyliodoalkane and allyl acetate into a four-neck flask with a condenser, a thermometer, a drying tube and a stirring paddle, heating to 93 ℃ and keeping for 3min, adding benzoyl peroxide, continuing to react for 30min after the temperature of the reaction rapidly rises to 150 ℃ after the heat release is suddenly increased, adding n-hexane and potassium hydroxide when the reaction temperature is reduced to 80 ℃, reacting for 6h, cooling and filtering, washing with n-hexane, carrying out reduced pressure distillation on the filtrate to collect 77-80 ℃/40mmHg fractions, obtaining 3-perfluorohexyl-1, 2-epoxypropane, wherein the dosage ratio of perfluorohexyliodoalkane, allyl acetate and n-hexane is 0.1 mol: 0.1-0.13 mol: 100-200mL, wherein the adding mass of the benzoyl peroxide is 0.1-0.3% of the adding mass of the perfluorohexyliodoalkane, and the adding mass of the potassium hydroxide is 1-5% of the adding mass of the perfluorohexyliodoalkane;

s12, adding 3-perfluoro-n-hexyl-1, 2-epoxypropane, methanol and 28% ammonia water by mass into a completely sealed flask, stirring for 12 hours, removing the ammonia water and the methanol by rotary evaporation, then adding the 3-perfluoro-n-hexyl-1, 2-epoxypropane and the methanol again, continuing to react for 8 hours, dissolving a reaction crude product with diethyl ether, washing with distilled water, separating to obtain an organic layer, drying with anhydrous sodium sulfate, performing suction filtration, removing the methanol by rotary evaporation, recrystallizing with chloroform, cooling to obtain perfluoro-hexyl dihydric alcohol, and performing ring-opening reaction by using an epoxy group and ammonia, wherein the dosage ratio of the 3-perfluoro-n-hexyl-1, 2-epoxypropane, the methanol and the ammonia water is 0.1 mol: 20-40 mL: 80-150mL, the amount of the 3-perfluoro-n-hexyl-1, 2-epoxypropane added again is equal to the amount of the 3-perfluoro-n-hexyl-1, 2-epoxypropane added for the first time, and the amount of the methanol added again is one tenth of the amount of the methanol added for the first time.

The molecular structural formula of the perfluorohexyl diol is shown as follows:

further, the diamine monomer is prepared by the following steps:

x1, adding hydroxymethylbenzaldehyde, aniline and aniline hydrochloride into a four-neck flask with a stirring magneton and a nitrogen introducing device, after being stirred evenly, the reaction system is heated to 113 ℃ by an oil bath pot and reacts for 2 hours at constant temperature, then heating the reaction system to 152 ℃, continuing to react for 1.5h at constant temperature, after the reaction is finished, reducing the pressure and distilling for 30min when the system is cooled to 55 ℃, then adding 2mol/L dilute hydrochloric acid to dissolve the residual substances, filtering, taking filtrate, neutralizing the filtrate with 2mol/L dilute sodium hydroxide solution until the pH value is 7-8, generating precipitate at the moment, filtering after the precipitate is completely precipitated, taking filter cake, repeatedly washing for 3-5 times to obtain a crude product, recrystallizing twice with ethanol/water, finally drying in vacuum for 24h at 60 ℃ to obtain aniline derivatives, wherein, the dosage ratio of the hydroxymethylbenzaldehyde to the aniline hydrochloride is 0.1 mol: 0.11-0.13 mol: 4-6 mL;

the molecular structural formula of the aniline derivative is shown as follows:

x2 Aniline derivative, (Boc)₂Adding O, triethylamine and dichloromethane into a three-neck flask with a stirrer and a condensing device, stirring and reacting for 36h at room temperature under the atmosphere of nitrogen, performing suction filtration to collect filtrate, washing for 3 times with saturated saline solution, drying over night with anhydrous sodium sulfate, filtering, concentrating, and drying in vacuum to constant weight to obtain an intermediate 1, wherein (Boc) is utilized₂Reaction of O with amino groups, of which aniline derivatives, (Boc)₂The dosage ratio of O, triethylamine and dichloromethane is 0.01 mol: 0.02-0.023 mol: 0.02 mol: 50-100 mL;

the molecular structural formula of the intermediate 1 is shown as follows:

x3, adding the intermediate 1 and glacial acetic acid into a four-neck flask with a stirrer, a condensing device and a nitrogen protection device, uniformly stirring, introducing nitrogen to replace air, adding 3-glycidyl ether oxypropyl trimethoxysilane and triethylamine, heating to 143 ℃, reacting for 5 hours, and performing rotary evaporation to remove the glacial acetic acid to obtain the organic silicon modified aniline derivative, wherein the molar ratio of the intermediate 1, the 3-glycidyl ether oxypropyl trimethoxysilane to the triethylamine is 1: 1.1-1.3: 1.3-1.5;

the molecular structural formula of the organic silicon modified aniline derivative is as follows:

in the reaction, a siloxane chain is connected to the aniline derivative by utilizing the reaction of hydroxyl in the intermediate 1 and epoxy in 3-glycidyl ether oxypropyl trimethoxy silane, so as to obtain the organosilicon modified aniline derivative;

x4, dissolving the organosilicon modified aniline derivative in dichloromethane, adding trifluoroacetic acid, reacting at room temperature for 12h, removing dichloromethane by reduced pressure distillation, dissolving the obtained residue with water, adjusting the pH to 11.5 by using 1M sodium hydroxide solution, extracting with ethyl acetate, combining organic phases, drying with anhydrous magnesium sulfate, filtering, concentrating the filtrate, drying in vacuum to constant weight to obtain diamine monomer, and performing deprotection reaction by using tert-butyloxycarbonyl, wherein the usage ratio of the organosilicon modified aniline derivative, the dichloromethane and the trifluoroacetic acid is 1-1.2 mmol: 10-30 mL: 1-2 mL.

A preparation method of a high-brightness coating comprises the following steps:

the modified polyester resin, the filler, the pigment, the triglycidyl isocyanurate and the accelerator are uniformly mixed, extruded by a double-screw melt extruder, tabletted, crushed and sieved by a 150-mesh sieve to obtain the high-brightness coating.

The invention has the beneficial effects that:

according to the invention, the carboxyl fluorine-containing polyester is formed by utilizing the polymerization reaction of terephthalic acid and perfluorohexyl glycol, firstly, the polyester contains a fluorine-containing branched chain, and the fluorine-containing branched chain is easy to migrate to the periphery of a main chain due to the low surface energy property of fluorine, so that a layer of fluorine-containing chain layer is formed, ester groups in a polyester chain are surrounded by the fluorine-containing branched chain, and the water resistance and the acid and alkali resistance of the polyester are further improved due to the high water resistance and the high acid and alkali resistance of the fluorine-containing chain;

the molecular chain of the carboxyl fluorine-containing polyester is prolonged by utilizing the polycondensation reaction of the carboxyl fluorine-containing polyester and the diamine monomer, so that the molecular chain is connected with the structure of the diamine monomer, the purpose is to utilize the siloxane branched chain in the structure of the diamine monomer, so that the molecular chain of the modified polyester resin is introduced into the siloxane branched chain, the compatibility of the modified polyester resin with a filler, a pigment and an accelerator is improved by utilizing the good flexibility and compatibility of the siloxane branched chain, the processing performance of the corresponding coating is improved, and the siloxane branched chain is similar to the fluorine-containing branched chain and is easy to surround the periphery of the polyester main chain to form a silicon oxide layer, so that the water resistance and the acid and alkali resistance of the polyester are improved.

In conclusion, the high-brightness coating provided by the invention is mainly composed of the modified polyester resin, has the characteristics of a saturated polyester coating film, namely high glossiness and good fullness, and overcomes the defect of poor water resistance of the polyester coating film due to a large amount of ester groups.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the perfluorohexyl glycol is prepared by the following steps:

s11, adding 0.1mol of perfluorohexyliodoalkane and 0.1mol of allyl acetate into a four-neck flask with a condensing tube, a thermometer, a drying tube and a stirring paddle, heating to 93 ℃ and keeping for 3min, adding benzoyl peroxide with the mass being 0.1% of that of the perfluorohexyliodoalkane, continuing to react for 30min after the rapid reaction heat release is increased to 150 ℃, adding 100mL of n-hexane and 1% of potassium hydroxide with the mass being that of the perfluorohexyliodoalkane when the reaction temperature is reduced to 80 ℃, reacting for 6h, cooling and filtering, washing with the n-hexane, distilling the filtrate under reduced pressure to collect 77 ℃/40mmHg fraction, and obtaining 3-perfluoro-hexyl-1, 2-propylene oxide;

s12, adding 0.1mol of 3-perfluoro-n-hexyl-1, 2-epoxypropane, 20mL of methanol and 80mL of ammonia water with the mass fraction of 28%, stirring for 12h, removing the ammonia water and the methanol by rotary evaporation, then adding 0.1mol of 3-perfluoro-n-hexyl-1, 2-epoxypropane and 2mL of methanol again, continuing to react for 8h, dissolving the reaction crude product with diethyl ether, washing with distilled water, separating liquid, taking an organic layer, drying with anhydrous sodium sulfate, filtering, removing the methanol by rotary evaporation, recrystallizing with chloroform, and cooling to obtain the perfluorohexyl diol.

Example 2:

the perfluorohexyl glycol is prepared by the following steps:

s11, adding 0.1mol of perfluorohexyliodoalkane and 0.13mol of allyl acetate into a four-neck flask with a condensing tube, a thermometer, a drying tube and a stirring paddle, heating to 93 ℃ and keeping for 3min, adding benzoyl peroxide with the mass being 0.3% of that of the perfluorohexyliodoalkane, continuing to react for 30min after the rapid reaction heat release is increased to 150 ℃, adding 200mL of n-hexane and 1-5% of potassium hydroxide with the mass being that of the perfluorohexyliodoalkane when the reaction temperature is reduced to 80 ℃, reacting for 6h, cooling and filtering, washing with the n-hexane, distilling the filtrate under reduced pressure and collecting 80 ℃/40mmHg fractions, thus obtaining 3-perfluoro-n-hexyl-1, 2-propylene oxide;

s12, adding 0.1mol of 3-perfluoro-n-hexyl-1, 2-epoxypropane, 40mL of methanol and 150mL of ammonia water with the mass fraction of 28%, stirring for 12h, removing the ammonia water and the methanol by rotary evaporation, then adding 0.1mol of 3-perfluoro-n-hexyl-1, 2-epoxypropane and 4mL of methanol again, continuing to react for 8h, dissolving the reaction crude product with diethyl ether, washing with distilled water, separating liquid to obtain an organic layer, drying with anhydrous sodium sulfate, filtering, removing the methanol by rotary evaporation, recrystallizing with chloroform, and cooling to obtain the perfluorohexyl diol.

Example 3:

the diamine monomer is prepared by the following steps:

x1, adding 0.1mol of hydroxymethyl benzaldehyde, 0.11mol of aniline and 4mL of aniline hydrochloride into a four-neck flask with a stirring magneton and a nitrogen introducing device, uniformly stirring, heating a reaction system to 113 ℃ by using an oil bath pot, reacting at a constant temperature for 2 hours, heating the reaction system to 152 ℃, continuing to react at the constant temperature for 1.5 hours, after the reaction is finished, reducing the temperature of the system to 55 ℃, distilling under reduced pressure for 30 minutes, adding 2mol/L of dilute hydrochloric acid to dissolve the rest substances, filtering, neutralizing the filtrate with 2mol/L of dilute sodium hydroxide solution until the pH is 7, generating a precipitate, filtering after the precipitate is completely, repeatedly washing a filter cake for 3 times, recrystallizing a crude product with ethanol/water for two times, and finally drying at 60 ℃ in vacuum for 24 hours to obtain an aniline derivative;

x2, 0.01mol of an aniline derivative, 0.02mol (Boc)₂O, 0.02mol triethylamine and 50mL dichloromethane are added into a three-neck flask with a stirrer and a condensing deviceIn the nitrogen atmosphere, stirring and reacting for 36h at room temperature, carrying out suction filtration and collecting filtrate, washing for 3 times by using saturated saline solution, drying over night by using anhydrous sodium sulfate, filtering, concentrating, and drying in vacuum to constant weight to obtain an intermediate 1;

x3, adding 0.1mol of the intermediate 1 and glacial acetic acid into a four-neck flask with a stirrer, a condensing device and a nitrogen protection device, uniformly stirring, introducing nitrogen to replace air, adding 0.11mol of 3-glycidyl ether oxypropyl trimethoxysilane and 0.13mol of triethylamine, heating to 143 ℃, reacting for 5 hours, and performing rotary evaporation to remove the glacial acetic acid to obtain an organic silicon modified aniline derivative;

x4, dissolving 1mmol of organic silicon modified aniline derivative in 10mL of dichloromethane, adding 1mL of trifluoroacetic acid, reacting at room temperature for 12h, carrying out reduced pressure distillation to remove dichloromethane, dissolving the obtained residue with water, adjusting the pH to 11.5 with 1M sodium hydroxide solution, extracting with ethyl acetate, combining organic phases, drying with anhydrous magnesium sulfate, filtering, concentrating the filtrate, and drying in vacuum to constant weight to obtain the diamine monomer.

Example 4:

the diamine monomer is prepared by the following steps:

x1, adding 0.1mol of hydroxymethyl benzaldehyde, 0.13mol of aniline and 6mL of aniline hydrochloride into a four-neck flask with a stirring magneton and a nitrogen introducing device, uniformly stirring, heating a reaction system to 113 ℃ by using an oil bath pot, reacting at a constant temperature for 2 hours, heating the reaction system to 152 ℃, continuing to react at the constant temperature for 1.5 hours, after the reaction is finished, reducing the temperature of the system to 55 ℃, distilling under reduced pressure for 30 minutes, adding 2mol/L of dilute hydrochloric acid to dissolve the rest substances, filtering, neutralizing the filtrate with 2mol/L of dilute sodium hydroxide solution until the pH is 8, generating a precipitate, filtering after the precipitate is completely, repeatedly washing a filter cake for 3-5 times, recrystallizing a crude product with ethanol/water for two times, and finally drying at 60 ℃ in vacuum for 24 hours to obtain an aniline derivative;

x2, 0.01mol of an aniline derivative, 0.023mol of (Boc)₂O, 0.02mol of triethylamine and 100mL of dichloromethane are added into a three-neck flask with a stirrer and a condensing device, stirred and reacted for 36 hours at room temperature under the atmosphere of nitrogen, filtrate is collected by suction filtration and washed for 3 times by saturated saline solution,drying over night with anhydrous sodium sulfate, filtering, concentrating, and vacuum drying to constant weight to obtain intermediate 1;

x3, adding 0.1mol of the intermediate 1 and glacial acetic acid into a four-neck flask with a stirrer, a condensing device and a nitrogen protection device, uniformly stirring, introducing nitrogen to replace air, adding 0.13mol of 3-glycidyl ether oxypropyl trimethoxysilane and 0.15mol of triethylamine, heating to 143 ℃, reacting for 5 hours, and performing rotary evaporation to remove the glacial acetic acid to obtain an organic silicon modified aniline derivative;

x4, dissolving 1.2mmol of organic silicon modified aniline derivative in 30mL of dichloromethane, adding 2mL of trifluoroacetic acid, reacting at room temperature for 12h, distilling under reduced pressure to remove dichloromethane, dissolving the obtained residue with water, adjusting the pH to 11.5 with 1M sodium hydroxide solution, extracting with ethyl acetate, combining organic phases, drying with anhydrous magnesium sulfate, filtering, concentrating the filtrate, and drying in vacuum to constant weight to obtain the diamine monomer.

Example 5:

the modified polyester resin is prepared by the following steps:

s1, adding 0.2mol of terephthalic acid, 0.1mol of perfluorohexyl diol prepared in example 1 and p-toluenesulfonic acid with the mass being 1.5% of that of the terephthalic acid into a reaction kettle, heating to 215 ℃ under the protection of nitrogen, stirring, dehydrating, esterifying for 5 hours, cooling, reducing pressure, taking out a reactant, washing the reactant with ethyl acetate for 2 times, taking an organic layer, carrying out reduced pressure rotary evaporation, and drying at 50 ℃ to obtain carboxyl type fluorine-containing polyester;

s2, stirring 100mg of carboxyl fluorine-containing polyester, 5mg of a mixture of EDC and NHS, 2mg of water and 80mLDMF for 1h at 50 ℃ in a nitrogen atmosphere, then adding 110mg of diamine monomer prepared in example 3, heating to 76 ℃ in the nitrogen atmosphere, stirring for reacting for 6h, cooling to room temperature, precipitating with ethanol, filtering, washing with ethyl acetate for 2 times, and carrying out reduced pressure rotary evaporation to obtain the modified polyester resin, wherein the mass ratio of EDC to NHS in the mixture of EDC and NHS is 1: 1.

example 6:

the modified polyester resin is prepared by the following steps:

s1, adding 0.23mol of terephthalic acid, 0.1mol of perfluorohexyl diol prepared in example 2 and 4% p-toluenesulfonic acid by mass of the terephthalic acid into a reaction kettle, heating to 215 ℃ under the protection of nitrogen, stirring, dehydrating, esterifying for 5 hours, cooling, reducing pressure, taking out a reactant, washing the reactant with ethyl acetate for 3 times, taking an organic layer, reducing pressure, performing rotary evaporation, and drying at 50 ℃ to obtain carboxyl fluorine-containing polyester;

s2, stirring 100mg of carboxyl fluorine-containing polyester, 10mg of mixture of EDC and NHS, 4mg of water and 150mLDMF for 1h at 50 ℃ in a nitrogen atmosphere, then adding 150mg of diamine monomer prepared in example 4, heating to 76 ℃ in the nitrogen atmosphere, stirring for reacting for 6h, cooling to room temperature, precipitating with ethanol, filtering, washing with ethyl acetate for 3 times, and carrying out reduced pressure rotary evaporation to obtain the modified polyester resin, wherein the mass ratio of EDC to NHS in the mixture of EDC and NHS is 1: 1.3.

example 7:

a high-brightness coating comprises the following raw materials in parts by weight: 40 parts of modified polyester resin prepared in example 5, 15 parts of filler, 8 parts of pigment, 1.5 parts of triglycidyl isocyanurate and 4 parts of accelerator, wherein the filler is titanium dioxide and barium sulfate according to a mass ratio of 2: 13, the accelerant is a flatting agent and a brightener in a mass ratio of 1: 1, the flatting agent is MF-8501, and the brightener is acrylate copolymer.

The high-brightness coating is prepared by the following steps:

the modified polyester resin prepared in example 5, the filler, the pigment, the triglycidyl isocyanurate and the accelerator are stirred and mixed uniformly in a high-speed mixer at 1000r/min, extruded by a double-screw melt extruder, tabletted, crushed and sieved by a 150-mesh sieve to obtain the high-brightness coating.

Example 8:

a high-brightness coating comprises the following raw materials in parts by weight: 50 parts of modified polyester resin prepared in example 6, 25 parts of filler, 12 parts of pigment, 2 parts of triglycidyl isocyanurate and 6 parts of accelerator, wherein the filler is titanium dioxide and barium sulfate in a mass ratio of 1: 4, the accelerant is a flatting agent, a degassing agent and a brightener in a mass ratio of 2: 3: 3, the flatting agent is MF-8501, the degassing agent is benzoin, and the brightener is acrylate copolymer.

The high-brightness coating is prepared by the following steps: the procedure is as in example 7.

Example 9:

a high-brightness coating comprises the following raw materials in parts by weight: 60 parts of modified polyester resin prepared in example 5, 30 parts of filler, 16 parts of pigment, 3 parts of triglycidyl isocyanurate and 7 parts of accelerator, wherein the filler is titanium dioxide and barium sulfate according to a mass ratio of 3: 7, the accelerant is a flatting agent, a degassing agent and a brightener in a mass ratio of 5: 4: 4, the flatting agent is MF-8501, the degassing agent is benzoin, and the brightener is acrylate copolymer.

The high-brightness coating is prepared by the following steps: the procedure is as in example 7.

Comparative example 1:

the modified polyester resin was the carboxyl type fluorine-containing resin prepared in step S1 of example 5.

Comparative example 2:

the modified polyester resin was the aniline derivative prepared in step X1 in example 1 and the carboxyl type fluorine-containing resin prepared in step S1 in example 6, which were prepared according to the preparation method of step S2 in example 6.

Comparative example 3:

a high-brightness coating comprises the following raw materials in parts by weight: 40 parts of modified polyester resin prepared in comparative example 1, 15 parts of filler, 8 parts of coloring material, 1.5 parts of triglycidyl isocyanurate, 4 parts of accelerator, and the rest is the same as in example 7.

Comparative example 4:

a high-brightness coating comprises the following raw materials in parts by weight: 50 parts of modified polyester resin prepared in comparative example 2, 25 parts of filler, 12 parts of pigment, 2 parts of triglycidyl isocyanurate and 6 parts of accelerator, and the rest is the same as in example 8.

Example 10:

the coatings obtained in examples 7 to 9 and comparative examples 3 to 4 were electrostatically sprayed on parts under the same electrostatic spraying conditions and at a voltage current of 0.5KV/80UA for curing in an oven at 160 ℃ for 20min to give a final coating film having a smooth surface without orange peel, and then subjected to the following performance tests:

boiling resistance: experimental method of immersing in boiling water in GB/T1733-1993 determination of water resistance of paint film;

smoke corrosion resistance: according to the test of GB/T1771-2007 multi-performance determination of neutral salt resistance of colored paint and varnish, the salt spray corrosion resistance spraying pressure is 0.098Mpa, and the salt solution concentration is 5%; the pH is 6.5-7.2, the temperature of the test box is 35 ℃, the temperature of the saturated barrel is 45 ℃, and the spray amount is 2mL/80cm²H, the spraying time is 500 h;

alkali resistance: immersing the coated part into a sodium hydroxide aqueous solution with the mass concentration of 5%, soaking for 240h, and observing whether the coating falls off, foams and has color difference;

acid resistance: soaking the coated part in 3% hydrochloric acid for 240 hr, and observing whether the coating falls off, foams and color difference;

the above test data are shown below.

From the data, the high-brightness coating provided by the invention has excellent water resistance and acid and alkali resistance.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.