Epoxy cured polyester resin used for powdery paint having high surface decorative performance and high water resistance and preparation method thereof

Abstract

The invention relates to epoxy cured polyester resin used for a powdery paint having high surface decorative performance and high water resistance and a preparation method thereof. The provided polyester resin has appropriate glass-transition temperature, a prepared powdery paint film has excellent dynamic mechanical properties, high surface decoration performance and high water resistance. The polyester resin is prepared by melt phase polycondensation of the raw materials of polyol, polyprotic acid, an acidulate agent, an esterification catalyst, an anti-oxidant and a curing accelerator. The method of the polyester resin comprises the following steps: 1) the polyol is delivered into a reaction kettle at a needed ratio, rapid heating esterification is carried out, water is generated, and is removed via distillation; 2) temperature is increased gradually, and an obtained material is maintained to be clear; 3) sample examination is carried out; 4) negative pressure polycondensation is carried out; and 5) cooling is carried out, the antioxidant and the curing accelerator are added, stirring dispersing is carried out, and an obtained product is cooled, and is collected.

Description

technical field

[0001] The invention relates to a polyester resin, especially an epoxy-cured polyester resin for powder coatings with high surface decoration and high water resistance, and also relates to a preparation method of the polyester resin. Background technique

[0002] Powder coating is an environment-friendly green coating with superior performance, high efficiency and no organic solvent. It is widely used in building materials, electrical appliances and home decoration. According to the different curing systems of powder coatings, it is mainly divided into: 1) Powder coatings cured by triglycidyl isocyanurate (TGIC). This type of powder coatings is mainly used in outdoor building materials and has excellent water resistance and weather resistance. , the disadvantage is that TGIC has reproductive toxicity; 2) powder coating cured by β-hydroxyalkylamide (HAA), which is mainly used in home appliances, has the characteristics of environmental friendliness and no toxi...

Examples

Embodiment a

[0041] In a 3000ml four-neck flask equipped with a stirrer, condenser, thermometer and nitrogen protection, add 120 parts of diethylene glycol, 85 parts of ethylene glycol, 287 parts of neopentyl glycol, 180 parts of 2-methyl Base 1,3-propanediol, 3 parts of tetraisopropyl titanate, 1100 parts of terephthalic acid, 30 parts of 1,6-adipic acid, 20 parts of isophthalic acid, nitrogen protection; when the temperature rises At 160°C, esterification water begins to flow out; continue to heat up to 250°C, and when the amount of esterification water reaches 95% of the theoretical value, take a sample and test, and the acid value reaches 18.0-24.0mgKOH / g; add polyacid end-capping agent 1 , 80 parts of 2,4-benzenetricarboxylic anhydride, heat preservation and reaction at 240°C-250°C for 40-50 minutes; after the reaction was completed, the acid value reached 46.0-52.0mgKOH / g, at -0.113~-0.095MPa Negative compression polymerization for 1 hour, negative compression polymerization at -0.09...

Embodiment b

[0043] In a 3000ml four-neck flask equipped with a stirrer, condenser, thermometer and nitrogen protection, add 120 parts of diethylene glycol, 85 parts of ethylene glycol, 295 parts of neopentyl glycol, 180 parts of 2-methyl 1,3-propanediol, 1.5 parts of tetraisopropyl titanate, 1.5 parts of stannous oxalate, 30 parts of hydrogenated dimer acid, 1100 parts of terephthalic acid, 30 parts of 1,6-adipic acid , 20 parts of isophthalic acid, filled with nitrogen for protection; when the temperature rises to 160°C, esterification water begins to flow out; when the temperature continues to rise to 250°C, when the amount of esterification water effluent reaches 95% of the theoretical value, sampling and testing, the acid value Reach 18.0-24.0mgKOH / g; add 80 parts of polybasic acid end-capping agent 1,2,4-benzenetricarboxylic anhydride, keep warm and react for 40-50 minutes at 240℃~250℃; Reach 46.0~52.0mgKOH / g, polymerize under negative compression at -0.113~-0.095MPa for 1 hour, and ...

Embodiment c

[0045] In a 3000ml four-neck flask equipped with a stirrer, condenser, thermometer and nitrogen protection, add 120 parts of diethylene glycol, 85 parts of ethylene glycol, 308 parts of neopentyl glycol, 180 parts of 2-methyl 1,3-propanediol, 3 parts of stannous oxalate, 60 parts of hydrogenated dimer acid, 1100 parts of terephthalic acid, 30 parts of 1,6-adipic acid, 20 parts of isophthalic acid, full Nitrogen protection; when the temperature rises to 160°C, esterification water begins to flow; when the temperature continues to rise to 250°C, when the amount of esterification water reaches 95% of the theoretical value, sampling and testing shows that the acid value reaches 18.0-24.0mgKOH / g; add multi-component 80 parts of acid-blocking agent 1,2,4-benzenetricarboxylic anhydride, heat preservation reaction at 240°C-250°C for 40-50 minutes; Negative compression polymerization at 0.113~-0.095MPa for 1 hour, negative compression polymerization at -0.095~-0.099MPa for 1 hour; cool...

technical field

[0001] The invention relates to a polyester resin, especially an epoxy-cured polyester resin for powder coatings with high surface decoration and high water resistance, and also relates to a preparation method of the polyester resin. Background technique

[0002] Powder coating is an environment-friendly green coating with superior performance, high efficiency and no organic solvent. It is widely used in building materials, electrical appliances and home decoration. According to the different curing systems of powder coatings, it is mainly divided into: 1) Powder coatings cured by triglycidyl isocyanurate (TGIC). This type of powder coatings is mainly used in outdoor building materials and has excellent water resistance and weather resistance. , the disadvantage is that TGIC has reproductive toxicity; 2) powder coating cured by β-hydroxyalkylamide (HAA), which is mainly used in home appliances, has the characteristics of environmental friendliness and no toxi...

Examples

Embodiment a

[0041] In a 3000ml four-neck flask equipped with a stirrer, condenser, thermometer and nitrogen protection, add 120 parts of diethylene glycol, 85 parts of ethylene glycol, 287 parts of neopentyl glycol, 180 parts of 2-methyl Base 1,3-propanediol, 3 parts of tetraisopropyl titanate, 1100 parts of terephthalic acid, 30 parts of 1,6-adipic acid, 20 parts of isophthalic acid, nitrogen protection; when the temperature rises At 160°C, esterification water begins to flow out; continue to heat up to 250°C, and when the amount of esterification water reaches 95% of the theoretical value, take a sample and test, and the acid value reaches 18.0-24.0mgKOH / g; add polyacid end-capping agent 1 , 80 parts of 2,4-benzenetricarboxylic anhydride, heat preservation and reaction at 240°C-250°C for 40-50 minutes; after the reaction was completed, the acid value reached 46.0-52.0mgKOH / g, at -0.113~-0.095MPa Negative compression polymerization for 1 hour, negative compression polymerization at -0.09...

Embodiment b

[0043] In a 3000ml four-neck flask equipped with a stirrer, condenser, thermometer and nitrogen protection, add 120 parts of diethylene glycol, 85 parts of ethylene glycol, 295 parts of neopentyl glycol, 180 parts of 2-methyl 1,3-propanediol, 1.5 parts of tetraisopropyl titanate, 1.5 parts of stannous oxalate, 30 parts of hydrogenated dimer acid, 1100 parts of terephthalic acid, 30 parts of 1,6-adipic acid , 20 parts of isophthalic acid, filled with nitrogen for protection; when the temperature rises to 160°C, esterification water begins to flow out; when the temperature continues to rise to 250°C, when the amount of esterification water effluent reaches 95% of the theoretical value, sampling and testing, the acid value Reach 18.0-24.0mgKOH / g; add 80 parts of polybasic acid end-capping agent 1,2,4-benzenetricarboxylic anhydride, keep warm and react for 40-50 minutes at 240℃~250℃; Reach 46.0~52.0mgKOH / g, polymerize under negative compression at -0.113~-0.095MPa for 1 hour, and ...

Embodiment c

[0045] In a 3000ml four-neck flask equipped with a stirrer, condenser, thermometer and nitrogen protection, add 120 parts of diethylene glycol, 85 parts of ethylene glycol, 308 parts of neopentyl glycol, 180 parts of 2-methyl 1,3-propanediol, 3 parts of stannous oxalate, 60 parts of hydrogenated dimer acid, 1100 parts of terephthalic acid, 30 parts of 1,6-adipic acid, 20 parts of isophthalic acid, full Nitrogen protection; when the temperature rises to 160°C, esterification water begins to flow; when the temperature continues to rise to 250°C, when the amount of esterification water reaches 95% of the theoretical value, sampling and testing shows that the acid value reaches 18.0-24.0mgKOH / g; add multi-component 80 parts of acid-blocking agent 1,2,4-benzenetricarboxylic anhydride, heat preservation reaction at 240°C-250°C for 40-50 minutes; Negative compression polymerization at 0.113~-0.095MPa for 1 hour, negative compression polymerization at -0.095~-0.099MPa for 1 hour; cool...

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