阅读说明：本技术 一种耐手印型聚酯树脂及其制备方法 (Fingerprint-resistant polyester resin and preparation method thereof ) 是由 翟春海 于 2019-09-09 设计创作，主要内容包括：本发明的目的是提供一种耐手印型聚酯树脂及其制备方法,原料采用二元羧酸,二元醇,三元醇,酯化催化剂,封端剂,固化促进剂,抗氧剂,并且提供该树脂制备方法,采用该树脂制备粉末涂料,200℃/10min固化后的涂层机械性能、附着力、耐候性能较好,汗手接触后,在120～140℃烘烤一定时间后,无明显手印现象,且无失光现象,可用于高光、橘纹、砂纹等多种类型粉末涂料。(the invention aims to provide a fingerprint-resistant polyester resin and a preparation method thereof, wherein dicarboxylic acid, dihydric alcohol, trihydric alcohol, an esterification catalyst, a blocking agent, a curing accelerator and an antioxidant are adopted as raw materials, the resin is used for preparing a powder coating, the mechanical property, the adhesive force and the weather resistance of the coating cured at the speed of 200 ℃/10min are better, after the coating is contacted with sweaty hands, the coating is baked for a certain time at the temperature of 120-140 ℃, the obvious fingerprint phenomenon and the light loss phenomenon do not exist, and the resin can be used for various types of powder coatings such as highlight, orange veins, sand veins and the like.)

1. a fingerprint-resistant polyester resin is characterized in that: the feed comprises the following raw materials in parts by weight: 5.4-5.5 parts of dicarboxylic acid, 3.6-4.1 parts of dihydric alcohol, 0.05-0.15 part of trihydric alcohol, 0.01 part of esterification catalyst, 1.15-1.35 parts of end capping agent, 0.005-0.01 part of curing accelerator and 0.02-0.03 part of antioxidant.

2. The fingerprint resistant polyester resin as claimed in claim 1, wherein: the dicarboxylic acid is a mixture of terephthalic acid and isophthalic acid, and the mass ratio of the terephthalic acid to the isophthalic acid is 4.2-4.65: 0.75-1.2.

3. The fingerprint resistant polyester resin as claimed in claim 1, wherein: the dihydric alcohol is one or more of neopentyl glycol, ethylene glycol, cyclohexanedimethanol and 2-butyl-2-ethyl-1, 3-propylene glycol, wherein the neopentyl glycol is necessarily contained; the mass ratio of neopentyl glycol, ethylene glycol, cyclohexanedimethanol and 2-butyl-2-ethyl-1, 3-propanediol is 3.35-3.75: 0-0.3: 0-0.4: 0-0.35.

4. the fingerprint resistant polyester resin as claimed in claim 1, wherein: the trihydric alcohol is one or two of trimethylolpropane and trimethylolethane.

5. The fingerprint resistant polyester resin as claimed in claim 1, wherein: the esterification catalyst is monobutyl tin oxide.

6. The fingerprint resistant polyester resin as claimed in claim 1, wherein: the end capping agent is one or more of isophthalic acid, adipic acid, cyclohexanedicarboxylic acid and succinic acid, wherein isophthalic acid is certain; the mass ratio of the isophthalic acid, the adipic acid, the cyclohexanedicarboxylic acid and the succinic acid is 0.8-1.05: 0-0.3: 0-0.45: 0-0.35.

7. The fingerprint resistant polyester resin as claimed in claim 1, wherein: the curing accelerator is ethyl triphenyl phosphonium bromide.

8. The fingerprint resistant polyester resin as claimed in claim 1, wherein: the antioxidant is 168 or 1010.

9. A process for preparing the fingerprint-resistant polyester resin as claimed in any one of claims 1 to 8, wherein: the preparation method comprises the following steps:

A. Putting the dihydric alcohol and the trihydric alcohol with the formula amount into a reaction kettle, heating the reaction kettle to 90-110 ℃, starting stirring, then putting the dicarboxylic acid and the esterification catalyst with the formula amount, slowly heating to 245-248 ℃, and maintaining the reaction until the acid value is 6-10 mgKOH/g;

B. Reducing the temperature of the kettle to 220-230 ℃, adding a blocking agent, then heating to 230-240 ℃, and maintaining the reaction until the acid value is 43-48 mgKOH/g;

C. Vacuumizing for 2-3h at the temperature of 225-235 ℃ under the vacuum degree of-0.094 to-0.098 MPa to ensure that the acid value is 30-35mgKOH/g, then reducing the temperature of the kettle to 180-210 ℃, adding a curing accelerator and an antioxidant, and maintaining for 15-25min to obtain the fingerprint-resistant polyester resin.

Technical Field

The invention relates to the technical field of coatings, in particular to fingerprint-resistant polyester resin and a preparation method thereof.

Background

The powder coating has the characteristics of energy conservation, environmental protection and excellent comprehensive performance, and has the advantage of no solvent volatilization compared with the traditional liquid coating. However, in the actual spraying and curing process, a small amount of small molecular substances still volatilize in the powder coating, and the most common phenomenon is the smoking phenomenon in the curing process. Still another phenomenon is easily overlooked, that is, the phenomenon of 'fingerprint'. For example: when a sprayed workpiece is placed, hands of workers directly contact with the coating film, so that the phenomenon of 'hand mark' is easily caused; or the workpiece has flaws, secondary spraying is solidified, and fingerprints of previous contacts can often appear in places without secondary spraying, particularly in summer, the coating is in contact with hand sweat components of a human body, and the fingerprints are more obvious; adhesion between the coating films can also be problematic if the secondary spray is just where the hands were previously touching. The phenomenon of 'fingerprint' is visible everywhere, and is more obvious particularly for bright products.

Patents CN103131295B and CN103146272B respectively report a fingerprint-resistant metal powder coating and a preparation method thereof, and a metal powder coating for enhancing glittering effect and a preparation method thereof, the fingerprint resistance mentioned in the patents refers to the phenomenon that the instability of metal pigments causes the metal powder coating to be not wear-resistant and easy to rub off, and different from the phenomenon of fingerprint, the specific functional uses are different. Patent CN103360585B relates to a fluorine modified high scratch-resistant glossy resin and a preparation method thereof, and introduces a scratch-resistant fingerprint-resistant fluorine-containing resin which can be used in the field of powder coatings and has good fingerprint resistance to be proved.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a fingerprint-resistant polyester resin and a preparation method thereof, wherein dicarboxylic acid, dihydric alcohol, trihydric alcohol, an esterification catalyst, a blocking agent, a curing accelerator and an antioxidant are adopted as raw materials, the resin is used for preparing a powder coating, the mechanical property, the adhesive force and the weather resistance of the coating after curing at 200 ℃/10min are better, after sweat hands are contacted, the coating is baked for a certain time at 120-140 ℃, the obvious fingerprint phenomenon and the light loss phenomenon do not exist, the fingerprint-resistant polyester resin can be used for various types of powder coatings such as highlight, orange veins, sand veins and the like, and the problems in the background art are solved.

The invention aims to provide fingerprint-resistant polyester resin which comprises the following raw materials in parts by weight: 5.4-5.5 parts of dicarboxylic acid, 3.6-4.1 parts of dihydric alcohol, 0.05-0.15 part of trihydric alcohol, 0.01 part of esterification catalyst, 1.15-1.35 parts of end capping agent, 0.005-0.01 part of curing accelerator and 0.02-0.03 part of antioxidant.

The further improvement lies in that: the dicarboxylic acid is a mixture of terephthalic acid and isophthalic acid, and the mass ratio of the terephthalic acid to the isophthalic acid is 4.2-4.65: 0.75-1.2.

The further improvement lies in that: the dihydric alcohol is one or more of neopentyl glycol, ethylene glycol, cyclohexanedimethanol and 2-butyl-2-ethyl-1, 3-propylene glycol, wherein the neopentyl glycol is necessarily contained; the mass ratio of neopentyl glycol, ethylene glycol, cyclohexanedimethanol and 2-butyl-2-ethyl-1, 3-propanediol is 3.35-3.75: 0-0.3: 0-0.4: 0-0.35.

The further improvement lies in that: the trihydric alcohol is one or two of trimethylolpropane and trimethylolethane.

The further improvement lies in that: the esterification catalyst is monobutyl tin oxide.

The further improvement lies in that: the end capping agent is one or more of isophthalic acid, adipic acid, cyclohexanedicarboxylic acid and succinic acid, wherein isophthalic acid is certain; the mass ratio of the isophthalic acid, the adipic acid, the cyclohexanedicarboxylic acid and the succinic acid is 0.8-1.05: 0-0.3: 0-0.45: 0-0.35.

The further improvement lies in that: the curing accelerator is ethyl triphenyl phosphonium bromide.

The further improvement lies in that: the antioxidant is 168 or 1010.

The preparation method of the fingerprint-resistant polyester resin comprises the following steps:

A. Putting the dihydric alcohol and the trihydric alcohol with the formula amount into a reaction kettle, heating the reaction kettle to 90-110 ℃, starting stirring, then putting the dicarboxylic acid and the esterification catalyst with the formula amount, slowly heating to 245-248 ℃, and maintaining the reaction until the acid value is 6-10 mgKOH/g;

B. Reducing the temperature of the kettle to 220-230 ℃, adding a blocking agent, then heating to 230-240 ℃, and maintaining the reaction until the acid value is 43-48 mgKOH/g;

C. Vacuumizing for 2-3h at the temperature of 225-235 ℃ under the vacuum degree of-0.094 to-0.098 MPa to ensure that the acid value is 30-35mgKOH/g, then reducing the temperature of the kettle to 180-210 ℃, adding a curing accelerator and an antioxidant, and maintaining for 15-25min to obtain the fingerprint-resistant polyester resin.

the invention has the beneficial effects that: the raw materials of the invention adopt dicarboxylic acid, dihydric alcohol, trihydric alcohol, esterification catalyst, end capping agent, curing accelerator and antioxidant, and the resin preparation method is provided, the powder coating prepared by adopting the resin has better mechanical property, adhesive force and weather resistance of the coating after curing at 200 ℃/10min, after the coating is contacted with sweaty hands, no obvious fingerprint phenomenon and no light loss phenomenon are generated after the coating is baked for a certain time at 120-140 ℃, and the resin can be used for various types of powder coatings such as highlight, orange veins, sand veins and the like.

Detailed Description

For the purpose of enhancing understanding of the present invention, the present invention will be further described in detail with reference to the following examples, which are provided for illustration only and are not to be construed as limiting the scope of the present invention.