阅读说明：本技术 一种改性水性聚酯多元醇及其制备方法和应用 (Modified water-based polyester polyol and preparation method and application thereof ) 是由 凌立志 李本祥 肖勋 陈玉文 于 2021-09-30 设计创作，主要内容包括：本发明公开了一种改性水性聚酯多元醇及其制备方法和应用。一种改性水性聚酯多元醇,制备原料包括：芳香多元酸和芳香酸酐中的至少一种,α-乙酰基-γ-丁内酯和1,2-丁二醇-2-磺酸盐。本发明的改性水性聚酯多元醇能够兼顾其疏水效果和水溶性,还能提升抗腐蚀能力,因此将改性水性聚酯多元醇用于制备涂料后,可以延长被保护基材的寿命,还能提升涂料的疏水效果。(The invention discloses a modified waterborne polyester polyol and a preparation method and application thereof. A modified aqueous polyester polyol is prepared from the following raw materials: at least one of aromatic polybasic acid and aromatic acid anhydride, alpha-acetyl-gamma-butyrolactone and 1, 2-butanediol-2-sulfonate. The modified water-based polyester polyol can give consideration to both the hydrophobic effect and the water solubility, and can improve the corrosion resistance, so that the service life of a protected substrate can be prolonged and the hydrophobic effect of a coating can be improved after the modified water-based polyester polyol is used for preparing the coating.)

1. The modified water-based polyester polyol is characterized by being prepared from the following raw materials: polybasic acid, polyhydric alcohol, alpha-acetyl-gamma-butyrolactone.

2. The modified aqueous polyester polyol of claim 1, wherein the polyacid comprises: fatty polybasic acids and aromatic polybasic acids.

3. The modified aqueous polyester polyol according to claim 2, wherein the aromatic polybasic acid comprises at least one of isophthalic acid, phthalic acid, terephthalic acid, phthalic anhydride, and trimellitic anhydride.

4. The modified aqueous polyester polyol according to claim 2, wherein the fatty polyacid comprises at least one of adipic acid and 1, 4-cyclohexanedicarboxylic acid.

5. The modified aqueous polyester polyol according to claim 1, wherein the polyol comprises: at least one of dihydric alcohol, trihydric alcohol and tetrahydric alcohol, and preferably, the dihydric alcohol includes: at least one of neopentyl glycol, ethylene glycol, butylene glycol, 1, 2-propanediol, and hexylene glycol; preferably, the trihydric alcohols include: at least one of trimethylolpropane and glycerol; preferably, the tetrahydric alcohols include: pentaerythritol.

6. A method for preparing the modified aqueous polyester polyol according to any one of claims 1 to 5, comprising the steps of:

d1: carrying out a ring-opening reaction on the polyhydric alcohol and the alpha-acetyl-gamma-butyrolactone to obtain an intermediate 1;

d2: and reacting the intermediate 1 with the aliphatic polybasic acid and the aromatic polybasic acid to obtain the modified waterborne polyester polyol.

7. A polyester polyol coating, characterized in that the preparation raw materials comprise adipic acid dihydrazide and the modified aqueous polyester polyol as claimed in any one of claims 1 to 5.

8. The polyester polyol coating according to claim 7, wherein the raw materials for preparing the polyester polyol coating further comprise a leveling agent;

preferably, the polyester polyol coating is prepared from the raw materials which also comprise water;

preferably, the polyester polyol coating also comprises a surface slipping agent as a preparation raw material;

preferably, the polyester polyol coating comprises the following preparation raw materials in parts by weight: 4-5 parts of adipic acid dihydrazide and 80-100 parts of modified waterborne polyester polyol.

9. A method for preparing the polyester polyol coating of claim 7 or 8, comprising the steps of:

s1: adding water into the modified water-based polyester polyol for emulsification;

s2: and adding the adipic acid dihydrazide after the emulsification is finished to obtain the polyester polyol coating.

10. An architectural aluminum template, wherein a coating is arranged on the surface of the architectural aluminum template, and the coating is prepared from the polyester polyol coating of claim 7 or 8.

Technical Field

The invention belongs to the field of coatings, and particularly relates to modified waterborne polyester polyol as well as a preparation method and application thereof.

Background

At present, the civil engineering construction is rapidly developing, and concrete is the most abundant man-made product in the world, and the annual average consumption of the concrete is only second to that of water. The concrete is formed by fixing the concrete by means of a template, and the template is removed after the concrete has certain strength.

When the template in the related technology is used, only the front surface of the template is coated with anticorrosive paint and a release agent, and the back surface of the template is rarely subjected to anticorrosive treatment, so that the back surface of the template is easily corroded, and meanwhile, concrete adhered to the back surface of the template is difficult to drop after being hardened in construction, and needs manual removal, so that the cost is increased.

When the oily anticorrosive paint in the related technology is used for carrying out anticorrosive treatment on the back surface of the template, the cost is high, the VOC emission is large, the water-based anticorrosive paint in the related technology can play a certain anticorrosive effect, but concrete adhered to the water-based anticorrosive paint in the related technology is hard to fall off after hardening, so that the water-based anticorrosive paint with a certain demoulding effect and an environment-friendly building aluminum back surface needs to be developed.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the invention provides a modified water-based polyester polyol. Due to the adjustment of the preparation raw materials, the hydrophobic effect and the water solubility of the modified waterborne polyester polyol can be considered, and the corrosion resistance can be improved, so that the service life of a protected substrate can be prolonged and the hydrophobic effect of the coating can be improved after the modified waterborne polyester polyol is used for preparing the coating.

The invention provides a preparation method of the modified waterborne polyester polyol.

The invention also provides a polyester polyol coating comprising the modified water-based polyester polyol.

The invention also provides a preparation method of the polyester polyol coating.

The template which comprises the polyester polyol coating for forming the coating is provided.

The invention further provides the building aluminum template, the surface of the building aluminum template is provided with a coating, and the preparation raw material of the coating comprises the polyester polyol coating.

The first aspect of the invention provides a modified aqueous polyester polyol, which is prepared from the following raw materials: polybasic acid, polyhydric alcohol, alpha-acetyl-gamma-butyrolactone.

The modified waterborne polyester polyol has at least the following beneficial effects;

1. the polyester polyol modified by the alpha-acetyl-gamma-butyrolactone has a ketone carbonyl structure functional group in the alpha-acetyl-gamma-butyrolactone, and the ketone carbonyl structure functional group and adipic acid dihydrazide can generate dehydration reaction at room temperature, so that the modified waterborne polyester polyol can be cured into a film at room temperature after being added with the adipic acid dihydrazide.

2. The modified water-based polyester polyol contains benzene rings, the benzene rings have a protection effect on ester bonds in the coating and can prevent the coating from hydrolyzing under an alkaline condition, so that the corrosion resistance of the coating under the alkaline condition is improved, the back of the aluminum membrane plate can be effectively protected from corrosion, in addition, the benzene rings enable the coating after film forming to have a certain hydrophobic effect, concrete adhered to the coating is easy to fall off after hardening, and the cost of manual removal is reduced.

3. 1, 2-butanediol-2-sulfonate is used in the polyol which is subjected to ring opening with alpha-acetyl-gamma-butyrolactone, so that the modified water-based polyester polyol has water solubility, water can be used as a diluent without using an organic solvent, and VOC emission in a curing film-forming process can be reduced.

In some embodiments of the invention, the polyacid comprises: fatty polybasic acids and aromatic polybasic acids.

In some embodiments of the invention, the aromatic polyacid comprises at least one of isophthalic acid, phthalic acid, terephthalic acid, phthalic anhydride, and trimellitic anhydride.

In some embodiments of the invention, the fatty polyacid comprises at least one of adipic acid and 1, 4-cyclohexanedicarboxylic acid.

In some embodiments of the invention, the polyol comprises: at least one of dihydric alcohol, trihydric alcohol and tetrahydric alcohol.

In some embodiments of the invention, the glycol comprises: at least one of neopentyl glycol, ethylene glycol, butylene glycol, 1, 2-propanediol, and hexylene glycol.

In some embodiments of the invention, the triol comprises: at least one of trimethylolpropane and glycerol.

In some embodiments of the invention, the tetrahydric alcohols include: pentaerythritol.

The second aspect of the present invention provides a method for preparing the above-described modified polyester polyol, comprising the steps of:

d1: carrying out a ring-opening reaction on the polyhydric alcohol and the alpha-acetyl-gamma-butyrolactone to obtain an intermediate 1;

d2: and reacting the intermediate 1 with the aliphatic polybasic acid and the aromatic polybasic acid to obtain the modified waterborne polyester polyol.

In some embodiments of the invention, the polyol: the molar ratio of polyacid is about 1: 1.

in some embodiments of the present invention, the aromatic polyacid has a specific gravity of 40 to 60% in the polyacid.

In some embodiments of the present invention, the aromatic polyacid has a specific gravity of 40 to 60% in the polyacid.

In some embodiments of the invention, the diacid is present in the polyacid in a proportion of about 90% by weight.

In some embodiments of the present invention, the modified aqueous polyester polyol, the preparation raw materials further comprise: a catalyst.

In some embodiments of the invention, the catalyst in step D1 comprises at least one of tetrabutyl titanate, isopropyl titanate, titanium acetylacetonate, lithium chloride, butyllithium, and phenyllithium germanate.

In some embodiments of the invention, the catalyst in step D2 comprises at least one of tetrabutyl titanate, isopropyl titanate, tin chloride, butyl lithium, and phenyl lithium germanate.

The preparation method of the modified water-based polyester polyol has at least the following beneficial effects:

the modified water-based polyester polyol has good water solubility, avoids the use of organic solvents and reduces the discharge of VOC.

In some embodiments of the invention, in step D1, the reaction temperature is 120 ℃ to 130 ℃ and the reaction time is 4 to 5 hours in the ring-opening reaction.

In some embodiments of the invention, in step D1, the first catalyst participates in the ring-opening reaction.

In some embodiments of the invention, in step D2, the second catalyst participates in the reaction.

In some embodiments of the invention, the reaction temperature in step D2 is 200-250 ℃.

In some embodiments of the invention, the reaction is stopped in step D2 when the acid number in the system drops below 2 mg/KOH/g.

In some embodiments of the present invention, step D2 further comprises reducing the temperature of the system to about 80 ℃.

The first catalyst and the second catalyst may be the same or different.

The third aspect of the invention provides a polyester polyol coating, and the preparation raw materials comprise adipic acid dihydrazide and the modified waterborne polyester polyol.

The polyester polyol coating has at least the following beneficial effects;

the polyester polyol coating provided by the invention can prevent the corrosion of the aluminum template and prolong the service life of the template.

In some embodiments of the invention, the polyester polyol coating, raw material for preparation, further comprises a leveling agent;

in some embodiments of the invention, the leveling agent comprises at least one of BYK-333, BYK-306, XYS-5630A, and MONENG-1153.

In some embodiments of the present invention, the polyester polyol coating, raw material for preparation, further comprises water.

In some embodiments of the present invention, the polyester polyol coating, raw material for preparation, further comprises a surface slipping agent.

In some embodiments of the invention, the surface slip agent comprises at least one of S-660F, GWA-L, GWC-L and GWN-N.

In some embodiments of the present invention, the polyester polyol coating comprises the following preparation raw materials in parts by weight: 4-5 parts of adipic acid dihydrazide and 80-100 parts of modified waterborne polyester polyol.

In some embodiments of the present invention, the α -acetyl- γ -butyrolactone modifies the polyester polyol so that the modified polyester polyol has a ketone carbonyl structure, and the ketone carbonyl is dehydrated and crosslinked with the hydrazide-type material at room temperature.

In some embodiments of the present invention, the polyester polyol coating further comprises the following preparation raw materials in parts by weight: 100-200 parts of deionized water, 0.1-0.5 part of flatting agent and 0.1-0.3 part of surface slipping agent.

The fourth aspect of the present invention provides a method for preparing the above polyester polyol coating, comprising the steps of:

s1: adding the water into the modified water-based polyester polyol for emulsification;

s2: and adding the adipic acid dihydrazide after emulsification is finished to obtain the polyester polyol coating.

The preparation method of the polyester polyol coating has at least the following beneficial effects:

the modified waterborne polyester polyol and the adipic dihydrazide can be cured into a film at room temperature, so that high-temperature curing is avoided, and the running cost of equipment is reduced.

The fifth aspect of the invention provides application of a polyester polyol coating in the field of coatings.

According to a preferred embodiment of the present invention, at least the following advantages are provided:

1. the polyester polyol coating can prevent the corrosion of an aluminum template in the coating, and prolong the service life of the template;

2. the polyester polyol coating of the present invention makes concrete adhered to the back surface of the form easily fall off. The labor cost of manually shoveling concrete residues on the back of the template is reduced.

In some embodiments of the invention, the method of preparing the coating comprises: the polyester polyol coating is sprayed on the back of an aluminum alloy template for a building, dried in the air, placed at room temperature for 5-7 days, and cured to form a film.

Detailed Description

The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

Example 1:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of 1, 2-butanediol-2 sulfonate, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 45 parts of isophthalic acid and 40 parts of adipic acid, adding 0.5 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Example 2

The embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 80 parts of the modified waterborne polyester polyol obtained in the example 1 into 100 parts of deionized water at 80 ℃ for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 4 parts of adipic acid dihydrazide was added to the solution obtained in step B2, and dehydration reaction was carried out at room temperature (about 25 ℃ C.) to obtain a polyester polyol coating.

Example 3:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of 1, 2-butanediol-2 sulfonate, 5 parts of glycerol and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 45 parts of phthalic anhydride and 44 parts of adipic acid, adding 0.5 part of lithium chloride, performing esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Example 4:

the embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 80 parts of the modified waterborne polyester polyol obtained in the example 1 into 100 parts of deionized water at 80 ℃ for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 4 parts of adipic acid dihydrazide was added to the solution obtained in step B2, and dehydration reaction was carried out at room temperature (about 25 ℃ C.) to obtain a polyester polyol coating.

Example 5:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 50 parts of 1, 2-butanediol-2 sulfonate, 40 parts of butanediol, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 64 parts of isophthalic acid and 56 parts of adipic acid, adding 0.73 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Example 6:

the embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 100 parts of deionized water at 80 ℃ into 100 parts of the modified waterborne polyester polyol obtained in the example 1 for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 5 parts of adipic acid dihydrazide is added to the step B2, and dehydration reaction is carried out at room temperature (about 25 ℃) to obtain the polyester polyol coating.

Example 7:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 30 parts of 1, 2-butanediol-2 sulfonate, 60 parts of butanediol, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 74 parts of isophthalic acid and 65 parts of adipic acid, adding 0.73 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Example 8:

the embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 100 parts of deionized water at 80 ℃ into 100 parts of the modified waterborne polyester polyol obtained in the example 1 for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 5 parts of adipic acid dihydrazide is added to the step B2, and dehydration reaction is carried out at room temperature (about 25 ℃) to obtain the polyester polyol coating.

Example 9:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of 1, 2-butanediol-2 sulfonate, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 35 parts of isophthalic acid and 47 parts of adipic acid, adding 0.48 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Example 10:

the embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 80 parts of the modified waterborne polyester polyol obtained in the example 1 into 100 parts of deionized water at 80 ℃ for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 4 parts of adipic acid dihydrazide was added to the solution obtained in step B2, and dehydration reaction was carried out at room temperature (about 25 ℃ C.) to obtain a polyester polyol coating.

Example 11:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of 1, 2-butanediol-2 sulfonate, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 59 parts of isophthalic acid and 44 parts of adipic acid, adding 0.6 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Example 12:

the embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 80 parts of the modified waterborne polyester polyol obtained in the example 1 into 100 parts of deionized water at 80 ℃ for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 4 parts of adipic acid dihydrazide was added to the solution obtained in step B2, and dehydration reaction was carried out at room temperature (about 25 ℃ C.) to obtain a polyester polyol coating.

Example 13:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of 1, 2-butanediol-2 sulfonate, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 45 parts of isophthalic acid and 40 parts of adipic acid, adding 0.5 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Example 14

The embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 80 parts of the modified waterborne polyester polyol obtained in the example 1 into 100 parts of deionized water at 80 ℃ for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 4 parts of adipic acid dihydrazide was added to the solution obtained in step B2, and dehydration reaction was carried out at room temperature (about 25 ℃ C.) to obtain a polyester polyol coating.

Comparative example 1:

the comparative example prepares the modified waterborne polyester polyol by the specific steps of:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of butanediol, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 80 parts of isophthalic acid and 78 parts of adipic acid, adding 0.92 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Comparative example 2

The comparative example prepares a polyester polyol coating, and the specific steps are as follows:

B1. adding 100 parts of deionized water at 80 ℃ into 100 parts of the modified waterborne polyester polyol obtained in the example 1 for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 5 parts of adipic acid dihydrazide is added to the step B2, and dehydration reaction is carried out at room temperature (about 25 ℃) to obtain the polyester polyol coating.

Comparative example 3:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 6 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of 1, 2-butanediol-2 sulfonate, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 30 parts of isophthalic acid and 61 parts of adipic acid, adding 0.5 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Comparative example 4

The embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 80 parts of the modified waterborne polyester polyol obtained in the example 1 into 100 parts of deionized water at 80 ℃ for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 4 parts of adipic acid dihydrazide was added to the solution obtained in step B2, and dehydration reaction was carried out at room temperature (about 25 ℃ C.) to obtain a polyester polyol coating.

Comparative example 5:

the embodiment prepares the modified waterborne polyester polyol, and the specific steps are as follows:

A1. adding 2 parts of alpha-acetyl-gamma-butyrolactone, 90 parts of 1, 2-butanediol-2 sulfonate, 5 parts of trimethylolpropane and 5 parts of pentaerythritol into a reactor, heating and stirring, adding 0.5 part of lithium chloride, controlling the reaction temperature at 120 ℃, and reacting for 4 hours;

A2. adding 45 parts of isophthalic acid and 40 parts of adipic acid, adding 0.5 part of lithium chloride, carrying out esterification dehydration reaction at 200 ℃, reducing the acid value of a reaction system to be below 2mg/KOH/g, and cooling to about 80 ℃ to obtain the modified waterborne polyester polyol.

Comparative example 6:

the embodiment prepares the polyester polyol coating, and the specific steps are as follows:

B1. adding 80 parts of the modified waterborne polyester polyol obtained in the example 1 into 100 parts of deionized water at 80 ℃ for emulsification;

B2. after emulsification is finished, 0.1 part of a leveling agent BYK-333 and 0.1 part of a surface slipping agent S-600F are added into the mixture obtained in the step B1;

B3. 4 parts of adipic acid dihydrazide was added to the solution obtained in step B2, and dehydration reaction was carried out at room temperature (about 25 ℃ C.) to obtain a polyester polyol coating.

Test examples

TABLE 1 results of performance test of polyester polyol coatings prepared in examples 2, 4, 6, 8, 10, 12 and comparative examples 2, 4, 6

From the performance test results in table 1 above, it can be seen that:

1. examples 2, 4, 6, 8, 10, and 12 show that: examples 2, 4, 10 and 12 have the same reaction conditions except for the difference in the kind and content of aromatic acid, but all are within the range provided by the present invention, and the curing degree, the concrete adhesion degree, the corrosion resistance and the water solubility of the coatings prepared in examples 2, 4, 10 and 12 have no substantial difference; the reaction conditions of examples 2, 6 and 8 were the same, except that the contents of sulfonate were different, but they were within the ranges provided by the present invention, and the curing degree, the concrete adhesion degree, the corrosion resistance and the water solubility of the coatings prepared in examples 2, 6 and 8 were not substantially different.

2. Combining comparative example 4 and examples 2, 4, 10, 12, it can be seen that: in the esterification reaction, the aromatic polybasic acid is not added in the comparative example 4, and the aromatic polybasic acid is added in the examples 2, 4, 10 and 12, and it can be seen from the table that when the polyester polyol coating does not contain benzene rings, the corrosion resistance of the polyester polyol coating is reduced because the benzene rings prevent the coating from hydrolyzing under the alkaline condition, and the corrosion resistance of the coating under the alkaline condition is improved, so that the back surface of the aluminum plate is effectively protected from being corroded, and in addition, the benzene rings enable the coating after film forming to have good hydrophobic effect, so that the concrete adhered to the coating is easy to fall off after hardening.

3. Combining comparative example 2 and examples 2, 6, and 8, it can be seen that: in performing the ring-opening reaction of α -acetyl- γ -butyrolactone, comparative example 2 does not add sulfonate, and examples 2, 6, 8 add 1, 2-butanediol sulfonate, and it can be seen from table one that when 1, 2-butanediol sulfonate is not added in the ring-opening reaction of α -acetyl- γ -butyrolactone, the water solubility of the polyester polyol coating decreases, because 1, 2-butanediol sulfonate can change the water solubility of the polyester polyol, water can be used as a diluent without using an organic solvent, and thus VOC emission during curing to form a film can also be reduced.

4. Combining comparative example 6 with examples 2, 4, and 6, it can be seen that: the film of comparative example 6 was poor in curing degree due to insufficient amount of α -acetyl- γ -butyrolactone, and the α -acetyl- γ -butyrolactone-modified polyester polyol had a ketone carbonyl functional group in α -acetyl- γ -butyrolactone, which could undergo dehydration reaction with adipic acid dihydrazide at room temperature, so that the modified aqueous polyester polyol could be cured into a film at room temperature after addition of adipic acid dihydrazide, and thus the amount of α -acetyl- γ -butyrolactone should be within the range provided by the present invention.

While the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.