阅读说明：本技术 一种羟基丙烯酸树脂水分散体及其制备方法 (Hydroxyl acrylic resin aqueous dispersion and preparation method thereof ) 是由 欧阳洁 谭星 于 2020-11-23 设计创作，主要内容包括：本发明属于水性树脂技术领域,公开了一种羟基丙烯酸树脂水分散体及其制备方法。所述羟基丙烯酸树脂水分散体包括如下的制备原料：含羟基不饱和单体A-1,含憎水不饱和单体B-1,含羟基不饱和单体A-2,含憎水不饱和单体B-2,含HDI三聚体结构的不饱和单体C,含羧酸或磺酸亲水单体D。本发明使用含HDI三聚体结构的不饱和单体C制备的所述羟基丙烯酸树脂水分散体可以与价格实惠的溶剂型异氰酸酯固化剂复配,得到高光泽的水性双组份聚氨酯涂料。所述水性双组份聚氨酯涂料具有优异的无泡膜厚、可使用时间、耐水性。(The invention belongs to the technical field of water-based resin, and discloses a hydroxyl acrylic resin aqueous dispersion and a preparation method thereof. The hydroxyl acrylic resin aqueous dispersion comprises the following preparation raw materials: unsaturated monomer A containing hydroxyl group 1 Containing hydrophobic unsaturated monomers B 1 Unsaturated monomer A containing hydroxyl group 2 Containing hydrophobic unsaturated monomers B 2 An unsaturated monomer C containing HDI tripolymer structure and a hydrophilic monomer D containing carboxylic acid or sulfonic acid. The invention uses HDI-containingThe hydroxyl acrylic resin aqueous dispersion prepared from the unsaturated monomer C with the trimer structure can be compounded with a solvent type isocyanate curing agent with low price to obtain the high-gloss water-based two-component polyurethane coating. The water-based two-component polyurethane coating has excellent foamless film thickness, service life and water resistance.)

1. An aqueous dispersion of a hydroxyacrylic resin, characterized in that it comprises the following preparation raw materials: unsaturated monomer A containing hydroxyl group₁Containing hydrophobic unsaturated monomers B₁Unsaturated monomer A containing hydroxyl group₂Containing hydrophobic unsaturated monomers B₂An unsaturated monomer C containing an HDI tripolymer structure and a hydrophilic monomer D containing carboxylic acid or sulfonic acid;

with unsaturated monomers A containing hydroxy groups₁And a hydrophobic unsaturated monomer B₁Based on the total mass of the hydroxyl group-containing unsaturated monomer A₁In a mass ratio of 10-50%, the hydrophobic unsaturated monomer B₁The mass ratio of (A) is 50-90%;

with unsaturated monomers A containing hydroxy groups₂Containing hydrophobic unsaturated monomers B₂The hydroxyl group-containing unsaturated monomer A based on the total mass of the HDI trimer structure-containing unsaturated monomer C and the carboxylic acid-or sulfonic acid-containing hydrophilic monomer D₂In a mass ratio of 10-50%, the hydrophobic unsaturated monomer B₂The mass ratio of the HDI-containing trimer structure is 0-40%, the mass ratio of the HDI-containing trimer structure-containing unsaturated monomer C is 20-70%, and the mass ratio of the carboxylic acid-containing or sulfonic acid-containing hydrophilic monomer D is 5-40%.

2. The aqueous dispersion of hydroxyacrylic resins according to claim 1, wherein the hydroxyl group-containing unsaturated monomer A is used₁And a hydrophobic unsaturated monomer B₁Based on the total mass of the hydroxyl group-containing unsaturated monomer A₁20-40% by mass of the hydrophobic unsaturated monomer B₁The mass ratio of the components is 60-80%;

with unsaturated monomers A containing hydroxy groups₂Containing hydrophobic unsaturated monomers B₂Unsaturated monomer C containing HDI trimer structure, total of hydrophilic monomer D containing carboxylic acid or sulfonic acidMass meter of the hydroxyl group-containing unsaturated monomer A₂20-40% by mass of the hydrophobic unsaturated monomer B₂The mass ratio of the HDI-containing trimer structure is 0-20%, the mass ratio of the HDI-containing trimer structure-containing unsaturated monomer C is 40-60%, and the mass ratio of the carboxylic acid-containing or sulfonic acid-containing hydrophilic monomer D is 10-30%.

3. The aqueous dispersion of a hydroxyacrylic resin according to claim 1 or 2, wherein the hydroxyl group-containing unsaturated monomer A₁And a hydroxyl group-containing unsaturated monomer A₂Comprising at least one of the following monomers: hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoester acrylate, ring-opening addition products of the above monomers with epsilon-caprolactone.

4. The aqueous dispersion of a hydroxyacrylic resin according to claim 1 or 2, characterized in that the hydrophobic unsaturated monomer B is contained₁And a hydrophobic unsaturated monomer B₂Comprising at least one of the following monomers: methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, n-butyl methacrylate, n-butyl acrylate, isobutyl methacrylate, isobutyl acrylate, t-butyl methacrylate, t-butyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexyl acrylate, dodecyl methacrylate, dodecyl acrylate, octadecyl methacrylate, octadecyl acrylate, glycidyl methacrylate, glycidyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, 4-t-butylcyclohexyl methacrylate, 4-t-butylcyclohexyl acrylate, isobornyl methacrylate, isobornyl acrylate, vinyl acetate, vinyl chloride, dichloroethylene, styrene, methyl methacrylate, ethyl acrylate, n-butyl methacrylate, n-butyl acrylate, isobutyl methacrylate, ethyl methacrylate, isobutyl methacrylate, vinyl acetate, vinyl chloride, styrene, vinyl acetate, p-methylstyrene, m-methylstyrene, alpha-methylstyrene, methacrylonitrile, acrylonitrile, methacrylamide, acrylamide, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, polypropylene glycol dimethacrylateAlcohol dimethacrylate, polypropylene glycol diacrylate, 1, 4-butanediol dimethacrylate, 1, 4-butanediol diacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate.

5. The aqueous dispersion of a hydroxyacrylic resin according to claim 1 or 2, characterized in that the unsaturated monomer C containing HDI trimer structure has the structure:

wherein X ═ O or NH; y ═ H or Me; n is 1-20; p is 1-10; q is 1-10; r is C1-50 linear or branched alkyl.

6. The aqueous dispersion of hydroxyacrylic resins according to claim 1 or 2, characterized in that the carboxylic acid-or sulfonic acid-containing hydrophilic monomer D comprises at least one of the following monomers: methacrylic acid, acrylic acid, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium 2-acrylamido-2-methylpropanesulfonate, styrenesulfonic acid, and sodium styrenesulfonate.

7. The aqueous dispersion of hydroxyacrylate resins according to claim 1 or 2, further comprising a radical initiator, an amine neutralizer E and an organic solvent, wherein the radical initiator is a peroxide-based radical initiator, and the peroxide-based radical initiator is at least one of cumene hydroperoxide, tert-butylcumyl hydroperoxide, di-tert-butyl peroxide and di-tert-amyl peroxide; the amine neutralizer E is at least one of ammonia water, triethylamine, triethanolamine, dimethylethanolamine, 2-methyl-2-aminopropanol, dimethylisopropanolamine, methyldiethanolamine, ethyldiisopropylamine, diethylethanolamine, morpholine and N-methylmorpholine, and the neutralization degree is 50-120%; with unsaturated monomers A containing hydroxy groups₁Containing a hydrophobic unsaturated monomer B₁Unsaturated monomer A containing hydroxyl group₂Containing a hydrophobic unsaturated monomer B₂The mass ratio of the peroxide free radical initiator is 1-10%, and the mass ratio of the organic solvent is 5-30% of the total mass of the HDI trimer structure-containing unsaturated monomer C and the carboxylic acid or sulfonic acid hydrophilic monomer D.

8. The aqueous dispersion of a hydroxyacrylic resin according to claim 1 or 2, wherein the aqueous dispersion of a hydroxyacrylic resin has a solids content of 30 to 60% by weight and the aqueous dispersion of a hydroxyacrylic resin has an organic solvent content of 2 to 10% by weight.

9. The method for preparing an aqueous dispersion of a hydroxyacrylic resin according to claim 1, comprising the steps of:

(1) adding an organic solvent into a reaction kettle, introducing nitrogen, stirring and heating to obtain a hydroxyl-containing unsaturated monomer A₁Containing a hydrophobic unsaturated monomer B₁Uniformly mixing with a free radical initiator, dropwise adding into a reactor at a constant speed, keeping the reaction temperature at 80-170 ℃, and preserving heat for 0.5-1 hour after dropwise adding;

(2) unsaturated monomer A containing hydroxyl₂Containing a hydrophobic unsaturated monomer B₂Uniformly mixing an unsaturated monomer C containing an HDI tripolymer structure, a hydrophilic monomer D containing carboxylic acid or sulfonic acid and a free radical initiator, dropwise adding into a reaction vessel at a constant speed, keeping the reaction temperature at 80-170 ℃, and preserving heat for 1-3 hours after dropwise adding; the total dropping time of the monomers in the step (1) and the step (2) is 2-5 hours;

(3) and after the polymerization is finished, cooling, adding an amine neutralizer E for neutralization, and then adding water for uniform dispersion to obtain the hydroxyl acrylic resin aqueous dispersion.

10. The water-based two-component polyurethane coating is characterized by comprising the hydroxyl acrylic resin aqueous dispersion and a solvent-based HDI isocyanate curing agent.

Technical Field

The invention belongs to the technical field of water-based resin, and particularly relates to a hydroxyl acrylic resin aqueous dispersion and a preparation method thereof.

Background

As environmental regulations become more stringent, solvent-based coatings are increasingly being restricted in their use, and low VOC waterborne coatings are currently the trend in the coatings industry. The water-based two-component polyurethane coating has the characteristics of high gloss and fullness, good weather resistance, good chemical resistance and the like, and the comprehensive performance is close to or reaches that of a solvent-based two-component polyurethane coating, so the water-based two-component polyurethane coating is widely concerned at home and abroad, and the research and development are more active.

At present, hydrophilic modified water-dispersible isocyanate curing agents and hydroxyl acrylic resin aqueous dispersions are frequently used for compounding water-based two-component polyurethane coatings, but the hydrophilic group content of the hydrophilic modified water-dispersible isocyanate curing agents is high, the curing agents are easy to generate side reaction with water, the problems of no bubble film thickness, short service time and poor water resistance are generally solved, and the performance difference with solvent-based coatings is still obvious. Because the price of the water-dispersible isocyanate curing agent is high, the overall cost of the coating is much higher than that of a solvent-based coating, and the further popularization of the water-based two-component polyurethane coating is limited.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the hydroxyl acrylic resin aqueous dispersion and the preparation method thereof.

In order to achieve the purpose, the invention adopts the technical scheme that: an aqueous dispersion of hydroxy acrylic resin and a preparation method thereof, wherein the aqueous dispersion of hydroxy acrylic resin comprises the following preparation raw materials: unsaturated monomer A containing hydroxyl group₁Containing hydrophobic unsaturated monomers B₁Unsaturated monomer A containing hydroxyl group₂Containing hydrophobic unsaturated monomers B₂An unsaturated monomer C containing an HDI tripolymer structure and a hydrophilic monomer D containing carboxylic acid or sulfonic acid;

with unsaturated monomers A containing hydroxy groups₁And a hydrophobic unsaturated monomer B₁Based on the total mass of the hydroxyl group-containing unsaturated monomer A₁In a mass ratio of 10-50%, toThe hydrophobic unsaturated monomer B₁The mass ratio of (A) is 50-90%;

with unsaturated monomers A containing hydroxy groups₂Containing hydrophobic unsaturated monomers B₂The hydroxyl group-containing unsaturated monomer A based on the total mass of the HDI trimer structure-containing unsaturated monomer C and the carboxylic acid-or sulfonic acid-containing hydrophilic monomer D₂In a mass ratio of 10-50%, the hydrophobic unsaturated monomer B₂The mass ratio of the HDI-containing trimer structure is 0-40%, the mass ratio of the HDI-containing trimer structure-containing unsaturated monomer C is 20-70%, and the mass ratio of the carboxylic acid-containing or sulfonic acid-containing hydrophilic monomer D is 5-40%.

The hydroxyl acrylic resin aqueous dispersion prepared by using the unsaturated monomer C containing the HDI tripolymer structure can be compounded with a solvent type isocyanate curing agent with low price, the defect that the water dispersion type isocyanate curing agent is easy to generate side reaction with water can be avoided, and the compounded coating has good foamless film thickness, usable time and water resistance.

As a preferred embodiment of the present invention, a hydroxyl group-containing unsaturated monomer A₁And a hydrophobic unsaturated monomer B₁Based on the total mass of the hydroxyl group-containing unsaturated monomer A₁20-40% by mass of the hydrophobic unsaturated monomer B₁The mass ratio of the components is 60-80%;

with unsaturated monomers A containing hydroxy groups₂Containing hydrophobic unsaturated monomers B₂The hydroxyl group-containing unsaturated monomer A based on the total mass of the HDI trimer structure-containing unsaturated monomer C and the carboxylic acid-or sulfonic acid-containing hydrophilic monomer D₂20-40% by mass of the hydrophobic unsaturated monomer B₂The mass ratio of the HDI-containing trimer structure is 0-20%, the mass ratio of the HDI-containing trimer structure-containing unsaturated monomer C is 40-60%, and the mass ratio of the carboxylic acid-containing or sulfonic acid-containing hydrophilic monomer D is 10-30%.

As a preferred embodiment of the present invention, the hydroxyl group-containing unsaturated monomer A₁And a hydroxyl group-containing unsaturated monomer A₂Comprising at least one of the following monomers: hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate,hydroxybutyl methacrylate, polyethylene glycol methacrylate monoesters, polyethylene glycol acrylate monoesters, ring-opening addition products of the above monomers with epsilon-caprolactone.

As a preferred embodiment of the present invention, the hydrophobic unsaturated monomer B₁And a hydrophobic unsaturated monomer B₂Comprising at least one of the following monomers: methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, n-butyl methacrylate, n-butyl acrylate, isobutyl methacrylate, isobutyl acrylate, t-butyl methacrylate, t-butyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexyl acrylate, dodecyl methacrylate, dodecyl acrylate, octadecyl methacrylate, octadecyl acrylate, glycidyl methacrylate, glycidyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, 4-t-butylcyclohexyl methacrylate, 4-t-butylcyclohexyl acrylate, isobornyl methacrylate, isobornyl acrylate, vinyl acetate, vinyl chloride, dichloroethylene, styrene, methyl methacrylate, ethyl acrylate, n-butyl methacrylate, n-butyl acrylate, isobutyl methacrylate, ethyl methacrylate, isobutyl methacrylate, vinyl acetate, vinyl chloride, styrene, vinyl acetate, p-methylstyrene, m-methylstyrene, α -methylstyrene, methacrylonitrile, acrylonitrile, methacrylamide, acrylamide, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, 1, 4-butanediol dimethacrylate, 1, 4-butanediol diacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate.

As a preferred embodiment of the invention, the unsaturated monomer C structure containing HDI trimer structure is:

wherein X ═ O or NH; y ═ H or Me; n is 1-20; p is 1-10; q is 1-10; r is C1-50 linear or branched alkyl. Wherein n is 2-4 is the best; p is 4-8 is the best; q is 4-8, the best; r is preferably an alkyl group having 8 to 20 carbon atoms.

According to the invention, the unsaturated monomer C containing the HDI tripolymer structure grafted and modified by the alkyl polyether is adopted, and the unsaturated monomer C is very close to the HDI tripolymer in structure and has a surface active group with a nonionic structure, so that the unsaturated monomer C has a good emulsifying effect on a solvent-based HDI isocyanate curing agent when a two-component coating is prepared, and the prepared water-based two-component polyurethane coating has very high gloss.

As a preferred embodiment of the present invention, the carboxylic acid or sulfonic acid-containing hydrophilic monomer D includes at least one of the following monomers: methacrylic acid, acrylic acid, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium 2-acrylamido-2-methylpropanesulfonate, styrenesulfonic acid, and sodium styrenesulfonate. Methacrylic acid and acrylic acid are preferable for the reaction system of the present invention.

As a preferred embodiment of the present invention, the aqueous dispersion of a hydroxyacrylic resin further comprises a radical initiator, an amine neutralizer E, and an organic solvent, wherein the radical initiator is a peroxide radical initiator, and the peroxide radical initiator is at least one of cumyl peroxide, tert-butyl cumyl peroxide, di-tert-butyl peroxide, and di-tert-amyl peroxide; the amine neutralizer E is at least one of ammonia water, triethylamine, triethanolamine, dimethylethanolamine, 2-methyl-2-aminopropanol, dimethylisopropanolamine, methyldiethanolamine, ethyldiisopropylamine, diethylethanolamine, morpholine and N-methylmorpholine, and the neutralization degree is 50-120%; with unsaturated monomers A containing hydroxy groups₁Containing a hydrophobic unsaturated monomer B₁Unsaturated monomer A containing hydroxyl group₂Containing a hydrophobic unsaturated monomer B₂The mass ratio of the peroxide free radical initiator is 1-10%, the mass ratio of the organic solvent is 5-30%, the optimal mass ratio of the peroxide free radical initiator is 3-7%, and the half-life temperature of the peroxide free radical initiator in 0.2mol of benzene is 100-150 ℃; the optimal value of the neutralization degree is 80-100%.

As a preferred embodiment of the present invention, the aqueous dispersion of a hydroxyacrylic resin has a solids content of 30 to 60% by weight, and the aqueous dispersion of a hydroxyacrylic resin has an organic solvent content of 2 to 10% by weight. More preferably, the aqueous dispersion of a hydroxyacrylic resin has a solids content of 35 to 50 wt.%.

In addition, the invention also provides a preparation method of the hydroxyl acrylic resin aqueous dispersion, which comprises the following steps:

(1) adding an organic solvent into a reaction kettle, introducing nitrogen, stirring and heating to obtain a hydroxyl-containing unsaturated monomer A₁Containing a hydrophobic unsaturated monomer B₁Uniformly mixing with a free radical initiator, dropwise adding into a reactor at a constant speed, keeping the reaction temperature at 80-170 ℃, and preserving heat for 0.5-1 hour after dropwise adding; wherein the preferred reaction temperature is 100-105 ℃;

(2) unsaturated monomer A containing hydroxyl₂Hydrophobic unsaturated monomer B₂Uniformly mixing an unsaturated monomer C containing an HDI tripolymer structure and a hydrophilic monomer D containing carboxylic acid or sulfonic acid, dropwise adding into a reaction vessel at a constant speed, keeping the reaction temperature at 80-170 ℃, and preserving heat for 1-3 hours after dropwise adding; the total dropping time of the monomers in the step (1) and the step (2) is 2-5 hours; wherein the preferred reaction temperature is 100-105 ℃;

(3) and after the polymerization is finished, cooling, adding an amine neutralizer E for neutralization, and then adding water for uniform dispersion to obtain the hydroxyl acrylic resin aqueous dispersion.

The invention also claims a water-based two-component polyurethane coating which comprises the hydroxyl acrylic resin aqueous dispersion composition and a solvent-based HDI isocyanate curing agent.

The hydroxyl acrylic acid dispersoid composition and the solvent HDI isocyanate curing agent are compounded to obtain the water-based two-component polyurethane coating, and a coating film of the coating has excellent gloss, no bubble film thickness, usable time and water resistance.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, after the unsaturated monomer C containing the HDI tripolymer structure grafted and modified by the alkyl polyether is reacted into the acrylic polymer through free radical polymerization, the unsaturated monomer C is very close to the HDI tripolymer in structure and has a surface active group with a nonionic structure, so that the unsaturated monomer C has a good emulsifying effect on a solvent type HDI isocyanate curing agent when a two-component coating is prepared, and the prepared water-based two-component polyurethane coating has very high gloss. Meanwhile, because the hydrophilic modified water dispersible isocyanate curing agent is not used, hydrophilic components in a film forming substance are reduced, the occurrence of side reactions is reduced, and the thickness, the service life and the water resistance of the foamless film are greatly improved.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

Example 1

The invention relates to a hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent and an embodiment of a preparation method thereof, which comprises the following specific steps:

(1) synthesis of unsaturated monomer IM1 containing HDI trimer structure

100.0g of Desmodur N3300 (Colesine HDI trimer, NCO value 21.8%), 0.16g of BHT and 0.16g of bismuth isooctanoate were charged into a reaction vessel, the temperature was raised to 90 ℃ and 19.3g of hydroxyethyl methacrylate was slowly dropped into the reaction vessel, dropping was completed in about 30 minutes, and then the temperature was maintained at 90 ℃ for 3 hours. 113.4g of Dehydrol O4 (Corning nonionic surfactant, adduct of 1mol of octanol with 4mol of ethoxy) were slowly added dropwise over a period of about 30 minutes and then incubated at 90 ℃ until the NCO value became zero. The obtained clear transparent liquid is an unsaturated monomer IM1 containing HDI tripolymer structure, the approximate structure of which is shown as follows, and the structural formula of the monomer is shown as (C):

(2) synthesis of hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent

Introducing nitrogen, adding 27.0g of propylene glycol butyl ether and 27.0g of light naphtha into a reaction vessel, stirring and heating to 140 ℃, uniformly mixing 46.0g of methyl methacrylate, 46.0g of isobornyl methacrylate, 20.0g of isobutyl methacrylate, 69.0g of hydroxypropyl methacrylate, 41.0g of n-butyl acrylate and 10.0g of dicumyl peroxide, dropwise adding into the reaction vessel at a constant speed within 140min, keeping the reaction temperature at 138 and 142 ℃, and preserving the temperature for 30 min after the dropwise adding is finished. 21.0g of hydroxypropyl methacrylate, 32.0g of unsaturated monomer IM1, 11.0g of methacrylic acid and 2.8g of dicumyl peroxide are mixed and uniformly dripped into a reaction vessel within 40min, the reaction temperature is kept at 138-142 ℃, and after the dripping is finished, the temperature is kept for 120 min. Cooling to about 90 ℃, adding 10.0g N and N-dimethylethanolamine, stirring for 20 minutes, slowly dripping 317.0g of deionized water under high-speed stirring, and finishing dripping for about 2 hours to obtain the milky-white emulsion resin dispersion with blue light.

The dispersion had a solids content of 44 wt%, a viscosity of 2200cps, a hydroxyl content of 3.6 wt% of the solids component, and a solvent content of 8%.

Example 2

The invention relates to a hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent and an embodiment of a preparation method thereof, which comprises the following specific steps:

(1) synthesis of unsaturated monomer IM1 containing HDI trimer structure

100.0g of Desmodur N3300 (Colesine HDI trimer, NCO value 21.8%), 0.16g of BHT and 0.16g of bismuth isooctanoate were charged into a reaction vessel, the temperature was raised to 90 ℃ and 19.3g of hydroxyethyl methacrylate was slowly dropped into the reaction vessel, dropping was completed in about 30 minutes, and then the temperature was maintained at 90 ℃ for 3 hours. 113.4g of Dehydrol O4 (Corning nonionic surfactant, adduct of 1mol of octanol with 4mol of ethoxy) were slowly added dropwise over a period of about 30 minutes and then incubated at 90 ℃ until the NCO value became zero. The obtained clear transparent liquid is an unsaturated monomer IM1 containing HDI tripolymer structure, the approximate structure of which is shown as follows, and the structural formula of the monomer is shown as (C):

(2) synthesis of hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent

Introducing nitrogen, adding 27.0g of propylene glycol butyl ether and 27.0g of light naphtha into a reaction vessel, stirring and heating to 140 ℃, uniformly mixing 46.0g of methyl methacrylate, 46.0g of isobornyl methacrylate, 20.0g of isobutyl methacrylate, 69.0g of hydroxypropyl methacrylate, 41.0g of n-butyl acrylate and 10.0g of dicumyl peroxide, dropwise adding into the reaction vessel at a constant speed within 140min, keeping the reaction temperature at 138 and 142 ℃, and preserving the temperature for 30 min after the dropwise adding is finished. 21.0g of hydroxypropyl methacrylate, 6.0g of methyl methacrylate, 6.0g of butyl acrylate, 20.0g of unsaturated monomer IM1, 11.0g of methacrylic acid and 2.8g of dicumyl peroxide are mixed and dripped into a reaction vessel at a constant speed within 40min, the reaction temperature is kept at 138-142 ℃, and after the dripping is finished, the temperature is kept for 120 min. Cooling to about 90 ℃, adding 10.0g N and N-dimethylethanolamine, stirring for 20 minutes, slowly dripping 317.0g of deionized water under high-speed stirring, and finishing dripping for about 2 hours to obtain the milky-white emulsion resin dispersion with blue light.

The dispersion had a solids content of 44 wt%, a viscosity of 2500cps, a hydroxyl content of 3.6 wt% of the solids component, and a solvent content of 8%.

Example 3

The invention relates to a hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent and an embodiment of a preparation method thereof, which comprises the following specific steps:

(1) synthesis of unsaturated monomer IM2 containing HDI trimer structure

100.0g Desmodur N3300 (Colesine HDI trimer, NCO value 21.8%), 0.16g BHT, 0.16g bismuth isooctanoate were added to a reaction vessel, the temperature was raised to 90 ℃, 21.4g 4-hydroxybutyl acrylate was slowly dropped into the reaction vessel, dropping was completed within about 30 minutes, and then the temperature was maintained at 90 ℃ for 3 hours. 172.0g of Lutensol TO-6 (Pasteur nonionic surfactant, adduct of 1mol of isomeric tridecanol with 6mol of ethoxy group) were slowly added dropwise over a period of about 30 minutes and then incubated at 90 ℃ until the NCO value became zero. The obtained clear transparent liquid is an unsaturated monomer IM1 containing HDI tripolymer structure, the approximate structure of which is shown as follows, and the structural formula of the monomer is shown as (C):

(2) synthesis of hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent

Introducing nitrogen, adding 27.0g of propylene glycol butyl ether and 27.0g of light naphtha into a reaction vessel, stirring and heating to 140 ℃, uniformly mixing 46.0g of methyl methacrylate, 46.0g of isobornyl methacrylate, 20.0g of isobutyl methacrylate, 69.0g of hydroxypropyl methacrylate, 41.0g of n-butyl acrylate and 10.0g of dicumyl peroxide, dropwise adding into the reaction vessel at a constant speed within 140min, keeping the reaction temperature at 138 and 142 ℃, and preserving the temperature for 30 min after the dropwise adding is finished. 21.0g of hydroxypropyl methacrylate, 32.0g of unsaturated monomer IM2, 11.0g of methacrylic acid and 2.8g of dicumyl peroxide are mixed and uniformly dripped into a reaction vessel within 40min, the reaction temperature is kept at 138-142 ℃, and after the dripping is finished, the temperature is kept for 120 min. Cooling to about 90 ℃, adding 10.0g N and N-dimethylethanolamine, stirring for 20 minutes, slowly dripping 317.0g of deionized water under high-speed stirring, and finishing dripping for about 2 hours to obtain the milky-white emulsion resin dispersion with blue light.

The dispersion had a solids content of 44 wt%, a viscosity of 2200cps, a hydroxyl content of 3.6 wt% of the solids component, and a solvent content of 8%.

Example 4

The invention relates to a hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent and an embodiment of a preparation method thereof, which comprises the following specific steps:

(1) synthesis of unsaturated monomer IM3 containing HDI trimer structure

100.0g of Desmodur N3300 (Colesine HDI trimer, NCO value 21.8%), 0.16g of BHT and 0.16g of bismuth isooctanoate were charged into a reaction vessel, the temperature was raised to 90 ℃ and 19.3g of hydroxyethyl methacrylate was slowly dropped into the reaction vessel, dropping was completed in about 30 minutes, and then the temperature was maintained at 90 ℃ for 3 hours. The temperature is lowered to 50 ℃ and 181.3g of octadecylamine polyoxyethylene ether (5) (an adduct of 1mol of octadecylamine and 5mol of ethoxy group, euphorbia chemistry) are slowly dropped off over about 30 minutes, and then the temperature is raised to 70 ℃ and the temperature is maintained until the NCO value is zero. The yellow clear transparent liquid is obtained as an unsaturated monomer IM1 containing HDI tripolymer structure, the approximate structure of which is shown as follows, and the structural formula of the monomer is shown as (C):

(2) synthesis of hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent

Introducing nitrogen, adding 27.0g of propylene glycol butyl ether and 27.0g of light naphtha into a reaction vessel, stirring and heating to 140 ℃, uniformly mixing 46.0g of methyl methacrylate, 46.0g of isobornyl methacrylate, 20.0g of isobutyl methacrylate, 69.0g of hydroxypropyl methacrylate, 41.0g of n-butyl acrylate and 10.0g of dicumyl peroxide, dropwise adding into the reaction vessel at a constant speed within 140min, keeping the reaction temperature at 138 and 142 ℃, and preserving the temperature for 30 min after the dropwise adding is finished. 21.0g of hydroxypropyl methacrylate, 32.0g of unsaturated monomer IM3, 11.0g of methacrylic acid and 2.8g of dicumyl peroxide are mixed and uniformly dripped into a reaction vessel within 40min, the reaction temperature is kept at 138-142 ℃, and after the dripping is finished, the temperature is kept for 120 min. Cooling to about 90 ℃, adding 10.0g N and N-dimethylethanolamine, stirring for 20 minutes, slowly dripping 317.0g of deionized water under high-speed stirring, and finishing dripping for about 2 hours to obtain the milky-white emulsion resin dispersion with blue light.

The dispersion had a solids content of 44 wt%, a viscosity of 1500cps, a hydroxyl content of 3.6 wt% of the solids component, and a solvent content of 8%.

Comparative example 1

The invention relates to a hydroxyl acrylic resin aqueous dispersion compatible with solvent type isocyanate curing agent and a comparative example of a preparation method thereof, which comprises the following specific steps:

introducing nitrogen, adding 27.0g of propylene glycol butyl ether and 27.0g of light naphtha into a reaction vessel, stirring and heating to 140 ℃, uniformly mixing 46.0g of methyl methacrylate, 46.0g of isobornyl methacrylate, 20.0g of isobutyl methacrylate, 69.0g of hydroxypropyl methacrylate, 41.0g of n-butyl acrylate and 10.0g of dicumyl peroxide, dropwise adding into the reaction vessel at a constant speed within 140min, keeping the reaction temperature at 138 and 142 ℃, and preserving the temperature for 30 min after dropwise adding. Uniformly mixing 15.0g of methyl methacrylate, 21.0g of hydroxypropyl methacrylate, 17.0g of butyl acrylate, 11.0g of methacrylic acid and 2.8g of dicumyl peroxide, dropwise adding the mixture into a reaction container at a constant speed within 40min, keeping the reaction temperature at 138-142 ℃, and preserving the temperature for 120 min after the dropwise adding is finished. Cooling to about 90 ℃, adding 10.0g N and N-dimethylethanolamine, stirring for 20 minutes, slowly dripping 317.0g of deionized water under high-speed stirring, and finishing dripping for about 2 hours to obtain the milky-white emulsion resin dispersion with blue light.

The dispersion had a solids content of 44 wt%, a viscosity of 2500cps, a hydroxyl content of 3.6 wt% of the solids component, and a solvent content of 8%.

Test example 1: performance testing

The hydroxyl acrylic dispersions prepared in examples 1 to 4 and comparative example 1 and the commercial hydroxyl acrylic dispersion PA-4842 (Guangzhi, hydroxyl content 3.3%, solid content 43%) were respectively tested with the following isocyanate curing agents:

curing agent 1: guanzhi OS-9016, a commercial water-dispersible HDI type curing agent, solid content: 80% and NCO value 16.3%.

Curing agent 2: kesichun 3300, commercial HDI trimer curing agent, solid content: 100% and NCO value 21.8%. When in use, the solution is diluted to 70 percent of solid content by PMA.

Curing agent 3: asahi to TPA-100, commercial HDI trimer curing agent, solid content: 100%, NCO value 23.1%. When in use, the solution is diluted to 70 percent of solid content by PMA.

Curing agent 4: wanhua HT-100, commercial HDI trimer curing agent, solid content: 100%, NCO value 22.0%. When in use, the solution is diluted to 70 percent of solid content by PMA.

Aqueous two-component polyurethane coatings were formulated according to the formulations in table 1 for performance comparison. The addition of the curing agent was calculated as NCO/OH 1.5.

TABLE 1 aqueous two-component polyurethane coating formulation

The curing construction conditions are as follows: and (3) spraying tinplate, placing the tinplate for 20min at room temperature, then placing the tinplate into a blast oven at 80 ℃ for baking for 1 lab, and then placing the tinplate for 3 days at room temperature to perform gloss and water resistance tests. The bubble-free film thickness is the highest dry film thickness that does not bubble upon spraying. The paint is prepared and placed at the temperature of 35 ℃, the gloss of the paint film and the viscosity of the paint are measured at intervals, and the time without obvious change is the service life. The water resistance is that after the drying is completed, the mixture is soaked into water at 40 ℃, and the time of no foaming and light loss is observed. The test results are shown in table 2.

TABLE 2 Performance test results for aqueous two-component polyurethane coatings

The results show that the hydroxy acrylic acid dispersoids synthesized in the embodiments 1 to 4 contain an HDI trimer structure grafted and modified by alkyl polyether, have very good emulsification effect on different HDI trimer curing agents for non-hydrophilic modified solvent-based coatings, and can obtain paint films with high gloss and high fullness. When conventional hydroxyacrylic dispersions (comparative example 1 and Guanzhi PA-4842) were added to a non-hydrophilically modified HDI trimer curing agent, the curing agent was not well emulsified and only a very low gloss coating film was obtained. Compared with a hydrophilic modified water dispersible isocyanate curing agent OS-9016 water-based two-component polyurethane coating, the HDI trimer curing agent for the non-hydrophilic modified solvent-based coating has very good foamless film thickness, service life and water resistance.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.