1. A preparation method of a polyurethane modified acrylic acid water-based polymer dispersant is characterized by comprising the following steps:

s1, preparation of polyhydroxy acrylic acid copolymer: adding tetramethylbenzene into a first reaction vessel, dropwise adding the monomer mixture and the initiator at the temperature of 140 ℃ and 150 ℃ under the protection of nitrogen, after the dropwise adding is finished, keeping the temperature for reacting for 1-3h, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic acid copolymer solution; wherein the mass ratio of the tetramethylbenzene to the monomer mixture is 1: 1, the mass of the initiator is 1-3% of that of the monomer mixture; the monomer mixture comprises the following components in percentage by mass: 10-40% of conventional acrylate monomer, 30-50% of hydroxypropyl acrylate and 20-50% of nonionic acrylate monomer.

S2, preparing a polyurethane modified acrylic acid water-based polymer dispersing agent: adding styrenated phenol polyoxyethylene ether into a second reaction vessel, adding an aromatic isocyanic acid polymer under the protection of nitrogen at 50-70 ℃, and carrying out heat preservation reaction for 0.5-1 h; then adding the polyhydroxy acrylic acid copolymer and the organic metal catalyst prepared in the step S1, heating to 75-90 ℃, and continuing to perform heat preservation reaction for 1-3 h; heating to 140 ℃ and 160 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding distilled water, mixing uniformly, and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant; wherein the molar ratio of the styrenated phenol polyoxyethylene ether to the aromatic isocyanic acid polymer is (2-5): 1, the molar ratio of the polyhydroxy acrylic acid copolymer to the aromatic isocyanic acid polymer is (0.2-0.6): 1, the adding mass of the organic metal catalyst is 0.2-0.5% of the total mass of the reactants in the step S2; the addition amount of the distilled water is 40-70% of the total mass of the reactants.

2. The method according to claim 1, wherein the conventional acrylate monomer is a mixture of two or more of an acrylate monomer or a methacrylate monomer having a carbon chain length of 5 to 12.

3. The method of claim 1, wherein the initiator is selected from di-t-butyl peroxide and/or di-t-amyl peroxide.

4. The method according to claim 1, wherein the nonionic acrylate monomer is at least one of an acrylate monomer and a methacrylate monomer having a carbon chain length of 10 to 40 and containing a polyethylene glycol segment.

5. The method according to claim 1, wherein the styrenated phenol polyoxyethylene ether is one of nonionic polymers containing 10 to 20 polyethylene glycol segment structures and using phenol with a polybasic aryl structure as an initiator.

6. The method according to claim 1, wherein the aromatic isocyanate polymer is an isocyanate polymer containing 2 to 10 aromatic hydrocarbon structures.

7. The method of claim 1, wherein the organometallic catalyst is an organometallic bismuth catalyst.

8. The polyurethane-modified acrylic aqueous polymer dispersant prepared by the preparation method according to any one of claims 1 to 7.

Background

In coating and ink applications, common pigments include inorganic pigments, organic pigments, carbon black, and the like. Wherein, the organic pigment has the characteristics of bright color, strong tinting strength, no toxicity and the like, and is widely applied in the fields of coatings and printing ink. Different pigment surfaces have different physical and chemical properties, requiring different anchoring groups for different pigments. Such as acid group carboxylic acid, phosphoric acid, sulfuric acid, etc. have good wetting effect on inorganic pigments; carbon black has a larger specific surface, requires more anchoring groups, and is optimally wetted by amino-containing groups as a general experience; the aromatic groups are particularly helpful for the wetting and stabilization of organic pigments. Therefore, the dispersant with an aromatic hydrocarbon structure is selected to have better wetting and stabilizing effects on the organic pigment.

In addition, an important factor determining the dispersing performance of the dispersant is the number of anchor groups, and if only one anchor group is on one molecular chain, the dispersant and pigment particles can be peeled off once replaced by other solvent groups, so that the pigment is flocculated. The molecular chain is provided with a plurality of anchoring groups, so that the stripping is not easy to occur, and the long-term stability is kept. Therefore, the high-performance organic pigment dispersant is a high-molecular dispersant containing a plurality of aromatic hydrocarbon structures on a molecular chain.

With the continuous and deep research and application of water-based coatings and inks, water-based dispersants are also developed, and compared with solvent-based dispersants, the water-based dispersants have hydrophilic groups and hydrophilic segments, such as ammonium salts and polyethylene glycol segments, besides anchor groups. The ammonium salt micromolecules have excellent hydrophilicity, but the strong ionization effect of the ammonium salt micromolecules has great influence on the water resistance, salt mist resistance and other properties of the coating film. Therefore, high performance aqueous dispersants must avoid containing a large amount of ammonium salt ions, and polymeric aqueous dispersants containing polyethylene glycol segments are the focus of research.

In conclusion, the development of an environment-friendly water-based polymeric dispersant containing a plurality of aromatic hydrocarbon groups, containing no ammonium salt ions, and containing no organic solvent and organic tin metal is an important research direction of the current water-based organic pigment dispersant.

Disclosure of Invention

In view of the above problems in the prior art, an object of the present invention is to provide a method for preparing an aqueous polymeric dispersant for organic pigments, the polymeric dispersant prepared by the method contains a plurality of aromatic hydrocarbon groups, does not contain ammonium salt ions, does not contain organic solvents and organotin metals, and is environmentally friendly.

In order to achieve the above purpose, the invention provides the following technical scheme:

a preparation method of a polyurethane modified acrylic acid water-based polymer dispersant comprises the following steps:

s1, preparation of polyhydroxy acrylic acid copolymer: adding tetramethylbenzene into a first reaction vessel, dropwise adding the monomer mixture and the initiator at the temperature of 140 ℃ and 150 ℃ under the protection of nitrogen, after the dropwise adding is finished, keeping the temperature for reacting for 1-3h, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic acid copolymer solution; wherein the mass ratio of the tetramethylbenzene to the monomer mixture is 1: 1, the mass of the initiator is 1-3% of that of the monomer mixture; the monomer mixture comprises the following components in percentage by mass: 10-40% of conventional acrylate monomer, 30-50% of hydroxypropyl acrylate and 20-50% of nonionic acrylate monomer.

S2, preparing a polyurethane modified acrylic acid water-based polymer dispersing agent: adding styrenated phenol polyoxyethylene ether into a second reaction vessel, adding an aromatic isocyanic acid polymer under the protection of nitrogen at 50-70 ℃, and carrying out heat preservation reaction for 0.5-1 h; then adding the polyhydroxy acrylic acid copolymer and the organic metal catalyst prepared in the step S1, heating to 75-90 ℃, and continuing to perform heat preservation reaction for 1-3 h; heating to 140 ℃ and 160 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding distilled water, mixing uniformly, and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant; wherein the molar ratio of the styrenated phenol polyoxyethylene ether to the aromatic isocyanic acid polymer is (2-5): 1, the molar ratio of the polyhydroxy acrylic acid copolymer to the aromatic isocyanic acid polymer is (0.2-0.6): 1, the adding mass of the organic metal catalyst is 0.2-0.5% of the total mass of the reactants in the step S2; the addition amount of the distilled water is 40-70% of the total mass of the reactants.

In the above scheme, "the total mass of the reactants in step S2" refers to the total mass of the raw materials participating in the reaction in step S2, and specifically includes: sum of mass of styrenated phenol polyoxyethylene ether, aromatic isocyanic acid polymer and polyhydroxyacrylic acid copolymer; the "total mass of reactants" in the "amount of distilled water added is 40 to 70% of the total mass of reactants" specifically means the sum of the mass of the monomer mixture, the initiator in step S1, and the mass of the styrenated phenol polyoxyethylene ether, the aromatic isocyanate polymer, and the polyhydroxyacrylic acid copolymer in step S2.

Further, the conventional acrylate monomer is a mixture of two or more of acrylate monomers or methacrylate monomers having a carbon chain length of 5 to 12. Two or more of methyl methacrylate, butyl acrylate and isooctyl acrylate are preferred.

Further, the non-ionic acrylate monomer is at least one of an acrylate monomer or a methacrylate monomer which contains a polyethylene glycol segment and has a carbon chain length of 10 to 40. Preferably methoxypolyethylene glycol (550) monomethacrylate (sartomer CD552), methoxypolyethylene glycol (550) monoacrylate (sartomer CD553), methoxypolyethylene glycol monoacrylate (sartomer SR 551).

Further, the initiator is selected from di-tert-butyl peroxide and/or di-tert-amyl peroxide, preferably di-tert-amyl peroxide.

Furthermore, the styrenated phenol polyoxyethylene ether is one of nonionic polymers which take phenol with a polybasic aryl structure as an initiator and contain 10-20 polyethylene glycol chain segment structures. Preferably, the nonionic polymer contains 10 polyethylene glycol segments (Shanghai loyalty BEO-100) or 20 polyethylene glycol segments (Shanghai loyalty BEO-200).

Further, the aromatic isocyanate polymer is an isocyanate polymer containing 2 to 10 aromatic hydrocarbon structures. Preferred kesi woundIL1451BA, sapes poiurea hr.b.s.

Further, the organometallic catalyst is an organometallic bismuth catalyst. Preferably ZHUHAI gold ball-532B。

The second object of the present invention is to provide a polyurethane-modified acrylic aqueous polymer dispersant prepared by the preparation method according to any one of the above embodiments.

Compared with the prior art, the invention has the beneficial effects that:

1) the polyurethane modified acrylic acid water-based high molecular dispersing agent prepared by the invention is polymerized with styrenated phenol polyoxyethylene ether through an aromatic isocyanate polymer, and then is connected to an acrylate molecular chain through reaction with hydroxyl, so that a multi-element aromatic hydrocarbon structure is provided on the molecular structure, the polyurethane modified acrylic acid water-based high molecular dispersing agent has more excellent wetting dispersibility on organic pigments, and the viscosity of the system is more effectively reduced.

2) The polyurethane modified acrylic acid waterborne polymer dispersant prepared by the invention has the advantages that the non-ionic acrylate monomer participates in free radical copolymerization, the polyurethane reaction introduces styrenated phenol polyoxyethylene ether and the like for reaction, and the hydrophilicity of the dispersant is adjusted by introducing hydrophilic polyethylene glycol chain segment groups on the molecular structure. The coating has high molecular weight and does not contain ionic salt with strong hydrophilicity, and the water resistance, salt spray resistance and other properties of the coating are not influenced.

3) The polyurethane modified acrylic acid aqueous polymer dispersant prepared by the invention uses organic metal bismuth to replace the traditional organic tin as a catalyst, and is an environment-friendly polymer dispersant with high performance and no organic solvent or organic metal.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to specific 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

A polyurethane modified acrylic acid water-based polymer dispersant is prepared from the following raw materials: methyl methacrylate, butyl acrylate, isooctyl acrylate, hydroxypropyl acrylate, sartomer CD553, di-tert-amyl peroxide, tetramethylbenzene,IL1451BA、BEO-200、532B, distilled water;

the preparation method of the water-based polymer dispersant specifically comprises the following steps:

s1, adding 50g of tetramethylbenzene into a first reaction container, weighing 10g of methyl methacrylate, 2.5g of butyl acrylate, 7.5g of isooctyl acrylate, 15g of hydroxypropyl acrylate, 15g of sartomera CD553 and 0.5g of di-tert-amyl peroxide, and uniformly mixing to form a mixture; dropwise adding a mixture consisting of a monomer mixture and an initiator under the protection of nitrogen at 150 ℃, after dropwise adding is finished for 2 hours, preserving heat for reaction for 2 hours, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic acid copolymer solution;

s2, adding 40g of BEO-200 into a second reaction vessel, adding 26.47g of BEO-200 into the second reaction vessel at 70 ℃ under the protection of nitrogenIL1451BA, and keeping the temperature for 0.5 h; 13.49g of the polyhydroxyacrylic acid copolymer prepared in step S1 and 0.24g of532B, then heating to 75 ℃, and continuing the heat preservation reaction for 3 hours; and then heating to 140 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding 40.16g of distilled water, uniformly mixing and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant.

Example 2

A polyurethane modified acrylic acid water-based polymer dispersant is prepared from the following raw materials: methyl methacrylate, butyl acrylate, isooctyl acrylate, hydroxypropyl acrylate, sartomer SR551, di-tert-amyl peroxide, tetramethylbenzene, POLURENE HR.B.S, BEO-100,532B, distilled water;

the preparation method of the water-based polymer dispersant specifically comprises the following steps:

s1, adding 50g of tetramethylbenzene into a first reaction container, weighing 2.5g of methyl methacrylate, 2.5g of butyl acrylate, 5g of isooctyl acrylate, 15g of hydroxypropyl acrylate, 25g of sartomera SR551 and 1.5g of di-tert-amyl peroxide, and uniformly mixing to obtain a mixture; dropwise adding a mixture consisting of a monomer mixture and an initiator at 140 ℃ under the protection of nitrogen, keeping the temperature for 2 hours after the dropwise adding is finished for 3 hours, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic acid copolymer solution;

s2, adding 40g of BEO-100 into a second reaction vessel, adding 37.21g of POLURENE HR.B.S under the protection of nitrogen at 50 ℃, and reacting for 1 hour under the condition of heat preservation; further, 20.49g of the polyhydroxyacrylic acid copolymer prepared in step S1 and 0.39g of532B, then heating to 80 ℃, and continuing to perform heat preservation reaction for 2 hours; and then heating to 150 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding 69.22g of distilled water, uniformly mixing and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant.

Example 3

A polyurethane modified acrylic acid water-based polymer dispersant is prepared from the following raw materials: butyl acrylate, isooctyl acrylate, hydroxypropyl acrylate, sartomer CD552, di-tert-amyl peroxide, tetramethylbenzene,IL1451BA、BEO-100、532B, distilled water;

the preparation method of the water-based polymer dispersant specifically comprises the following steps:

s1, adding 50g of tetramethylbenzene into a first reaction container, weighing 2.5g of butyl acrylate, 7.5g of isooctyl acrylate, 20g of hydroxypropyl acrylate, 20g of sartomer CD552 and 1g of di-tert-amyl peroxide, and uniformly mixing; dropwise adding a monomer and initiator mixture at 150 ℃ under the protection of nitrogen, keeping the temperature for reaction for 3 hours after the dropwise adding is finished for 4 hours, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic copolymer solution;

s2, adding 40g of BEO-100 into a second reaction vessel, and adding 40.23g of BEO-100 into the second reaction vessel at 60 ℃ under the protection of nitrogenIL1451BA, and keeping the temperature for 1 h; further, 15.37g of the polyhydroxyacrylic acid copolymer prepared in step S1 and 0.48g of532B, then heating to 80 ℃, and continuing to perform heat preservation reaction for 2 hours; then heating to 160 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding 102.31g of distilled water, mixing uniformly, and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant.

Example 4

A polyurethane modified acrylic acid water-based polymer dispersant is prepared from the following raw materials: butyl acrylate, isooctyl acrylate, hydroxypropyl acrylate, sartomer SR551, di-tert-amyl peroxide, tetramethylbenzene, POLURENE HR.B.S, BEO-200, and,532B, distilled water;

the preparation method of the water-based polymer dispersant specifically comprises the following steps:

s1, adding 50g of tetramethylbenzene into a first reaction container, weighing 2.5g of butyl acrylate, 2.5g of isooctyl acrylate, 20g of hydroxypropyl acrylate, 25g of sartomer SR551 and 1.5g of di-tert-amyl peroxide, and uniformly mixing; dropwise adding a mixture of a monomer and an initiator at 140 ℃ under the protection of nitrogen, keeping the temperature for reaction for 1h after dropwise adding is finished for 2h, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic copolymer solution;

s2, adding 40g of BEO-200 into a second reaction vessel, adding 24.48g of POLURENE HR.B.S under the protection of nitrogen at 70 ℃, and carrying out heat preservation reaction for 0.5 h; further, 10.12g of the polyhydroxyacrylic acid copolymer prepared in step S1 and 0.12g of532B, then heating to 75 ℃, and continuing to perform heat preservation reaction for 2 hours; then heating to 150 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding 134.27g of distilled water, mixing uniformly, and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant.

Example 5

A polyurethane modified acrylic acid water-based polymer dispersant is prepared from the following raw materials: methyl methacrylate, butyl acrylate, isooctyl acrylate, hydroxypropyl acrylate, sartomer SR551, di-tert-amyl peroxide, tetramethylbenzene,IL1451BA、BEO-100、532B, distilled water;

the preparation method of the water-based polymer dispersant specifically comprises the following steps:

s1, adding 50g of tetramethylbenzene into a first reaction container, weighing 5g of methyl methacrylate, 2.5g of butyl acrylate, 7.5g of isooctyl acrylate, 25g of hydroxypropyl acrylate, 10g of sartomera SR551 and 1g of di-tert-amyl peroxide, and uniformly mixing; dropwise adding a mixture of a monomer and an initiator at 140 ℃ under the protection of nitrogen, keeping the temperature for 2 hours after the dropwise adding is finished, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic copolymer solution;

s2, adding 40g of BEO-100 into a second reaction vessel, and adding 40.23g of BEO-100 into the second reaction vessel at 70 ℃ under the protection of nitrogenIL1451BA, and keeping the temperature for 0.5 h; further, 12.3g of the polyhydroxyacrylic acid copolymer prepared in step S1 and 0.28g of532B, then raising the temperature to 90 ℃, and continuing the heat preservation reaction for 1 h; and then heating to 160 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding 100g of distilled water, uniformly mixing and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant.

Example 6

A polyurethane modified acrylic acid water-based polymer dispersant is prepared from the following raw materials: methyl methacrylate, isooctyl acrylate, hydroxypropyl acrylate, sartomer CD552, di-t-amyl peroxide, tetramethylbenzene, POLURENE HR.B.S, BEO-200, and,532B, distilled water;

the preparation method of the water-based polymer dispersant specifically comprises the following steps:

s1, adding 50g of tetramethylbenzene into a first reaction vessel, weighing 2.5g of methyl methacrylate, 2.5g of isooctyl acrylate, 25g of hydroxypropyl acrylate, 20g of sardoxa CD552 and 0.5g of di-tert-amyl peroxide, and uniformly mixing. Dropwise adding a mixture of a monomer and an initiator at 140 ℃ under the protection of nitrogen, keeping the temperature for reacting for 3 hours after dropwise adding is finished for 4 hours, cooling to 60 ℃ after the reaction is finished, and filtering to obtain a polyhydroxy acrylic copolymer solution;

s2, adding 40g of BEO-200 into a second reaction vessel, adding 24.48g of POLURENE under the protection of nitrogen at 50 DEG CHR, B and S, and reacting for 1 hour under the condition of heat preservation; further, 8.09g of the polyhydroxyacrylic acid copolymer prepared in step S1 and 0.36g ofAnd (4) 532B, then raising the temperature to 75 ℃, and continuing the heat preservation reaction for 2 h. Heating to 140 ℃, closing nitrogen, vacuumizing, removing tetramethylbenzene, cooling to 60 ℃, adding 66.53g of distilled water, mixing uniformly, and filtering to obtain the polyurethane modified acrylic acid aqueous polymer dispersant.

The aqueous polymeric dispersants prepared in examples 1-6 and the commercially available 190 dispersant were added to an organic red paste formulation (table 1), and glass beads (particle size 2-2.5mm) 1.8 times the weight of the paste formulation were added, and the mixture was milled at high speed for 5 hours on a shaker and filtered to obtain pastes whose properties were measured as shown in table 2.

TABLE 1 organic Red slurry grinding formulation

TABLE 2 organic Red paste test results

From the results of the tests in Table 2, it can be seen that the aqueous organic red non-resin color paste prepared from the dispersion of example 5 and the commercial 190 dispersant has the best performance.

The dispersant prepared in example 5 and the commercially available dispersant 190 were added to a phthalocyanine blue color paste formulation (table 3), and glass beads (particle size 2-2.5mm) 1.8 times the weight of the color paste formulation were added, and the mixture was milled at high speed for 5 hours in a shaker and filtered to obtain color pastes whose properties were measured as shown in table 4.

TABLE 3 Phthalein blue color paste grinding formula

TABLE 4 phthalocyanine blue color paste test results

Test items	Example 5	Commercially available 190
			Fineness of the scraping plate	≤5μm	≤5μm
Color paste viscosity (mpa.s)	325	355
			Transparency of color paste scraper	Good transparency	Good transparency
Color paste storage stability (14 days at 50 ℃ C.)	The viscosity rises by less than or equal to 10 percent and does not coarsen	The viscosity rises by less than or equal to 10 percent and does not coarsen

The test results in Table 4 show that the aqueous phthalocyanine blue non-resin color paste prepared by the dispersion of the example 5 and the commercial 190 dispersant has good performance.

The dispersant prepared in example 5 and the water-based organic red resin-free color paste prepared by the commercial 190 dispersant are respectively added into5201 Water soluble acrylic baking finish system, as shown in Table 5.

TABLE 5 Water-soluble acrylic baking varnish formulations

The dispersant prepared in example 5 and a commercially available 190 dispersant were used to prepare an aqueous red acrylic baking varnish, the components were weighed according to the formulation shown in table 5, mixed uniformly by a conventional method in the art, scraped and cured, and the film properties were tested, and the test results are shown in table 6.

TABLE 6 test results of waterborne Red acrylic baking varnish films

Test items	Example 5	Commercially available 190
			Gloss (60 degree)	92	91
Color development property	Good color development and no fog shadow	Good color development and no fog shadow
			Water resistance (40 ℃ C. 12h)	Complete paint film, no blistering and no peeling off	Slight blistering and no flaking of paint film
Salt spray resistance (5% NaCl 120h)	Complete paint film without large-area corrosion	Complete paint film and slightly serious rust

The test results show that the dispersant prepared in example 5 has excellent dispersing effect on organic pigments, does not affect the water resistance and salt spray resistance of paint films, and meets the design requirements.

In conclusion, the polyurethane modified acrylic acid aqueous polymer dispersant prepared by the invention is polymerized with styrenated phenol polyoxyethylene ether through an aromatic isocyanate polymer, and then is connected to an acrylate molecular chain through reaction with hydroxyl, so that a multi-element aromatic hydrocarbon structure is provided on the molecular structure, the polyurethane modified acrylic acid aqueous polymer dispersant has more excellent wetting dispersibility on organic pigments, and the viscosity of the system can be effectively reduced. The hydrophilicity of the dispersant is adjusted by introducing hydrophilic polyethylene glycol chain segment groups on a molecular structure through the reaction of taking part in free radical copolymerization of acrylic acid by a nonionic acrylate monomer and introducing styrenated phenol polyoxyethylene ether in a polyurethane reaction. The coating has high molecular weight and does not contain ionic salt with strong hydrophilicity, and the water resistance, salt spray resistance and other properties of the coating are not influenced. In addition, the organic metal bismuth is used for replacing the traditional organic tin as a catalyst, and the prepared polyurethane modified acrylic acid water-based polymer dispersant is an environment-friendly polymer dispersant which has high performance, does not contain organic solvent and organic metal.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

While the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.