阅读说明：本技术 一种底面合一聚氨酯涂料及其制备方法 (Primer-topcoat polyurethane coating and preparation method thereof ) 是由 崔定伟 陈震生 于 2021-07-27 设计创作，主要内容包括：本发明涉及一种底面合一聚氨酯涂料,由A组分和B组分混合而成,所述的A组分由以下按质量份数比的组分制备而成：丙烯酸树脂、分散剂、消泡剂、防沉剂、颜料、填料、溶剂、所述的B组分为固化剂；所述的溶剂由二甲苯、醋酸丁酯和丙二醇甲醚醋酸酯按质量比为6:3:1混合而成。特殊羟基丙烯酸树脂的引入使涂料对不锈钢、镀锌板、铝合金、冷轧钢、碳钢和镁合金等基材都具有良好的附着力,划格附着力可以达到0级。本发明的颜料是环保型防锈颜料,加入后涂料具有良好的防腐性能,其耐中性盐雾可以达到600h以上。本发明耐紫外灯老化时间可以达到2000h以上。(The invention relates to a primer-topcoat polyurethane coating which is prepared by mixing a component A and a component B, wherein the component A is prepared from the following components in parts by mass: acrylic resin, a dispersing agent, a defoaming agent, an anti-settling agent, a pigment, a filler and a solvent, wherein the component B is a curing agent; the solvent is formed by mixing xylene, butyl acetate and propylene glycol methyl ether acetate according to the mass ratio of 6:3: 1. The introduction of the special hydroxyl acrylic resin ensures that the coating has good adhesive force to base materials such as stainless steel, galvanized sheet, aluminum alloy, cold rolled steel, carbon steel, magnesium alloy and the like, and the cross-cut adhesive force can reach 0 grade. The pigment is an environment-friendly antirust pigment, and the paint has good corrosion resistance after being added, and the neutral salt spray resistance of the paint can reach more than 600 h. The ultraviolet lamp aging resistant time of the invention can reach more than 2000 h.)

1. The primer-topcoat polyurethane coating is characterized by being prepared by mixing a component A and a component B, wherein the component A is prepared from the following components in parts by mass:

the component B is a curing agent;

the solvent is formed by mixing xylene, butyl acetate and propylene glycol methyl ether acetate according to the mass ratio of 6:3: 1.

2. The primer-topcoat polyurethane coating of claim 1, wherein: the acrylic resin is hydroxyl acrylic resin with a hydroxyl value ranging from 40 to 80 mgKOH/g.

3. The primer-topcoat polyurethane coating of claim 1, wherein: the defoaming agent is a defoaming polymer solution without organic silicon.

4. The primer-topcoat polyurethane coating of claim 1, wherein: the anti-settling agent is prepared by mixing polyamide wax and bentonite according to the mass ratio of 2: 1.

5. The primer-topcoat polyurethane coating of claim 1, wherein the pigment is a mixture of one of zinc phosphate, aluminum tripolyphosphate or zinc phosphomolybdate and titanium dioxide in a mass ratio of 1: 5.

6. The primer-topcoat polyurethane coating of claim 1, wherein the filler is feldspar powder or barium sulfate.

7. A method for preparing a primer-topcoat polyurethane coating of any one of claims 1-6, characterized in that:

the preparation method of the component A comprises the following steps:

adding 50-60% of solvent, acrylic resin, dispersant, defoamer and anti-settling agent into the reaction kettle at the rotation speed of 300-500r/min, and then uniformly stirring;

then adding 30-35% of solvent, pigment and filler into the reaction kettle at the rotation speed of 500-700r/min, stirring to be uniform, then grinding until the fineness is less than or equal to 30 mu m, then adding the rest solvent, mixing and adjusting the viscosity to 70-90Ku, and obtaining the component A.

8. The method for preparing a primer-topcoat polyurethane coating according to claim 7, wherein the primer-topcoat polyurethane coating comprises the following steps: when the paint is used, the component A and the component B are mixed according to the mass ratio of 15.1-22.5: 1, and obtaining the primer-topcoat polyurethane coating.

Technical Field

The invention relates to the technical field of coatings, in particular to a primer-topcoat polyurethane coating and a preparation method thereof.

Background

The development direction of the anticorrosive paint is environmental protection, energy conservation, high performance and functionalization. At present, the prior domestic anticorrosion systems mostly adopt a primer, an intermediate paint and a finish paint or a composite anticorrosion coating system of the primer and the finish paint. The primer mainly has the advantages that a foundation is laid on a substrate, the primer has good adhesion to the substrate, and the primer has antirust performance; the intermediate paint has the main effects of increasing the film thickness, providing good shielding effect, and simultaneously enabling a coating film to be smooth and beneficial to finish paint coating; the finish paint is mainly used for preventing the influence of harmful corrosive media in the external environment on a base material, and simultaneously, the coating has good attractive appearance and decoration. The conventional process not only wastes manpower, material resources, time and cost, but also considers the compatibility between coatings in the using process. The primer-topcoat polyurethane coating not only solves the problem of compatibility, but also has good decorative effect and wide application prospect.

Stainless steel, galvanized sheet, aluminum alloy, cold rolled steel, carbon steel and magnesium alloy, because of their different surface energies, the adhesion of the coating on their surfaces is relatively poor. The conventional method is to develop different coatings according to different base materials so as to meet the influence of different base materials on the comprehensive properties of adhesion, flexibility, corrosion resistance and the like.

The publication No. CN 104449166A discloses a single-component primer-topcoat integrated coating commonly used on stainless steel, galvanized sheet and aluminum alloy and a preparation method thereof, which comprises the following components: epoxy modified acrylic resin, dimethylbenzene, butyl acetate, a flatting agent, a defoaming agent, an adhesion promoter, chlorinated paraffin, barium sulfate, titanium dioxide, medium chromium yellow powder, polyamide wax and the like. The technical scheme has the defects of poor weather resistance, need of spraying finish and the like besides being environment-friendly.

Publication No. CN 112358799A discloses a primer-topcoat polyurethane coating, which is composed of modified hydroxyl acrylic resin, activated siloxane modified nano mica powder, superfine talcum powder, superfine barium sulfate and the like. The technical scheme has the defects of complex manufacturing process, poor corrosion resistance and the like.

Therefore, the prior primer-topcoat coating generally has the defects of poor corrosion resistance, limited types of coated substrates, deviation of weather resistance and the like.

Disclosure of Invention

The primer-topcoat polyurethane coating has good adhesive force to base materials such as stainless steel, galvanized sheets, aluminum alloy, cold rolled steel, carbon steel, magnesium alloy and the like, and also has good corrosion resistance and excellent weather resistance.

The invention is realized by the following technical scheme

The technical problem can be solved by the following two aspects:

the primer-topcoat polyurethane coating is formed by mixing a component A and a component B, wherein the component A is prepared from the following components in parts by mass:

the component B is a curing agent;

the solvent is formed by mixing xylene, butyl acetate and propylene glycol methyl ether acetate according to the mass ratio of 6:3: 1.

Further, the acrylic resin is hydroxyl acrylic resin with a hydroxyl value ranging from 40 to 80 mgKOH/g.

Further, the defoaming agent is a silicone-free foam breaking polymer solution.

Further, the anti-settling agent is prepared by mixing polyamide wax and bentonite according to the mass ratio of 2: 1. The anti-settling agent disclosed by the invention has better dustproof effect and thixotropy.

Further, the pigment is formed by mixing one of zinc phosphate, aluminum tripolyphosphate or zinc phosphomolybdate and titanium dioxide according to the mass ratio of 1: 5. The invention has better anti-corrosion effect.

Further, the solvent is formed by mixing xylene, butyl acetate and propylene glycol monomethyl ether acetate according to the mass ratio of 6:3:1

A preparation method for preparing the primer-topcoat polyurethane coating comprises the following steps:

adding 50-60% of solvent, acrylic resin, dispersant, defoamer and anti-settling agent into the reaction kettle at the rotation speed of 300-500r/min, and then uniformly stirring;

then adding 30-35% of solvent, pigment and filler into the reaction kettle at the rotation speed of 500-700r/min, stirring to be uniform, then grinding until the fineness is less than or equal to 30 mu m, and then adding the rest mixed solvent to adjust the viscosity to 70-90Ku, thus obtaining the component A.

When the paint is used, the component A and the component B are mixed according to the mass ratio of 15.1-22.5: 1, and mixing to obtain the product.

Compared with the prior art, the invention has the following beneficial effects: the introduction of the special hydroxyl acrylic resin ensures that the coating has good adhesive force to base materials such as stainless steel, galvanized sheet, aluminum alloy, cold rolled steel, carbon steel, magnesium alloy and the like, and the cross-cut adhesive force can reach 0 grade.

The pigment is an environment-friendly antirust pigment, and the paint has good corrosion resistance after being added, and the neutral salt spray resistance of the paint can reach more than 600 h.

The invention adopts the high weather-resistant hexamethylene diisocyanate based polymer curing agent and the special hydroxyl acrylic resin to compound, so that the coating has excellent weather resistance, and the ultraviolet lamp aging resistance time can reach more than 2000 h.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the present invention by way of specific embodiments thereof.

The primer-topcoat polyurethane coating is formed by mixing a component A and a component B, wherein the component A is prepared from the following components in parts by mass:

the component B is a curing agent.

The acrylic resin is hydroxyl acrylic resin with a hydroxyl value ranging from 40 to 80 mgKOH/g.

The defoaming agent is a defoaming polymer solution without organic silicon.

The anti-settling agent is prepared by mixing polyamide wax and bentonite according to the mass ratio of 2: 1.

The pigment is prepared by mixing titanium dioxide and zinc phosphate, aluminum tripolyphosphate or zinc phosphomolybdate according to the proportion of 5: 1.

The curing agent is hexamethylene diisocyanate biuret polyisocyanate solution or hexamethylene diisocyanate polyisocyanate solution.

The solvent is formed by mixing xylene, butyl acetate and propylene glycol monomethyl ether acetate according to the mass ratio of 6:3: 1.

A preparation method for preparing the primer-topcoat polyurethane coating comprises the following steps:

adding 50-60% of solvent, acrylic resin, dispersant, defoamer and anti-settling agent into the reaction kettle at the rotation speed of 300-500r/min, and then uniformly stirring;

then adding 30-35% of solvent, pigment and filler into the reaction kettle at the rotation speed of 500-700r/min, stirring to be uniform, then grinding until the fineness is less than or equal to 30 mu m, and then adding the rest mixed solvent to adjust the viscosity to 70-90Ku, thus obtaining the component A.

When the paint is used, the component A and the component B are mixed according to the mass ratio of 15.1-22.5: 1, and mixing to obtain the product.

Example 1

The primer-topcoat polyurethane coating is formed by mixing a component A and a component B, wherein the component A is prepared from the following components in parts by mass:

the component B is a curing agent.

The acrylic resin is hydroxyl acrylic resin with a hydroxyl value ranging from 40 to 80 mgKOH/g.

The defoaming agent is a defoaming polymer solution without organic silicon.

The anti-settling agent is prepared by mixing polyamide wax and bentonite according to the mass ratio of 2: 1.

The pigment is prepared by mixing titanium dioxide and zinc phosphate, aluminum tripolyphosphate or zinc phosphomolybdate according to the proportion of 5: 1.

The curing agent is hexamethylene diisocyanate biuret polyisocyanate solution or hexamethylene diisocyanate polyisocyanate solution.

The solvent is formed by mixing xylene, butyl acetate and propylene glycol monomethyl ether acetate according to the mass ratio of 6:3: 1.

A preparation method for preparing the primer-topcoat polyurethane coating comprises the following steps:

adding 60 percent of solvent, acrylic resin, dispersant, defoamer and anti-settling agent into the reaction kettle at the rotating speed of 300r/min, and then uniformly stirring;

and then adding 35 percent of solvent, pigment and filler into the reaction kettle at the rotating speed of 500r/min, stirring the mixture until the mixture is uniform, grinding the mixture until the fineness is less than or equal to 30 mu m, and then adding the residual mixed solvent to adjust the viscosity to 70Ku, thus obtaining the component A.

When in use, the component A and the component B are mixed according to the mass ratio of 22.5: 1, and mixing to obtain the product.

Example 2

The primer-topcoat polyurethane coating is formed by mixing a component A and a component B, wherein the component A is prepared from the following components in parts by mass:

the component B is a curing agent.

The acrylic resin is hydroxyl acrylic resin with a hydroxyl value ranging from 40 to 80 mgKOH/g.

The defoaming agent is a defoaming polymer solution without organic silicon.

The anti-settling agent is prepared by mixing polyamide wax and bentonite according to the mass ratio of 2: 1.

The pigment is prepared by mixing titanium dioxide and zinc phosphate, aluminum tripolyphosphate or zinc phosphomolybdate according to the proportion of 5: 1.

The curing agent is hexamethylene diisocyanate biuret polyisocyanate solution or hexamethylene diisocyanate polyisocyanate solution.

The solvent is formed by mixing xylene, butyl acetate and propylene glycol monomethyl ether acetate according to the mass ratio of 6:3: 1.

A preparation method for preparing the primer-topcoat polyurethane coating comprises the following steps:

adding 55 percent of solvent, acrylic resin, a dispersing agent, a defoaming agent and an anti-settling agent into a reaction kettle at the rotating speed of 500r/min, and then uniformly stirring;

then 32 percent of solvent, pigment and filler are added into the reaction kettle at the rotating speed of 700r/min, the mixture is stirred to be uniform, then the mixture is ground until the fineness is less than or equal to 30 mu m, and then the residual mixed solvent is added to adjust the viscosity to 90Ku, thus obtaining the component A.

When in use, the component A and the component B are mixed according to the mass ratio of 15.1: 1, and mixing to obtain the product.

Example 3

The primer-topcoat polyurethane coating is formed by mixing a component A and a component B, wherein the component A is prepared from the following components in parts by mass:

the component B is a curing agent.

The acrylic resin is hydroxyl acrylic resin with a hydroxyl value ranging from 40 to 80 mgKOH/g.

The defoaming agent is a defoaming polymer solution without organic silicon.

The anti-settling agent is prepared by mixing polyamide wax and bentonite according to the mass ratio of 2: 1.

The pigment is prepared by mixing titanium dioxide and zinc phosphate, aluminum tripolyphosphate or zinc phosphomolybdate according to the proportion of 5: 1.

The curing agent is hexamethylene diisocyanate biuret polyisocyanate solution or hexamethylene diisocyanate polyisocyanate solution.

The solvent is formed by mixing xylene, butyl acetate and propylene glycol monomethyl ether acetate according to the mass ratio of 6:3: 1.

A preparation method for preparing the primer-topcoat polyurethane coating comprises the following steps:

adding 50 percent of solvent, acrylic resin, dispersant, defoamer and anti-settling agent into a reaction kettle at the rotating speed of 400r/min, and then uniformly stirring;

then 32 percent of solvent, pigment and filler are added into the reaction kettle at the rotating speed of 600r/min, the mixture is stirred to be uniform, then the mixture is ground until the fineness is less than or equal to 30 mu m, and then the residual mixed solvent is added to adjust the viscosity to 80Ku, thus obtaining the component A.

When in use, the component A and the component B are mixed according to the mass ratio of 18.1: 1, and mixing to obtain the product.

Preparation of bottom-surface-in-one polyurethane coating B component

The polyurethane coatings prepared in the above examples 1-3 were respectively coated on stainless steel, galvanized sheet, aluminum alloy, cold rolled steel, carbon steel and magnesium alloy, and then adhesion, corrosion resistance and weather resistance were tested by using HG/T2454-2014 solvent type polyurethane paint, and the results were as follows:

test of Corrosion resistance

Neutral salt spray, h	Stainless steel	Galvanized sheet	Aluminium alloy	Cold rolled steel	Carbon steel	Magnesium alloy
							Example 1	1000	1500	1000	800	600	1200
Example 2	900	1450	980	780	620	1000
							Example 3	950	1520	1100	850	586	1220

Weather resistance test

UVA	Stainless steel	Galvanized sheet	Aluminium alloy	Cold rolled steel	Carbon steel	Magnesium alloy
							Example 1	2000	2100	2000	1900	2200	2000
Example 2	2100	2000	2200	2000	2100	1900
							Example 3	2000	1900	2100	2100	2000	2100

The table shows that the adhesive force on the stainless steel, the galvanized sheet, the aluminum alloy, the cold-rolled steel and the magnesium alloy reaches 0 grade, and the adhesive force on the stainless steel, the galvanized sheet, the aluminum alloy, the cold-rolled steel and the magnesium alloy is good, the adhesive force on the carbon steel is larger than 18MPa and is far larger than 4MPa, so the adhesive force on the carbon steel is also good.

In the test of the corrosion resistance, the corrosion resistance time is longer, which shows that the corrosion resistance is good, and in the test of the weather resistance, the time is longer when UVA ultraviolet ray is resisted, which shows that the weather resistance is good.

The acrylic resin adopts ETERAETERAC 7382-S-50 of Changxing chemical technology corporation;

the curing agent adopts hexamethylene diisocyanate biuret polyisocyanate solution or hexamethylene diisocyanate polyisocyanate solution. Desmodur N3390 or Desmodur N75 MPA/X

The filler is feldspar powder or barium sulfate.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.