CN118772706A - A water-based two-component metallic paint for rail transit coating and a preparation method thereof - Google Patents

Abstract

The present invention belongs to the technical field of coatings, and in particular to a water-based two-component metallic paint for rail transit coating and a preparation method thereof. The water-based two-component metallic paint for rail transit coating provided by the present invention includes component A and component B, wherein the component A includes the following components and their mass fractions: 30-40 parts of water-based hydroxy acrylic resin, 7-12 parts of polycarbonate type waterborne polyurethane dispersion, 0.3-0.6 parts of dispersant, 3-8 parts of orienting agent, 0.2-0.6 parts of wetting agent, 0.1-0.4 parts of defoamer, 0.8-1.6 parts of rheological agent, 0.2-1.0 parts of amine neutralizer, 1-5 parts of ethylene glycol butyl ether, 1-5 parts of dipropylene glycol butyl ether, 6-10 parts of water-based silver paste, 30-45 parts of water; the component B includes the following components and their mass fractions: 40-60 parts of propylene glycol diacetate, 40-60 parts of curing agent. The metal arrangement of the present invention is good and the construction performance is excellent.

Description

A water-based two-component metallic paint for rail transit coating and a preparation method thereof

Technical Field

The invention belongs to the technical field of coatings, and in particular relates to a water-based two-component metallic paint for rail transit coating and a preparation method thereof.

Background Art

In recent years, with the increasing prominence of environmental problems and people's urgent need for healthy life, the use of water-based paints has become more and more widespread, especially in the construction and home improvement industries, where solvent-based paints have been basically replaced by water-based paints. Rail transit, engineering machinery, vehicle manufacturing, shipbuilding and other industries have also accelerated the application of water-based paints. For example, trucks and subways in the rail transit industry have already used water-based paints. For example, Chinese patent application CN110982377A discloses a water-based epoxy paint for rail transit interior decoration and a preparation method, wherein the water-based epoxy paint includes component A and component B; by weight, component A includes 30 to 50 parts of bisphenol A epoxy resin emulsified with a phosphate emulsifier, 10 to 15 parts of water and other additives and additives; by weight, component B includes 60 to 80 parts of a curing agent, 20 to 40 parts of water and other additives. Chinese patent application CN104817929A discloses a water-based epoxy two-component coating for rail transit and a preparation method thereof, comprising components A and B. Component A comprises 3 to 6 parts of film-forming aid alcohol ester twelve, 0.5 to 1 part of water-based epoxy dispersant, 0.5 to 1 part of chelating water-based coupling agent, 15 to 20 parts of red iron oxide, 15 to 20 parts of talcum powder, 4 to 6 parts of polymer modified zinc phosphate, 3 to 4 parts of modified aluminum tripolyphosphate, 20 to 25 parts of high molecular weight epoxy resin, 2 parts of emulsifier containing epoxy group, 0.1 to 0.5 parts of water-based wetting agent, 0.1 to 0.5 parts of water-based defoaming agent, 1 part of anti-settling agent, 1 part of anti-flash rust agent, 0.3 parts of water-based anti-sagging agent, and 20 to 30 parts of deionized water; component B comprises 80 parts of water-based polyamide epoxy curing agent and 20 parts of deionized water.

Metallic paint is also called metallic glitter paint. Metallic paint is obtained by adding metallic pigment as a special pigment to the base material. Metallic paint has a unique glitter effect and metallic luster. The body of the vehicle sprayed with metallic paint looks gorgeous and luxurious. More and more rail vehicle bodies use metallic paint as their "outer coat". The metallic pigment in metallic paint is flaky, lying flat like many small mirrors to reflect external light. When viewed from the front, the reflection effect is the greatest and the color appears shiny; when viewed from the side, the amount of light reflection will decrease, making the color look darker. Because the propagation of light in silver powder paint produces a special glitter effect, the effect of metallic paint is greatly affected by external light. The glitter effect is better in the sun, but the color will appear darker indoors.

However, the existing metal paint for rail transit painting has problems such as poor metal arrangement and particles on the paint film surface when spraying in an environment with a humidity below 50%.

Summary of the invention

In view of the shortcomings of the prior art, the purpose of the present invention is to provide a water-based two-component metallic paint for rail transit coating and a preparation method thereof. The water-based two-component metallic paint for rail transit coating provided by the present invention has good metal arrangement, and the paint film surface is flat and particle-free when sprayed in an environment with a humidity of less than 50%. The water-based two-component metallic paint for rail transit coating of the present invention is used on large rail transit vehicles, and has a strong metallic feel and excellent construction performance.

The technical solution of the present invention is:

A water-based two-component metallic paint for rail transit coating, comprising component A and component B, wherein component A comprises the following components and their weight fractions: 30-40 parts of water-based hydroxy acrylic resin, 7-12 parts of polycarbonate type water-based polyurethane dispersion, 0.3-0.6 parts of dispersant, 3-8 parts of orienting agent, 0.2-0.6 parts of wetting agent, 0.1-0.4 parts of defoaming agent, 0.8-1.6 parts of rheological agent, 0.2-1.0 parts of amine neutralizer, 1-5 parts of ethylene glycol butyl ether, 1-5 parts of dipropylene glycol butyl ether, 6-10 parts of water-based silver paste, and 30-45 parts of water;

The B component includes the following components and their weight fractions: 40-60 parts of propylene glycol diacetate and 40-60 parts of a curing agent.

Further, the component A includes the following components and their mass fractions: 35 parts of water-based hydroxy acrylic resin, 10 parts of polycarbonate type water-based polyurethane dispersion, 0.5 parts of dispersant, 4 parts of orienting agent, 0.5 parts of wetting agent, 0.3 parts of defoaming agent, 1 part of rheological agent, 0.7 parts of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of aqueous silver paste, and 36 parts of water;

The B component includes the following components and their weight fractions: 50 parts of propylene glycol diacetate and 50 parts of a curing agent.

Furthermore, the dispersant is composed of BYK-192 dispersant and TEGO Dispers 652 wetting dispersant in a mass ratio of 2-4:9-15.

Furthermore, the orienting agent is BYK-8421 water-based pigment orienting agent.

Furthermore, the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 8-12:1.

Furthermore, the defoamer is BYK-011 defoamer.

Furthermore, the rheological agent is Digo 3030 rheological agent.

Furthermore, the amine neutralizer is amine neutralizer AMP-95.

Furthermore, the curing agent is Bayhydur XP 2655 water-based curing agent.

The method for preparing the above-mentioned water-based two-component metallic paint for rail transit coating comprises the following steps:

(1) Adding a formula amount of ethylene glycol butyl ether, dipropylene glycol butyl ether, a dispersant, a wetting agent, a defoamer, and 1/10 of the amount of water into a container and stirring at a stirring speed of 200-300 rpm for 3-8 minutes, adding an aqueous silver paste, stirring at a speed of 200-300 rpm for 25-35 minutes, and soaking for 1.5-2.5 hours to obtain the soaked silver paste;

(2) adding the water-based hydroxylated acrylic resin, the polycarbonate-based water-based polyurethane dispersion, and the remaining amount of water into a container in order, and stirring at a speed of 300-600 rpm for 5-10 minutes to obtain a mixed material A;

(3) adding the silver paste obtained after soaking in step (1) to the mixed material A obtained in step (2) while stirring, and stirring at a speed of 300-600 rpm for 5-10 minutes to obtain a mixed material B;

(4) adding an amine neutralizer to the mixed material B obtained in step (3) while stirring, stirring at a speed of 300-600 rpm for 5-10 minutes, adding an orienting agent, and stirring at a speed of 300-600 rpm for 5-10 minutes to obtain a mixed material C;

(5) adding a rheological agent to the mixed material C obtained in step (4) while stirring, and stirring at a speed of 300-600 rpm for 15-25 minutes to obtain component A;

(6) Propylene glycol diacetate is added into a container, and after the water content is determined to be acceptable, a curing agent is added to obtain component B.

The method for using the water-based two-component metallic paint for rail transit coating provided by the present invention is: mixing component A, component B and deionized water in a mass ratio of 100:10:10-20, and then applying it on the surface of transportation tools such as rail transit body interior panels.

In the present invention, the water-based hydroxy acrylic resin and the polycarbonate-type water-based polyurethane dispersion are used together, which can not only balance the hardness and bending of the paint film, enhance the adhesion of the paint film multilayer, increase toughness, and make the paint film have excellent resistance, but also with the assistance of cosolvents (ethylene glycol butyl ether, dipropylene glycol butyl ether), the paint mist can also have good fusion, so that the paint film is not easy to form particles, the surface is flat, and it is conducive to the formation of metal pigment flakes parallel to the surface of the substrate. The metal is well arranged, which solves the problems of poor metal arrangement in the metal paint for rail transit coating in the current prior art, and particles on the surface of the paint film when spraying in an environment with a humidity of less than 50%. In addition, the A component in the present invention is mainly composed of water-based hydroxy acrylic resin, which can extend the storage period of the metal paint, and solve the problem that the metal paint has a short storage period and poor stability.

Water-based paint uses water as a solvent and has a large surface tension. The wetting effect of the water-based paint in the prior art on the substrate is much worse than that of the solvent-based paint. In the present invention, the wetting agent compounded by BYK-347 wetting agent and cocamidopropyl betaine can not only improve the surface tension and permeability of the coating, have a good wetting effect on the substrate, improve the adhesion of the coating, but also can synergize with the dispersant to prevent the coating from precipitating during storage and improve the storage period of the coating.

Compared with the prior art, the present invention has the following advantages:

(1) The water-based two-component metallic paint for rail transit coating of the present invention is used on large rail transit vehicles. It has a strong metallic feel and excellent construction performance, especially in high and low temperature weather, with excellent interlayer adhesion; in terms of resistance, it has excellent water resistance, high and low temperature resistance, weather resistance, acid resistance, alkali resistance, gasoline resistance, engine oil resistance and other properties; in terms of physical properties, the hardness and toughness are very good, the composite layer paint film has good adhesion, good MEK wiping resistance, and passes the high and low temperature cycle alternation test (60 cycles).

(2) The water-based two-component metallic paint for rail transit coating of the present invention can be applied to rail transit coating fields such as rail transit vehicle body interior panels.

DETAILED DESCRIPTION

The present invention is further illustrated below through the description of specific implementation modes, but this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of the present invention, but as long as they do not deviate from the basic idea of the present invention, they are all within the scope of the present invention.

Unless otherwise specified, the raw materials used in the present invention are commercially available.

The purchasing information of each raw material in the following examples and comparative examples is shown in Table 1.

Table 1: Purchase information of each raw material

Example 1: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, wherein the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 30 parts of water-based hydroxy acrylic resin, 7 parts of polycarbonate type water-based polyurethane dispersion, 0.3 parts of dispersant, 3 parts of orienting agent, 0.2 parts of wetting agent, 0.1 parts of defoaming agent, 0.8 parts of rheological agent, 0.2 parts of amine neutralizer, 1 part of ethylene glycol butyl ether, 1 part of dipropylene glycol butyl ether, 6 parts of water-based silver paste, and 30 parts of water; the dispersant comprises BYK-192 dispersant and TEGO Dispers The 652 wetting and dispersing agent is composed of a mass ratio of 2:15; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 8:1; the defoaming agent is BYK-011 defoaming agent; the rheological agent is Digo 3030 rheological agent; the amine neutralizing agent is amine neutralizing agent AMP-95;

The B component includes the following components and their weight fractions: 60 parts of propylene glycol diacetate and 40 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The method for preparing the water-based two-component metallic paint for rail transit coating comprises the following steps:

(1) adding a formula amount of ethylene glycol butyl ether, dipropylene glycol butyl ether, a dispersant, a wetting agent, a defoamer, and 1/10 amount of water into a container and stirring at a stirring speed of 200 rpm for 3 minutes, adding an aqueous silver paste, stirring at a speed of 200 rpm for 25 minutes, and soaking for 1.5 hours to obtain the soaked silver paste;

(2) adding the water-based hydroxy acrylic resin, the polycarbonate type water-based polyurethane dispersion and the remaining amount of water into a container in sequence, and stirring at a speed of 300 rpm for 5 minutes to obtain a mixed material A;

(3) adding the silver paste obtained after soaking in step (1) to the mixed material A obtained in step (2) while stirring, and stirring at a speed of 300 rpm for 5 minutes to obtain a mixed material B;

(4) adding an amine neutralizer to the mixed material B obtained in step (3) while stirring, stirring at a speed of 300 rpm for 5 minutes, adding an orienting agent, and stirring at a speed of 300 rpm for 5 minutes to obtain a mixed material C;

(5) adding a rheological agent to the mixed material C obtained in step (4) while stirring, and stirring at a speed of 300 rpm for 15 minutes to obtain component A;

(6) Propylene glycol diacetate is added into a container, and after the water content is determined to be acceptable, a curing agent is added to obtain component B.

When in use, component A, component B and deionized water are mixed in a mass ratio of 100:10:10, and then applied to the surface of transportation vehicles such as rail transit vehicle body interior panels.

Example 2: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, wherein the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 40 parts of water-based hydroxy acrylic resin, 12 parts of polycarbonate water-based polyurethane dispersion, 0.6 parts of dispersant, 8 parts of orienting agent, 0.6 parts of wetting agent, 0.4 parts of defoaming agent, 1.6 parts of rheological agent, 1.0 parts of amine neutralizer, 5 parts of ethylene glycol butyl ether, 5 parts of dipropylene glycol butyl ether, 10 parts of water-based silver paste, and 45 parts of water; the dispersant comprises BYK-192 dispersant and TEGO Dispers The 652 wetting and dispersing agent is composed of a mass ratio of 4:9; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 12:1; the defoaming agent is BYK-011 defoaming agent; the rheological agent is Digo 3030 rheological agent; the amine neutralizing agent is amine neutralizing agent AMP-95;

The B component includes the following components and their weight fractions: 40 parts of propylene glycol diacetate and 60 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The method for preparing the water-based two-component metallic paint for rail transit coating comprises the following steps:

(1) adding a formula amount of ethylene glycol butyl ether, dipropylene glycol butyl ether, a dispersant, a wetting agent, a defoamer, and 1/10 amount of water into a container and stirring at a stirring speed of 300 rpm for 8 minutes, adding an aqueous silver paste, stirring at a speed of 300 rpm for 35 minutes, and soaking for 2.5 hours to obtain the soaked silver paste;

(2) adding the water-based hydroxylated acrylic resin, the polycarbonate type water-based polyurethane dispersion and the remaining amount of water into a container in sequence, and stirring at a speed of 600 rpm for 10 minutes to obtain a mixed material A;

(3) adding the silver paste obtained after soaking in step (1) to the mixed material A obtained in step (2) while stirring, and stirring at a speed of 600 rpm for 10 minutes to obtain a mixed material B;

(4) adding an amine neutralizer to the mixed material B obtained in step (3) while stirring, stirring at a speed of 600 rpm for 10 minutes, adding an orienting agent, and stirring at a speed of 600 rpm for 10 minutes to obtain a mixed material C;

(5) adding a rheological agent to the mixed material C obtained in step (4) while stirring, and stirring at a speed of 600 rpm for 25 minutes to obtain component A;

(6) Propylene glycol diacetate is added into a container, and after the water content is determined to be acceptable, a curing agent is added to obtain component B.

When in use, component A, component B and deionized water are mixed in a mass ratio of 100:10:20, and then applied on the surface of transportation vehicles such as rail transit vehicle body interior panels.

Example 3: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, wherein the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 35 parts of water-based hydroxy acrylic resin, 10 parts of polycarbonate type water-based polyurethane dispersion, 0.5 parts of dispersant, 4 parts of orienting agent, 0.5 parts of wetting agent, 0.3 parts of defoaming agent, 1 part of rheological agent, 0.7 parts of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of water-based silver paste, and 36 parts of water; the dispersant comprises BYK-192 dispersant and TEGO Dispers The 652 wetting and dispersing agent is composed of a mass ratio of 3:13; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 10:1; the defoamer is BYK-011 defoamer; the rheological agent is Digo 3030 rheological agent; the amine neutralizer is amine neutralizer AMP-95; the curing agent is Bayhydur XP 2655 water-based curing agent;

The B component includes the following components and their weight fractions: 50 parts of propylene glycol diacetate and 50 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The method for preparing the water-based two-component metallic paint for rail transit coating comprises the following steps:

(1) adding a formula amount of ethylene glycol butyl ether, dipropylene glycol butyl ether, a dispersant, a wetting agent, a defoamer, and 1/10 amount of water into a container and stirring at a stirring speed of 250 rpm for 5 minutes, adding an aqueous silver paste, stirring at a speed of 250 rpm for 25 minutes, and soaking for 2 hours to obtain a silver paste after soaking;

(2) adding the water-based hydroxylated acrylic resin, the polycarbonate-type water-based polyurethane dispersion, and the remaining amount of water into a container in order, and stirring at a speed of 500 rpm for 10 minutes to obtain a mixed material A;

(3) adding the silver paste obtained after soaking in step (1) to the mixed material A obtained in step (2) while stirring, and stirring at a speed of 500 rpm for 10 minutes to obtain a mixed material B;

(4) adding an amine neutralizer to the mixed material B obtained in step (3) while stirring, stirring at a speed of 500 rpm for 8 minutes, adding an orienting agent, and stirring at a speed of 400 rpm for 8 minutes to obtain a mixed material C;

(5) adding a rheological agent to the mixed material C obtained in step (4) while stirring, and stirring at a speed of 500 rpm for 20 minutes to obtain component A;

(6) Propylene glycol diacetate is added into a container, and after the water content is determined to be acceptable, a curing agent is added to obtain component B.

When in use, component A, component B and deionized water are mixed in a mass ratio of 100:10:15, and then applied to the surface of transportation vehicles such as rail transit vehicle body interior panels.

Comparative Example 1: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, and the mass ratio of component A to component B is 100:10; the water-based two-component metallic paint for rail transit coating comprises component A and component B, and the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 35 parts of water-based hydroxy acrylic resin, 10 parts of aliphatic polyurethane-acrylic copolymer dispersion (NeoPac E-123), 0.5 parts of dispersant, 4 parts of orienting agent, 0.5 parts of wetting agent, 0.3 parts of defoaming agent, 1 part of rheological agent, 0.7 parts of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of water-based silver paste, and 36 parts of water; the dispersant is a BYK-192 dispersant and a TEGO Dispersant. The 652 wetting and dispersing agent is composed of a mass ratio of 3:13; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 10:1; the defoamer is BYK-011 defoamer; the rheological agent is Digo 3030 rheological agent; the amine neutralizer is amine neutralizer AMP-95; the curing agent is Bayhydur XP 2655 water-based curing agent;

The B component includes the following components and their weight fractions: 50 parts of propylene glycol diacetate and 50 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The preparation method of the water-based two-component metallic paint for rail transit coating is similar to that of Example 3.

The difference from Example 3 is that the polycarbonate-based aqueous polyurethane dispersion is replaced by an aliphatic polyurethane-acrylic copolymer dispersion (NeoPac E-123).

Comparative Example 2: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, wherein the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 22.5 parts of water-based hydroxy acrylic resin, 22.5 parts of polycarbonate water-based polyurethane dispersion, 0.5 parts of dispersant, 4 parts of orienting agent, 0.5 parts of wetting agent, 0.3 parts of defoaming agent, 1 part of rheological agent, 0.7 parts of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of water-based silver paste, and 36 parts of water; the dispersant comprises BYK-192 dispersant and TEGO Dispers The 652 wetting and dispersing agent is composed of a mass ratio of 3:13; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 10:1; the defoamer is BYK-011 defoamer; the rheological agent is Digo 3030 rheological agent; the amine neutralizer is amine neutralizer AMP-95; the curing agent is Bayhydur XP 2655 water-based curing agent;

The B component includes the following components and their weight fractions: 50 parts of propylene glycol diacetate and 50 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The preparation method of the water-based two-component metallic paint for rail transit coating is similar to that of Example 3.

The difference from Example 3 is that the mass fraction of the water-based hydroxy acrylic resin in component A is changed from 35 parts to 22.5 parts, and the mass fraction of the polycarbonate type water-based polyurethane dispersion is changed from 10 parts to 22.5 parts.

Comparative Example 3: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, wherein the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 35 parts of water-based hydroxy acrylic resin, 10 parts of polycarbonate type water-based polyurethane dispersion, 0.5 parts of dispersant, 4 parts of orienting agent, 0.5 parts of wetting agent, 0.3 parts of defoaming agent, 1 part of rheological agent, 0.7 parts of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of water-based silver paste, and 36 parts of water; the dispersant comprises BYK-192 dispersant and TEGO Dispers The 652 wetting and dispersing agent is composed of a mass ratio of 13:3; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 10:1; the defoamer is BYK-011 defoamer; the rheological agent is Digo 3030 rheological agent; the amine neutralizer is amine neutralizer AMP-95; the curing agent is Bayhydur XP 2655 water-based curing agent;

The B component includes the following components and their weight fractions: 50 parts of propylene glycol diacetate and 50 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The preparation method of the water-based two-component metallic paint for rail transit coating is similar to that of Example 3.

The difference from Example 3 is that the dispersant is composed of BYK-192 dispersant and TEGO Dispers652 wetting dispersant in a mass ratio of 13:3.

Comparative Example 4: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, wherein the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 35 parts of water-based hydroxy acrylic resin, 10 parts of polycarbonate type water-based polyurethane dispersion, 0.5 parts of dispersant, 4 parts of orienting agent, 0.5 parts of wetting agent, 0.3 parts of defoaming agent, 1 part of rheological agent, 0.7 parts of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of water-based silver paste, and 36 parts of water; the dispersant comprises BYK-192 dispersant and TEGO The Dispers755W wetting and dispersing agent is composed of a mass ratio of 3:13; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is composed of BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 10:1; the defoamer is BYK-011 defoamer; the rheological agent is Digo 3030 rheological agent; the amine neutralizer is amine neutralizer AMP-95; and the curing agent is Bayhydur XP 2655 water-based curing agent;

The B component includes the following components and their weight fractions: 50 parts of propylene glycol diacetate and 50 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The preparation method of the water-based two-component metallic paint for rail transit coating is similar to that of Example 3.

The difference from Example 3 is that the dispersant is composed of BYK-192 dispersant and TEGO Dispers755W wetting dispersant in a mass ratio of 3:13.

Comparative Example 5: A water-based two-component metallic paint for rail transit coating

The water-based two-component metallic paint for rail transit coating comprises component A and component B, wherein the mass ratio of component A to component B is 100:10; the component A comprises the following components and their mass fractions: 35 parts of water-based hydroxy acrylic resin, 10 parts of polycarbonate type water-based polyurethane dispersion, 0.5 parts of dispersant, 4 parts of orienting agent, 0.5 parts of wetting agent, 0.3 parts of defoaming agent, 1 part of rheological agent, 0.7 parts of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of water-based silver paste, and 36 parts of water; the dispersant comprises BYK-192 dispersant and TEGO Dispers The 652 wetting and dispersing agent is composed of a mass ratio of 3:13; the directing agent is BYK-8421 water-based pigment directing agent; the wetting agent is BYK-347 wetting agent; the defoaming agent is BYK-011 defoaming agent; the rheological agent is Digo 3030 rheological agent; the amine neutralizing agent is amine neutralizing agent AMP-95; and the curing agent is BayhydurXP 2655 water-based curing agent;

The B component includes the following components and their weight fractions: 50 parts of propylene glycol diacetate and 50 parts of a curing agent; the curing agent is Bayhydur XP 2655 water-based curing agent.

The preparation method of the water-based two-component metallic paint for rail transit coating is similar to that of Example 3.

The difference from Example 3 is that the wetting agent is BYK-347 wetting agent.

Test Example 1: Performance Test

1. Test materials: water-based two-component metallic paint for rail transit coating prepared in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 5.

2. Test method: Refer to GB/T 6742 for testing the bending performance, refer to GB/T 9286-2021 "Scratch test for paints and varnishes" for testing the single-layer adhesion and (composite layer) adhesion of the test material, refer to ASTM D5402 for MEK (methyl ethyl ketone) rubbing test, refer to GB-T 9753-2007 "Cupping test for paints and varnishes" for cupping test, refer to GB-T5209-1985 "Determination of water resistance of paints and varnishes - immersion method" for water resistance test, refer to GB/T 6739-2006 "Determination of film hardness by pencil method for paints and varnishes" for testing the paint film hardness, and conduct high and low temperature cycle alternation test (60 cycles).

Tinplate was used for the bending performance test, and 1mm aluminum plate was used for other tests. After grinding, it was degreased, sprayed with water-based primer at 60℃ for 2h, dried, and polished with water-based mid-coat at 60℃ for 2h, sprayed with water-based two-component metallic paint, dried, and sprayed with water-based two-component clear varnish at 60℃ for 2h. For the single-layer adhesion test, 1mm aluminum plate was used, degreased after grinding, sprayed with water-based two-component metallic paint, dried, and sprayed with water-based two-component clear varnish at 60℃ for 2h.

The high and low temperature cycle test should be carried out in a programmable high and low temperature humidity test chamber. The test conditions are: (80±2)℃, humidity (95±5)%RH for 4h, temperature change rate of 1℃/min to -40℃, (-40±2)℃ for 4h, temperature change rate of 1℃/min to 80℃, 95%RH, and the above 12h as a cycle. The test plate is taken out after the test according to the prescribed cycle and visually observed. After the state is adjusted for 16h, the X-cut test and the pull-off adhesion test are carried out; insert a blade along the surface of the substrate and pry the coating, and judge the adhesion change according to the coating peeling situation.

3. The test results are shown in Table 2.

Table 2: Performance test results of water-based two-component metallic paint for rail transit coating

As can be seen from Table 2, the surface sprayed with water-based two-component metallic paint for rail transit coating of the present invention is free of particles, the surface is flat, and the composite layer is subjected to water resistance test for 10 days at 40°C. The paint film has no blistering and no gloss loss. The adhesion is measured to be 0-1 level, and the hardness of the composite layer can reach 3H, bending performance (cylindrical axis, 1mm), single layer and composite layer adhesion 0 level, cupping test ≥4.5mm, butanone-resistant back and forth wiping 10 times without leakage and dissolution of the paint film, and the appearance is basically unchanged, and the high and low temperature cycle alternation test (60 cycles) is passed. The effect of spraying with water-based two-component metallic paint for rail transit coating using Comparative Examples 1, Comparative Example 2, and Comparative Example 5 is obviously not as good as the present invention. It can be seen that the water-based two-component metallic paint for rail transit coating prepared by the present invention has excellent performance.

Test Example 2: Metal Arrangement Performance Test

1. Test materials: water-based two-component metallic paint for rail transit coating prepared in Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2.

2. Test methods:

Use 1mm aluminum plate, polish and degrease, spray water-based primer at 60℃ for 2h and dry, water-based mid-coat at 60℃ for 2h and dry, polish, spray water-based two-component metallic paint, blow dry, spray water-based two-component clear varnish at 60℃ for 2h. Use BYK-MAC colorimeter to measure the coating appearance data.

3. The test results are shown in Table 3.

Table 3: Metal arrangement performance test results

The higher the 45°L value, the lower the 15°L value, that is, the darker the front side is, the poor metal arrangement, and vice versa, the lower the 45°L value, the higher the 15°L value, the better the metal arrangement. It can be seen from Table 3 that the 45°L value of the coating using the water-based two-component metallic paint for rail transit coating of Examples 1-3 of the present invention is significantly lower than that of Comparative Examples 1-2, and the 15°L value is significantly higher than that of Comparative Examples 1-2, which shows that the water-based two-component metallic paint for rail transit coating prepared by the present invention has good metal arrangement.

Test Example 3: Storage stability test

Component A of the water-based two-component metallic paint for rail transit coating prepared in Example 1, Example 2, Example 3, Comparative Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5 was placed in a container and placed in a constant temperature water bath for storage at room temperature for 1 year. After 1 year, samples were taken to observe whether there was precipitation. The experimental results are shown in Table 4.

Table 4: Storage stability test results

It can be seen from Table 4 that component A in the water-based two-component metallic paint for rail transit coating prepared in Examples 1, 2 and 3 of the present invention has no precipitation after being stored at room temperature for one year, while component A in the water-based two-component metallic paint for rail transit coating prepared in Comparative Examples 2-5 has precipitation after being stored at room temperature for one year. It can be seen that component A in the water-based two-component metallic paint for rail transit coating prepared in the present invention has good long-term storage stability.

Claims (10)

1. The water-based double-component metallic paint for rail transit coating is characterized by comprising a component A and a component B, wherein the component A comprises the following components in parts by weight: 30-40 parts of aqueous hydroxyl acrylic resin, 7-12 parts of polycarbonate type aqueous polyurethane dispersoid, 0.3-0.6 part of dispersing agent, 3-8 parts of directing agent, 0.2-0.6 part of wetting agent, 0.1-0.4 part of defoamer, 0.8-1.6 part of rheological agent, 0.2-1.0 part of amine neutralizer, 1-5 parts of ethylene glycol butyl ether, 1-5 parts of dipropylene glycol butyl ether, 6-10 parts of aqueous silver paste and 30-45 parts of water;

The component B comprises the following components in parts by weight: 40-60 parts of propylene glycol diacetate and 40-60 parts of curing agent.

2. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1, wherein the component a comprises the following components in parts by mass: 35 parts of aqueous hydroxyl acrylic resin, 10 parts of polycarbonate type aqueous polyurethane dispersoid, 0.5 part of dispersing agent, 4 parts of directing agent, 0.5 part of wetting agent, 0.3 part of defoamer, 1 part of rheological agent, 0.7 part of amine neutralizer, 3 parts of ethylene glycol butyl ether, 3 parts of dipropylene glycol butyl ether, 8 parts of aqueous silver paste and 36 parts of water;

The component B comprises the following components in parts by weight: 50 parts of propylene glycol diacetate and 50 parts of curing agent.

3. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1 or 2, wherein the dispersant comprises BYK-192 dispersant and Di high TEGO Dispers 652 wetting dispersant in a mass ratio of 2-4: 9-15.

4. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1 or 2, wherein the directing agent is BYK-8421 aqueous pigment directing agent.

5. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1 or 2, wherein the wetting agent comprises BYK-347 wetting agent and cocamidopropyl betaine in a mass ratio of 8-12: 1.

6. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1 or 2, wherein the defoamer is BYK-011 defoamer.

7. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1 or 2, wherein the rheology agent is digao 3030 rheology agent.

8. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1 or 2, wherein the amine neutralizer is an amine neutralizer AMP-95.

9. The aqueous two-component metallic paint for rail transit coating as claimed in claim 1 or 2, wherein the curing agent is a Bayhydur XP 2655 aqueous curing agent.

10. The method for preparing the aqueous two-component metallic paint for rail transit coating as claimed in any one of claims 1 to 9, comprising the steps of:

(1) Adding ethylene glycol butyl ether, dipropylene glycol butyl ether, a dispersing agent, a wetting agent, a defoaming agent and 1/10 of water into a container, stirring at a stirring speed of 200-300 rpm for 3-8 minutes, adding water-based silver paste, stirring at a stirring speed of 200-300 rpm for 25-35 minutes, and soaking for 1.5-2.5 hours to obtain soaked silver paste;

(2) Sequentially adding a formula amount of aqueous hydroxy acrylic resin, polycarbonate type aqueous polyurethane dispersoid and the rest amount of water into a container, and stirring at a speed of 300-600 rpm for 5-10 minutes to obtain a mixed material A;

(3) Adding the soaked silver paste obtained in the step (1) into the mixed material A obtained in the step (2) while stirring, and stirring at a speed of 300-600 rpm for 5-10 minutes to obtain a mixed material B;

(4) Adding an amine neutralizer into the mixed material B obtained in the step (3) while stirring, stirring for 5-10 minutes at a speed of 300-600 rpm, adding an orienting agent, and stirring for 5-10 minutes at a speed of 300-600 rpm to obtain a mixed material C;

(5) Adding a rheological agent into the mixed material C obtained in the step (4) while stirring, and stirring at a speed of 300-600 rpm for 15-25 minutes to obtain a component A;

(6) And (3) adding propylene glycol diacetate into a container, and adding a curing agent after the water content is determined to be qualified to obtain the component B.