CN110951356A

CN110951356A - Preparation method of high-hardness matte water-based paint for stainless steel

Info

Publication number: CN110951356A
Application number: CN201911048527.0A
Authority: CN
Inventors: 邵昊天; 陆洪彬; 唐伟
Original assignee: HAIAN INSTITUTE OF HIGH-TECH RESEARCH NANJING UNIVERSITY
Current assignee: HAIAN INSTITUTE OF HIGH-TECH RESEARCH NANJING UNIVERSITY
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-04-03

Abstract

The application discloses a high-hardness matte water-based paint for stainless steel. The method specifically comprises the following steps: a) the method specifically comprises the following steps: uniformly mixing 28-36 parts of water-based resin, 40-60 parts of deionized water, 1-2 parts of a film-forming assistant, 7-15 parts of a silane coupling agent, 4-8 parts of a lotus leaf hydrophobing agent, 0.5-1 part of a catalyst and 5-10 parts of a cross-linking agent in sequence to obtain a component A, and dispersing and sieving 69 parts of water, 70 parts of barium sulfate, 1 part of an anti-settling agent and 0.5 part of a dispersing agent at a high speed to obtain a component B) for mixing treatment: mixing the AB component obtained in the step a) and dispersing for 0.5h at a high speed to obtain a finished product. The film forming process is the conventional surface coating treatment of the stainless steel, such as spraying, roller coating, drying and the like. The stainless steel paint prepared by the method has the adhesive force of 0 grade, the hardness of 2H and the stain resistance test Δ E of less than or equal to 1.0. The performance of the paint is close to that of the stainless steel oil paint, and the paint can be used as a substitute product of the oil paint. The paint has good antifouling performance, matte appearance, no air holes, attractive appearance and clean and environment-friendly preparation process.

Description

Preparation method of high-hardness matte water-based paint for stainless steel

Technical Field

The invention relates to the field of stainless steel anticorrosive paint, in particular to a formula and a preparation method of high-hardness matte water-based paint used on a stainless steel plate.

Background

At present, in the industry of stainless steel coating, oily paint using n-butyl alcohol, n-amyl alcohol and the like as solvents is common, and the oily paint has the advantages of good hardness, good appearance, quick curing time and the like, and is widely used in the industry. In recent years, due to the pressure in environmental protection, the industry begins to gradually transform to use water-based coatings, and the water-based coatings have the characteristics of environmental protection, low price, no harm to the environment and people, and the like. However, in the formulation of the common water-based paint, the solubility and dispersibility of the resin in water are poor, and the water-based paint material has the problems of poor stain resistance, air holes in appearance, poor glossiness, poor ageing resistance and the like. The invention provides a water-based paint with improved stain resistance, improved performance, high-performance stain resistance and environmental protection, and improved market share.

Disclosure of Invention

The invention aims to provide a preparation method of a high-hardness matte water-based paint. By proper component proportion and proper production process, the water-based stainless steel coating has the advantages of high hardness, acid and alkali resistance, corrosion resistance, high adhesive force and the like. When the stainless steel surface is covered, the appearance is matte, uniform and beautiful.

The AB group allocation used in the present invention is as follows

Component A

1) 28-36 parts of water-based resin

2) 40-60 parts of deionized water

3) 1-2 parts of film-forming assistant

4) 7-15 parts of silane coupling agent

5) 4-8 parts of lotus leaf hydrophobing agent

6) 0.5 to 1 portion of catalyst

7) 5-10 parts of cross-linking agent

B component

1) Barium sulfate 70 parts

2) 69 parts of deionized water

3) 1 part of anti-settling agent

4) 0.5 part of dispersant

Preferably, the aqueous resin is an aqueous propylene modified epoxy resin, and the resin has an epoxy structure.

The waterborne acrylic modified epoxy resin is an epoxy resin modified by acrylic resin and water serving as a dispersion medium. Has outstanding salt fog resistance, water resistance and hardness, and has good adhesive force to metal base materials. The water is used as solvent, so that the method is pollution-free, safe and reliable.

Preferably, the lotus leaf hydrophobing agent is Sp-2405 hydrophobing agent.

The Sp-2405 hydrophobic agent is composed of wax waterproof substances, can be mutually dissolved with water in any proportion, forms a hydrophobic protective film after being cured, effectively prevents corrosive substances in the environment from permeating, provides excellent hydrophobic property for the surface, can increase the hardness of a paint film, and improves the scratch resistance of the paint film. Compared with various hydrophobic agents and wax substances, Sp-2405 has the best compatibility and hydrophobic property.

Preferably, the cross-linking agent is Enlish 917 amino resin

The amino resin can improve the crosslinking degree of the resin, and multiple experiments show that the crosslinking efficiency between the Enlish 917 amino resin and the epoxy resin is high, the toughness of a paint film can be kept after the 917 amino resin is crosslinked, the impact resistance is improved, and the higher the crosslinking degree is, the better the stain resistance and the aging resistance are.

Preferably, the barium sulfate used is 6000 mesh barium sulfate powder.

The barium sulfate is used as an inorganic filler, has good covering power, can uniformly cover the surface of the stainless steel under the condition of compounding with the coating, roughens the surface of the stainless steel to achieve the aim of physical extinction, and can effectively improve the hardness, wear resistance, ageing resistance and stain resistance of the finished product due to good chemical stability and physical performance of the barium sulfate. The barium sulfate powder with the particle size of 6000 meshes can achieve the purpose of physical extinction under the condition of ensuring the smooth appearance, thereby realizing the matte effect. The thicker barium sulfate powder is 2000 meshes, the appearance of a paint film is influenced after the paint film is coated, so that the surface of the paint film has granular feel, and the 6000 meshes of powder can meet the performance requirement through multiple comparison experiments.

Preferably, BHN organic bentonite is selected as the anti-settling agent.

BHN organic bentonite can be coated on the surface of barium sulfate in the barium sulfate slurry, so that the compatibility between barium sulfate and water is improved, the stability of the barium sulfate slurry is improved, and the effectiveness of the barium sulfate slurry in long-time storage is ensured, thereby being suitable for large-scale industrial production. Compared with various types of bentonite, BHN organic bentonite has the best performance, and the settlement amount in 7 days is only 1%.

Preferably, the sieving process adopts a 600-mesh sieve

Because large barium sulfate particles which are not uniformly dispersed exist in the barium sulfate water slurry, the uniformity and the stability of a coating film are influenced, a 600-mesh screen is needed to remove the large particles, and the attractive appearance of the coating after roller coating is ensured.

Detailed Description

The invention provides a preparation method of a high-hardness matte water-based paint for stainless steel, which comprises the following specific implementation modes:

the first implementation mode comprises the following steps:

1) take 42 parts of deionized water in a beaker

2) Adding 2 parts of alcohol ester 12, and stirring for 0.5h

3) Adding 32 parts of propylene modified epoxy resin, and stirring for 0.5h

4) Adding 10 parts of silane coupling agent, and stirring for 0.5h

5) Adding 5 parts of lotus leaf hydrophobing agent, stirring for 0.5h

6) Adding 0.5 part of catalyst, and stirring for 0.5h

7) Adding 8 parts of cross-linking agent, stirring for 0.5h to obtain component A for later use

8) Taking 29 parts of water and putting the water in a beaker

9) Adding 1 part of anti-settling agent, dispersing with high speed disperser at 3000rpm for 3min

10) Adding 0.5 part of dispersant, continuing to disperse at the rotating speed of 3000rpm for 10min

11) Adding 70 parts of barium sulfate, continuing to disperse at the rotating speed of 3000rpm for 0.5h

12) Slowly adding 40 parts of deionized water, continuing to disperse at the rotating speed of 1000rpm for 10min

13) Sieving the product obtained in 12) with 600 mesh sieve, collecting the sieved water slurry as component B

14) Mixing the component A and the component B in a ratio of 19: 1, the rotation speed is 3000rpm, and the sanding time is 0.5 h.

15) Coating the sample obtained in the step 14) on the surface of a clean stainless steel plate by adopting a roller coating method, wherein the coating thickness is 12 mu m, putting the stainless steel plate into a 180 ℃ oven to bake for 10min, taking out the stainless steel plate and naturally cooling the stainless steel plate

Implementation method two

Changing deionized water in component A into 52 portions, and implementing method three in the rest

The proportion of the component A to the component B is changed to 24: 1, the rest is unchanged

And (4) carrying out paint film adhesion test, hardness test and stain resistance test on the stainless steel plate obtained by the first to third implementation methods.

Table 1

The paint film on the surface of the stainless steel is flat in appearance and has no air holes. As shown in Table 1, the adhesion and hardness of the water-based paint film meet certain requirements, the water-based paint film is close to the common oil-based protective paint film on the surface of stainless steel, and the color change (Δ E) before and after the water-based paint film is subjected to a stain resistance test is less than or equal to 1.0, which means that the surface of the water-based paint film has no obvious change after pollutants are wiped on the surface of the water-based paint film, so that the water-based paint film can effectively prevent the paint surface from being damaged, and has better stain resistance and stain resistance. The reflectivity of the paint film is greatly reduced after the paint film is coated, which shows that the appearance of the stainless steel plate is changed into a matte appearance, and light is absorbed by the paint film. The paint film has smooth appearance and no air holes.

Claims

1. A high-hardness matte water-based paint for stainless steel specifically comprises the following components: a) the method specifically comprises the following steps: uniformly mixing 28-36 parts of water-based resin, 40-60 parts of deionized water, 1-2 parts of a film-forming assistant, 7-15 parts of a silane coupling agent, 4-8 parts of a lotus leaf hydrophobing agent, 0.5-1 part of a catalyst and 5-10 parts of a cross-linking agent in sequence to obtain a component A, and dispersing and sieving 69 parts of water, 70 parts of barium sulfate, 1 part of an anti-settling agent and 0.5 part of a dispersing agent at a high speed to obtain a component B) for mixing treatment: mixing the AB component obtained in the step a) and dispersing for 0.5h at a high speed to obtain a finished product.

2. The film forming process is the conventional surface coating treatment of the stainless steel, such as spraying, roller coating, drying and the like.

3. The high-hardness matte water-based paint for stainless steel prepared by the method of claim 1).

4. The water-based acrylic modified epoxy resin is characterized in that the type of the resin in the formula is water-based acrylic modified epoxy resin, and the addition amount is 28-36 parts.

5. The resin has excellent performance, can form a compact protective film after being cured on the surface of stainless steel, is tightly combined with the stainless steel, and improves the adhesive force.

6. The high-hardness matte water-based paint for stainless steel prepared by the method of claim 1).

7. The water repellent agent is characterized in that Sp-2405 is added in an amount of 4-8 parts, so that the water repellent performance and hardness of a paint film can be improved.

8. The water-based high-hardness high-transparency stainless steel coating prepared by the method according to claim 1), wherein the preferable amino resin is Enlish 917, and the addition amount is 5-10 parts, so that the compactness of a paint film can be improved, the corrosion resistance of the paint film can be improved, and a certain impact resistance can be maintained.

9. The high-hardness matte water-based paint for stainless steel prepared by the method of claim 1).

10. The method is characterized in that the barium sulfate water slurry is prepared into high-concentration barium sulfate water slurry by mixing and sieving, and the barium sulfate water slurry can be stably stored after being added into resin, so that the flatness of a paint film is not influenced, and the hardness of the water-based paint after curing is improved.