CN102070966A - Organic and inorganic mixed fingerprint-resistance coating and preparation method thereof - Google Patents

Abstract

The invention relates to a method for preparing an organic-inorganic hybrid anti-fingerprint coating. The weight percentages of the chemical components involved in the coating are: 40-70wt% of water-based resin, 3-10wt% of modified silica sol, and 2-15wt% of amino resin , polyisocyanate 2~10wt%, inorganic salt 1~5wt%, water-based polyethylene wax slurry 1~6wt%, adhesion promoter 1~9wt%, leveling agent 0.1~0.5wt%, deionized water 10~40wt% , and the percentage by weight of each raw material is 100%. The present invention obtains an organic/inorganic hybrid anti-fingerprint coating, which does not contain metal ions polluting the environment. Apply it on electro-galvanized steel sheet, hot-dip galvanized steel sheet, tin-plated steel sheet or cold-rolled steel sheet. After coating, it can be cured in 8-15 seconds, and the final transparent coating is formed. It has excellent fingerprint resistance, corrosion resistance, high hardness, scratch resistance, electrical conductivity, self-lubrication and coating properties.

Description

A fingerprint-resistant coating based on organic-inorganic hybridization and its preparation method

technical field

The invention relates to a metal surface protective coating composition, in particular to an organic/inorganic hybrid anti-fingerprint coating and a preparation method thereof.

Background technique

In recent years, galvanized steel sheets have been widely used in industries such as home appliances, automobiles, office supplies, and toys. With the continuous improvement of people's quality of life, the products used are not only required to be aesthetically pleasing, but also environmentally friendly. Fingerprint-resistant steel plate is a high value-added surface treatment product. Compared with the general bare galvanized steel plate, it not only has fingerprint resistance, but also has corrosion resistance, electrical conductivity and repaintability. Today, the market demand for anti-fingerprint steel products is increasing day by day, which also promotes the research on anti-fingerprint processing technology and the development of new application fields for anti-fingerprint coatings. The chemical treatment agent used in anti-fingerprint treatment in the prior art is a compound of chromate-based passivator and water-based organic coating. Because it contains hexavalent chromium which is extremely harmful to the environment, this makes this type of coating difficult to prepare and store. , Transportation and use have greater pollution to the environment.

At present, the improvement of the requirements for anti-fingerprint coatings is reflected in the fact that after coating the anti-fingerprint coatings, the anti-fingerprint steel plate not only has fingerprint resistance and environmental protection, but also has a variety of properties (high gloss, corrosion resistance, high hardness, scratch resistance, etc.) scratch resistance, electrical conductivity, self-lubricating properties and coating properties) in one, and fingerprint-resistant steel plates that can meet a variety of use requirements have broad application prospects.

Among some published patents at home and abroad, the patent (publication number: EP1426466A1) applied by Japan Parker Seisei Co., Ltd. discloses a metal surface treatment agent, which is characterized in that cationic or nonionic polyurethane resin, It is composed of acrylic resin, epoxy resin, polyester resin, polyamide resin, resin of specific structure and compounds of Zr, Ti, V, Mo, W, Mn and Ce mixed with water. The invention does not contain chromium, and can endow metal materials with excellent corrosion resistance, alkali resistance and fingerprint resistance. In addition, European patent (publication number: EP780452A2) application discloses a kind of " water-based paint ", and it directly adopts epoxy-modified acrylic resin to be film-forming agent, but this paint is used for container, is to adopt post-coating, for the need Pre-coated galvanized steel is not suitable. In China, Shanghai Baoshan Iron and Steel (Group) Co., Ltd. and Shanghai Luosi Chemical Building Materials Co., Ltd. disclosed in 1996 (public number: CN1118790) a production method for fingerprint-resistant steel plates, mainly based on water-based acrylic emulsion, adding organic silicon solution, A water-based polymer organic coating composed of film-forming aids and water. In addition, Jiangsu Lanling Polymer Material Co., Ltd. applied and disclosed (publication number: CN101121860A) a chromium-free metal surface treatment agent that endows galvanized sheets with superior corrosion resistance and fingerprint resistance, which is mainly water-based polyurethane , add silica sol, water-based PTFE wax slurry, wetting agent, defoamer and film-forming aids to form a water-based coating. Jiangyin Changfa Anti-Fingerprint Steel Plate Co., Ltd. applied on August 30, 2005 (application number: CN200710141563.2) to replace chromium with zirconium anti-fingerprint water-based paint, which was published on May 28, 2008. The acrylic resin is used as the main film-forming agent, and 0.5-1.0 wt% of metal zirconium ions, wax components and the like are added. Tongji University applied on November 6, 2008 (application number: CN200810202325.2) for a patent for an environmentally friendly anti-fingerprint coating, which was published in 2009. The coating mainly uses water-based epoxy resin as the matrix resin, but its composition It is two components of A and B, and there are problems such as complicated operation and long-term storage after deployment. Shanghai Baoshan Iron and Steel Co., Ltd. published on August 19, 2009 (publication number: CN101509131A) a metal surface treatment agent with corrosion resistance and fingerprint resistance, which is a kind of organic polymer resin and silicone resin. Waterborne polymer organic coating composed of wax, nano oxide, metal compound, silane mixture and water. Recently, China Metallurgical Continuous Casting Technology Engineering Co., Ltd. disclosed on December 16, 2009 (public number: CN101602910A) a water-based anti-fingerprint coating for galvanized sheets, which is mainly composed of water-based resin, inorganic salt, silica sol , Auxiliary A, Auxiliary B and water raw materials, the curing time is 20 seconds to 1 minute. On July 8, 2010, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences applied (application number: CN201010226044.8) for a high-hardness anti-fingerprint coating and its preparation method, using fluorocarbon resin as the main film-forming substance, and then adding amino Resin, nanoparticles, polytetrafluoroethylene, polyethylene wax, additives and organic solvents are combined, but the coating is solvent-based and has certain pollution to the environment.

Contents of the invention

Technical problem: The object of the present invention is to provide an anti-fingerprint coating based on organic/inorganic hybrid and its preparation method.

Technical solution: The present invention is an anti-fingerprint coating based on organic/inorganic hybridization. Its main chemical components are water-based resin, modified silica sol, amino resin, polyisocyanate, inorganic salt, water-based polyethylene wax paste, adhesion promotion It is prepared from the raw materials of agent, leveling agent and deionized water, and the weight percentage of each raw material is:

Water-based resin 40～70wt%

Modified silica sol 3～10wt%

Amino resin 2～15wt%

Polyisocyanate 2～10wt%

Inorganic salt 1～5wt%

Water-based polyethylene wax slurry 1～6wt%

Adhesion promoter 1～9wt%

Leveling agent 0.1～0.5wt%

Deionized water 10～40wt%

The percentage by weight of each raw material is 100%.

In the present invention, the water-based resin is any one of water-based acrylic resin, water-based epoxy resin or water-based polyurethane.

In the present invention, the modified silica sol is silica sol surface-modified by a silane coupling agent, and the particle diameter ranges from 10 to 100 nm.

In the present invention, the silane coupling agent is any one of vinyltriethoxysilane, (methacryloxy)propyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, etc. .

In the present invention, the amino resin is partially methylated amino resin.

In the present invention, the polyisocyanate is a blocked polyisocyanate emulsion, and the unblocking temperature is 90-120°C.

In the present invention, the inorganic salt is any one of ammonium fluorotitanate, ammonium zirconium carbonate, or ammonium fluorozirconate.

In the present invention, the adhesion promoter is any one of titanate coupling agent or organic phosphonate polymer.

In the present invention, the leveling agent is a water-based leveling agent containing silicone.

Among them, water-based resin is the main film-forming substance, and silica sol is used to improve the fingerprint resistance and hardness of the coating film, especially the modified silica sol can be better dispersed in the organic resin without affecting the gloss of the coating. Amino resin and polyisocyanate are used as curing agents, and metal zirconium ions are used instead of heavy metal chromium for inorganic salts, mainly because the oxide film _ZrO2 formed by metal zirconium ions has corrosion resistance and plays a passivation role. Water-based polyethylene wax is used to improve coating film Excellent self-lubrication, scratch resistance and processing performance, adhesion promoter is used to improve the adhesion of the coating film.

Among the present invention, the preparation method of the anti-fingerprint coating of described a kind of organic/inorganic hybrid is characterized in that it comprises the following steps:

Step 1: using silica sol as a raw material; adding a silane coupling agent according to the mass ratio of SiO ₂ in the silica sol (the amount of the silane coupling agent is 10% to 50% of the mass of SiO ₂ in the silica sol). Stir in a water bath at 50-90°C and keep the reaction for 2-6 hours to obtain the modified silica sol.

Step 2: According to the weight percentage of each raw material, put 40-70wt% of water-based resin into the reactor, and add 3-10wt% of modified silica sol, 1-5wt% of inorganic salt, and water-based polyethylene wax slurry while stirring 1~6wt%, then add 2~15wt% amino resin, 2~10wt% polyisocyanate and 1~9wt% adhesion promoter, and finally add 0.1~0.5wt% leveling agent and the remaining deionized 10-40% by weight of water, and then continue to stir for 15-45 minutes to obtain an organic/inorganic hybrid anti-fingerprint paint.

The invention is a water-based chromium-free system, and the components do not contain metal ions that pollute the environment.

The present invention can be coated on the surface of hot-dip galvanized steel sheet, electro-galvanized steel sheet and cold-rolled steel sheet by means of dip coating, spray coating, roller coating, etc., and only needs to coat a coating of about 0.8-1.2 microns on the metal surface, and then solidify After 8 to 15 seconds, it can meet the requirements of corrosion resistance, high gloss, high hardness, scratch resistance, electrical conductivity, self-lubrication and coating properties required for galvanized steel sheets after coating, and has Anti-fingerprint performance and good adhesion, bending resistance and impact resistance.

Detailed ways

The present invention is further illustrated below by way of examples.

Example 1:

A preferred organic/inorganic hybrid anti-fingerprint coating specific proportion is as follows:

Table 1

Put 600g of water-based epoxy resin into the reaction kettle, add 80g of modified silica sol, 30g of ammonium zirconium carbonate, 12g of water-based polyethylene wax slurry while stirring, then add 71732g of amino resin, 48g of blocked polyisocyanate and 45g of adhesion promoter , and finally put 2 g of leveling agent and 260 g of remaining deionized water into the reaction kettle, and continue to stir for 15 to 45 minutes to obtain organic/inorganic hybrid anti-fingerprint coating No. 1.

Example 2:

A preferred organic/inorganic hybrid anti-fingerprint coating specific proportion is as follows:

Table 2

Put 750g of water-based epoxy resin into the reaction kettle, add 110g of modified silica sol, 38g of ammonium fluorotitanate, 15g of water-based polyethylene wax slurry while stirring, then add 71743g of amino resin, 55g of blocked polyisocyanate and titanate bismuth 20g of joint agent, and finally put 2.5g of leveling agent and the remaining 294g of deionized water into the reaction kettle, and continue stirring for 15 to 45 minutes to obtain organic/inorganic hybrid anti-fingerprint coating No. 2.

The performance of the organic/inorganic hybrid anti-fingerprint coating prepared in Example 1 and Example 2 was tested.

table 3

Claims (10)

1. A fingerprint-resistant coating based on organic-inorganic hybridization, characterized in that its chemical component content: Water-based resin 40~70wt% Modified silica sol 3~10wt% Amino resin 2~15wt% Polyisocyanate 2~10wt% Inorganic salt 1~5wt% Water-based polyethylene wax slurry 1~6wt% Adhesion Promoter 1~9wt% Leveling agent 0.1~0.5wt% Deionized water 10~40wt%. 2. The anti-fingerprint coating based on organic-inorganic hybridization according to claim 1, wherein the water-based resin is any one of water-based acrylic resin, water-based epoxy resin or water-based polyurethane. 3. The anti-fingerprint coating based on organic-inorganic hybridization according to claim 1, wherein the modified silica sol is prepared by the following method: using ethanol-dispersed or water-dispersed silica sol as raw material, according to Add a silane coupling agent to the mass ratio of SiO ₂ in the silica sol, stir in a water bath at 50-90°C for 2-6 hours, add deionized water to obtain a modified silica sol, and the particle size of the modified silica sol is 10-100nm ; The silane coupling agent is any one of vinyltriethoxysilane, (methacryloxy)propyltrimethoxysilane, and γ-glycidyloxypropyltrimethoxysilane. 4. The anti-fingerprint coating based on organic-inorganic hybridization according to claim 3, characterized in that: the amount of the silane coupling agent is 10% to 50% of the mass of _SiO2 in the silica sol. 5. An organic-inorganic hybrid anti-fingerprint paint according to claim 1, characterized in that: said amino resin is partially methylated amino resin. 6. The anti-fingerprint coating based on organic-inorganic hybridization according to claim 1, characterized in that: the polyisocyanate is a blocked polyisocyanate emulsion, and the unblocking temperature is 90-120°C. 7. The anti-fingerprint coating based on organic-inorganic hybridization according to claim 1, wherein the inorganic salt is any one of ammonium fluorotitanate, ammonium zirconium carbonate or ammonium fluorozirconate. 8. A kind of anti-fingerprint coating based on organic-inorganic hybridization according to claim 1, characterized in that: said adhesion promoter is any one of titanate coupling agent or organic phosphonate polymer . 9. The anti-fingerprint coating based on organic-inorganic hybridization according to claim 1, characterized in that: said leveling agent is a leveling agent containing organic silicon. 10. A kind of anti-fingerprint paint preparation method based on organic-inorganic hybridization according to claim 1, it is characterized in that it comprises the steps: according to the percentage by weight of each raw material, drop into water-based resin in the reactor, while stirring Add modified silica sol, inorganic salt, water-based polyethylene wax slurry, then add amino resin, polyisocyanate and adhesion promoter, and finally put leveling agent and remaining deionized water into the reaction kettle, and continue stirring for 15~ In 45 minutes, an organic/inorganic hybrid anti-fingerprint coating is obtained.