Selection and application of decorative vacuum coating for coating

  Due to the development of bottom and surface coating material, vacuum coating equipment of continuous improvement and continuous, large-scale, vacuum plating in the stage of the industrialization of production, also penetrated into all fields of science, has become in the world since the 1980s are competing for the use of advanced surface treatment technology of, widely used in a variety of substrate, metal, wood, paper, plastic, etc. the plating part and gradually reveal the unique role in the application of vacuum plating. The selection and application of coating is an important factor to the quality of decorative vacuum coating.

The curing reaction time can be shortened, and the performance and stability of the film can be improved. Commonly used photosensitizer is benzoin ethers, in recent years the development of sulfur mixed anthrone compounds and N, N, - dimethyl ethanolamine combined high hardness of the coating can be obtained.

Photosensitive resin containing double bond, which can be used in the coating, it is the main film forming material, it determines the performance of the film, commonly used photosensitive resin has vinyl and acrylic acyl type two.

Reactive diluent containing unsaturated double bond monomer or oligomer, which can reduce the paint viscosity, and may participate in the curing reaction, together with the photosensitive resin into film, reactive diluent also vinyl and acrylic base type.

The surface tension of coating can be improved by adding leveling agent, which can make the film to be smooth, and the usual leveling agents include cellulose and sorbitol.

(2) acrylate coating:

Acrylate coatings are generally made of a copolymer of methyl methacrylate and acrylic ester. What are the coatings used in vacuum coating and how to improve the application of the coating technology in the actual production?. In the decorative vacuum coating, depending on the perfect coating technology, the coating with high wear resistance, good adhesion and high brightness can be acquired.

1 the role and requirements of the coating

Decorative vacuum plating coating is generally divided into two kinds of bottom coating and surface coating. In order to meet the different technical requirements of the product, can be applied to the coating and surface coating, or coating on the surface and then apply color coating, protective coating, etc.. The main effect of these coatings is:

Improve the adhesion of the film. Using the same coating method, the coating of the coating on the plastic substrate can be applied to vacuum coating, which can improve the bonding strength of the film.

Reduce the surface roughness of the plating parts, improve the brightness of the light. General plating surface micro roughness, not necessarily coating thickness the leveling of, can fill the plating surface defects, plating the surface of mirror surface roughness.

Can protect metal film. The vacuum coating layer is generally only 100nm, the wear resistance and anti discoloration ability of the film layer is poor, and the coating layer is not directly contacted with the outside surface, and the coating layer can protect the coating layer.

Requirements for bottom coating in vacuum plating:

The good contact performance and high bonding strength between the coating and the coating layer, the thermal expansion coefficient of the thermal expansion coefficient is small, does not react, and the leveling performance is good.

Has good vacuum performance. After the curing of the bottom coating, the gas discharge quantity is little, the thermal stress is small, and the heat resistance performance is good.

The film-forming properties, properties of the coating density, coverage, solvent resistance and light resistance ability is good.

The surface coating has good compatibility. As the coated thin layer has pores, coating and surface coating requirements at the end of the solvent and diluent has good compatibility.

The application of good performance. Leveling performance is good, has the appropriate viscosity, curing time is short.

Requirements for vacuum plating of opposite coating:

Good contact with coating layer;

There must be some compatibility with the bottom coating;

The film forming performance and application performance are excellent, with the appropriate mechanical strength;

The moisture-proof, anti solvent, good corrosion resistance. Strong anti aging performance.

Due to the special needs of products, in the face of the coating can be further coated with super hard coating or color coating, etc..

2 commonly used coatings

Vacuum coating is commonly used in coating, such as UV curing coating, acrylic ester coating, alkyd resin coating, epoxy resin coating, polyurethane coating, etc..

(1) UV curing coating:

UV curing coating is a coating which is under the irradiation of UV light at the wavelength of 250~450nm. Characteristic is:

Paint does not need the direct heating, as long as with ultraviolet light can not be cured, energy conservation, curing speed, to the minute and second, suitable for automatic assembly line; excellent coating performance and coating binding force, covering high, low surface roughness, good vacuum performance, low solvent content, is conducive to environmental protection and so on.

The UV curing coatings including photosensitizer polymerization initiator), photosensitive resin prepolymer, active diluent, and add the necessary stabilizers, flow and leveling agent and pigment etc..

Photosensitive resin containing double bond occurring self polymerization reaction can be solidified into a film. Choose appropriate photosensitive

Acrylate coating features: excellent color and gloss, good color retention properties, moisture, mildew, anti solvent, acid and alkali resistance, heat resistance is good, can use in 180 degrees centigrade.

(3) alkyd resin coating:

Alkyd resin is a polyol resin and polybasic acid and fatty acid esterification into three together. Alkyd resin coating is the main form of alkyd resin.

Characteristics of alkyd resin coatings with excellent gloss and gloss and color retention performance good, coating layer of flexible fast, friction resistance, but the anti salt fog, mouldproof, moistureproof performance is poor.

(4) epoxy resin coating:

Epoxy resin coating is a film forming material based on epoxy resin.

The characteristics of epoxy resin coatings: chemical stability, resistance to alkali particularly strong, the coating layer attached to the excellent thermal stability and electrical insulation resistance and color retention of good performance, but poor weather resistance, easy loss of light, powder.

(5) polyurethane coatings:

This coating contains a considerable number of urethane bonds.

The characteristics of polyurethane coatings: wear resistance is particularly strong, with excellent adhesion can be obtained extremely hard coating and highly flexible elastic coating, chemical stability, in high temperature drying, in low temperature curing, the coating has excellent protective function, the appearance of decoration.

3 application methods

Commonly used methods of application of dip coating, spraying and brush coating, can be used manually or automatic coating method construction.