Acrylic polyurethane coating and preparation method and application thereof

Abstract

The invention discloses an acrylic polyurethane coating and a preparation method and application thereof in manufacture of a connecting material or a protective coating. The acrylic polyurethane coating is prepared by mixing hydroxyl acrylic resin, a hydroxyl polyurethane plasticizer and a polyisocyanate curing agent. The acrylic polyurethane coating is mainly used for making the resin connecting material of an optical diffusion film, and the coating after the film formation has good light transmittance and light diffusion property and high scratch resistance, and has the advantages of prevention of falling off of resin micro beads in a diffusion layer. The acrylic polyurethane coating can also be used for making optical films such as brightening films and reflecting films, and the ratio of the three components can be adjusted according to the use and the substrate characteristics of different optical films so as to achieve the coating performances required by different purposes.

Description

technical field [0001] The invention relates to an acrylic polyurethane coating and a preparation method and application thereof. Background technique [0002] An optical diffusion film is used in liquid crystal displays of mobile phones, digital cameras, televisions, etc., and its function is to evenly diffuse the light of point light sources or line light sources into uniform, high-brightness surface light sources. The commonly used optical diffusion film is composed of base material, diffusion particles and connecting material. The commonly used base material is PET film, or other plastic films; the diffusion particles are generally polymethacrylic resin microbeads, or other polymers Microbeads; the linker is commonly used as a mixture of hydroxyl acrylic resin and polyisocyanate curing agent. The manufacturing process of the diffusion film is to mix the diffusion particles and the binder together, and then coat it on the substrate. When the resin in the binder and the c...

AI Technical Summary

Problems solved by technology

CN103044615A discloses a preparation method of hydroxyacrylic resin for reflective film, the resin has a lower glass transition temperature, and the embrittlement temperature can be as low as -51°C, which mainly improves the low-temperature flexibility of the resin and has a lower hardness. The resin cannot meet the requirements of the diffusion film

The copolymer composition of hydroxy acrylic resin is designed, although the hardness, flexibility and bonding strength of the diffusion film are improved, but the high hardness, flexibility, wear resistance, It is more difficult to coordinate and unify adhesion, low viscosity and fast surface drying

If the hardness and wear resistance are improved only by increasing the Tg, molecular weight and crosslinking density of the acrylic resin, the following problems will be brought about: ①The glass transition temperature of the copolymer is increased, and the chain segment becomes hard, which is beneficial to improve the surface hardness, but with The film layer becomes brittle and the adhesion decreases; ②The increase in molecular weight is beneficial to improve the strength, but it will increase the viscosity, deteriorate the leveling property, and appear defects such as ripples and crystal points; ③If the molecular weight reduction is used The loss of strength is compensated by increasing the content of hydroxyl groups and increasing the crosslinking density, but it will cause the surface of the adhesive layer to dry slowly during construction, the base material will be sticky and difficult to roll, and the elasticity of the coating will decrease, and the scratch resistance will deteriorate.

Therefore, it is difficult to achieve the performance and construction coordination required by the binder only by changing the composition formula of the hydroxyacrylic acid copolymer

[0006] At present, some domestic optical film manufacturers use hydroxyl acrylic resin imported from Japan and South Korea and HDI trimer to cure and prepare the bonding material. The quality of the diffusion film is not high enough, mainly due to the scratch resistance of the diffusion film coating. Poor, poor leveling, prone to scratches, ripples, folds and other defects on the surface, the rate of superior products is low (below 50%)