1. Concept: Solvent type hydroxy acrylic resin refers to a copolymer of a non-functional monomer and a hydroxyl group-containing monomer. They have a low molecular weight and cross-link with polyisocyanate after application to form a polymer network structure. The film-forming material is insoluble and infusible.

2. Application: The film formed after cross-linking reaction of hydroxyl acrylic resin with polyisocyanate has good hardness, gloss and color retention, gloss, fullness, scratch resistance, chemical resistance, etc. Cross-link curing at room temperature, in the automotive maintenance, construction machinery, home appliances, light industrial products and ABS, PVC, PP, PC, PS and other plastic surface secondary processing applications are more common.

3. Choice: The performance of the hydroxy acrylic resin film forming material is not the same as that of the thermoplastic material. It depends not only on the molecular weight and TG, but also the "-OH" content and the "-OH" property. "-OH" content is high, crosslink density, hardness and chemical resistance and other properties are more prominent, the fullness of the paint film is also relatively good (need to add the appropriate amount of -NCO); but "-OH" content is high, the resin system Relatively high polarity, Viscosity will be relatively large, the dilution of the resin is relatively poor. At the same time dryness and adhesion (especially in plastic materials such as ABS) will also decline, and the cost of resins and coatings will be relatively high. Therefore, designing and selecting the right "-OH" is more critical for both formulators and application engineers. In general, hydroxyl resins of 2.0 and below are referred to as low hydroxyl resins, 2.0 to 3.0 hydroxyl groups are referred to as middle hydroxyl resins, and 3.0 or higher are referred to as high hydroxyl resins. Low hydroxyl resin, in order to ensure the coating performance, the resin TG and molecular weight will be relatively higher, suitable for primer or plastic paint; high hydroxyl resin, the general molecular weight is relatively low, need more hydrazine -NCO" to crosslink, coating Layer gloss fullness will be higher, suitable for topcoat or varnish; medium hydroxyl resin is somewhere in between, generally suitable for industrial paints such as construction machinery or auto repair paint.