UV-curable Polyurethane-acrylate Coatings And Its Application

UV-curable polyurethane coating with good adhesion, abrasion resistance excellent optical properties and weather resistance are widely used in electronics, printing, furniture, home appliances and many other industries, but this technique has never been used in the production of protective coatings of stones. Polymers based on acrylic and methacrylic monomers(such as Paraloid B72), siloxane polymers and fluorine-containing polymers are widely used in the protection and conservation of stone. Acrylic acid and methyl acrylic polymers have poor adhesion to substrates, silane-type protective agent is vulnerable to oil stain, and fluorinated acrylate has high prices. These drawbacks have restricted their use and raised demand for alternatives. What's more, these products mostly apply thermal curing technology, which is not suitable for large-scale stone surface protection.Aimed at decorative stone protection, this paper prepared and screened UV curable polyurethane coatings suitable for stone surface protection by researching the relationship between the composition and performance. In order to further develop the use of UV-curable polyurethane coating, we also applied the coating to screen printing photosensitive emulsions and porcelain plate and glass surface decorative coating, and studied the relevant technology. The main research contents and achievements of the thesis are as follows:(1) According to the mechanism of UV curing polyurethane coating, we did preliminary research on the coating composition of photoinitiators, oligomers and reactive diluents. When using 1173 as photo-initiator and 5% as the amount of photoinitiator, the coating curing time is acceptable(about 10 s), coating adhesion, impact resistance and other properties are good. On this basis, to get a good overall performance film requires the adjustment of the ratio between oligomers and the use mixture of reactive diluent. This paper also analyzed the process of coating, UV absorption and heat resistance by FTIR, UV/Vis spectrometry and comprehensive thermal analysis respectively.(2) This study prepared stone protective agent based on polyurethane system that our group used. The relationship between UV-curable polyurethane coating composition and performance were investigated as well as on the cured films properties. The basic parameters of the coating are: hardness was 7H, adhesion level was 2, shrinkage rate was 1.5%, the impact resistance is more than 50 cm, gloss more than 80. The coating is applied to the marble, and the test results show that the UV curable polyurethane coatings have good water repellent, stain, acid and alkali resistance and temperature resistance, but the ultra-violet resistance needs to be improved, suitable for stone protective materials. Construction technology research has shown that the best comprehensive performance of coating could be obtained via the roller coating method.(3) When applying UV curing polyurethane coating for silk screen printing photosensitive emulsions, its flexibility, abrasion resistance and scratch resistance basically meet the performance requirements of screen printing photosensitive emulsions; the UV-curable polyurethane coatings used as porcelain and glass surfaces decorative coatingshave good adhesion, decorative effect and the degree of saturation.These technologies need to be further developed.