Study On Preparation And Application Of High-solid And Low-viscosity Hydroxy Acrylic Resin

With the strict requirements of environmental protection policies,environmentally friendly coatings have attracted much attention and use,and water-based coatings are one of its main varieties.However,water-based coatings have a narrow construction window and low construction tolerance,which can cause pollution to water bodies.The high-solid resin of the homogeneous system has the characteristics of high film gloss,fullness and excellent chemical resistance.However,there are still difficulties in the development of high-solid and low-viscosity resins.In order to reduce the viscosity of the resin,the molecular weight of the resin is reduced,which has caused the drying speed of the paint film to slow down.Therefore,this article conducts the following investigations for the above-mentioned problems.This article uses multi-arm structured polyester polyols as reactive diluents to replace some solvents.At the same time,it also explores the effects of polymerization process,solvents and viscosity reducing monomers on the molecular weight and viscosity of the resin and the drying speed of the paint film.A high-solid,low-viscosity hydroxy acrylic resin with a solid content of 82%and a viscosity of 2280mpa·s was prepared.The results of the study show that:using a polyester polyol（DSPP-2）with a theoretical hydroxyl functionality of 4,a hydroxyl value of 320mg KOH/g,a viscosity of 825mpa·s,and a molecular weight of 1040（DSPP-2）,the addition amount is 12.5%;the polymerization temperature is 150°C,Using a two-layer process,adding 2%di-tert-amyl peroxide（DTAP）as initiator and 0.25%dodecyl mercaptan(C₁₂SH)as chain transfer agent;adding 15%glycidyl tertiary carbonate（E10p）And 7.5%methacrylic isobornyl resin（IBOMA）;the added amount is a compound solvent composed of 70%xylene（XY）and 30%butyl acetate（BAC）,which can successfully prepare high-solid,low-viscosity hydroxy acrylic resin HLAR has the smallest viscosity of the prepared resin,the fastest drying speed of the paint film,and the best overall performance.In order to reduce the viscosity of the paint,reduce the volatilization of organic matter,and speed up the drying speed of the paint film.In this paper,by exploring the type and amount of curing agent,the type and amount of leveling agent and defoamer,and the ratio of thinner and other related factors on the performance of the paint film prepared by HLAR,successfully prepared the appearance of excellent decorative properties,mechanical properties and The two-component polyurethane coating with good chemical resistance has a fast drying speed of the prepared paint film,which meets the needs of fast drying in the field of automobile repair.The specific results are as follows:This article successfully screened out the curing agent Desmodur N3300（GA）,-NCO:-OH=1.1:1 through the inspection of the drying speed of the paint film and the performance of the paint film;through the viscosity of the paint And the drying speed of the paint film,it is determined that the diluent ratio with the strongest dissolving ability for the paint,the best viscosity reduction effect,and the shortest drying time of the paint film;through the inspection of the appearance of the paint film and the state of the paint,it is screened out The best defoaming agent and leveling agent are found,and it is found that when adding 0.05%BYK-028 and 0.15%BYK-392 defoaming agent,0.2%BYK-306 leveling agent,the overall performance of the prepared paint film is the best excellent.