Terminated unsaturated polyester resin and preparation method thereof

Abstract

The invention relates to a terminated unsaturated polyester resin which is a polycondensate of dihydric alcohol and a dibasic acid or estolide. The dibasic acid or estolide comprises a saturated dibasic acid or estolide and an unsaturated dibasic acid or estolide; a reaction system of the dihydric alcohol and the dibasic acid or the estolide is terminated by monohydric alcohol; the terminated unsaturated polyester resin has molecular weight of 800-1500 and comprises the following components by mass percent; 22-30 percent of dihydric alcohol, 24-30 percent of saturated dibasic acid, 15-19 percent of unsaturated dibasic acid, 3-6 percent of monohydric alcohol and 22-29 percent of cross linker, wherein the monohydric alcohol is one of isooctanol, cyclohexanol and phenylcarbinol. The invention has the advantages as follows: a termination method is used for preparing the unsaturated polyester resin, thus being capable of improving the hydrolysis resisting stability and the scale-resisting performance and reducing the volatilization and shrinkage of resin; and when the resin prepared by the method is taken as matrix resin to produce boards such as rostone, deck plate, quartz and the like, the yield of products can be improved, the cracking phenomenon can be reduced, and the products can be used in occasions with higher water-proof requirement.

Description

technical field [0001] The invention relates to a high-quality end-blocking unsaturated polyester resin and a preparation method thereof. The unsaturated polyester resin prepared by this method has higher strength, lower shrinkage and water absorption. Background technique [0002] The traditional unsaturated polyester resin is a linear polymer compound with ester bonds and unsaturated double bonds formed by polycondensation of saturated dibasic acids, unsaturated dibasic acids and diols. Usually, the polyester polycondensation reaction is carried out at 190-220°C until the desired acid value (or viscosity) is reached. After the polyester polycondensation reaction is completed, a certain amount of cross-linking monomer is added while it is hot to form a viscous of liquid. The unsaturated polyester resin prepared by this traditional method has many defects in water resistance, etc. There are mainly three reasons for these defects: [0003] 1. The general unsaturated polyes...

AI Technical Summary

Problems solved by technology

[0003] 1. The general unsaturated polyester resin has more active groups, such as hydroxyl, carboxyl and other hydrophilic groups, and has strong polarity, which is easy to form hydrogen bonds with water, resulting in high water absorption of the resin;

[0004] 2. The unsaturated polyester resin prepared by the traditional preparation method has a relatively large molecular weight, more hydroxyl carboxyl groups at the end groups, and poor compatibility with styrene, so it is necessary to add more benzene to achieve a certain viscosity. Ethylene (for example, if the viscosity of the system needs to reach 220mPa.S, the resin prepared by the traditional method, the content of the added diluent is 33% to 40%);

But this will lose some strength