Japan Catalyst Develops New Unsaturated Polyester

Nippon Shokubai developed an unsaturated polyester resin containing a high percentage of recycled PET resin. The company's proprietary technology for catalysts and resins has increased the content of recycled PET bottles from the original 10% to 25%, and has now obtained environmental protection product recommendation marks. With regard to various physical properties and formability, the same performance as the original product is ensured, and the use of fiber-reinforced plastic (FRP) will be centered. At present, the company's annual sales volume of resin containing recycled PET bottles is about 1,666 tons, and the year 2003 is To expand to 3,000 tons.

The developed resin is obtained by pulverizing a recovered PET bottle into a sheet, adding ethylene glycol for transesterification reaction (depolymerization reaction), and reacting an unsaturated acid to dissolve in a liquid crosslinking agent to make an unsaturated polyester. Although the technology for producing unsaturated polyesters from waste PET resins has been known for a long time, the problem of coloring has not been generally solved since the precipitation and hardening properties of crystals change with time.