Sughrue, Mion, Zinn, Macpeak, and Seas
Process for producing lactone polymer and an anti-shrinking thermosetting resin composition having formulated therein said lactone polymer as an anti-shrinking agent
 A process for producing a lactone polymer which comprises reacting an ester compound synthesized from an alcohol and an acid or acid anhydride thereof with a lactone and a ring-opening polymerization initiator without being accompanied by condensation. The thus produced lactone polymer is effective for preventing shrinkage of thermosetting resins, particularly unsaturated polyester resins. 
Daicel Chemical Industries, Ltd.
C C
C08G C08L
inventional inventional
Tomohisa Takaaki Naoki Takuya Yoshiyuki Kimio Shoji
Isobe Murai Nakashima Miho Ikemoto Inoue Watanabe