Title:
PRODUCTION OF POLYURETHANE PREPOLYMER
Document Type and Number:
Japanese Patent JPH05155962
Kind Code:
A
Abstract:
PURPOSE:To produce a polyurethane prepolymer having a narrow mol.wt. distribution, a low viscosity, and an excellent storage stability safely in a short time. CONSTITUTION:A polyurethane prepolymer is produced by reacting a polyhydroxyl compd. with a polyisocyanate compd. in the presence of a catalyst which is added to the reaction system in at least two steps: the first step comprises adding 60-90wt.% of the catalyst and the second and following steps are conducted after the conversion (%) of the isocyanate groups, [(NCO% before reaction)-(NCO% when measured)]/[(NCO% before reaction)mu100], reaches at least 30%.
Inventors:
KITAMURA TETSUJI
SAITO HITOSHI
DANJO MASAMICHI
SAITO HITOSHI
DANJO MASAMICHI
Application Number:
JP32063891A
Publication Date:
June 22, 1993
Filing Date:
December 04, 1991
Export Citation:
Assignee:
YOKOHAMA RUBBER CO LTD
International Classes:
C08G18/10; C08G18/16; (IPC1-7): C08G18/10; C08G18/16
Attorney, Agent or Firm:
Nobuto Watanabe (1 person outside)