Title:
PRODUCTION OF POLYVINYL ALCOHOL-BASED RESIN MOLDED PRODUCT
Document Type and Number:
Japanese Patent JP3509026
Kind Code:
B2
Abstract:
PURPOSE: To efficiently obtain the subject molded product improved in thermal stability such as a high-quality film free from discoloration and fish-eyes by molding in a molten state a PVA-based resin having each specific aqueous solution viscosity and methanol solubles.
CONSTITUTION: A polyvinyl alcohol-based resin ≤10cps in the 4wt.% aqueous solution viscosity at 20°C and ≤5wt.% in methanol solubles is dried under a vacuum at 50°C for 12hr and then heated to 220°C into a melt, which is in turn, pelletized using a small-sized, twin-screw extruder. Thence, the resulting pellets are fed into a conventional extruder equipped with an inflation die with a screw bore diameter of 40mm, L/D of 28 and number of revolutions of 29rpm to carry out melt molding at a screw compressive part maximum temperature of 220°C and delivery port temperature of 200°C, thus obtaining the molded product improved in thermal stability such as a high-quality film having the above-mentioned advantages.
Inventors:
Tomita, Munetoshi
Noma, Shinji
Noma, Shinji
Application Number:
JP14351892A
Publication Date:
March 22, 2004
Filing Date:
May 08, 1992
Export Citation:
Assignee:
NIPPON SYNTHETIC CHEM IND CO LTD:THE
International Classes:
C08F8/12; C08F6/00; C08F16/02; C08F16/06; C08F216/14; C08J5/00; (IPC1-7): C08J5/00; C08F6/00; C08F216/14