Title:
PRELIMINARY POLYMERIZATION FOR MONOMER COMPOSITION CONTAINING DIETHYLENEGLYCOLBIS(ARYLCARBONATE)
Document Type and Number:
Japanese Patent JPS61223008
Kind Code:
A
Abstract:
A prepolymerization step prior to casting reduces shrinkage during polymerization of a composition containing diethylene glycol bis(allyl carbonate) with up to 40% of a vinyl ester, preferably vinyl acetate, and one or more free radical type initiators. The prepolymerization step includes adding a small amount of free radical type initiator, which may be the same or different than that used just prior to casting, and heating to a temperature higher than one hour half-lifetime temperature of the initiator. In this manner, most of the added initiator is consumed and the prepolymerization produces the highest possible conversion while preventing overpolymerization. High yield of lenses of ophthalmic quality is obtained.
Inventors:
ROBAATO AI IZURIERABU
GUREN PEEJI JIYONSON
MERUBIN II KAMEN
DONARUDO HARII PETSUCHIEN
GUREN PEEJI JIYONSON
MERUBIN II KAMEN
DONARUDO HARII PETSUCHIEN
Application Number:
JP4208086A
Publication Date:
October 03, 1986
Filing Date:
February 28, 1986
Export Citation:
Assignee:
COBURN OPTICAL IND
International Classes:
C08F4/36; C08F18/00; C08F18/24; A61L27/00; C08F218/00; C08F263/06; G02B1/04; (IPC1-7): A61L27/00; C08F218/00; C08F218/04
Attorney, Agent or Firm:
Takehiko Saito
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