US 5,314,979 AGranted

Optical fibers and core - forming compositions

AssigneesShin-Etsu Chemical Co., Ltd., Hitachi Cable, Ltd.

InventorsHiroshige Okinoshima, Shohei Kozakai, Tomiya Abe

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Abstract

A composition comprising (A) an organopolysiloxane having a unit of the formula: R.sup.1 SiO.sub.3/2 wherein R.sup.1 is methyl, phenyl or vinyl in its molecule and having at least 0.05 alkenyl groups each directly attached to a silicon atom per silicon atom, (B) an organohydrogenpolysiloxane having at least 2 hydrogen atoms each directly attached to a silicon atom per molecule, (C) a platinum catalyst, and (D) an organosilane or organopolysiloxane of the formula: R.sup.2.sub.a (R.sup.3 O).sub.b SiO.sub.(4-a-b)/2 wherein R.sup.2 and R.sup.3 are hydrogen, methyl, phenyl or vinyl maintains good light transmission in cured form when exposed to humidity and is thus suitable for forming cores of optical fibers. Similar benefits are obtained with a composition comprising components (A) and (B), (C') a platinum catalyst and/or a radical polymerization initiator, and (E) a carboxylate.

Claims19

Dependent claims

A composition for forming optical fiber cores, comprising

(A) an organopolysiloxane having a unit of formula (1):
R.sup.1 SiO.sub.3/2 ( 1)
wherein R.sup.1 is an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms in its molecule or a halogenated derivative thereof and has at least 0.05 alkenyl groups, each directly attached to a silicon atom, per silicon atom,
(B) an organopolysiloxane having at least 2 hydrogen atoms each directly attached to a silicon atom per molecule,
(C') a platinum catalyst or a radical polymerization initiator or both, and
(E) a carboxylate of formula (3):
##STR6## wherein R.sub.A a hydrogen or a methyl group and R.sub.B is hydrogen an unsubstituted monovalent hydrocarbon group having 1 to 18 carbon atoms or a halogenated monovalent hydrocarbon group having 1 to 18 carbon atoms;
wherein said carboxylate (E) is contained in an amount of about 0.5 to about 50% by weight based on the total weight of the composition.

5 more elements

Dependencies are inferred from the claim text.