US 5,424,339 AGranted

Method for producing an optical material having a high refractive index

AssigneeMitsubishi Petrochemical Co., Ltd.

InventorsYukihito Zanka, Tsutomu Isaka, Yutaka Tamura

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Abstract

An optical material with a high refractive index comprising a resin which is obtainable by polymerization and curing of a composition comprising the following components (A), (B) and (C): component (A): a sulfur-containing (meth)acrylic monomer represented by the following formula [I], or a mixture of the monomer [I] and a sulfur-containing (meth)acrylic monomer represented by the following formula [II]: ##STR1## in each of which formulas, R.sup.1 represents a hydrogen atom or a methyl group, R.sup.2 and R.sup.3 independently represent a hydrocarbyl group of 1 to 12 carbon atoms, X represents a halogen atom except fluorine, and n represents 0 or an integer of 1 to 4, provided that those groups which are in plurality may be the same or different, the weight ratio of the compound [I]/the compound [II] being from 10/0 to 1/9; component (B): a hydroxy(meth)acrylic monomer represented by the following formula [III]: ##STR2## wherein R.sup.5 represents a hydrogen atom or a methyl group, R.sup.4 represents a hydrocarbyl group of 1 to 20 carbon atoms which may or may not contain an ether oxygen atom, Y represents a halogen atom except fluorine, and m represents 0 or an integer of 1 or 2, provided that those groups which are in plurality may be the same or different, and p is 1 or 2, the weight ratio of the component (A)/the component (B) being from 95/5 to 50/50; and component (C): an isocyanate compound having a plurality of --NCO groups, the ratio (--NCO/--OH) of the number of --NCO group in the component (C) to the total number of --OH group in the components (A) and (B) being from 0.2 to 3. The above material for lenses has a low specific gravity and improved refractive index, transparency and impact resistance.

A method for producing an optical material having a high refractive index, which comprises:

irradiating a composition comprising the following components (A), (B) and (C), a radical polymerization initiator and a urethanization catalyst with ultraviolet radiation thereby causing the curing of the composition by a radical polymerization of unsaturated groups in reactants (A) and (B) and by the urethanization reaction of reactants (A) and (B) with isocyanate reactant (C);
and
heating the irradiating composition to complete curing:
component (A):
a sulfur-containing (meth)acrylic monomer represented by the following formula [I], or a mixture of the monomer [I] and a sulfur-containing (meth)acrylic monomer represented by the following formula [II]:
##STR10## in each of which formulas, R.sup.1 represents a hydrogen atom or a methyl group, R.sup.2 and R.sup.3 independently represent a hydrocarbyl group of 1 to 12 carbon atoms, X represents a halogen atom except fluorine, and n represents 0 or an integer of 1 to 4, provided that those groups which are in plurality may be the same or different,
the weight ratio of the compound [I]/the compound [II] being from 10/0 to 1/9;
component (B):
a hydroxy(meth)acrylic monomer represented by the following formula [III]:
##STR11## wherein R.sup.5 represents a hydrogen atom or a methyl group, R.sup.4 represents a hydrocarbyl group of 1 to 20 carbon atoms which may or may not contain an ether oxygen atom, Y represents a halogen atom except fluorine, m represents 0 or an integer of 1 or 2, provided that those groups which are in plurality may be the same or different, and p is 1 or 2,
the weight ratio of the component (A)/the component (B) being from 95/5 to 60/40;
and
component (C):
an isocyanate compound having a plurality of --NCO groups,
the ratio (--NCO/--OH) of the number of --NCO group in the component (C) to the total number of --OH group in the components (A) and (B) being from 0.2 to 3.

12 more elements

Abstract

Claims11