Liquid crystal display and photopolymerizable sealant therefor

Claim 2

An improved liquid crystal display cell comprising a pair of half-cells having portions thereof bonded together by organic seal means wherein the improvement comprises an organic seal means comprising a photopolymerized sealant comprising a polymerized mixture of: (a) cationically polymerizable epoxide with a functionality of at least 1, and; (b) an organic aromatic onium catalyst comprising an aromatic adduct of (1) a diaromatic, triaromatic, or tetraaromatic organoatomic cation of a Group Va, VIa, or VIIa atom and (2) an anion; said onium catalyst being represented by the formula: ##STR5## wherein R 2 is an aromatic group at least as electron withdrawing as benzene, R 1 is an alkyl or alkenyl group, A is a Group Va, VIa, or VIIa atom, X is an anion, n is a positive whole integer of at least 2 up to the valence of A plus one, a is 0 or a positive whole integer up to the valence of A minus one, and n plus a is equal to the valence of A plus one and wherein at let two of said R 2 groups are bonded to A; said photopolymerized sealant being chemically resistant to liquid crystal materials.

Claim 3

An improved liquid crystal display cell in accordance with claim 1, wherein said sealant comprises an adhesive-aiding amount of glycidoxpropyl triethoxy silane or its precondensate.

Claim 4

An improved liquid crystal display cell in accordance with claim 2, wherein said cationically polymerizable epoxide is selected from the group consisting of: (a) a mixture of Bisphenol A diglycidyl ether epoxy, triglycidyl ether epoxies of trihydroxymethyl propane, and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexene carboxylate, and; (b) 3,4 epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, and; (c) Bisphenol A diglycidyl ether; wherein said organic aromatic onium catalyst is triphenyl sulfonium hexafluorophosphate, and said adhesion-aiding amount of glycidoxypropyl triethoxy silane or its precondensate is 4-30% by weight of said photopolymerizable sealant.

Claim 5

An improved liquid crystal display cell in accordance with claim 1, wherein said seal means defines a plurality of cavities within said liquid crystal display cell.

Claim 6

An improved liquid crystal display cell in accordance with claim 1, wherein said display cell includes liquid crystal material disposed in said cell.

Claim 7

An improved multi-cavity liquid crystal display according to claim 1, 4 or 5 wherein: (a) said cationically polymerizable epoxide is a mixture of 55 parts by weight Bisphenol A diglycidyl ether epoxy, 25 parts triglycidyl ether epoxies of trihydroxymethyl propane, and 20 parts 3,4-epoxy-cyclohexylmethyl-3,4-epoxycyclohexene carboxylate; (b) said organic aromatic onium catalyst is triphenyl sulfonium hexafluorophosphate; (c) said adhesion-aiding amount of glycidoxypropyl triethoxy silane or its precondensate is 4-30% by weight of said photopolymerizable sealant.

Claim 8

A process for bonding a radiation-transparent substrate to a second substrate comprising: A. disposing a layer of an adhesive, sealant composition between said substrates and in contact therewith; said sealant composition comprising: (a) a cationically polymerizable epoxide with a functionality of at least 1, and (b) an organic aromatic onium catalyst comprising an aromatic adduct of (1) a diaromatic, triaromatic, or tetraaromatic organoatomic cation of a Group Va, VIa, or VIIa atom and (2) an anion; said onium catalyst being represented by the formula: ##STR6## wherein R 2 is an aromatic group at least as electron withdrawing as benzene, R 1 is an alkyl or alkenyl group, A is a Group Va, VIa, or VIIa atom, X is an anion, n is a positive whole integer of at least 2 up to the valence of A plus one, a is 0 or a positive whole integer up to the valence of A minus one, and n plus a is equal to the valence of A plus one and wherein at least two of said R 2 groups are bonded to A, and (c) an adhesion-aiding amount of glydicoxypropyl triethoxy silane or its precondensate; and said sealant composition being chemically resistant to liquid crystal materials; and B. exposing said layer to polymerizing radiation through said radiation-transparent substrate in an amount and for a time sufficient to polymerize said layer.

Claim 9

A process for bonding a radiation-transparent substrate to a second substrate comprising: A. disposing a layer of an adhesive, sealant composition between said substrates and in contact therewith; said sealant composition comprising: (a) a cationically polymerizable epoxide with a functionality of at least 1, and (b) an organic aromatic onium catalyst comprising an aromatic adduct of (1) a diaromatic, triaromatic, or tetraaromatic organoatomic cation of a Group Va, VIa, or VIIa atom and (2) an anion; said onium catalyst being represented by the formula: ##STR6## wherein R 2 is an aromatic group at least as electron withdrawing as benzene, R 1 is an alkyl or alkenyl group, A is a Group Va, VIa, or VIIa atom, X is an anion, n is a positive whole integer of at least 2 up to the valence of A plus one, a is 0 or a positive whole integer up to the valence of A minus one, and n plus a is equal to the valence of A plus one and wherein at least two of said R 2 groups are bonded to A, and (c) an adhesion-aiding amount of glydicoxypropyl triethoxy silane or its precondensate; and said sealant composition being chemically resistant to liquid crystal materials; and B. exposing said layer to polymerizing radiation through said radiation-transparent substrate in an amount and for a time sufficient to polymerize said layer.

Claim 10

A process for bonding a radiation-transparent substrate to a second substrate according to claim 7 wherein, said radiation-transparent substrate and said second substrate are both portions of a liquid crystal display cell.

Claim 13

A method according to claim 9 wherein said pattern defines a plurality of cavities.

Claim 14

A method according to claim 9 or 10 wherein said cavity is subsequently filled with a liquid crystal material and the cavity is plugged.