Storage stable photopolymerizable composition and element for refractive index imaging

Claim 2

A substantially solid, storage stable, photopolymerizable composition suited for forming a refractive-index image upon exposure to actinic radiation as the sole processing step, said composition consisting essentially of: (a) approximately 25 to 95% of a solvent soluble, thermoplastic, polymeric binder; (b) approximately 5 to 40% of N-vinyl carbazole; and (c) approximately 0.1 to 10% of a hexaarylbiimidazole photoinitiator system having a hydrogen donor component, wherein the hydrogen donor component is a mercapto compound having a pK HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer.

Claim 3

The composition of claim 1 that will have a refractive index modulation of at least approximately 0.005 after exposure to actinic radiation.

Claim 4

The composition of claim 1 which also contains at least one liquid ethylenically unsaturated monomer capable of addition polymerization having a boiling point above 100° C.

Claim 5

The composition of claim 3 wherein the liquid monomer contains a substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine and wherein the solvent soluble, thermoplastic, polymeric material is substantially free of said substituents.

Claim 6

The composition of claim 3 wherein the liquid monomer is selected from the group consisting of phenoxyalkyl acrylate or methacrylate; a phenol ethoxylate acrylate or methacrylate; a phenyl alkyl acrylate or methacrylate; 2-(1-naphthyloxy)ethyl acrylate; the di(2-acryloxyethyl)ether of bisphenol-A; and ethoxylated bisphenol-A diacrylate.

Claim 7

The composition of claim 3 wherein said binder is present in the amount of approximately 25 to 75%, N-vinyl carbazole is present in the amount of approximately 5 to 40% the ethylenically unsaturated monomers are present in the amount of approximately 5 to 60%, and said photoinitiator system is present in the amount of approximately 0.1 to 10% by weight, based on total weight of said composition.

Claim 8

The composition of claim 3 in which a solid ethylenically unsaturated monomer is also present.

Claim 9

The composition of claim 7 in which the solid ethylenically unsaturated monomer contains the carbazole group.

Claim 10

The composition of claim 7 wherein the solid ethylenically unsaturated monomer is selected from the group consisting of 3,6-dibromo-9-vinyl carbazole, 2,4,6-tribromophenyl acrylate or methacrylate, pentachlorophenyl acrylate or methacrylate, 2-naphthyl acrylate or methacrylate, 2-(2-naphthyloxy)ethyl acrylate or methacrylate, and the di-(2-acryloxyethyl)ether of tetrabromo-bisphenol A, and mixtures thereof.

Claim 11

The composition of claim 3 in which a plasticizer is also present, said plasticizer being selected from the group consisting of tris(2-ethylhexyl)phosphate, glyceryl tributyrate, and a compound having the general formula: ##STR3## wherein each of R 1 and R 2 is an alkyl group of 1 to 10 carbon atoms; R 3 is H or an alkyl group of 8 to 16 carbon atoms, R 4 is H or CH 3 ; x is 1-4; y is 2-20 and z is 1-20.

Claim 12

The composition of claim 10 wherein the plasticizer is selected from the group consisting of triethylene glycol dicaprylate, triethylene glycol bis(2-ethylhexanoate), diethyl adipate, dibutyl adipate, tetraethylene glycol diheptanoate, dibutyl suberate, diethyl sebacate, tris(2-ethylhexyl)phosphate, and glyceryl tributyrate.

Claim 13

The composition of claim 10 in which said plasticizer is substituted for at least a portion of the liquid ethylenically unsaturated monomer.

Claim 14

The composition of claim 1 wherein said binder is selected from the group consisting of cellulose acetate butyrate; an acrylate or methacrylate polymer or interpolymer; a vinyl butyral, acetal or formal polymer or interpolymer; and a vinyl acetate polymer or interpolymer.

Claim 15

A substantially solid, storage stable, photopolymerizable composition that will have a refractive index modulation of at least approximately 0.005 after exposure to actinic radiation, said composition consisting essentially of: (a) approximately 25 to 95% of a solvent soluble, thermoplastic binder; (b) approximately 5 to 40% of N-vinyl carbazole; (c) approximately 5 to 60% of a liquid ethylenically unsaturated monomer capable of addition polymerization and having a boiling point above 100° C; (d) approximately 0 to 25% of a plasticizer; and (e) approximately 0.1 to 10% of a hexaarylbiimidazole photoinitiator system having a hydrogen donor component, wherein the hydrogen donor component is a mercapto compound having a pK HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer, said percentages being weight percentages of the total composition, and one of said binder or said liquid monomer containing a substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine, and the other being substantially free of said substituents.

Claim 16

A substantially solid, storage stable, photopolymerizable composition that will have a refractive index modulation of at least approximately 0.005 after exposure to actinic radiation, said composition consisting essentially of: (a) approximately 25 to 95% of a solvent soluble, thermoplastic binder; (b) approximately 5 to 40% of N-vinyl carbazole; (c) approximately 5 to 60% of a liquid ethylenically unsaturated monomer capable of addition polymerization and having a boiling point above 100° C; (d) approximately 0 to 25% of a plasticizer; and (e) approximately 0.1 to 10% of a hexaarylbiimidazole photoinitiator system having a hydrogen donor component, wherein the hydrogen donor component is a mercapto compound having a pK HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer, said percentages being weight percentages of the total composition, and one of said binder or said liquid monomer containing a substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine, and the other being substantially free of said substituents.

Claim 17

A substantially solid, storage stable element adapted to record a refractive index image upon exposure to actinic radiation as the sole processing step, said element comprising a substrate that supports a substantially solid, storage stable composition consisting essentially of: (a) approximately 25 to 95% of a solvent soluble, thermoplastic, polymeric binder; (b) approximately 5 to 40% of N-vinyl carbazole; and (c) approximately 0.1 to 10% of a hexaarylbiimidazole photoinitiator system having a hydrogen donor component, wherein the hydrogen donor component is a mercapto compound having a pK HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer, said percentages being weight percentages of the total composition.

Claim 18

A substantially solid, storage stable element adapted to record a refractive index image upon exposure to actinic radiation as the sole processing step, said element comprising a substrate that supports a substantially solid, storage stable composition consisting essentially of: (a) approximately 25 to 95% of a solvent soluble, thermoplastic, polymeric binder; (b) approximately 5 to 40% of N-vinyl carbazole; and (c) approximately 0.1 to 10% of a hexaarylbiimidazole photoinitiator system having a hydrogen donor component, wherein the hydrogen donor component is a mercapto compound having a pK HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer, said percentages being weight percentages of the total composition.

Claim 19

The recording element of claim 15 that will have a refractive index modulation of at least approximately 0.005 after exposure to actinic radiation.

Claim 20

The recording element of claim 16 wherein said composition also contains approximately 5 to 60% of at least one liquid ethylenically unsaturated monomer capable of addition polymerization and having a boiling point above 100° C., one of said binder or said liquid monomer containing a substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine, and the other being substantially free of said substituents.

Claim 21

The recording element of claim 17 wherein said binder contains the substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine, and said liquid monomer is substantially free of said substituents.

Claim 22

The recording element of claim 17 wherein said liquid monomer contains the substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine, and said binder is substantially free of said substituents.

Claim 23

The recording element of claim 17 wherein said binder is present in the amount of approximately 25 to 75%, N-vinyl carbazole is present in the amount of approximately 5 to 40% the ethylenically unsaturated monomers are present in the amount of approximately 5 to 60%, and said photoinitiator system is present in the amount of approximately 0.1 to 10% by weight, based on total weight of said composition.

Claim 24

The recording element of claim 16 in which a solid ethylenically unsaturated monomer is also present in said composition.

Claim 25

The recording element of claim 21 in which the solid ethylenically unsaturated monomer contains the carbazole group.

Claim 26

The recording element of claim 21 wherein the solid ethylenically unsaturated monomer is selected from the group consisting of 3,6-dibromo-9-vinyl carbazole, 2,4,6-tribromophenyl acrylate or methacrylate, pentachlorophenyl acrylate or methacrylate, 2-naphthyl acrylate or methacrylate, 2-(2-naphthyloxy)ethyl acrylate or methacrylate, and the di-(2-acryloxyethyl)ether of tetrabromo-bisphenol A, and mixtures thereof.

Claim 27

The recording element of claim 16 in which a plasticizer is also present in said composition, said plasticizer being selected from the group consisting of tris(2-ethylhexyl)phosphate, glyceryl tributyrate, and a compound having the general formula: ##STR4## wherein each of R 1 and R 2 is an alkyl group of 1 to 10 carbon atoms; R 3 is H or an alkyl group of 8 to 16 carbon atoms, R 4 is H or CH 3 ; x is 1-4; y is 2-20 and z is 1-20.

Claim 28

The composition of claim 24 wherein the plasticizer is selected from the group consisting of triethylene glycol dicaprylate, triethylene glycol bis(2-ethylhexanoate), diethyl adipate, dibutyl adipate, tetraethylene glycol diheptanoate, dibutyl suberate, diethyl sebacate, tris(2-ethylhexyl)phosphate, and glyceryl tributyrate.

Claim 29

The composition of claim 24 in which said plasticizer is substituted for at least a portion of the liquid ethylenically unsaturated monomer.

Claim 30

The recording element of claim 15 wherein said binder is selected from the group consisting of cellulose acetate butyrate; an acrylate or methacrylate polymer or interpolymer; a vinyl butyral, acetal or formal polymer or interpolymer; and a vinyl acetate polymer or interpolymer.

Claim 31

A substantially solid, storage stable element adapted to record a refractive index image upon exposure to actinic radiation as the sole processing step, said element comprising a substrate that supports a composition that will have a refractive index modulation of at least approximately 0.005 after exposure to actinic radiation, said composition consisting essentially of: (a) approximately 25 to 95% of a solvent soluble, thermoplastic binder; (b) approximately 5 to 40% of N-vinyl carbazole; (c) approximately 5 to 60% of a liquid ethylenically unsaturated monomer capable of addition polymerization and having a boiling point above 100° C; (d) approximately 0 to 25% of a plasticizer; and (e) approximately 0.1 to 10% of a hexaarylbiimidazole photoinitiator system having a hydrogen donor component, wherein the hydrogen donor component is a mercapto compound having a pK HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer, said percentages being weight percentages of the total composition, and one of said binder or said liquid monomer containing a substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine, and the other being substantially free of said substituents.

Claim 32

A substantially solid, storage stable element adapted to record a refractive index image upon exposure to actinic radiation as the sole processing step, said element comprising a substrate that supports a composition that will have a refractive index modulation of at least approximately 0.005 after exposure to actinic radiation, said composition consisting essentially of: (a) approximately 25 to 95% of a solvent soluble, thermoplastic binder; (b) approximately 5 to 40% of N-vinyl carbazole; (c) approximately 5 to 60% of a liquid ethylenically unsaturated monomer capable of addition polymerization and having a boiling point above 100° C; (d) approximately 0 to 25% of a plasticizer; and (e) approximately 0.1 to 10% of a hexaarylbiimidazole photoinitiator system having a hydrogen donor component, wherein the hydrogen donor component is a mercapto compound having a pK HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer, said percentages being weight percentages of the total composition, and one of said binder or said liquid monomer containing a substituent selected from the group consisting of phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatic containing up to three aromatic rings, chlorine and bromine, and the other being substantially free of said substituents.

Claim 33

The composition of claim 1 wherein said hydrogen donor component is at least one mercapto compound selected from the group consisting of 5-chloro-2-mercaptobenzothiazole; 2-mercaptobenzothiazole; 1H-1,2,4-triazole-3-thiol; 6-ethoxy-2-mercaptobenzothiazole; 4-methyl-4H-1,2,4-triazole-3-thiol; and 1-dodecanethiol.

Claim 34

The composition of claim 14 wherein said hydrogen donor component is at least one mercapto compound selected from the group consisting of 5-chloro-2-mercaptobenzothiazole; 2-mercaptobenzothiazole; 1H-1,2,4-triazole-3-thiol; 6-ethoxy-2-mercaptobenzothiazole; 4-methyl-4H-1,2,4-triazole-3-thiol; and 1-dodecanethiol.

Claim 35

The recording element of claim 15 wherein said hydrogen donor component is at least one mercapto compound selected from the group consisting of 5-chloro-2-mercaptobenzothiazole; 2-mercaptobenzothiazole; 1H-1,2,4-triazole-3-thiol; 6-ethoxy-2-mercaptobenzothiazole; 4-methyl-4H-1,2,4-triazole-3-thiol; and 1-dodecanethiol.

Claim 36

The recording element of claim 28 wherein said hydrogen donor component is at least one mercapto compound selected from the group consisting of 5-chloro-b 2-mercaptobenzothiazole; 2-mercaptobenzothiazole; 1H-1,2,4-triazole-3-thiol; 6-ethoxy-2-mercaptobenzothiazole; 4-methyl-4H-1,2,4-triazole-3-thiol; and 1-dodecanethiol.