Storage stable photopolymerizable composition and element for refractive index imaging
AssigneeE. I. Du Pont de Nemours and Company
InventorWilliam K. Smothers
Life of this patent
Estimating the term…
Abstract
Solid storage stable photopolymerizable compositions are provided that are useful in preparing optical elements, and especially holograms. The composition contains a polymeric binder, N-vinyl carbazole and a photoinitiator system that has a hydrogen donor component.
Claims32
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.sub.HNP greater than 8.0, as measured in methanol with a glass electrode calibrated with aqueous buffer.
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.degree. 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.sub.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.
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.sub.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.
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.degree. 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.sub.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.
Dependencies are inferred from the claim text.