Data storage medium comprising colloidal metal and preparation process thereof
AssigneeAprilis, Inc.
InventorsErdem A. Cetin, Richard T. Ingwall, Richard A. Minns, David A. Waldman, Larry C. Takiff
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Abstract
Disclosed is a photopolymerizable holographic recording medium for data storage that comprises colloidal metal, and which exhibits a threshold for a second stage polymerization which is substantially insensitive to the light used for both forming holograms and interrogating the medium during servo and/or read events. Also disclosed is a method of preparing said photopolymerizable holographic recording medium. Also disclosed is a method for preparing a colloidal without additives in a viscous medium.
Claims65
A holographic recording medium, which medium comprises:
- a first acid generator capable of producing an acid upon exposure to actinic radiation;
- at least one monomer or oligomer which is capable of undergoing cationic polymerization initiated by the acid produced from the first acid generator;
- a binder which is capable of supporting cationic polymerization of said monomer or oligomer;
- a transition metal colloid as a nanoparticle suspension which exhibits absorbance upon exposure to actinic radiation and which is thereby capable of generating heat;
- a second acid generator capable of producing an acid upon exposure to heat, and which is substantially insensitive to actinic radiation even in the presence of sensitizers;
- and at least one monomer or oligomer which is capable of undergoing cationic polymerization initiated by the acid produced from the second acid generator.
A holographic recording medium, comprising:
- 1) at least one monomer or oligomer which undergoes cationic polymerization;
- 2) a binder which is capable of supporting cationic polymerization;
- 3) a transition metal colloid suspended in the medium which generates heat when exposed to actinic radiation;
- 4) a compound, referred to as “a first acid generator” which produces acid upon exposure to actinic radiation;
- and 5) a compound, referred to as a “second acid generator” which produces acid when exposed to heat.
A method of preparing a holgraphic recording medium, said method comprising the steps of:
- a) thermally decomposing an organotransition metal compound in a solution comprising a monomer or oligomer that polymerizes under cationic conditions and a second component, referred to as a “binder”, that is capable of supporting cationic polymerization, thereby forming a dispersion of stable transition metal colloidal nanoparticles in the solution;
- and
- b) adding to the dispersion formed in step a) a compound, referred to as “a first acid generator” which produces acid upon exposure to actinic radiation and a compound, referred to as a “second acid generator” which produces acid when exposed to heat.
A composition comprising stable transition metal colloidal nanoparticles dispersed in a solution having a viscosity greater than about 10 centipoise.
A method of preparing a stable transition metal colloid dispersion comprising the step of thermally decomposing an organotransition metal compound in a solution having a viscosity greater than about 10 centipoise.
A holographic recording medium, comprising:
- 1) at least one monomer or oligomer which undergoes cationic polymerization;
- 2) a binder which is capable of supporting cationic polymerization;
- 3) a transition metal colloid suspended in the medium which generates heat when exposed to actinic radiation;
- and 4) a compound which produces acid when exposed to heat.
A holographic recording medium, comprising:
- 1) at least one epoxide monomer that is a siloxane;
- 2) a (polymethyl phenyl siloxane);
- 3) a Pd(0) or Pt(0) colloid suspended in the medium which generates heat when exposed to actinic radiation;
- and 4) a compound, referred to as a “first acid generator” which produces acid when exposed to actinic radiation;
- 5) a compound, referred to as a “second acid generator” which produces acid when exposed to heat;
- and 6) a compound, referred to as a “sensitizer”, which sensitizes the first acid generator to produce acid at a particular wavelength of light.
Dependencies are inferred from the claim text.