PHOTOPOLYMER FOR VOLUME HOLOGRAPHIC RECORDING AND ITS PRODUCTION PROCESS

• US 20120183888A1
• Filed: 01/18/2012
• Published: 07/19/2012
• Est. Priority Date: 01/19/2011
• Status: Abandoned Application

• Current Assignee: Müller, Martin, Sergio Assumpção Oliveira
• Original Assignee: Müller, Martin, Sergio Assumpção Oliveira
• Inventors: Oliveira, Sergio Assumpção, MÜLLER, Martin
• Application Number:
  US13/352,723
• Publication Number:
  US 20120183888A1
• Time in Patent Office: Days
• US Class Current: 430/2
• CPC Class Codes: G03F 7/001 Phase modulating patterns, e.g. refractive index patterns
• CPC Class Codes: G03F 7/029 Inorganic compounds; Onium compounds; Organic compounds having hetero atoms other than oxygen, nitrogen or sulfur

Abstract

The present invention refers to the manufacturing method of a holographic film and its development; the compositions of the films used in this invention are substantially solid and applied on a substrate in film or glass form; the photopolymerizable layer consists of a thickness of about 10 to 100 μm (microns), consisting of: a) 70% to 90% over the total weight of a thermoplastic “polymer”, b) 10% to 30% over the total weight of a preferably mono-functional photopolymerizable monomer reactive to light and, c) 1% to 10% per weight of an expansion agent that when heated at a minimum of 75° C. produces a gas in the unhardened or monomer polymerized areas of the hologram; furthermore, the composition contains a photoinitiator system sensitive to visible light, surfactants, plasticizers, etc.; photopolymerizable monomers used in this invention contains at least one part unsaturated ethylene with a boiling temperature equal or higher than 100° C.

Claims

1. A photopolymer for volume holographic recording through refraction index difference, characterized by the presence of an expansion agent that forms gas in micro-bubbles in unexposed regions of the holographic fringe, comprising per weight:

a) 70% to 90% of a thermoplastic “

polymer’

, b) 10% to 30% of a preferably mono-functional photopolymerizable monomer reactive to light, c) 1% to 10% of an expansion agent that when heated at a minimum 75°

C. produces a gas and forms bubbles in the unhardened or monomer polymerized areas of the hologram and, d) 0.1% to 1% of a photoinitiator that activates the polymerization of the said monomer with exposure of the actinic radiation.

2. The photopolymer for volume holographic recording according to claim 1, wherein the photoinitiator comprises the association of ionic pairs of cyanine and triphenyl butyl borate or tetrabutyl borate or even dibutyl phenyl borate dyes.

3. The photopolymer for volume holographic recording according to claim 1, wherein the thermoplastic is selected from the group consisting of vinylidene chloride, vinylidene/methacrylate chloride and vinylidene/vinylideneacetate chloride and cellulose acetate butyrate.

4. The photopolymer for volume holographic recording according to claim 1, wherein the monomer comprises acrylates or methacrylates selected from the group consisting of methyl acrylate, ethyl acrylate, isobornyl acrylate, phenyl acrylate, p-chlorophenyl acrylate, p-bromophenyl acrylate and preferably O-phenylphenoxyethyl acrylate, AGISYN®

2871, VEOVA®

9 or VEOVA®

10 of Shell Company, aromatic vinyl like N-Vinylpyrrolidone and 9-vinylcarbazole.

5. The photopolymer for volume holographic recording according to claim 1, wherein the expansion agent is selected from the group consisting of oxalate salts, inorganic acids, 4-ketobenzotriazine, 1,1″

-Azobis (cyanocyclohexane), Dupont®

, VAZO®

88, VAZO®

67, VAZO®

64 and VAZO®

52.

6. A production process of a photopolymer for volume hologram recording through which the exposed element containing a reflection or transmission hologram, according to claim 1 comprising the step of heating by a laminator, infrared radiation, thermal printers or by other means for a short period of time at a temperature between 75°

C. to 165°

C. to vaporize the element contained to form bubbles in the anti-nodal regions, at the same time softening the surrounding polymeric stratum.

7. The production process of a photopolymer for volume hologram recording through which the exposed element containing a reflection or transmission hologram, according to claim 1 comprising the step of transferring the photopolymer for volume hologram recording to another substrate through heating to a temperature between 120°

C. and 165°

C. and pressure with the polymer surface in direct contact with the transfer surface, and recording the holographic film after removal of the original polyester film used as a carrier.