Photopolymer composition

Patent metadata

Field	Value
Publication number	US-11226557-B2
Application number	US-201816607588-A
Country	US
Kind code	B2
Filing date	Dec 7, 2018
Priority date	Dec 8, 2017
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

The present disclosure relates to a hologram recording medium having a main relaxation temperature (Tr) of 0° C. or less, wherein the Tr is a point where a rate of change of phase angle with respect to temperature is the largest in a range of −80° C. to 30° C. in dynamic mechanical analysis. The present disclosure also relates to an optical element including the same and a holographic recording method using the hologram recording medium.

First claim

The invention claimed is:

1. A hologram recording medium having a main relaxation temperature (Tr) of 0° C. or less, wherein the Tr is a point where a rate of change of phase angle with respect to temperature is the largest in a range of −80° C. to 30° C. in dynamic mechanical analysis,
wherein the dynamic mechanical analysis is performed under conditions of a strain of 0.1%, a frequency of 1 Hz, and a heating rate of 5° C/min, and the phase angle is an angular value of tan delta calculated as G″(loss modulus)/G′(storage modulus),
wherein the hologram recording medium comprises a polymer matrix or a precursor thereof; and a photoreactive monomer, and
wherein the polymer matrix or the precursor thereof comprises a (meth)acrylate-based (co)polymer having a silane-based functional group in a branched chain, and a silane cross-linking agent.

2. The hologram recording medium of claim 1 , wherein the hologram recording medium further comprises a photoinitiator.

3. The hologram recording medium of claim 1 ,
wherein the hologram recording medium further comprises at least one selected from the group consisting of a phosphate-based compound and a low refractive fluorine-based compound.

4. The hologram recording medium of claim 3 ,
wherein the low refractive fluorine-based compound comprises at least one functional group selected from the group consisting of an ether group, an ester group and an amide group; and at least two difluoromethylene groups.

5. The hologram recording medium of claim 3 ,
wherein the low refractive fluorine-based compound has a refractive index of less than 1.45.

6. The hologram recording medium of claim 1 , wherein the polymer matrix has a refractive index of 1.45 to 1.70.

7. The hologram recording medium of claim 1 ,
wherein the silane cross-linking agent comprises a linear polyether main chain having a weight average molecular weight of 100 to 2000 and a silane-based functional group bound to the main chain as a terminal group or a branched chain.

8. The hologram recording medium of claim 1 ,
wherein the photoreactive monomer comprises a polyfunctional (meth)acrylate monomer having a refractive index of 1.5 or more, or a monofunctional (meth)acrylate monomer having a refractive index of 1.5 or more.

9. An optical element comprising the hologram recording medium of claim 1 .

10. A holographic recording method comprising selectively polymerizing photoreactive monomers contained in the photopolymer composition of claim 1 by electromagnetic radiation.

Assignees

• Lg Chemical Ltd

Inventors

• Jang Seokhoon
• Lee Hyunsup
• Kim Heon
• Kwon Se Hyun
• Chang Yeongrae

Classifications

• G11B7/24044

  for storing optical interference patterns, e.g. holograms; for storing data in three dimensions [3D], e.g. volume storage (G11B7/24038 takes precedence) · CPC title

• C08L83/12

  containing polyether sequences · CPC title

• C08L51/08

  grafted on to macromolecular compounds obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds · CPC title

• C08L75/04

  Polyurethanes · CPC title

• G11B7/083 Primary

  relative to record carriers storing information in the form of optical interference patterns, e.g. holograms · CPC title