Optical laminate comprising hard coat layer comprised of cured product of composition comprising (meth)acrylic prepolymer having hydroxyl group

Patent metadata

Field	Value
Publication number	US-9720134-B2
Application number	US-201214111866-A
Country	US
Kind code	B2
Filing date	Apr 18, 2012
Priority date	Apr 22, 2011
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

There is provided an optical laminate excellent in adhesiveness between a (meth)acrylic resin film (base material film) having low moisture permeability and a UV absorbing ability and a hard coat layer, and has suppressed interference unevenness. An optical laminate according to an embodiment of the present invention includes: a base material layer formed of a (meth)acrylic resin film; a hard coat layer formed by applying a composition for forming a hard coat layer to the (meth)acrylic resin film; and a penetration layer formed through penetration of the composition for forming a hard coat layer into the (meth)acrylic resin film, the penetration layer being placed between the base material layer and the hard coat layer, wherein the penetration layer has a thickness of 1.2 μm or more.

First claim

The invention claimed is:

1. An optical laminate, comprising:
a base material layer formed of a (meth)acrylic resin film;
a hard coat layer comprising a cured product of a composition comprising a (meth)acrylic prepolymer having a hydroxyl group;
a penetration layer formed through penetration of the composition comprising the (meth)acrylic prepolymer having a hydroxyl group into the (meth)acrylic resin film, the penetration layer being placed between the base material layer and the hard coat layer, wherein the penetration layer has a thickness of 1.2 μm or more; and
a block layer on a side of the hard coat layer opposite the penetration layer.

2. An optical laminate according to claim 1 , wherein in the penetration layer, a concentration of a (meth)acrylic resin forming the (meth)acrylic resin film continuously increases from a side close to the hard coat layer to a side close to the base material layer.

3. An optical laminate according to claim 1 , wherein an amplitude of a reflection spectrum of the hard coat layer in a wavelength region of 500 nm to 600 nm is 0.5% or less.

4. An optical laminate according to claim 1 , wherein an absolute value of a difference between a refractive index of the base material layer and a refractive index of the hard coat layer is 0.01 to 0.15.

5. An optical laminate according to claim 1 , wherein the (meth)acrylic resin film has a transmittance for light having a wavelength of 380 nm of 15% or less.

6. An optical laminate according to claim 1 , wherein a (meth)acrylic resin forming the (meth)acrylic resin film has a structural unit expressing positive birefringence and a structural unit expressing negative birefringence.

7. An optical laminate according to claim 1 , wherein the composition comprising the (meth)acrylic prepolymer having a hydroxyl group contains a curable compound having two or more (meth)acryloyl groups.

8. An optical laminate according to claim 7 , wherein the composition comprising the (meth)acrylic prepolymer having a hydroxyl group further contains a monofunctional monomer.

9. An optical laminate according to claim 8 , wherein the monofunctional monomer has a weight-average molecular weight of 500 or less.

10. An optical laminate according to claims 8 , wherein the monofunctional monomer has a hydroxyl group.

11. An optical laminate according to claim 10 , wherein the monofunctional monomer comprises a hydroxyalkyl (meth)acrylate and/or an N-(2-hydroxyalkyl) (meth)acrylamide.

12. An optical laminate according to claim 1 , wherein the composition comprising the (meth)acrylic prepolymer having a hydroxyl group contains a urethane (meth)acrylate and/or an oligomer of the urethane (meth)acrylate.

13. An optical laminate according to claim 1 , wherein the composition comprising the (meth)acrylic prepolymer having a hydroxyl group is free of a solvent.

14. An optical laminate according to claim 1 , wherein a surface of the hard coat layer opposite to the penetration layer has an uneven structure.

15. An optical laminate according to claim 1 , further comprising an antireflection layer on a side of the hard coat layer opposite to the penetration layer.

16. A polarizing film, comprising the optical laminate according to claim 1 .

17. An image display apparatus, comprising the optical laminate according to claim 1 .

18. An optical laminate according to claims 9 , wherein the monofunctional monomer has a hydroxyl group.

Assignees

• Shibata Shusaku
• Takada Katsunori
• Takemoto Hiroyuki
• Nitto Denko Corp

Inventors

• Shibata Shusaku
• Takada Katsunori
• Takemoto Hiroyuki

Classifications

• G02B1/105

  Physics · mapped topic

• G02B1/04 Primary

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title

• C08L33/10

  Homopolymers or copolymers of methacrylic acid esters · CPC title

• C08L33/08

  Homopolymers or copolymers of acrylic acid esters · CPC title

• G02F2201/50

  Protective arrangements · CPC title