Interlayer filler material for touch panels, and touch panel laminate

Patent metadata

Field	Value
Publication number	US-10647895-B2
Application number	US-201615764983-A
Country	US
Kind code	B2
Filing date	Oct 6, 2016
Priority date	Oct 7, 2015
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

The present invention aims to provide an interlayer filling material for a touch panel which is used for filling an interlayer space between a touch panel and another component or an interlayer space between transparent conductive films included in the touch panel in production of a personal digital assistant, is less likely to cause cracks or breakage in a surface protection panel or a glass substrate, and enables production of a touch panel laminate that is not likely to display images with color irregularity. The present invention also aims to provide a touch panel laminate produced using the interlayer filling material for a touch panel. The present invention relates to an interlayer filling material for a touch panel used for filling an interlayer space between a touch panel and another component, or at least one of interlayer spaces included in the touch panel between transparent conductive films, between a glass sheet and one of the transparent conductive films, between a glass sheet and another glass sheet, between a glass sheet and a polarizing film, between a substrate and a glass sheet, between a substrate and one of the transparent conductive films, and between a substrate and a polarizing film, the interlayer filling material containing: a polyvinyl acetal; and a plasticizer, the interlayer filling material having a residual stress Kpa (25° C., 2 min) after two minutes at 25° C. of 300 kPa or less.

First claim

The invention claimed is:

1. An interlayer filling material for a touch panel used for filling an interlayer space between a touch panel and another component, or at least one of interlayer spaces included in the touch panel between transparent conductive films, between a glass sheet and one of the transparent conductive films, between a glass sheet and another glass sheet, between a glass sheet and a polarizing film, between a substrate and a glass sheet, between a substrate and one of the transparent conductive films, and between a substrate and a polarizing film,
the interlayer filling material comprising: a polyvinyl acetal; and a plasticizer,
the interlayer filling material having a residual stress Kpa (25° C., 2 min) after two minutes at 25° C. of 300 kPa or less as measured in conformity with JIS K 6263:2004.

2. The interlayer filling material for a touch panel according to claim 1 ,
wherein a stress relaxation rate after two minutes at 25° C. is 75% or higher,
wherein the stress relaxation rate after two minutes at 25° C. is a value in percentage obtained by dividing stress after two minutes by maximum stress and then subtracting the resulting value from 1.

3. The interlayer filling material for a touch panel according to claim 1 ,
wherein the polyvinyl acetal is polyvinyl butyral.

4. The interlayer filling material for a touch panel according to claim 1 ,
wherein the polyvinyl acetal has an average degree of polymerization of 2,000 or less.

5. The interlayer filling material for a touch panel according to claim 1 ,
wherein the amount of the plasticizer relative to 100 parts by weight of the polyvinyl acetal is 10 to 75 parts by weight.

6. The interlayer filling material for a touch panel according to claim 1 , further comprising:
a reactive diluent; and
a photopolymerization initiator.

7. The interlayer filling material for a touch panel according to claim 6 ,
wherein the reactive diluent is a (meth)acrylic reactive diluent, an epoxy reactive diluent, or a silicone reactive diluent.

8. The interlayer filling material for a touch panel according to claim 6 ,
wherein the amount of the reactive diluent relative to 100 parts by weight of the polyvinyl acetal is 0.1 to 30 parts by weight.

9. A touch panel laminate comprising:
a touch panel; and
the interlayer filling material for a touch panel according to claim 1 , the interlayer filling material for a touch panel filling at least one interlayer space selected from the group consisting of an interlayer space between a surface protection panel and the touch panel, an interlayer space between the touch panel and a polarizing film, and interlayer spaces included in the touch panel between transparent conductive films, between a glass sheet and one of the transparent conductive films, between a glass sheet and another glass sheet, between a glass sheet and a polarizing film, between a substrate and a glass sheet, between a substrate and one of the transparent conductive films, and between a substrate and a polarizing film.

Assignees

• Sekisui Chemical Co Ltd

Inventors

• Fukatani Juichi
• Uenomachi Kiyomi
• Okabayashi Takazumi
• EBINA Ryousuke
• Wada Atsushi

Classifications

• G06F3/041

  Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means · CPC title

• C09J129/14 Primary

  Homopolymers or copolymers of acetals or ketals obtained by polymerisation of unsaturated acetals or ketals or by after-treatment of polymers of unsaturated alcohols · CPC title

• C09J11/06

  organic · CPC title

• C09J163/00

  Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins · CPC title

• C09J183/06

  containing silicon bound to oxygen-containing groups (C09J183/12 takes precedence) · CPC title