Interlayer filler material and laminate for touch panels

Abstract

The purpose of this invention is to provide an interlayer filler material for touch panels and a laminate manufactured using the interlayer filler material for touch panels. The interlayer filler material for touch panels is used in the manufacture of portable information terminals and the like to fill the interlayer between touch panels and other components or between multiple transparent conductive films constituting the touch panel. It has excellent following properties for the height difference of decorative printing parts or wiring during interlayer filling (lamination) and excellent degassing properties for bubbles entrained during interlayer filling (lamination) or bubbles remaining near the height difference. It does not whiten even when exposed to high temperature and high humidity and does not degrade the ITO film. This invention relates to an interlayer filler material for touch panels, which is used to fill the interlayer between a touch panel and other components or between multiple transparent conductive films constituting the touch panel. The interlayer filler material for touch panels contains polyvinyl acetal, a plasticizer, and an organic acid. The plasticizer is selected from at least one of triethylene glycol di-2-ethylhexanoate, tetraethylene glycol di-2-ethylhexanoate, triethylene glycol di-pentarate, and di-(2-butoxyethyl)adipate. The organic acid is selected from at least one of 2-ethylhexanoic acid, adipic acid, and phthalic acid.

Description

Technical Field [0001] This invention relates to an interlayer filler material for touch panels and a laminate manufactured using the interlayer filler material for touch panels. The interlayer filler material for touch panels is used in the manufacture of portable information terminals and the like to fill the interlayer between touch panels and other components or between multiple transparent conductive films constituting the touch panel. It has excellent following properties for the height difference of decorative printing or wiring during interlayer filling (lamination) and excellent degassing properties for bubbles entrained during interlayer filling (lamination) or bubbles remaining near the height difference. It does not whiten even when exposed to high temperature and high humidity and does not degrade the ITO film. Background Technology [0002] Touch panels are used in various fields, such as in portable information terminals like smartphones and tablets. They are pl...

AI Technical Summary

Problems solved by technology

[0005] However, when bonding an acrylic adhesive or an adhesive tape as a filling material, there is a problem that air bubbles may be entangled during bonding and bubbles may remain between the surface protection panel and the filling material. Reduced visibility or durability

In addition, on the back surface of the surface protection panel, a printed part is formed in the peripheral part for the purpose of masking, etc., and there is a problem that the difference in height formed by such a printed part or the boundary part of the difference in height of the wiring formed in the touch panel arises. Bubbles remain, reducing visibility or durability

In particular, in recent years, with the miniaturization, thinning, or weight reduction of portable information terminals, thinner filler materials are desired, but in conventional acrylic adhesives or adhesive tapes, it is difficult to achieve both thinness and sufficient follow-up. The property of not remaining air bubbles in height difference (level difference followability)