Adhesive sheet and method for producing adhesive sheet

Patent metadata

Field	Value
Publication number	US-10676649-B2
Application number	US-201615762907-A
Country	US
Kind code	B2
Filing date	Sep 27, 2016
Priority date	Sep 28, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A pressure sensitive adhesive sheet including, on a substrate or a release material, a resin layer, at least a surface (α) of the resin layer on the opposite to the side on which the substrate or release material is provided having pressure sensitive adhesiveness, wherein a concave portion and a flat face exist on the surface (α) of the resin layer, and a width of the concave portion observed from the side of the surface (α) is non-uniform, and in a region (D) of 8 mm in length×10 mm in width as freely-selected on the surface (α), a concave portion having an area of 70 to 99.99% relative to 100% of a total area of the concave portions existing in the region (D) exists.

First claim

The invention claimed is:

1. A pressure sensitive adhesive sheet, comprising:
a substrate or a release material; and
a resin layer provided on the substrate or the release material and comprising a resin part (X) comprising a resin as a main component and a particle part (Y) consisting of fine particles having a mean particle size of 0.01 to 100 μm,
wherein the fine particles comprise at least one selected from the group consisting of silica particles comprising 85 to 100% by mass of silica, metal oxide particles, and smectite particles,
at least a surface (α) of the resin layer on the side opposite to the side on which the substrate or the release material is provided has pressure sensitive adhesiveness,
the surface (α) of the resin layer has a concave portion and a flat face such that a width of the concave portion observed from the side of the surface (α) is non-uniform,
a region (D) of 8 mm in length×10 mm in width freely-selected on the surface (α) includes a concave portion having an area of 70 to 99.99% relative to 100% of a total area of all concave portions in the region (D), and
at least one concave portion in the region (D) does not have contour lines that are approximately parallel straight lines of 50 μm on both sides of the concave portion.

2. The pressure sensitive adhesive sheet according to claim 1 , wherein the flat face comprises at least one flat face (f 1 ) having an area within which a region surrounded by a circle having a diameter of at least 100 μm is selectable.

3. The pressure sensitive adhesive sheet according to claim 1 , wherein the flat face comprises at least one flat face (f 2 ) having an area of 0.2 mm 2 or more.

4. The pressure sensitive adhesive sheet according to claim 1 , wherein the shape of the flat face observed from the side of the surface (α) is irregular.

5. The pressure sensitive adhesive sheet according to claim 1 , wherein the region (D) includes a plurality of flat faces, and a skewness Sk value relative to a normal distribution curve between an area and a frequency of each of at least one flat face (S) excluding flat faces having a cumulative relative frequency of 30% or less determined by adding a relative frequency from the plurality of flat faces with a smaller area is 1.0 or more.

6. The pressure sensitive adhesive sheet according to claim 5 , wherein a kurtosis Ku value relative to the normal distribution curve between the area and the frequency of each of the at least one flat face (S) is 1.8 or more.

7. The pressure sensitive adhesive sheet according to claim 1 , wherein the surface (α) has a plurality of flat faces such that positions of the flat faces do not have periodicity.

8. The pressure sensitive adhesive sheet according to claim 1 , wherein the concave portion has a height difference of 0.5 μm or more at maximum.

9. The pressure sensitive adhesive sheet according to claim 1 , wherein the concave portion is not formed by using a release material having an embossed pattern.

10. The pressure sensitive adhesive sheet according to claim 1 , wherein when a 5 mm×5 mm square region (P) is freely selected on the surface (α) and the pressure sensitive adhesive sheet is cut along each of two diagonal lines of the region (P) in a thickness direction perpendicular to the region (P) on the surface (α) to expose two cross sections of the pressure sensitive adhesive sheet, a plurality of concave portions having a maximum height difference of 40% or more of a total thickness of the resin layer and having a different shape of the cut part and a flat portion corresponding to the cut part of the flat face in the region (P) and approximately parallel to the surface of the substrate or release material contacting the resin layer exist in at least one cross section (P 1 ) of the two cross sections on the side of the surface (α) of the cross section (P 1 ).

11. The pressure sensitive adhesive sheet according to claim 1 , wherein the resin layer comprises 3 to 90% by mass of the fine particles.

12. The pressure sensitive adhesive sheet according to claim 1 , wherein the resin in the resin part (X) comprises a pressure sensitive adhesive resin.

13. The pressure sensitive adhesive sheet according to claim 1 , wherein the resin part (X) further comprises at least one selected from the group consisting of a metal chelate crosslinking agent and an epoxy crosslinking agent.

14. The pressure sensitive adhesive sheet according to claim 1 , wherein a surface (β) of the resin layer on the side on which the substrate or release material is provided has pressure sensitive adhesiveness.

15. The pressure sensitive adhesive sheet according to claim 1 , wherein the resin layer is a multilayer structure in which a layer (Xβ) mainly containing the resin part (X), a layer (Y 1 ) containing the particle part (Y) in an amount of 15% by mass or more, and a layer (Xα) mainly containing the resin part (X) are laminated in this order from the side on which the substrate or release material is provided.

16. The pressure sensitive adhesive sheet according to claim 15 , wherein
the layer (Xβ) is formed by a composition (xβ) comprising the resin and less than 15% by mass of the fine particles,
the layer (Y 1 ) is formed by a composition (y) comprising the fine particles in an amount of 15% by mass or more, and
the layer (Xα) is formed by a composition (xα) comprising the resin and less than 15% by mass of the fine particles.

17. A method for producing the pressure sensitive adhesive sheet according to claim 1 , comprising:
forming a coating film (x′) by a composition (x) comprising the resin and less than 15% by mass of the fine particles and a coating film (y′) by a composition (y) comprising 15% by mass or more of the fine particles; and
simultaneously drying the coating film (x′) and the coating film (y′).

18. A method for producing the pressure sensitive adhesive sheet according to claim 1 , comprising:
forming, on the substrate or the release material, a coating film (xβ′) formed by a composition (xβ) comprising the resin and less than 15% by mass of the fine particles, a coating film (y′) by a composition (y) comprising the fine particles in an amount of 15% by mass or more, and a coating film (xα′) by a composition (xα) comprising the resin and less than 15% by mass of the fine particles, by laminating in an order of the coating film (xβ′), the coating film (y′), and the coating film (xα′) from the side of the substrate or the release material; and
simultaneously drying the coating film (xβ′), the coating film (y′), and the coating film (xα′).

19. A method for producing the pressure sensitive adhesive sheet according to claim 1 , comprising:
forming, on a layer (Xβ) provided on the substrate or the release material and mainly comprising the resin part (X), a coating film (y′) by a composition (y) comprising 15% by mass or more of the fine particles and a coating film (xα′) by a composition (xα) comprising the resin and less than 15% by mass of the fine particles, by laminating in an order of the coating film (y′) and the coating film (xα′) from a side of the layer (Xβ); and
simultaneously drying the coating film (y′) and the coating film (xα′).

Assignees

• Lintec Corp

Inventors

• Uemura Kazue
• Kato Kiichiro
• Amino Yumiko
• Tsuchibuchi Koji
• Kase Takamasa
• Matsuoka Yusuke

Classifications

• C09J11/02

  Non-macromolecular additives · CPC title

• C09J2467/005

  in the release coating · CPC title

• B32B2264/10

  Inorganic particles · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• C09J2433/00

  Presence of (meth)acrylic polymer · CPC title