# US 2025/0093553 A1 · Surface-protective film and optical member with surface-protective film

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- Number: US 2025/0093553 A1
- Document ID: US20250093553A1
- Status: Published application
- Kind: A1
- Application number: 18/729,609
- Filed: 2022-12-27
- Published: 2025-03-20
- Earliest claimed: 2022-01-19
- Assignees: Nitto Denko Corporation
- Applicants: Nitto Denko Corporation
- Inventors: Takuya TANAKA; Keita OGAWA
- Web page: https://patentgrep.com/patent/US20250093553A1

## CPC

- B32B 27/00: Layered products comprising {a layer of} synthetic resin {(fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18)}
- G02B 1/14: Protective coatings, e.g. hard coatings
- B32B 7/12: using interposed adhesives or interposed materials with bonding properties
- B32B 27/30: comprising vinyl {(co)polymers; comprising acrylic (co)polymers}
- B32B 27/40: comprising polyurethanes
- C09J 7/22: Plastics; Metallised plastics
- C09J 7/38: Pressure-sensitive adhesives [PSA]
- C09J 2203/318: for the production of liquid crystal displays
- C09J 2301/312: parameters being the characterizing feature
- C09J 2433/00: Presence of (meth)acrylic polymer
- G02B 1/04: made of organic materials, e.g. plastics (G02B1/08 takes precedence)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)

## Abstract

Provided is a surface-protective film that allows an object to be protected to be accurately inspected even when the object to be protected is subjected to foreign matter inspection and air bubble inspection under a state in which the surface-protective film is bonded to the object to be protected. The surface-protective film according to an embodiment of the present invention includes a base material and an adhesion layer laminated on the base material. An absolute value of a maximum valley depth (Sv) of a surface of the adhesion layer on an opposite side to the base material is 500 nm or less. When the base material is subjected to microscopic observation, the number of defects each having a maximum Feret diameter of 10 μm or more is less than 3 in an observation region measuring 100 μm by 100 μm.

## Claims

### Claim 1

A surface-protective film, comprising:
a base material; and
an adhesion layer laminated on the base material,
wherein an absolute value of a maximum valley depth (Sv) of a surface of the adhesion layer on an opposite side to the base material is 500 nm or less, and
wherein, when the base material is subjected to microscopic observation, the number of defects each having a maximum Feret diameter of 10 μm or more is less than 3 in an observation region measuring 100 μm by 100 μm.

### Claim 2 (depends on 1)

The surface-protective film according to claim 1, wherein an absolute value of an arithmetic average height (Sa) of the surface of the adhesion layer on the opposite side to the base material is 25 nm or less.

### Claim 3 (depends on 1)

The surface-protective film according to claim 1, wherein, when the surface-protective film is subjected to microscopic observation, the number of defects each having a maximum Feret diameter of 10 μm or more is less than 3 in an observation region measuring 100 μm by 100 μm.

### Claim 4 (depends on 1)

The surface-protective film according to claim 1, wherein, when the surface-protective film is subjected to microscopic observation, the number of defects each having a maximum Feret diameter of less than 10 μm is 5 or less in an observation region measuring 100 μm by 100 μm.

### Claim 5 (depends on 1)

The surface-protective film according to claim 1, wherein the base material has a tear strength of 1 N/mm or more.

### Claim 6 (depends on 1)

The surface-protective film according to claim 1, wherein the adhesion layer contains at least one kind of pressure-sensitive adhesive selected from the group consisting of: a (meth)acrylic pressure-sensitive adhesive; a urethane-based pressure-sensitive adhesive; and a silicone-based pressure-sensitive adhesive.

### Claim 7 (depends on 1)

An optical member with a surface-protective film, comprising:
an optical member; and
the surface-protective film of claim 1 bonded to the optical member via the adhesion layer.