# US 2021/0276316 A1 · Polyester film

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- Number: US 2021/0276316 A1
- Document ID: US20210276316A1
- Status: Published application
- Kind: A1
- Application number: 16/332,123
- Filed: 2017-09-28
- Published: 2021-09-09
- Earliest claimed: 2016-09-30
- Assignees: Unitika Ltd.
- Applicants: Unitika Ltd.
- Inventors: Masafumi Yamamoto; Sumito Kihara; Takashi Ando
- Web page: https://patentgrep.com/patent/US20210276316A1

## CPC

- B32B 27/36: comprising polyesters
- B32B 7/06: permitting easy separation
- B32B 7/12: using interposed adhesives or interposed materials with bonding properties
- 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)}
- B32B 27/08: of synthetic resin
- B32B 27/18: characterised by the use of special additives
- B32B 27/20: using fillers, pigments, thixotroping agents
- C08J 3/22: using masterbatch techniques
- C08J 5/18: Manufacture of films or sheets
- C08K 7/00: Use of ingredients characterised by shape
- C08L 67/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence)
- C08L 101/00: Compositions of unspecified macromolecular compounds
- C09J 7/255: {Polyesters}
- B32B 2250/02: 2 layers
- B32B 2250/244: All polymers belonging to those covered by group B32B27/36
- B32B 2264/0214: Particles made of materials belonging to B32B27/00
- B32B 2264/0235: Aromatic vinyl resin, e.g. styrenic (co)polymers
- B32B 2264/025: Acrylic resin particles, e.g. polymethyl methacrylate or ethylene-acrylate copolymers
- B32B 2307/4026: within the layer by addition of a colorant, e.g. pigments, dyes
- B32B 2307/408: Matt, dull surface
- B32B 2307/409: Iridescent, pearlescent surface
- B32B 2307/538: Roughness
- B32B 2307/724: Permeability to gases, adsorption
- B32B 2307/746: Slipping, anti-blocking, low friction
- B32B 2307/748: Releasability
- B32B 2367/00: Polyesters, e.g. PET, i.e. polyethylene terephthalate
- C08K 2201/003: Additives being defined by their diameter
- C09J 2467/005: in the release coating
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- 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

This polyester film has at least one surface constituted of a polyester film layer A, and is characterized in that: a polyester resin constituting the polyester film layer A has an inherent viscosity of 0.63 to 0.85 dl/g; the polyester film layer A contains organic particles and the surface of the polyester film layer A has an arithmetic average roughness (Ra) of a roughness curve of 0.2 to 1.0 μm, and an average length (RSm) of roughness curve elements of 10 to 250 μm.

## Claims

### Claim 1

A polyester film comprising:
a polyester film layer A constituting at least one surface of the polyester film, wherein a polyester resin constituting the polyester film layer A has an inherent viscosity of 0.63 to 0.86 dl/g;
the polyester film layer A contains organic particles; and
the surface of the polyester film layer A has an arithmetic average roughness (Ra) of a roughness curve of 0.2 to 1.0 μm and an average length (RSm) of roughness curve elements of 10 to 250 μm.

### Claim 2 (depends on 1)

The polyester film according to claim 1, wherein the organic particles have an average particle diameter of 0.5 to 15 μm.

### Claim 3 (depends on 1)

The polyester film according to claim 1, wherein a ratio (D/T) of the average particle diameter (D) of the organic particles and a thickness (T) of the polyester film layer A is 0.3 to 1.5.

### Claim 4 (depends on 1)

The polyester film according to claim 1, wherein a content of the organic particles in the polyester film layer A is 0.1 to 20 mass %.

### Claim 5 (depends on 1)

The polyester film according to claim 1, wherein the polyester film contains a layer other than the polyester film layer A and the layer other than the polyester film layer A contains a pigment.

### Claim 6 (depends on 1)

The polyester film according to claim 1, wherein a gloss retention rate (G/G0×100) obtained from a gloss (G) of a mold surface after repeating an operation of loading the polyester film in contact with the heated mold cavity; evacuating an inside of the cavity; and releasing a vacuum after a certain period of time and an initial gloss (G0) is 70% or more.

### Claim 7 (depends on 1)

The polyester film according to claim 1, wherein one surface is constituted of the polyester film layer A and an adhesive layer is laminated onto another surface.

### Claim 8 (depends on 1)

A protective film for an adhesive sheet, using the polyester film according to claim 1.

### Claim 9 (depends on 1)

A release film for mold, using the polyester film according to claim 1.