# US 12,119,142 B2 · Film, method for producing film, metal-clad laminate, and coated metal conductor

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- Number: US 12,119,142 B2
- Document ID: US12119142B2
- Status: Granted
- Kind: B2
- Application number: 17/591,755
- Filed: 2022-02-03
- Published: 2022-05-19
- Granted: 2024-10-15
- Earliest claimed: 2019-08-27
- Assignees: AGC Inc.
- Applicants: Agc Inc.
- Inventors: Wataru Kasai; Tomoya Hosoda; Atsumi Mitsunaga; Tatsuya Terada; Sota Yuki
- Web page: https://patentgrep.com/patent/US12119142B2

## CPC

- H01B 3/306: {Polyimides or polyesterimides}
- B32B 7/025: Electric or magnetic properties
- B32B 15/08: of synthetic resin
- B32B 15/20: comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)}
- B32B 27/281: {comprising polyimides}
- B32B 37/24: with at least one layer not being coherent before laminating, e.g. made up from granular material sprinkled onto a substrate (B32B37/15 takes precedence)
- C08J 7/04: Coating
- C08J 7/043: Improving the adhesiveness of the coatings per se, e.g. forming primers (adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50)
- C08K 5/07: Aldehydes; Ketones
- C08K 5/20: Carboxylic acid amides
- C08L 27/18: Homopolymers or copolymers or tetrafluoroethene
- C08L 33/06: of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
- C08L 79/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- H01B 1/026: {Alloys based on copper}
- H01B 3/445: {from vinylfluorides or other fluoroethylenic compounds}
- H05K 1/03: Use of materials for the substrate
- B32B 2037/243: {Coating}
- B32B 2250/03: 3 layers
- B32B 2250/40: Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
- B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer
- B32B 2255/26: Polymeric coating
- B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers
- B32B 2307/202: Conductive
- B32B 2307/204: Di-electric
- B32B 2307/206: Insulating
- B32B 2307/40: having particular optical properties
- B32B 2307/538: Roughness
- B32B 2307/54: Yield strength; Tensile strength
- B32B 2307/7265: Non-permeable
- B32B 2307/732: Dimensional properties
- B32B 2307/748: Releasability
- B32B 2457/00: Electrical equipment
- B32B 2457/04: Insulators
- B32B 2605/08: Cars
- B32B 2605/18: Aircraft
- H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K})
- 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)
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS

## Abstract

A heat-resistant film that has high adhesion and low warping, a method for producing the film, and a metal-clad laminate and a coated metal conductor, using the film. The film includes an aromatic polyimide base film, and a layer containing a polymer having units based on tetrafluoroethylene and units based on a perfluoro(alkyl vinyl ether) and an aromatic polymer, formed on each side of the base film.

## Claims

### Claim 1

A film comprising an aromatic polyimide base film, and a layer containing (i) a polymer having units based on tetrafluoroethylene and units based on a perfluoro(alkyl vinyl ether) and (ii) an aromatic polymer, formed on each side of the base film,
wherein in the layer, an amount of the aromatic polymer (ii) to a total amount of the polymer (i) and the aromatic polymer (ii) is 10 mass % or less.

### Claim 2 (depends on 1)

The film according to claim 1, wherein the base film and each layer are directly in contact with each other.

### Claim 3 (depends on 1)

The film according to claim 1, wherein the polymer is a polymer having units based on tetrafluoroethylene and units based on a perfluoro(alkyl vinyl ether), and having a polar functional group, or a polymer having units based on tetrafluoroethylene and units based on a perfluoro(alkyl vinyl ether) in a proportion of the units based on a perfluoro(alkyl vinyl ether) of from 2.0 to 5.0 mol % to all units, and having no functional polar group.

### Claim 4 (depends on 1)

The film according to claim 1, wherein the aromatic polymer is an aromatic polyimide.

### Claim 5 (depends on 1)

The film according to claim 1, wherein polar functional groups are present at the surface of the layer.

### Claim 6 (depends on 1)

The film according to claim 1, wherein the film has a thickness of 25 μm or more, and the ratio of the total thickness of the two layers to the thickness of the base film is 1 or more.

### Claim 7 (depends on 1)

The film according to claim 1, which has a water absorption coefficient of 0.1% or lower.

### Claim 8 (depends on 1)

The film according to claim 1, which has an optical absorption coefficient at a wavelength of 355 nm of 50% or higher.

### Claim 9 (depends on 1)

The film according to claim 1, which has a loss tangent of less than 0.003.

### Claim 10 (depends on 1)

A metal-clad laminate, comprising the film as defined in claim 1, and a metal foil bonded to each side of the film.

### Claim 11 (depends on 1)

A coated metal conductor, comprising a metal conductor, and the film as defined in claim 1 formed to coat the metal conductor.

### Claim 12

A method for producing a film, which comprises applying a powder dispersion containing a powder of a polymer having units based on tetrafluoroethylene and units based on a perfluoro(alkyl vinyl ether), an aromatic polymer or its precursor, and a liquid medium, to the surface of an aromatic polyimide base film, followed by heating to form a layer, thereby to obtain a film having the layer formed on each side of the base film,
wherein in the layer, an amount of the aromatic polymer to a total amount of the polymer having units based on tetrafluoroethylene and units based on a perfluoro(alkyl vinyl ether) and the aromatic polymer is 10 mass % or less.

### Claim 13 (depends on 12)

The production method according to claim 12, wherein the powder dispersion further contains a thermally decomposable nonionic surfactant.

### Claim 14 (depends on 12)

The production method according to claim 12, wherein heating is conducted in an atmosphere containing an oxygen gas to form the layer.