LCP extruded film and method for manufacturing the same, LCP extruded film for stretch treatment, LCP stretched film, heat-shrinkable LCP stretched film, insulating material for circuit substrate, and metal foil-clad laminate

Patent metadata

Field	Value
Publication number	US-12447662-B2
Application number	US-202318375798-A
Country	US
Kind code	B2
Filing date	Oct 2, 2023
Priority date	Dec 9, 2020
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

The present invention provides an LCP extruded film comprising a thermoplastic liquid crystal polymer and having a thickness of 15 μm or more and 300 μm or less, wherein coefficients of linear thermal expansion in a MD direction and a TD direction at 23 to 200° C. as measured by a TMA method according to JIS K7197 are each within a range of −30 to 55 ppm/K, and the following conditions (A) and/or (B) are satisfied, and a method for manufacturing the same, an LCP extruded film for stretch treatment, an LCP stretched film, a heat-shrinkable LCP stretched film, an insulating material for a circuit substrate, and a metal foil-clad laminate:
(A) a degree of orientation α1 (%) of a film surface S 1 exposed and a degree of orientation α2 (%) of a film surface S 2 located at a depth of 5 μm from the film surface S 1 satisfy a relationship of −4.0≤[(α2−α1)/α1]×100≤0.0; (B) a hardness H 1 at a point of a depth of 1 μm located at a position of 1 μm from a film surface in a thickness direction and a hardness H 2 at a thickness center point, as measured by subjecting a film cross section in parallel with a MD direction to a nanoindentation method, satisfy −10.0≤100×(H 2 −H 1 )/H 1 ≤0.0.

First claim

The invention claimed is:

1. A method for manufacturing an LCP extruded film, the method comprising:
a step of respectively preparing a resin composition A for a first surface layer comprising a thermoplastic resin, a resin composition B for an intermediate layer comprising a thermoplastic liquid crystal polymer, and a resin composition C of a second surface layer comprising a thermoplastic resin,
a step of co-extruding the resin composition A, the resin composition B and the resin composition C in conditions of a shear stress of 40 kPa or less and a drawdown ratio of 3.5 or less, from a two-kind three layer extruder, to form a two-kind three layer film having the first surface layer, the intermediate layer, and the second surface layer at least in the listed order, and
a step of removing the first and second surface layers from the two-kind three layer film to obtain an LCP extruded film having a thickness of 15 μm or more and 300 μm or less.

2. The method for manufacturing an LCP extruded film according to claim 1 , wherein the LCP extruded film is obtained in which a hardness H 1 at a point of a depth of 1 μm located at a position of 1 μm from a film surface in a thickness direction and a hardness H 2 at a thickness center point, as measured by subjecting a film cross section in parallel with a MD direction to a nanoindentation method, satisfy −10.0≤100×(H 2 −H 1 )/H 1 ≤0.0, and coefficients of linear thermal expansion in a MD direction and a TD direction at 23 to 200° C. as measured by a TMA method according to JIS K7197 are each within a range of −30 to 55 ppm/K.

3. The method for manufacturing an LCP extruded film according to claim 1 , wherein the thermoplastic liquid crystal polymer comprises a wholly aromatic polyester resin.

4. The method for manufacturing an LCP extruded film according to claim 1 , wherein the thermoplastic resin comprises one selected from the group consisting of: a polyolefin-based resin, an acrylic resin, a polyamide resin, an acrylonitrile-butadiene-styrene copolymer, polystyrene, polyvinyl chloride, polybutylene terephthalate, polyethylene terephthalate, polycarbonate, polyether ether ketone, and polyphenyl sulfide.

5. The method for manufacturing an LCP extruded film according to claim 1 , wherein the resin composition B further comprises an inorganic filler.

6. The method for manufacturing an LCP extruded film according to claim 1 , wherein the resin composition A, the resin composition B, and the resin composition C are co-extruded from a T-die.

7. The method for manufacturing an LCP extruded film according to claim 1 , wherein the LCP extruded film obtained has a coefficient of linear thermal expansion in a TD direction, of 55 ppm/K or less.

8. The method for manufacturing an LCP extruded film according to claim 1 , wherein the LCP extruded film obtained is subjected to heating and pressurizing treatment under a condition of 200 to 360° C.

9. The method for manufacturing an LCP extruded film according to claim 1 , wherein the LCP extruded film obtained does not comprise any skin layer that is peelable by a tape in an adhesiveness test by a cross-cutting method according to JIS K5600-5-6, on the film surface.

10. A method for manufacturing an LCP extruded film, the method comprising:
a step of respectively preparing a resin composition A for a first surface layer comprising a thermoplastic resin, a resin composition B for an intermediate layer comprising a thermoplastic liquid crystal polymer, and a resin composition C of a second surface layer comprising a thermoplastic resin,
a step of co-extruding the resin composition A, the resin composition B and the resin composition C in conditions of a shear stress of 40 kPa or less and a drawdown ratio of 3.5 or less, from a two-kind three layer extruder, to form a two-kind three layer film having the first surface layer, the intermediate layer, and the second surface layer at least in the listed order, and
a step of removing the first and second surface layers from the two-kind three layer film to obtain an LCP extruded film having a thickness of 15 μm or more and 300 μm or less, wherein a degree of orientation α1(%) of a film surface S 1 exposed and a degree of orientation α2(%) of a film surface S 2 exposed by etching treatment in a thickness direction of the film surface S 1 and located at a depth of 5 μm from the film surface S 1 satisfy a relationship of −4.0≤{(α2−α1)/α1}×100≤0.0, and coefficients of linear thermal expansion in a MD direction and a TD direction at 23 to 200° C. as measured by a TMA method according to JIS K7197 are each within a range of −30 to 55 ppm/K.

11. The method for manufacturing an LCP extruded film according to claim 10 , wherein the thermoplastic liquid crystal polymer comprises a wholly aromatic polyester resin.

12. The method for manufacturing an LCP extruded film according to claim 10 , wherein the thermoplastic resin comprises one selected from the group consisting of: a polyolefin-based resin, an acrylic resin, a polyamide resin, an acrylonitrile-butadiene-styrene copolymer, polystyrene, polyvinyl chloride, polybutylene terephthalate, polyethylene terephthalate, polycarbonate, polyether ether ketone, and polyphenyl sulfide.

13. The method for manufacturing an LCP extruded film according to claim 10 , wherein the resin composition B further comprises an inorganic filler.

14. The method for manufacturing an LCP extruded film according to claim 10 , wherein the resin composition A, the resin composition B, and the resin composition C are co-extruded from a T-die.

15. The method for manufacturing an LCP extruded film according to claim 10 , wherein the LCP extruded film is obtained which has a coefficient of linear thermal expansion in a TD direction, of 55 ppm/K or less.

16. The method for manufacturing an LCP extruded film according to claim 10 , wherein the LCP extruded film obtained is subjected to heating and pressurizing treatment under a condition of 200 to 360° C.

17. The method for manufacturing an LCP extruded film according to claim 10 , wherein the LCP extruded film obtained does not comprise any skin layer that is peelable by a tape in an adhesiveness test by a cross-cutting method according to JIS K5600-5-6, on the film surface S 1 .

Assignees

• Denka Company Ltd

Inventors

• Masuda Yusuke
• Ogawa Naoki

Classifications

• H05K2201/029

  Woven fibrous reinforcement or textile · CPC title

• C08J2367/04

  Polyesters derived from hydroxy carboxylic acids, e.g. lactones (C08J2367/06 takes precedence) · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• B32B2457/08

  PCBs, i.e. printed circuit boards · CPC title

• B32B2307/536

  Hardness · CPC title