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US-12624254-B2 - Multilayer sheet and production method thereof

US12624254B2US 12624254 B2US12624254 B2US 12624254B2US-12624254-B2

Abstract

A multilayer sheet includes: a substrate layer (A) that includes 40 to 99.9% by mass of a polyphenylene ether (a1), 0 to 59.9% by mass of a polystyrene (a2), and an amino group-containing polymer (a3); and an adhesive layer (B) that includes an acid-modified polyolefin.

Inventors

  • Makoto Imahori
  • Kentaro MIYAMURA
  • Keigo IWATSUKI
  • Takashi Tsuda

Assignees

  • TOAGOSEI CO., LTD.

Dates

Publication Date
20260512
Application Date
20220427
Priority Date
20210428

Claims (17)

  1. 1 . A multilayer sheet, comprising: a substrate layer (A) that comprises 40 to 99.9% by mass of a polyphenylene ether (a1), 0 to 59.9% by mass of a polystyrene (a2), and an amino group-containing polymer (a3); and an adhesive layer (B) that comprises an acid-modified polyolefin, wherein the substrate layer (A) has a softening point of 175° C. or higher.
  2. 2 . The multilayer sheet according to claim 1 , wherein a content of the amino group-containing polymer (a3) in the substrate layer (A) is from 2 to 40% by mass.
  3. 3 . The multilayer sheet according to claim 1 , wherein the substrate layer (A) has a softening point of 180° C. or higher.
  4. 4 . The multilayer sheet according to claim 1 wherein the substrate layer (A) has a storage modulus at 160° C. of 500 MPa or more.
  5. 5 . The multilayer sheet according to claim 1 , wherein the amino group-containing polymer (a3) in the substrate layer (A) comprises a polystyrene chain having an amino group at a terminal thereof.
  6. 6 . The multilayer sheet according to claim 5 , wherein the amino group-containing polymer (a3) in the substrate layer (A) is a styrene-diene-styrene block copolymer.
  7. 7 . The multilayer sheet according to claim 1 , wherein the acid-modified polyolefin is a maleic anhydride-modified polyolefin.
  8. 8 . The multilayer sheet according to claim 1 , wherein the substrate layer (A) has a thickness of from 50 to 300 μm and the adhesive layer (B) has a thickness of from 10 to 100 μm.
  9. 9 . The multilayer sheet according to claim 1 , wherein the adhesive layers (B) are arranged on both upper and lower surfaces of the multilayer sheet.
  10. 10 . A method of producing a multilayer sheet, the method comprising: bringing, in a molten state of 160° C. or higher, a substrate layer (A) that comprises 40 to 99.9% by mass of a polyphenylene ether (a1), 0 to 59.9% by mass of a polystyrene (a2), and an amino group-containing polymer (a3) into contact with an adhesive layer (B) that comprises an acid-modified polyolefin.
  11. 11 . A multilayer sheet comprising, a substrate layer (A) that comprises 40 to 99.9% by mass of a polyphenylene ether (a1), 0 to 59.9% by mass of a polystyrene (a2), and an amino group-containing polymer (a3); and an adhesive layer (B) that comprises an acid-modified polyolefin, wherein the substrate layer (A) has a storage modulus at 160° C. of 500 MPA or more.
  12. 12 . The multilayer sheet according to claim 11 , wherein a content of the amino group-containing polymer (a3) in the substrate layer (A) is from 2 to 40% by mass.
  13. 13 . The multilayer sheet according to claim 11 , wherein the substrate layer (A) has a softening point of 175° C. or higher.
  14. 14 . The multilayer sheet according to claim 11 , wherein the amino group-containing polymer (a3) in the substrate layer (A) comprises a polystyrene chain having an amino group at a terminal thereof.
  15. 15 . The multilayer sheet according to claim 14 , wherein the amino group-containing polymer (a3) in the substrate layer (A) is a styrene-diene-styrene block copolymer.
  16. 16 . The multilayer sheet according to claim 11 , wherein the acid-modified polyolefin is a maleic anhydride-modified polyolefin.
  17. 17 . The multilayer sheet according to claim 11 , wherein the substrate layer (A) has a thickness of from 50 to 300 μm and the adhesive layer (B) has a thickness of from 10 to 100 μm.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a US national phase entry of International Patent Application No. PCT/JP2022/019093, filed Apr. 27, 2022, and claims priority to Japanese Patent Application No. JP 2021-075960, filed Apr. 28, 2021, both of which are incorporated by reference herein in their entirety for all purposes. TECHNICAL FIELD The present invention relates to a multilayer sheet excellent in adhesiveness and heat resistance, which can be used for bonding and sealing various parts and which itself can be used as a sheet-shaped member, and a production method thereof. BACKGROUND ART In recent years, hot-melt adhesive compositions have come to be used as adhesive films or sheets (hereinafter, collectively referred to as “adhesive members”) for chemical batteries such as lithium-ion batteries and fuel cells incorporated in notebook computers, smartphones, tablets, and automobiles, as well as physical batteries such as solar cells and capacitors. In order to bond metal substrates such as iron, aluminum, titanium, other metals, and alloys thereof, which are used as substrates for constituent members of these batteries, it is known that relatively good adhesion strength can be obtained by using a hot-melt adhesive composition containing an acid-modified olefin-based thermoplastic resin (hereinafter, also referred to as “acid-modified polyolefin”) as a main component. For battery applications, hot-melt adhesive compositions are required to have durability to battery constituent materials in addition to adhesion strength. In lithium-ion batteries, lithium hexafluorophosphate used as an electrolyte may react with moisture to generate hydrofluoric acid, and in fuel cells, acids such as hydrofluoric acid may be generated from an electrolyte membrane, which is a constituent member of the battery, and acid resistance is required. Furthermore, lithium-ion batteries require durability against ethylene carbonate, diethyl carbonate, or the like used as a solvent for the electrolyte, and nickel-hydrogen batteries require durability against strong alkaline aqueous solutions. Further, in fuel cells, a cooling liquid containing ethylene glycol, propylene glycol, or the like is circulated inside the cell for the purpose of cooling the cell that has generated heat due to power generation, so durability against ethylene glycol or the like is also required. Patent Document 1 discloses a resin composition composed of 50 to 99% by mass of a low-viscosity propylene-based polymer that satisfies specific properties and 1 to 50% by mass of an acid-modified propylene-based elastomer that satisfies specific properties, as well as a hot-melt adhesive including the resin composition. It has excellent adhesiveness to polyolefin-based substrates and also has excellent adhesion strength to metal substrates. Patent Document 2 describes an acid-modified polypropylene as an adhesive between metal and nylon resin. By layering an acid-modified polyolefin-based adhesive film or sheet on a substrate layer to form a multilayer sheet, it is also possible to obtain an adhesive member with even higher performance and functionality. An engineering plastic having excellent rigidity and heat resistance is used for the substrate layer of this multilayer sheet. By configuring the acid-modified polyolefin-based adhesive into such a multilayer sheet, strength, rigidity, gas barrier properties, chemical resistance, acid/alkali resistance, heat resistance, etc. are improved, and it can be suitably used for applications that require these durability, such as the aforementioned lithium-ion batteries and fuel cells. In addition, by using the multilayer sheet as an adhesive member for lithium-ion batteries and fuel cells, it is possible to reduce the number of constituent members and parts, thereby reducing costs and improving productivity. As engineering plastics used as substrates for multilayer sheets, polyethylene naphthalate, heat-resistant polyolefins such as cycloolefin polymers, polyphenylene ether-based alloys, and aromatic polyamide resins have been used in terms of heat resistance, rigidity, dimensional stability, and cost. For example, Patent Document 3 describes a layered sheet for sealing an electronic device, in which a first sheet and a second sheet are layered, the first sheet includes an acid-modified polyolefin thermoplastic resin, the second sheet has a higher melting point than that of the first sheet, and the peel strength of the second sheet to the first sheet at 25° C. is from 0.5 to 10.0 [N/15 mm]. Patent Document 3 describes polyethylene naphthalate as a specific example of the second sheet. PRIOR ART DOCUMENT Patent Document Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2013-060521Patent Document 2: Japanese Patent Application Laid-Open (JP-A) No. 2017-109613Patent Document 3: International Publication No. 2011/013389 SUMMARY OF INVENTION Technical Problem As described above, a multi