# US 2026/0085218 A1 · Sealant resin composition, and use thereof

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- Number: US 2026/0085218 A1
- Document ID: US20260085218A1
- Status: Published application
- Kind: A1
- Application number: 19/108,680
- Filed: 2023-09-05
- Published: 2026-03-26
- Earliest claimed: 2022-09-05
- Assignees: Mitsui Chemicals, Inc.
- Applicants: Mitsui Chemicals, Inc.
- Inventors: Takahiro MIZUMA; Manabu ITAKURA; Nozomi KAMIYA; Kiminori NODA; Makoto EGAWA
- Web page: https://patentgrep.com/patent/US20260085218A1

## CPC

- C08L 23/14: Copolymers of propene (C08L23/16 takes precedence)
- C09K 3/1006: {characterised by the chemical nature of one of its constituents}
- B32B 15/085: comprising polyolefins
- B32B 15/20: comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)}
- B32B 27/08: of synthetic resin
- B32B 27/10: of paper or cardboard
- B32B 27/302: {comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers}
- B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)}
- B32B 27/34: comprising polyamides
- B32B 27/36: comprising polyesters
- C08J 5/18: Manufacture of films or sheets
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 50/105: Pouches or flexible bags
- H01M 50/119: Metals
- H01M 50/121: Organic material
- H01M 50/124: having a layered structure
- H01M 50/131: characterised by physical properties, e.g. gas permeability, size or heat resistance
- H01M 50/134: Hardness
- B32B 2255/00: Coating on the layer surface
- B32B 2307/31: Heat sealable
- B32B 2439/00: Containers; Receptacles
- C08J 2323/12: Polypropene
- C08J 2423/06: Polyethene
- C08J 2423/08: Copolymers of ethene (C08J2423/16 takes precedence)
- C09K 2200/0617: Polyalkenes
- C09K 2200/062: Polyethylene
- Y02E 60/10: Energy storage using batteries
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- 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)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The purpose of the present invention is to provide a sealant resin composition having excellent resistance to whitening during stretching, and good heat seal strength, as well as good heat seal strength after heat aging. The present invention relates to a sealant resin composition (X) including a 1-butene/ethylene copolymer (A) satisfying a specific requirement, and a propylene-based polymer (B), the resin composition satisfying the following requirements (X1) and (X1-2): requirement (X1): having a Shore D hardness measured in accordance with ASTM D2240 being in a range of 44 to 80; and requirement (X1-2): having a melt flow rate (MFR) measured at 230° C. and a load of 2.16 kg in accordance with ASTM D1238 being 0.1 to 100 g/10 min.

## Claims

### Claim 1

A sealant resin composition (X) comprising a 1-butene/ethylene copolymer (A) satisfying the following requirements (A1), (A2) and (A5), and a propylene-based polymer (B), the resin composition satisfying the following requirements (X1) and (X1-2):
requirement (A1): having a content of constituent units (i) derived from 1-butene being in a range of 70 to 99.9 mol %, and a content of constituent units (ii) derived from ethylene being in a range of 0.1 to 30 mol %, provided that a total of the constituent units (i) and the constituent units (ii) is 100 mol %;
requirement (A2): having an isotactic pentad fraction (mmmm) calculated by 13C-NMR being in a range of 80 to 99.9%;
requirement (A5): having no observed melting peak during second temperature raising when, using a differential scanning calorimeter (DSC), the temperature is first lowered from 30° C. to −70° C. at a cooling rate of 20° C./min (first temperature lowering), then maintained at −70° C. for 5 minutes, raised from −70° C. to 200° C. at a heating rate of 20° C./min (first temperature raising), maintained at 200° C. for 10 minutes, then lowered to −70° C. at a cooling rate of 20° C./min (second temperature lowering), maintained at −70° C. for 1 minute, and then raised again from −70° C. to 200° C. at a heating rate of 20° C./min (the second temperature raising);
requirement (X1): having a Shore D hardness measured in accordance with ASTM D2240 being in a range of 44 to 80; and
requirement (X1-2): having a melt flow rate (MFR) measured at 230° C. and a load of 2.16 kg in accordance with ASTM D1238 being in a range of 0.1 to 100 g/10 min.

### Claim 2 (depends on 1)

The sealant resin composition (X) according to claim 1, satisfying the following requirement (X2):
requirement (X2): having a melting enthalpy ΔHfus of in a range of 20 to 100 J/g when, using a differential scanning calorimeter (DSC), the temperature is first lowered from 30° C. to −70° C. at a cooling rate of 20° C./min (first temperature lowering), then maintained at −70° C. for 5 minutes, raised from −70° C. to 200° C. at a heating rate of 20° C./min (first temperature raising), and maintained at 200° C. for 10 minutes, and the temperature is then lowered to −70° C. at a cooling rate of 20° C./min (second temperature lowering), maintained at −70° C. for 1 minute, and then raised again from −70° C. to 200° C. at a heating rate of 20° C./min (second temperature raising).

### Claim 3 (depends on 1)

The sealant resin composition (X) according to claim 1, comprising an ethylene-based polymer (C).

### Claim 4 (depends on 1)

The sealant resin composition (X) according to claim 1, which satisfies the following requirement (X3):
requirement (X3): having a content of the 1-butene/ethylene copolymer (A) being in a range of 1 to 50 mass %, a content of the propylene-based polymer (B) being in a range of 30 to 99 mass %, and a content of the ethylene-based polymer (C) being in a range of 0 to 20 mass %, provided that a total of the 1-butene/ethylene copolymer (A), the propylene-based polymer (B) and the ethylene-based polymer (C) is 100 mass %.

### Claim 5 (depends on 1)

The sealant resin composition (X) according to claim 1, wherein the 1-butene/ethylene copolymer (A) satisfies the following requirement (A3):
requirement (A3): having an intrinsic viscosity [η] in decalin solvent at 135° C. being in a range of 0.7 to 4.0 dl/g.

### Claim 6 (depends on 1)

The sealant resin composition (X) according to claim 1, wherein the propylene-based polymer (B) comprises one or more selected from the group consisting of a random copolymer and a block copolymer.

### Claim 7 (depends on 1)

A single-layered or multi-layered sealant film, comprising at least one layer containing the sealant resin composition (X) according to claim 1.

### Claim 8 (depends on 7)

A laminate comprising a layer of the sealant film according to claim 7 and at least one base material film selected from the group consisting of a polyolefin film, a polystyrene film, a polyester film, a polyamide film, a laminated film of a polyolefin and a gas barrier resin film, a metal foil, paper and a vapor deposition film, the base material film being laminated on the layer of the sealant film.

### Claim 9 (depends on 8)

The laminate according to claim 8, wherein the layer of the sealant film and the base material film are bonded by a extrusion coating method, a thermal lamination method or a dry lamination method.

### Claim 10 (depends on 8)

The laminate according to claim 8, wherein the base material film is an aluminum foil.

### Claim 11 (depends on 9)

A package comprising the laminate according to claim 9.

### Claim 12 (depends on 9)

An electrical storage device comprising the laminate according to claim 9.

### Claim 13 (depends on 9)

A package for lithium ion batteries comprising the laminate according to claim 9.

### Claim 14

An electrical storage device comprising a sealant resin composition (X),
the sealant resin composition (X) comprising a 1-butene/ethylene copolymer (A) and a propylene-based polymer (B), and satisfying the following requirement (X1):
requirement (X1): having a Shore D hardness measured in accordance with ASTM D2240 being in a range of 44 to 80.

### Claim 15 (depends on 14)

The electrical storage device according to claim 14, which is a lithium ion battery.