# US 12,378,051 B2 · Packaging bag

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- Number: US 12,378,051 B2
- Document ID: US12378051B2
- Status: Granted
- Kind: B2
- Application number: 17/414,202
- Filed: 2019-12-05
- Published: 2022-01-27
- Granted: 2025-08-05
- Earliest claimed: 2018-12-17
- Assignees: Toyo Seikan Co., Ltd.; Toyo Seikan Group Holdings, Ltd.
- Applicants: Toyo Seikan Co., Ltd.; Toyo Seikan Group Holdings, Ltd.
- Inventors: Masahiro Hongo; Takahiro Kurosawa; Takashi Miura; Kazuaki Ohashi; Yoshiyuki Yuasa; Takahiro Akahane
- Web page: https://patentgrep.com/patent/US12378051B2

## CPC

- B65D 65/40: Applications of laminates for particular packaging purposes {(B65D1/0215, B65D1/28, B65D3/22, B65D5/0281, B65D5/563, B65D9/30, B65D29/02, B65D31/02, B65D75/26, B65D77/2024, B65D81/1275, B65D81/3811, B65D81/3823, B65D81/3834, B65D81/3846, B65D81/3858, B65D81/3874, B65D81/3886, B65D81/3897 take precedence; laminates per se or laminated packages characterised by the composition or)}
- B32B 1/00: Layered products having a non-planar shape
- B32B 3/266: {characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12}
- B32B 7/12: using interposed adhesives or interposed materials with bonding properties
- B32B 27/08: of synthetic resin
- B32B 27/16: specially treated, e.g. irradiated
- B32B 27/20: using fillers, pigments, thixotroping agents
- 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
- B65D 75/008: {Standing pouches, i.e. "Standbeutel"}
- B65D 75/5805: {for tearing a side strip parallel and next to the edge, e.g. by means of a line of weakness}
- B65D 81/3461: {Flexible containers, e.g. bags, pouches, envelopes}
- B32B 37/12: characterised by using adhesives
- B32B 2250/02: 2 layers
- B32B 2250/03: 3 layers
- B32B 2250/04: 4 layers
- B32B 2250/24: All layers being polymeric
- B32B 2250/244: All polymers belonging to those covered by group B32B27/36
- B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer
- B32B 2255/20: Inorganic coating
- B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers
- B32B 2307/306: Resistant to heat
- B32B 2307/31: Heat sealable
- B32B 2307/518: bi-axially
- B32B 2307/702: Amorphous
- B32B 2307/7246: Water vapor barrier
- B32B 2307/732: Dimensional properties
- B32B 2439/46: Bags
- B32B 2439/70: Food packaging
- B65D 75/58: Opening or contents-removing devices added or incorporated during package manufacture {(B65D75/36, B65D85/1027 take precedence)}
- B65D 2581/3428: Cooking unusual food, i.e. none of the above foods
- B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

## Abstract

A packaging bag including a polyester-based multilayer film. The multilayer film includes at least: an innermost layer formed of a biaxially stretched polyethylene terephthalate film; a layer formed of polybutylene terephthalate; and/or a layer formed of a blend of polyethylene terephthalate and polybutylene terephthalate. The biaxially stretched polyethylene terephthalate film has a heat sealing portion that is amorphized or low-crystallized by laser light irradiation. The packaging bag is formed by allowing the innermost layers of the polyester-based multilayer film to be opposed to and superimposed on each other, and heat sealing the heat sealing portions.

## Claims

### Claim 1

A packaging bag comprising a polyester-based multilayer film, the multilayer film including at least: an innermost layer formed of a biaxially stretched polyethylene terephthalate film; and a layer formed of a blend of polyethylene terephthalate and polybutylene terephthalate, the multilayer film further including a layer formed of a polyethylene terephthalate film, wherein a blend ratio (mass ratio) of polyethylene terephthalate to polybutylene terephthalate in the blend is in a range of 10:90 to 90:10;
the layer formed of the blend of polyethylene terephthalate and polybutylene terephthalate has a thickness of 5 to 50 um;
the innermost layer has a thickness of 5 to 50 μm;
the multilayer film as a whole has a thickness of 20 to 100 μm;
the biaxially stretched polyethylene terephthalate film has a heat sealing portion that is amorphized or low-crystallized by laser light irradiation under conditions including each of: an output of 10 to 400 W; a spot diameter of 0.14 to 15 nmmm; a scanning line interval of 0.05 to 15 mm; and an irradiation energy density of 0.5 to 8 J/cm2, and the packaging bag is formed by: allowing the innermost layers of the polyester-based multilayer film to be opposed to and superimposed on each other; and heat sealing the heat sealing portions; and
the layer formed of a polyethylene terephthalate film is an outermost layer that is formed of a biaxially stretched polyethylene terephthalate and has an easy-opening portion that is amorphized or low-crystallized by laser light irradiation under conditions including each of: an output of 10 to 400 W; a spot diameter of 0.14 to 15 mm; a scanning line interval of 0.05 to 15 mm; and an irradiation energy density of 0.5 to 8 J/cm2, and an intermediate layer located between the outermost layer and the innermost layer has a slit.

### Claim 2 (depends on 1)

The packaging bag according to claim 1, wherein in the multilayer film, a position where the slit is formed matches a position where the easy-opening portion is formed.

### Claim 3 (depends on 1)

The packaging bag according to claim 1, wherein the intermediate layer is formed of polybutylene terephthalate and/or polyethylene terephthalate.

### Claim 4 (depends on 1)

The packaging bag according to claim 1, wherein either of the layers except for the innermost layer is a film on which an inorganic vapor deposition layer or a barrier coating layer is formed.

### Claim 5 (depends on 1)

The packaging bag according to claim 1, wherein the polyester-based multilayer film has a layer configuration in which an outer layer formed of a polyethylene terephthalate film/a vapor deposition layer or a barrier coating layer/an intermediate layer formed of a blend of polyethylene terephthalate and polybutylene terephthalate/and the innermost layer formed of a biaxially stretched polyethylene terephthalate film are laminated in order from the outer layer.

### Claim 6 (depends on 1)

The packaging bag according to claim 1, wherein the polyester-based multilayer film has a layer configuration in which an outer layer formed of a blend of polyethylene terephthalate and polybutylene terephthalate/a vapor deposition layer or a barrier coating layer/an intermediate layer formed of a polyethylene terephthalate film or a blend of polyethylene terephthalate and polybutylene terephthalate/and the innermost layer formed of a biaxially stretched polyethylene terephthalate film are laminated in order from the outer layer.

### Claim 7 (depends on 1)

The packaging bag according to claim 1, wherein the polyester-based multilayer film has a layer configuration in which an outer layer formed of a polybutylene terephthalate film/a vapor deposition layer or a barrier coating layer/an intermediate layer formed of a blend of polyethylene terephthalate and polybutylene terephthalate/and the innermost layer formed of a biaxially stretched polyethylene terephthalate film are laminated in order from the outer layer.