Method for manufacturing film, film, laminated body, and packaging material

Patent metadata

Field	Value
Publication number	US-11524439-B2
Application number	US-202017070999-A
Country	US
Kind code	B2
Filing date	Oct 15, 2020
Priority date	Aug 24, 2018
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

To provide a process for producing a film excellent in water vapor barrier property, tensile elongations, and transparency. A resin material containing polychlorotrifluoroethylene (PCTFE) is melted and extruded into a film from an extrusion die, the extruded product is brought into contact with a cooling roll having a surface temperature of at most 120° C. in a state such that the surface temperature of the extruded product is higher than the crystallization temperature of PCTFE to form a film web, and the film web is subjected to heat treatment at from 80 to 200° C. to obtain a film.

First claim

What is claimed is:

1. A process for producing a film, comprising:
melting a resin material containing polychlorotrifluoroethylene;
extruding the melted resin material into a film from an extrusion die;
bringing the extruded film into contact with a cooling roll having a surface temperature of at most 120° C. in a state that a surface temperature of the extruded film is higher than a crystallization temperature of the polychlorotrifluoroethylene to form a film web; and
subjecting the film web to heat treatment at from 80 to 200° C. to obtain the film.

2. The process according to claim 1 , wherein the film web has a haze per thickness 100 μm of at most 3%.

3. The process according to claim 1 , wherein the film web has tensile elongations in MD and in TD at 23° C. of respectively at least 30%.

4. The process according to claim 1 , wherein the heat treatment is carried out such that a density of the film after the heat treatment is from 100.2 to 102.5% of a density of the film web.

5. The process according to claim 1 , wherein a density of the film web is at most 2.120 g/cm 3 .

6. The process according to claim 5 , wherein the heat treatment is carried out such that a density of the film is at least 2.125 g/cm 3 .

7. The process according to claim 1 , wherein the heat treatment is applied to the film web wound into a roll.

8. The process according to claim 1 , wherein the heat treatment is applied while the film web wound into a roll is unwound and conveyed, or while the film web is conveyed without being wound.

9. The process according to claim 1 , wherein the film
has a water vapor transmission rate of at most 0.07 g/(m 2 ·day) per thickness 100 μm at 37.8° C. under a relative humidity of 100%,
has a haze per thickness 100 μm of at most 3%, and
has tensile elongations in MD and in TD at 23° C. of respectively at least 30%.

10. The process according to claim 1 , wherein the heat treatment is carried out such that a density of the film is 2.173 g/cm 3 or less.

11. A process for producing a laminate, comprising:
producing a film by the process according to claim 1 ; and
laminating the film and at least one other layer.

12. A process for producing a packaging material, comprising:
producing a laminate by the process according to claim 11 ; and
forming at least one pocket portion in the laminate.

13. A process for producing a packaging material for blister packaging; comprising:
producing a laminate by the process according to claim 11 ;
forming at least one pocket portion in the laminate; and
sealing an opening portion of the pocket portion with a cover.

14. The process according to claim 1 , wherein the film is not subjected to an orientation treatment.

15. The process according to claim 1 , wherein a difference (T 1 −T r1 ) between the surface temperature of the extruded film when brought into contact with the cooling roll (T 1 ) and the surface temperature of the cooling roll (T r1 ) is at least 100° C.

16. The process according to claim 1 , wherein the surface temperature of the extruded film when brought into contact with the cooling roll is at least the crystallization temperature of the polychlorotrifluoroethylene+10° C.

Assignees

• Agc Inc

Inventors

• Higuchi Yoshiaki
• Fukunaga Shintaro
• Yaoita Takatoshi

Classifications

• B32B2553/00

  Packaging equipment or accessories not otherwise provided for · CPC title

• B29C48/88

  Thermal treatment of the stream of extruded material, e.g. cooling · CPC title

• B32B27/08

  of synthetic resin · CPC title

• B65D65/02

  Wrappers or flexible covers · CPC title

• B29C2948/92209

  Temperature · CPC title