METHOD FOR PRODUCING ETHYLENE-VINYL ALCOHOL COPOLYMER RESIN, ETHYLENE-VINYL ALCOHOL COPOLYMER RESIN, AND LAMINATE

• US 20140018462A1
• Filed: 03/23/2012
• Published: 01/16/2014
• Est. Priority Date: 03/30/2011
• Status: Active Grant

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Jouett, Ray, Armstrong, Robert, Yamamoto, Yoshio, Tsuboi, Toshio, Nakano, Kenji, Ikeda, Kazutaka
• Granted Patent: US 9,416,208 B2
• Time in Patent Office: Days
• US Class Current: 522/113
• CPC Class Codes: B29C 48/03 characterised by the shape of the extruded material at extrusion
• CPC Class Codes: B29C 48/287 Raw material pre-treatment while feeding B29C48/78 takes precedence
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/306 comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: C08F 2/01 characterised by special features of the polymerisation apparatus used
• CPC Class Codes: C08F 210/02 Ethene
• CPC Class Codes: C08F 216/06 Polyvinyl alcohol ; Vinyl alcohol
• CPC Class Codes: C08F 218/08 Vinyl acetate
• CPC Class Codes: C08F 6/12 Separation of polymers from solutions
• CPC Class Codes: C08F 6/26 Treatment of polymers prepared in bulk also solid polymers or polymer melts, C08F6/001, C08F6/006, C08F6/008, C08F6/02, C08F6/04 take precedence
• CPC Class Codes: C08F 8/12 Hydrolysis
• CPC Class Codes: C08J 2329/02 Homopolymers or copolymers of unsaturated alcohols C08J2329/14 takes precedence
• CPC Class Codes: C08J 2329/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08J 3/28 Treatment by wave energy or particle radiation
• CPC Class Codes: C08J 7/123 Treatment by wave energy or particle radiation C08J7/18 takes precedence
• CPC Class Codes: C08J 7/14 with acids, their salts or anhydrides

Abstract

Provided are a method for producing an EVOH resin having sufficient long-run workability in melt molding and enabling prevention of coloring such as yellowing, an EVOH resin obtained by this method for production, and a laminate obtained from this resin. Additionally, a method for producing an ethylene-vinyl alcohol copolymer resin capable of efficiently drying while inhibiting deterioration of qualities is provided. The method for producing an ethylene-vinyl alcohol copolymer resin of the present invention includes a step of irradiation with an infrared ray for irradiating with an infrared ray an ethylene-vinyl alcohol copolymer or an ethylene-vinyl ester copolymer that is a precursor of the ethylene-vinyl alcohol copolymer.

Claims

1. A method for producing an ethylene-vinyl alcohol copolymer resin, the method comprising irradiating an ethylene-vinyl alcohol copolymer with an infrared ray, to produce an ethylene-vinyl alcohol copolymer resin,

wherein:

the irradiation with an infrared ray is carried out on a solid matter comprising an ethylene-vinyl alcohol copolymer and water; and

the solid matter is dried by the irradiation with an infrared ray.

2. The method according to claim 1, wherein the irradiation occurs with an infrared ray lamp.

3. The method according to claim 1, wherein the wavelength of the infrared ray in the irradiation is 700 nm or greater and 1,000,000 nm or less.

4. The method according to claim 1, wherein the intensity of the infrared ray in the irradiation is 30×

10³ W/m³ or greater and 3,000×

10³ W/m³ or less.

5. The method according to claim 1, wherein the irradiation time in the irradiation is 0.1 hours or longer and 20 hours or shorter.

6. The method according to claim 1, further comprising saponifying the ethylene-vinyl ester copolymer to obtain an ethylene-vinyl alcohol copolymer.

7. The method according to claim 6, wherein the temperature of the ethylene-vinyl alcohol copolymer resin in the irradiation is the glass transition temperature or greater and the melting temperature or less of the ethylene-vinyl alcohol copolymer.

8. The method according to claim 6, further comprising pelletizing a solution or paste comprising the ethylene-vinyl alcohol copolymer obtained by the saponification, to obtain a pellet comprising the ethylene-vinyl alcohol copolymer, wherein the irradiation occurs after the pelletization.

9. The method according to claim 8, further comprising drying the pellet to give a water content of 0.01% by mass or greater and less than 10% by mass, wherein the irradiation occurs simultaneously with or after the drying.

10. The method according to claim 9, wherein the pellet has a water content before irradiating of 0.01% by mass or greater and less than 10% by mass.

13. The method according to claim 1, wherein an atmospheric temperature in the irradiating is 10°

C. or greater and 100°

C. or less.

14. The method according to claim 1, wherein the water content of the solid matter subjected to the irradiation is 0.5% by mass or greater and 200% by mass or less.

15. The method according to claim 1, wherein the water content of the solid matter after the irradiation is less than 0.5% by mass.

16. The method according to claim 1, wherein the solid matter is granular, and the infrared ray is irradiated while agitating the solid matter.

17. The method according to claim 1, wherein the solid matter is granular, and the infrared ray is irradiated while conveying the solid matter on a conveyor.

18. An ethylene-vinyl alcohol copolymer resin obtained by the method according to claim 1.

19. The ethylene-vinyl alcohol copolymer resin according to claim 18, which has a pellet form or film form.

20. A laminate having at least one layer comprising the ethylene-vinyl alcohol copolymer resin according to claim 18.

11-12. -12. (canceled)