SAPONIFIED ETHYLENE-VINYL ESTER COPOLYMER PELLET AND METHOD FOR PRODUCING SAPONIFIED ETHYLENE-VINYL ESTER COPOLYMER PELLET

• US 20160311984A1
• Filed: 12/22/2014
• Published: 10/27/2016
• Est. Priority Date: 12/24/2013
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Nippon Synthetic Chemical Industry Company Limited (Mitsubishi Chemical Group Corp.)
• Inventors: FUKUYAMA, Shuuichi, ONO, Atsushi, YAMADA, Kouji, NAGAO, Yoshiharu, HONDA, Seiichi, TANAKA, Shinichi, MIYAZUMI, Shinta
• Granted Patent: US 10,450,426 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B29B 9/06 in the form of filamentary material, e.g. combined with extrusion
• CPC Class Codes: B29B 9/065 under-water, e.g. underwater pelletizers
• CPC Class Codes: B29C 48/06 Rod-shaped
• CPC Class Codes: B29K 2031/00 Use of polyvinylesters or derivatives thereof as moulding material
• CPC Class Codes: B29L 2031/00 Other particular articles
• CPC Class Codes: C08F 16/06 Polyvinyl alcohol ; Vinyl alcohol
• CPC Class Codes: C08F 8/12 Hydrolysis
• CPC Class Codes: C08J 2323/08 Copolymers of ethene C08J2323/16 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 3/14 by precipitation from solutions C08J3/122 takes precedence
• CPC Class Codes: C08J 3/16 by coagulating dispersions C08J3/122 takes precedence

Abstract

The invention provides a saponified ethylene-vinyl ester copolymer pellet which can be inhibited from cracking, chipping and generation of fine powder at the time of transport and is excellent in melt moldability. The saponified ethylene-vinyl ester copolymer pellet of the invention is a pellet which is obtained from a resin composition containing a saponified ethylene-vinyl ester copolymer resin and in which an amount of fine powder after an impact crushing test with ball mill is 400 ppm or less with respect to the saponified ethylene-vinyl ester copolymer pellet.

Claims

1. A saponified ethylene-vinyl ester copolymer pellet which is obtainable from a resin composition containing a saponified ethylene-vinyl ester copolymer resin and in which an amount of fine powder after an impact crushing test with ball mill is 400 ppm or less with respect to the saponified ethylene-vinyl ester copolymer pellet.

2. The saponified ethylene-vinyl ester copolymer pellet according to claim 1, which is obtainable by extruding a solution of a saponified ethylene-vinyl ester copolymer resin into a coagulating liquid of 2.0°

C. or less and then cutting to be pelletized.

5. The saponified ethylene-vinyl ester copolymer pellet according to claim 1, which is cylindrical and has a diameter of the bottom surface of from 1 to 6 mm and a length of from 1 to 6 mm.

6. The saponified ethylene-vinyl ester copolymer pellet according to claim 2, wherein the solution of a saponified ethylene-vinyl ester copolymer resin is the solution in which a saponified ethylene-vinyl ester copolymer resin is dissolved in a mixed solution having a mixing weight ratio of water/solvent from 80/20 to 5/95.

7. The saponified ethylene-vinyl ester copolymer pellet according to claim 2, wherein a temperature at the time of extrusion of the solution of a saponified ethylene-vinyl ester copolymer resin into a coagulating liquid is from 45 to 70°

C.

8. The saponified ethylene-vinyl ester copolymer pellet according to claim 2, wherein the coagulating liquid is a water/alcohol mixed solution.

3. A method for producing a saponified ethylene-vinyl ester copolymer pellet which comprises extruding a solution of a saponified ethylene-vinyl ester copolymer resin into a coagulating liquid and then cutting to be pelletized, wherein temperature of the coagulating liquid is 2.0°

C. or less.

4. The method for producing a saponified ethylene-vinyl ester copolymer pellet according to claim 3, wherein a solution in which the saponified ethylene-vinyl ester copolymer resin is dissolved in a mixed solution having a mixing weight ratio of water/solvent from 80/20 to 5/95 is extruded into the coagulating liquid.

9. The method for producing a saponified ethylene-vinyl ester copolymer pellet according to claim 3, wherein a temperature at the time of extrusion of the solution of a saponified ethylene-vinyl ester copolymer resin into a coagulating liquid is from 45 to 70°

C.

10. The method for producing a saponified ethylene-vinyl ester copolymer pellet according to claim 3, wherein the coagulating liquid is a water/alcohol mixed solution.

11. The method for producing a saponified ethylene-vinyl ester copolymer pellet according to claim 3, wherein a retention time of the saponified ethylene-vinyl ester copolymer resin in the coagulating liquid is from 10 to 400 seconds.