Resin composition and method for producing same

Patent metadata

Field	Value
Publication number	US-11512197-B2
Application number	US-201816004531-A
Country	US
Kind code	B2
Filing date	Jun 11, 2018
Priority date	Dec 17, 2015
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

The purpose of the present invention is to establish a more precise method for evaluating long-run moldability and, based on this method, improve long-run moldability of a resin composition containing an EVOH-based resin and a nylon 6-based polyamide. Provided is a resin composition having improved long-run moldability and containing an EVOH-based resin and a nylon 6-based polyamide, wherein the amount of ε-caprolactam is 200 ppm or less. When the resin composition comprises an EVOH-based resin and a nylon 6-based polyamide, contacting the resin composition with water can reduce the amount of ε-caprolactam.

First claim

The invention claimed is:

1. A method for producing a melt-molded article comprising a resin composition comprising a saponified ethylene-vinyl ester-based copolymer and nylon 6-based polyamide, the method comprising
a process of contacting the nylon 6-based polyamide with water having a temperature of 20 to 60° C. for 10 minutes to 24 hours;
wherein ε-caprolactam is contained in the resin composition at a concentration of 10 to 200 ppm;
wherein a ratio of the amounts in weight of the saponified ethylene-vinyl ester-based copolymer to the nylon 6-based polyamide (saponified ethylene-vinyl ester-based copolymer:nylon 6-based polyamide) in the resin composition is from 50:50 to 90:10;

mixing the saponified ethylene-vinyl ester-based copolymer and nylon 6-based polyamide;
to form a resin composition having a water content of greater than 0.15% by weight to 1% by weight; and
melt-molding the resin composition having a water content of greater than 0.15% by weight to 1% by weight to form the melt-molded article.

2. The method for producing a melt-molded article according to claim 1 , wherein the contact process is carried out at any one of i)-iv) shown below:
i) prior to mixing the saponified ethylene-vinyl ester-based copolymer with the nylon 6-based polyamide;
ii) when mixing the saponified ethylene-vinyl ester-based copolymer with the nylon 6-based polyamide;
iii) after mixing the saponified ethylene-vinyl ester-based copolymer with the nylon 6-based polyamide;
or iv) a combination of two or more of i) to iii).

3. The method for producing a melt-molded article according to claim 2 , wherein the amount of ε-caprolactam contained in the resin composition is reduced to 10 to 200 ppm by the contact process.

4. The method for producing a melt-molded article according to claim 1 , wherein the amount of ε-caprolactam contained in the resin composition is reduced to 10 to 200 ppm by the contact process.

5. The method for producing a melt-molded article according to claim 1 , wherein the process of contacting is carried out for 10 minutes to 12 hours.

Assignees

• Nippon Synthetic Chem Ind Co Ltd
• Mitsubishi Chem Corp

Inventors

• Inoue Kota

Classifications

• C08L29/04 Primary

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08J3/005

  Processes for mixing polymers · CPC title

• C08J2477/02

  Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08J2477/10 takes precedence) · CPC title

• C08J2329/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08J3/12

  Powdering or granulating · CPC title