Resin composition of good long-run workability comprising ethylene-vinyl alcohol copolymer

a technology of ethylenevinyl alcohol and composition, which is applied in the direction of synthetic resin layered products, layered products, chemistry apparatus and processes, etc., can solve the problems of not meeting the requirements of known moldings and no one can find out a satisfactory evoh composition

Inactive Publication Date: 2005-05-05
KURARAY CO LTD
View PDF14 Cites 16 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0125] In the method where EVOH is dipped in a solution containing a carboxylic acid (A) and optionally an alkali metal salt (B), an alkaline earth metal salt (C), a phosphate compound (D) and a boron compound (E), the concentration of the carboxylic acid (A) and optionally alkali metal salt (B), alkaline earthmetal salt (C), phosphate compound (D) and boron compound (E) to be in the solution is not specifically defined. The solvent for the solution is also not specifically defined. In view of its handlability, preferred is an aqueous solution. The dipping time will vary, depending on the morphology of EVOH, but is preferably not shorter than 1 hour, more preferably not shorter than 2 hours, for EVOH pellets having a size of from 1 to 10 mm or so.
[0126] Regarding the dipping treatment of EVOH in the solution of the compounds, EVOH may be dipped in a plurality of different solutions separately containing any of the compounds, or may be dipped in one solution containing all the compounds. In particular, especially preferred is dipping EVOH in one solution containing all of a carboxylic acid (A) and optionally an alkali metal salt (B), an alkaline earth metal salt (C), a phosphate compound (D) and a boron compound (E), as the treatment in that manner is simple. After having been dipped in the solution, EVOH is finally dried and the intended EVOH composition is thus obtained.
[0127] The EVOH resin composition obtained in the above manner is molded in melt into various moldings such as films, sheets, containers, pipes, fibers, etc. The moldings can be recycled by grinding and re-molding them. The films, sheets and fibers of the composition may be uniaxially or biaxially stretched. For molding the composition in melt, employable is any mode of extrusion, inflation extrusion, blow molding, melt spinning, injection molding, etc. The temperature at which the resin composition is melted varies, depending on the melting point of EVOH in the composition, but preferably falls between 150 and 270° C. or so.
[0128] The EVOH resin composition of the invention may be molded into single-layered moldings of the composition alone, but, in practical use, it is often molded into multi-layered structures comprising at least one layer of th

Problems solved by technology

In the related art disclosures (1) to (5), however, no one can find out an EVOH composition satisfying all the necessary requirements of long-run workability in melt molding, good appearance of moldings, recyclability, yellowing res

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Resin composition of good long-run workability comprising ethylene-vinyl alcohol copolymer
  • Resin composition of good long-run workability comprising ethylene-vinyl alcohol copolymer

Examples

Experimental program
Comparison scheme
Effect test

example 1-1

[0202] A 45% solution in methanol of ethylene-vinyl acetate copolymer having an ethylene content of 38 mol % was put into a reactor for saponification, to which was added a solution of sodium hydroxide in methanol (80 g / liter), the amount of sodium hydroxide added being 0.4 equivalents to the vinyl acetate moiety of the copolymer. Then, methanol was added thereto to produce a solution having a copolymer concentration of 20%. This was heated up to 60° C. and reacted for about 4 hours with nitrogen gas being introduced into the reactor. After 4 hours, this was neutralized with acetic acid to stop the reaction. This was extruded out into water through a die having a circular opening, solidified therein and cut into pellets each having a diameter of about 3 mm and a length of about 5 mm. The resulting pellets were dewatered in a centrifuge. A large amount of water was added thereto, and the pellets were again dewatered. This operation was repeated.

[0203] 100 parts by weight of the wet ...

examples 1-2 to 1-6

, Comparative Examples 1-1 to 1-4

[0210] Dry pellets were prepared in the same manner as in Example 1-1. In this, however, EVOH having an intrinsic viscosity as in Table 2 was used. After having been saponified, washed and dewatered, pellets of EVOH having an ethylene content of 38 mol % and a degree of saponification of 99.4% were blended with or not blended with the lubricant, and then dipped in different processing solutions as in Table 1. The dry pellets were formed into films and tested. The test data are in Table 3.

TABLE 1Composition of Processing SolutionCarboxylicAlkaliAlkaline EarthPhosphateBoronAcidMetal SaltMetal SaltCompoundCompoundAmountAmountAmountAmountAmountType(g / L)Type(g / L)Type(g / L)Type(g / L)Type(g / L)Example 1-1lactic acid0.08sodium lactate0.8magnesium0.31KH2PO40.17H3BO30.32lactateExample 1-2lactic acid0.08sodium lactate0.8calcium lactate0.45KH2PO40.17H3BO30.32Example 1-3lactic acid0.08sodium lactate0.8magnesium0.31KH2PO40.17—lactateExample 1-4lactic acid0.08sodium...

example 2-1

[0213] A 45% solution in methanol of ethylene-vinyl acetate copolymer having an ethylene content of 38mol % was put into a reactor for saponification, to which was added a solution of sodium hydroxide in methanol (80 g / liter), the amount of sodium hydroxide added being 0.4 equivalents to the vinyl acetate moiety of the copolymer. Then, methanol was added thereto to produce a solution having a copolymer concentration of 20%. This was heated up to 60° C. and reacted for about 4 hours with nitrogen gas being introduced into the reactor. After 4 hours, this was neutralized with acetic acid to stop the reaction. This was extruded out into water through a die having a circular opening, solidified therein and cut into pellets each having a diameter of about 3 mm and a length of about 5 mm. The resulting pellets were dewatered in a centrifuge. A large amount of water was added thereto, and the pellets were again dewatered. This operation was repeated.

[0214] 100 parts by weight of the wet E...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Temperatureaaaaaaaaaa
Temperatureaaaaaaaaaa
Weightaaaaaaaaaa
Login to view more

Abstract

Disclosed are a resin composition comprising an ethylene-vinyl alcohol copolymer and a multi-layered structure comprising the resin composition. The resin composition comprises an ethylene-vinyl alcohol copolymer, and is characterized in that, when it is heated in a nitrogen atmosphere at 220° C., its MFR (at 230° C. under a load of 10.9 kg) shows a minimum value within 10 hours after the start of heating it, and shows a maximum value (MFRmax) within 100 hours after showing its minimum value, that it contains from 0.05 to 4 μmols/g of a carboxylic acid (A), and that it satisfies the following formulae (1) and (2):
0.5≦MFRmax/MFR0≦45   (1)
0.1≦(a1)/(A)≦1.0   (2)
wherein MFRmax indicates the maximum value of MFR (at 230° C. under a load of 10.9 kg) of the resin composition heated in a nitrogen atmosphere at 220° C.; MFR0 indicates MFR (at 230° C under a load of 10.9 kg) of the resin composition not heated; (A) indicates the total content (μmol/g) of the carboxylic acid (A) and its salt in the resin composition; (a1) indicates the content (μmol/g) of a carboxylic acid (a1) having a molecular weight of at least 75 and its salt in the resin composition. The resin composition has good interlayer adhesiveness when fabricated into laminates, and its moldings are yellowed little and have good appearances with few fish eyes (gels or hard spots) and streaks. While molded in melt, the resin composition ensures good long-run workability not smelling so much, and when recycled, it is yellowed little.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a resin composition comprising an ethylene-vinyl alcohol copolymer (EVOH) and a multi-layered structure comprising the resin composition. The resin composition has good interlayer adhesiveness when fabricated into laminates, and its moldings are yellowed little and have good appearance with few fish eyes (gels or hard spots) and streaks. While molded in melt, the resin composition ensures good long-run workability, and when recycled, it is yellowed little. [0003] 2. Description of the Related Art [0004] EVOH is a useful polymer material having good oxygen barrier properties, oil resistance, antistatic properties and mechanical strength, and is widely used for various wrapping and packaging materials such as films, sheets, containers, etc. Such wrapping and packaging materials are generally produced by molding polymers in melt. Therefore, the polymers for them are required to have goo...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): B32B27/28C08L29/04C08K3/24C08K3/32C08K3/38C08K5/09C08K5/098
CPCC08K3/32C08K3/38C08K5/098C08K5/20C08L29/04C08K5/09C08K3/24B32B27/28
Inventor INOMATA, NAOKIYOSHINDOME, HIROYUKITUBOI, TOSHIOHIMI, NAOYUKI
Owner KURARAY CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap