JPH07118470A - Ethylene-vinyl acetate copolymer saponified substance-based resin composition co-extruded laminate containing layer of the same - Google Patents

Abstract

PURPOSE:To obtain the subject composition effectively preventing occurrence of gel, thickening with time and retention in a die even in the case of co- extrusion with a polyamide-based resin, comprising a saponified material of an ethylene-vinyl acetate copolymer and a specific polyamide-based resin. CONSTITUTION:This composition comprises (A) a saponified material of an ethylene-vinyl acetate copolymer having 20-60mol% ethylene content and >=90mol% saponification degree of vinyl acetate unit, (B) an end modified polyamide-based resin controlled by an end modifier in such a way that the number (x) of end COOH groups and that (y) of end CONRR' groups (R is l-22C hydrocarbon; R' is H or 1-22C hydrocarbon) satisfy the formula, (C) a hindered phenol-based compound, (D) an alkaline earth metal of an aliphatic carboxylic acid amide and (E) a compound selected from an ethylene-bis-fatty acid amide, a higher fatty acid metal salt, a polymer ester, a fatty acid ester and a hydrocarbon compound in the weight ratio of the component A/B of 70:30-96:4 and the ratio of the component C to the sum of the components A and B of 0.01-1wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition comprising a saponified ethylene-vinyl acetate copolymer and a specific polyamide resin, and a coextrusion laminate containing layers of the composition.

[0002]

2. Description of the Related Art A composition of a saponified ethylene-vinyl acetate copolymer and a polyamide resin has a property of imparting oxygen barrier property, oil resistance and solvent resistance based on the former and impact resistance based on the latter. Therefore, it is used for various purposes such as a film for food packaging, a sheet and a container. In particular, a coextrusion laminate obtained by arranging a layer of this composition in an intermediate layer and arranging a layer of a polyamide resin in at least one outer layer is expected to be used as a packaging material capable of retort sterilization or boil sterilization. it can.

JP-A-54-78749 discloses that the saponified product of ethylene-vinyl acetate copolymer is 60 to 95% by weight.
And 5 to 40% by weight of aliphatic copolyamide having caproamide as a main constituent unit and having a ratio of the number of methylene groups to the number of amide groups of 5.2 to 6.5.

JP-A-54-78750 discloses that a saponified product of an ethylene-vinyl acetate copolymer is 60 to 95% by weight.
And a polyamide composition containing 5 to 50% by weight of a polyamide having 5 to 50% by weight of a caproamide unit as a main structural unit and containing 5 to 50% by weight of an aromatic and / or alicyclic structural unit.

Japanese Unexamined Patent Publication (Kokai) No. 62-225535 discloses that ethylene-vinyl acetate copolymer (a) and polyamide (b) are used as a solvent for (a) and (b) and in the periodic table.
A method for producing an ethylene-vinyl alcohol copolymer composition is disclosed in which a water-soluble salt of a Group I or Group II metal is used to uniformly dissolve and then the solvent is removed. Water-soluble salts of Group I or Group II metals of the Periodic Table include lithium chloride, calcium chloride, magnesium chloride, calcium acetate, magnesium acetate and the like.

Japanese Patent Laid-Open No. 4-76040 discloses a saponified ethylene-vinyl acetate copolymer of 60 to 95% by weight and a polyamide of 5 to 40% by weight, wherein the polyamide is caproamide and at least two different fats. The melting point obtained by randomly copolymerizing a group polyamide is 120 to 2
In the range of 00 ° C., and the terminal carboxyl group content [X] and the terminal amino group content [Y] are [Y] <[X] + 0.5 × 10 ⁻⁵ (however, [X], [ The unit of Y] is a resin composition satisfying mol / g · polymer). Carboxylic acid having 2 to 23 carbon atoms and 2 to 2 carbon atoms as the terminal group amount adjusting agent
It has also been shown to use diamines of 2 and the like.

JP-A-4-178447 discloses that an ethylene-vinyl alcohol copolymer is composed of 60 to 95% by weight of polyamide and 5 to 40% by weight of polyamide, and the polyamide is mainly composed of caproamide, and the number of methylene groups is An aliphatic polyamide in which the ratio of the number of amide groups satisfies 5.20 ≦ CH ₂ /NHCO≦6.50, and the terminal carboxyl group content [X] and the terminal amino group content [Y] are obtained by using an end modifier. Is adjusted to satisfy [Y] <[X] + 0.5 × 10 ⁻⁵ (where the units of [X] and [Y] are mol / g polymer), and the melting point is 160 to 21.
A 5 ° C. resin composition is shown.

Japanese Patent Application No. 4-131237 discloses a resin outer layer (A) having a water vapor transmission rate of 40 g / m ² · day or more, an ethylene-vinyl alcohol copolymer resin 50.
~ 97 wt%, and a polyamide resin 45-3 wt%,
Gas comprising a layer (B) of a composition comprising at least one water-soluble or alcohol-soluble metal compound in an amount of 0.005 to 5% by weight, and a resin inner layer (C) having a water vapor transmission rate of 20 g / m ² · day or less. A barrier multi-layer package is shown. Here, the water-soluble or alcohol-soluble metal compound includes, specifically, lithium chloride, lithium hydroxide, sodium chloride, sodium hydroxide, potassium chloride, potassium hydroxide, calcium chloride, calcium nitrate, aluminum nitrate, and chloride chloride. 2 Iron, zinc chloride, sodium borate, sodium acetate and the like. Further, in this publication, as antioxidants, 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4-thiobis- (6-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-
t-butylphenol), octadecyl-3- (3 ',
There is also a description that 5'-di-t-butyl-4'-hydroxyphenyl) propionate, 4,4'-thiobis- (6-t-butylphenol) and the like may be added.

JP-A-4-185322 discloses at least 3 comprising a polyamide resin layer, a saponified ethylene-vinyl acetate copolymer layer, and a polyamide resin layer.
At least one of the polyamide-based resin layers in a multilayer film having a layered structure, which is formed into a flat film and sequentially biaxially stretched has a nylon 6 resin 50-
95% by weight and amorphous polyamide resin 50 to 5% by weight
A multi-layer film which is a mixed resin layer of

Japanese Patent Publication No. 5-1819 (Japanese Patent Laid-Open No. 62-
22840), (i) saponified ethylene-vinyl acetate copolymer, and (ii) terminal carboxyl group (-C).
OOH) number (A) and terminal -CONRR 'group (however,
R is a hydrocarbon group having 1 to 22 carbon atoms, and R'is a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms) and the ratio (B) is 100 × (B) / [(A) + (B )] ≧ 5, a resin composition comprising a polyamide resin is shown. This publication describes in Japanese Patent Laid-Open No. 54-
Reference is also made to the problems of the resin compositions disclosed in Japanese Patent No. 78749 and Japanese Patent Laid-Open No. 54-78750.

[0011]

A resin composition composed of a saponified ethylene-vinyl acetate copolymer and a polyamide resin is expected to make full use of the characteristics of the respective resins. Has a problem in molding that gel is likely to occur during melt molding and long-run molding is difficult.

In the inventions of the above-cited publications, a low melting point copolyamide or a terminally regulated polyamide is used as the polyamide resin, or both resins are premixed with a solvent, or a metal compound is used in combination. However, there is still room for improvement from an industrial point of view.

In particular, when the resin composition comprising a saponified ethylene-vinyl acetate copolymer and a polyamide resin is coextruded with a blend of nylon-6 and amorphous polyamide, Since the molding is performed at a high temperature such as 230 to 250 ° C., it is necessary to completely prevent the generation of gel and the prevention of thickening with time.

In order to solve such a problem, the present applicant has previously filed Japanese Patent Application Nos. 5-164012 and 5-164013.
Filed a patent application. Then, the Applicant further researches and uses the resin composition comprising a saponified ethylene-vinyl acetate copolymer and a polyamide resin, for example, by coextrusion with a blend of nylon-6 and amorphous polyamide. Even if the
64012 and Japanese Patent Application No. 5-164013, to provide a resin composition capable of more effectively preventing gel generation, viscosity increase with time, and retention in a die, and a method using such a resin composition. It is intended to provide an extruded laminate.

[0015]

The ethylene-vinyl acetate copolymer saponified resin composition of the present invention comprises an ethylene-acetic acid having an ethylene content of 20 to 60 mol% and a vinyl acetate unit saponification degree of 90 mol% or more. Saponified vinyl copolymer (A), the number (x) of terminal COOH groups and terminal CONRR 'groups (where R is a hydrocarbon group having 1 to 22 carbon atoms, R'is H or 1 to 22) depending on the terminal adjuster. The number (y) of (hydrocarbon groups of) is adjusted so as to satisfy 100 × y / (x + y) ≧ 5, a terminal-adjusted polyamide resin (B), a hindered phenol compound (C), an aliphatic carboxylic acid Alkaline earth metal salt (D) and ethylene bis fatty acid amide, higher fatty acid metal salt, polymer ester,
It is composed of at least one compound (E) selected from fatty acid esters and hydrocarbon compounds, and the weight ratio of (A) to (B) is 70:30 to 96: 4, and (A) and (B). And the ratio of (C) to the total amount is 0.01 to 1
In weight%, the ratio of (D) to the total amount of (A) and (B) is 0.5 to 15 μmol / g in terms of metal, and the ratio of (E) to the total amount of (A) and (B). Is 0.01-1
It is characterized in that it is% by weight.

The coextrusion laminate of the present invention comprises the above resin composition layer as an intermediate layer and a polyamide resin layer as at least one outer layer.

The present invention will be described in detail below.

The saponified product of ethylene-vinyl acetate copolymer (A) has an ethylene content of 20 to 60 mol% (preferably 25 to 55 mol%) and a saponification degree of vinyl acetate units of 90 mol% or more (preferably 95). Mol% or more, more preferably 98 mol% or more) is used. If the ethylene content is too low, the melt moldability will be lowered, and if the ethylene content is too high, the oxygen barrier property will be lowered. When the saponification degree is smaller than the above range, the oxygen barrier property is deteriorated.
The ethylene-vinyl acetate copolymer saponified product (A) is a small amount of α-olefin, unsaturated carboxylic acid compound, unsaturated sulfonic acid compound, (meth) acrylonitrile, (meth) acrylamide, vinyl ether, chloride. It may be "copolymer-modified" with another comonomer such as vinyl or styrene. Further, “post-modification” such as urethanization, acetalization, cyanoethylation and the like may be carried out within a range not impairing the gist of the present invention.

As the terminal-adjusting polyamide resin (B), the number of terminal COOH groups (x) and the terminal CONRR 'group (where R is a hydrocarbon group having 1 to 22 carbon atoms and R'is H Or 1 to 22 hydrocarbon groups) (y)
Is adjusted to satisfy 100 × y / (x + y) ≧ 5. An end-adjusted polyamide resin is used.

The terminal-adjusted polyamide resin (B) is produced by polycondensing a polyamide raw material in the presence of a monoamine having 1 to 22 carbon atoms or a monocarboxylic acid having 2 to 23 carbon atoms. .

As the polyamide raw material, lactams (ε-caprolactam, enanthlactam, capryllactam, lauryllactam, α-pyrrolidone, α-piperidone, etc.), ω-amino acids (6-aminocaproic acid, 7-aminoheptane, etc.) are used. Acid, 9-aminononanoic acid, 11
-Aminoundecanoic acid, etc.) dibasic acids (adipic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, hexadecanedioic acid, eicosadiendioic acid, diglycolic acid, 2,2,4-trimethyladipic acid, xylylenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, etc., diamines (hexamethylenediamine, tetramethylenediamine, nonamethylenediamine, undecamethylenediamine) , Dodecamethylenediamine, 2,2,4 (or 2,4,4-)
Trimethylhexamethylenediamine, bis- (4,4 '
-Aminocyclohexyl) methane, metaxylylenediamine, etc.).

Examples of monoamines having 1 to 22 carbon atoms include aliphatic monoamines (methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecyl. Amine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, eicosylamine, docosylamine), alicyclic monoamine (cyclohexylamine,
Methylcyclohexylamine, etc.), aromatic monoamines (benzylamine, β-phenylethylamine, etc.), symmetrical secondary amines (N, N-dimethylamine, N, N-diethylamine, N, N-dipropylamine, N, N-) Bibutylamine, N, N-dihexylamine, N, N-dioctylamine, N, N-didecylamine, etc.), mixed secondary amines (N-methyl-N-ethylamine, N-methyl-
N-butylamine, N-methyl-N-dodecylamine,
N-methyl-N-octadecylamine, N-ethyl-N
-Hexadecylamine, N-ethyl-N-octadecylamine, N-propyl-N-hexadecylamine, N-
Methyl-N-cyclohexylamine, N-methyl-N-
Benzylamine etc.) and the like.

As the monocarboxylic acid having 2 to 23 carbon atoms, aliphatic monocarboxylic acids (acetic acid, propionic acid,
Butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid,
Capric acid, pelargonic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, myritoleic acid, palmitic acid, stearic acid, oleic acid, linoleic acid,
Arachidic acid, behenic acid, etc.), alicyclic monocarboxylic acids (cyclohexanecarboxylic acid, methylcyclohexanecarboxylic acid, etc.), aromatic monocarboxylic acids (benzoic acid, toluic acid, ethylbenzoic acid, phenylacetic acid, etc.) .

If necessary, in addition to the above monoamine or the monocarboxylic acid, an aliphatic diamine (ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, decamethylenediamine) may be used. , Dodecamethylenediamine, 2, 2, 4 (or 2,
4,4-) trimethylhexamethylenediamine) etc.),
Alicyclic diamine (cyclohexanediamine, bis-
(4,4'-aminocyclohexyl) methane, etc., aromatic diamine (xylylenediamine, etc.), aliphatic dicarboxylic acid (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid) , Dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, octadecenedioic acid, eicosadionic acid, eicosendioic acid, docosanedioic acid, 2,2,4-trimethyladipic acid, alicyclic dicarboxylic acid ( Diamines such as 1,4-cyclohexanedicarboxylic acid) and aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic acid, xylylenedicarboxylic acid, etc.) and dicarboxylic acids can be coexistent.

In producing the terminal-adjusted polyamide resin (B), the above-mentioned polyamide raw material may be used and the reaction may be started according to a conventional method. The above-mentioned carboxylic acid and amine start the reaction under reduced pressure from the start of the reaction. Can be added at any stage up to. The carboxylic acid and amine may be added simultaneously or separately.

The amounts of the carboxylic acid and amine used are the amounts of the carboxyl group and amine group, and the polyamide raw material 1
2 to 20 meq / mol, preferably 3 to 19 meq / mol with respect to the mol (monomer constituting the repeating unit or 1 mol of the monomer unit) (the equivalent of the amine group reacts with 1 equivalent of the carboxylic acid in a ratio of 1: 1). The amount of amino groups forming an amide bond is 1 equivalent). If this amount is too small, it becomes impossible to produce a polyamide-based resin having the effect of the present invention. On the contrary, if it is too large, it becomes difficult to produce a polyamide having a high viscosity, which may adversely affect the physical properties of the polyamide-based resin. become.

The reaction pressure is preferably such that the end of the reaction is 400 Torr or less, preferably 300 Torr or less. If the pressure at the end of the reaction is high, the desired relative viscosity cannot be obtained. The low pressure is not particularly inconvenient. The reduced pressure reaction time was 0.
It is preferable that the time is 5 hours or more, usually about 1 to 2 hours.

The hydrocarbon group represented by R or R'in the -CONRR 'group at the terminal of the terminal-adjusting polyamide resin (B) is an aliphatic hydrocarbon group (methyl group,
Ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group,
Tridecyl group, tetradecyl group, tetradecylene group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, eicosyl group, docosyl group, etc., alicyclic hydrocarbon group (cyclohexyl group, methylcyclohexyl group, cyclohexylmethyl group, etc.), aromatic Examples thereof include group hydrocarbon groups (phenyl group, toluyl group, benzyl group, β-phenylethyl group, etc.).

Terminal Adjustment Polyamide resin (B) terminal-
The conversion ratio of the COOH group to the -CONRR 'group is adjusted by the presence of an amine or a carboxylic acid with the amine during the production of the polyamide resin. In the present invention, the degree of this conversion depends on the number of terminal -COOH groups ( x) and the end-
The relationship with the number of CONRR 'groups (y) is 100 × y /
(X + y) ≧ 5, preferably 100 × y / (x + y) ≧
10 is satisfied, the -COOH group is -CONRR '
The amount of unconverted —COOH groups is preferably 50 μeq / g · polymer or less, preferably 40 μeq / g · polymer or less. When the degree of this conversion is small, the effect of the present invention cannot be expected, and on the contrary, increasing the degree of conversion does not cause any inconvenience in terms of physical properties, but since it becomes difficult to produce, the amount of the unmodified terminal carboxyl group is not improved. Is 1 μeq / g
・ It is a good idea to limit the amount to be a polymer.

The hydrocarbon groups represented by R and R'of the above-CONRR 'group can be measured by gas chromatography after hydrolyzing the polyamide resin with hydrochloric acid. The —COOH group can be measured by dissolving a polyamide resin in benzyl alcohol and titrating with 0.1N caustic soda.

As the terminal group of the polyamide-based resin, in addition to the above-mentioned -CONRR 'group, there are a -COOH group and a -NH ₂ group derived from the above polyamide raw material.

The terminal amino group may or may not be modified, but it is desirable that it is modified with the above-mentioned hydrocarbon group since it has good fluidity and melt heat stability.

The hindered phenol compound (C) is N, N'-hexamethylenebis (3,5-di-t).
-Butyl-4-hydroxyhydrocinnamide), 1,
1,3-tris (2-methyl-4-hydroxy-5-t
-Butylphenyl) butane, 1,3,5-trimethyl-
2,4,6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3
-(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate], n-octadecyl-β-
(4'-hydroxy-3 ', 5'-di-t-butylphenyl) propionate, 2,2'-methylenebis (4-
Methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol),
4,4'-thiobis (6-t-butyl-m-cresol), 4,4'-thiobis (3-methyl-6-t-butylphenol), pentaerythrityl-tetrakis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] and the like.

Examples of the alkaline earth metal salt of aliphatic carboxylic acid (D) include acetic acid, propionic acid, butyric acid, valeric acid,
Examples thereof include beryllium salts, magnesium salts, calcium salts, strontium salts and barium salts of aliphatic carboxylic acids having about 1 to 9 carbon atoms such as caproic acid and capric acid, and particularly magnesium salts of aliphatic carboxylic acids having 2 to 4 carbon atoms. And calcium salts are important.

As the compound (E), ethylene bis fatty acid such as ethylene bis-stearyl amide (having 16 to 16 carbon atoms)
18) Higher fatty acid metal salts such as amide, zinc stearate, aluminum stearate, calcium stearate and magnesium stearate, adipate condensate of polypropylene glycol, sebacate condensate of polypropylene glycol, spalm aceti (NOF CORPORATION),
Polymeric esters such as Hoechst Wax-E (Hoechst Japan), Lytole (Sanwa Yushi), Kiwa (Noda Wax), butyl stearate, Nissan Castor Wax-A (Nippon Yushi), TB-121 (Matsumoto Yushi Seiyaku). Fatty acid ester such as, molecular weight of 900 to 30 by viscosity method
Low molecular weight polyolefin such as polyethylene of 1,000, a molecular weight of 1,000 to 20,000 and an acid value of 5 by the viscosity method.
Examples include low molecular weight polyolefins such as modified polyethylene and modified polypropylene in the range of 100.

The resin composition of the present invention comprises the above-mentioned saponified ethylene-vinyl acetate copolymer (A), terminal-adjusted polyamide resin (B), hindered phenolic compound (C), and aliphatic carboxylic acid. Alkaline earth metal salt (D),
It comprises at least one compound (E) selected from ethylene bis fatty acid amide, higher fatty acid metal salt, polymer ester, fatty acid ester, and hydrocarbon compound.

Here, the weight ratio of (A) to (B) must be in the range of 70:30 to 96: 4,
When the proportion of the terminal-adjusted polyamide-based resin (B) is too small, the effect of improving the boiling resistance of the saponified ethylene-vinyl acetate copolymer (A) does not sufficiently appear, and the terminal-adjusted polyamide-based resin (B) is If the proportion is too large, the enzyme barrier properties and other properties of the saponified ethylene-vinyl acetate copolymer (A) are impaired.

The proportion of the hindered phenol compound (C) needs to be in the range of 0.01 to 1% by weight based on the total amount of (A) and (B). When the proportion of the hindered phenolic compound (C) is less than the above range, the antioxidant property is insufficient and oxidizable gel or die retention is likely to occur during molding. On the other hand, even if the ratio is more than the above range, the effect of suppressing the oxidative gel does not exceed a certain limit and is disadvantageous in cost, and the range is preferably 0.05 to 0.8% by weight.

Furthermore, the proportion of the fatty acid carboxylic acid alkaline earth metal salt (D) is based on the total amount of (A) and (B).
0.5 to 15 μmol / g in terms of metal, preferably 1 to 9
It is necessary to be μmol / g, and when it is too small, the melt viscosity is increased, and when it is too large, gel is generated or foaming occurs at the time of molding, and the film is colored or the moldability becomes unstable. Sometimes.

The ratio of the compound (E) is (A) and (B).
It is necessary to be 0.01 to 1% by weight relative to the total amount of the above, and an excessive amount thereof causes an increase in the amount of stays in the extruder and the die, and an excessive amount thereof causes a surge phenomenon during molding to be stable. However, it is preferably 0.1 to 1% by weight.

Additives such as a plasticizer, a stabilizer, a filler, a colorant, an antiblocking agent and an antistatic agent may be added to the above resin composition.

The resin composition is formed into a film, sheet, container or the like by melt molding. As the melt molding method, any melt molding method including an extrusion molding method (including a blow molding method and an extrusion coating method) and an injection molding method is adopted.

In the above resin composition, the resin composition is placed in the intermediate layer,
It is particularly useful when a laminate is obtained by multi-layer coextrusion molding with a polyamide resin disposed on at least one outer layer. Here, as the polyamide resin,
Various nylons such as nylon-6, nylon-6,6, nylon-7, nylon-11 and nylon-12 can be mentioned, but a blend of nylon-6 and amorphous polyamide is particularly important. . In addition to the polyamide-based resin, another resin layer may be further provided on at least one of the above laminated bodies.

The resulting coextruded laminate is useful as a packaging material that can be retort sterilized or boiled.

[0045]

In the present invention, the end-adjusted polyamide resin (B) which is a special polyamide resin is used as the resin to be blended with the saponified ethylene-vinyl acetate copolymer (A), and the hindered phenol is used as an auxiliary agent. Resin (C)
And at least one compound (E) selected from fatty acid carboxylic acid alkaline earth metal salt (D), ethylene bis fatty acid amide, higher fatty acid metal salt, polymer ester, fatty acid ester, and hydrocarbon compound.

Therefore, even when the resin composition is used for coextrusion with a blend of nylon-6 and amorphous polyamide having a high molding temperature, the molding temperature is 230 to 250 ° C. Even though the molding is performed at a high temperature, generation of an oxidative gel and viscosity increase with time are effectively prevented, and long-run molding becomes possible.

When this resin composition is coextruded with a blend of nylon-6 and amorphous polyamide, the interlaminar adhesion is also significantly improved. Therefore, the packaging material obtained by the coextrusion is retort sterilized. Delamination does not occur even when subjected to boiled sterilization or boiling.

[0048]

The present invention will be further described with reference to the following examples.

<Preparation of end-adjusted polyamide resin (B)> B-1: 60 k of ε-caprolactam in an autoclave
g, 1.2 kg of water, and octadecylamine were charged to 6.78 meq per mol of ε-caprolactam, sealed under a nitrogen atmosphere, heated to 250 ° C., and stirred under pressure for 2 hours. After the reaction, release the pressure to 180
After reducing the pressure to Torr and carrying out the reaction for 2 hours, then introducing nitrogen and returning to normal pressure, stirring was stopped, the contents were extracted as strands and made into chips, and unreacted monomers were extracted and removed with boiling water and dried. thing. Terminal COOH group: 9 μeq / g · polymer 100 × y / (x + y) = 87

B-2: Octadecylamine and acetic acid were added to 5.3 mol each of 1 mol of ε-caprolactam.
q Add 5.30 meq and adjust the end pressure of the polymerization reaction to 270 Torr
Other than the above, manufactured in the same manner as in the case of B-1. Terminal COOH group: 26 μeq / g · polymer 100 × y / (x + y) = 64

B-3: Same as B-1 except that octadecylamine and stearic acid were added at 3.39 meq and 3.39 meq to 1 mol of ε-caprolactam, respectively, and the final pressure of the polymerization reaction was set at 200 Torr. Manufactured by. Terminal COOH group: 20 μeq / g · polymer 100 × y / (x + y) = 60

<Preparation of Other Raw Materials> Saponified product of ethylene-vinyl acetate copolymer (A) A-1: 32 mol% of ethylene content, 99.5 mol% of saponification degree of vinyl acetate unit, melt index = 3 ( 21
0 ° C) ethylene-vinyl acetate copolymer

C-1: N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamide) ("Irganox 10" manufactured by Ciba Geigy)
98 ") C-2: 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene (" Irganox 133 manufactured by Ciba Geigy ")
0 ") C-3: pentaerythrityl-tetrakis [3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate] (“Irganox 1 manufactured by Ciba Geigy”)
010 ")

Fatty acid carboxylic acid alkaline earth metal salt
(D) D-1: magnesium acetate tetrahydrate D-2: calcium propionate D-3: magnesium butyrate

Compound (E) E-1: Ethylenebisstearylamide E-2: Low molecular weight polyethylene having a molecular weight of 3200 and an acid value of 20 by the viscosity method E-3: Zinc stearate E-4: Magnesium stearate E-5: Zinc stearate: calcium stearate =
1: 0.5 (weight ratio) E-6: Zinc stearate: Aluminum stearate = 1: 0.7 (weight ratio)

<Single Layer Melt Molding> As shown in Table 1, after the components (C), (D) and (E) are added to the component (A), a single screw extruder or a twin screw extruder is used. After melt extrusion, it was cooled and pelletized. Further, the component (B) is added and premixed with a Henschel mixer, and then supplied to an extruder equipped with a coat hanger die for melt kneading,
A film having a thickness of 50 μm was formed. The extrusion molding conditions were set as follows. Extruder: 40 mm diameter extruder Screw: Full flight type Extrusion temperature: Extruder temperature 230 ° C, die temperature 250 ° C Die width: 400 mm

<Coextrusion Molding> A polyamide resin Y containing 90% by weight of nylon-6 resin and 10% by weight of amorphous polyamide, and a resin composition X of Examples or Comparative Examples were heated to a temperature of 250 ° C. Coextrusion was carried out from the set T die so as to have a layer structure of Y / X / Y, and the film was cooled by a chill roll in which cooling water circulated to obtain a flat three-layer film. Then, it is stretched 3 times by a roll stretching machine at 90 ° C., further stretched 3.5 times by a tenter stretching machine in an atmosphere at 140 ° C., and then the width is reduced by about 4% by the same tenter.
It was heat set in an atmosphere at 10 ° C. The thickness of the obtained film was Y / X / Y = 5/10/5 (μm).

<Evaluation items and evaluation method> Using a melt viscosity ratio Capillograph (manufactured by Toyo Seiki Co., Ltd.), the viscosity η ₄₀ after dwelling for 40 minutes under the conditions of a temperature of 250 ° C. and a shear rate of 122 sec ⁻¹ and dwelling for 10 minutes. The subsequent viscosity η ₁₀ was measured, and the melt viscosity ratio η ₄₀ / η ₁₀ at that time was obtained.

Gelation Fraction Pellets of each composition were heated and deteriorated in a gear open at 250 ° C. for 20 minutes in an air atmosphere, and the deteriorated product was dissolved in formic acid at 60 ° C. for 4 hours to obtain 200 mesh. Filtration was performed using gold steel, and the gelation fraction was determined from the formic acid insoluble content after drying at 130 ° C. for 2 hours. The case where the gelation fraction was less than 2% was evaluated as ○, the case where it was 2% or more and less than 2.5% was evaluated as Δ, and the case where it was 2.5% or more was evaluated as ×.

Long-run moldability Long-run moldability was judged by the time during which the above-mentioned single-layer melt molding was carried out for a long time and a gelled product appeared on the film surface. In the case of Example 1, the relative evaluation was made as ◯, the one slightly inferior to this was evaluated as Δ, and the inferior one was evaluated as x.

Die Retained Material In the above single layer melt molding, the die temperature was 250 ° C.
After continuous molding for 3 hours, the polyethylene was replaced with 3 kg, the die was disassembled, and the melting point (melting point of the component (A)) in the die manifold portion was evaluated by the degree of decrease. Melting point drop less than 5 ° C: ○, 5 ° C or more and less than 10 ° C:
A temperature of 10 ° C or higher was judged as x.

Boil resistance Using the three-layer film obtained by the above coextrusion molding, 95
The appearance of the film and the presence or absence of delamination when immersed in hot water under conditions of 30 ° C for 30 minutes were evaluated. The case where there was no change in the transparency before and after the treatment and the delamination did not occur was evaluated as ◯, and the other cases were evaluated as x.

Retort resistance The appearance of the film and the presence or absence of delamination were evaluated when the three-layer film obtained by the above coextrusion molding was held in a steam atmosphere at 121 ° C. for 30 minutes. ○ When there is no change in transparency before and after treatment and delamination does not occur
And other than that was judged as x.

<Conditions and Results> Tables 1 to 3 show conditions and results of Examples 1 to 6 and Comparative Examples 1 to 6. (C) component,
The blending amount of component (E) is based on the total amount of component (A) and component (B). The description of the component (D) is the type of alkaline earth metal and the amount of alkaline earth metal added (μmol / g) based on the total amount of the components (A) and (B).
Is.

[0065]

[Table 1] Example 1 Example 2 Example 3 Example 4 (A) component A-1 90 parts A-1 80 parts A-1 70 parts A-1 70 parts (B) component B-1 10 parts B -1 20 parts B-1 30 parts B-1 30 parts (C) Component C-1 4000ppm C-3 4000ppm C-2 8000ppm C-1 600ppm (D) Component D-1 Mg 3.5 D-1 Mg 2.0 D- 3 Mg 2.3 D-2 Ca 6.5 (E) component E-6 1700ppm E-5 1500ppm E-3 1300ppm E-4 1000ppm Melt viscosity ratio 0.9 1.0 0.97 0.95 Gelation fraction ○ ○ ○ ○ Long run molding ○ ○ ○ ○ Die Remains ○ ○ ○ ○ Boil resistance ○ ○ ○ ○ Retort resistance ○ ○ ○ ○

[0066]

[Table 2] Example 5 Example 6 Comparative Example 1 Comparative Example 2 (A) component A-1 90 parts A-1 90 parts A-1 90 parts A-1 90 parts (B) component B-2 10 parts B -3 10 parts B-1 10 parts B-1 10 parts (C) Component C-2 1000ppm C-3 4000ppm − C-3 4000ppm (D) Component D-1 Mg 2.0 D-2 Ca 4.0 − D-1 Mg 3.5 (E) component E-2 5000ppm E-1 5000ppm − − Melt viscosity ratio 1.05 0.75 2.3 0.3 Gelation fraction ○ ○ × ○ Long run molding ○ ○ × ○ Die residue ○ ○ × × Boil resistance ○ ○ ○ ○ Retort resistance ○ ○ ○ ○

[0067]

[Table 3] Comparative Example 3 Comparative Example 4 Comparative Example 5 (A) Component A-1 90 parts A-1 90 parts A-1 90 parts (B) Component B-1 10 parts B-1 10 parts B-1 10 Part (C) Component-C-1 4000ppm C-2 50ppm (D) Component D-1 Mg 3.5 D-3 Mg 18 D-1 Mg 3.5 (E) Component E-6 1500ppm E-6 1700ppm E-6 1700ppm Melted Viscosity ratio 1.1 Unmeasurable 1.1 Gelation fraction × ○ × Long-run molding △ Discharge instability △ Die retention × ○ △ Boil resistance ○ ○ ○ Retort resistance ○ ○ ○

[0068]

[Table 4] (D'is sodium acetate)

[0069]

The resin composition of the present invention has a temperature at the time of molding even when it is used for coextrusion with a blend of nylon-6 and amorphous polyamide having a high molding temperature. Despite being molded at a high temperature of 230 to 250 ° C., generation of an oxidizing gel, viscosity increase with time, and retention in a die are effectively prevented, and long-run molding is possible.

When this resin composition is coextruded with a blend of nylon-6 and amorphous polyamide, the interlaminar adhesion is also remarkably improved. Therefore, the packaging material obtained by the coextrusion is retort sterilized. Delamination does not occur even when subjected to boiled sterilization or boiling.

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[Procedure amendment]

[Submission date] January 10, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction content]

In the above resin composition, the resin composition is placed in the intermediate layer,
It is particularly useful when a laminate is obtained by multi-layer coextrusion molding with a polyamide resin disposed on at least one outer layer. Here, as the polyamide resin,
Various nylons such as nylon-6, nylon-6,6, nylon-7, nylon-11 and nylon-12 can be mentioned, but a blend of nylon-6 and amorphous polyamide is particularly important. . In addition to the polyamide-based resin, another resin layer may be further provided on at least one of the above laminated bodies. The above resin composition is
From the viewpoint of long-run moldability and the like at the time of extrusion molding, the composition
It is preferable to mold at a resin temperature of 235 to 255 ° C.
Yes.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

<Preparation of Other Raw Materials> Saponified product of ethylene-vinyl acetate copolymer (A) A-1: 32 mol% of ethylene content, 99.5 mol% of saponification degree of vinyl acetate unit, melt index = 3 ( 21
Saponified ethylene-vinyl acetate copolymer at 0 ° C

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0054

[Correction method] Change

[Correction content]

[0054] Aliphatic carboxylic acids alkaline earth metal salt (D) D-1: Magnesium acetate tetrahydrate D-2: calcium propionate D-3: acid Magnesium

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0064

[Correction method] Change

[Correction content]

<Conditions and Results> Tables 1 to 4 show the conditions and results of Examples 1 to 6 and Comparative Examples 1 to 6. (C) component,
The blending amount of component (E) is based on the total amount of component (A) and component (B). The description of the component (D) is the type of alkaline earth metal and the amount of alkaline earth metal added (μmol / g) based on the total amount of the components (A) and (B).
Is.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C08K 5/20 C08L 29/04 77/00 LQS // B29K 23:00 77:00 B29L 9:00

Claims (5)

[Claims] 1. An ethylene-vinyl acetate copolymer saponification product (A) having an ethylene content of 20 to 60 mol%, a saponification degree of vinyl acetate units of 90 mol% or more, and a terminal C by a terminal control agent.
The number (y) of the number (x) of OOH groups and the terminal CONRR ′ group (wherein R is a hydrocarbon group having 1 to 22 carbon atoms, R is H or a hydrocarbon group having 1 to 22) is 100 × y / End-adjusted polyamide resin (B), hindered phenol compound (C), aliphatic carboxylic acid alkaline earth metal salt (D), ethylene bis fatty acid amide, and higher fatty acid adjusted to satisfy (x + y) ≧ 5 Metal salt, polymer ester,
It is composed of at least one compound (E) selected from fatty acid ester and hydrocarbon compounds, and the weight ratio of (A) and (B) is 70:30 to 96: 4, and (A) and (B). And the ratio of (C) to the total amount is 0.01 to 1
In weight%, the ratio of (D) to the total amount of (A) and (B) is 0.5 to 15 μmol / g in terms of metal, and the ratio of (E) to the total amount of (A) and (B). Is 0.01-1
% Saponified ethylene-vinyl acetate copolymer resin composition. 2. The compound (E) is at least one selected from ethylene bis fatty acid (carbon 16 to 18) amide, zinc stearate, calcium stearate, magnesium stearate, and a low molecular weight polyolefin having a molecular weight of 900 to 30,000 by a viscosity method. The resin composition according to claim 1, wherein 3. A coextrusion laminate comprising a layer of the resin composition according to claim 1 or 2 as an intermediate layer and a polyamide resin layer as at least one outer layer. 4. The coextrusion laminate according to claim 3, wherein the polyamide resin is a blend of nylon-6 and amorphous polyamide. 5. The laminate according to claim 3, wherein the coextruded laminate is a packaging material which can be retort sterilized or boil sterilized.