JPH06345919A - Saponified ethylene-vinyl acetate copolymer resin composision and coextrusion laminate having layer formed therefrom - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. which does not gel during melt molding by compounding a saponified ethylene-vinyl acetate copolymer, a specific polyamide, a hinderd phenol, and an aliph. carboxylic acid salt in a specified ratio, and to provide a coextrusion laminate of the compsn. with a polyamide. CONSTITUTION:This resin compsn. is prepd. by compounding 100 pts.wt. polymer component comprising 70-96wt.% saponified ethylene-vinyl acetate copolymer having an ethylene content of 20-60mol% and a degree of saponificaiton of 90mol% or more and 30-4wt.% polyamide having the number of terminal COOH groups (x) and the number of terminal CONRR' groups (wherein R is a 1-22C hydrocarbon group) (y) satisfying the relation: 100y/(x+y)>=5, 0.1-1 pt.wt. hindered phenol compd. based on 100 pts.wt. polymer component, and an alkaline earth metal salt of an aliph. carboxylic acid in an amt. of 0.5-15mumol (in terms of metal) per g of the polymer components. The compsn. is coextruded with a polyamide resin to give a laminate having polyamide layers on both sides.

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 Compositions of saponified ethylene-vinyl acetate copolymers and polyamide resins have oxygen barrier properties, oil resistance and solvent resistance based on the former, and impact resistance based on the latter. Therefore, it is used in various applications such as food packaging films, sheets and containers. In particular, a coextrusion laminate having a layer of the composition as an intermediate layer and a layer of polyamide resin as both outer layers can be expected to be used as a packaging material capable of retort sterilization or boil sterilization.

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 methylene groups to 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 copolymerized polyamide containing 5 to 50 wt% of a caproamide unit as a main constitutional unit and containing 5 to 50 wt% of an aromatic and / or alicyclic constitutional unit.

JP-A-62-225535 discloses an ethylene-vinyl alcohol copolymer (a) and a polyamide (b) as a solvent for (a) and (b) and a group I or II of the periodic table. A method for producing an ethylene-vinyl alcohol copolymer composition in which a water-soluble salt of a group metal is uniformly dissolved and then the solvent is removed is shown. 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, the terminal carboxyl group content [X] and the terminal amino group content [Y] are [Y] <[X] + 0.5 × 10 ^-5 (where [X], [Y] The unit of] is a resin composition satisfying mol / g · polymer). It is also shown that a carboxylic acid having 2 to 23 carbon atoms, a diamine having 2 to 22 carbon atoms, and the like are used as the terminal group amount adjusting agent.

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 with a ratio of the number of amide groups satisfying 5.20 ≦ CH ₂ /NHCO≦6.50, and using a terminal adjuster, the terminal carboxyl group content [X] and terminal amino group content [Y] are [Y] A resin composition having a melting point of 160 to 215 ° C., which is adjusted to satisfy <[X] + 0.5 × 10 ^-5 (where [X] and [Y] units are mol / g polymer), is shown. Has been done.

Japanese Patent Application No. 4-131237 discloses a resin outer layer (A) having a moisture permeability of 40 g / m ² · day or more, and an ethylene-vinyl alcohol copolymer resin of 50 to 97% by weight.
And 45 to 3% by weight of polyamide resin, and at least one water-soluble or alcohol-soluble metal compound 0.005
-5% by weight of the composition layer (B), and moisture vapor transmission rate 20
A gas barrier multi-layer package comprising a resin inner layer (C) having a value of g / m ² · day or less is shown. Here, the water-soluble or alcohol-soluble metal compound, specifically,
Examples thereof include lithium chloride, lithium hydroxide, sodium chloride, sodium hydroxide, potassium chloride, potassium hydroxide, calcium chloride, calcium nitrate, aluminum nitrate, ferric chloride, zinc chloride, sodium borate and sodium acetate. Further, in this publication, as an antioxidant, 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 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate, 4,4'-thiobis- (6-t-butylphenol) ) Etc. 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 the multilayer film having a layered structure and formed into a flat film and sequentially biaxially stretched is nylon 6 resin 50 to 50.
95% by weight and amorphous polyamide resin 50 to 5% by weight
A multi-layered film which is a mixed resin layer with is shown.

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

Under the above circumstances, the present invention provides a resin composition comprising a saponified ethylene-vinyl acetate copolymer and a polyamide resin, for example, a coextrusion of a blend of nylon-6 and an amorphous polyamide. To provide a resin composition capable of effectively preventing the generation of gel and thickening with time even when using such a method, and to provide a coextrusion laminate using such a resin composition. The purpose is.

[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),
Depending on the terminal regulator, the number of terminal COOH groups (x) and terminal CON
RR 'group (where R is a hydrocarbon group having 1 to 22 carbon atoms,
R ′ is H or a hydrocarbon group of 1 to 22) and the end-adjusted polyamide resin is adjusted so that the number (y) of the two satisfies 100 × y / (x + y) ≧ 5.
(B), hindered phenolic compound (C), and aliphatic carboxylic acid alkaline earth metal salt (D),
The weight ratio with (B) is 70:30 to 96: 4, (A)
The ratio of (C) to the total amount of and (B) is 0.1-1% by weight.
The ratio of (D) to the total amount of (A) and (B) is 0.5 to 15 μmol / g in terms of metal.

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

The present invention will be described in detail below.

Saponified 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 9
Those of 0 mol% or more (preferably 95 mol% or more, more preferably 98 mol% or more) are 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.
Ethylene-saponified vinyl acetate copolymer (A), if a small amount, α-olefin, unsaturated carboxylic acid compound,
"Copolymerization modification" with other comonomers such as unsaturated sulfonic acid compounds, (meth) acrylonitrile, (meth) acrylamide, vinyl ether, vinyl chloride, styrene
It does not matter if it is done. 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),
Depending on the terminal regulator, the number of terminal COOH groups (x) and terminal CON
RR 'group (where R is a hydrocarbon group having 1 to 22 carbon atoms,
R ′ is H or a hydrocarbon group of 1 to 22) and a polyamide resin adjusted so that the number (y) thereof satisfies 100 × y / (x + y) ≧ 5 is used.

[0020] Such a 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, dodecadioic acid, hexadecadioic acid, eicosadiendioic acid, diglycolic acid, 2,2,4-trimethyladipic acid, xylylenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,
Terephthalic acid, isophthalic acid, etc.), diamines (hexamethylenediamine, tetramethylenediamine, nonamethylenediamid, undecamethylenediamine, dodecamethylenediamine, 2,2,4 (or 2,4,4) -trimethylhexamethylene Examples thereof include diamine, bis- (4,4′-aminocyclohexyl) methane, metaxylylenediamine and the like.

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.

Examples of the monocarboxylic acid having 2 to 23 carbon atoms include aliphatic monocarboxylic acids (acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, capric acid, pelargonic acid, undecanoic acid, lauryl). acid,
Tridecanoic acid, myristic acid, myritolic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, behenic acid, etc.), alicyclic monocarboxylic acids (cyclohexanecarboxylic acid, methylcyclohexanecarboxylic acid, etc.), aromatic Monocarboxylic acid (benzoic acid, toluic acid,
Ethylbenzoic acid, phenylacetic acid, etc.) and the like.

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. , Decamethylenediamine, dodecamethylenediamine,
2,2,4 (or 2,4,4-) trimethylhexamethylenediamine), alicyclic diamine (cyclohexanediamine, bis- (4,4'-aminocyclohexyl) methane, etc.), aromatic diamine (xylyl) Diamine, etc.), aliphatic dicarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecadiodioic acid, hexadecanedioic acid, hexadecenedioic acid) , Octadecadionic acid, octadecenedionic acid, eicosadionic acid, eicosendioic acid, docosandionic acid, 2,2,4-trimethyladipic acid, etc.), alicyclic dicarboxylic acid (1,4-cyclohexanedicarboxylic acid, etc.), Aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic acid, xylylenediene Or in the presence of diamines and dicarboxylic acids, such as carboxylic acid, etc.).

In producing the terminal-adjusted polyamide resin (B), the above-mentioned polyamide raw materials are 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 amount of carboxylic acid and amine used is 2 to 20 meq / mol, preferably 1 to 10 mol of the polyamide raw material (1 mol of the monomer or monomer unit constituting the repeating unit), as the amount of the carboxyl group and amine group. Is 3 to 19 meq / mol (the equivalent of amine group is 1 equivalent of the amount of amino group which reacts with 1 equivalent of carboxylic acid in a ratio of 1: 1 to form an amide bond). 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. Reduced pressure reaction time is 0.5
It is preferable that the time is not less than 1 hour, 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). , A pentyl group, a hexyl group, a heptyl group, an octyl group, a 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 hydrocarbon group (phenyl group, toluyl group, benzyl group, β-phenylethyl group, etc.) and the like.

End-adjusting end of polyamide resin (B) -C
The conversion ratio of the OOH 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, but in the present invention, the degree of this conversion depends on the number of terminal -COOH groups ( x) and end-CO
The relationship with the number of NRR 'groups (y) is 100 × y / (x +
y) ≧ 5, preferably 100 × y / (x + y) ≧ 10, preferably the —COOH group is converted to a —CONRR ′ group, and the amount of unconverted —COOH group Is 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. It is a good idea to limit the amount to 1 μeq / g · polymer.

The hydrocarbon groups represented by R and R'in the -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 —COOH group and —NH ₂ group derived from the above polyamide raw material.

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

As the hindered phenol compound (C), 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.

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

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 an aliphatic carboxylic acid alkaline earth metal salt (D).

Here, the ratio of (A) and (B) is 7 by weight.
It is necessary to be in the range of 0:30 to 96: 4, and when the ratio of the terminal-adjusted polyamide resin (B) is too small, the saponification product (A) of the ethylene-vinyl acetate copolymer may have poor boiling resistance. If the improvement effect is not sufficiently exhibited and the ratio of the terminal-adjusted polyamide resin (B) is too large, the oxygen barrier property and other characteristics of the saponified ethylene-vinyl acetate copolymer (A) are impaired.

The proportion of the hindered phenolic compound (C) needs to be in the range of 0.1 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 an oxidizable gel is likely to be formed 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 the cost becomes disadvantageous.

Furthermore, the proportion of the aliphatic carboxylic acid alkaline earth metal salt (D) must be 0.5 to 15 μmol / g in terms of metal, based on the total amount of (A) and (B). If it is too small, the melt viscosity will increase, and if it is too large, gel may be generated or foaming may occur during molding, or the film may be colored or the moldability may become unstable.

Additives such as a plasticizer, a stabilizer, a filler, a colorant, a lubricant, an antiblocking agent and an antistatic agent may be added to the above resin composition. Particularly as a lubricant, for example, ethylene bis fatty acid (having 16 to 1 carbon atoms)
8) It is desirable to blend amide, higher fatty acid (carbon number 8 to 22) amide, polyethylene wax, polymer ester, fatty acid ester, higher fatty acid metal salt such as hydroxy fatty acid magnesium, zinc stearate and the like.

The above resin composition is molded 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, this is arranged in the intermediate layer,
It is particularly useful when a laminate is obtained by multi-layer coextrusion molding in which a polyamide resin is placed on both outer layers. Here, as the polyamide-based resin, nylon-6,
Various nylons such as 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 provided on at least one of the outer layers.

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

[0043]

In the present invention, the terminal-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),
Besides, the hindered phenolic resin (C) and the alkaline earth metal salt of aliphatic carboxylic acid (D) are used together as an auxiliary agent.

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, so the packaging material obtained by the coextrusion is retort sterilized. Delamination does not occur even when subjected to boiled sterilization or boiling.

[0046]

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

Examples 1 to 6 and Comparative Examples 1 to 6 <Preparation of end-adjusted polyamide resin (B)> B-1: 60 kg of ε-caprolactam and water in an autoclave
After charging 1.2 kg and octadecylamine to 6.78 meq per 1 mol of ε-caprolactam, sealing under a nitrogen atmosphere, raising the temperature to 250 ° C., and reacting under pressure for 2 hours with stirring After releasing the pressure and reducing the pressure to 180 Torr and performing the reaction for 2 hours, then introducing nitrogen and returning to normal pressure, stirring is stopped, the contents are extracted as strands and made into chips, and unreacted monomers are extracted and removed with boiling water. And dried. Terminal COOH group: 9μeq / g ・ Polymer 100 × y / (x + y) = 87

B-2: Octadecylamine and acetic acid were combined with ε-
5.31meq and 5.30me for 1 mol of caprolactam, respectively
q Manufactured in the same manner as in B-1 except that the final pressure of the polymerization reaction was adjusted to 270 Torr by adding q. Terminal COOH group: 26 μeq / g ・ Polymer 100 × y / (x + y) = 64

B-3: Octadecylamine and stearic acid were added at 3.39 meq per mol of ε-caprolactam, respectively.
, 3.39 meq was added and the final pressure of the polymerization reaction was set to 200 Torr, except that it was produced in the same manner as in the case of B-1. Terminal COOH group: 20μeq / g ・ Polymer 100 × y / (x + y) = 60

<Preparation of Other Raw Materials> The following raw materials were prepared. Saponified ethylene-vinyl acetate copolymer (A) A-1: 32 mol% ethylene content, 99.5 mol% saponification degree of vinyl acetate unit, melt index = 3 (210 ° C)
Ethylene-vinyl acetate copolymer

Hindered Phenol Compound (C) C-1: N, N'-hexamethylenebis (3,5-di-t
-Butyl-4-hydroxyhydrocinnamide) (Ciba
"Irganox 1098" manufactured by Geigy) C-2: 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl)
Benzene (“Irganox 13 manufactured by Ciba Geigy”
30 ") C-3: pentaerythrityl-tetrakis [3- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate] ("Irganox 10 manufactured by Ciba Geigy")
10 ")

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

<Single Layer Melt Molding> After adding the above-mentioned component (C) and component (D) to component (A), the mixture is melt extruded by a twin-screw extruder or a single-screw extruder, then cooled and pelletized. . further
The component (B) was added and premixed with a Henschel mixer, and then supplied to an extruder equipped with a T-die and melt-kneaded to form a film having a thickness of 50 μm. 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 Screw rotation speed: 40 rpm

<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 of Examples or Comparative Examples were prepared.
A T-die set to a temperature of 250 ° C. was used to coextrude the film into a Y / X / Y layer structure, and the film was cooled by a chill roll circulating cooling water to obtain a flat three-layer film. After that, the film is stretched 3 times by a 90 ° C roll stretching machine, and further stretched 3.5 times by a tenter stretching machine in an atmosphere of 140 ° C.
Then, while reducing the width by about 4% with the same tenter, 210
It was heat set in an atmosphere at ° 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 The pellet of each composition was heated and deteriorated in a gear oven at 250 ° C. for 20 minutes in an air atmosphere, and the gelation fraction was determined from the formic acid insoluble matter. ○ 2 when the gelation fraction is less than 2%
% Or more and less than 2.5% was evaluated as △, and 2.5% or more was evaluated as x.

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.

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 the condition of ° C x 30 minutes were evaluated. The case where there was no change in transparency before and after the treatment and delamination did not occur was judged as ◯.

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. The case where there was no change in transparency before and after the treatment and delamination did not occur was judged as ◯.

<Conditions and Results> Tables 1 to 3 show the conditions and results of Examples 1 to 6 and Comparative Examples 1 to 6. The blending amount of the component (C) is based on the total amount of the component (A) and the 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) with respect to the total amount of the components (A) and (B).

[0061]

[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 4000ppm C-1 4000ppm (D) Component D-1 Mg 1.1 D-1 Mg 1.3 D-3 Mg 1.9 D -2 Ca 5.0 Melt viscosity ratio 1.10 0.95 0.97 0.99 Gelation fraction ○ ○ ○ ○ Long run molding ○ ○ ○ ○ Boil resistance ○ ○ ○ ○ ○ Retort resistance ○ ○ ○ ○

[0062]

[Table 2] Example 5 Example 6 Comparative Example 1 Comparative Example 2 (A) Component A-1 90 parts A-1 90 parts A-1 80 parts A-1 80 parts (B) Component B-2 10 parts B-3 10 parts B-1 20 parts B-1 20 parts (C) Component C-2 4000ppm C-1 4000ppm − C-3 4000ppm (D) Component D-1 Mg 1.5 D-2 Ca 4.0 − − Melt viscosity ratio 1.1 0.75 2.5 2.3 Gelation fraction ○ ○ × △ Long run molding ○ ○ × × Boil resistance ○ ○ ○ ○ Retort resistance ○ ○ ○ ○

[0063]

[Table 3] Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 (A) Component A-1 80 parts A-1 90 parts A-1 90 parts A-1 90 parts (B) Component B-1 20 parts B-1 10 parts B-2 10 parts B-1 10 parts (C) Component − C-1 4000ppm C-2 500ppm C-1 4000ppm (D) Component D-3 Mg 1.5 D-1 Mg 18 D-2 Ca 4.0 D'Na 3.0 Melt viscosity ratio 0.97 Unmeasurable 0.55 3.0 Gelation fraction × ○ △ × Long run molding △ × (Discharge instability) × × Boil resistance ○ ○ ○ ○ Retort resistance ○ ○ ○ ○ (D 'is sodium acetate)

[0064]

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 and viscosity increase with time 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] August 16, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

In the above resin composition, this is arranged in the intermediate layer,
It is particularly useful when a laminate is obtained by multi-layer coextrusion molding in which a polyamide resin is placed on both outer layers. Here, as the polyamide-based resin, nylon-6,
Various nylons such as 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 provided on at least one of the outer layers. The resin composition has a long
The resin temperature of the composition is 235 to 25 in view of run moldability and the like.
It is preferable to mold at 5 ° C.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

<Preparation of Other Raw Materials> The following raw materials were prepared. Ethylene-vinyl acetate copolymer saponified product (A) A-1: Ethylene content 32 mol%, saponification degree of vinyl acetate unit 99.5 mol%, melt index = 3 (2
Ethylene 10 ° C.) - vinyl acetate copolymer saponified

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Claims (4)

[Claims] 1. An ethylene-vinyl acetate copolymer saponification product (A) having an ethylene content of 20 to 60 mol% and a saponification degree of vinyl acetate units of 90 mol% or more, and a terminal COO by a terminal adjuster.
The number of H groups (x) and the number of terminal CONRR ′ groups (wherein R is a hydrocarbon group having 1 to 22 carbon atoms, R ′ is H or a hydrocarbon group having 1 to 22 carbon atoms) are 100 × y / End-adjusted polyamide-based resin adjusted to satisfy (x + y) ≧ 5
(B), hindered phenolic compound (C), and aliphatic carboxylic acid alkaline earth metal salt (D),
The weight ratio with (B) is 70:30 to 96: 4, (A)
The ratio of (C) to the total amount of and (B) is 0.1-1% by 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 a saponified ethylene-vinyl acetate copolymer resin composition. 2. A coextrusion laminate comprising a resin composition layer according to claim 1 as an intermediate layer and a polyamide resin layer as both outer layers. 3. The coextrusion laminate according to claim 2, wherein the polyamide resin is a blend of nylon-6 and amorphous polyamide. 4. The coextruded laminate according to claim 2 or 3, which is a packaging material that can be retort sterilized or boiled.