JPH0797491A - Resin composition and package - Google Patents

Abstract

(57) [Summary] [Structure] Ethylene content 20-65 mol%, saponification degree 9
0% or more of ethylene-vinyl alcohol copolymer resin 40
.About.97 wt.% And polyamide resin 60 to 3 wt.%, And based on the total amount of said resin, the periodic table II
A resin composition containing 0.01 to 0.1% by weight as a total amount of at least two kinds of metal salts of Group I in terms of the metal. [Effects] According to the present invention, it is possible to obtain a film or a multi-layer structure which has less appearance even after long-time operation and has an excellent appearance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition containing an ethylene-vinyl alcohol copolymer resin (hereinafter abbreviated as EVOH) and a polyamide resin as main components, and a multilayer structure and a package using the same.

[0002]

2. Description of the Related Art A composition of EVOH and a polyamide resin is provided with EVOH oxygen barrier properties, oil resistance, chemical resistance, and aromatic component shielding properties, as well as moldability, impact resistance, and hot water resistance based on polyamide. It has a very useful property and is widely used in containers and films.

However, when such a composition is continuously melt-molded for a long time, a gel is generated in the molded product, or a deteriorated resin adheres to a screw or a die of an extruder, which causes the surface of the molded product. Roughness may occur, and sometimes the deteriorated resin may peel off and enter the molded product. For this reason,
It was necessary to stop the operation and dismantle and clean the machine in a relatively short time.

As a measure against such a problem, a method of adding a fluorine-containing resin has been proposed. Although these have some effects, they are not enough effects for the purpose. It is also disadvantageous in terms of cost. In addition, JP-A-6
In 0-238345, when a long-time operation of 6 hrs or more is carried out, microscopic lumps frequently occur, and a large amount of resin deteriorates adhered to the die, leaving a problem in long-time drivability. Also, hydrotalcite-based stabilizers have improved long-term drivability, but are still insufficient.

[0005]

The composition of ordinary EVOH and polyamide (hereinafter abbreviated as PA) is generally poor in long-time melt moldability (hereinafter abbreviated as long run property). This is considered to be due to gelation of EVOH and PA, and this gelation is considered to be due to a chemical reaction. The most suspicious reaction is EVO with the terminal carboxyl group (COOH) formed at the end of PA or during thermal decomposition.
It is considered that gelation occurs due to cross-linking by esterification reaction of hydroxyl group (OH) of H or amide bond and amide-transesterification reaction of hydroxyl group (OH) of EVOH. This is because when the change of the carboxyl group (COOH) concentration and the amino group (NH ₂ ) concentration in the composition with the melting time was measured,
The concentration of the latter increases, which can be proved by the fact that the concentration of the former is constant. In any case, the COOH group of PA and EVOH
Is considered to be a reaction with the OH group of Therefore, the present invention suppresses the gelation of the composition of EVOH and PA, or easily discharges the gel-like material in the extruder flow path, has a small amount of fine lumps on the film surface, and does not deteriorate the resin adhered to the die. The purpose is to reduce the number and enable a very long drivability.

[0006]

In order to solve the above problems, the present inventors have extensively studied the gelling behavior of EVOH resin and PA compositions and the influence of various factors, and as a result, The composition of PA contains at least two kinds of metal salts of Group II of the Periodic Table as a nuclear metal in a total amount of 0.01 to 0.1% by weight, and preferably satisfies the following formula. As a result, it has been found that a film, a container or the like having a good film surface, in which the gelled substance can be easily discharged and the gelled substance is extremely small, can be molded for a very long time.

10 ≦ MI (0-60) ≦ 200 (1) 200 ≦ MI (60-360) ≦ 10,000 (2) 10 ≦ MI (360-600) ≦ 10,000 (3) ( 1) MI (0 to 60) ... 0 to less than 60 minutes, 220 ° C
Maximum melt index (g / 10 minutes) when heated in (in nitrogen) (2) MI (60 to 360) ... 60 to less than 360 minutes, 2
Maximum melt index (g / 10 minutes) when heated at 20 ° C. (in nitrogen) (3) MI (360 to 600) ... 360 to 600 minutes, 2
Maximum melt index (g / 10 minutes) when heated at 20 ℃ (in nitrogen) Melt index (MI) is 230 ℃, 10.9kg
It is a value measured under load.

In the present invention, by using a specific amount of at least two metal salts of Group II of the periodic table, it is possible to operate for a long time. In addition, when only one type of metal salt of Group II of the Periodic Table is used, the resin deteriorated in adhesion to the die is improved, but many minute lumps are seen, which is also a cause of breakage during film formation and stretching. It is not preferable. But 2
By using at least one kind of metal salt in combination, a resin having a deteriorated adhesion to the die can be reduced and a film having a good film surface can be obtained. The reason for this is not clear, but it is presumed that the use of two or more metal salts of Group II of the periodic table causes an interaction between the metals and improves the thermal stability. Further, when the resin composition of the present invention is used for molding at low temperature, the film surface is good and the long-term drivability is further improved.

In the present invention, metals belonging to Group II of the periodic table include beryllium (Be) and magnesium (M
g), calcium (Ca), zinc (Zr), barium (Ba), and a typical example of the metal salt is a fatty acid salt of the metal. The fatty acid constituting the fatty acid salt has 2 carbon atoms. Fatty acids in the range of ~ 22, such as lower fatty acids (acetic acid, propionic acid, butyric acid, caproic acid,
Caprylic acid, etc.) and higher fatty acids (lauric acid, stearic acid, myristic acid, etc.). Of these, higher fatty acid salts having 8 to 22 carbon atoms are preferable. As a method of adding these metal salts, EVOH
Preliminarily applied to resin or PA resin [for example, during polymerization (including a series of steps such as saponification during polymerization, washing with water, etc.)
A method in which EVOH and PA are added and melt-extruded by a single-screw or twin-screw extruder (in the same or different directions), and then pelletized under cooling, EVOH resin and P
When melt-kneading the resin A, these substances may be added in the form of powder or liquid. Furthermore, a method of adding a masterbatch blend in which these substances are added at a high concentration during actual molding can also be used.

The composition ratio of EVOH and PA forming the composition is 40 to 97% by weight: 60 to 3% by weight, preferably 45 to 90% by weight: 55 to 10% by weight. If the content of PA is small, the reforming effect of PA is small, and if it is too large, the gas barrier property of EVOH cannot be exhibited. The content of the metal belonging to Group II of the periodic table is 0.01 to 0.1% by weight, preferably 0.01 to 0.05% by weight, based on the total amount of EVOH and PA. . In addition, at least two kinds of metal salts are used in combination with at least two kinds of different metal salts, and the above-mentioned fatty acid salts are particularly representative. When two kinds of metal salts are used, the mixing ratio of each metal salt is 1: 1 to 1: 5, preferably 1: 1 to 1: 2 in terms of metal, and The compounding amount is preferably at least 0.005% by weight in terms of metal.

Further, in the present invention, the above-mentioned at least two different metal salts are added to the above formulas (1), (2) and (3).
It is preferable to blend so as to satisfy By satisfying the above formulas (1), (2), and (3), it is possible to operate for a long time, and a film, a container or the like having a very small amount of gelated product and a good appearance can be obtained. In addition, lowering the molding temperature further reduces the amount of gelled product, improving long-term operation, and further reducing the COOH at the molecular end of the PA resin.
By using the one in which the group was blocked with an amide group, the long-term drivability was further improved. Further, in the multilayer film using the present composition, especially the multilayer film for retort,
It is noteworthy that hot water resistance is also improved.

EVO which is one of the resins forming the composition
H includes any substance as long as it is obtained by hydrolyzing a vinyl acetate unit in a copolymer of ethylene and vinyl acetate, and particularly as a content suitable for the purpose of the present invention, the content of the ethylene unit is 20 to 65. Mol%, preferably 20-50
And those having a vinyl acetate unit saponification degree of 96% or more, particularly 99% or more. E with different ethylene content or degree of polymerization
You may use it in the form which mixed 2 or more types of VOH. The EVOH referred to in the present invention may be modified with a copolymerization monomer in the range of 5 mol% or less, and examples of the modified monomer include propylene, 1-butene, 1-hexene, 4-methyl-1 pentene and acryl. Acid ester, methacrylic acid ester, maleic acid, fumaric acid, itaconic acid, higher fatty acid vinyl ester, alkyl vinyl ether, N-
Examples include (2-dimethylaminoethyl) methacrylamides or quaternary compounds thereof, N-vinylpyrrolidone, N, N-butoxymethylacrylamide, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane and the like. .

As the polyamide resin (PA) which is one of the resins forming the composition, polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7) and poly-ω-aminononane. Acid (nylon-
9), polyundecane amide (nylon-11), polylauryl lactam (nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4-6), polyhexamethylene adiba Mido (nylon-6,6), polyhexamethylene sebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), poly Decamethylene adipamide (nylon-10,8), or caprolactam / lauryllactam copolymer (nylon-6 / 12), caprolactam / ω-aminononanoic acid copolymer (nylon-6 / 9), caprolactam / hexamethylene Diammonium adipate copolymer (nylon-6 / 6,6) Lauryllactam / hexamethylene diammonium adipate copolymer (nylon-12
/ 6,6), hexamethylene diammonium adipate copolymer (nylon-2,6 / 6,6), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon-6,6 / 6,10), ethylene diammonium adipate / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon-6 / 6,6 / 6,10), polyhexamethylene isophthalamide, polyhexamethylene terephthalamide ,
Hexamethylene isophthalamide / terephthalamide copolymer and the like can be mentioned. Those obtained by modifying these PAs with aromatic amines such as methylbenzylamine and metaxylylenediamine are also preferable. Also preferred is meta-xylylene diammonium adipate.

These PAs can be used alone or in a mixture of two or more. Among these PAs, the most preferable one for the present invention is a caprolactam / lauryllactam copolymer, that is, one containing nylon-6 / 12 as a main component. Nylon-6 / 12 in 6
There is no particular limitation on the composition of the ingredients and 12 ingredients, but 12 ingredients are 5
It is preferably from 60 to 60% by weight, more preferably from 5 to 50%. The relative viscosity is in the range of 2.0 to 4.0, more preferably 2.4 to 3.9.

These PAs, especially nylon-6 /
Polyamides having a polyether bond in the polymer chain may be added by adding polyether diamines and dicarboxylic acid (such as dimer acid) during the polycondensation of 12. At the time of condensation, a monoamine such as NH ₃ , an aliphatic amine such as hexamethylenediamine or laurylamine, or an aromatic amine such as metaxylylenediamine is added to reduce the amount of carboxyl end groups in the polyamide. What was made
That is, the one with the terminal blocked is preferable. In that case, it is preferable that the amino group is 5 × 10 ⁻⁵ equivalent / g or more and the carboxyl terminal group is 3 × 10 ⁻⁵ equivalent / g or less.

In the composition of the present invention, other polymers or antioxidants, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, etc. may be added within the range not impairing the object of the present invention. Can also be added. Other polymers include polypropylene resins, polyester resins, polystyrene resins, polyvinyl chloride resins, acrylic resins, polyvinylidene chloride resins, polyurethane resins and the like. Furthermore, an ethylenically unsaturated monomer (for example, olefins such as ethylene and propylene) containing 2 to 25 mol% of at least one component unit selected from vinyl acetate, acrylic acid ester and methacrylic acid ester, copolymer Alternatively, the saponified product may be blended to impart flexibility to the laminated structure. In addition, specific examples of additives other than polymers include the following.

Stabilizers: Heidoltalcites, metals, etc.

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 ',
5'-di-t-butyl-4'-hydroxyphenyl) propionate, 4,4'-thiobis- (6-t-butylphenol) and the like.

UV absorber: ethyl-2-cyano-3,
3'-diphenyl acrylate, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2-
(2'-Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy -4-octoxybenzophenone and the like.

Plasticizer: dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphoric acid ester and the like.

Antistatic agent: pentaerythritol monostearate, sorbitan monovalmitate, sulfated olefinic acid, polyethylene oxide, carbon wax and the like.

Lubricants: ethylene bis stearamide, butyl stearate, etc.

Coloring agents: carbon black, phthalocyanine, quinacridone, indoline, azo pigments, titanium oxide, red iron oxide and the like.

Filler: Glass fiber, asbestos, mica, sericite, talc, glass flake, ballastonite calcium silicate, aluminum silicate, montmorillonite, etc.

A composition comprising 5 to 60% by weight of a filler selected from mica, sericite, talc and glass flakes, and montmorillonite, and 95 to 40% by weight of the above composition (composition of EVOH and PA). Is preferably used as the layer (B) because the gas barrier property is improved. This is mainly applicable to containers such as cups and trays.

Of the above-mentioned inorganic fillers, the water-swelling phyllosilicates represented by montmorillonite can be kneaded by a usual melt blending method, but when they are mixed by the following method, the effect is exhibited with a small filling amount. , And more preferably.
Alcohol such as methyl alcohol, n-propanol or isopropyl alcohol, water and EVOH are added to a colloidal montmorillonite dispersion using water as a dispersion medium.
After adding and heating and stirring to dissolve EVOH, a usual method, that is, a method of cooling and solidifying the solution, pulverizing, drying and pelletizing can be applied. Alternatively, the above method may be applied after adding and stirring montmorillonite to an EVOH solution which is heated and dissolved in the above alcohol-water mixed solvent. Alternatively, the above method may be applied after mixing and stirring the EVOH solution and a colloidal montmorillonite dispersion liquid forming a sol using water or the above alcohol water mixed solvent as a dispersion medium.
Alternatively, when obtaining an EVOH composition in which a desired amount of montmorillonite is uniformly dispersed, an EVOH composition containing a high concentration of montmorillonite is prepared in advance by the method described above, and this is used so as to have a final desired concentration. May be. Further, a method in which a pent type kneading extruder is used and a water-based sol of montmorillonite is dropped while the EVOH is melting above the melting point and kneading is also applicable.

The composition thus obtained is, after melt-molding, a multilayer structure having a single layer or a layer using this composition, such as multilayer sheets, films, bottles and tubes, as well as fibers and machine parts. It is used as a molded product such as. The molding method is not particularly limited, but a usual method can be used. It is also possible to stretch (uniaxially stretch or biaxially stretch) a single layer or multiple layers containing the composition.

The form of the composition of the present invention is not particularly limited, but when it is used as an intermediate layer of a multilayer sheet or film, it plays a role of a gas barrier material, and in this case, its thickness. Has a direct effect on the barrier performance and is selected from the range of 10 to 250μ, usually 15 to 100μ.

If desired, an inorganic film may be laminated on the layer comprising the composition of the present invention. Here, the inorganic film is
A transparent inorganic film is desirable. In particular, an inorganic oxide film,
Examples thereof include aluminum oxide (AlO _x ) and silicon oxide (SiO _x ). These inorganic films are typically laminated by a vapor deposition method and have a thickness of 100Å to 500.
Å, preferably 200 to 400 Å.

Next, a multi-layered package using a layer comprising the composition of the present invention as an intermediate layer will be described. The moisture permeability of the outer layer (A) has to be carefully selected because it affects the appearance and gas barrier property after retort treatment when used as the packaging material for the multilayer package of the present invention, especially for the multilayer film type retort. The multilayer package obtained by the present invention has 10
A resin with low heat resistance can be used when subjected to so-called boil sterilization treatment at 0 ° C or lower, but when it is subjected to retort treatment carried out at 105 to 135 ° C, particularly when it exceeds 100 ° C. It is also necessary to consider heat resistance. Further, in the present invention, it has been found that the higher the moisture permeability of the appearance, the better the effect on the appearance and gas barrier property after retort. As a method for evaluating the moisture permeability, a method shown in JIS-Z-0208, that is, a film having an arbitrary thickness is attached to a cup containing a hygroscopic agent, and after sealing and fixing, 40 ° C. and 90% relative humidity are set. A convenient method is to leave it in a controlled constant temperature and humidity apparatus and measure the rate of weight increase. Water vapor permeability measured by this method (unit: g / m ² ·
When a material having a day) of 40 or more, particularly 50 or more, and more preferably 100 or more is used, the gas barrier property can be rapidly recovered during storage after the retort treatment.

In the present invention, the resin for the outer layer (A) that is preferably used is PA, polyester, or polycarbonate, and the resin for the outer layer that is most preferably used is PA. Examples of the PA include the various PAs described above, but especially nylon-6 and nylon-6.
6, nylon 6/6, 6 and the like. The thickness of this resin is 900 to 110 for the water vapor permeability per 10μ in the non-stretched product.
It is 0 g / m ² · day. The moisture vapor transmission rate is substantially proportional to the thickness of the resin layer (A). Therefore, it is preferable that the resin is thin, but depending on the resin, the resin cannot be thinly molded, and the thinness may cause defects such as strength.

The unstretched nylon is used in an amount of 275 μ or less, particularly 110 μ or less, more preferably 15 to 40 μ. The biaxially stretched nylon can be used in a thickness of 97 μ or less, particularly 39 μ or less, and more preferably 10 to 20 μ. As another resin, a polycarbonate resin (a water vapor permeability of 10 μm is 120 to 150 g / m ² ·
Day can be mentioned, and it is preferable to use it in a thickness range of 10 to 38 μ.

Polyester resins can also be used for the purpose of the present invention. In particular, polyethylene terephthalate resin has a moisture permeability of the stretched film of 60g per 10μ thickness.
Since it is / m ² · day, it is preferably used at 15 μm or less.

In addition, the moisture vapor transmission rate (in parentheses) per 10 μ of the resin film used for the appearance (A) that can be used for the purpose of the present invention is shown. Polyether ketone (14
3), polysulfone (490), polyether sulfone (500), polyetherimide (218), polyimide (208), polyarylate (510). on the other hand,
Polyvinyl chloride and polystyrene are suitable for the constitution of the multilayer package of the present invention in that they have high moisture permeability, but they are limited in special applications such as low temperature sterilization because they have low heat resistance. In addition, polypropylene has low moisture permeability (1 per 10μ
Since it is 4 to 35 g / m ² · day), it is usually difficult to use. Polyethylene is also unsuitable because it has low moisture permeability and low heat resistance.

A commercially available film can be used as the outer layer (A), such as a non-stretched nylon film (CN), a biaxially stretched nylon film (ON), a biaxially stretched polyethylene terephthalate film (O-PET), and a polycarbonate film. Is preferable, but a biaxially stretched film is particularly preferable.

Regarding the moisture permeability of the resin used for the outer layer (A), the moisture permeability of the single layer film can be measured, and for those laminated by the dry laminating method, the value of the moisture permeability of the monolayer film is used. Can be done. The influence of the adhesive on the moisture permeability of the dry laminate is small and is not considered.
For multi-layered packages (laminated products or co-extruded products) that have already been laminated, the moisture vapor transmission rate of the film used as a single layer of the resin used for the outer layer is substituted for the moisture vapor transmission rate of the outer layer of the multi-layer package. be able to. When the outer layer is composed of two or more layers, the moisture permeability of the outer layer composed of multiple layers can be determined by a conventional method from the moisture permeability of the film formed as a single layer for each of the constituent resins. This concept of moisture permeability can be applied to the inner layer described below.

In the multi-layer package of the present invention, it is important that the inner layer (C) has low moisture permeability. The low water-absorbent thermoplastic resin used for the inner layer is not particularly limited, but depending on the purpose, it is possible to obtain an excellent packaging material by taking into consideration moisture permeability, heat resistance, heat sealability, transparency, etc. it can.

First, in general, the lower the moisture permeability of the inner layer, the higher the oxygen gas barrier property of the multilayer structure obtained. It is believed that this is because the lower the moisture permeability of the inner layer, the lower the relative humidity of the intermediate layer. The above-mentioned moisture permeability is preferably 20 g / m ² · day or less, more preferably 10 g / m ² · day or less, for example polypropylene 60μ (water vapor permeability 6 g / m ² · day).
Suitable results are obtained by using. Polypropylene can provide satisfactory results in terms of heat resistance, heat sealability and transparency. Polypropylene is suitable as the resin for the inner layer for many purposes, but other thermoplastic resins can be used. Examples include polyolefin resins other than polypropylene, polyamide resins, polyester resins, polystyrene resins. Examples thereof include polyvinyl chloride-based resin, acrylic resin, polyvinylidene chloride-based resin, polyacetal-based resin, and polycarbonate-based resin, and these resins may be used alone or in a laminated form.

As the film used for the inner layer (C), a nylon film (CN or ON), a non-stretched polypropylene film (CPP), a biaxially stretched polypropylene film (OPP), a polyethylene film, a polyvinylidene chloride film or the like is preferable. However, when importance is attached to the retort property and the heat seal property, it is desirable to use an unstretched polypropylene film for the innermost layer.

The moisture permeability of the inner layer (C) can be lowered by selecting a resin or adjusting the thickness ratio of the inner layer and the outer layer. Further, when a part of the layers of the laminated structure of the present invention is formed by a coextrusion method, a usual technique of laminating an adhesive resin as a main resin of an intermediate layer and an inner layer is adopted. Polypropylene as the adhesive resin,
A resin obtained by modifying a polyolefin such as polyethylene or a copolymer of ethylene and a monomer copolymerizable with ethylene (such as vinyl acetate or acrylic ester) by adding maleic anhydride is used. The resin used for the outer layer or the inner layer may be added with the above-mentioned additives such as an antioxidant, a colorant and a filler.

The multilayer structure of the present invention can be manufactured by the following various laminating methods. In the co-extrusion method, dry laminating method, sand laminating method, extrusion laminating method, co-extrusion method, when PA is used for the outer layer, an adhesive resin may not be required between the outer layer and PA, which is advantageous in the process. . When the adhesive resin layer is provided, it is preferable that the moisture permeability of the outer layer and the adhesive resin layer combined be as high as possible, especially 40 g / m ² · day or more. The dry lamination is generally performed by laminating three or more kinds of films of an outer layer, an intermediate layer, and an inner layer. Therefore, the inorganic film is, if necessary, laminated at a desired position by a vapor deposition method before the bonding.

In addition to the above, the following layers can be used as the layer structure of the multilayer structure and the multilayer package of the present invention. (A) /
(B) / (A) / (C), (A) / (B) / (A) /
(B) / (C). An adhesive layer may be provided between these respective layers as needed, and other layers such as a resin layer may be provided between the respective layers.

As described above, when the composition containing the acid of the present invention is used, the hot water temperature is improved. Although the mechanism has not been clarified, it is clear that the acid component has a function of decomposing nylon during molding as described above.
It is considered that the decomposition causes nylon to have a low molecular weight and the number of molecules to increase, resulting in a finer dispersion of nylon in EVOH. This should be confirmed by electron microscope observation, but unfortunately, even without acid addition, the dispersion is fine and the dispersed form cannot be clearly captured, so a clear difference is confirmed with or without acid addition. It has not been.

[0044]

The present invention will be further described with reference to the following examples, but the present invention is not limited thereto.

Example 1 As EVOH, ethylene content 28 mol%, saponification degree 99.8%, melt index (190 ° C., 2160)
g) is 1.2 g / 10 minutes, and 80% by weight of resin pellets and P
As A, PA-6 / 12 copolymer (weight ratio of caprolactam unit to lauryllactam unit is 80/20%
Then, after the dry blending with a melting point of 196 ° C. and a relative viscosity of 2.5) 20% by weight, magnesium stearate (Mg = 120 ppm in terms of metal) based on the total amount of the resin,
Zn = 120 ppm of zinc stearate in terms of metal was added, melt-extruded with a uniaxial extruder having a diameter of 40 mm (die temperature 230 ° C), and the blended pellets were dried, and then the resin (1)
Got This resin (1) was used to form a transparent unstretched film of a composition having a thickness of 25 μ using an extruder having a full flight type screw having a diameter of 20 mm and a coat hanger die having a width of 350 mm (temperature: 230 ° C.). The operation was carried out for 12 hours. After operating for 12 hours, the film forming machine was then operated with 1.5 g of polyethylene to replace the film, and then the device was disassembled and the inner surface of the device was observed. Almost no deposit was found on the screw, and about 90 g of deposit was found on the inner surface of the die. Similarly, the operation was carried out for 6 hours, and almost no deposit was found on the screw, and about 40 g of deposit was found on the inner surface of the die.

Examples 2 to 4 Table 1 shows the contents and types of the metal salts of Group II of the Periodic Table.
Modifications were made as shown in, and the other procedure was the same as in Example 1. Good results were obtained in all cases.

Example 5 Film formation was carried out in the same manner as in Example 1 except that the film forming temperature was changed from 230 ° C. to 210 ° C., and somewhat better results than in Example 1 were obtained.

Example 6 PA-6 / 12 in which the terminal carboxyl group was blocked with an amino group, PA-6 / 12 (amino group: 4.34 mol /
Film formation was carried out in the same manner as in Example 1 except that g) was replaced, and somewhat better results than in Example 1 were obtained.

Comparative Example 1 In Example 1, the same procedure as in Example 1 was carried out except that the metal salt of Group II of the periodic table was not added, and gel was not formed on the film surface until 1 hour after the start of operation. Almost never seen,
The gel increased sharply 1 hour after the start of the operation, and the film surface was defective thereafter until the end of the operation. The amount of the adhered deterioration resin adhered to the inner surface of the die was about 90 g, and the operation for 12 hours was impossible.

Comparative Examples 2 and 3 Film formation was carried out in the same manner as in Example 1 except that a metal salt of Group II of the Periodic Table was used as the metal salt. There was also a large amount of adhered deterioration resin adhered to.

Comparative Examples 4 and 5 Film formation was carried out in the same manner as in Example 1 except that a metal salt of Group II of the periodic table was used as the metal salt, but the adhesion deterioration resin adhered to the inner surface of the die. The amount was reduced and improved, but microscopic spots frequently occurred and the film surface was defective.

Comparative Example 9 A film was formed in the same manner as in Example 1 except that a hydrotalcite-based compound was used as the metal salt, but the resin deteriorated in adhesion to the inner surface of the die was reduced, but fine particles were generated. .

Example 7 and Comparative Example 6 In Example 1, EVOH had an ethylene content of 44 mol%, a saponification degree of 99.8% and a melt index (19).
At 0 ° C., 2160 g), resin pellets of 5.5 g / 10 min were used, and when film formation was performed for 6 hours in the same manner, the gel increased after 4 hours and the amount of adhesion to the inner surface of the die was 24 g.
(Example 7). In the same manner as in Comparative Example 1, when the metal salt was not added, the gel increased from 1 hour later, and the adhesion amount on the inner surface of the die was 85 g (Comparative Example 6).

Example 8 and Comparative Example 7 When PA was changed to PA-12 in Example 1 and film formation was carried out for 6 hours in the same manner as in Example 1 except for the above, gel increased after 5 hours and the inner surface of the die was increased. The amount adhered to was 12 g (Example 8). As in Comparative Example 1, when the metal salt was not added, the gel increased after 1 hour, and the amount attached to the inner surface of the die was 100 g (Comparative Example 7).

Example 9, Comparative Example 8 In Example 1, the blend ratio was EVOH 50% by weight,
Produce blended pellets with PA resin 50% by weight,
When a film was formed for 6 hours in the same manner, the amount of gel increased after 3 hours, and the amount attached to the inner surface of the die was 38 g (Example 9). In the same manner as in Comparative Example 1, when the metal salt was not added, the gel increased after 1 hour, and the adhesion amount on the inner surface of the die was 120 g (Comparative Example 8). In Examples 7, 8 and 9, by using two or more kinds of metal salts of Group II of the periodic table, long-term drivability was significantly improved.

Example 10 and Comparative Example 10 The original film 150 μ prepared in Example 1 was processed by Toyo Seiki's biaxial stretching tester No586, 3.3 times length × width 3.
A film which was stretched 3 times (15 μ after stretching) and heat-treated at 160 ° C. for 1 minute was produced as a trial. This is dry laminated,
It is a multilayer film, and its constitution is from the outer layer to biaxially stretched nylon (ON) 15μ / the above stretched film 15μ / non-stretched P
P film (CPP) is 60μ. The brand is ON: Emblem RT manufactured by Unitika Ltd., CPP is RxC-7 manufactured by Tohcello Chemical Co., Ltd., and the adhesive is Takelac A385 / Takenate A-50 series manufactured by Takeda Pharmaceutical Co., Ltd. When this was used as a pouch, water was added as the content, and retort was carried out at 130 ° C. for 30 minutes. As a result, there was no delamination and the appearance was good (Example 10). When a raw material containing no metal salt of Group II of the periodic table of Comparative Example 1 was used and retorted in the same manner, delamination occurred in 4 out of 10 pieces and the appearance was poor (Comparative Example 10).

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a film or a multi-layer structure having a good appearance with less generation of gel and the like even after running for a long time.

Claims (2)

[Claims] 1. An ethylene-content 20-65 mol%, 40-97% by weight of an ethylene-vinyl alcohol copolymer resin having a saponification degree of 90% or more and a polyamide resin 60-3% by weight, and the total amount of the resin. On the other hand, a resin composition containing 0.01 to 0.1% by weight in total of at least two kinds of metal salts of Group II of the Periodic Table converted to the metals. 2. Water vapor transmission rate (measured at 40 ° C. and 90% RH)
The outer layer (A) having a value of 40 g / m ² · day or more,
A package comprising an intermediate layer (B) made of the resin composition according to claim 1 and an inner layer (C) having a moisture permeability of 20 g / m ² · day or less.