JP2000026689A - Resin composition and its manufacture and use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition, which is capable of forming a film having excellent processability and gas barrier property by including a saponified product of an ethylene-vinyl acetate copolymer, a salt of an alkaline earth metal salt of a fatty acid, and a water-swelling, layer-structured inorganic compound wherein the alkaline earth metal salt of the fatty acid is contained in a specified amount in terms of the alkaline earth metal. SOLUTION: A resin composition comprises 100 parts by weight of a saponified product of an ethylene-vinyl acetate copolymer, an alkaline earth metal salt of a fatty acid, such as calcium acetate, used in an amount of 10 to 1,000 ppm of the composition when calculated in terms of the alkaline earth metal, and not greater than 30 parts by weight of a water-swelling, layer-structured inorganic compound. The water-swelling layer-structured inorganic compound has a swell of 30 ml/g or over relative to a mixed solvent of water/alcohol = 70/30 on the weight basis at 20 deg.C, and includes a clay mineral such as smectite or the like, and a fluorine mica mineral such as Na-type taeniolite or the like. The saponified product of the ethylene- vinyl acetate copolymer should preferably have an ethylene content of 10 to 60 mole %, a degree of saponification of 80 mole % or over, and a melt index of 0.5 to 50 g/10 minutes (210 deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) resin composition containing a water-swellable layered inorganic compound, a method for producing the same, and a use thereof. More specifically, the present invention relates to a resin composition having excellent gas barrier properties and processability, a method for producing the same, and uses thereof.

[0002]

2. Description of the Related Art In general, saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) is excellent in transparency, antistatic property, oil resistance, solvent resistance, gas barrier property, fragrance retention property and the like. It is a thermoplastic resin that can be melt-molded and is used for various packaging materials such as food packaging. However, such an EVOH has a drawback that gas barrier properties and mechanical properties are greatly changed by changes in the environment such as external humidity and temperature. On the other hand, in recent years, a blend of EVOH and a water-swellable inorganic compound has been receiving attention for the purpose of improving gas barrier properties. For example, Japanese Patent Application Laid-Open No. 5-39392 discloses that Describes mixing EVOH with a water-swellable phyllosilicate.

[0003]

However, as a result of a detailed study conducted by the present inventor, in the above-described disclosed technology, since water-swellable phyllosilicate is charged in the presence of water, so-called mamaco is likely to be generated. Therefore, it cannot be uniformly dispersed, and it has been found that a considerable amount of time is required for uniform dispersion. In addition, a blend of EVOH and a water-swellable phyllosilicate tends to thicken over time. However, it has been found that there is a problem that a large amount of stagnation is generated during extrusion processing, and that streaks and the like are generated in the molded product, which is not yet satisfactory. Further, when the resin composition obtained by the disclosed technique is formed into a film by extrusion, there is a problem that a difference occurs in gas barrier properties between the film at the time of startup and the film after long-run molding for several hours. There was found. Under such a background, in the present invention, in the present invention, a resin composition which is excellent in processability, and a film excellent in gas barrier property is obtained stably, and a method for producing the same,
It is intended to provide its use.

[0004]

Means for Solving the Problems Accordingly, the present inventor has conducted intensive studies in view of the above circumstances, and has found that EVOH
(A), an alkaline earth metal fatty acid salt (B) and a water-swellable layered inorganic compound (C), and the content of the alkaline earth metal fatty acid salt (B) is based on the entire resin composition. As a result, the present inventors have found that a resin composition having an alkaline earth metal equivalent of 10 to 1000 ppm satisfies the above object and completed the present invention.

In the present invention, when a resin composition containing EVOH (A), an alkaline earth metal fatty acid salt (B) and a water-swellable layered inorganic compound (C) is produced,
The water-swellable layered inorganic compound (C) is converted to water / alcohol = 0
/ 100 to 50/50 (weight ratio), and then further added water to make water / alcohol = 90/10
After adjusting the water-swellable layered inorganic compound (C) by adjusting the weight ratio to about 51/49 (weight ratio), the resin composition (I) obtained by mixing the EVOH (A) is mixed with an alkaline earth metal. Water / alcohol = 90/10 to 51/49 before the method for producing a resin composition in which EVOH (D) containing fatty acid salt (B) is mixed, particularly when EVOH (A) is mixed.
A manufacturing method of mixing an EVOH (A) solution dissolved in a (weight ratio) mixed solvent is preferable, and the effect of the present invention is remarkably exhibited.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The EVOH (A) used in the present invention is not particularly limited, but preferably has an ethylene content of 10 to 60 mol% and a degree of saponification of 80 mol% or more. The ethylene content is preferably from 20 to 50 mol% and the degree of saponification is preferably at least 90 mol%. Ethylene content is 1
If the amount is less than 0 mol%, the gas barrier property and the melt moldability at high humidity decrease, and if it exceeds 80 mol%, a sufficient gas barrier property cannot be obtained, which is not preferable. On the other hand, when the saponification degree is less than 80 mol%, the gas barrier property, heat stability and moisture resistance are undesirably reduced.

The EVOH (A) preferably has a melt index (MI) of 0.5 to 50 g / 10 min (210 ° C.), more preferably 1 to 35 g / 10 min (210 ° C.).
C). The melt index (M
If I) is smaller than the above range, the inside of the extruder will be in a high torque state during molding and extrusion processing will be difficult, and if it is larger than this range, the mechanical strength of the molded product will be insufficient. Not preferred.

The EVOH (A) is obtained by saponification of an ethylene-vinyl acetate copolymer, and the ethylene-vinyl acetate copolymer can be produced by any known polymerization method, for example, suspension polymerization, emulsion polymerization. , A solution polymerization or the like, and saponification of an ethylene-vinyl acetate copolymer can be carried out by a known method.

The EVOH (A) may be propylene, isobutene, α-octene, α-octane in a small amount as long as characteristics such as transparency, gas barrier properties and solvent resistance are not impaired.
Α-olefins such as dodecene and α-octadecene, unsaturated carboxylic acids or salts thereof, partial alkyl esters, complete alkyl esters, unsaturated sulfonic acid compounds, (meth) acrylonitrile, (meth) acrylamide, vinyl ether, vinyl silane compounds, chloride Comonomers such as vinyl and styrene may be included as copolymer components. Further, post-modification such as urethanization, acetalization, and cyanoethylation may be performed as long as the gist of the present invention is not impaired.

The alkaline earth metal fatty acid salt (B) includes, for example, acetates such as calcium acetate and magnesium acetate, and other long-chain fatty acid salts. Preferably, calcium acetate and magnesium acetate are used. Is done. Alternatively, these can be used alone or in combination. The content of the alkaline earth metal fatty acid salt (B) is 10 to 1000 p in terms of alkaline earth metal with respect to the entire resin composition.
pm, preferably 20 to 500 ppm, more preferably 30 to 200 ppm. If the content of the alkaline earth metal fatty acid salt (B) is less than 10 ppm, the thermal stability becomes insufficient, so that there is no effect on long-run molding, and
If it exceeds 00 ppm, the melt moldability becomes insufficient and the effect of the present invention is not exhibited.

In the present invention, as a method for containing an alkaline earth metal fatty acid salt (B) in a resin composition, a method for containing an alkaline earth metal fatty acid salt (B) in an arbitrary shape as it is, and the method described later. As described above, the alkaline earth metal fatty acid salt (B) is contained in EVOH, and the EVOH (D) containing the alkaline earth metal fatty acid salt (B) is EVOH (D).
There is also a method in which (A) and the water-swellable layered inorganic compound (C) are contained. About such EVOH, the above EVOH
Any of the same EVOHs as in (A) can be used.

The water-swellable layered inorganic compound (C) used in the present invention is not particularly limited, and includes clay minerals such as smectite and vermiculite, and synthetic mica. Specific examples of the former smectite are given below. Examples include montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stevensite and the like. These may be natural or synthetic. Among these, smectite, particularly montmorillonite is preferred. Further, water-swellable fluoromica-based minerals such as Na-type tetrasilicon mica, Na-type teniolite, Li-type teniolite, and Na-type hectorite are also preferably used.

The swelling power of the water-swellable layered inorganic compound (C) is at least 30 ml / 2 g, preferably 40 ml / 2 g, at 20 ° C. in a mixed solvent of water / alcohol = 70/30 (weight ratio). Above, more preferably, 50 ml
/ 2 g or more, and if it is less than 30 ml / 2 g, the gas barrier property becomes insufficient, which is not preferable. still,
The swelling power of the water-swellable layered inorganic compound (C) is measured by the standard test method volumetric method of the Japan Bentonite Industry Association.

The amount of the water-swellable layered inorganic compound (C) is preferably not more than 30 parts by weight, more preferably from 0.5 to 100 parts by weight of EVOH (A).
20 parts by weight, particularly preferably 1 to 15 parts by weight. If the amount is more than 30 parts by weight, the melt moldability becomes poor, which is not preferable.

Thus, the resin composition of the present invention is obtained from the EVOH (A), the alkaline earth metal fatty acid salt (B) and the water-swellable layered inorganic compound (C). The method for producing the resin composition is as follows. Is not particularly limited. For example, E
Among the VOH (A), the alkaline earth metal fatty acid salt (B), and the water-swellable layered inorganic compound (C), any two components may be mixed, and the remaining components may be mixed, or the three components may be mixed at once. An EV containing an alkaline earth metal fatty acid salt (B) instead of mixing the alkaline earth metal fatty acid salt (B)
It is appropriately selected and used such as mixing as OH (D).

As a method for obtaining such EVOH (D), a method of mixing an alkaline earth metal fatty acid salt (B) in a desired form with EVOH powder, pellets, and granules is provided.
At any stage during the production of EVOH, ie during polymerization, during saponification,
At the time of the post-treatment and at the time of drying, a method in which a predetermined amount of the alkaline earth metal fatty acid salt (B) is contained, a method in which EVOH is impregnated in the alkaline earth metal fatty acid salt (B), and the like are exemplified. In addition, the alkaline earth metal fatty acid salt (B) is adjusted by neutralizing the alkali used in the saponification step with a fatty acid (acetic acid or the like) to reduce the amount of the alkaline earth metal fatty acid salt (B) by-produced by water washing or the like. It is also possible to adjust by a drying process or the like. However, it is not limited to these.

Further, the EVOH (A), the EVOH (D) containing the alkaline earth metal fatty acid salt (B) or the alkaline earth metal fatty acid salt (B), and the water-swellable layered inorganic compound (C) are mixed. In that case, it is also preferable to dissolve and mix in a mixed solvent such as water-alcohol.

Further, in the present invention, the water-swellable layered inorganic compound (C) is prepared by adding water / alcohol = 0/100 to 50/50.
(Weight ratio), and water was further added to adjust the water / alcohol ratio to 90/10 to 51/49 (weight ratio) to swell the water-swellable layered inorganic compound (C). After that, a production method of mixing EVOH (D) containing an alkaline earth metal fatty acid salt (B) with a resin composition (I) obtained by mixing EVOH (A) is preferable, and mamako is generated. Without dispersing them uniformly, and the effect of the present invention is remarkably exhibited. Particularly preferably, water / alcohol = 90/10 to 51/49 in advance
It is preferable to mix an EVOH (A) solution dissolved in a (weight ratio) mixed solvent.

Hereinafter, a preferred method for producing the resin composition of the present invention will be described in detail. First, the water-swellable layered inorganic compound (C) is dispersed in a mixed solvent of water / alcohol. water/
The mixed solvent of alcohol is water / alcohol = 0 / 100-
50/50 (weight ratio), preferably 20/80 to 40 /
60 (weight ratio) is used. If the mixing ratio of water / alcohol is out of the above range, the dispersibility becomes poor and the effect of the present invention is not exhibited. As the alcohol, isopropyl alcohol, n-propyl alcohol, methanol, ethanol and the like are used.

Next, water is further added, and water / alcohol = 90/10 to 51/49 (weight ratio), preferably 80/50.
/ 20-60 / 40 (weight ratio) to swell the water-swellable layered inorganic compound (C),
(A) is mixed. If the ratio of water / alcohol at this time is out of the range of 90/10 to 51/49 (weight ratio), EV
The solubility of OH (A) becomes insufficient.

In the present invention, when mixing EVOH (A), it may be added in the form of pellets or powder,
There is a method of dissolving VOH (A) in a mixed solvent of water / alcohol and adding it as an EVOH (A) solution. Above all, it is preferable to add as an EVOH (A) solution from the viewpoint of compatibility.
(A) The composition of a water / alcohol mixed solvent for forming a solution is dissolved using a mixed solvent having the same composition ratio in the range of water / alcohol = 90/10 to 51/49 (weight ratio). Is preferred. When added as an EVOH (A) solution, it is desired to adjust the concentration to 5 to 30% by weight, preferably 10 to 20% by weight.

Incidentally, water / alcohol = 9 was further added by adding water.
After adjusting to 0/10 to 51/49 (weight ratio), the mixture is usually stirred at 20 to 60 ° C. for about 0.5 to 4 hours,
The water-swellable layered inorganic compound (C) can be swelled.

The resin solution thus obtained is discharged into cold water at about 5 to 25 ° C., or the container containing the resin solution is cooled with ice water to precipitate as a resin composition.
It is dried to obtain the resin composition (I). The drying is not particularly limited, and is performed by air drying, hot air drying, infrared drying, vacuum drying, or the like. Further, EVOH (D) containing an alkaline earth metal fatty acid salt (B) is mixed with the obtained resin composition (I) to obtain the resin composition of the present invention. At the time of mixing, EVOH (D) is appropriately selected such as dry blending, blending in the form of a solution, or blending in a molten state.

The resin composition of the present invention contains other thermoplastic resins (polyolefins, polyamides, polyesters, polystyrenes, etc.) as long as the object of the present invention is not impaired.
EVOH, etc.), a plasticizer, a heat stabilizer, an ultraviolet absorber, an antioxidant, a coloring agent, a filler, a drying agent, an antistatic agent, and the like. In addition, as an anti-gelling agent, hydrotalcite compounds, hindered phenol compounds,
A hindered amine heat stabilizer and a metal salt of a higher aliphatic carboxylic acid can also be added.

Thus, the resin composition of the present invention is frequently used for molded articles, and is formed into pellets, films, sheets, containers, fibers, rods, pipes, various molded articles, etc. by melt molding or the like. Pulverized products (such as when reused products are reused) or pellets can be used for melt molding again. As the melt molding, an extrusion molding method (T-die extrusion,
Inflation extrusion, blow molding, melt spinning, profile extrusion, etc.) and injection molding are mainly employed. The melt molding temperature is often selected from the range of 150 to 250 ° C.

The resin composition of the present invention can be used for a molded product as described above. In particular, the resin composition may be used as a laminate in which a thermoplastic resin layer is laminated on at least one surface of a layer made of the resin composition. Preferably, a laminate suitable for practical use is obtained.

In producing the laminate, another substrate is laminated on one or both sides of the layer of the resin composition of the present invention. Examples of the lamination method include the following methods. However, it is not limited to these.

Solution coating method A water-alcohol (or solvent) -containing solution of the resin composition is thermoplastically coated by a known method such as a roller coating method such as a Meyer bar, gravure and reverse roll method, a spray coating method, a dip coating method and the like. A laminate is prepared by coating a resin film. afterwards,
Drying is performed by a known method. For example, when the drying temperature is 40 to 180 ° C, preferably about 60 to 140 ° C,
What is necessary is just to heat for about 2 to 5 minutes. In this drying, the volatile components (water, alcohol or solvent) in the coating film are removed, and the drying is usually performed until the volatile component becomes 2% by weight or less. In order to improve the adhesive strength between the resin composition layer of the present invention and the thermoplastic resin film, a usual anchor coating agent (polyurethane, polyester or the like) may be previously coated on the film.

Extrusion coating method A thermoplastic resin is melt-extruded on a film or sheet of the resin composition of the present invention to produce a laminate. Conversely, the resin composition of the present invention is melt-extruded on a base material such as a thermoplastic resin to prepare a laminate.

Extrusion Molding Method The resin composition of the present invention is extruded alone or coextruded with another thermoplastic resin to produce a laminate. In the case of co-extrusion, as a counterpart resin, linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ionomer, ethylene-propylene copolymer, ethylene-acryl Acid ester copolymer, polypropylene, propylene
α-olefin (α-olefin having 4 to 20 carbon atoms) copolymer, homo- or copolymer of olefin such as polybutene, polypentene, or homo- or copolymer of these olefins with unsaturated carboxylic acid or ester thereof Broadly defined polyolefin resins such as graft-modified resins, polyesters, polyamides, copolymerized polyamides, polyvinyl chloride, polyvinylidene chloride, acrylic resins, polystyrene resins, vinyl ester resins, polyester elastomers, polyurethane elastomers, chlorinated polyethylene Chlorinated polypropylene, EVOH and the like. Among the above, polypropylene, polyamide, polyethylene, ethylene-vinyl acetate copolymer, polystyrene, polyethylene terephthalate, etc. are preferably used from the viewpoint of ease of coextrusion film formation and practicality of film physical properties (particularly strength). In the case of co-extrusion, the resin composition of the present invention is a thermoplastic resin, the thermoplastic resin is blended with the resin composition of the present invention, or at least one of the resin composition and the thermoplastic resin of the present invention has a surface of both layers. In some cases, a resin for improving the adhesiveness is blended.

As another laminating method described above, a film or sheet of the resin composition of the present invention and a film or sheet of another base material may be bonded to a known adhesive such as an organic titanium compound, an isocyanate compound, a polyester compound or a polyurethane compound. Laminates can also be made by laminating with an agent. Among them, the extrusion molding method is advantageous in that stable production is possible.

Further, a molded product such as a film or a sheet is once obtained from the resin composition of the present invention, and another substrate is extrusion-coated on this, or a film or sheet of another substrate is formed by using an adhesive. When laminating, any substrate (paper, metal foil, uniaxially or biaxially oriented plastic film or sheet, woven fabric, nonwoven fabric, metal cotton strip, wood surface, etc.) other than the above-mentioned thermoplastic resin can be used. .

As for the layer structure of the laminate, the layer of the resin composition of the present invention is a (a1, a2,...), And another base material, for example, a thermoplastic resin layer is b (b1, b2,...).・)
In the case of a film, a sheet, or a bottle, not only a two-layer structure of a / b but also b / a / b, a / b / a, a1 / a2 /
Any combination such as b, a / b1 / b2, b2 / b1 / a / b1 / b2 is possible. In the filament form, a and b are bimetal type, core (a) -sheath (b) type, core ( b)-sheath (a)
Any combination such as a mold or an eccentric sheath-core type is possible.

The above-mentioned resin composition or laminate is used as it is in various shapes. However, it is preferable that the resin composition or the laminate is subjected to a stretching treatment in order to improve physical properties. Either method may be used, and it is better to perform stretching at the highest possible magnification in terms of physical properties.

The stretching method includes a roll stretching method, a tenter stretching method, a tubular stretching method, a stretching blow method, and the like.
Those having a high draw ratio such as deep drawing and vacuum forming can also be used. In the case of biaxial stretching, any of a simultaneous biaxial stretching method and a sequential biaxial stretching method can be adopted. Stretching temperature is 80-1
70 ° C, preferably selected from the range of about 100 to 160 ° C.

After completion of the stretching, heat setting is performed. The heat setting can be performed by a well-known means, and heat treatment is performed at 80 to 170 ° C., preferably 100 to 160 ° C. for about 2 to 600 seconds while keeping the stretched film in a tensioned state. Also, the obtained stretched film, if necessary, cooling, rolling, printing, dry lamination,
Solution or melt coating processing, bag making processing, deep drawing processing, box processing, tube processing, split processing, and the like can be performed.

The shape of a molded article such as a laminate thus obtained may be arbitrary, and examples thereof include a film, a sheet, a bottle, a pipe, a filament, and an extrudate having a modified cross section. The films, sheets, containers, and the like obtained as described above are useful as various packaging materials such as general foods, retort foods, pharmaceuticals, industrial chemicals, and agricultural chemicals.

The resin composition of the present invention comprises EVOH (A),
Since it is composed of a specific amount of the alkaline earth metal fatty acid salt (B) and the water-swellable layered inorganic compound (C), it exerts excellent effects on processability and gas barrier properties of the film during long run molding.

[0039]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” mean on a weight basis unless otherwise specified.

Example 1 120 parts of isopropyl alcohol was placed in a 5 liter container, and then natural montmorillonite was used as a water-swellable layered inorganic compound (C) [swelling power was water / isopropyl alcohol = 70/30 (weight ratio). 67ml /
2 g] and stirred to obtain a dispersion liquid (a).

Further, 280 parts of water was gradually added thereto, and 4
After stirring at 0 ° C. for 2 hours to swell (C), EVOH
(A1) (Ethylene content 30 mol%, saponification degree 99.
100 parts of pellets having 6 mol% and a melt index (MI) of 8 g / 10 min (210 ° C., load 2160 g) were added and stirred at 90 ° C. for 2 hours to completely dissolve. Next, the obtained solution was poured into 700 parts of cold water (5 ° C.) to precipitate a resin composition, followed by vacuum drying.

EVOH (D1) containing calcium acetate (ethylene content 35 mol%, saponification degree 99.8 mol%, melt index (MI) 3 g) was added to 100 parts of the resin composition obtained by drying. / 10 minutes (210 ° C., load 2160 g), 100 parts of EVOH and a calcium acetate content of 200 ppm in terms of calcium were mixed to obtain a resin composition of the present invention. (The content of the alkaline earth metal salt was 310 ppm in total with respect to the entire resin composition in terms of alkaline earth metal.)

The method for quantifying the alkaline earth metal was as follows. (Alkaline earth metal) About 80 g of the dried sample is precisely weighed,
About 10 g of the mixture was placed in a constant weight platinum evaporation dish and carbonized with an electric heater. Next, the mixture was heated with a gas burner and baked until smoke disappeared. The platinum evaporating dish was placed in an electric furnace at about 400 ° C., covered with a magnetic crucible lid, and gradually heated to 700 ° C. It was kept at 700 ° C. for 3 hours for complete incineration. 2 ml of special grade hydrochloric acid and 3 ml of pure water were put in a platinum crucible and dissolved by heating with an electric heater. 50 ml of the above solution
Pure water was poured into a volumetric flask, and pure water was further added up to the marked line to obtain a sample for atomic absorption analysis.

Separately, atomic absorbance was measured using the prepared standard solution (1 ppm alkaline earth metal, 0.5 N hydrochloric acid) as a control solution, and the amount of alkaline earth metal was determined from the ratio of the absorbance. The measurement conditions are as follows. Instrument: Hitachi 180-30 Atomic absorption / flame light spectrophotometer Wavelength: 422.7 nm (calcium) 285.2
nm (magnesium) Frame: acetylene-air

The obtained resin composition was supplied to a single-screw extruder, and a film was formed by a T-die casting method under the conditions of an extruder set temperature of 210 ° C. to obtain a film having a thickness of 30 μm. The film was evaluated as follows.

(Workability) In the film forming process, the occurrence of streaks on the film was observed and evaluated according to the following criteria.・ ・ ・: No streak occurred even after 3 hours of processing. ×: Streaks occurred within 3 hours of processing.

(Oxygen Permeability) The film obtained immediately after the start of film formation and the film obtained 5 hours after the start of the film formation were subjected to 20 ° C. using OXTRAN manufactured by MOCON.
The measurement was performed under the conditions of 100% RH, and the ratio (S2 / S) of the oxygen permeability (S2) of the film obtained 5 hours after the start and the oxygen permeability (S1) of the film obtained immediately after the start was obtained.
1) was evaluated.・ ・ ・: S2 / S1 is less than 1.5 ×: S2 / S1 is 1.5 or more

Example 2 A 5-liter container was charged with 150 parts of isopropyl alcohol and 1 part of water.
50 parts, and then a water-swellable layered inorganic compound (C)
5 parts of natural montmorillonite [the swelling power is 67 ml / 2 g with respect to a mixed solvent of water / isopropyl alcohol = 70/30 (weight ratio)], and the mixture is stirred and dispersed.
I got Further, 100 parts of water was gradually added thereto,
After swelling (C) by stirring for 2 hours with EVOH (A
2) (Ethylene content 30 mol%, saponification degree 99.6 mol%, melt index (MI) 3 g / 10 min (21
500 parts of a water-alcohol mixed solution (concentration 20%, water / alcohol = 50/50 (weight ratio)) at 0 ° C. under a load of 2160 g) was added thereto, and the mixture was stirred at 90 ° C. for 2 hours to completely dissolve. Next, the obtained solution was mixed with 700 parts of cold water (5 parts).
C.) to precipitate the resin composition, followed by vacuum drying.

EVOH (D2) containing magnesium acetate was added to 100 parts of the resin composition obtained by drying.
(Ethylene content 35 mol%, degree of saponification 99.8 mol%, melt index (MI) 3 g / 10 min (210
° C, load 2160 g), and the content of magnesium acetate with respect to EVOH is 50 ppm in terms of magnesium).
0 parts were mixed to obtain a resin composition of the present invention. (The content of the alkaline earth metal salt was 345 ppm in terms of alkaline earth metal relative to the entire resin composition.) The same evaluation as in Example 1 was performed on the obtained resin composition.

Example 3 In Example 1, the water-swellable layered inorganic compound (C) was Na-type tetrasilicon mica [swelling power was 96 ml with respect to a mixed solvent of water / isopropyl alcohol = 70/30 (weight ratio)]. / 2g], except that 2 parts were used, and evaluation was performed in the same manner as in Example 1.

Comparative Example 1 In Example 1, EVOH containing calcium acetate was used.
Without mixing (D1), EVOH (A1) and water-swellable layered inorganic compound (C) were mixed with water / isopropyl alcohol = 2
Evaluation was performed in the same manner as in Example 1 except that the mixture was mixed in a mixed solvent of 80 parts / 120 parts.

Comparative Example 2 In Example 1, EVOH containing calcium acetate was used.
(Ethylene content 35 mol%, degree of saponification 99.8 mol%, melt index (MI) 3 g / 10 min (210
° C, load 2160 g), and the content of calcium acetate with respect to EVOH is 1300 ppm in terms of calcium.
Evaluation was performed in the same manner as in Example 1 except that 0 parts were mixed. (The content of the alkaline earth metal salt is 1100 pp with respect to the entire resin composition in terms of alkaline earth metal.
m)

Comparative Example 3 In Example 1, no natural montmorillonite was added.
The same procedure was performed except that a film was formed using a resin composition comprising EVOH (A1) and calcium acetate (the content of an alkaline earth metal salt was 160 ppm based on the entire resin composition in terms of alkaline earth metal). Evaluation was performed in the same manner as in Example 1. Table 1 shows the results of Examples and Comparative Examples.

[0054]

[Table 1] Immediately after the start of oxygen permeability (cc / m ² · day · atm) Five hours after start Ratio Evaluation workability (S1) (S2) (S2 / S1) Example 1 ○ 9 9 1 ○ ○ 2 ○ 9 9 1 ○ 〃 3 ○ 9 9 1 ○ Comparative Example 1 × 17 31 1.8 × 〃 2 × 2 360 2.6 × 〃 3 ○ 19 30 1.6 ×

[0055]

EFFECT OF THE INVENTION The resin composition of the present invention comprises EVOH
(A) Since it is composed of a specific amount of an alkaline earth metal fatty acid salt (B) and a water-swellable layered inorganic compound (C), it is excellent in workability of a film, a sheet, etc., and furthermore, gas barrier property of the film in long run molding It shows an excellent effect. These resin compositions are provided in films, sheets, containers, and the like, and are useful as various packaging materials such as general foods, retort foods, pharmaceuticals, industrial chemicals, and agricultural chemicals.

Claims (8)

[Claims] An alkaline earth metal comprising a saponified ethylene-vinyl acetate copolymer (A), an alkaline earth metal fatty acid salt (B) and a water-swellable layered inorganic compound (C). A resin composition characterized in that the content of the fatty acid salt (B) is 10 to 1000 ppm in terms of alkaline earth metal relative to the entire resin composition. 2. The resin according to claim 1, wherein the saponified ethylene-vinyl acetate copolymer (A) has an ethylene content of 10 to 60 mol% and a saponification degree of 80 mol% or more. Composition. 3. The water-swellable layered inorganic compound (C) contains 20
It has a swelling power of 30 ml / 2 g or more (measurement standard: Japan Bentonite Industry Association Standard Test Method Volumetric Method) with respect to a mixed solvent of water / alcohol = 70/30 (weight ratio) at ℃. 3. The resin composition according to 1 or 2. 4. The resin composition according to claim 1, wherein the water-swellable layered inorganic compound (C) is smectite or a water-swellable fluoromica-based mineral. 5. A saponified ethylene-vinyl acetate copolymer (A) having a water-swellable layered inorganic compound (C) content of 10%.
The resin composition according to any one of claims 1 to 4, wherein the amount is 30 parts by weight or less based on 0 part by weight. 6. A method for producing a resin composition comprising a saponified ethylene-vinyl acetate copolymer (A), an alkaline earth metal fatty acid salt (B) and a water-swellable layered inorganic compound (C). After dispersing the water-swellable layered inorganic compound (C) in a mixed solvent of water / alcohol = 0/100 to 50/50 (weight ratio), water is further added, and water / alcohol = 90/10. ~ 51/49 (weight ratio)
After swelling the water-swellable layered inorganic compound (C), the resin composition (I) obtained by mixing the saponified ethylene-vinyl acetate copolymer (A) is added to the alkaline earth metal fatty acid salt (B). A method for producing a resin composition, comprising mixing a saponified ethylene-vinyl acetate copolymer (D) containing 7. Water / alcohol = 90/10 to 5 in advance
Ethylene dissolved in a 1/49 (weight ratio) mixed solvent
The method for producing a resin composition according to claim 6, wherein a solution of the saponified vinyl acetate copolymer (A) is mixed. 8. A laminate comprising at least one layer of the resin composition according to claim 1.