JP2000063607A - Resin composition, its production, and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition having excellent moldability and giving a film excellent in gas barrier properties by incorporating an ethylene-vinyl acetate copolymer saponificate with a phosphoric acid compound and a water- swellable layered inorganic compound. SOLUTION: This composition comprises 100 pts.wt. ethylene-vinyl acetate copolymer saponificate, 10-1,000 ppm, based on the entire composition, of phosphoric acid or a phosphoric acid compound such as an alkali metal hydrogenphosphate, at most 30 pts.wt. water-swellable layered inorganic compound, another thermoplastic resin, and additives such as a plasticizer, a heat stabilizer, an antioxidant, a filler, or an antistatic agent. The ethylene-vinyl acetate copolymer saponificate used is one having an ethylene content of 10-60 mol.%, a degree of saponification of at least 80 mol.%, and a melt index of 0.5-50 g/10 min (at 210 deg.C). The water-swellable layered inorganic compound is exemplified by smectite or vermiculite and has a swelling power of 30 ml/2 g at 20 deg.C in a mixed solvent having 70/30 wt.% water/alcohol weight ratio.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD 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 uses thereof. More specifically, it relates to a resin composition having excellent gas barrier properties and moldability, a method for producing the same, and its use.

[0002]

2. Description of the Related Art Generally, a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) is excellent in transparency, antistatic property, oil resistance, solvent resistance, gas barrier property, aroma retaining property and the like. In addition, it is a melt-moldable thermoplastic resin, and is used for various packaging material applications such as food packaging. However, such EVOH has a drawback that gas barrier properties and mechanical properties are greatly changed due to environmental changes 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 attracting attention for the purpose of improving gas barrier properties. For example, JP-A-5-39392 discloses the presence of water. Describes mixing EVOH with a water-swellable phyllosilicate.

[0003]

However, as a result of a detailed study by the present inventor, in the above disclosed technology, since the water-swelling phyllosilicate is added in the presence of water, so-called Mamako tends to occur, Therefore, it was found that it could not be uniformly dispersed, and that it took a considerable amount of time to be uniformly dispersed, and that a blend of EVOH and a water-swellable phyllosilicate was likely to thicken with time. However, it was found that there is a problem that a lot of stagnant matters are generated during extrusion and streaks, fish eyes, coloring, etc. are generated on the molded article during long-run molding, which is not yet satisfactory. Further, when a resin composition obtained by the technique disclosed in the publication is formed into a film by extrusion, there is a problem that a gas barrier property of the film at the time of start-up differs from the gas barrier property of the film after long-run molding for several hours. There was found. Therefore, under such a background, in the present invention,
It is an object of the present invention to provide a resin composition which is excellent in molding processability and which can stably obtain a film excellent in gas barrier property, a method for producing the same, and an application thereof.

[0004]

[Means for Solving the Problems] Therefore, the present inventor has conducted extensive studies in view of the above circumstances, and as a result, EVOH
The present invention was completed by finding that a resin composition containing (A), a phosphoric acid compound (B) and a water-swellable layered inorganic compound (C) meets the above object.

In the present invention, in producing a resin composition containing EVOH (A), a phosphoric acid compound (B) and a water-swellable layered inorganic compound (C), a water-swellable layered inorganic compound (C) is used. Water / alcohol = 0/100 to 50 /
After dispersing in a mixed solvent of 50 (weight ratio), water is further added to adjust water / alcohol = 90/10 to 51/49 (weight ratio) to obtain a water-swellable layered inorganic compound (C). The resin composition (1) obtained by mixing the EVOH (A) after swelling the EVOH containing the phosphoric acid compound (B)
Method for producing resin composition by mixing (D), especially EVO
Before mixing H (A), water / alcohol =
A production method of mixing an EVOH (A) solution dissolved in a mixed solvent of 90/10 to 51/49 (weight ratio) is preferable, and the effect of the present invention is remarkably exhibited.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. 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 saponification degree of 80 mol% or more. The ethylene content is preferably 20 to 50 mol% and the saponification degree is preferably 90 mol% or more. Ethylene content is 1
If it is less than 0 mol%, the gas barrier property at high humidity and the melt moldability are deteriorated, and if it exceeds 60 mol%, sufficient gas barrier property cannot be obtained, which is not preferable. If the saponification degree is less than 80 mol%, the gas barrier property, heat stability, and moisture resistance will deteriorate, which is not preferable.

Further, the melt index (MI) of the EVOH (A) is preferably 0.5 to 50 g / 10 minutes (210 ° C.), more preferably 1 to 35 g / 10 minutes (210).
C.) is preferred. The melt index (M
When I) is smaller than the range, the inside of the extruder is in a high torque state at the time of molding, which makes extrusion difficult, and when larger than the range, mechanical strength of the molded product is insufficient. Not preferable.

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

Further, the EVOH (A) is propylene, isobutene, α-octene, α-, as long as it is in a small amount as long as the properties such as transparency, gas barrier property 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) acrylamides, vinyl ethers, vinylsilane compounds, chlorides It does not matter if a comonomer such as vinyl or styrene is contained as a copolymerization component. Further, post-modification such as urethanization, acetalization, cyanoethylation, etc. may be carried out within a range not impairing the gist of the present invention.

The phosphoric acid compound (B) is preferably contained in the resin composition in an amount of 10 to 1000 ppm, more preferably 20 to 500 ppm, and particularly preferably 20 to 150 ppm, in terms of phosphate radicals. If the content is less than 10 ppm, the effect of the present invention cannot be obtained, and if it exceeds 1000 ppm, fish eyes frequently occur in the molded product, resulting in poor appearance, which is not preferable.

Examples of the phosphoric acid compound (B) include phosphoric acid and alkali metal phosphates.
Specific examples of the alkali metal phosphates include alkali metal hydrogen phosphates and alkali metal second or third phosphates. The alkali metal hydrogen phosphates include sodium monohydrogen phosphate, Examples thereof include sodium dihydrogen phosphate, potassium monohydrogen phosphate, potassium dihydrogen phosphate, and the like, and sodium dihydrogen phosphate and potassium dihydrogen phosphate are more preferably used. Examples of the second or third alkali metal phosphate include dipotassium hydrogenphosphate, disodium hydrogenphosphate, tripotassium phosphate, and trisodium phosphate. These are used alone or in combination.

In the present invention, as a method of incorporating the phosphoric acid compound (B) into the resin composition, in addition to the method of incorporating the phosphoric acid compound (B) in an arbitrary shape as it is, a phosphoric acid compound ( B) is contained in EVOH, and as the EVOH (D) containing the phosphoric acid compound (B), EVO
There is also a method of incorporating H (A) and the water-swellable layered inorganic compound (C). For such EVOH, refer to the above EVOH
It is optionally used from EVOHs similar to (A).

The water-swellable layered inorganic compound (C) used in the present invention is not particularly limited, and examples thereof include clay minerals such as smectite and vermiculite, and synthetic mica. Specific examples of the former smectite include Examples thereof include montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite and stevensite. These may be natural or synthetic. Of these, smectite is preferable, and among them, montmorillonite is preferable. Further, water-swellable fluoromica-based minerals such as Na-type tetrafluorosilicon 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) at 20 ° C. is 30 ml / 2 g or more, preferably 40 ml / 2 g, in a mixed solvent of water / alcohol = 70/30 (weight ratio). More preferably, 50 ml
It is preferably not less than 2 g, and less than 30 ml / 2 g is not preferable because the gas barrier property is insufficient. still,
The swelling power of the water-swellable layered inorganic compound (C) is measured by the Japan Bentonite Industry Association standard test method volumetric method.

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

Thus, the resin composition of the present invention is obtained from EVOH (A), phosphoric acid compound (B) and water-swellable layered inorganic compound (C). Without limitation, for example, EVOH
(A), phosphoric acid compound (B), water-swellable layered inorganic compound (C), after mixing any two components, the remaining components are mixed, or the three components are mixed together, or phosphoric acid Instead of mixing the compound (B), it is appropriately selected and used, such as mixing as the EVOH (D) containing the phosphoric acid compound (B).

The EVOH (D) can be obtained by mixing the powder, pellets, and granules of EVOH with the phosphoric acid compound (B) in any form, at any stage during EVOH production, that is, during polymerization. Examples include a method of incorporating a predetermined amount of the phosphoric acid compound (B) during saponification, post-treatment, and drying, and a method of impregnating EVOH into the phosphoric acid compound (B). However, it is not limited to these.

Further, the EVOH (A), the phosphoric acid compound (B), or the EVOH containing the phosphoric acid compound (B).
When mixing (D) and the water-swellable layered inorganic compound (C), it is also preferable to dissolve and mix them in a mixed solvent such as water-alcohol.

Further, in the present invention, the water-swellable layered inorganic compound (C) is added to water / alcohol = 0/100 to 50/50.
After being dispersed in a mixed solvent (weight ratio), water is further added to adjust water / alcohol = 90/10 to 51/49 (weight ratio) to swell the water-swellable layered inorganic compound (C). Then, EVOH containing phosphoric acid compound (B) is added to resin composition (1) obtained by mixing EVOH (A).
A manufacturing method in which (D) is mixed is preferable, and it is possible to uniformly disperse without causing mamako, and the effect of the present invention is remarkably exhibited. Particularly preferably, in advance,
It is preferable to mix an EVOH (A) solution dissolved in a mixed solvent of water / alcohol = 90/10 to 51/49 (weight ratio).

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

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

Further, in the present invention, when EVOH (A) is mixed, it may be added in the form of pellets or powder, or may be mixed in advance with E
There is a method in which VOH (A) is dissolved in a mixed solvent of water / alcohol and added as an EVOH (A) solution. Among them, EVOH (A) solution is preferably added in terms of compatibility, and further, such EVOH
(A) Dissolve the composition of the water / alcohol mixed solvent to be a solution using the mixed solvent having the same composition ratio in the range of water / alcohol = 90/10 to 51/49 (weight ratio). Is preferred. When it is 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.

Water / alcohol = 9 by further adding water
After adjusting to 0/10 to 51/49 (weight ratio), usually by stirring at 20 to 60 ° C. for about 0.5 to 4 hours,
The water-swellable layered inorganic compound (C) can be swollen.

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 be deposited as a resin composition,
It is dried to obtain the resin composition (1). The drying is not particularly limited and may be air drying, hot air drying, infrared ray drying, vacuum drying, or the like. Furthermore, EVOH containing the phosphoric acid compound (B) in the obtained resin composition (1)
The resin composition of the present invention is obtained by mixing (D). At the time of mixing, EVOH (D) is appropriately blended, such as dry blending, blending in solution, blending in a molten state, and the like.

In the resin composition of the present invention, other thermoplastic resins (polyolefin, polyamide, polyester, polystyrene,
EVOH, etc.), a plasticizer, a heat stabilizer, an ultraviolet absorber, an antioxidant, a colorant, a filler, a desiccant, an antistatic agent and the like can also be added. Also, as a gelation inhibitor, hydrotalcite-based compounds, hindered phenol-based compounds,
It is also possible to add a hindered amine heat stabilizer and a metal salt of a higher aliphatic carboxylic acid.

Thus, the resin composition of the present invention is often used for molded articles, and is formed into pellets, films, sheets, containers, fibers, rods, tubes, various molded articles, etc. by melt molding and the like. It is also possible to use the pulverized product (such as when the recovered product is reused) or the pellet 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 methods are mainly adopted. 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 in the above-mentioned molded article, but in particular, it is 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 can be obtained.

In producing the laminate, another substrate is laminated on one side or both sides of the layer of the resin composition of the present invention. Examples of the laminating 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 thermoplastic by a known method such as a roller coating method such as a Meyer bar, a gravure and a reverse roll method, a spray coating method or a dip coating method. A resin film is coated to produce a laminate. afterwards,
Drying is performed by a known method. For example, the drying temperature is 40 to 180 ° C., preferably 60 to 140 ° C.
It may be heated for about 2 seconds to 5 minutes. Although the volatile components (water, alcohol or solvent) in the coating film are removed by such drying, it is usually carried out until the volatile components become 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 type, polyester type, etc.) may be coated on the film in advance.

Extrusion Coating Method A thermoplastic resin is melt-extruded into a film or sheet of the resin composition of the present invention to prepare a laminate. On the contrary, the resin composition of the present invention is melt-extruded on a base material such as a thermoplastic resin to produce a laminate.

Extrusion Molding Method The resin composition of the present invention is extruded alone or coextruded with another thermoplastic resin to prepare a laminate. In the case of coextrusion, the other resin is linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ionomer, ethylene-propylene copolymer, ethylene-acrylic. 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 its ester Polyolefin resin in a broad sense such as graft-modified, polyester, polyamide, copolyamide, polyvinyl chloride, polyvinylidene chloride, acrylic resin, polystyrene resin, vinyl ester resin, polyester elastomer, polyurethane elastomer, chlorinated polyethylene , Chlorinated polypropylene, EVOH and the like. Among the above, polypropylene, polyamide, polyethylene, ethylene-vinyl acetate copolymer, polystyrene, polyethylene terephthalate and the like are preferably used from the viewpoint of ease of coextrusion film formation and practicality of film physical properties (particularly strength). In the case of coextrusion, 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 resin that improves the adhesion may be blended.

As another laminating method described above, a film or sheet of the resin composition of the present invention and a film of another substrate may be adhered to a known adhesive of an organic titanium compound, an isocyanate compound, a polyester compound, a polyurethane compound or the like. It is also possible to laminate using an agent to produce a laminate. Among the above, the extrusion molding method is advantageous in that stable production is possible.

Further, a molded product such as a film or sheet is once obtained from the resin composition of the present invention, and another substrate is extrusion coated thereon, or the film or sheet of the other substrate is coated with an adhesive. When laminating, any base material (paper, metal foil, uniaxially stretched or biaxially stretched plastic film or sheet, woven cloth, non-woven cloth, metallic cotton strip, wood surface, etc.) can be used in addition to the thermoplastic resin. .

As the layer structure of the laminate, a layer of the resin composition of the present invention is a (a1, a2, ...) And another substrate, for example, a thermoplastic resin layer is b (b1, b2, ...).・)
If it is a film, sheet or bottle, not only a / b two-layer structure but also b / a / b, a / b / a, a1 / a2 /
b, a / b1 / b2, b2 / b1 / a / b1 / b2, etc. can be used in any combination. In the filament form, a and b are bimetal type, core (a) -sheath (b) type, core ( b) -sheath (a)
Any combination of a mold, an eccentric core-sheath type, and the like is possible.

The above-mentioned resin composition or laminate is used in various shapes as it is, but it is preferable to subject it to a stretching treatment in order to improve the physical properties. For such stretching, uniaxial stretching or biaxial stretching is used. Any of these may be used, and it is better in terms of physical properties to perform stretching at the highest possible ratio.

Examples of the stretching method include a roll stretching method, a tenter stretching method, a tubular stretching method and a stretching blow method.
It is also possible to employ materials with a high draw ratio such as deep drawing and vacuum forming. In the case of biaxial stretching, either simultaneous biaxial stretching method or sequential biaxial stretching method can be adopted. Stretching temperature is 80-1
It is selected from the range of 70 ° C, preferably about 100 to 160 ° C.

After the stretching is completed in this way, heat setting is then carried out. The heat setting can be carried out by a known means, and the stretched film is heat-treated at 80 to 170 ° C., preferably 100 to 160 ° C. for about 2 to 600 seconds while keeping the stretched state. Further, the obtained stretched film may be subjected to cooling treatment, rolling treatment, printing treatment, dry laminating treatment, as necessary.
Solution or melt coating treatment, bag making processing, deep drawing processing, box processing, tube processing, split processing and the like can be performed.

Molded articles such as laminates thus obtained may have any shape, and examples thereof include films, sheets, bottles, pipes, filaments, and modified cross-section extrudates. The film, sheet or container obtained as described above is useful as various packaging materials for general foods, retort foods, pharmaceuticals, industrial chemicals, agricultural chemicals and the like.

The resin composition of the present invention comprises EVOH (A),
Phosphoric acid compound (B) and water-swellable layered inorganic compound (C)
Therefore, it exhibits an excellent effect on the moldability and the gas barrier property of the film at the time of long-run molding.

[0040]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, "part" and "%" mean weight basis unless otherwise specified. Example 1 120 parts of isopropyl alcohol was placed in a 5 l container, and then natural montmorillonite was used as a water-swellable layered inorganic compound (C) [with respect to a mixed solvent of water / isopropyl alcohol = 70/30 (weight ratio). 67 ml /
2 g] 2 parts were added and stirred to obtain a dispersion liquid (a).

Further, 280 parts of water is 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 completely dissolved by stirring at 90 ° C. for 2 hours. Next, the obtained solution was poured into 700 parts of cold water (5 ° C.) to precipitate the resin composition, and vacuum drying was performed.

Based on 100 parts of the resin composition obtained by drying, EVOH (D1) containing phosphoric acid (B) (ethylene content 35 mol%, saponification degree 99.8 mol%, melt index ( MI) 3 g / 10 min (210 ° C., load 2160 g), 100 parts of phosphoric acid content with respect to EVOH was 100 ppm in terms of phosphate radical) were mixed to obtain a resin composition of the present invention. (The content of phosphoric acid was 50 ppm in terms of phosphate radicals based on the entire resin composition.)

The quantitative determination of phosphoric acid and alkali metal phosphate was carried out by the molybdenum blue (ascorbic acid) absorptiometry according to JIS K 0102. However, the sample was prepared by the following procedure. 1. 1 g of a sample is precisely weighed and put into a 300 ml Kjeldahl flask. 2. About 5 ml of pure water is added, and about 15 ml of concentrated sulfuric acid is gradually added dropwise. 3. Heat the Kjeldahl flask with a heater to remove water and sulfuric acid until just before it is dried. 4. After cooling, add about 5 ml of concentrated sulfuric acid, cover the mouth of the Kjeldahl flask with a funnel and heat again.

5. After white smoke began to fill the Kjeldahl flask, a few drops of concentrated sulfuric acid were gradually added, and after the Kjeldahl flask became brown with NOx gas, the dropping of sulfuric acid was stopped and it was replaced with white smoke. Continue heating. The operation of dropping sulfuric acid under heating is repeated several times. 6. After the solution in the Kjeldahl flask becomes colorless to yellowish green and transparent, the addition of sulfuric acid is stopped and the residual sulfuric acid and residual water in the solution are expelled. 7. Remove the funnel that covered the Kjeldahl flask mouth,
Ignite sulfuric acid by igniting until the remaining amount becomes 2-3 ml. ◎ Perform a blank test without adding (sample) separately.

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

(Processability) In film forming process, 3
The following items were evaluated by observing the appearance on the film after continuous molding for a certain time. The presence or absence of streaks was evaluated according to the following criteria: No streaks were observed even after 3 hours of processing. X: Generation of streaks was observed within 3 hours of processing.

Fish eye Presence / absence of fish eye (film size: 10 cm × 1
0 cm) was evaluated according to the following criteria. ○: less than 3 △: 4 to 20 × ... 21 or more

Coloring The presence or absence of coloring was evaluated according to the following criteria. ◯: No coloring was observed. B: Yellow coloring was slightly observed. X: Yellow coloring was severe and practically difficult to use.

(Oxygen permeability) A film obtained immediately after the start of film formation and a film obtained 5 hours after the start of film formation were subjected to OXTRAN manufactured by MOCON at 20 ° C.
At 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 measured.
It was evaluated according to 1). ○: S2 / S1 is less than 1.5 × ... S2 / S1 is 1.5 or more

Example 2 150 parts of isopropyl alcohol and 1 part of water in a 5 l container.
Add 50 parts and then water-swellable layered inorganic compound (C)
5 parts natural montmorillonite [swelling power is 67 ml / 2 g in a mixed solvent of water / isopropyl alcohol = 70/30 (weight ratio)] and stirred to disperse the liquid (b)
Got Further, 100 parts of water is gradually added thereto, and the temperature is 40 ° C.
After swelling (C) by stirring for 2 hours, 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)) of 0 ° C. and a load of 2160 g)) was added and completely dissolved by stirring at 90 ° C. for 2 hours. Next, 700 parts of cold water (5
(° C) and the resin composition was deposited and vacuum dried.

EVO containing sodium dihydrogen phosphate (B) was added to 100 parts of the resin composition obtained by drying.
H (D2) (ethylene content 35 mol%, saponification degree 9
9.8 mol%, melt index (MI) 3 g / 10
Min (210 ℃, load 2160g), the content of sodium dihydrogen phosphate to EVOH is 440 in terms of phosphate radical conversion
(ppm) was mixed with 300 parts to obtain a resin composition of the present invention. (The content of sodium dihydrogen phosphate was 110 ppm in terms of phosphate radicals based on the entire resin composition)
The resin composition thus obtained was evaluated in the same manner as in Example 1.

Example 3 The same procedure as in Example 1 was carried out except that the phosphoric acid was changed to disodium hydrogen phosphate, and the same evaluation as in Example 1 was carried out. (The content of disodium hydrogen phosphate was 60 ppm based on the phosphate group based on the whole resin composition)

Example 4 In Example 1, as the water-swellable layered inorganic compound (C), Na-type fluorine tetrasilicon mica [swelling power is 96 ml against a mixed solvent of water / isopropyl alcohol = 70/30 (weight ratio)] / 2 g] was performed in the same manner except that 2 parts were used, and the same evaluation as in Example 1 was performed.

Comparative Example 1 EVOH containing phosphoric acid (B) in Example 1
Without mixing (D1), EVOH (A1) and water-swellable layered inorganic compound (C) were added to water / isopropyl alcohol = 2.
The same evaluation as in Example 1 was carried out except that the mixed solvent was 80 parts / 120 parts.

Comparative Example 2 In Example 1, natural montmorillonite was not added,
A resin composition comprising EVOH (A1) and phosphoric acid (B) (content of phosphoric acid is 75 ppm in terms of phosphoric acid radical, based on the total amount of the resin composition) was carried out in the same manner except that a film was formed. Evaluation was performed in the same manner as in Example 1. The results of Examples and Comparative Examples are shown in Table 1.

[0056]

[Table 1] Appearance of film Oxygen permeability (cc / m ² · day · atm) Immediately after start 5 hours after start Ratio evaluation Streak Eye coloration (S1) (S2) (S2 / S1) Example 1 ○ ○ ○ 9 9 1.0 ○ 〃 2 ○ ○ ○ 9 9 1.0 ○ 〃 3 ○ ○ △ 9 9 1.0 1.0 〃 4 ○ △ △ △ 9 9 1.0 ○ Comparative Example 1 ○ × × 9 9 1.0 ○ 〃 2 × × △ 17 31 1.8 ×

[0057]

INDUSTRIAL APPLICABILITY The resin composition of the present invention is EVOH
Since it is composed of (A), a phosphoric acid compound (B) and a water-swellable layered inorganic compound (C), it has excellent processability for forming films, sheets, etc., and also has an excellent effect on the gas barrier property of the film during long-run molding. It is shown. These resin compositions are provided in films, sheets, containers, etc., and are useful as various food packaging materials such as general foods, retort foods, pharmaceuticals, industrial chemicals, and agricultural chemicals.

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[Procedure amendment]

[Submission date] October 15, 1999 (1999.10.
15)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0051

[Correction method] Change

[Correction content]

EV containing sodium dihydrogen phosphate (B) based on 100 parts of the resin composition obtained by drying
OH (D2) (ethylene content 35 mol%, saponification degree 9
9.8 mol%, melt index (MI) 3 g / 10
Min (210 ℃, load 2160g), the content of sodium dihydrogen phosphate to EVOH is 440 in terms of phosphate radical conversion
(ppm) was mixed with 300 parts to obtain a resin composition of the present invention. (Content of sodium dihydrogen phosphate is the terms of phosphate radical and a counter 330ppm in the entire resin composition) The obtained resin composition was evaluated in the same manner as in Example 1.

Claims (9)

[Claims] 1. A resin composition comprising a saponified ethylene-vinyl acetate copolymer (A), a phosphoric acid compound (B) and a water-swellable layered inorganic compound (C). 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 content of the phosphoric acid compound (B) is 10 to 1000 ppm in terms of phosphate radical based on the entire resin composition.
The resin composition according to claim 1 or 2, wherein 4. The water-swellable layered inorganic compound (C) is 20
It has a swelling power (measurement standard: Japan Bentonite Industry Association standard test method volume method) of 30 ml / 2 g or more with respect to a mixed solvent of water / alcohol = 70/30 (weight ratio) at ° C. The resin composition according to any one of 1 to 3. 5. The resin composition according to claim 1, wherein the water-swellable layered inorganic compound (C) is smectite or a water-swellable fluoromica-based mineral. 6. A saponified product of an ethylene-vinyl acetate copolymer (A) 10 containing a water-swellable layered inorganic compound (C).
It is 30 parts by weight or less relative to 0 parts by weight, and the resin composition according to claim 1. 7. A water-swelling process for producing a resin composition containing a saponified ethylene-vinyl acetate copolymer (A), a phosphoric acid compound (B) and a water-swellable layered inorganic compound (C). After dispersing the layered inorganic compound (C) in a mixed solvent of water / alcohol = 0/100 to 50/50 (weight ratio), water is further added to the mixture, and water / alcohol = 90 /
The resin composition obtained by adjusting to 10 to 51/49 (weight ratio) to swell the water-swellable layered inorganic compound (C) and then mixing the saponified ethylene-vinyl acetate copolymer (A). A method for producing a resin composition, wherein the saponified product of ethylene-vinyl acetate copolymer (D) containing a phosphoric acid compound (B) is mixed with the product (1). 8. Water / alcohol = 90 / 10-5 in advance
Ethylene dissolved in a mixed solvent of 1/49 (weight ratio)
The method for producing a resin composition according to claim 7, wherein a saponified vinyl acetate copolymer (A) solution is mixed. 9. A laminate comprising at least one layer of the resin composition according to claim 1.