JP2000297193A - Saponified ethylene-vinyl acetate copolymer and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a saponified ethylene-vinyl acetate copolymer blend which is excellent in fabricability and gas barrier properties by mixing at least two water-alcohol solutions of saponified ethylene-vinyl acetate copolymers different from each other in ethylene content and/or degree of saponification to form a dope and bringing the dope into contact with a coagulating liquid to precipitate the copolymer blend. SOLUTION: At least two water-alcohol mixed solutions of saponified ethylene-vinyl acetate copolymers different from each other in ethylene content (by 3-25 mol%) and/or degree of saponification (by 25 mol% or lower), each copolymer satisfying expression I, are mixed at 40-110 deg.C to give a dope, which is brought into contact with an aqueous alcohol-containing coagulating liquid satisfying expression II at -10 to 40 deg.C to precipitate the objective saponified ethylenevinyl acetate copolymer blend. In the expressions, X is the ethylene content (mol%); Y is the water content in a solvent of the water-alcohol solution; M is the alcohol content in the coagulating liquid; (y) is the water content in the solvent of the dope; and Z is the content of saponified ethylene-vinyl acetate copolymers in the dope.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blend of two or more saponified ethylene-vinyl acetate copolymers (hereinafter abbreviated as EVOH) and a laminate thereof, and more particularly to a secondary moldability and a gas barrier. The present invention relates to an EVOH (blend) having excellent properties and a laminate thereof.

[0002]

2. Description of the Related Art In general, EVOH is excellent in transparency, gas barrier properties, fragrance retention, solvent resistance, oil resistance, and the like.
Taking advantage of such characteristics, it is used by being formed into films and sheets of food packaging materials, pharmaceutical packaging materials, industrial chemical packaging materials, agricultural chemical packaging materials, and the like, or containers such as bottles. In such molding, pelletized EVOH
Is often formed into a desired shape after being formed into a film, a sheet, or the like, and is often used as a so-called secondary molding. The secondary formability is also an important required performance.

In order to improve the secondary formability, a specific EV is required.
Attempts have been made to blend two types of OH. For example, Japanese Unexamined Patent Publication (Kokai) No. 60-173038 discloses that, for the purpose of obtaining a resin composition having good secondary moldability and stretch blow moldability, special conditions such as a DSC (differential scanning calorimeter) peak and a molecular weight distribution are required. It has been proposed to mix two types of EVOH so as to obtain a mixture as described in JP-A-63-2646.
JP-A-56-2 discloses an EVOH blend having a specific relationship between dynamic viscoelasticity and melt index for the purpose of obtaining a resin composition having good secondary moldability.
No. 30757 discloses that there is a specific SP value relationship.
Each type of EVOH blend is disclosed.

[0004] However, these EVOH blends all blend EVOH in a molten state, and it is necessary to raise the kneading effect by raising the melting temperature in order to uniformly blend the EVOH. Raise E
VOH may be thermally degraded, and there is still room for improvement. If attention is paid to such uniformity, two types of EVOH (hydrotalcite) may be used as described in Examples of JP-A-5-200865. It is presumed that it is also useful to blend the mixture under a mixed solvent of methanol and water), remove the solvent, and then dry the mixture.

[0005]

However, the present inventor has studied the method described in the above-mentioned Japanese Patent Application Laid-Open No. 5-200865 in detail, and as a result, has found an improvement effect in terms of thermal degradation of two or more EVOH blends. However, it was found that there was unevenness in terms of the uniformity of the blend, and that the secondary formability was uneven.

[0006]

In view of the above situation, the present inventors have conducted intensive studies on the blending of EVOH with a water-alcohol mixed solution, and as a result, the ethylene content and / or the degree of saponification are different. After mixing a water-alcohol mixed solution of two or more types of EVOH each satisfying the following formula (1) to form a dope, the EVOH obtained by contacting the dope with a coagulation liquid to precipitate is used for the above purpose. The inventors have found that they match, and have completed the present invention. 0.0933 × (50−X) ² + 26 ≧ Y ≧ 0.0933 × (50−X) ² +6 (1) [X is the ethylene content (mol%), and Y is the water content in the solvent of the mixed solution. (% By weight)] In the present invention, when the coagulating solution satisfies the following formula (2) in an alcohol-containing aqueous solution, the effect of the present invention can be remarkably obtained. M <100− (y + Z) (2) [M is the alcohol content (% by weight) in the coagulation liquid, y is the water content (% by weight) in the solvent of the dope, and Z is the ethylene in the dope. -Content of saponified vinyl acetate copolymer (% by weight)]

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
As described above, the EVOH of the present invention satisfies the expression (1).
A mixture obtained by blending two or more VOH water-alcohol mixed solutions to form a mixed solution (dope), and then contacting the dope with a coagulation solution to precipitate the mixture, prepares the EVOH water-alcohol mixed solution. In doing so, there is no particular limitation as long as the one satisfying the above equation (1) is obtained.
For example, EVOH may be dissolved in a water-alcohol mixed solution.
It is preferable to prepare a water-alcohol mixed solution of OH, and such a method will be described below, but is not limited thereto.

[0008] Usually, EVOH is obtained by saponifying an ethylene-vinyl acetate copolymer, and the ethylene-vinyl acetate copolymer as a raw material is not particularly limited. However, considering the required performance of the obtained EVOH, The ethylene content is preferably 20 to 50 mol% (more preferably 25 to 50 mol%, particularly 27 to 48 mol%). When the ethylene content is less than 20 mol%, the EVOH obtained has a high gas barrier property at high humidity. On the other hand, if the moldability exceeds 50 mol%, sufficient gas barrier properties of the obtained EVOH cannot be obtained, which is not preferable.

The ethylene-vinyl acetate copolymer may contain, in addition to ethylene and vinyl acetate, an ethylenically unsaturated monomer copolymerizable therewith as a copolymer component. Examples of the monomer include olefins such as propylene, isobutylene, α-octene, α-dodecene, and α-octadecene; and unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, and itaconic acid. Acids or their salts or mono- or dialkyl esters, etc., acrylonitrile, nitriles such as methacrylonitrile, acrylamide, amides such as methacrylamide, ethylene sulfonic acid, allyl sulfonic acid,
Olefin sulfonic acids such as methallyl sulfonic acid or salts thereof, alkyl vinyl ethers, N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethylallylvinylketone, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride, polyoxyethylene ( Polyoxyalkylene (meth) allyl ethers such as (meth) allyl ether and polyoxypropylene (meth) allyl ether; polyoxyalkylene (meth) acrylates such as polyoxyethylene (meth) acrylate and polyoxypropylene (meth) acrylate; Polyoxyalkylene (meth) acrylamides such as oxyethylene (meth) acrylamide and polyoxypropylene (meth) acrylamide; Len (1- (meth) acrylamide-1,1-dimethylpropyl) ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinylamine, polyoxypropylene vinylamine, etc. Is mentioned.

[0010] The saponification of the ethylene-vinyl acetate copolymer is carried out in the presence of an alkali catalyst, and the alkali catalyst is used for the saponification reaction of polyvinyl acetate or ethylene-vinyl acetate copolymer with an alkali catalyst. Can be used as it is. Specifically, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; alkali metal alcoholates such as sodium methylate and potassium t-butoxy;
-Diazabicyclo [5,4,10] undecene-7 (D
Examples thereof include strongly basic amines represented by BU), and alkali metal carbonates and alkali metal hydrogencarbonates. Of these, sodium hydroxide is preferred from the viewpoint of ease of handling and catalyst cost.

The amount of the catalyst used varies depending on the required degree of saponification, the reaction temperature and the like, but it is used in an amount of 0.05 equivalent or less, preferably 0.03 equivalent, based on the residual acetic acid groups in the ethylene-vinyl acetate copolymer. It is as follows. Further, instead of the alkali catalyst, an acid catalyst such as hydrochloric acid and sulfuric acid can be used.

In the saponification, the ethylene-vinyl acetate copolymer is dissolved in an alcohol or an alcohol-containing medium to a concentration of usually about 20 to 60% by weight, and an alkali catalyst or an acid catalyst is added. 40-1
React at a temperature of 40 ° C. EV at the solution temperature
The concentration of the EVOH is not particularly limited as long as OH is not precipitated.
The content may be 5% by weight, preferably 15 to 50% by weight. As the alcohol, alcohols such as methanol, ethanol, and propanol are used, and preferably, methanol is used.

The degree of saponification of the vinyl acetate component of EVOH obtained by such saponification is preferably from 70 to 100 mol%, and more preferably from 80 to 100 mol%. When the saponification degree is less than 70 mol%, the thermal stability when the EVOH is melt-molded is unfavorably deteriorated.

Next, a water-alcohol mixed solution of EVOH is obtained by adding water to the alcohol solution of EVOH obtained above. In the present invention,
As described above, it is necessary to prepare a mixed solution of EVOH with water so as to contain water so as to satisfy the condition of the following formula (1). When such a condition is not satisfied, the effect of the present invention is obtained. It becomes difficult. In other words, EV
It is necessary to add water so as to satisfy the following equation (1) depending on the ethylene content in OH. 0.0933 × (50−X) ² + 26 ≧ Y ≧ 0.0933 × (50−X) ² +6 (1) where X is the ethylene content (mol%), and Y is the water-alcohol mixed solution of EVOH. Water content in solvent (% by weight)
Respectively.

In the condition of the above equation (1), when water is contained so that the value of Y is smaller than the calculated value on the right side, when EVOH is precipitated later by contacting with a coagulating liquid, EVOH is reduced. Precipitation is difficult, and the resin loss of EVOH increases. Conversely, when water is contained so as to be larger than the calculated value on the left side, the viscosity of the EVOH water-alcohol mixed solution becomes unstable and the coagulation liquid Before the precipitation of EVOH, EVOH precipitates, making it difficult to achieve the object of the present invention.

In the present invention, two or more EVOH water-alcohol mixed solutions satisfying the above formula (1) are prepared, and then these two or more EVOH water-alcohol mixed solutions are mixed. Dope,
The EVOH mixed at this time differs in ethylene content and / or saponification degree, and the difference is preferably 3 to 25 mol% (more preferably 3 to 20 mol%). Is less than 3 mol%, the effect of improving the secondary formability is poor. Conversely, if it exceeds 25 mol%, EV
It is not preferable because it is difficult to uniformly blend OH with each other, and the difference in the degree of saponification is preferably 25 mol% or less (more preferably 15 mol% or less).
If it exceeds mol%, the thermal stability during molding is undesirably reduced. When three or more EVOHs are mixed, the maximum amount of the EVOH to be mixed and the next most mixed EVOH
It is sufficient that the relationship with satisfies the above relationship.

Also, the DSC (differential scanning calorimeter) of the maximum amount of EVOH to be mixed and the next most EVOH to be mixed
When the respective melting points measured by the main endothermic peak temperature at a heating rate of 10 ° C./min) are Ta (° C.) and Tb (° C.), it is preferable that the following expression (3) is satisfied. 0 ≦ Ta−Tb ≦ 60 (3) In the above relationship, when Ta <Tb, the effect of improving the secondary formability is small, and when Ta−Tb> 60, the melt mixing of the blend is performed. The properties (uniformity) are undesirably reduced.

In the present invention, each EV
It is sufficient that the OH water-alcohol mixed solution satisfies the above formula (1). Preferably, the content of water in the solvent of each mixed solution, that is, the value of Y is 5 to 50% by weight (furthermore, It is preferable that the difference be less than 5% by weight, EVOH is not uniformly mixed,
Conversely, if it exceeds 50% by weight, the viscosity of the dope after mixing becomes unstable, which is not preferable.

The method of mixing the mixed solution (the method of preparing the dope) is not particularly limited, and two or more mixed solutions may be mixed using a known rotary mixing stirrer or line mixer. In producing such a dope, it is preferable that each of the mixed solutions to be mixed be brought to 40 to 110 ° C. and then mixed. If the temperature is lower than 40 ° C., the viscosity of the solution becomes high and uniform mixing becomes difficult. If the temperature exceeds 110 ° C., the dope may be undesirably colored. The mixed solution (dope) of the EVOH water-alcohol mixed solution thus obtained is then brought into contact with a coagulating solution to precipitate the desired EVOH, and such a method is not particularly limited. Provides such a dope in a coagulation solution, where EVOH
Is precipitated (solidified).

In the present invention, at this time, the E in the aqueous alcohol-containing coagulating solution satisfying the condition of the following formula (2):
Preferably, VOH (a blend of two or more) is deposited. In other words, the amount of alcohol contained in the coagulation liquid is adjusted so as to satisfy the following expression (2). Such adjustment may be performed before the dope is added to the coagulation liquid. However, if the condition of the following formula (2) is not satisfied during the deposition of the EVOH in the coagulation liquid, the adjustment may be performed in each case. It may be adjusted. In the present invention,
Even if the condition of the following formula (2) is deviated during such a precipitation step, if the condition of the following formula (2) is satisfied during the step, the desired product can be suitably obtained at that time. M <100− (y + Z) (2) where M is the alcohol content (% by weight) in the coagulation liquid, y
Represents the content (% by weight) of water in the solvent in the dope, and Z represents the content (% by weight) of EVOH in the dope.

Under the conditions of the above formula (2), when the alcohol content (M) in the coagulating liquid is larger than the calculated value on the right side, the precipitation rate tends to be slow, and the resin loss tends to increase, which is not preferable. . As the alcohol in the coagulation liquid, an alcohol such as methanol, ethanol, or propanol is used. Preferably, methanol is used, and the same alcohol as the alcohol in the EVOH alcohol solution described above is preferable.

In such a coagulation solution, a saturated aliphatic amide (for example, stearic acid amide), an unsaturated fatty acid amide (for example, olefinic acid amide), a bisfatty acid amide (for example, ethylene) may be contained within a range not to impair the object of the present invention. Lubricants such as bisstearic acid amide, fatty acid metal salts (eg, calcium stearate, etc.), low molecular weight polyolefins (eg, low molecular weight polyethylene having a molecular weight of about 500 to 10,000, or low molecular weight polypropylene, etc.), inorganic salts (eg, hydro Talcite, etc.), plasticizers (e.g., aliphatic polyhydric alcohols such as ethylene glycol, glycerin, hexanediol, etc.), inorganic fillers (silicon oxide,
Titanium dioxide, clay, talc, bentonite, etc.). Further, the temperature of the coagulation liquid is -10 to 4
Operation at 0 ° C. is preferred, and operation at 0 to 20 ° C. and as low a temperature as possible is effective because resin loss can be reduced.

Thus, the dope is precipitated in the coagulation liquid to obtain a blend of two or more EVOHs. In the case of such a precipitation, usually, the dope is formed into a strand form in the coagulation liquid by a nozzle having an arbitrary shape. After being extruded and precipitated, it is cut and formed into a pellet.

The steps will be described below. The shape of the nozzle is not particularly limited, but is preferably a cylindrical shape, and the inner diameter is 0.1 to 10 cm, preferably 0.2 to 5.0 cm. The number of strands extruded from the nozzle is not necessarily one, and any number between several and several hundreds can be extruded. The EVOH extruded in the form of a strand is cut, pelletized, and then washed with water after coagulation proceeds sufficiently.

The washing conditions are as follows:
Rinse in a 60 ° C. water bath. By such water washing, EVO
The oligomers and impurities in H are removed, and in particular, sodium acetate is removed to 0.5% by weight or less. The washed pellets are preferably subjected to an acid treatment, for example, acetoacetic acid, formic acid, acetic acid, adipic acid, phosphoric acid, boric acid, etc., and more preferably acetic acid.

As the conditions of the acid treatment, for example, the substrate is washed in an aqueous acetic acid solution of 3% by weight or less, and the treatment is performed so that the pH of the washing solution becomes 3 to 8. In addition, the shape of the pellet is 2 to 5 m in the case of a cylindrical shape from the viewpoint of workability during molding and handling.
m, 2 to 5 mm in length, and 2 to 5 in case of spherical
Those having a size of about 5 mm are practical.

Thus, the EVOH (blend) of the present invention, which is excellent in secondary moldability and gas barrier properties, can be obtained. The EVOH may further contain a plasticizer, a lubricant, a coloring agent, if necessary. It is also possible to use additives such as antibacterial agents, fillers and other resins. In particular, a hydrotalcite-based compound or a metal salt of a higher aliphatic carboxylic acid can be added as a gel generation inhibitor.

The EVOH of the present invention can be obtained by melt molding or the like.
It can be formed into films, sheets, containers, fibers, rods, tubes, various molded products, etc., and can be subjected to melt molding again using these crushed products (such as when reused products are reused). Extrusion molding and injection molding are mainly employed as molding methods. Melt molding temperature is 150-300
Often selected from the range of ° C. Also, the EVOH of the present invention
Can be used as a single layer, or it is also useful to laminate a thermoplastic resin layer or the like on at least one surface of the EVOH layer and use it as a multilayer laminate.

In manufacturing the laminate, the EV
The other substrate is laminated on one side or both sides of the layer made of OH. As a lamination method, for example, a method of melt-extruding a thermoplastic resin on a film or sheet made of the EVOH, and conversely, a method of laminating a thermoplastic resin or the like A method of melt-extruding the EVOH to a substrate, a method of co-extrusion of the EVOH and another thermoplastic resin, and a film or sheet of the EVOH and a film of another substrate, an organic titanium compound, A dry lamination method using a known adhesive such as an isocyanate compound, a polyester-based compound, or a polyurethane compound may, for example, be mentioned.

In the case of co-extrusion, the mating resin may be a linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ionomer, ethylene-propylene copolymer, ethylene -Acrylate copolymer, polypropylene, propylene-α-olefin (having 4 to 20 carbon atoms)
Α-olefins) copolymers, polyolefins such as polybutene and polypentene, and polyolefins in a broad sense such as homo- or copolymers of these olefins or graft-modified homo- or copolymers of these olefins with unsaturated carboxylic acids or esters thereof Resin, polyester, polyamide, copolymerized polyamide, polyvinyl chloride, polyvinylidene chloride, acrylic resin, polystyrene, vinyl ester resin,
Examples thereof include polyester elastomer, polyurethane elastomer, chlorinated polyethylene, and chlorinated polypropylene. Other EVOHs can be coextruded. Among the above, from the viewpoint of ease of coextrusion film formation and practicality of film physical properties (particularly strength), polypropylene, polyamide,
Polyethylene, ethylene-vinyl acetate copolymer, polystyrene, and PET are preferably used.

Furthermore, a molded product such as a film or a sheet is once obtained from the EVOH of the present invention, and another substrate is extrusion-coated thereon, or a film or sheet of another substrate is laminated using an adhesive. In the case, any substrate other than the above-mentioned thermoplastic resin (paper, metal foil, uniaxially or biaxially stretched plastic film or sheet, woven fabric, nonwoven fabric, metal flocculent, woody, etc.)
Can be used.

The layer structure of the laminate is such that the layer composed of the EVOH is a (a ₁ , a ₂ ,...), And another base material, for example, a thermoplastic resin layer is b (b ₁ , b ₂ ,...). ·) that when a film, a sheet, if a bottle shape, not only the double layer structure of a / b, b / a / b, a / b / a, a 1 / a 2 / b, a /
Any combination such as b ₁ / b ₂ , b ₂ / b ₁ / a / b ₁ / b ₂ is possible. In the filament form, a and b are bimetal type, core (a) -sheath (b) type, core Any combination such as (b) -sheath (a) type or eccentric core-sheath type is possible.

The shape of the thus obtained laminate may be any shape, and examples thereof include a film, a sheet, a tape, a bottle, a pipe, a filament, and an extrudate having a modified cross section. Further, the obtained laminate is heat-treated, cooled, rolled, printed, dry-laminated,
Solution or melt coating processing, bag making processing, deep drawing processing, box processing, tube processing, split processing, and the like can be performed. The films, sheets, containers and the like obtained as described above are useful as various packaging materials for foods, pharmaceuticals, industrial chemicals, agricultural chemicals and the like.

[0034]

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

Example 1 Ethylene content (X1) 30 mol%, saponification degree 99.7
Water-methanol containing 40% by mol of EVOH [water / methanol weight ratio = 50/50, water content (Y
1) = 50%] mixed solution and ethylene content (X2) 4
5% by mole, 40% of EVOH having a saponification degree of 99.3% by mole
Water-methanol contained [water / methanol weight mixing ratio =
15/85, water content (Y2) = 15%] The mixed solution was mixed at a ratio of mixed solution / mixed solution = 80/20 (weight ratio) to prepare a dope. Incidentally, the water content (Y1) in the solvent of the mixed solution is 50%, and the above ethylene content (X1 = 30 mol%) is substituted into the expression (1) in the text, so that 63 ≧ Y1 ≧ 43. , Such water content (Y
1) satisfies the formula (1), and the water content (Y2) in the solvent of the mixed solution is 15%, and the above ethylene content (X2 = 45 mol%) is expressed by ( By substituting into the expression (1), 28 ≧ Y2 ≧ 8, and the water content (Y2) satisfies the expression (1).

Next, the obtained dope was treated with methanol 5
%, And a coagulation solution maintained at 5 ° C. consisting of 95% water [The alcohol content (M) in the coagulation solution at this time is 5%, and the water content in the solvent of the dope (y = Y1 × 0. 80 + Y2 × 0.
20 = 43%) and the EVOH content (Z
= 40%) into the expression (2) in the text, M <10
0- (43 + 40) = 17, and the alcohol content (M) in the coagulation liquid did not deviate from the condition of the formula (2)]. I let it.

After the solidification was completed, the strands were cut with a cutter, washed in a water bath at a temperature of 30 ° C. for one hour, and washed with water for 4 hours.
Repeatedly to remove impurities such as sodium acetate,
Further, it is washed in acetic acid water at a temperature of 30 ° C. for 1 hour, dried, and dried with EVOH pellets (diameter 3.8 mm, length 4 mm).
I got Using the obtained EVOH pellets, secondary formability and gas barrier properties were evaluated in the following manner.

(Secondary moldability) The obtained EVOH pellets, thermoplastic resin (polypropylene, ASTM D12)
MI = 2.4 g / 10 min as measured by E.38), an adhesive resin (modified polyolefin resin, “M” manufactured by Mitsubishi Chemical Corporation).
ODIC-AP P523 ", MI = 2.5 g / 10 min as measured by ASTM D1238).
Using a seed five-layer co-extrusion T-die sheet manufacturing apparatus, a thermoplastic resin layer (400 μm) / adhesive resin layer (50 μm) / resin composition layer (65 μm) / adhesive resin layer (50 μm) / thermoplastic resin layer (400 μm) ) Was obtained, and then the laminate was heated at a hot plate temperature of 500 ° C. and a heating time of 30 to 40 seconds using a pressurized air vacuum forming machine manufactured by Asano Research Institute Co., Ltd.
The temperature of the laminate was controlled to be 160 ° C., and 100 cups (cylindrical shape having a diameter of 9 cm and a depth of 7 cm) were formed. The surface of the obtained cup was visually observed and evaluated as follows. went. ○ −−− No cracks were observed in all 100 pieces △ −−− Cracks occurred in 1 to 5 pieces × −−− Cracks occurred in 6 or more pieces

(Gas Barrier Property) The cup obtained as described above was placed in an oxygen permeability measuring apparatus (“OXTRAN1” manufactured by MOCON).
0/50 ”), the oxygen permeability (cc / day · air) of the cup was measured at 23 ° C. and 50% RH atmosphere with the inside of the cup being 100% RH.

Example 2 Ethylene content (X1) 35 mol%, saponification degree 99.2
Water-methanol containing 38% by mol of EVOH [water / methanol weight ratio = 35/65, water content (Y
1) = 35%] mixed solution and ethylene content (X2) 4
7 mol%, 35% EVOH having a saponification degree of 99.0 mol%
Water-methanol contained [water / methanol weight mixing ratio =
15/85, water content (Y2) = 15%] The mixed solution was mixed at a ratio of mixed solution / mixed solution = 80/20 (weight ratio) to prepare a dope. The water content (Y1) in the solvent of the mixed solution is 35%, and when the above ethylene content (X1 = 35 mol%) is substituted into the expression (1) in the text, 47 ≧ Y1 ≧ 27. , Such water content (Y
1) satisfies the expression (1), the water content (Y2) in the solvent of the mixed solution is 15%, and the above ethylene content (X2 = 47 mol%) is expressed by ( By substituting into the expression (1), 27 ≧ Y2 ≧ 7, and the water content (Y2) satisfies the expression (1).

Next, the obtained dope was treated with methanol 5
%, And a coagulation solution maintained at 5 ° C. consisting of 95% water [the alcohol content (M) in the coagulation solution at this time is 5%, and the water content in the solvent of the dope is 35% (y = 35%). %), EV
Water and methanol were added such that the OH content was 35% (Z = 35). Substituting this into the expression (2) in the text gives M <100- (35 + 35) = 30, and the alcohol content (M) in the coagulation solution satisfies the expression (2), and is about 5 minutes. Precipitation was performed, but did not deviate from the condition of formula (2).] The mixture was extruded into a tank from a nozzle (inner diameter: 4 mm) in the form of a strand and precipitated (solidified).

After the coagulation is completed, the strand is cut with a cutter, washed in a water bath at a temperature of 30 ° C. for one hour, and
After repeated removal of sodium acetate, the temperature was further increased to 30.
Wash in acetic acid water at ℃ for 1 hour, dry and
Pellets (diameter 3.8 mm, length 4 mm) were obtained. A cup was prepared using the obtained EVOH pellets in the same manner as in Example 1, and the cup was evaluated in the same manner.

Example 3 Ethylene content (X1) 38 mol%, saponification degree 99.6
Water-methanol containing 40% by mole of EVOH [water / methanol weight ratio = 30/70, water content (Y
1) = 30%] mixed solution and ethylene content (X2) 4
5% by mole, 40% of EVOH having a saponification degree of 97.0% by mole
Water-methanol contained [water / methanol weight mixing ratio =
23/77, water content (Y2) = 23%]. The mixed solution was mixed at a ratio of mixed solution / mixed solution = 70/30 (weight ratio) to prepare a dope. The content of water (Y1) in the solvent of the mixed solution was 30%, and the above ethylene content (X1 = 38 mol%) was substituted into the expression (1) in the text to obtain 39 ≧ Y1 ≧ 19. , Such water content (Y
1) satisfies the expression (1), the water content (Y2) in the solvent of the mixed solution is 23%, and the above ethylene content (X2 = 45 mol%) is expressed by ( By substituting into the expression (1), 28 ≧ Y2 ≧ 8, and the water content (Y2) satisfies the expression (1).

Next, the obtained dope was treated with methanol 5
%, And a coagulation solution maintained at 5 ° C. consisting of 95% water [The alcohol content (M) in the coagulation solution at this time is 5%, and the water content in the solvent of the dope (y = Y1 × 0. 70 + Y2 × 0.
30 = 28%) and the EVOH content (Z
= 40%) into the expression (2) in the text, M <10
0- (40 + 28) = 32, and the alcohol content (M) in the coagulation solution satisfies the expression (2). Precipitation was performed for about 5 minutes. None] was extruded into a tank from a nozzle (inner diameter 4 mm) in the form of a strand and precipitated (coagulated).

After the coagulation was completed, the strand was cut with a cutter and washed in a water bath at a temperature of 30 ° C. for 1 hour.
After repeated removal of sodium acetate, the temperature was further increased to 30.
Wash in acetic acid water at ℃ for 1 hour, dry and
Pellets (diameter 3.8 mm, length 4 mm) were obtained. A cup was prepared using the obtained EVOH pellets in the same manner as in Example 1, and the cup was evaluated in the same manner.

Example 4 Ethylene content (X1) 30 mol%, saponification degree 99.2
Water-methanol containing 40% by mol of EVOH [water / methanol weight mixing ratio = 55/45, water content (Y
1) = 55%] mixed solution and ethylene content (X2) 3
8 mol%, 40% EVOH having a saponification degree of 96.0 mol%
Water-methanol contained [water / methanol weight mixing ratio =
35/65, water content (Y2) = 35%]. The mixed solution was mixed at a ratio of mixed solution / mixed solution = 60/40 (weight ratio) to prepare a dope. Incidentally, the water content (Y1) in the solvent of the mixed solution is 55%, and when the above ethylene content (X1 = 30 mol%) is substituted into the expression (1) in the text, 63 ≧ Y1 ≧ 43. , Such water content (Y
1) satisfies the expression (1), the water content (Y2) in the solvent of the mixed solution is 35%, and the above ethylene content (X2 = 38 mol%) is expressed by ( By substituting into the expression (1), 39 ≧ Y2 ≧ 19, and the water content (Y2) satisfied the expression (1).

Next, the obtained dope was treated with methanol 8
%, And a coagulation liquid maintained at 5 ° C. consisting of 92% water [The alcohol content (M) in the coagulation liquid at this time is 8%, and the water content in the solvent of the dope (y = Y1 × 0. 60 + Y2 × 0.
40 = 47%) and the EVOH content (Z
= 40%) into the expression (2) in the text, M <10
0− (47 + 40) = 13, and the alcohol content (M) in the coagulation solution satisfies the expression (2), and the precipitation was performed for about 5 minutes. None] was extruded into a tank from a nozzle (inner diameter 4 mm) in the form of a strand and precipitated (coagulated).

After the coagulation was completed, the strand was cut with a cutter and washed in a water bath at a temperature of 30 ° C. for 1 hour.
After repeated removal of sodium acetate, the temperature was further increased to 30.
Wash in acetic acid water at ℃ for 1 hour, dry and
Pellets (diameter 3.8 mm, length 4 mm) were obtained. A cup was prepared using the obtained EVOH pellets in the same manner as in Example 1, and the cup was evaluated in the same manner.

Example 5 Ethylene content (X1) 45 mol%, saponification degree 99.7
Water-methanol containing 40% by mole of EVOH [water / methanol weight ratio = 20/80, water content (Y
1) = 20%] mixed solution and ethylene content (X2) 3
8 mol%, 40% EVOH having a saponification degree of 97.0 mol%
Water-methanol contained [water / methanol weight mixing ratio =
35/65, water content (Y2) = 35%]. The mixed solution was mixed at a ratio of mixed solution / mixed solution = 55/45 (weight ratio) to prepare a dope. Incidentally, the water content (Y1) in the solvent of the mixed solution is 20%, and when the above ethylene content (X1 = 45 mol%) is substituted into the expression (1) in the text, 28 ≧ Y1 ≧ 18. , Such water content (Y
1) satisfies the expression (1), the water content (Y2) in the solvent of the mixed solution is 35%, and the above ethylene content (X2 = 38 mol%) is expressed by ( By substituting into the expression (1), 39 ≧ Y2 ≧ 19, and the water content (Y2) satisfied the expression (1).

Next, the obtained dope was treated with methanol 5
%, And a coagulation solution maintained at 5 ° C. consisting of 95% water [The alcohol content (M) in the coagulation solution at this time is 5%, and the water content in the solvent of the dope (y = Y1 × 0. 55 + Y2 × 0.
45 = 27%) and the EVOH content (Z
= 40%) into the expression (2) in the text, M <10
0- (27 + 40) = 33, and the alcohol content (M) in the coagulation solution satisfies the expression (2). Precipitation was performed for about 5 minutes. None] was extruded into a tank from a nozzle (inner diameter 4 mm) in the form of a strand and precipitated (coagulated).

After the coagulation is completed, the strand is cut with a cutter and washed in a water bath at a temperature of 30 ° C. for 1 hour.
After repeated removal of sodium acetate, the temperature was further increased to 30.
Wash in acetic acid water at ℃ for 1 hour, dry and
Pellets (diameter 3.8 mm, length 4 mm) were obtained. A cup was prepared using the obtained EVOH pellets in the same manner as in Example 1, and the cup was evaluated in the same manner.

Comparative Example 1 In Example 1, the mixed solution was an EVO having an ethylene content (X2) of 45 mol% and a saponification degree of 97.5 mol%.
Water-methanol containing 40% H [water / methanol weight ratio = 35/65, water content (Y1) = 35%]
A cup was obtained in the same manner except that the mixed solution was used, and the cup was evaluated in the same manner. The water content (Y2) in the solvent of the mixed solution was 35%, and the ethylene content (X = 4
5 mol%) into the expression (1) in the text, 28 ≧ Y
.Gtoreq.8, and the water content (Y2) did not satisfy the expression (1).

Comparative Example 2 In Example 1, the mixed solution was an EVO having an ethylene content (X1) of 30 mol% and a saponification degree of 99.7 mol%.
Water-methanol containing 40% H [water / methanol weight ratio = 30/70, water content (Y1) = 30%]
A cup was obtained in the same manner except that the mixed solution was used, and the cup was evaluated in the same manner. The water content (Y1) in the solvent of the mixed solution was 30%, and the above ethylene content (X = 3
0 mol%) into the expression (1) in the text, 63 ≧ Y
≧ 43, and the water content (Y1) did not satisfy the expression (1). Table 1 summarizes the evaluation results of the above Examples and Comparative Examples.

[0054]

[Table 1]

[0055]

Since the EVOH (blend) of the present invention is manufactured under specific conditions, it is excellent in secondary moldability and gas barrier properties, and can be formed into various kinds of laminates. It is very useful for applications such as films, sheets, tubes, bags, containers and the like for packaging products and industrial chemicals.

Claims (3)

[Claims] 1. A water-alcohol mixed solution of two or more saponified ethylene-vinyl acetate copolymers having different ethylene contents and / or degrees of saponification and each satisfying the following formula (1): A saponified ethylene-vinyl acetate copolymer, which is obtained by contacting the dope with a coagulating liquid and precipitating the resulting dope. 0.0933 × (50−X) ² + 26 ≧ Y ≧ 0.0933 × (50−X) ² +6 (1) [X is the ethylene content (mol%), and Y is the water content in the solvent of the mixed solution. (weight%)] 2. The saponified ethylene-vinyl acetate copolymer according to claim 1, wherein the coagulating liquid in contact with the dope is an aqueous alcohol-containing solution and satisfies the following formula (2). M <100− (y + Z) (2) [M is the alcohol content (% by weight) in the coagulation liquid, y is the water content (% by weight) in the solvent of the dope, and Z is the ethylene in the dope. -Content of saponified vinyl acetate copolymer (% by weight)] 3. A laminate comprising at least one layer containing the saponified ethylene-vinyl acetate copolymer according to claim 1 or 2.