JPH11293079A - Preparation of resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for the preparation of resin compositions of saponified products of ethylene/vinyl acetate copolymers without occurrence of fine fish eyes when formed into multi-layered laminates and with excellent long run moldability. SOLUTION: In the preparation of a resin composition containing (A) 100 pts.wt. saponified product of an ethylene/vinyl acetate copolymer and (B) 0.001-0.05 pts.wt. acetate salt (in terms of the metal), the saponified product (A) of an ethylene/vinyl acetate copolymer having a water content of 20-80 wt.% is brought into contact with an aqueous solution of an acetate salt (B) such that the content of the acetate salt in the aqueous solution of an acetate salt (B) is rendered 0.001-0.5 pt.wt., based on 100 pts.wt. total amount of the water content in the saponified product (A) of an ethylene/vinyl acetate copolymer and the water content in the aqueous solution of an acetate salt (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin composition of saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH), and more particularly, to the melt moldability of a multilayer laminate. The present invention relates to a method for producing a resin composition of EVOH having excellent properties.

[0002]

2. Description of the Related Art In general, EVOH is excellent in transparency, gas barrier property, fragrance retention, solvent resistance, oil resistance and the like. It is used after being formed into materials, films and sheets of packaging materials for agricultural chemicals, containers such as bottles, and the like. In such molding, usually, melt molding is performed, and by such molding, it is processed into a shape such as a film shape, a sheet shape, a bottle shape, a cup shape, a tube shape, a pipe shape, and is provided for practical use. (Moldability) is very important, and in order to improve such moldability, EVO
Methods of incorporating a metal salt such as sodium acetate into H (JP-A-51-91988, JP-A-56-41204, JP-A-64-66262, etc.) have been conventionally proposed.

[0003]

However, in order to cope with the recent increase in performance required for a new molded product, the above-mentioned technology has been studied in detail, and as a result, a fisheye having a diameter of 0.1 mm or more has been obtained. Although improvements such as gels and the like are recognized, small ones of less than 0.1 mm are not necessarily solvable with the above technology,
In particular, sufficient consideration has not been given to the production of the multilayer laminate, and it is not possible to set the thickness of the multilayer laminate in accordance with the molding conditions.
Fish eyes less than 1 mm may occur,
It has been found that new improvements are desired.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
In view of this situation, as a result of intensive research, EVOH
(A) 0.001 parts by weight of acetate (B) per 100 parts by weight
EVOH having a water content of 20 to 80% by weight when producing a resin composition containing 0.05 to 0.05 parts by weight (in terms of metal).
(A) is brought into contact with an aqueous solution of acetate (B), and the content of acetate (B) in the aqueous solution of acetate (B) is adjusted to EVOH
0.001 to 0.5 with respect to 100 parts by weight of the total amount of water contained in (A) and water contained in the aqueous solution of acetate (B).
By setting the amount by weight, EVOH resin which is excellent in melt moldability, in particular, can suppress generation of fish eyes having a diameter of less than 0.1 mm during production of a multilayer laminate, and has good long run moldability. The composition is obtained, and further, after the EVOH (A) and the acetate (B) are brought into contact with each other, fluid drying is performed, and static drying is performed before or after the fluid drying, thereby obtaining the effects of the present invention. Was found to be remarkably obtained, and the present invention was completed.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The EVOH (A) used in the present invention is not particularly limited, but has an ethylene content of 20 to 60 mol% (furthermore, 25 to 55 mol%) and a saponification degree of 90 mol% or more (furthermore, 95 mol%). When the ethylene content is less than 20 mol%, the gas barrier properties and melt moldability at high humidity are reduced, and when it exceeds 60 mol%, sufficient gas barrier properties cannot be obtained. If the saponification degree is less than 90 mol%, the gas barrier properties, thermal stability, moisture resistance, etc. are undesirably reduced. EVOH (A) has a melt index (MI) (210 ° C., load 2160 g) of 0.1 to 100 g / 10 minutes (further 0.5 to 50 g / 1).
0 minutes) is preferable. When the melt index is smaller than the range, the inside of the extruder is in a high torque state at the time of molding to make extrusion difficult, and when the melt index is larger than the range, melt molding is performed. The properties and the mechanical strength of the molded product are undesirably reduced.

The EVOH (A) is obtained by saponifying an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer can be produced by any known polymerization method, for example, suspension polymerization, emulsion polymerization, solution polymerization, and the like. Manufactured by polymerization, etc.
Saponification of the ethylene-vinyl acetate copolymer can also be performed by a known method. If EVOH is used in a small amount, other comonomers such as α-olefin, unsaturated carboxylic acid compound, unsaturated sulfonic acid compound, (meth) acrylonitrile, (meth) acrylamide, vinyl ether, vinyl silane compound, vinyl chloride and styrene And may be "copolymerized". Also, "post-modified" such as urethanization, acetalization, and cyanoethylation may be used as long as the gist of the present invention is not impaired.

The acetate (B) used in the present invention includes sodium acetate, potassium acetate, calcium acetate, magnesium acetate, zinc acetate, barium acetate, manganese acetate and the like. , Potassium acetate, calcium acetate, and magnesium acetate are used. In the present invention, using (A) and (B) as described above, 0.001 to 0.05 parts by weight (in terms of metal) of acetate (B) is contained with respect to 100 parts by weight of EVOH (A). In producing the resin composition, a water content of 2
0-80% by weight of EVOH (A) is contacted with an aqueous solution of acetate (B) and acetate (B) in aqueous solution of acetate (B)
Of 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the total amount of water contained in the EVOH (A) and the aqueous solution of the acetate (B) aqueous solution. Now, such a method will be specifically described.

The water content is 20 to 80% by weight (further 30 to 7% by weight).
In preparing the EVOH (A) of 0% by weight (particularly 35 to 65% by weight), there is no particular limitation. Even if EVOH (pellet or powder) and water are mixed and stirred, the EVOH absorbs water. Good, and a method of blowing steam is also adopted. It is also possible to contain water together with a small amount of alcohol such as methanol or isopropyl alcohol during the production of EVOH. At this time, a small amount of a plasticizer such as ethylene glycol, propylene glycol or glycerin may be contained. If the water content is less than 20% by weight, fine fish eyes frequently occur when the obtained resin composition is melt-molded, and if it exceeds 80% by weight, pellets or powders are formed in the subsequent drying step. EVOH causes fusion and fails to achieve the object of the present invention.

In the present invention, such EVOH is preferably a porous precipitate, and such a porous precipitate is
It has a microporous internal structure in which pores having a diameter of 0.1 to 10 μm are uniformly distributed, and a solution of EVOH (water /
When extruding the alcohol mixed solvent into the coagulation bath, the concentration of the EVOH solution (20 to 80% by weight), the temperature (45 to 70 ° C.), and the type of the solvent (water / alcohol mixed weight ratio = 80/20 to 5 / 95), the temperature of the coagulation bath (1-2)
0 ° C.), the residence time (0.25 to 30 hours), the amount of EVOH in the coagulation liquid (0.02 to 2% by weight) and the like can be arbitrarily adjusted. Further, the content of the acetate (B) in the aqueous solution of the acetate (B) is set to 0 with respect to 100 parts by weight of the total amount of the water contained in the EVOH (A) and the water contained in the aqueous solution of the acetate (B). 0.001 to 0.5 parts by weight (further, 0.005 to 0.4 parts by weight, particularly 0.01 to 0.3 parts by weight) in consideration of water (water content) in EVOH (A). To prepare an aqueous solution of acetate (B). If the concentration of the aqueous solution is less than 0.001% by weight, EVOH
It is difficult to make the (A) contain a predetermined amount of the acetate (B). Conversely, if it exceeds 0.5% by weight, the fine fish-eye frequently occurs in the molded article of the resin composition, and the object of the present invention cannot be achieved. . At this time, about 0.001 to 0.1% by weight of methanol, ethanol, propanol, methyl acetate, ethyl acetate or the like may be contained.

The desired resin composition is obtained by bringing the thus obtained EVOH (A) into contact with an aqueous solution of acetate (B), and the EVOH (A) is added to the aqueous solution of acetate (B).
And finally the EVOH (A) and the acetate (B)
May be contained (adhered), and such a method is not particularly limited, and EVOH is directly added to the aqueous solution of the acetate (B).
(A) a method of immersing the pellets and powders and the like, and a method of immersing a porous precipitate of a mixed solution of EVOH (A) in water / alcohol in an aqueous solution of acetate (B) to contain the EVOH (A). A method of adding an aqueous solution of acetate (B) to a water / alcohol mixed solution of A), and then precipitating (in a coagulation tank or the like) and adding the aqueous solution of acetate (B) to EVOH (A) in a molten state. Although a method of making it contain, etc. are mentioned, in order to make the acetate (B) more uniformly and efficiently contained, the above method is preferably used.

Thus, the desired resin composition is obtained by the method of the present invention. Usually, the resin composition is obtained through a drying step after the above-mentioned contact treatment. In the present invention, various drying methods can be employed as such a drying method.
Fluid drying is performed, and a drying method of performing static drying before or after the fluid drying, that is, a method of performing static drying after fluid drying or a method of performing fluid drying after static drying is particularly preferable. The drying method will be described. Fluid drying referred to herein means drying performed while the resin composition in the form of pellets or powder is stirred or dispersed by mechanical or hot air, and as a dryer for performing the drying, , A cylindrical / groove type stirring dryer, a cylindrical dryer, a rotary dryer, a fluidized bed dryer, a vibrating fluidized bed dryer, a conical rotary dryer, and the like. The drying means that the composition is not given dynamic action such as stirring and dispersion, and as a dryer for performing the drying, a batch box dryer as a material stationary type is a material transfer type. Examples thereof include, but are not limited to, a band dryer, a tunnel dryer, and a vertical silo dryer.

First, a method of performing a stationary drying process after a fluidized drying process will be described. Air or an inert gas (nitrogen gas,
Helium gas, argon gas, etc.), and the temperature of the heating gas is preferably 95 ° C. or less, more preferably 40 ° C.
When the temperature exceeds 95 ° C, pellet-like or powder-like EVOH undesirably fuses. Further, the velocity of the heating gas in the dryer is 0.7 to 10
m / sec, more preferably 0.7 to 5.
At a speed of less than 0.7 m / sec, fusion of pellet-like or powder-like EVOH is likely to occur.
If it exceeds m / sec, chipping of pellets and generation of fine powder are likely to occur, which is not preferable. In addition, the time for fluidized drying depends on the treatment amount of the resin composition, but is usually preferably 5 minutes to 36 hours, and more preferably 10 minutes to 24 hours.

The resin composition is subjected to a fluid drying treatment under the above conditions, and the water content of the resin composition after the treatment is 5.
When the water content is less than 5.0% by weight, discharge fluctuations occur when the final product after the standing drying treatment is melt-molded. Conversely, if the content exceeds 60% by weight, fusion of the pellet-like or powder-like resin composition is likely to occur during the subsequent standing drying treatment, and a fine fisheye may be formed when the obtained resin composition is melt-molded. It is not preferable because it tends to occur frequently. In addition, in such a fluidized drying treatment, it is preferable to lower the water content by 5.0% by weight or more (more preferably 10 to 45% by weight) than before the treatment. In addition, when the obtained resin composition is melt-molded, fine fish eyes tend to occur frequently, which is not preferable.

The resin composition subjected to the fluid drying treatment as described above is then subjected to a stationary drying treatment. The heating gas used for the stationary drying treatment is also an inert gas (nitrogen gas, helium gas). Gas, argon gas, etc.), but the temperature of the heating gas is preferably 75 ° C. or higher, more preferably 85 to 150 ° C., and when the temperature is lower than 75 ° C., the drying time needs to be extremely long, It is economically disadvantageous and is not preferred. Further, the gas velocity in the dryer is 1.0 m
/ Sec or less, more preferably 0.01 to
0.5 m / sec is preferable, and the speed is 1 m / sec.
When the value exceeds c, it is difficult to keep the resin composition in a stationary state, which is not preferable. In addition, the time of the standing drying treatment cannot be unconditionally determined depending on the treatment amount of the resin composition, but is usually from 10 minutes to
72 hours is preferable, and 1.0 to 48 hours is more preferable.

Under the above conditions, the resin composition is subjected to a stationary drying treatment to finally obtain a target resin composition. The water content of the resin composition after the treatment (final) is 0.00
The content is preferably set to 1 to 2.0% by weight (more preferably 0.01 to 1.0% by weight). If the water content is less than 0.001% by weight, the long-run moldability of the resin composition decreases. Conversely, if it exceeds 2.0% by weight, water foaming tends to occur in the molded product, which is not preferable.

Next, a method of performing a fluidized drying treatment after the stationary drying treatment will be described. The conditions at the time of the static drying at this time are basically the same as the conditions at the time of the static drying, but the temperature of the heating gas is preferably 100 ° C. or less, and more preferably 40 to 95 ° C. ° C is preferred and the temperature is 1
If the temperature exceeds 00 ° C., pellet-like or powder-like EVOH is liable to be fused, which is not preferable. In addition, the time for the standing drying treatment depends on the treatment amount of the resin composition, but is usually preferably 10 minutes to 48 hours, and more preferably 30 minutes to 36 hours.
Time is preferred.

The water content of the resin composition after the treatment is 10 to 7
It is preferably 0% by weight (more preferably 15 to 60% by weight). When the water content is less than 10% by weight, when the final product after the fluidized drying treatment is melt-molded, fine fish eyes tend to occur frequently. On the contrary, even if it exceeds 70% by weight,
When the final product is melt-molded, discharge fluctuations are likely to occur, which is not preferable. Further, in such a stationary drying process,
It is preferable to lower the water content by 3.0% by weight or more (more preferably 5.0 to 30% by weight) before the treatment, and when the decrease in water content is less than 3.0% by weight, fine powder is added to the final product. This is not preferable because chipping or chipping of the pellet is likely to occur.

The resin composition subjected to the stationary drying treatment as described above is then subjected to a fluidized drying treatment. The conditions of the fluidized drying treatment are basically the same as those of the fluidized drying treatment described above. However, the temperature of the heating gas is preferably 80 ° C. or higher, more preferably 95 to 150 ° C. If the temperature is lower than 80 ° C., the drying time needs to be extremely long, which is economically disadvantageous. It is not preferable. The time of the fluidized drying treatment also depends on the treatment amount of the resin composition, but is usually preferably 10 minutes to 48 hours, more preferably 30 minutes to 24 hours.

Through such a fluidized drying treatment, a resin composition having a desired water content of 0.001 to 2.0% by weight is finally obtained in the same manner as described above. In the present invention, the content of acetate (B) relative to 100 parts by weight of EVOH (A) in the obtained resin composition is 0.1% in terms of metal of the salt.
001 to 0.05 parts by weight (further 0.0015 to 0.0
4 parts by weight, especially 0.002 to 0.03 parts by weight). If the amount of the acetate (B) is less than 0.001 part by weight, the moldability of the target resin composition is poor. Conversely, if the content exceeds 0.05 parts by weight, the appearance of the molded product is deteriorated.

In order to adjust the content of the acetate (B), the concentration of the aqueous solution of the acetate (B), the water content of the EVOH (A), the contact time, the temperature, and the stirring speed during the contact treatment described above. Etc. may be controlled, and there is no particular limitation. According to the method of the present invention as described above, a resin composition having excellent heat stability and long-run moldability can be obtained. However, such a resin composition may further include a plasticizer and a heat stabilizer, if necessary. It is also possible to use additives such as ultraviolet absorbers, antioxidants, coloring agents, antibacterial agents, fillers, and other resins. In particular, a hydrotalcite-based compound, a hindered phenol-based, a hindered amine-based heat stabilizer, and a metal salt of a higher aliphatic carboxylic acid can also be added as a gel generation inhibitor. It is also possible to use two or more different EVOHs as the EVOH (A). In this case, a blend of EVOHs having an ethylene content different by 5 mol% or more and / or a saponification degree different by 1 mol% or more. By using the material, while maintaining the gas barrier properties,
Further, it is useful because the stretchability at the time of high stretching and the secondary workability such as vacuum pressure forming and deep drawing are improved.

The resin composition thus obtained is frequently used for molded articles, and is formed into pellets, films, sheets, containers, fibers, rods, tubes, various molded articles by melt molding or the like. Pulverized products (such as when reused products are reused) or pellets can be used for melt molding again. Examples of such melt molding methods include extrusion molding methods (T-die extrusion, inflation extrusion, blow molding, melt spinning). , Profile extrusion, etc.) and injection molding.
The melt molding temperature is often selected from the range of 150 to 300 ° C. In addition, the resin composition obtained in the present invention can be used as a single layer, but as described above, the effect of the present invention can be sufficiently exerted, particularly when the resin composition is used for a laminated body. Specifically, it is useful to laminate a thermoplastic resin layer or the like on at least one surface of a layer made of the resin composition and use it as a multilayer laminate.

In producing the laminate, another substrate is laminated on one or both sides of the resin composition layer. The laminating method is, for example, a method in which a film or sheet of the resin composition is heat-coated. A method of melt-extruding a thermoplastic resin, a method of melt-extruding the resin composition on a base material such as a thermoplastic resin, a method of co-extrusion of the resin composition with another thermoplastic resin, and further a method of the present invention. A method of dry laminating a film or sheet of the obtained resin composition and a film or sheet of another substrate with a known adhesive such as an organic titanium compound, an isocyanate compound, a polyester compound, or a polyurethane compound, and the like. Can be

In the case of co-extrusion, the mating resin includes 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 polybutenes and polypentenes, or 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. EVOH can also be co-extruded. Among these, polypropylene, polyamide, polyethylene, ethylene-vinyl acetate copolymer, polystyrene, and PET are preferably used from the viewpoint of ease of coextrusion film formation and practicality of film physical properties (particularly strength).

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

The layer structure of the laminate is such that the layer of the resin composition obtained in the present invention is a (a ₁ , a ₂ ,...) And another base material, for example, a thermoplastic resin layer is b (b ₁ , B ₂ ,...), In the case of a film, sheet, or bottle, not only a / b two-layer structure but also b / a / b, a / b / a, a ₁ / a ₂
/ B, a / b ₁ / b ₂ , b ₂ / b ₁ / a / b ₁ / b _{2, and} any combination is possible. In the filament form, a and b are bimetallic, and the core (a) -sheath ( Any combination such as b) type, core (b) -sheath (a) type, or eccentric core-sheath type is possible.

The laminate is used as it is in various shapes. However, in order to further improve the physical properties of the laminate, it is preferable to carry out a stretching treatment.
Either uniaxial stretching or biaxial stretching may be used. Stretching at the highest possible magnification is preferable in terms of physical properties, such as a stretched film or a stretched sheet which does not generate pinholes, cracks, stretch unevenness, delamination, etc. during stretching. Is obtained.

The stretching method includes a roll stretching method, a tenter stretching method, a tubular stretching method, a stretching blow method, and the like.
Of the deep drawing, vacuum forming and the like, those having a high stretching ratio can be employed. 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
To 170 ° C, preferably about 100 to 160 ° C.

After the completion of the stretching, heat setting is then 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.
Further, when used for heat shrink packaging of raw meat, processed meat, cheese, etc., the product film is not heat-set after stretching, and the raw meat, processed meat, cheese, etc. are stored in the film, 50-130 ° C, preferably 70-120 ° C
Then, the film is subjected to a heat treatment for about 2 to 300 seconds to thermally shrink the film to perform tight packaging.

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.

[0030]

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 EVOH [Ethylene content 35 mol%, saponification degree 99.
5 mol%, MI 12 g / 10 min (210 ° C., load 216
0 g)] water / methanol of (A) (water / methanol = 4)
0/60 mixture weight ratio) solution (60 ° C, EVOH concentration 45
%) Was extruded into a water tank maintained at 5 ° C. in the form of a strand and solidified, and then cut with a cutter to obtain pellet-shaped (4 mm in diameter and 4 mm in length) EVOH.
H was poured into warm water of 30 ° C., and the mixture was stirred for about 4 hours to obtain a porous precipitate having a water content of 50% (microporous having an average diameter of 4 μm was uniformly present). Next, 100 parts of the obtained porous precipitate was put into 200 parts of a 0.05% aqueous solution of calcium acetate (B) (0.04 part of calcium acetate (B) based on 100 parts of total water), and 30 ° C. For 5 hours, and a resin composition comprising EVOH (A) and acetate (B) [containing 0.008 parts by weight of acetate (B) in terms of calcium based on 100 parts by weight of EVOH (A)] I got The obtained resin composition was dried by the following method.

<Fluidized drying step> The resin composition obtained above was dried for about 3 hours while flowing nitrogen gas at 75 ° C using a batch type fluidized bed dryer (tower type) to obtain a water content. A resin composition of 20% was obtained. In addition, the water content of the resin composition before fluid drying was 50%, and the difference in water content between the resin composition before and after fluid drying was 30%. <Standing drying step> Next, the resin composition after the fluidized drying treatment was dried with a nitrogen gas at 125 ° C for about 18 hours using a batch-type box dryer (ventilated) to obtain a water content of 0.3. % Of the target resin composition [containing 0.008 parts by weight of acetate (B) in terms of calcium based on 100 parts by weight of EVOH (A)].

Next, the obtained resin composition was supplied to a multilayer extruder equipped with a feed block 5-layer T-die, and a polyethylene layer (“Novatech LD LF5” manufactured by Mitsubishi Chemical Corporation) was used.
25H ") / adhesive resin layer (" Modic A "manufactured by Mitsubishi Chemical Corporation)
P240H ") / resin composition layer / adhesive resin layer (same as left) /
A multilayer laminate (thickness: 50/10/20/10/50 (μm)) of three types and five layers of polyethylene layers (same as the left) was obtained, and a fine fisheye having a diameter of less than 0.1 mm was obtained in the following manner. Generation and long-run formability were evaluated. (Fisheye) Film immediately after molding (10c
mx 10 cm) with a diameter of 0.01 to 0.1 mm
The occurrence of fish eyes of less than was visually observed and evaluated as follows. ◎ −−− 0 to 3 pieces ○ −−− 4 to 10 pieces △ −−− 11 to 50 pieces × −−− 51 or more (long-run moldability) In the same manner, the increase in the number of fish eyes was visually observed with respect to the formed film, and evaluated as follows. ○ −−− No increase was observed △ −−− A slight increase was observed × −−− A remarkable increase was observed

Example 2 EVOH [Ethylene content 40 mol%, saponification degree 99.
0 mol%, MI 6 g / 10 min (210 ° C., load 2160
g)] water / methanol of (A) (water / methanol = 20)
/ 80 mixture weight ratio) The solution (60 ° C) was extruded into a water tank maintained at 5 ° C in the form of a strand and solidified, and then cut with a cutter to obtain a pellet-shaped (4 mm in diameter and 4 mm in length) EVOH. Further, after washing the EVOH with warm water at 30 ° C., throw it into an acetic acid aqueous solution and stir for about 2 hours to remove a porous precipitate having a water content of 55% (microporous having an average diameter of 5 μm is uniformly present). Obtained. Next, 100 parts of the obtained porous precipitate is put into 300 parts of a 0.06% aqueous potassium acetate (B) solution (0.05 parts of potassium acetate (B) is added to 100 parts of total water), and 30 ° C. And stirred for 5 hours.
A resin composition comprising VOH (A) and acetate (B) [E
Acetate (B) is contained in an amount of 0.01 part by weight in terms of potassium based on 100 parts by weight of VOH (A). The obtained resin composition was dried by the following method.

<Fluidized drying step> The resin composition obtained above was heated to 75 ° C using a fluidized bed drier (continuous horizontal multi-chamber type).
The resin was dried for about 3 hours while flowing nitrogen gas to obtain a resin composition having a water content of 20%. The water content of the resin composition before fluid drying was 55%, and the difference in water content of the resin composition before and after fluid drying was 35%. <Standing drying step> Next, the resin composition after the fluidized drying treatment was dried with nitrogen gas at 120 ° C. for about 24 hours using a batch-type box dryer (vented) to obtain a water content of 0.2. % Of the target resin composition [containing 0.01 part by weight of acetate (B) in terms of potassium based on 100 parts by weight of EVOH (A)]. The obtained resin composition was evaluated in the same manner as in Example 1.

Example 3 A target resin composition was obtained in the same manner as in Example 1 except that the drying treatment was performed in the following manner, except that the drying treatment was changed as follows. <Standing drying step> The obtained resin composition is dried with a nitrogen gas at 70 ° C for about 5 hours using a batch box dryer (ventilation type) to obtain a resin composition having a water content of 30%. Obtained. In addition, the water content of the resin composition before standing drying was 50%, and the difference in water content of the resin composition before and after standing drying was 20%. <Flow drying step> Next, the resin composition after the standing drying treatment was dried for about 18 hours while flowing nitrogen gas at 120 ° C using a batch-type box dryer (ventilation type) to obtain a water-containing composition. A target resin composition having a rate of 0.2% was obtained.

Example 4 EVOH [Ethylene content 30 mol%, saponification degree 99.
6 mol%, MI 12 g / 10 min (210 ° C., load 216
0 g)] water / methanol of (A) (water / methanol = 5)
(0/50 mixture weight ratio) The solution (60 ° C.) was extruded into a water tank maintained at 5 ° C. in the form of a strand and solidified, and then cut with a cutter to form a pellet (diameter 4 mm, length 5 mm).
After washing the EVOH with warm water at 30 ° C., throw it into an acetic acid aqueous solution and stir for about 2 hours to obtain a porous precipitate having a water content of 50% (microporous having an average diameter of 4 μm in diameter). Uniformly present). Next, 100 parts of the obtained porous precipitate was added to 250 parts of a 0.06% aqueous sodium acetate (B) solution, and the mixture was stirred at 30 ° C. for about 4 hours.
A resin composition comprising VOH (A) and acetate (B) [E
Acetate (B) is contained in an amount of 0.015 part by weight in terms of sodium based on 100 parts by weight of VOH (A). The obtained resin composition was dried by the following method.

<Still drying step> The obtained resin composition was subjected to 70 ° C. nitrogen gas using a batch-type air-flow box type drier.
Drying was performed for about 8 hours to obtain a resin composition having a water content of 25%. In addition, the water content of the resin composition before standing drying was 50%.
The difference in water content of the resin composition before and after drying under standing was 25%. <Flow drying step> Next, the resin composition after the standing drying treatment was dried for about 18 hours using a batch type fluidized bed dryer while flowing nitrogen gas at 125 ° C to obtain a water content of 0. 0.3% of the target resin composition [EVOH (A) 10
Acetate (B) is contained in an amount of 0.015 part by weight in terms of sodium based on 0 parts by weight]. The obtained resin composition was evaluated in the same manner as in Example 1.

Comparative Example 1 The procedure of Example 1 was repeated, except that the water content of the porous precipitate of EVOH (A) was adjusted to 10%, to thereby prepare a resin composition [100 parts by weight of EVOH (A). , Containing 0.01 parts by weight of acetate (B) in terms of calcium], dried under the same conditions, and evaluated in the same manner. However, the water content of the resin composition after the fluidized drying treatment was 6%.
%, And the resin composition [EVOH (A) 1
The amount of acetate (B) is 0.01 part by weight in terms of calcium based on 00 parts by weight].

Comparative Example 2 A resin composition [EVOH] was prepared in the same manner as in Example 1 except that the water content of the porous precipitate of the water / methanol solution after saponification of EVOH (A) was adjusted to 90%. (A) 1
0.005 parts by weight of the acetate (B) with respect to 00 parts by weight], dried under the same conditions, and evaluated in the same manner. However, the water content of the resin composition after the fluid drying treatment was 30%, and the resin composition after the standing drying treatment [100 parts by weight of EVOH (A) was used.
Containing 0.005 parts by weight of acetate (B) in terms of calcium]. The final moisture content was 0.3%.

Comparative Example 3 The procedure of Example 1 was repeated, except that the acetate (B) was adjusted to 0.0005 parts with respect to 100 parts of the total water, to obtain a resin composition [100 parts by weight of EVOH (A). , Containing 0.0006 parts by weight of acetate (B) in terms of calcium], dried under the same conditions, and evaluated in the same manner. However, the water content of the resin composition after the fluid drying treatment was 20%, and the resin composition after the standing drying treatment [100 parts by weight of the EVOH (A) and the acetate (B)
Of 0.0006 parts by weight in terms of calcium] was 0.3%.

COMPARATIVE EXAMPLE 4 The procedure of Example 1 was repeated except that the amount of acetate (B) was adjusted to 1 part with respect to 100 parts of total water. Containing 0.1 part by weight of salt (B) in terms of calcium], and then subjected to a drying treatment under the same conditions, and evaluated in the same manner. However, the water content of the resin composition after the fluidized drying treatment is 2%.
0%, the resin composition after standing drying treatment [EVOH (A)
The acetate (B) was contained in an amount of 0.1 part by weight in terms of calcium with respect to 100 parts by weight], and the final moisture content was 0.3%. Table 1 shows the evaluation results of the examples and comparative examples.

[0042]

[Table 1] Fisheye long-run moldability Example 1 ◎ ○ 〃 2 ◎ ○ 〃 3 ◎ ○ 〃 4 ◎ ○ Comparative Example 1 × △ 〃 2 △ × ３ 3 ○ × ４ 4 × ×

[0043]

The resin composition obtained by the method of the present invention comprises:
When formed into a multilayer laminate, there is no generation of fine fish eyes having a diameter of less than 0.1 mm, and it has excellent long-run moldability, and can be used as various laminates, and can be used in foods and pharmaceuticals,
It is very useful for applications such as films, sheets, tubes, bags, containers and the like for packaging of agricultural chemicals and industrial chemicals, and can also be suitably used for secondary processed products involving stretching.

Claims (4)

[Claims] An acetate (B) is added in an amount of 0.001 to 100 parts by weight of a saponified ethylene-vinyl acetate copolymer (A).
When producing a resin composition containing 0.05 to 0.05 parts by weight (in terms of metal), ethylene-containing water having a water content of 20 to 80% by weight is used.
The saponified vinyl acetate copolymer (A) is brought into contact with an aqueous solution of an acetate (B), and the content of the acetate (B) in the aqueous solution of the acetate (B) is adjusted to the saponified ethylene-vinyl acetate copolymer (A). ) And the total amount of water contained in the aqueous solution of acetate (B) is from 0.001 to 0.
A method for producing a resin composition, comprising 5 parts by weight. 2. The ethylene-vinyl acetate copolymer saponified product (A) is a porous precipitate.
A method for producing the resin composition as described above. 3. The method according to claim 1, wherein the saponified ethylene-vinyl acetate copolymer (A) is brought into contact with the acetate (B), followed by fluid drying, and static drying before or after the fluid drying. The method for producing a resin composition according to claim 1. 4. The method for producing a resin composition according to claim 3, wherein the difference between the moisture content of the resin composition before and after the fluidized drying is 5.0% by weight or more.