JPH11246729A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin compsn. which is excellent in gas barrier properties esp. at a high humidity by compounding PVA, a water-soluble polyacrylic acid compd., and an inorg. layered compd. SOLUTION: PVA pref. having a degree of saponification of 70% or higher and a degree of polymn. of 100-10,000, a water-soluble polyacrylic acid compd. (e.g. polyacrylic acid), and an inorg. layered compd. (e.g. montmorillonite) pref. having an aspect ratio of 50-5,000 and/or a particle size of 1 μm or lower are compounded by treating them pref. with a high-pressure dispersing apparatus. Pref., the wt. ratio of PVA to the water-soluble polyacrylic acid compd. is (95/5)-(20/80) and/or the vol. ratio of the inorg. layered compd. to the sum of PVA and the water-soluble polyacrylic acid compd. is (10/1)-(1/100). Pref., the high-pressure dispersing apparatus is one which performs dispersion treatment under a pressure of 100 kgf/cm<2> or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin composition.

[0002]

2. Description of the Related Art Polyvinyl alcohol, which has high gas barrier properties at a low relative humidity among resins, has been conventionally used for packaging materials and the like. Improvements have been made to provide high barrier properties in high relative humidity conditions,
A film comprising a composition in which PVA and polyacrylic acid are mixed has been reported (JP-A-6-220221).

[0003]

SUMMARY OF THE INVENTION However, PVA
The gas barrier property at a high relative humidity was not yet sufficient even with a mixture of styrene and polyacrylic acid. An object of the present invention is to provide a resin composition having excellent gas barrier properties, particularly excellent gas barrier properties at high relative humidity.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention provides a resin composition comprising polyvinyl alcohol, a water-soluble polyacrylic acid-based compound, and an inorganic layered compound.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The polyvinyl alcohol (hereinafter referred to as PV) used in the present invention
A may be referred to as A) is a polymer having a monomer unit of vinyl alcohol as a main component. Examples of such polyvinyl alcohol include, for example, a polymer obtained by hydrolyzing or transesterifying (saponifying) an acetic ester portion of a vinyl acetate polymer (exactly a copolymer of vinyl alcohol and vinyl acetate). And
Polymers obtained by saponifying trifluorovinyl acetate polymer, vinyl formate polymer, vinyl pivalate polymer, t-butyl vinyl ether polymer, trimethylsilyl vinyl ether polymer and the like (for details of “polyvinyl alcohol”, For example, Povarkai,
"The world of PVA", 1992, Polymer Publishing Association;
Nagano et al., "Poval", 1981, High Polymer Publishing Association) can be referred to).

"Saponification" in polyvinyl alcohol
Is preferably 70% or more in terms of mole percentage, and more preferably 85% or more. The degree of polymerization of polyvinyl alcohol is 100 or more and 10,000 or less (further,
200 to 6000, in particular, 300 to 3000).

In the present invention, a polyvinyl alcohol derivative having a functional group other than a hydroxyl group may be used as the polyvinyl alcohol. Examples of the functional group other than the hydroxyl group include an amino group, a thiol group, a carboxyl group, a sulfone group, and a phosphate group. Carboxylate group, sulfonic acid ion group, phosphate ion group, ammonium group, phosphonium group, silyl group, siloxane group, alkyl group, allyl group, fluoroalkyl group, alkoxy group, carbonyl group, halogen group and the like. Some or all of the hydroxyl groups in PVA may be replaced by one or more of these functional groups.

In the present invention, the water-soluble polyacrylic acid compound is a water-soluble compound among polyacrylic acid and compounds having a chemical structure similar to that of polyacrylic acid in a part of the molecule. Acid, polymethacrylic acid, sodium polyacrylate, sodium polymethacrylate, partially neutralized polyacrylic acid, partially neutralized polymethacrylic acid, partially esterified polyacrylic acid, partially esterified polymethacrylic acid, etc. Is included. The weight ratio of PVA / water-soluble polyacrylic acid compound is preferably from 95/5 to 20/80.

The inorganic layered compound used in the present invention is a compound or a substance having a layered structure in which unit crystal layers are stacked on each other. Here, the layered structure means that atoms are strongly bonded by a covalent bond or the like to form a dense structure. The surface arranged in
It refers to a structure that is stacked almost in parallel by weak coupling force such as van der Waals force.

Specific examples of the inorganic layered compound include graphite, phosphate derivative type compounds (zirconium phosphate type compounds, etc.), chalcogenides, hydrotalcite compounds, lithium aluminum composite hydroxides, clay minerals and the like. Can be mentioned. Here, “chalcogenide” refers to group IV (Ti, Zr, Hf) and group V (V, N
b, Ta) and / or a dichalcogenide of a group VI (Mo, W) element, which is represented by the formula MX ₂ (M is the above element, and X is chalcogen (S, Se, Te)). Say. From the viewpoint of dispersibility, an inorganic layered compound having the property of swelling and cleaving in a solvent as described below is preferable, and a clay mineral having swelling and cleaving property in a solvent is particularly preferable.

The degree of "swelling / cleaving" of the inorganic layered compound in a solvent can be evaluated by the following "swelling / cleaving" test. The swellability of the inorganic stratiform compound is preferably about 5 or more (more preferably about 20 or more) in the swellability test described below. On the other hand, the cleavage property of the inorganic layered compound is preferably about 5 or more (more preferably about 20 or more) in the following cleavage test. In these cases, a solvent having a density smaller than the density of the inorganic layered compound is used as the solvent. When the inorganic stratiform compound is a natural swellable clay mineral, it is preferable to use water as the solvent.

<Swellability test> 2 g of the inorganic layered compound is slowly added to 100 mL of a solvent (a 100 mL graduated cylinder is used as a container). After standing, the volume of the former (inorganic layered compound dispersed layer) is read from the scale at the interface between the inorganic layered compound dispersed layer and the supernatant after 24 hours at 23 ° C. The larger the value, the higher the swelling property.

<Cleaving test> 30 g of an inorganic layered compound was slowly added to 1500 mL of a solvent, and a dispersing machine (Despar MH-L, manufactured by Asada Tekko Co., Ltd., blade diameter 52 mm, rotation speed 3100 rpm, container capacity 3 L, bottom-blade distance) Distance 2
(8 mm) at a peripheral speed of 8.5 m / sec for 90 minutes (23 ° C.), take 100 mL of the dispersion, put it in a graduated cylinder and let it stand for 60 minutes, then, from the interface with the supernatant, the volume of the inorganic layered compound dispersion layer I Read.

The clay mineral generally has a two-layer structure having an octahedral layer made of aluminum, magnesium or the like as a central metal on a silica tetrahedral layer; and a silica tetrahedral layer comprising aluminum or magnesium. It is classified into a type having a three-layer structure in which an octahedral layer made of magnesium or the like as a central metal is narrowed from both sides. The former two-layer structure type includes kaolinite group and antigolite group, and the latter three-layer structure type includes smectite group, vermiculite group and mica group depending on the number of interlayer cations. Can be.

More specifically, these clay minerals include kaolinite, dickite, nacrite, halloysite, antigorite, chrysotile, pyrophyllite, montmorillonite, hectorite, tetrasilyl mica, sodium teniolite, Examples include muscovite, margarite, talc, vermiculite, phlogopite, zansophyllite, and chlorite. In addition, reference can be made to literatures such as Haruo Shimizu, "Clay Mineralogy", 1988, Asakura Shoten Co., Ltd.

The resin composition of the present invention contains the above-mentioned PVA, a water-soluble polyacrylic acid-based compound and an inorganic layered compound, and may further contain a solvent as described below. The manufacturing method is, for example, PV
A, the polyacrylic acid-based compound and the inorganic layered compound may be mixed or kneaded, but from the viewpoint of the dispersibility of the inorganic layered compound, PVA, the polyacrylic acid-based compound and the inorganic layered compound are separately dissolved or dispersed in a solvent. Then, a method of separately dissolving or dispersing the PVA, the polyacrylic acid-based compound and the inorganic layered compound in a solvent in a solvent and treating the resulting mixture in a high-pressure dispersing apparatus, followed by mixing, a method of mixing the PVA, the polyacrylic Examples of the method include mixing an acid-based compound and an inorganic layered compound and treating the mixture with a high-pressure dispersing apparatus, and treating the inorganic layered compound with a high-pressure dispersing apparatus and mixing the PVA and the polyacrylic acid-based compound. From the viewpoint of the dispersibility of the inorganic layered compound in the product, it is more preferable to carry out the treatment with a high-pressure dispersion device.

A high-pressure dispersing device is a device in which a mixture of particles to be dispersed and a medium such as a solvent is caused to pass through a plurality of thin tubes at high speed to collide with each other, so that a special condition such as high shearing or high pressure is applied. It is a device to produce. For example, the composition is preferably passed through a thin tube having a diameter of 1 to 1000 μm, and the composition has a maximum pressure condition of 100 kgf / c.
m ² or more is preferably applied, and 500 kgf
/ Cm ² or more is more preferable. When the composition passes through the high-pressure dispersion device, the maximum arrival speed of the composition is 100 m /
sec. or more, and the heat transfer rate is 1
It is preferably at least 00 kcal / hr.

In FIG. 1, the high
The principle of the high pressure processing unit in the pressure dispersion processing device is schematically shown.
Was. In FIG. 1, the pumps shown in FIG.
High pressure is applied to the processed sample in the tube section. And momentarily
The flow velocity at the point where the maximum velocity is reached is, for example, 300 m / sec.
In the case of c, the volume is 1 × 10^-3m^Three1 / (3 ×
10^Five) Pass in sec, sample temperature rises by 35 ° C
Energy transfer to the sample due to pressure loss
It is. The specific gravity of the sample is 1g / cm ^Three,specific heat
3.8 × 10 at 1 cal / g ° C.^Four kcal / h
r.

As such a high-pressure dispersion device, for example, Mi
ultra high pressure homogenizer (trade name: Microfluidizer) manufactured by crofluidics Corporation
Alternatively, there is a Nanomizer manufactured by Nanomizer, and a Menton-Gaulin-type high-pressure dispersing apparatus, such as a homogenizer manufactured by Izumi Food Machinery, may be used. When a microfluidizer is used as the high-pressure dispersing device, it is preferable to use a solution obtained by dissolving PVA and a polyacrylic acid-based compound in a solvent described below from the viewpoint of fluidity and the like.

Before and after the treatment in the high-pressure dispersion device, the PV
A, any operation may be performed on the water-soluble polyacrylic acid-based compound, the inorganic layered compound, and the composition thereof. The operations include mixing, separation, stirring, dissolving, dispersing, heating, cooling, drying, defoaming, extraction, and standing.
For example, PVA is dissolved in a solvent, an inorganic layered compound is dispersed in water, and a mixture thereof is treated with a high-pressure dispersing apparatus to obtain an inorganic layered compound-containing composition. The composition obtained by adding an additive such as an activator and stirring can be suitably used as a coating liquid as described below.

The method of mixing PVA, a water-soluble polyacrylic compound and an inorganic layered compound is not particularly limited. For example, when a PVA solution is used as PVA, PVA is first added and dissolved in a water / alcohol mixed solvent. Then, there is a plurality of methods such as a method of adding and dispersing an inorganic layered compound, a method of adding an inorganic layered compound and PVA in this order, and a method of mixing a dispersion liquid of an inorganic layered compound and a PVA solution. A method may be used.

The mixing pot is preferably provided with a jacket on the outer wall through which a heating medium such as hot water or steam can be passed for temperature control. In addition, from the viewpoint of uniformity of bubble entrapment and dispersion, those having baffles inside the kettle are used, and for the same reason, it is preferable that the position of the dispersion wing is slightly shifted (eccentric) instead of the center of the kettle. . In order to obtain a composition having a relatively high solid content and a good dispersion, use a composition in which PVA, a water-soluble polyacrylic acid-based compound and an inorganic layered compound and a solvent are mixed, and foam is hard to be caught. The method of high-speed stirring at 4000 to 7000 rpm in a kettle in which the inside pressure is reduced to 200 mmHg or less easily obtains an effect by a high shearing force.

Examples of the solvent include alcohols such as methanol, ethanol, 2-propanol, 1-butanol, pentanol, octanol, 1,3-pentanediol, ketones such as acetone and methyl ethyl ketone, methyl acetate, and ethyl acetate. And ethers such as n-butyl cellosolve and ethylene glycol. These solvents may be used alone or in combination of two or more.

When the resin composition of the present invention contains a solvent as described above, the composition may be used as it is for coating or the like. In that case, the solvent is a liquid at around room temperature, When the composition is dried, those that evaporate easily are preferably used. Such a solvent having a boiling point of 2
Those having a temperature of 00 ° C. or lower (more preferably 140 ° C. or lower) are preferable.

When the inorganic layered compound is added in the order of adding the inorganic layered compound to the mixed solution of the PVA-polyacrylic acid-based compound, it is more preferable to stir by heating from the viewpoint of dispersibility.
A solvent having a boiling point of 50 ° C. or more (more preferably 80 ° C. or more) is preferred. From the viewpoints of the boiling point and the melting point, as the solvent, water, methanol, ethanol, 1-butanol,
2-propanol, 1-propanol and the like are particularly preferred.

When the resin composition of the present invention is used after being coated, it is preferable that the concentration of PVA, polyacrylic acid compound and inorganic layered compound is as high as possible from the viewpoint of drying properties.

The composition ratio (volume ratio) of the inorganic layered compound to the PVA and the polyacrylic acid-based compound is not particularly limited, but the volume ratio of the inorganic layered compound / (PVA + polyacrylic acid-based compound) (at the time of “preparation”). Ratio) is usually 10 /
1 to 1/100, and from the viewpoint of gas barrier properties, 5 /
It is preferably at least 95, and more preferably at most 90/10 from the viewpoint of moldability. Further, from the viewpoint of the flexibility of the obtained molded product, the volume ratio is preferably 5/95 to 30/70, and 10/90.
-30/70 is particularly preferred. When used as a film or a laminate, the volume ratio is preferably 7/93 or more from the viewpoint of suppressing deterioration in physical properties due to bending, and from the viewpoint of suppressing flexibility or peeling from the substrate. Is preferably 17/83 or less.

The above volume ratio is determined based on the “charge” of these components.
The values of the weight ratio of the numerator (weight of the inorganic layered compound) and the denominator (PVA, weight of the polyacrylic acid-based compound) at the time of
It can be obtained by dividing by each density.

The composition containing an inorganic layered compound of the present invention includes:
Various solvents can be blended for the purpose of improving coating properties and adjusting viscosity, and additives can be blended as necessary. Examples of additives include pigments, surfactants, fungicides, preservatives, crosslinking agents, defoamers, antioxidants, and the like.

Examples of the pigment include a rust preventive pigment for a primer, a coloring pigment, a metal foil pigment, a brilliant pigment, an extender pigment and the like. Examples of the rust preventive pigment for a primer include strontium chromate, zinc chromate, zinc phosphate, lead red, zinc white, basic sulfate, and basic carbonate. Examples of the coloring pigment include phthalocyanine blue, phthalocyanine green, quinacdrine, indanthrone, isoindolinone, berylene, anthrapyrimidine, benzimidazolone, carbon black, titanium dioxide, graphite, yellow iron oxide, and red iron oxide.

As the metal foil pigment, aluminum foil, bronze foil, tin foil, gold foil, silver foil, copper foil, titanium metal foil, stainless steel foil, nickel foil, chromium foil, alloy foil of the above metals, and metal coated with plastic Foil and the like.

The glitter pigments include mica foil and foil-like phthalocyanine blue, and the extender pigments include calcium carbonate, gypsum, clay and talc.

As the surfactant, for example, nonionic,
It can be appropriately selected and used from any surfactants such as anionic, cationic and amphoteric surfactants in consideration of workability such as stability of processing solution, foaming property and coating property.

Examples of the nonionic surfactant include polyoxyethylene glycol, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glycol, polyoxyethylene alkyl phenyl ether, glycerin fatty acid partial ester, sorbitan fatty acid partial ester, and pentaerythritol fatty acid. Partial esters, polyoxyethylene sorbitan acid fatty partial esters, and polyoxyethylene alkyl ethers are exemplified.

Examples of the anionic surfactant include dialkyl sulfosuccinate, alkane sulfonate, alkylbenzene sulfonate, alkylnaphthalene sulfonate, polyoxyethylene alkyl sulfophenyl ether salt,
Examples thereof include alkyl phosphate salts, polyoxyethylene alkyl ether phosphate salts, fatty acid alkyl ester sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, and fatty acid monoglyceride sulfates. Examples of the cationic activator include an alkylamine salt and a dialkylamine salt, and examples of the amphoteric system include N, N, N-trialkyl-N-sulfoalkylene ammonium betaine.

The fungicides and preservatives include the fourth
Grade ammonium salts, nitrogen-containing sulfur compounds, halogen-containing nitrogen-sulfur compounds, organic iodine-based compounds, benzimidazole-based compounds, and the like can be used. Specific examples of the fungicide include 2-thiazol-4-ylbenzimidazole, methylbenzimidazol-2-ylcarbamate, N-dichlorofluoromethylthio-N ′, N′-dimethyl-N-phenylsulfamide, Methylthiuram disulfide, N- (trichloromethylthio)-
4-cyclohexene-1,2-dicarboximide,
2,4,5,6-tetrachloro-1,3-isophthalonitrile, and 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, bis (2-pyridylthio)
-Zinc-1,1-dioxide, etc., but considering heat resistance, 2-thiazol-4-ylbenzimidazole, methylbenzimidazol-2-ylcarbamate and 2,4,5,6-tetrachloro- 1,3-isophthalonitrile, bis (2-pyridylthio) -zinc-1,
1-dioxide is preferred.

Specific examples of the antibacterial agent include 1,2-benzisothiazolin-3-one (BIT),
2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, 10,10'-oxybisphenoxyarsine and the like are used.

Examples of the crosslinking agent include a titanium-based coupling agent, a silane-based coupling agent, a melamine-based coupling agent, an epoxy-based coupling agent, an isocyanate-based coupling agent, a copper compound, and a zirconium compound. From the viewpoint of improving water resistance, a zirconium compound is particularly preferably used. Specific examples of the zirconium compound include, for example, zirconium halides such as zirconium oxychloride, zirconium hydroxychloride, zirconium tetrachloride, and zirconium bromide; zirconium sulfate;
Zirconium salts of mineral acids such as basic zirconium sulfate and zirconium nitrate; zirconium salts of organic acids such as zirconium formate, zirconium acetate, zirconium propionate, zirconium caprylate and zirconium stearate; zirconium ammonium carbonate, sodium zirconium sulfate and zirconium acetate Zirconium complex salts such as ammonium, sodium zirconium oxalate, sodium zirconium citrate and ammonium zirconium citrate; The amount of the crosslinking agent to be added is not particularly limited, but the ratio (K = CN / H) of the number of moles of the crosslinking group (CN) of the crosslinking agent to the number of moles of the hydrogen bonding group (HN) of the resin
N) is preferably used so as to be in the range of 0.001 or more and 10 or less. More preferably, the molar ratio K is in the range of 0.01 or more and 1 or less.

When the resin composition of the present invention is used as a coating liquid, a solvent can be added for further improving the wettability during coating. As the solvent, a solvent which is a liquid at around room temperature and which evaporates when applied to a substrate and dried is preferably used. This includes, for example, methanol, ethanol, 2-propanol, 1
-Alcohols such as butanol, pentanol and octanol; acetone, methyl ethyl ketone, and ethyl acetate. A plurality of types of solvents may be used. The liquid thus prepared can be used by coating, dip coating, or brush.

The following are examples of indices for evaluating the dispersibility of the inorganic layered compound in the resin composition of the present invention. In the case of a liquid composition dispersed in a solvent, a method of thinly casting the composition on a smooth base material (for example, a glass plate) and judging by comparing the appearance (if the dispersion is poor, agglomeration The average particle diameter of the inorganic layered compound when dispersed in a PVA solution or dispersion (based on the average particle diameter (R0) of the inorganic layered compound when dispersed alone in the dispersion medium), R) is close to the value of R0.

The average particle size of the inorganic layered compound in the composition can be determined by a method based on a diffraction / scattering method, a method based on a dynamic light scattering method, a method based on a change in electric resistance, a method based on image processing after photographing with a microscope, and the like. It is. In the method by the diffraction / scattering method, when the composition has substantially no scattering (being transparent) and the scattering derived from the inorganic layered compound is dominant, only the particle size distribution of the inorganic layered compound regardless of the presence or absence of the resin Is relatively preferably used.

In the particle size distribution and average particle size measurement by the diffraction / scattering method, a diffraction / scattering pattern obtained when light is passed through a dispersion liquid is used to calculate the particle size distribution having the most consistent pattern using Mie scattering theory or the like. This is done by doing Commercially available devices include a laser diffraction / light scattering particle size analyzer LS230, LS200, LS10 manufactured by Coulter Inc.
0, laser diffraction particle size distribution analyzer S manufactured by Shimadzu Corporation
ALD2000, SALD2000A, SALD300
0, laser diffraction / scattering type particle size distribution analyzer LA910, LA700, LA500 manufactured by Horiba, Nikkiso Microtrac SPA and Microtrac FRA.

When measuring the particle size distribution, it is preferable to measure without dilution. In the case of a liquid that is too scattered and has low light transmittance, the liquid can be measured without dilution by shortening the optical path length (for example, in the case of LA910 manufactured by HORIBA, Ltd., the optical path length is remarkably measured by a batch type cell, a paste cell, or the like). Can be shortened). However, when diluted with a solvent having the same composition as the liquid solvent composition, the dispersibility often does not change. In such a case, the dispersibility may be evaluated by measuring the diluent.

In this measuring method, if the distance between the particles is smaller than the wavelength of the light source, the particles cannot be separated and identified.
A plurality of particles close to each other (with a resin or the like therebetween) are recognized as one particle. For this reason, not only poor dispersion due to aggregation of particles but also poor dispersion caused by the presence of a resin can be evaluated by the present method.

The inorganic layered compound used in the present invention has an aspect ratio of 50 from the viewpoint of gas barrier properties.
It is preferable that the number is at least 5,000. Here, the aspect ratio (Z) is a ratio obtained from the relationship of Z = L / a. Here, L is the particle size (volume-based median diameter) of the inorganic layered compound in the dispersion obtained by the particle size measurement method by the diffraction / scattering method described above, and a is the unit thickness of the inorganic layered compound. is there. The “unit thickness a” is a value determined based on the measurement of the inorganic stratiform compound alone by a powder X-ray diffraction method or the like described later. More specifically, as shown schematically in the graph of FIG. 1 in which the horizontal axis indicates 2θ and the vertical axis indicates the intensity of the X-ray diffraction peak, it corresponds to the lowest angle peak among the observed diffraction peaks. From the angle θ
Equation of g (nλ = 2D sin θ, n = 1, 2, 3,...)
Is defined as “unit thickness a” (for details of the powder X-ray diffraction method, see, for example, Jiro Shiokawa, “Guidance on Instrumental Analysis (a)”, p. 69 (1985))
(Chemistry Doujinsha can be referred to.)

When the resin composition obtained by removing the solvent from the dispersion is subjected to powder X-ray diffraction, it is usually possible to determine the interplanar spacing d of the inorganic layered compound in the resin composition. More specifically, as shown in the graph of FIG. 2 in which the horizontal axis indicates 2θ and the vertical axis indicates the intensity of the X-ray diffraction peak,
Of the diffraction peaks observed on the lower angle (larger interval) side than the diffraction peak position corresponding to the above “unit thickness a”, the interval corresponding to the peak at the lowest angle side is referred to as “plane interval d” ( a <d). As schematically shown in the graph of FIG. 3, when it is difficult to detect the peak corresponding to the “surface distance d” by overlapping with a halo (or background), the baseline on the lower angle side than 2θd is detected. The area of the portion excluding is set as a peak corresponding to the “surface distance d”. Here, “θd” is “(unit length a) +
(The width of a single resin chain) "(for details of the method of determining the spacing d, see, for example, Shuichi Iwami et al.," Encyclopedia of Clay ", p. 35 or less and p. 271 or less,
1985, Asakura Shoten Co., Ltd. can be referred to).

As described above, the "integrated intensity" of the diffraction peak (corresponding to the plane distance d) observed in the powder X-ray diffraction of the resin composition is the same as that of the reference diffraction peak (corresponding to "plane distance a"). The relative ratio to the integrated intensity is preferably 2 or more (more preferably 10 or more). Usually, the above-mentioned surface distance d
And the value of “unit thickness a”, that is, the value of k = (da) (when converted to “length”) is equal to or less than the width of a single resin chain constituting the resin composition. Large (k = (d
-A) ≧ resin single-chain width). Such “width of single resin chain” can be determined by simulation calculation or the like (for example, “Introduction to Polymer Chemistry”, 103-1)
10, page 1981, Kagaku Doujin), and in the case of polyvinyl alcohol, it is 4 to 5 angstroms (2 to 3 angstroms for water molecules).

The above aspect ratio Z = L / a is appropriate for approximating the “true aspect ratio” with the aspect ratio Z for the following reason. That is, it is extremely difficult to directly measure the “true aspect ratio” of the inorganic layered compound in the resin composition. On the other hand, there is a relationship of a <d between the spacing d obtained by the powder X-ray diffraction method of the resin composition and the “unit thickness a” obtained by the powder X-ray diffraction measurement of the inorganic layered compound alone. When the value of (da) is equal to or greater than the width of a single resin chain in the composition, the resin is inserted between the layers of the inorganic layered compound in the resin composition. Therefore,
The thickness of the inorganic layered compound in the resin composition is approximated by the “unit thickness a”, that is, the “true aspect ratio” in the resin composition is referred to as the “aspect ratio” in the dispersion of the inorganic layered compound. Approximating with "Z" is of sufficient relevance.

As described above, it is extremely difficult to measure the true particle size in the resin composition. However, the particle size of the inorganic stratiform compound in the resin is determined in the dispersion (resin / inorganic stratiform compound / solvent). Can be considered to be quite close to the particle size of the inorganic layered compound. However, since the particle diameter L in the dispersion obtained by the diffraction / scattering method is considered to be very unlikely to exceed the major axis Lmax of the inorganic layered compound, the true aspect ratio (Lmax / a) of the present invention is not so high. The probability of being lower than the “aspect ratio Z” used in (Lmax / a <Z) is theoretically quite low.

From the above two points, it is considered that the definition Z of the aspect ratio used in the present invention has sufficient validity. In the present specification, “aspect ratio” or “particle size” means “aspect ratio Z” defined above or “particle size L determined by a diffraction / scattering method”.

From the viewpoint of gas barrier properties, the inorganic layered compound used in the present invention preferably has an aspect ratio of 50 or more, more preferably 100 or more, still more preferably 200 or more, and particularly preferably 500 or more. From the viewpoint of productivity, the aspect ratio is preferably 5,000 or less, more preferably 3,000 or less, further preferably 2,000 or less, and particularly preferably 1500 or less.

The particle size of the inorganic layered compound used in the present invention measured by the method described above is 5 from the viewpoint of moldability.
μm or less, and from the viewpoint of transparency,
Preferably it is 3 μm or less. When used for applications where transparency is more important (for example, food packaging applications), the particle size is particularly preferably 2 μm or less.

The resin composition of the present invention can be formed into a molded product by a usual film forming method such as extrusion molding or a cast film forming method. In addition, a coating method of co-extrusion with a substrate, bonding with a substrate, or coating and drying on a substrate as described below is generally used.

Examples of the coating method include a direct gravure method, a reverse gravure method, a microgravure method, a two-roll beat coating method, a roll coating method such as a bottom feed three-reverse coating method, a doctor knife method, a die coating method, and a dip coating method. Methods, bar coating methods, and coating methods combining these methods.

In the case of a laminate, the thickness of the layer formed from the resin composition depends on the intended properties of the laminate, but is preferably 30 μm or less, more preferably 10 μm or less in terms of dry thickness. Further, when the thickness is 1 μm or less, the layer formed of the composition has an advantage that the transparency is remarkably high.
The lower limit is not particularly limited, but is preferably 1 nm or more, more preferably 10 nm or more, and particularly preferably 100 nm or more, in order to obtain an effect.

The substrate is not particularly limited, and there is no particular limitation on the form such as a film, a sheet, a bottle, and a tray. The material is resin, paper, aluminum foil, wood,
Known or general materials such as cloth and nonwoven fabric can be used according to the purpose and application. In particular, when it is in the form of a film, it may be uniaxially or biaxially stretched in addition to non-stretched. Of course, well-known undercoating or corona treatment may be applied, and these surface treatments may be applied not only to the film form but also to other forms of the substrate as long as the object of the invention is not impaired.

The resins constituting the base material include polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene , Ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ionomer resin and other polyolefin resins; polyethylene terephthalate (PE
T), polyester-based resins such as polybutylene terephthalate and polyethylene naphthalate; amide-based resins such as nylon-6, nylon-6,6, methaxylenediamine-adipic acid condensation polymer, and polymethylmethacrylimide;
Acrylic resins such as polymethyl methacrylate; styrene or acrylonitrile resins such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, and polyacrylonitrile; hydrophobicized cellulose resins such as cellulose triacetate and cellulose diacetate Resins; halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polytetrafluoroethylene (Teflon); hydrogen-bonding resins such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and cellulose derivatives; polycarbonate resins; Engineering plus for polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyphenylene oxide resin, polymethylene oxide resin, liquid crystal resin, etc. Click resins.

The molded article made of the resin composition of the present invention or the laminate obtained by laminating is used for various applications. For example, a retardation film using the birefringence, a gas / low-molecular diffusion barrier film / mold using the low-molecular diffusion delay effect of a layered structure, a greenhouse for agricultural facilities, a facility for use in a facility such as a tunnel, etc. Can be used. When used as a gas barrier film for packaging foods and pharmaceuticals, the film can be used as a molded product by printing or further laminating another film.

When the substrate is a transparent material, the resin composition of the present invention preferably has transparency. The transparency is preferably about 80% or more (more preferably 85% or more, particularly 90% or more) in terms of total light transmittance at a wavelength of 500 nm. Such transparency can be suitably measured with, for example, a commercially available spectrophotometer (manufactured by Hitachi, Ltd., self-recording spectrophotometer 330). Further, the haze (HAZE) is preferably 25% or less, more preferably 20% or less.
Particularly, it is preferably 15% or less, and a commercially available haze meter (manufactured by Suga Test Instruments) is used for the measurement.

Further, from the viewpoint of gas barrier properties, the film made of the resin composition of the present invention has a thickness of 1 μm at 23 ° C. and 50% RH.
The oxygen permeability at the bottom is preferably 30 cc / m ² · day · atm or less, and is preferably 5 cc / m ² · day · at.
m or less, more preferably 1 cc / m ² · da
It is more preferable that the value be y · atm or less. When used for applications requiring more gas barrier properties, 0.1 c
c / m ² · day · atm or less, preferably 0.05 c
c / m ² · day · atm or less, more preferably 0.0
Particularly preferred is ² cc / m ² · day · atm or less.

[0061]

The resin composition of the present invention containing PVA, polyacrylic acid and an inorganic stratiform compound is excellent in dispersibility of the inorganic stratiform compound. By molding the obtained resin composition, gas barrier properties, particularly high gas barrier properties, can be obtained. It is possible to obtain a film or sheet having a sufficient gas barrier property even at a relative humidity. The laminate obtained by laminating the resin composition of the present invention is not only excellent in oxygen barrier properties, but also other gas molecules, for example, helium, nitrogen, carbon dioxide, water, limonene, low molecular weight such as menthol It is also remarkably excellent in blocking properties of aroma components and the like.

[0062]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 High-purity montmorillonite (Kunipia G; Kunimine Kogyo Co., Ltd.) as an inorganic layered compound
And polyacrylic acid (average molecular weight: 150,000) as the polyacrylic acid-based compound. Polyvinyl alcohol is PVA117H (PVA117H; Co., Ltd.)
Kuraray, saponification degree; 99.6 mol%, polymerization degree 170
0) was used. 280 kg of pure water is charged into a dispersion pot (720-liter tank with a heating jacket, manufactured by Asada Tekko Co., Ltd.)
PVA117H under stirring with a 10-inch stirring blade at Despa (DESPA MH-1600, manufactured by Asada Tekko Co., Ltd.)
Was added, and the temperature was raised. When the temperature reached 95 ° C., the mixture was stirred at that temperature for 2 hours to completely dissolve. After lowering the temperature to 40 ° C. while stirring, 1-butanol 1
8.75 kg and 56.25 kg of 2-propanol are added dropwise to give a final alcohol fraction of 20% by weight.
Then, the temperature was raised to 60 ° C., and 10 kg of high-purity montmorillonite was added. Keep the temperature at 60 ° C,
After 120 minutes, the dispersion was completed. The calculated solid content concentration was 8% by weight, and the alcohol content in the whole liquid was 20% by weight. This is designated as solution A.

Further, 320 g of a 25% polyacrylic acid solution
The mixture was diluted with 840 g of water and placed in a dispersing pot (trade name: Despa MH-L, manufactured by Asada Iron Works Co., Ltd.), and stirred (1500 rpm, peripheral speed: 4.10 m / sec) at about 60 ° C.
75 g of 1-butanol and 22 of 2-propanol
5 g were added dropwise. Thereafter, 40 g of high-purity montmorillonite was added. After confirming that the high-purity montmorillonite had substantially settled in the liquid, high-speed stirring (3100 rpm, peripheral speed 8.47 m / sec) was performed, and the dispersion was completed after 90 minutes. The calculated solid content concentration was 8% by weight, and the alcohol content in the whole liquid was 20% by weight. This is designated as solution B.

Mix 800 g of solution A and 200 g of solution B,
The liquid prepared by stirring well is subjected to a high-pressure dispersion device (trade name: ultra-high pressure homogenizer M110-E / H, Microfluidics Corpo
ration), and treated once at 1750 kgf / cm ² to obtain a uniform dispersion having good dispersibility. This is designated as liquid C. When the particle size of the liquid C is measured in the same solvent, it is 0.7.
It was 58 μm.

Example 2 The liquid C prepared in Example 1 was applied to a 12 μm-thick biaxially stretched polyethylene terephthalate film (internal corona treated product, trade name Lumirror Q27; manufactured by Toray Industries, Inc.) as a base material. Using a gravure coater, the coating was performed at a line speed of 6 m / min at a drying temperature of 100 ° C. so as to have a dry film thickness of 0.6 μm, followed by drying to obtain a laminate. In addition, a 40 μm-thick unstretched LLDP is added to the laminate thus obtained.
E-film (Inner surface corona treated product TUX-FCS
# 40; manufactured by Tocelo Co., Ltd.) was dry-laminated using a commercially available adhesive, whereby a laminate having good transparency in appearance was obtained.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing the internal structure of a high-pressure dispersing apparatus and a mechanism for dispersing particles in a fine state by high-pressure, high-shear processing.

FIG. 2 shows an X-ray diffraction peak of an inorganic layered compound,
It is a graph which shows the relationship with the "unit thickness a" of this compound typically.

FIG. 3 is a graph showing X of a resin composition containing an inorganic layered compound;
4 is a graph schematically showing a relationship between a line diffraction peak and “plane spacing d” of the composition.

FIG. 4 is an X-ray diffraction peak of the resin composition when a peak corresponding to “plane spacing d” overlaps with a halo (or background) and is difficult to detect;
It is a graph which shows typically the relationship with the "plane spacing d" of this composition. In this figure, the area of the portion excluding the base line on the lower angle side than 2θd is set as the peak corresponding to “surface interval d”.

[Explanation of symbols]

 A: Sample injection B: Pump pressurization C: Channel branch D: Collision / shear E: Pressure release / processing completed

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09D 133/00 C09D 133/00 // C08J 5/18 CER C08J 5/18 CER

Claims (16)

[Claims] 1. A resin composition comprising polyvinyl alcohol, a water-soluble polyacrylic compound and an inorganic layer compound. 2. The resin composition according to claim 1, which is obtained by treating polyvinyl alcohol, a water-soluble polyacrylic compound and an inorganic layer compound with a high-pressure dispersion device. 3. The resin composition according to claim 1, wherein the weight ratio of polyvinyl alcohol / water-soluble polyacrylic compound is in the range of 95/5 to 20/80. 4. A volume ratio of the inorganic layer compound / (polyvinyl alcohol + water-soluble polyacrylic acid compound) of 10
The resin composition according to any one of claims 1 to 3, wherein the ratio is in the range of / 1/1/100. 5. The resin composition according to claim 1, wherein the inorganic layered compound has an aspect ratio of 50 or more and 5000 or less. 6. The resin composition according to claim 1, wherein the particle size of the inorganic layered compound is 1 μm or less. 7. The resin composition according to claim 2, wherein the high-pressure dispersing device performs a dispersing treatment under a pressure condition of 100 kgf / cm ² or more. 8. A film obtained at 23 ° C. per 1 μm thickness.
Oxygen permeability at 95% RH (relative humidity) is 30cc
The resin composition according to any one of claims 1 to 7, wherein the ratio is not more than / m ² · day · atm. 9. A laminate obtained by coating a substrate with the resin composition according to any one of claims 1 to 8. 10. A molded article obtained by forming a film of the composition according to any one of claims 1 to 8. 11. The laminate according to claim 9, which is used for packaging. 12. The molded article according to claim 10, which is used for packaging. 13. The laminate according to claim 9, which is used for a liquid crystal display. 14. The molded article according to claim 10, which is used for a liquid crystal display. 15. The laminate according to claim 9, which is used for greenhouse horticulture. 16. The molded article according to claim 10, which is used for greenhouse horticulture.