JP2003346741A - Battery case for sealed storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery case for a storage battery having excellent vapor barrier property restraining the water in the battery contained in electrolyte liquid from evaporation, capable of prolonging the life of electrode plates and the battery. <P>SOLUTION: The battery case for a storage battery is composed of a layer (A) made of a resin component of which, dispersion medium contains inorganic layered compound having expanding or cleaving property, or, the battery case for a storage battery is composed of the laminated body composed of a layer (A) made of a reins component, of which dispersion medium contains inorganic layered compound having expanding or cleaving property, and a layer (B) made of thermoplastic resin. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery case for a storage battery. More specifically, the present invention relates to a battery case for a storage battery having excellent water vapor barrier properties.

[0002]

2. Description of the Related Art A sealed storage battery generally has a battery case in which an electrode plate comprising a positive electrode, a negative electrode and a separator is housed, and an electrolytic solution is injected into the battery case. The battery case and the lid are welded. Materials for these battery case and lid are acid-alkali resistance, heat resistance,
Impact resistance is required, and PP, ABS, resin compositions composed of PP and polyphenylene ether and the like are currently used.

[0003] In recent years, there has been an increasing demand for smaller and lighter sealed storage batteries, and there has been a demand for a thinner battery case. When the battery case is thinned, the above-mentioned materials used at present have insufficient water vapor barrier properties, so that water in the electrolytic solution inside the battery easily evaporates, and the specific gravity of the electrolytic solution increases. In addition, the active material utilization rate of the electrode plate is extremely increased, which places a heavy burden on the electrode plate, and shortens the life of the electrode plate and the battery.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealed storage battery case having excellent water vapor barrier properties.

[0005]

Means for Solving the Problems In view of such circumstances, the present inventors have found that the present invention can solve the above-mentioned problems, and have completed the present invention. That is, one aspect of the present invention is a battery case for a sealed storage battery, which is provided with a layer (A) made of a resin composition containing an inorganic layered compound having a property of expanding or cleaving in a dispersion medium. It concerns the battery case. One aspect of the present invention is a battery case for a sealed storage battery, which comprises a layer (A) made of a resin composition containing an inorganic layered compound having a property of expanding or cleaving in a dispersion medium, and a thermoplastic resin ( B) The present invention relates to a sealed storage battery case made of a laminate having layers.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The sealed storage battery case of the present invention is provided with a layer (A) made of a resin composition containing an inorganic layered compound having the property of expanding or cleaving in a dispersion medium.

The inorganic stratiform compound used in the present invention includes:
An inorganic compound in which unit crystal layers are stacked on each other to form a layered structure. The layered structure refers to a structure in which planes in which atoms are strongly bonded by covalent bonds or the like and densely arranged are stacked substantially in parallel by a weak bonding force such as van der Waals force.

[0008] The above-mentioned inorganic layered compound is an inorganic layered compound having a property of swelling or cleaving in a dispersion medium.
The particle size is 5 μm or less, and the aspect ratio is preferably 50 to 5000, more preferably 200 to 3 from the viewpoint of water vapor barrier properties, technical problems in production, and economic efficiency.
000.

The aspect ratio of the above-mentioned inorganic layered compound is as follows:
The ratio is a ratio of the unit thickness of the inorganic layered compound to the particle size. The ratio is determined by a method using a combination of a diffraction / scattering method and powder X-ray diffraction (for example, a method described in detail in JP-A-7-247374). ) Can be used.

Specific examples of the above-mentioned inorganic layered compound include:
Examples include graphite, phosphate derivative-type compounds (such as zirconium phosphate compounds), chalcogenides, hydrotalcites, lithium aluminum composite hydroxides, and clay minerals. What is chalcogenide?
Formula: MX ₂ [M represents an atom of a group IV (Ti, Zr, Hf), group V (V, Nb, Ta) or group VI (Mo, W) element, and X represents a chalcogen (S, Se, Te) . ] The compound represented by this.

The above-mentioned inorganic layered compound is preferably a clay mineral having a property of swelling or cleaving in a dispersion medium, from the viewpoint of easily forming a highly dispersed state in the resin composition constituting the layer (A). It is.

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 the upper surface of a silica tetrahedral layer. Etc. are classified into types having a three-layer structure in which an octahedral layer having a central metal as a center is narrowed from both sides. The former belongs to the kaolinite group, the antigolite group, and the like, and the latter belongs to the smectite group, the vermiculite group, the mica group, and the like.

Specific examples of the clay mineral preferably used in the present invention include kaolinite, dickite, nacrite, halloysite, antigolite, chrysotile, pyrophyllite, montmorillonite, hectorite, tetrasilyl mica, sodium teniolite, Examples include muscovite, margarite, talc, vermiculite, phlogopite, zansophyllite, and chlorite. Regarding clay minerals, see Literature: Haruo Shiramizu,
"Clay Mineralogy", 1988, Asakura Shoten Co., Ltd. can be referred to.

As the resin composition for forming the layer (A) used in the present invention, a high hydrogen bonding resin having a high content of a hydrogen bonding group or an ionic group is desirably used. The high hydrogen bonding resin means that the content of the hydrogen bonding group or the ionic group in the high hydrogen bonding resin (when both are contained, the total amount of both) is 20 to 60 mol%, preferably 30 to 50 mol%. The content of these hydrogen bonding groups and ionic groups can be determined, for example, by nuclear magnetic resonance (NMR) techniques (such as ¹ H-NMR and ¹³ C-NMR).
Can be measured by

The above-mentioned hydrogen bonding group includes a hydroxyl group, an amino group, a thiol group, a carboxyl group, a sulfonic acid group, a phosphate group, and the like, and examples of the ionic group include a carboxylate group, a sulfonate ion group, and a phosphate ion group. , An ammonium group, a phosphonium group and the like. Among the hydrogen bonding groups or ionic groups, more preferred are a hydroxyl group, an amino group, a carboxyl group, a sulfonic acid group, a carboxylate group, a sulfonic acid ionic group, an ammonium group and the like.

Specific examples of the high hydrogen bonding resin include polyvinyl alcohol (PVA), an ethylene / vinyl alcohol copolymer having a vinyl alcohol fraction of 40 mol% or more, polysaccharides, polyacrylic acid, and polyacrylic acid. Examples include esters, sodium polyacrylate, polystyrene sulfonic acid, sodium polystyrene sulfonate, polyethylene imine, polyallylamine and quaternary ammonium salts thereof, polyvinyl thiol, and polyglycerin. Among the resins exemplified above, particularly preferred is P
Modified products of VA and PVA, polysaccharides, ethylene / vinyl alcohol copolymer, and modified products of ethylene / vinyl alcohol copolymer are exemplified. As the high hydrogen resin, specifically, those described in JP-A-11-314299 can be used.

The resin composition for forming the layer (A) may be, if necessary, a thermoplastic resin other than the above-mentioned high hydrogen bonding resin,
It may contain a surfactant, an ultraviolet absorber and the like.

The layer (A) of the present invention comprises a coating liquid obtained by dispersing or dissolving the above-mentioned inorganic layered compound and resin in a dispersion medium,
A coating film is formed by coating (coating), and the dispersion medium is removed from the coating film by, for example, drying. From the viewpoint of the water vapor barrier property of the obtained storage battery case, the dispersion medium is preferably a liquid that swells or cleaves the inorganic layered compound.

The dispersion medium for swelling or cleaving the inorganic layered compound is, for example, a natural swellable clay mineral,
Examples include water, alcohols such as methanol, ethanol, propanol, isopropanol, ethylene glycol, and diethylene glycol; dimethylformamide, dimethyl sulfoxide, and acetone; and alcohols such as water and methanol are more preferable.

In the case of organically modified clay minerals, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as ethyl ether and tetrahydrofuran, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, n-pentane, aliphatic hydrocarbons such as n-hexane and n-octane, chlorobenzene, carbon tetrachloride,
Halogenated hydrocarbons such as chloroform, dichloromethane, 1,2-dichloroethane, perchloroethylene, ethyl acetate, methyl methacrylate (MMA), dioctyl phthalate (DOP), dimethylformamide, dimethyl sulfoxide, methyl cellosolve, silicone oil And the like.

The composition ratio of the above-mentioned inorganic layered compound to the resin in the coating liquid is generally such that the weight ratio of the inorganic layered compound to the resin (weight of the inorganic layered compound / weight of the resin) is 1
/ 100 to 100/1, preferably 1
It is more preferably in the range of / 20 to 10/1, and even more preferably in the range of 1/20 to 2/1 from the viewpoint of bending resistance.

The concentration of the inorganic layered compound and the resin in the coating solution is usually 0.1 to 70% by weight in total of the two.
From the viewpoint of productivity, the content is preferably 1 to 15% by weight, and more preferably 4 to 10% by weight.

When the resin composition for forming the layer (A) used in the present invention contains a high hydrogen bonding resin, a crosslinking agent for a hydrogen bonding group is used from the viewpoint of improving the water resistance of the layer (A). Preferably, it is used.

In order to achieve excellent water vapor barrier properties of the layer (A) used in the present invention, the high hydrogen bonding resin in the resin composition constituting the layer (A) is preferably crosslinked. . Preferred examples of the crosslinking agent that can be used for crosslinking the high hydrogen bonding resin include a titanium-based coupling agent, a silane-based coupling agent, a melamine-based coupling agent, an epoxy-based coupling agent, and an isocyanate-based coupling agent. And the like, a water-soluble epoxy compound, a copper compound, a zirconium compound, an organometallic compound and the like. In particular, a silane coupling agent, a water-soluble epoxy compound, a zirconium compound, and an organometallic compound are preferred, and an organometallic compound such as an organotitanium compound is particularly preferred.

Preferred examples of the crosslinking agent include coupling agents such as titanium coupling agents, silane coupling agents, melamine coupling agents, epoxy coupling agents, isocyanate coupling agents, and the like. Epoxy compounds, copper compounds, zirconium compounds, organometallic compounds and the like. From the viewpoint of improving water resistance, an organic metal compound, a zirconium compound, a water-soluble epoxy compound, and a silane coupling agent are more preferably used, and an organic metal compound such as an organic titanium compound is more preferable.

The method for blending the above-mentioned inorganic layered compound and resin in the resin composition comprising the above-mentioned inorganic layered compound and resin or the method for producing the resin composition comprising the above-mentioned inorganic layered compound and resin is not particularly limited. From the viewpoint of uniformity during mixing and ease of operation, for example, after mixing a liquid in which a resin is dissolved in a solvent and a dispersion in which an inorganic layered compound has been swollen or cleaved in advance by a dispersion medium,
A method of removing the solvent and the dispersion medium, a method of mixing the dispersion obtained by swelling or cleaving the inorganic layered compound with the dispersion medium and the resin, dissolving the resin in the dispersion medium, and then removing the dispersion medium. A method in which an inorganic layered compound is added to a solution dissolved in a solvent, and the above-mentioned solvent is used as a dispersion medium to swell or cleave the above-mentioned inorganic layered compound to form a dispersion, and the above-mentioned solvent is removed. And the like. From the viewpoint that a large aspect ratio of the inorganic layered compound is easily obtained,
Is preferably used.

In the methods (1) to (4), the treatment using a high-pressure dispersing apparatus is preferred from the viewpoint of the dispersibility of the inorganic layered compound. As a high-pressure dispersion device, for example, Micr
There is an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by ofluidics Corporation or a nanomizer manufactured by Nanomizer, and a Menton-Gaulin type high-pressure dispersing apparatus such as a homogenizer manufactured by Izumi Food Machinery is also included.

In the above methods (1) to (4), heat-aging the obtained laminate at 110 ° C. or more and 220 ° C. or less after removing the solvent or the dispersion medium from the system particularly improves the water resistance of the laminate. Is preferred.

The layer (B) used in the present invention is a layer made of a thermoplastic resin. The thermoplastic resin forming the layer (B) includes an amorphous polymer, a crystalline polymer, a liquid crystal polymer and the like. Specifically, polyphenylene ether resin, polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylic resin, polyolefin resin, polyarylene sulfide resin, polycarbonate resin, polyester resin, polyamide resin, polyether sulfone resin , Polysulfone resin, polyimide resin and the like. Of these, polyolefin-based resins, polyphenylene ether-based resins, and ABS resins are preferred, and polyolefin-based resins are particularly preferred.

The above polyolefin resins include ethylene, propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, and 4-methylpentene.
Α-olefins such as 1, octene-1, decene-1, dodecene-1, tetradecene-1, hexadecene-1, octadecene-1, eicosene-1, etc .;
It is a homopolymer or copolymer of an olefin such as a cyclic olefin described in JP-B-48. In addition, a copolymer obtained by copolymerizing an olefin and a small amount of another unsaturated monomer, and a modified product of the copolymer and the above-mentioned olefin alone or copolymerized by oxidation, sulfonation, etc. are used as a polyolefin resin. Shall be included.

Examples of other unsaturated monomers copolymerizable with olefins include acrylic acid, methacrylic acid, maleic acid, itaconic acid, methyl acrylate, methyl methacrylate, maleic anhydride, arylmaleimide Organic acids or derivatives thereof, such as imides and alkylmaleimides; vinyl esters, such as vinyl acetate and vinyl butyrate; aromatic vinyl compounds, such as styrene and methylstyrene; vinyl trimethylmethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, etc. Vinylcyclosilane; dicyclopentadiene, 4-ethylidene-2-norbornene, 4-methyl-1,4-hexadiene, 5-methyl-
Non-conjugated dienes such as 1,4-hexadiene and the like can be mentioned. Among these, ethylene, propylene, butene
A copolymer or a homopolymer containing a majority weight of 1,3-methylbutene-1,4-methylpentene-1 is preferable, and a propylene homopolymer, a propylene-ethylene block,
Crystalline propylene polymers such as random copolymers and mixtures thereof are more preferred.

The melt flow rate (MFR) of the above polyolefin resin is generally 0.01 as represented by the MFR measured at a temperature of 230 ° C. and a load of 21.2 N.
To 400 g / 10 min, preferably 0.1 to 60 g / 10
Minutes.

The above-mentioned polyolefin resin can be produced by a conventionally known method such as polymerization or modification. Also, commercially available products are widely available, and can be appropriately selected from these and used.

The polyolefin resin used in (B) of the present invention preferably contains a polyphenylene ether resin. It is preferable to use a polyphenylene ether-based resin because heat resistance, strength and creep resistance are improved.

The polyphenylene ether resin is a resin comprising a homopolymer or a copolymer obtained by oxidatively polymerizing a phenol compound. As the phenol compound, phenol, o-, m- or p-cresol, 2,
6-, 2,5-, 2,4- or 3,5-dimethylphenol, 2-methyl-6-phenylphenol, 2,6-
Diphenylphenol, 2,6-diethylphenol,
2-methyl-6-ethylphenol, 2,3,5-,
2,3,6- or 2,4,6-trimethylphenol,
3-methyl-6-t-butylphenol, thymol, 2
-Methyl-6-allylphenol can be exemplified. Among these phenol compounds, 2,6-dimethylphenol, 2,6-diphenylphenol, 3-
Methyl-6-t-butylphenol and 2,3,6-trimethylphenol are preferred.

The phenol compound is bisphenol-
A, tetrabromobisphenol-A, resorcin, hydroquinone and polyhydric hydroxyaromatic compounds exemplified by novolak resins may be copolymerized, and these copolymers are also included in the polyphenylene ether-based resin according to the present invention. And

As polyphenylene ether resins, poly (2,6-dimethyl-1,4-phenylene ether), poly (2,6-diethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl) -1,4-phenylene ether), poly (2-methyl-6-propyl-1,4-phenylene ether), poly (2,6-dipropyl-1,4-phenylene ether), poly (2-ethyl-6) -Propyl-1,4-phenylene ether),
Poly (2,6-butyl-1,4-phenylene ether), poly (2,6-dipropenyl-1,4-phenylene ether), poly (2,6-dilauryl-1,4-phenylene ether), poly ( 2,6-diphenyl-1,
4-phenylene ether), poly (2,6-dimethoxy-1,4-phenylene ether), poly (2,6-diethoxy-1,4-phenylene ether), poly (2-methoxy-6-ethoxy-1, 4-phenylene ether), poly (2-ethyl-6-stearyloxy-1,
4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether), poly (2-methyl-1,4-phenylene ether), poly (2-ethoxy-1,4-phenylene ether) ), Poly (3-methyl-6-t-butyl-1,4-phenylene ether),
Examples thereof include poly (2,6-dibenzyl-1,4-phenylene ether) and various copolymers containing plural kinds of repeating units constituting these resins.

Preferred among the polyphenylene ether resins are poly (2,6-dimethyl-1,4-phenylene ether) and copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol. It is.

The weight ratio of the polyolefin resin to the polyphenylene ether resin (weight of the polyolefin resin / weight of the polyphenylene ether resin) of the layer (B) used in the present invention is determined from the viewpoint of water vapor barrier property, heat resistance and rigidity. It is usually 95/5 to 20/80, preferably 9
0/10 to 30/70.

When a higher impact strength is desired by the layer (B) used in the present invention, the resin composition containing the polyolefin resin and the polyphenylene ether resin used in the layer (B) contains an elastomer. It is desirable. Examples of the above elastomers include natural rubber, polybutadiene rubber, polyisoprene rubber, butyl rubber, ethylene-propylene copolymer rubber, butadiene styrene copolymer rubber, butadiene-acrylonitrile copolymer rubber, hydrogenated and non-hydrogenated Styrene-conjugated diene-based block copolymer rubber, polyester rubber, acrylic rubber, silicone rubber and the like, and modified products thereof.

Preferred elastomers among these are:
Styrene-isoprene diblock copolymers containing hydrogenated products, including terpolymers obtained by copolymerizing diene compounds and graft copolymers obtained by graft copolymerizing unsaturated monomers such as styrene, styrene-butadiene It is a styrene-conjugated diene block copolymer rubber such as a triblock copolymer.

When the above elastomers are used, the amount is from 0 to 70% by weight, preferably from 1 to 50% by weight, based on 100 parts by weight of the total of the polyolefin resin and the polyphenylene ether resin.

The resin composition containing a polyolefin resin and a polyphenylene ether resin used in the present invention may contain other substances other than the above substances, if desired. Examples of other substances that are preferably contained for a specific purpose include release agents such as other resins, nucleating agents, flame retardants, stabilizers, plasticizers, lubricants, pigments, reinforcing fibers, and fillers. And an antistatic agent.

As a method for obtaining a laminate having the layer (A) and the layer (B), a film having the layer (A) is added to a molded article composed of the layer (B) obtained by injection molding or the like. A method of laminating by bonding, thermal shrinking, etc. A coating liquid obtained by dispersing a resin composition containing a swollen or cleaved inorganic layered compound in a dispersion medium in a molded product comprising a layer (B) obtained by injection molding or the like. Is applied (coated) to form a coating film, and (A) a method of forming a layer (A) A film having a layer is inserted into a mold, and then a (B) layer is formed in the mold. Method of filling thermoplastic resin by injection molding or the like (insert molding) A coating liquid in which a resin composition containing an inorganic layered compound in a swollen or cleaved state is dispersed in a dispersion medium is coated in a mold, and then the above-described metal is coated. (B) layer in the mold Method of filling a thermoplastic resin which formed by injection molding or the like (in-mold coating molding) is exemplified.

The film having the layer (A) is prepared by applying (coating) a coating liquid obtained by dispersing a resin composition containing an inorganic layered compound in an expanded or cleaved state to a dispersion medium, for example, on a base film. It is obtained by forming a coating film and removing the dispersion medium from the coating film, for example, by drying.

Examples of the base film include polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, Polypropylene resin such as polypropylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, polyethylene terephthalate,
Polyamide resins such as polybutylene terephthalate and polyethylene naphthalate, amide resins such as nylon-6, nylon-6,6, methaxylenediamine-adipic acid condensation polymer, polymethyl methacrylimide,
Acrylic resins such as polymethyl methacrylate, polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, styrene-acrylonitrile resins such as polyacrylonitrile, hydrophobic cellulose-based resins such as cellulose triacetate and cellulose diacetate Resin, halogen-containing resin such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, Teflon (registered trademark), high hydrogen bonding resin such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, cellulose derivative, polycarbonate resin, polysulfone Engineering plastics such as resin, polyether sulfone resin, polyether ether ketone resin, polyphenylene ether resin, polymethylene oxide resin, liquid crystal resin Etc. The. Among these, biaxially stretched polypropylene, polyethylene terephthalate, nylon, and silica, alumina, aluminum evaporated polyethylene terephthalate, polypropylene,
Nylon and the like are preferably used.

Examples of the method of coating the base film with the coating liquid include a roll coating method such as a direct gravure method, a reverse gravure method, a microgravure method, a two-roll beat coating method, a bottom feed three-reverse coating method, and the like. Doctor knife method and die coat method,
Examples of the method include a dip coating method, a spray coating method, a spin coating method, a bar coating method, and a coating method combining these methods.

Examples of the method for directly coating the coating liquid on the molded product comprising the layer (B) include a dip coating method, a spray coating method and the like.

When the base film having the layer (A) and the layer (B) are laminated, the layer (A) may be on the side of the layer (B).
(B) It may be located on the opposite side of the layer.

The thickness of the layer (A) is from 1 nm to 1 nm in terms of dry thickness from the viewpoint of the weight of the laminate and the barrier property against water vapor.
Within the range of 00 μm, more preferably 10 nm to 50 μm
m, more preferably 0.1 μm to 10 μm
Is within the range.

Molded articles obtained from the resin composition of the present invention have excellent water vapor barrier properties, and are suitable for lead-acid batteries, nickel-cadmium batteries,
It is suitably used as a battery case of a storage battery such as a nickel hydrogen battery and a lithium hydrogen battery.

[0052]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. The methods for measuring various physical properties are described below. [Thickness Measurement] The thickness of 0.5 μm or more was measured with a commercially available digital thickness gauge (contact type thickness gauge, trade name: ultra-high precision decimicro head MH-15M, manufactured by Nippon Kogaku Co., Ltd.). On the other hand, the thickness of less than 0.5 μm is determined by the gravimetric analysis method (the measured value of the film of a certain area is divided by the area and further divided by the specific gravity of the composition) or the actual coating film thickness by the IR method. A calibration curve with IR absorption was prepared and determined from the calibration curve. Further, in the case of measuring the coating thickness of the resin composition of the present invention, for example, the elemental analysis method [the ratio of the specific inorganic element analysis value of the laminate (derived from the resin composition layer) to the specific element fraction of the inorganic layered compound alone] To determine the ratio between the resin composition layer of the present invention and the base film).

[Measurement of Particle Size] Using a laser diffraction / scattering particle size distribution analyzer (LA910, manufactured by HORIBA, Ltd.), the volume-based median of particles considered to be inorganic layered compounds present in the resin matrix of the medium. The diameter was measured as a particle diameter L. The undiluted liquid dispersion was measured with an optical path length of 50 μm in a paste cell, and the dilute liquid of the dispersion was measured with an optical path length of 4 mm by a flow cell method.

[Aspect ratio calculation] X-ray diffractometer (XD
-5A (manufactured by Shimadzu Corporation), the diffraction measurement of the inorganic layered compound alone and the resin composition by the powder method was performed. Thus, the unit thickness a of the inorganic layered compound was determined, and further, from the diffraction measurement of the resin composition, it was confirmed that there was a portion where the plane interval of the inorganic layered compound was widened. Using the particle diameter L obtained by the above method, the aspect ratio Z was calculated by the equation of Z = L / a.

[Bending elastic modulus and bending strength] ASTM D7
23, using 3.2 mm thick test specimens according to
The flexural modulus and flexural strength at ° C were measured.

[Izod Impact Strength] ASTM D25
23 ° C. using 3.2 mm thick test specimens according to 6.
The notched Izod impact strength was measured.

[Heat deformation temperature] According to ASTM D648, a test piece having a thickness of 6.4 mm was used and a load of 0.45 N was applied.
Was measured for the heat distortion temperature.

[Moisture Permeability] Based on JIS Z0208,
The moisture permeability of the film at a temperature of 40 ° C. and a humidity of 60% was measured. The smaller the moisture permeability, the more suitable as a battery case material.

Reference Example 1 The intrinsic viscosity of polyphenylene ether resin (measured in chloroform at 30 ° C.) of 0.1 was measured from the first feeder of a continuous twin-screw kneader having two feed ports (Model TEM-50A manufactured by Toshiba Machine Co., Ltd.). 40 dl / g of poly (2,6-dimethyl-
1,4-phenylene ether)) 27% by weight, hydrogenated styrene-isoprene-styrene copolymer (Septon 21)
04, manufactured by Kuraray Co., Ltd.) and 10% by weight of polypropylene resin (polypropylene resin (homo) having an MFR of 0.5 at 230 ° C. and 21N, trademark D501, Sumitomo Chemical Co., Ltd.) from the second feeder downstream of the first feeder. (Manufactured by Kogyo Co., Ltd.), and melt-kneaded under the conditions of a cylinder temperature of 280 ° C. and a screw rotation speed of 200 rpm to obtain a pellet-shaped resin composition PP-1. Test pieces were prepared from the obtained pellets using an injection molding machine set at a cylinder temperature of 280 ° C. and a mold temperature of 60 ° C., and the flexural modulus, flexural strength, Izod impact strength, and thermal deformation temperature were measured. Flexural modulus 1710 MPa, bending strength 52 MPa,
The Izod impact strength was 15 kJ / m ² and the heat deformation temperature was 143 ° C. Using this composition, press molding to a thickness of 320
A μm film 1 was produced.

Reference Example 2 [Coating liquid for resin composition layer] Dispersion pot [Product name: Despa MH]
-L, manufactured by Asada Tekko Co., Ltd.], 1860 g of ion-exchanged water (specific electric conductivity 0.7 μS / cm or less) was added,
Further, 128 g of PVA [PVA117H; manufactured by Kuraray Co., Ltd., degree of saponification; 99.6%, degree of polymerization 1700] was added.
Under low-speed stirring (1500 rpm, peripheral speed 4.10 m / mi
In n), the temperature was raised to 95 ° C., and the mixture was stirred for 1 hour and dissolved to obtain a solution (I).

Next, the solution (I) was stirred for 60 hours.
After lowering the temperature to 0 ° C., a solution obtained by adding 0.18 g of a nonionic surfactant (trade name: SH3746, manufactured by Dow Corning Toray Co., Ltd.) to a mixed solution of 125 g of 1-butanol and 375 g of isopropyl alcohol was added to the mixture. The above solution (I)
To obtain a mixture (II). The nonionic surfactant is a polydimethylsiloxane-polyoxyethylene copolymer.

1960 g of the mixed solution (II) was charged into a stirring emulsifier (trade name: vacuum emulsifier PVQ-3UN, manufactured by Mizuho Industry Co., Ltd.). Natural montmorillonite (Kunipia F; manufactured by Kunimine Kogyo Co., Ltd.) was used as a powder so that the weight ratio of the resin to the inorganic layered compound was 2: 1.
After adding 0 g and confirming that the montmorillonite was substantially precipitated in the solution, the mixture was rapidly stirred at 600 mmHg and 5000 rpm for 10 minutes to obtain a resin composition mixed solution (III).

2000 g of the resin composition mixture (III)
To a high-pressure dispersion device (trade name: ultra-high pressure homogenizer M11)
0-E / H, manufactured by Microfluidics Corporation)
By treating once at 1750 kgf / cm ² , a uniform dispersion (IV) having good dispersibility was obtained. The solid content concentration of the dispersion (IV) was 7.5% by weight.

The dispersion (IV) composed of PVA and montmorillonite was cast into a film and subjected to X-ray analysis to measure the interplanar spacing d of the swollen and cleaved montmorillonite (inorganic layered compound).

As a result of determining the plane distance d from the diffraction peak obtained from the X-ray analysis, the plane distance d was larger than the unit thickness a. Therefore, the montmorillonite was cleaved sufficiently for the reason described above. I found out. At this time, the aspect ratio of the cleaved inorganic layered compound is 20.
It was 0 or more.

The dispersion (IV) was adjusted with hydrochloric acid so that the pH of the dispersion (IV) was 3 or less under low-speed stirring (1500 rpm, peripheral speed 4.10 m / min). Titanium acetylacetonate [TC
And 100, manufactured by Matsumoto Pharmaceutical Co., Ltd.] were gradually added to obtain a coating liquid for a resin composition layer.

[Liquid Packaging Container] A biaxially oriented polypropylene (OPP) film having a thickness of 50 μm [Pyrene P21
02: manufactured by Toyobo Co., Ltd.] as a substrate film, and an anchor coat agent (urethane-based) [Adcoat AD335 / CAT] on the OPP film.
10 = 15/1 (weight ratio: manufactured by Toyo Morton Co., Ltd.)] (test coater; manufactured by Yasui Seiki: microgravure coating method, coating speed 3 m / min, drying temperature 80 ° C.)
did. The dry thickness of the anchor coat layer is 0.0
It was 5 μm.

Next, the coating solution for the resin composition layer was subjected to gravure coating (test coater; manufactured by Yasui Seiki Co., Ltd .: microgravure coating method, coating speed: 3 m / min, drying temperature: 100 ° C.), and onto the anchor coat layer. Then, a coating film 2 having a resin composition layer formed thereon based on the resin composition layer coating solution was obtained. The dry thickness of the resin composition layer was 0.5 μm.

Example 1 Film 1 and film 2 were superposed on each other, and the moisture permeability was evaluated. The water vapor transmission rate was 0.27 g / day · m ² .

Comparative Example 1 The moisture permeability of the film 1 was measured. The moisture permeability is 1.92g
/ Day · m ² .

[0071]

As described above, according to the present invention, it is possible to obtain a sealed storage battery case having excellent water vapor barrier properties. By using the sealed storage battery case of the present invention for the storage battery, evaporation of water in the electrolyte inside the battery can be suppressed, and the life of the electrode plate and the battery can be extended.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yuji Ikezawa             1-13-26 Nishiki, Naka-ku, Nagoya City, Aichi Prefecture 3             Inside Sumitomo Polyolefin Co., Ltd. F term (reference) 5H011 AA00 CC02 CC05 CC09 CC10                       KK02

Claims (5)

[Claims] 1. A sealed storage battery case, comprising: a (A) layer made of a resin composition containing an inorganic layered compound having the property of expanding or cleaving in a dispersion medium. Battery case 2. A container for a sealed storage battery, comprising: a layer (A) composed of a resin composition containing an inorganic layered compound having a property of expanding or cleaving in a dispersion medium; and a layer (B) composed of a thermoplastic resin. A battery case for a sealed storage battery, comprising a laminated body provided with: 3. The battery case for a sealed storage battery according to claim 2, wherein the resin composition of the layer (B) is a polyolefin resin. 4. An inorganic layered compound having an aspect ratio of 50 to 50.
3. The battery case for a sealed storage battery according to claim 2, wherein the battery case is 5000. 5. The resin composition of the layer (A) contains a high hydrogen bonding resin, and the weight ratio of the inorganic layer compound to the high hydrogen bonding resin (weight of inorganic layer compound / weight of high hydrogen bonding resin). )
Is (1/100) to (100/1). The battery case for a sealed storage battery according to claim 1 or 2, wherein