JP6657717B2 - Packaging materials for power storage devices - Google Patents

Description

  The present invention relates to a packaging material for a power storage device.

Secondary batteries typified by lithium ion batteries are used for various applications such as personal computers, portable terminal devices (mobile phones, PDAs, etc.), video cameras, electric vehicles, storage batteries for energy storage, robots, satellites, and the like.
The secondary battery contains an electrode, an electrolyte solution, and the like (hereinafter, also referred to as a battery main body) inside an exterior body. The exterior body is also referred to as a battery case, a packaging container, a packaging body, or the like.
As the outer package, a metal can type in which a metal is pressed into a cylindrical or rectangular parallelepiped container, or a laminate composed of an outer resin film layer, a metal foil layer, and a heat seal layer is formed into a bag shape. Pouch type, or an emboss type in which a recess is formed by press-molding the laminate and the battery body is housed in the recess.

There is a high demand for a pouch type and an embossed type in terms of the degree of freedom in shape and dimensions, and a higher demand for an embossed type in that a more compact exterior body can be obtained.
The pouch-type or emboss-type exterior body is formed by heat-sealing the heat-sealing layers. That is, the heat seal layer is located on the innermost side of the exterior body. On the other hand, the outer-layer-side resin film layer is located on the outermost side in the outer package.

The embossing type exterior body is formed by pressing and molding the laminate into the inside of the mold so that the outer resin film layer constituting the laminate contacts the inner surface of the concave mold. Therefore, good moldability is required for the outer-layer-side resin film layer that forms the convex outermost layer.
Further, when filling the molded container with the electrolyte solution or the like, even if the electrolyte solution or the like spills and adheres to the outside of the container, that is, the outer resin film layer, it does not damage the outer resin film layer. Is required.
Further, it is required that the heat-sealing layers are not separated from each other after the molded solution is filled with the electrolyte solution and the heat-sealing layers are heat-sealed.

  Generally, a nylon film is used for the outer layer side resin film, and aluminum having good stretchability is used for the metal foil layer. Nylon films are used because they have good adhesion to aluminum foil and have good stretchability compared to PET film or the like.

  In addition, a product name, a maker name, a lot number, and the like may be printed and printed on the surface of the resin film on the outer side of the molded power storage device packaging container. Therefore, the outer layer side resin film layer is required to have printability, printability, ink adhesion, and the like.

Patent Literatures 1 to 4 disclose laminates (packaging materials) for forming a pouch-type or emboss-type exterior body.
In Patent Document 1, a stretched film having a coating layer that is durable to an electrolytic solution containing chlorine or fluorine-containing lithium salt is laminated on the outermost surface of one side of an aluminum foil, and a surface of the aluminum foil is made of polypropylene or the like. A packaging material for a battery case, in which a film is laminated on the outermost surface of the other side of the aluminum foil, is disclosed. As a coating material for forming a coating layer that is durable against an electrolyte, polyvinylidene chloride, vinylidene chloride are used. -Use of vinyl chloride copolymer, maleic anhydride-modified polypropylene, polyester resin, epoxy resin, phenol resin, fluororesin, cellulose ester, urethane resin and acrylic resin is disclosed.

  Patent Document 2 discloses that a laminate composed of a base material layer, an adhesive layer, a chemical conversion treatment layer, aluminum, a chemical conversion treatment layer, an acid-modified PP coating layer, and an innermost layer is used for forming an embossed type exterior body. ing. In the eleventh paragraph, for the purpose of reducing the frictional resistance between the mold and the base material layer, the base material layer is multi-layered, and the surface of the base material layer is made of any one of a fluorine resin, an acrylic resin, and a silicone resin. It is stated that it is preferable to provide a film or a coating layer.

Patent Literature 3 discloses a fatty acid amide slip agent on the surface of a base material layer of a laminate including a base material layer, adhesiveness, a chemical conversion treatment layer 1, aluminum, a chemical conversion treatment layer 2, an acid-modified polyolefin layer, and a polyolefin layer. A coated embossed lithium ion battery packaging material is disclosed.
The third paragraph states that when stretched nylon is used as the base material layer, in embossing, the coefficient of friction between the forming female mold and the base material layer is large, and molding wrinkles and cuts may occur. I have. Therefore, in the fourth paragraph, the surface of the base material layer is coated with a fatty acid amide-based slip agent.
In the fifteenth paragraph, for the purpose of reducing the frictional resistance between the mold and the base material layer (or for imparting electrolyte solution resistance), the base material layer is multi-layered, and a fluorine resin, It is described that it is preferable to provide a film or a coating layer made of either an acrylic resin or a silicone resin.

  Patent Literature 4 discloses a battery packaging material using a base layer having a coating layer formed of a slip agent on the surface. It is disclosed that a vinyl-based copolymer is copolymerized using a siloxane-containing initiator as a slip agent. The 36th paragraph describes that by applying and coating a slip agent on the surface of the base material layer, the slipperiness between the base material layer surface and the mold is ensured during embossing and the press molding is stably performed. ing. When the exterior body is molded, the slipperiness between the surface of the base material layer and the mold (female mold) is important. It is described that a large frictional force between the exterior body and the mold causes peeling of the laminated structure and cracking of the barrier layer.

Although it does not disclose application to a battery packaging material, Patent Document 5 discloses that a slip agent is compounded in a protective coating resin of an aluminum foil laminate for drawing having a thermosetting resin protective coating. A technique using an aluminum foil laminate as a food packaging container is disclosed. The example discloses that stearic acid is compounded as a slip agent in an epoxy resin.
Laminates coated with an epoxy, nitrocellulose, or acrylic paint on aluminum foil are molded by pressing or the like, but as they are, the aluminum foil in the laminate will crack or break. In order to prevent this, it is described that a lubricant such as silicone oil or wax is applied to the surface of the molding material and then processed.

  Similarly, although it does not disclose application to a battery packaging material, Patent Document 6 discloses a polymer (A) obtained by copolymerizing acrylonitrile, a monomer having a crosslinkable functional group, and another monomer, a polyorganosiloxane. An antifouling coating agent comprising a polymer (B) obtained by copolymerizing a monomer having a chain, a monomer having a crosslinkable functional group, and another monomer is disclosed. Used for vehicle seats, sofas, wallpaper and other interior building materials by coating on a soft polyvinyl chloride base material, it prevents contamination and coloring due to the environment and contact during use, and easily removes attached contamination. A method that can be removed is proposed.

JP-A-2000-123799 JP 2001-176462 A JP 2002-216714 A JP 2007-294382 A JP-A-5-270563 JP 2000-212478 A

As described above, Patent Document 1 discloses the use of various resins as a coating material for forming a coating layer that is durable with respect to an electrolytic solution. And, specifically, when polyvinylidene chloride, vinylidene chloride-vinyl chloride, or an epoxy resin was used, no coating material was used, or a vinyl acetate resin was used as a coating material instead of the resin. It is described that the electrolyte resistance is improved as compared with the case.
However, in the case of the invention described in Patent Document 1, since the coating layer is not cured only by coating the coating material, the electrolyte solution resistance is insufficient and whitening cannot be prevented.

Further, as described above, Patent Document 2 suggests the use of a fluorine resin, an acrylic resin, or a silicone resin as a coating material.
However, the feature of the invention described in Patent Document 2 is to provide a chemical conversion treatment layer on both surfaces of aluminum, and there is no specific description of providing a coating layer from the above resin. Furthermore, even if a fluorine-based resin, an acrylic-based resin, or a silicone-based resin is used as the coating material, the resin is not cured, so that the electrolyte solution resistance is insufficient and whitening cannot be prevented.

Further, as described above, Patent Document 3 discloses the use of a fatty acid amide-based slip agent from the viewpoint of improving the moldability, and suggests the use of a fluorine-based resin, an acrylic-based resin, and a silicone-based resin. .
However, even if these are used as a coating material, they are not cured, so that the electrolyte solution resistance is insufficient and whitening cannot be prevented.

  The slip agent described in Patent Document 4 does not use a cross-linking agent when coating the substrate surface, so that the coating layer has insufficient electrolyte solution resistance and cannot prevent whitening.

Patent Literature 5 discloses a technique in which an aluminum foil laminate provided with a thermosetting resin protective film made of an epoxy resin mixed with stearic acid as a slipping agent is used as a food packaging container. In general, a food packaging container generally has a larger opening diameter than a bottom diameter due to a demand for finally taking out food. Moreover, the shape of the bottom and the opening is often circular or elliptical. In drawing of a container having a circular or elliptical bottom, the circumferential portion undergoes almost uniform shrinkage while being stretched to form a wall.
On the other hand, although the container for an electric storage device of the emboss type has a little roundness at the corner, the bottom is often a quadrilateral, and the diameter of the opening is almost the same as the diameter of the bottom in many cases. In the drawing of such a container having a quadrangular bottom, only expansion is applied to the wall, and shrinkage is concentrated at the corner.
Therefore, it can be said that drawing of a container having a quadrangular bottom is more severe than drawing of a container having a circular or oval bottom. Moreover, since the opening diameter and the bottom diameter are not substantially changed and the wall portion is almost vertical, the wall portion undergoes a larger shrinkage than the draw molding in which the opening portion diameter is larger than the bottom portion. Strict molding.

  Patent Document 6 discloses an antifouling coating agent, but does not disclose application to an electric storage device container.

  An object of the present invention is to provide a packaging material for an electricity storage device having an outermost layer having excellent moldability, electrolyte solution resistance, and printability, and capable of maintaining a stable sealed state after heat sealing.

The present invention is, in order from the outermost layer, a protective layer, an outer layer-side resin film layer, an outer layer-side adhesive layer, a metal foil layer, an inner layer-side adhesive layer, and a packaging material for an electricity storage device that essentially includes a heat seal layer. ,
The present invention relates to a packaging material for an electric storage device, wherein the protective layer satisfies all of the following conditions (1) to (5).
(1) The protective layer is a cured coating formed from a curable resin (I) having a hydroxyl group, a curing agent (II), and a curable protective paint containing waxes.
(2) The waxes are at least one selected from amide-based, vegetable oil-based, animal oil-based, and petroleum-based waxes.
(3) The curable resin (I) having a hydroxyl group is selected from the group consisting of an acrylic resin (A) having a hydroxyl group, a polyester resin (B) having a hydroxyl group, and an epoxy resin (C) having a hydroxyl group. Resin having at least one type of hydroxyl group.
(4) The dynamic friction coefficient of the protective layer in a 25 ° C., 50% RH atmosphere is 0.15 or less.
(5) The wetting index according to JIS standard of the protective layer is 33 × 10 ⁻³ (N / m) or more.

It is preferable that the packaging material for an electric storage device contains 5 to 200 parts by mass of a curing agent (II) based on 100 parts by mass of a curable resin (I) having a hydroxyl group.
The curing agent (II) preferably contains a polyisocyanate compound (E).
The acrylic resin (A) having a hydroxyl group has a hydroxyl value of 5 to 100 (mgKOH / g), a glass transition temperature of 20 to 90 ° C, and a mass average molecular weight (Mw) of 100,000 to 1,000,000. It is preferably a copolymer.

Further, the present invention relates to a power storage device container formed from the power storage device packaging material of the present invention, wherein the protective layer constitutes the outermost surface.
Furthermore, the present invention relates to a power storage device using the above-described power storage device container.

  According to the present invention, it has become possible to provide a packaging material for an electricity storage device having an outermost layer excellent in moldability and electrolyte solution resistance and capable of maintaining a stable sealed state after heat sealing. Furthermore, when a product name, a maker name, a production lot number, and the like are printed on the surface of the packaging material after manufacturing the power storage device, a packaging material in which characters are not faded or peeled off is produced.

1 is a schematic cross-sectional view of one embodiment of a packaging material for an electric storage device of the present invention. It is a typical perspective view of one mode (tray shape) of the container for electricity storage devices of the present invention.

As described above, the packaging material for an electricity storage device of the present invention, in order from the outermost layer, includes a protective layer, an outer resin film layer, an outer adhesive layer, a metal foil layer, an inner adhesive layer, and a heat seal layer. And a packaging material for an electricity storage device.
The protective layer is a cured coating formed from a curable protective coating containing a curable resin (I) having a hydroxyl group, a curing agent (II), and waxes.
The curable resin (I) having a hydroxyl group is selected from the group consisting of an acrylic resin (A) having a hydroxyl group, a polyester resin (B) having a hydroxyl group, and an epoxy resin (C) having a hydroxyl group. Each of them may be used alone, or two or three kinds may be used in combination.
Since a strong protective layer can be formed by the reaction between the curable resin (I) having a hydroxyl group and the curing agent (II), even if the highly soluble electrolyte solution touches the protective layer, whitening and dissolution can be prevented. .

The acrylic resin (A) having a hydroxyl group is a copolymer of a monomer having a hydroxyl group and another monomer having no hydroxyl group.
Examples of the monomer having a hydroxyl group include hydroxyalkyl (meth) acrylate and a product in which ε-caprolactone is added to the above hydroxyalkyl (meth) acrylate, and hydroxyalkyl (meth) acrylate is preferable.

Specific examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxyethyl (meth) acrylate. Hydroxyalkyl (meth) acrylates having 1 to 4 carbon atoms in the alkyl group, such as hydroxybutyl (meth) acrylate.
Specific examples of the product obtained by adding ε-caprolactone to hydroxyalkyl (meth) acrylate include 1 mol of ε-caprolactone of 2-hydroxyethyl (meth) acrylate and 2 mol of ε-caprolactone of 2-hydroxyethyl (meth) acrylate. Adducts, ε-caprolactone adducts of hydroxyalkyl (meth) acrylates having 1 to 4 carbon atoms, such as 3-mol adducts of ε-caprolactone of 2-hydroxyethyl (meth) acrylate, and the like, It is not limited only to such an example. These hydroxyl group-containing monomers may be used alone or in combination.

Examples of other acrylic monomers having no hydroxyl group include various monomers as shown below.
Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and sec-butyl (meth). Acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, Examples thereof include alkyl (meth) acrylates such as tert-butylhexyl (meth) acrylate, 2-acetoacetoxyethyl (meth) acrylate, and phenoxyethyl (meth) acrylate.

  Examples of the monomer having an alicyclic hydrocarbon group include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, Examples include dicyclopentenyl (meth) acrylate and dicyclopentenyl (meth) acrylate.

  Examples of the monomer having an epoxy group include glycidyl (meth) acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3,4-epoxycyclohexylmethyl methacrylate.

  Examples of the acidic group-containing monomer include (meth) acrylic acid, maleic anhydride, 2- (meth) acryloyloxyethyl-succinic acid, 2- (meth) acryloyloxyethyl-hexahydrophthalic acid, and 2- (meth) Acryloyloxyethyl-phthalic acid, 2- (meth) acryloyloxyethyl acid phosphate and the like can be mentioned.

The acrylic resin (A) having a hydroxyl group can be easily prepared by copolymerizing the monomer.
Examples of the method for polymerizing the monomer include a solution polymerization method, a bulk polymerization method, a suspension polymerization method, and an emulsion polymerization method, but the present invention is not limited to such a polymerization method. Among these polymerization methods, a solution polymerization method is preferable because the obtained reaction mixture can be used as it is.

  Hereinafter, an embodiment in which the acrylic resin (A) having a hydroxyl group is prepared by solution-polymerizing a monomer will be described, but the present invention is not limited to only the embodiment.

  Examples of the solvent used when the monomer is subjected to solution polymerization include, for example, aromatic solvents such as toluene and xylene; alcohol solvents such as n-butyl alcohol, propylene glycol monomethyl ether, diacetone alcohol, and ethyl cellosolve; ethyl acetate; Examples thereof include ester solvents such as butyl acetate and cellosolve acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; and dimethylformamide, but the present invention is not limited only to such examples. It is preferable that the amount of the solvent is appropriately determined according to the concentration of the simple substance mixture, the molecular weight of the target acrylic polymer, and the like.

  Examples of the polymerization initiator include 2,2′-azobis- (2-methylbutyronitrile), tert-butylperoxy-2-ethylhexanoate, 2,2′-azobisisobutyronitrile, and benzoyl Examples include peroxide and di-tert-butyl peroxide, but the present invention is not limited to only such examples. The amount of the polymerization initiator is usually preferably 0.01 to 30 parts by mass, more preferably 0.05 to 10 parts by mass, per 100 parts by mass of the monomer mixture.

  In the polymerization, a chain transfer agent such as n-dodecyl mercaptan may be used in order to adjust the molecular weight of the obtained acrylic resin (A) having a hydroxyl group.

  The polymerization temperature at the time of polymerizing the monomer is usually preferably from 40 to 200 ° C, more preferably from 40 to 160 ° C.

  Since the polymerization time of the monomer varies depending on the polymerization temperature, the composition of the monomer mixture, the type and the amount of the polymerization initiator, and the like, it cannot be unconditionally determined. Therefore, it is preferable to appropriately determine the polymerization time.

The acrylic resin (A) having a hydroxyl group thus obtained preferably has a hydroxyl value of 5 to 100 (mgKOH / g), more preferably 20 to 80 (mgKOH / g).
When the hydroxyl value is 5 (mgKOH / g) or more, the curable resin (I) containing the acrylic resin (A) having a hydroxyl group has an appropriate crosslinked structure by a reaction with a curing agent (II) described later. Since the protective layer is formed, resistance of the protective layer to an electrolyte solution can be improved.
On the other hand, when the hydroxyl value is 100 (mgKOH / g) or less, excessive crosslinking between the acrylic resin (A) and the curing agent (II) is suppressed. As a result, the adhesiveness to the outer resin film layer can be improved, and the moldability can be improved.
The hydroxyl value of the acrylic resin (A) can be controlled by the ratio of the hydroxyl group-containing monomer in the monomer component used for forming the acrylic resin (A).

The acrylic resin (A) preferably has a glass transition temperature of 20 to 90 ° C, more preferably 35 to 70 ° C.
When the glass transition temperature of the acrylic resin (A) is 20 ° C. or higher, blocking occurs when the outer layer-side resin film in which the cured resin layer reacted with the curing agent (II) is stacked or rolled up. To prevent

  Here, the glass transition temperature referred to here is the glass transition temperature of a resin obtained by drying a solution of the curable resin (I) having a hydroxyl group to a solid content of 100%, as measured by differential scanning calorimetry (DSC). Indicates that For example, the glass transition temperature is predicted by setting an aluminum pan containing a sample weighing about 10 mg of a sample and an aluminum pan containing no sample in a DSC device, and using the liquid pan in a nitrogen stream with liquid nitrogen. After cooling to a glass transition temperature minus 50 ° C., the temperature is raised to a predicted glass transition temperature plus 50 ° C. at a rate of 10 ° C./min, and a DSC curve is plotted. The slope of the straight line extending from the baseline on the low temperature side of this DSC curve (the portion of the DSC curve in the temperature region where no transition and reaction occurs in the test piece) to the high temperature side and the curve of the step change portion of the glass transition become maximum. From the intersection with the tangent drawn at such a point, the extrapolated glass transition onset temperature (Tig) can be determined, and this can be determined as the glass transition temperature. The glass transition temperature of the present invention describes a value measured by the above method.

The weight average molecular weight of the acrylic resin (A) having a hydroxyl group in the present invention is preferably from 100,000 to 1,000,000, and more preferably from 150,000 to 800,000. When the weight average molecular weight is 100,000 or more, a packaging material for an electricity storage device having a tough protective layer can be obtained. When the weight average molecular weight is 1,000,000 or less, a beautiful packaging material free from inclusion of a gel substance or the like can be obtained. Is obtained.
The above-mentioned mass average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (GPC) of the acrylic copolymer (A). For example, the temperature of a column (KF-805LKF-803L and KF-802, manufactured by Showa Denko KK) is 40 ° C., THF is used as an eluent, the flow rate is 0.2 ml / min, detection is RI, and sample concentration is Was set to 0.02%, and polystyrene was used as a standard sample. The mass average molecular weight of the present invention describes a value measured by the above method.

The hydroxyl group-containing polyester resin (B) in the present invention will be described.
The polyester resin (B) containing a hydroxyl group may be either linear or branched. In the case of a linear polyester-based resin, the hydroxyl value is preferably 5 to 100 (mgKOH /), and the glass transition temperature is preferably 20 to 90C, more preferably 30 to 70C.
Specific examples of the linear polyester-based resin include Byron 200 (hydroxyl value: 6 mgKOH / g, Tg: 67 ° C., Mn: 17,000), and Byron 220 (hydroxyl value: 50 mgKOH / g, manufactured by Toyobo Co., Ltd.) Tg: 53 ° C., Mn: 3,000), Byron 802 (hydroxyl value: 37 mg KOH / g, Tg: 60 ° C., Mn: 3,000), Byron 637 (hydroxyl value: 5 mg KOH / g, Tg: 21 ° C., Mn) : 29,000).

  As the branched polyester resin, a hydroxyl value is preferably 50 to 250 (mgKOH / g), and an alkyd resin modified with soybean oil fatty acid, dehydrated castor oil fatty acid, or the like can be used. Specific examples of the branched polyester resin include Vernock D-145-55BA (hydroxyl value: 65 to 72 mgKOH / g, acid value: 10 to 14 mgKOH / g) manufactured by DIC Corporation, and Vernock 11-408 (hydroxyl value). : 180 to 220 mgKOH / g, acid value: ≤ 9), and Vernock D-161 (hydroxyl value: 155 to 180 mgKOH / g, acid value: ≤ 4.5).

The hydroxyl-containing epoxy resin (C) in the present invention will be described.
As the epoxy resin, a bisphenol A type epoxy resin and a bisphenol F type epoxy resin are preferable. Among them, a modified epoxy resin modified with a soybean oil fatty acid, a dehydrated castor oil fatty acid, or the like is preferable. The hydroxyl value is preferably from 100 to 250 (mgKOH / g). Specific examples of the modified epoxy resin include Arakawa 9201N (hydroxyl value: 250 mgKOH / g, Tg: 94 ° C., Mw: 50,000) and Araquid 9205 (hydroxyl value: 220 mgKOH / g, Tg: manufactured by Arakawa Chemical Co., Ltd.). 84 ° C, Mw: 30,000), KA-1439A (hydroxyl value: 210 mgKOH / g, Tg: 77 ° C, Mw: 35,000).

Next, the curing agent (II) will be described. The curing agent (II) reacts with the hydroxyl group which is a crosslinkable functional group in the above-mentioned hydroxyl group-containing curable resin (I) to form a crosslinked protective layer.
By reacting with the hydroxyl group contained in the curable resin (I), the protective layer can be formed into a strong layer by crosslinking, so that erosion when the electrolyte solution adheres is prevented.
Examples of the curing agent (II) include a polyisocyanate compound (E), a urea formaldehyde resin, a melamine formaldehyde resin, a phenol formaldehyde resin, and an aluminum chelate compound. Compound (E) is preferred.

It is important that the polyisocyanate compound (E) used in the present invention has two or more isocyanate groups in one molecule, for example, aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate and the like. Can be raised.
One type of polyisocyanate compound may be used, or two or more types of compounds may be used in combination.

  Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, and 2,6-tolylene isocyanate. Range isocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 " -Can raise triphenylmethane triisocyanate, etc.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate , 2,4,4-trimethylhexamethylene diisocyanate and the like.

  Examples of the alicyclic polyisocyanate include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, and methyl-isocyanate. 2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), 1,4-bis (isocyanatomethyl) cyclohexane and the like can be mentioned.

  Further, in addition to the polyisocyanate, an adduct of the polyisocyanate and a polyol compound such as trimethylolpropane, a burette or an isocyanurate of the polyisocyanate, further, the polyisocyanate and a known polyether polyol or polyester polyol, Adducts with acrylic polyols, polybutadiene polyols, polyisoprene polyols and the like can be mentioned.

  Among these polyisocyanate compounds (E), a low yellowing type aliphatic or alicyclic polyisocyanate is preferable from the viewpoint of design properties, and an isocyanurate is preferable from the viewpoint of wet heat resistance. More specifically, an isocyanurate of hexamethylene diisocyanate (HDI) and an isocyanurate of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) are preferred. Also, a mixture of these is preferably used.

  Further, a blocked polyisocyanate compound may be used in the curable protective coating of the present invention from the viewpoint of storage stability of the resin solution. Examples of the blocked polyisocyanate compound include those obtained by blocking the above-mentioned non-blocked polyisocyanate compound with various blocking agents. As the blocking agent, those that dissociate at a relatively low temperature of about 80 ° C to 100 ° C are used. preferable. When a non-blocked polyisocyanate compound is used, a method in which the curable resin (I) and the curing agent (II) are separately packaged and mixed immediately before use is preferably used. .

  The curable protective coating of the present invention preferably contains 5 to 200 parts by mass, more preferably 10 to 180 parts by mass of the curing agent (II) based on 100 parts by mass of the curable resin (I) having a hydroxyl group. Is more preferable. Curable resin (I) having a hydroxyl group: When the curing agent (II) is contained in an amount of 5 parts by mass or more with respect to 100 parts by mass, the protective layer film becomes tough, and even if the electrolyte solution adheres to the protective layer, the protective layer is formed. Prevents the surface from whitening or dissolving. By containing the curing agent (II) in an amount of 200 parts by mass or less, it is possible to prevent the protective layer film from being excessively crosslinked and causing cracks or the like during molding.

Next, the waxes in the present invention will be described.
The protective layer in the present invention contains waxes. As the waxes, at least one selected from amides, vegetable oils, animal oils, and petroleum is used.

The amide wax is a reaction product of a long-chain fatty acid and an amine compound. Examples of long-chain fatty acids include saturated fatty acids such as lauric acid, stearic acid, palmitic acid, and behenic acid, and unsaturated fatty acids such as erucic acid and oleic acid, and erucic acid and stearic acid are preferred.
Examples of the vegetable oil wax include palm oil and coconut oil.
Examples of animal oil waxes include lanolin, whale oil, and tallow.
Examples of the petroleum-based wax include petrolatum, paraffin wax, microcrystalline wax, and the like, and synthetic hydrocarbon-based wax using petroleum as a raw material and linear higher alcohols.

The waxes preferably contain 1 to 20 parts by mass based on 100 parts by mass of the total of the curable resin (I) having a hydroxyl group and the curing agent (II).
By containing the waxes, the dynamic friction coefficient of the protective layer of the packaging material for an electric storage device is reduced, and slip properties are imparted. Specifically, the dynamic friction coefficient of the surface of the protective layer can be reduced to 0.15 or less by containing the wax. It is more preferably 0.12 or less, further preferably 0.10 or less. When the dynamic friction coefficient is 0.15 or less, the coefficient of friction between the molded female mold and the protective layer in embossing is reduced, and productivity can be improved.

In addition, the dynamic friction coefficient was measured by a method described below using FRICTION TESTERTR-2 manufactured by Toyo Seiki Co., Ltd. The measurement was performed according to JIS K7125 for plastic films and sheets of JIS standard.
That is, a thread having a base length of 63 mm × 63 mm and a mass of 200 g ± 2 g is placed on a flat protective layer obtained by applying and curing a curable protective paint on a base material at a predetermined film thickness. Tensile speed: The thread was pulled at a speed of 100 mm / min, and the stress at that time was measured with a load cell. The measurement was performed three times, and the average of the three measurements was taken as the dynamic friction coefficient. In addition, the load range was measured as 2N.

The surface of the protective layer of the present invention has a “wetting index” according to JIS standard of 33 × 10 ⁻³ (N / m) or more, and preferably 34 × 10 ⁻³ (N / m) or more.
By setting the wetting index to 33 × 10 ⁻³ (N / m) or more, the ink may be removed when the product name or the like is printed on the outermost layer (protective layer) of the power storage device packaging container after the power storage device is manufactured. In addition, the ink adhesion does not decrease.

The method for measuring the wetting index according to JIS K6768 will be described. Soak a cotton swab with the Wetting Index Standard Reagent and apply it only once in the lateral direction of the protective layer. The amount of liquid to be applied is always kept constant. The determination is made based on the state of the central part of the liquid film at the time when two seconds have elapsed after the application of the reagent. When the applied liquid film does not break and maintains its original state, it is determined to be "wet", and when it has broken, it is determined to be "not wet". The value of the surface tension of the reagent when it was just wet, 10 ⁻³ (N / m), is expressed as the wetting index of the sample film.
That is, the higher the surface tension (the larger the wetting index) of the surface of the protective layer, the more easily the ink is wetted.

The storage device container is formed by press-forming the storage device packaging material using a female mold and a male mold as described below, so that the heat seal layer has a concave surface and the protective layer has a convex surface. Embossing).
When the protective layer contains the curable resin (I) having a hydroxyl group, the curing agent (II), and waxes, the packaging container material is not broken or wrinkled during press molding.

The curable protective coating may be any other than the acrylic resin having a hydroxyl group (A), the polyester resin having a hydroxyl group (B), and the epoxy resin having a hydroxyl group (C), as long as the object of the present invention is not impaired. Resin, organic or inorganic fine particles, an organic solvent, and the like.
Examples of the resin other than the acrylic resin (A) having a hydroxyl group, the polyester resin (B) having a hydroxyl group, and the epoxy resin (C) having a hydroxyl group include urethane resin, fluorine resin, vinyl chloride resin, and vinylidene chloride. Resin, vinyl chloride-vinylidene chloride copolymer resin, phenol resin, cellulose ester resin and the like can be mentioned. These resins may have a crosslinkable functional group or may not have a crosslinkable functional group. It is preferable to have a crosslinkable functional group.

  A white or black pigment may be added to the curable protective paint to make the surface of the packaging material for an electric storage device white or black instead of being transparent. In the case of white color, titanium oxide is generally used. When making black, carbon black is generally used. Titanium oxide and carbon black are obtained by dispersing using a part of the curable resin (I) having a hydroxyl group, for example, using a wet media disperser, and adding it to the remaining curable resin (I). Can be done. Examples of the wet media dispersing machine include scandics, ball mills, paint shakers, basket mills, dyno mills, ultravisco mills, annular dispersers, jet mills, homogenizers, and the like.

  As a medium used for dispersion, zirconia, alumina, glass beads, steel beads, or the like can be used, and a medium having a diameter of 0.1 to 5 mm can be used.

By containing organic or inorganic fine particles in the curable protective coating, the surface of the protective layer is made uneven to impart an anti-blocking effect, or to give a matte feeling due to the surface unevenness, and to give the film strength. And make it hard to be damaged.
These fine particles are preferably contained in an amount of 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the curable resin (I) having a hydroxyl group. When the content is 0.01 parts by mass or more, the above effect can be expected. When the content is 30 parts by mass or less, a durable protective layer having excellent moldability can be formed.

  Specific examples of the organic fine particles include polytetrafluoroethylene resin, polyethylene resin, polypropylene resin, polymethyl methacrylate resin, polystyrene resin, nylon (registered trademark) resin, melamine resin, guanamine resin, phenol resin, urea resin, and silicone. Examples include polymer fine particles such as resin, methacrylate resin, and acrylate resin, or cellulose powder, nitrocellulose powder, wood powder, waste paper powder, rice husk powder, starch, and the like. One type of organic particles may be used, or two or more types may be used in combination.

  Specific examples of the inorganic fine particles include oxides, hydroxides, sulfates, carbonates, and silicates of metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, and titanium. Based fine particles. More specific examples include silica gel, aluminum oxide, calcium hydroxide, calcium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, zinc oxide, lead oxide, diatomaceous earth, zeolite, aluminosilicate, talc, white carbon, mica , Glass fiber, glass powder, glass beads, clay, wallazite, iron oxide, antimony oxide, titanium oxide, lithopone, pumice powder, aluminum sulfate, zirconium silicate, barium carbonate, dolomite, molybdenum disulfide, iron sand, carbon black, etc. Contained inorganic particles. One type of inorganic particles may be used, or two or more types may be used in combination.

  If necessary, a curing accelerator may be added to the curable protective coating as long as the effect of the present invention is not impaired. The curing accelerator serves as a catalyst for promoting a urethane bonding reaction between the hydroxyl group of the curable resin (I) having a hydroxyl group and the polyisocyanate compound (E). Examples of the curing accelerator include tin compounds, metal salts, and bases. Specific examples include tin octylate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, tin chloride, iron octylate, cobalt octylate, and naphthene. Zinc acid, triethylamine, triethylenediamine and the like. These can be used alone or in combination.

The curable protective coating may contain an organic solvent. Examples of the organic solvent include aromatic solvents such as toluene and xylene; alcohol solvents such as iso-propyl alcohol, n-butyl alcohol and propylene glycol monomethyl ether; and ester solvents such as ethyl acetate, butyl acetate and cellosolve acetate. Solvents include ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone.
The organic solvent preferably has a boiling point of 50 ° C to 200 ° C. If the boiling point is lower than 50 ° C., the solvent tends to evaporate when the curable protective coating is applied to the substrate, and the solid content increases, making it difficult to apply the coating with a uniform film thickness. When the boiling point is higher than 200 ° C., it becomes difficult to dry the solvent. Note that two or more solvents may be used.

For the purpose of imparting weather resistance to the curable protective coating, the curable protective coating may further include an ultraviolet absorber or an ultraviolet stabilizer.
Examples of the UV absorber include organic UV absorbers such as benzotriazole UV absorber, benzophenone UV absorber, triazine UV absorber, indole UV absorber, and inorganic UV absorbers such as zinc oxide. And ultraviolet absorbers.
As the ultraviolet stabilizer, an ultraviolet stabilizer such as a hindered amine compound is suitably used. An ultraviolet absorber or an ultraviolet stabilizer may be added to the curable protective coating as an additive, or an ultraviolet absorber or an ultraviolet stabilizer having a functional group may be used by reacting with an acrylic copolymer. Or may be used by reacting it with another resin.
These UV absorbers and UV stabilizers are used in an amount of 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the solid content of the curable protective coating excluding the UV absorbers and the UV stabilizers. Is preferred.

  In the curable protective coating of the present invention, if necessary, a filler, a thixotropy-imparting agent, an antioxidant, an antioxidant, an antistatic agent, a flame retardant, and a heat conductive agent as long as the effects of the present invention are not impaired. Various additives such as an improver, a plasticizer, an anti-sagging agent, an antifouling agent, an antiseptic, a bactericide, an antifoaming agent, a leveling agent, a curing agent, a thickener, a pigment dispersant, and a silane coupling agent are further added. It may be added.

  In the packaging material for an electricity storage device of the present invention, the dynamic friction coefficient of the protective layer in a 25 ° C., 50% RH atmosphere is 0.15 or less. It is preferably 0.12 or less, more preferably 0.10 or less. By making the dynamic friction coefficient 0.15 or less, the protective layer is provided with a slip property to reduce the dynamic friction coefficient, and the shear force acting between the molded female mold and the cured resin layer is reduced, thereby obtaining a laminated structure. Separation and cracking of the barrier layer can be prevented.

In the packaging material for an electric storage device of the present invention, the wetting index according to the JIS standard of the protective layer is 33 × 10 ⁻³ (N / m) or more, and preferably 34 × 10 ⁻³ (N / m) or more. When the wetting index of the protective layer is 33 × 10 ⁻³ (N / m) or more, when the power storage device is manufactured, the ink may be blurred when printing or printing the product name, the manufacturer name, the lot number, and the like. There is no decrease in adhesion.

Next, the configuration of the packaging material for a power storage device of the present invention will be described.
The power storage device packaging material is laminated from the outermost layer in the order of protective layer / outer layer resin film layer / outer layer adhesive layer / metal foil layer / inner layer adhesive layer / heat seal layer. In the packaging material for an electric storage device, a side scheduled to be located near the electrolyte solution with the metal foil layer as a boundary is referred to as an inner layer side, and a side scheduled to be located far away is referred to as an outer layer side. The above-described lamination structure shows an essential structure. For example, another film layer can be further laminated on the outer layer side and the inner layer side via an adhesive layer.

The outer layer side resin film in the present invention is preferably a nylon-based thermoplastic resin film or a polyester-based thermoplastic film. More preferably, it is a nylon-based thermoplastic film. Examples of the nylon include polyamide resins, that is, nylon 6, nylon 6,6, a copolymer of nylon 6 and nylon 6,6, nylon 6,10, and polymethaxylylene adipamide (MXD6).
Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, and polycarbonate.
These thermoplastic films may be used as they are, or may be used after providing a corona discharge treatment or an easy-adhesion layer. Further, it can be stretched.

A metal foil layer typified by an aluminum foil has a function of preventing water vapor from entering the power storage device from the outside. The thickness is preferably from 20 to 80 μm from the viewpoint of pinhole resistance and moldability.
It is preferable to use an aluminum foil containing 0.3 to 9% by mass of iron and 0.7 to 2% by mass of iron from the viewpoint of further improving the occurrence of pinholes and preventing the occurrence of cracks during molding. It is more preferable to use one. Such an aluminum foil has good spreadability, reduces the occurrence of pinholes due to bending as compared with an aluminum foil not containing iron, and can easily form a side wall when molding a power storage device container. .
The aluminum foil manufactured by cold rolling changes its flexibility, stiffness and hardness under annealing (so-called annealing) conditions. In the present invention, it is preferable to use an aluminum foil having a tendency to be soft, which has been slightly or completely annealed, rather than an unannealed hard processed product. The conditions for annealing the aluminum foil may be appropriately selected according to the degree of molding.

Next, an example of a method for manufacturing the packaging material for an electricity storage device of the present invention will be described. The method for manufacturing the power storage device packaging material of the present invention is not limited to this example.
One side of a 25 μm-thick nylon film is subjected to corona treatment. Next, a curable protective coating containing the curable resin (I) having a hydroxyl group and the polyisocyanate compound (E) is applied by a roll coating method so as to have a dry thickness of 5 μm (solid content). After drying in an oven at 50 ° C. to volatilize the solvent, the mixture is placed in a thermostatic chamber at 50 ° C. and left for 4 days, and the hydroxyl group and the polyisocyanate compound (E) contained in the curable resin (I) having a hydroxyl group are removed. To obtain a laminate of [protective layer / nylon film].

As a method of applying the curable protective coating to the outer resin film layer, a conventionally known method can be used. Specifically, comma coating, gravure coating, reverse coating, roll coating, lip coating, spray coating and the like can be mentioned.
The thickness of the protective layer is preferably from 0.5 to 30 μm, more preferably from 2 to 20 μm.

Next, an adhesive composition for the outer layer is applied to the nylon film surface of the laminate of the [protective layer / nylon film], the solvent is volatilized, and the [protective layer / nylon film / adhesive layer precursor] A laminate is obtained, and one surface of a double-sided chemically treated aluminum foil obtained by subjecting both surfaces of an aluminum foil having a thickness of 40 μm to a chemical conversion treatment is bonded to the adhesive layer precursor.
The laminated body of the [protective layer / nylon film / adhesive layer precursor / chemical conversion treated aluminum foil] was placed in a constant temperature room at 50 ° C. and left for 4 days to ripen the reaction of the adhesive layer precursor. A laminate of [protective layer / nylon film / adhesive layer / chemical conversion treated aluminum foil] is obtained.
Next, the emulsion of the acid-modified polypropylene-based adhesive was applied to the other surface of the double-sided chemically treated aluminum foil by a roll coating method, dried and heated to 180 ° C., and 30 μm was applied on the adhesive layer of the acid-modified polypropylene-based adhesive. To form a primary laminate.
In any of the chemical conversion treatments, an aqueous solution comprising a phenol resin, a chromium (3) compound, and phosphoric acid is applied as a treatment liquid by a roll coating method, and is baked under conditions where the film temperature is 180 ° C. or higher. The amount of chromium applied is 2 mg / m ² (dry weight).

As the outer layer-side adhesive used for bonding the outer layer resin film layer and the metal foil layer of the packaging material for an electric storage device of the present invention, various types such as a thermosetting type, a hot-melt type, a UV-curing type, etc. Can be used.
Examples of the thermosetting adhesive include an adhesive obtained by blending various polyol components and a curing agent component represented by an isocyanate component. For example, examples of the polyester-based adhesive include TOMOFLEX TM-K55 / CAT-10L (trade name, manufactured by Toyo Morton Co., Ltd.). Examples of the hot melt adhesive include a product manufactured by Dow Corning Toray Co., Ltd.
The adhesive used for bonding the outer resin film layer and the metal foil layer of the packaging material for an electric storage device of the present invention is not limited to the above example.

  The inner adhesive layer is for laminating the metal foil layer and the heat seal layer. Examples of the inner layer-side adhesive for forming the inner layer-side adhesive layer include a polyolefin-based resin having a carboxyl group or an acid anhydride group, and those containing the polyolefin-based resin and a curing agent.

The container for an electricity storage device of the present invention can be obtained by molding the above-described packaging material for an electricity storage device so that the protective layer forms a convex surface and the heat seal layer forms a concave surface.
Note that the “concave surface” in the present invention is a surface having a recess capable of accommodating an electrolyte solution when a flat packaging material for an electric storage device is formed into a tray shape as shown in FIG. In the present invention, the “convex surface” means a back surface (an opposite surface, a back surface) of the surface having the depression.

  A power storage device such as a secondary battery includes a battery main body, a plurality of terminals respectively connected to a positive electrode and a negative electrode of the battery main body, a battery container, and an electrolyte solution. That is, the power storage device of the present invention is one in which an electrode, an electrolyte solution, and the like are housed in the power storage device container. At the time of storage, the inside can be sealed by facing the heat seal layers, heat sealing the outer peripheral portion, and integrating the heat seal layers. The heat seal layer other than the sealed outer peripheral portion is in contact with the electrolyte solution.

  The packaging material for a power storage device of the present invention can be suitably used as a packaging material (laminate) for forming a container of a power storage device such as a lithium ion battery, an electric double layer capacitor, and a lithium ion capacitor.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In Examples, “parts” indicates “parts by mass” and “%” indicates “% by mass”.

Synthesis Example 1 "Acrylic resin A-1 solution"
150 parts of methyl ethyl ketone (MEK) was charged into a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen inlet tube, and the temperature was raised to 80 ° C. while stirring under a nitrogen atmosphere. When the temperature in the flask reaches 80 ° C., 57.07 parts of n-butyl methacrylate, 40.00 parts of methyl methacrylate, 1.16 parts of 2-hydroxyethyl methacrylate, 0.77 parts of methacrylic acid, A monomer solution obtained by mixing 1.00 part of FA-711MM (HALS monomer manufactured by Hitachi Chemical Co., Ltd.) and 0.08 part of azobisisobutyronitrile was added dropwise over 2 hours.
One hour after the completion of the dropwise addition of the monomer, the reaction was continued by adding 0.02 parts of azobisisobutyronitrile every hour, and the reaction was continued until the unreacted monomer in the solution became 1% or less. When the amount of unreacted monomer became 1% or less, the reaction was terminated by cooling, and an acrylic resin A-1 solution having a hydroxyl content of about 40% solid content was obtained.
The acrylic resin A-1 had a glass transition temperature of 50 ° C., an acid value of 5.0 (mg KOH / g), a hydroxyl value of 5.0 (mg KOH / g), and a weight average molecular weight of 300,000.

Synthesis Examples 2 to 12 “Acrylic Resin A-2 to A-12 Solutions”
The reaction was performed according to the composition shown in Table 1 to obtain solutions of acrylic resins A-2 to A-12. Table 1 shows the glass transition temperature, acid value, hydroxyl value, and mass average molecular weight.
The solid content, acid value, hydroxyl value, and mass average molecular weight (Mw) were measured by the methods described below.

《Measurement of solid content》
The weight of an aluminum dish with a lid having a diameter of 55 mm and a depth of 15 mm is measured to four decimal places. Approximately 1.5 g of the resin solution is collected in an aluminum dish, immediately closed, and quickly and accurately weighed. With the lid removed, place in a 150 ° C. oven and dry for 10 minutes. After cooling to room temperature, the weight of the aluminum dish and the lid is measured, and the solid content is calculated by the following formula.
Solid content (%) = (weight after drying−weight of aluminum dish) ÷ (weight before drying−weight of aluminum dish) × 100

<< Measurement of acid value (AV) >>
About 1 g of the resin solution is precisely weighed and placed in a stoppered Erlenmeyer flask, and dissolved by adding 50 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution. To this, phenolphthalein TS is added as an indicator and kept for 30 seconds. Thereafter, the solution is titrated with a 0.1 mol / L alcoholic potassium hydroxide solution until the solution turns red.
The acid value was determined by the following equation. The acid value was a value in a dry state of the resin.
Acid value (mgKOH / g) = (a × F × 56.1 × 0.1) / S
S: sampled amount x (solid content of sample / 100) (g)
a: Titration of 0.1 mol / L alcoholic potassium hydroxide solution (ml)
F: titer of 0.1 mol / L alcoholic potassium hydroxide solution

<< Measurement of hydroxyl value (OHV) >>
About 1 g of the resin solution is precisely weighed and placed in a stoppered Erlenmeyer flask, and dissolved by adding 50 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution. Further, exactly 5 ml of an acetylating agent (a solution prepared by dissolving 25 g of acetic anhydride in pyridine to a volume of 100 ml) is added, and the mixture is heated to 100 ° C. and stirred for about 1 hour. To this, phenolphthalein TS is added as an indicator and lasts for 30 seconds. Thereafter, the solution is titrated with a 0.5 mol / L alcoholic potassium hydroxide solution until the solution turns red. Separately, as a blank test, an acetylating agent is added only to the toluene / ethanol mixture, and the solution heated at 100 ° C. for 1 hour is titrated with a 0.5 mol / L alcoholic potassium hydroxide solution.
The hydroxyl value was determined by the following equation. The hydroxyl value was a value in a dry state of the resin.
Hydroxyl value (mgKOH / g) = {(ba) × F × 56.1 × 0.5} / S + D
S: sampled amount x (solid content of sample / 100) (g)
a: Titration of 0.5 mol / L alcoholic potassium hydroxide solution (ml)
b: Titration (ml) of 0.5 mol / L alcoholic potassium hydroxide solution in blank experiment
F: titer of 0.5 mol / L alcoholic potassium hydroxide solution D: acid value (mgKOH / g)

<< Mass average molecular weight (Mw) >>
The measurement was performed using a Shodex GPC-104 / 101 system manufactured by Showa Denko KK
Column Shodex KF-805L + KF-803L + KF-802
Detector Differential refractometer (RI)
Column temperature 40 ° C
Eluent Tetrahydrofuran (THF)
Flow rate 1.0ml / min
Sample concentration 0.02%
Standard sample for calibration curve TSK standard polystyrene

Synthesis Example 13 “Polyester resin B-1 solution”
In a four-necked flask equipped with a cooling tube, a stirrer, a thermometer, and a nitrogen inlet tube, 100 parts of Byron 200 manufactured by Toyobo Co., Ltd., 233.3 parts of methyl ethyl ketone was added, and the mixture was stirred under a nitrogen atmosphere. The temperature was raised to 80 ° C. Stirring was continued until Byron 200 was completely dissolved. After confirming complete dissolution, the mixture was cooled to room temperature to obtain a polyester resin solution B-1 having a solid content of about 30%.
The polyester resin B-1 solution had an acid value of 2 (mg KOH / g), a hydroxyl value of 6 (mg KOH / g), a glass transition temperature of 67 ° C, and a number average molecular weight of 17,000.

Synthesis Example 14 “Polyester resin B-2 solution”
By a method similar to that for the polyester resin B-1, Byron 802 manufactured by Toyobo Co., Ltd. was dissolved to obtain a polyester resin solution B-2.
The polyester resin B-2 solution had an acid value of <1 (mg KOH / g), a hydroxyl value of 37 mg KOH / g, a glass transition temperature of 60 ° C., and a number average molecular weight of 3,000.

Synthesis Example 15 “Polyester resin B-3 solution”
In the same manner as for the polyester resin B-1, Vernock D-161 manufactured by DIC Corporation was dissolved to obtain a polyester resin solution B-3.
The polyester solution resin B-3 had an acid value of 4 (mg KOH / g) and a hydroxyl value of 165 (mg KOH / g).

Synthesis Example 16 “Epoxy resin C-1 solution”
In the same manner as for the polyester resin B-1, Arakid 9205 manufactured by Arakawa Chemical Co., Ltd. was dissolved to obtain an epoxy resin solution C-1 having a solid content of about 30%.
The epoxy solution resin C-1 solution had an acid value of 0 (mg KOH / g), a hydroxyl value of 220 (mg KOH / g), a glass transition temperature of 84 ° C, and a weight average molecular weight of 30,000.

Synthesis Example 17 “Epoxy resin C-2 solution”
In the same manner as for the polyester resin B-1, bisphenol A type epoxy resin jer-1007 manufactured by Mitsubishi Chemical Corporation was dissolved to obtain an epoxy resin C-2 solution having a solid content of about 30%.
The epoxy resin C-2 solution had an epoxy equivalent of 1600 to 1900, a softening point of 127 to 133 ° C., and a molecular weight of 2,900.

"Production of polyisocyanate compound (E-1)"
The mixed isocyanurate of hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI) was diluted with ethyl acetate to obtain a solution of a polyisocyanate compound (E-1) as a resin solution having a solid content of 50%.

"Production of polyisocyanate compound (E-2)"
An adduct of hexamethylene diisocyanate (HDI) was diluted with ethyl acetate to obtain a solution of a polyisocyanate compound (E-2) as a resin solution having a solid content of 50%.

"Example 1"
Solution containing 4.96 parts by mass (solid mass) of polyisocyanate compound (E-1) in 250 parts by mass of solution containing 100 parts by mass (solid mass) of acrylic resin (A-1) obtained in Synthesis Example 1 9.92 parts by mass, a diamond L-200 containing 1.1 parts by mass of erucic acid amide is added, and methyl ethyl ketone (MEK) is further added so as to have a solid content of 30%, followed by stirring to obtain a curable protective coating. Obtained.

Using a bar coater, the obtained curable protective paint is applied to a corona-treated surface of a stretched nylon film having a thickness of 25 μm that has been subjected to corona treatment in advance, and dried in an oven at 100 ° C. for 1 minute to remove solvents. Volatilized. A bar coater was selected so that the film thickness after drying was 5 μm.
Subsequently, the reaction between the acrylic resin and the polyisocyanate compound was aged for 4 days in a constant temperature chamber at 50 ° C. to form a protective layer on the stretched nylon film.

Next, a polyester-based laminating adhesive is applied to the stretched nylon film on the side opposite to the surface on which the protective layer is formed, to form a precursor of the outer layer-side adhesive layer having a thickness of 10 μm when dried. On the precursor, an aluminum foil having a thickness of 40 μm, on both surfaces of which a chemical conversion treatment was performed, was overlaid. The laminate of the protective layer / stretched nylon film / outer layer side adhesive precursor / aluminum foil was left in a room at 50 ° C. for 4 days to ripen the reaction of the outer layer side adhesive precursor.
Next, an emulsion of an acid-modified polypropylene-based adhesive was applied to the other surface of the aluminum foil by a roll coating method, dried, and heated to 180 ° C. to form an acid-modified polypropylene-based adhesive layer having a thickness of 30 μm. A polypropylene film was attached to form a primary laminate.
In the chemical conversion treatment, an aqueous solution comprising a phenol resin, a chromium fluoride (3) compound, and phosphoric acid was applied as a treatment liquid by a roll coating method, and was baked under conditions where the film temperature was 180 ° C. or higher. The applied amount of chromium is 2 mg / m ² (dry weight).
Using the obtained primary laminate, the dynamic friction coefficient, wetting index, printability, moldability, electrolyte solution resistance, and delamination were evaluated according to the methods described below, and the results are shown in Table 2.

≪Dynamic friction coefficient≫
The laminated body obtained by coating and drying the curable protective coating material of the present invention on the stretched nylon film subjected to corona treatment is allowed to stand in a constant temperature room at 50 ° C. for 4 days to mature the reaction between the hydroxyl group of the curable resin and the polyisocyanate compound. Let it. A stainless steel rectangular parallelepiped with a base length of 63 mm x 63 mm and a mass of 200 g is placed on the coated surface of the aged stretched nylon film. Tensile speed: A rectangular block made of stainless steel is pulled at a speed of 100 mm / min, and the stress at that time is measured. The measurement is performed three times, and the average of the three measurements is defined as stress (g).
Dynamic friction coefficient (μ) = stress (g) / weight of stainless steel block (g)
4: Dynamic friction coefficient less than 0.08 3: Dynamic friction coefficient 0.08 to less than 0.10 2: Dynamic friction coefficient 0.10 to less than 0.15 1: Dynamic friction coefficient 0.15 or more

≪Wetting index≫
With respect to the protective layer after aging, the wetting index was measured using a wetting index standard solution specified in JIS K6768. The measurement was performed in an atmosphere of 25 ° C. and 50% RH, and the others were performed according to the method specified in JIS K6768.
4: Wetting index is 34 dyn / cm or more 3: Wetting index is 33 dyn / cmm
2: 32 dyn / cm wettability index
1: The wetting index is 31 dyn / cm or less

≪Printability≫
The ripened protective layer (20 cm × 15 cm) was coated with a solvent type gravure ink (black) manufactured by Toyo Ink Co., Ltd. using a bar coater # 6 and dried at 60 ° C. for 1 minute.
The repelling degree of the ink was visually evaluated according to the following criteria.
4: No repelling of ink was observed on the coated surface of the stretched nylon film.
3: Repelling of ink occurred on the coated surface of the stretched nylon film within 3 pieces.
2: Repelling of the ink occurred on the coated surface of the stretched nylon film within 10 pieces.
1: 10 or more ink cissing occurred on the coated surface of the stretched nylon film.

≪Moldability≫
Using the primary laminate, a polypropylene was placed on a molding machine having a bottom surface of 30 mm x 50 mm such that the polypropylene side was on the inside and the protective layer was on the outside, and the wall (side surface) was 7 mm. Mold until the depth is reached. The state of cracks, tears, and wrinkles on the wall (side surface) and corners is evaluated.
4: No cracking, tearing, or wrinkling is observed up to a depth of 7 mm.
3: At a depth of less than 5 to 7 mm, any of cracks, tears and wrinkles is observed.
2: At a depth of less than 3 to 5 mm, any of cracks, tears, and wrinkles is observed.
At a depth of less than 1: 3 mm, any of cracks, tears, and wrinkles is observed.

≫Electrolyte solution resistance≫
Electrolyte solution (electrolyte solution adjusted so that LiPF ₆ has a concentration of 1 mol, mixed solution of ethylene carbonate: diethyl carbonate: dimethyl carbonate = 1: 1: 1) on the outermost layer of the primary laminate, that is, the protective layer. And let stand in an oven at 70 ° C. for 3 hours. After 3 hours, it is taken out and the surface of the outermost layer is visually observed.
4: No abnormality is observed on the surface.
3: A whitened portion is seen in a dot shape.
2: Whitening is observed throughout.
1: The film is dissolved.

層 間 Delamination of heat seal part ≫
The primary laminate was once wound into a roll and then unwound. From the unwound primary laminate, a molded product molded into a shape of 30 mm × 50 mm × 7 mm is obtained. Next, the opening side of the molded product and the polypropylene side of the unmolded flat primary laminate (unwound) were placed on three sides of the four sides at 190 ° C., 98 N / cm ² for 5 seconds. Heat seal under conditions. The above-mentioned electrolyte solution is poured into the opening that is not heat-sealed, and the mouth is also heat-sealed. After each sample was stored in a thermo-hygrostat at 60 ° C. and 90% RH for 7 days, delamination of the heat-sealed portion was visually evaluated.
4: Delamination was not observed in all 10 of the 10 molded products.
3: Delamination is observed in less than 3 out of 10 molded pieces.
2: Delamination is seen in less than 3 to 5 out of 10 molded pieces.
Delamination is observed in 5 or more of the 1:10 molded pieces.

"Examples 2 to 23", "Comparative Examples 1, 4, 5, 6"
According to Table 2, a primary laminate was formed in the same manner as in Example 1. The dynamic friction coefficient, the wetting index, the printability, the moldability, the electrolyte solution resistance, and the delamination were evaluated in the same manner as in Example 1, and the results are shown in Table 2.
As the slip agent, a liquid at room temperature was added as it was, and a solid at room temperature was subjected to dispersion treatment in MEK using Scandex.

"Comparative Example 2"
To 250 parts by mass of a solution containing 100 parts by mass (solid mass) of the acrylic resin (A-3) obtained in Synthesis Example 3, Diamid L-200 containing 4.3 parts by mass of erucic acid amide was added, and further, Methyl ethyl ketone (MEK) was added so that the solid content was 30%, and the mixture was stirred to obtain a curable protective coating.
A primary laminate was formed in the same manner as in Example 1, and the dynamic friction coefficient, wettability index, printability, moldability, electrolyte solution resistance, and delamination were evaluated in the same manner as in Example 1. It is shown in Table-2.

"Comparative Example 3"
Solution containing 59.89 parts by mass (solid mass) of polyisocyanate compound (E-2) in 250 parts by mass of solution containing 100 parts by mass (solid mass) of acrylic resin (A-3) obtained in Synthesis Example 3 119.78 parts by mass were added, and methyl ethyl ketone (MEK) was further added so that the solid content became 30%, followed by stirring to obtain a curable protective coating.
A primary laminate was formed in the same manner as in Example 1, and the dynamic friction coefficient, wettability index, printability, moldability, electrolyte solution resistance, and delamination were evaluated in the same manner as in Example 1. It is shown in Table-2.

"Comparative Example 7"
A chemical conversion treatment was applied to both sides of an aluminum foil having a thickness of 40 μm, and a non-corona-treated surface of a stretched nylon film subjected to a corona treatment was adhered to one surface of the chemical conversion treatment by a dry lamination method using a polyester-based laminating adhesive. Then, the reaction of the polyester adhesive was aged at 50 ° C. for 4 days. Next, an emulsion of an acid-modified polypropylene-based adhesive was applied to the other surface of the chemically treated aluminum foil by a roll coating method, dried, and heated to 180 ° C. to form a 30 μm thick film on the acid-modified polypropylene-based adhesive layer. The polypropylene film was bonded to each other to form a primary laminate having no protective layer. Using this primary laminate, the dynamic friction coefficient, wettability index, printability, moldability, electrolyte solution resistance, and delamination were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

  As shown in Table 2, Comparative Example 1 is inferior in electrolyte solution resistance because the acrylic resin (A) does not contain a hydroxyl group, and Comparative Example 2 does not contain a curing agent (II).

  In Comparative Example 3, since the protective coating did not contain a slip agent, the slip property of the cured resin film was poor. At the time of molding, the frictional resistance between the cured resin film and the molded female mold increases, and cracks, tears, and wrinkles occur in the molded product.

Comparative Examples 5 and 6 contain a slip agent, but have a low wetting index. Although the moldability is excellent due to the low dynamic friction coefficient, the printability and delamination are inferior.
In Comparative Example 7, since no resin film was provided on the stretched nylon film, slip properties were poor, and cracks, tears, and wrinkles occurred during molding. Also, if the electrolyte solution adheres, it is contaminated.

A laminate obtained by applying and curing the curable protective coating of the present invention on a plastic film or molded plastic, an aluminum foil, an aluminum plate, a copper foil, a tin plate, a galvanized steel plate, a glass plate, a glass bottle, etc. It can be used for solar cell backside protection sheet, outdoor display, marking film, glass shatterproof film, antireflection film, heat ray prevention film, etc.Because it is excellent in solvent resistance and abrasion resistance, It can also be suitably used as a hard coat agent.

Furthermore, the curable protective coating of the present invention provides a resin film having excellent barrier properties because of its excellent electrolyte solution resistance.
Accordingly, the curable protective coating of the present invention includes, for example, various recording materials, IC cards, IC tags, etc., packaging materials for medicines and foods, back protective sheets for solar cells, marking films, photosensitive resin plates, adhesives Resins for building materials such as sheets, dye-sensitized solar cells, resin films for protecting polarizing plates, resin films for antireflection, light diffusion films, etc., glass shatterproof resin films, decorative sheets, and resin films for windows It can be used for films, display materials, resin films for overlays inside and outside such as illuminated signs, shrink films, and the like.

(10): protective layer (11): outer layer side resin film layer (12): outer layer side adhesive layer (13): metal foil layer (14): inner layer side adhesive layer (15): heat seal layer

Claims (7)

In order from the outermost layer, a protective layer, an outer-layer-side resin film layer, an outer-layer-side adhesive layer, a metal foil layer, an inner-layer-side adhesive layer, and a packaging material for an electricity storage device that essentially requires a heat seal layer,
The packaging material for an electricity storage device, wherein the protective layer is a protective layer that has not been subjected to a surface treatment, and satisfies all of the following conditions (1) to (5).
(1) The protective layer is a cured coating formed from a curable resin (I) having a hydroxyl group, a curing agent (II), and a curable protective paint containing waxes.
(2) The waxes are at least one selected from amide-based, vegetable oil-based, animal oil-based, and petroleum-based waxes.
(3) a curable resin having a hydroxyl group (I) is, I Oh an acrylic resin (A) having a hydroxyl group, an acrylic resin having a hydroxyl group (A) has a hydroxyl value of 5 to 100 (mg KOH / g), a glass transition temperature of 20 to 90 ° C., the weight average molecular weight (Mw) of 100,000 to 1,000,000, Ru copolymer der with other monomers not containing monomer and a hydroxyl group having a hydroxyl group .
(4) The dynamic friction coefficient of the protective layer in a 25 ° C., 50% RH atmosphere is 0.15 or less.
(5) The wetting index according to the JIS standard of the protective layer is 33 × 10 ⁻³ (N / m) or more.   The packaging material for an electricity storage device according to claim 1, wherein the curing agent (II) is contained in an amount of 5 to 200 parts by mass based on 100 parts by mass of the curable resin (I) having a hydroxyl group.   The packaging material for an electric storage device according to claim 1 or 2, wherein the curing agent (II) includes a polyisocyanate compound (E). The packaging material for an electric storage device according to any one of claims 1 to 3, wherein the monomer having a hydroxyl group is a hydroxyalkyl (meth) acrylate .   The packaging material for an electric storage device according to any one of claims 1 to 4, wherein the outer resin film layer is a nylon-based thermoplastic resin film or a polyester-based thermoplastic film.   A power storage device container formed from the packaging material for a power storage device according to claim 1, wherein the protective layer forms an outermost surface. A power storage device using the power storage device container according to claim 6.