JP6606851B2 - Packaging materials for electricity storage devices - Google Patents

Description

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

Secondary batteries typified by lithium ion batteries are used for various applications such as personal computers, portable terminal devices (cell phones, PDAs, etc.), video cameras, electric vehicles, energy storage batteries, robots, satellites, and the like.
A secondary battery accommodates 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 an exterior body, a metal can type obtained by pressing a metal into a cylindrical or rectangular parallelepiped container, or a pouch type in which a laminate composed of a base material layer, an aluminum foil, and a sealant layer is formed into a bag shape, There is an embossed type in which the laminate is press-molded to form a recess, and the battery body is housed in the recess.

The demand for the pouch type and the embossed type is high in terms of the freedom of shape and dimensions, and the demand for the embossed type is higher in that a more compact exterior body can be obtained.
Pouch-type and embossed-type exterior bodies are formed by heat-sealing sealant layers. That is, the sealant layer is located on the innermost side in the exterior body. On the other hand, a base material layer will be located in the outermost side in an exterior body.

The embossed-type exterior body is formed by pressing the laminate into the mold so that the base material layer constituting the laminate is in contact with the inner surface of the concave mold. Therefore, the base material layer that forms the convex outermost layer is required to have good moldability.
Further, when the molded container is filled 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 base material layer, it is required that the base material layer is not damaged.
Furthermore, after the molded container is filled with the electrolyte solution and the heat seal layers are heat sealed, it is required that the heat seal layers do not peel off.

Patent Documents 1 to 4 disclose laminated bodies (packaging materials) for forming pouch-type and embossed-type exterior bodies.
Patent Document 1 laminates a stretched film having a coating layer that is durable against an electrolytic solution containing chlorine or a fluorine-containing lithium salt on the outermost surface of one surface of an aluminum foil, and is made of polypropylene or the like. A battery case packaging material in which a film is laminated on the outermost surface of an aluminum foil is disclosed. Polyvinylidene chloride, vinylidene chloride as a coating material for forming a coating layer durable to an electrolyte -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 film 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 multilayered, 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 described that it is preferable to provide a film or a coating layer.

Patent Document 3 discloses that a fatty acid amide slip agent is formed on the surface of a base material layer of a laminate comprising 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.
In the third paragraph, when stretched nylon is used as the base material layer, it is described that in emboss molding, the coefficient of friction between the formed female mold and the base material layer is large, and molding wrinkles or breakage may occur. Yes. In the fourth paragraph, as a solving means, it is described that the surface of the base material layer is coated with a fatty acid amide slip agent.
In the fifteenth paragraph, in order to reduce the frictional resistance between the mold and the base material layer or to impart electrolyte solution resistance, the base material layer is multilayered, and the surface of the base material layer is made of a fluororesin or acrylic resin. It is described that it is preferable to provide a film or a coating layer made of either a resin or a silicone resin.

  Patent Document 4 discloses a battery packaging material using a base material layer having a coating layer made of a slip agent on the surface. It is disclosed that a vinyl copolymer is copolymerized using a siloxane-containing initiator as a slip agent. In the 36th paragraph, a slip agent is applied and coated on the surface of the base material layer, so that the slip property between the surface of the base material layer and the mold is ensured during emboss molding, and stable press molding is described. ing. That is, when the exterior body is molded, the slipperiness between the surface of the base material layer and the mold (female mold) is important. The 53rd paragraph describes that when the frictional force between the outer package and the mold is large, peeling of the laminated structure and cracking of the barrier layer are caused.

  In addition, although it does not disclose the application to the battery packaging material, Patent Document 5 discloses a drawing aluminum having a thermosetting resin protective film in order to prevent cracking and tearing of the aluminum foil during molding. A technique of using an aluminum foil laminate in which a slip agent is blended in a protective film resin of a foil laminate as a food packaging container is disclosed. In the Examples, it is disclosed that stearic acid is blended as a slip agent in an epoxy resin.

  Similarly, although it does not disclose application to battery packaging materials, Patent Document 6 discloses a polymer (A) obtained by copolymerization of acrylonitrile, a monomer having a crosslinkable functional group, and another monomer, 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. It is coated on a soft polyvinyl chloride base material and used for interior seating materials such as vehicle seats, sofas, and wallpaper, preventing contamination and coloring due to the environment and contact during use, and easily adhering contamination. A method that can be removed is proposed.

JP 2000-123799 A JP 2001-176462 A JP 2002-216714 A JP 2007-294382 A Japanese Patent Laid-Open No. 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 having durability against an electrolytic solution. Specifically, when polyvinylidene chloride, vinylidene chloride-vinyl chloride, epoxy resin is used, no coating material is used, or a vinyl acetate resin is used as a coating material instead of the resin. It is described that the electrolytic solution resistance is improved as compared with the case.
However, in the case of the invention described in Patent Document 1, since only the coating material is applied and the coating layer is not cured, the electrolyte solution resistance is insufficient and whitening cannot be prevented.

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

Furthermore, as described above, Patent Document 3 discloses the use of a fatty acid amide slip agent from the viewpoint of improving the moldability, and suggests the use of a fluorine resin, an acrylic resin, or a silicone 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.

  Since the slip agent described in Patent Document 4 does not use a cross-linking agent when coating on the surface of the base material, the coating layer has insufficient electrolyte solution resistance and cannot prevent whitening.

Patent Document 5 discloses a technique of using, as a food packaging container, an aluminum foil laminate in which a thermosetting resin protective film composed of, for example, an epoxy resin and stearic acid as a slip agent is provided. The food packaging container generally has an opening diameter larger than the bottom diameter because of the demand for finally taking out food. In addition, the shape of the bottom or opening is often circular or elliptical. In the drawing of a container having a circular or elliptical bottom, the circumferential portion is stretched and is subjected to substantially uniform shrinkage to form a wall portion.
On the other hand, although the embossed type container for an electricity storage device has a slight roundness at the corner portion, the bottom portion is often a quadrilateral and the opening diameter is often almost the same as the bottom diameter. In such drawing of a container having a quadrilateral bottom, only the wall portion is stretched and the shrinkage is concentrated on the corner portion.
Therefore, it can be said that the drawing of a container having a quadrilateral bottom is a stricter molding than the drawing of a container having a circular or elliptical bottom. In addition, the draw molding in which the opening diameter and the bottom diameter are not substantially changed and the wall portion is substantially vertical, because the wall portion is more contracted than the draw molding in which the opening diameter is larger than the bottom diameter. It is a strict molding.

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

  An object of the present invention is to provide a packaging material for an electricity storage device that has an outermost layer excellent in moldability and electrolyte solution resistance and can maintain a stable sealed state after heat sealing.

The present invention, in order from the outermost layer, is a packaging material for an electricity storage device that essentially includes 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 heat seal layer. ,
It is related with the packaging material for electrical storage devices in which the said protective layer satisfy | fills all the conditions of following (1)-(3).
(1) The protective layer is formed from a curable protective paint containing a curable resin (I) having a hydroxyl group and a curing agent (II).
(2) The curable resin (I) having a hydroxyl group includes a silicone resin (A) having a hydroxyl group and a polysiloxane structure.
(3) 0.01 to 10% by mass of a Si element derived from a polysiloxane structure is contained in a total of 100% by mass of the curable resin (I) having a hydroxyl group and the curing agent (II).

The silicone resin (A) having a hydroxyl group and a polysiloxane structure includes an acrylic monomer having a hydroxyl group and having no polysiloxane structure, an acrylic monomer having a polysiloxane structure and having no hydroxyl group, and a hydroxyl group. Copolymerized with other acrylic monomers that do not have a polysiloxane structure,
Alternatively, an acrylic monomer having a hydroxyl group and a polysiloxane structure is copolymerized with another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure.
Alternatively, it is obtained by copolymerizing an acrylic monomer having a hydroxyl group and a polysiloxane structure, an acrylic monomer having a hydroxyl group and not having a polysiloxane structure, and another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure. ,
It is preferably a copolymer having a hydroxyl value of 5 to 100 (mgKOH / g), a glass transition temperature of 30 ° C. or less, and a mass average molecular weight (Mw) of 10,000 to 800,000.

Moreover, it is preferable that the packaging material for electrical storage devices of this invention contains 5-200 mass parts of hardening | curing agents (II) with respect to 100 mass parts of curable resin (I) which has a hydroxyl group.
The curing agent (II) preferably contains a polyisocyanate compound (E).

In the power storage device packaging material of the present invention, the protective layer preferably has a dynamic friction coefficient of 0.15 or less.
In the packaging material for an electricity storage device of the present invention, the outer resin film layer is preferably a nylon-based thermoplastic resin film or a polyester-based thermoplastic film.

The packaging material for an electricity storage device of the present invention comprises a curable resin (I) having a hydroxyl group, in addition to a silicone resin (A) having a hydroxyl group and a polysiloxane structure, an acrylic resin (B) having a hydroxyl group, and a hydroxyl group. It preferably contains a resin having at least one hydroxyl group selected from the group consisting of a polyester-based resin (C) and an epoxy-based resin (D) having a hydroxyl group,
0.2 to 50 parts by mass of the silicone resin (A) with respect to 100 parts by mass in total of the acrylic resin (B) having a hydroxyl group, the polyester resin (C) having a hydroxyl group, and the epoxy resin (D) having a hydroxyl group. It is preferable to contain a part.
The acrylic resin (B) has a hydroxyl value of 5 to 5, which is obtained by copolymerizing an acrylic monomer having a hydroxyl group and not having a polysiloxane structure with another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure. The copolymer is preferably 100 (mg KOH / g), a glass transition temperature of 20 to 90 ° C., and a weight average molecular weight (Mw) of 30,000 to 800,000.

The present invention also relates to an electricity storage device container formed of the electricity storage device packaging material of the present invention, wherein the protective layer constitutes the outermost surface.
Furthermore, this invention relates to the electrical storage device formed using the said container for electrical storage devices.

  According to the present invention, it has become possible to provide an energy storage device packaging material that has an outermost layer excellent in moldability and electrolyte solution resistance and can maintain a stable sealed state after heat sealing.

It is typical sectional drawing of the one aspect | mode of the packaging material for electrical storage devices of this invention. It is a typical perspective view of one mode (tray form) of the container for electrical storage devices of the present invention.

As described above, the packaging material for an electricity storage device of the present invention 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 in order from the outermost layer. A packaging material for an electricity storage device.
The protective layer is formed from a curable protective paint containing a curable resin (I) having a hydroxyl group and a curing agent (II). The curable resin (I) having a hydroxyl group includes a silicone resin (A) having a hydroxyl group and a polysiloxane structure (hereinafter abbreviated as silicone resin (A)).
The protective layer formed from the curable protective coating mainly has a function of imparting electrolyte solution resistance to the outer resin film layer and imparting puncture resistance by “curing”. In addition, the “polysiloxane structure” imparts slip properties to the protective layer, lowers the coefficient of dynamic friction, lowers the shear force acting between the molding knife and the protective layer, and destroys the laminated state (delamination). ) And the barrier layer cracking prevention function.

The silicone resin (A) having a hydroxyl group and a polysiloxane structure is composed of an acrylic monomer having a hydroxyl group and not having a polysiloxane structure, an acrylic monomer having a polysiloxane structure and having no hydroxyl group, and It is a copolymer with other acrylic monomers not having a siloxane structure,
Alternatively, it is a copolymer of an acrylic monomer having a hydroxyl group and a polysiloxane structure and another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure,
Alternatively, it is a copolymer of an acrylic monomer having a hydroxyl group and a polysiloxane structure, an acrylic monomer having a hydroxyl group and not having a polysiloxane structure, and another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure. It is preferable.

Specific examples of acrylic monomers having a polysiloxane structure include organopolysiloxane compounds containing one terminal (meth) acryloxy group such as Silaplane FM-0711, FM-0721, FM-0725 manufactured by Chisso Corporation, Single-end methacryl-modified silicone compounds such as X-22-164A, X-22-164B, X-22-164C, and X-22-2404 manufactured by Shin-Etsu Chemical Co., Ltd., and fragments such as TSL9705 manufactured by Toshiba Silicone Co., Ltd. Examples include terminal vinyl group-containing polyorganosiloxane compounds.
These acrylic monomers may be used alone or in combination.

  Examples of the monomer having a hydroxyl group and not having a polysiloxane structure include hydroxyalkyl (meth) acrylate and a product obtained by adding ε-caprolactone to the hydroxyalkyl (meth) acrylate, and hydroxyalkyl (meth) acrylate. Is preferred.

Specific examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Examples thereof include 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 adduct of 2-hydroxyethyl (meth) acrylate, 2 mol of ε-caprolactone of 2-hydroxyethyl (meth) acrylate. Examples of the adduct include an ε-caprolactone adduct of a hydroxyalkyl (meth) acrylate having 1 to 4 carbon atoms, such as an adduct, an ε-caprolactone 3 mol adduct of 2-hydroxyethyl (meth) acrylate, and the like. It is not limited only to such illustration. These hydroxyl group-containing monomers may be used alone or in combination.

Examples of other acrylic monomers having neither a hydroxyl group nor a polysiloxane structure 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, phenoxyethyl (meth) acrylate and the like.

  As a monomer having an alicyclic hydrocarbon group, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, Examples thereof include dicyclopentenyl (meth) acrylate and dicyclopentanyl (meth) acrylate.

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

  Acid group-containing monomers include (meth) acrylic acid, maleic anhydride, 2- (meth) acryloyloxyethyl-succinic acid, 2- (meth) acryloyloxyethyl-hexahydrophthalic acid, 2- (meth) Examples include acryloyloxyethyl-phthalic acid and 2- (meth) acryloyloxyethyl acid phosphate.

The silicone resin (A) having a hydroxyl group and a polysiloxane structure can be easily prepared by copolymerizing the monomers.
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, the solution polymerization method is preferable because the obtained reaction mixture can be used as it is.

  Hereinafter, one embodiment in the case of preparing a silicone-based resin (A) having a hydroxyl group and a polysiloxane structure by solution polymerization of monomers will be described. However, the present invention is not limited only to the embodiment. Absent.

  Examples of the solvent used for solution polymerization of the monomer include 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; dimethylformamide and the like, but the present invention is not limited to such examples. The amount of the solvent is preferably determined as appropriate according to the concentration of the single 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, benzoyl Although a peroxide, di-tert-butyl peroxide, etc. are mentioned, this invention is not limited only to this illustration. 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, for example, a chain transfer agent such as n-dodecyl mercaptan may be used in order to adjust the molecular weight of the resulting silicone resin (A) having a hydroxyl group and a polysiloxane structure.

  The polymerization temperature when the monomer is polymerized is usually preferably 40 to 200 ° C, more preferably 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 amount of the polymerization initiator, and cannot be determined unconditionally, it is preferably determined appropriately according to them.

The thus obtained silicone resin (A) having a hydroxyl group and a polysiloxane structure 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 silicone resin (A) having a hydroxyl group and a polysiloxane structure is moderately reacted with the curing agent (II) described later. Since the protective layer having a proper cross-linked structure is formed, contamination of the heat seal layer surface due to the detachment of the silicone resin (A) can be prevented, and the electrolyte solution resistance of the protective layer can be improved.
On the other hand, when the hydroxyl value is 100 (mgKOH / g) or less, excessive crosslinking between the silicone resin (A) and the curing agent (II) is suppressed. As a result, the adhesion to the base material layer can be improved, and the polysiloxane structure derived from the silicone resin (A) can be prevented from being excessively fixed inside the protective layer, thereby improving the moldability.
The hydroxyl value of the silicone resin (A) can be controlled by the ratio of the hydroxyl group-containing monomer in the monomer component used for the formation of the silicone resin (A).

The silicone resin (A) preferably has a glass transition temperature of 30 ° C. or lower, more preferably 20 ° C. or lower, and further preferably −10 to 10 ° C.
When the glass transition temperature of the silicone resin (A) is 30 ° C. or less, the degree of freedom of the side chain derived from the silicone resin (A) in the protective layer reacted with the curing agent (II) is increased, and the slip property is increased. Can be improved. If slip property can be improved, the dynamic friction coefficient is lowered, and the shear force acting between the molded knife and the cured resin layer is reduced, thereby preventing the destruction of the laminated state (delamination) and cracking of the barrier layer. I can do it.

  The glass transition temperature mentioned here indicates the glass transition temperature measured by differential scanning calorimetry (DSC) for a resin obtained by drying a solution of the silicone resin (A) to a solid content of 100%. . 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 not containing a sample in a DSC apparatus and using liquid nitrogen in a nitrogen stream. The glass transition temperature is reduced to minus 50 ° C., then the temperature is raised to a predicted glass transition temperature plus 50 ° C. at a heating rate of 10 ° C./min, and a DSC curve is plotted. The slope of the DSC curve on the low temperature side (the DSC curve portion in the temperature region where no transition or reaction occurs in the test piece) is extended to the high temperature side, and the slope of the step change portion of the glass transition is maximized. From the intersection with the tangent drawn at such a point, the extrapolated glass transition start temperature (Tig) can be determined, and this can be determined as the glass transition temperature. The glass transition temperature of this invention has described the value measured by said method.

The mass average molecular weight of the silicone resin (A) in the present invention is preferably 10,000 to 800,000, and more preferably 20,000 to 500,000. When the mass average molecular weight is 10,000 or more, a packaging material for an electricity storage device having a tough film is obtained, and when it is 800,000 or less, a beautiful packaging material free from mixing of a gel is obtained. .
In addition, said mass mean molecular weight is the value of polystyrene conversion by the gel permeation chromatography (GPC) of a (meth) acrylic-type 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, sample concentration 0.02%, and polystyrene was used as a standard sample. The mass average molecular weight of the present invention describes the value measured by the above method.

In the present invention, the curable resin (I) having a hydroxyl group includes an acrylic resin (B) having a hydroxyl group, a polyester resin (C) having a hydroxyl group, and an epoxy having a hydroxyl group, in addition to the silicone resin (A) described above. Further, a resin having at least one hydroxyl group selected from the group consisting of the resin series (D) (hereinafter also referred to as “other resin having a hydroxyl group”) can be included. By using “another resin having a hydroxyl group”, the moldability improving function can be mainly assigned to the silicone resin (A), and the electrolyte solution resistance can be mainly assigned to “another resin having a hydroxyl group”. .
The curable protective coating in the present invention contains 0.01 to 10% by mass of a Si element derived from a polysiloxane structure in a total of 100% by mass of the curable resin (I) having a hydroxyl group and the curing agent (II) described later. It is important to contain it, and it is preferable to contain 0.05-5 mass% of Si elements derived from a polysiloxane structure.
By including 0.01 mass% or more of Si elements derived from the polysiloxane structure, the dynamic friction coefficient of the protective layer can be made 0.15 or less. When the coefficient of dynamic friction is 0.15 or less, in emboss molding, the coefficient of friction between the molded female mold and the base material layer is reduced, preventing destruction of the laminated state (delamination) and cracking of the barrier layer during molding. be able to. In addition, a reduction in the dynamic friction coefficient can be expected to improve productivity during molding. On the other hand, when the Si element derived from the polysiloxane structure is 10% by mass or less, the moldability and the sealed state after heat sealing can be maintained.
In order to make the Si element content derived from the polysiloxane structure within the above range, a small amount of the silicone resin (A) containing a large amount of the polysiloxane structure and a “other resin having a hydroxyl group” can be used in a large amount. In addition, it is possible to use only a silicone resin (A) containing an appropriate amount of a polysiloxane structure, or a large amount of a silicone resin (A) containing a small amount of a polysiloxane structure together with a small amount of “other resin having a hydroxyl group”. It can also be used.

In addition, the Si element content rate derived from the polysiloxane structure in 100% by mass of the silicone resin (A) is a monomer having a polysiloxane structure contained in a total of 100 g of monomers used for forming the silicone resin (A). Is obtained by multiplying the content (g) by the content of Si element derived from the polysiloxane structure in the monomer having the polysiloxane structure.
The content of Si element derived from the polysiloxane structure in the monomer having the polysiloxane structure was determined by ICP emission spectroscopic analysis. Specifically, about 0.1 g of a solution obtained by diluting a sample about 100 times with acetone was precisely weighed, treated by an acid decomposition method using a microwave wet decomposition apparatus, and then made up to a constant volume of 50 ml with distilled water.

In addition, the measurement of the dynamic friction coefficient was performed by the method described below using Toyo Seiki Co., Ltd. FRITTION TESTERTR-2. The measurement was performed according to JIS K7125 for plastic film and sheet of JIS standard.
On a flat laminate obtained by applying and curing the resin composition of the present invention to a substrate with a predetermined film thickness,
A thread having a base length of 63 mm × 63 mm and a mass of 200 g ± 2 g is placed. Pulling 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 made three times, and the average of the three times was taken as the dynamic friction coefficient. In addition, the load range was measured as 2N.

Next, one of the “other resins having a hydroxyl group”, the acrylic resin (B) will be described.
The acrylic resin (B) has a hydroxyl group and does not have a polysiloxane structure. It can obtain similarly except not using the acryl-type monomer which has a polysiloxane structure among the monomers illustrated in the case of a silicone-type resin (A).
The hydroxyl value of the acrylic resin (B) is preferably 5 to 100 (mg KOH / g), the glass transition temperature is preferably 20 to 90 ° C., and the mass average molecular weight (Mw) is 30,000 to 800. , 000 is preferable.
When the hydroxyl value is 5 (mgKOH / g) or more, the outermost layer of the packaging material for an electricity storage device forms an appropriate cross-linked structure by reaction with the curing agent (II), and can improve the resistance to the electrolyte solution at the time of filling. . On the other hand, by setting the hydroxyl value to less than 100 (mgKOH / g), it is possible to improve the adhesion to the base material layer and to effectively prevent the protective layer from cracking during molding.

The hydroxyl value of the acrylic resin (B) depends on the ratio of the hydroxyl group-containing monomer in the monomer component used for forming the acrylic resin (B).
In order to obtain an acrylic copolymer (B) having a hydroxyl value of 5 to 100 (mgKOH / g), it is preferable to copolymerize 1 to 40% by mass of the hydroxyl group-containing monomer in a total of 100% by mass of the monomers. .
Specific examples of the hydroxyl group-containing monomer include, for example, hydroxyalkyl (meth) acrylate and a product obtained by adding ε-caprolactone to the hydroxyalkyl (meth) acrylate, as used in the silicone resin (A). And hydroxyalkyl (meth) acrylates are preferred.

As will be described later, the container for the electricity storage device uses a female-type and male-type “mold”, and press-molds the packaging material for the electricity storage device so that the heat seal layer forms a concave surface and the protective layer forms a convex surface ( It is also called embossing).
When the mass average molecular weight of the acrylic resin (B) in the present invention is 30,000 or more, the electrolyte solution resistance can be improved.
From the viewpoint of preventing the formation and mixing of a gel-like product, the acrylic resin (B) preferably has a mass average molecular weight (Mw) of 800,000 or less.
When the gel-like material is mixed into the cured resin film, molding wrinkles or cuts may occur in emboss molding.
Moreover, by setting the mass average molecular weight (Mw) of the acrylic resin (B) to 800,000 or less, a curable protective coating material having an appropriate viscosity and an appropriate solid content can be obtained, and the surface of the base material layer can be obtained. When applying, defects are less likely to occur.

  The glass transition temperature of the acrylic resin (B) in the present invention is preferably 20 to 90 ° C. More preferably, it is 30 ° C. or higher, and more preferably 70 ° C. or lower. When the glass transition temperature is 20 ° C. or higher, tackiness hardly occurs on the surface of the protective layer. Therefore, when the packaging material for an electricity storage device is made into a roll after production, blocking hardly occurs.

  By setting the glass transition temperature of the acrylic resin (B) to 90 ° C. or lower, when forming the convex portion by press molding the packaging material for the electricity storage device, the protective layer cracks at the shoulder or corner portion of the convex portion. Can be prevented.

The glass transition temperature of the acrylic resin (B) is determined by the composition ratio of other monomers copolymerized with the hydroxyl group-containing monomer.
As specific examples of other monomers, the same monomers as used for the silicone resin (A) can be used.

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

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

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

Next, the curing agent (II) will be described. The curing agent (II) reacts with a hydroxyl group that is a crosslinkable functional group in the above-described curable resin (I) having a hydroxyl group to form a crosslinked protective layer.
By reacting with the hydroxyl group contained in the silicone resin (A), the silicone resin (A) is prevented from being detached from the protective layer. Furthermore, since the protective layer can be made strong by crosslinking, erosion when the electrolyte solution adheres is prevented.
Examples of the curing agent (II) include polyisocyanate compound (E), urea formaldehyde resin, melamine formaldehyde resin, phenol formaldehyde resin, and 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, etc. Raised.
One type of polyisocyanate compound (E) may be used, or two or more types of compounds may be used in combination.

  Aromatic polyisocyanates include 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-triisocyanate. 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 increase triphenylmethane triisocyanate, etc.

  Aliphatic polyisocyanates 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 alicyclic polyisocyanates include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl- 2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylene bis (cyclohexyl isocyanate), 1,4-bis (isocyanate methyl) cyclohexane and the like can be raised.

  In addition to the polyisocyanate, an adduct of the polyisocyanate and a polyol compound such as trimethylolpropane, a burette or isocyanurate of the polyisocyanate, and further, the polyisocyanate and a known polyether polyol or polyester polyol, Examples include adducts such as acrylic polyol, polybutadiene polyol, polyisoprene polyol and the like.

  Among these polyisocyanate compounds (E), a low-yellowing aliphatic or alicyclic polyisocyanate is preferable from the viewpoint of design, and an isocyanurate is preferable from the viewpoint of heat and heat resistance. More specifically, an isocyanurate form of hexamethylene diisocyanate (HDI) and an isocyanurate form of 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI) are preferred. Moreover, these mixtures are also used suitably.

Moreover, you may use a block-ized polyisocyanate compound for the curable protective coating material of this invention from a viewpoint of the storage stability of a resin solution. Examples of the blocked polyisocyanate compound include those obtained by blocking the above-mentioned non-blocked polyisocyanate compound with various blocking agents, and the blocking agent is one that deviates at a relatively low temperature of about 80 ° C to 100 ° C. preferable. In the case of using a non-blocked polyisocyanate compound, a method in which the curable resin (I) and the curing agent (II) are separately packaged and mixed immediately before use is suitably used. .

In the curable protective coating material of the present invention, the Si element derived from the polysiloxane structure contained in the silicone resin (A) is contained in a total of 100% by mass of the curable resin (I) having a hydroxyl group and the curing agent (II). It is important to include both of them so as to include 0.01 to 10% by mass, and it is preferable to include 0.05 to 5% by mass of Si element derived from the polysiloxane structure.
The polysiloxane structure contained in the silicone resin (A) is present in the vicinity of the surface of the protective layer after curing, and improves the moldability of the protective layer.

  For example, it is preferable to contain 5-200 mass% of polyisocyanate compound (E) with respect to 100 mass parts of curable resin (I) which has a hydroxyl group, and it is more preferable to contain 10-180 mass%.

  By setting the polyisocyanate compound (E) to 5% by mass or more with respect to 100 parts by mass of the curable resin (I) having a hydroxyl group, a cured resin film having excellent resistance to an electrolyte solution is formed. On the other hand, by making the polyisocyanate compound (E) 200 mass% or less with respect to 100 parts by mass of the total of the curable resin (I) having a hydroxyl group, an excessive crosslinking structure is suppressed and Inhibition of adhesion can be prevented, and cracking during molding can be prevented.

Furthermore, the curable protective coating of the present invention includes a resin other than the silicone resin (A) and other resins having a hydroxyl group, organic or inorganic fine particles, and the like within the range in which the object of the present invention is not impaired. In addition, an organic solvent or the like may be contained.
Examples of resins other than the silicone resin (A) and other resins having a hydroxyl group include, for example, urethane resins, fluororesins, vinyl chloride resins, vinylidene chloride resins, vinyl chloride-vinylidene chloride copolymer resins, phenol resins, and cellulose esters. Resin etc. 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 can be added to the curable protective coating of the present invention to make the surface of the power storage device packaging material white or black instead of transparent. When white is used, titanium oxide is generally used. In the case of black, carbon black is generally used. Titanium oxide and carbon black are obtained by a method in which a part of the curable resin (I) having a hydroxyl group is dispersed using, for example, a wet media disperser and added to the remaining curable resin (I). I can do it. As the wet media disperser, scan dix, ball mill, paint shaker, basket mill, dyno mill, ultra visco mill, annular disperser, jet mill, homogenizer and the like can be used.

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

By containing organic or inorganic fine particles in the curable protective coating of the present invention, the surface of the protective layer is made uneven to give an anti-blocking effect, the matte feeling due to the surface unevenness, and the strength of the film To make it difficult to get scratched.
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 with respect to 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 strong protective layer excellent in 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, silicone. Polymer fine particles such as resin, methacrylate resin, acrylate resin, cellulose powder, nitrocellulose powder, wood powder, waste paper powder, rice husk powder, starch and the like can be raised. 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 inorganic oxides such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony, titanium, and other metal oxides, hydroxides, sulfates, carbonates, silicates, and the like. System fine particles are raised. Further 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, wollastonite, iron oxide, antimony oxide, titanium oxide, lithopone, pumice powder, aluminum sulfate, zirconium silicate, barium carbonate, dolomite, molybdenum disulfide, iron sand, carbon black, etc. Examples thereof include inorganic particles. One kind of inorganic particles may be used, or two or more kinds may be used in combination.

  Moreover, you may add a hardening accelerator to the curable protective coating material in this invention in the range which does not prevent the effect by this invention as needed. A hardening accelerator plays the role as a catalyst which accelerates | stimulates the urethane bond reaction of the hydroxyl group of curable resin (I) which has a hydroxyl group, and a polyisocyanate compound (E). Examples of the curing accelerator include tin compounds, metal salts, bases, etc. Specific examples include tin octylate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, tin chloride, iron octylate, cobalt octylate, naphthene. Examples include zinc acid, triethylamine, and triethylenediamine. These can be used alone or in combination.

The curable protective paint of the present invention 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; ester systems such as ethyl acetate, butyl acetate and cellosolve acetate. Solvent; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone are listed.
It is preferable to use an organic solvent having a boiling point of 50 ° C to 200 ° C. When the boiling point is lower than 50 ° C., the solvent tends to volatilize when the curable protective coating is applied to the substrate, and the solid content becomes high, making it difficult to apply with a uniform film thickness. When the boiling point is higher than 200 ° C., it is difficult to dry the solvent. Two or more solvents may be used.

For the purpose of imparting weather resistance to the curable protective coating material of the present invention, it may further contain an ultraviolet absorber, an ultraviolet stabilizer and the like.
Examples of the UV absorber include organic UV absorbers such as benzotriazole UV absorbers, benzophenone UV absorbers, triazine UV absorbers, and indole UV absorbers, and inorganic UV absorbers such as zinc oxide. UV absorbers such as
As the ultraviolet stabilizer, an ultraviolet stabilizer such as a hindered amine compound is preferably 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 is used after reacting with an acrylic copolymer. Alternatively, it may be used by reacting with another resin.
These ultraviolet absorbers and ultraviolet stabilizers are used in an amount of 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass with respect to 100 parts by mass of the solid content of the curable protective coating excluding the ultraviolet absorber and the ultraviolet stabilizer. It is preferable.

  In the curable protective coating according to the present invention, a filler, a thixotropy imparting agent, an anti-aging agent, an antioxidant, an antistatic agent, a flame retardant, and thermal conductivity, as long as the effects of the present invention are not hindered. Various additives such as improvers, plasticizers, anti-sagging agents, antifouling agents, antiseptics, bactericides, antifoaming agents, leveling agents, curing agents, thickeners, pigment dispersants, silane coupling agents, etc. It may be added.

Next, the structure of the packaging material for an electricity storage device of the present invention will be described.
The packaging material for an electricity storage device is laminated in the order of protective layer / outer layer side resin film layer / outer layer side adhesive layer / metal foil layer / inner layer side adhesive layer / heat seal layer from the outermost layer side. In the packaging material for an electricity storage device, the side that is close to the electrolyte solution with the metal foil layer as a boundary is called the inner layer side, and the side that is scheduled to be far away is called the outer layer side. Said laminated structure shows an essential structure, For example, another film layer can also be laminated | stacked through an adhesive layer further on the outer layer side and the inner layer side, respectively.

The outer layer-side resin film layer (base material layer) in the present invention is preferably a nylon-based thermoplastic resin film or a polyester-based thermoplastic film. A nylon-based thermoplastic film is more preferable.
The base layer is made of stretched nylon or polyester film. As nylon, polyamide resin, that is, nylon 6, nylon 6,6, copolymer of nylon 6 and nylon 6,6, nylon 6,10, polymer Taxylylene adipamide (MXD6) etc. are mentioned.
Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, and polycarbonate.

A metal foil layer typified by an aluminum foil has a function of preventing water vapor from entering inside the electricity storage device from the outside. From the viewpoint of pinhole resistance and molding processability, the thickness is preferably 20 to 80 μm.
It is preferable to use an aluminum foil containing 0.3 to 9% by mass of iron from the viewpoint of further improving the generation of pinholes and preventing the occurrence of cracks during molding, and containing 0.7 to 2% by mass of iron. It is more preferable to use one. Such an aluminum foil is more malleable than an aluminum foil that does not contain iron, reduces the occurrence of pinholes due to bending, and can easily form sidewalls when molding an electricity storage device container. .
Moreover, the aluminum foil manufactured by cold rolling changes its flexibility, waist strength, and hardness under annealing (so-called annealing treatment) conditions. In the present invention, it is preferable to use an aluminum foil having a soft tendency that has been annealed somewhat or completely, rather than a hard-treated product that has not been annealed. The conditions for annealing the aluminum foil may be appropriately selected according to the degree of molding.

Next, an example of the manufacturing method of the packaging material for electrical storage devices of this invention is demonstrated. The manufacturing method of the electrical storage device packaging material of the present invention is not limited to this example.
Corona treatment is applied to one side of a 25 μm thick nylon film. Next, the curable protective paint containing the silicone resin (A), the other resin having a hydroxyl group, and the polyisocyanate compound (E) is roll-coated so that the thickness after drying is 5 μm (solid content). It is applied and dried in an oven at 100 ° C. to volatilize the solvent. The stretched nylon film coated and dried with a curable protective coating is placed in a thermostatic chamber at 50 ° C. and left for 4 days, and the hydroxyl group and polyisocyanate compound contained in the silicone resin (A) and other resins having a hydroxyl group ( Aging reaction with E).

A conventionally well-known method can be used as a method of apply | coating a curable protective coating material to an outer layer side resin film layer. Specifically, comma coating, gravure coating, reverse coating, roll coating, lip coating, spray coating, etc. can be raised.
The thickness of the protective layer is preferably 0.5 to 30 μm, and more preferably 2 to 20 μm.

Next, a chemical conversion treatment was performed on both surfaces of a 40 μm-thick aluminum foil, and the non-coated surface of the stretched nylon film obtained by laminating the curable protective coating of the present invention was bonded to one surface of the chemical conversion treatment by a dry lamination method. Next, an emulsion of acid-modified polypropylene is applied and dried on the other surface of the chemically treated aluminum by a roll coating method, baked at a temperature of 180 ° C., and a polypropylene film having a thickness of 30 μm is thermally laminated on the baked surface. A primary laminate is formed.
In each of the chemical conversion treatments, an aqueous solution comprising a phenol resin, a chromium fluoride (3) compound, and phosphoric acid is applied as a treatment liquid by a roll coating method, and baked under a condition where the film temperature is 180 ° C. or higher. . The amount of chromium applied is 2 mg / m @ 2 (dry weight).

The outer layer side adhesive used for bonding the outer layer side resin film layer and the metal foil layer of the packaging material for an electricity storage device of the present invention may be various ones such as a hot melt type and a UV curable type in addition to thermosetting. Can be used.
Examples of the thermosetting adhesive include adhesives formed by blending various polyol components and curing agent components represented by isocyanate components. For example, as a polyester-type adhesive agent, Toyo Morton Co., Ltd. brand name: TOMOFLEX TM-K55 / CAT-10L etc. are mentioned. Examples of hot melt adhesives include products manufactured by Toray Dow Corning Co., Ltd.
The adhesive used for adhesion | attachment with the outer layer side resin film layer of the packaging material for electrical storage devices of this invention and a metal foil layer is not limited only to this illustration.

  The inner layer side 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 polyolefin resins having a carboxyl group or an acid anhydride group, and those containing the polyolefin resin and a curing agent.

The container for an electricity storage device of the present invention can be obtained by using the above-described packaging material for an electricity storage device, and molding so that the protective layer forms a convex surface and the heat seal layer forms a concave surface.
The “concave surface” as used in the present invention is a surface having a dent that can accommodate an electrolyte solution when the flat packaging material for an electricity storage device is molded into a tray shape as shown in FIG. The term “convex surface” as used in the present invention refers to the self-back surface (opposite surface, back surface) of the surface having the depression.

  An electricity storage device such as a secondary battery includes a battery body, a plurality of terminals respectively joined to a positive electrode and a negative electrode of the battery body, a battery container, and an electrolyte solution. That is, the electricity storage device of the present invention is one in which an electrode, an electrolyte solution, and the like are accommodated in the electricity storage device container. At the time of accommodation, 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 an electricity storage device of the present invention can be suitably used as a packaging material (laminate) for forming a container for an electricity storage device such as a lithium ion battery, an electric double layer capacitor, or a lithium ion capacitor.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by a following example. In the examples, “parts” represents “parts by mass” and “%” represents “% by mass”.

Synthesis Example 1 “Silicone Resin A-1 Solution”
A four-necked flask equipped with a cooling tube, a stirring device, a thermometer, and a nitrogen introducing tube was charged with 150 parts of methyl ethyl ketone (MEK) and heated to 80 ° C. while stirring in a nitrogen atmosphere. When the temperature in the flask reached 80 ° C., 43.22 parts of n-butyl methacrylate, 55.00 parts of 2-ethylhexyl methacrylate, 1.28 parts of 4-hydroxybutyl acrylate, and Silaplane FM-0721 A monomer solution in which 0.50 part and 0.08 part of azobisisobutyronitrile were mixed was added dropwise over 2 hours.
The reaction was continued by adding 0.02 part of azobisisobutyronitrile every hour from 1 hour after the completion of the monomer addition, and the reaction was continued until the unreacted monomer in the solution was 1% or less. When the unreacted monomer was 1% or less, the reaction was terminated by cooling to obtain a silicone resin A-1 solution having a solid content of about 40%.
Silicone resin A-1 has a glass transition temperature of 2 ° C., an acid value of 0.0 (mg KOH / g), a hydroxyl value of 5.0 (mg KOH / g), a mass average molecular weight of 300,000, and 100 g. The content of Si element derived from the per polysiloxane structure was 0.17 g.
The content of Si element derived from polysiloxane structure per 100 g of Silaplane FM-0721 is 34 g.

Synthesis Examples 2 to 9 “Silicone Resin A-2 to A-9 Solution”
Reaction was performed according to the composition of Table 1 to obtain silicone resin A-2 to A-9 solutions. Table 1 shows the glass transition temperature, acid value, hydroxyl value, mass average molecular weight, and polysiloxane structure-derived Si element content.
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 pan with a lid having a diameter of 55 mm and a depth of 15 mm is measured to 4 digits after the decimal point. About 1.5 g of the resin solution is collected in an aluminum dish, and the lid is immediately covered, and the weight is quickly and accurately measured. With the lid removed, place in an oven at 150 ° C. for 10 minutes to dry. After cooling to room temperature, the weight of the aluminum pan 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 accurately weighed in an Erlenmeyer flask with a stopper, and 50 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. To this is added phenolphthalein reagent as an indicator and held for 30 seconds. Thereafter, the solution is titrated with a 0.1 mol / L alcoholic potassium hydroxide solution until the solution becomes light red.
The acid value was determined by the following formula. The acid value is a numerical value of the dry state of the resin.
Acid value (mgKOH / g) = (a × F × 56.1 × 0.1) / S
S: Amount of sample collected x (solid content of sample / 100) (g)
a: Titration of 0.1 mol / L alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1 mol / L alcoholic potassium hydroxide solution

<< Measurement of hydroxyl value (OHV) >>
About 1 g of the resin solution is accurately weighed in an Erlenmeyer flask with a stopper, and 50 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution is added and dissolved. Further, 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride is dissolved in pyridine to make a volume of 100 ml) is added accurately, heated to 100 ° C. and stirred for about 1 hour. To this, phenolphthalein reagent 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 becomes light red. Separately, as a blank test, a solution obtained by adding an acetylating agent only to a toluene / ethanol mixed solution and heating 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 formula. The hydroxyl value was a numerical value of the dry state of the resin.
Hydroxyl value (mgKOH / g) = {(ba) × F × 56.1 × 0.5} / S + D
S: Amount of sample collected x (solid content of sample / 100) (g)
a: Titration volume of 0.5 mol / L alcoholic potassium hydroxide solution (ml)
b: Titration volume of 0.5 mol / L alcoholic potassium hydroxide solution in the blank experiment (ml)
F: Potency 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.
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 101 “Acrylic Resin B-1 Solution”
233.3 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 introduction tube, and the temperature was raised to 80 ° C. while stirring in a nitrogen atmosphere. When the temperature in the flask reached 80 ° C., 22.00 parts of methyl methacrylate, 76.84 parts of n-butyl methacrylate, 1.16 parts of 2-hydroxyethyl methacrylate, 0.08 of azobisisobutyronitrile The monomer solution mixed with the parts was added dropwise over 2 hours.
The reaction was continued by adding 0.02 part of azobisisobutyronitrile every hour from 1 hour after the completion of the monomer addition, and the reaction was continued until the unreacted monomer in the solution was 1% or less. When the unreacted monomer was 1% or less, the reaction was terminated by cooling to obtain an acrylic resin B-1 solution having a solid content of about 30%.
The acrylic resin B-1 had a glass transition temperature: 36 ° C., an acid value: 0.0 (mg KOH / g), a hydroxyl value: 5.0 (mg KOH / g), and a mass average molecular weight: 310,000.

Synthesis Examples 102 to 113 “Acrylic Resin B-2 to B-13 Solution”
Reaction was performed according to the composition of Table-2, and acrylic resin B-2 to B-13 solutions were obtained. Table 2 shows the glass transition temperature, acid value, hydroxyl value, and mass average molecular weight.
In addition, solid content, glass transition temperature, acid value, hydroxyl value, and mass average molecular weight (Mw) were measured by the same method as what was used by the measurement of silicone resin.

Synthesis Example 114 “Polyester Resin C-1 Solution”
100 parts of Byron 200 manufactured by Toyobo Co., Ltd. and 233.3 parts of methyl ethyl ketone are added to a four-necked flask equipped with a cooling tube, a stirring device, a thermometer, and a nitrogen introduction tube, and stirring is performed in 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 C-1 having a solid content of about 30%.
Polyester solution resin C-1 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 115 “Polyester resin C-2 solution”
Byron 802 manufactured by Toyobo Co., Ltd. was dissolved in the same manner as the polyester resin C-1 to obtain a polyester resin solution C-2.
Polyester solution resin C-2 had an acid value: <1 (mgKOH / g), a hydroxyl value: 37 mgKOH / g, a glass transition temperature: 60 ° C., and a number average molecular weight: 3,000.

Synthesis Example 116 “Polyester Resin C-3 Solution”
DIC Corporation Burnock D-161 was dissolved in the same manner as the polyester resin C-1 to obtain a polyester resin solution C-3.
Polyester-based solution resin C-3 had an acid value of 4 (mgKOH / g) and a hydroxyl value of 165 (mgKOH / g).

Synthesis Example 117 “Epoxy resin D-1 solution”
Arakid 9205 manufactured by Arakawa Chemical Co., Ltd. was dissolved in the same manner as the polyester resin C-1 to obtain an epoxy resin solution D-1 having a solid content of about 30%.
Epoxy solution resin D-1 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 mass average molecular weight of 30,000.

Synthesis Example 118 “Epoxy resin D-2 solution”
By the same method as polyester resin C-1, bisphenol A type epoxy resin jer-1007 manufactured by Mitsubishi Chemical Corporation was dissolved to obtain an epoxy resin solution D-2 having a solid content of about 30%.
Epoxy resin solution D-2 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)"
The isocyanurate form of hexamethylene diisocyanate (HDI) was diluted with ethyl acetate to obtain a polyisocyanate compound (E) solution as a resin solution having a solid content of 50%.

"Example 1"
0.5 parts by mass (solid weight) of the silicone resin (A-3) obtained in Synthesis Example 1, 100 parts by mass (solid weight) of acrylic resin (B-1), and polyisocyanate compound (E) 7 Mass part (solid weight) was added, and methyl ethyl ketone (MEK) was further added and stirred so that the solid content was 30% to obtain a curable protective coating.

The obtained curable protective coating was applied to the corona-treated surface of a 25 μm-thick stretched nylon film that had been previously corona-treated using a bar coater, and dried in an oven at 100 ° C. for 1 minute to remove the solvents. Volatilized. The bar coater was selected so that the film thickness after drying was 5 μm.
Subsequently, the reaction between the silicone resin, the acrylic resin, and the polyisocyanate compound was aged in a thermostatic chamber at 50 ° C. for 4 days to form a cured resin coating layer on the stretched nylon film.
Next, a chemical conversion treatment was performed on both surfaces of a 40 μm-thick aluminum foil, and the non-coated surface of the stretched nylon film obtained by laminating the curable protective coating of the present invention was bonded to one surface of the chemical conversion treatment by a dry lamination method. Next, an emulsion of acid-modified polypropylene is applied and dried on the other surface of the chemically treated aluminum foil by a roll coating method and baked at a temperature of 180 ° C., and a 30 μm-thick polypropylene film is thermally laminated on the baked surface. Thus, a primary laminate was formed.
In the chemical conversion treatment, an aqueous solution composed of a phenol resin, a chromium fluoride (3) compound, and phosphoric acid was applied as a treatment liquid by a roll coating method, and baked under conditions where the film temperature was 180 ° C. or higher. The application amount of chromium is 2 mg / m 2 (dry weight).
According to the method shown below, dynamic friction coefficient, moldability 1, moldability 2, electrolyte solution resistance, delamination were evaluated, and the results are shown in Table-3.

≪Dynamic friction coefficient≫
The laminate obtained by applying and drying the curable protective coating of the present invention on a stretched nylon film subjected to corona treatment is allowed to stand in a thermostatic chamber at 50 ° C. for 4 days to mature the reaction between the hydroxyl group of the curable resin and the polyisocyanate compound. Let A smooth stainless steel block rectangular parallelepiped having a bottom length of 63 mm × 63 mm and a mass of 200 g is placed on the coated surface of the stretched nylon film after aging. Pulling speed: A stainless steel block cuboid 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 times is defined as stress (g).
Coefficient of dynamic friction (μ) = Stress (g) ÷ Weight of stainless steel block (g)
4: Dynamic friction coefficient less than 0.10 3: Dynamic friction coefficient 0.10 to less than 0.15 2: Dynamic friction coefficient 0.15 to less than 0.20 1: Dynamic friction coefficient 0.20 or more

≪Moldability 1≫
Using the primary laminate, a molding test was performed using a mold of a circular container (flange diameter: 80 mmφ, bottom diameter: 57 mmφ, depth: 27 mm) having a capacity of 75 ml. The evaluation was performed on the side surface portion from the flange to the bottom portion, and evaluated the cracking state of the laminate, the outer layer side resin film layer, and wrinkles. The test performed 50 molding tests for each laminate.
4: Cracks, tears, and wrinkles are not observed in all 50 pieces.
3: Two out of fifty pieces were cracked, broken or wrinkled.
2: Cracks, tears, or wrinkles were observed in 5 out of 50 pieces.
1: Ten out of 50 pieces were cracked, broken or wrinkled.

«Moldability 2»
Using the primary laminate, the embossed shape is placed on a punching molding machine having a size of 30 mm × 50 mm so that the polypropylene side of the primary laminate is inside, so that the cured resin film of the present invention is outside. Die cut to a depth of 7 mm. Evaluate the state of cracks, tears and wrinkles on the side and corners of the emboss.
4: Cracks, tears, and wrinkles are not observed up to a depth of 7 mm.
3: At a depth of less than 5 to 7 mm, generation of any one of cracks, tears and wrinkles is observed.
2: At a depth of 3 to 5 mm or less, generation of any one of cracks, tears and wrinkles is observed.
At a depth of less than 1: 3 mm, any occurrence of cracks, tears and wrinkles is observed.

≪Electrolytic solution resistance≫
On the outermost layer of the primary laminate, the cured resin film layer of the present invention, an electrolyte solution (an electrolyte solution adjusted so that LiPF6 has a concentration of 1 mol, ethylene carbonate: diethyl carbonate: dimethyl carbonate = 1: 1: 1). ) 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: Whitened portions are observed in the form of dots.
2: Whitening is observed throughout.
1: The film is dissolved.

≪Delamination of heat seal part≫
The primary laminate was once wound into a roll and then rewound. A molded product obtained by punching into an embossed shape is obtained from the rewound primary laminate. Next, the molded product and the unstripped flat primary laminate (rewinded) on the polypropylene side are heat-sealed under the conditions of three of the four sides at 190 ° C., 98 N / cm ² , 5 seconds. To do. The electrolyte solution is poured from an opening that is not heat-sealed, and the mouth is also heat-sealed. Each specimen was stored in a constant temperature and humidity layer at 60 ° C. and 90% RH for 7 days, and then the delamination of the heat seal part was visually evaluated.
4: No delamination was observed on all 10 of the 10 molded.
3: Delamination is observed in less than 3 of 10 molded products.
2: Delamination is observed in less than 3 to 5 of 10 molded products.
The delamination is observed in 5 or more of the 1:10 molded pieces.

"Examples 2 to 23", "Comparative Examples 1 to 3"
A primary laminate was formed in the same manner as in Example 1 according to Table-3. The dynamic friction coefficient, moldability 1, moldability 2, electrolyte solution resistance, and delamination were evaluated in the same manner as in Example 1, and the results are shown in Table 3.

“Comparative Example 4”
To 100 parts by mass (solid weight) of the acrylic resin (B-3) obtained in Synthesis Example 3, 55 parts by mass (solid weight) of the polyisocyanate compound (E) is added, and Silaplane FM-0721 as a slip agent. 3 parts by mass (solid weight) of (methacryloxy silicone macromer manufactured by Chisso Corporation) was added. Further, methyl ethyl ketone (MEK) was added so as to have a solid content of 30% and 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, moldability 1, moldability 2, electrolyte solution resistance, and delamination were evaluated in the same manner as in Example 1. -3.
Although 3 parts by mass (solid weight) of Silaplane FM-0721 was added to 100 parts by mass (solid weight) of acrylic resin (B-3), the content of Si element derived from the polysiloxane structure was 1.0 [g / 100 g].

"Comparative Example 5"
In Comparative Example 5, only 5 parts by mass (solid weight) of the silicone resin (A-3) and 100 parts by mass (solid weight) of the acrylic resin (B-3) were added, and the polyisocyanate compound (E) was added. However, a primary laminate was formed in the same manner as in Example 1. The dynamic friction coefficient, moldability 1, moldability 2, electrolyte solution resistance, and delamination were evaluated in the same manner as in Example 1, and the results are shown in Table 3.

“Comparative Example 6”
The both sides of the 40 μm-thick aluminum foil were subjected to chemical conversion treatment, and the non-corona-treated surface of the stretched nylon film subjected to corona treatment was bonded to one side of the chemical conversion treatment by a dry laminating method, followed by chemical conversion treatment. The other surface of the aluminum foil is coated with an acid-modified polypropylene emulsion, dried by roll coating, baked at a temperature of 180 ° C., and a 30 μm-thick polypropylene film is thermally laminated on the baked surface to form a primary laminate. Formed. Using this primary laminate, evaluation was performed in the same manner as in Example 1. The dynamic friction coefficient, moldability 1, moldability 2, electrolyte solution resistance, and delamination were evaluated in the same manner as in Example 1, and the results are shown in Table 3.

  As shown in Table 3, in Comparative Examples 1 and 2, since the silicone resin (A) does not contain a hydroxyl group, the silicone compound is not fixed to the cured resin film. When the laminate is wound up, the silicone compound falls off from the cured resin film and adheres to the polypropylene film on the opposite surface, thereby impairing heat sealability.

Since the comparative example 3 does not contain a polysiloxane structure in the cured resin film, the slip property of the cured resin film is inferior. At the time of molding, the frictional resistance between the resin cured film and the molded female mold increases, and cracks, tears and wrinkles occur in the molded product.
In Comparative Example 4, since a silaplane containing no hydroxyl group was added to the slip agent, when the laminate was wound up, the silicone compound dropped off from the cured resin film and adhered to the polypropylene film on the opposite surface, and heat sealability Damage.

In Comparative Examples 5 and 6, the silicone resin (A) contains a hydroxyl group, but does not contain the curing agent (II), and therefore the resin film is not crosslinked or cured. Therefore, it is easily contaminated by the electrolyte solution, and the silicone-based resin drops off from the resin film and adheres to the opposite polypropylene film, thereby impairing heat sealability.
In Comparative Example 7, since no resin film is provided on the stretched nylon film, the slip property is poor, and cracks, tears, and wrinkles occur during molding. Moreover, if an electrolyte solution adheres, it will be contaminated.

A laminate obtained by applying and curing the curable protective coating of the present invention to a plastic film, a plastic molding, 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 back surface protection sheet, outdoor display, marking film, glass scattering prevention 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, since the curable protective paint of the present invention is excellent in electrolyte solution resistance, it gives a resin film having excellent barrier properties.
Accordingly, the curable protective coating of the present invention includes, for example, various recording materials, IC cards, IC tags, etc., packaging materials such as chemicals and foods, back surface protection sheets for solar cells, marking films, photosensitive resin plates, adhesives. Sheets, dye-sensitized solar cells, polarizing plate protecting resin films, antireflection resin films, optical resin films such as light diffusion films, glass scattering prevention resin films, decorative sheets, resin for building materials such as window resin films It can be used for resin films for indoor and outdoor overlays such as films, display materials, and electric signboards, and shrink films.

(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 (10)

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 heat-sealable packaging material for a heat seal layer,
The protective layer is, meets all of the following conditions (1) to (3), for a power storage device packaging material dynamic friction coefficient of 0.15 or less of the protective layer.
(1) The protective layer is formed from a curable protective paint containing a curable resin (I) having a hydroxyl group and a curing agent (II).
(2) The curable resin (I) having a hydroxyl group includes a silicone resin (A) having a hydroxyl group and a polysiloxane structure.
(3) 0.01 to 10% by mass of a Si element derived from a polysiloxane structure is contained in a total of 100% by mass of the curable resin (I) having a hydroxyl group and the curing agent (II). The silicone resin (A) having a hydroxyl group and a polysiloxane structure is composed of an acrylic monomer having a hydroxyl group and not having a polysiloxane structure, an acrylic monomer having a polysiloxane structure and having no hydroxyl group, and Copolymerized with other acrylic monomers that do not have a siloxane structure,
Alternatively, an acrylic monomer having a hydroxyl group and a polysiloxane structure is copolymerized with another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure.
Alternatively, it is obtained by copolymerizing an acrylic monomer having a hydroxyl group and a polysiloxane structure, an acrylic monomer having a hydroxyl group and not having a polysiloxane structure, and another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure. ,
The package for an electricity storage device according to claim 1, which is a copolymer having a hydroxyl value of 5 to 100 (mgKOH / g), a glass transition temperature of 30 ° C or less, and a mass average molecular weight (Mw) of 10,000 to 800,000. material. The packaging material for an electricity storage device according to claim 1 or 2, wherein 5 to 200 parts by mass of the curing agent (II) is contained with respect to 100 parts by mass of the curable resin (I) having a hydroxyl group. The packaging material for electrical storage devices according to any one of claims 1 to 3, wherein the curing agent (II) comprises a polyisocyanate compound (E). The packaging material for electrical storage devices according to any one of claims 1 to 4 , wherein the outer layer-side resin film layer is a nylon-based thermoplastic resin film or a polyester-based thermoplastic film. The curable resin (I) having a hydroxyl group includes an acrylic resin (B) having a hydroxyl group, a polyester resin (C) having a hydroxyl group, and a hydroxyl group in addition to the silicone resin (A) having a hydroxyl group and a polysiloxane structure. The packaging material for an electrical storage device according to any one of claims 1 to 5 , further comprising a resin having at least one hydroxyl group selected from the group consisting of epoxy-based resins (D). 0.2 to 50 parts by mass of the silicone resin (A) with respect to 100 parts by mass in total of the acrylic resin (B) having a hydroxyl group, the polyester resin (C) having a hydroxyl group, and the epoxy resin (D) having a hydroxyl group. The packaging material for an electricity storage device according to claim 6 , which is contained in a part. The acrylic resin (B) has a hydroxyl value of 5 to 5, which is obtained by copolymerizing an acrylic monomer having a hydroxyl group and not having a polysiloxane structure with another acrylic monomer having neither a hydroxyl group nor a polysiloxane structure. The packaging material for electrical storage devices of Claim 6 or 7 which is a copolymer of 100 (mgKOH / g), a glass transition temperature of 20-90 degreeC, and a mass mean molecular weight (Mw) of 30,000-800,000. The container for electrical storage devices formed from the packaging material for electrical storage devices of any one of Claims 1-8 , Comprising: The protective layer has comprised the outermost surface. An electrical storage device using the electrical storage device container according to claim 9 .

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