JP2017228520A - Seal material composition for lithium ion battery, cured product thereof, and lithium ion battery arranged by use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal material for a lithium ion battery, which is superior in adhesion, sealability and heat resistance in a lithium ion battery, which has both of the resistance against an electrolyte solution, and the resistance against various kinds of refrigerant, and which can be easily cured by exposure to light.SOLUTION: A light-cured type seal material for a lithium ion battery comprises, as components, a hydrolysis condensate (A) of alkoxysilane (a1) including a thiol group and represented by the formula (1) below, and a compound (B) having two or more carbon-carbon double bonds, which can be obtained by exposure to light. The light-cured type seal material for a lithium ion battery further comprises a compound having two or more epoxy groups. RSi(OR)(1) (where Ris a hydrocarbon group with C1-8 having at least one thiol group, or an aromatic hydrocarbon group having at least one thiol group, and Ris H, a hydrocarbon group with C1-8 or an aromatic hydrocarbon group).SELECTED DRAWING: None

Description

The present invention relates to a sealing material composition for a lithium ion battery, a cured product thereof, and a lithium ion battery using the same.

In recent years, lithium-ion batteries that are small and lightweight as well as capable of high output and high energy density are rapidly spreading as secondary batteries, and their applications are expanding. Until now, round or square lithium-ion batteries have been built into personal computers, mobile phones, etc., and because of precision equipment, there is a demand for further higher energy density and cost reduction while ensuring safety. More recently, the use in electric vehicles has been studied in earnest, and the package shape that can achieve high energy density has become the mainstream in the form of pouches, and there is a need for further improvements in heat resistance and further durability associated with high-speed charge / discharge. ing.

In this battery, the power generation element is housed in a metal container or a metal pouch bag and sealed. The power generation element includes an electrolytic solution, a positive electrode and a negative electrode, a separator, and the like. Since the positive electrode and the negative electrode active material are substances that can occlude and release lithium ions, they are extremely substances that dislike moisture, and the supporting electrolyte constituting the electrolyte reacts with water such as LiPF6, LiBF4, and LiClO4. And are easily hydrolyzed. For this reason, even if a very small amount of moisture enters the battery, the battery performance is extremely lowered. Further, as the organic electrolyte solvent, for example, a flammable organic solvent such as propylene carbonate, ethylene carbonate, diethyl carbonate or the like is used. There is a risk of ignition due to leakage outside the battery. For this reason, lithium ion secondary batteries are required to have high sealing properties that completely prevent water from entering the inside of the battery and completely prevent leakage of the electrolyte.

As a sealant for obtaining such a high sealing property, a material obtained by adding a polymer as a modifier to a pitch-based material such as coal tar and asphalt, and a resin-based sealant such as a polyolefin adhesive have been proposed. . Further, a rubber-based sealing material such as butyl rubber is known as a sealing agent for a coin-type lithium secondary battery using a metal active material such as metallic lithium for the negative electrode. However, these lithium ion batteries, which have been developed for the purpose of increasing the capacity (high energy density), cannot be said to have sufficient sealing performance, and are exposed to high temperatures due to temperature differences and high-speed charge / discharge. There is concern about heat resistance in automotive applications. Furthermore, heat generation due to the internal resistance of the battery during charging / discharging can be suppressed by cooling with a refrigerant, but the above-described sealing material does not have sufficient resistance to the refrigerant.

In addition, the power generation element inside the lithium ion battery typically includes a positive electrode active material layer disposed on both surfaces of the metal foil current collector, and a negative electrode active material layer disposed on both surfaces of the metal foil current collector. However, when the electrodes are stacked in the power generation element manufacturing process and the stacked electrode group is wound, the position of the electrodes facing each other through the separator is shifted. Cheap. The misalignment is caused by the fact that the reaction surface of the active material layer between the opposing negative electrode and the positive electrode does not match, so that when the battery is charged, Li ions desorbed from the positive electrode active material are not inserted into the negative electrode active material. Precipitates and causes a decrease in the life of the secondary battery. For this reason, a seal by heat fusion has been proposed in order to fix the power generation element during battery manufacture and to prevent accurate positioning of the electrodes and displacement of the position during charging and discharging. However, in order to heat-seal the laminated sealing material, it is necessary to increase the external heating temperature, which causes an internal short circuit due to thermal contraction of the separator.

By the way, a compound having a thiol group can be photocured by a ene-thiol reaction with a compound having a carbon-carbon double bond, and use as an ultraviolet curable sealing material has also been proposed. The ene-thiol reaction proceeds by ultraviolet irradiation regardless of the presence or absence of a polymerization initiator. Therefore, there are advantages such as that the reaction is not inhibited by oxygen in general radical polymerization that requires a polymerization initiator, and that curing shrinkage is small. However, in order to apply the obtained cured product to a sealing material of a lithium ion battery, it is not sufficiently satisfactory in terms of resistance to a refrigerant.

On the other hand, as a means of further improving the characteristics of the organic material, by combining the organic material and the inorganic material, the so-called high heat resistance, chemical resistance, high surface hardness, etc., which are the characteristics of the inorganic material, have been imparted. There are organic-inorganic hybrid technologies. Among the techniques, an organic-inorganic hybrid method using silsesquioxane is a method that is excellent in transparency and capable of thick film curing. As a kind of silica, silsesquioxane represented by the general formula RSiO _3/2 can easily provide an organic-inorganic hybrid cured product by giving R a substituent capable of reacting with an organic material. A practical application study is underway. The present inventors also referred to a so-called random silsesquioxane having a thiol group containing sulfur (an alkoxysilyl group or a silanol group remaining) and an organic substance having a carbon-carbon double bond as an ene-thiol. An organic-inorganic hybrid cured product obtained by reacting (Patent Document 1), an epoxy group-containing compound, and an organic-inorganic hybrid cured product thermally cured with isocyanates (Patent Document 2) have been proposed. The cured product is excellent in heat resistance and has a high refractive index because it contains sulfur. However, the cured material is required to have adhesion, sealability, heat resistance, electrolyte resistance, and resistance to various refrigerants. The applicability of this is not considered.

JP 2007-291313 A JP 2007-217673 A

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a photocurable composition containing a hydrolysis condensate of a thiol group-containing alkoxysilane and a compound having a carbon-carbon double bond is a lithium ion battery. The present inventors have found that the above-described problems of the sealing material can be solved, and have completed the present invention. The “photo-curing type” in the present invention means a material that accelerates curing by irradiating light energy such as ultraviolet rays and electron beams.

That is, this invention 1 is general formula (1):
R ¹ Si (OR ² ) ₃ (1)
(In the formula, R ¹ represents a hydrocarbon group having 1 to 8 carbon atoms having at least one thiol group or an aromatic hydrocarbon group having at least one thiol group, and R ² represents a hydrogen atom or 1 carbon atom) The thiol group-containing alkoxysilanes (a1) represented by -8 hydrocarbon groups or aromatic hydrocarbon groups) are hydrolyzed condensates (A) (hereinafter referred to as component (A)), and A photocuring type lithium ion battery sealing material composition (hereinafter referred to as sealing material composition) comprising a compound (B) having two or more carbon-carbon double bonds (hereinafter referred to as component (B)) May be abbreviated as).

The present invention 2 also relates to a photocurable lithium ion battery sealing material composition further comprising a compound (C) having two or more epoxy groups (hereinafter referred to as component (C)).

Invention 3 is a cured product of the photocuring type lithium ion battery sealing material composition of Invention 1 or Invention 2, and the weight change rate when immersed in dimethyl carbonate at 25 ° C. for 40 hours is less than 1%. The present invention relates to a sealing material for lithium ion batteries (hereinafter sometimes abbreviated as a sealing material).

The present invention 4 is characterized in that a part or the whole of the outer peripheral portion of the power generation element in which the positive electrode, the negative electrode, and the separator are laminated is sealed with the cured product of the photocurable lithium ion battery sealing material of the present invention 3. The present invention relates to a lithium ion battery.

The present invention 5 is characterized in that the sealing portion of the battery exterior body in which the power generating element and the electrolyte are accommodated is sealed with the cured product of the photocuring type lithium ion battery sealing material of the present invention 3. The present invention relates to a lithium ion battery.

According to the sealing material composition of the present invention, in a lithium ion battery used for a personal computer, a mobile phone, an electric vehicle, etc., it has excellent adhesion, sealing properties, and heat resistance, and has both resistance to an electrolyte solution and various refrigerants. A sealing material for a lithium ion battery that can be easily cured by light irradiation can be provided.
The sealing material of the present invention is not only suitable as a sealing material for a battery exterior body containing a power generation element and an electrolyte solution, but also applied to a sealing material on the outer periphery of a power generation element having a laminated structure of a positive electrode, a negative electrode, and a separator inside the battery. By doing so, it is possible to prevent the deviation of the laminated structure and the internal short circuit that occur due to the battery manufacturing process and the repeated charging / discharging, and it is possible to obtain a long-life battery with stable charging / discharging characteristics.

The component (A) used in the present invention has the general formula (1):
R ¹ Si (OR ² ) ₃ (1)
(In the formula, R ¹ represents a hydrocarbon group having 1 to 8 carbon atoms having at least one thiol group, or an aromatic hydrocarbon group having at least one thiol group, and R ² represents a hydrogen atom, having 1 to 1 carbon atoms. 8 is a compound obtained by hydrolysis and condensation of a thiol group-containing alkoxysilane (a1) represented by formula (8) or an aromatic hydrocarbon group.

Specific examples of the thiol group-containing alkoxysilanes (a1) (hereinafter referred to as the component (a1)) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltripropoxysilane, 3 -Mercaptopropyltributoxysilane, 1,4-dimercapto-2- (trimethoxysilyl) butane, 1,4-dimercapto-2- (triethoxysilyl) butane, 1,4-dimercapto-2- (tripropoxysilyl) Butane, 1,4-dimercapto-2- (tributoxysilyl) butane, 2-mercaptomethyl-3-mercaptopropyltrimethoxysilane, 2-mercaptomethyl-3-mercaptopropyltriethoxysilane, 2-mercaptomethyl-3- Mercaptopropyltripro Xysilane, 2-mercaptomethyl-3-mercaptopropyltributoxysilane, 1,2-dimercaptoethyltrimethoxysilane, 1,2-dimercaptoethyltriethoxysilane, 1,2-dimercaptoethyltripropoxysilane, 1, Examples include 2-dimercaptoethyltributoxysilane, and the exemplary compounds can be used alone or in appropriate combination. Among the exemplified compounds, 3-mercaptopropyltrimethoxysilane is particularly preferable because of high reactivity of hydrolysis reaction and easy availability.

In addition to the component (a1), metal alkoxides (a2) (hereinafter referred to as the component (a2)) can be used. As component (a2), trialkylalkoxysilanes such as trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyl Dialkyl dialkoxysilanes such as dimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, methyltrimethoxysilane, methyltrimethoxysilane Ethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyl Alkyltrialkoxysilanes such as ethoxysilane, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane and tetrabutoxysilane, tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium and other tetra Examples include alkoxy titaniums, tetraalkoxy zirconiums such as tetraethoxy zirconium, tetrapropoxy zirconium, and tetrabutoxy zirconium. (A2) A component can be used individually or in combination of 2 or more types. Among these, the crosslinking density of the component (A) can be adjusted by using trialkylalkoxysilanes, dialkyldialkoxysilanes, and tetraalkoxysilanes. By using alkyltrialkoxysilanes, the amount of thiol groups contained in component (A) can be adjusted. By using tetraalkoxy titanium and tetraalkoxy zirconium, the refractive index of the finally obtained cured product can be increased.

When the component (a1) and the component (a2) are used in combination, [number of moles of thiol group contained in the component (a1)] / [total number of moles of component (a1) and component (a2)] (per molecule The average number of thiol groups contained is preferably 0.2 or more. If it is less than 0.2, the number of thiol groups contained in the component (A) obtained is reduced, so that the ultraviolet curability is lowered and the effect of improving the physical properties such as the surface hardness of the cured product is insufficient. Tend to be. [Total number of moles of each alkoxy group contained in the components (a1) and (a2)] / [Total number of moles of the components (a1) and (a2)] (average of alkoxy groups contained in one molecule) The number is preferably from 2.5 to 3.5, and more preferably from 2.7 to 3.2. When it is less than 2.5, the crosslinking density of the obtained component (A) is low, and the heat resistance of the cured product tends to decrease. Moreover, when it exceeds 3.5, when manufacturing (A) component, it exists in the tendency which becomes easy to gelatinize.

The component (A) used in the present invention can be obtained by condensing the component (a1) alone or in combination with the component (a2) and hydrolyzing them. That is, the component (A) is a hydrolysis condensate of these components. By the hydrolysis reaction, the alkoxy group contained in the component (a1) or the component (a2) becomes a hydroxyl group, and alcohol is by-produced. The amount of water required for the hydrolysis reaction is [number of moles of water used in the hydrolysis reaction] / [total number of moles of each alkoxy group contained in the components (a1) and (a2)] (molar ratio). 4 or more and 10 or less, preferably 1. When it is less than 0.4, there is an alkoxy group remaining without being hydrolyzed in the component (A), which is not preferable. On the other hand, when it exceeds 10, the amount of water to be removed in the subsequent condensation reaction (dehydration reaction) increases, so that the production time becomes longer, which is economically disadvantageous.

In addition, when (a2) component is used together with tetraalkoxytitanium, tetraalkoxyzirconium, etc., particularly metal alkoxides with high hydrolyzability and condensation reactivity, hydrolysis and condensation reaction proceed rapidly, and the system May gel. In this case, gelation can be avoided by adding the component (a2) after the hydrolysis reaction of the component (a1) is completed and all water has been consumed.

The catalyst used for the hydrolysis reaction is not particularly limited, and a conventionally known hydrolysis catalyst can be arbitrarily used. Of these, formic acid is preferred because it has high catalytic activity and also functions as a catalyst for the subsequent condensation reaction. The amount of formic acid added is preferably 0.1 to 25 parts by weight and more preferably 1 to 10 parts by weight with respect to 100 parts by weight as a total of the components (a1) and (a2). When the amount is more than 25 parts by weight, the stability of the resulting sealing material composition tends to decrease, and even if formic acid can be removed in a subsequent step, the removal amount tends to increase. On the other hand, when the amount is less than 0.1 parts by weight, the reaction does not substantially proceed or the reaction time tends to be long. Although reaction temperature and time can be arbitrarily set according to the reactivity of the component (a1) or the component (a2), it is usually about 0 to 100 ° C., preferably about 20 to 60 ° C., about 1 minute to 2 hours. The hydrolysis reaction can be carried out in the presence or absence of a solvent. The type of the solvent is not particularly limited, and one or more arbitrary solvents can be selected and used, but it is preferable to use the same solvent as that used in the condensation reaction described later. When the reactivity of the component (a1) or the component (a2) is low, it is preferable to carry out without a solvent.

The hydrolysis reaction is carried out by the above method, but the [number of moles of hydroxyl group formed by hydrolysis] / [total number of moles of each alkoxy group contained in the components (a1) and (a2)] (molar ratio) is 0. It is preferable to make it progress so that it may become 0.5 or more, and it is still more preferable to adjust to 0.8 or more. The condensation reaction following the hydrolysis reaction proceeds not only between the hydroxyl groups generated by hydrolysis but also between the hydroxyl groups and the remaining alkoxy groups, so that at least half (molar ratio is 0.5 or more) is hydrolyzed. Just do it.

In the condensation reaction, water is by-produced between the hydroxyl groups, and alcohol is by-produced between the hydroxyl group and the alkoxy group to form a siloxane bond. A conventionally known dehydration condensation catalyst can be arbitrarily used for the condensation reaction. As described above, formic acid is preferable because it has high catalytic activity and can be used as a catalyst for hydrolysis reaction. The reaction temperature and time can be arbitrarily set depending on the reactivity of the components (a1) and (a2), but are usually about 40 to 150 ° C., preferably 60 to 100 ° C., and about 30 minutes to 12 hours. .

The condensation reaction is carried out by the above method. [Total number of moles of unreacted hydroxyl group and unreacted alkoxy group] / [Total number of moles of alkoxy groups contained in component (a1) and component (a2)] (molar ratio) ) Is preferably 0.3 or less, and more preferably 0.2 or less. When it exceeds 0.3, the unreacted hydroxyl group and alkoxy group undergo a condensation reaction during storage of the sealing material composition to cause gelation, or after curing, a condensation reaction occurs to generate a volatile matter and cracks occur. This is not preferable because it tends to impair the performance.

The condensation reaction is preferably performed by diluting with a solvent so that the concentration of component (a1) (or both when component (a2) is used in combination) is about 2 to 80% by weight. More preferably. It is preferable to use a solvent having a boiling point higher than that of water and alcohol generated by the condensation reaction because these can be distilled off from the reaction system. When the concentration is less than 2% by weight, the component (A) contained in the obtained sealing material composition is decreased, which is not preferable. When it exceeds 80% by weight, the molecular weight of the component (A) that is gelled or generated during the reaction tends to be too large, and the storage stability of the resulting sealing material composition tends to deteriorate. As the solvent, one or more arbitrary solvents can be selected and used. It is preferable to use a solvent having a boiling point higher than that of water and alcohol produced by the condensation reaction because these can be distilled off from the reaction system. Moreover, (B) component can also be used as a part of solvent.

It is preferable to remove the used catalyst after completion of the condensation reaction because the stability of the finally obtained sealing material composition is improved. The removal method can be appropriately selected from various known methods depending on the catalyst used. For example, when formic acid is used, it can be easily removed by a method such as heating to above the boiling point or depressurization after completion of the condensation reaction, and formic acid is also preferred in this respect.

The carbon-carbon double bond of the component (B) is carbon-carbon in preference to the reaction between a functional group having a carbon-carbon double bond and a thiol group from the viewpoint of storage stability of the sealing material composition. It is preferable to use those having low radical polymerizability so as not to cause inconvenience of polymerization of functional groups having double bonds. Examples of such component (B) include compounds having one or more allyl groups. Compounds containing one allyl group include cinnamic acid, monoallyl cyanurate, monoallyl isocyanurate, pentaerythritol monoallyl ether, trimethylolpropane monoallyl ether, glycerin monoallyl ether, bisphenol A monoallyl ether, bisphenol Examples thereof include F monoallyl ether, ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, triethylene glycol monoallyl ether, propylene glycol monoallyl ether, dipropylene glycol monoallyl ether, and tripropylene glycol monoallyl ether. Compounds containing two allyl groups include diallyl phthalate, diallyl isophthalate, diallyl cyanurate, diallyl isocyanurate, pentaerythritol diallyl ether, trimethylolpropane diallyl ether, glyceryl diallyl ether, bisphenol A diallyl ether, bisphenol F diallyl ether Ethylene glycol diallyl ether, diethylene glycol diallyl ether, triethylene glycol diallyl ether, propylene glycol diallyl ether, dipropylene glycol diallyl ether, tripropylene glycol diallyl ether, and the like. Examples of the compound containing three or more allyl groups include triallyl isocyanurate, pentaerythritol triallyl ether, pentaerythritol tetraallyl ether, trimethylolpropane triallyl ether, and the like. These compounds can be used either alone or in combination. Among these, compounds having only one carbon-carbon double bond in the molecule do not cause cross-linking between molecules, so that the effect of improving the physical properties such as heat resistance and surface hardness of the cured product is insufficient. Because of the tendency, compounds having two or more carbon-carbon double bonds in the molecule are preferable, and among them, triallyl isocyanurate, diallyl phthalate, and pentaerythritol triallyl ether are particularly preferable.

Further, as the component (B), those having a higher molecular weight than the compound having an allyl group can also be used. The sealing material composition using a high molecular weight component (B) tends to improve the flexibility of the resulting cured product. Moreover, generally there exists a tendency for radical polymerizability to become low, and it can use preferably also from such a viewpoint.
High molecular weight products include copolymers of methylallylsiloxane and dimethylsiloxane, copolymers of epichlorohydrin and allyl glycidyl ether (Daiso Co., Ltd .: trade name “Epichromer”, Nippon Zeon Co., Ltd .: trade name "Gechron" etc.), allyl group-terminated polyisobutylene polymer (Kaneka Co., Ltd .: trade name "Epion"), urethane acrylate (Arakawa Chemical Industries, Ltd .: trade name "Beamset 550B", manufactured by Toagosei Co., Ltd. : Product name “Aronix M313”, manufactured by Kyoeisha Chemical Co., Ltd .: Product names “UF-C051”, “UF-C053”), acrylate (manufactured by Kyoeisha Chemical Co., Ltd .: product name “HOA-MPE (N)”) Epoxy ester (manufactured by Kyoeisha Chemical Co., Ltd .: trade names “70PA”, “80MFA”, “200PA”) It is below. These compounds can be used alone or in combination of two or more.

As the urethane acrylates, polyfunctional urethane acrylates having two or more acryloyl groups or methacryloyl groups can be suitably used. Specific examples include those obtained by reacting a polyisocyanate compound with a hydroxyl group-containing acrylate compound, and those obtained by reacting a polyol compound, a polyisocyanate compound and a hydroxyl group-containing acrylate compound. Examples of the polyol compound include polyester polyol, polyether polyol, caprolactone diol, and the like. Examples of polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate. Examples thereof include nato and isophorone diisocyanate, and isocyanurate ring structures, biuret structures, and allophanate structures. In particular, a polyisocyanate having an isocyanurate ring structure can be suitably used because the cured product is excellent in electrolytic solution resistance. Examples of the hydroxyl group-containing acrylate compound include 2-hydroxy acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 1,6-hexanediol monoacrylate, pentaerythritol triacrylate, and the like. These compounds can be used either alone or in combination.

The lithium ion battery sealing material composition of the present invention can be blended with a compound (C) having two or more epoxy groups (hereinafter referred to as component (C)) for the purpose of supplementing photocurability. By blending the component (C), the seal material composition shortens the pot life, while the irradiation amount necessary for photocuring is reduced and the mass productivity is improved. Curing on the surface becomes possible.
The component (C) having two or more epoxy groups is not particularly limited, and a conventionally known compound having an epoxy group can be appropriately used. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, stilbene type Epoxy resin, epoxy resin having triazine skeleton, epoxy resin having fluorene skeleton, linear aliphatic epoxy resin, alicyclic epoxy resin, glycidylamine type epoxy resin, triphenolphenolmethane type epoxy resin, alkyl-modified triphenolmethane type Epoxy resin, biphenyl type epoxy resin, epoxy resin having dicyclopentadiene skeleton, epoxy resin having naphthalene skeleton, aryl alkylene type epoxy resin, And epoxy compounds having an isocyanurate ring structure. These compounds can be used alone or in combination of two or more. Among the above exemplified compounds, multifunctional epoxy resins (Mitsubishi Chemical Corporation: trade names “jER152”, “jER604”, “jER630”, etc.), bisphenol A type epoxy resins (Mitsubishi Chemical Corporation: trade names “ jER828 "," jER834 ", etc.), bisphenol F type epoxy resin (Mitsubishi Chemical Corporation: trade name" jER807 ", etc.), hydrogenated bisphenol A type epoxy resin (Toto Kasei Co., Ltd .: trade name" Santoto ST-3000 ") ), Alicyclic epoxy resins (Daicel Chemical Industries, Ltd .: trade name “Celoxide 2021”, etc.), and epoxy compounds having an isocyanurate ring structure (Nissan Chemical Industries, Ltd .: trade name “TEPIC”, etc.) The cured product finally obtained is particularly preferable because it is excellent in colorless transparency, heat resistance, etc. and is easily available.

  As the component (C), one having a higher molecular weight than the above compound can be used. A sealing material composition having a high molecular weight tends to improve the flexibility of the resulting cured product. As the high molecular weight one, among bisphenol A type epoxy resin and bisphenol F type epoxy resin, those having an epoxy equivalent of 2000 g / eq or more (Japan Epoxy Resin Co., Ltd .: trade names “Epicoat 1010”, “Epicoat 4007P” And epoxy-modified silicone (Shin-Etsu Chemical Co., Ltd .: trade name “X-22-163A”, etc.). These compounds can be used alone or in combination of two or more.

The total concentration of the component (A) and the component (B) in the sealing material composition of the present invention, or the total concentration of the component (A), the component (B) and the component (C) when the component (C) is used These are collectively referred to simply as “total concentration”) can be appropriately determined according to the application, and can be adjusted by blending a solvent as necessary. The solvent only needs to be non-reactive with the component, and various conventionally known solvents can be appropriately selected and used.
When the objects to be bonded are bonded together with the sealing material composition, the total concentration is preferably 95% by weight or more, more preferably 98% by weight or more in the sealing material composition. The total concentration can be obtained by calculation based on the concentration of each of the components (A), (B) and (C) and the amount of solvent added at the time of charging the sealing material composition. It can be obtained by heating for about 2 hours at a temperature equal to or higher than the boiling point of the solvent contained in the solvent and by changing the weight before and after heating (nonvolatile content). When the amount is less than 95% by weight, foaming may occur at the time of bonding and molding, or a solvent may remain in the cured product, which tends to lower the physical properties of the cured product. In addition, since the solvent is essential when synthesizing the component (A), the solvent should be volatilized after the reaction so that the non-volatile content is 95% by weight or more when used for this purpose. That's fine. Moreover, after preparing a sealing material composition, the used solvent can be volatilized and a total density | concentration can also be raised.
Moreover, when coating and using a sealing material composition, what is necessary is just to dilute with a solvent and to make it a desired viscosity.

For curing the sealing material composition of the present invention, a photopolymerization initiator can be used as necessary. It does not specifically limit as a photoinitiator, A conventionally well-known photocationic initiator, photoradical initiator, etc. can be selected arbitrarily. Examples of the photocation initiator include sulfonium salts, iodonium salts, metallocene compounds, benzoin tosylate, and the like, which are compounds that generate an acid upon irradiation with ultraviolet rays. Examples of such commercially available products include Cyracure UVI-6970 and UVI. -6974, UVI-6990 (all trade names manufactured by Union Carbide, Inc.), Irgacure 264 (Ciba Specialty Chemicals), CIT-1682 (manufactured by Nippon Soda Co., Ltd.), and the like. The usage-amount of a photocationic polymerization initiator is about 10 weight part or less normally in 100 weight part of sealing material compositions, Preferably it is 1-5 weight part. Examples of the photo radical initiator include Darocur 1173, Irgacure 651, Irgacure 184, Irgacure 907 (both trade names manufactured by Ciba Japan), benzophenone, and the like.
In 100 parts by weight of the sealing material composition, it is about 15 parts by weight or less, preferably 1 to 15 parts by weight.

In the sealing material composition, the thiol group reacts one-to-one with the carbon-carbon double bond and / or the epoxy group by performing light irradiation. Therefore, the blending ratio of the component (A), the component (B), and / or the component (C) is
[The number of moles of carbon-carbon double bonds contained in component (B) and the total number of moles of epoxy groups contained in component (C)) / number of moles of thiol groups contained in component (A)] (molar ratio) May be appropriately determined so as to be in the vicinity of 1. Considering the flexibility of the obtained sealing material (cured product), the blending ratio is preferably in the range of 0.9 to 1.1. Moreover, since the adhesive force with respect to a metal base material tends to improve with the remainder of a thiol group, it is more preferable in it being the range of 0.9-1.0.
When the component (C) is used in combination, the blending ratio of the component (B) is [number of moles of carbon-carbon double bonds contained in the component (B)] / number of moles of thiol groups contained in the component (A)]. (Molar ratio) is preferably at least 0.5, more preferably 0.7 or more.

In the sealing material composition of the present invention, the concentration of thiol groups in the active ingredient is preferably 3 mmol / g or less. When it exceeds 3 mmol / g, the curing shrinkage when curing the sealing material composition is increased, and when obtaining a sealing material having a thickness such as a decrease in adhesion to the base material or thick film molding or mold molding, Prone to cracking.
The concentration of the thiol group in the active ingredient is the total weight of each component contained in the obtained sealing material composition and the number of moles of the thiol group contained in the component (a1) used during the production of the component (A). The total weight of non-volatile components excluding volatile components such as solvents may be calculated.

Furthermore, the sealing material composition has a photosensitizer, a polymerization inhibitor, a plasticizer, a weathering agent, an antioxidant, and a thermal stability, as long as the effects of the present invention are not impaired. An agent, a lubricant, an antistatic agent, a whitening agent, a colorant, a conductive agent, a release agent, a surface treatment agent, a viscosity modifier, a filler, an adhesion imparting agent, and the like may be blended. However, regarding the plasticizer, the conductive material, the filler, and the adhesion imparting material, the photocurability may be impaired, so the amount is 5 parts by weight or less with respect to 100 parts by weight of the total weight of the A component, the B component, and the C component. It is desirable.
Examples of the photosensitizer include benzoin compounds, benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, oxime ester compounds, amines, and quinones. Specific compounds include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1- ON, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy- 2-methyl-propionyl) -benzyl] phenyl] -2-methyl-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2- (dimethylamino ) -2-[(4-Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl -Phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H) -Pyrrol-1-yl) -phenyl) titanium, 1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone 1- [9-ethyl-6- (2- Methylbenzoyl) -9H-carbazol-3-yl] -1- (0-acetyloxime) and the like.

  As the polymerization inhibitor, phosphorus compounds such as triphenylphosphine and triphenyl phosphite; p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2, 6-di-tert-butyl-p-cresol, 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol) Radical), N-nitrosophenylhydroxylamine aluminum salt, diphenylnitrosamine and other radical polymerization inhibitors; benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (diaminomethyl) phenol, diaza Tertiary amines such as bicycloundecene; 2-methylimidazole, 2-ethyl 4-methylimidazole, hexyl imidazole 2-ethylhexyl, 2-undecyl imidazole, imidazoles such as 1-cyanoethyl-2-methyl-imino Dahl and the like.

  Examples of the viscosity modifier include silicas (manufactured by Nippon Aerosil Co., Ltd .: trade names “AEROSIL R805”, “AEROSIL RY200S”, “AEROSIL RY300”, etc., manufactured by Tosoh Silica Co., Ltd .: trade name “NIPSIL E-200A”. , “NIPSIL N-300A”, etc. Asahi Kasei Wacker Silicone Co., Ltd .: trade name “HDK H18”, etc., Polyolefin cotton fiber (Mitsui Chemicals Co., Ltd .: trade name “Chemibest FDSS-2” etc.), etc. Can be given.

  As an adhesion imparting material, Maruzen, such as petroleum resins (manufactured by Arakawa Chemical Industries, Ltd .: trade names “Arcon M-100”, “Arcon P-100”, “Arcon P-125”, “Alcon P-140”, etc. Petrochemical Co., Ltd .: trade names “M-845A”, “M-890A”, etc.), chlorinated polyolefins (manufactured by Nippon Paper Industries Co., Ltd .: trade names “Supercron 390S”, “Supercron 814HS”, etc.), Examples thereof include modified polyolefin resins (manufactured by Nippon Paper Industries Co., Ltd .: trade names “Auroren 350S”, “Aurolen 500S”, “Aurolen 550S”, etc.).

The sealing material for lithium ion batteries of the present invention is obtained by curing the sealing material composition containing the component (A), the component (B), and the component (C) as described above in detail by irradiating with ultraviolet light or the like. can get. According to the sealing material of the present invention, leakage of the electrolyte solution of the lithium ion battery and entry of water from the outside to the inside of the battery can be prevented. The irradiation amount of the ultraviolet rays may be appropriately determined according to the type and film thickness of the sealing material composition. However, when a high pressure mercury lamp is used, the irradiation is performed so that the integrated light amount at 365 nm is about 50 to 10,000 mJ / cm ^2. That's fine. In addition, for example, when a sealing material composition is applied to a thick film on a base material to obtain a sealing material having a thickness of 1 mm or more, or when a predetermined mold or cavity is filled to obtain a thick sealing material As mentioned above, it is preferable to improve photocurability by adding a photoreaction initiator or a photosensitizer to the composition. In this way, the component (A) and the component (B) are reacted to cause the curing to proceed completely.

The sealing material of the present invention is required to have resistance to the electrolyte solution of the lithium ion battery. As a method for measuring the resistance to electrolytic solution, the sealing material composition of the present invention was coated on a Teflon sheet with a 400 μm applicator, and cured by irradiating 365 nm ultraviolet light so that the integrated light amount became 300 mJ / cm 2. The cured film is peeled from the PET film and cut to about 1 g to obtain a cured film piece. The cured film piece is fully immersed in the lithium ion battery electrolyte and allowed to stand at 25 ° C. for 4072 hours. The cured film piece is taken out, dried with a vacuum dryer at 0.1 Pa and 80 ° C. for 3 hours, and measured from the change in weight of the cured film piece before and after. When the weight reduction rate exceeds 1% of the weight after drying, it is not preferable because the sealing material expands due to the electrolyte solution and the strength of the sealing material decreases.

Specific examples of the molding method for the sealing material of the present invention include JP-A-55-30148, JP-A-56-32671, JP-A-56-32672, JP-A-58-10365, JP-A-59-91660, JP 59-112565, JP-A 6-124694, JP-A 6-5270, JP-A 2006-44303, JP-A 5-174863, JP-A 2004-362967, JP-A 2010-62081, JP-A 2014-56799, JP Examples of methods described in JP-A-2015-128020, JP-A-2006-146269, JP-A-2006-146270, and the like can be given.

The sealing material thus obtained is an organic-inorganic hybrid cured product containing a silica structure (SiO ₂ ) derived from the component (A). The content of SiO _{2 in} the sealing material is preferably 10 to 90%. By setting it to 10% or more, heat resistance, chemical resistance, and high surface hardness due to the silica structure can be secured, and by setting it to 90% or less, flexibility can be secured.

The application range of the sealing material of the present invention is not particularly limited as long as the purpose is to seal an electrolyte solution generally used in a lithium ion battery from the outside. Specifically, it is suitably used for sealing the outer peripheral part of the power generation element in which the positive electrode, the negative electrode, and the separator are laminated, and sealing the sealing part (sealing part) of the battery exterior body containing the power generation element and the electrolyte solution. it can.
By applying the sealing material of the present invention to a part or all of the outer peripheral portion of the power generation element, leakage of the electrolyte solution of the battery body is prevented, and the stacked power generation elements in the battery manufacturing process are wound. Therefore, it is possible to perform accurate alignment at the time, to prevent deterioration of battery performance due to misalignment, internal short circuit, and the like, and to repeatedly charge and discharge with position due to repeated charge and discharge.

When the sealing material of the present invention is applied to the seal of the outer peripheral portion of the power generation element in which the positive electrode, the negative electrode, and the separator are laminated, there is no particular limitation. For example, the outer peripheral portion of the power generation element in which the electrodes are laminated through the separator In addition, there is a method in which the sealing material of the present invention is applied using a dispenser, a seal gun, or the like and photocured to form the sealing material of the present invention. In addition to preventing electrolyte leakage, the sealing material prevents Li metal deposition and short-circuiting by preventing the opposing electrodes from shifting in the battery manufacturing process and repeated charging and discharging. can do.

When the sealing material of the present invention is applied to the seal of the sealing portion of the battery outer package in which the power generation element and the electrolyte are accommodated in the internal space, an appropriate method can be selected depending on the type of the outer package. When the exterior body is a rectangular or cylindrical container, a gasket seal material made of polyethylene, polypropylene, metal or the like is generally used for the sealing portion. The sealing material of the present invention may be used in place of the gasket seal, and a sealing material obtained by photocuring into a predetermined shape in advance may be used, but it is preferable to use it together with the gasket sealing material. As one example, there may be mentioned a method in which the sealing material composition of the present invention is applied to a sealing surface of a gasket sealing material using a dispenser or a seal gun and is photocured to form a sealing material. In this method, after the power generation element is accommodated in the container and filled with the electrolyte solution, the container is sealed with a gasket sealing material in which the sealing material of the present invention is formed on the sealing surface. As another example, there is a method in which the sealing material composition of the present invention is applied to the surface of the exterior container sealed with the gasket sealing material using a dispenser or a seal gun, and is photocured to form the sealing material. It is done. In any of the above examples, after the power generation element is accommodated in the container and filled with the electrolyte solution, the sealing performance of the sealing material of the present invention is added to the gasket sealing material, and higher sealing performance can be realized.

When the exterior body is a pouch type, the power generation element is housed in a pouch bag made of aluminum or SUS that can be heat-sealed, filled with an electrolyte solution, and then on the outer peripheral surface of the heat-sealed sealing portion. The method of apply | coating the sealing material composition of this invention and photocuring, etc. are mentioned. Since the curing of the sealing material is photocuring, it can be safely sealed without increasing the temperature of the electrolyte solution and without changing the volume of the electrolyte solution.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In each example, parts and% are based on weight unless otherwise specified.

Production Example 1 (Production of condensate (A-1))
In a reactor equipped with a stirrer, a condenser, a water separator, a thermometer, and a nitrogen inlet, 2700 g of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: trade name “KBM-803”), methyltri Methoxysilane (manufactured by Tama Chemical Industry Co., Ltd .: trade name “methyltrimethoxysilane”) 374.6 g ([number of moles of thiol group contained in component (a1)] / [(a1) component and (a2) component Total number of moles] = 0.83, [total number of moles of each alkoxy group contained in component (a1) and component (a2)] / [total number of moles of component (a1) and component (a2)] = 3), 847 g of ion-exchanged water ([number of moles of water used for hydrolysis reaction] / [total number of moles of alkoxy groups contained in components (a1) and (a2)] (molar ratio) = 0.95), 95% 30 g of formic acid is charged and 3 at room temperature Minutes to hydrolysis reaction. During the reaction, the temperature increased by a maximum of 35 ° C. due to exotherm. After the reaction, 2535 g of toluene was charged and heated. When the temperature was raised to 71 ° C., methanol generated by hydrolysis and a part of toluene began to be distilled off. The temperature was raised to 75 ° C. over 2 hours, and the water was distilled off by condensation reaction. After further reacting at 75 ° C. for 1 hour, the pressure was reduced at 70 ° C. and 20 kPa to distill off a part of the remaining toluene, methanol, water, and formic acid. Furthermore, pressure reduction was carried out at 70 degreeC and 0.7 kPa, and toluene was distilled off, and 2140g of condensates (A-1) were obtained. [Mole number of unreacted hydroxyl group and alkoxy group] / [Mole number of alkoxy group contained in component (a1)] (molar ratio) was 0.08, and the concentration was 99.0%. The concentration of the thiol group in the condensate (A-1) was 6.40 mmol / g.

Production Example 2 (Production of condensate (A-2))
In the same reactor as in Production Example 1, 2100 g of 3-mercaptopropyltrimethoxysilane and 1020 g of methyltrimethoxysilane ([number of moles of thiol group contained in component (a1)] / [(a1) component and (a2) component Total number of moles] = 0.59, [total number of moles of each alkoxy group contained in components (a1) and (a2)] / [total number of moles of components (a1) and (a2)] = 3) , 983 g of ion-exchanged water ([number of moles of water used for hydrolysis reaction] / [total number of moles of each alkoxy group contained in components (a1) and (a2)] (molar ratio) = 1.00), 95 % Formic acid (31 g) was charged and subjected to a hydrolysis reaction at room temperature for 30 minutes. During the reaction, the temperature increased by a maximum of 35 ° C. due to exotherm. After the reaction, 2535 g of toluene was charged and heated. When the temperature was raised to 71 ° C., methanol generated by hydrolysis and a part of toluene began to be distilled off. The temperature was raised to 75 ° C. over 2 hours, and the water was distilled off by condensation reaction. After further reacting at 75 ° C. for 1 hour, the pressure was reduced at 70 ° C. and 20 kPa to distill off a part of the remaining toluene, methanol, water, and formic acid. Furthermore, 2075g of condensates (A-2) were obtained by depressurizing at 70 degreeC and 0.7 kPa, and distilling toluene off. [Mole number of unreacted hydroxyl group and alkoxy group] / [Mole number of alkoxy group contained in component (a1)] (molar ratio) was 0.12, and the concentration was 99.0%. The concentration of the thiol group in the condensate (A-2) was 5.15 mmol / g.

Production Example 3 (Production of condensate (A-3))
In the same reactor as in Production Example 1, 1200 parts of 3-mercaptopropyltrimethoxysilane, 606 parts of phenyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: trade name “KBM-103”) (in the [(a1) component) Number of moles of thiol group contained] / [total number of moles of component (a1) and component (a2)] = 0.66, [total number of moles of alkoxy groups contained in component (a1) and component (a2)] / [Total number of moles of component (a1) and component (a2)] = 3), 496 parts of ion-exchanged water ([number of moles of water used for hydrolysis reaction] / [included in component (a1) and component (a2)) The total number of moles of each alkoxy group] (molar ratio) = 1.0) and 36 parts of 95% formic acid were charged and subjected to a hydrolysis reaction at room temperature for 30 minutes. During the reaction, the temperature increased by 32 ° C. due to exotherm. After the reaction, 3010 parts of toluene was charged and heated. When the temperature was raised to 71 ° C., part of methanol and toluene generated by hydrolysis began to be distilled off. The temperature was raised to 75 ° C. over 1 hour, and the water was distilled off by condensation reaction. After further reacting at 75 ° C. for 1 hour, the pressure was reduced at 70 ° C. and 20 kPa to distill off a part of the remaining toluene, methanol, water, and formic acid. Furthermore, 1250 parts of condensates (A-3) were obtained by depressurizing at 70 degreeC and 0.7 kPa, and distilling toluene off. [Number of moles of unreacted hydroxyl group and alkoxy group] / [total number of moles of each alkoxy group contained in components (a1) and (a2)] (molar ratio) is 0.10, and the concentration is 98.9%. there were. Moreover, the density | concentration of the thiol group of a condensate (A-3) was 4.90 mmol / g.

Production Example 4 (Production of urethane acrylate (B-1))
In a reaction vessel equipped with a stirrer, a cooling tube, a dropping funnel and a nitrogen introduction tube, 300 parts of polypropylene glycol (product name “Excenol 720” manufactured by Asahi Glass Co., Ltd.), 2 parts of methoquinone, isocyanurate of hexamethylene diisocyanate ( After charging 510 parts of Tosoh Corporation product name “Coronate HX”, the temperature in the system was raised to about 50 ° C. Subsequently, 0.5 part of tin octylate (manufactured by Mitsubishi Chemical Corporation: product name “STANOCTO”) was added, the temperature was raised to 80 ° C., and the temperature was kept for 2 hours. Subsequently, 200 parts of hydroxyethyl acrylate and 0.5 part of stanocto were added and kept at 80 ° C. for 2 hours, and then cooled to obtain urethane acrylate (B-1).

Production Example 5 (Production of urethane acrylate (B-2))
In a reaction vessel equipped with a stirrer, a cooling tube, a dropping funnel and a nitrogen introduction tube, 225 parts of caprolactone diol (manufactured by Daicel Corporation: product name “Placcel 205”), 2 parts of methoquinone, isocyanurate of hexamethylene diisocyanate ( After charging 510 parts of Tosoh Corporation product name “Coronate HX”, the temperature in the system was raised to about 50 ° C. Subsequently, 0.5 part of tin octylate (manufactured by Mitsubishi Chemical Corporation: product name “STANOCTO”) was added, the temperature was raised to 80 ° C., and the temperature was kept for 2 hours. Next, 200 parts of hydroxyethyl acrylate and 0.5 part of stanocto were added and kept at 80 ° C. for 2 hours, and then cooled to obtain urethane acrylate (B-2).

Production Example 6 (Production of urethane acrylate (B-3))
In a reaction vessel equipped with a stirrer, a cooling tube, a dropping funnel and a nitrogen introducing tube, 700 parts of polypropylene glycol (product name “Exenol 720” manufactured by Asahi Glass Co., Ltd.), 1 part of methoquinone, isophorone diisocyanate (Suika Covestrourethane) (Product name: “Death Module I”)) 445 parts were charged, and the temperature inside the system was raised to about 50 ° C. Subsequently, 0.5 part of tin octylate (manufactured by Mitsubishi Chemical Corporation: product name “STANOCTO”) was added, the temperature was raised to 80 ° C., and the temperature was kept for 2 hours. Next, 230 parts of hydroxyethyl acrylate and 0.5 part of stannoct were added and kept at 80 ° C. for 2 hours, followed by cooling to obtain urethane acrylate (B-3).

Example 1 (Preparation of sealing material composition)
With respect to 63.9 g of the condensate (A-1) obtained in Production Example 1, triallyl isocyanurate (manufactured by Nippon Kasei Co., Ltd .: trade name “TAIC”, carbon-carbon double bond) as component (B) Concentration is 12.0 mmol / g, hereinafter referred to as “TAIC”) 35.9 g ([number of moles of carbon-carbon double bonds contained in component (B)) / [of thiol groups contained in component (A) Mole number] (molar ratio) = 1.05), hydroxycyclohexyl phenyl ketone (Ciba Japan Co., Ltd .: trade name “Irgacure 184”, hereinafter referred to as Irg184)) 0.20 g as a photopolymerization initiator, polymerization inhibitor As a sealing material composition (D-1), 0.002 g of nitrosophenylhydroxylamine aluminum salt (manufactured by Wako Pure Chemical Industries, Ltd .: trade name “Q-1301”, hereinafter referred to as Q-1301) It was obtained.

Example 2 (Preparation of sealing material composition)
For 59.9 g of the condensate (A-1) obtained in Production Example 1, 28.7 g of TAIC as component (B), and jER828 (bisphenol A type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation) as component (C) : Trade name “jER828”, epoxy group concentration is 5.41 mmol / g, hereinafter referred to as jER828) 11.1 g ([component (B) and the number of moles of carbon-carbon double bonds and (C) The total number of moles of epoxy groups contained in the component] / [number of moles of thiol groups contained in the component (A)] (molar ratio) = 1.05), 0.20 g of Irg184 as a photopolymerization initiator, nitrosophenylhydroxyl A sealing material composition (D-2) was obtained by blending 0.002 g of an amine aluminum salt (manufactured by Wako Pure Chemical Industries, Ltd .: trade name “Q-1301”, hereinafter referred to as Q-1301).

Example 3 (Preparation of sealing material composition)
25.6 g of TAIC as the component (B) and 16.8 g of jER828 as the component (C) with respect to 57.3 g of the condensate (A-1) obtained in Production Example 1 ([included in component (B) The number of moles of carbon-carbon double bonds and the total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 1.08), As a photopolymerization initiator, 0.20 g of Irg184 and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-3).

Example 4 (Preparation of sealing material composition)
25.2 g of TAIC ”as component (B) and 10.1 g of jER828 as component (C) to 64.5 g of condensate (A-2) obtained in Production Example 2 (into component (B)) The number of moles of carbon-carbon double bonds contained and the total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 1.05) As a photopolymerization initiator, 0.20 g of Irg184 and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-4).

Example 5 (Preparation of sealing material composition)
24.1 g of TAIC "as component (B) and 9.2 g of jER828 as component (C) (for [Component (B)), with respect to 66.5 g of the condensate (A-3) obtained in Production Example 3. The number of moles of carbon-carbon double bonds contained and the total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 1.05) As a photopolymerization initiator, 0.20 g of Irg184 and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-5).

Example 6 (Preparation of sealing material composition)
26.9 g of TAIC "as component (B) and 20.6 g of condensate (A-1) obtained in Production Example 1, and 10.6 g of jER828 as component (C) ([component (B) Number of moles of carbon-carbon double bonds contained and total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 0.95) As a photopolymerization initiator, 0.20 g of Irg184 and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-6).

Example 7 (Preparation of sealing material composition)
Polyfunctional urethane acrylate (manufactured by Arakawa Chemical Industries, Ltd .: trade name “Beam Set 550B”, carbon-carbon bismuth) as component (B) based on 24.9 g of the condensate (A-1) obtained in Production Example 1. The concentration of the heavy bond is 2.25 mmol / g, hereinafter referred to as BS-550B) 74.9 g ([number of moles of carbon-carbon double bond contained in component (B)) / [thiol contained in component (A)] Number of moles of group] (molar ratio) = 1.05), 0.20 g of Irg184, and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-7). The concentration of the thiol group in the sealing material composition (D-7) was 1.60 mmol / g.

Example 8 (Preparation of sealing material composition)
Based on 28.8 g of the condensate (A-1) obtained in Production Example 1, 59.9 g of BS-550B as component (B) and 11.1 g of jER828 as component (C) ([component (B) The number of moles of carbon-carbon double bonds contained in and the total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 1.05 ), 0.20 g of Irg184 and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-8). The concentration of the thiol group in the sealing material composition (D-8) was 1.85 mmol / g.

Example 9 (Preparation of sealing material composition)
Based on 30.8 g of the condensate (A-1) obtained in Production Example 1, 58.4 g of BS-550B as component (B) and 10.6 g of jER828 as component (C) ([component (B) The number of moles of carbon-carbon double bonds contained in the total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 0.95 )], (Molar ratio) = 1.05), 0.20 g of Irg184, and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-8). The concentration of the thiol group in the sealing material composition (D-9) was 1.99 mmol / g.

Example 10 (Preparation of sealing material composition)
For 30.3 g of the condensate (A-1) obtained in Production Example 1, 69.5 g of urethane acrylate (B-1) obtained in Production Example 4 as Component (B) ([Component (B) Number of moles of carbon-carbon double bonds contained] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 0.95), Irg184 is 0.20 g, Q-1301 is 0.002 g The sealing material composition (D-10) was obtained by blending.

Example 11 (Preparation of sealing material composition)
For 30.3 g of the condensate (A-1) obtained in Production Example 1, 69.5 g of urethane acrylate (B-2) obtained in Production Example 5 as Component (B) ([Component (B) Number of moles of carbon-carbon double bonds contained] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 0.95), Irg184 is 0.20 g, Q-1301 is 0.002 g The sealing material composition (D-11) was obtained by blending.

Example 12 (adjustment of sealing material composition)
80.7 g of urethane acrylate (B-3) obtained in Production Example 6 as component (B) was added to 19.1 g of condensate (A-1) obtained in Production Example 1 (in [Component (B) Number of moles of carbon-carbon double bonds contained] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 0.95), Irg184 is 0.20 g, Q-1301 is 0.002 g The sealing material composition (D-12) was obtained by blending.

Example 13 (Preparation of sealing material composition)
30.3 g of TAIC as component (B) and 5.3 g of jER152 as component (C) (included in component (B)) with respect to 64.2 g of condensate (A-1) obtained in Production Example 1 The number of moles of carbon-carbon double bonds and the total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 0.95), As a photopolymerization initiator, 0.20 g of Irg184 and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-13).

Example 14 (Preparation of sealing material composition)
30.3 g of TAIC as component (B) and 3.7 g of jER630 as component (C) (included in component (B)) with respect to 65.8 g of condensate (A-1) obtained in Production Example 1 The number of moles of carbon-carbon double bonds and the total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 0.95), As a photopolymerization initiator, 0.20 g of Irg184 and 0.002 g of Q-1301 were blended to obtain a sealing material composition (D-14).

Example 15 (Preparation of sealing material composition)
30.3 g of TAIC as the component (B) and TEPIC-SP (manufactured by Nissan Chemical Industries, Ltd.) as the component (B) with respect to 65.7 g of the condensate (A-1) obtained in Production Example 1. 3.8 g ([number of moles of carbon-carbon double bonds contained in component (B) and total number of moles of epoxy groups contained in component (C)] / [component (A)] The number of moles of thiol groups contained in the polymer] (molar ratio) = 0.95), 0.20 g of Irg184 and 0.002 g of Q-1301 were blended as a photopolymerization initiator to obtain a sealing material composition (D-15). It was.

Comparative Example 1 (Preparation of sealing material composition)
As component (A), trimethylolpropane tris (3-mercaptopropionate) (manufactured by Sakai Chemical Industry Co., Ltd .: trade name “TMMP”, thiol group concentration is 7.52 mmol / g, hereinafter referred to as TMMP) 69.6 g of TAIC as component (B) ([number of moles of carbon-carbon double bond contained in component (B)] / [number of moles of thiol group contained in component (A)] (Molar ratio) = 1.05), 0.20 g of Irg184, and 0.002 g of Q-1301 were blended to obtain a sealing material composition (d-1). The concentration of the thiol group in the sealing material composition (d-1) was 4.53 mmol / g.

Comparative Example 2 (Preparation of sealing material composition)
(A) TMMP 56.3 g as component (B) TAIC 31.7 g and (C) component jER828 11.9 g ([carbon-carbon double bond contained in component (B) The total number of moles of epoxy groups contained in component (C)] / [number of moles of thiol groups contained in component (A)] (molar ratio) = 1.05), 0.20 g of Irg184, Q- 0.001 g of 1301 was blended to obtain a sealing material composition (d-2). The concentration of the thiol group in the sealing material composition (d-2) was 4.24 mmol / g.

Comments and symbols in the table are as follows.
* Note 1); (B) / (A) is [(total number of moles of carbon-carbon double bond of component (B))] / [number of moles of thiol group contained in component (A)] (mole Ratio).
* Note 2); ((B) + (C)) / (A) is [total number of moles of carbon-carbon double bond of component (B) and epoxy group contained in component (C))] / [ (A) The number of moles of thiol groups contained in the component] (molar ratio).
TAIC; triallyl isocyanurate (manufactured by Nippon Kasei Co., Ltd .: trade name “TAIC”)
BS-550B; urethane acrylate (manufactured by Arakawa Chemical Industries, Ltd .: trade name “Beam Set 550B”, concentration of carbon-carbon double bond is 2.25 mmol / g)
jER828; bisphenol A type liquid epoxy resin (Mitsubishi Chemical Corporation: trade name “jER828”)
jER152: Phenol novolac epoxy resin (Mitsubishi Chemical Corporation: trade name “jER152”)
jER630: Multifunctional epoxy resin (Mitsubishi Chemical Corporation: trade name “jER630”)
TEPIC-SP; triglycidyl isocyanurate (manufactured by Nissan Chemical Industries, Ltd .: trade name “TEPIC-SP”)
Irg184; hydroxycyclohexyl phenyl ketone (Ciba Japan KK: trade name “Irgacure 184”)
Q-1301; nitrosophenylhydroxylamine aluminum salt (manufactured by Wako Pure Chemical Industries, Ltd .: trade name “Q-1301”)
TMMP; trimethylolpropane tris (3-mercaptopropionate) (manufactured by Sakai Chemical Industry Co., Ltd .: trade name “TMMP”, concentration of thiol group is 7.52 mmol / g)

Adhesion, heat resistance, sealing properties, electrolytic solution resistance, and refrigerant resistance were evaluated using the sealing material compositions of Examples and Comparative Examples.
After applying the sealing material composition of each example and comparative example on each substrate using a bar coater, the ultraviolet light is irradiated using an ultraviolet irradiation device so that the integrated light amount is 300 mJ, and cured to obtain a sealing material. It was.
(SiO ₂ content)
The SiO ₂ content (% by weight) of the obtained sealing material is a general formula (weight) of the part (SiO _3/2 ) of the silsesquioxane structure used for the component (A), that is, the component (a1) used. The weight of 1) excluding R ¹ was regarded as the weight of SiO ₂ and this value was divided by the weight of the entire cured product.
(Adhesion)
Evaluation was made by a cross cut test according to a general test method of JIS K5400. The results were expressed as O for 100/100, Δ for 70/100 or more, and x for less than 70/100.

(Heat-resistant)
The electrolytic solution dimethyl carbonate was poured into an aluminum pouch bag, the sealing material composition was applied, and an ultraviolet ray was irradiated using an ultraviolet ray irradiation device so that the integrated light amount was 300 mJ, and the electrolyte solution was sealed.
The prepared electrolytic solution-enclosed aluminum pouch bag was heated in a constant temperature bath at 100 ° C. for 72 hours to determine weight loss before and after heating. A change in weight of less than 1% was indicated by ○, and 1% or more was indicated by ×.

(Sealability)
In the heat resistance test, it was confirmed whether or not an odor peculiar to the electrolyte was felt. The case where no odor was felt was indicated by ○, and the case where it was felt was indicated by ×.

(Electrolytic solution resistance)
About 0.5 g of the sealing material composition was poured out on the Teflon sheet, and an ultraviolet ray was irradiated using an ultraviolet irradiation device so that the integrated light amount was 300 mJ, and the sealing material composition was cured to obtain a sealing agent.
The sealing material was immersed in dimethyl carbonate and allowed to stand at room temperature for 40 hours. The sealing material is taken out from the liquid, dried under reduced pressure at 80 ° C. for 3 hours, and the weight reduction rate ((weight of the cured product before the test−weight of the cured product after the test) / before the test). The weight of the cured product was calculated.

(Refrigerant resistance)
Evaluation was made in the same manner as the electrolytic solution resistance except that the immersion liquid was changed to Galden HT-200.

Example 16 (Production of sealed lithium ion battery)
In accordance with the method described in Example 1 of JP-A-2000-243359, an electrode, a separator, and the like were prepared, wound to create an electrode group, and inserted into an iron can. After injecting the electrolytic solution, a gasket is attached, and the sealing material composition used in Examples 2, 4, 5, 6, 7, 10, and 13 of the present invention is applied, photocured, sealed, and cylindrical lithium A battery was created.

Example 17
According to the battery manufacturing method described in JP-A-2006-146270, a power generation element in which electrodes and separators are laminated is prepared, and the sealing material composition used in Examples 2, 4, 5, 6, 9, 10, and 13 on the outer peripheral portion The power generation element that had been coated and photocured was wound and inserted into an iron can. After injecting the electrolyte, a gasket was attached to produce a cylindrical lithium battery.

Example 18 (Production of pouch-type lithium battery)
In accordance with the method described in Example 1 of Japanese Patent Application Laid-Open No. 2000-243359, an electrode, a separator, and the like were prepared and inserted into a pouch-type lithium ion battery case. After injecting the electrolyte in a vacuum state, heat sealing was performed to obtain a heat-sealed pouch-type lithium ion battery. Subsequently, in order to obtain the lithium battery of the present invention, the sealing material composition used in Examples 2, 4, 5, 7, 10, and 13 was applied to the heat-sealed pouch-type lithium ion battery, and ultraviolet irradiation was performed. The device was used to irradiate with ultraviolet rays so that the integrated light amount was 300 mJ, cured, and sealed to create a pouch-type lithium battery.

Example 19
According to the battery manufacturing method described in JP-A-2006-146270, a power generation element in which electrodes, separators, and the like are laminated is created, and the sealing material used in Examples 2, 4, 5, 6, 9, 10, and 13 on the outer peripheral portion The power generation element, which was photocured by applying the composition, was inserted into a pouch-type lithium ion battery case. After injecting the electrolyte in a vacuum state, heat sealing and sealing were performed to prepare a pouch-type lithium battery.

None of the lithium ion batteries had any operational problems.
From the above results, it is recognized that the sealing material is suitable as a sealing material for lithium ion batteries.

Claims (5)

General formula (1):
R ¹ Si (OR ² ) ₃ (1)
(In the formula, R ¹ represents a hydrocarbon group having 1 to 8 carbon atoms having at least one thiol group or an aromatic hydrocarbon group having at least one thiol group, and R ² represents a hydrogen atom or 1 carbon atom) Hydroxyl condensates (A) of thiol group-containing alkoxysilanes (a1) represented by -8 hydrocarbon groups or aromatic hydrocarbon groups) and two carbon-carbon double bonds A sealing material composition for a photocurable lithium ion battery, comprising the compound (B) as described above. Furthermore, the sealing material composition for lithium ion batteries of Claim 1 containing the compound (C) which has 2 or more of epoxy groups. A cured product of the photocuring type lithium ion battery sealing material composition according to claim 1, wherein a weight change rate when immersed in dimethyl carbonate at 25 ° C. for 40 hours is less than 1%. Sealing material for lithium ion batteries. A part or all of an outer peripheral portion of a power generation element formed by laminating a positive electrode, a negative electrode, and a separator is sealed with the photocuring type lithium ion battery sealing material according to claim 3. Lithium-ion battery. 4. A lithium ion battery, wherein a sealing portion of a battery exterior body in which a power generation element and an electrolyte are accommodated is sealed with the photocuring type lithium ion battery sealing material according to claim 3.