Composition for adhesive layer of non-aqueous secondary battery, adhesive layer for non-aqueous secondary battery and method for manufacturing the same, laminate for non-aqueous secondary battery and method for manufacturing the same, and non-aqueous secondary battery

Abstract

The purpose of the present invention is to provide a composition for nonaqueous secondary battery adhesive layers, the composition enabling the achievement of a nonaqueous secondary battery adhesive layer which is capable of firmly bonding battery members to each other by means of pressurization at room temperature, while ensuring inkjet ejection characteristics, and the composition enabling a nonaqueous secondary battery to exhibit excellent battery characteristics. A composition for nonaqueous secondary battery adhesive layers according to the present invention is characterized by containing a particulate polymer, while being also characterized in that the value of the pressure sensitivity of adhesive force as determined by formula (1) is more than 20 but less than 80. (1): Pressure sensitivity of adhesive force (N / (m·MPa)) = (T3 - T1) / 2 (In the formula, T1 represents the adhesive force (N / m) between a polyethylene separator and an adhesive layer for nonaqueous secondary batteries, the adhesive layer being obtained from this composition for nonaqueous secondary battery adhesive layers, in the case where the polyethylene separator and the adhesive layer for nonaqueous secondary batteries are pressure-bonded to each other for 10 seconds at a pressure of 1 MPa at 25°C; and T3 represents the adhesive force (N / m) between a polyethylene separator and an adhesive layer for nonaqueous secondary batteries, the adhesive layer being obtained from this composition for nonaqueous secondary battery adhesive layers, in the case where the polyethylene separator and the adhesive layer for nonaqueous secondary batteries are pressure-bonded to each other for 10 seconds at a pressure of 3 MPa at 25°C.)

Description

Technical Field

[0001] The present invention relates to a composition for an adhesive layer of a non-aqueous secondary battery, an adhesive layer for a non-aqueous secondary battery and a method for producing the same, a laminate for a non-aqueous secondary battery and a method for producing the same, and a non-aqueous secondary battery.

Background Art

[0002] Non-aqueous secondary batteries such as lithium-ion secondary batteries (hereinafter also referred to as "secondary batteries") are small, lightweight, have a high energy density, and can be repeatedly charged and discharged, and are used in a wide range of applications. And secondary batteries generally include battery members such as a positive electrode, a negative electrode, and a separator that separates the positive electrode and the negative electrode to prevent a short circuit between the positive electrode and the negative electrode.

[0003] In secondary batteries, battery members provided with an adhesive layer for improving the adhesiveness between battery members are used. Specifically, electrodes formed by further forming an adhesive layer on an electrode substrate formed by providing an electrode mixture layer on a current collector, and separators formed by forming an adhesive layer on a separator substrate are used as battery members. This adhesive layer is usually formed by supplying a slurry-like composition for a non-aqueous secondary battery adhesive layer (hereinafter also referred to as "composition for adhesive layer") containing a binder component and a solvent such as water onto a substrate such as an electrode substrate or a separator substrate and drying it.

[0004] Here, in recent years, in order to firmly adhere battery members to each other, exhibit excellent battery characteristics in secondary batteries, and further improve the manufacturing efficiency of secondary batteries, the composition for an adhesive layer is ejected from a nozzle as fine droplets by an inkjet method to form an adhesive layer (adhesive material). has been studied. For example, Patent Document 1 describes coating a non-aqueous secondary battery slurry containing a particulate polymer having a core-shell structure, a predetermined amount of polyhydric alcohol compound, and water using an inkjet method. Furthermore, Patent Document 1 reports that by using this non-aqueous secondary battery slurry, even when employing an inkjet method, it is possible to efficiently apply adhesive material to the surface of battery components while ensuring strong adhesion between battery components and excellent low-temperature output characteristics of the secondary battery. Furthermore, Patent Document 2 describes coating an adhesive layer composition containing organic particles having a core-shell structure, a thixotropic agent, and water, which satisfies predetermined properties, using an inkjet method. Patent Document 2 also reports that by using this adhesive layer composition, an adhesive layer can be formed well even when using an inkjet method, and the substrate and the object to be adhered can be firmly bonded through the adhesive layer. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2019 / 221056 [Patent Document 2] International Publication No. 2020 / 045246 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, our investigations have revealed that while the conventional non-aqueous slurries and adhesive layer compositions for secondary batteries can be successfully coated onto battery components by inkjet technology, when battery components are bonded together at room temperature and under pressure via an adhesive layer (adhesive material) formed by drying the coated adhesive layer composition during the secondary battery manufacturing process, the adhesive strength between the battery components is insufficient, impairing the productivity of secondary batteries and potentially degrading their performance.

[0007] In other words, the conventional technology described above still had room for improvement in terms of ensuring inkjet ejection characteristics, firmly bonding battery components together under room temperature pressure, and imparting excellent battery characteristics to secondary batteries.

[0008] Therefore, the present invention aims to provide an adhesive layer for non-aqueous secondary batteries that can firmly bond battery components together at room temperature and pressure while ensuring inkjet ejection characteristics, and to provide a composition for a non-aqueous secondary battery adhesive layer that can enable the non-aqueous secondary battery to exhibit excellent battery characteristics. Furthermore, the present invention aims to provide an adhesive layer for non-aqueous secondary batteries that can firmly bond battery components together under room temperature pressure and exhibit excellent electrical properties in non-aqueous secondary batteries. Furthermore, the present invention aims to provide a laminate for non-aqueous secondary batteries that can exhibit excellent electrical characteristics in non-aqueous secondary batteries. Furthermore, the present invention aims to provide a non-aqueous secondary battery with excellent electrical properties. Furthermore, the present invention aims to provide a method for manufacturing an adhesive layer for non-aqueous secondary batteries that can firmly bond battery components together under room temperature pressure and exhibit excellent electrical properties in non-aqueous secondary batteries. Furthermore, the present invention aims to provide a method for manufacturing a laminate for non-aqueous secondary batteries that can exhibit excellent electrical properties in non-aqueous secondary batteries. [Means for solving the problem]

[0009] The inventors diligently conducted research with the aim of solving the above problems. As a result, the inventors discovered that if a non-aqueous secondary battery adhesive layer obtained from a polyethylene separator and a non-aqueous secondary battery adhesive layer is used in which the degree of change in adhesive strength (pressure sensitivity) when the two are pressed together under different pressures under predetermined conditions satisfies a predetermined relationship, then it is possible to firmly bond battery components together at room temperature and pressure while ensuring inkjet ejection characteristics, and to enable the non-aqueous secondary battery to exhibit excellent battery characteristics, thus completing the present invention.

[0010] In other words, the present invention aims to advantageously solve the above problems, and the non-aqueous secondary battery adhesive layer composition of the present invention is a non-aqueous secondary battery adhesive layer composition containing a particulate polymer, characterized in that the pressure sensitivity value of the adhesive force, which can be determined by the following formula (1), is greater than 20 and less than 80. The pressure sensitivity of the adhesive force (N / (m·MPa)) = (T3-T1) / 2···(1) (In the formula, T1 represents the adhesive strength (N / m) between the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition when the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition are bonded at 25°C and a pressure of 1 MPa for 10 seconds, and T3 represents the adhesive strength (N / m) between the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition when the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition are bonded at 25°C and a pressure of 3 MPa for 10 seconds). In this way, by using a non-aqueous secondary battery adhesive layer composition in which the pressure sensitivity of the adhesive strength is within a predetermined range, it is possible to firmly bond battery components together at room temperature and pressure while ensuring inkjet ejection characteristics, and to enable non-aqueous secondary batteries to exhibit excellent battery characteristics. In this invention, the pressure sensitivity of the adhesive force can be measured by the method described in the examples.

[0011] Furthermore, the non-aqueous secondary battery adhesive layer composition of the present invention preferably has a core-shell structure comprising a core portion and a shell portion that partially covers the outer surface of the core portion, wherein the glass transition temperature of the core portion is -50°C to 25°C, the glass transition temperature of the shell portion is 50°C to 200°C, and the mass ratio of the shell portion to the total of the core portion and the shell portion is 2% by mass to 15% by mass. In this way, by using a particulate polymer having a core-shell structure comprising a core portion and a shell portion that partially covers the outer surface of the core portion, where the glass transition temperatures of the core portion and the shell portion are each within a predetermined range, and the mass ratio of the shell portion to the total of the core portion and the shell portion is within a predetermined range, it is possible to further suppress nozzle clogging when using an inkjet method and further improve inkjet ejection characteristics, as well as to bond battery components more firmly to each other at room temperature and enable non-aqueous secondary batteries to exhibit even better battery characteristics. In this invention, the "glass transition temperature" can be measured using the measurement method described in the examples of this specification.

[0012] Furthermore, it is preferable that the glass transition temperature of the core portion of the non-aqueous secondary battery adhesive layer composition of the present invention is between -40°C and 25°C. Thus, if the glass transition temperature of the core portion is within the above predetermined range, the inkjet ejection characteristics can be further improved.

[0013] Furthermore, it is preferable that the volume-average particle diameter of the particulate polymer in the non-aqueous secondary battery adhesive layer composition of the present invention is 100 nm or more and 1500 nm or less. If the volume-average particle diameter of the particulate polymer is 100 nm or more, it is possible to suppress deterioration of battery characteristics due to an increase in the resistance of the secondary battery caused by obstructing the lithium ion path of the substrate (electrode or separator). In addition, if the volume-average particle diameter is 1500 nm or less, it is possible to further suppress nozzle clogging when the non-aqueous secondary battery adhesive layer composition is coated by an inkjet method, thereby improving the inkjet ejection characteristics. In this invention, "volume-average particle diameter" refers to the particle diameter at which the cumulative volume calculated from the smallest diameter side accounts for 50% of the volume-based particle diameter distribution measured by laser diffraction, and can be measured using the measurement method described in the examples of this specification.

[0014] Furthermore, this invention aims to advantageously solve the above-mentioned problems, and the adhesive layer for non-aqueous secondary batteries of the present invention is characterized by being made using any of the above-described compositions for non-aqueous secondary battery adhesive layers. In this way, the adhesive layer for non-aqueous secondary batteries made using any of the above-described compositions for non-aqueous secondary battery adhesive layers can firmly bond battery components such as separators and electrodes together under room temperature pressure, and can also enable non-aqueous secondary batteries to exhibit excellent battery characteristics.

[0015] Furthermore, this invention aims to advantageously solve the above problems, and the method for manufacturing an adhesive layer for non-aqueous secondary batteries of the present invention is characterized by comprising the steps of: coating any of the above-described non-aqueous secondary battery adhesive layer compositions onto a substrate by an inkjet method; and drying the non-aqueous secondary battery adhesive layer composition coated onto the substrate. In this way, by using any of the above-described non-aqueous secondary battery adhesive layer compositions, even when an inkjet method is employed, the occurrence of nozzle clogging can be suppressed and inkjet ejection characteristics can be ensured, so that an adhesive layer for non-aqueous secondary batteries can be formed well on the substrate.

[0016] Furthermore, this invention aims to advantageously solve the above-mentioned problems, and the laminate for a non-aqueous secondary battery of the present invention is a laminate for a non-aqueous secondary battery comprising an electrode and a separator, characterized in that the electrode and the separator are bonded together via the above-described adhesive layer for a non-aqueous secondary battery. In this way, the laminate for a non-aqueous secondary battery comprising battery components bonded together using the above-described adhesive layer for a non-aqueous secondary battery has strong adhesion between the battery components, and the non-aqueous secondary battery comprising the laminate for a non-aqueous secondary battery can exhibit excellent battery characteristics.

[0017] Also, this invention aims to advantageously solve the above problems. The method for manufacturing a laminate for a non-aqueous secondary battery of this invention includes a step of supplying an adhesive material to at least one bonding surface of an electrode and a separator, and a step of pressing and bonding the electrode and the separator at room temperature through the bonding surface to which the adhesive material has been supplied. The adhesive material is characterized by being formed using any of the above-described compositions for a non-aqueous secondary battery adhesive layer. Thus, by using an adhesive material obtained from any of the above-described compositions for a non-aqueous secondary battery adhesive layer, the electrodes can be firmly bonded to each other at room temperature. In the present invention, "room temperature" refers to a temperature range of 25°C ± 5°C.

[0018] Also, this invention aims to advantageously solve the above problems. The non-aqueous secondary battery of this invention is characterized by including the above-described laminate for a non-aqueous secondary battery. Thus, a non-aqueous secondary battery including the above-described laminate for a non-aqueous secondary battery can exhibit excellent battery characteristics.

Effects of the Invention

[0019] According to the present invention, it is possible to provide an adhesive layer for a non-aqueous secondary battery that can firmly bond battery members to each other at room temperature under pressure while ensuring inkjet ejection characteristics, and it is also possible to provide a composition for a non-aqueous secondary battery adhesive layer that can cause a non-aqueous secondary battery to exhibit excellent battery characteristics. Also, according to the present invention, it is possible to provide an adhesive layer for a non-aqueous secondary battery that can firmly bond battery members to each other at room temperature under pressure and cause a non-aqueous secondary battery to exhibit excellent electrical characteristics. Also, according to the present invention, it is possible to provide a laminate for a non-aqueous secondary battery that can cause a non-aqueous secondary battery to exhibit excellent electrical characteristics. Also, according to the present invention, it is possible to provide a non-aqueous secondary battery having excellent electrical characteristics. Also, according to the present invention, it is possible to provide a method for manufacturing an adhesive layer for a non-aqueous secondary battery that can firmly bond battery members to each other at room temperature under pressure and cause a non-aqueous secondary battery to exhibit excellent electrical characteristics. Furthermore, according to the present invention, it is possible to provide a method for manufacturing a laminate for a non-aqueous secondary battery that can exhibit excellent electrical properties in a non-aqueous secondary battery. [Brief explanation of the drawing]

[0020] [Figure 1] This is a schematic cross-sectional view showing the structure of an example of a particulate polymer. [Figure 2] This figure illustrates an example of the manufacturing process for a laminate for a non-aqueous secondary battery according to the present invention. [Figure 3] This figure illustrates the manufacturing process of laminates for non-aqueous secondary batteries in the examples and comparative examples. [Modes for carrying out the invention]

[0021] Embodiments of the present invention will be described in detail below. Herein, the non-aqueous secondary battery adhesive layer composition of the present invention can be used when forming the non-aqueous secondary battery adhesive layer of the present invention. The non-aqueous secondary battery adhesive layer of the present invention can be manufactured, for example, by the method for manufacturing the non-aqueous secondary battery adhesive layer of the present invention. The non-aqueous secondary battery adhesive layer of the present invention can be used when manufacturing the non-aqueous secondary battery laminate and the non-aqueous secondary battery of the present invention. The non-aqueous secondary battery laminate of the present invention can be used when manufacturing the non-aqueous secondary battery of the present invention, and can be manufactured, for example, by the method for manufacturing the non-aqueous secondary battery laminate of the present invention. The non-aqueous secondary battery of the present invention comprises the non-aqueous secondary battery laminate of the present invention.

[0022] (Non-aqueous secondary battery adhesive layer composition) The non-aqueous secondary battery adhesive layer composition of the present invention contains a particulate polymer. The non-aqueous secondary battery adhesive layer composition of the present invention is usually a slurry composition in which a particulate polymer is dispersed in a solvent such as water, and may optionally contain other components in addition to the particulate polymer. Furthermore, the non-aqueous secondary battery adhesive layer composition of the present invention requires that the pressure sensitivity value of the adhesive strength, as determined by the following formula (1), is greater than 20 and less than 80. The pressure sensitivity of the adhesive force (N / (m·MPa)) = (T3-T1) / 2···(1) (In the formula, T1 represents the adhesive strength (N / m) between the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition when the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition are bonded together at 25°C and a pressure of 1 MPa for 10 seconds, and T3 represents the adhesive strength (N / m) between the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition when the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition are bonded together at 25°C and a pressure of 3 MPa for 10 seconds).

[0023] The "pressure sensitivity of adhesive strength" calculated by the above formula (1) is the difference (T3-T1) between the adhesive strength T3 (N / m) when a non-aqueous secondary battery adhesive layer made of a polyethylene separator and a non-aqueous secondary battery adhesive layer composition is pressed and bonded at 25°C and a pressure of 3 MPa for 10 seconds, and the adhesive strength T1 (N / m) when a non-aqueous secondary battery adhesive layer obtained from a polyethylene separator and a non-aqueous secondary battery adhesive layer composition is pressed and bonded at 25°C and a pressure of 1 MPa for 10 seconds, divided by the difference (3-1 (=2)) in the pressures (MPa) during each pressing and bonding. In other words, the pressure sensitivity of adhesive strength corresponds to the slope between 1 MPa and 3 MPa on a graph with the pressure during bonding on the horizontal axis and the adhesive strength on the vertical axis, and represents the degree to which the adhesive strength when bonded under pressure of 3 MPa is greater than the adhesive strength when bonded under pressure of 1 MPa.

[0024] Furthermore, the non-aqueous secondary battery adhesive layer composition of the present invention has an adhesive pressure sensitivity value greater than 20 and less than 80, which allows for strong adhesion between battery components under room temperature pressure while ensuring inkjet ejection characteristics, and enables the non-aqueous secondary battery to exhibit excellent battery characteristics. If the above value is 20 or less, ejection by the inkjet method becomes impossible, or adhesive strength cannot be ensured when attempting to bond battery components under room temperature pressure. On the other hand, if the above value is 80 or more, when bonding is performed as a process and the battery's durability is evaluated, the particulate polymer deforms due to the internal pressure caused by the swelling of the battery, causing clogging of the separator, which increases the resistance of the secondary battery and deteriorates the battery characteristics. Furthermore, the "adhesive layer for non-aqueous secondary batteries" is a dried product of the composition for the adhesive layer of non-aqueous secondary batteries.

[0025] Furthermore, from the viewpoint of achieving a high level of balance between inkjet ejection characteristics, adhesion between battery components when bonded at room temperature and pressure, and battery characteristics of the secondary battery, the pressure sensitivity of the adhesive force is preferably 30 or higher, more preferably 40 or higher, even more preferably 45 or higher, preferably 70 or lower, and more preferably 60 or lower.

[0026] The pressure sensitivity of the adhesive force can be controlled, for example, by using a particulate polymer alloy consisting of a polymer with a low glass transition temperature and a polymer with a high glass transition temperature, or by changing the glass transition temperature of the core portion, the glass transition temperature of the shell portion, and / or the mass ratio of the shell portion to the total mass of the core portion in a particulate polymer having a core-shell structure.

[0027] <Particulate polymer> The particulate polymer contained in the non-aqueous secondary battery adhesive layer composition of the present invention functions as a binder in the adhesive layer (adhesive material) that bonds battery components such as separators and electrodes together. In the present invention, either a particulate polymer having a core-shell structure or a particulate polymer without a core-shell structure may be used as the particulate polymer, but it is preferable to use at least a particulate polymer having a core-shell structure.

[0028] <<Particulate polymer with core-shell structure>> A particulate polymer having a core-shell structure comprises a core portion and a shell portion that covers the outer surface of the core portion. By using a particulate polymer having a core-shell structure, it becomes easier to control the pressure sensitivity of the adhesion described above.

[0029] Here, the shell portion may cover the entire outer surface of the core portion, or it may partially cover the outer surface of the core portion. Even if the outer surface of the core portion appears to be completely covered by the shell portion in appearance, if there is a hole connecting the inside and outside of the shell portion, then that shell portion is a shell portion that partially covers the outer surface of the core portion.

[0030] Figure 1 shows a cross-sectional structure of an example of a particulate polymer. In Figure 1, the particulate polymer 300 has a core-shell structure comprising a core portion 310 and a shell portion 320. Here, the core portion 310 is the part of the particulate polymer 300 that is inside the shell portion 320. The shell portion 320 is the part that covers the outer surface 310S of the core portion 310, and is usually the outermost part of the particulate polymer 300. In the example in Figure 1, the shell portion 320 does not cover the entire outer surface 310S of the core portion 310, but only partially covers the outer surface 310S of the core portion 310.

[0031] Furthermore, particulate polymers may have any components other than the core and shell portions described above, as long as they do not significantly impair the desired effects. Specifically, for example, a particulate polymer may have a portion formed of a different polymer inside the core portion. To give a specific example, seed particles used when producing particulate polymers by seed polymerization may remain inside the core portion. However, from the viewpoint of significantly exhibiting the desired effects, it is preferable that the particulate polymer consists only of a core portion and a shell portion.

[0032] [Core section] -Glass transition temperature- The glass transition temperature of the polymer in the core of the particulate polymer is preferably -50°C or higher, more preferably -45°C or higher, even more preferably -40°C or higher, preferably 25°C or lower, more preferably 10°C or lower, and even more preferably 0°C or lower. If the glass transition temperature of the polymer in the core is above the lower limit, the inkjet ejection characteristics can be improved. On the other hand, if the glass transition temperature of the polymer in the core is below the upper limit, the polymer in the core can exhibit good adhesion, and the battery components can be bonded together even more firmly at room temperature and pressure via the adhesive layer. Furthermore, the glass transition temperature of the polymer in the core can be adjusted, for example, by changing the type and proportion of monomers used in the preparation of the polymer in the core.

[0033] -composition- Monomers used to prepare the core polymer include, for example, vinyl chloride monomers such as vinyl chloride and vinylidene chloride; vinyl acetate monomers such as vinyl acetate; aromatic vinyl monomers such as styrene, α-methylstyrene, styrenesulfonic acid, butoxystyrene, and vinylnaphthalene; vinylamine monomers such as vinylamine; vinylamide monomers such as N-vinylformamide and N-vinylacetamide; methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate. Examples include fluorine-free (meth)acrylic acid ester monomers such as ethyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate; (meth)acrylamide monomers such as acrylamide and methacrylamide; (meth)acrylonitrile monomers such as acrylonitrile and methacrylonitrile; fluorine-containing (meth)acrylic acid ester monomers such as 2-(perfluorohexyl)ethyl methacrylate and 2-(perfluorobutyl)ethyl acrylate; maleimide; and maleimide derivatives such as phenylmaleimide. These may be used individually or in combination of two or more in any ratio. In this invention, (meth)acrylic means acrylic and / or methacrylic, and (meth)acrylonitrile means acrylonitrile and / or methacrylonitrile.

[0034] Among these monomers, it is preferable to use at least a (meth)acrylic acid ester monomer as the monomer used in preparing the polymer of the core portion, from the viewpoint of further strengthening the adhesion between battery components via an adhesive layer, more preferably a combination of a (meth)acrylic acid ester monomer and an aromatic vinyl monomer, or more preferably a combination of a (meth)acrylic acid ester monomer and a (meth)acrylonitrile monomer, and particularly preferably a combination of a (meth)acrylic acid ester monomer and an aromatic vinyl monomer. That is, it is preferable that the polymer of the core portion contains at least a (meth)acrylic acid ester monomer unit, more preferably a combination of a (meth)acrylic acid ester monomer unit and an aromatic vinyl monomer unit, and even more preferably a combination of a (meth)acrylic acid ester monomer unit and an aromatic vinyl monomer unit. In this invention, "containing monomer units" means "the polymer obtained using the monomer contains repeating units derived from the monomer." Furthermore, in the present invention, "(meth)acrylic acid ester monomer" refers to a monofunctional (meth)acrylic acid ester monomer having only one polymerization-reactive group.

[0035] Furthermore, the proportion of (meth)acrylic acid ester monomer units in the polymer of the core portion is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, preferably 80% by mass or less, and more preferably 70% by mass or less, with the total repeating units (total monomer units) contained in the polymer of the core portion being 100% by mass, from the viewpoint of further strengthening the adhesion between battery components via the adhesive material. Furthermore, when the polymer in the core portion contains (meth)acrylic acid ester monomer units and aromatic vinyl monomer units, the proportion of aromatic vinyl monomer units in the polymer in the core portion is preferably 15% by mass or more, more preferably 20% by mass or more, particularly preferably 25% by mass or more, preferably 95% by mass or less, more preferably 80% by mass or less, and particularly preferably 70% by mass or less, with the total repeating units (total monomer units) contained in the polymer in the core portion being 100% by mass. Furthermore, if the polymer in the core portion contains (meth)acrylic acid ester monomer units and (meth)acrylonitrile monomer units, the proportion of (meth)acrylonitrile monomer units in the polymer in the core portion is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 15% by mass or more, preferably 30% by mass or less, and more preferably 25% by mass or less, with the total repeating units (total monomer units) contained in the polymer in the core portion being 100% by mass, from the viewpoint of further strengthening the adhesion between battery components via the adhesive material.

[0036] Furthermore, the polymer in the core portion may contain acid group-containing monomer units. Examples of acid group-containing monomers include monomers having acid groups, such as monomers having carboxylic acid groups, monomers having sulfonic acid groups, and monomers having phosphate groups.

[0037] Examples of monomers having a carboxylic acid group include monocarboxylic acids and dicarboxylic acids. Examples of monocarboxylic acids include acrylic acid, methacrylic acid, and crotonic acid. Examples of dicarboxylic acids include maleic acid, fumaric acid, and itaconic acid. Examples of monomers having a sulfonic acid group include vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth)allyl sulfonic acid, ethyl (meth)acrylate-2-sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, and 3-alyloxy-2-hydroxypropanesulfonic acid. Furthermore, examples of monomers having a phosphate group include 2-(meth)acryloyloxyethyl phosphate, methyl-2-(meth)acryloyloxyethyl phosphate, and ethyl-(meth)acryloyloxyethyl phosphate. In this invention, (meth)allyl means allyl and / or methallyl, and (meth)acryloyl means acryloyl and / or methacryloyl. Among these, monomers containing acidic groups are preferably monomers having a carboxylic acid group, and among these, monocarboxylic acids are preferred, and (meth)acrylic acid is more preferred. Furthermore, the acid group-containing monomer may be used individually or in combination of two or more types in any ratio.

[0038] Furthermore, the proportion of acid group-containing monomer units in the core polymer is preferably 0.1% by mass or more, more preferably 1% by mass or more, preferably 15% by mass or less, and more preferably 10% by mass or less, based on 100% by mass of all repeating units (total monomer units) contained in the core polymer. By keeping the proportion of acid group-containing monomer units within the above range, the dispersibility of the core polymer can be improved during the preparation of the particulate polymer, and a shell portion that partially covers the outer surface of the core polymer can be easily formed.

[0039] Furthermore, it is preferable that the polymer in the core portion contains crosslinkable monomer units in addition to the above monomer units. A crosslinkable monomer is a monomer that can form a crosslinked structure during or after polymerization by heating or irradiation with energy rays.

[0040] Examples of crosslinkable monomers include polyfunctional monomers having two or more polymerization-reactive groups. Examples of such polyfunctional monomers include divinyl monomers such as divinylbenzene, 1,3-butadiene, isoprene, and allyl methacrylate; di(meth)acrylic acid ester monomers such as ethylene dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, and 1,3-butylene glycol diacrylate; tri(meth)acrylic acid ester monomers such as trimethylolpropane trimethacrylate and trimethylolpropane triacrylate; ethylenically unsaturated monomers containing epoxy groups such as allyl glycidyl ether and glycidyl methacrylate; and γ-methacryloxypropyltrimethoxysilane. Among these, di(meth)acrylic acid ester monomers are more preferred. Furthermore, these may be used individually or in combination of two or more in any ratio.

[0041] Furthermore, the proportion of crosslinkable monomer units in the core polymer is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, particularly preferably 0.4% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less, based on 100% by mass of all repeating units (total monomer units) contained in the core polymer. By keeping the proportion of crosslinkable monomer units within the above range, the battery components can be bonded together even more firmly via the adhesive layer.

[0042] [Shell section] -Glass transition temperature- The glass transition temperature of the polymer in the shell portion of the particulate polymer is preferably 50°C or higher, more preferably 53°C or higher, even more preferably 55°C or higher, even more preferably 60°C or higher, preferably 200°C or lower, more preferably 120°C or lower, and even more preferably 105°C or lower. If the glass transition temperature of the polymer in the shell portion is above the lower limit, the inkjet ejection characteristics can be further improved. On the other hand, if the glass transition temperature of the polymer in the shell portion is below the upper limit, the particulate polymer becomes moderately soft, allowing the battery components to be bonded more firmly to each other at room temperature via the adhesive layer. The glass transition temperature of the shell polymer can be adjusted, for example, by changing the type and proportion of monomers used in the preparation of the shell polymer.

[0043] Furthermore, the glass transition temperature of the polymer in the shell portion is preferably 25°C or more higher, and more preferably 50°C or more higher, than the glass transition temperature of the polymer in the core portion, from the viewpoint of maintaining the shape of the particulate polymer after bonding the battery components together and suppressing an increase in resistance.

[0044] -composition- Examples of monomers used to prepare the polymer of the shell portion include monomers similar to those exemplified as monomers that can be used to produce the polymer of the core portion. Furthermore, such monomers may be used individually or in combination of two or more types in any ratio.

[0045] Among these monomers, it is preferable to use at least one of (meth)acrylic acid ester monomers and aromatic vinyl monomers as monomers used in preparing the polymer of the shell portion, from the viewpoint of further strengthening the adhesion between battery components via the adhesive layer, and it is more preferable to use both (meth)acrylic acid ester monomers and aromatic vinyl monomers. In other words, it is preferable that the polymer of the shell portion contains at least one of (meth)acrylic acid ester monomer units and aromatic vinyl monomer units, and it is more preferable that it contains both (meth)acrylic acid ester monomer units and aromatic vinyl monomer units.

[0046] Furthermore, from the viewpoint of further strengthening the adhesion between battery components via the adhesive layer, the proportion of (meth)acrylic acid ester monomer units in the polymer of the shell portion is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 32.5% by mass or more, preferably 90% by mass or less, and more preferably 85% by mass or less, with the total repeating units (total monomer units) contained in the polymer of the shell portion being 100% by mass.

[0047] Furthermore, from the viewpoint of further strengthening the adhesion between battery components via the adhesive layer, the proportion of aromatic vinyl monomer units in the polymer of the shell portion is preferably 50% by mass or more, more preferably 65% ​​by mass or more, preferably 99% by mass or less, and more preferably 95% by mass or less, with the total repeating units (total monomer units) contained in the polymer of the shell portion being 100% by mass.

[0048] The polymer in the shell portion may contain acid group-containing monomer units in addition to (meth)acrylic acid ester monomer units and aromatic vinyl monomer units. Here, examples of acid group-containing monomers include monomers having acid groups, such as monomers having carboxylic acid groups, monomers having sulfonic acid groups, and monomers having phosphate groups. Specifically, examples of acid group-containing monomers include monomers similar to those that can be used to form the core portion. Among these, monomers containing acidic groups are preferably monomers having a carboxylic acid group, more preferably monocarboxylic acids, and even more preferably (meth)acrylic acid. Furthermore, the acid group-containing monomer may be used individually or in combination of two or more types in any ratio. Furthermore, the proportion of acid group-containing monomer units in the polymer of the shell portion is preferably 0.1% by mass or more, more preferably 0.4% by mass or more, even more preferably 0.7% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, with the total repeating units (total monomer units) contained in the polymer of the shell portion being 100% by mass. By keeping the proportion of acid group-containing monomer units within the above range, the dispersibility of the particulate polymer can be improved, and the battery components can be bonded together even more firmly via the adhesive layer.

[0049] Here, the polymer in the shell portion may contain hydroxyl group-containing monomer units. Examples of hydroxyl group-containing monomers that can form hydroxyl group-containing monomer units in the shell polymer include monomers similar to those used to form the core. Furthermore, the proportion of hydroxyl group-containing monomer units in the polymer of the shell portion is preferably 0.1% by mass or more, more preferably 0.4% by mass or more, even more preferably 0.7% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, with the total repeating units (total monomer units) contained in the polymer of the shell portion being 100% by mass. By keeping the proportion of hydroxyl group-containing monomer units within the above range, the dispersibility of the particulate polymer can be improved, and the battery components can be bonded together even more firmly via the adhesive layer.

[0050] Furthermore, the polymer in the shell portion may contain crosslinkable monomer units. Examples of crosslinkable monomers include those similar to those exemplified as crosslinkable monomers that can be used in the polymer in the core portion. Among these, di(meth)acrylic acid ester monomers and allyl methacrylate are preferred. In addition, one type of crosslinkable monomer may be used alone, or two or more types may be used in any ratio.

[0051] Furthermore, the proportion of crosslinkable monomer units in the polymer of the shell portion is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, preferably 4% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, with the total repeating units (total monomer units) contained in the polymer of the shell portion being 100% by mass.

[0052] [The mass ratio of the shell to the total mass of the core and shell] In particulate polymers having a core-shell structure, the mass ratio of the shell portion to the total mass of the core portion is preferably 2% by mass or more, preferably 15% by mass or less, and more preferably 10% by mass or less. If the mass ratio of the shell portion is above the lower limit, the inkjet ejection characteristics can be further improved. Furthermore, if the mass ratio of the shell portion is below the upper limit, the battery components can be bonded more firmly to each other under room temperature pressure, and the secondary battery can exhibit even better battery characteristics. Here, the mass ratio of the shell portion to the total mass of the core portion and shell portion is determined from the ratio of the thicknesses of the core portion and shell portion, which will be described later, and the specific gravity of the particulate polymer.

[0053] [Volume-average particle diameter of particulate polymers having a core-shell structure] The volume-average particle diameter of the particulate polymer having a core-shell structure is preferably 100 nm or more, more preferably 200 nm or more, preferably 1500 nm or less, more preferably 900 nm or less, even more preferably 800 nm or less, and even more preferably 700 nm or less. If the volume-average particle diameter of the particulate polymer having a core-shell structure is 100 nm or more, it is possible to suppress deterioration of battery characteristics due to increased resistance of the secondary battery caused by obstruction of the lithium ion path of the substrate (electrode or separator). Furthermore, if the volume-average particle diameter is 1500 nm or less, it is possible to further suppress nozzle clogging when the non-aqueous secondary battery adhesive layer composition is coated by the inkjet method, and improve inkjet ejection characteristics.

[0054] [Ratio of average shell thickness to volume-average particle diameter] The ratio of the average thickness of the shell portion to the volume-average particle diameter of a particulate polymer having a core-shell structure is preferably 0.1% or more, more preferably 0.5% or more, more preferably 15% or less, and more preferably 10% or less. If the average thickness of the shell portion is above the lower limit, the inkjet ejection characteristics can be further improved. Also, if the average thickness of the shell portion is below the upper limit, the battery components can be bonded together more firmly when the battery components are pressed at room temperature.

[0055] Here, the average thickness of the shell portion of a particulate polymer having a core-shell structure is determined by observing the cross-sectional structure of the particulate polymer having a core-shell structure using a transmission electron microscope (TEM). Specifically, the maximum thickness of the shell portion in the cross-sectional structure of the particulate polymer is measured using a TEM, and the average of the maximum thicknesses of the shell portions of 20 or more arbitrarily selected particulate polymer particles is taken as the average thickness of the shell portion. However, if the shell portion is composed of polymer particles, and the particles constituting the shell portion do not overlap in the radial direction of the particulate polymer particles, and these polymer particles constitute the shell portion as a single layer, then the number-average particle diameter of the particles constituting the shell portion is taken as the average thickness of the shell portion.

[0056] [Method for preparing particulate polymers having a core-shell structure] Furthermore, particulate polymers having the core-shell structure described above can be prepared, for example, by using monomers of the core polymer and monomers of the shell polymer, and polymerizing them stepwise while changing the ratio of these monomers over time. Specifically, particulate polymers can be prepared by a continuous multi-step emulsion polymerization method and a multi-step suspension polymerization method in which polymers from later stages sequentially coat polymers from earlier stages.

[0057] Therefore, the following is an example of how to obtain a particulate polymer having the above core-shell structure by a multi-step emulsion polymerization method.

[0058] During polymerization, according to conventional methods, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium dodecyl sulfate, nonionic surfactants such as polyoxyethylene nonylphenyl ether and sorbitan monolaurate, or cationic surfactants such as octadecylamine acetate can be used as emulsifiers. Furthermore, as polymerization initiators, peroxides such as t-butylperoxy-2-ethylhexanoate, potassium persulfate, and cumene peroxide, or azo compounds such as 2,2'-azobis(2-methyl-N-(2-hydroxyethyl)-propionamide) and 2,2'-azobis(2-amidinopropane) hydrochloride can be used.

[0059] The polymerization procedure involves first mixing the monomers that form the core and an emulsifier, and then performing emulsion polymerization in a single step to obtain particulate polymers that constitute the core. Furthermore, by polymerizing the monomers that form the shell in the presence of these particulate polymers that constitute the core, a particulate polymer having the aforementioned core-shell structure can be obtained.

[0060] In this case, when preparing a particulate polymer in which the outer surface of the core is partially covered by a shell, it is preferable to supply the monomers forming the shell polymer to the polymerization system in multiple portions or continuously. By supplying the monomers forming the shell polymer to the polymerization system in portions or continuously, the polymer constituting the shell is formed in particulate form, and these particles combine with the core to form a shell that partially covers the core.

[0061] <<Particulate polymer without core-shell structure>> [Glass transition temperature] Here, the glass transition temperature of the particulate polymer without a core-shell structure is preferably -40°C or higher, more preferably -35°C or higher, even more preferably -30°C or higher, preferably 0°C or lower, more preferably -10°C or lower, and even more preferably -20°C or lower. If the glass transition temperature of the particulate polymer without a core-shell structure is -40°C or higher, the battery components can be bonded together even more firmly via the adhesive material. On the other hand, if the glass transition temperature of the particulate polymer without a core-shell structure is 0°C or lower, the shedding of the particulate polymer from the substrate can be suppressed.

[0062] [composition] Monomers used to prepare particulate polymers without a core-shell structure include the same monomers exemplified above as monomers that can be used to produce the core polymer of particulate polymers having a core-shell structure. For example, (meth)acrylic acid ester monomers, aromatic vinyl monomers, acid group-containing monomers, and crosslinkable monomers are preferred as monomers used to prepare particulate polymers without a core-shell structure. Such monomers may be used individually or in combination of two or more types in any ratio.

[0063] In particulate polymers without a core-shell structure, the proportion of (meth)acrylic acid ester monomer units is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, with the total repeating units (total monomer units) contained in the polymer being 100% by mass, from the viewpoint of further strengthening the adhesion between battery components via the adhesive layer.

[0064] In particulate polymers without a core-shell structure, the proportion of aromatic vinyl monomer units is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on the total repeating units (total monomer units) contained in the polymer, with 100% by mass being the reference value for further strengthening the adhesion between battery components via the adhesive layer.

[0065] In particulate polymers without a core-shell structure, the proportion of acid group-containing monomer units is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of all repeating units (total monomer units) contained in the polymer. By keeping the proportion of acid group-containing monomer units in particulate polymers without a core-shell structure within the above range, the dispersibility of the particulate polymer can be improved.

[0066] In particulate polymers without a core-shell structure, the proportion of crosslinkable monomer units is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, based on the total repeating units (total monomer units) contained in the polymer being 100% by mass, from the viewpoint of further strengthening the adhesion between battery components via an adhesive layer.

[0067] [Volume-average particle diameter of particulate polymers without a core-shell structure] The volume-average particle diameter of the particulate polymer without a core-shell structure is preferably 50 nm or more, more preferably 100 nm or more, even more preferably 200 nm or more, preferably 600 nm or less, more preferably 500 nm or less, and even more preferably 400 nm or less. If the volume-average particle diameter of the particulate polymer without a core-shell structure is within the above predetermined range, the battery components can be bonded together even more firmly via the adhesive material.

[0068] [Content of particulate polymers that do not have a core-shell structure] The content of particulate polymers without a core-shell structure in the adhesive layer composition can be appropriately adjusted within the range in which the desired effects of the present invention can be obtained, but it is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more, per 100 parts by mass of particulate polymers having a core-shell structure. If the content of particulate polymers without a core-shell structure is above the above lower limit, the shedding of particulate polymers from the substrate can be suppressed.

[0069] [Method for producing particulate polymers without a core-shell structure] Particulate polymers without a core-shell structure are not particularly limited and can be prepared, for example, by polymerizing a monomer composition containing the above-mentioned monomers in an aqueous solvent such as water. Here, the proportion of each monomer in the monomer composition is usually the same as the proportion of each monomer unit in a particulate polymer without a core-shell structure. Furthermore, the polymerization method and polymerization reaction are not particularly limited and known polymerization methods and polymerization reactions can be used.

[0070] <<Electrolyte Swelling Degree>> The degree of swelling of particulate polymers in an electrolyte (a solution prepared by dissolving LiPF6 at a concentration of 1 mol / L in a mixed solvent of ethylene carbonate / diethyl carbonate in a volume ratio of 3 / 7) is not specified, but it is preferable that they do not dissolve in the electrolyte. If they dissolve, there is a concern that the battery characteristics may deteriorate. The degree of swelling of the particulate polymer in relation to the above electrolyte can be measured by the method described in the examples of this specification.

[0071] <Solvent> The solvent used to disperse the above-mentioned particulate polymer is not particularly limited, but for example, water, organic solvents, and mixtures thereof can be used. Examples of organic solvents are not particularly limited, but include cyclic aliphatic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; ketones such as ethyl methyl ketone and cyclohexanone; esters such as ethyl acetate, butyl acetate, γ-butyrolactone, and ε-caprolactone; nitriles such as acetonitrile and propionitrile; ethers such as tetrahydrofuran and ethylene glycol diethyl ether; and alcohols such as methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, and ethylene glycol monomethyl ether. Among the options mentioned above, using water is preferable from the standpoint of simplifying the equipment. At least a portion of the solvent described above may be removed by drying or other means during the manufacturing process of the laminate for non-aqueous secondary batteries.

[0072] <Other ingredients> Other components that can be optionally included in the non-aqueous secondary battery adhesive layer composition of the present invention are not particularly limited, but include, for example, surface tension modifiers, dispersants different from the dispersant used in the polymerization described above, viscosity modifiers, reinforcing materials, and electrolyte additives. These are not particularly limited as long as they do not affect the battery reaction, and known components, such as those described in International Publication No. 2012 / 115096, can be used. These components may be used individually or in combination of two or more in any ratio.

[0073] <Method for preparing a composition for a non-aqueous secondary battery adhesive layer> The method for preparing the composition for the non-aqueous secondary battery adhesive layer of the present invention is not particularly limited, and for example, it can be prepared by stirring and mixing a particulate polymer with any other component in the presence of a solvent. Here, the stirring and mixing method is not particularly limited and can be carried out by known methods. Specifically, a general stirring vessel, ball mill, sand mill, bead mill, pigment disperser, ultrasonic disperser, lye crusher, homogenizer, planetary mixer, film mixer, etc., can be used. The mixing conditions are not particularly limited, but can usually be carried out in a range of room temperature or above 80°C for 10 minutes or more and for several hours or less.

[0074] (Adhesive layer for non-aqueous secondary batteries) The adhesive layer for non-aqueous secondary batteries of the present invention is obtained using the composition for adhesive layers for non-aqueous secondary batteries of the present invention. Furthermore, the adhesive layer for non-aqueous secondary batteries of the present invention functions as an adhesive material for bonding battery components used in non-aqueous secondary batteries together. The adhesive layer for non-aqueous secondary batteries of the present invention can be obtained, for example, by the method for manufacturing the adhesive layer for non-aqueous secondary batteries of the present invention, as described later. Here, the adhesive layer for non-aqueous secondary batteries of the present invention is a dried product obtained by drying the composition for the adhesive layer of non-aqueous secondary batteries of the present invention. Therefore, the adhesive layer for non-aqueous secondary batteries of the present invention contains at least the particulate polymer described above, and optionally contains the other components described above.

[0075] Furthermore, while the particulate polymer exists in particle form in the composition for the adhesive layer of a non-aqueous secondary battery, it may be in particle form or any other arbitrary shape in the adhesive layer of a non-aqueous secondary battery.

[0076] The shape of the adhesive layer is not particularly limited and can be formed into any planar shape such as stripes, dots, or a grid. In particular, from the viewpoint of reducing the resistance of the secondary battery, it is preferable to form the adhesive layer in a dot shape. A dot-shaped adhesive layer can be obtained, for example, by an inkjet method using a coating machine (51-54 in Figure 2) described later.

[0077] The diameter of the dots in the adhesive layer, which are arranged in a dot-like pattern, is preferably 10 μm or more, more preferably 20 μm or more, preferably 300 μm or less, and more preferably 200 μm or less. If the diameter of the dots in the adhesive layer is above the lower limit, the adhesive strength between the electrode and the separator can be increased. On the other hand, if the diameter of the dots in the adhesive layer is below the upper limit, the decrease in the output characteristics of the secondary battery can be suppressed.

[0078] The thickness of the dots in the adhesive layer, which are arranged in a dot-like pattern, is preferably 5 μm or more. If the thickness of the dots in the adhesive layer is greater than or equal to the lower limit mentioned above, the adhesive strength between the electrode and the separator can be increased.

[0079] Furthermore, the basis weight of the adhesive layer is 0.02 g / m². 2 Preferably, it should be 1.0 g / m 2 Preferably, it is 0.35 g / m 2 The following is more preferable: If the basis weight of the adhesive layer is above the lower limit, sufficient adhesion between the electrode and the separator can be ensured. Also, if the basis weight of the adhesive layer is below the upper limit, sufficiently high output characteristics of the secondary battery can be ensured.

[0080] Furthermore, the coverage rate of the adhesive layer is preferably 1% or more, more preferably 5% or more, preferably 50% or less, and more preferably 30% or less. If the coverage rate of the adhesive layer is above the lower limit, the adhesive strength between the electrode and the separator can be ensured. Also, if the coverage rate of the adhesive layer is below the upper limit, the output characteristics of the secondary battery can be ensured to be sufficiently high.

[0081] Here, "adhesive layer coverage rate" on a given surface or region refers to the ratio of the area covered by the adhesive layer to the total area of ​​that surface or region [(Area covered by the adhesive layer / Total area of ​​the surface or region) × 100 (%)]. Furthermore, when using an adhesive layer composition containing particulate polymer and solvent, "adhesive layer" in "coverage rate of adhesive layer" refers to the dried product of the adhesive layer composition.

[0082] The coverage of the adhesive layer can be adjusted by changing the arrangement pattern of the adhesive layer placed (coated) in each region. Specifically, if the adhesive layer is arranged (coated) in a region in a dot-like pattern, the coverage of the adhesive layer in that region can be adjusted by changing the radius and the distance between the centers of the dots in the adhesive layer. For example, in a region where the adhesive layer is arranged (coated) in a dot-like pattern with dots formed at regular intervals in two orthogonal directions, the coverage of the adhesive layer can be calculated using the following formula (2), with the distance between the centers (pitch) x and y of the dots and the radius r of the dots. Coverage of the adhesive layer = {πr 2 / (x·y)} × 100(%)···(2)

[0083] (Method for manufacturing adhesive layers for non-aqueous secondary batteries) The present invention provides a method for manufacturing an adhesive layer for non-aqueous secondary batteries, comprising the steps of: coating the non-aqueous adhesive layer composition of the present invention onto the surface of a substrate by an inkjet method (coating step); and drying the non-aqueous adhesive layer composition coated on the substrate (drying step). The present invention also provides a method for manufacturing an adhesive layer for non-aqueous secondary batteries, which may include a step of peeling off the non-aqueous adhesive layer formed on the substrate after the drying step (peeling step). Here, when the adhesive layer for non-aqueous secondary batteries is formed on an electrode substrate or separator substrate as a base material, the electrode substrate and the separator substrate can be directly bonded together to form a laminate. Also, when the adhesive layer for non-aqueous secondary batteries is formed on a release substrate as a base material, the adhesive layer for non-aqueous secondary batteries can be peeled off the release agent and then used to bond the electrode substrate and the separator substrate.

[0084] <Coating Process> In the coating process, droplets of the non-aqueous secondary battery adhesive layer composition of the present invention are coated onto substrates such as electrode substrates, separator substrates, and release substrates via the nozzles of an inkjet coating machine. Conventional inkjet coating machines can be used, and coating can be performed using, for example, the coating machines described later (51-54 in Figure 2). From the viewpoint of manufacturing efficiency, it is preferable to coat the non-aqueous secondary battery adhesive layer composition onto the electrode substrate or separator substrate, and from the viewpoint of facilitating the drying process, it is preferable to coat the non-aqueous secondary battery adhesive layer composition onto the electrode substrate. The coating conditions by the inkjet method are not particularly limited as long as the non-aqueous secondary battery adhesive layer composition can be coated onto the substrate, and can be appropriately adjusted according to the desired form of the resulting adhesive layer (planar shape, dot diameter, dot thickness, dot pitch, coverage, basis weight, etc.).

[0085] <<Electrode base material>> The electrode substrate is not particularly limited, and any known electrode substrate can be used. For example, the electrode substrate can be an electrode made of an electrode substrate having an electrode composite layer formed on one or both sides of a current collector, or an electrode having a porous film layer further formed on the electrode composite layer of the electrode substrate. Furthermore, the current collector, electrode composite layer, and porous film layer are not particularly limited, and any current collector, electrode composite layer, and porous film layer that can be used in the field of secondary batteries can be used, such as those described in Japanese Patent Application Publication No. 2013-145763.

[0086] <<Separator Substrate>> The separator substrate is not particularly limited, and known separator substrates such as organic separator substrates can be used. Organic separator substrates are porous members made of organic materials. Examples of organic separator substrates include microporous membranes or nonwoven fabrics containing polyethylene, polyolefin resins such as polypropylene, and aromatic polyamide resins. Microporous membranes or nonwoven fabrics made of polyethylene are preferred due to their excellent strength. Furthermore, from a safety standpoint, heat-resistant separators coated with ceramic on the above separator are preferred. Furthermore, the separator substrate may have a porous film layer formed on one or both sides. The porous film layer refers to a layer containing non-conductive particles, such as the one described in Japanese Patent Application Publication No. 2013-145763.

[0087] <<Release base material>> The release agent is not particularly limited, and any known agent can be used.

[0088] <Drying process> In the drying process, the adhesive layer composition coated onto the substrate is dried to form an adhesive layer on the substrate consisting of the dried adhesive layer composition. The drying method is not particularly limited and known methods can be used. Examples of drying methods include drying using heating devices such as heaters, dryers, and heat rollers. The drying conditions are not particularly limited, but the drying temperature is preferably 50°C to 90°C, and the drying time is preferably 1 second to 120 seconds.

[0089] <Peeling process> In the peeling process, the adhesive layer for non-aqueous secondary batteries formed on the substrate is peeled off. If the adhesive layer for non-aqueous secondary batteries is formed on a release substrate, the adhesive layer can be peeled off the release substrate and used, for example, in the manufacture of a laminate for non-aqueous secondary batteries, as described later.

[0090] (Laminate for non-aqueous secondary batteries) The laminate for a non-aqueous secondary battery of the present invention is a laminate for a non-aqueous secondary battery comprising electrodes and a separator, wherein the electrodes and the separator are bonded together via the non-aqueous secondary battery adhesive layer of the present invention described above. Here, the electrodes that constitute the laminate for a non-aqueous secondary battery when bonded to the separator may be only a positive electrode, only a negative electrode, or both a positive and a negative electrode. Furthermore, when obtaining a laminate for a non-aqueous secondary battery by bonding both a positive and a negative electrode to a separator, the number of positive electrodes, negative electrodes, and separators in the laminate for a non-aqueous secondary battery may be one, two or more, respectively. In other words, the structure of the laminate for a non-aqueous secondary battery of the present invention may be any of the following (1) to (6). (1) Positive electrode / separator (2) Negative electrode / separator (3) Positive electrode / separator / negative electrode (4) Positive electrode / Separator / Negative electrode / Separator (5) Separator / Positive electrode / Separator / Negative electrode (6) A structure in which multiple positive and negative electrodes are alternately stacked with separators in between (for example, "separator / negative electrode / separator / positive electrode / separator / negative electrode... / separator / positive electrode", etc.)

[0091] <Electrode> The electrodes are not particularly limited, and known electrodes can be used; for example, those described in the section "Method for Manufacturing an Adhesive Layer for Non-Aqueous Secondary Batteries" can be used.

[0092] <Separator> The separator is not particularly limited, and any known separator can be used; for example, the one described in the section "Method for Manufacturing an Adhesive Layer for Non-Aqueous Secondary Batteries" can be used.

[0093] <Adhesive layer> The adhesive layer that bonds the electrode and the separator is, as described above, a dried product of the adhesive layer composition for non-aqueous secondary batteries of the present invention. That is, the dried product contains at least a polymer derived from particulate polymer, and optionally contains the other components described above. Furthermore, the preferred morphology of the adhesive layer (dot diameter, dot thickness, dot pitch, coverage, basis weight, etc.) is the same as that described in the section on <Adhesive Layer for Non-Aqueous Secondary Batteries>. Furthermore, while the particulate polymer exists in particle form in the composition for the adhesive layer of a non-aqueous secondary battery, in the adhesive layer of the laminate, it may be in particle form or any other arbitrary shape.

[0094] (Method for manufacturing laminates for non-aqueous secondary batteries) The present invention provides a method for manufacturing a laminate for a non-aqueous secondary battery, comprising the steps of: supplying an adhesive material to at least one bonding surface of an electrode and a separator (i.e., the surface forming the adhesive layer) (supply step); and bonding the electrode and the separator together at room temperature by pressurizing them through the bonding surface to which the adhesive material has been supplied (bonding step). The present invention also provides a method for manufacturing a laminate for a non-aqueous secondary battery, which may include a step of cutting the resulting laminate after the bonding step (cutting step).

[0095] <Supply process> In the supply process, adhesive material is supplied to the bonding surface of at least one of the electrodes (positive electrode, negative electrode) and the separator. The adhesive material can be supplied by coating the non-aqueous secondary battery adhesive layer composition of the present invention by an inkjet method and drying it. Alternatively, the adhesive material may be supplied by transferring (laminating) the non-aqueous secondary battery adhesive layer obtained by peeling it off the release substrate as described above onto the bonding surface.

[0096] The conditions for the inkjet method are not particularly limited as long as it is possible to coat the non-aqueous secondary battery adhesive layer composition, and can be appropriately adjusted according to the desired form of the resulting adhesive material (planar shape, dot diameter, dot thickness, dot pitch, coverage, basis weight, etc.).

[0097] When a non-aqueous secondary battery adhesive layer composition is applied by inkjet printing, the electrode and separator can be transported to the bonding start position without contacting other components to the bonding surface to which the non-aqueous secondary battery adhesive layer composition is supplied, while the non-aqueous secondary battery adhesive layer composition is dried during transport. Since other components are not allowed to contact the bonding surface to which the non-aqueous secondary battery adhesive layer composition is supplied, problems such as blocking do not occur, and the secondary battery laminate can be manufactured efficiently. When supplying a non-aqueous secondary battery adhesive layer obtained by peeling it off a release substrate, drying is not necessary. In this invention, the term "bonding start position" refers to the position where the bonding surface of the electrode and the bonding surface of the separator come into contact when bonding the electrode and the separator.

[0098] The transport of electrodes and separators is not particularly limited and can be carried out using any transport mechanism such as rollers, belt conveyors, manipulators, or suction bands. In particular, from the viewpoint of further improving the manufacturing efficiency of laminates for secondary batteries, it is preferable to transport at least one of the electrodes and separators using rollers.

[0099] Furthermore, the drying of the non-aqueous secondary battery adhesive layer composition can be carried out using a heating device such as a heater, dryer, or heat roller, without any particular limitations. The temperature of the electrode and / or separator to which the non-aqueous secondary battery adhesive layer composition is supplied during drying is not particularly limited, but is preferably 50°C to 90°C. The drying time is also not particularly limited, but is preferably 1 second to 120 seconds.

[0100] <Bonding process> In the bonding process, the electrode and separator are bonded together via the bonding surface. Bonding is performed by applying pressure to the laminate of the electrode and separator, which are stacked together via the bonding surface, at room temperature.

[0101] The pressure applied when pressurizing the laminate can be adjusted as appropriate depending on the type and amount of particulate polymer used, but it is preferably greater than 1 MPa and less than or equal to 5 MPa.

[0102] <Cutting process> The cutting process involves cutting the bonded body obtained in the bonding process to the desired dimensions. Any cutting machine that can be used in the field of secondary battery manufacturing can be used for cutting, such as a cutting machine that cuts the bonded body by sandwiching it between cutting blades from both sides in the thickness direction.

[0103] <<Electrodes and Separators>> The electrodes and separators are not particularly limited, and known electrodes and separators can be used. For example, the electrodes and separators described in the section "Method for Manufacturing an Adhesive Layer for Non-Aqueous Secondary Batteries" can be used.

[0104] <<Adhesive material>> The adhesive material used to bond the electrode and the separator is a dried product of the adhesive layer composition for non-aqueous secondary batteries of the present invention. That is, the dried product contains at least a polymer derived from particulate polymers and optionally contains the other components mentioned above. Furthermore, the preferred form of the adhesive material (dot diameter, dot thickness, dot pitch, coverage, basis weight, etc.) is the same as that described in the section on <Adhesive layer for non-aqueous secondary batteries>. Furthermore, while the particulate polymer exists in particle form in the non-aqueous secondary battery adhesive layer composition, in the non-aqueous secondary battery adhesive layer of the laminate after pressurization, it may be in particle form or any other arbitrary shape.

[0105] An example of the manufacturing process for the laminate for non-aqueous secondary batteries of the present invention will be described below with reference to Figure 2. Referring to Figure 2, a long first separator roll 10A, unwound from a first separator roll, is bonded to one surface of the negative electrode material, which consists of a long negative electrode roll 20A unwound from a negative electrode roll, via adhesive material supplied from a coating machine 51. At the same time, a long second separator roll 30A, unwound from a second separator roll, is bonded to the other surface of the negative electrode material, which consists of the negative electrode roll 20A, via adhesive material supplied from a coating machine 52. The bonding can be performed, for example, using pressure rollers 61 and 62. Then, the positive electrode 40 is bonded to the surface of the first separator roll 10A opposite to the negative electrode roll 20A side via adhesive material supplied from a coating machine 53 at a predetermined arrangement pitch, thereby obtaining a bonded body with a positive electrode. In Figure 2, adhesive material is supplied from the coating machine 54 to the surface of the second separator roll 30A opposite to the negative electrode roll 20A side, and the laminates obtained by cutting the bonded body between adjacent positive electrodes 40 in the longitudinal direction are stacked to create a laminated body, ensuring good adhesion between the laminates. Then, the bonded body is cut using the cutting machine 70 to obtain a laminate.

[0106] (Non-aqueous secondary battery) The non-aqueous secondary battery of the present invention comprises a laminate for non-aqueous secondary batteries of the present invention. The non-aqueous secondary battery of the present invention comprises, for example, electrodes (positive electrode and negative electrode), an electrolyte, and a separator. At least one of the positive electrode and the negative electrode and the separator are bonded together via an adhesive layer for non-aqueous secondary batteries of the present invention, forming a laminate for non-aqueous secondary batteries of the present invention. Because the non-aqueous secondary battery of the present invention comprises a laminate for non-aqueous secondary batteries of the present invention, it can exhibit excellent battery characteristics.

[0107] <Electrode> The electrodes used in the secondary battery of the present invention are not limited, and known electrodes can be used, for example, those described in the section "Method for manufacturing an adhesive layer for a non-aqueous secondary battery" can be used.

[0108] <Separator> The separator used in the secondary battery of the present invention is not limited, and known separators can be used, for example, those described in the section "Method for manufacturing an adhesive layer for a non-aqueous secondary battery" can be used.

[0109] <Electrolyte> The electrolyte used in the secondary battery of the present invention is typically an organic electrolyte obtained by dissolving a support electrolyte in an organic solvent. For example, if the non-aqueous secondary battery is a lithium-ion secondary battery, a lithium salt is used as the support electrolyte. Examples of lithium salts include LiPF6, LiAsF6, LiBF4, LiSbF6, LiAlCl4, LiClO4, CF3SO3Li, C4F9SO3Li, CF3COOLi, (CF3CO)2NLi, (CF3SO2)2NLi, and (C2F5SO2)NLi. Among these, LiPF6, LiClO4, and CF3SO3Li are preferred, and LiPF6 is particularly preferred, because they are easily soluble in the solvent and exhibit a high degree of dissociation. Note that one type of electrolyte may be used alone, or two or more types may be used in any ratio. Generally, lithium ion conductivity tends to increase as the support electrolyte with a higher degree of dissociation is used, so lithium ion conductivity can be adjusted by the type of support electrolyte.

[0110] Furthermore, the organic solvent used in the electrolyte is not particularly limited as long as it can dissolve the supporting electrolyte, but suitable examples include carbonates such as dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), butylene carbonate (BC), and ethyl methyl carbonate (EMC); esters such as γ-butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane and tetrahydrofuran; and sulfur-containing compounds such as sulfolane and dimethyl sulfoxide. A mixture of these solvents may also be used. Among these, carbonates are preferred because they have a high dielectric constant and a wide stable potential range, and a mixture of ethylene carbonate and ethyl methyl carbonate is even more preferred. Furthermore, known additives such as vinylene carbonate (VC), fluoroethylene carbonate (FEC), and ethylmethyl sulfone may be added to the electrolyte.

[0111] (Manufacturing method for secondary batteries) The secondary battery of the present invention can be manufactured, for example, by stacking laminates to obtain a laminated body, winding or folding it as needed according to the battery shape, placing it in a device container (battery container), injecting an electrolyte into the device container, and sealing it. The laminated body may be the laminate itself, or it may be manufactured by stacking multiple laminates. The laminated body may also be made by stacking a laminate with additional battery components (electrodes and / or separators, etc.). Furthermore, the secondary battery of the present invention may be provided with a fuse, an overcurrent prevention element such as a PTC element, expanded metal, lead plates, etc., as needed, to prevent internal pressure rise, overcharging and discharging, etc. The shape of the secondary battery may be, for example, coin-shaped, button-shaped, sheet-shaped, cylindrical, rectangular, flat, etc. [Examples]

[0112] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" used to express quantities refer to mass unless otherwise specified. Furthermore, in polymers produced by copolymerizing multiple types of monomers, the proportion of a monomer unit formed by polymerizing a certain monomer in the polymer is, unless otherwise specified, usually equal to the ratio (starting ratio) of that particular monomer to the total monomers used in the polymerization of the polymer. Various measurements and evaluations in the examples and comparative examples were performed by the following methods.

[0113] <Glass transition temperature> Samples were prepared by drying aqueous dispersions of particulate polymers prepared in each manufacturing example at 130°C for 1 hour. 10 mg of the sample was weighed into an aluminum pan, and measurements were performed using a differential thermal analysis analyzer (EXSTAR DSC6220, manufactured by SII Nanotechnology Co., Ltd.) within the measurement temperature range of -100°C to 200°C at a heating rate of 10°C / min, under the conditions specified in JIS Z8703, to obtain differential scanning calorimetry (DSC) curves. An empty aluminum pan was used as a reference. During this heating process, the glass transition temperature (°C) was determined by finding the intersection of the baseline just before the endothermic peak of the DSC curve (where the differential signal (DDSC) is 0.05 mW / min / mg or higher) and the tangent to the DSC curve at the first inflection point after the endothermic peak.

[0114] <Volume-average particle size> The volume-average particle diameter of the particulate polymers prepared in each manufacturing example was measured by laser diffraction. Specifically, an aqueous dispersion solution (solid content concentration 0.1% by mass) containing the prepared particulate polymer was used as the sample, and the volume-average particle diameter D50 (nm) was determined by the particle size at which the cumulative volume calculated from the smallest diameter side in the particle size distribution (volume-based) obtained using a laser diffraction particle size distribution analyzer (Beckman Coulter, product name "LS-13 320").

[0115] <Electrolyte swelling degree> The aqueous dispersions of particulate polymers prepared in each manufacturing example were dried, and approximately 0.2 g of the resulting dry material was pressed for 2 minutes at a temperature of 200°C and a pressure of 5 MPa to obtain a film. The obtained film was cut into 1 cm squares to form test pieces, and the mass W2 (g) of each test piece was measured. Next, the test pieces were immersed in an electrolyte solution (a solution in which LiPF6 was dissolved at a concentration of 1 mol / L in a mixed solvent of ethylene carbonate / diethyl carbonate = 3 / 7 by volume) at a temperature of 60°C for 72 hours. After that, the test pieces were removed from the electrolyte solution, the mixed solvent on the surface was wiped off, and the mass W3 (g) of the test piece was measured. The degree of swelling (%) was then calculated according to the following formula. Electrolyte swelling degree (%) = W3 / W2 × 100

[0116] <Weight of the adhesive layer> The basis weight of the adhesive layer was determined from the difference in mass per unit area on the substrate before supplying the adhesive layer composition and after supplying and drying the adhesive layer composition.

[0117] <Coverage rate of the adhesive layer> Using a laser microscope (Keyence VR-3100), the distance between the centers of the dots (pitch) x and y, as well as the radius r of the dots, were measured in a region where the adhesive material was arranged (coated) in a dot pattern. These values ​​were then used to determine the coverage of the adhesive layer using the following equation (2). Coverage of the adhesive layer = {πr 2 / (x·y)} × 100(%)···(2)

[0118] <Pressure sensitivity of adhesive strength> The non-aqueous secondary battery adhesive layer compositions prepared in each example and comparative example were applied to the rough side of a PET substrate (PTHA-25 polyester film manufactured by Unitika Corporation) using a bar coater, and then dried at 50°C for 2 minutes. After drying, the basis weight on the PET substrate was 4-5 g / m². 2 A thin film was formed. After punching it out to 10 x 50 mm, it was placed on top of a PE separator (Asahi Kasei ND412, surface roughness Sa: 0.10~0.20 μm) cut to 25 x 60 mm, and pressed in a precision press machine at a temperature of 25°C, a pressure of 1 MPa, and a pressing time of 10 seconds to obtain an evaluation sample. Subsequently, the evaluation sample was fixed to the base of a peel test device (load cell) with the PE separator side attached with double-sided tape, and the PET substrate was pulled at a speed of 50 mm / min at a peel angle of 90° to measure the peel strength. The peel strength was similarly measured for evaluation samples that were precision pressed at a temperature of 25°C, a pressure of 3 MPa, and a pressing time of 10 seconds. The difference between the peel strength when pressed at a pressure of 3 MPa and the peel strength when pressed at a pressure of 1 MPa, divided by 2, was defined as the "pressure sensitivity".

[0119] <Inkjet ejection characteristics> Discharge tests were conducted on the non-aqueous secondary battery adhesive layer compositions prepared in each example and comparative example using a high-performance discharge test kit (IJK-200S, Microjet Corporation). The discharge characteristics were then evaluated according to the following criteria. A: Dispensing is possible, and re-dispensing is possible even after standing for more than 5 minutes. B: Dispensing is possible, but after a standing time of 5 minutes, re-dispensing becomes impossible. C: Unable to discharge

[0120] <Adhesion strength between electrodes and separators> Under the same conditions as in each example and comparative example, a negative electrode and a separator, each coated with an adhesive layer (adhesive material) on one side, were pressed for 10 seconds at a temperature of 25°C and a pressure of 2 MPa. The resulting laminate (i.e., a laminate consisting of one negative electrode and one separator bonded together via the adhesive material) was taken and used as a test specimen. The test specimen was placed with the negative electrode current collector side facing downwards, and cellophane tape was attached to the negative electrode current collector side surface. The cellophane tape used was the type specified in JIS Z1522. The cellophane tape was fixed to a horizontal test stand. The stress was then measured when one end of the separator was pulled vertically upwards at a tensile speed of 50 mm / min and peeled off. This measurement was performed a total of six times, and the average stress value was determined as the peel strength. The adhesion between the negative electrode and the separator was then evaluated according to the following criteria. A higher peel strength indicates better adhesion between the electrode (negative electrode) and the separator. A: Peel strength of 5.0 N / m or more B: Peel strength of 3.0 N / m or more and less than 5.0 N / m C: Peel strength of 1.0 N / m or more and less than 3.0 N / m D: Peel strength of 0.5 N / m or more and less than 1.0 N / m E: Peel strength less than 0.5 N / m

[0121] <Lithium deposition rate on the negative electrode surface> The manufactured lithium-ion secondary batteries were fully charged to 100% depth of charge (SOC) at a constant current of 1C in an environment of -10°C. The fully charged secondary batteries were then disassembled, the negative electrodes were removed, and the surface condition of the negative electrode composite layer was observed. The area of ​​lithium deposited on the surface of the negative electrode composite layer was measured, and the lithium deposition rate on the negative electrode surface was calculated as follows: Lithium deposition rate on the negative electrode surface = (Area of ​​deposited lithium / Surface area of ​​the negative electrode composite layer) × 100 (%). This was then evaluated according to the following criteria: A lower lithium deposition rate on the negative electrode surface indicates that lithium deposition on the negative electrode surface during charging is suppressed. A: Lithium deposition rate is less than 10% B: Lithium deposition rate is 10% or more but less than 15% C: Lithium deposition rate is 15% or more but less than 20% D: Lithium deposition rate is 20% or higher

[0122] <Output Characteristics> The fabricated lithium-ion secondary batteries were charged to 4.3V using constant current constant voltage (CCCV) in an atmosphere of 25°C to prepare the cells. The prepared cells were discharged to 3.0V in an atmosphere of -10°C using the constant current method at 0.2C and 1C, and their capacitance was determined. The discharge capacity retention rate, expressed as the capacitance ratio (= (capacity at 1C / capacitance at 0.2C) × 100 (%)), was then calculated. These measurements were performed on five lithium-ion secondary battery cells, and the average value of the calculated discharge capacity retention rate was evaluated as the output characteristic according to the following criteria. A larger value indicates superior output characteristics. A: The average discharge capacity retention rate is 80% or higher. B: The average discharge capacity retention rate is 70% or more but less than 80%. C: The average discharge capacity retention rate is between 60% and 70%. D: The average discharge capacity retention rate is less than 60%.

[0123] <Increase in resistance during cycle testing> The fabricated lithium-ion secondary battery was fastened with a pressure jig to achieve a surface pressure of 1 MPa, and then a cycle test was performed at 45°C. The cycle test conditions were 1C CC+CV charging (4.3V, 1 / 50C Cut) and 1C CC discharge (3.0V Cut), and the charge-discharge cycle was repeated 500 times. After that, with the pressure jig still fastened, the temperature was lowered to 25°C, and the output characteristics were measured in the same manner as described above for <Output Characteristics>. The resistance retention rate (%) before and after the cycle (= discharge capacity retention rate after cycle test / discharge capacity retention rate before cycle test × 100) was calculated and evaluated according to the following criteria. A higher resistance retention rate before and after the cycle indicates a smaller increase in resistance during the cycle test. A: Resistivity maintenance ratio of 80% or higher B: Resistivity maintenance ratio is 60% or more but less than 80% C: Resistivity maintenance rate is between 40% and 60% D: Resistivity maintenance rate is less than 40%

[0124] (Manufacturing Example 1) <Production of particulate polymer 1> In a reactor equipped with a stirrer, 100 parts of deionized water and 0.3 parts of ammonium persulfate were supplied, the gas phase was replaced with nitrogen gas, and the temperature was raised to 80°C. Meanwhile, in a separate container, 40 parts of deionized water, 0.2 parts of sodium dodecylbenzenesulfonate as an emulsifier, 28.3 parts of styrene as an aromatic monovinyl monomer, 66.6 parts of 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts of methacrylic acid as an acidic group-containing monomer, and 0.1 parts of ethylene glycol dimethacrylate as a crosslinkable monomer were mixed to obtain a monomer composition for forming the core. This monomer composition for forming the core was continuously added to the reactor over 3 hours, and a polymerization reaction was carried out at a temperature of 80°C. Polymerization was continued until the polymerization conversion rate reached 95%, obtaining an aqueous dispersion containing particulate polymers that constitute the core. Next, a monomer composition for forming a shell, containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer, was continuously supplied to this aqueous dispersion over 60 minutes to continue polymerization. When the polymerization conversion rate reached 98%, the reaction was stopped by cooling to prepare an aqueous dispersion containing particulate polymer 1. The volume-average particle size, degree of swelling, and glass transition temperature of the obtained particulate polymer 1 were measured. The results are shown in Table 1. Furthermore, by observing the cross-sectional structure of the particulate polymer using a transmission electron microscope (TEM), it was confirmed that the particulate polymer has a core-shell structure in which the shell portion partially covers the outer surface of the core portion.

[0125] (Manufacturing example 2) <Production of particulate polymer 2> In the production of the particulate polymer of Production Example 1, an aqueous dispersion of particulate polymer 2 having a core-shell structure was prepared in the same manner as in Production Example 1, except that 0.02 parts of sodium dodecylbenzenesulfonate as an emulsifier was added to 100 parts of ion-exchanged water and 0.3 parts of ammonium persulfate in a reactor equipped with a stirrer. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0126] (Manufacturing Example 3) <Production of particulate polymer 3> An aqueous dispersion of particulate polymer 3 having a core-shell structure was prepared in the same manner as in Production Example 2, except that the amount of sodium dodecylbenzenesulfonate added to the reactor equipped with a stirrer was changed from 0.02 parts to 0.04 parts. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0127] (Manufacturing example 4) <Production of particulate polymer 4> In the production of the particulate polymer of Production Example 2, an aqueous dispersion of particulate polymer 4 having a core-shell structure was prepared in the same manner as in Production Example 2, except that a monomer composition for forming the shell portion containing 1.9 parts of styrene as an aromatic monovinyl monomer and 0.1 parts of methacrylic acid as an acidic group-containing monomer was used instead of the monomer composition for forming the shell portion containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer. Various measurements were then performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0128] (Manufacturing example 5) <Production of particulate polymer 5> In the production of the particulate polymer of Production Example 2, instead of a core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, the following was used: 27.4 parts styrene as an aromatic monovinyl monomer, 64.5 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and crosslinkable An aqueous dispersion of particulate polymer 5 having a core-shell structure was prepared in the same manner as in Production Example 2, except that a monomer composition for forming the core containing 0.1 parts of ethylene glycol dimethacrylate as a neutral monomer was used, and instead of a monomer composition for forming the shell containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer, a monomer composition for forming the shell containing 4.9 parts of styrene as an aromatic monovinyl monomer and 0.1 parts of methacrylic acid as an acidic group-containing monomer was used. Various measurements were then performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0129] (Manufacturing example 6) <Production of particulate polymer 6> In the production of the particulate polymer of Production Example 2, instead of a core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, the composition contains 24.5 parts styrene as an aromatic monovinyl monomer, 57.9 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, and 2.5 parts methacrylic acid as an acidic group-containing monomer. An aqueous dispersion of particulate polymer 6 having a core-shell structure was prepared in the same manner as in Production Example 2, except that a monomer composition for forming the core portion containing 0.1 parts of ethylene glycol dimethacrylate as a crosslinking monomer was used, and instead of a monomer composition for forming the shell portion containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer, a monomer composition for forming the shell portion containing 14.8 parts of styrene as an aromatic monovinyl monomer and 0.2 parts of methacrylic acid as an acidic group-containing monomer was used. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0130] (Manufacturing example 7) <Production of particulate polymer 7> In the production of the particulate polymer of Production Example 2, instead of a core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, the composition is replaced with 31.1 parts styrene as an aromatic monovinyl monomer, 63.8 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and crosslinkable An aqueous dispersion of particulate polymer 7 having a core-shell structure was prepared in the same manner as in Production Example 2, except that a monomer composition for forming the core containing 0.1 parts of ethylene glycol dimethacrylate as a monomer was used, and instead of a monomer composition for forming the shell containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer, a monomer composition for forming the shell containing 1.9 parts of styrene as an aromatic monovinyl monomer and 0.1 parts of methacrylic acid as an acidic group-containing monomer was used. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0131] (Manufacturing example 8) <Production of particulate polymer 8> In the production of the particulate polymer of Production Example 2, instead of a core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, the composition contains 18.9 parts styrene as an aromatic monovinyl monomer, 75.2 parts butyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 2.9 parts methacrylic acid as an acidic group-containing monomer, and a crosslinkable monomer. An aqueous dispersion of particulate polymer 8 having a core-shell structure was prepared in the same manner as in Production Example 2, except that a monomer composition for forming the core containing 1 part of ethylene glycol dimethacrylate as a monomer was used, and instead of a monomer composition for forming the shell containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer, a monomer composition for forming the shell containing 1.9 parts of styrene as an aromatic monovinyl monomer and 0.1 parts of methacrylic acid as an acidic group-containing monomer was used. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0132] (Manufacturing example 9) <Production of particulate polymer 9> In a reactor equipped with a stirrer, 90 parts of deionized water and 0.5 parts of ammonium persulfate were supplied, the gas phase was replaced with nitrogen gas, and the temperature was raised to 80°C. Meanwhile, in a separate container, 15 parts of deionized water, 1.0 part of Neoperex G15 (manufactured by Kao Chemical Co., Ltd.) as an emulsifier, 70.0 parts of 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 25.0 parts of styrene as an aromatic monovinyl monomer, 1.7 parts of allyl glycidyl ether and 0.3 parts of allyl methacrylate as crosslinkable monomers, and 3.0 parts of acrylic acid as an acidic group-containing monomer were mixed to obtain a monomer composition. Polymerization was carried out by continuously adding this monomer composition to the reactor over a period of 4 hours. During the continuous addition, the reaction was carried out at a temperature of 80°C. After the continuous addition was completed, the reaction was terminated by stirring at a temperature of 80°C for another 3 hours. The obtained aqueous dispersion was cooled to 25°C, and then an aqueous sodium hydroxide solution was added to adjust the pH to 8.0. Unreacted monomers were then removed by introducing steam to obtain an aqueous dispersion of particulate polymer 9 that does not have a core-shell structure. Various measurements were then performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0133] (Manufacturing example 10) <Production of particulate polymer 10> In a reactor equipped with a stirrer, 90 parts of deionized water, 0.05 parts of sodium dodecylbenzenesulfonate (Kao Chemical Co., Ltd., "Neoperex G-15") as an emulsifier, and 0.23 parts of ammonium persulfate were supplied, the gas phase was replaced with nitrogen gas, and the temperature was raised to 70°C. Meanwhile, in a separate container, 50 parts of deionized water, 0.1 part of sodium dodecylbenzenesulfonate as an emulsifier, 2.5 parts of methacrylic acid (MAA) as an acidic functional group-containing monomer, 10 parts of acrylonitrile (AN) as a (meth)acrylonitrile monomer, 85.3 parts of n-butyl acrylate (BA) as a monofunctional (meth)acrylic acid ester monomer, 0.2 parts of allyl methacrylate (AMA) as a crosslinkable monomer, and 2.0 parts of acrylamide (Aam) as a (meth)acrylamide monomer were mixed to obtain a monomer composition. This monomer composition was continuously added to the reactor over 4 hours to carry out polymerization. The reaction was carried out at 80°C during the addition. After the addition was completed, the reaction was further stirred at 80°C for 3 hours to finish, and an aqueous dispersion containing particulate polymer 10 without a core-shell structure was produced. Various measurements were then performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0134] (Comparative manufacturing example 1) <Production of particulate polymer 11> In the production of the particulate polymer of Production Example 2, instead of a core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, the following was used: 20.2 parts styrene as an aromatic monovinyl monomer, 47.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 2.1 parts methacrylic acid as an acidic group-containing monomer, and crosslinkable An aqueous dispersion of particulate polymer 11 having a core-shell structure was prepared in the same manner as in Production Example 2, except that a monomer composition for forming the core portion containing 0.1 parts of ethylene glycol dimethacrylate as a neutral monomer was used, and instead of a monomer composition for forming the shell portion containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer, a monomer composition for forming the shell portion containing 29.7 parts of styrene as an aromatic monovinyl monomer and 0.3 parts of methacrylic acid as an acidic group-containing monomer was used. Various measurements were then performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0135] (Comparative manufacturing example 2) <Production of particulate polymer 12> In the production of the particulate polymer of Production Example 2, instead of the core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, a core-forming monomer composition containing 28.9 parts styrene as an aromatic monovinyl monomer, 68 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer was used, and the shell-forming monomer composition was not supplied. An aqueous dispersion of particulate polymer 10 without a core-shell structure was prepared in the same manner as in Production Example 2. Various measurements were then performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0136] (Comparative manufacturing example 3) <Production of particulate polymer 13> In the production of the particulate polymer of Production Example 2, instead of a core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, a composition containing 28.6 parts styrene as an aromatic monovinyl monomer, 67.3 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and a crosslinkable monomer is used. An aqueous dispersion of particulate polymer 13 having a core-shell structure was prepared in the same manner as in Production Example 2, except that a monomer composition for forming the core containing 0.1 parts of ethylene glycol dimethacrylate as a monomer was used, and instead of a monomer composition for forming the shell containing 1.3 parts of styrene as an aromatic monovinyl monomer, 0.65 parts of butyl acrylate, and 0.05 parts of methacrylic acid as an acidic group-containing monomer, a monomer composition for forming the shell containing 0.95 parts of styrene as an aromatic monovinyl monomer and 0.05 parts of methacrylic acid as an acidic group-containing monomer was used. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0137] (Comparative manufacturing example 4) <Production of particulate polymer 14> In the production of the particulate polymer of Production Example 1, instead of using a core-forming monomer composition containing 28.3 parts styrene as an aromatic monovinyl monomer, 66.6 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer, an aqueous dispersion of particulate polymer 14 having a core-shell structure was prepared in the same manner as in Production Example 1, except that a core-forming monomer composition containing 56.5 parts styrene as an aromatic monovinyl monomer, 38.4 parts 2-ethylhexyl acrylate as a monofunctional (meth)acrylic acid ester monomer, 3 parts methacrylic acid as an acidic group-containing monomer, and 0.1 parts ethylene glycol dimethacrylate as a crosslinkable monomer was used. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0138] (Comparative manufacturing example 5) (Production of particulate polymer 15) In a 5 MPa pressure vessel equipped with a stirrer, 60 parts of 2-ethylhexyl acrylate, 15 parts of styrene, and 5 parts of methacrylic acid, which are monomer compositions used to manufacture the core, along with 1 part of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of deionized water, and 0.5 parts of potassium persulfate as a polymerization initiator, were placed and thoroughly stirred. Then, the mixture was heated to 60°C to start polymerization. Polymerization was continued until the polymerization conversion rate reached 96%, yielding an aqueous dispersion containing particulate polymers that constitute the core. Next, 20 parts of styrene were continuously added to this aqueous dispersion as a monomer composition to be used in the production of the shell portion, and polymerization was continued by heating to 70°C. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling, thereby preparing an aqueous dispersion containing particulate polymer 15 having a core-shell structure. Then, various measurements were performed in the same manner as in Production Example 1. The results are shown in Table 1.

[0139] (Example 1) <Preparation of adhesive layer composition> The aqueous dispersion of particulate polymer 1 obtained in Production Example 1 and the aqueous dispersion of particulate polymer 9 obtained in Production Example 9 were mixed so that the mass ratio of solid content was 100:10. Deionized water was then added to further dilute the mixture to a solid content concentration of 10.5%. Propylene glycol was then added to the resulting mixture to adjust the solid content concentration to 10%, thereby obtaining an adhesive layer composition.

[0140] <Fabrication of negative electrode material> In a 5 MPa pressure vessel equipped with a stirrer, 33 parts of 1,3-butadiene, 3.5 parts of itaconic acid, 63.5 parts of styrene, 0.4 parts of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of deionized water, and 0.5 parts of potassium persulfate as a polymerization initiator were added and thoroughly stirred. The mixture was then heated to 50°C to start polymerization. When the polymerization conversion rate reached 96%, the reaction was stopped by cooling to obtain a mixture containing a binder for the negative electrode composite layer (SBR). A 5% aqueous sodium hydroxide solution was added to the mixture containing the binder for the negative electrode composite layer to adjust the pH to 8, and unreacted monomers were removed by heated vacuum distillation. The mixture was then cooled to below 30°C to obtain an aqueous dispersion containing the desired binder for the negative electrode composite layer. Next, 100 parts of artificial graphite (volume average particle size: 15.6 μm) as the negative electrode active material, 1 part of a 2% aqueous solution of carboxymethylcellulose sodium salt (manufactured by Nippon Paper Industries, product name "MAC350HC") as a viscosity modifier (based on solid content), and deionized water were mixed to adjust the solid content to 68%, and the mixture was further mixed at 25°C for 60 minutes. Furthermore, the solid content was adjusted to 62% with deionized water, and the mixture was further mixed at 25°C for 15 minutes. To the resulting mixture, 1.5 parts of an aqueous dispersion containing the above-mentioned binder for the negative electrode composite layer (based on solid content) and deionized water were added to adjust the final solid content to 52%, and the mixture was further mixed for 10 minutes. This was then defoamed under reduced pressure to obtain a slurry composition for a non-aqueous secondary battery negative electrode with good fluidity. The obtained non-aqueous secondary battery negative electrode slurry composition was applied to both sides of a 20 μm thick copper foil current collector using a comma coater, so that the dried film thickness would be approximately 150 μm, and then dried. This drying was performed by transporting the copper foil at a speed of 0.5 m / min in an oven at 60°C for 2 minutes. After that, it was heat-treated at 120°C for 2 minutes to obtain a negative electrode base roll before pressing. This negative electrode base roll before pressing was rolled in a roll press to obtain a negative electrode base roll after pressing with a negative electrode composite layer thickness of 80 μm.

[0141] <Preparation of positive electrode material> 100 parts of LiCoO2 with a volume-average particle size of 12 μm as the positive electrode active material, 2 parts of acetylene black (manufactured by Denka Co., Ltd., product name "HS-100") as a conductive material, 2 parts of polyvinylidene fluoride (manufactured by Kureha Corporation, product name "#7208") in terms of solid content as a binder, and N-methylpyrrolidone as a solvent were mixed to obtain a total solid content concentration of 70%. These were mixed using a planetary mixer to obtain a slurry composition for the positive electrode of a non-aqueous secondary battery. The obtained non-aqueous slurry composition for the positive electrode of a secondary battery was coated onto both sides of a 20 μm thick aluminum foil, which served as the current collector, using a comma coater, so that the film thickness after drying would be approximately 150 μm, and then dried. This drying was performed by transporting the aluminum foil at a speed of 0.5 m / min in an oven at 60°C for 2 minutes. After that, it was heat-treated at 120°C for 2 minutes to obtain the positive electrode base material. Then, the obtained cathode raw material was rolled using a roll press to obtain a pressed cathode raw material with a cathode composite layer.

[0142] <Preparation of separator raw material> We prepared polyethylene (PE) separator raw material (product name "ND412" manufactured by Asahi Kasei).

[0143] <Manufacturing of laminates> A laminate was fabricated using the prepared adhesive layer composition, negative electrode base material, positive electrode base material, and separator base material as shown in Figure 3. In Figure 3, reference numeral 91 denotes a conveyor roller and reference numeral 92 denotes a heat roller. Specifically, the negative electrode roll 20A, unwound from the negative electrode roll, was transported at a speed of 10 m / min. An adhesive layer composition was supplied onto one surface of the negative electrode roll 20A from the inkjet head of an inkjet coating machine 52 (Konica Corporation, KM1024 (shear mode type)), and the second separator roll 30A, unwound from the separator roll, and the negative electrode roll 20A were bonded together using pressure rollers 61 and 62. In addition, an adhesive layer composition was supplied onto the other surface of the negative electrode roll 20A from the inkjet head of an inkjet coating machine 51 (Konica Corporation, KM1024 (shear mode type)), and the first separator roll 10A, unwound from the separator roll, and the laminate of the negative electrode roll 20A and the second separator roll 30A were bonded together using pressure rollers 61 and 62. Furthermore, an adhesive layer composition was supplied from the inkjet head of an inkjet coating machine 53 (Konica Corporation, KM1024 (shear mode type)) to the surface of the first separator roll 10A opposite to the negative electrode roll 20A side. After placing the pre-cut positive electrode 40 on top, the laminate of the first separator roll 10A, negative electrode roll 20A, and second separator roll 30A was bonded to the positive electrode 40 using pressure rollers 61 and 62. Then, an adhesive layer composition was supplied onto the positive electrode 40 from the inkjet head of an inkjet coating machine 54 (Konica Corporation, KM1024 (shear mode type)), and the laminate was cut with a cutting machine 70 to obtain a laminate in which the second separator, negative electrode, first separator, and positive electrode were laminated in this order. Here, at the ends of the current collectors of the positive electrode 40 and the negative electrode base material 20A, portions are provided where no electrode composite layer (positive electrode composite layer or negative electrode composite layer) is formed. These portions are punched out in advance to form tabs of a desired size, and the positive electrode tabs and negative electrode tabs are arranged on the same edge side of the bonding surfaces X and Y between the electrodes and the separator. The bonding process using the pressure rollers 61 and 62 was performed at a temperature of 25°C and a pressure of 2 MPa. Furthermore, the supplied adhesive layer composition was dried by using a heat roller 92 on part of the conveyor roller 91 (drying temperature: 70°C, drying time: 1 second).

[0144] Here, the adhesive layer composition was supplied from coating machines 51-54 in such a way that it formed a uniform dot pattern. The dot size was 100 μm in diameter, and the spacing between them was 400 μm. The basis weight of the adhesive material was 0.2 g / m². 2 Furthermore, the coverage rate was measured to be 6.5%.

[0145] <Manufacturing of secondary batteries> Furthermore, five of the laminates prepared above were stacked and pressed at 25°C and 2 MPa for 10 seconds to create a laminated body. This laminated body was then wrapped in an aluminum packaging material and injected with an electrolyte solution (solvent: ethylene carbonate / diethyl carbonate / vinylene carbonate = 68.5 / 30 / 1.5 (volume ratio), electrolyte: 1 M LiPF6). Subsequently, the opening of the aluminum packaging material was closed with a heat seal at 150°C to create a laminated lithium-ion secondary battery with a capacity of 800 mAh. The lithium deposition rate on the negative electrode surface, output characteristics, and resistance increase during cycle testing of the obtained secondary battery were evaluated. The results are shown in Table 2.

[0146] (Example 2) In preparing the adhesive layer composition for Example 1, the aqueous dispersion of particulate polymer 2 obtained in Production Example 2 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Otherwise, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0147] (Example 3) Except for preparing the adhesive layer composition of Example 1, in which the aqueous dispersion of particulate polymer 3 obtained in Production Example 3 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0148] (Example 4) In preparing the adhesive layer composition for Example 1, the aqueous dispersion of particulate polymer 4 obtained in Production Example 4 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Otherwise, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0149] (Example 5) In preparing the adhesive layer composition of Example 1, the aqueous dispersion of particulate polymer 5 obtained in Production Example 5 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Otherwise, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0150] (Example 6) In preparing the adhesive layer composition of Example 1, the aqueous dispersion of particulate polymer 6 obtained in Production Example 6 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Otherwise, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0151] (Example 7) Except for preparing the adhesive layer composition of Example 1, in which the aqueous dispersion of particulate polymer 7 obtained in Production Example 7 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0152] (Example 8) In preparing the adhesive layer composition of Example 1, the aqueous dispersion of particulate polymer 8 obtained in Production Example 8 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Otherwise, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0153] (Example 9) Except for preparing the adhesive layer composition of Example 1, in which the aqueous dispersion of particulate polymer 10 obtained in Production Example 10 was used instead of the aqueous dispersion of particulate polymer 9 obtained in Production Example 9, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0154] (Example 10) Except for using a polypropylene (PP) separator roll (product name: Cellguard #2500) instead of a polyethylene (PE) separator roll (product name: Asahi Kasei Corporation's "ND412"), the adhesive layer composition, negative electrode roll, positive electrode roll, separator roll, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0155] (Comparative Example 1) Except for preparing the adhesive layer composition of Example 1, in which the aqueous dispersion of particulate polymer 11 obtained in Comparative Production Example 1 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0156] (Comparative Example 2) In preparing the adhesive layer composition of Example 1, the adhesive layer composition, negative electrode base material, positive electrode base material, and separator base material were prepared in the same manner as in Example 1, except that the aqueous dispersion of particulate polymer 12 obtained in Comparative Production Example 2 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2. When the inkjet ejection characteristics of the adhesive layer composition were evaluated in the same manner as in Example 1, it was found that the adhesive layer composition could not be ejected. Therefore, it was not possible to manufacture a laminate or a secondary battery.

[0157] (Comparative Example 3) In preparing the adhesive layer composition of Example 1, the aqueous dispersion of particulate polymer 13 obtained in Comparative Production Example 3 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Otherwise, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0158] (Comparative Example 4) Except for preparing the adhesive layer composition of Example 1, in which the aqueous dispersion of particulate polymer 14 obtained in Comparative Production Example 4 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0159] (Comparative Example 5) In preparing the adhesive layer composition for Example 1, the aqueous dispersion of particulate polymer 15 obtained in Comparative Production Example 5 was used instead of the aqueous dispersion of particulate polymer 1 obtained in Production Example 1. Otherwise, the adhesive layer composition, negative electrode base material, positive electrode base material, separator base material, laminate, and secondary battery were manufactured and prepared in the same manner as in Example 1. Then, various measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 2.

[0160] In Tables 1 and 2 below, "MMA" stands for methyl methacrylate. "BA" indicates butyl acrylate. "2EHA" indicates 2-ethylhexyl acrylate. "AN" stands for acrylonitrile. "St" stands for styrene. "MAA" indicates methacrylic acid. "AA" indicates acrylic acid. "Aam" stands for acrylamide. "AGE" stands for allyl glycidyl ether. "AMA" indicates allyl methacrylate. "EDMA" refers to ethylene glycol dimethacrylate. "PE" stands for polyethylene. "PP" stands for polypropylene. [Table 1] [Table 2]

[0161] As can be seen from the results shown in Table 2, in Examples 1 to 10, which used non-aqueous secondary battery adhesive layer compositions with adhesive pressure sensitivity values ​​greater than 20 and less than 80, it is possible to achieve a high level of simultaneous improvement in inkjet ejection characteristics, adhesive strength, and battery characteristics (output characteristics, resistance increase in cycle tests). In contrast, in Comparative Examples 1 to 5, which used non-aqueous secondary battery adhesive layer compositions with adhesive pressure sensitivity values ​​outside the range of greater than 20 and less than 80, it is not possible to achieve a high level of simultaneous improvement in inkjet ejection characteristics, adhesive strength, and battery characteristics (output characteristics, resistance increase in cycle tests). The reason for the deterioration of adhesive strength in Example 6 is presumed to be the high mass proportion of the shell portion, which has a high glass transition temperature. The reason for the slight deterioration in battery characteristics in Example 8 is presumed to be the high butyl acrylate monomer content of the particulate polymer, resulting in a high degree of swelling. The reason why the adhesive strength was slightly worse in Example 10 is presumed to be because the polypropylene separator has higher hydrophobicity than the polyethylene separator. [Industrial applicability]

[0162] According to the present invention, it is possible to provide an adhesive layer for non-aqueous secondary batteries that can firmly bond battery components together at room temperature and pressure while ensuring inkjet ejection characteristics, and to provide a composition for a non-aqueous secondary battery adhesive layer that can enable the non-aqueous secondary battery to exhibit excellent battery characteristics. Furthermore, according to the present invention, it is possible to provide an adhesive layer for non-aqueous secondary batteries that can firmly bond battery components together under room temperature pressure and exhibit excellent electrical properties in non-aqueous secondary batteries. Furthermore, according to the present invention, it is possible to provide a laminate for non-aqueous secondary batteries that can exhibit excellent electrical characteristics in non-aqueous secondary batteries. Furthermore, according to the present invention, it is possible to provide a non-aqueous secondary battery with excellent electrical properties. Furthermore, according to the present invention, it is possible to provide a method for manufacturing an adhesive layer for non-aqueous secondary batteries that can firmly bond battery components together under room temperature pressure and exhibit excellent electrical properties in non-aqueous secondary batteries. Furthermore, according to the present invention, it is possible to provide a method for manufacturing a laminate for a non-aqueous secondary battery that can exhibit excellent electrical properties in a non-aqueous secondary battery. [Explanation of Symbols]

[0163] 10A First Separator Raw Material 20A negative electrode material 30A Second Separator Raw Material 40 positive electrode 50 droplets 51-54 Coating machine (nozzle head) 61, 62 Crimping rollers 70 cutting machine 91 Conveyor roller 92 Heat Roller 300 Particulate polymer 310 Core section 310S Outer surface of the core 320 Shell section

Claims

1. A composition for a non-aqueous secondary battery adhesive layer containing particulate polymer, The pressure sensitivity value of the adhesive force, calculated using the following formula (1), is greater than 20 and less than 80. The particulate polymer has a core-shell structure comprising a core portion and a shell portion that covers the outer surface of the core portion. The glass transition temperature of the core portion is between -50°C and 25°C, and the glass transition temperature of the shell portion is between 50°C and 200°C. A composition for a non-aqueous secondary battery adhesive layer, wherein the mass ratio of the shell portion to the total mass of the core portion and the shell portion is 2% by mass or more and 15% by mass or less. Pressure sensitivity of adhesive force (N / (m·MPa)) = (T3 - T1) / 2 ... (1) (In the formula, T1 represents the adhesive strength (N / m) between the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition when the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition are bonded at 25°C and a pressure of 1 MPa for 10 seconds, and T3 represents the adhesive strength (N / m) between the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition when the polyethylene separator and the non-aqueous secondary battery adhesive layer obtained from the non-aqueous secondary battery adhesive layer composition are bonded at 25°C and a pressure of 3 MPa for 10 seconds).

2. The non-aqueous secondary battery adhesive layer composition according to claim 1, wherein the glass transition temperature of the core portion is -40°C or higher and 25°C or lower.

3. The composition for a non-aqueous secondary battery adhesive layer according to claim 1 or 2, wherein the volume-average particle diameter of the particulate polymer is 100 nm or more and 1500 nm or less.

4. An adhesive layer for a non-aqueous secondary battery, comprising the composition for a non-aqueous secondary battery adhesive layer described in any one of claims 1 to 3.

5. A step of coating a non-aqueous secondary battery adhesive layer composition according to any one of claims 1 to 3 onto a substrate by an inkjet method, A method for producing an adhesive layer for a non-aqueous secondary battery, comprising the step of drying the non-aqueous secondary battery adhesive layer composition coated on the substrate.

6. A laminate for a non-aqueous secondary battery comprising electrodes and a separator, A laminate for a non-aqueous secondary battery, wherein the electrode and the separator are bonded together via the adhesive layer for a non-aqueous secondary battery described in claim 4.

7. A step of supplying an adhesive material to at least one bonding surface of an electrode and a separator, The process includes a step of pressing the electrode and the separator together at room temperature through the bonding surface to which the adhesive material has been supplied, The adhesive material is a composition for a non-aqueous secondary battery adhesive layer according to any one of claims 1 to 3, and the method for manufacturing a laminate for a non-aqueous secondary battery is as follows.

8. A non-aqueous secondary battery comprising the laminate for a non-aqueous secondary battery described in claim 6.

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