TWI701862B - Adhesive for the laminating, the laminate using it and production method thereof, and rechargeable battery and production method thereof - Google Patents

Abstract

The subject of the present invention is to provide an adhesive composition for a laminated body, in which the metal layer and the plastic layer of the laminated body are excellent in adhesiveness, have both electrolyte resistance even when hardened at low temperature, and have a high retention rate , And will not peel off over time; and provide a manufacturing method of the adhesive composition, a laminate using the adhesive and a secondary battery.

This problem is solved by the following adhesive for laminates, which is an adhesive for laminates containing polyolefin resin (A) and epoxy compound (B). Among them, the monomer of polyolefin resin (A) is propylene and 1-butene is a polymer with the main component, and the crystallization peak temperature is in the range of 28°C to 38°C.

Description

Adhesive for build-up, build-up using the same, and manufacturing method thereof, and secondary battery and manufacturing method thereof

The present invention relates to a laminate adhesive for sealing electrolytes used in secondary batteries, and to laminates and secondary batteries using the adhesive.

Secondary batteries represented by lithium-ion batteries are composed of a positive electrode, a negative electrode, and an electrolyte sealed in between. In addition, as a sealing bag for sealing the "leads for conducting the charge of the positive electrode and the negative electrode to the outside", a laminate in which a metal foil such as aluminum foil or a metal vapor-deposited layer and plastic are bonded is used.

For example, Patent Document 1 proposes a sealed bag in which a maleic acid-modified polyolefin resin is used in the innermost layer of a laminate, and the same maleic acid-modified polyolefin resin is used to form a heat-sealed part. Improve sealing reliability. The maleic acid-modified polyolefin resin has excellent adhesion and heat sealability to metals, so it is generally used as an adhesive resin. However, if it is used as a sealing film for the battery, it exhibits excellent adhesive force at the time of lamination at high temperature, but its electrolyte resistance is low, interlayer peeling occurs over time, and it cannot be used as a sealing film.

Patent Document 2 describes a laminate for a battery electrolyte sealing film or a laminate for a battery electrode part protective film, which includes: a metal layer; a surface treatment layer formed on the surface of the metal layer; and an adhesive resin layer formed on The surface treatment layer contains polyolefin modified by carboxylic acid group or its derivative.

Patent Document 3 describes an adhesive resin composition comprising: (A) a polyolefin resin having at least one functional group selected from the group consisting of an acid anhydride group, a carboxyl group, and a carboxylic acid metal salt; and ( B) Epoxidized vegetable oil, which has 2 or more epoxy groups and a molecular weight of 3000 or less; the blending amount of (B) component is 0.01-5 parts by mass relative to 100 parts by mass of (A) component.

Patent Document 4 describes a resin composition for an adhesive for secondary battery electrodes, which is characterized by containing an acid-modified polyolefin resin (A) and a polyurethane resin (B) relative to 100 parts by mass (A) and (B) are 0.5-100 parts by mass.

Prior art literature Patent literature

Patent Document 1 Japanese Patent Application Publication No. 09-283101

Patent Document 2 WO2007017043 Publication

Patent Document 3 JP 08-193148 A

Patent Document 4 JP 2010-277959 A

The subject of the present invention is to provide an unprecedented build-up adhesive to provide a laminate that has excellent adhesion between the metal layer and the plastic layer, and has both electrolyte resistance even when hardened at low temperatures, and its retention rate is high. Adhesive composition for a laminate that does not cause delamination over time; and provides a manufacturing method, laminates and secondary batteries using the adhesive.

The inventors of the present case have conducted studies, and as a result, the above-mentioned problems have been solved by an adhesive for lamination, which is an adhesive for lamination containing polyolefin resin (A) and epoxy compound (B), among which polyolefin resin (A) is The monomer is a polymer with propylene and 1-butene as the main components, and the crystallization peak temperature is in the range of 28°C to 38°C.

Moreover, in the manufacturing method of the adhesive agent of this invention, it can provide a laminated body which solves the problem of this invention by having the step of aging in the range of 25-80 degreeC.

According to the present invention, it is possible to provide an adhesive composition for a laminate, in which the metal layer and the plastic layer of the laminate are excellent in adhesiveness, have both electrolyte resistance even if they are cured at a low temperature, and have a high retention rate without any change. Delamination occurs over time; and the manufacturing method, laminates and secondary batteries using the adhesive are provided.

In addition, in the manufacturing method of the adhesive, by having a step of aging in the range of 25 to 80°C, it is possible to provide a laminate that solves the problem of the present invention. This temperature is lower than the conventional processing temperature, so energy can be saved during manufacturing and cost can be reduced.

a‧‧‧ represents the peak value of the methyl group of polybutene-1 (equivalent to A in Figure 2)

b‧‧‧ represents the peak of the methyl group of polypropylene (equivalent to A in Figure 1)

c‧‧‧represents the peak value of the methylene group of polypropylene (equivalent to B in Figure 1)

d‧‧‧ represents the peak value of the methyl group of the copolymer with polyethylene (equivalent to A in Figure 3)

e‧‧‧ represents the peak of the methyl group of polypropylene (equivalent to A in Figure 1)

f‧‧‧represents the peak of the methylene group of polypropylene (equivalent to B in Figure 1)

Figure 1 is a ¹³ C-NMR chart of polypropylene as a sample.

Figure 2 is a ¹³ C-NMR chart of polybutene-1 as a sample.

Figure 3 is a ¹³ C-NMR chart of polypropylene (copolymer with ethylene) as a sample.

Figure 4 is a ¹³ C-NMR chart of HARDLEN NS-2002 used as the polyolefin resin (A) in Example 1-4.

Figure 5 is a ¹³ C-NMR chart of GMP5070E used as the polyolefin resin (A) in Example 5.

Figure 6 is a ¹³ C-NMR chart of GMP3020E used as the polyolefin resin (A) in Comparative Example 1.

Figure 7 is a ¹³ C-NMR chart of Auroren 350S used as the polyolefin resin (A) in Comparative Example 4.

Figure 8 is a ¹³ C-NMR chart of Auroren 550S used as the polyolefin resin (A) in Comparative Example 5.

The form used to implement the invention

In order to solve the above-mentioned problems, the present invention is composed of the following items.

1. An adhesive for laminates, which is an adhesive for laminates containing polyolefin resin (A) and epoxy compound (B), wherein the monomers of polyolefin resin (A) are mainly propylene and 1-butene Component polymer, and the crystallization peak temperature is in the range of 28℃~38℃; 2. Adhesive for laminates as in 1, wherein the polyolefin resin (A) contains modified polyolefin resin with an acid value of 1~200mgKOH/g and/or modified polyolefin with a hydroxyl value of 1~200mgKOH/g Resin; 3. Adhesives for lamination as in 1 or 2, wherein the epoxy compound (B) has 2 or more epoxy groups in one molecule and one or more hydroxyl groups in one molecule, and the weight average molecular weight is An epoxy compound of 3000 or less is an essential component; 4. The adhesive for build-up of any one of 1 to 3, wherein, relative to 100 parts by mass of the polyolefin resin (A), the ratio is 0.01-30 parts by mass Blending epoxy compound (B); 5. Adhesive for laminates as in any one of 1 to 4, which further contains thermoplastic elastomer, tackifier, catalyst, phosphoric acid compound, melamine resin, silane coupling agent or reaction Elastic body; 6. A laminated body, which is formed between the metal layer and the polyolefin resin layer by using an adhesive for laminated layers such as any one of 1 to 5; 7. A method for manufacturing a laminated body, which is The manufacturing method of the laminate of 6 has a step of aging in the range of 25 to 80°C; 8. A secondary battery, which is the laminate of 6 or the laminate obtained by the manufacturing method of 7 Used as electrolyte sealing film or electrode protection film.

(Polyolefin resin (A))

The polyolefin resin (A) of the present invention has the following characteristics: the monomer is a polymer mainly composed of propylene and 1-butene, and the crystallization peak temperature is in the range of 28°C to 38°C.

When the above-mentioned crystallization peak temperature is less than 28°C, the electrolyte resistance (retention rate) is low, and when it exceeds 38°C, the initial adhesion is lowered.

The monomer of the polyolefin resin (A) is mainly composed of propylene and 1-butene, which means that the total mol of propylene and 1-butene used as the monomer is more than 50% of the total mol of the monomer polymer.

The total moles of propylene and 1-butene are particularly preferably 80% or more of the total moles of monomers.

In addition, the polyolefin resin (A) of the present invention may contain propylene and 1-butene as its main components, and may also contain other monomers, such as ethylene. In this case, it is preferably one of other monomers. A polymer having a molar number less than that of propylene and 1-butene, respectively, preferably does not contain other monomers.

Here, the comparison of the molar numbers of propylene, 1-butene, ethylene, etc., which are monomers constituting the polyolefin resin (A), can be judged from the peak height of ¹³ C-NMR.

Examples of the polyolefin resin (A) of the present invention include copolymers of olefins having 2 to 8 carbon atoms, copolymers of olefins having 2 to 8 carbon atoms and other monomers.

Specific examples include: high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene resin and other polyethylene, polypropylene, polyisobutylene, poly(1-butene), poly4-methyl Pentene, polyvinylcyclohexane, polystyrene, poly(p-methylstyrene), poly(α-methylstyrene), ethylene. Propylene block copolymer, ethylene. Propylene random copolymer, ethylene. Butene-1 copolymer, ethylene. 4-methyl-1-pentene copolymer, ethylene. Alpha-olefin copolymers such as hexene copolymers, ethylene. Vinyl acetate copolymer, ethylene. C Acrylic acid copolymer, ethylene. Methyl methacrylate copolymer, ethylene. Vinyl acetate. Methyl methacrylate copolymer, ionic polymer resin, etc. Furthermore, chlorinated polyolefins obtained by chlorinating these polyolefins can also be used.

Furthermore, the polyolefin resin (A) of the present invention has the following characteristics: its crystallization peak temperature is in the range of 28°C to 38°C. Here, the crystallization peak temperature in the present invention is the peak top temperature of the crystallization peak when the resin is cooled after being melted by heating, and the temperature is raised again. Here, the peak top temperature of the crystallization peak in the present invention is measured by differential scanning calorimetry (DSC method).

In the present invention, polyolefin resins having different crystallization peak temperatures can be used alone or in combination, and there is no limitation as long as the crystallization peak temperature is in the range of 28°C to 38°C.

In addition, the crystallization peak heat amount described in the examples and the like is a value measured from the area of the crystallization peak when the resin is cooled after melting at a temperature, and the temperature is raised again.

In addition, the polyolefin resin (A) of the present invention may contain a modified polyolefin resin having an acid value of 1 to 200 mgKOH/g and/or a modified polyolefin resin having a hydroxyl value of 1 to 200 mgKOH/g.

The polyolefin resin (A) used in the present invention, as described above, can be various resins, but is more preferably a modified polyolefin resin in which various functional groups (such as carboxyl groups, hydroxyl groups, etc.) are introduced into the polyolefin resin. Furthermore, among these modified polyolefin resins, from the viewpoint of further improving the adhesion of the metal layer and having excellent electrolyte resistance, a modified polyolefin resin having an acid value of 1 to 200 mgKOH/g is more preferred. Olefin resin (hereinafter referred to as acid-modified polyolefin resin) and/or modified polyolefin resin having a hydroxyl value of 1 to 200 mgKOH/g (hereinafter referred to as hydroxy-modified polyolefin resin).

The acid-modified polyolefin resin is a polyolefin resin having a carboxyl group or a carboxylic anhydride group in the molecule, which is synthesized by modifying a polyolefin with an unsaturated carboxylic acid or its derivative. As this modification method, graft modification or copolymerization can be used.

Acid-modified polyolefin resin is a graft-modified polymer formed by graft-modifying or copolymerizing at least one polymerizable ethylenically unsaturated carboxylic acid or its derivative with the polyolefin resin before modification. Olefin. Examples of the polyolefin resin before modification include the above-mentioned polyolefin resins, but among them, a homopolymer of propylene, a copolymer of propylene and α-olefin, and the like are preferable. These polymers may be used individually by 1 type, and may be used in combination of 2 or more types.

Examples of ethylenically unsaturated carboxylic acids or their derivatives to be graft-modified or copolymerized with the polyolefin resin before modification include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and citraconic acid , Mesaconic acid, maleic anhydride, 4-methylcyclohex-4-ene-1,2-dicarboxylic anhydride, bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, 1, 2,3,4,5,8,9,10-octahydronaphthalene-2,3-dicarboxylic anhydride, 2-octyl-1,3-diketospiro[4.4]non-7-ene, bicyclo[2.2. 1]Hept-5-ene-2,3-dicarboxylic anhydride, maleopimaric acid, tetrahydrophthalic anhydride, methyl-bicyclo[2.2.1]hept-5-ene-2,3-di Carboxylic anhydride, methyl-norborn-5-ene-2,3-dicarboxylic anhydride, norborn-5-ene-2,3-dicarboxylic anhydride, etc. Preferably, maleic anhydride is used. These components can be used individually or in combination of 2 or more types.

In order to graft a grafting monomer selected from ethylenically unsaturated carboxylic acids or derivatives thereof onto the polyolefin resin before modification, various methods can be adopted. Examples include: melting the polyolefin resin and adding a grafting monomer to it to carry out the grafting reaction; dissolving the polyolefin resin in a solvent A method of forming a solution and adding a grafting monomer to the grafting reaction; mixing a polyolefin resin dissolved in an organic solvent with the unsaturated carboxylic acid, etc., and proceeding at a temperature above the softening temperature of the polyolefin resin or the melting point Heating, the method of simultaneously carrying out radical polymerization and hydrogen removal reaction in a molten state, etc. In either case, in order to efficiently graft copolymerize the grafting monomer, it is preferable to perform the grafting reaction in the presence of a radical initiator. The grafting reaction is generally carried out at 60~350℃. Relative to 100 parts by mass of the polyolefin resin before modification, the use ratio of the radical initiator is generally in the range of 0.001 to 1 part by mass.

In the adhesive of the present invention, a radical initiator can be used. As a preferred initiator, an imidazole-based radical initiator may be mentioned, but it is not limited thereto.

Examples include triphenylphosphine, 1,8-diazebicyclo(5.4.0)undecene-7 (DBU)-phenate, DBU-octanoate, and the like.

Examples of such acid-modified polyolefin resins include maleic anhydride modified polypropylene, ethylene-(meth)acrylic acid copolymer, ethylene-acrylate-maleic anhydride terpolymer, or ethylene-methacrylic acid Ester-maleic anhydride terpolymer. Specifically, commercially available: "MODIC" manufactured by Mitsubishi Chemical Corporation, "Admer" and "UNISTOLE" manufactured by Mitsui Chemicals Co., Ltd., "TOYOTAC" manufactured by Toyobo Co., Ltd., and "Umex" manufactured by Sanyo Chemical Co., Ltd. , Japan Polyethylene Co., Ltd. "REXPEARL EAA" and "REXPEARL ET", Dow Chemical Co., Ltd. "PRIMACOR", DUPONT-MITSUI POLYCHEMICALS "NUCREL", ARKEMA's "BONDINE".

Hydroxy-modified polyolefin resin is a polyolefin resin having a hydroxyl group in the molecule, which is synthesized by grafting or copolymerizing polyolefin with the following hydroxyl-containing (meth)acrylate or hydroxyl-containing vinyl ether . The polyolefin resin before modification and the modification method are the same as the case of acid-modified polyolefin resin.

Examples of the hydroxyl-containing (meth)acrylate include: hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycerol (meth)acrylate, lactone modified (meth) Hydroxyethyl acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, etc. Examples of the hydroxyl-containing vinyl ether include 2-hydroxyethyl vinyl ether and diethylene glycol monovinyl ether , 4-hydroxybutyl vinyl ether, etc.

(Epoxy compound (B))

Examples of the epoxy compound (B) of the present invention include ethylene glycol, propylene glycol, hexylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol, glycerin, diglycerin, and sorbitol. Polyhydric alcohol diglycidyl ether type epoxy resin such as sugar alcohol, spiroglycerin or hydrogenated bisphenol A.

In addition, examples include diglycidyl ether type epoxy resins such as bisphenol A, bisphenol F, bisphenol S, and bisphenol AD, or phenol novolak resin or glycidyl ether of cresol novolak resin, novolac type Aromatic epoxy resins such as epoxy resins; diglycidyl ether type epoxy resins of polyols such as ethylene oxide or propylene oxide adducts of aromatic polyhydroxy compounds.

In addition, examples include: polyglycidyl ether type epoxy resins of polyether polyols such as polyethylene glycol, polypropylene glycol or polytetramethylene glycol; bis(3,4-ring Cycloaliphatic type polyepoxy resins such as oxycyclohexylmethyl) adipate, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate and the like.

In addition, polyglycidyl ester type epoxy resins of polycarboxylic acids such as tricarboxylic acid, butanetetracarboxylic acid, adipic acid, phthalic acid, terephthalic acid, or trimellitic acid; Bi-epoxy resins of hydrocarbon-based dienes such as ene, hexadiene, octadiene, dodecadiene, cyclooctadiene, α-pinene, or vinylcyclohexene.

或乙內醯脲之含有各種雜環的環氧樹脂等。 In addition, examples include epoxy resins of diene polymers such as polybutadiene or polyisoprene; or tetraglycidyl diamino diphenylmethane, tetraglycidyl diamino methyl cyclohexane, diglycidyl Glycidylamine epoxy resin such as glycerol aniline or tetraglycidyl metaxylylenediamine, or

Or hydantoin containing various heterocyclic epoxy resins, etc.

Among these resins, if an aromatic epoxy resin such as a bisphenol A epoxy resin is used, the adhesiveness and corrosion resistance are good, which is preferable.

As specific examples, bisphenol A epoxy resins include: "EPICLON 850, 860, 1050, 1055, 2055" manufactured by DIC Co., Ltd., and "jER828, 834, 1001, 1002, 1004, 1007" manufactured by Mitsubishi Chemical Co., Ltd. "Wait.

In addition, it may be an epoxy resin containing an epoxy compound as an essential component: an epoxy compound having two or more epoxy groups in one molecule and one or more hydroxyl groups in one molecule, and a weight average molecular weight of 3000 or less.

Preferably, the epoxy compound (B) is blended in a ratio of 0.01 to 30 parts by mass with respect to 100 parts by mass of the polyolefin resin (A).

If it is less than 0.01 parts by mass, its adhesion to the substrate becomes low and unfavorable.

Moreover, if it is more than 30 parts by mass, the cohesive force of the coating film will be low and unfavorable.

(Other additives)

In the present invention, as other additives, conventionally used thermoplastic elastomers, tackifiers, catalysts, phosphoric acid compounds, melamine resins, silane coupling agents, or reactive elastomers can be used. In the range that does not impair the function of the adhesive of the present invention, the content of these additives can be appropriately adjusted for use.

(Layered body)

The laminate of the present invention is a combination of the adhesive composition for laminates of the present invention, a metal layer such as aluminum foil, and one or more polyolefin sheets such as polyethylene and polypropylene, polyethylene terephthalate, etc. It is obtained by laminating plastic layers such as polyester.

Next, the adhesive composition for build-up of the present invention can form an adhesive layer by, for example, dissolving/dispersing it in an ester solvent, ketone solvent, aromatic hydrocarbon, aliphatic hydrocarbon, and lipid in an arbitrary ratio. An appropriate solvent or dispersant such as cyclohydrocarbon is applied to the metal foil using a conventional coating method such as roll coating, gravure coating, and bar coating, and then dried.

The dry coating weight of the adhesive composition for build-up of the present invention is preferably in the range of 0.5 to 20.0 g/m ² . If it is less than 0.5g/m ² , it is difficult to obtain continuous and uniform coating properties. On the other hand, if it exceeds 20.0g/m ² , the solvent removal after coating will be reduced, the workability will be significantly reduced, and the problem of residual solvent will occur .

After coating the adhesive composition for lamination of the present invention on one side of the metal foil, it overlaps the plastic layer, and is bonded by a dry lamination method (dry lamination method) to obtain the laminate of the present invention. The temperature of the laminated roller is preferably about room temperature to 120°C, and the pressure is preferably about 3 to 300 kg/cm ² .

In addition, the laminate of the present invention is preferably cured after production. As the maturation conditions, the preferred temperature is 25-80°C and the time is 12-240 hours, and the bonding strength is produced within this range.

(Secondary battery)

The laminate of the present invention can be used as an electrolyte sealing film or an electrode part protective film of a primary or secondary battery. In this case, a polar organic solvent and/or salt or the like are brought into contact with the plastic layer side. In particular, it can be used in a state where it is in contact with a non-aqueous electrolyte containing a polar organic solvent and salt, and is particularly suitable for use as a secondary battery electrolyte sealing film or secondary battery electrode for non-aqueous electrolyte batteries, solid batteries, etc. Department of protective film. In this case, it is folded and heat-sealed in a manner facing the plastic layer, thereby being used as a battery sealing bag. The adhesive used in the present invention has excellent heat sealability, so it can prevent leakage of non-aqueous electrolyte and can be used as a battery for a long time.

The polar organic solvent is an aprotic polar solvent, and examples thereof include alkyl carbonates, esters, and ketones. Specific examples include: ethylene carbonate, propylene carbonate, butyl carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane , Tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, methyl formate, 4-methyl-1,3-dioxolane formate , Methyl acetate, Methyl propionate, etc.

Examples of the salt include alkali metal salts such as lithium salt, sodium salt, and potassium salt. For batteries, lithium salts such as LiPF ₆ , LiBF ₄ , and Li-imine are generally used.

The non-aqueous electrolyte is one in which 0.5-3 mmol of the alkali metal salt is dissolved in an aprotic polar organic solvent such as a cyclic carbonate, a chain carbonate, a mixture of these esters, and the like.

Even if the laminate of the present invention is used in a state in which it is in contact with the polar solvent and/or salt, especially the non-aqueous electrolyte of a mixture of these, the interlayer of the metal layer, adhesive layer, and plastic layer will not occur. Peel off, but can be used for a long time.

The battery of the present invention is a battery having a battery electrolyte sealing film or a battery electrode portion protective film including the laminate. The battery of the present invention, because the above-mentioned film does not peel off between layers and can prevent leakage of the non-aqueous electrolyte, it can be used stably as a battery for a long time.

As described above, the laminate of the present invention has excellent adhesion between the metal layer and the plastic layer, and has excellent durability against polar organic solvents or salts. Even if it comes into contact with a non-aqueous electrolyte, interlayer peeling does not occur. Therefore, the use of this laminate as a battery electrolyte sealing film or a battery electrode protective film, and a secondary battery using it as a secondary battery electrolyte sealing film or a secondary battery electrode protective film, can be used for a long time Stable use.

[Example]

Hereinafter, the present invention will be described in detail with examples. The description "parts" means parts by mass.

The structure of various polyolefin resins (A) was analyzed by ¹³ C-NMR, and the structure of the monomer contained in it was determined from the spectrum.

Device name: ECX-400P (manufactured by JEOL)

Measuring solvent: CDCl ₃

Measuring temperature: 25℃

Cumulative times: 1000 times

In addition, the graphs in Figures 1 to 3 are quoted from "Infrared Absorption and ¹³ CNMR Spectra Collection of Major Polymers" (Japanese Society of Analytical Chemistry/Polymer Analysis Research Conference).

(Example 1)

Add 100 parts of HARDLEN NS-2002, 0.01 part of CUREZOL 2E4MZ, 0.5 part of Denacol EX-321 and stir well, use a bar coating device to coat 5g/m ² (dry type) on the aluminum foil, and dry it at 80°C After 1 minute, it was laminated with the CPP film at 100°C to produce a coating. Thereafter, after aging at 60°C for 5 days, the initial adhesion strength was measured.

(Example 2) ~ (Example 5)

As shown in Table 1, other components were blended, and the adhesive was produced in the same manner as in Example 1. Furthermore, each laminated body was produced by the same manufacturing method as the laminated body 1.

In the laminates obtained in each example, the adhesive performance and the electrolyte resistance (retention rate) were evaluated. The results are shown in Table 1.

In addition, the conditions of each test are as follows.

(Measurement of initial bonding strength)

In the TENSILON test manufactured by A&D Co., Ltd., the sample was cut into a width of 15 mm, and the 180°C peel strength (180°C N/15mm) was measured.

(Measurement method of crystallization peak temperature and crystallization peak heat)

In the present invention, the measurement of the crystallization peak temperature and the crystallization peak heat quantity is performed under the following conditions.

Device: Hitachi High-Tech Science Corporation/X-DSC7000

Container: Hitachi High-Tech Science Corporation/Open aluminum container

Conditions: sample 5mg; reference material: empty container; gas environment: nitrogen flow rate 20mL/min

Measuring temperature: 30℃(0min)→-10℃/min→-80℃(0min)→10℃/min→200℃/min

(Retention rate of electrolyte resistance)

At 85°C, the laminate was immersed in the electrolyte "ethylene carbonate: ethyl methyl carbonate: dimethyl carbonate = 1:1:1 (wt%) + LiPF ₆ : 1 mol + vinyl carbonate: 1 wt%" For 7 days, the retention of adhesive strength before and after immersion was evaluated based on the following criteria.

○: 60% or more, △: 60~50%, ×: 50% or less

●HARDLEN NS-2002 (manufactured by Toyobo Co., Ltd.) modified polyolefin resin with non-volatile content 20%, peak crystallization temperature 36.1°C, peak crystallization heat 20.2mj/mg

(Refer to Figure 4 for NMR chart)

●GMP5070E (manufactured by Lotte Chemical) modified polyolefin resin with a non-volatile content of 100%, peak crystallization temperature 28.8℃, peak crystallization heat 31.0mj/mg

(Refer to Figure 5 for NMR chart)

●CUREZOL 2E4MZ (manufactured by Shikoku Chemical Industry Co., Ltd.) imidazole non-volatile content 100%

●U-CAT SA 1 (manufactured by San-Apro Co., Ltd.) DBU-phenolate non-volatile content 100%

●U-CAT SA 102 (manufactured by San-Apro Co., Ltd.) DBU-caprylate non-volatile content 100%

●FTR-8120 (manufactured by Mitsui Chemicals Co., Ltd.) Tackifier with 100% non-volatile content

●Denacol EX-321 (manufactured by Nagase ChemteX Co., Ltd.) epoxy resin, epoxy equivalent 140, non-volatile content 100%

●Epiclon 860 (made by DIC Co., Ltd.) bisphenol A epoxy resin, epoxy equivalent 240, non-volatile content 100%

(Comparative example 1) ~ (Comparative example 5)

Blending was performed as shown in Table 2, and a laminate was produced in the same manner as in the examples as a comparative example. In addition, using this laminate, the initial adhesive strength and electrolyte resistance (retention rate) were evaluated. The results are shown in Table 2.

●GMP3020E (manufactured by Lotte Chemical) modified polyolefin resin with a non-volatile content of 100%, peak crystallization temperature 19.5°C, peak crystallization heat 16.0mj/mg

(Refer to Figure 6 for NMR chart)

●GMP7550E (manufactured by Lotte Chemical) modified polyolefin resin with non-volatile content 100%, peak crystallization temperature 24.6℃, peak crystallization heat 19.1mj/mg

●Auroren 350S (manufactured by Nippon Paper Co., Ltd.) modified polyolefin resin, non-volatile content 100%, crystallization peak temperature 8.6°C, crystallization peak heat value 3.9mj/mg

(Refer to Figure 7 for NMR chart)

●Auroren 550S (manufactured by Nippon Paper Co., Ltd.) modified polyolefin resin, non-volatile content 100%, crystallization peak temperature 38.9°C, crystallization peak heat value 37.0mj/mg

(Refer to Figure 8 for NMR chart)

●CUREZOL 2E4MZ (manufactured by Shikoku Chemical Industry Co., Ltd.) imidazole non-volatile content 100%

●U-CAT SA 1 (manufactured by San-Apro Co., Ltd.) DBU-phenolate non-volatile content 100%

●Denacol EX-321 (manufactured by Nagase ChemteX Co., Ltd.) epoxy resin, epoxy equivalent 140, non-volatile content 100%

●Epiclon 860 (made by DIC Co., Ltd.) bisphenol A epoxy resin, epoxy equivalent 240, non-volatile content 100%

The HARDLEN NS-2002 and GMP5070E of the polyolefin resin (A) used in the examples are compared with NMR measurement samples. It can be seen that the monomers are mainly composed of propylene and 1-butene, and the crystallization peak temperature is 28°C. ~38°C range.

On the other hand, the comparison of GMP3020E, GMP7550E, Auroren 350S, and Auroren 550S of the polyolefin resin (A) used in the comparative example shows that the monomers are mainly composed of propylene and 1-butene. The crystallization peak temperature is out of the range of 28°C to 38°C.

Therefore, even if the monomers of the polyolefin resin (A) are mainly composed of propylene and 1-butene, and the crystallization peak temperature is within the range of 28°C to 38°C, the electrolyte resistance (retention rate) is excellent and can be The problem of the present invention is solved, but if the temperature is outside the range, the problem cannot be solved obviously.

From the above results, it is clear that the laminate obtained by using this adhesive has excellent initial adhesive strength and electrolyte resistance (retention rate).

Industrial availability

The adhesive for build-up of the present invention has excellent adhesiveness between the metal layer and the plastic layer, has both electrolyte resistance even at low temperature curing, and has a high retention rate. Therefore, the laminate obtained by using the adhesive is It can also be cured at low temperature and has electrolyte resistance and does not peel off over time, so it is suitable for use as a laminate for secondary batteries.

Claims (10)

An adhesive for laminates, which is an adhesive for laminates containing polyolefin resin (A) and epoxy compound (B), wherein the polyolefin resin (A)-based monomer contains propylene and 1-butene as main components The crystallization peak temperature is in the range of 28°C to 38°C; relative to 100 parts by mass of the polyolefin resin (A), the epoxy compound (B) is blended in a ratio of 0.01 to 30 parts by mass. Such as the adhesive for laminate of claim 1, wherein the polyolefin resin (A) contains a modified polyolefin resin with an acid value of 1 to 200 mgKOH/g and/or a modified polyolefin with a hydroxyl value of 1 to 200 mgKOH/g Resin. As claimed in claim 1 or 2, wherein the epoxy compound (B) has two or more epoxy groups in one molecule and one or more hydroxyl groups in one molecule, and the weight average molecular weight is 3000 or less The epoxy compound is an essential ingredient. The adhesive for build-up of claim 1 or 2, wherein the epoxy compound (B) is blended in a ratio of 0.01 to 5.5 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). According to claim 1 or 2, wherein the crystallization peak temperature is the peak top temperature of the crystallization peak when the polyolefin resin is heated and melted, then the resin is cooled and the temperature is raised again; the conditions for the reheating are Use Hitachi High-Tech Science Corporation/X-DSC7000 and 30℃(0min)→-10℃/min→-80℃(0min)→10℃/min→200℃/min, the crystallization peak temperature is 28℃~38 ℃ range. For example, the adhesive for laminates of claim 1 or 2 further contains thermoplastic elastomer, tackifier, catalyst, phosphoric acid compound, melamine resin, silane coupling agent or reactive elastomer. A laminated body which is formed by using the adhesive for laminated layers according to any one of claims 1 to 6 between a metal layer and a polyolefin resin layer. A method for manufacturing a laminate, which is the method for manufacturing a laminate according to claim 7, which has a step of aging in the range of 25 to 80°C. A secondary battery that uses the laminate of claim 7 or the laminate obtained by the manufacturing method of claim 8 as an electrolyte sealing film or electrode part protective film. A method for manufacturing a secondary battery, which uses the laminate obtained by the manufacturing method of claim 8 as an electrolyte sealing film or an electrode portion protective film.

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