JP2010052365A - Insert resin molding product and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an insert resin molding product which has an adhesive layer containing sulfur in the interface between a metallic insert component and a resin molding portion, and exhibits a high adhesion; a method for manufacturing the product; and a cell equipped with the molding product. <P>SOLUTION: The method for manufacturing the insert resin molding product, provided with the adhesive layer 90 formed of an adhesive including a component containing sulfur atoms at the interface between the metallic insert 64 and the resin molding portion 70 composed of a thermoplastic resin, includes: preparing an insert product wherein the adhesive layer 90 is formed at the interface between the metallic insert 64 and the resin molding portion 70; and heating the insert product for a specific period of time to bind free sulfur in the adhesive layer 90 with the thermoplastic resin constituting the resin molding portion 70 so that the free sulfur in the adhesive layer 90 is reduced, as compared to before heating. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an insert resin molded article and a method for producing the same. Specifically, the present invention relates to an insert resin molded product provided with an adhesive layer containing a component containing a sulfur atom on a boundary surface between a metal insert member and a resin molded part, and a method for manufacturing the same. Further, the present invention relates to a battery provided with the molded product in an electrode terminal extraction part.

  The insert resin molded product is a composite manufactured by loading an insert member into a molding die and injecting a molten resin by injection molding or the like to solidify. Examples of the insert member used for this type of insert resin molded product include various materials such as metal, plastic, wood, glass, and elements. In particular, the molded article using a metal as an insert member is indispensable for automobile-related parts, electrical and electronic parts, etc. that use different physical properties, that is, resin insulation and metal conductivity.

As one form of the insert resin molded product using a metal as an insert member, there is a shape in which a part of the metal is exposed to the outside from the resin molded portion. For example, the molded article formed in such a shape is used for the electrode terminal extraction portion of the battery. In particular, in the case of a secondary battery such as a lithium ion battery, since it is placed in an environment where temperature changes due to charge and discharge are repeated, cracks occur at the interface between the insert member and the resin molded part due to the difference in thermal expansion coefficient between the metal and the resin. Or peeling easily occurs, which may impair the adhesion and may deteriorate the charge / discharge characteristics.
Patent document 1 is mentioned as a related technique regarding the insert resin molded product which uses a metal as an insert member. In the technique described in Patent Document 1, the adhesiveness is improved by loading a filler having a specified viscosity between the insert member and the resin portion, and the intrusion of moisture or the like into the interfacial gap is suppressed.

Japanese Patent Laid-Open No. 10-100191

  However, many fillers or adhesives provided at the interface between the insert member and the resin molded part contain a sulfur component. In this case, the moisture of the outside air (typically, the moisture resulting from the environment where the insert resin molded product is installed, for example, the concept including water) and the sulfur component react slowly to produce sulfuric acid, which causes cracks and cracks. There is a risk of causing it. In addition, when the metal insert member and the resin portion are separated, moisture or the like enters the gap and the metal corrodes, so that the desired functions (adhesion, insulation, etc.) cannot be achieved.

  The present invention has been made in view of such problems, and its main object is to provide an insert resin molded article with high adhesion provided with an adhesive layer containing sulfur on the boundary surface between the metal insert member and the resin molded portion. And a method of manufacturing the product. Another object is to provide a battery including the molded product.

In order to achieve the above object, according to the present invention, an insert comprising an adhesive layer formed of an adhesive containing a component containing sulfur atoms at the boundary surface between a metal insert member and a resin molded portion made of a thermoplastic resin. A method for producing a resin molded product is provided.
This manufacturing method prepares an insert molded body in which the adhesive layer is formed on the boundary surface between the insert member and the resin molded portion, and heats the molded body for a predetermined time, thereby free sulfur in the adhesive layer. And the thermoplastic resin constituting the resin molded portion are combined to reduce free sulfur in the adhesive layer more than before heating.

  In an adhesive layer formed from an adhesive containing a component containing sulfur atoms arranged on the boundary surface in order to improve the adhesion between the metal insert member and the resin molded portion, the adhesive layer is in a chemically unstable state. There is residual free sulfur. When a large amount of free sulfur is contained in the adhesive layer, there is a possibility that sulfuric acid is generated due to a slow reaction between the moisture in the outside air and free sulfur, causing cracks and cracks. In the present invention, the insert molded body after the insert molding is then heat-treated for a predetermined time, thereby binding the free sulfur in the adhesive layer and the thermoplastic resin constituting the resin molded portion (including chemical bonding or adsorption). ) Thereby, since free sulfur in the adhesive layer is reduced, sulfuric acid is hardly generated. As a result, a method for producing an insert resin molded product in which the adhesion between the metal insert member and the resin molded portion has been maintained for a long period of time is provided.

In a preferred aspect of the method for producing an insert resin molded product provided by the present invention, the insert member is a copper member, and the insert molded body in which the resin molded portion is made of polyphenylene sulfide is 1 to 85 to 150 ° C. It is characterized by heating for more than an hour.
Copper inserts are prepared as insert members, and the insert molded body that has been insert-molded by melting polyphenylene sulfide is heat-treated at 85 to 150 ° C. for 1 hour or longer to reduce free sulfur in the adhesive layer. it can. As a result, there is provided a method for manufacturing an insert resin molded product in which the adhesion between the insert member and the resin molded portion is maintained for a long time.

The present invention also provides an insert resin molded product comprising an adhesive layer formed of an adhesive containing a component containing sulfur atoms at the interface between a metal insert member and a resin molded portion made of a thermoplastic resin. To do. By the heat treatment after insert molding, the amount of free sulfur contained in the adhesive layer is reduced as compared with that before the heating.
If a large amount of free sulfur remaining without being cross-linked exists in the adhesive layer, sulfuric acid is generated due to a slow reaction with moisture in the outside air, which may cause cracks and cracks. In the present invention, after the molding resin filled with the insert member is filled with the molten resin and the insert molding is performed, the insert molded body is heat-treated, whereby the boundary surface between the metal insert member and the resin molding portion The free sulfur in the adhesive layer provided in advance decreases due to bonding with the resin molded part made of thermoplastic resin. As a result, free sulfur, which is an incentive to cause cracks and cracks, is reduced, and an insert resin molded product in which the adhesion between the metallic insert member and the resin molded portion is maintained for a long period of time is provided.

In a preferred embodiment of the insert resin molded product provided by the present invention, the insert member is a copper member, and the resin molded portion is the insert molded body made of polyphenylene sulfide, and after predetermined insert molding, 85 It is characterized by being heated at ~ 150 ° C for 1 hour or more.
An insert molded body including a copper insert member and a resin molded portion made of polyphenylene sulfide, which is one of thermoplastic resins, reduces free sulfur in the adhesive layer by heat treatment. Adhesion with polyphenylene sulfide is improved. As a result, an insert resin molded product having a long-lasting adhesive effect is provided.

Moreover, this invention provides a battery provided with the insert resin molded product disclosed here or the insert resin molded product obtained by the said manufacturing method as another side surface.
Further, in a preferred aspect of the battery provided by the present invention, the battery includes an electrode body unit, a case for housing the electrode body unit, and an electrode terminal connected to the electrode body unit, The insert resin molded product constitutes an electrode terminal extraction portion for extracting a part of the electrode terminal to the outside of the case.

In this specification, the “battery” refers to a power storage device that can extract predetermined electrical energy, and is not limited to a specific power storage mechanism (configuration of electrode body or electrolyte), but includes a primary battery and a secondary battery. It is. In addition to so-called chemical batteries such as lithium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, and lead acid batteries, electric storage elements (physical batteries) that can be used in the same industrial fields as various chemical batteries such as electric double layer capacitors Is a typical example included in the battery here.
In the present specification, the “electrode body unit” refers to a structure constituting the main body of a battery including at least one positive electrode and one negative electrode.
Further, in this specification, the “case” is one member constituting the battery disclosed herein, and stores the electrode body unit and the electrolytic solution, and has an opening (that is, an electrode body unit storage port). It means a housing for the company.
In addition, the “electrode terminal extraction portion” is a portion where each electrode terminal of the positive and negative electrodes provided in a part of the battery case is fixed to a part of the case in a state of protruding from the case, The part responsible for electrical connection with the outside.

  The insert resin molded product disclosed here constitutes a battery, typically the electrode terminal extraction part, thereby providing a battery having high sealing performance (sealing performance) and insulation. The battery thus provided can be suitably used as a power source for a vehicle (such as a hybrid vehicle), for example.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

The insert resin molded article of the present invention is characterized by including an adhesive layer formed of an adhesive containing a component containing sulfur atoms at the boundary surface between a metal insert member and a resin molded portion made of a thermoplastic resin. It is done. Therefore, as one preferred embodiment of the present invention, an insert resin molded product provided in a battery (typically, an electrode terminal extraction portion) will be described below as an example, but the present invention is limited to this embodiment. Instead, the shape and size can be appropriately changed depending on the application and the electronic device parts provided.
In the following, an insert resin molded product provided in the battery will be described in detail by taking a square-shaped lithium ion battery as an example, but the present invention is intended to be limited to the one described in the embodiment. It is not a thing. In addition, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect actual dimensional relationships.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals are given to members / parts having the same action.
With reference to FIGS. 1 and 2, a battery 100 according to the present embodiment (hereinafter also simply referred to as “battery”) will be described. FIG. 1 is a cross-sectional view schematically showing the structure of a battery 100 according to an embodiment of the present invention. FIG. 2 is an enlarged view of an electrode terminal extraction portion 30 that is a portion surrounded by a dotted line II in FIG. It is typical sectional drawing shown.

As shown in FIG. 1 and FIG. 2, the battery 100 according to the present embodiment roughly includes an electrode body unit 80 and a rectangular parallelepiped case that accommodates the electrode body unit 80 and an appropriate electrolytic solution therein. 10. The opening 12 of the case 10 is hermetically sealed by a lid 20 that is substantially the same size and shape as the bottom surface of the case 10 and forms one surface of the case 10.
Further, a positive terminal 44 and a negative terminal 64 for external connection are provided in the case 10 in the vicinity of both ends in the longitudinal direction of the lid 20. A part of the positive electrode terminal 44 and the negative electrode terminal 64 is inserted through the lid body 20 and is fixed together with the resin molding portion 70 at the electrode terminal extraction portion 30 of the lid body 20 in a state of protruding from the surface side of the lid body 20. ing. Furthermore, the positive electrode terminal 44 and the negative electrode terminal 64 are joined to the positive electrode current collector 42 and the negative electrode current collector 62 of the electrode body unit 80 accommodated inside the case 10, respectively, so that electrical connection with the outside is achieved. It is configured.
In the following description, the characteristic part of the present embodiment is mainly described with respect to the negative electrode 60 side. However, the application of the electrode terminal extraction portion 30 according to the present invention is not limited to the negative electrode 60 side, and the positive electrode 40 side. Can be applied to both the negative electrode 60 side and the positive electrode 40 side or the negative electrode 60 side. In the battery 100 according to this embodiment, the structure of the electrode terminal extraction part 30 on the positive electrode 40 side and the negative electrode 60 side is substantially the same.

In the present embodiment, the electrode terminal extraction part 30 is provided with an insert resin molded product.
The insert resin molded product is a composite of so-called different materials (in the present embodiment, each of the insert member and the resin molding portion). The insert member is loaded in advance into the molding die, and the molten resin is put into the die. The insert member and the resin molded portion are integrally formed by insert molding such as injection molding that is injected and solidified. In the insert member of this embodiment, a metal member is used. In addition, an adhesive layer 90 formed of an adhesive containing a component containing sulfur atoms is provided on a boundary surface between the electrode terminals 44 and 64 serving as the insert member and the resin molded portion 70.
In addition, although mentioned later for details, in this embodiment, after insert-molding the "insert molded body (composite body)" of the said structure further, the "insert resin molded product" obtained by heat-processing this molded body is used. It is provided in the electrode terminal extraction part 30.

First, the structure of the electrode terminal extraction part 30 of this embodiment provided with such an insert resin molded product will be described taking the negative electrode 60 side as an example.
As shown in FIG. 2, the electrode terminal extraction portion 30 according to the present embodiment has a negative electrode terminal 64 at the central axis portion of a cylindrical insertion portion 24 formed so as to rise slightly from the flat portion of the lid body 22. It is inserted and protrudes from the lid 20. That is, the negative electrode terminal 64 is inserted into the circular hole of the insertion portion 24 in a direction orthogonal to the planar direction of the lid body 22, and the electrode terminal extraction portion 30 is configured.
The resin molded portion 70 covers the outer peripheral surface of the negative electrode terminal 64 and the cylindrical insertion portion 24 of the lid body 22 so as to wrap around the portion where the negative electrode terminal 64 passes through the lid body 22. Therefore, the electrode terminal extraction portion 30 has a configuration in which the entire portion where the negative electrode terminal 64 is inserted into the lid body 22 is covered with the resin molding portion 70.

Next, the constituent materials of the members constituting the insert resin molded product in the electrode extraction part 30 will be described.
The constituent material of the insert member according to the present embodiment is a metal. Examples of the insert member include aluminum, copper, iron, tin, nickel, and zinc, but an aluminum alloy or an alloy such as stainless steel may be used. Further, a member whose surface is plated with aluminum, tin, nickel, gold or the like can also be preferably used.
In the present embodiment, the electrode terminals 44 and 64 are insert members. As the constituent material, a metal material is preferably used as described above. This is because the electrode terminals 44 and 64 are joined to the electrode current collectors 42 and 62 inside the case 10 to form an electrical connection with the outside. For example, as the constituent material of the negative electrode terminal 64, a metal material (for example, copper) of the same type as the negative electrode current collector 62 of the negative electrode 60 connected to the terminal 74 can be preferably used. On the other hand, as the constituent material of the positive electrode terminal 44, a metal material (for example, aluminum or aluminum alloy) of the same type as the positive electrode current collector 42 of the positive electrode 40 connected to the terminal 44 can be preferably used.

Moreover, as a constituent material of the lid 20, a metal material that is lightweight and has good thermal conductivity can be suitably used. Examples of such a metal material include aluminum, aluminum alloy, stainless steel, nickel-plated steel, and the like. A particularly preferable material is aluminum or an aluminum alloy that is lightweight and has good thermal conductivity.
The constituent material constituting the lid 20 may be the same material as the molding material constituting the case 10 or may be constituted using a different material. However, the case 10 and the lid body 20 made of the same material are preferable because they have the same physical properties such as thermal conductivity and melting temperature, and therefore, for example, there is no bias in melting due to laser welding heat. In the present embodiment, both the case 10 and the lid 20 are made of aluminum. The case 10 and the lid 20 having the above shapes are formed into a desired shape by pressing or the like using a plate material made of an appropriate metal material.

Furthermore, as a constituent material of the resin molding portion 70, a thermoplastic resin that can be subjected to insert molding such as injection molding and that serves as an insulating material is preferable. General-purpose resins or engineering resins (so-called engineering plastics) may be used, and crystalline resins or amorphous resins may be used. Super engineering plastics are particularly preferred.
For example, polyethylene (PE), polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene copolymer (ABS), polymethyl methacrylate (PMMA), polyamide (PA), polycarbonate (PC), polyacetal (POM), polyphenylene Examples thereof include oxide (PPO) and modified polyphenylene ether (m-PPE). In addition to these, various grades of polyvinyl chloride (PVC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and the like can be used. More preferably, super engineering plastics such as polyphenylene sulfide (PPS), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polyether ether ketone (PEEK) and the like having high strength and higher heat resistance temperature are mentioned. It is done.
In addition to the above, it is also possible to use different materials by two-color molding or the like of the resin molding part 70. In that case, in addition to the thermoplastic resin, various thermoplastic elastomers (TPE) can be suitably used as the constituent material of the resin molded portion 70. Various TPEs such as styrene-based, olefin-based, vinyl-based, and ester-based are mentioned. For example, it is possible to select an appropriate TPE from the viewpoint of heat resistance, oil resistance, chemical resistance, strength, and the like. .
In addition, various auxiliary components may be contained as necessary. Examples of such auxiliary components include antioxidants, light stabilizers, ultraviolet absorbers, plasticizers, lubricants, colorants, flame retardants, dispersants, antibacterial agents, and antistatic agents.
In the present embodiment, polyphenylene sulfide (PPS) is used as a constituent material of the resin molded portion 70.

Further, an adhesive layer 90 is disposed on the boundary surface between the negative electrode terminal 64 and the resin molded portion 70, and the adhesion of the boundary surface is enhanced.
As described above, since the negative electrode terminal 64 is connected to the negative electrode current collector 62 inside the case 10, the metal temperature of the negative electrode terminal 64 rises when the battery 100 is used (when it is energized) and is not used. Sometimes it cools down and goes down. In particular, in the case of a secondary battery, the temperature of the negative electrode terminal 64 changes up and down each time it is charged and discharged, and this change is repeated over a long period of time, so this temperature change occurs in the resin molded portion 70 adjacent to the negative electrode terminal 64. Susceptible to.
Further, the thermoplastic resin forming the resin molded portion 70 and the metal of the negative electrode terminal 64 have different thermal expansion coefficients. For this reason, the adhesiveness between the two gradually decreases due to the repeated temperature change of the negative electrode terminal 64, and cracks and peeling are likely to occur near the boundary. Therefore, in this embodiment, in order to maintain long-term adhesion between the negative electrode terminal 64 made of metal and the resin molded portion 70 made of an insulating member in contact with the terminal 64, an adhesive layer is formed on the boundary surface. 90 is provided.
In the present embodiment, the electrode terminal extraction portion 30 has a configuration in which the adhesive layer 90 is formed only on the boundary surface between the negative electrode terminal 64 and the resin molding portion 70, and the lid main body 22 (typically, the insertion portion 24). ) And the resin molded portion 70 are not formed with an adhesive layer 90 unlike the boundary surface with the negative electrode terminal 64. This is because the insertion portion 24 of the lid body 22 is integrally formed by insert molding, but is not directly energized like the negative electrode terminal 64, and therefore is not affected by the vertical change in temperature. . However, it is also possible to insert-mold such that the adhesive layer 90 is also formed on the boundary surface between the lid body 22 and the resin molding portion 70.

The adhesive layer 90 is formed of an adhesive containing a component containing sulfur atoms. As such an adhesive, a conventionally known commercially available adhesive can be appropriately selected. The adhesive containing a component containing a sulfur atom is, for example, inorganic sulfur (eg powdered sulfur, precipitated sulfur, colloidal sulfur), as exemplified by an elastomeric adhesive containing a sulfur-based crosslinking (vulcanizing) agent, Examples thereof include an adhesive containing an organic sulfur compound (for example, morpholine disulfide, alkylphenol disulfide) and the like. Of these, one may be used alone, or two or more may be used in combination. In addition to the crosslinking agent (vulcanizing agent), additives usually used for improving properties such as hardness and durability, for example, a crosslinking accelerator (vulcanization aid), a vulcanization acceleration aid, Sulfur atoms are added to softeners, processing aids, fillers, antioxidants, antiozonants, reinforcing agents, UV absorbers, flame retardants, colorants, foaming agents, coupling agents, dispersants, mold release agents, etc. A component to be contained may be added.
A wide range of natural and synthetic rubbers are used as the rubber component. Typical examples include natural rubber (NR), nitrile rubber (acrylonitrile-butadiene rubber) (NBR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene. Rubber (EPR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), butyl rubber (IIR), hydrogenated nitrile rubber, acrylonitrile-isoprene rubber (NIR), acrylonitrile-isoprene-butadiene rubber (NBIR), ethylene- Examples thereof include acrylic acid ester copolymer rubber (EAM). These rubbers include, for example, carboxylated rubbers (carboxylated nitrile rubber (XNBR)) containing acids such as unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, and maleic anhydride as comonomers. Modified rubber and other modified rubbers are also included. These rubbers may be used individually by 1 type, and may be used in mixture of 2 or more types.
In this embodiment, a TRI system (manufactured by Toa Denka Co., Ltd.) containing a triazine compound (a triazine derivative having a sulfur atom such as a thiol group as a substituent or a salt thereof) is used. The triazine compound is generally used as a vulcanizing agent such as acrylonitrile-butadiene rubber (NBR) having excellent heat resistance and oil resistance and an additive for improving various properties.

Next, the manufacturing method of the insert resin molded product which comprises the said electrode extraction part 30 is demonstrated.
First, a copper negative electrode terminal 64 serving as an insert member is prepared, and the above adhesive containing a triazine compound (TRI system, manufactured by Toa Denka Co., Ltd.) is applied to a portion corresponding to the boundary surface with the resin molded portion 70 (typically Was immersed). Then, the negative electrode terminal 64 to which the adhesive was applied was inserted into a circular hole formed in the insertion part 24 of the lid 20. Here, before inserting the negative electrode terminal 64 into the lid 20, the negative electrode current collector 62 and the negative electrode terminal 64 of the electrode body unit 80 may be connected in advance, but it is easy to handle at the time of insertion. In this order, the negative electrode terminal 64 is inserted into the lid body 22 and then connected to the negative electrode current collector 62.
Then, the negative electrode terminal 64 inserted through the lid 20 was placed (loaded) at a predetermined position in the injection mold. After loading, liquid polyphenylene sulfide, which was heated and melted with the mold closed, was injected into the mold and filled with molten resin. Then, the mold was kept for a predetermined time with the mold closed, cooled and solidified, and an insert molded body which was a composite of polyphenylene sulfide resin integrated with a copper insert member was molded.
In addition, as an apparatus used in order to implement such insert molding, the present invention is not characterized, but a general injection molding machine can be used.

In this embodiment, after the insert molding, the molded insert molded body composite was heat-treated. As heating temperature, 85-150 degreeC is preferable. In addition, More preferably, it is 120-150 degreeC, for example, 120 degreeC.
Furthermore, it is preferable to heat at the said heating temperature for about 1 hour or more. Particularly preferred is heating for 5 hours or more.
After the insert molding, the adhesive layer 90 formed from an adhesive containing a component containing sulfur atoms contains free sulfur remaining without being crosslinked. However, by performing the above heat treatment, the free sulfur in the adhesive layer 90 and the thermoplastic resin (polyphenylene sulfide in the present embodiment) constituting the resin molding portion 70 are covalently bonded or adsorbed, and so on. Free sulfur in it is reduced. The presence of free sulfur in the adhesive layer 90 does not cause a problem in the short term. However, when the free sulfur is contained in the adhesive layer 90 in a large amount, the moisture of the outside air and the free sulfur react slowly so that sulfuric acid is removed. May occur, resulting in a decrease in adhesion and may cause cracks and cracks. In this embodiment, since the free sulfur in the adhesive layer 90 is reduced by heat treatment after insert molding, sulfuric acid is hardly generated. As a result, an insert resin molded product in which the adhesion between the negative electrode terminal 64 and the resin molded portion 70 is maintained for a long time can be obtained.
In the present embodiment, an insert resin molded product in which the insert molded body is heat-treated at 120 ° C. for 5 hours to reduce free sulfur is used for the electrode terminal extraction portion 30.

The insert resin molded product used for the electrode terminal extraction part 30 on the negative electrode 70 side has been described above, but the electrode terminal extraction part 30 on the positive electrode 60 side is exactly the same as that on the negative electrode 70 side.
In addition, the case 10, the electrode body unit 80, the electrolytic solution, and the like, which are other constituent elements, are not particularly limited as long as the object of the present invention can be achieved. Since the lithium ion battery 100 including the electrode body unit has been constructed, other components will be described below. However, it is not intended to limit the present invention to such embodiments.

The case 10 only needs to have a shape that can accommodate the electrode body unit 80, and is not particularly limited to a cylindrical shape, a square shape, or the like. The case 10 only needs to be configured so that at least one end thereof is open and the electrode unit 80 can be accommodated from the opening 12. As shown in FIG. 1, a square-shaped case 10 is used in the present embodiment. The case 10 has a bottomed square shape with an opening 12 at one end, and the peripheral edge of the opening 12 is rectangular.
The constituent material of the case 10 is preferably made of a metal material that is lightweight, has good thermal conductivity, and good workability. As such a metal material, for example, an aluminum alloy (including pure aluminum), stainless steel, nickel-plated steel, or the like can be preferably used.

As shown in FIG. 1, an electrode body unit 80 is accommodated in the case 10. The electrode unit 80 includes a positive electrode sheet having a positive electrode active material layer on the surface of a long sheet-like positive electrode current collector 42 and a negative electrode sheet having a negative electrode active material layer on the surface of a long sheet-like negative electrode current collector 62. And a long sheet-like separator 82, and the positive electrode sheet and the negative electrode sheet are wound together with two separators and wound, and the resulting wound body is crushed from the side surface and crushed to form a flat shape. Has been. Examples of the separator 82 include those made of a porous polyolefin resin.
The positive electrode terminal 44 and the negative electrode terminal 64 are joined to the end portions of the positive electrode current collector 42 and the negative electrode current collector 62, respectively. It is electrically connected to the seat. As each joining method of the electrode terminals 44 and 64 and the electrode current collectors 42 and 62, various welding methods such as an ultrasonic welding method and a resistance welding method can be used.

As the positive electrode current collector 42 constituting the positive electrode sheet, a sheet material made of a metal having good conductivity can be used. For example, a conductive member made of aluminum or an alloy mainly composed of aluminum can be given. Moreover, as an electrode active material which is a main component of the positive electrode active material layer, one or more kinds of materials conventionally used in lithium ion batteries can be used without particular limitation. For example, a lithium transition metal composite oxide can be preferably used. Typical examples of such lithium transition metal composite oxides include lithium nickel composite oxides, lithium cobalt composite oxides, and lithium manganese composite oxides.
On the other hand, as the negative electrode current collector 62 constituting the negative electrode sheet, for example, a sheet material made of a metal such as copper can be used. For example, copper foil is mentioned as a preferable conductive member. Moreover, as an electrode active material which is a main component of the negative electrode active material layer, one or more kinds of materials conventionally used in lithium ion batteries can be used without particular limitation. For example, a particulate carbon material including a graphite structure (layered structure) can be given.
The positive electrode sheet and the negative electrode sheet can be preferably prepared by applying a composition in which the above electrode active material is dispersed in an appropriate solvent to each current collector and drying the composition. As the solvent, for example, an aqueous solvent such as water, or a non-aqueous solvent such as N-methyl-2-pyrrolidone (NMP), methyl ethyl ketone, and toluene can be preferably used.
Further, it is appropriately selected from polymers such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC). One or two or more selected polymer materials can be suitably used as various additives such as a binder and a thickener. The operation of applying (typically applying) the composition in which the electrode active material is dispersed in an appropriate solvent to each of the current collectors 42 and 62 is, for example, an appropriate application device (slit coater, die coater). A predetermined amount of the composition can be applied using a comma coater or the like.

After the electrode body unit 80 in which the electrode terminals 44 and 64 and the electrode current collectors 42 and 62 are joined is accommodated in the case 10, an electrolytic solution is injected into the case 10. Examples of the electrolytic solution for a lithium ion battery include a nonaqueous electrolytic solution containing a nonaqueous solvent and a lithium salt (supporting salt) that is added to and dissolved in the solvent.
Examples of the non-aqueous solvent include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), 1,2-dimethoxyethane, 1,2- Diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, 1,3-dioxolane, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, acetonitrile, propionitrile, nitromethane, N, N-dimethylformamide, dimethyl sulfoxide, sulfolane, γ-butyrolactone, etc. 1 type, or 2 or more types selected from non-aqueous solvents that are generally known to be usable in electrolytes of non-aqueous batteries (lithium ion secondary batteries, etc.) In combination it can be used.
As the supporting salt to be contained in the electrolytic solution, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , 1 type, or 2 or more types of lithium compounds (lithium salt) selected from LiI etc. can be used.
After injecting the electrolyte, the lid 20 covering the opening 12 of the case 10 and the periphery of the case are joined by laser welding or the like, so that the rectangular lithium which is a preferred embodiment of the present invention is used. An ion battery 100 is constructed.

[Evaluation test of heat treatment]
An evaluation test of the temperature and time of the heat treatment after insert molding was conducted.
First, a copper insert member was prepared and immersed in the adhesive containing a triazine compound (TRI system, manufactured by Toa Denka Co., Ltd.). The immersed member was loaded into a mold, and heated and melted polyphenylene sulfide (PPS) was filled into the mold to form a butt-type insert molded body (a composite of copper and polyphenylene sulfide). After insert molding, heat treatment was performed at different temperatures and times.
As each sample, a sample not subjected to heat treatment, that is, a sample stored at room temperature (sample 1) and one subjected to various heat treatments (samples 2 to 8) were prepared. As samples for the heat treatment, the following samples having different heating temperatures and heating times were prepared. 5 hours at 85 ° C. (Sample 2), 1 hour at 120 ° C. (Sample 3), 5 hours at 120 ° C. (Sample 4), 1 hour at 150 ° C. (Sample 5), 5 hours at 150 ° C. (Sample 6), One hour at 200 ° C. (sample 7) and 5 hours at 200 ° C. (sample 8) were set.
And after heat-processing each sample, it immersed in the prepared electrolyte solution at 80 degreeC for 220 hours, and measured the tensile strength of each sample using the commercially available tensile tester. As a test electrolyte, a non-aqueous electrolyte having a composition in which 1 mol / L LiPF ₆ was dissolved in a 1: 1 (volume ratio) mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) was used. . FIG. 3 shows the measurement results of tensile strength (MPa).

As shown in FIG. 3, the sample with the highest tensile strength (MPa) was Sample 4 that was heat-treated at 120 ° C. for 5 hours after insert molding. The tensile strength was about 25 MPa, and the tensile strength was about 15% greater than that of Sample 1 that was not subjected to heat treatment.
The samples having the second highest tensile strength after Sample 4 were Sample 3 that had been heat-treated at 120 ° C. for 1 hour and Sample 6 that had been heat-treated at 150 ° C. for 5 hours. Both samples had almost the same tensile strength.
In addition, the tensile strength of the sample 2 heat-processed at 85 degreeC for 5 hours was slightly larger than the sample 1 which did not heat-process. Further, Samples 7 and 8, which were heat-treated at 200 ° C. for 1 hour and 200 ° C. for 5 hours, had a lower tensile strength than Sample 1 which was not heat-treated.
From this, it was shown that the tensile strength is increased by performing a suitable heat treatment after the insert molding. That is, it is suggested that the adhesion between the insert member and the resin molded portion is improved. The most suitable condition was a heat treatment at 120 ° C. for 5 hours.

[X-ray photoelectron spectroscopy]
Next, the sample 1 that was not heat-treated and the sample 4 that was heat-treated at 120 ° C. for 5 hours, which had the highest tensile strength, were analyzed using an X-ray photoelectron spectrometer. FIG. 4 is a diagram showing the results analyzed by X-ray photoelectron spectroscopy. The upper row shows the spectrum of sample 1 (without heat treatment), and the lower row shows the spectrum of sample 4 (with heat treatment).

As a result of the X-ray photoelectron spectroscopic analysis, as shown in FIG. 4, both the spectrum of the sample 4 subjected to the heat treatment and the spectrum of the sample 1 not subjected to the heat treatment both have a peak (S-Cu) of about 163 eV, A broad peak (free sulfur) was observed around 166 to 171 eV in the same positional relationship.
However, in sample 4 (with heat treatment), the peak (S-Cu) at about 163 eV is particularly large compared to sample 1 (without heat treatment). Furthermore, the peak (S-Cu) at about 163 eV of sample 4 was higher than any peak of the peak population (free sulfur) of 166 to 171 eV, and it was confirmed that the energy intensity was large.
On the other hand, in Sample 1, a peak (S-Cu) of about 163 eV is confirmed, but the peak population (free sulfur) of 166 to 171 eV and the peak (S-Cu) of about 163 eV are peaks of almost the same height. Therefore, it was shown that the number of S—Cu bonds in sample 1 is not as large as that of sample 4.
As is clear from the results shown in FIG. 4, it was confirmed that in sample 4 heated after insert molding, free sulfur was reduced and S-Cu bonds were increased.

[Measurement test of crack growth]
Furthermore, the prismatic lithium ion battery (Examples A to C) provided with the insert resin molded product subjected to the heat treatment at 120 ° C. for 5 hours in the present embodiment in the negative electrode terminal take-out portion, and the heat treatment is not performed after the insert molding. A prismatic lithium ion battery (Comparative Examples A to C) provided with a normal insert resin molded product in the negative electrode terminal takeout part was constructed. And the crack growth amount formed in the boundary surface of each resin-molded part and insert member after each endurance was measured and compared by the following methods.
Note that one of the electrolyte Both ethylene carbonate (EC) and diethyl carbonate (DEC): 1 electrolyte (volume ratio) composition obtained by dissolving LiPF ₆ of 1 mol / L in a mixed solvent (water content 250 ppm by weight ) Was used. About another component and a manufacturing method, there is no difference in an Example and a comparative example.

  The lithium ion batteries of Examples A to C and Comparative Examples A to C were stored at 65 ° C. for 150 hours. Thereafter, the vicinity of the bottom of each battery (below the bonding surface between the lid and the case) was cut, and the electrode terminal extraction part on the negative electrode side was immersed in a fluorescent reagent (Super Glow fluorescent penetrant flaw detector manufactured by Marktec). . And the insertion part in this cover body of the electrode terminal extraction part by the side of a negative electrode was fixed, the force of the upper direction was applied to the negative electrode terminal protruded from the cover body, and the part covered with the resin molding part was pulled out. After drawing, the portion stained with the fluorescent reagent was observed, and the amount of crack propagation was measured. Table 1 shows the measurement results of the crack growth amounts of Examples A to C and Comparative Examples A to C.

As is clear from the results shown in Table 1, there was a difference of one order in the amount of crack growth between Examples A and B and Example C, but all of Examples A to C had a crack growth amount of 1 mm or less. It was. Further, the amount of crack propagation in Examples A and B was 0.1 mm or less, and it was shown that the cracks could be endured even if immersed in an electrolyte for 150 hours.
On the other hand, in Comparative Examples A to C, the crack progress amount was 1 mm or more. Among them, Comparative Example A had the largest crack growth amount, and cracks of 2 mm or more were confirmed.
As is apparent from the above measurement results, in Examples A to C in which heat treatment was performed after insert molding, the adhesion between the insert member and the resin molded portion was maintained even when immersed in the electrolytic solution for a long time. Therefore, it was confirmed that the crack growth was suppressed.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible. For example, the type of battery is not limited to the above-described lithium ion battery, but batteries having various contents with different electrode body constituent materials and electrolytes, for example, lithium secondary batteries having a negative electrode made of lithium metal or lithium alloy, nickel metal hydride batteries, nickel cadmium A so-called physical battery such as a battery or an electric double layer capacitor may be used.

It is sectional drawing which shows typically the structure of the battery 100 which concerns on one Embodiment. It is typical sectional drawing which expands and shows the part (electrode terminal extraction part 30) enclosed with the dotted line II in FIG. It is the measurement result of the tensile strength by the sample from which heat processing conditions differ. It is a comparison figure of the spectrum by X-ray photoelectron spectroscopy analysis of sample 1 which is not heat-treated, and sample 4 which is heat-treated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Case 12 Opening part 20 Lid body 22 Lid main body 24 Insertion part 30 Electrode terminal extraction part 40 Positive electrode 42 Positive electrode collector 44 Positive electrode terminal (insert member)
60 Negative electrode 62 Negative electrode current collector 64 Negative electrode terminal (insert member)
DESCRIPTION OF SYMBOLS 70 Resin molding part 80 Electrode body unit 82 Separator 90 Adhesion layer 100 Sealed battery

Claims (6)

A method for producing an insert resin molded article, comprising an adhesive layer formed of an adhesive containing a component containing sulfur atoms at the boundary surface between a metal insert member and a resin molded portion made of a thermoplastic resin,
An insert molded body in which the adhesive layer is formed on a boundary surface between the insert member and the resin molded portion is prepared, and the sulfur is contained in the adhesive layer and the resin molded portion by heating the molded body for a predetermined time. A method for producing an insert resin molded article, wherein the free sulfur in the adhesive layer is reduced more than before heating by bonding with a thermoplastic resin that constitutes the above.   The method according to claim 1, wherein the insert member is a copper member, and the insert molded body in which the resin molded portion is made of polyphenylene sulfide is heated at 85 to 150 ° C. for 1 hour or more. An insert resin molded article comprising an adhesive layer formed from an adhesive containing a component containing sulfur atoms at the interface between a metal insert member and a resin molded portion made of a thermoplastic resin,
An insert resin molded product characterized in that the amount of free sulfur contained in the adhesive layer is reduced by heat treatment after insert molding than before the heating. The insert member is a copper member, and the resin molded part is the insert resin molded product made of polyphenylene sulfide,
The insert resin molded product according to claim 3, wherein the insert resin molded product is heated at 85 to 150 ° C. for 1 hour or more after predetermined insert molding.   A battery comprising either the insert resin molded product obtained by the manufacturing method according to claim 1 or 2 and the insert resin molded product according to claim 3 or 4. A battery comprising an electrode body unit, a case for housing the electrode body unit, and an electrode terminal connected to the electrode body unit,
The battery according to claim 5, wherein the insert resin molded product constitutes an electrode terminal extraction portion for extracting a part of the electrode terminal to the outside of the case.

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