JP5482357B2 - Flat cable covering material and flat cable - Google Patents

Description

  The present invention relates to a flat cable covering material. More specifically, since the adhesive layer has initial tackiness, the work efficiency of the production process for manufacturing the flat cable is good, and the completed flat cable has good adhesion to the conductor. The present invention relates to a flat cable covering material for a flat cable used for electrical equipment, electronic equipment, and the like having excellent flexibility and heat resistance, and a flat cable using the same.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “PET” is an abbreviation, functional expression, common name, or industry term for “polyethylene terephthalate” and “FFC” is “flexible flat cable”.

(Background Art) Conventionally, in electronic devices such as OA devices and game machines, flat cables are used for electrical connection between computers and electronic components and various wirings. The flat cable is routed in a narrow casing of the electronic device, slid as the electronic component moves, and used in a high-temperature environment accompanying heat generation of the electronic component. For this reason, the flat cable covering material covering the flat cable is required to have flexibility with respect to sliding, heat resistance against high temperatures, and flame retardancy. Furthermore, in the disposal process after use, it can be a cause of environmental destruction. In recent years, automobiles and household appliances have become lighter and thinner, flexible flat cables (hereinafter referred to as FFC) are widely used for wiring between circuit boards, and the use of FFC is diversified. . For example, there are an increasing number of fields that require heat resistance around automobile engines, exhaust heat parts such as copying machines, heating furnaces, and flexibility at high temperatures. However, in conventional FFCs, polyester-based resins or the like are generally used as adhesives for embedding conductive wires, and there are drawbacks in that heat resistance is difficult and adhesive strength in high-temperature environments is insufficient. . In addition, even in a sliding environment accompanying the movement of parts, it is necessary to have excellent adhesion to the conductor and have sufficient flexibility and heat resistance. In addition, in the manufacturing process in which conductors are arranged and adhered to the flat cable covering material, the flat cable covering material has no initial adhesive force and the conductor wires are peeled off. There was also a problem that it was extremely slow and expensive.
Flat cable covering material has excellent adhesion to conductors under high temperature and severe sliding environment, and has sufficient flexibility and heat resistance. After holding the conducting wire, it is heated and heat-cured, so the manufacturing speed of the bonding and bonding processes can be increased at the same time, or it can be heat-treated in batches in a large quantity, so it must be low in cost. It has been.

JP-A-8-60108 JP-A-9-221642 JP 2001-89736 A Japanese Utility Model Publication No. 3-26008 JP 2006-40817 A

(Prior Art) Conventionally, a non-halogen flame retardant flat cable using an adhesive layer made of a polyimide film and a phosphorus-modified saturated polyester copolymer is known (for example, see Patent Document 1). A halogen-free flame retardant flat cable using an adhesive layer containing a thermoplastic polyester resin and a phosphorus flame retardant is known (see, for example, Patent Document 2). A non-halogen flame retardant flame retardant adhesive comprising a polyester resin, a polyphosphoric flame retardant, and a non-polyphosphoric nitrogen-containing organic flame retardant is known (for example, see Patent Document 3). However, in all of Patent Documents 1 to 3, the base film of the flat cable uses a polyester film or a polyimide film, and the polyester film alone has insufficient flame retardancy, and the polyimide film has a low price. There is a problem that it is expensive. In addition, in flat cable covering materials that use halogen-based flame retardants in the adhesive layer (also known as an adhesive layer), flat cables using the flat cable covering materials are discarded after use with electronic devices. Later, there is a drawback that the flame retardant may leak into the environment for some reason or may be taken into the human body and harm health. Furthermore, flame retardants using phosphorous, polyphosphoric acid, non-polyphosphoric nitrogen-containing organic substances, etc. as non-halogen flame retardants must be contained in large amounts to obtain sufficient flame retardancy. When it is contained, the adhesive strength with the conductor is reduced.
The present applicant also discloses a flat cable covering material in which an electrically insulating support material, a thermally crosslinkable resin layer, and a flame retardant thermoplastic adhesive layer are sequentially laminated (for example, a patent). Reference 4). There is also disclosed a flat cable covering material that achieves both adhesiveness with conductors and self-adhesiveness between the covering materials and flame retardancy (for example, see Patent Document 5). However, since all of Patent Documents 4 to 5 hold and fix the conductive wire by the flame-retardant thermoplastic adhesive layer, there are disadvantages that the production speed is extremely slow and the cost is high.

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. The purpose is to have excellent adhesion to the conductor even in high temperature and severe sliding environment, and have sufficient flexibility and heat resistance. It is to provide a flat cable covering material and a flat cable using the same, which can improve the manufacturing efficiency at the same time by bonding and bonding processes by heating and thermosetting after holding.

In order to solve the above problems, a flat cable covering material according to the invention of claim 1 of the present invention is a base cable and a flat cable covering material in which at least an adhesive layer is laminated on one surface of the base material. The adhesive that constitutes the adhesive layer contains an acrylic resin, an epoxy resin, and a curing agent.
The flat cable covering material according to the invention of claim 2 is such that the adhesive layer is such that the acrylic resin and the epoxy resin have a sea-island structure.
The flat cable covering material according to the invention of claim 3 is an acrylic ester copolymer in which the acrylic resin is obtained by radical polymerization of a monomer having EA-BA-AN, and the epoxy resin is NBR (nitrile butadiene rubber). ) It consists of a modified epoxy resin and a bis-A type epoxy resin so that the curing agent is a dicyandiamide compound.
The flat cable according to the invention of claim 4 is a flat cable formed by covering a conductor array in which a plurality of conductors are arranged in the same plane from both sides with a flat cable covering material. And a flat cable covering material in which at least an adhesive layer is laminated on one surface of the substrate, and the adhesive constituting the adhesive layer is an acrylic resin, an epoxy resin, and It contains a curing agent and the adhesive layer is thermally cured.

According to the present invention of claim 1, even under high temperature and severe sliding environment, it has excellent adhesion to the conductor, has sufficient flexibility and heat resistance, and in the production of the flat cable, After holding the conductive wire with the initial adhesive force, heating and thermosetting can simultaneously increase the production speed of the bonding and bonding processes, and the effect is low.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the production efficiency can be improved and the cost can be reduced.
According to the third aspect of the present invention, in addition to the effects of the first and second aspects, the adhesiveness to the conductor is excellent and sufficient flexibility and heat resistance are obtained even under higher temperatures and severe sliding environments. It has the combined effect.
According to the present invention of claim 4, in manufacturing, after holding the lead wire with initial adhesive force, heating and thermosetting can simultaneously improve the manufacturing efficiency of the bonding and bonding processes, and the cost is low. Moreover, it has excellent adhesion to the conductor even under high temperature and severe sliding environment, and has the effect of combining sufficient flexibility and heat resistance.

It is sectional drawing of the flat cable coating | covering material which shows one Example of this invention. It is a flat cable schematic top view which shows one Example of this invention. It is AA sectional drawing of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (Flat cable covering material) The flat cable covering material 10 of the present invention is formed by laminating a base material 11 and at least an adhesive layer 13 on one surface of the base material 11, as shown in FIG. The adhesive 15 constituting the adhesive layer 13 includes an acrylic resin, an epoxy resin, and a curing agent. In addition, in order to improve adhesive force between the base material 11 and the adhesive layer 13, you may provide the primer layer 12 as needed. Preferably, the adhesive layer 13 has an island-island structure of an acrylic resin and an epoxy resin. More preferably, the acrylic resin is an acrylic ester copolymer obtained by radical polymerization of a monomer having EA-BA-AN, and the epoxy resin is an NBR (nitrile butadiene rubber) -modified epoxy resin, and bis-A. It is made of a type epoxy resin, and the curing agent is a dicyandiamide compound. In addition, the flat cable coating | covering material 10 may laminate | stack release paper on the adhesive layer 13 surface from the point of the preservation | save before use and the handleability at the time of use, and the base material 11 / adhesive bonding It is good also as a structure of the layer 13 / release paper.

  (Effect) By setting it as said structure, it can be set as the thermosetting flat cable coating | covering material 10 with initial stage adhesion. That is, since the adhesive layer 13 of the flat cable covering material 10 has initial tackiness, in the production of the flat cable, after holding the conducting wire with the initial tackiness, by heating and thermosetting, The bonding and bonding processes are separate processes, but the manufacturing speed of the bonding process can be increased, the manufacturing speed of the bonding process can also be increased, or batch processing can be performed in batches, resulting in a result. The cost can be reduced. In addition, the adhesive layer 13 and the lead wire are bonded by a thermosetting reaction, so that the adhesive strength with the lead wire is also strong, and the adhesive strength has the effect of not deteriorating due to temperature change, even under high temperature and severe sliding environment. It is excellent in adhesion to the conductor and can have sufficient flexibility and heat resistance.

  (Substrate) The substrate 11 is excellent in mechanical strength and has excellent heat resistance, chemical resistance, solvent resistance, flexibility, insulation, etc., for example, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc. Polyester film, polyamide film such as nylon 6, nylon 66, nylon 610, polyimide film such as polyimide, polyamideimide, polyetherimide, fluorine film, polyethersulfone, polyetherketone, polyethersulfide, polyarylate Polyester ether, wholly aromatic polyamide, polyaramid, polypropylene film, polycarbonate film and the like can be applied. Usually, polyalkylene terephthalates such as polyethylene terephthalate and polyethylene naphthalate are preferably used.

  As the substrate 11, an unstretched film or a stretched film can be applied, and a stretched film is preferable for the purpose of improving the strength. A film stretched in a uniaxial direction or a biaxial direction is particularly preferable. The surface of the base film may be subjected to, for example, corona treatment, plasma treatment, ozone treatment, or other pretreatment as necessary. The thickness of the substrate film is usually 5 μm to 200 μm, and preferably 10 μm to 100 μm. When the thickness is less than 5 μm, the mechanical strength is insufficient, and suitability for forming the primer layer 12, the adhesive layer 13, and the like is reduced. When the thickness is 200 μm or more, the flexibility is insufficient and the slidability is deteriorated. By using such a thickness, the strength required for the flat cable covering material 10 can be imparted, and the flat Good flexibility can be imparted to the cable covering material 10.

  (Primer layer) Next, the primer layer 12 is applied to the substrate 11 as necessary. The primer layer 12 firmly adheres the adhesive layer 13 to the base material 11, resists sliding during use in electronic equipment, suppresses delamination between layers, and provides insulation and durability. It is for improvement. Examples of the material of the primer layer 12 include a polyfunctional compound having an isocyanate group, a blocked isocyanate group, and / or a carbodiimide group, and a polyester resin having a glass transition point of 20 ° C to 120 ° C, preferably 30 ° C to 100 ° C. A primer agent containing a polyurethane resin can be applied. Further, as the primer agent, a so-called anchor coating agent mainly composed of a polyethyleneimine compound, an organic titanium compound, an isocyanate compound, a urethane compound, a polybutadiene compound, or the like can also be applied.

  Apply the diluted solution of primer 12 by roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, rod coating, kiss coating, knife coating, die coating, comma coating, flow coating, spray coating, etc. Dry and remove the solvent to form the primer layer 12. If necessary, it is aged at a temperature of 30 ° C to 70 ° C. The thickness of the primer layer 12 is usually about 0.05 μm to 10 μm, preferably about 0.1 μm to 5 μm.

  (Release paper) Release paper is also called release film, separate paper, separate film, separate paper, release film, release paper. The release paper has a release layer on one side or both sides of a release paper base such as fine paper, coated paper, impregnated paper, and plastic film.

  (Release layer) The release layer is not particularly limited as long as it is a material having releasability. For example, silicone resin, organic resin-modified silicone resin, fluororesin, aminoalkyd resin, melamine resin, acrylic Resin, polyester resin and the like. These resins can be used in any of emulsion type, solvent type and solventless type.

  (Formation of Release Layer) The release layer is formed by applying a coating liquid in which a release layer component is dispersed and / or dissolved on one surface of a release film base film, followed by heating and drying and / or curing. As a coating method of the coating liquid, a known and arbitrary coating method can be applied, and examples thereof include roll coating, gravure coating, and spray coating. Moreover, you may form a release layer in the whole surface or a part of at least single side | surface of a base film as needed.

  (Peeling force) The peeling force of the release layer is preferably about 1 to 2000 mN / cm and more preferably 100 to 1000 mN / cm with respect to the pressure-sensitive adhesive tape. When the release force of the release layer is less than 1 mN / cm, the release force from the pressure-sensitive adhesive sheet or the material to be bonded is weak, and it peels off or partially floats. Moreover, when larger than 2000 mN / cm, the peeling force of a release layer is strong and it is hard to peel. From the viewpoint of stable releasability and workability, addition and / or polycondensation-type curable silicone resins for release paper, which are mainly composed of polydimethylsiloxane, are preferred.

  (Adhesive layer) The adhesive layer 13 includes an acrylic resin having adhesiveness, an epoxy resin mainly having adhesiveness to an adherend, and a curing agent that reacts with these resins. It can be set as the flat cable coating | covering material 10 which has both adhesiveness and adhesiveness.

  (Epoxy) Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A epoxy resin and bisphenol F epoxy resin, novolac type epoxy resins such as novolac epoxy resin and cresol novolac epoxy resin, biphenyl type epoxy resin, and stilbene type. Examples include epoxy resins such as epoxy resins, triphenolmethane type epoxy resins, alkyl-modified triphenolmethane type epoxy resins, triazine nucleus-containing epoxy resins, dicyclopentadiene-modified phenol type epoxy resins, and also phenol novolac resins and cresol novolak resins. , Novolak type phenolic resin such as bisphenol A novolac resin, phenolic resin such as resol phenolic resin, urea (urea) resin, melamine resin, etc. Resins having a triazine ring, unsaturated polyester resins, bismaleimide resins, polyurethane resins, diallyl phthalate resins, silicon resins, resins having a benzoxazine ring, cyanate ester resins can be exemplified.

  From these resins, it is preferable to include at least a relatively soft epoxy resin and a hard epoxy resin. Here, “soft” and “hard” are relative comparisons, and a soft or hard material having a difference in hardness may be used.

  (Hard epoxy) As the hard epoxy resin, a crystalline epoxy resin is preferable, and a rigid structure such as a biphenyl skeleton, a bisphenol skeleton, and a stilbene skeleton has a main chain and a relatively low molecular weight. Preferably, for example, bisphenol type epoxy resins such as bisphenol A epoxy resin and bisphenol F epoxy resin, and bisphenol A type epoxy resins are particularly preferable. A bisphenol A type epoxy resin having a main chain of 1 to 3 is liquid at normal temperature, and a bisphenol A type epoxy resin having a main chain of 2 to 10 is solid at normal temperature. Among the crystalline epoxy resins, those that are crystallized and solid at room temperature also rapidly melt and change to a low-viscosity liquid when the temperature reaches the melting point or higher, so that the adhesive portion of the adhesive layer 13 is covered. It is possible to increase the adhesive strength by closely adhering to the back surface of the adherend in the initial stage and further adhering. A hard epoxy resin has a high crosslink density, and therefore has high mechanical strength, good chemical resistance, high curability, and low hygroscopicity (because the free volume is small).

  As the hard epoxy resin, a bisphenol A type epoxy resin is preferable, but it is more preferable to use a plurality of different hardnesses. Examples of the plural include ones having different numbers of main chains of a bisphenol skeleton having a rigid structure. For example, a bisphenol A type epoxy resin having a main chain of 1 to 3 and a bisphenol A type epoxy having a main chain of 2 to 10 What is necessary is just to use resin together. By using together, since some softness | flexibility can be obtained, maintaining mechanical strength, it is excellent in adhesiveness. By mixing solid epoxy, the film forming property can be improved. Here, the difference in hardness is a relative comparison, and it is sufficient if there is a difference in hardness, and a harder one or a harder one may be used. Specifically, as a bisphenol A type epoxy resin having a main chain of 1 to 3, manufactured by Japan Epoxy Resin Co., Ltd., JER828 is used as a bisphenol A type epoxy resin having a main chain of 2 to 10 manufactured by Japan Epoxy Resin Co., Ltd. JER1001 etc. can be illustrated.

  (Soft Epoxy) As the soft epoxy resin, an epoxy resin modified to include a rubber component is preferable. In particular, NBR (nitrile butadiene rubber) -modified epoxy resin is preferable because it is less likely to discolor due to heating and is easily mixed with a crystalline epoxy resin that is a hard epoxy resin. Specific examples include EPR4030 manufactured by ADEKA. In order to follow dimensional changes due to thermal expansion of the adherend, it is excellent in terms of improved heat resistance, impact resistance and flexibility.

  The (acrylic) acrylic resin is not particularly limited as long as it has adhesiveness. For example, in addition to a polymer obtained by polymerizing acrylic acid, methacrylic acid and ester monomers thereof, non-polymerizable with the above monomers. A copolymer obtained by copolymerizing a saturated monomer (for example, vinyl acetate, styrene, acrylonitrile, etc.) can be used. As the acrylic resin, an acrylate copolymer is preferable, and a copolymer having at least one of acrylic acid, acrylic acid ester, methacrylic acid ester, and acrylonitrile as a monomer component is exemplified. Among these, an acrylate copolymer having a compound having an epoxy group, a hydroxyl group, a carboxyl group, a nitrile group, or the like as a functional group is preferable. Thereby, the adhesiveness to a to-be-adhered body improves more. Specific examples include SG-P3 manufactured by Nagase ChemteX Corporation.

  Particularly preferably, the acrylic resin is an acrylic ester copolymer formed by radical polymerization of a monomer having EA-BA-AN (ethyl acrylate-butyl acrylate-acrylonitrile), In addition, it is possible to improve applicability and film formability when forming the adhesive layer 11. Moreover, it is possible to ensure the initial tackiness of the adhesive layer 11.

  The weight average molecular weight of the acrylate copolymer is not particularly limited, but is preferably 100,000 or more, particularly preferably 150,000 to 1,000,000, and application of the adhesive layer 11 when the weight average molecular weight is within this range. Improves. In order to increase the cohesive strength, a rosin resin, a terpene resin, a coumarone resin, a phenol resin, a tackifier such as an aliphatic or aromatic petroleum resin, and the like may be added.

  (Curing agent) Examples of the curing agent include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and metaxylylene diamine (MXDA), diaminodiphenylmethane (DDM), and m-phenylenediamine (MPDA). In addition to aromatic polyamines such as diaminodiphenylsulfone (DDS), amine-based curing agents such as polyamine compounds including dicyandiamide (DICY) and organic acid dihydralazide, hexahydrophthalic anhydride (HHPA), methyltetrahydrophthalic anhydride (MTHPA) Acid anhydride such as alicyclic acid anhydride (liquid acid anhydride), trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), benzophenone tetracarboxylic acid (BTDA), etc. Physical curing agent, Phenolic curing agent such as Nord resin can be exemplified. In particular, dicyandiamide (DICY) is a latent curing agent, and thus is excellent in storage stability and has a pot life of several weeks even at room temperature storage. Moreover, you may include imidazoles as a hardening accelerator.

  (Additives) Further, the adhesive 13 may be processed, for example, in terms of workability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, difficulty. For the purpose of improving and modifying flammability, antifungal properties, electrical properties, strength, etc., for example, lubricants, plasticizers, fillers, fillers, antistatic agents, antiblocking agents, crosslinking agents, antioxidants UV absorbers, light stabilizers, colorants such as dyes and pigments, and the like may be added. Further, if necessary, a coupling agent such as silane, titanium, and aluminum can be further included.

  (Sea Island) The adhesive 13 is mainly composed of an acrylic resin and an epoxy resin, but a sea island structure is preferable. It is preferable that the acrylic resin is in a sea state and the epoxy resin is in an island state in the sea. Although epoxy resin consists of multiple types, it is presumed to be in a compatible state. With this preferable structure, it is presumed that the sea state of the acrylic resin develops initial tackiness, and the island-shaped poxy resin comes into contact with and adheres to the adherend by pressure heating. Further, the dispersed state is preferable because a certain distance (several μm) at which the sea and the islands do not come into contact with each other can be avoided, and the interface strength can be kept high.

  (Blend ratio) The adhesive 13 is composed of an acrylic resin, a hard epoxy resin, and a soft epoxy resin, and the blend ratio is acrylic resin: hard epoxy resin: soft epoxy resin: curing agent = 100: 75 to 175: 10 to about 100: 2 to 20, preferably acrylic resin: hard epoxy resin: soft epoxy resin = 100: 100 to 150: 25 to 75: 5 to 10. In addition, when using two or more hard epoxy resins, it is set as the sum total. If the hard epoxy resin and the soft epoxy resin are less than this range with respect to the acrylic ester copolymer, the adhesive strength is too strong, resulting in defects when work needs to be replaced or reduced workability. In other words, the adhesive strength with the adherend is reduced. Above this range, the adhesive strength with the adherend is improved, but the adhesive strength is low, and temporary fixing is required and workability is reduced. Moreover, when the compounding ratio of the curing agent is less than this range, the heat resistance after joining is low, and the adhesive strength is likely to deteriorate due to a temperature change. Above this range, the flat cable covering material 10 is stored until it is joined to the adherend, but the storage stability during that period is lowered, and the unreacted curing agent remains, resulting in a decrease in adhesive strength. There is also a point.

  (Flame Retardancy) The adhesive layer 13 is mainly composed of an epoxy resin and thus has flame retardancy. However, a flame retardant component may be added for further improvement. As the flame retardant component, it is preferable to use one or more non-halogen flame retardants such as an aminotriazine sulfate compound, a hydrated metal compound and / or a metal oxide compound. The aminotriazine sulfate compound is a non-halogen flame retardant, and melamine sulfate, acetoguanamine sulfate, guanylmelamine sulfate, melem sulfate, melam sulfate, etc. can be applied. As the hydrated metal compound, aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, titanium hydroxide, zinc hydroxide, and the like can be applied. However, the hydroxide is excellent in flame retardancy and advantageous in terms of cost. Aluminum and magnesium hydroxide are preferred. These hydrated metal compounds can be used alone or in combination of two or more. As the metal oxide compound, for example, antimony oxide compounds, zinc stannate, zinc borate, tin oxide, molybdic acid, molybdenum oxide, boron oxide, silicon dioxide, and the like can be applied.

  The adhesive layer 13 has various additives such as an antioxidant, a metal corrosion inhibitor, a colorant (pigment, dye), an antiblocking agent, a resin and the like as long as the effect of the present invention is not affected. Various coupling agents, cross-linking agents, cross-linking aids, fillers, antistatic agents, and flame retardant catalysts that increase the cohesive force with the flame retardant may be added as appropriate. The size of the inorganic flame retardant particles is about 0.01 to 15 μ as primary particles. In terms of flame retardant performance, the more flame retardant components are better, the more the flame retardants, the fewer synthetic resin components, and the film cannot be formed when forming and processing the flame retardant adhesive layer. The necessary adhesion performance cannot be obtained. As a composition having flame retardancy and good workability, 20 to 99% by mass of the synthetic resin component and 1 to 80% by mass of the flame retardant component are suitable.

  (Manufacturing method) First, the adhesive agent 15 composition for forming the adhesive layer 13 is produced, and this adhesive agent 15 composition should just be apply | coated to the base material 11. FIG. It is preferable that the release paper is adhered to protect the adhesive layer 13 surface after application. When using multiple types as a hard epoxy resin using a stirrer, first mix and stir, then mix and stir the curing agent, dilute with a solvent, mix and stir the soft epoxy resin, and then acrylic The system resin was mixed and stirred to obtain an adhesive 15 composition.

  (Composition) The stirrer for producing the adhesive 15 composition may be prepared by mixing desired materials, kneading and dispersing as necessary, and is not particularly limited. Conventional kneading and dispersing machines such as two-roll mills, three-roll mills, pebble mills, tron mills, Szegvari attritors, high-speed impeller dispersers, high-speed stone mills, high-speed impact mills, despers, high-speed mixers, ribbon blenders, and kneaders Intensive mixers, tumblers, blenders, dispersers, homogenizers, ultrasonic dispersers, and the like can be applied.

(Coating method) The coating method is not particularly limited. For example, roll coating, reverse roll coating, transfer roll coating, gravure coating, gravure reverse coating, comma coating, rod coating, blade coating, bar coating, Wire bar coat, die coat, lip coat, dip coat, etc. can be applied.
If this composition is applied to the surface of the base material 11 by the above-described coating method and dried, and then release paper is attached as necessary, the flat cable covering material 10 is obtained. The viscosity of the composition (coating liquid) is adjusted to about 1 to 20000 centistokes (25 ° C.), preferably 1 to 200 centistokes. In the case of impregnating and coating 15, a lower viscosity is preferable, and it is 1 to 100 centistokes.

  (Flat Cable) As shown in FIG. 2, the flat cable 1 covers a conductor array in which a plurality of conductors 21 are arranged in the same plane with a flat cable covering material 10 from both sides. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. The conductor 21 rows are thermally cured in an embedded state by the adhesive layer 13 of the flat cable covering material 10 covered from both sides. Are firmly bonded.

  (Adhesion method with a conductive wire) The conventional adhesion method with a conductive wire is such that the surfaces of the adhesive layers of two flat cable covering materials are opposed to each other, and a plurality of conductors 21 such as metals are placed on the same plane. In the state where the conductor row arranged inside is interposed, the flat cable covering material and the conductor 21 are heat-pressed and heat-sealed to closely bond the heat-sealable adhesive layer and the conductor 21, The adhesive layer itself is made by a manufacturing method in which the adhesive layers are adhered to each other. In this way, two flat cable covering materials facing each other and the conductor 21 are closely bonded, and the conductor 21 is embedded in the adhesive layer and integrated into a flat cable.

  (Conventional Manufacturing Method) In the above-described conventional manufacturing method, a polyester resin or the like is generally used for the adhesive of the adhesive layer in which the conductive wire 21 is embedded, and a flat cable covering material is used when arranging the conductive wire. In the process of bonding together, the adhesive of the conventional adhesive layer has no initial adhesive force, so the conductors are easy to peel off, and the flat cable covering material and the conductor 21 are heated and pressurized within the same traveling process. Must be heat sealed. This heat sealing process heats and presses the covering material for the flat cable and the conductor 21 and requires the temperature rise energy of these materials, the melting energy of the adhesive layer and a great deal of heat energy, and the heat sealing process is inevitably slow. Has been. For this reason, the work efficiency in the manufacturing process of a flat cable falls. Moreover, the heat resistance is difficult, and the problem of insufficient adhesive strength at high temperatures has also been attached.

(Manufacturing method of the present invention) On the other hand, in the present invention, a flat cable covering material 10 having a thermosetting adhesive layer 13 having initial tackiness is used, and bonding is conventionally performed in the same process. The bonding process is a separate process. First, (1) using the two flat cable covering materials 10 of the present invention, the surfaces of the respective adhesive layers 13 are overlapped with each other, and a plurality of conductors 21 such as metals are provided between the layers. The conductor rows arranged in the same plane are overlapped and laminated together with the conductors 21 held by the adhesive force of the respective adhesive layers 13 to perform a bonding process.
In addition, when it is set as the structure of the base material 11 / adhesive layer 13 / release paper which laminated the release paper on the adhesive layer 13, the release paper is peeled off and removed in advance or at the first stage of the process. That's fine. Next, (2) the flat cable covering material 10/21 conductors / flat cable covering material 10 is heated to heat-cure the adhesive layer 13, thereby two opposing flat cables. The adhesive layer 13 and the conductor 21 row of the coating material 10 and the adhesive layer 13 are also adhered to each other, and the conductor 21 is embedded in the adhesive layer 13 and integrated into the flat cable 1. .

  The adhesion process for curing the adhesive layer 11 is performed by heating or pressure heating, and the heating temperature is about 100 to 300 ° C, preferably 150 to 250 ° C. The heating time is 1 to 240 minutes, preferably 10 to 60 minutes. The adhering step may be performed in a wound form or cut and processed in a sheet form.

  Conventionally, since the adhesive of the adhesive layer does not have an initial adhesive force, it cannot be pasted once, and it is at a speed that matches the extremely slow heat sealing process within the same running process. However, since the laminating process is also performed, the work efficiency has been significantly reduced. However, since the adhesive layer 13 of the flat cable coating material 10 of the present invention has initial tackiness, the flat cable is manufactured by holding the conductor with the initial tackiness and then heating and thermosetting. I can. The bonding and bonding processes are separate processes. (1) Since the bonding process is only bonding, the production speed can be remarkably increased, and (2) the bonding process is batch-processed in large quantities. Since heat treatment can be performed, the cost can be reduced as a result. In addition, the adhesive layer 13 and the conductive wire are bonded by a thermosetting reaction to obtain a strong adhesive strength due to the epoxy resin, and the adhesive strength with the conductive wire is also strong, and the adhesive strength deteriorates even with temperature change. In addition, it has low brittleness due to the acrylic resin, and has excellent shear strength, high impact resistance, and heat resistance, so it can adhere to conductors even under high temperatures and severe sliding conditions. In addition, it can have both sufficient flexibility and heat resistance.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this. In addition, except a solvent, each composition of each layer is a mass part of solid content conversion.
Further, the bisphenol A type epoxy resin (main chain 1 to 3) is referred to as EPX-1, the bisphenol A type epoxy resin (main chain 2 to 10) is referred to as EPX-2, and the NBR modified epoxy resin is referred to as EPX-3.

(Example 1) The following raw materials were mixed with a stirrer to prepare an adhesive 15 composition.
-Acrylic ester copolymer 100 parts-EPX-1 50 parts-EPX-2 100 parts-EPX-3 50 parts-Dicyandiamide 7 parts Next, a base material 11 having a thickness of 23 μm polyethylene terephthalate (manufactured by Toyobo Co., Ltd., E-5107) is used to form the adhesive layer 13 by applying and drying the steam adhesive composition 15 with a comma coater so that the weight after drying is 50 g / m ^2. After that, a light-peeling separator film (SP-PET 01BU, manufactured by Tosero) was attached to the surface of the adhesive layer 13 to obtain the flat cable coating material 10 of Example 1.

Next, using the two flat cable covering materials 10 of Example 1 slit to a width of 25 mm, each release paper was peeled off and removed, and then a tin-plated annealed copper conductor (thickness 50 μm) was interposed between the adhesive layers 13. , 0.8 mm in width) are arranged in parallel so that the adhesive layer 13 of the two flat cable covering materials 10 face each other and pass between the metal roll and the rubber roll at a speed of 30 m / min. The pressure was applied to hold the conductive wire only with the adhesive force, and the wire was cut every 250 mm to obtain a flat cable before curing.
6400 flat cables before curing were put together and cured by heating in a hot oven at 180 ° C. for 1 hour to obtain a flat cable 1.
The conventional production speed is about 640 sheets per hour because it is heated and pressurized between a metal roll heated to 150 ° C. and a rubber roll at a speed of 3 m / min. Efficiency. Even if the bonding step was performed as a separate step, the efficiency was sufficiently good.

(Comparative Example 1) As the adhesive 15 composition, polyester resin having a glass transition point of -30 ° C: polyester resin having a glass transition point of 5 ° C: polyester resin having a glass transition point of 80 ° C = 24: 5: 1 (mass ratio) ) Is mixed with a one-to-one mixed solvent of toluene and methyl ethyl ketone, mixed with melam sulfate: tin oxide: aluminum hydroxide = 1: 10: 20 as a flame retardant, and has a solid content of 50% by mass. The flat cable coating material 10 of Comparative Example 1 was obtained in the same manner as Example 1 except that the composition was used.
Next, 17 tin-plated annealed copper conductors (thickness 50 μm, width 0.8 mm) are arranged in parallel between the layers, and a metal roll heated to 150 ° C. with the two heat-bonding layers of the flat cable covering 10 facing each other. The flat cable 1 was manufactured by passing between the rubber roll and the rubber roll at a speed of 3 m / min and heating and pressing.
Since the flat cable coating material 10 of Comparative Example 1 uses a conventional polyester adhesive instead of an epoxy resin, the adhesive was a hot melt type and was not thermally cured.

  (Comparative Example 2) The flat cable coating material 10 of Comparative Example 2 was prepared as Example 1 except that the acrylic ester copolymer was not used as the adhesive 15 composition.

  (Comparative Example 3) The flat cable coating material 10 of Comparative Example 3 was obtained as Example 1 except that EPX-3 was not used as the adhesive 15 composition.

  (Comparative example 4) The flat cable coating material 10 of the comparative example 4 was set as Example 1 except not using EPX-1 as an adhesive agent 15 composition.

  (Evaluation method) The initial adhesive strength, workability, heat resistance, and flexibility were used. The results are shown in Table 1.

(Measuring method)
<Measurement Method of Initial Adhesive Strength> The flat cable covering material 10 that was allowed to stand for 24 hours in an atmosphere of 23 ° C. and 50% RH was cut into a width of 25 mm and a length of 250 mm to obtain a test sample. Thereafter, the release paper of the sample is peeled off and placed on the cleaned glass plate so that the adhesive layer is in contact. From there, it was pasted with a manual crimping apparatus (JIS0237), with a crimping speed of about 5 mm / sec, one reciprocation. One of the pasted test pieces was peeled off at a speed of 300 mm / min with Tensilon (Orientec RTC1310A), and the stress at that time was defined as adhesive strength.
<Workability> A case where there is an initial adhesive force and the production traveling speed is twice or more that of the conventional production method is indicated as “O”, and a case where any of them is not reached is indicated as “No”. ".
<Heat resistance> A case where the peel strength after standing at 150 ° C. for 24 hours is 10 N / 10 mm width or more is indicated as “O”, and a case where the peel strength is less than this is indicated as “X”.
<Flexibility> U-shaped sliding bending test: Performed at a temperature of 23 ° C., a bending radius R = 8 mm, and a bending speed of 1500 times / minute according to JIS-C5016.
When the conductor current for monitoring is stopped for 10 ^-6 seconds or more, or when the conductor resistance is increased by 10% from the initial stage, the bending life is considered to be 10 million times or more. And indicated by “x”. The results are shown in Table 1.

  (Evaluation result) The flat cable coating material 10 of Example 1 has good initial adhesive strength, workability, heat resistance, and flexibility.

  (Industrial Applicability) The present invention is applied to a flat cable used in electrical equipment, electronic equipment, etc. having excellent adhesion to a conductor and having sufficient flexibility and heat resistance. Can do.

1: Flat cable 10: Flat cable covering material 11: Base material 13: Adhesive layer 15: Adhesive 21: Conductor

Claims (4)

  In a flat cable coating material in which at least an adhesive layer is laminated on one surface of the substrate, the adhesive constituting the adhesive layer is an acrylic resin, an epoxy resin, and a curing agent. A flat cable covering material comprising:   The flat cable covering material according to claim 1, wherein the adhesive layer includes an acrylic resin and an epoxy resin having a sea-island structure.   The acrylic resin is an acrylic ester copolymer obtained by radical polymerization of a monomer having EA-BA-AN. The epoxy resin is composed of an NBR (nitrile butadiene rubber) -modified epoxy resin and a bis-A type epoxy resin. The flat cable coating material according to claim 1, wherein the curing agent is a dicyandiamide-based compound.   In a flat cable formed by covering a conductor array in which a plurality of conductors are arranged in the same plane from both sides with a flat cable covering material, the flat cable covering material on at least one side is composed of a base material and one of the base materials It is composed of a flat cable covering material having at least an adhesive layer laminated on its surface, and the adhesive that constitutes the adhesive layer includes an acrylic resin, an epoxy resin, and a curing agent, and the adhesive A flat cable characterized in that the layer is thermally cured.

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