JP4610947B2 - Conductive sheet-like elastic body and method for producing the same - Google Patents

Description

  The present invention relates to a conductive sheet-like elastic body and a method for manufacturing the same, and more specifically, has conductivity and is suitably used as a sealing material such as a gasket or packing for electronic equipment, precision equipment, etc. The present invention relates to a conductive sheet-like elastic body that can be prevented and a method for producing the same.

  A display unit such as a liquid crystal display, a microphone unit, and other input / output units such as a speaker unit are provided in an electric device such as a mobile phone, a television, and other computer displays. Such an input / output unit is provided in a portion where the electrical equipment casing is opened to the outside. For example, in the case of liquid crystal, the intrusion of dust and liquid crystal display is performed through a slight gap between the opening and the liquid crystal. A packing for preventing light leakage of the backlight used and rattling of the casing is disposed between the periphery of the liquid crystal and the casing. Since the material used for this packing is usually an insulator such as resin or rubber, static electricity is easily charged. In such a state, an adverse effect such as so-called electrostatic breakdown occurs due to electrostatic discharge on the liquid crystal or the like. In addition, there is a problem that dust, dust, and other dust adhere to the surrounding input / output unit and casing due to static electricity.

Therefore, in order to prevent the charging of the packing, for example, a conductive material such as a conductive agent, an electron conductive filler such as carbon fiber, or a cationic or nonionic surfactant is mixed in the raw material. A method of imparting conductivity is generally employed. However, in order to increase the conductivity of the packing to the extent that charging can be sufficiently prevented, it is necessary to use a large amount of conductive filler and disperse it uniformly in the packing. It is difficult to use itself, and the use of a large amount of conductive filler causes a problem that various physical properties such as packing moldability and tensile strength are lowered. Therefore, by reacting a long-chain polyol having a heat of fusion of 200 kJ / mol or less and an organic polyisocyanate, the glass transition temperature is 30 ° C. or less and the volume resistivity is about 10 ⁶ to 10 ¹⁰ Ω. The polyurethane resin which has is proposed (refer patent document 1). Since the “polyurethane resin” according to the invention disclosed in Patent Document 1 does not add additives such as a conductive agent, it can impart conductivity without degrading the above-mentioned physical properties. When used, sufficient electrical conductivity required for electrical equipment or the like cannot be obtained.

Also, the surface of the packing is coated or impregnated with a resin containing a conductive material such as a conductive agent to impart conductivity, or a conductive sheet such as a metal foil is integrally molded or a pressure sensitive adhesive or adhesive. There is also a method of providing conductivity by integrating them. As in the invention “electromagnetic wave shielding material” disclosed in Patent Document 2, a material imparted with conductivity by laminating a coating film containing a conductive conductive agent and a metal thin film layer on a base material such as polyurethane resin Proposed. In order to exhibit sufficient sealing performance corresponding to the complicated internal structure of electrical equipment, this packing is designed to exhibit the required flexibility and elasticity by carefully setting each physical property such as density and compressive load. Although it is designed, by laminating a conductive sheet consisting of a metal thin film layer on the base material, there is a drawback that the elasticity and flexibility of the base material are impaired due to the rigidity of this conductive sheet, and because of the metal It is easy to rust, and there is a possibility that required conductivity may not be expressed over time. Further coating comprising a conductive agent, the conductive agent and the base resins, are formed by applying a coating material is dissolved or dispersed in (1) water or (2) an organic solvent, (1) When the solvent is water, drying in a short time is difficult and the production efficiency is lowered. (2) When the solvent is an organic solvent, the base material such as polyurethane resin is deteriorated and its environmental load is high. It becomes a problem.

In addition, there is a method of providing a sputtered layer having conductivity by sputtering a metal, an alloy, or a metal oxide on the front side surface of the base sheet (see Patent Document 3). However, in this method, since the production process is a batch type, mass productivity is poor and production efficiency is very poor. In addition, it is necessary to maintain the entire base sheet in a vacuum atmosphere of a certain level or more during sputtering. However, when the base sheet is a foam having high flexibility and followability, the degree of vacuum is set to a required value. In order to do so, for example, a process over a long period of time such as 24 hours or more is required, and there is a problem that practical use is difficult.
JP-A-9-227649 JP-A-8-331382 JP 2003-42296 A

  That is, the present invention has been proposed in order to suitably solve these problems inherent in the conventional conductive sheet-like elastic body and the method for producing the same, and has good conductivity and flexibility. Alternatively, it is an object to provide a conductive sheet-like elastic body that can have both elasticity and improve production efficiency, and a method for manufacturing the same.

In order to overcome the above-mentioned problems and achieve the intended purpose, the conductive sheet-like elastic body according to the present invention comprises:
In a conductive sheet-like elastic body comprising a sheet-like elastic substrate made of polyurethane foam and a conductive layer laminated on at least one surface of the sheet-like elastic substrate,
The conductive layer is made of a polyurethane resin or a styrene butadiene styrene copolymer , and a base resin having an elastic modulus at 25 ° C. set in a range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa, and the base resin Composed of a conductive agent dispersed in and made of conductive carbon,
The conductive sheet-like elastic body is set so as to satisfy at least one of a maximum point elongation / elongation at break of 0.95 or more and a maximum point stress / maximum point elongation of 0.1 or less. And

In order to overcome the above-mentioned problems and achieve the intended object, a method for producing a conductive sheet-like elastic body according to still another invention of the present application,
A conductive agent made of conductive carbon is dispersed in a base resin made of polyurethane resin or styrene butadiene styrene copolymer whose elastic modulus at 25 ° C. is set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa. conductive layer composed Te, to prepare the conductive layer transfer film form shape on one surface of the substrate film,
Supplying the elastic substrate material in a fluidized state to the conductive layer side of the conductive layer transfer film;
The supplied elastic base material is bonded to the conductive layer by reacting and curing in a transferable temperature range in which the conductive layer is in a rubber state and the elastic modulus is 1.0 × 10 ⁶ Pa or less. Forming a sheet-like elastic substrate made of polyurethane foam of the required thickness,
The conductive film is transferred to the sheet-like elastic substrate by peeling the base film from the conductive layer .

In order to overcome the above-mentioned problems and achieve the intended object, a method for producing a conductive sheet-like elastic body according to still another invention of the present application,
A conductive agent made of conductive carbon is dispersed in a base resin made of polyurethane resin or styrene butadiene styrene copolymer whose elastic modulus at 25 ° C. is set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa. conductive layer composed Te, to prepare the conductive layer transfer film form shape on one surface of the substrate film,
Supplying the elastic substrate material in a fluidized state to the conductive layer side of the conductive layer transfer film;
Next, another conductive layer transfer film is continuously supplied to the elastic substrate material on the conductive layer so that the conductive layer faces the elastic substrate material,
By reacting and curing the supplied elastic base material in a transferable temperature range in which the conductive layer is in a rubber state and the elastic modulus is 1.0 × 10 ⁶ Pa or less, the both sides of the elastic base material are respectively provided. A sheet-like elastic substrate made of polyurethane foam with a required thickness to which the conductive layers are bonded,
The corresponding base film is peeled off from each of the conductive layers, whereby the conductive layer is transferred to a sheet-like elastic substrate .

In order to overcome the above-mentioned problems and achieve the intended object, a method for producing a conductive sheet-like elastic body according to still another invention of the present application,
A conductive agent made of conductive carbon is dispersed in a base resin made of polyurethane resin or styrene butadiene styrene copolymer whose elastic modulus at 25 ° C. is set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa. Prepare a conductive layer transfer film formed on one surface of the base film, the conductive layer configured,
Supply the elastic base material in a fluid state on the base sheet,
The conductive layer transfer film is continuously supplied to the elastic substrate material so that the conductive layer faces the elastic substrate material ,
By reacting and curing the supplied elastic base material in a transferable temperature range in which the conductive layer is in a rubber state and the elastic modulus is 1.0 × 10 ⁶ Pa or less, it is applied to one surface of the elastic base material. Forming a sheet-like elastic substrate made of polyurethane foam to which the conductive layer is bonded;
By peeling the base film from the conductive layer, the conductive layer is transferred to one surface of the sheet-like elastic substrate.

In order to overcome the above-mentioned problems and achieve the intended object, a method for producing a conductive sheet-like elastic body according to still another invention of the present application,
A sheet-like elastic substrate made of polyurethane foam having a required thickness, and a polyurethane resin or a styrene butadiene styrene copolymer having an elastic modulus at 25 ° C. set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa. base resin in the conductive layer formed by dispersing a conductive agent composed of conductive carbon, was prepared and one of the conductive layers transcribed form form the surface film of the base film,
After laminating a conductive layer transfer film so that the conductive layer faces the sheet-like elastic substrate, the sheet-like elastic substrate and the conductive layer are in a rubber state, and the elastic modulus is 1.0 × 10. Heating and / or pressurizing in a transferable temperature range of ⁶ Pa or less,
The conductive film is transferred to the sheet-like elastic substrate by peeling the base film from the conductive layer .

  According to the conductive sheet-like elastic body and the method for manufacturing the same according to the present invention, the conductive sheet-like elastic body is composed of a base resin that is a main component constituting the conductive layer and a conductive agent dispersed in the base resin, and melts into a sheet-like elasticity. A conductive layer adjusted so as to be sufficiently bonded to the sheet-like elastic body by performing controlled heating so as not to penetrate into the body or cause the conductive agent dispersed inside to be unevenly distributed, After forming on a separately prepared substrate film, the conductive layer is transferred to at least one surface of the sheet-like elastic body, and the substrate film is removed, so that the conductive layer is laminated on the sheet-like elastic body in a laminated manner. Since the conductive layer does not hinder the development of physical properties such as elasticity or flexibility from the sheet-like elastic substrate, it has both good physical properties and sufficient conductivity to prevent charging. Excellent in mass production May produce a conductive sheet-like elastic body was.

Next, the conductive sheet-like elastic body and the method for producing the same according to the present invention will be described below with reference to the accompanying drawings, taking preferred examples. The inventor of the present application disperses a required conductive agent on at least one surface of a sheet-like elastic substrate having physical properties required for packing, such as cushioning and sealing properties, and the sheet-like elastic substrate. Accordingly, a cushioning property that can be suitably used as a packing for a mobile phone or the like by laminating a conductive layer transfer film in which a conductive layer made of a base resin having physical properties is formed on a base film and transferring the conductive layer It has been found that a thin conductive sheet-like elastic body having various physical properties such as sealing property, flexibility, shape following property and shape retaining property and having required conductivity is obtained. In addition, by performing the heating at a predetermined temperature to control the physical properties of the base resin that can also play a role as an adhesive in the conductive layer, specifically, the elastic modulus is bonded to the sheet-like elastic substrate, The followability of the conductive layer to the sheet-like elastic substrate can be ensured, and the conductive layer can penetrate into the sheet-like elastic substrate due to flow and adversely affect physical properties such as hardness, and can be dispersed inside. It was also confirmed that uneven distribution due to floating or sedimentation due to differences in specific gravity of the conductive agent can be avoided.

  As shown in FIG. 1, a conductive sheet-like elastic body 10 according to a preferred embodiment of the present invention is a sheet made of an elastic body that achieves various physical properties such as required cushioning properties, sealing properties, flexibility, and shape following properties. And a conductive layer 14 (described later [0020]) transferred to at least one surface of the sheet-like elastic substrate 12. The sheet-like elastic base 12 is a member that forms the main body of the conductive sheet-like elastic body 10 and has various physical properties required for a sealing material such as packing. As the material, it is possible to maintain functions such as dust proofing and light leakage over a long period of time, that is, a material having little settling and gas generation, and having cushioning property, flexibility, followability to a curved surface, etc. Substances such as foams such as synthetic resins and elastomers can be used. Specifically, olefin resins such as urethane resin, polyethylene resin or polypropylene resin, various resins such as polystyrene resin, silicone resin, acrylic resin, polyvinyl chloride, NBR (acrylonitrile butadiene copolymer), SBR (styrene butadiene copolymer). Polymers), solids or foams made of various rubbers such as EPDM (ethylene propylene diene terpolymer) or EPM (ethylene propylene copolymer) are preferably used.

  The physical properties of the elastic substrate 12 conform to those of the sheet-like elastic substrate 12 suitably used for packing. For example, the 25% compression hardness (hereinafter referred to as 25% CLD) is set to 0.035 MPa or less. When this value is exceeded, an excessive load is always applied to the casing to be sealed, which may cause physical defects such as chipping in the casing. In this respect, the sheet-like elastic substrate 12 is particularly preferably a low-hardness polyurethane foam produced by a mechanical floss method. The details of this mechanical flossing method are described in, for example, Japanese Examined Patent Publication No. 53-8735, and will not be described in detail. Basically, however, this is a two-component urethane raw material comprising a polyol and an isocyanate component as main raw materials. On the other hand, an auxiliary raw material such as a catalyst or a foam stabilizer is added as necessary, and a foaming gas such as nitrogen is further mixed, and further mixed and stirred by an Oaks mixer or the like to obtain an elastic base material M to be described later. To get.

  The thickness of the sheet-like elastic base 12 is set in the range of 0.1 to 5.0 mm. If this thickness is out of the above-mentioned range, it will be difficult to develop sufficient sealing properties. In particular, when the thickness exceeds 5.0 mm, not only the sealing performance is deteriorated, but also the recoverability due to the winding at the time of manufacture (described later [0045]) is lowered due to the thickness, and the production efficiency may be deteriorated. The length is preferably a long product of 5 m or longer. In this case, it is possible to continuously perform processing such as punching or the like to process the manufactured conductive sheet-like elastic body 10 into a required shape, so that reduction in manufacturing cost due to improvement in production efficiency can be expected.

The conductive layer 14 that imparts conductivity to the sheet-like elastic substrate 12 includes a required base resin 15 and a conductive agent 16 dispersed in the base resin 15, and is used for avoiding various adverse effects due to static electricity or the like. The surface resistance value is set in the range of 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ Ω according to the above. In the present invention, the conductive layer 14 is bonded to the sheet-like elastic substrate 12 so that the maximum elongation / breakage of the conductive sheet-like elastic body 10 is obtained as described later (see [0027] to [0031]). TenShindo is set to 0.95 or more Ruoyobi / or maximum point stress / maximum point elongation thereof is set to 0.1 or less.

The thickness of the conductive layer 14 is set in the range of 1 to 10 μm regardless of the type of the base resin 15. If the thickness of the conductive layer 14 is less than 1 μm, the surface resistance value may exceed 1.0 × 10 ⁶ Ω, which can avoid various adverse effects due to static electricity or the like. laminate of the conductive layer 14 and, that is, may impair the cushioning of the conductive sheet-like elastic body 10.

Further, the sheet-like elastic substrate 12 is prevented from being unevenly distributed such as floating or settling due to a difference in physical properties such as the specific gravity of the conductive agent 16 dispersed therein without adversely affecting the physical properties thereof. The conductive layer 14 according to the present invention is preferably applied with heat applied to the sheet-like elastic substrate 12 (hereinafter, expressed by this heat) so that the electrical conductivity can be suitably expressed and can be bonded to such an extent that it cannot be easily peeled off. The temperature range is referred to as the transferable temperature range), so that it does not melt. Specifically, in the transferable temperature range, the conductive layer 14 is in a rubber state (in the present invention, the conductive layer 14 is not in a glass state or in a completely molten state, but is maintained in a slightly molten state, that is, a layer shape. The melted viscous state is maintained, and the elastic modulus is set to 1.0 × 10 ⁶ Pa or less. The elastic modulus in the transferable temperature range is preferably set to a lower limit of 4.0 × 10 ³ Pa.

If the conductive layer 14 is not in a rubber state, that is, (1) glass state or (2) in a molten state, in the case of (1), it is not bonded to the sheet-like elastic substrate 12, or (2) In this case, the fluid penetrates into the sheet-like elastic base 12 as a fluid, or the conductive agent 16 in the fluidized conductive layer 14 is unevenly distributed, and as a result, the conductive sheet-like elasticity according to the present invention. It does not become the body 10. Even if it is in a rubber state, when its elastic modulus exceeds 1.0 × 10 ⁶ Pa in the transferable temperature range, the property becomes a glass state, and as a result, the above-mentioned (1) and It will be in the same state.

The base resin 15 is selected in view of the physical properties of the sheet-like elastic substrate 12, specifically, thermal properties, flexibility, elasticity, and the like, and is a known substance having cushioning properties, followability to curved surfaces, etc. Synthetic resins and elastomers can be used. Specifically, polyurethane resin, polyester resin, ethylene-vinyl acetate copolymer, polyester modified urethane, SIS (styrene-isoprene-styrene copolymer), SBS (styrene-butadiene-styrene block copolymer), etc. You can select and adopt. Among these base resins, those having an elastic modulus (measured by TMA (thermomechanical analysis) at 25 ° C.) (hereinafter referred to as “25 ° C. elastic modulus”) of 2.0 × 10 ⁸ Pa or less are particularly preferable. If the 25 ° C. elastic modulus is higher than this, the cushioning property of the conductive layer 14 is lowered, which is not preferable. The 25 ° C. elastic modulus of the base resin 15 alone is preferably set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa. Furthermore, it is preferable to use a base resin 15 having a glass transition temperature of 0 ° C. or higher in order to reduce tackiness on the surface of the conductive layer 14.

  The conductive agent 16 is appropriately selected from the conductivity (surface resistance value) required for the obtained conductive sheet-like elastic body 10 and the amount that can be added to the base resin 15. For example, zinc sulfide, copper sulfide , Conductive fillers that impart conductivity to sulfides such as cadmium sulfide, nickel sulfide or palladium sulfide, metal oxides such as barium sulfate or tin oxide, zinc oxide, indium oxide or titanium oxide, conductive carbon fillers, Examples thereof include conductive fillers such as silicon organic compounds or surface metal plating fillers, and general conductive agents such as cationic or nonionic surfactants. Among these, conductive carbon such as carbon black, oil furnace black, channel black, lamp black, thermal black, acetylene black, and metal particles such as carbon nanotubes or silver having a nano-unit size are preferable. From the viewpoint of conductivity (surface resistance value) and the amount that can be added to the base resin 15, acetylene black or oil furnace black having a high structure and high conductivity is preferably used.

  The conductive layer 14 transferred to the surface of the sheet-like elastic substrate 12 is used as a packing that develops according to physical properties such as flexibility (easy to compress) or elasticity (easy to bend) of the sheet-like elastic substrate 12. A suitable followability that does not impede performance is required. Specifically, when the sheet-like elastic base 12 that forms the main body of the conductive sheet-like elastic body 10 according to the present invention is deformed, the conductive layer 14 joined and integrated with the sheet-like elastic base 12 is It is sufficient that sufficient followability for the deformation is exhibited and a gap such as a wrinkle is generated to cause a problem in sealing performance.

  In the present invention, this followability is basically expressed by the difference in flexibility (easiness of compression) of both the sheet-like elastic substrate 12 and the conductive layer 14, and each flexibility is defined by the elongation rate. I am doing so. Specifically, tension is applied to the sheet-like elastic substrate 12 and the conductive layer 14 in the laminated state, that is, the conductive sheet-like elastic body 10, and the maximum elongation at break and the elongation at break are measured. As described above ([0020]), the compositions of the sheet-like elastic substrate 12 and the conductive layer 14 are determined so that the maximum elongation / breaking elongation is 0.95 or more. The smaller the difference between the flexibility of the sheet-like elastic substrate 12 and the conductive layer 14, that is, the elongation rate, the closer to a single state made of the same substance, and therefore it can be evaluated that the followability is good.

  Here, the elongation at break means that a tensile force is applied to the conductive sheet-like elastic body 10 composed of the sheet-like elastic base 12 and the conductive layer 14, and both the sheet-like elastic base 12 and the conductive layer 14 are broken to break. The maximum point elongation is a point at which the force pulling the conductive sheet-like elastic body 10 reaches a maximum (the force used for pulling at this point is referred to as the maximum point stress). ) Is a numerical value representing the elongation rate. In the conductive sheet-like elastic body 10 in which the sheet-like elastic substrate 12 and the conductive layer 14 are laminated, the maximum point stress is any one from the state where both the sheet-like elastic substrate 12 and the conductive layer 14 are not yet broken. It is measured at the moment when the state shifts to a broken state and the force opposite to the tension suddenly decreases. In other words, the maximum point elongation indicates the elongation at the moment when one of the sheet-like elastic substrate 12 and the conductive layer 14 is broken.

  Therefore, when the maximum elongation / breaking point elongation of the conductive sheet-like elastic body 10 is 0.95 or more, both the sheet-like elastic substrate 12 and the conductive layer 14 constituting the conductive sheet-like elastic body 10 are This means that they are torn almost at the same time and break. That is, the flexibility expressed by the elongation rates of the sheet-like elastic substrate 12 and the conductive layer 14 is substantially the same, and therefore it can be estimated that the followability that can be expressed by the difference in both flexibility is also good. .

In the above item ([0029]), the followability of the conductive layer 14 to the sheet-like elastic substrate 12 is said to be good if both the flexibility is substantially the same. When the conductive layer 14 is laminated, if the presence of the conductive layer 14 does not affect the expression of physical properties (especially flexibility) of the sheet-like elastic substrate 12, it is possible to obtain good results in the same manner. . The inventor of the present application uses the maximum point elongation and the maximum point stress. When the value of the maximum point stress / maximum point elongation exceeds 0.1, wrinkles and cracks are generated on the surface of the conductive layer 14. If the value is 0.1 or less, the presence of the conductive layer 14 does not affect the expression of the physical properties of the sheet-like elastic substrate 12, and good results with respect to followability and the like can be obtained (described later). experiment 1 [0061] reference) was confirmed. That is, by using the maximum point elongation and the maximum point stress and using the maximum point stress / maximum point elongation index, the conductive sheet-like structure constituted by the sheet-like elastic substrate 12 and the conductive layer 14 according to the present invention is also used. An elastic body 10 may be defined. Further, it is desirable that the value of maximum point stress / maximum point elongation is 0.01 or less. In this case, fine wrinkles are compared with a numerical range of 0.1 or less and exceeding 0.01. Etc. were not observed at all, and very good follow-up expression was confirmed. And about these two parameters | indexes, the conductive sheet-like elastic body 10 which concerns on this invention can be defined even if each is independent or it is an overlapping condition. The maximum point stress / maximum point elongation value is a pseudo representation of the Young's modulus of the conductive sheet-like elastic body 10.

In addition, as for the followability of the sheet-like elastic substrate 12, the 25 ° C. elastic modulus described above ([0024]) as an index of flexibility (easiness of compression) and an index of elasticity (ease of bending). It can also be defined by (pseudo) Young's modulus. It has also been confirmed that suitable follow-up properties are manifested by setting the 25 ° C. elastic modulus to 2.0 × 10 ⁸ Pa or less and the Young's modulus to a certain value or less. When the 25 ° C. elastic modulus is greater than 2.0 × 10 ⁸ Pa or the Young's modulus is greater than a certain value, the flexibility or elasticity decreases, and the followability deteriorates. Or the expression of elasticity is inhibited and various physical properties required for packing cannot be obtained.

  A conductive sheet-like elastic body according to Example 1 transferred by integrally forming a conductive layer on a sheet-like elastic substrate (hereinafter referred to as an integral molding method) will be described below. The structure is the same as that of FIG. 1, and a sheet-like elastic substrate 12 made of an elastic body that achieves the required physical properties such as cushioning properties, sealing properties, flexibility, and shape following properties, and the sheet-like elastic substrate 12. It is basically composed of a conductive layer 14 transferred to at least one surface.

As described above ([0020]), the conductive layer 14 that imparts conductivity to the sheet-like elastic substrate 12 includes a required base resin 15 and a conductive agent 16 that is a conductivity imparting substance dispersed in the base resin 15. consists of a, a surface resistance value of the conductive sheet-like elastic-material elements 1 0 to ensure the conductivity as a range of ^{1.0 × 10 2 ~1.0 × 10 6} Ω, avoiding various harmful effects due to static electricity or the like Is. In Example 1, the conductive layer 14 is transferred to the sheet-like elastic substrate 12 by using a conductive layer transfer film 20 in which the conductive layer 14 is previously formed on the base film 18 with a required thickness. . Specifically, a fluidized elastic substrate material M, which is a material of the sheet-like elastic substrate 12, is supplied onto the conductive layer 14 of the conductive layer transfer film 20, and this is heated and reacted and cured. The sheet-like elastic substrate 12 is bonded to the conductive layer 14 and then the base film 18 is peeled off from the conductive layer 14. The heating temperature at this time is set within the transferable temperature range of the conductive layer 14. By setting the transferable temperature range and the selection of the type of the base resin 15, the conductive layer 14 is maintained in a predetermined rubber state, and the conductive layer 14 and the sheet-like elastic base 12 are bonded more firmly. Is also possible.

Further, as described above ([0022]), the conductive layer 14 maintains a rubber state in a transferable temperature range applied at the time of bonding to the sheet-like elastic substrate 12 and has an elastic modulus of 1.0 × 10 ⁶ Pa or less. It only has to be. This condition is specifically achieved in Example 1 when the glass transition temperature measured using DSC (Differential Scanning Calorimetry) is 0 ° C. or higher, and the base resin 15 is a non-crystalline substance. or it is, or when the base resin 15 is a crystalline substance that melting temperature is preferably achieved by being set to be more than 0.99 ° C.. As described later ([0043] and [0044]), the transfer of the conductive layer 14 to the sheet-like elastic substrate 12 by the integral molding method is in a fluid state with respect to the conductive layer 14 formed on the conductive layer transfer film 20. The elastic substrate material M is supplied, and heat is applied to the elastic substrate material M to cause reaction and curing. The conductive layer 14 can withstand a high temperature state when heated to a predetermined temperature (curing temperature) in order to react and cure the elastic base material M, that is, the curing temperature is within the transferable temperature range and is at least melted and liquid. It is necessary to have a thermal property that retains the layer shape without being converted into a layer. As described above, this is preferably achieved by using the amorphous base resin 15. Even the crystalline base resin 15 can be used if its melting temperature is higher than the curing temperature of the elastic base material M.

  The sheet-like elastic substrate 12 and the conductive layer 14 are joined by utilizing a change when the elastic substrate material M that is in a fluidized state by heating is reacted and cured to form a solid. At this time, only the elastic base material M determines the bonding strength. However, if the heating temperature of the elastic base material M is set within a transferable temperature range such as the melting temperature of the base resin 15, the base resin 15. Further, both the elastic base material M and the above-mentioned bonding can be expected to be stronger. Further, when a foam is used as the sheet-like elastic substrate 12, not only chemical bonding but also physical anchoring effect between the cell opened on the bonding surface and the conductive layer 14 can be expected to develop stronger bonding strength.

In the integral molding method, the conductive agent 16 is used in the range of 10 to 65 parts by mass with respect to 100 parts by mass of the base resin 15. If the amount of the conductive agent 16 used (mixing ratio) is less than 10 parts by mass, the surface resistance value of the resulting conductive sheet-like elastic body 10 will exceed 1.0 × 10 ⁶ Ω to ensure sufficient conductivity. I can't. On the other hand, when the usage-amount of the electrically conductive agent 16 exceeds 65 mass parts, while the surface resistance value of the electroconductive sheet-like elastic body 10 becomes small, the conductive layer forming raw material mentioned later ([0042]) As a result, physical problems such as an increase in viscosity, deterioration in moldability of the conductive layer 14, an increase in hardness, and deterioration in brittleness occur, resulting in an increase in manufacturing cost and the conductive layer after being transferred to the sheet-like elastic substrate 12. 14 will deteriorate.

  The base film 18 that constitutes the conductive layer transfer film 20 and forms the base material of the conductive layer 14 is provided with a rigidity to the conductive layer 14 formed on one surface thereof. Alternatively, physical damage such as tearing is prevented and shape retention is improved, but in Example 1, it also serves as a transfer medium for the elastic base material M, which is a raw material for the sheet-like elastic base 12. As the material, for example, stainless steel foil or copper foil, which does not stretch to a predetermined tension so as to form a homogeneous and stable conductive layer 14 and has sufficient heat resistance to withstand heating to the elastic substrate material M, for example. Alternatively, a metal film such as an aluminum foil, or a resin film such as polyolefin, polyester, polyamide, or polyvinyl chloride is preferably used. In addition, a normal paper material or a paper material or nonwoven fabric reinforced with resin fibers can be used. . In addition, the thickness of the conductive layer 14 is sufficient to provide the necessary rigidity, that is, shape retention, and can withstand pulling during transfer. Specifically, in the case of a metal film, the thickness is 10 to 100 μm, preferably 10 to 70 μm. In the case of a film, paper or non-woven fabric, it is basically set to 10 to 500 μm, preferably 25 to 100 μm.

(Production method of Example 1)
Next, an example of a manufacturing apparatus that suitably manufactures the conductive sheet-like elastic body according to Example 1 and a manufacturing method using the manufacturing apparatus will be described below. It is assumed that a conductive layer transfer film 20 in which an elastic base material M as a raw material and a conductive layer 14 are formed on one surface of a base film 18 is prepared. As shown in FIG. 2, the manufacturing process of the conductive sheet-like elastic body 10 basically includes a raw material preparation step S1, a raw material supply / forming step S2, a heating step S3, a film removal step S4, and a final step S5. It is preferably manufactured by the manufacturing apparatus 30 shown in FIG. This manufacturing apparatus 30 basically performs the above-described raw material supply / molding step S2, heating step S3, film removal step S4 and final step S5 continuously, and the raw material preparation step S1 is performed by another device. is doing. Note that the raw material preparation step S1 is a step of preparing the elastic base material M to be the sheet-like elastic base 12 by an appropriate publicly known method and further preparing the conductive layer transfer film 20 by a method described later ([0042]). The detailed description is omitted and an example is given in Experimental Example 1 described later.

(About manufacturing equipment)
As shown in FIG. 3, the manufacturing apparatus 30 has a conductive layer 14 formed, and a conductive layer transfer film 20 serving as a transfer medium for an elastic base material M mixed from various raw materials by, for example, raw material adjustment in a mechanical froth method. , A roll mechanism 32 composed of a supply roll 32a driven by a drive source (not shown), a base film recovery roll 32b and a product recovery roll 32c, a discharge nozzle 34 for supplying the elastic substrate material M onto the conductive layer 14, and a discharge nozzle 34 Basically, a product thickness control means 36 that forms a sheet with a predetermined thickness from the supplied elastic base material M, and a tunnel-type heating furnace 38 with a predetermined length provided downstream thereof. Composed.

  The roll mechanism 32 applies a predetermined tension to the base film 18 (conductive layer transfer film 20) on which the conductive layer 14 is formed and supplies it to the production line, and as a result, the obtained conductive sheet-like elastic body 10 and In this mechanism, the base film 18 after the conductive layer 14 is transferred to the sheet-like elastic substrate 12 is collected. Then, the conductive layer transfer film 20 is wound around the supply roll 32a installed in the uppermost stream of the manufacturing apparatus 30 and is sent out under control. And the base film collection | recovery roll 32b and the product collection | recovery roll 32c installed in the most downstream of the manufacturing apparatus 30 become predetermined tension | tensile_strength to the film 20 for conductive layer transfer (base film 18) by making a pair with the supply roll 32a. And the winding and collecting of the conductive sheet-like elastic body 10 in which the conductive layer 14 is transferred to the sheet-like elastic substrate 12 in a laminated manner, and the substrate film 18 is unwound and plays a role of collecting and removing. In addition, the base film 18 wound up by the base film collection | recovery roll 32b can be used as the conductive layer transfer film 20 in which the conductive layer 14 was formed again.

  The discharge nozzle 34 is disposed above the conductive layer transfer film 20 that is transferred in a state where the conductive layer 14 is exposed on the upper side and is applied with a predetermined tension, and the elastic base material M is controlled on the conductive layer 14. One end is connected to an elastic base material M mixing / storage device (not shown). The product thickness control means 36 makes the elastic base material M discharged and supplied onto the conductive layer 14 into a sheet-like material having a predetermined thickness. Specifically, a conventionally known means such as a knife coater or a roll coater is used. Adopted. The tunnel-type heating furnace 38 is for heating the elastic base material M having a predetermined thickness under control to cause the reaction / curing to proceed to form the sheet-like elastic base 12. Any heating method can be adopted as long as it can sufficiently react and cure the sheet-like elastic substrate 12. At this time, the elastic substrate material M reacts and cures on the conductive layer 14, and as a result, the elastic substrate material M and the conductive layer 14 are firmly bonded.

(About preparation of the conductive layer transfer film in the raw material preparation step S1)
In Example 1, the conductive layer transfer film 20 prepared in advance is manufactured as follows. That is, a conductive layer forming raw material in which a predetermined amount of the conductive agent 16 is mixed with the raw material of the base resin 15 dissolved in an organic or aqueous solvent and dispersed at high speed with a homomixer or the like is produced. Then, this conductive layer forming raw material is applied to one surface of the base film 18 at a predetermined thickness using a general application means such as a baker type applicator and dried by a drying means such as a dryer or a drying furnace. The conductive layer 14 having a predetermined thickness is formed on one surface of the base film 18 so as to be peelable. When the conductive layer transfer film 20 is manufactured, a release agent such as a silicone-based material or a polyolefin-based material is provided on the side of the base film 18 where the conductive layer 14 is formed to enhance the peelability during transfer. Is applied in advance by known means such as various coaters, and the conductive layer 14 is formed through this release agent.

(About raw material supply and molding process S2)
The raw material supply / forming step S2 was obtained in the raw material preparation step S1 on the conductive layer transfer film 20 supplied horizontally with a predetermined tension applied by the roll mechanism 32, as shown in FIG. This is a process in which the elastic base material M is continuously discharged from the discharge nozzle 34 and is made a predetermined thickness by the product thickness control means 36 (see FIG. 4A).

(About heating process S3)
In the main heating step S3, the elastic base material M having a predetermined thickness is heated on the conductive layer 14 through the pre-raw material supply / molding step S2 to be reacted and cured, and the conductive layer 14 has a sheet-like elasticity. This is a step of bonding the substrate 12 (see FIG. 4B). Specifically, the temperature is raised to a predetermined temperature when passing through the tunnel-type heating furnace 38 and held for a certain period of time. The heating temperature at this time is set within the transferable temperature range of the conductive layer 14 described above ([0022]). Specifically, the transferable temperature range is set to a temperature of about 150 to 200 ° C. at which the elastic base material M can be reacted and cured by heating.

(About film removal step S4 and final step S5)
In the film removal step S4, the base film 18 is separated and removed by the base film recovery roll 32b from the joined body of the conductive layer transfer film 20 and the sheet-like elastic base 12 obtained through the heating step S3. This is a process (see FIG. 4C), and the final process S5 is a process for final processing and inspection before shipment, which is performed continuously following the film removal process S4. And the elongate thing of the electroconductive sheet-like elastic body 10 by which only the electroconductive layer 14 was transcribe | transferred with respect to the sheet-like elastic base | substrate 12 is obtained by passing through film removal process S4. The long sheet of the conductive sheet-like elastic body 10 is wound and collected by the product collection roll 32c while undergoing a final inspection, and is shipped as it is. The long conductive sheet-like elastic body 10 is not collected by the product collection roll 32c, but is continuously subjected to final processing such as punching into a predetermined shape and other inspections, and various final products such as packing. It is good. In addition, in consideration of the shape strength and handling properties of the conductive sheet-like elastic body 10, the substrate film 18 is not separated and used after being shipped as a final product that has been punched into a required shape. You may make it use by isolate | separating immediately before. In this case, the film removal step S4 becomes unnecessary.

  Thus, the conductive sheet-like elastic body 10 utilizes heat for reacting and curing the elastic substrate material M when transferring the conductive layer 14 from the conductive layer transfer film 20 prepared in advance to the sheet-like elastic substrate 12. Therefore, the efficiency can be improved and energy saving can be achieved, and since continuous transfer can be performed, the mass productivity is excellent and the production efficiency can be improved. Moreover, since the conductive layer transfer film 20 in which the conductive layer 14 is formed in a separate process from the manufacturing process of the conductive sheet elastic body 10 is prepared in advance, the manufacturing process of the conductive sheet elastic body 10 with respect to the organic solvent. In the manufacturing process of the conductive sheet-like elastic body 10, it is possible to improve the working environment and the environment due to the reduction of waste, and to prevent the sheet-like elastic substrate 12 from being deteriorated by the organic solvent. Can do.

  In Example 1, the conductive layer transfer film 20 is prepared in advance and is then wound around a roll so as to be incorporated into the manufacturing apparatus 30. However, only the base film 18 is wound around the supply roll 32a and controlled. The conductive layer forming raw material for forming the conductive layer 14 is continuously supplied on the upstream side of the discharge nozzle 34, and the conductive layer transfer film 20 is continuously produced in the manufacturing apparatus 30. The sheet-like elastic body 10 may be manufactured.

(Change example)
In the above-described first embodiment, the conductive sheet-like elastic body 10 in which the conductive layer 14 is transferred only to one surface of the sheet-like elastic substrate 12 has been described. However, the present invention is not limited to this. A configuration in which the conductive layers 14 and 14 are transferred onto both sides of the sheet-like elastic base 12 is also conceivable, as shown in FIG. The conductive sheet-like elastic body 24 has a feature that it can cope with a case where static elimination or conductivity is required on both sides. The conductive sheet-like elastic body 24 is manufactured by, for example, a manufacturing apparatus 50 shown in FIG. The manufacturing apparatus 50 basically has the same structure as that of the manufacturing apparatus 30 described above ([0039]), and is separated from above the elastic base material M in the laminated state and the elastic base material M of the conductive layer transfer film 20. The conductive layer transfer film 20 is continuously supplied so that the conductive layer 14 faces the elastic base material M, so that the conductive layers 14 and 14 are transferred onto both surfaces of the sheet-like elastic base 12. This is an apparatus for producing the sheet-like elastic body 24. Accordingly, the manufacturing apparatus 50 is installed downstream of the discharge nozzle 34 with respect to the manufacturing apparatus 30 and is driven by a driving source (not shown) to supply another conductive layer transfer film 20 and a second supply roll 33a. The second roll mechanism 33 including the two base film recovery rolls 33b is added.

(Another change example)
Further, in the first embodiment and the modified example described above, the conductive sheet-like elastic body having the structure in which the conductive layer 14 is transferred to at least one surface of the sheet-like elastic substrate 12 is described. A form such as a conductive sheet-like elastic body 26 in which a base sheet 22 is integrally laminated to improve physical strength such as tensile strength with respect to one surface of the elastic substrate 12 is also conceivable. Specifically, as shown in FIG. 7, the conductive sheet-like elastic body 26 has a predetermined base sheet 22 integrally laminated on one surface of the main sheet-like elastic substrate 12, and a conductive material on the other surface. The layer 14 is transferred.

  The conductive sheet-like elastic body 26 is manufactured by, for example, a manufacturing apparatus 60 shown in FIG. The manufacturing apparatus 60 basically has the same structure as the manufacturing apparatus 50 (see [0048]), and is continuously supplied instead of the conductive layer transfer film 20 used as a transfer medium for the elastic base material M. The elastic base material M is supplied onto the base material sheet 22, and the conductive layer transfer film 20 is continuously supplied from above the elastic base material M so that the conductive layer 14 faces the elastic base material M. Then, the elastic base material M is made into the sheet-like elastic base 12 by heating, and the conductive layer 14 is bonded to one surface thereof, and the base film 18 is peeled off from the conductive layer 14, thereby forming the sheet-like elastic base 12. This is an apparatus for producing a conductive sheet-like elastic body 26 in which the conductive layer 14 is transferred and the base sheet 22 is integrally laminated on the other surface.

  Since the base material sheet 22 used in the manufacturing apparatus 60 is a member that basically plays the same role as the base material film 18, the required physical properties, materials, and the like are set equally. Further, when the conductive sheet-like elastic body 26 is manufactured using the base sheet 22, the base sheet 22 is integrally laminated on the sheet-like elastic base 12, and the conductive sheet-like elastic body 26 as a whole is obtained. In order to improve the physical strength, it is possible to prevent the tearing and cutting, and to improve the handling properties. For this reason, it is preferable to use a metal or resin having excellent durability as the material, and in particular, when laminated with the sheet-like elastic base 12, it can flexibly follow the movement, and is inexpensive, for example. A polyester resin such as polyethylene terephthalate (PET) is preferred. In particular, when a thermoplastic resin such as PET is used as the base sheet 22, softening due to heating or the like can be considered. Therefore, when a tension is applied to the conductive sheet-like elastic body 26, “splitting” or “creep” And the like, and the thickness is 10 to 500 μm, preferably 25 to 250 μm. Note that a material such as a metal, for example, a stainless steel foil, a copper foil, or an aluminum foil can be used as the base sheet 22.

In Example 2, the conductive layer 14 is laminated on the sheet-like elastic substrate 12 prepared by reacting and curing the elastic substrate material M in advance, and heat is applied to the sheet-like elastic substrate 12 and the conductive layer. joining the 14 (hereinafter, referred to as thermal transfer method) conductive sheet-like elastic body has been transferred will be described. In addition, about the structure which is common in Example 1, description is abbreviate | omitted and only a different structure is demonstrated.

In the conductive sheet-like elastic body 28 according to Example 2, the conductive layer 14 of the conductive layer transfer film 20 is brought into contact with the sheet-like elastic base 12 prepared in advance and heated, and both are thermally bonded. Thus, the conductive layer 14 is transferred to the sheet-like elastic base 12. That is, the conductive layer 14 (the base resin 15 forming the main body) that has been changed to a rubber state by heating also functions as a binder. Here, the temperature at which the conductive layer 14 is thermally bonded to the sheet-like elastic substrate 12 is within a transferable temperature range, that is, the conductive layer 14 maintains a rubber state, and its elastic modulus is 1.0 × 10 ⁶ Pa or less. This temperature range is determined by the relationship between the sheet-like elastic base 12 and the base resin 15 forming the conductive layer 14. In the second embodiment, an elastic modulus at 150 ° C. (hereinafter referred to as 150 ° C. elastic modulus) in which the elastic base material M is reacted and cured on the sheet-like elastic base 12 can be adopted as an index.

In the plastic material such as the base resin 15 according to the present invention, the elastic modulus is closely related to the viscosity indicating the adhesiveness, and has an advantage that it can be easily measured by using a rheometer or the like. Therefore, the conductive layer 14 according to Example 2 is set so that the 150 ° C. elastic modulus measured using a rheometer is 1.0 × 10 ⁶ Pa or less. If this value is larger than 1.0 × 10 ⁶ Pa, it becomes a glass state as described above ([0023]) and cannot be suitably bonded to the sheet-like elastic substrate 12.

In the case of using the thermal transfer method, the conductive layer 14 is preferably used in an amount (mixing ratio) of the conductive agent 16 of 30 parts by mass or less with respect to 100 parts by mass of the base resin 15 from the viewpoint of transferability. When the amount of the conductive agent 16 used exceeds 30 parts by mass, the amount of the base resin 15 with respect to the conductive agent 16 is relatively reduced, so that the bonding strength of the conductive layer 14, that is, the transferability is deteriorated, and the sheet is further reduced. The followability to the elastic substrate 12 is also deteriorated. The amount of the conductive agent 16 used is appropriately selected depending on the surface resistance value that the conductive layer 14 should achieve. For example, in applications such as packing that can prevent troubles due to static electricity, the surface resistance value is 1.0 × 10. ^{2 to} 1.0 × 10 ⁶ Ω is desired, but such a surface resistance value is obtained by adding a conductive agent 16 made of carbon black such as acetylene black or oil furnace black to 100 parts by mass of the base resin 15. This is achieved by using in the range of 10 to 30 parts by mass.

(Production method of Example 2)
In Example 2, similarly to the conductive layer transfer film 20, a sheet-like elastic substrate 12 is prepared in advance, and both of them are placed in a state in which the base resin 15 can be transferred under control, that is, dissolved while maintaining the layer shape. The sheet-like elastic substrate 12 and the conductive layer 14 are laminated by heat bonding by heating to a transferable temperature range that does not penetrate into the sheet-like elastic substrate 12, and then the base film 18 is removed from the conductive layer 14. The conductive sheet-like elastic body 28 is manufactured by peeling and removing. The conductive sheet-like elastic body 28 basically has the same configuration as that of the conductive sheet-like elastic body 10 shown in FIG. 1, and is manufactured by a manufacturing apparatus 70 shown in FIG. The manufacturing apparatus 70 basically has the same structure as the manufacturing apparatus 30 described above ([0039]). However, the sheet-like elastic base 12 is not supplied and cured as the elastic base material M, but in a separate process. The elastic base 12 is manufactured in advance and wound into a roll, and this roll-shaped sheet-like elastic base 12 is used as a sheet-like elastic base supply roll 32d that constitutes a part of the roll mechanism 32. The elastic substrate 12 is supplied. The manufacturing apparatus 70, downstream of the sheet-like elastic body supply roll 32d, while heating to reliably supply heat to the conductive layer 14, a pair to reliably bond the elastic sheet body 12 and the conductive layer 14 heated Pressing rolls 35 and 35 are provided. That is, in the manufacturing apparatus 70, the conductive layer 14 and the sheet-like elastic base 12 are heated by the pair of heating and pressing rolls 35, 35, so that the sheet is formed by the chemical / physical adhesive force of the base resin 15 in a transferable state. The elastic substrate 12 and the conductive layer 14 are bonded and thermally transferred. The heat applied to the conductive layer 14 is set in a range of 60 to 150 ° C. that does not adversely affect the sheet-like elastic substrate 12 that is a transfer target and is a base material. If this temperature is less than 60 ° C., with control becomes difficult in a momentary conditions exerted by a pair of heated pressure rolls 35, 35, and sufficient elasticity to transcription regardless what如the base resin 15 If the temperature exceeds 150 ° C., the influence of the composition constituting the sheet-like elastic substrate 12 on the use as the conductive sheet-like elastic body 10 such as thermosetting cannot be ignored.

  In addition, the conductive layer transfer film 20 is electrically conductive to both surfaces of the sheet-like elastic substrate 12 as well as a mode in which the conductive layer 14 of the conductive layer transfer film 20 is opposed to one surface of the sheet-like elastic substrate 12 and thermally bonded. A mode in which the layers 14 are respectively supplied and the conductive layers 14 and 14 are thermally bonded to both surfaces of the sheet-like elastic substrate 12 at a time may be employed. Further, as the base resin 15, a so-called pressure-sensitive material that exhibits adhesiveness corresponding to a pressure (pressurization) above a certain level is used instead of a material that becomes transferable by heating, and a pair of heating materials is used. A pair of pressing rolls may be employed in place of the pressing rolls 35, 35. In this case, since no heat is applied to the sheet-like elastic base 12 when the conductive layer 14 is transferred, the elastic base material As M, a thermoplastic resin or the like can also be adopted.

Thus, in the manufacturing of the conductive sheet-like elastic body by the thermal transfer method can work to similarly environmental improvement and the improvement of production efficiency as in Example 1. Furthermore, since the sheet-like elastic substrate 12 and the conductive layer transfer film 20 in an amount to be manufactured can be set in advance with respect to the manufacturing apparatus 70, for example, it can easily cope with a small number of lots and flexibly respond to various product demands. In addition, the manufacturing range can be expanded.

Note Example 1, modification, in another variation or embodiment 2, respectively the conductive sheet-like elastic body 10,24,26 and 28 are Ru Tei is continuously produced, the invention is not limited thereto For example, the conductive substrate transfer film 20 of about 5 m and the base sheet 22 may be used to supply and heat the elastic base material M in batches. Further, the sheet-like elastic substrate 12 and the conductive layer 14 are firmly and integrally laminated by developing an adhesive action during reaction and curing of the heated elastic substrate material M in the integral molding method, and heated in the thermal transfer method. The sheet 14 is firmly joined by the adhesive action of the base resin 15 of the layer 14, but the sheet is formed by using a hot-melt adhesive or the like applied to the surface of the conductive layer 14 facing the sheet-like elastic body 12. The joint strength between the elastic substrate 12 and the conductive layer 14 can be further improved. This is done by providing an adhesive application mechanism upstream of the discharge nozzle 34 or by applying an adhesive in advance to the exposed surface of the conductive layer 14 in the conductive layer transfer film preparation step.

(Experimental example)
Below, the experiment about the electroconductive sheet-like elastic body which concerns on this invention was conducted. The present invention is not limited to this experimental example.

(Experiment 1) Regarding the followability of the conductive sheet-like elastic body The conductive layer forming raw material according to each base resin (A to D, J and K) and the amount (parts by mass) of the conductive agent described in Tables 1 and 2 Then, a solution obtained by uniformly mixing and dissolving 400 parts by mass of methyl ethyl ketone was coated on a 50 μm-thick release PET film with a baker type applicator, and heated at a temperature of 130 ° C. for 3 minutes. A film for conductive layer transfer capable of transferring a conductive layer having a thickness of 5 μm is produced by drying. Then, the conductive layer transfer film and the sheet-like elastic substrate are laminated and joined by both the integral molding method described in Example 1 and the thermal transfer method described in Example 2 to produce a conductive sheet-like elastic body ( For details of the production method, see Experiment 2 and Experiment 3 described later), and Examples 1-1 to 1-6 and Comparative Examples 1-1 and 1- 1 relating to the integral molding method described in Example 1 from this elastic body. 2 test specimens (see Table 1) were prepared as test specimens of Examples 1-7 to 1-12 and Comparative Examples 1-3 and 1-4 (see Table 2) according to the thermal transfer method described in Example 2, respectively. Then, by measuring the maximum point stress, maximum point elongation and elongation at break by a tensile test, the maximum point elongation / breaking point elongation and maximum point stress / maximum point elongation indicating the followability are calculated. In addition, the thermal transfer process described in Example 2 is further described with respect to followability and surface tackiness. As for transferability, ○: good, Δ: somewhat bad, x: unusable in three stages or o: good, x: unusable in two stages (details will be described later [0064]), Further, from these values and evaluation, the overall evaluation as a conductive sheet-like elastic body was shown as ◯: good, x: unusable. For reference, the glass transition temperature (° C.) and 150 ° C. elastic modulus (Pa) of the conductive layer composed of the base resin and the conductive agent and the peel force (N / 25 mm) indicating tackiness are also shown. As a reference example, the same measurement / calculation was performed for a state in which the conductive layer was not bonded, that is, only for the sheet-like elastic substrate.

The starting materials, conductive agent: oil furnace Bed rack sheet elastic base: polyurethane foam (trade name SR-S-24; manufactured by Inoac Corporation)
Base resin A: polyurethane (weight average molecular weight 240,000, glass transition temperature by TMA (thermomechanical analysis) measurement-35.3 ° C.))
Base resin B: Polyester-modified polyurethane (mass average molecular weight 52,000, glass transition temperature 26.3 ° C. by TMA measurement)
Base Resin C: styrene porcine diene styrene copolymer (weight average molecular weight 93,000, glass transition temperature of 83.4 ° C. by TMA measurement (weight ratio 40:60 of styrene monomer and blanking Tajien monomer) )
Base resin D: Polyester-modified polyurethane (mass average molecular weight 100,000, glass transition temperature 75.0 ° C. by TMA measurement)
Base resin J: Polyurethane (weight average molecular weight 105,000, glass transition temperature 48.0 ° C. by TMA (thermomechanical analysis) measurement))
Base resin K: Polyester-modified polyurethane (mass average molecular weight 27,000, glass transition temperature 34.2 ° C. by TMA measurement)

・ Measurement of maximum elongation at break, elongation at break and maximum stress Using a commercially available tensile tester, maximum elongation at the test piece cross-sectional area: 0.6 mm ² , tensile speed: 200 mm / min The elongation at break and the maximum point stress were measured.
-About measurement of the 150 degreeC elasticity modulus of an electroconductive layer It measured by the frequency of a single (1 Hz) using the commercially available rheometer under automatic shear stress control (shear constant).
-About the glass transition temperature measurement of a conductive layer It measured on the conditions of the temperature increase rate of 5 degree-C / min in the tension | tensile_elasticity mode using commercially available TMA.

・ About the follow-up evaluation method The conductive sheet-like elastic body according to each example or comparative example is placed on a glass substrate so that the conductive layer is on top, and a 5 mmφ glass rod is pushed until it cannot be pushed into the conductive layer. The state of the conductive layer when applied was visually observed, and evaluation was made as follows: ○: no occurrence of wrinkles or cracks, x: occurrence of wrinkles or cracks.
・ Surface tackiness evaluation method (peeling force measurement method)
The conductive sheet-like elastic body according to each example or comparative example was cut to a width of 25 mm and a length of 250 mm under the conditions of a temperature of 23 ° C. and a humidity of 65% RH to obtain a test piece. Using a 2 kg rubber roller to a glass plate with a thickness of 1.1 mm, reciprocating once at a speed of 300 mm / min, and letting it stand under conditions of 23 ° C. and 65% RH for 20 minutes, using a tensile tester Then, the peeling force (N / 25 mm) when the conductive layer was peeled off in the 180 ° direction under the condition of a pulling speed of 300 mm / min was measured. Further, based on this measurement value, if the value is 0.2 (N / 25 mm) or less empirically, the material deposited on the conductive sheet-like elastic body according to the present invention can be easily peeled off. As for ◯, if it exceeds 0.2 (N / 25 mm), it is considered that peeling is somewhat difficult. X evaluation was given to each. In addition, the glass plate used what dried after wash | cleaning the surface with ethanol before sticking a test piece.
・ About transferability evaluation method (thermal transfer method only)
When the base film was peeled from the conductive layer transfer film, the state on the base film was visually observed, and evaluation was made as follows: ○: the conductive layer was not completely left, x: the conductive layer was left. did.

(Result of Experiment 1)
The results of Experiment 1 are also shown in Tables 1 and 2 above. From Table 1 and Table 2, it was confirmed that favorable followability and the like are exhibited by setting conditions such as physical properties of the base resin within the range according to the present invention.

(Experiment 2) About the conductive sheet-like elastic body manufactured by the integral molding method according to Example 1 The conductive sheet-like elastic body according to the present invention is manufactured by the integral molding method, specifically, the manufacturing method described above ([0039]). About the conductive sheet-like elastic body manufactured by the following procedure using the apparatus 30, the types of base resins shown in Table 3 (A to C and E to I among the base resins used in Experiment 1) and the conductive agent The conductive sheet-like elastic bodies according to Experimental Examples 2-1 to 2-11 in the used amount were manufactured, and the surface resistance value (Ω) and the followability were measured and determined. Here, the followability was evaluated in three stages: ○: good, Δ: somewhat bad, x: unusable. Note Reference to the base resin and made of a conductive material conductive layer glass transition temperature (° C.), and are also shown for the 25 ° C. modulus (Pa) and 0.99 ° C. modulus (Pa). The raw materials used but not explained in Experiment 1 are described below.

Substances used: Base resin E: Polyurethane (weight average molecular weight: 83,000, glass transition temperature measured by TMA (thermomechanical analysis) 40.0 ° C))
Base resin F: Polyester-modified polyurethane (mass average molecular weight 76,000, glass transition temperature 75.0 ° C. by TMA measurement)
Base resin G: Polyester-modified polyurethane (mass average molecular weight 72,000, glass transition temperature 70.0 ° C. by TMA measurement)
Base Resin H: styrene porcine diene styrene copolymer (weight average molecular weight of 150,000, a glass transition temperature of 90.0 ° C. by TMA measurement (weight ratio 31:69 of styrene monomer and blanking Tajien monomer) )
Base resin I: Polyester-modified polyurethane (mass average molecular weight 67,000, glass transition temperature 65.0 ° C. by TMA measurement)

(Production method)
-Preparation of conductive layer transfer film In another step, a PET film (base film) having a thickness of 50 µm was used as the base film, and the base resins A to C used in Experiment 1 as the base resin and the above E to I were used. A conductive layer transfer film according to each experimental example was prepared using the oil furnace black as a conductive agent and forming a conductive layer with a thickness of 5 μm by the above-mentioned procedure ([0042]). This is set on the supply roll 32a.

With respect to 100 parts by mass of polyether polyol (average molecular weight 3000, hydroxyl value 43.0), a mixture was obtained from 0.1 part by mass of a metal catalyst (stannous octoate) and 3 parts by mass of a silicone foam stabilizer. Here, nitrogen as a foaming gas at a flow rate of 0.1 NL / min, and a polyisocyanate (crude MDI, NCO content: 31%) set to have an isocyanate index of 0.9 to 1.1, Are mixed and sheared to obtain the elastic base material M. The elastic base material M is continuously supplied from the supply roll 32a in a state where a tension of about 29.4 to 98.1 N (3 to 10 kgf) (when the object to be tensioned is 1000 mm wide) is applied on the roll mechanism 32. Is supplied from the discharge nozzle 34 onto the conductive layer of the conductive layer transfer film that is supplied to the sheet-like elastic substrate so that the density upon completion of the sheet-like elastic substrate is 300 kg / m ³ . The thickness of the conductive sheet-like elastic body when the product is completed is set to 0.5 mm. Then, heating is carried out in conditions of 150 to 200 ° C. for 1 to 3 minutes in a tunnel-type heating furnace, and the reaction and curing of the elastic substrate raw material M is advanced so that the sheet-like elastic substrate is bonded to the conductive layer. The conductive sheet-like elastic body is recovered by the product recovery roll 32c, while only the base film laminated thereon is removed and recovered by the base film recovery roll 32b. .

  Then, test pieces having dimensions of 100 mm (length) × 100 mm (width) × 0.5 mm (thickness) were obtained from the conductive sheet-like elastic body according to each experimental example, and measurement of each measurement / evaluation item described above was obtained.・ Evaluated. The equipment and measurement conditions used for the measurement are the same as in Experiment 1. The measurement / judgment items for Experiment 2 only are described below.

Measurement of the surface resistance value on the conductive layer side of the conductive sheet-like elastic body Measuring instrument: trade name ULTRA HIGH RESISTANCE METER R8340; manufactured by Advantest Measurement conditions: applied voltage: 10 V, discharge: 10 seconds, charge: 10 seconds, The test piece according to each experimental example was measured after being left in the adjustment room under conditions of 22 ° C. × 55% RH and 24 hours.

(Result of Experiment 2)
The results of Experiment 2 are also shown in Table 3 above. From Table 3, by setting the type of base resin, the amount of conductive agent used, and the conditions of the conductive layer within the range according to the present invention, the conductivity according to the present invention is achieved and good followability is achieved. It was confirmed that

(Experiment 3) About the conductive sheet-like elastic body manufactured by the thermal transfer method according to the second embodiment The conductive sheet-like elastic body according to the present invention is manufactured by the thermal transfer method, specifically, the manufacturing apparatus 70 described above ([0056]). For the conductive sheet-like elastic body produced by the following procedure, the types of base resins shown in Table 4 (A to E, H, J and K among the base resins used in Experiment 1 or Experiment 2, L to N) and a conductive sheet-like elastic body according to Experimental Examples 3-1 to 3-14 according to the amount of the conductive agent used, and measurement of the surface resistance (Ω), followability and transferability Judgment was made about. Here, the manufacturing method of the conductive layer transfer film and the measurement method of the elastic modulus and the like are the same as in Experiment 1 or Experiment 2, and the obtained conductive layer transfer film according to each experimental example is set on the supply roll 32a. . The thickness of the conductive layer was set to 10 μm only in Experimental Example 3-14, and 5 μm in other cases. Further, the followability was evaluated in three stages: ◯: good, Δ: somewhat bad, x: unusable, and transferability was evaluated in two stages: ◯: good, x: unusable. Note Reference to the base resin and made of a conductive material conductive layer glass transition temperature (° C.), and are also shown for the 25 ° C. modulus (Pa) and 0.99 ° C. modulus (Pa). The raw materials used but not explained in Experiment 1 or Experiment 2 are described below.

For use substances based resin L: Styrene porcine diene styrene copolymer (weight average molecular weight of 130,000, a glass transition temperature of 44.8 ° C. by TMA measurement (weight ratio of styrene monomer and blanking Tajien monomer 30 : 70))
Base resin M: Polyester-modified polyurethane (mass average molecular weight 100,000, glass transition temperature 12.0 ° C. by TMA measurement)
Base resin N: Polyester-modified polyurethane (mass average molecular weight 65,000, glass transition temperature 65.0 ° C. by TMA measurement)

A separately prepared sheet-like elastic substrate (trade name PORON SR-S-40P; manufactured by INOAC Corporation) having a thickness of 0.5 mm is set on the sheet-like elastic substrate supply roll 32d, and is 29 with respect to the conductive layer and the sheet-like elastic substrate. It is continuously supplied at a speed of 1 m / min under a tension of about .4 to 98.1 N (3 to 10 kgf) (when the object to be tensioned is 1000 mm wide). And it passes between a pair of heating press rolls 35 and 35 to which the (cylinder) pressure of 3 kg / cm < ² > and the heat | fever of 100 degreeC were applied with respect to a conductive layer and a sheet-like elastic base | substrate, with respect to a sheet-like elastic base | substrate. The conductive sheet-like elastic body having the conductive layer bonded thereto is obtained, and the completed conductive sheet-like elastic body is obtained while removing and collecting only the base film laminated thereon by the base film recovery roll 32b. It collects with the product collection roll 32c.

Then, test pieces having dimensions of 100 mm (length) × 100 mm (width) × 0.5 mm (thickness) were obtained from the conductive sheet-like elastic body according to each experimental example, and measurement of each measurement / evaluation item described above was obtained.・ Evaluated. The equipment and conditions used for measurement, the measurement conditions, and the like are the same as in Experiments 1 and 2.

(Result of Experiment 3)
The results of Experiment 3 are also shown in Table 4 above. From Table 4, by setting the type of the base resin and the condition of the conductive layer within the range according to the present invention, the conductivity according to the present invention is achieved, and good followability and transferability are exhibited. Was confirmed.

  The conductive sheet elastic body according to the present invention and the method for manufacturing the same are provided in a mobile phone, a television, and other electrical devices such as a computer display, such as a liquid crystal display unit, a microphone unit, and other input / output units such as a speaker unit. It is arranged at the peripheral part of the internal device, and is interposed between the casing that is the main body of the device and the peripheral edge of the internal device, and is used to prevent light leaks such as dust, backlight, and rattling. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing a conductive sheet elastic body according to a preferred embodiment 1 of the present invention with a part cut away. 3 is a process diagram illustrating a method for producing a conductive sheet-like elastic body of Example 1. FIG. It is an example of the manufacturing apparatus which manufactures the electroconductive sheet-like elastic body of Example 1 by the mechanical floss method. It is a state figure which shows roughly the state in each process, such as an elastic base material, a sheet-like elastic base, a conductive layer, and a base film, used when manufacturing the conductive sheet-like elastic body of Example 1. It is a longitudinal cross-sectional view which expands and shows the electroconductive sheet-like elastic body which concerns on the example of a change of Example 1. FIG. It is the schematic which shows the manufacturing apparatus of the electroconductive sheet-like elastic body which concerns on the example of a change of Example 1. FIG. It is a longitudinal cross-sectional view which expands and shows the electroconductive sheet-like elastic body which concerns on another modification of Example 1. FIG. It is the schematic which shows the manufacturing apparatus of the electroconductive sheet-like elastic body which concerns on another modification of Example 1. FIG. It is the schematic which shows the manufacturing apparatus of the electroconductive sheet-like elastic body of Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Conductive sheet-like elastic body 12 Sheet-like elastic substrate 14 Conductive layer 15 Base resin 16 Conductive agent 18 Base film 22 Base material sheet 24 Conductive sheet-like elastic body 26 Conductive sheet-like elastic body 28 Conductive sheet-like elastic body M Elastic base material

Claims (15)

Conductive agent made of conductive carbon on base resin (15) made of polyurethane resin or styrene butadiene styrene copolymer whose elastic modulus at 25 ° C. is set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa A conductive layer transfer film (20) in which a conductive layer (14) constituted by dispersing (16) is formed on one surface of a base film (18) is prepared,
The elastic substrate material (M) in a fluid state is supplied to the conductive layer (14) side of the conductive layer transfer film (20),
The supplied elastic base material (M) is reacted and cured in a transferable temperature range in which the conductive layer (14) is in a rubber state and its elastic modulus is 1.0 × 10 ⁶ Pa or less. Forming a sheet-like elastic substrate (12) made of polyurethane foam having a required thickness joined to the conductive layer (14),
A conductive sheet-like elastic body, wherein the conductive layer (14) is transferred to the sheet-like elastic substrate (12) by peeling the base film (18) from the conductive layer (14). Production method. Conductive agent made of conductive carbon on base resin (15) made of polyurethane resin or styrene butadiene styrene copolymer whose elastic modulus at 25 ° C. is set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa A conductive layer transfer film (20) in which a conductive layer (14) constituted by dispersing (16) is formed on one surface of a base film (18) is prepared,
The elastic substrate material (M) in a fluid state is supplied to the conductive layer (14) side of the conductive layer transfer film (20),
Next, another conductive layer transfer film (20) is continuously applied to the elastic substrate material (M) on the conductive layer (14) so that the conductive layer (14) faces the elastic substrate material (M). Supply
The supplied elastic base material (M) is reacted and cured in a transferable temperature range in which the conductive layer (14) is in a rubber state and its elastic modulus is 1.0 × 10 ⁶ Pa or less. The sheet-like elastic substrate (12) made of polyurethane foam having a required thickness in which the respective conductive layers (14) are bonded to both surfaces thereof, and
The conductive layer (14) is transferred to the sheet-like elastic substrate (12) by peeling the corresponding base film (18) from each of the conductive layers (14). A method for producing a sheet-like elastic body. Conductive agent made of conductive carbon on base resin (15) made of polyurethane resin or styrene butadiene styrene copolymer whose elastic modulus at 25 ° C. is set in the range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa A conductive layer transfer film (20) in which a conductive layer (14) constituted by dispersing (16) is formed on one surface of a base film (18) is prepared,
Supply the elastic base material (M) in a fluid state on the base sheet (22),
The conductive layer transfer film (20) is continuously supplied to the elastic base material (M) so that the conductive layer (14) faces the elastic base material (M),
The supplied elastic base material (M) is reacted and cured in a transferable temperature range in which the conductive layer (14) is in a rubber state and its elastic modulus is 1.0 × 10 ⁶ Pa or less. Forming a sheet-like elastic substrate (12) made of polyurethane foam having the conductive layer (14) bonded to one surface thereof;
The conductive layer (14) is transferred to the one surface of the sheet-like elastic substrate (12) by peeling the base film (18) from the conductive layer (14). For producing a sheet-like elastic body.   Carbon black is used as the conductive agent (16), and the amount used is set in the range of 10 to 65 parts by mass with respect to 100 parts by mass of the base resin (15). The manufacturing method of the electroconductive sheet-like elastic body of one term. A sheet-like elastic substrate (12) made of polyurethane foam having a required thickness, and a polyurethane resin or styrene-butadiene-styrene copolymer having an elastic modulus at 25 ° C. of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa. For conductive layer transfer, a conductive layer (14) formed by dispersing a conductive agent (16) made of conductive carbon in a base resin (15) made of a coalescence is formed on one surface of a base film (18). Prepare the film (20),
After laminating the conductive layer transfer film (20) so that the conductive layer (14) faces the sheet-like elastic substrate (12), the sheet-like elastic substrate (12) and the conductive layer (14) are combined with the conductive layer ( 14) is in a rubber state, and is bonded by heating and / or pressing in a transferable temperature range where the elastic modulus is 1.0 × 10 ⁶ Pa or less,
A conductive sheet-like elastic body, wherein the conductive layer (14) is transferred to the sheet-like elastic substrate (12) by peeling the base film (18) from the conductive layer (14). Production method.   The method for producing a conductive sheet-like elastic body according to claim 5, wherein the transferable temperature range of the conductive layer (14) is in the range of 60 to 150 ° C.   The conductive material according to claim 5 or 6, wherein carbon black is used as the conductive agent (16), and the amount used is in the range of 10 to 30 parts by mass with respect to 100 parts by mass of the base resin (15). For producing a sheet-like elastic body. In a conductive sheet-like elastic body comprising a sheet-like elastic substrate (12) made of polyurethane foam and a conductive layer (14) laminated on at least one surface of the sheet-like elastic substrate (12),
The conductive layer (14) is made of a polyurethane resin or a styrene butadiene styrene copolymer, and a base resin (15 having an elastic modulus at 25 ° C. set in a range of 1.0 × 10 ^{4 to} 9.0 × 10 ⁷ Pa. And a conductive agent (16) made of conductive carbon, dispersed in the base resin (15),
The conductive sheet-like elastic body is set so as to satisfy at least one of a maximum point elongation / elongation at break of 0.95 or more and a maximum point stress / maximum point elongation of 0.1 or less. A conductive sheet-like elastic body.   The conductive layer transfer film (20) having the conductive layer (14) formed on the substrate film (18) is bonded to the sheet-like elastic substrate (12) on the conductive layer (14) side. The conductive sheet-like elastic body according to claim 8, wherein the conductive layer (14) is transferred to the surface of the sheet-like elastic substrate (12) by peeling off the base film (18).   The conductive sheet-like elastic body according to claim 8 or 9, wherein the sheet-like elastic substrate (12) has a 25% compression hardness set to 0.035 MPa or less. 11. The surface resistance value of the conductive sheet-like elastic body (10, 24, 26, 28) is set in a range of 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ Ω. The conductive sheet-like elastic body according to one item.   The conductive sheet-like elastic body according to any one of claims 8 to 11, wherein the thickness of the conductive layer (14) is set in a range of 1 to 10 µm.   The conductive sheet-like elastic body according to any one of claims 8 to 12, wherein carbon black is used as the conductive agent (16).   The conductive sheet-like elasticity according to any one of claims 8 to 13, wherein the conductive agent (16) is added in a range of 5 to 20 parts by mass with respect to 100 parts by mass of the base resin (15). body. The conductive sheet-like elastic body according to any one of claims 8 to 14, wherein the base resin (15) has a glass transition temperature of 0 ° C or higher .

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