JP3901489B2 - Manufacturing method of rubber sheet composite - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention is a rubber sheet compositethe body'sSpecifically, the present invention provides a rubber sheet composite having a thin film shape that is suitable as a precision product having a fluid passage, for example, a battery or capacitor gasket, and having a high sealing property.
[0002]
[Prior art]
Sealing materials are used to prevent leakage of liquids and gases in precision products that enclose liquids and gases such as fuel cells, but various types of sealing materials have been proposed for the purpose of miniaturizing products. ing. For example, a gasket is used (see JP-A-9-231987, JP-A-7-226220, JP-A-7-153480, etc.), and a gasket is formed by stacking a foam layer on a rubber plate (JP-A-9-27480). 7-312223), or a gasket body made of a metal or resin sheet combined with a sealing material made of liquid rubber or silicone resin (see JP 2000-231927, JP 2001-57220, etc.) In addition, a rubber thin film having a rubber thin film pattern printed on the surface of a fuel cell separator (see JP 2001-196078 A) is known. However, these gasket-like sealing materials have a problem that they are insufficient in terms of sealing properties and thinning, and workability when incorporating the sealing material is low.
[0003]
On the other hand, the inventor of this application has made various proposals regarding a thin film rubber film composite in which a rubber film such as a silicone rubber and a plastic film such as a polyester film are directly integrated without using an adhesive ( JP-A-10-53659, JP-A-10-58605, JP-A-10-86282, JP-A-10-95071 and JP-A-11-157010, etc.), according to these Thinning of the body is easy. However, in order to seal the hydrogen gas in the fuel cell, the sealing performance may be insufficient, and it is necessary to increase the area of the seal portion or increase the tightening pressure, and improvements have been desired.
[0004]
[Problems to be solved by the invention]
The present invention can be used as a sealing gasket for preventing leakage of fluids such as liquids and gases in precision products such as batteries and capacitors, and can be made thin, enabling downsizing of the above products. The present invention provides a rubber sheet composite having a high degree of sealing performance and good workability at the time of incorporation into the product.
[0005]
[Means for Solving the Problems]
Rubber sheet composite according to the present inventionManufacturing methodIs a rubber sheet composite for a gasket, in which a rubber sheet is combined on at least one surface of a base material sheet so as to be interposed and sealed on a joint surface between two arbitrary members.A rubber obtained by dissolving a rubber composition in a solvent on at least one side of a sheet made of a simple substance of plastic, metal, glass and ceramics or a composite of two or more as the base material sheet A non-crosslinked rubber sheet is laminated by applying and drying the solution, the cover sheet is peelably laminated on the surface of the rubber sheet, and an uncrosslinked or semi-crosslinked rubber is stamped on the cover sheet. At least one protrusion is formed on the surface of the sheet along the line that needs to be sealed, and then subjected to a crosslinking treatment to directly integrate the base sheet and the rubber sheet.It is characterized by that.
[0006]
The rubber sheet composite can effectively seal between the joint surfaces of the two members by interposing so that the protrusions are sandwiched between the joint surfaces of any two members and compressed. . And when the inner side of a protrusion is punched and used, the fluid channel over 2 members can be connected. On the other hand, when the rubber sheet composite is used as it is, it functions as a partition plate for a fluid passage extending over two members. And, for example, when a functional membrane such as a polymer electrolyte membrane or an air permeable membrane is used as a base sheet, and a rubber sheet is compounded only along the necessary sealing line around it, the functional membrane is used as it is. Can function.
[0007]
The above-mentioned base material sheet supports or reinforces the rubber sheet to improve the handling and workability of the rubber sheet, and to improve the workability when the rubber sheet is incorporated into a product containing the rubber sheet. , A sheet made of a simple substance of metal, glass and ceramics or a composite of two or more. The composition thereof is arbitrary, and the structure can be appropriately selected from a sheet (including a thickness in a range called a film) or a woven fabric. In addition, a functional film can be selected as described above. Although the thickness of the said base material sheet is also arbitrary, 3-200 micrometers is preferable.
[0008]
It is desirable that the rubber sheet side surface of the base material sheet is subjected in advance to an easy adhesion treatment for enhancing the adhesion to the rubber sheet. Examples of the easy adhesion treatment include active ray treatment and surface treatment with an easy adhesion polymer. And these processes may perform only any one and may use both together.
[0009]
Examples of the active ray treatment include radiation treatment such as electron beam treatment and γ-ray, ultraviolet treatment, corona treatment, plasma treatment, flame treatment, and the like. You may carry out combining the process of a seed | species or more. The atmosphere during the treatment is not particularly limited, but an atmosphere of an inert gas or a reducing gas is preferable.
[0010]
Examples of the polymer for the surface treatment with the easily adhesive polymer include, but are not limited to, a polyester polymer, a polyurethane polymer, a polyacrylic polymer, a mixture of two or more of these polymers, or a copolymer. These polymers can also be crosslinked with an isocyanate-based crosslinking agent.
[0011]
The rubber sheet of the present invention includes natural rubber (NR), silicone rubber (Q), ethylene propylene diene rubber (EPDM), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), chloroprene rubber (CR), acrylic rubber ( ACM) and any rubber such as fluoro rubber (FK), or a rubber composition made of a mixture of two or more.
[0012]
In the rubber sheet composite of the present invention, the base sheet and the rubber sheet are combined and integrated. And even if the rubber sheet is thinned, since at least one linear protrusion is formed on the surface of the rubber sheet of the base sheet, the gasket is interposed between any two members. When this ridge portion is compressed by two members, a high sealing property is expressed. In general, the rubber sheet is preferably cross-linked. However, when the rubber sheet is combined on both the front and back surfaces of the base sheet as described later, when the protrusion is not formed on the rubber sheet on one side, Cross-linking of the rubber sheet can be omitted.
[0013]
The shape of the rubber sheet is arbitrary as long as it is a flat sheet shape that covers the sealing required lines on the joint surfaces of the two components, for example, battery and capacitor components, and has flange-like protruding portions on both sides of the sealing lines. The whole surface of the base sheet may be covered, and a circular, oval, oval, square, triangular or any other closed loop shape that covers a part of the base sheet, or an open loop in which a part of the closed loop is opened Any shape may be used, and the shape can be appropriately selected according to the shape and required characteristics of a product or a part incorporating the rubber sheet composite.
[0014]
Further, the protrusion on the surface of the rubber sheet has an arbitrary cross-sectional shape such as a semicircular shape or a square shape, and at least one of the protrusions is formed in the closed loop shape or the open loop shape along the required seal line. The height of the ridge is arbitrarily set according to the shape and purpose of the product or member into which the rubber sheet is incorporated, but is generally preferably 0.01 to 0.6 mm. The total thickness of the base material sheet and the rubber sheet is not particularly limited, but for the purpose of thinning the film, it is preferably 1 mm or less, particularly preferably 0.8 mm or less, and most preferably 0.6 mm or less at the protruding portion. . Although the minimum of the said thickness is not limited, 0.05 mm is preferable at the point of the sealing effect expression. Further, in the above rubber sheet, the width of the portion protruding into the flange shape on both sides of the necessary seal line, in other words, the width of the portion where the flat portion of the rubber sheet protrudes on both sides from the base of the protrusion is preferably 2 mm or more, and less than 2 mm Sealing performance is reduced. In the case where the rubber sheet is formed in a closed loop shape or an open loop shape along the necessary seal line, the above-mentioned width is preferably 30 mm or less at maximum.
[0015]
It is preferable that a cover sheet is detachably laminated on the surface of the rubber sheet. By laminating the cover sheets, the surface of the rubber sheet is protected and can be prevented from being damaged or contaminated before the start of use, and the rubber sheet can be easily wound and workability is improved. Furthermore, process passage property and workability at the time of manufacturing a rubber sheet composite as described later are improved.
[0016]
The above cover sheet is peeled off when the rubber sheet composite is used. Therefore, unlike the base material sheet, it is necessary to lower the adhesiveness to the rubber sheet to give the peelability, and therefore, a material having low adhesiveness to the rubber sheet is selected as the material. For example, poly-4-methylpentene-1 and ethylene / methyl methacrylate copolymer are preferable. Moreover, an easily peelable treatment can be applied to the adhesive film surface in advance. The thickness of the cover sheet is not particularly limited, but is generally preferably 0.005 to 0.2 mm.
[0017]
The means for combining and integrating the base material sheet and the rubber sheet is optional, but it is preferable that the base sheet and the rubber sheet are integrated directly without using an adhesive, which facilitates the thinning of the rubber sheet composite. . In particular, when a rubber sheet composite having excellent heat resistance is produced by combining heat resistant materials, it is possible to prevent a decrease in heat resistance due to the adhesive. Furthermore, it becomes economically advantageous. In addition, the above-mentioned adhesive expresses adhesive force by forming a layer having a thickness of 0.03 mm or more, and is different from the above-mentioned easy adhesion treatment layer so-called anchor treatment layer for improving adhesion. It is.
[0018]
As a means for directly integrating without using the above-mentioned adhesive, a cross-linking adhesion in which an adhesion improver is blended with the rubber component and bonded simultaneously with the cross-linking is preferable. The adhesion improver is preferably a compound containing a reactive group active against radical reaction, and examples thereof include acrylic acid derivatives, methacrylic acid derivatives and allyl derivatives. Among them, two or more unsaturated bonds, particularly 3 A derivative having more than one is preferred. These compounds are widely used as rubber co-crosslinking agents, and examples thereof include acrylic acid esters and methacrylic acid esters of polyhydric alcohols, allyl esters of polycarboxylic acids, triallyl isocyanurate, triallyl cyanurate, and the like. .
[0019]
The polyhydric alcohol acrylic ester or methacrylic ester is an ester compound obtained by esterifying two or more alcoholic hydroxyl groups of a polyhydric alcohol having two or more alcoholic hydroxyl groups with acrylic acid or methacrylic acid. Glycol diacrylate, ethylene glycol dimethacrylate, 1,3 butanediol diacrylate, 1,3 butanediol dimethacrylate, 1,4 butanediol acrylate, 1,4 butanediol methacrylate, 1,6 hexanediol diacrylate, 1,6 Hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 2,2'bis (4-acryloxydiethoxyphenyl) propane, 2,2'bis (4-methacrylate) Roxydiethoxyphenyl) prone, glycerol dimethacrylate, glycerol triacrylate, glycerol trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, Examples include pentaerythritol tetramethacrylate, tetramethylol methane diacrylate, tetramethylol methane dimethacrylate, tetramethylol methane triacrylate, tetramethylol methane trimethacrylate, tetramethylol tetraacrylate, tetramethylol tetramethacrylate, etc., especially 3 or more allyl acids Compounds containing ester or methacrylic acid ester.
[0020]
In addition, although said compound illustrated each single ester compound of acrylic acid and methacrylic acid, the form of mixed ester of acrylic acid and methacrylic acid may be sufficient. Examples of the allyl ester of polyvalent carboxylic acid include phthalic acid diarylate, trimellitic acid triarylate, and pyromellitic acid tetraarylate. And the adhesive improvement agent of the said rubber sheet may be used individually by 1 type, and may use 2 or more types together. Further, the adhesion improver used in the present invention is not limited to the above exemplary compounds.
[0021]
The compounding amount of the above adhesion improver is 0.2 to 20 parts by weight, preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the total rubber component, and if it is less than 0.2 parts by weight, the adhesive strength with the base sheet is insufficient. On the other hand, if it exceeds 20 parts by weight, the effect of improving the adhesive strength reaches saturation, and the physical properties of the rubber decrease. If necessary, reinforcing fillers, pigments, dyes, antioxidants, antioxidants, mold release agents, flame retardants, thixotropic agents, filler dispersants, and the like can be blended. In addition, when RTV silicone rubber is used as the rubber, the blending of the above-mentioned adhesion improver can be omitted.
[0022]
In this invention, a peroxide can be blended as an adhesion improvement accelerator for promoting the adhesion enhancement effect by the above adhesion improver, and by this combination, the interlayer between the rubber sheet and the base sheet can be blended. Peel strength is further improved. However, the compounding amount of the above peroxide is preferably 0.05 to 10 parts by weight, particularly 0.1 to 5 parts by weight with respect to 100 parts by weight of the total rubber component. When the amount exceeds 10 parts by weight, the above-mentioned accelerating effect is saturated and the physical properties of the rubber sheet are lowered.
[0023]
The peroxide may be either acyl-based or alkyl-based, such as benzoyl peroxide, monochlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl- 2,5-bis (t-butylperoxy) hexane, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-bis-t-butylperoxy-3,3 Examples include 5-trimethylcyclohexane, di-t-butyl peroxide, t-butylcumyl peroxide and the like. In addition, when the above-described peroxide is crosslinked by a heating method, it has an action of initiating a crosslinking reaction, and therefore it is necessary to blend it as a rubber component.
[0024]
The rubber sheet composite of the present invention can be used as a seal for precision products and parts other than batteries and capacitors, but it is a rubber sheet for gaskets of batteries and capacitors, particularly high capacity capacitors of fuel cells and interface double layer type. Most suitable as a complex. That is, a battery or capacitor component is used as the two optional members, and a functional film of the battery or capacitor as the base sheet, such as a separator film, a polymer electrolyte film, an air permeable film, a diffusion film, or a current collecting film In this case, it is possible to further reduce the size of the fuel cell and the high-capacitance capacitor by sufficiently exhibiting the advantageous function of providing a high degree of sealing performance while being a thin film of the rubber sheet composite. it can.
[0025]
The rubber sheet composite is formed by laminating an uncrosslinked rubber sheet on at least one surface of the base sheet, and forming a ridge on the rubber sheet surface by imprinting in an uncrosslinked or semi-crosslinked state on the rubber sheet side, Subsequently, it can manufacture by performing a crosslinking process. In this case, after laminating the rubber sheet, it is preferable to laminate the cover sheet on the surface of the rubber sheet and form a protrusion by engraving from the cover sheet side. In this case, a mold or an emboss roll This is advantageous in that it prevents soiling.
[0026]
The means for laminating the uncrosslinked rubber sheet on the base sheet isA method of applying a solution containing an uncrosslinked rubber composition to the surface of the base sheet and drying is preferable.. The uncrosslinked rubber sheet may be a single layer or a multilayer of two or more layers. In the case of multiple layers, the above lamination method may be repeated or may be laminated at once with a multilayer die. Moreover, when laminating | stacking on the specific shape which covers the said seal | sticker required line, for example, the shape of an open loop or a closed loop, it can laminate | stack by printing methods, such as screen printing, using the solution containing said rubber composition.
[0027]
The protrusion on the surface of the rubber sheet is formed by pressing the rubber sheet surface directly or through a cover sheet using a press plate or press roll engraved with a desired pattern. The above engraving needs to be performed in an uncrosslinked or semi-crosslinked state of the rubber sheet, which makes the engraving significantly easier than after the crosslinking. The temperature at the time of engraving is also arbitrary, but is preferably in the range of room temperature to 100 ° C. However, the temperature may be set to 100 ° C. or higher when heating crosslinking is performed simultaneously. The pattern shape of the marking is arbitrary as long as it is a shape along the seal required line, and as described above, it is set according to the shape and required performance of the product or part incorporating the rubber sheet composite. For example, when used in a fuel cell, it is formed according to the shape of the flow path such as hydrogen gas, air or water, and in this case, rubber is preferably formed with a width of 2 to 30 mm on both sides of the protrusion along the seal required line. A flat portion of the sheet is formed.
[0028]
Examples of the crosslinking method of the rubber sheet include a heating method and a method of irradiating active rays such as electron beams, γ rays, and ultraviolet rays. The active ray irradiation method includes a crosslinking agent such as sulfur and peroxide, Since the addition of a crosslinking aid or the like is unnecessary, when the rubber sheet composite is used as, for example, a sealing material for a fuel cell, it is possible to avoid mixing catalyst poisons and the like. The rubber sheet may be subjected to crosslinking treatment either after engraving or at the same time as engraving. However, it is preferable to perform the heating type crosslinking treatment simultaneously with the engraving.
[0029]
In this invention, said rubber sheet can be laminated | stacked on the front and back both surfaces of a base material sheet. And when laminating | stacking on both surfaces, the said protrusion can be shape | molded only to the rubber sheet of one side, and it can be used flat without forming a protrusion on the rubber sheet of the other side. For example, when used as a gasket for a fuel cell or a capacitor, the rubber sheet on one side can be in contact with the separator, and the rubber sheet on the other side can be in contact with the polymer electrolyte membrane. Usually, since the separator is made of a hard material such as metal or graphite, it is advantageous in terms of sealing properties that a protrusion is present on the surface in contact with the separator. On the other hand, since the polymer electrolyte membrane is flexible, the need for protrusions is low. Rather, it is more effective to integrate the rubber sheet and the polymer electrolyte membrane with a tightening pressure. Depending on the material of the polymer electrolyte membrane, the rubber sheet may be in an uncrosslinked or semi-crosslinked state.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
An adhesion improver is added to each of the first rubber composition and the second rubber composition that is the same as or different from the first rubber composition, and dissolved in a solvent such as toluene to give the first rubber solution and the second rubber solution. prepare. In addition, an easy-adhesive plastic film such as a polyethylene terephthalate film whose front and back surfaces are treated with a plasma treatment or an easy-adhesive treatment agent is prepared as a base sheet. In addition, as the first cover sheet and the second cover sheet, at least one surface of an easily peelable plastic film is prepared.
[0031]
A first rubber solution is applied to the surface of the base sheet, dried, a first cover sheet is laminated on the surface of the first rubber layer, and an electron beam is irradiated from the first cover sheet side to crosslink the first rubber layer. To do. Next, a second rubber solution is applied to the back surface of the base sheet and dried, and a second cover sheet is laminated on the surface of the second rubber layer. After that, from the top of the second cover sheet on the surface of the unvulcanized second rubber layer in the laminate composed of five layers of the first cover sheet, the first rubber layer, the base sheet, the second rubber layer and the second cover sheet. Imprint the ridges in the form of a single closed loop. And an electron beam is irradiated to said laminated body from the 2nd cover sheet side, and a 2nd rubber layer is bridge | crosslinked.
[0032]
1 and 2, reference numeral 10 denotes a rubber sheet composite, which is shown in a state where the first cover sheet and the second cover sheet are peeled off. Reference numeral 11 is a base sheet, 12 is a first rubber sheet (crosslinked first rubber layer), 13 is a second rubber sheet (crosslinked second rubber layer), and a protrusion 13a is formed on the second rubber sheet 13. Is shaped to draw one closed loop.
[0033]
The rubber sheet composite is formed into a gasket having a shape in which a flat portion having a width of 5 to 10 mm remains on both sides of the ridge 13a by punching in a square shape along the two-dot chain lines 14a and 14b on both sides of the ridge 13a. This is interposed between the two members in the shape of the chain double-dashed line, and is fixed by tightening so that one fluid passage extending over the two members is communicated, and leakage at the connecting portion is caused by the protrusion 13a and the flat portions on both sides. Prevent jointly. In the above embodiment, the shape of the closed loop can be a circle, an ellipse, or any other shape. Moreover, the protrusion of the same shape can be shape | molded also to the 1st rubber sheet 12 as needed.
[0034]
Embodiment 2
In the first embodiment, only one flow path is formed, but a plurality of flow paths can be provided. For example, in FIG. 3, 20 is a rubber sheet composite, 21 is a base sheet, 22 is a frame-like rubber sheet, 22a is a ridge, and the whole is formed vertically symmetrical with respect to the chain line NN. An inner side 21a of a central large rectangular frame composed of 22 and an inner side 21b of a small rectangular frame arranged along the upper side and the lower side are respectively punched to form fluid passages 21a and 21b for various fluids. That is, it is formed so that a part of two adjacent closed loops overlaps along a plurality of closed loops. The obtained rubber sheet composite 20 can be used as a gasket for a fuel cell or the like in which a plurality of flow paths are arranged in parallel.
[0035]
Embodiment 3
In the first or second embodiment, the second rubber composition is preliminarily compounded with a peroxide, and the second rubber layer is formed simultaneously with the molding by using the heating at the time of molding the protrusions 13a and 22a on the second rubber layer. Thus, the irradiation of the electron beam to the second rubber layer in Embodiments 1 and 2 is omitted, and the others are obtained in the same manner as in Embodiments 1 and 2.
[0036]
Embodiment 4
In the first and second embodiments, the first rubber solution is applied to the surface of the base sheet, dried, the first cover sheet is laminated on the surface, and then the first rubber layer is placed on the first rubber layer from above the first cover sheet. The first rubber layer is formed into a closed loop shape, the first rubber layer is cross-linked by electron beam irradiation, and then the second rubber solution to which the adhesion improving agent is not added is applied to the back surface of the base sheet and dried. Laminate sheets. Then, with the second rubber sheet made of the second rubber solution in an unvulcanized state, the laminate is punched in the same manner as described above, and the front and back cover sheets are peeled off and used as a gasket. In this case, since the second rubber sheet is unvulcanized, the familiarity with the hard member is better than that of the vulcanized rubber sheet.
[0037]
Embodiment 5
A functional membrane such as a polymer electrolyte membrane of a fuel cell is used as the base sheet, and both the front and back surfaces of this base sheet are subjected to easy adhesion treatment, and a rubber solution is applied to the outer peripheral edge of the front and back faces in a rectangular frame shape. (See chain lines 14a and 14b in FIG. 1), and after drying, the above cover films are laminated on the front and back rubber layers, respectively, and the ridges are formed along the center line of the front and back frame-shaped EPDM layers, After that, an electron beam is irradiated to crosslink the front and back rubber layers, and a rubber sheet with ridges is formed on both front and back surfaces. In this case, it can be used as a functional film with a gasket by using it as it is without punching the inside of the frame-like rubber sheet.
[0038]
【Example】
Various rubber sheet composites were prototyped and their performance was compared. In the following description, “parts” indicates parts by weight. For comparison, the delamination strength was measured as follows.
Delamination strength:
A knife was put at the interface between the base sheet and the rubber sheet, and force was applied to the part or immersion in toluene was performed to cause interface peeling, and measurement was performed by a T-type peeling method according to JIS-K6854.
[0039]
Example 1
To 100 parts of EPDM rubber composition (rubber hardness: 50 degrees), to 5 parts of pentaerythritol tetraacrylate and dissolved in toluene, and 100 parts of commercially available silicone rubber compound (rubber hardness: 50 degrees) Silicone rubber solutions prepared by mixing 5 parts of pentaerythritol tetraacrylate and dissolving in toluene were prepared. Further, as the base sheet, an easy-adhesive polyethylene terephthalate film (thickness: 0.1 mm) whose front and back surfaces were treated with a polyurethane-based easy-adhesive treating agent was prepared. In addition, as the first cover sheet, a polyethylene terephthalate film (thickness: 0.025 mm) subjected to an easily peelable process was prepared. Furthermore, a film (thickness: 0.05 mm) containing poly-4-methylpentene-1 as a main component was prepared as a second cover sheet.
[0040]
The base sheet is supplied to a roll coater, and the EPDM solution is applied to one side of the roll so as to have a thickness of 0.05 mm, and then introduced into an oven and dried. 1 The easy-peelable treated surfaces of the cover sheet were stacked and continuously laminated by pressing with a pressure roller. The obtained laminate was introduced into an electron beam irradiation apparatus, and 200 KV, 15 Mrad electron beam was irradiated twice from the first cover sheet side to carry out a crosslinking treatment. The obtained EPDM composite is supplied again to the roll coater, and the above silicone rubber solution is applied to the opposite side of the base sheet so that the thickness is 0.15 mm after drying, then introduced into an oven and dried, The second cover sheet was overlaid on the silicone rubber layer, and was continuously laminated by pressing with a pressure roller.
[0041]
The obtained laminate was introduced into a pressing machine, and a press plate having a size of 120 mm × 150 mm and engraved with a groove on the surface was used, and the temperature was 110 ° C. from the top of the second cover sheet on the silicone rubber layer side. Pressure is 70 kgf / cm² In this way, a plurality of closed-loop ridges were formed corresponding to the flow paths of hydrogen gas, air, water, and the like (see FIG. 3). The width of the ridge is set to 2 mm and the height is set to 0.5 mm. Next, the laminate was introduced into an electron beam irradiation apparatus, and irradiated with an electron beam of 200 KV and 15 Mrad twice from the second cover sheet side to crosslink the silicone rubber layer.
[0042]
In the obtained laminate, that is, the rubber sheet composite, the delamination strength between the silicone rubber sheet and the base sheet was strong, and only the interface could be produced. Moreover, the delamination strength of the EPDM sheet and the base sheet was strong and was 14 N / 20 mm. On the other hand, the delamination strength of the first and second cover sheets was as low as 0.4 N / 20 mm and could be easily peeled off. Further, the total thickness of the rubber sheet composite after peeling off the cover sheets on both sides was 0.45 mm at the ridge portion.
[0043]
The obtained rubber sheet composite of Example 1 was punched out so that flat portions having a width of 5 to 10 mm remained on both sides of the ridge, and used as a gasket for a fuel cell. In any case, the sealing property was good, and since the polyethylene terephthalate film was combined as the base material sheet, the handling property was excellent and the practicality was good.
[0044]
Comparative Example 1
In Example 1 above, a rubber sheet composite of Comparative Example 1 having no ridges was obtained in the same manner as in Example 1 except that the formation of the ridges by the marking process of the silicone rubber layer was omitted. When the rubber sheet composite of Comparative Example 1 was punched out in the same manner as in Example 1 and used as a gasket for a fuel cell, the handleability was good as in Example 1, but the sealability was in Example 1. It was inferior in comparison and lacked practicality.
[0045]
Comparative Example 2
In Example 1 above, the lamination of the EPDM layer and the blending of pentaerythritol tetraacrylate with the silicone rubber were omitted, and the thickness of the silicone rubber layer was changed to 0.35 mm. A rubber sheet composite was obtained. When the rubber sheet composite of Comparative Example 2 was punched out in the same manner as in Example 1 and used as a fuel cell gasket, the sealing property was good, but the delamination strength between the silicone rubber sheet and the base film was high. Since the silicone rubber sheet peeled off easily with 0.5N / 20mm, it was inferior in handleability and lacked practicality.
[0046]
Example 2
The rubber sheet composite of Example 2 was obtained in the same manner as in Example 1 except that the polyethylene terephthalate film of the base sheet was changed to a polyetherimide film in Example 1. Its characteristics are the same as in Example 1. As a gasket material for a fuel cell, it is as high in quality and practical as in Example 1, and the heat resistance of the base film is superior to that in Example 1, and at a high temperature. It was suitable for use.
[0047]
Example 3
2,5 dimethyl-2,5-di (t-butylperoxy) hexane was added to the silicone rubber solution of Example 2 in a ratio of 0.5 part to 100 parts of the silicone rubber compound, and the stamped state (110 ℃ × 70 kgf / cm² ) Was held for 0.25 minutes, and the silicone rubber layer was cross-linked at the same time as the marking, and the rubber sheet composite of Example 3 was obtained in the same manner as in Example 2 except that. This rubber sheet composite had a high delamination strength of 10 N / 20 mm between the silicone rubber sheet and the base sheet, and was excellent in practicality as a gasket material for fuel cells as in Example 1.
[0048]
Example 4
As a base sheet, a polyethylene terephthalate film (thickness: 0.05 mm) treated on both sides with a polyester-based easy adhesion treatment agent was used, and this base sheet was supplied to a roll coater. After the solution is dried, it is applied to a thickness of 0.1 mm, then introduced into an oven and dried. The EPDM layer surface is overlaid with the easily peelable surface of the first cover sheet of Example 1 and pressed with a pressure roller. And laminated continuously.
[0049]
The obtained laminate is introduced into a press machine, and an engraving roller at a temperature of 100 ° C. is pressed onto the first cover sheet of the laminate, and the above EPDM layer is projected from a protrusion having a width of 1.5 mm and a height of 0.1 mm. A square loop with a size of 10 cm × 20 cm was engraved (see FIG. 1). Next, this engraved laminate was introduced into an electron beam irradiation apparatus, and 200 KV, 15 Mrad electron beam was irradiated twice from the first cover film side to crosslink the EPDM layer. The delamination strength between the obtained EPDM sheet and the base sheet was 14 N / 20 mm.
[0050]
The obtained EPDM sheet composite was again supplied to the roll coater, and an EPDM solution not added with pentaerythritol tetraacrylate was applied to the opposite side of the base sheet so that the thickness after drying was 0.05 mm, followed by The polyethylene terephthalate film (thickness: 0.025 mm) whose surface was treated with silicon as a second cover film was stacked on the EPDM layer, and pressed and laminated continuously with a pressure roller.
[0051]
When the obtained laminate is punched out so that a flat part with a width of 5 mm remains on both sides of the ridge, it is used as a gasket material for a water-based electrolytic double layer type capacitor. It had sex. In Example 4, since the EPDM sheet on the side having no protrusions is used in an unvulcanized state, the familiarity with the current collector is good, and the sealing property is also good in this respect.
[0052]
Example 5
As the base sheet, a polymer electrolyte membrane for a fuel cell made of a fluorine-based polymer was used, and after performing easy adhesion treatment by electron beam irradiation on both the front and back surfaces of this base sheet, the EPDM solution of Example 1 was applied to both the front and back faces A rectangular frame according to the shape of the separator (refer to chain lines 14a and 14b in FIG. 1), and after drying, printing is performed by screen printing so that the thickness is 0.1 mm, and drying in an oven. The first cover film of Example 1 was laminated to each other, and the obtained laminate was introduced into a press machine, and a protrusion having a width of 1.5 mm and a height of 0.15 mm along the center line of the front and back frame-shaped EPDM layers. A strip was formed and then introduced into an electron beam irradiation apparatus, and an electron beam of 750 KV and 15 Mrad was irradiated from the front and back to crosslink the front and back EPDM layers.
[0053]
In the obtained rubber sheet composite of Example 5, the delamination strength of the base sheet and the cover sheet with respect to the EPDM sheet was 8 N / 20 mm and 0.5 N / 20 mm, respectively, and excellent in adhesion to the base sheet. The peelability was good for the cover sheet. In this rubber sheet composite, the base sheet is made of a polymer electrolyte membrane, and an EPDM rubber sheet is laminated in accordance with the shape of the separator, and this rubber sheet acts as a gasket. It can be incorporated into a fuel cell without being used, and a good sealing property can be obtained, and a significant reduction in thickness can be achieved.
[0054]
【The invention's effect】
As stated above, claim 1The invention according to the present invention is a method for producing a rubber sheet composite,It can be effectively sealed using a gasket or the like interposed between the joint surfaces of any two members.The rubber sheet composite can be easily manufactured. Then, after laminating a rubber sheet on the base film, a cover sheet is laminated on the surface of the rubber sheet and stamped from above the cover sheet to form at least one ridge. The rubber sheet composite can be easily handled. Particularly, in the invention according to claim 2, the manufacturing process of the rubber sheet composite is shortened. Further, the invention according to claim 3 can be directly integrated with the base film by the cross-linking adhesion that adheres simultaneously with the cross-linking. The invention according to claim 4 further improves the adhesion of the base sheet to the rubber sheet.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a plan view of another embodiment.
[Explanation of symbols]
10, 20: Rubber sheet composite
11, 21: Base sheet
12, 13, 22: Rubber sheet
13a, 22a: ridge
21a, 21b: Inside of a rectangular frame made of the rubber sheet 22 (fluid passage)

Claims (4)

In the method for producing a rubber sheet composite for a gasket, in which a rubber sheet is combined on at least one surface of a base sheet so as to be interposed and sealed on the joint surface between any two members , plastic is used as the base sheet. An uncrosslinked rubber sheet is obtained by applying a sheet of metal, glass and ceramic alone or a composite of two or more, and applying and drying a rubber solution obtained by dissolving a rubber composition in a solvent on at least one side of the sheet. The cover sheet is laminated on the surface of the rubber sheet so that the cover sheet can be peeled off. The seal sheet is engraved from above the cover sheet, and at least one protrusion is sealed on the rubber sheet surface in an uncrosslinked or semi-crosslinked state. rubber sheet composite, wherein a molded along the line required, then subjected to a crosslinking treatment to integrate the base sheet and the rubber sheet directly The method of production. The method for producing a rubber sheet composite according to claim 1, wherein the crosslinking treatment is performed simultaneously with the forming of the protrusions by engraving . The method for producing a rubber sheet composite according to claim 1 or 2, wherein the rubber component of the rubber sheet is blended with a compound containing a reactive group active against radical reaction as an adhesion improver . 4. The method according to claim 1, wherein one or both of active ray treatment and surface treatment with an easily adhesive polymer is applied to the rubber sheet side surface of the base sheet as an easily adhesive treatment for enhancing the adhesion to the rubber sheet. A method for producing the rubber sheet composite according to claim 1.

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