JP6172732B2 - Graphite sheet composite material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a graphite sheet composite material used for a sealing material and the like, and a method for producing the same.

  Sealing materials such as gaskets and packings that seal liquids and gases are used in many fields such as automobiles, airplanes, agricultural equipment, chemical plants, and others.

  Among such sealing materials, a gland packing used for sealing a rotating shaft in a valve or the like is required to have sliding characteristics in order to dynamically contact the rotating shaft. For example, as for what is used in a comparatively low temperature range, the thing which used the string which knit the fiber as it was, or soaked with grease etc. is used.

  On the other hand, packing exposed to high-temperature gas or liquid requires characteristics such as high heat resistance, chemical resistance, and low expansion coefficient in addition to sliding characteristics, so that asbestos has been conventionally used. However, the use of asbestos is prohibited as a harmful substance, and various materials that can substitute for asbestos have been studied.

  For example, as a material for a sealing material used as a gland packing in a high temperature range, it has been proposed to use a graphite sheet obtained by forming expandable graphite into a sheet (see, for example, Patent Document 1).

  Graphite sheets made of expansive graphite are excellent in slidability, heat resistance, chemical resistance, etc., have high compression recovery and airtightness, and are easy to become familiar with the mating material to be used. It can be used as a sealing material in automobile engines, high-temperature furnaces, chemical plants, and the like.

  However, since the graphite sheet made of expansive graphite is flexible, there is a phenomenon of malleability in which the graphite sheet is extended and thinned by continuing to apply pressure. For this reason, if it is used for a long time as a sealing material, the thickness may be reduced due to malleability and the sealing performance may be reduced.

  Therefore, Patent Document 2 proposes using a graphite sheet as a gland packing in which a tape-like carbon fiber sheet is stacked on a graphite sheet and the graphite sheet is reinforced with the carbon fiber sheet.

JP 2004-204991 A JP 2006-342932 A

  In Patent Document 2, since the graphite sheet is reinforced with the carbon fiber sheet, the gland packing can reduce the malleability of the graphite sheet with the carbon fiber sheet, but the malleability that the carbon fiber sheet itself becomes thin when pressure is applied. Therefore, there is a problem that it is not possible to sufficiently obtain the effect of reinforcing the graphite sheet with a carbon fiber sheet to prevent deterioration of the sealing performance over time.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a graphite sheet composite material and a sealing material that can suppress malleability and prevent deterioration of sealing performance over time. is there.

The graphite sheet composite material according to the present invention is formed by including a graphite sheet obtained by forming expandable graphite into a sheet, a fiber layer laminated on the graphite sheet, and a cured product of a thermosetting resin. The layers are alternately stacked and a plurality of layers of graphite sheets are stacked on the surface portion that is in sliding contact with the counterpart material, and the cured product of the thermosetting resin adheres to the graphite sheet and the fiber layer and the graphite sheet. And a fiber layer are bonded to each other.

  By laminating a fiber layer on the graphite sheet, the graphite sheet can be reinforced with the fiber layer, and the cured product of the thermosetting resin adheres to the graphite sheet and the fiber layer, thereby providing a graphite sheet. And the spreading of the fiber layer can be suppressed with a cured product of the thermosetting resin, and the graphite sheet is reinforced with the fiber layer by bonding the graphite sheet and the fiber layer with the cured product of the thermosetting resin. It is possible to obtain a high effect, and even if the pressure is applied for a long time, it is possible to keep the graphite sheet from spreading and to reduce the thickness, and to prevent deterioration of the sealing performance over time. It can be done.

In the present invention, the cured product of the thermosetting resin is characterized in that is obtained by curing the impregnating each of black lead sheet and the fiber layer.

  Since the graphite sheet and fiber layer are impregnated with the thermosetting resin and cured, the graphite sheet and fiber layer can be hardened with the thermosetting resin, and the effect of suppressing the malleability of the graphite sheet and fiber layer can be achieved. It can be obtained high.

  Moreover, in this invention, the fiber layer is formed from the fiber sheet which consists of at least one of a woven fabric and a nonwoven fabric, It is characterized by the above-mentioned.

  A fiber sheet formed of a woven fabric or a non-woven fabric has high tensile strength, and a high reinforcing effect of the graphite sheet by the fiber layer can be obtained.

In the present invention, the graphite sheet has a density of 0.1 to 1.5 g / cm ³ .

  When the density of the graphite sheet is within this range, the amount of the thermosetting resin impregnated into the graphite sheet becomes appropriate, and the malleability of the graphite sheet can be further reduced.

  In the present invention, the fiber layer is made of silica fibers.

  Since silica fiber has extremely high heat resistance and chemical resistance, it is possible to obtain a graphite sheet composite suitable for use in a high temperature range.

  In the present invention, the thermosetting resin is selected from a phenol resin and a furan resin. The phenol resin and furan resin may be used alone or in combination.

  Even if the thermosetting resin is carbonized using graphite sheet composites at high temperature conditions, phenol resin and furan resin have a high residual carbon content, so the effect of suppressing malleability can be kept high, and sealing performance Can be effectively suppressed.

  And the graphite sheet composite material which concerns on this invention is used as sealing materials, such as a gasket and packing, It is characterized by the above-mentioned.

  Since the graphite sheet composite of the present invention can suppress malleability as described above, it is possible to suppress a decrease in thickness even when pressure is applied for a long time. Therefore, it is possible to provide a sealing material that does not deteriorate in performance.

  Moreover, since the graphite sheet is excellent in sliding properties, it is particularly suitable for use as a gland packing.

Method for manufacturing graphite sheet composite according to the present invention, the expandable graphite thermosetting resin impregnated graphite sheets and fiber sheet into a sheet, by heating and pressing thermosetting with overlaying the graphite sheet and the fiber sheet The resin is cured.

  Thus, by superimposing the graphite sheet and the fiber sheet and curing the thermosetting resin by heating and pressing, the graphite sheet composite material can be easily manufactured, and the graphite sheet and the fiber layer are heated. Since the curable resin is impregnated and cured, the graphite sheet and the fiber layer can be hardened with the thermosetting resin, and at the same time, the graphite sheet and the fiber layer can be firmly bonded with the thermosetting resin. It is.

  At this time, if the graphite sheet and the fiber sheet are impregnated with the thermosetting resin, respectively, the graphite sheet and the fiber layer can be hardened with the thermosetting resin, and the graphite sheet and the fiber layer of the thermosetting resin can be solidified. The adhesive strength can be increased.

  According to this invention, it can reinforce with the fiber layer which laminated | stacked the graphite sheet. And since the hardened | cured material of a thermosetting resin has adhered to the graphite sheet and the fiber layer, while being able to suppress the malleability of a graphite sheet or a fiber layer with the hardened | cured material of a thermosetting resin, a thermosetting resin By adhering the graphite sheet and the fiber layer with the cured product, it is possible to obtain a high effect of reinforcing the graphite sheet with the fiber layer, and the graphite sheet is extended even if the pressure is applied for a long time. Thus, the reduction in thickness can be suppressed to a low level, and the deterioration of sealing performance over time can be prevented.

An example of the sealing material which concerns on this invention is shown, (a) is a perspective view, (b), (c) is sectional drawing. The manufacturing method of a sealing material same as the above is shown, (a), (b) is a perspective view, respectively. The other example of the sealing material which concerns on this invention is shown, (a) is a perspective view, (b), (c) is sectional drawing. It is a perspective view which shows the manufacturing method of a sealing material same as the above. The other example of the sealing material which concerns on this invention is shown, (a) is a perspective view, (b) is sectional drawing. The manufacturing method of a sealing material same as the above is shown, (a), (b) is a perspective view, respectively. It shows the test method of malleability, (a) is a front view, (b) is a front view with a part broken.

  Embodiments of the present invention will be described below.

  Expandable graphite is obtained by rapidly heating an acid-graphite interphase compound to 900 to 1000 ° C., and the interlayer of graphite expands 100 to 300 times to obtain expandable graphite having a honeycomb structure. . The graphite sheet used in the present invention is formed into a sheet by pressurizing and compressing the expandable graphite.

The graphite sheet is not particularly limited, but it is preferable to use a graphite sheet having a density in the range of 0.1 to 1.5 g / cm ³ . If the density of the graphite sheet is less than 0.1 g / cm ³ , the denseness of the graphite sheet is low, so that the permeability when the thermosetting resin penetrates into the graphite sheet as described later is too good. The thermosetting resin is excessively impregnated, and if the graphite sheet composite is used under high temperature conditions and the thermosetting resin is carbonized, carbonization shrinkage may occur greatly. On the contrary, if the density of the graphite sheet is higher than 1.5 g / cm ³ , the graphite sheet is dense and difficult to penetrate the thermosetting resin, and by containing a cured product of the thermosetting resin in the graphite sheet. There is a possibility that the effect of suppressing the malleability of the graphite sheet cannot be sufficiently obtained.

  The thickness of the graphite sheet is not particularly limited, but is preferably in the range of about 0.1 to 1.5 mm. When the thickness of the graphite sheet is less than 0.1 mm, the ratio of the thermosetting resin to the graphite sheet increases, so that the shrinkage due to carbonization of the thermosetting resin may increase as described above, and the graphite having a large thickness In manufacturing a sheet composite material, it is necessary to increase the number of laminated graphite sheets, which may cause problems in manufacturing man-hours and the like. On the other hand, if the thickness of the graphite sheet exceeds 1.5 mm, the ratio of the fiber layer to be laminated on the graphite sheet will be low, and the reinforcing effect by the fiber layer will be insufficient, and the effect of suppressing the malleability of the graphite sheet will be reduced. May decrease. In addition, when the thickness of the graphite sheet is so thick, it becomes difficult to adjust the thickness of the graphite sheet composite material by the number of laminated graphite sheets. Particularly when the graphite sheet composite material is used as a sealing material such as packing, the thickness is precisely set. It becomes difficult to adjust.

  The graphite sheet composite according to the present invention is formed by laminating this graphite sheet and a fiber layer. As this fiber layer, it is common to use fiber sheets such as woven fabrics (woven fabrics) woven with fiber yarns, knitted fabrics (knitted fabrics) knitted with fiber yarns, and nonwoven fabrics intertwined with fibers. A fiber layer can also be formed by using a chop cut to a length of about 1 to 30 mm and depositing and stacking the chop on the surface of the graphite sheet as described later.

  The fiber forming the fiber layer is not particularly limited, but organic fibers such as polyphenylenebenzbisoxador fiber and polyphenylenebenzbisthiazole fiber, silica fiber, carbon fiber, glass fiber, alumina fiber, silicon carbide Inorganic fibers such as fibers, steel fibers, mineral fibers, and basalt fibers can be used, and these are all preferable because of high heat resistance. Among these, when a graphite sheet composite material is used under a high temperature condition of 300 ° C. or higher, it is preferable to use inorganic fibers. Among inorganic fibers, silica fibers have high heat resistance and high chemical resistance. Therefore, it is particularly preferable.

  A graphite sheet composite according to the present invention is formed from the above graphite sheet, a fiber layer, and a cured product of a thermosetting resin that adheres to the graphite sheet and the fiber layer and adheres the graphite sheet and the fiber layer. Is.

  As the thermosetting resin, any resin such as phenol resin, furan resin, epoxy resin, urea resin, melamine resin can be used, but in the case of a graphite sheet composite material used under high temperature conditions, it is thermosetting. It is preferable to use a phenol resin or a furan resin as the resin. Since phenol resin and furan resin have a high residual carbon content of 40 to 60% by mass, even if the thermosetting resin is carbonized when the graphite sheet composite is used under high temperature conditions, the graphite sheet or fiber is made of thermosetting resin. The effect of reinforcing the layer and suppressing the malleability is not greatly deteriorated. Therefore, even if the graphite sheet composite material is used under high temperature conditions, the effect of suppressing the spreading of the graphite sheet composite material with the thermosetting resin can be maintained, and the deterioration of the sealing property is prevented. The effect can be maintained even under high temperature conditions. A phenol resin and a furan resin can be used alone or in combination, for example, by mixing both.

  In producing the graphite sheet composite material, the thermosetting resin is used in an uncured state. If this uncured thermosetting resin is liquid, it can be used as it is, or it can be used by lowering the viscosity by dissolving in a solvent, and if the uncured thermosetting resin is solid It can be used by dissolving or dispersing in a solvent to form a liquid.

  Then, this thermosetting resin liquid is attached to the graphite sheet or the above-described fiber sheet, and the thermosetting resin attached to the graphite sheet or the fiber sheet is cured by stacking the graphite sheet and the fiber sheet and forming by heating and pressing. And a graphite sheet and a fiber sheet are laminated and integrated with a thermosetting resin to obtain a graphite sheet composite. At this time, the thermosetting resin penetrates between the graphite layers of the graphite sheet, and penetrates between the fibers of the fiber sheet to be cured.

  At this time, when adhering the thermosetting resin liquid to the graphite sheet or the fiber sheet, the graphite sheet or the fiber sheet is immersed in the thermosetting resin liquid, and the graphite sheet or the fiber sheet is impregnated with the thermosetting resin. Alternatively, the thermosetting resin liquid may be applied to the surface of the graphite sheet or the surface of the fiber sheet. In this case, in order to uniformly infiltrate and adhere the thermosetting resin to the graphite sheet or fiber sheet, it is preferable to impregnate the graphite sheet or fiber sheet with the thermosetting resin liquid.

  When impregnating the fiber sheet with the thermosetting resin liquid in this way, graphite powder such as natural graphite or artificial graphite may be dispersed in the thermosetting resin liquid. In this case, when the fiber sheet is impregnated with the thermosetting resin liquid, the graphite powder enters the gaps between the fibers, and the sliding characteristics of the fiber sheet can be improved.

  Further, either one of the graphite sheet and the fiber sheet may be impregnated and coated with a thermosetting resin, but both the graphite sheet and the fiber sheet are impregnated and coated with the thermosetting resin. It is preferable because the thermosetting resin can be uniformly attached to both sheets.

  Furthermore, when using a solid thermosetting resin dissolved or dispersed in a solvent, after impregnating and applying a thermosetting resin liquid to a graphite sheet or fiber sheet, the solvent is evaporated and dried to obtain a prepreg state. Thus, it is preferable to produce a graphite sheet composite material by lamination molding.

  When using a chop cut to a length of about 1 to 30 mm as the fiber, for example, the fiber chop is dispersed in a thermosetting resin liquid, and the thermosetting resin liquid containing the fiber chop is dispersed on the surface of the graphite sheet. After coating or immersing the graphite sheet in a thermosetting resin liquid containing fiber chop, this is heated and pressurized to form a layer by depositing the fiber chop on the surface of the graphite sheet In addition, the fiber layer is laminated and integrated with the graphite sheet with the cured thermosetting resin to obtain a graphite sheet composite material. From the viewpoint of ease of molding and the like, it is desirable to form a fiber layer using the above fiber sheet.

And the conditions of the heating and pressurization when performing the above-mentioned lamination molding to produce a graphite sheet composite material vary depending on the type and content of the thermosetting resin. When using a furan resin, it is preferable to set the temperature to about 100 to 250 ° C., the pressure to about 100 to 2000 N / cm ² , and the molding time to about 10 to 120 minutes.

  In producing a graphite sheet composite by lamination molding as described above, it is preferable to produce a graphite sheet composite by laminating a plurality of graphite sheets and fiber layers, but the number of laminated sheets is arbitrary depending on the application. Can be set to In this case, it is preferable to alternately laminate the graphite sheets and the fiber layers. However, one of the graphite sheets and the fiber layers may be partially laminated continuously, and the layer structure of the lamination is arbitrary. is there.

  The graphite sheet composite material of the present invention formed by laminating a graphite sheet and a fiber layer with a thermosetting resin as described above, the graphite sheet is reinforced with the fiber layer, and when the graphite sheet is pressed Spreading and spreading can be suppressed with a fiber layer having a smaller malleability than the graphite sheet. And since the cured product of the thermosetting resin adheres to the entire surface of the graphite sheet or the fiber layer, not only the malleability of the graphite sheet but also the malleability of the fiber layer is suppressed by the cured product of the thermosetting resin. In addition, since the graphite sheet and the fiber layer are bonded with a cured product of a thermosetting resin, a high effect of reinforcing the graphite sheet with the fiber layer can be obtained. As a result, the graphite sheet composite according to the present invention can keep the graphite sheet from being stretched even if the pressure is applied for a long time, and can prevent the graphite sheet composite from becoming thin. It is something that can be done.

  Here, in the graphite sheet composite of the present invention, the amount of the thermosetting resin contained in the graphite sheet or the resin layer is set to be in the range of 0.5 to 25% by mass with respect to the graphite sheet composite. It is preferable to do this. When the amount of the thermosetting resin is less than 0.5% by mass, the effect of suppressing spread by the cured product of the thermosetting resin becomes insufficient. On the contrary, if the amount of the thermosetting resin exceeds 25% by mass, the sliding property of the graphite sheet may be deteriorated, and the volume content of the thermosetting resin in the graphite sheet composite increases, and the graphite sheet When the thermosetting resin is carbonized when the composite material is used under high temperature conditions, the generation of voids due to carbonization increases, and the sealing performance may be reduced.

  The graphite sheet composite according to the present invention is applied to applications such as fireproof doors, semiconductor crucibles, heat insulating materials such as quartz protective materials, fuel cell separators, heat dissipation sheets for electric and electronic parts, electromagnetic wave shielding materials, etc. However, it is particularly suitable mainly for applications of sealing materials such as gaskets and packings that mainly prevent liquids from leaking. Specific examples of such gaskets and packings include packings for turbines, refractory furnaces, flues, fuel cells, automobile gaskets, nuclear parts, petroleum refining plants, packings for airplane engine outlets, gland packings, etc. There is.

  As described above, the graphite sheet composite of the present invention has suppressed spreadability and can prevent a decrease in thickness even when the pressure is applied for a long time, thus preventing deterioration in sealing performance over time. Thus, high sealing performance can be maintained over a long period of time. In addition, since the graphite sheet composite material of the present invention is formed of a graphite sheet having excellent sliding characteristics, among the sealing materials, such as a gland packing used for sealing a rotating shaft, etc., it is dynamically contacted and sealed. It is particularly suitable for applications where

  When the graphite sheet composite of the present invention is used as a sealing material, it is generally formed in a ring shape. FIGS. 1A and 1B show an example of a sealing material B, which is formed by laminating a graphite sheet 1 and a fiber layer 2 with a thermosetting resin in the thickness direction of the ring.

  The ring-shaped sealing material B in which the graphite sheet 1 and the fiber layer 2 are laminated in the thickness direction is formed by laminating the graphite sheet 1 and the fiber layer 2 as described above, for example, as shown in FIG. The graphite sheet composite material A is produced, and then, as indicated by the chain line in FIG. 2 (a), the graphite sheet composite material A is punched into a ring shape in a direction perpendicular to the laminated surface and cut out. be able to.

  Further, the graphite sheet 1 impregnated with the thermosetting resin and the fiber layer 2 formed by impregnating the fiber sheet with the thermosetting resin are cut out in a ring shape, and the ring-shaped graphite sheet 1 and the fiber layer 2 are cut out. 2B, the graphite sheet 1 and the fiber layer 2 fitted in the inner mold 5 are heated while being pressed by an outer mold (not shown). Thereby, the ring-shaped sealing material B which laminated | stacked the graphite sheet 1 and the fiber layer 2 in the thickness direction with the thermosetting resin can be manufactured.

  The ring-shaped sealing material B in which the graphite sheet 1 and the fiber layer 2 are laminated in the thickness direction as described above is mainly used for applications in which both surfaces in the thickness direction are in contact with the mating material. For applications where the mating material in contact with the sealing material B does not move or uses where the frequency is low even when the mating material moves, either the graphite sheet 1 or the fiber layer 2 is exposed on the surface in the thickness direction of the sealing material B. However, in the case of an application in which the mating material with which the sealing material B is in contact moves with a high frequency by rotating or linearly moving, the thickness direction of the sealing material B as shown in FIG. It is preferable to laminate the graphite sheet 1 and the fiber layer 2 so that the graphite sheet 1 is exposed on the surface. Thus, when the graphite sheet 1 is exposed on the surface in the thickness direction of the sealing material B and comes into contact with the mating material, the movement of the mating material becomes smooth due to the sliding characteristics of the graphite sheet 1, and the mating material is damaged. Such a thing will disappear. When the fiber layer 2 is exposed on the surface in the thickness direction of the sealing material B and comes into contact with the mating material, there is a risk of damaging the mating material, particularly when the fiber layer 2 is formed of inorganic fibers. .

  When laminating the graphite sheet 1 on the surface in the thickness direction of the sealing material B as described above, two layers of the graphite sheet 1 are formed on the surface in the thickness direction of the sealing material B as shown in FIG. For example, a plurality of layers may be stacked. In this case, since the thickness of the graphite sheet 1 on the surface of the sealing material B is increased, even if the graphite sheet 1 is worn by sliding contact with the counterpart material, the sliding characteristics of the graphite sheet 1 are maintained over a long period of time. Is something that can be done.

  FIGS. 3A and 3B show another embodiment of the sealing material B, which is formed by concentrically laminating a graphite sheet 1 and a fiber layer 2 with a thermosetting resin in the diameter direction of the ring. It is.

  The ring-shaped sealing material B in which the graphite sheet 1 and the fiber layer 2 are laminated concentrically in the diameter direction is formed by, for example, the graphite sheet 1 impregnated with a thermosetting resin and the fiber sheet impregnated with a thermosetting resin. Each of the fiber layers 2 is cut into a tape shape, and the tape-like graphite sheet 1 and the fiber layer 2 are alternately wound around the outer periphery of the cylindrical inner mold 6 as shown in FIG. By heating the graphite sheet 1 and the fiber layer 2 while pressurizing them with an outer mold (not shown), a ring-shaped sealing material B in which the graphite sheet 1 and the fiber layer 2 are laminated concentrically with a thermosetting resin is obtained. Can be manufactured. At this time, the graphite sheet 1 and the fiber layer 2 may be wound around the outer periphery of the inner mold 6.

  The ring-shaped sealing material B in which the graphite sheet 1 and the fiber layer 2 are concentrically stacked in the diameter direction as described above is mainly used for sealing in which both inner and outer surfaces are in contact with the mating material. For applications where the mating material in contact with the sealing material B does not move, or when the mating material moves less frequently, either the graphite sheet 1 or the fiber layer 2 on the inner or outer surface of the sealing material B May be exposed, but in applications where the mating material that is in contact with the sealing material B moves at a high frequency by rotating or linearly moving, the sealing material B can be exposed as shown in FIG. It is preferable to laminate the graphite sheet 1 and the fiber layer 2 so that the graphite sheet 1 is exposed on the circumference or outer circumferential surface. In this way, the graphite sheet 1 is exposed on the inner and outer peripheral surfaces of the sealing material B and comes into contact with the mating material, whereby the mating material moves smoothly due to the sliding characteristics of the graphite sheet 1, and the mating material. The thing that hurts is lost. When the fiber layer 2 is exposed on the inner and outer peripheral surfaces of the sealing material B and comes into contact with the mating material, there is a risk of damaging the mating material, particularly when the fiber layer 2 is formed of inorganic fibers. Is big.

  When laminating the graphite sheet 1 so that the graphite sheet 1 is exposed on the inner and outer surfaces of the sealing material B as described above, the graphite sheet is formed on the inner and outer surfaces of the sealing material B as shown in FIG. 1 may be laminated by stacking a plurality of layers such as two layers. In this case, since the thickness of the graphite sheet 1 on the surface of the sealing material B is increased, even if the graphite sheet 1 is worn by sliding contact with the counterpart material, the sliding characteristics of the graphite sheet 1 are maintained over a long period of time. Is something that can be done.

  5 (a) and 5 (b) show another embodiment of the sealing material B, in which a graphite sheet 1 and a fiber layer 2 are laminated with a thermosetting resin in a direction perpendicular to the thickness direction of the ring. Formed.

  In producing this sealing material B, for example, first, the graphite sheet 1 and the fiber layer 2 are laminated and formed by the method described above to produce a block-shaped graphite sheet composite material A ′ as shown in FIG. Next, this block-like graphite sheet composite material A ′ is cut perpendicularly to the lamination surface as shown by a chain line, and the graphite sheet 1 and the fiber layer 2 are laminated in the plane direction as shown in FIG. 6B. A graphite sheet composite material A is produced. Then, as shown by a chain line in FIG. 6 (b), this graphite sheet composite A is punched out in a ring shape in a direction perpendicular to the laminated surface and cut out, so that the graphite sheet 1 and A ring-shaped sealing material B on which the fiber layer 2 is laminated can be manufactured.

  The ring-shaped sealing material B in which the graphite sheet 1 and the fiber layer 2 are laminated in a direction perpendicular to the thickness direction as described above has both the graphite sheet 1 and the fiber layer 2 on the surface in the thickness direction of the sealing material B. Since both the graphite sheet 1 and the fiber layer 2 are exposed on the inner and outer peripheral surfaces of the sealing material B, both the thickness direction both surfaces are in contact with the mating material, It can be used for any application in which both surfaces of the outer periphery are in contact with the mating material for sealing.

  Next, the present invention will be specifically described with reference to examples.

(Preparation of graphite sheet substrate prepreg 1)
As a graphite sheet made of natural expanded graphite, “GRAFOIL GTB” (thickness 0.762 mm, density 1.1 g / cm ³ ) manufactured by Sakai Kogyo Co., Ltd. was used. In addition, a resol type phenolic resin “R-5” manufactured by Lignite Co., Ltd. was used as a thermosetting resin, and this resol type phenolic resin “R-5” was dissolved in methanol to prepare a phenol resin solution having a concentration of 20% by mass. did.

  And after immersing a graphite sheet in this phenol resin liquid for 5 hours, it pulled up and dried at room temperature for one week, thereby obtaining a graphite sheet substrate prepreg 1 having a phenol resin content of 20% by mass.

(Preparation of graphite sheet base material prepreg 2)
Phenol resin was prepared in the same manner as described above (preparation of graphite sheet substrate prepreg 1) except that a phenol resin solution having a concentration of 10% by mass prepared by dissolving resol type phenol resin “R-5” in methanol was used. A graphite sheet base material prepreg 2 having a resin content of 10.3 mass% was obtained.

(Preparation of fiber sheet substrate prepreg 1)
As a fiber sheet, silica cloth “BCM-430” (thickness 0.40 mm, weight 270 g / m ² ) manufactured by Nippon Mineral Co., Ltd. was used, and the above-mentioned resol type phenolic resin “R-5” was dissolved in methanol. After immersing the fiber sheet in a phenol resin solution prepared to a concentration of 20% by mass for 5 hours, the fiber sheet substrate prepreg 1 having a phenol resin content of 13% by mass is obtained by lifting and drying at room temperature for one week. It was.

(Preparation of fiber sheet substrate prepreg 2)
Phenol resin was prepared in the same manner as above (preparation of fiber sheet substrate prepreg 1) except that a phenol resin solution having a concentration of 10% by mass prepared by dissolving resol-type phenol resin “R-5” in methanol was used. A fiber sheet substrate prepreg 2 having a resin content of 7.0% by mass was obtained.

( Reference Example 1)
40 sheets of graphite sheet base material prepreg 1 and 39 pieces of fiber sheet base material prepreg 1 were used, and these were alternately repeated. Then, this load is placed on a mirror plate on a press hot plate preheated to 150 ° C., and a mirror plate is further placed thereon. Then, a pressure of 500 N / cm ² is applied, and the pressure is kept for 30 minutes. By molding, a graphite sheet composite having a length and width of 30 cm and a thickness of 25.2 mm was obtained.

( Reference Example 2)
Except for using 40 sheets of graphite sheet base material prepreg 1 and 39 sheets of fiber sheet base material prepreg 2, a graphite sheet composite material having a length and width of 30 cm and a thickness of 24.3 mm was obtained in the same manner as in Reference Example 1. Obtained.

( Reference Example 3)
Except for using 40 sheets of graphite sheet base material prepreg 2 and 39 sheets of fiber sheet base material prepreg 1, a graphite sheet composite material having a length and width of 30 cm and a thickness of 23.5 mm was obtained in the same manner as in Reference Example 1. Obtained.

( Reference Example 4)
Except for using 40 sheets of graphite sheet base material prepreg 2 and 39 sheets of fiber sheet base material prepreg 2, a graphite sheet composite material having a length and width of 30 cm and a thickness of 22.1 mm was obtained in the same manner as in Reference Example 1. Obtained.

(Comparative Example 1)
The above-mentioned “GRAFOIL GTB” manufactured by Sakai Kogyo Co., Ltd. was used as it was as a graphite sheet, and 60 sheets thereof were stacked. And this was hot-press molded in the same manner as in Reference Example 1 to obtain a graphite sheet laminate having a length and width of 30 cm and a thickness of 24.1 mm.

(Comparative Example 2)
The above-mentioned “GRAFOIL GTB” manufactured by Sakai Kogyo Co., Ltd. is used as it is as the graphite sheet, and the above-mentioned silica cloth “BCM-430” manufactured by Nippon Mineral Co., Ltd. is used as it is as the fiber sheet, 40 graphite sheets, fiber sheet 39 sheets were alternately stacked. Then, this was hot-press molded in the same manner as in Reference Example 1 to obtain a graphite sheet composite having a length and width of 30 cm and a thickness of 22.5 mm.

(Comparative Example 3)
The graphite sheet base material prepreg 2 was used and 60 sheets thereof were stacked. And this was hot-press molded in the same manner as in Reference Example 1 to obtain a graphite sheet laminate having a length and width of 30 cm and a thickness of 23.4 mm.

A test piece was cut out from the graphite sheet composites (graphite sheet laminates) obtained in Reference Examples 1 to 4 and Comparative Examples 1 to 3 in the direction parallel to the layers, and the length was measured according to JIS K 6911 (1995). The bending strength and bending elastic modulus were measured for a test piece having a length of 80 mm, a width of 15 mm, and a height of 20 mm, and the compressive strength and the compressive elastic modulus were measured for a test piece having a length of 15 mm, a width of 15 mm, and a height of 20 mm. . Further, the hardness was measured on a D scale using a Shore hardness meter.

  Further, the test piece was put in a drier set at 400 ° C. in advance and heated for 24 hours to be baked, and the compressive strength, compression elastic modulus, and hardness of the test piece after heat treatment were also measured. These results are shown in Table 1.

The malleability was evaluated by applying pressure to the test piece. That is, the test piece C, whose dimensions were measured in advance, is sandwiched between two metal plates 7 as shown in FIG. 7 (a), and clamped with a C-shaped clam vise 9 to apply a pressure of 300 N / cm ² to the test piece C. It was over. This pressure was confirmed with a digital torque tool “Digiratche” manufactured by Kyoto Machine Tool Co., Ltd. And after leaving it in this state for 168 hours, the vise 9 was removed, the test piece C was taken out, and the dimension of the test piece C was measured.

The dimensional change rate in the length direction was calculated from the change in the longitudinal direction dimension of the test piece C before and after the pressurization, and the dimensional change rate in the thickness direction was calculated from the change in the thickness dimension from the following equations. The results are shown in Table 1.
Dimensional change rate (%) = [(Dimension after pressurization−Dimension before pressurization) / Dimension before pressurization] × 100

Moreover, since there is a sealing material that is used in a state in which the sealing material is fitted in a recess or the like so as not to spread, the malleability was evaluated assuming such a sealing material. That is, a metal plate 7 provided with a recess 8 having the same size as the test piece C is used, and the test piece C which has been measured in advance is fitted into the recess 8 as shown in FIG. It was sandwiched between two metal plates 7 in a constrained state, and tightened with a C-shaped clam vise 9 to apply a pressure of 300 N / cm ² to the test piece C.

  And after leaving it in this state for 168 hours, the vise 9 is removed, the test piece C is taken out, the dimension of the test piece C is measured, and the change in the longitudinal dimension of the test piece C before and after pressurization is measured. From the above, the dimensional change rate in the length direction was calculated, and the dimensional change rate in the thickness direction was calculated from the change in thickness dimension. The results are shown in Table 1.

Next, malleability was evaluated assuming a sealing material used under high temperature conditions. That is, as shown in FIG. 7 (a) above, the specimen C is sandwiched between two metal plates 7 without being constrained, and a pressure of 300 N / cm ² is applied with a vise 9, and FIG. As shown in (b), a test piece C fitted in the recess 8 and restrained is sandwiched between two metal plates 7 and a pressure of 300 N / cm ² is applied with a vise 9 in advance. It put into the dryer set to 400 degreeC, and heat-processed by baking for 24 hours.

  In the same manner as described above, the dimensional change rate in the length direction is calculated from the change in the longitudinal dimension of the test piece C before and after pressing, and the dimensional change rate in the thickness direction is calculated from the change in thickness dimension. did. The results are shown in Table 1.

As seen in Table 1, all of Reference Examples 1 to 4 are superior to those of Comparative Examples 1 to 3 in physical properties such as bending strength, bending elastic modulus, compressive strength, and compressive elastic modulus. It is confirmed that In addition, compared with Comparative Example 1 consisting only of a graphite sheet, Comparative Example 2 consisting only of a graphite sheet and a fiber sheet, and Comparative Example 3 consisting only of a graphite sheet substrate prepreg, each reference example has a dimensional change rate in the thickness direction. Is −0.3% or less, which is reduced, and it is confirmed that malleability is suppressed and thickness reduction can be reduced.

  And when not heat-processing, when it tests in a restraint state, the dimensional change rate of the thickness direction is -0.07% or less, and it is confirmed that the effect of reducing that thickness becomes thin is large. In addition, when heat treatment was performed so that the thermosetting resin was carbonized, the difference in the dimensional change rate in the thickness direction was small between when tested in an unconstrained state and when tested in a restrained state. It was.

DESCRIPTION OF SYMBOLS 1 Graphite sheet 2 Fiber layer A Graphite sheet composite material B Sealing material

Claims (9)

Graphite sheet of expandable graphite and sheeted, and the fiber layer laminated on the graphite sheet is formed by and a cured product of the thermosetting resin, together with the graphite sheet and the fibrous layer are alternately laminated opponent In the surface portion that is in sliding contact with the material, multiple layers of graphite sheets are laminated and laminated, and the cured product of the thermosetting resin adheres to the graphite sheet and the fiber layer and adheres the graphite sheet and the fiber layer. Characteristic graphite sheet composite. The graphite sheet composite according to claim 1 , wherein the cured product of the thermosetting resin is obtained by impregnating and curing each of the graphite sheet and the fiber layer. The graphite sheet composite according to claim 1 or 2 , wherein the fiber layer is formed of a fiber sheet selected from a woven fabric, a knitted fabric, and a non-woven fabric. Graphite sheet graphite sheet composite of any of claims 1 to 3, wherein the density of 0.1 to 1.5 g / cm ^3. The graphite sheet composite according to any one of claims 1 to 4 , wherein the fiber layer is made of silica fibers. Graphite sheet composite of any of claims 1 to 5 The thermosetting resin may be equal to those selected from phenolic resin and furan resin. The graphite sheet composite material according to any one of claims 1 to 6 , wherein the graphite sheet composite material is used as a sealing material. The graphite sheet composite according to claim 7 , wherein the sealing material is a gland packing. In producing the graphite sheet composite material according to any one of claims 1 to 8 , a graphite sheet and a fiber sheet obtained by forming expandable graphite into sheets are impregnated with a thermosetting resin , respectively. And a method for producing a graphite sheet composite, wherein the thermosetting resin is cured by heating and pressing.

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