JP2014159091A - Metal mold and production method of resin composition made flat plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal mold in which a yield of a raw material is improved, air contamination is suppressed, a molding material is uniformly charged, and breakage at a molding time is suppressed, thereby hot pressing molding can be easily performed.SOLUTION: A metal mold comprises as follows. A bottom force comprises a concavity for resin composition raw material charging formed in a central part, a concavity for resin composition molding formed in a peripheral part thereof, and a bottom force periphery side wall formed in a periphery. A top force comprises a salient for resin composition pressing force formed in a central part, a flat part for resin composition pressing force formed in a peripheral part thereof, and a top force periphery side wall formed in a periphery. The bottom force and the top force are designed to fit at a pressing time to cause the resin composition to drift from the central part to the periphery of the bottom force such that a resin composition made flat plate can be pressure-molded. In at least one part of a salient or a concavity other than the concavity for resin composition molding that is formed on a surface of the bottom force or a surface of the top force that forms a space in which the resin composition drifts, a corner part thereof is formed by a curved surface, and the bottom force periphery side wall and the top force periphery side wall are designed to form an aperture of 50-150 μm when the bottom force and the top force are fitted.

Description

  The present invention particularly relates to a mold that can be suitably used for producing a resin composition flat plate such as a frame member for a fuel cell and a method for producing a resin composition flat plate.

  Fuel cells convert the chemical energy of fuel directly into electrical energy, which has high conversion efficiency to electrical energy and low noise and vibration, so it can be used in various fields such as portable devices, automobiles, railways, and cogeneration. Future development is expected as a power source.

Among fuel cells, a polymer electrolyte fuel cell (PEFC) sandwiches both surfaces of an ion conductive polymer membrane (ion exchange membrane) between an anode electrode plate and a cathode electrode plate carrying a catalyst such as platinum, A single cell in which plate separators are arranged on both outer sides is a basic structural unit, and is composed of a stack in which several tens to several hundreds of single cells are stacked and two current collectors provided on the outside thereof. It will be.
Among the PEFCs, in-vehicle PEFCs have hundreds of single cells stacked per stack, so that the number of separators used is several hundred.

As PEFC separators, various types of separators have been proposed. Recently, a fuel gas plate (anode plate) facing the anode electrode, an oxidant gas plate (cathode plate) facing the cathode electrode, and the like. In addition, an apparatus including an intermediate plate (frame member) sandwiched between these plates has been proposed (see Japanese Patent Application Laid-Open No. 2010-40450).
In the separator, each plate constituting the separator is provided with a through hole for supplying and discharging fuel gas and oxidant gas from the outside, and fuel gas is supplied from the anode plate to the anode electrode through the frame member. The communication hole to be supplied and the communication hole to supply the oxidant gas from the cathode plate to the cathode electrode through the frame member are provided, and since it has the above structure, uniform gas supply is possible.

JP 2010-40450 A

By the way, in recent years, as a separator for in-vehicle PEFC, a thin and light-weight separator has been required, so in individual separators and frame members that form a stack, it can withstand loads during assembly and fastening. What has higher intensity | strength has come to be calculated | required.
In addition, separators for in-vehicle PEFCs must have high durability (fatigue characteristics) and reliability that can withstand loads caused by repeated thermal expansion and cooling cycles caused by starting and stopping of PEFCs and automobile vibrations. It has come to be,
There is a demand for a frame member having similar characteristics.

  On the other hand, the frame member for the fuel cell is industrially manufactured by a flash-type compression molding die. For example, the flash-type compression molding for forming the frame member F having a planar shape shown in FIG. As the mold, a mold 11 having a lower mold 12 and an upper mold 13 shown in a schematic cross-sectional view in FIG.

FIG.3 (c) is the figure which expanded the right side dotted-line part of the metal mold | die 11 shown in FIG.3 (b).
When the frame member F is manufactured using the flash type compression molding die 11, the thermosetting resin composition R is formed in the resin composition filling recess 14 provided in the center of the lower die 12 shown in FIG. Then, the lower mold 12 is pressed from above by the resin composition pressing convex portion 18 provided on the upper mold 13 under heating conditions. The thermosetting resin composition R filled in the resin composition filling recess 14 is pressed by the upper mold 13 to satisfy the resin composition molding recesses 15a and 15b provided in the lower mold, It flows in the end direction indicated by arrow D. In the example shown in FIG. 3 (c), for the purpose of securing a space for accommodating the surplus resin composition R when the resin composition R flows, a recess (burr groove for forming surplus resin composition accommodating space in the upper mold 13. ) 16a and 16b are provided, and the resin composition R flows in the end direction while passing through the flow space formed by the recesses 16a and 16b. When the upper mold 13 is pressed to the target position, the resin composition molding recesses 15a and 15b provided in the lower mold 12 are filled with a desired amount of the resin composition R, and the resin composition R is provided in the upper mold 13. The resin composition pressing flat portions 19a and 19b are pressed and molded, and the surplus resin composition R is provided with the recesses 16a and 16b for forming the surplus resin composition containing space provided in the upper mold and the lower mold. It is accommodated in the space formed by the surface and flows out from the gap G formed between the end of the upper mold 13 and the end of the lower mold 12.
While maintaining the above pressurized state, the upper mold and the lower mold are heated for curing for a predetermined time under a temperature condition equal to or higher than the thermosetting temperature, and then released from the mold. A frame member F having a planar shape shown in FIG. 3A can be produced by cutting excess portions (burrs) of the outer peripheral portion and appropriately cutting and polishing.

  However, when the viscosity of the resin constituting the resin composition R is low, the resin composition R easily flows out from the gap G at the end of the mold 11 during pressure molding, and is provided in the lower mold 12. Resin composition R becomes difficult to spread over the four corners of resin composition molding recesses 15a and 15b, and defective filling tends to occur. For this reason, conventionally, in order to avoid the above-mentioned filling failure, it was necessary to fill the mold with an excessive amount of the resin composition, but not only the raw material yield was deteriorated but also the protrusion from the mold. Further, there is a technical problem that it is difficult to easily mass-produce industrially because it is necessary to remove the resin composition.

  Further, in order to improve the viscosity of the resin composition R and make the thermal expansion coefficient of the obtained frame member equal to the thermal expansion coefficient of the metallic separator, a filler such as glass fiber may be blended in the resin composition. However, since the resin composition R flows out of contact with the surfaces of the lower mold 12 and the upper mold 13 when flowing out from the gap G at the end of the mold 11, depending on the filler component, the surface of the mold Could be damaged.

  Furthermore, in the flash-type compression mold 11, when the resin composition R flows in the end direction indicated by the arrow D, the air in the space formed between the lower mold 12 and the upper mold 13 is also in the same direction. However, when the resin composition R flows in the space formed by the lower mold 12 and the upper mold 13, the resin composition R flows while entraining air remaining in the space and is pressure-molded. There was a technical problem that pores were formed in the obtained molded body, and the bending strength and repeated bending fatigue strength of the molded body obtained by the pores were liable to decrease.

  Molding of the resin composition using the flash type compression molding die is widely performed in fields other than the field of manufacturing the fuel cell frame member, and for adjusting physical properties such as viscosity, for example, phenol resin or Various filler materials such as wood powder, glass fiber, and talc are added to resins such as epoxy resins, but in these fields as well, mixing of air is suppressed and the molding material is made homogeneous. There has been a demand for a resin composition molded body in which molds that can be hot-pressed while being filled, and formation of pores due to mixing of residual air are suppressed, and a molding material is uniformly dispersed.

  Under such circumstances, the present invention improves the yield of raw materials, suppresses air mixing and uniformly fills the molding material, and suppresses damage at the time of molding, and can easily perform hot pressure molding. The purpose of the present invention is to provide a flat plate made of a resin composition in which pore formation due to mixing of residual air is suppressed, the molding material is uniformly dispersed, and can exhibit excellent strength and durability. It is.

  The inventors further studied to solve the above technical problem and found that a mold for producing a substantially frame-shaped resin composition flat plate having a hollow portion, which has a pair of lower mold and upper mold. The lower mold has a resin composition raw material filling recess formed in the center, a resin composition molding recess formed in the periphery thereof, and a lower mold outer peripheral side wall formed in the outer periphery. The upper mold has a resin composition pressing convex part formed in the center part, a resin composition pressing flat part formed in the peripheral part thereof, and an upper mold outer peripheral part side wall formed in the outer peripheral part. The lower mold and the upper mold are designed so that a resin composition flat plate can be press-molded while fitting when pressed and the resin composition flows from the central part to the outer peripheral part of the lower mold. The resin group formed on the surface of the lower mold or the surface of the upper mold that forms a space in which the fluid flows At least a part of the convex portion or the concave portion other than the product-forming concave portion has a corner formed by a curved surface, and the lower mold outer peripheral side wall and the upper mold outer peripheral side wall are 50 when the lower mold and the upper mold are fitted. It has been found that the above technical problem can be solved by a mold designed to form a gap of ˜150 μm, and the present invention has been completed based on this finding.

That is, the present invention
(1) A mold for producing a substantially frame-shaped resin composition flat plate having a hollow portion,
Having a pair of lower and upper molds,
The lower mold has a resin composition raw material filling recess formed in the center, a resin composition molding recess carved into a shape corresponding to the frame shape in the periphery, and the lower mold outer periphery on the outer periphery. The side wall is formed,
The upper mold has a resin composition pressing convex portion formed at a position corresponding to the lower mold resin composition filling concave portion in the center portion, and corresponds to the lower mold resin composition molding concave portion in the peripheral portion thereof. The flat portion for pressing the resin composition is formed at the position to be formed, and the upper mold outer peripheral portion side wall is formed at a position corresponding to the lower mold outer peripheral portion side wall of the outer peripheral portion,
The lower mold and the upper mold are designed to be capable of press-molding a resin composition flat plate while fitting when pressed and allowing the resin composition to flow from the center portion to the outer peripheral portion of the lower mold. And
At least part of the convex portions or concave portions other than the concave portion for molding the resin composition formed on the surface of the lower mold or the surface of the upper mold forming a space in which the resin composition flows, the corners are curved surfaces Formed,
The lower mold outer peripheral side wall and the upper mold outer peripheral side wall are designed so that a gap of 50 to 150 μm can be formed when the lower mold and the upper mold are fitted,
(2) The substantially frame-shaped resin composition flat plate has a hollow portion formed in the frame portion;
In the above (1), the lower mold is formed by forming an inner peripheral side molding concave portion and an outer peripheral side molding concave portion as the resin composition molding concave portion in the periphery of the resin composition raw material filling concave portion. Mold,
(3) A method for producing a substantially frame-shaped resin composition flat plate using the mold according to the above (1) or (2),
A resin composition comprising a thermosetting resin binder and carbonaceous powder, and blending 20 to 100 parts by mass of carbonaceous powder with respect to 100 parts by mass of the thermosetting resin binder,
The resin composition is characterized in that after filling the lower mold resin composition filling recess, the upper mold is fitted and hot press molding is performed at a temperature of 150 to 200 ° C. at 5 to 30 MPa. Manufacturing method of flat plate,
(4) The method for producing a flat plate made of a resin composition according to the above (3), wherein the resin composition is preformed into a flat plate shape,
(5) The method for producing a resin composition flat plate according to (3) or (4), wherein the substantially frame-shaped resin composition flat plate is a fuel cell frame member.
Hereinafter, the frame member for the fuel cell is appropriately referred to as a frame member.

  According to the present invention, while improving the yield of the raw material, while suppressing the mixing of air and uniformly filling the molding material, while providing a mold that can be easily hot-pressure molded to suppress damage during molding, The formation of pores due to the mixing of residual air is suppressed, the molding material is homogeneously dispersed, and a flat plate made of a resin composition that can exhibit excellent strength and durability can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for illustrating one embodiment of a mold according to the present invention, and FIG. 1 (a) is a substantially frame-shaped resin composition flat plate having a hollow portion H to be formed using the mold. FIG. 1B is a schematic diagram of a cross section of a mold according to this embodiment, and FIG. 1C is a right dotted line part of the mold 1 shown in FIG. FIG. FIG. 2 is a view for showing another example of the mold according to the present invention, and FIG. 2 (a) shows a substantially frame shape having a hollow portion H to be formed using the mold. It is a top view of the flat plate F made from a resin composition, FIG.2 (b) is a schematic diagram of the cross section of the metal mold | die which concerns on this embodiment, FIG.2 (c) is a metal mold | die shown in FIG.2 (b). 1 is an enlarged view of a right dotted line portion of FIG. FIG. 3 is a diagram for explaining a conventional mold, and FIG. 3A is a substantially frame-shaped resin composition flat plate F having a hollow portion H to be formed using the mold. 3 (b) is a schematic diagram of a cross section of the mold, and FIG. 3 (c) is an enlarged view of the right dotted line portion of the mold 1 shown in FIG. 3 (b). . FIG. 4 is a view for explaining a mold according to a comparative example of the present invention, and FIG. 4A is a substantially frame-shaped resin having a hollow portion H to be formed using the mold. It is a top view of the flat plate F made from a composition, FIG.4 (b) is a schematic diagram of the cross section of the said metal mold | die, FIG.4 (c) is the right side dotted line part of the metal mold | die 1 shown in FIG.4 (b). FIG.

First, the metal mold | die of this invention is demonstrated.
The mold of the present invention is a mold for producing a substantially frame-shaped resin composition flat plate having a hollow portion, and has a pair of a lower mold and an upper mold, and the lower mold has a central portion. A resin composition raw material filling recess is formed, a resin composition molding recess engraved in a shape corresponding to the frame shape is formed on the periphery thereof, and a lower mold outer periphery side wall is formed on the outer periphery. The upper mold is formed with a resin composition pressing convex portion at a position corresponding to the lower mold resin composition filling concave portion in the central portion, and the lower mold for molding the lower mold resin composition. A flat portion for pressing the resin composition is formed at a position corresponding to the concave portion, and an upper mold outer peripheral portion side wall is formed at a position corresponding to the lower mold outer peripheral portion side wall of the outer peripheral portion. The mold is fitted when pressed and the resin composition flows from the center part of the lower mold to the outer peripheral part. The resin composition, which is designed to press-mold a fat composition flat plate, and is formed on the surface of the lower mold or the surface of the upper mold that forms a space in which the resin composition flows. At least a part of the convex part other than the molding concave part or the concave part is formed by a curved corner, and the lower mold outer peripheral side wall and the upper mold outer peripheral side wall are 50 when the lower mold and the upper mold are fitted. It is designed to form a gap of ˜150 μm.

Hereinafter, the mold of the present invention will be described with reference to the drawings as appropriate.
FIG. 1 is a diagram for illustrating one embodiment of a mold according to the present invention, and FIG. 1A is a substantially frame-shaped resin having a hollow portion H to be formed using the mold. It is a top view of the flat plate F made from a composition, FIG.1 (b) is a schematic diagram of the cross section of the metal mold | die 1 which concerns on this embodiment, FIG.1 (c) is a metal mold | die shown in FIG.1 (b). 1 is an enlarged view of a right dotted line portion of FIG.

  As shown in FIG. 1 (b) and FIG. 1 (c), a mold 1 according to the present invention is a mold for manufacturing a substantially frame-shaped resin composition flat plate having a hollow portion, The lower mold 2 and the upper mold 3 are provided.

  As shown in FIGS. 1 (b) and 1 (c), the lower mold 2 is formed with a resin composition raw material filling recess 4 at the center, and is carved into a shape corresponding to the frame shape at the periphery. The resin composition molding recesses 5a and 5b are formed, and the lower mold outer peripheral side wall 7 is formed on the outer peripheral portion.

As shown in FIG. 1 (b) and FIG. 1 (c), the resin composition raw material filling recess 4 forms a filling space for the resin composition R to be molded, and is obtained from the resin composition obtained. It is preferable to define the formation position of the central hollow portion surrounded by the frame portion constituting the flat plate.
In the mold of the present invention, the depth L of the resin composition raw material filling recess (the depth between the deepest part of the resin composition raw material filling recess and the molding surface formed when the upper mold is fitted to the lower mold) Is not particularly limited, but when the upper mold is fitted and the resin composition flows in the direction of the end of the lower mold, a necessary amount of the resin composition is formed in the recess for forming the resin composition flow space. It is preferable that it is the depth which can form sufficient resin composition filling space which can satisfy | fill, and it is preferable that it is about 1.0-3.0 mm in depth.

In the mold of the present invention, at least a part of the convex part or the concave part other than the concave part for molding the resin composition formed on the surface of the lower mold or the surface of the upper mold forming the space through which the resin composition flows, The corner portion is formed by a curved surface, and the corner portion preferably has a curvature radius of 0.5 to 3.0 mm, more preferably a curvature radius of 1.0 to 3.0 mm, and still more preferably a curvature radius of 2.0. It is preferably formed by a curved surface of ˜3.0 mm.
For this reason, in the mold of the present invention, at least a part of the corner of the concave portion for filling the resin composition raw material is preferably a radius of curvature of 0.5 to 3.0 mm, more preferably a radius of curvature of 1.0 to 3. It is preferably formed by a curved surface having a curvature radius of 2.0 to 3.0 mm, more preferably 0.0 mm.
As described above, in the conventional flash-type compression mold, it becomes easy to form pores in the flat plate made of resin composition obtained by entraining air when the resin composition flows, but in the mold of the present invention, Since the convex part or concave part formed on the lower mold surface or the upper mold surface that forms the flow space of the resin composition is formed by a curved surface, the gold during the flow of the resin composition Residual air in the mold can be easily extruded to the outside, and formation of pores in the resulting resin composition flat plate can be suppressed.

The shape of the resin composition molding recesses 5a and 5b is defined by the shape of the frame-shaped portion of the resin composition flat plate F to be obtained.
As illustrated in FIG. 1B and FIG. 1C, in the mold of the present invention, the bottoms of the resin composition molding recesses 5a and 5b are more than the bottom of the resin composition raw material filling recesses 4 described above. It is preferable that it is designed to be located at a high position. By designing in this way, it is easy to uniformly fill the resin composition into the recess for molding the resin composition when the upper mold is fitted. Become.

The lower mold outer peripheral side wall 7 serves as a protective wall that suppresses the outflow of the resin composition when fitted to the upper mold, as will be described later.
In the mold of the present invention, the height l of the lower mold outer peripheral side wall (the difference in height between the top of the lower mold outer peripheral side wall and the molding surface formed when the upper mold is fitted to the lower mold) is: Although it does not restrict | limit especially if it can suppress the outflow of a resin composition when it fits with an upper mold | type, It is preferable that it is about 3.0-10.0 mm in height.
In the mold of the present invention, the lower mold outer peripheral side wall may be capable of forming an inclination angle α of 85 to 89 ° with respect to a molding surface formed when the upper mold is fitted to the lower mold. It is more preferable that an inclination angle of about 90 ° can be formed.
In the mold of the present invention, the inclination angle α formed by the lower mold outer peripheral side wall is that the plane corresponding to the lower mold outer peripheral side wall 7 and the upper mold are fitted to the lower mold as shown in FIG. It means an angle formed by a plane corresponding to a molding surface that is sometimes formed. For this reason, in the metal mold | die of this invention, as shown in FIG. 1, even if it is a case where the molding surface side edge part of the lower mold outer peripheral part side wall 7 is formed in a curved surface shape, the lower mold outer peripheral part side wall 7 The inclination angle α can be obtained by drawing a virtual line formed by a plane corresponding to the surface and a virtual line formed by a plane corresponding to the molding surface formed when the upper mold is fitted to the lower mold.

In the mold of the present invention, at least a part of the convex part or the concave part other than the concave part for molding the resin composition formed on the surface of the lower mold or the surface of the upper mold forming the space through which the resin composition flows, The part is formed by a curved surface, and the end part and at least a part of the side wall of the lower mold outer peripheral part are preferably 0.5 to 3.0 mm in radius of curvature, more preferably 1.0 to 3.0 mm in radius of curvature. More preferably, it is formed by a curved surface having a curvature radius of 2.0 to 3.0 mm.
As described above, in the conventional flash-type compression mold, it becomes easy to form pores in the flat plate made of resin composition obtained by entraining air when the resin composition flows, but in the mold of the present invention, Since the convex part or concave part formed on the lower mold surface or the upper mold surface that forms the flow space of the resin composition is formed by a curved surface, the gold during the flow of the resin composition It becomes easy to extrude the air in the mold to the outside, and the formation of pores in the resulting resin composition-made flat plate can be suppressed.

  As illustrated in FIG. 1B and FIG. 1C, the upper mold 3 has a resin composition pressing convex portion 8 at a position corresponding to the lower mold resin composition filling concave portion 4 in the central portion. Resin composition pressing flat portions 9a, 9b are formed at positions corresponding to the lower mold resin composition molding recesses 5a, 5b in the peripheral portion, and the lower mold outer peripheral portion side wall in the outer peripheral portion is formed. The upper mold 3 has a flat portion for pressing the resin composition, as illustrated in FIGS. 1 (b) and 1 (c). It is preferable that recesses 6a and 6b for forming the surplus resin composition-containing space are formed in at least a part of positions other than 9a and 9b.

  As shown in FIG. 1B and FIG. 1C, the resin composition pressing convex portion 8 presses the resin composition R filled in the resin composition raw material filling concave portion 4, and thereby the upper mold 3. (Or lower mold 2) The resin composition is made to flow in the end direction D, and the formation position of the hollow portion surrounded by the frame-shaped portion constituting the obtained resin composition-made flat plate can be defined. Preferably there is.

  In the mold of the present invention, the shape (projection shape) of the convex portion for pressing the resin composition is not particularly limited, but has a convex shape corresponding to the shape of the concave portion for filling the resin composition raw material of the lower mold. Is preferred.

In the mold of the present invention, at least a part of the convex part or the concave part formed on the surface of the lower mold or the surface of the upper mold that forms a space in which the resin composition flows is formed by a curved surface at the corner. The convex part for pressing the resin composition also has at least a part of its corners, preferably a radius of curvature of 0.5 to 3.0 mm, more preferably a radius of curvature of 1.0 to 3.0 mm, still more preferably. It is preferably formed by a curved surface having a curvature radius of 2.0 to 3.0 mm.
As described above, in the conventional flash-type compression mold, it becomes easy to form pores in the flat plate made of resin composition obtained by entraining air when the resin composition flows, but in the mold of the present invention, Since the convex part or concave part formed on the lower mold surface or the upper mold surface that forms the flow space of the resin composition is formed by a curved surface, the gold during the flow of the resin composition Residual air in the mold can be easily extruded to the outside, and formation of pores in the resulting resin composition flat plate can be suppressed.

  As shown in FIGS. 1B and 1C, the upper mold 3 has resin composition pressing flat portions 9a and 9b at positions corresponding to the lower mold resin composition molding recesses 5a and 5b. When the upper mold 3 is formed and the lower mold 2 is fitted, the frame portion of the flat plate made of the resin composition can be pressed.

Moreover, in the metal mold | die of this invention, as illustrated in FIG.1 (b) and FIG.1 (c), in the upper mold | type 3, at least one part of positions other than the said resin composition press flat part 9a, 9b. In addition, in order to form a space for accommodating the surplus resin composition R, it is preferable that the recesses (burr grooves) 6a and 6b for forming the surplus resin composition accommodating space are formed.
In the mold of the present invention, the recess for forming the surplus resin composition containing space is formed by pressing the upper mold 3 on the pressing surface of the upper mold 3 (the resin composition pressing flat portion 9a in the example shown in FIG. It is preferable to be provided in at least a part of the portion other than 9b), and it is desirable to be provided adjacent to the flat portion that becomes the molding surface.

In the mold of the present invention, at least a part of the convex part or the concave part formed on the surface of the lower mold or the surface of the upper mold that forms a space in which the resin composition flows is formed by a curved surface at the corner. The excessive resin composition-containing space forming recess also has at least a part of its corner, preferably a radius of curvature of 0.5 to 3.0 mm, more preferably a radius of curvature of 1.0 to 3.0 mm, It is preferably formed by a curved surface having a curvature radius of 2.0 to 3.0 mm.
As described above, in the conventional flash-type compression mold, it becomes easy to form pores in the flat plate made of resin composition obtained by entraining air when the resin composition flows, but in the mold of the present invention, Since the convex part or concave part formed on the lower mold surface or the upper mold surface that forms the flow space of the resin composition is formed by a curved surface, the gold during the flow of the resin composition Residual air in the mold can be easily extruded to the outside, and formation of pores in the resulting resin composition flat plate can be suppressed.

As shown in FIGS. 1B and 1C, the mold of the present invention has an upper mold outer peripheral portion side wall 10 at a position corresponding to the lower mold outer peripheral portion side wall 7 in the outer peripheral portion of the upper mold 3. Formed.
In the mold of the present invention, the upper mold outer peripheral side wall also serves as a protective wall that suppresses the outflow of the resin composition when the upper mold is fitted to the lower mold, like the lower mold outer peripheral side wall.
In the mold according to the present invention, the height of the upper mold outer peripheral side wall (the difference in height between the top of the upper mold outer peripheral side wall and the molding surface formed when the upper mold is fitted to the lower mold) is Although it does not restrict | limit as long as it can suppress the outflow of a resin composition when it fits with a type | mold, It is preferable that it is about 3.0-10.0 mm, and is the same height as a lower mold | type outer peripheral part side wall. More preferably.
In the mold of the present invention, it is more preferable that the inclination angle of the upper mold outer peripheral side wall corresponds to the inclination angle of the lower mold outer peripheral side wall.
In the mold according to the present invention, the inclination angle formed by the upper mold outer peripheral side wall corresponds to the upper mold outer peripheral side wall 10 shown in FIG. 1 in the same manner as the inclination angle α formed by the lower mold outer peripheral side wall described above. Means an angle formed by a plane to be formed and a plane corresponding to a molding surface formed when the upper mold is fitted to the lower mold.

In the mold of the present invention, at least a part of the convex part or the concave part formed on the surface of the lower mold or the surface of the upper mold that forms a space in which the resin composition flows is formed by a curved surface at the corner. Further, at least a part of the end portion of the upper mold outer peripheral side wall is preferably a curvature radius of 0.5 to 3.0 mm, more preferably a curvature radius of 1.0 to 3.0 mm, and still more preferably a curvature radius of 2. It is preferably formed by a curved surface of 0 to 3.0 mm.
As described above, in the conventional flash-type compression mold, it becomes easy to form pores in the flat plate made of resin composition obtained by entraining air when the resin composition flows, but in the mold of the present invention, Since the convex part or concave part formed on the lower mold surface or the upper mold surface that forms the flow space of the resin composition is formed by a curved surface, the gold during the flow of the resin composition Residual air in the mold can be easily extruded to the outside, and formation of pores in the resulting resin composition flat plate can be suppressed.

In the mold of the present invention, the upper mold outer peripheral side wall functions as a protective wall that suppresses the outflow of the resin composition to the outside when the upper mold is fitted to the lower mold, and the upper mold outer peripheral side wall and The outflow of the resin composition to the outside is also suppressed when the lower mold outer peripheral side wall faces and fits with almost no gap.
On the other hand, if the gap formed between the upper mold outer peripheral side wall and the lower mold outer peripheral side wall is too narrow, the mold surface may be damaged at the time of fitting by a filler or the like contained in the resin composition. If it is too high, it will be difficult to achieve the purpose of suppressing the flow of the resin composition.
Therefore, in the mold of the present invention, the lower mold outer peripheral side wall and the upper mold outer peripheral side wall are designed so that a gap of 50 to 150 μm can be formed when the lower mold and the upper mold are fitted. And is preferably designed so as to be able to form a gap of 50 to 100 μm, and more preferably designed so as to be able to form a gap of 50 to 80 μm.

The metal mold | die of this invention can take a various form according to the shape of the substantially frame-shaped resin composition plate made to obtain.
For example, as shown in FIG. 1A, when the substantially frame-shaped resin composition flat plate F to be obtained has a hollow portion h formed in the frame portion, ) And FIG. 1 (c), the lower mold 2 can be formed by forming the inner peripheral side molding concave portion 5 a and the outer peripheral side molding concave portion 5 b as the resin composition molding concave portion.

  FIG. 2 is a view for showing another example of the mold according to the present invention, and FIG. 2 (a) shows a substantially frame shape having a hollow portion H to be formed using the mold. It is a top view of the flat plate F made from a resin composition, FIG.2 (b) is a schematic diagram of the cross section of the metal mold | die 1 which concerns on this embodiment, FIG.2 (c) is gold | metal | money shown in FIG.2 (b) 3 is an enlarged view of a right dotted line part of the mold 1; FIG.

  As shown in FIG. 2 (a), the present embodiment is an example in which the substantially frame-shaped resin composition flat plate F to be obtained has no hollow portion formed in the frame portion. As shown in FIG. 2 (b) and FIG. 2 (c), the lower mold 2 is formed with a recess 5 as a resin composition molding recess, and the upper mold 3 has a lower mold resin composition filling recess. 5, a resin composition pressing flat portion 9 is formed at a position corresponding to 5, and a resin composition flow space forming concave portion 6 is formed on the outside thereof.

  As shown in FIGS. 1B and 1C (or FIG. 2B and FIG. 2C), the lower mold 2 and the upper mold 3 are fitted when the mold of the present invention is pressed. Thus, the resin composition is designed so that the resin composition flat plate can be pressed while flowing the resin composition from the central portion of the lower mold 2 to the outer peripheral portion.

When the resin composition flat plate F is manufactured as a substantially frame-shaped resin composition flat plate having a hollow portion using the mold 1 shown in FIGS. 1B and 1C, FIG. ) Or the resin composition filling recess 4 provided at the center of the lower mold 2 shown in FIG. 1 (c) is filled with the thermosetting resin composition R, and then the upper mold 3 is fitted under heating conditions. And press the lower mold 2.
The thermosetting resin composition filled in the recess 4 for filling the resin composition is pressed by the upper mold 3 to satisfy the recesses 5a and 5b for molding the resin composition provided in the lower mold, while the arrows It flows in the end direction indicated by D. In the example shown in FIG. 1C, the resin composition R flows in the end direction while passing through the flow space formed by the surplus resin composition-containing space forming recesses 6a and 6b. When the upper mold 3 is pressed to a target position, the resin composition R is in a state where the outflow to the outside is suppressed by a protective wall or gap formed by the lower mold outer peripheral side wall 7 and the upper mold outer peripheral side wall 10. A desired amount of the resin composition R is filled in the resin composition molding recesses 5 a and 5 b provided in the lower mold 2.

  In this case, in the example shown in FIG. 1B and FIG. 1C, the convex portion or the concave portion formed on the surface of the lower mold 2 or the surface of the upper mold 3 forming the space through which the resin composition flows. Since at least a part of the corner is formed by a curved surface, the resin composition can be molded into a desired flat plate shape while suppressing entrainment of air remaining in the mold. Further, by providing the lower mold outer peripheral side wall and the upper mold outer peripheral side wall, the outflow of the resin composition to the outside of the mold is suppressed, and the gap formed by the lower mold outer peripheral side wall and the upper mold outer peripheral side wall By controlling the width of the resin composition within a predetermined range, the outflow of the resin composition to the outside can be suppressed while suppressing damage to the mold due to the filler.

The upper mold and the lower mold may be heated and cured for a predetermined time under a temperature condition equal to or higher than the thermosetting temperature while maintaining the above-mentioned pressure state, and then may be further machined as necessary.
That is, the resin composition having a desired shape is obtained by cutting the hollow portion forming portion and the excess portion (burr) of the end portion of the obtained cured molded article after appropriate heat-curing, and cutting and polishing appropriately. A product flat plate can be produced.
For example, when the mold 1 shown in FIG. 1 (b) or FIG. 1 (c) is used as a hot pressing mold, the lower resin composition filling recess in the resin composition flat plate obtained. The portion pressed by the convex part 8 for pressing the resin composition 4 or the upper mold is a hollow part H, but a molding burr may be generated in the pressing part, so that by appropriately performing cutting, cutting or polishing treatment It is preferable to remove the molding burr.
Further, when the mold 1 shown in FIG. 1B or FIG. 1C is used, in the obtained resin composition flat plate, there is a portion facing the upper mold surplus resin composition housing space forming recess 6a. Although it becomes the hollow part h, since the molding burr | flash may arise also in the said location, it is preferable to remove the said shaping | molding burr | flash by performing a cutting | disconnection, cutting, or grinding | polishing processing suitably.
Moreover, when the metal mold 1 shown in FIG. 1B or FIG. 1C is used, in the obtained resin composition flat plate, the outer peripheral side of the lower mold resin composition molding recess 5b is an unnecessary portion. Therefore, it is preferable to remove the unnecessary portion by appropriately performing cutting, cutting or polishing treatment.

  In the mold of the present invention, the resin composition includes a thermosetting resin binder and carbonaceous powder, and is formed by blending 20 to 100 parts by mass of carbonaceous powder with respect to 100 parts by mass of the thermosetting resin binder. Things can be mentioned.

In the mold of the present invention, as the carbon powder constituting the resin composition, specifically, carbon black, graphite powder such as artificial graphite powder, natural graphite powder, isotropic graphite powder, and coke such as needle coke One or more types selected from the class and the like can be mentioned, and it is preferable to select appropriately according to the flat plate made of the resin composition to be obtained.
For example, when the resin composition flat plate to be obtained is a frame member, the insulation required for the frame member and the strength to withstand the difference in thermal expansion between the metal plate such as the anode plate and the cathode plate, low elution Needle coke is preferable because it can provide sufficient properties, insulation, and sufficient rigidity.

Needle coke can be produced by the following method.
First, by conducting a coking reaction at a temperature of about 400 to 600 ° C. by a delayed coking method using coal-based heavy oil such as coal tar rich in polycyclic aromatics, coal tar pitch, or petroleum heavy oil as a raw material. Get raw coke. The raw coke is calcined at 1000 to 1400 ° C. below the graphitization temperature in a rotary kiln furnace, a lead hammer furnace, a rotary hearth furnace or the like, whereby needle-like needle coke can be obtained.

In the mold of the present invention, the carbonaceous powder constituting the resin composition preferably has an average particle size of 3 to 80 μm, more preferably 30 to 60 μm, and even more preferably 40 to 60 μm. .
When the average particle size of the carbonaceous powder is smaller than 3 μm, the viscosity of the resin composition is lowered and the filling is likely to be poor. When the average particle diameter is larger than 80 μm, the bending fatigue strength of the obtained resin composition flat plate is decreased. It becomes easy.

The carbonaceous powder functions as a filler, and by adopting the carbonaceous powder as the filler, elution of impurities such as metal ions is suppressed and high chemical resistance is imparted to the resulting resin composition flat plate. It can also exhibit excellent corrosion resistance against highly erodible chemicals such as hydrofluoric acid and sulfuric acid.
Moreover, when the substantially frame-shaped resin composition flat plate produced by the mold of the present invention is a fuel cell frame member, the thermal expansion coefficient of stainless steel, which is generally a constituent material of a metal separator, is 16 × 10 ^−6. For example, the thermal expansion coefficient of titanium is about 8 × 10 ⁻⁶ , whereas the thermal expansion coefficient of an epoxy resin used as a constituent material of a frame member is about 60 × 10 ⁻⁶ , for example. However, by adopting carbonaceous powder as a filler, the difference in thermal expansion coefficient from the metal separator can be reduced. For this reason, the separator and the frame member can be removed by starting and stopping the fuel cell stack. Even in the case of thermal expansion or contraction, excellent fatigue strength characteristics can be exhibited by suppressing repeated stress at the bonding interface.

In the mold of the present invention, the thermosetting binder constituting the resin composition is not particularly limited. For example, furan series such as phenol resin, furfuryl alcohol resin, furfuryl alcohol furfural resin, furfuryl alcohol phenol resin, etc. Resins, polyimide resins, polycarbodiimide resins, polyacrylonitrile resins, pyrene-phenanthrene resins, polyvinyl chloride resins, bifunctional aliphatic alcohol ether type epoxy resins and polyfunctional phenol type epoxy resins and other epoxy resins, urea resins, diallyl phthalate resins , Unsaturated polyester resin, melamine resin, and the like. These can be used alone or in combination of two or more, and it is preferable to select appropriately according to the flat plate made of the resin composition to be obtained.
For example, when the resin composition flat plate to be obtained is a frame member, among the above-mentioned various resins, acid resistance to an electrolyte such as sulfonic acid having a pH of about 2-3 and a fuel cell of about 60-100 ° C. Those having heat resistance capable of withstanding the operating temperature are preferred.
In the metal mold of the present invention, the thermosetting binder constituting the resin composition is preferably an epoxy resin that hardly generates condensed water or the like that causes pores, can be easily adjusted in viscosity, and has chemical resistance.

In the mold of the present invention, the resin composition may include a curing accelerator as a part of the thermosetting binder.
Although it does not restrict | limit especially as a hardening accelerator, For example, when using a polyfunctional phenol type epoxy resin as a thermosetting resin binder, what is normally used for anion hardening of an epoxy resin can be mentioned, Specifically, Can include one or more selected from tertiary amines, quaternary ammonium salts, imidazoles such as 2-methylimidazole and 2-phenyl-4-methylimidazole, phosphines, phosphonium salts and the like.
Among the above-mentioned curing accelerators, particularly imidazoles exhibit high activity with respect to epoxy resins even in a small amount used, and can be cured in a short time even at a relatively low curing temperature, for example, about 170 ° C. in about 10 seconds. Can be preferably used.

  In the mold of the present invention, the resin composition preferably contains 20 to 100 parts by mass of carbonaceous powder, and 40 to 90 parts by mass in terms of solid content with respect to 100 parts by mass of the thermosetting resin binder. It is preferable that it contains 50-60 parts by mass.

  When the content of the carbonaceous powder with respect to 100 parts by mass of the thermosetting resin binder is 20 parts by mass or more, a decrease in viscosity at the time of melting can be suppressed, and the outflow of the resin composition from the gap of the mold can be suppressed. At the same time, the resin composition can be sufficiently pressurized. Moreover, the fluidity | liquidity of a resin composition is improved and the filling property to the metal mold | die of this invention is improved because content of the carbonaceous powder with respect to 100 mass parts of thermosetting resin binders is 100 mass parts or less. Can do.

Further, in the mold of the present invention, the resin composition preferably includes a thermosetting resin binder and a carbonaceous powder in a total amount of 90 to 100% by mass, more preferably 95 to 100% by mass, More preferably, the content is 98 to 100% by mass.
The resin composition may contain, for example, a small amount of a fibrous filler for strength improvement as the third component.

The resin composition filled in the mold of the present invention is preferably preliminarily molded into a flat plate shape. In this case, a powder resin composition having a predetermined mass is added as the preform. Examples include those formed by pressing into a predetermined shape.
It is preferable that the size of the preform corresponds to the size of the concave portion for filling the lower resin composition.
By using such a preform, a desired amount of the resin composition can be easily molded while being easily handled.

  According to the present invention, it is possible to provide a mold that improves the yield of raw materials, suppresses air mixing and uniformly fills a molding material, and suppresses damage during molding and can be easily hot-pressure molded. it can.

Next, the manufacturing method of the resin composition flat plate of the present invention will be described.
The method for producing a resin composition flat plate of the present invention is a method of producing a substantially frame-shaped resin composition flat plate using the mold of the present invention, comprising a thermosetting resin binder and a carbonaceous powder, The resin composition obtained by blending 20 to 100 parts by mass of carbonaceous powder with respect to 100 parts by mass of the thermosetting resin binder is filled in the concave part for filling the resin composition of the lower mold, and then the upper mold is fitted. In combination, hot press molding is performed at 5 to 30 MPa under a temperature condition of 150 to 200 ° C.

  In the method for producing a flat plate made of a resin composition of the present invention, details of the mold and the resin composition are as described above.

In the production method of the present invention, the temperature at the time of hot pressing is usually 150 to 200 ° C, suitably 150 to 180 ° C, more suitably 150 to 160 ° C.
In the production method of the present invention, when the resin composition contains a curing accelerator, the hot pressing temperature is within the above temperature, and hot pressing is performed at a temperature equal to or higher than the reaction start temperature of the curing accelerator, When using a plurality of curing accelerators, hot pressing is performed at a temperature equal to or higher than the highest temperature among the reaction start temperatures of the curing accelerators used.

  In the production method of the present invention, the applied pressure during hot pressing is 5 to 30 MPa, preferably 10 to 30 MPa, and more preferably 10 to 20 MPa.

The pressing time at the time of hot pressing can be appropriately determined depending on the type of the thermosetting resin binder, but is preferably about 1.5 to 3 times the gelation time of the thermosetting resin binder. More preferably, it is about double.
When the pressurization time is within the above range, the thermosetting resin binder can be sufficiently solidified to reduce the adhesiveness, and can be easily removed from the mold while improving the productivity (manufacturing cycle).

The obtained hot pressing product may be further machined as necessary.
For example, when the mold 1 shown in FIG. 1 (b) or FIG. 1 (c) is used as a hot pressing mold, the lower resin composition filling recess in the resin composition flat plate obtained. The portion pressed by the convex part 8 for pressing the resin composition 4 or the upper mold is a hollow part H, but a molding burr may be generated in the pressing part, so that by appropriately performing cutting, cutting or polishing treatment It is preferable to remove the molding burr.
Further, when the mold 1 shown in FIG. 1B or FIG. 1C is used, in the obtained resin composition flat plate, there is a portion facing the upper mold surplus resin composition housing space forming recess 6a. Although it becomes the hollow part h, since the molding burr | flash may arise also in the said location, it is preferable to remove the said molding burr | flash by performing a cutting | disconnection, cutting, or grinding | polishing processing suitably.
Moreover, when the metal mold 1 shown in FIG. 1B or FIG. 1C is used, in the obtained resin composition flat plate, the outer peripheral side of the lower mold resin composition molding recess 5b is an unnecessary portion. Therefore, it is preferable to remove the unnecessary portion by appropriately performing cutting, cutting or polishing treatment.

  In the production method of the present invention, the obtained hot-pressed product may be appropriately subjected to after-curing at a temperature of about 150 to 200 ° C., if necessary, and may be removed from the surface of the mold during mold release. In order to remove the release agent that has been released and adhered, and to improve the adhesion to the mating member, a surface treatment such as sandblasting may be applied as appropriate.

According to the production method of the present invention, a desired substantially frame-shaped resin composition flat plate can be obtained in this manner.
As a substantially frame-shaped resin composition-made flat plate, a frame member etc. can be mentioned, for example.

The resin composition-made flat plate obtained by the production method of the present invention preferably contains 20 to 100 parts by mass of carbonaceous powder and 100 to 90 parts by mass with respect to 100 parts by mass of the thermosetting resin binder. Preferably, it contains 50 to 60 parts by mass.
Further, the resin composition-made flat plate obtained by the production method of the present invention preferably comprises 90 to 100% by mass of the thermosetting resin binder and the carbonaceous powder, and 95 to 100% by mass. More preferably, it is more preferably 98 to 100% by mass. The resin composition flat plate obtained by the production method of the present invention may contain, for example, a small amount of a fibrous filler as a third component for strength improvement.

The resin composition flat plate obtained by the production method of the present invention preferably has a density of 98% or more of the theoretical density, more preferably 99% or more of the theoretical density, and 99.5% of the theoretical density. The above is more preferable.
Here, the theoretical density means a value obtained by dividing the blending ratio (mass%) of each component constituting the resin composition by the true specific gravity of each component and dividing the sum by 100.
For example, when the resin composition is composed of component A and component B, the theoretical density is represented by the following formula (the denominator of the following formula represents the volume per 100 g of the resin composition).
Theoretical density = 100 / {(mixing ratio of component A (mass%) / true specific gravity of component A) + (mixing ratio of component B (mass%) / true specific gravity of component B)}
When the density of the resin composition flat plate obtained by the production method of the present invention is within the above range, for example, when the resin composition flat plate is a frame member, the generation of pores is suppressed and the stack is tightened. The thing which has the outstanding intensity | strength which can suppress generation | occurrence | production of the crack of the frame member in etc. can be provided.
In addition, in this application document, the density of the flat plate made from a resin composition means the value measured by the Archimedes method.

The resin composition flat plate obtained by the production method of the present invention preferably has a bending maximum point stress of 120 MPa or more, more preferably 140 MPa or more, and even more preferably 160 MPa or more.
When the bending maximum point stress of the resin composition flat plate is within the above range, for example, when the resin composition flat plate is a frame member, it is possible to suppress the occurrence of cracking of the frame member at the time of stack tightening or the like. .
In addition, in this application document, the bending maximum stress of the flat plate made of a resin composition means a value measured by a method conforming to the bending test method of the standard relating to the general test method for thermosetting plastics of JIS K 6911. .

In the resin composition flat plate obtained by the production method of the present invention, the bending fracture strain of the resin composition flat plate is preferably 2.2% or more, more preferably 2.4% or more, and 2.6. % Or more is more preferable.
When the bending fracture strain of the resin composition flat plate is within the above range, for example, when the resin composition flat plate is a frame member, high bending strength can be exhibited.
In addition, in this application document, the bending fracture strain of the flat plate made of a resin composition means a value measured by a method based on a bending test method of a standard relating to a general test method for thermosetting plastics of JIS K 6911. .

In the resin composition flat plate obtained by the production method of the present invention, the resin composition flat plate preferably has a 0.45% strain repeated bending fracture number of 30,000 times or more, more preferably 50,000 times or more. What is 100,000 times or more is more preferable.
When the 0.45% strain repeated bending fracture of the resin composition flat plate is within the above range, for example, when the resin composition flat plate is a frame member, high bending strength can be exhibited.
In addition, in this application document, the 0.45% strain repeated bending fracture number of the resin composition flat plate is determined by a four-point bending test method, and the distance between fulcrums is 20 mm between outer fulcrums and 10 mm between inner fulcrums. Then, by measuring the number of times until rupture by applying a 5 Hz sine wave with the test piece and each fulcrum in contact with the top dead center and the location with 0.45% strain applied as the bottom dead center Means the calculated value.

  According to the production method of the present invention, it is possible to provide a flat plate made of a resin composition in which formation of pores due to mixing of residual air is suppressed, a molding material is homogeneously dispersed, and can exhibit excellent strength and durability. Can do.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited at all by the following examples.

Example 1
(1) Preparation of resin composition
66 parts by mass of an epoxy resin (Nippon Kayaku Co., Ltd. cresol novolac epoxy resin, melting point 70 ° C.) and 33 parts by mass of a phenol resin (Maywa Kasei Co., Ltd. phenol novolac, melting point 70 ° C.) which are thermosetting resin binders And curing accelerator (Shikoku Kasei Co., Ltd., imidazole, reaction start temperature 90 ° C.) 1 part by mass (for 100 parts by mass of thermosetting resin binder (epoxy resin + phenol resin + cure accelerator)), average particle A resin composition was prepared by blending 60 parts by mass of mosaic artificial graphite having a diameter of 50 μm, kneading the mixture with a two-roll mill a plurality of times while being heated and melted at 80 ° C., and solidifying by cooling.
The resin composition is pulverized once, loaded with 75 g into a 210 mm long and 120 mm wide mold, and compressed in a press machine while being melted at 80 ° C. in a vacuumed state. A resin composition preformed in a shape (longitudinal 210 mm, lateral 120 mm, thickness 2.2 mm) was formed.
By the evacuation, it is possible to suppress the formation of pores (closed pores) at the time of melting by the air between the particles generated by once pulverizing.

(2) Production of flat plate made of resin composition A pair of lower mold 2 and upper mold 3 having a form as shown in FIG. 1 (b) or FIG. Hot pressing was performed using the mold 1 to be included.
The mold 1 used in this embodiment is designed so that the lower mold outer peripheral side wall 7 and the upper mold outer peripheral side wall 10 can form a gap of 60 μm when the lower mold 2 and the upper mold 3 are fitted. It was a thing.
In addition, the mold 1 used in this example is a molding surface in which the top of the lower mold outer peripheral side wall 7 and the top of the upper mold outer peripheral side wall 10 are formed by fitting the upper mold 3 to the lower mold 2 ( It has a height l of 6.0 mm from the surface formed by the flat portions 9a and 9b.
Furthermore, the mold 1 used in this example is a molding surface in which the deepest part of the resin composition raw material filling recess 4 of the lower mold 2 is formed by fitting the upper mold 3 to the lower mold 2. It has a depth L of 3.0 mm from the (surface formed by the flat portions 9a and 9b).
The mold 1 used in this example is a convex portion and a concave portion excluding the concave portions 5a and 5b for molding the resin composition provided on the surface forming the space where the resin composition of the lower die 2 and the upper die 3 flows. However, the lower mold outer peripheral side wall 7 is formed when the upper mold 3 is fitted to the lower mold 2 so that the curvature radius is 2.0 to 3.0 mm. An inclination angle α of 90 ° with respect to the molding surface can be formed.
Specifically, the hot press molding treatment is performed by placing the resin composition R preformed in the above plate shape on the resin composition raw material filling recess 4 of the lower mold 2 preheated to 160 ° C. By fitting the mold 3 to the lower mold 2, the molten resin composition is sufficiently filled in the four corners of the resin composition molding recesses 5 a and 5 b provided in the lower mold, and in the end direction D. Fluidized.
After fitting the upper mold 3 to a predetermined position of the lower mold 2 and clamping the mold at 160 ° C. for 3 minutes under a pressure of 20 MPa, the mold is opened, the mold is removed, and the hot-pressure molded product is taken out. It was. During the hot-press molding, a hot-press molded product could be obtained while suppressing the outflow of the resin composition to the outside.
In the obtained hot-pressed product, the excess portion (molding burr) formed in the resin composition flow space or the outer peripheral portion of the lower mold 2 and the upper mold 3 is appropriately cut, cut, and removed. A flat plate made of a resin composition having a frame shape of 200 mm in length, 300 mm in width, 1.0 mm in thickness, and 0.2 mm in thickness of the thinnest wall portion, which is formed with a hollow portion H and a hollow portion h shown in FIG. A fuel cell frame member) was obtained.
The obtained resin composition-made flat plate had no pores or the like when the appearance was observed. Further, no damage or the like was confirmed on the surface of the mold.

The obtained resin composition-made flat plate had excellent dimensional accuracy with a mass of 25 g, a density of 1.41 (g / cm ³ ), and a difference between the maximum value and the minimum value of the thickness dimension of each part was as small as 25 μm.
The obtained resin composition flat plate has a maximum point stress of 168 MPa in a bending fracture test, 2.6% strain at break (bending fracture strain), and 100,000 in a 5 Hz repeated bending fatigue test with 0.45% applied. The durability was more than once, and the strength and durability were excellent.

(Example 2)
In Example 1 (1), the amount of the pulverized resin composition loaded into the mold was changed from 75 g to 90 g, and preformed into a plate-shaped preform (210 mm long, 120 mm wide, 2.6 mm thick). A hot-pressed product was prepared in the same manner as in Example 1 except that the resin composition was prepared and the preform was hot-pressed.
At this time, the resin composition is sufficiently filled up to the four corners of the resin composition molding recesses 5a and 5b provided in the lower mold, and the surplus resin composition is provided in the lower mold and the recesses 6a and 6b provided in the upper mold. The resin composition flow space formed between the molds was filled and flowed to the gap portion between the lower mold outer peripheral side wall 7 and the upper mold outer peripheral side wall 10, but the outflow to the outside of the mold was suppressed. In the obtained hot-pressed product, the excess portion (molding burr) formed in the resin composition flow space or the outer peripheral portion of the lower mold 2 and the upper mold 3 is appropriately cut, cut, and removed. A flat plate made of a resin composition having a frame shape of 200 mm in length, 300 mm in width, 1.0 mm in thickness, and 0.2 mm in thickness of the thinnest wall portion, which is formed with a hollow portion H and a hollow portion h shown in FIG. A fuel cell frame member) was obtained.
The obtained resin composition-made flat plate had no pores or the like when the appearance was observed. Further, no damage or the like was confirmed on the surface of the mold.
The obtained resin composition-made flat plate was excellent in dimensional accuracy with a mass of 24 g, a density of 1.38 (g / cm ³ ), and the difference between the maximum value and the minimum value of the thickness of each part was as small as 40 μm.
In addition, the obtained resin composition flat plate has a maximum point stress in a bending fracture test of 156 MPa, a strain at break (bending fracture strain) of 2.8%, and a 5 Hz repeated bending fatigue test with 0.45% applied in a 100,000 Hz repeated bending fatigue test. The durability was more than once, and the strength and durability were excellent.

(Example 3)
In Example 1 (1), the amount of mosaic artificial graphite having an average particle diameter of 50 μm with respect to 100 parts by mass of the thermosetting resin binder was changed from 60 parts by mass to 90 parts by mass, and the amount of the pulverized resin composition A pre-molded resin composition was prepared by changing the amount loaded into the mold from 75 g to 60 g and pre-molding a plate-shaped preform (plate length 210 mm, width 120 mm, thickness 1.6 mm). A hot-press molded product was produced in the same manner as in Example 1 except that was hot-press molded.
At this time, hot pressing can be performed while sufficiently filling the resin composition up to the four corners of the resin composition molding recesses 5a, 5b provided in the lower mold. In the obtained hot pressing, By cutting, cutting and removing the excess portion (molding burr) formed in the resin composition flow space or the outer peripheral portion of the lower mold 2 and the upper mold 3, the hollow portion H and the hollow shown in FIG. Part h was formed, and a resin composition flat plate (frame member for fuel cell) having a frame shape of 200 mm in length, 300 mm in width, 1.0 mm in thickness, and 0.2 mm in the thinnest wall thickness was obtained.
The obtained resin composition-made flat plate had no pores or the like when the appearance was observed. Further, no damage or the like was confirmed on the surface of the mold.
The obtained resin composition-made flat plate had a mass of 26 g, a density of 1.44 (g / cm ³ ), and a difference between the maximum value and the minimum value of the thickness dimension of each part was 40 μm.
Further, the obtained resin composition flat plate has a maximum point stress of 171 MPa in a bending fracture test, a strain at break (bending fracture strain) of 2.5%, and a 100,000 Hz in a repeated bending fatigue test at 0.45%. The durability was more than once, and the strength and durability were excellent.

(Comparative Example 1)
Concavities and convexities provided on the surfaces of the lower mold 12 and the upper mold 13 that form a space in which the resin composition R flows as shown in FIG. 3B or FIG. A hot-press molded product was produced in the same manner as in Example 1 except that those having substantially right-angled corners were used.
In this example, the resin composition was not sufficiently filled in the four corners of the resin composition molding recesses 15a and 15b provided in the lower mold, and could not be molded into a predetermined shape.

(Comparative Example 2)
Concavities and convexities provided on the surfaces of the lower mold 12 and the upper mold 13 that form a space in which the resin composition R flows as shown in FIG. 3B or FIG. Each of which has a substantially right-angled corner, and the amount of the pulverized resin composition loaded into the mold is changed from 75 g to 220 g to produce a plate-shaped preform, and the preform A hot-press molded product was produced in the same manner as in Example 1 except that was hot-press molded.
At this time, the surplus resin composition fills the resin composition flow space formed between the recesses 16a and 16b provided in the upper mold and the lower mold, and the surplus resin composition further includes the lower mold end and the upper mold. It flowed out from the gap G formed between the mold ends.
In the obtained hot-press molded product, an excess portion (burr) formed at a location corresponding to the resin composition flow space or the outer peripheral portion is appropriately cut, cut, and removed, as shown in FIG. A flat plate made of a resin composition having a hollow portion H and a hollow portion h and having a frame shape of 200 mm in length, 300 mm in width, 1.0 mm in thickness, and 0.2 mm in the thinnest wall thickness (frame member for fuel cell) Got.
The obtained resin composition-made flat plate was confirmed to have pores in the cross section when the appearance was observed, and had a mass of 24 g and a density as small as 1.36 g / cm ³ .
The obtained flat plate made of a resin composition has a maximum point stress in a bending fracture test of 90 MPa, strain at break (bending fracture strain) of 1.4%, and 100 Hz in a 5 Hz repeated bending fatigue test with 0.45% applied. The following strength and durability were inferior, and could not be put to practical use as a fuel cell frame member.

(Comparative Example 3)
Concavities and convexities provided on the surfaces of the lower mold 12 and the upper mold 13 that form a space in which the resin composition R flows as shown in FIG. 4B or FIG. Each of which has a substantially right-angled corner, a lower mold outer peripheral side wall 27 is provided on the outer peripheral part of the lower mold 12, and an upper mold outer peripheral part side wall 30 is provided on the outer peripheral part of the upper mold 13. , Except that the amount of the pulverized resin composition loaded into the mold was changed from 75 g to 95 g to prepare a plate-shaped preform, and the preform was hot-press molded, as in Example 1. Thus, a hot-pressed product was produced.

FIG. 4 shows a mold 11 shown in FIGS. 3B and 3C in which a lower mold outer peripheral side wall 27 is provided on the outer peripheral part of the lower mold 12 and an upper mold outer peripheral side wall is provided on the outer peripheral part of the upper mold 13. 4A is a view showing an example of a mold provided with 30, and FIG. 4A is a substantially frame-shaped resin composition flat plate having a hollow portion H to be formed using the mold (a). 4B is a schematic diagram of a cross section of the mold 21 according to this embodiment, and FIG. 4C is a right dotted line portion of the mold 21 shown in FIG. 4B. FIG.
In this example, after filling the thermosetting resin composition R into the resin composition filling recess 24 provided at the center of the lower mold 22 shown in FIG. The lower mold 22 was pressed from above by the provided resin composition pressing convex portion 28. The thermosetting resin composition R filled in the resin composition filling recess 24 is pressed by the upper mold 23 to satisfy the resin composition molding recesses 25a and 25b provided in the lower mold, It flowed in the direction of the end indicated by arrow D. In the mold 21 shown in FIG. 4 (c), the surplus resin composition is formed in the upper mold 23 in order to ensure the fluidity of the resin composition R and form a space for accommodating the surplus resin composition R during pressurization. Recesses 26a, 26b for object storage space formation were provided, and the resin composition R flowed in the end direction while passing through the flow space formed by the recesses 26a, 26b. When the upper mold 23 is pressed to a target position, a desired amount of the resin composition R is filled to the four corners of the resin composition molding recesses 25a and 25b provided in the lower mold 22, and the resin composition R is filled with the upper mold 23. Were pressed by the flat portions 29a and 29b for pressing the resin composition, and hot pressed.

In the obtained hot-press molded product, an excess portion (burr) formed at a location corresponding to the resin composition flow space or the outer peripheral portion is appropriately cut, cut, and removed, as shown in FIG. A flat plate made of a resin composition having a hollow portion H and a hollow portion h and having a frame shape of 200 mm in length, 300 mm in width, 1.0 mm in thickness, and 0.2 mm in the thinnest wall thickness (frame member for fuel cell) Got.
The obtained resin composition-made flat plate was confirmed to have pores in the cross section when the appearance was observed, and had a mass of 25 g and a density of 1.40 g / cm ³ .
In this example, the resin composition was sufficiently filled in the four corners of the resin composition molding recesses 25a and 25b provided in the lower mold, but the obtained resin composition flat plate was observed when the appearance was observed. A void was confirmed in the cross section.
Further, the obtained resin composition flat plate has a maximum point stress in a bending fracture test of 147 MPa, a strain at break (bending fracture strain) of 2.3%, and a 5 Hz repeated bending fatigue test in which 0.45% is applied, and 30,000. It was inferior in strength and durability to less than the number of times, and could not be put to practical use as a fuel cell frame member.

  From Table 1 and the like, the molds of the present invention used in Examples 1 to 3 are simply hot-press molded while improving the raw material yield, suppressing air contamination and uniformly filling the molding material. In addition, by hot-press molding using this mold, the formation of pores due to the mixing of residual air is suppressed, and the molding material is uniformly dispersed, and exhibits excellent strength and durability. It can be seen that a flat plate made of a resin composition can be provided.

  On the other hand, from Table 1, Comparative Example 1 to Comparative Example 3 are formed by hot-press molding using a conventional flash-type compression mold or a mold that does not satisfy the provisions of the present invention. Resin composition having sufficient strength characteristics, such that the four corners of the recesses 15a, 15b are not sufficiently filled with the resin composition (Comparative Example 1), the raw material yield is low, and the productivity is low (Comparative Example 2). It turns out that a product flat plate cannot be obtained (Comparative Example 2 and Comparative Example 3).

  According to the present invention, it is possible to improve the yield of raw materials, suppress air mixing, and provide a mold that can be easily hot-pressure molded while uniformly filling a molding material, and form pores by mixing residual air. Is suppressed, the molding material is uniformly dispersed, and a flat plate made of a resin composition capable of exhibiting excellent strength and durability can be provided.

DESCRIPTION OF SYMBOLS 1 Mold 2 Lower mold 3 Upper mold 4 Resin composition raw material filling recessed part 5 Resin composition molding recessed part 6 Resin composition flow space forming recessed part 7 Lower mold outer peripheral side wall 8 Resin composition pressing convex part 9 Resin composition Object pressing flat part 10 Upper mold outer peripheral side wall

Claims (5)

A mold for producing a substantially frame-shaped resin composition flat plate having a hollow part,
Having a pair of lower and upper molds,
The lower mold has a resin composition raw material filling recess formed in the center, a resin composition molding recess carved into a shape corresponding to the frame shape in the periphery, and the lower mold outer periphery on the outer periphery. The side wall is formed,
The upper mold has a resin composition pressing convex portion formed at a position corresponding to the lower mold resin composition filling concave portion in the center portion, and corresponds to the lower mold resin composition molding concave portion in the peripheral portion thereof. The flat portion for pressing the resin composition is formed at the position to be formed, and the upper mold outer peripheral portion side wall is formed at a position corresponding to the lower mold outer peripheral portion side wall of the outer peripheral portion,
The lower mold and the upper mold are designed to be capable of press-molding a resin composition flat plate while fitting when pressed and allowing the resin composition to flow from the center portion to the outer peripheral portion of the lower mold. And
At least part of the convex portions or concave portions other than the concave portion for molding the resin composition formed on the surface of the lower mold or the surface of the upper mold forming a space in which the resin composition flows, the corners are curved surfaces Formed,
The lower die outer peripheral side wall and the upper die outer peripheral side wall are designed so that a gap of 50 to 150 μm can be formed when the lower die and the upper die are fitted. The substantially frame-shaped resin composition flat plate has a hollow part formed in the frame part,
2. The lower mold is formed by forming an inner peripheral side molding concave portion and an outer peripheral side molding concave portion as a resin composition molding concave portion in the peripheral portion of the resin composition raw material filling concave portion. Mold. A method of producing a substantially frame-shaped resin composition flat plate using the mold according to claim 1 or 2,
A resin composition comprising a thermosetting resin binder and carbonaceous powder, and blending 20 to 100 parts by mass of carbonaceous powder with respect to 100 parts by mass of the thermosetting resin binder,
The resin composition is characterized in that after filling the lower mold resin composition filling recess, the upper mold is fitted and hot press molding is performed at a temperature of 150 to 200 ° C. at 5 to 30 MPa. A method for manufacturing a flat plate.   The method for producing a resin composition flat plate according to claim 3, wherein the resin composition is preformed into a flat plate shape.   The method for producing a resin composition flat plate according to claim 3 or 4, wherein the substantially frame-shaped resin composition flat plate is a fuel cell frame member.

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