WO2011090151A1

WO2011090151A1 - Carbon fiber laminated molded product, and method for producing same

Info

Publication number: WO2011090151A1
Application number: PCT/JP2011/051053
Authority: WO
Inventors: 康岡田; 貴亀山; 啓二長山; 嘉裕有本; 勝弘遊佐
Original assignee: 株式会社クレハ
Priority date: 2010-01-22
Filing date: 2011-01-21
Publication date: 2011-07-28
Also published as: TW201139151A; CN102712168A; JPWO2011090151A1

Abstract

Provided are a carbon fiber laminated molded product and a method for producing same wherein it is possible to improve processability and to reduce the cost of the carbon fiber laminated molded product which can be used as a heat insulating material for high temperature furnaces. The carbon fiber laminated molded product is characterized by comprising a carbon fiber paper, a carbon fiber felt laminate, and a woven layer formed from at least one carbon fiber woven fabric in which a carbon fiber spun yarn is woven. The method for producing the carbon fiber laminated molded product involves: a step (a) for laminating by coating an adhesive and for compression molding at least one carbon fiber woven fabric in which a hybrid carbon fiber spun yarn is woven, a laminate of a carbon fiber felt which is impregnated with a thermosetting resin, and a carbon fiber paper; and a step (b) for firing the compression molded laminate thus obtained.

Description

Carbon fiber laminated molded body and method for producing the same

The present invention relates to a carbon fiber laminated molded body and a method for producing the same. According to the carbon fiber laminated molded body of the present invention, the cost of the carbon fiber laminated molded body that can be used as a high-temperature furnace heat insulating material can be reduced, and the workability can be improved. Moreover, according to the manufacturing method of the present invention, the manufacturing process can be simplified.

Since the carbon fiber laminated molded article has excellent heat insulation performance and low heat capacity characteristics, it is widely used as a heat insulating material for high temperature furnaces such as a single crystal pulling furnace, a vacuum evaporation furnace, or a ceramic sintering furnace. . As the carbon fiber laminate molded body, for example, a carbon fiber felt is impregnated with a resin having a high carbonization rate, and the laminate is compression molded to form a carbon fiber felt laminate, which is obtained by firing the carbon fiber laminate. A shaped body was known. Such a carbon fiber laminated molded body has high heat resistance under an inert atmosphere and can withstand use up to about 3000 ° C.
However, in an actual use environment, oxidizing gas and vaporized metal are generated in the high-temperature furnace, and the carbon fiber laminated molded body may react with them and cause wear and deterioration. In order to solve this problem, a composite carbonaceous heat insulating material (Patent Document 1) having a carbonaceous protective layer on the surface of a carbon fiber laminate molded body, or a woven fabric obtained by weaving carbon fiber spun yarn on a carbon fiber felt laminate. A carbon fiber-containing laminate molded body (Patent Document 2) in which layers are bonded has been proposed. In particular, the fabric layer in the latter carbon fiber-containing laminated molded body has a protective function against damage from external impacts and stresses in addition to a protective action from oxidizing gas and vaporized metal. By adhering to both surfaces of a laminate of fiber felt, a carbon fiber-containing laminate molded article having both sufficient strength and peel resistance can be obtained (Patent Document 2).

However, the carbon fiber laminated molded body is required to reduce the manufacturing cost and improve the workability when used as a heat insulating material, and further improvement is expected.

JP 2000-327441 A International Publication No. 2008/023777

In order to reduce the manufacturing cost, the inventors of the present invention tried to bond a fabric layer made of a single fabric only on the surface in contact with the oxidizing gas or vaporized metal in the laminate of carbon fiber felt. However, at the time of firing, the shrinkage of the fabric layer and the adhesive bonding the fabric layer is higher than the shrinkage of the carbon fiber felt laminate. I knew it would warp.
As a result of diligent research to solve this problem, the present inventors have solved the warpage of the carbon fiber laminated molded body by bonding the carbon fiber paper to the surface opposite to the surface to which the fabric layer is bonded. I found out.

Furthermore, the present inventors have intensively studied on the simplification of the production process in the method for producing a carbon fiber laminated molded body. As a result, the compression molding of the carbon fiber felt laminate, the carbon fiber felt laminate, and the fabric layer are performed. And the bonding of the carbon fiber paper can be performed simultaneously, thereby reducing the manufacturing process and reducing the manufacturing cost. That is, in the Example of Patent Document 2, compression molding and subsequent firing of a carbon fiber felt laminate (base material) as a base material are performed, and a fabric layer is adhered to both surfaces of the obtained base material with an adhesive. Further, compression molding and firing were performed, and the steps of compression molding and firing were performed twice. In the method of the present invention, the compression molding and firing steps are performed once, the production is simplified, and the production cost is reduced.
In addition, in the manufacturing method of the present invention, the present inventors tried to use a fabric layer instead of carbon fiber paper. That is, the fabric layer was adhered to both surfaces of the carbon fiber felt laminate (base material), and an attempt was made to perform the compression molding and firing steps in one time. In this case, since the compression molding of the carbon fiber felt laminate and the subsequent firing are not performed in advance, the upper surface of the carbon fiber felt laminate is in a flexible state. In addition, since the fabric layer is also relatively flexible, when the fabric layer and the carbon fiber felt laminate are coated with an adhesive and compression molded together, especially in the fabric layer laminated on the top surface of the carbon fiber felt laminate. It has been found that wrinkles are formed, the commercial value may be lowered, and the yield is deteriorated. In the present invention, since carbon fiber paper having a relatively high hardness is used on the upper surface of the laminate of carbon fiber felt, wrinkles are not formed on the carbon fiber paper, and the commercial value is not lowered. There was no decrease in yield.
The present invention is based on these findings.

Accordingly, the present invention relates to a carbon fiber laminate molded body comprising a woven fabric layer composed of at least one carbon fiber fabric woven with carbon fiber spun yarn, a carbon fiber felt laminate, and carbon fiber paper.
In a preferred embodiment of the carbon fiber laminate molded body of the present invention, a fabric layer composed of at least one carbon fiber fabric in which the carbon fiber spun yarn is woven, a carbon fiber felt laminate, and carbon fiber paper are laminated in this order.
In a preferred embodiment of the carbon fiber laminated molded body of the present invention, the carbon fiber spun yarn includes a carbon fiber for a core material having an average fiber diameter of 12 μm or less and a carbon fiber for a sheath material having an average fiber diameter of more than 12 μm. It is spun yarn.
Moreover, this invention relates to the heat insulating material for high temperature furnaces which consists of the said carbon fiber laminated molded object.
Further, the present invention provides (a) at least one carbon fiber fabric woven with hybrid carbon fiber spun yarn, a laminate of carbon fiber felt impregnated with a thermosetting resin, and carbon fiber paper by applying an adhesive. It is related with the manufacturing method of a carbon fiber laminated molded object including the process of laminating | stacking and compression-molding, and the process of baking the obtained compression molded laminated body (b).
In a preferred embodiment of the method for producing a raw fiber laminated molded body of the present invention, in the step (a), a woven fabric layer comprising at least one carbon fiber woven fabric woven with carbon fiber spun yarn, a carbon fiber felt laminate, and carbon Fiber paper is laminated in this order.

According to the carbon fiber laminate molded body of the present invention, carbon fiber paper is used instead of one fabric layer as compared with a conventional carbon fiber laminate molded body having a fabric layer on both sides of a carbon fiber felt laminate. Thus, the cost can be reduced.
In addition, the method for producing a carbon fiber laminate molded body of the present invention can be produced by only one compression molding step and firing step, and is produced in comparison with a conventional method for producing a carbon fiber laminate molded body. The number of processes is reduced, and the manufacturing cost can be reduced.
Furthermore, in the method of the present invention, when a woven fabric layer is used instead of carbon fiber paper, that is, the woven fabric layer is laminated with the carbon fiber felt without performing the compression molding step and the firing step of the carbon fiber felt laminate. When bonded to both sides of the body and subjected to the compression molding process, wrinkles were formed particularly in the upper woven fabric layer, resulting in poor yield. In the production method of the present invention, since carbon fiber paper was used, no generation of wrinkles was observed, the commercial value was not decreased, and the yield was not decreased.

It is sectional drawing which shows one embodiment of the carbon fiber laminated molded body of this invention. It is sectional drawing (schematic diagram) which shows one embodiment of the compression molding process in the manufacturing method of the carbon fiber laminated molded body of this invention.

1. Carbon Fiber Laminated Molded Body The carbon fiber laminated molded body of the present invention is characterized by comprising a fabric layer composed of at least one carbon fiber fabric woven with hybrid carbon fiber spun yarn, a carbon fiber felt laminate, and carbon fiber paper. Preferably, the fabric layer, the carbon fiber felt laminate, and the carbon fiber paper are laminated in this order.

[Textile layer]
The carbon fiber fabric constituting the fabric layer in the present invention is not particularly limited as long as the carbon fiber spun yarn is woven. For example, as carbon fiber spun yarn, spun yarn made of polyacrylonitrile (PAN) carbon fiber, spun yarn made of pitch anisotropic carbon fiber, spun yarn made of rayon carbon fiber, pitch isotropic carbon Although the hybrid carbon fiber spun yarn which consists of spun yarn which consists of fibers, or those combination can be mentioned, Especially a hybrid carbon fiber spun yarn is preferable. Examples of the hybrid carbon fiber spun yarn include a hybrid carbon fiber spun yarn described in International Publication No. 2006/090643 and a carbon fiber spun yarn described in International Publication No. 2008/023777.
The carbon fiber spun yarn described in International Publication No. WO 2008/023777 includes a core carbon fiber having an average fiber diameter of 12 μm or less, preferably 5 to 12 μm, and a sheath having an average fiber diameter of more than 12 μm, preferably more than 12 μm to 20 μm. This is a hybrid carbon fiber spun yarn containing carbon fibers for materials. If the average fiber diameter of the carbon fiber for the core material is less than 5 μm, the production efficiency is lowered. On the other hand, when the average fiber diameter of the carbon fiber for sheath material exceeds 20 μm, the tensile strength is lowered or yarn breakage is likely to occur when twisted.

The hybrid carbon fiber spun yarn that can be used in the present invention is preferably a spun yarn in which the carbon fiber for the core material is an anisotropic carbon fiber and the carbon fiber for the sheath material is an isotropic carbon fiber. High tensile strength and high elastic modulus can be realized by the carbon fiber for the core material, and good adhesion to the heat-treated product by the adhesive can be realized by the carbon fiber for the sheath material.

In this specification, the “anisotropic carbon fiber” means a structure in which the tensile strength of the carbon fiber is 1000 MPa or more or the tensile elastic modulus is 100 GPa or more, and the carbon layer surface is selectively oriented in the fiber axis direction. The fiber which has. Specific examples include polyacrylonitrile-based (PAN-based) carbon fibers, pitch-based anisotropic carbon fibers, and rayon-based carbon fibers, and polyacrylonitrile-based (PAN-based) carbon fibers are particularly preferable.

In this specification, the “isotropic carbon fiber” refers to a fiber having a structure in which the tensile strength of the carbon fiber is less than 1000 MPa or the tensile elastic modulus is less than 100 GPa, and the carbon layer surface is not oriented. Pitch based isotropic carbon fibers are preferred.

The carbon fiber for core material usually has a longest fiber length of 20 m or less in the molded body. As a raw material fiber constituting the carbon fiber for core material, an average fiber length of usually 500 mm or more is preferable, more preferably 1000 mm or more, and still more preferably 3 m or more. There is no particular upper limit on the average fiber length of the raw material fibers constituting the carbon fiber for the core material, and it can be appropriately selected from available fiber lengths according to the use. Usually, continuous long fibers of 5000 m or less are industrial. Are available. In spun yarn, as the fiber length used is longer, the joining point between the fibers decreases, so that the strength of the spun yarn can be improved. Moreover, the average fiber length of the raw material fibers constituting the carbon fiber for sheath material is usually less than 500 mm, preferably 300 mm or less, and more preferably 200 mm or less, which is industrially available. Further, carbon fibers having an average fiber length of 150 mm or more and less than 500 mm are contained in an amount of 3 to 30% by mass, preferably 5 to 20% by mass, and carbon fibers having an average fiber length of less than 150 mm are contained in an amount of 97 to 70% by mass, preferably 95 to 80% by mass. Is particularly preferred. If there is too little carbon fiber with an average fiber length of 150 mm or more, the tensile strength of the carbon fiber spun yarn will decrease, and if it is too much, yarn breakage will easily occur in the spinning process, resulting in variations in fineness, resulting in lumps called slabs and flies. It becomes easier and the quality decreases.

Density of the carbon fiber core material is preferably in the range of 1.65 ~ 2.30g / cm ^3, more preferably in the range of ^{1.70 ~ 2.00g / cm 3, 1.70} ~ 1.90g / cm 3 The range of is particularly preferable. If the density of the carbon fiber for the core material is too small, carbonization is insufficient, and if it is too large, the crystallization proceeds too much, and in any case, the strength decreases and the function as a carbon fiber for the core material increases the strength of the fabric. It will be difficult to achieve.

The density of the carbon fiber sheath material is preferably in the range of 1.50 ~ 1.80g / cm ^3, more preferably in the range of ^{1.50 ~ 1.70g / cm 3, 1.55} ~ 1.70g / A range of cm ³ is particularly preferred. If the density of the carbon fiber for the sheath material is too small, carbonization is insufficient and the strength of the carbon fiber is lowered. If the density is too large, the wettability with the resin (adhesive) is deteriorated, and the fabric is adhered to the carbon fiber felt laminate. It becomes difficult to achieve the function as carbon fiber for sheath material.

The ratio of the carbon fiber for the core material to the carbon fiber for the sheath material is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 30% by mass, and more preferably 15% by mass to 15% by mass. 25 mass% is still more preferable. If the blending amount of the carbon fiber for the core material is less than 5% by mass, the strength of the spun yarn may be insufficient, and if it exceeds 50% by mass, the adhesiveness between the spun yarn and the carbon fiber felt laminate decreases. In some cases, the (bending) strength of the molded body cannot be secured.

The mass (fineness) per 1000 m of the carbon fiber spun yarn composed of the carbon fiber for the core material and the carbon fiber for the sheath material is preferably 30 to 1000 tex, more preferably 30 to 750 tex. When the amount is less than the above range, the production cost of spun yarn is required, and when the amount is large, weaving may be difficult. The method for producing the carbon fiber spun yarn is not particularly limited, and a normal method for producing hybrid carbon fiber spun paper can be used. For example, the method described in International Publication No. 2006/090643, and the international method can be used. The method described in Japanese Patent Publication No. 2008/023777 can be used.

The carbon fiber woven fabric used in the present invention can be woven using the carbon fiber spun yarn. For example, a plain weave, a twill weave, a satin weave, or a basket weave can be used using a shuttle loom or a rapier loom.

The basis weight (FAW) in the carbon fiber fabric is preferably 300 to 1200 g / m ² , more preferably 400 to 1000 g / m ^2, and most preferably 600 to 800 g / m ² . A larger basis weight is preferable from the viewpoint of protecting the laminate of carbon fiber felt, but the carbon fiber fabric becomes thicker and the workability is lowered, so that it is preferably within the above range.

In the carbon fiber fabric, the driving density is preferably 15 to 20 / inch, more preferably 16 to 19 / inch in both the warp direction and the weft direction. The driving density in the warp direction and the weft direction may be different, but the same driving density is preferable. The driving density is preferably as high as the basis weight from the viewpoint of protection of the carbon fiber felt laminate, but is preferably within the above range because the carbon fiber fabric becomes thick and the workability decreases.

The thickness of the carbon fiber fabric is preferably 0.3 to 2.0 mm, more preferably 0.6 to 1.5 mm, and most preferably 0.8 to 1.3 mm. The thickness of the carbon fiber fabric is determined by the fineness (tex) of the carbon fiber spun yarn, the driving density of the carbon fiber fabric, and the like. Accordingly, the same thickness as the basis weight is preferred from the viewpoint of protection of the carbon fiber felt laminate, but if it is too thick, the workability is lowered, and therefore it is preferably within the above range.

In the carbon fiber laminated molded body of the present invention, the fabric layer is composed of at least one carbon fiber fabric. The carbon fiber laminated molded body can include two or more carbon fiber fabrics, but a fabric layer composed of one carbon fiber fabric is preferable from the viewpoint of cost reduction. The thickness of the woven fabric layer is preferably 0.3 to 2.0 mm, more preferably 0.6 to 1.5 mm, and most preferably 0.8 to 1.3 mm.

[Carbon fiber felt laminate]
The carbon fiber felt laminate in the carbon fiber laminate molded product of the present invention is a laminate of one or more carbon fiber felts. Specifically, carbon fiber felt impregnated with a resin is laminated and fired after compression molding. The number of layers of the carbon fiber felt is not particularly limited and can be appropriately determined depending on the application. For example, when used as a heat insulating material for a high temperature furnace, it is preferably 1 to 30 layers, and more 2 to 20 layers are preferable, and 4 to 10 layers are more preferable.

Further, the thickness of the carbon fiber felt laminate varies depending on the application and is not particularly limited. However, when the molded article of the present invention is used as a heat insulating material for a high temperature furnace, a range of usually 5 to 300 mm is preferable. A range of 10 to 150 mm is more preferable. It is because productivity will fall when the thickness of a carbon fiber felt laminated body is too thick, and heat insulation will fall when too thin.

The bulk density of the carbon fiber felt laminate is preferably in the range of 0.05 to 0.40 g / cm ³ , and more preferably in the range of 0.10 to 0.30 g / cm ³ . If it is less than 0.05 g / cm ^3, it reduces the heat insulating property, when it exceeds 0.40 g / cm ^3, productivity is lowered because the molding pressure is increased.

The carbon fiber constituting the carbon fiber felt preferably has an average fiber diameter of 5 to 20 μm, more preferably 8 to 18 μm. If it is less than 5 μm, the production efficiency may decrease, and if it exceeds 20 μm, the heat insulation may decrease. The fiber length of the carbon fibers constituting the carbon fiber felt is preferably in the range of 30 to 500 mm, more preferably in the range of 50 to 250 mm. If it is less than 30 mm, the bending strength of the carbon fiber felt laminate may be weak, and if it exceeds 500 mm, it is difficult to uniformly disperse the fibers and it may be difficult to make a uniform felt. Examples of the carbon fibers constituting the carbon fiber felt include pitch-based isotropic carbon fibers, polyacrylonitrile-based (PAN-based) carbon fibers, rayon-based carbon fibers, and quinol carbon fibers. Carbon fiber is preferred.

Carbon fiber felt can be obtained by needle punching the carbon fiber. The thickness of the carbon fiber felt is preferably 5 to 30 mm, more preferably 10 to 30 mm. The carbon content of the carbon fiber felt is preferably 80% or more, more preferably 90% or more, and most preferably 95% or more.

[Carbon fiber paper]
Carbon fiber paper made by adding a binder to short carbon fibers, or carbon fiber paper obtained by impregnating a resin into the obtained carbon fiber paper and firing it, can be used.

As the carbon short fibers used in the carbon fiber paper, polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, or rayon-based carbon fibers can be used without particular limitation, but pitch-based carbon fibers are preferable.

The average fiber length of the short carbon fibers is preferably 1 to 10 mm. If the average fiber length of the short carbon fibers is shorter than 1 mm, the number of fibers that are lost in the paper making process may increase, and the product yield may be reduced. If the average fiber length of the short carbon fibers is longer than 10 mm, the dispersion may be poor in the dispersion step, and a mass portion may be generated, so that the quality may be deteriorated. The average fiber diameter of the short carbon fibers is preferably 5 to 20 μm. When the average fiber diameter of the short carbon fibers is smaller than 5 μm, the production cost may be increased. When the average fiber diameter of the short carbon fibers is larger than 20 μm, the paper strength is lowered and the quality may be lowered.

Examples of the binder include polyvinyl alcohol, polyacrylonitrile, cellulose, and polyvinyl acetate, but polyvinyl alcohol (PVA) is preferable because it has excellent binding power in the paper making process and less carbon short fibers are removed. . The binder is preferably used in an amount of 5 to 50 parts by mass with respect to 100 parts by mass of the carbon fiber.

Examples of the paper making method for carbon fiber paper include a wet method in which carbon short fibers are dispersed in a liquid medium and paper making, and a dry method in which carbon short fibers are dispersed in air to deposit them. In order to mix uniformly, a wet method is preferable.

Examples of the resin used for the carbon fiber paper include a phenol resin, a furan resin, an epoxy resin, a melamine resin, an imide resin, a urethane resin, an aramid resin, a pitch, and the like, or a mixture thereof.
The amount of the resin with respect to the carbon fiber paper is preferably impregnated with 1 to 120 resin with respect to 100 parts by mass of the short carbon fiber and fired.

The basis weight of the carbon fiber paper is preferably 20 to 60 g / m ² , and more preferably 30 to 50 g / m ² . If it is less than 20 g / m ² , the strength in the wet paper state (state before drying and binder curing) may be low. If it exceeds 60 g / m ² , the weight in the wet paper state becomes heavy, This is because it may be damaged.

2. Method for Producing Carbon Fiber Laminated Molded Body A method for producing a carbon fiber laminated molded body according to the present invention includes: (a) at least one carbon fiber fabric woven with hybrid carbon fiber spun yarn; carbon fiber felt impregnated with thermosetting resin And a step of laminating and compression-molding the carbon fiber paper by application of an adhesive, and (b) firing the obtained compression-molded laminate, preferably a carbon fiber fabric, carbon fiber A felt laminate and carbon fiber paper are laminated in this order.
In the method for producing a carbon fiber laminated molded body of the present invention, the carbon fiber fabric to be used is a carbon fiber fabric in which the hybrid carbon fiber spun yarn is woven, and one or two or more carbon fiber fabrics are used. it can. When two or more carbon fiber fabrics are used, the respective carbon fiber fabrics are bonded using an adhesive.
The carbon fiber felt is obtained by needle punching carbon fibers. One or more carbon fiber felts are impregnated with a thermosetting resin and laminated to be used as a laminate.
The carbon fiber paper may be an organic binder carbon fiber paper made by adding a binder to short carbon fibers as described above, or a carbon binder carbon fiber paper obtained by impregnating and firing a resin. it can.

Since the adhesive used in the production method of the present invention is carbonized by firing, it preferably contains a large amount of carbon, but is not particularly limited by the carbon content.
Specifically, 60 to 100 parts by mass of thermosetting prepolymer, 20 to 60 parts by mass of thermosetting resin; 5 to 20 parts by mass of short carbon fiber, carbon black, carbon powder or graphite powder; An adhesive composition in which 5 parts by mass of water and 5 to 20 parts by mass of water are uniformly mixed and dispersed can be used.

As thermosetting prepolymers, urea resin prepolymers; melamine resin prepolymers, urea-modified melamine resin prepolymers; guanamine resin prepolymers; guanamine-modified melamine resin prepolymers; furan resin prepolymers; alkyd resin prepolymers; Polymers such as novolac type phenol resin prepolymers, resol type phenol resin prepolymers, novolac type alkyl phenol resin prepolymers, resol type alkylphenol resin prepolymers and their xylene / formaldehyde condensates, toluene / formaldehyde condensates, or melamine resins, guanamines Modified resin prepolymer with resin or urea resin; epoxy resin prepolymer such as bisphenol A diglycidyl ether, alicyclic Diglycidyl ethers of alcohols, bisphenol A bis (alpha-methyl glycidyl ether), alicyclic dialcohol bis (alpha-methylglycidyl d - ether), and the like preferably. You may mix a hardening | curing agent, a hardening catalyst, etc. as needed. Among these, a resin prepolymer having a high carbonization yield is preferable, and a novolak type phenol resin prepolymer, a resol type phenol resin prepolymer, a novolac type alkylphenol resin prepolymer, and a resol type alkylphenol resin prepolymer can be particularly preferably used.
Thermosetting resins include urea resins; melamine resins; urea-modified melamine resins; guanamine resins; guanamine-modified melamine resins; alkyd resins; furan resins; unsaturated polyester resins; phenol resins such as novolak-type phenol resins and resol-type phenol resins. , Novolac-type alkylphenol resins, resol-type alkylphenol resins; epoxy resins such as bisphenol A diglycidyl ether, alicyclic dialcohol diglycidyl ether, bisphenol A bis (α-methylglycidyl ether), alicyclic dialcohol bis ( Preferred examples include α-methyl glycidyl ether). Among these, resins having a high carbonization yield are preferable, and novolak-type phenol resins, resol-type phenol resins, novolac-type alkylphenol resins, and resol-type alkylphenol resins can be particularly preferably used.
As the solvent, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, 2-furylmethanol, toluene, xylene, dimethyl sulfoxide, or the like can be preferably used.

The adhesive is used to bond a laminate of carbon fiber fabric and carbon fiber felt, and a laminate of carbon fiber felt and carbon fiber paper. The amount of adhesive used between them is preferably 500 to 3000 g / m ^2, more preferably 1000 to 2500 g / m ^{2, and} more preferably 1200 to 2200 g / m ² with respect to the carbon fiber woven fabric or carbon fiber felt laminate. ² is most preferred. This is because if it is less than 500 g / m ² , the adhesive strength becomes weak, and if it exceeds 3000 g / m ² , the adhesive is cured after firing, and the workability of the carbon fiber laminate molded article is deteriorated.
As a method for applying the adhesive, a normal method can be used. For example, the adhesive can be applied with a spatula, a brush, or a roller.

Examples of the thermosetting resin impregnated in the carbon fiber felt include urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester resin, alkyd resin, urethane resin, furan resin, etc., but the carbonization yield is high. Phenol resin is preferred.

The carbon fiber felt is impregnated with the resin, and the number of sheets necessary for the intended use is laminated to prepare a carbon fiber felt laminate. The impregnation amount of the resin is preferably 10 to 100 parts by mass, more preferably 15 to 50 parts by mass with respect to 100 parts by mass of the carbon fiber felt.

[Compression molding process]
The compression molding step in the production method of the present invention will be described with reference to FIG.
In the compression molding step, the carbon fiber fabric (12) is set on the stainless steel plate (23) on the lower surface of the compression molding apparatus (2), and a predetermined amount of adhesive (25) is applied to the carbon fiber fabric. . When two or more carbon fiber fabrics are used, the second carbon fiber fabric is laminated, and a predetermined amount of adhesive is applied to the upper surface thereof. One or more carbon fiber felts (14) impregnated with a thermosetting resin are laminated on the carbon fiber woven fabric to form a carbon fiber felt laminate (13). A predetermined amount of adhesive (25) is applied to the uppermost surface of the carbon fiber felt laminate, and the carbon fiber paper (10) is laminated. The resulting carbon fiber fabric, carbon fiber felt laminate, and laminate made of carbon fiber paper are compression molded at a pressure and temperature at which the thermosetting resin impregnated in the carbon fiber felt laminate is cured, and thermoset. The resin and the adhesive can be cured to obtain a compression molded body.
In order to make a laminate comprising a carbon fiber woven fabric, a carbon fiber felt laminate, and a carbon fiber paper into a compression molded article having a target thickness, after arranging a spacer (22) having a target thickness around the laminate, By compression molding, the thickness of the compression molded body can be adjusted. Moreover, it is possible to adjust the bulk density of the carbon fiber felt laminate by adjusting the thickness of the compression molded body.

The pressure in the compression molding step is not particularly limited as long as the above-mentioned spacer is used. For example, the pressure can be 0.1 to 1 MPa. The temperature of the hot press plate is not particularly limited as long as the thermosetting resin impregnated in the carbon fiber felt is cured. For example, it can be performed at 150 to 200 ° C. Further, the compression molding time can be appropriately determined, but can be performed, for example, in 10 minutes to 5 hours.
In addition, in this specification, a carbon fiber felt laminated body means what was impregnated and laminated | stacked with resin, and means both the thing before compression molding and the thing after compression molding.

[Baking process]
The firing step in the production method of the present invention can be performed at 3000 ° C. or less in a non-oxidizing atmosphere. Examples of the non-oxidizing atmosphere include a vacuum state, a nitrogen atmosphere, and an argon atmosphere. The temperature is not particularly limited as long as carbonization occurs.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.
In the examples, the physical properties of the spun yarn fabric were measured by the following methods.
[Tensile strength of spun yarn fabric]
When a spun yarn fabric is pulled with a Tensilon universal testing machine ("Orientec Co., Ltd.," RTC-1310 ") under the conditions of a load cell rating of 10 kN, a sample length of 150 mm, a sample width of 50 mm, and a tensile speed of 200 mm / min. The tensile strength of the spun yarn fabric was defined as a value obtained by converting the breaking strength of 1 to 1 cm of the sample width.
[Thickness of spun yarn fabric]
A sample was cut into a 100 mm × 100 mm square at an inner side of 30 mm or more from the end of the spun yarn fabric, and the central portion was measured with a micrometer (manufactured by Mitutoyo Corporation, U-shaped micrometer “PMU 150-2”). The thickness of the spun yarn fabric was used.

Example 1
[Manufacture of carbon fiber fabrics]
A carbon fiber spun yarn composed of 20% by mass of a PAN-based carbon fiber core and 80% by mass of a pitch-based carbon fiber sheath is twilled as warp and weft to create a spun yarn fabric (twill weave, FAW 700 g / m ^2). The driving density was 17.0 lines / inch in the warp direction and 17.0 lines / inch in the weft direction, the tensile strength was 0.32 kN, and the thickness was 1.0 mm.

[Adhesive adjustment]
As an adhesive for bonding a spun yarn fabric and a carbon fiber felt laminate, and a carbon fiber felt laminate and carbon fiber paper, a phenol resin-based impregnating liquid [Showa High Polymer Co., Ltd., “Showonol BRS-3897”] 15 Parts by mass, powdered phenol resin [manufactured by Cashew Co., Ltd., “Cashew Resin No. 05”], carbon short fiber [manufactured by Kureha Co., Ltd., Kureka Chop M-107T, average fiber length 0.7 mm, L / D≈39] 10 parts by mass, 2-furylmethanol [manufactured by Junsei Chemical Co., Ltd., grade 1] 10 parts by mass, ethanol mixed solution [manufactured by Nippon Alcohol Sales Co., Ltd., “Solmix H-23”] 40 parts by mass Parts were mixed and dispersed uniformly to prepare an adhesive.

<Compression molding process>
Pitch-based carbon fiber felt (manufactured by Kureha Co., Ltd., “Klecafert F-110”) in 100 parts by mass, phenol resin-based impregnating solution (Showa High Polymer Co., Ltd., “Shonol BRS-3896”) in 44 parts by mass Was impregnated and 6 layers were laminated in a flat plate shape to produce a carbon fiber felt laminate.
The carbon fiber fabric was set in a compression molding apparatus, and the adhesive was applied with a brush at a basis weight of 1200 g / m ² . A carbon fiber felt laminate was laminated on the carbon fiber fabric without applying pressure. Further, the adhesive was applied to the top surface of the carbon fiber felt laminate with a brush at a basis weight of 1200 g / m ² . Carbon fiber paper (manufactured by Kureha Co., Ltd., “Kureka Paper E-204”) soaked in 15 parts by mass of a phenol resin-based impregnating solution (Showa High Polymer Co., Ltd., “Shonol BRS-3896”) was laminated.
A spacer for adjusting the thickness of the target compression molded product to 40 mm is arranged around the formed carbon fiber fabric, carbon fiber felt laminate, and carbon fiber paper laminate, and then compressed and heated. The resin was cured to obtain a compression molded body.

<< Baking process >>
The compression-molded body obtained was graphitized in a vacuum nitrogen atmosphere at 2000 ° C. for 1 hour, and a flat plate shape in which a fabric layer was laminated on one side of a carbon fiber felt laminate and carbon fiber paper was laminated on the other side. A carbon fiber laminate molded body was obtained.

Example 2
Except for using spun yarn fabric (Twill weave, FAW785g / m ² , driving density warp direction 18.0 / inch and weft direction 18.0 / inch, tensile strength 0.34kN, thickness 1.1mm) A carbon fiber-containing laminate molded body was obtained in the same manner as in Example 1.

Example 3
Except for using spun yarn fabric (twill weave, FAW 700 g / m ² , driving density warp direction 16.0 pieces / inch and weft direction 18.0 pieces / inch, tensile strength 0.32 kN, thickness 1.0 mm) A carbon fiber-containing laminate molded body was obtained in the same manner as in Example 1.
In any of the carbon fiber-containing laminate moldings of Examples 1 to 3, the spun yarn fabric layer was flat and no wrinkles were observed. Also, there were no problems such as warping.

The carbon fiber-containing laminated molded body of the present invention can be used as a heat insulating material for a high temperature furnace such as a crystal pulling furnace, a vacuum evaporation furnace, or a ceramic sintering furnace.
As mentioned above, although this invention was demonstrated along the specific aspect, the deformation | transformation and improvement obvious to those skilled in the art are included in the scope of the present invention.

1 ... Carbon fiber laminated molded body;
10 ... carbon fiber paper;
11 ... carbon fiber felt laminate;
12 ... carbon fiber fabric;
13 ... carbon fiber felt laminate;
14 ... carbon fiber felt;
2 ... compression molding apparatus;
21 ... Hot press plate (upper surface);
22 ... spacer;
23 ... stainless steel plate;
24 ... hot press plate (lower surface);
25: Adhesive.

Claims

A carbon fiber laminate molded body comprising a woven fabric layer composed of at least one carbon fiber fabric woven from carbon fiber spun yarn, a carbon fiber felt laminate, and carbon fiber paper.
The carbon fiber laminate molded product according to claim 1, wherein a fabric layer composed of at least one carbon fiber fabric woven from the carbon fiber spun yarn, a carbon fiber felt laminate, and carbon fiber paper are laminated in this order.
The carbon according to claim 1 or 2, wherein the carbon fiber spun yarn is a hybrid carbon fiber spun yarn including carbon fibers for a core material having an average fiber diameter of 12 µm or less and carbon fibers for a sheath material having an average fiber diameter exceeding 12 µm. Fiber laminated molded body.
A heat insulating material for a high temperature furnace comprising the carbon fiber laminated molded body according to any one of claims 1 to 3.
(A) At least one carbon fiber fabric woven with hybrid carbon fiber spun yarn, a laminate of carbon fiber felt impregnated with a thermosetting resin, and carbon fiber paper are laminated by applying an adhesive and compression-molded. A step, and (b) a step of firing the obtained compression-molded laminate,
A method for producing a carbon fiber laminated molded body comprising
6. The carbon fiber laminate according to claim 5, wherein in the step (a), a fabric layer made of at least one carbon fiber fabric woven with carbon fiber spun yarn, a carbon fiber felt laminate, and carbon fiber paper are laminated in this order. Manufacturing method of a molded object.