CN102712168A - Carbon fiber laminated body and preparation method thereof - Google Patents

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 body and preparation method thereof

technical field

The invention relates to a carbon fiber laminated body and a preparation method thereof. According to the carbon fiber laminated product of the present invention, the cost of the carbon fiber laminated product usable as a heat insulating material for a high-temperature furnace can be reduced, and workability can be improved. In addition, according to the preparation method of the present invention, the preparation process can be simplified.

Background technique

Carbon fiber laminated products are widely used as heat insulating materials for high-temperature furnaces such as single crystal pulling furnaces, vacuum evaporation furnaces, and ceramic sintering furnaces due to their excellent heat insulation performance and low heat capacity. As the above-mentioned carbon fiber laminated product, for example, carbon fiber felt is known to be impregnated with a resin with a high carbonization rate, and the laminated product is compression-molded to form a carbon fiber felt laminate, and the carbon fiber obtained by calcining it is known. Laminated molding. Such a carbon fiber laminated molded body has high heat resistance in an inert atmosphere and can withstand use up to about 3000°C.

However, in the actual use environment, oxidizing gases or vaporized metals are often generated in the high-temperature furnace, and the carbon fiber laminated molded body reacts with them to cause consumption and deterioration. In order to solve this problem, a composite carbonaceous heat insulating material (patent document 1) with a carbonaceous protective layer on the surface of a carbon fiber laminated molded body is proposed, or a carbon fiber mat woven by carbon fiber yarn is bonded on a laminated body of carbon fiber felt. A carbon fiber-containing laminated molded product of a fabric layer (Patent Document 2). Especially the fabric layer in the latter carbon fiber-containing laminated body, in addition to protecting it from oxidizing gases or gasified metals, also has a function of preventing damage from external impact and stress. As a protective function, by bonding to both sides of a carbon fiber mat laminate, a carbon fiber-containing laminate molded product having both sufficient strength and peeling resistance can be obtained (Patent Document 2).

However, there are demands for reduction of production cost and improvement of workability when used as a heat insulating material in the carbon fiber laminated molded body, and further improvement is expected.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2000-327441

Patent Document 2: International Publication No. 2008/023777.

Contents of the invention

The problem to be solved by the invention

In order to reduce the production cost, the present inventors tried to bond a fabric layer comprising a fabric only on the surface contacting the oxidizing gas or vaporized metal in the laminated body of the carbon fiber felt. However, since the shrinkage of the fabric layer and the adhesive bonding it during firing is higher than that of the carbon fiber felt laminate, it can be seen that the bonding surface side of the fabric layer shrinks more and the carbon fiber laminate molded body warps. .

As a result of intensive research to solve this problem, the present inventors have found that the warping of the carbon fiber laminated molded body can be eliminated by bonding carbon fiber paper to the surface opposite to the surface to which the fabric layer is bonded.

In addition, the present inventors have intensively studied the simplification of the production process in the production method of the carbon fiber laminated body, and found that the compression molding of the carbon fiber felt laminate and the carbon fiber felt laminate, the fabric layer, and the carbon fiber paper can be performed simultaneously. The bonding can reduce the preparation process and reduce the preparation cost. That is, in the examples of Patent Document 2, the steps of compression molding and firing are performed twice respectively: compression molding of a carbon fiber felt laminate (substrate) as a base material and subsequent firing are performed, and the fabric is bonded by an adhesive. Layers were bonded to both sides of the obtained substrate, which was further subjected to compression molding and calcination. In the method of the present invention, the steps of compression molding and calcination are performed once, the preparation is simplified, and the preparation cost is reduced.

It should be noted that the inventors tried to use a fabric layer instead of carbon fiber paper in the preparation method of the present invention. That is, an attempt was made to bond fabric layers to both surfaces of a carbon fiber felt laminate (substrate), and perform compression molding and firing at one time. At this time, the upper surface of the carbon fiber felt laminate is in a soft state because the compression molding of the carbon fiber felt laminate and the subsequent firing are not performed in advance as conventionally done. In addition, it has been found that since the fabric layer is relatively soft, if the fabric layer and the carbon fiber felt laminate are coated with an adhesive and then compression-molded together, wrinkles are often formed especially in the fabric layer laminated on the upper surface of the carbon fiber felt laminate. , the value of the product decreases, and the yield becomes worse. In the present invention, since the carbon fiber paper with high hardness is used on the carbon fiber felt laminate, no wrinkles are formed on the carbon fiber paper, the commercial value is not lowered, and the yield rate is not lowered.

The present invention has been accomplished based on such knowledge.

means of solving problems

Therefore, the present invention relates to a carbon fiber laminated product characterized by comprising: a fabric layer comprising at least one carbon fiber fabric woven from carbon fiber yarns, a carbon fiber felt laminate, and carbon fiber paper.

In a preferred embodiment of the carbon fiber laminated molded product of the present invention, the fabric layer comprising at least one carbon fiber fabric woven from carbon fiber yarn, the carbon fiber felt laminate, and the carbon fiber paper are laminated in this order.

In a preferred embodiment of the carbon fiber laminated molded article of the present invention, the carbon fiber yarn is a hybrid carbon fiber yarn containing 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.

Moreover, this invention relates to the heat insulating material for high temperature furnaces containing the said carbon fiber laminated body.

In addition, the present invention relates to a method for preparing a carbon fiber laminated body, the preparation method comprising: (a) at least one carbon fiber fabric woven from mixed carbon fiber yarns, a laminate of carbon fiber felt impregnated with a thermosetting resin, and carbon fiber A process of laminating the paper by applying an adhesive, compression molding, and (b) a process of calcining the obtained compression-molded laminate.

In a preferred embodiment of the method for preparing a carbon fiber laminated molded body of the present invention, in the above step (a), a fabric layer comprising at least one carbon fiber fabric woven from carbon fiber yarn, a carbon fiber felt laminate, and a carbon fiber Papers are laminated in this order.

The effect of the invention

According to the carbon fiber laminated product of the present invention, compared with the conventional carbon fiber laminated product having fabric layers on both sides of the carbon fiber felt laminate, cost can be reduced by using carbon fiber paper instead of one fabric layer.

In addition, with regard to the production method of the carbon fiber laminated body of the present invention, the compression molding process and the calcination process can be produced only once, and compared with the preparation method of the existing general carbon fiber laminated body, the preparation can be reduced. process, reducing preparation costs.

In addition, in the method of the present invention, when the fabric layer is used instead of the carbon fiber paper, that is, the compression molding process and the calcination process of the carbon fiber felt laminate are not performed, and the fabric layer is bonded to both sides of the carbon fiber felt laminate, During the compression molding process, especially in the upper fabric layer, wrinkles are formed, and the yield is deteriorated. In the preparation method of the present invention, since the carbon fiber paper is used, no wrinkles are observed, the commodity value is not lowered, and the yield rate is not lowered.

Description of drawings

[FIG. 1] A cross-sectional view showing one embodiment of the carbon fiber laminated molded body of the present invention.

[ Fig. 2 ] A cross-sectional view (schematic diagram) showing one embodiment of the compression molding step in the method for producing a carbon fiber laminated molded article of the present invention.

Detailed ways

1. Carbon fiber laminated molded body

The carbon fiber laminated product of the present invention is characterized in that it comprises: a fabric layer comprising at least one carbon fiber fabric woven from mixed carbon fiber yarns, a carbon fiber felt laminate, and carbon fiber paper; preferably the fabric layer, the carbon fiber felt laminate, and Carbon fiber paper is laminated in this order.

[fabric layer]

The carbon fiber fabric constituting the fabric layer in the present invention is not particularly limited as long as it is a carbon fiber fabric woven from carbon fiber yarn. For example, as carbon fiber yarns, yarns containing polyacrylonitrile-based (PAN-based) carbon fibers, yarns containing pitch-based anisotropic carbon fibers, yarns containing rayon-based carbon fibers, yarns containing pitch-based isotropic carbon fibers, or A hybrid carbon fiber yarn comprising a combination thereof, particularly preferably a hybrid carbon fiber yarn. Examples of the hybrid carbon fiber yarn include the hybrid carbon fiber yarn described in International Publication No. 2006/090643 and the carbon fiber yarn described in International Publication No. 2008/023777.

The carbon fiber yarn described in International Publication No. 2008/023777 is one containing carbon fibers for a core material with an average fiber diameter of 12 μm or less, preferably 5 to 12 μm, and carbon fibers for a sheath material with an average fiber diameter of more than 12 μm, preferably more than 12 μm but 20 μm or less. Hybrid carbon fiber yarn. When the average fiber diameter of the carbon fiber for core materials is less than 5 micrometers, production efficiency will fall. Moreover, when the average fiber diameter of the carbon fiber for sheath materials exceeds 20 micrometers, tensile strength will fall, and it will become easy to generate|occur|produce thread breakage at the time of twisting.

The hybrid carbon fiber yarn usable in the present invention is preferably a yarn in which the carbon fibers for the core material are anisotropic carbon fibers, and the carbon fibers for the sheath material are isotropic carbon fibers. High tensile strength and high modulus of elasticity can be realized by the carbon fiber for the core material, and good adhesion to the heat-treated object can be realized by the adhesive agent by the carbon fiber for the sheath material.

In this specification, "anisotropic carbon fiber" refers to a carbon fiber having a tensile strength of 1000 MPa or more or a tensile modulus of 100 GPa or more and a structure in which carbon layers are selectively oriented in the fiber axis direction. Specifically, polyacrylonitrile-based (PAN-based) carbon fibers, pitch-based anisotropic carbon fibers, or rayon-based carbon fibers are exemplified, and polyacrylonitrile-based (PAN-based) carbon fibers are particularly preferred.

In this specification, "isotropic carbon fiber" refers to a carbon fiber having a tensile strength of less than 1000 MPa or a tensile modulus of less than 100 GPa and a structure in which the carbon layers are not oriented, and pitch-based isotropic carbon fibers are particularly preferred.

The above-mentioned carbon fiber for a core material usually has a longest fiber length of 20 m or less in the molded article. The raw material fiber constituting the carbon fiber for core material generally has an average fiber length of preferably 500 mm or more, 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, and it can be appropriately selected from available fiber lengths according to the application, but continuous long fibers of 5000 m or less are usually industrially obtained. In the yarn, as the length of the fibers used is longer, the joining points of the fibers decrease, so the strength of the yarn can be increased. In addition, the average fiber length of the raw material fibers constituting the carbon fiber for sheath material is generally less than 500 mm industrially available, preferably 300 mm or less, more preferably 200 mm or less. In addition, it is particularly preferable to contain 3 to 30% by mass, preferably 5 to 20% by mass of carbon fibers with an average fiber length of 150 mm or more and less than 500 mm, and to contain 97 to 70% by mass, preferably 95 to 80% by mass of carbon fibers of less than 150 mm. If there are too few carbon fibers with an average fiber length of 150mm or more, the tensile strength of the carbon fiber yarn will decrease. If it is too much, it will easily cause thread breakage in the spinning process, and deviations in denier will easily occur, which are called slubs and flying flowers. The blocky part, the quality is reduced.

The density of the carbon fiber for core material is preferably in the range of 1.65 to 2.30 g/cm ³ , more preferably in the range of 1.70 to 2.00 g/cm ³ , and particularly preferably in the range of 1.70 to 1.90 g/cm ³ . If the density of the carbon fiber for the core is too small, the carbonization will be insufficient, and if it is too large, it will be excessively crystallized, and in either case the strength will decrease, making it difficult to achieve the function of the carbon fiber for the core to reinforce the strength of the fabric.

In addition, the density of the carbon fibers for the sheath material is preferably in the range of 1.50 to 1.80 g/cm ³ , more preferably in the range of 1.50 to 1.70 g/cm ³ , and particularly preferably in the range of 1.55 to 1.70 g/cm ³ . If the density of the carbon fiber for the sheath material is too small, the carbonization will be insufficient, and the strength of the carbon fiber will decrease. The sheath material on the pressed body is made of carbon fiber.

In terms of the ratio of the carbon fiber for the core material to the carbon fiber for the sheath material, the blending amount of the carbon fiber for the core material is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 30% by mass, and even more preferably 15% by mass ~25% mass. If the blending amount of the carbon fiber for the core material is less than 5% by mass, the strength of the yarn may be insufficient, and if it exceeds 50% by mass, the adhesion between the yarn and the carbon fiber mat laminate may decrease, resulting in failure to secure a molded product. (bending) strength.

The mass (fineness) per 1000 m of the carbon fiber 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. If it is less than the above range, the production cost of the yarn will be consumed, and if it is more than the above range, weaving may become difficult. The method for preparing carbon fiber yarn is not particularly limited, and conventional methods for preparing hybrid carbon fiber yarn can be used, for example, the method described in International Publication No. 2006/090643 and the method described in International Publication No. 2008/023777 can be used.

The above-mentioned carbon fiber yarn can be used to weave the carbon fiber fabric used in the present invention. For example, a shuttle loom or a rapier loom can be used to make fabrics such as plain weave, twill weave, satin weave or basket weave.

The basis weight (FAW) of 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 . From the viewpoint of protecting the carbon fiber felt laminate, it is preferable that the basis weight is high, but since the carbon fiber fabric becomes thick and the processability decreases, it is preferable to set it within the above range.

In the carbon fiber fabric, the yarn count density (打ち込み density) is preferably 15 to 20 yarns/inch in both the warp and weft directions, and more preferably 16 to 19 yarns/inch. The thread count densities in the warp and weft directions can also be different, but preferably have the same thread count density. From the viewpoint of protecting the carbon fiber felt laminate, it is preferable that the yarn count density is high as in the basis weight, but since the carbon fiber fabric becomes thicker and the processability decreases, it is preferable to set it within the above range.

The thickness of the carbon fiber fabric is preferably 0.3-2.0 mm, more preferably 0.6-1.5 mm, most preferably 0.8-1.3 mm. The thickness of the carbon fiber fabric is determined by the fineness (tex) of the carbon fiber yarn and the yarn count density of the carbon fiber fabric. Therefore, from the viewpoint of protecting the carbon fiber felt laminate, it is preferable to have a thick thickness as in the basis weight. However, if it is too thick, workability will be reduced, so it is preferable to set it within the above-mentioned range.

The fabric layer in the carbon fiber laminated molded article of the present invention contains at least one carbon fiber fabric. Although the carbon fiber laminated molded article may contain two or more types of carbon fiber fabrics, it is preferable to include a fabric layer of one type of carbon fiber fabric from the viewpoint of cost reduction. The thickness of the fabric layer is preferably 0.3-2.0 mm, more preferably 0.6-1.5 mm, most preferably 0.8-1.3 mm.

[Carbon fiber felt laminate]

In the carbon fiber laminated molded body of the present invention, the carbon fiber felt laminate is formed by laminating one or more types of carbon fiber felts. Specifically, resin-impregnated carbon fiber mats are laminated, compression-molded, and then calcined. The number of layers of carbon fiber felt is not particularly limited, and can be appropriately determined according to its use. For example, when used as a heat insulating material for a high-temperature furnace, it is preferably 1 to 30 layers, more preferably 2 to 20 layers, and even more preferably 4 to 10 layers. .

In addition, the thickness of the carbon fiber felt laminate also varies depending on the application and is not particularly limited. However, when the molded body of the present invention is used as a heat insulating material for a high-temperature furnace, it is usually preferably in the range of 5 to 300 mm, and more preferably 10 to 150 mm. scope. The reason for this is that if the thickness of the carbon fiber felt laminate is too thick, the productivity will decrease, and if it is too thin, the heat insulation performance will decrease.

The bulk density of the carbon fiber felt laminate is preferably in the range of 0.05 to 0.40 g/cm ³ , more preferably in the range of 0.10 to 0.30 g/cm ³ . If it is less than 0.05 g/cm ³ , the thermal insulation performance will decrease, and if it exceeds 0.40 g/cm ³ , the molding pressure will increase, so the productivity will decrease.

The carbon fibers constituting the carbon fiber mat preferably have an average fiber diameter of 5 to 20 μm, and carbon fibers having 8 to 18 μm can be used more preferably. If it is less than 5 μm, the production efficiency may decrease, and if it exceeds 20 μm, the heat insulating property may decrease. In addition, the fiber length of the carbon fibers constituting the carbon fiber mat 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 mat laminate may be weak, and if it exceeds 500 mm, it may be difficult to uniformly disperse the fibers and it may be difficult to prepare a uniform mat. As the carbon fibers constituting the carbon fiber mat, pitch-based isotropic carbon fibers, polyacrylonitrile-based (PAN-based) carbon fibers, rayon-based carbon fibers, or Kynol (Kynol, Kainol) carbon fibers, etc., are preferably pitch-based isotropic carbon fibers. .

The carbon fiber felt can be obtained by needle-punching the above-mentioned carbon fibers. The thickness of the carbon fiber felt is preferably 5-30 mm, more preferably 10-30 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 obtained by adding a binder to short carbon fibers for papermaking, or carbon fiber paper obtained by further impregnating a resin and carbonizing the binder by firing can be used.

As the short carbon 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 preferred.

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, protruding fibers in the papermaking process may increase and the product yield may decrease. If the average fiber length of the short carbon fibers is longer than 10 mm, the quality of the short carbon fibers tends to deteriorate due to poor dispersion in the dispersion process and lumpy parts. 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 less than 5 μm, the production cost tends to increase. When the average fiber diameter of the short carbon fibers exceeds 20 μm, the quality of the paper tends to decrease due to a decrease in paper strength.

Examples of binders include polyvinyl alcohol, polyacrylonitrile, cellulose, and polyvinyl acetate, but polyvinyl alcohol (PVA) has excellent adhesion in the papermaking process and less shedding of short carbon fibers. And preferred. It is preferable to use 5-50 mass parts of binders with respect to 100 mass parts of carbon fibers.

Papermaking methods for carbon fiber paper include: a wet method in which short carbon fibers are dispersed in a liquid medium, and a dry method in which short carbon fibers are dispersed in the air to deposit them; however, in order to uniformly mix the binder, Wet methods are preferred.

As the resin used in carbon fiber paper, phenolic resin, furan resin, epoxy resin, melamine resin, imide resin, polyurethane resin, aramid resin, pitch, etc. can be listed alone, or their mixtures can be listed.

Regarding the amount of resin relative to the carbon fiber paper, it is preferable to impregnate 1 to 120 parts of the resin with respect to 100 parts by mass of the short carbon fibers before firing.

The weight per unit area of the carbon fiber paper is preferably 20-60 g/m ² , preferably 30-50 g/m ² . The reason is that if it is less than 20 g/m ² , the strength in the wet paper state (the state before drying and curing of the adhesive) may decrease, and if it exceeds 60 g/m ² , the weight in the wet paper state may increase. The case where it eventually breaks due to its own weight.

2. Preparation method of carbon fiber laminated body

The preparation method of the carbon fiber laminated molded body of the present invention comprises: (a) at least one carbon fiber fabric woven from mixed carbon fiber yarns, a carbon fiber felt laminate impregnated with a thermosetting resin, and carbon fiber paper are coated with an adhesive A process of lamination, compression molding, and (b) a process of calcining the obtained compression-molded laminate; it is preferable to laminate the carbon fiber fabric, the carbon fiber felt laminate, and the carbon fiber paper in this order.

In the method for preparing a carbon fiber laminated molded body of the present invention, the carbon fiber fabric used is a carbon fiber fabric woven from the above-mentioned mixed carbon fiber yarn, and one or more than two types of carbon fiber fabrics can be used. When using two or more types of carbon fiber fabrics, each carbon fiber fabric is bonded with an adhesive.

The carbon fiber mat can be obtained by needle-punching carbon fibers, impregnating one or more types of carbon fiber mats with a thermosetting resin, and laminating them to form a laminate.

In addition, as the carbon fiber paper, an organic binder carbon fiber paper obtained by adding a binder to short carbon fibers as described above for papermaking, or a carbon binder carbon fiber paper obtained by further impregnating a resin and calcining can be used.

The binder used in the production method of the present invention is carbonized by being calcined, and thus preferably contains a large amount of carbon components, but is not particularly limited depending on the carbon content.

Specifically, an adhesive composition obtained by uniformly mixing and dispersing the following components can be used: 60-100 parts by mass of thermosetting prepolymer, 20-60 parts by mass of thermosetting resin; 5-20 parts by mass of short fiber Carbon fiber, carbon black, carbon powder or graphite powder; 5-20 parts by mass of solvent; and 5-20 parts by mass of water.

As the thermosetting prepolymer, preferably enumerated: urea resin prepolymer; melamine resin prepolymer, urea-modified melamine resin prepolymer; guanamine resin prepolymer; guanamine-modified melamine resin prepolymer furan resin prepolymers; alkyd resin prepolymers; phenolic resin prepolymers, such as novolak-type phenolic resin prepolymers, resol-type phenolic resin prepolymers, novolak-type alkylphenolic resin prepolymers Resole type alkyl phenolic resin prepolymers and their xylene/formaldehyde condensates, toluene/formaldehyde condensates, or modified resin prepolymers using melamine resins, guanamine resins or urea resins; cyclic Oxygen resin prepolymers, such as bisphenol A diglycidyl ether, diglycidyl ether of alicyclic diol, bisphenol A bis (α-methyl glycidyl ether), bis (α-methyl glycidyl ether) of alicyclic diol methyl glycidyl ether), etc. A curing agent, a curing catalyst, and the like may also be mixed as necessary. Among them, resin prepolymers with a high carbonization yield are preferred, and novolak-type phenolic resin prepolymers, resole-type phenolic resin prepolymers, novolac-type alkylphenolic resin prepolymers, and resol-type phenolic resin prepolymers are particularly preferably used. Type alkylphenolic resin prepolymer.

As the thermosetting resin, preferably, urea resin; melamine resin; urea-modified melamine resin; guanamine resin; guanamine-modified melamine resin; alkyd resin; furan resin; unsaturated polyester resin; phenolic resin , such as novolak-type phenolic resins, resol-type phenolic resins, novolac-type alkylphenolic resins, resole-type alkylphenolic resins; epoxy resins, such as bisphenol A diglycidyl ether, alicyclic diol Diglycidyl ether of bisphenol A bis(α-methyl glycidyl ether), bis(α-methyl glycidyl ether) of alicyclic diol, etc. Among them, resins with a high carbonization yield are preferable, and novolak-type phenolic resins, resol-type phenolic resins, novolac-type alkylphenol resins, and resol-type alkylphenol resins are particularly preferably used.

As the solvent, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, 2-furyl methanol, toluene, xylene, dimethyl sulfoxide or the like can be preferably used.

The adhesive bonds carbon fiber fabrics and carbon fiber felt laminates, and bonds carbon fiber felt laminates to carbon fiber paper. The amount of the adhesive used between them is preferably 500 to 3000 g/m ² , more preferably 1000 to 2500 g/m ² , most preferably 1200 to 2200 g/m ² with respect to the carbon fiber fabric or carbon fiber felt laminate . The reason is that if it is less than 500 g/m ² , the adhesive force will be weak, and if it is more than 3000 g/m ² , the adhesive will harden after firing, and the processability of the carbon fiber laminated molded body will deteriorate.

The adhesive can be applied by a usual method, for example, it can be applied with a doctor blade, a brush, a roller, or the like.

As the thermosetting resin impregnated in the above-mentioned carbon fiber felt, urea resin, melamine resin, phenolic resin, epoxy resin, unsaturated polyester resin, alkyd resin, polyurethane resin, furan resin, etc. can be listed, but the preferred carbonization yield High phenolic resin.

The carbon fiber mat is impregnated with the above-mentioned resin, and the number of sheets having the thickness required for the intended use is laminated to prepare a carbon fiber mat laminate. The amount of resin impregnated is preferably 10 to 100 parts by mass, more preferably 15 to 50 parts by mass, relative to 100 parts by mass of the carbon fiber mat.

[Compression molding process]

The compression molding step in the production method of the present invention will be described with reference to FIG. 2 .

In the compression molding process, the carbon fiber fabric (12) is placed on the stainless steel plate (23) under the compression molding device (2), and a prescribed amount of adhesive (25) is coated on the carbon fiber fabric. When using two or more types of carbon fiber fabrics, the second carbon fiber fabrics are laminated, and a predetermined amount of adhesive is also applied thereon. One or more carbon fiber mats (14) impregnated with a thermosetting resin are laminated on the carbon fiber fabric to form a carbon fiber mat laminate (13). A predetermined amount of adhesive (25) is applied to the uppermost surface of the carbon fiber felt laminate, and carbon fiber paper (10) is laminated. The obtained laminate comprising the carbon fiber fabric, the carbon fiber felt laminate and the carbon fiber paper can be compressed and molded under the pressure and temperature at which the thermosetting resin impregnated in the carbon fiber felt laminate is cured, so that the thermosetting resin and the adhesive are cured, A compression molded body was obtained.

In order to make a laminate of carbon fiber fabric, carbon fiber felt laminate and carbon fiber paper into a compression molded body of target thickness, by arranging a separator (22) of target thickness around the above laminate, and then compression molding , The thickness of the compression molded body can be adjusted. In addition, by adjusting the thickness of the compression molded body, the bulk density of the carbon fiber felt laminate can be adjusted.

The pressure in the compression molding step is not particularly limited as long as the above-mentioned separator is used, and it can be performed at, for example, 0.1 to 1 MPa. In addition, the temperature of the above-mentioned hot press plate is not limited as long as it is the temperature at which the thermosetting resin impregnated into the carbon fiber mat is cured, and it can be performed at, for example, 150 to 200°C. In addition, the time of compression molding can also be determined suitably, for example, it can carry out in 10 minutes - 5 hours.

In this specification, the carbon fiber felt laminate refers to a laminate impregnated with a resin and laminated, and means both a laminate before compression molding and a laminate after compression molding.

[Calcination process]

The calcining step in the preparation method of the present invention can be performed at a temperature below 3000° C. in a non-oxidizing atmosphere. As a non-oxidizing atmosphere, a vacuum state, nitrogen atmosphere, or an argon atmosphere is mentioned, for example. The temperature is not particularly limited as long as it is a temperature at which carbonization occurs.

Example

The present invention will be specifically described below based on examples, but they do not limit the scope of the present invention.

In Examples, various physical properties of yarn fabrics were measured by the following methods.

[Tensile strength of yarn fabric]

Tensilon (テンシロン) universal testing machine [manufactured by Orientec Co., Ltd. (Orientec), "RTC-1310 type"] will be used to test the load cell rated 10kN, sample length 150mm, sample width 50mm, tensile speed The breaking strength when the yarn fabric was stretched under the condition of 200 mm/min was converted into a value per 1 cm of sample width, and this was taken as the tensile strength of the yarn fabric.

[Thickness of yarn fabric]

The value obtained by cutting the sample into a square of 100 mm x 100 mm at least 30 mm from the edge of the yarn fabric, and measuring the central part with a micrometer [manufactured by Mitsutoyo Co., Ltd., U-shaped micrometer "PMU 150-2"] As the thickness of yarn fabric.

"Example 1"

[Preparation of carbon fiber fabric]

A carbon fiber yarn composed of a core comprising PAN-based carbon fibers of 20% by mass and a sheath comprising pitch-based carbon fibers of 80% by mass is used as warp and weft yarns for twill weaving to obtain a yarn fabric (twill weave, FAW is 700g/m ² , The yarn count was 17.0 yarns/inch in the warp direction and 17.0 yarns/inch in the weft direction, the tensile strength was 0.32 kN, and the thickness was 1.0 mm).

[Preparation of Adhesive]

]、10质量份的2-呋喃甲醇[纯正化学(株)制，纯正1级]、40质量份的乙醇混合溶液[Japan Alcohol Trading Co., Ltd. (日本アルコール販売(株))制，“Solmix (ソルミックス) H-23”]。 As an adhesive for bonding the yarn fabric and the carbon fiber felt laminate and for bonding the carbon fiber felt laminate and the carbon fiber paper, prepare the adhesive by uniformly mixing and dispersing the following: 15 parts by mass of phenolic resin-based impregnating solution [Shonol (ショウノール) BRS-3897” manufactured by Showa Polymer Co., Ltd.], 25 parts by mass of powdered phenolic resin [Cashew Co., Ltd. .05 "], 10 parts by mass of short carbon fiber [Kureha Corporation ((strain) クレハ) system, Curecachop (クレカチョップ) M-107T, average fiber length 0.7mm,

], 10 parts by mass of 2-furanmethanol [manufactured by Junsei Chemical Co., Ltd., pure grade 1], 40 parts by mass of ethanol mixed solution [Japan Alcohol Trading Co., Ltd. (Japan Alcohol Trading Co., Ltd.) system, " Solmix (ソルミックス) H-23”].

《Compression forming process》

44 parts by mass of a phenolic resin-based impregnating solution [manufactured by Showa Polymer Co., Ltd., "Shonol (ショウノール) BRS-3896"] was impregnated into 100 parts by mass of a pitch-based carbon fiber mat [Kureha Corporation (Kureha Corporation) クレハ), "Curecafelt (クレカフェルト) F-110"], laminated 6 layers into a flat plate to prepare a carbon fiber felt laminate.

Place the above-mentioned carbon fiber fabric on a compression molding device, and apply the above-mentioned adhesive with a brush at a basis weight of 1200 g/m ² . A carbon fiber felt laminate is laminated on the carbon fiber fabric without pressure. Furthermore, the above-mentioned adhesive was applied with a brush at a basis weight of 1200 g/m ² on the uppermost surface of the carbon fiber felt laminate. Carbon fiber paper [manufactured by Kureha Corporation (Kureha Corporation, "Curecappaper") impregnated with 15 parts by mass of a phenolic resin-based impregnating solution [manufactured by Showa Polymer Co., Ltd., "Shonol (ショウノール) BRS-3896"] (クレカペーパー) E-204”] lamination.

Around the formed laminate comprising carbon fiber fabric, carbon fiber felt laminate, and carbon fiber paper, a spacer for adjusting the thickness of the target compression molded body to 40 mm was arranged, and compression and heating were performed to cure the resin to obtain Compression molded body.

"Calcination Process"

The obtained compression-molded body was subjected to graphitization treatment at 2000°C for 1 hour in a vacuum nitrogen atmosphere to obtain a flat carbon fiber in which a fabric layer was laminated on one side of the carbon fiber felt laminate and carbon fiber paper was laminated on the other side. Laminated molding.

"Example 2"

Except using yarn fabric (twill weave, FAW is 785g/m ² , yarn count density is 18.0 threads/inch in warp direction and 18.0 threads/inch in weft direction, tensile strength is 0.34kN, thickness is 1.1mm), and embodiment 1 in the same manner to obtain a carbon fiber-containing laminated molded body.

"Example 3"

In addition to using yarn fabric (twill weave, FAW is 700g/m ² , yarn count density is 16.0 threads/inch in warp direction and 18.0 threads/inch in weft direction, tensile strength is 0.32kN, thickness is 1.0mm), and the implementation Example 1 was carried out in the same manner to obtain a laminated body containing carbon fibers.

The yarn fabric layers of any of the carbon fiber-containing laminated products in Examples 1 to 3 were flat, and no wrinkles were observed. In addition, abnormalities such as warpage were not found.

Industrial availability

The carbon fiber-containing laminated molded body of the present invention can be used as a heat insulating material for high-temperature furnaces such as crystal pulling furnaces, vacuum evaporation furnaces, and ceramic sintering furnaces.

As mentioned above, although this invention was demonstrated based on the specific embodiment, the modification or improvement obvious to those skilled in the art is also included in the scope of the present invention.

Symbol Description

1··· carbon fiber laminated body;

10···Carbon fiber paper;

11···Carbon fiber felt laminated body;

12···Carbon fiber fabric;

13···Carbon fiber felt laminate;

14···Carbon fiber felt;

2···Compression forming device;

21···Hot pressing plate (above);

22···Separator;

23···Stainless steel plate;

24···Hot pressing plate (below);

25···Binder.

Claims (6)

1. carbon fiber layer is pressed into body, it is characterized in that comprising: the tissue layer, carbon fiber felt layered product and the carbon fiber paper that comprise at least a kind of carbon fibre fabric that is made into by the carbon fiber yarn.

2. the carbon fiber layer of claim 1 is pressed into body, and wherein, above-mentioned tissue layer, carbon fiber felt layered product and the carbon fiber paper that comprises at least a kind of carbon fibre fabric that is made into by the carbon fiber yarn is according to this order lamination.

3. claim 1 or 2 carbon fiber layer are pressed into body; Wherein, Above-mentioned carbon fiber yarn is the mixed carbon fibre yarn, and said mixed carbon fibre yarn contains the core of fiber diameter below 12 μ m uses carbon fiber with the sheath material that carbon fiber and fiber diameter surpass 12 μ m.

4. high temperature furnace used heat-barrier material, said material comprise that each carbon fiber layer is pressed into body in the claim 1 ~ 3.

5. carbon fiber layer is pressed into the preparation method of body, and said preparation method comprises:

Laminate and the carbon fiber paper of carbon fiber felt that at least a kind of carbon fibre fabric that (a) will be made into by the mixed carbon fibre yarn, infiltration have a thermosetting resin through coating adhesive lamination, compression molding operation and

(b) operation of the compression molding layered product of calcining acquisition.

6. the carbon fiber layer of claim 5 is pressed into the preparation method of body, and wherein, in above-mentioned operation (a), tissue layer, carbon fiber felt layered product and the carbon fiber paper that will comprise at least a kind of carbon fibre fabric that is made into by the carbon fiber yarn are according to this order lamination.

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