JP6914106B2 - Carbon short fiber non-woven fabric - Google Patents

Description

The present invention relates to short carbon fiber non-woven fabrics.

Carbon fiber is lighter than iron and has excellent mechanical properties such as high strength. Therefore, carbon fiber composite materials are used in a wide range of fields such as aircraft, automobiles, tennis rackets, fishing rods, and blades for wind power generation, and their applications are expected to expand in the future.

Currently, the carbon fibers are mainly PAN-based carbon fibers obtained by carbonizing and graphitizing polyacrylonitrile, and pitch-based carbon fibers obtained by melt-spinning tar-pitch liquefied coal and then carbonizing and graphitizing. Carbon fiber is used. The carbon fibers thus produced were processed as a woven fabric or arranged in one direction, and then a material called carbon fiber prepreg impregnated with an uncured resin was cut to fit the target molded product mold. It is often used as a carbon fiber reinforced resin (hereinafter abbreviated as "CFRP") obtained by curing the resin later. Alternatively, when carbon fiber obtained by recycling CFRP waste material is used, it cannot be processed as a woven fabric because the carbon fiber is shortened to carbon short fiber in the recycling process, so that it is processed as a non-woven fabric. Is common.

As a method of forming a carbon short fiber non-woven fabric into a sheet of carbon short fibers, a method of dispersing carbon short fibers and water-swelled fibrillated fibers in water to prepare a papermaking slurry and entwining the fibers is shown. .. Examples of the water-swelled fibrillated fibers include fibrillated para-type aromatic polyamide fibers and fibrillated acrylic fibers (see Patent Document 1). However, this method does not consider the problem that fine carbon short fibers fall off in steps such as cutting and compression when the carbon short fiber non-woven fabric is processed into CFRP. The lost carbon short fibers may irritate the operator's skin and cause inflammation, which may impair the health condition, or may invade the electrical system and cause a short circuit.

Further, as another method of forming a non-woven fabric by sheeting carbon short fibers, a method for producing a carbon short fiber non-woven fabric composed of 75% by mass to 97% by mass of carbon short fibers and 25% by mass to 3% by mass of cellulose contains nitrogen. An aqueous dispersion aid containing an organic solvent is added to a predetermined amount of water with 10% by mass or less of the carbon short fibers and the carbon short fibers are added and stirred, and the slurry solid content concentration is 0.05% by mass or less with water. A method of wet papermaking after undergoing a step of diluting and circulating the paper is shown (see Patent Document 2). However, the carbon short fiber non-woven fabric of Patent Document 2 is a non-woven fabric having gas permeability and conductivity, and is not a non-woven fabric used for CFRP. Therefore, when the carbon short fiber non-woven fabric is processed into CFRP, it may be cut or compressed. The problem of fine carbon short fibers falling off in the process was not considered.

International Publication No. 2014/021366 Pamphlet Japanese Unexamined Patent Publication No. 2004-353124

An object of the present invention is to provide a carbon short fiber non-woven fabric capable of suppressing fallen fibers generated when the carbon short fiber non-woven fabric is processed.

As a result of conducting research to solve this problem, the present inventors have found the following means.

(1) A carbon short fiber non-woven fabric containing carbon short fibers (excluding activated carbon fibers), cellulose fibers and binder synthetic fibers, and a porous base material and cellulose containing carbon short fibers (excluding activated carbon fibers) as essential components. A carbon short fiber non-woven fabric in which a network structure containing fibers as an essential component is mixed and contained, and the binder synthetic fiber is a polyvinyl alcohol-based fiber.
(2) The carbon short fiber non-woven fabric according to (1) above, wherein the average fiber length of carbon short fibers (excluding activated carbon fibers) is 1.0 mm or more.
(3) The short carbon fiber non-woven fabric according to (1) or (2) above, wherein the cellulose fiber is a beaten lyocell fiber.
(4) The short carbon fiber non-woven fabric according to any one of (1) to (3) above , which has a basis weight of 10 g / m ^{2 or more.}
(5) The carbon short fiber non-woven fabric according to (4) above, wherein the blending ratio (mass standard) of carbon short fibers (excluding activated carbon fibers) is 10% or more and less than 99% .

According to the present invention, it is possible to obtain a short carbon fiber non-woven fabric in which shed fibers are suppressed.

It is an SEM photograph of a carbon short fiber non-woven fabric containing a porous base material containing carbon short fibers as an essential component and a network structure containing cellulose fibers as an essential component. It is an SEM photograph of a carbon short fiber non-woven fabric which does not contain a network structure.

In a non-woven fabric containing carbon short fibers, when a force such as cutting or compression is applied, the carbon short fibers may be broken and fine carbon short fibers may be scattered. Short carbon fibers do not have self-adhesive elements, and the fibers are less likely to be entangled with each other, so that shed fibers tend to occur easily. In addition, since it is highly irritating to the skin of the human body, it is possible that the health condition of the operator may be impaired. In addition, since carbon short fibers have electrical conductivity, they may enter the inside of the machine and cause a short circuit, which may cause a malfunction in the machine. For these reasons, prevention of fallen fibers is necessary for stable production.

Since carbon short fibers do not have an element for self-adhesion, it is possible to increase the adhesive strength between carbon short fibers and prevent shedding fibers by blending cellulose fibers or binder synthetic fibers having a self-adhesive function. By entwining the cellulose fibers with a plurality of carbon short fibers, as shown in FIG. 1, carbon containing a porous base material containing the carbon short fibers 1 as an essential component and a network structure 2 containing the cellulose fibers as an essential component. It becomes a short fiber non-woven fabric and has the effect of suppressing the loss of carbon short fibers. As shown in FIG. 2, in the carbon short fiber non-woven fabric that does not contain the network structure 2 containing the cellulose fiber as an essential component, the carbon short fiber becomes a weak bond only by point adhesion between the fibers, and the carbon short fiber easily falls off. ..

As the carbon short fibers, carbon short fibers manufactured by any manufacturing method such as PAN type and pitch type can be used. In addition, there is no problem with new and unused carbon short fibers or carbon short fibers obtained by recycling discarded carbon fibers. Considering the cost required to obtain carbon short fibers, carbon short fibers obtained by recycling are more preferable.

The average fiber length of the carbon short fibers is preferably 1.0 mm or more, more preferably 3.0 mm or more, and even more preferably 5.0 mm or more. The longer the average fiber length of the carbon short fibers, the more adhesive points per fiber, and the more the fibers are suppressed from falling out. Therefore, it is preferable that the average fiber length of the carbon short fibers is long, but when the fiber length is too long. , Operability may become unstable when making sheets by the papermaking method.

Here, the average fiber length of the short carbon fibers is obtained by the following method. First, 20 short carbon fibers are randomly collected and their fiber lengths are measured. After that, the average fiber length of the short carbon fibers is calculated by the following calculation method.

Average fiber length = {(fiber length of carbon short fiber 1 (mm)) + (fiber length of carbon short fiber 2 (mm)) + (fiber length of carbon short fiber 3 (mm)) + ... (carbon short fiber 20) Fiber length (mm))} / 20

As cellulose fibers, wood pulps such as coniferous pulp and broadleaf pulp; natural pulp fibers such as straw pulp, bamboo pulp, linter pulp, and kenaf pulp, and herbaceous pulp, and recycled cellulose such as rayon, cupra, and lyocell. Fiber can also be used. These cellulose fibers may be fibrillated as long as the effects of the present invention can be obtained. Further, natural pulp fibers obtained from used paper, waste paper and the like may be used. Among the above-mentioned cellulose fibers, it is preferable to use one or more kinds of cellulose fibers selected from the group of softwood pulp, linter pulp, and lyocell, and it is more preferable to use lyocell. Further, it is preferable that the lyocell fiber is fibrillated (beaten). By using these preferable cellulose fibers, a network structure containing cellulose fibers as an essential component can be easily formed, and the fibers can be suppressed from falling off. In addition, the effect of stabilizing the operability when the carbon short fiber non-woven fabric is produced by the papermaking method can be obtained.

The beating (fibrillation) cellulose fiber can be produced by fibrillating the above-mentioned cellulose fiber. Devices for fibrillation include beaters, PFI mills, single disc refiners (SDRs), double disc refiners (DDRs), ball mills used for dispersing and grinding pigments, dyno mills, mixers, grinders, and high-speed. A rotary blade homogenizer that applies shear force by a rotary blade, a double cylindrical high-speed homogenizer that generates shear force between a cylindrical inner blade that rotates at high speed and a fixed outer blade, and miniaturization by impact by ultrasonic waves. Apply a pressure difference of at least 20 MPa to the ultrasonic crusher and fiber suspension to pass through a small-diameter orifice to increase the speed, and collide with this to make a sudden deceleration to apply shearing force and cutting force to the fiber. Examples include devices such as a homogenizer. Fibrilized cellulose fibers can be produced by using these devices alone or in combination. Then, by adjusting the fibrillation conditions such as the type of these devices, the processing conditions (fiber concentration, temperature, pressure, rotation speed, shape of the refiner blade, gap between the refiner plates, number of processings), the desired fibrillation is achieved. You can get the state.

Examples of the binder synthetic fiber include composite fibers such as core-sheath fibers (core-shell type), parallel fibers (side-by-side type), and radial split fibers; undrawn fibers; low melting point synthetic resin single fibers; and hot water-soluble fibers. The binder synthetic fiber has a low glass transition temperature or melting temperature (melting point) of the whole fiber or a part of the fiber, and exhibits the binder ability in the drying step of the paper machine. Since the composite fiber is difficult to form a film, the mechanical strength can be improved while maintaining the space of the carbon short fiber non-woven fabric. More specifically, as the composite fiber, a combination of polypropylene (core) and polyethylene (sheath), a combination of polypropylene (core) and ethylene vinyl alcohol (sheath), a high melting point polyester (core) and a low melting point polyester (sheath). The combination of. Examples of the undrawn fiber include undrawn fibers such as polyester. In addition, low melting point synthetic resin single fibers such as single fibers (total fusion type) composed only of low melting point resins such as polyethylene and polypropylene, and hot water soluble fibers such as polyvinyl alcohol type form a film in the drying process. It is easy to use, but it can be used in the present invention. In the present invention, a polyvinyl alcohol-based binder synthetic fiber, which is a hot water-soluble fiber, is preferable because it easily forms a hydrogen bond with a functional group on the surface of a short carbon fiber and easily exhibits strength. Further, in the present invention, by including both the cellulose fiber and the binder synthetic fiber, a network structure containing the cellulose fiber as an essential component is easily formed, and the effect of suppressing the loss of short carbon fiber is enhanced. This effect is higher when the binder synthetic fiber is a polyvinyl alcohol-based fiber.

In the carbon short fiber non-woven fabric of the present invention, in addition to carbon short fibers, cellulose fibers and binder synthetic fibers, synthetic fibers having no binder ability and inorganic fibers are blended with the carbon short fiber non-woven fabric as long as the performance is not impaired. Can be done. For example, synthetic fibers such as polyolefin-based, polyamide-based, polyacrylic-based, vinylon-based, polyvinylidene chloride-based, polyvinyl chloride-based, polyester-based, benzoate-based, polyclaral-based, and phenol-based, glass fiber, rock fiber, and slug fiber. And inorganic fibers such as metal fibers. Further, semi-synthetic fiber acetate, triacetate, promix and the like can also be used.

The fiber length of the synthetic fiber and the inorganic fiber is not particularly limited, but is preferably 3 mm or more and less than 30 mm. The longer the fiber length of the synthetic fiber and the inorganic fiber, the more contact points between the fibers per fiber, and the more difficult it is for the fiber to fall off. Therefore, the fiber length of the synthetic fiber and the inorganic fiber should be 3 mm or more. Is preferable. If the fiber length is too long, the papermaking property and the texture of the non-woven fabric may deteriorate, so that the fiber length is preferably less than 30 mm. The fiber diameter is also not particularly limited, but is preferably 1 μm or more and less than 30 μm, and particularly preferably 2 μm or more and less than 20 μm. When a fiber having a fiber diameter of less than 1 μm is blended, the inside of the carbon short fiber non-woven fabric becomes a dense structure. May go down. When the fiber diameter is 30 μm or more, synthetic fibers or inorganic fibers having no binder ability may easily fall off.

The blending ratio (mass basis) of the short carbon fibers is preferably 10% or more and less than 99%, more preferably 20% or more and less than 98%, and further preferably 30% or more and less than 97%. When the blending ratio of the carbon short fibers is less than 10%, the effect of "high strength and light mass" of the carbon short fibers when processed may not be sufficiently exhibited. When the blending ratio of the short carbon fibers is 99% or more, even if the cellulose fibers and the binder synthetic fibers are contained, the network structure containing the cellulose fibers as an essential component cannot be sufficiently formed, and the fibers are bound to each other. It may be insufficient and the shed fibers may not be suppressed.

The blending ratio (mass basis) of the cellulose fibers is not particularly limited, but is preferably 0.5% or more and less than 50%, and particularly preferably 1% or more and less than 30%. When the blending ratio of the cellulose fibers is lower than 0.5%, a network structure containing the cellulose fibers as an essential component is not formed so much, and the effect of suppressing the shed fibers may be reduced. If it is 50% or more, the permeation of the resin may be hindered by the cellulose fibers, and the resin may not uniformly permeate into the short carbon fiber non-woven fabric.

The blending ratio (mass basis) of the binder synthetic fiber is not particularly limited, but is preferably 0.5% or more and less than 90%, and particularly preferably 1% or more and less than 70%. When the blending ratio of the binder synthetic fiber is lower than 0.5%, the network structure containing the cellulose fiber as an essential component is not formed so much, and the effect of suppressing the fallen fiber may be reduced. When the blending ratio of the binder synthetic fiber is 90% or more, the blending ratio of the carbon short fiber is small, and the effect of the carbon short fiber "high strength and light mass" when the carbon short fiber non-woven fabric is processed is sufficient. It may not be possible to demonstrate it.

In the present invention, the short carbon fibers are made into a sheet by a paper machine. That is, a short carbon fiber non-woven fabric is produced by a papermaking method.

In the papermaking method, for example, a long net type, a circular net type, and an inclined wire type can be used. A paper machine having these paper making methods alone may be used, or a combination paper machine in which two or more paper machines of the same type or different types are installed online may be used. In order to produce a carbon short fiber non-woven fabric having excellent uniformity, it is preferable to use a papermaking method capable of gently dehydrating the slurry on the wire, such as a long net type or an inclined wire type. The short carbon fiber non-woven fabric of the present invention may be a single layer or a multi-layer.

In the papermaking method, when the fibers are dispersed in water for the purpose of uniformly dispersing the fibers in water or imparting various functions, various anionic, nonionic, cationic or amphoteric dispersants and defoamers are used. , Hydrophilic agents, drainage agents, paper strength improvers, adhesives, antistatic agents, polymer adhesives, mold release agents, antibacterial agents, bactericides, pH adjusters, pitch control agents, slime control agents, etc. It may be added.

A sizing agent can be added to the short carbon fiber non-woven fabric of the present invention, if necessary. As the sizing agent, a strengthened rosin sizing agent, a rosin emulsion sizing agent, a petroleum resin-based sizing agent, a synthetic sizing agent, a neutral rosin sizing agent, and an alkyl keten dimer (AKD) as long as they do not impair the desired effect of the present invention. ) And other sizing agents can be used.

Wet paper produced by a paper machine is dried with a Yankee dryer, an air dryer, a cylinder dryer, a suction drum type dryer, an infrared type dryer, or the like to obtain a carbon short fiber non-woven fabric. When the wet paper is dried, it is brought into close contact with a heat roll such as a Yankee dryer and heat-pressure dried, so that the smoothness of the adhered surface is improved. Hot pressure drying means drying by pressing wet paper against the hot roll with a touch roll or the like. The surface temperature of the heat roll is preferably 100 to 180 ° C, more preferably 100 to 160 ° C, and even more preferably 110 to 160 ° C. The pressure is preferably 50 to 1000 N / cm, more preferably 100 to 800 N / cm.

The basis weight of the short carbon fiber nonwoven fabric of the present invention is not particularly limited, but is preferably less than 10 g / ^{m 2} or more 350 g / ^{m 2,} less than 30 g / ^{m 2} or more 300 g / ^{m 2} is more preferable. When the basis weight is ^{less than 10 g / m 2} , the adhesive surface between the carbon short fibers is small and the strength of the carbon short fiber non-woven fabric is weak, so that the effect of preventing the carbon short fibers from falling off may be low. When the basis weight is 350 g / m ² or more, it is difficult to dry uniformly when drying with a dryer, and the quality of the carbon short fiber non-woven fabric may be uneven.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to this example. The number of copies and percentages in the examples are based on mass. Examples 5 and 6 are reference examples.

Example 1
Short carbon fibers (average fiber length 5 mm), beaten lyocell fibers, and PVA binder fibers (manufactured by Kuraray, product name: VPB107-1) are added to water at the blending ratio (mass basis) shown in Table 1 for 10 minutes. After mixing and dispersing, the wet paper is wet-made by single-layer papermaking by the inclined wire method, dried by a Yankee dryer with a surface temperature of 130 ° C., and a carbon short fiber non-woven fabric ^{having a papermaking speed of 20 m / min and a basis weight of 50 g / m 2.} Got

Examples 2-8
The carbon short fiber non-woven fabrics of Examples 2 to 8 were obtained in the same manner as in Example 1 except that the composition of the fibers was changed to the contents shown in Table 1.

Comparative Examples 1 to 4
The carbon short fiber non-woven fabrics of Comparative Examples 1 to 4 were obtained in the same manner as in Example 1 except that the composition of the fibers was changed to the contents shown in Table 1.

Examples 9-12
The carbon short fiber non-woven fabrics of Examples 9 to 12 were obtained in the same manner as in Example 1 except that the average fiber length of the carbon short fibers was changed to the value shown in Table 1.

Examples 13-17
The carbon short fiber non-woven fabrics of Examples 13 to 17 were obtained in the same manner as in Example 1 except that the basis weight of the carbon short fiber non-woven fabric was changed to the values shown in Table 1.

Examples 18-21
The carbon short fiber non-woven fabrics of Examples 18 to 21 were obtained in the same manner as in Example 1 except that the composition of the fibers was changed to the contents shown in Table 1.

The details of the fibers listed in Table 1 are as follows.

Beating lyocell: Lyocell fibers (fineness 1.4 dtex, fiber length 3 mm) were treated with a double disc refiner and prepared so as to generate branches having an average fiber diameter of 1 μm or less from a trunk having an average fiber diameter of 14.0 μm. fiber.
Beating softwood pulp: Natural softwood pulp prepared to have a free water content of 500 ml CSF.
Beating linter: A fiber adjusted to have a mass average fiber length of 0.33 mm by dispersing the linter in ion-exchanged water so as to have a concentration of 5% by mass and repeatedly treating the linter 20 times at a pressure of 50 MPa using a high-pressure homogenizer. ..
PET fiber: Fineness 1.7 decitex, fiber length 5 mm
Aramid fiber: Fineness 0.9 decitex, fiber length 5 mm
PET binder: Polyethylene terephthalate unstretched binder fiber, fineness 1.2 decitex, fiber length 5 mm
PP / PE binder: Polypropylene / polyethylene core-sheath type binder fiber, fineness 0.8 decitex, fiber length 5 mm, core-sheath area ratio: 1/1

Table 2 shows the presence or absence of a network structure of the produced short carbon fiber non-woven fabric and the evaluation results of the fallen fibers in Examples and Comparative Examples.

<Reticulated structure>
The produced short carbon fiber non-woven fabric was observed by SEM to confirm the presence or absence of a network structure, and the result was evaluated.

◯: A reticular structure was confirmed.
Δ: A small amount of reticulated structure was confirmed.
X: No reticular structure was confirmed.

<Fibers that have fallen off>
^{A 3 cm 2} tape was attached to the thermal roll contact surface of the produced short carbon fiber non-woven fabric, pressure was once applied with a 5 kg stainless rod, and then the tape was peeled off to evaluate the fibers that had fallen off.

◯: Almost no fibers were shed.
Δ: Slightly shed fibers were observed.
X: Many fibers were shed.

<Paperability>
When making the carbon short fiber non-woven fabric, the carbon short fibers adhering to the roll or the machine were confirmed, and the scattering state was confirmed.
◯: Almost no scattered short carbon fibers were observed.
Δ: Slightly scattered carbon short fibers were observed. ×: Many scattered carbon short fibers were observed.

In Examples 1 to 8 which are carbon short fiber non-woven fabrics containing a porous base material containing carbon short fibers as an essential component and a network structure containing cellulose fibers as an essential component, almost no shed fibers were observed, which was excellent. It can be seen that it is a carbon short fiber non-woven fabric. Further, from the results of Examples 1 and 2, it can be seen that there is no problem in either case whether the cellulose fiber is a regenerated cellulose fiber (Example 1) or a naturally derived cellulose fiber (Example 2). .. Further, the carbon short fiber non-woven fabrics of Examples 1 and 2 are carbon short fiber non-woven fabrics composed of carbon short fiber, cellulose fiber and binder synthetic fiber, but from the results of Examples 3 and 4, synthesis having no binder ability is further obtained. It can be seen that there is no problem even if it contains fibers.

Further, as the binder fiber, the PVA binder and the PET binder are used in combination in Example 7, and the PVA binder and the PP / PE binder are used in combination in Example 8, but both of the short carbon fiber non-woven fabrics contain a network structure. Almost no shed fibers are seen, indicating that there is no problem. Further, in Example 5 in which the PVA fiber is not contained as the binder fiber and only the PET binder is used, the amount of the network structure formed is smaller than that in the case where the PVA fiber is contained, and the effect of suppressing the scattered fiber tends to be small. Was done. Similarly, in Example 6 in which the PVA fiber was not contained as the binder fiber and only the PP / PE binder was used, it was confirmed that the network structure was small and the scattered fiber was slightly large. From these facts, it can be seen that the PVA fiber easily forms a network structure and is particularly excellent among the binder synthetic fibers.

On the other hand, in Comparative Examples 1 and 2 containing short carbon fibers and synthetic binder fibers but not containing cellulose fibers and not containing a network structure containing cellulose fibers as an essential component, the binding between the short carbon fibers was weak. Fallen fibers are likely to occur. Therefore, a large amount of fallen fibers are generated when the carbon short fiber non-woven fabric is manufactured or processed, and there is a possibility that troubles such as skin irritation and electric short circuit may occur.

Further, in Comparative Example 3 containing only carbon short fibers and cellulose fibers and not containing binder synthetic fibers, and Comparative Example 4 containing only carbon short fibers and aramid fibrid and not containing binder synthetic fibers and cellulose fibers, cellulose fibers were used. A network structure containing the above as an essential component was not formed, and many fallen fibers were generated. Therefore, troubles such as skin irritation and electric short circuit may occur.

In Examples 9 to 12, which are carbon short fiber non-woven fabrics containing a porous base material containing carbon short fibers as an essential component and a network structure containing cellulose fibers as an essential component, almost no shed fibers were observed, which was excellent. It can be seen that it is a carbon short fiber non-woven fabric. In Example 9, which includes a porous base material containing short carbon fibers as an essential component and a network structure containing cellulose fibers as an essential component, the average fiber length of the short carbon fibers is shorter than 1.0 mm, the short carbon fibers are used. The number of fibers bound around one fiber is small, the fibers are slightly shed, and the short carbon fibers are scattered a little during the fabrication. The average fiber length of the short carbon fibers is preferably 1.0 mm or more. I understand.

In Examples 13 to 17, which are non-woven fabrics of carbon short fibers containing a porous base material containing short carbon fibers as an essential component and a network structure containing cellulose fibers as an essential component, almost no shed fibers were observed, which was excellent. It can be seen that it is a carbon short fiber non-woven fabric. In Example 13 in which the basis weight is smaller than 10 g / m ^2, the density of the carbon short fiber non-woven fabric is low, and the number of bonds between the carbon short fibers is small. Is scattered a little, and it can be seen that the basis weight of the carbon short fiber non-woven fabric ^{is preferably 10 g / m 2 or more.} Further, in Example 17 having a basis weight of 350 g / m ² or more, it is difficult to uniformly dry during papermaking, a network structure is somewhat difficult to be formed in a poorly dried state, and shed fibers are slightly generated. The result was that it was easy to do.

In Examples 18 to 21, which are carbon short fiber non-woven fabrics containing a porous base material containing carbon short fibers as an essential component and a network structure containing cellulose fibers as an essential component, shedding fibers are suppressed and carbon shorts are suppressed. It can be seen that an excellent short carbon fiber non-woven fabric can be obtained when the blending ratio (mass basis) of the fibers is 10 to 99%. In Example 21 in which the blending ratio of the short carbon fibers was as high as 98%, the amount of the cellulose fibers and the binder synthetic fibers was small, and the network structure formed was slightly small, so that the result was that the shed fibers were slightly generated. rice field.

According to the present invention, it is possible to obtain a short carbon fiber non-woven fabric in which shed fibers are suppressed.

1 Carbon short fiber 2 Reticulated structure

Claims (5)

It is a carbon short fiber non-woven fabric containing carbon short fibers (excluding activated carbon fibers), cellulose fibers and binder synthetic fibers, and a porous base material containing carbon short fibers (excluding activated carbon fibers) and cellulose fibers are essential. A carbon short fiber non-woven fabric in which a network structure as a component is mixed and contained, and the binder synthetic fiber is a polyvinyl alcohol-based fiber. The carbon short fiber non-woven fabric according to claim 1, wherein the average fiber length of the carbon short fibers (excluding activated carbon fibers) is 1.0 mm or more. The carbon short fiber non-woven fabric according to claim 1 or 2, wherein the cellulose fiber is a beaten lyocell fiber. The carbon short fiber non-woven fabric according to any one of claims 1 to 3, which has a basis weight of 10 g / m ² or more. The carbon short fiber non-woven fabric according to any one of claims 1 to 4, wherein the blending ratio (mass standard) of carbon short fibers (excluding activated carbon fibers) is 10% or more and less than 99%.

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