WO2003006723A1

WO2003006723A1 - Resin compositions for composite fiber

Info

Publication number: WO2003006723A1
Application number: PCT/JP2002/006996
Authority: WO
Inventors: Hiroshi Yasuda; Motoyoshi Ito; Masao Irisawa; Asao Oya
Original assignee: Calp Corporation; Gun Ei Chemical Industry Co., Ltd.
Priority date: 2001-07-10
Filing date: 2002-07-10
Publication date: 2003-01-23
Also published as: JP2003020517A

Abstract

A resin composition for composite fibers which comprises 10 to 50 wt.% phenolic resin and 90 to 50 wt.% polypropylene having an MI of 10 to 100 g/10 min as measured at 230°C under a load of 21.18 N; or a resin composition for composite fibers which comprises 10 to 50 wt.% phenolic resin and 90 to 50 wt.% polyethylene having a density of 0.940 g/cm3 or higher and an MI of 10 to 30 g/10 min. The resin compositions are for obtaining composite fibers suitable for use as a precursor for ultrafine carbon fibers. By carbonizing the composite fibers obtained, ultrafine carbon fibers having an average fiber diameter of 0.5 µm or smaller can be easily produced.

Description

Description. Resin composition for composite fiber

Technical field

The present invention relates to a resin composition for a composite fiber, a composite fiber comprising the resin composition, an ultrafine carbon fiber obtained by carbonizing the composite fiber, an ultrafine activated carbon fiber obtained by activating the carbon fiber, and It relates to a shaped article of fiber.

Background art

Funinol-based carbon fibers obtained by carbonizing FUNOOL resin fibers and activated carbon fibers obtained by activating them have excellent heat resistance, chemical resistance, conductivity, etc. Insulation materials, sealing materials, canisters for automobiles, flue gas desulfurization adsorbents, dioxin adsorbents. Charge double layer capacitors, lithium batteries, charge double layer capacitors, fuel cell electrode materials, separators, etc. It is used in a wide range of fields, and further use is expected.

One of the methods for further improving the performance of such carbon fibers is to make the fibers extremely fine. When considering electrode materials as an application development of ultrafine carbon fibers, by further activating ultrafine carbon fibers with a large surface area per unit weight (specific surface area) to obtain ultrafine activated carbon fibers, higher performance can be achieved. It can be expected as a material with high quality. In addition, when considering the application of ultrafine carbon fiber as a filler for composite materials, not only can a high-rigidity composite material be obtained, but also as a high-rigidity material that can be used for thin-walled molded products. And high conductive paths are formed. A conductive material can be obtained.

In order to produce ultra fine carbon fiber of fenol resin, it is necessary to make ultra fine phenol resin fiber. Conventional methods for producing ultrafine funor resin fibers using melt spinning techniques include a method in which the diameter of the resin discharge port in the spinneret is reduced, and the spinning speed is increased to melt spin the fuynol resin fibers. The phenolic resin and other resin are extruded from a special die to melt spin the sea-island composite fiber, and only the resin of the sea component is removed mechanically or by using a solvent or the like to remove the island component. For example, there is a method of taking out only the phenol resin. Then, these precursor fibers are carbonized to produce ultrafine carbon fibers.

However, phenol resin, which is a raw material of phenol resin fibers, is an amorphous resin and has a low degree of polymerization, so that spinning is difficult. Further, the obtained fininol resin fiber had problems that strength and elongation were insufficient and that it was extremely brittle. For this reason, there is a problem that productivity is extremely reduced in a method of increasing the spinning speed by using a small-diameter spinneret. Also, since the discharged phenol resin is cooled and solidified at a position very close to the spinneret, the drawing effect during spinning can hardly be expected, and the fiber diameter was limited to about 12 m. In addition, since the phenolic resin was brittle, it was impossible to perform a stretching treatment after spinning, and it was practically impossible to make the phenolic resin fiber finer by elongation. In addition, when a special die is used, the shape of the die becomes extremely complicated, so that productivity is remarkably reduced, and it is not possible to obtain phenol resin fibers having a fiber diameter of 10 or less. It was impossible. In addition, the method of removing sea components with a solvent or the like requires a large amount of solvent, which has a problem that the working environment is significantly deteriorated.

A method for obtaining a phenolic ultrafine carbon fiber is disclosed in Japanese Unexamined Patent Publication No. Although it is proposed in Japanese Patent Publication No. 226, etc., when simply combining a phenolic resin and a polyethylene resin, the ultrafine carbon fiber finally obtained shrinks or the fibers are fused together. There is a problem of doing so. Disclosure of the invention

The present invention has been made in view of the above circumstances, and provides a resin composition for obtaining a conjugate fiber suitable as a precursor of an ultrafine carbon fiber, and an ultrafine carbon fiber obtained by carbonizing the conjugate fiber. It is an object of the present invention to provide an ultrafine activated carbon fiber obtained by activating this carbon fiber, and a shaped article obtained by shaping these fibers.

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, a resin resin composition in which a phenolic resin and a specific polypropylene or a specific polyethylene are mixed at a specific ratio is a resin set for a composite fiber. The composite fiber obtained by spinning the resin composition is suitable as a precursor of the ultrafine carbon fiber, and the average fiber diameter is obtained by carbonizing the composite fiber. It was found that ultrafine carbon fibers having an average particle diameter of 0.5 or less were obtained, and by activating this ultrafine carbon fiber, an ultrafine activated carbon fiber was obtained. The present invention has been completed based on such findings.

That is, in the present invention, the MI (melt index) measured under the conditions of 10 to 50% by mass of the phenolic resin and a temperature of 230 ° (: a load of 21.18 N) is 10 to 1%. 0 0 g 1 0 minute polypropylene 9 0-5 0 consist mass% conjugate fiber resin composition, 1 0-5 0 mass% phenol resin and density 0. 9 4 0 g / cm ³ or more, the temperature MI (mel index) measured under the condition of 190 ° C and load of 2. Resin composition for composite fiber consisting of 90 to 50% by mass of polyethylene of 30 g / 10 minutes, having an average fiber diameter of 5 to 100 m obtained by spinning these resin compositions. Provided are a conjugate fiber, an ultrafine carbon fiber having an average fiber diameter of 0.5 μm or less obtained by carbonizing the conjugate fiber, and an ultrafine activated carbon fiber obtained by activating this ultrafine carbon fiber. Is what you do. The present invention also provides a shaped article obtained by shaping these fibers. BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 shows the aggregate of the fuynol-based ultrafine carbon fibers in Example 1.

It is a 1000 times electron microscope photograph.

It is a 5000 times electron microscope photograph.

Figure 3 shows the phenolic carbon fiber aggregate in Comparative Example 1.

It is a 1000 times electron microscope photograph.

Figure 4 shows the aggregate of phenolic carbon fibers in Comparative Example 1.

It is a 5000 times electron microscope photograph.

Figure 5 shows the aggregate of the phenolic microfine carbon fibers in Comparative Example 2.

It is a 1000 times electron microscope photograph.

Figure 6 shows the aggregate of the fininol-based ultrafine carbon fibers in Comparative Example 2.

It is an electron micrograph at a magnification of 500 times. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. The funinol resin used in the present invention is obtained by subjecting a funinol and an aldehyde to a condensation polymerization reaction in the presence of a reaction catalyst. As phenols, for example, Phenol, o_cresol, m-cresol, p-cresol, bisphenol A, 2,3—xylenol, 3,5—xylenol, p—tertiary butylphenol, resorcinol And the like. Examples of the aldehydes include formaldehyde, paraformaldehyde, hexamethylene tetramine, furfural, benzaldehyde, and salicylaldehyde.

The molar ratio between the aldehydes and the phenols is not particularly limited, but is preferably 0.6: 1 to 0.886: 1. Examples of the reaction catalyst include inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as oxalic acid and p-toluenesulfonic acid, oxycarboxylic acids such as citric acid and tartaric acid, and zinc compounds such as zinc chloride and zinc acetate. Is mentioned.

The phenol resin used in the present invention is not limited to a linear molecule but may be a partially branched molecule. The composition may be a single phenol resin or a mixture of two or more components at an arbitrary ratio. The molecular weight of the phenol resin is also not particularly limited, but in order to be fusible in a temperature range appropriate for melt spinning and to have a viscosity range appropriate for melt spinning, the average molecular weight is from 500 to 50, It is preferably in the range of 0 0 0. The softening point of the phenol resin is not particularly limited, but is preferably 90 ° C. or more, and particularly preferably 120 to 130 ° C. In the present invention, a novolac type phenol resin having a softening point of 90 ° C. or more is preferable.

Examples of the polypropylene used in the present invention include homopolypropylene, block polypropylene and random polypropylene.

Here, the homopolypropylene is a resin obtained by polymerizing propylene alone, and the block polypropylene and the random polypropylene are It is a copolymer of propylene and another comonomer. As the other comonomer, use ethylene or C4 to C6 olefin (1-butene, 1-pentene, 1-hexene, etc.) Can be.

Examples of polyethylene include high-pressure low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and other homopolymers of ethylene or copolymers of ethylene and α-olefin; 'Copolymers of ethylene with other vinyl monomers, such as vinyl acetate copolymers, and the like.

Examples of the α-olefin copolymerized with ethylene include propylene, 1-butene, 4-methyl-11-pentene, 11-hexene, and 1-octene. Other vinyl monomers include, for example, butyl esters such as butyl acetate; (meth) acrylic acid, (methyl) methyl acrylate, (meth) ethyl acrylate, Examples include (meth) acrylic acid such as η-butyl (meth) acrylate and its alkyl ester.

In the present invention, the ΜI (mel to index) measured under the condition of a temperature of 230 ° (: load 21.18Ν) is 10 to 100 g / 10 min. Use polyethylene with an MI (mel index) of 10 to 30 g / 10 minutes measured under conditions of 940 or more, temperature of 190 ° C, and load of 2.1.8 N.

If the MI of the polypropylene is less than 10 g / 10 minutes, the phenolic resin islands in the sea-island structure will not be formed well when producing a conjugate fiber described later, and the spinnability and the like will be significantly reduced. When the MI exceeds 100 g / 10 minutes, the sea-island structure with the phenol resin becomes non-uniform, so that the spinnability is remarkably reduced and stable fiber formation cannot be performed. In the case of using polyethylene, if the density is less than 0.940 g / cm, the carbon fibers are shrunk in the step of carbonizing the composite fibers. Density polyethylene, the preferred properly a 0. 9 4 0~0. 9 6 8 g / cm 3. If the MI of the polyethylene is less than 10 g / 0 min, the fiber will be cut when spinning the conjugate fiber, making it difficult to perform good spinning. If the MI of the polyethylene exceeds 30 g / 10 minutes, phase separation occurs between the phenol resin and the polyethylene, so that the fibers are cut and it becomes difficult to perform good spinning.

In the present invention, the mixing ratio of the phenol resin to the polypropylene or the polyethylene is 10 to 50% by mass of the phenol resin and 90 to 50% by mass of the propylene resin or the polyethylene. resin 1 0-3 0 weight ^_0/0, polypropylene or port Ryechiren is 9 0-7 0% by weight. If the phenolic resin content is less than 10% by mass, sufficient fininol-based ultrafine carbon fibers cannot be obtained, and if the phenolic resin content exceeds 50% by mass, a good sea-island structure cannot be obtained. Deterioration or the structure of carbon fiber obtained by carbonization becomes uneven.

Various additives may be added to the resin composition for composite fibers of the present invention as needed. Examples of the additive include an antioxidant, an ultraviolet absorber, a pigment, and a dye.

The resin composition for a conjugate fiber of the present invention can be obtained by mixing and kneading a fuñol resin with polypropylene or polyethylene by a known method. As the kneading apparatus, a known kneading apparatus can be used, and examples thereof include an extruder-type kneading machine, a mixing roll, a Banbury mixer, and a high-speed twin-screw continuous mixer. H The kneading time of the phenolic resin and polypropylene or polyethylene is appropriately selected depending on the amount of the resin, the mixing ratio of the phenolic resin and the polypropylene or polyethylene, and the desired fiber diameter of the phenolic resin as an island component. However, there is no particular limitation.

The kneading temperature of the phenol resin and the polypropylene or polyethylene is not particularly limited, but is preferably in the range of 180 to 280 ° C, more preferably in the range of 200 to 260 ° C. It is.

The resin composition thus obtained is extruded in a molten state from a spinneret and melt-spun to form a sea-island composite in which the sea component is a polyolefin resin and the island component is a fuyunol resin. Fiber can be obtained. Further, by subjecting the island component phenol resin to a curing treatment, a cured composite fiber can be obtained. Next, the cured composite fiber is carbonized under an inert atmosphere to obtain a fluorinated ultrafine carbon fiber. By activating this ultrafine carbon fiber, an ultrafine activated carbon fiber can be obtained. In the present invention, the finol-based ultrafine carbon fiber can be obtained by simply carbonizing the conjugate fiber, so that the working environment is remarkably improved and the finol-based ultrafine carbon fiber can be easily manufactured.

The temperature during melt spinning is not particularly limited, but is preferably in the range of 150 to 300 ° C, more preferably in the range of 160 to 250 ° C. The pore diameter of the spinneret is appropriately selected depending on the fiber diameter of the intended conjugate fiber, and is not particularly limited, but is preferably from 0.1 to 5.0 mm, more preferably from 0.2 to 4.0 mm. As the melting method, a known method can be used, and examples thereof include an extruder method and a melter method. As the heating method, any of an electric heating method, a steam heating method, and a heating medium heating method can be used. Spinning speed is not particularly limited However, it is preferably from 50 to 6,000 m / min, more preferably from 200 to 4,000 m / min. In melt spinning, a phenol resin and polyethylene may be melted and kneaded, and this may be directly spun in a molten state, or the phenol resin and polyethylene may be kneaded, pelletized once, and then melted. It may be spun.

The curing treatment of the phenolic resin is performed by a known method, for example, a method of curing the phenolic resin with an aldehyde in the presence of a bridge catalyst. Examples of the cross-linking catalyst include acidic catalysts such as hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, and p-toluenesulfonic acid, ammonia, hydroxylic acid sodium, sodium hydroxide, potassium hydroxide, and barium hydroxide. Basic catalysts such as sodium carbonate are exemplified. Examples of the aldehydes include formaldehyde, paraformaldehyde, and benzaldehyde furfural.

The reaction conditions during the curing treatment are appropriately selected according to the type, amount used, reaction method, etc. of the crosslinking catalyst and aldehydes.For example, when hydrochloric acid is used as the crosslinking catalyst and formaldehyde is used as the aldehydes The mixture is treated with an aqueous solution of 5 to 20% by mass of hydrochloric acid and 5 to 20% by mass of formaldehyde at 60 to 110 ° C for 3 to 30 hours.

In this way, a composite fiber having an average fiber diameter of 5 to 100 m can be obtained. By carbonizing such a composite fiber, an ultrafine carbon fiber having an average fiber diameter of 0.5 Hm or less can be obtained.

The carbonization of the composite fiber is performed by a known method. Examples of the inert gas used for carbonization include nitrogen, argon, and the like. The carbonization temperature is preferably in the range of 600 to 1200 ° C, more preferably in the range of 800 to 1000 ° C. The activation of microfine carbon fibers can be performed by subjecting the microfine carbon fibers to a gasification reaction with steam. it can.

Examples of the shaped article of the conjugate fiber, the ultrafine carbon fiber, and the ultrafine activated carbon fiber of the present invention include chopped strands, nonwoven fabrics, cloths, felts, papers, and long fibers. Can be manufactured.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The method for measuring the physical properties of each fiber in this example is as follows.

(1) Fiber diameter

Photographing was performed using a scanning electron microscope JSM-T22OA manufactured by JEOL Ltd., and the fiber diameter was measured based on the electron micrograph.

(2) Specific surface area

The measurement was performed using Bell Soap 8SA manufactured by Bell Japan.

[Example 1]

1,00 g of phenol, 373.2 g of 37% by mass formalin and 5 g of oxalic acid were charged into a reaction vessel equipped with a stirrer and a reflux condenser, and the reaction was carried out for 100 minutes in 40 minutes. ° C, and then kept at this temperature for 4 hours. After heating to 200 ° C. and dehydrating and concentrating under reduced pressure, 110 g of a novolac phenol resin having a softening point of 125 ° C. was obtained by cooling. A phenol resin powder obtained by repeating the same operation three times was mixed with polypropylene (MID measured at 230 ° C and a load of 21.18 N) having a MI of 60 g / 10 min (Idemitsu Petrochemical Co., Ltd.). Y-605 GM) was mixed so that the mass ratio was 30:70. 20000 g of this mixed resin was kneaded at 230 ° C. using a kneading PCM 30 co-directional twin screw extruder manufactured by Ikegai Iron Works to obtain a composite resin bellet.

Next, the obtained composite resin was melt-spun at a nozzle temperature of 170 ° C. An island-shaped uncured conjugate fiber was obtained. The obtained uncured conjugate fiber was immersed in an aqueous solution of hydrochloric acid-formaldehyde (18% by mass of hydrochloric acid and 10% by mass of formaldehyde) at 96 ° C. for 24 hours to obtain a cured fiber. Next, the cured fiber was carbonized in a nitrogen stream at 600 ° C. for 10 minutes to remove propylene, a sea component, to obtain a phenolic ultrafine carbon fiber. The obtained phenolic ultrafine carbon fiber is

Activation treatment was performed at 900 ° C. for 5 minutes to obtain ultrafine activated carbon fibers. The fiber diameter and specific surface area of these ultrafine carbon fibers and ultrafine activated carbon fibers were measured by the above-described methods. Table 1 shows the results.

Figures 1 and 2 show electron micrographs of the obtained phenolic ultrafine carbon fiber. FIG. 1 is an electron micrograph at a magnification of 1000 ×, and FIG. 2 is an electron micrograph at a magnification of 500 ×. From the electron micrographs, it was found that the polypropylene (sea portion) disappeared due to the heat, and a number of ultrafine carbon fibers (average fiber diameter 0.2 urn) extending long in the fiber axis were formed independently. It was confirmed that. By activating the ultrafine carbon fiber, an ultrafine activated carbon fiber having a specific surface area of 220 m ² / g could be obtained.

[Example 2]

In Example 1, polypropylene having an MI of 60 g / 10 minutes and a polypropylene having an MI of 20 g / 10 minutes measured at 230 ° C. under a load of 2.1.18 N (Idemitsu Petrochemical Co., Ltd.) In the same manner as in Example 1 except that Y-2000 GV) was used to obtain a cured composite fiber having an average fiber diameter of 30 m. In the same manner as in Example 1, the obtained composite fiber was carbonized to obtain a carbon fiber, and the carbon fiber was activated to obtain an activated carbon fiber. Table 1 shows the measurement results.

According to the electron micrograph, the ultra-fine carbon fiber (average fiber diameter 0.2 m) It was confirmed that they were formed individually and independently. Further, by performing the activation treatment of the ultrafine carbon fibers, it was possible to obtain the ultrafine activated carbon fibers having a specific surface area of 250 m ² / g.

[Example 3]

In Example 1, polypropylene having a MI of 60 g / 10 minutes was used.

Example 1 was repeated except that the MI measured at 230 ° C and a load of 21.18 N was changed to polypropylene (Y-900 GV, manufactured by Idemitsu Petrochemical Co., Ltd.) with a weight of 10 g / 10 minutes. Similarly, a cured composite fiber having an average fiber diameter of 30 m was obtained. In the same manner as in Example 1, the obtained composite fiber was carbonized to obtain a carbon fiber, and the carbon fiber was activated to obtain an activated carbon fiber. Table 1 shows the measurement results.

Electron micrographs confirmed that the ultrafine carbon fibers (average fiber diameter: 0.2 m) were formed independently of each other. In addition, by performing the activation treatment of the ultrafine carbon fiber, an ultrafine activated carbon fiber having a specific surface area of 197 m ² / g was obtained.

[Example 4]

In Example 1, the MI was measured at a density of 0.963 g / cm ^{3 at} 190 ° C. and a load of 21.18 N with a MI of 14 g. The average fiber diameter was changed in the same manner as in Example 1 except that the polyethylene fiber was changed to 1/10 min.

30 m of cured bicomponent fibers were obtained. In the same manner as in Example 1, the obtained conjugate fiber was carbonized to obtain a carbon fiber, and the carbon fiber was activated to obtain an activated carbon fiber. Table 1 shows the measurement results. Electron micrographs confirmed that the ultrafine carbon fibers (average fiber diameter 0.2 m) were formed individually and independently. In addition, by performing the activation treatment of the ultrafine carbon fiber, the specific surface area is 230 An ultra-fine activated carbon fiber of m ² / g was obtained.

[Example 5]

In Example 1, the polypropylene having MI of 60 g / 10 min was measured at a density of 0.964 g / cm ^{3 at} 190 ° C. and a load of 21. Cured bicomponent fibers having an average fiber diameter of 30πι were obtained in the same manner as in Example 1 except that the polyethylene fiber was changed to polyethylene (120 YK, manufactured by Idemitsu Petrochemical Co., Ltd.) for 10 minutes. In the same manner as in Example 1, the obtained conjugate fiber was carbonized to obtain a carbon fiber, and the carbon fiber was activated to obtain an activated carbon fiber. Table 1 shows the measurement results.

Electron micrographs confirmed that the ultrafine carbon fibers (average fiber diameter 0.2 m) were formed individually and independently. By activating the ultrafine carbon fibers, ultrafine activated carbon fibers having a specific surface area of 199 m ² / g could be obtained.

[Example 6]

In Example 1, the polypropylene having MI of 60 g / 10 min was measured at a density of 0.940 g / cm ³ , 190 ° C., and a load of 21.18 N to have a MI of 20 g / 10 N. Cured bicomponent fibers having an average fiber diameter of 30 m were obtained in the same manner as in Example 1 except that the polyethylene was changed to 10-minute polyethylene (074 G, manufactured by Idemitsu Petrochemical Co., Ltd.). In the same manner as in Example 1, the obtained composite fiber was carbonized to obtain a carbon fiber, and the carbon fiber was activated to obtain an activated carbon fiber. Table 1 shows the measurement results.

Electron micrographs confirmed that the ultrafine carbon fibers (average fiber diameter 0.2 m) were formed individually and independently. Further, by performing the activation treatment of the ultrafine carbon fiber, an ultrafine activated carbon fiber having a specific surface area of 270 m ² / g could be obtained. table 1

[Comparative Example 1]

The phenol resin synthesized in Example 1 was melt-spun at a nozzle temperature of 150 ° C. to obtain a raw phenol fiber. Further, the obtained raw fibers were immersed in an aqueous solution of hydrochloric acid-formaldehyde (18% by mass of hydrochloric acid, 10% by mass of formaldehyde) at 96 ° C. for 24 hours to obtain hardened fibers. Next, the cured fiber was carbonized in a nitrogen stream at 900 ° C. for 30 minutes to obtain a phenolic carbon fiber. The obtained fuynol-based carbon fiber is activated using steam at 900 ° C. for 5 minutes to obtain activated carbon. Fiber was obtained. The fiber diameter and specific surface area of these carbon fibers and activated carbon fibers were measured by the methods described above. The results are shown in Table 2, and the electron micrographs of the obtained phenolic carbon fiber are shown in Figs. FIG. 3 is a 1000 × magnification electron micrograph, and FIG. 4 is a 500 × magnification electron micrograph. The obtained fuynol-based carbon fiber has an average fiber diameter of 10 m, and the activated carbon fiber has a specific surface area of 500 m ² / g.

[Comparative Example 2]

In Example 1, a polypropylene having an MI of 60 g / 10 minutes and a MI of 34 g / 10 minutes measured at 230 ° C. under a load of 21.18 N (Idemitsu Petrochemical Co., Ltd.) In the same manner as in Example 1 except that the cured composite fiber had an average fiber diameter of 30 m. In the same manner as in Example 1, the obtained conjugate fiber was carbonized to obtain a fine carbon fiber, and this carbon fiber was activated to obtain an activated carbon fiber. Table 2 shows the measurement results.

FIGS. 5 and 6 show electron micrographs of the obtained ultrafine carbon fiber. FIG. 5 is a photomicrograph of × 100 magnification and FIG. 6 is a photomicrograph of × 500 magnification. From the electron micrographs, it was confirmed that the ultrafine carbon fibers (average fiber diameter: 0.2 μm) were formed individually, but were fused and shrunk. By activating the ultrafine carbon fibers, ultrafine activated carbon fibers having a specific surface area of 2000 m ² / g could be obtained.

[Comparative Example 3]

In Example 1, MI was measured at 60 g / 10 min with a polypropylene at 190 ° C. under a load of 2.18 N. Chemical company, 210 JZ) In the same manner as in Example 1, a composite resin bellet was obtained.

Next, the obtained composite resin was melt-spun at a nozzle temperature of 150 ° C. In the spinning process, stable extrusion could not be performed, and good spinning could not be performed due to fiber breakage, but sea-island uncured conjugate fibers with an average fiber diameter of 100 m could be obtained. . In the same manner as in Example 1, the obtained conjugate fiber was cured and carbonized to obtain a carbon fiber, and the carbon fiber was activated to obtain an activated carbon fiber. Table 2 shows the measurement results.

From the electron micrograph, it was confirmed that the ultrafine carbon fibers (average fiber diameter: 0.3 m) were formed individually and independently. Further, by performing the activation treatment of the ultrafine carbon fiber, an ultrafine activated carbon fiber having a specific surface area of 198 m ² / g could be obtained.

[Comparative Example 4]

In Example 1, a polypropylene having an MI of 4.0 g / 10 min measured at 230 ° C. under a load of 21.'18 N was prepared from polypropylene having an MI of 60 g / 10 min. A composite resin velvet was obtained in the same manner as in Example 1 except that Y-400 GP manufactured by Chemical Co., Ltd. was used.

Next, the obtained composite resin was melt-spun at a nozzle temperature of 170 ° C. In the spinning process, stable extrusion could not be performed, and good spinning could not be performed because the fibers were cut.However, it was not possible to obtain sea-island type uncured composite fibers having an average fiber diameter of 100 μm. The obtained composite fiber was cured and carbonized to obtain carbon fiber in the same manner as in Example 1, and the carbon fiber was activated to obtain an activated carbon fiber. Table 2 shows the measurement results.

From the electron micrograph, it was confirmed that the ultrafine carbon fibers (average fiber diameter: 0.3 m) were formed individually and independently. Also the pole By activating the fine carbon fiber, the specific surface area is 230

HI ² / g ultra-fine activated carbon fibers were obtained. Table 2

Industrial applicability

By carbonizing the composite fiber obtained from the resin composition for a composite fiber of the present invention, an ultrafine carbon fiber having an average fiber diameter of 0.5 Um or less can be easily produced.

Claims

The scope of the claims

1. Phenol resin 10 to 50% by mass and temperature 230 ° (MI: Melt index measured under the condition of load 2 1.18 N) is 10 to 100 g / 100. Resin composition for composite fibers, comprising 90 to 50% by mass of polypropylene for 1 minute.

2. The resin composition according to claim 1, wherein the phenolic resin is a nopolak-type phenolic resin having a softening point of 90 ° C or more.

3. A conjugate fiber having an average fiber diameter of 5 to 100 m, obtained by spinning the resin composition according to claim 1.

4. An ultrafine carbon fiber having an average fiber diameter of 0.511 m or less obtained by carbonizing the conjugate fiber according to claim 3.

5. An ultrafine activated carbon fiber obtained by activating the ultrafine carbon fiber according to claim 4.

6 · A shaped article obtained by shaping the fiber according to any one of claims 3 to 5.

7. Fuwenoru resin 1 0-5 0% by weight and density 0. 9 4 0 g / cm ³ or more, a temperature 1 9 0 ° C, MI, measured under a load of 2 1. 1 8 N (Mel Toys Nde' box) Is a resin composition for conjugate fiber comprising 90 to 50% by mass of polyethylene of 10 to 30 g / 10 minutes.

8. The resin composition according to claim 7, wherein the phenol resin is a nopolak phenol resin having a softening point of 90 ° C. or higher.

9. A conjugate fiber having an average fiber diameter of 5 to 100 m, obtained by spinning the resin composition according to claim 7.

10. An ultrafine carbon fiber having an average fiber diameter of 0.5 m or less obtained by carbonizing the conjugate fiber according to claim 9.

11. An ultrafine activated carbon fiber obtained by activating the ultrafine carbon fiber according to claim 10.

12. A shaped article obtained by shaping the fiber according to any one of claims 9 to 11.