JP3101909B2 - Phenolic resin fiber and phenolic resin-based carbon fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fiber, particularly a phenol resin fiber and a phenol resin carbon fiber prepared using the same.

[0002]

2. Description of the Related Art Phenolic resin fibers have been used for a long time in a wide range of fields such as industrial materials because of their relatively inexpensiveness and versatility, but because of their insufficient strength and elastic modulus, For example, the application range is limited because it is difficult to use as a reinforcing material.

[0003] Further, carbon fibers obtained by firing phenol resin fibers, for example, carbon fibers obtained by firing novoloid fibers are known. This type of carbon fiber is rich in flexibility, hardly generates fly waste and dust during processing, and has good lubricating properties.However, compared to polyacrylonitrile-based or pitch-based carbon fiber, Therefore, its strength and elastic modulus are low, and its application range is limited as in the case of phenol resin fibers. In particular, when activated, the strength is remarkably reduced, and the availability is extremely poor.

[0004] It is an object of the present invention to increase the strength and elastic modulus of phenolic resin fibers and carbon fibers prepared using the same.

[0005]

SUMMARY OF THE INVENTION A phenolic resin fiber according to the present invention contains a phenolic resin component prepared using phenols and aldehydes, and a crystalline component.
Here, the phenol resin component is, for example, a novolak resin. On the other hand, the crystalline component has, for example, three strong lines in the range of 2θ ≦ 25 ° in X-ray diffraction using CuKα radiation, and is specifically a calixarene. Incidentally, the crystalline component is usually contained in an amount of 1 to 50% by weight.

[0006] The phenolic resin-based carbon fiber according to the present invention is obtained by calcining a phenolic resin fiber containing a phenolic resin component prepared using phenols and aldehydes and a crystalline component. Here, the phenol resin fiber is, for example, 500 to 500 in an inert gas atmosphere.
Fired at 2800 ° C. The carbon fibers include, for example, activated activated carbon fibers.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Phenol resin fiber The phenol resin component used in the present invention is not particularly limited, and phenols such as phenol, alkyl-substituted phenol and bisphenol A, formaldehyde, acetaldehyde and furfuryl aldehyde And those prepared using aldehydes such as There are various known phenol resins, and specifically, a resole resin, a novolak resin, and a mixture thereof can be used as the phenol resin component. When a novolak resin is used as the phenol resin component, melt spinning can be easily performed.

The crystalline component used in the present invention is not particularly limited as long as it is a substance exhibiting crystallinity (particularly, a substance exhibiting crystallinity even in a mixture with a phenol resin component). (Particularly, a molecular weight of 500 to
About 2000 organic compounds). Two or more crystalline components can be used in combination. By using a crystalline component having three strong lines at 2θ ≦ 25 ° in X-ray diffraction using CuKα ray, it is possible to more effectively increase the strength and elastic modulus of the objective phenol resin fiber and carbon fiber. it can. In this case, since the obtained phenol resin fiber contains the above-mentioned crystalline component, it has a peak at 2θ ≦ 25 ° in X-ray diffraction using CuKα ray.

In X-ray diffraction using CuKα ray, 2θ
Examples of the crystalline component having three strong lines at ≦ 25 ° include calixarenes. Calixarenes are compounds in which phenols are cyclically linked via a methylene group, and are represented, for example, by the following general formula (A). In the general formula (A), n is an integer of 3 or more (usually 12 or less). R represents hydrogen or an organic group such as an alkyl group (for example, an alkyl group having 1 to 6 m carbon atoms).

[0010]

Embedded image

Various calixarenes are known, and specific examples thereof include the following. R in the formula is hydrogen or an alkyl group (eg, te
rt-butyl group).

[0012]

Embedded image

In the present specification, for the sake of convenience, the calixarenes of the above formulas (1), (2), (3), (4) and (5) are referred to as calixarenes [4] and [4], respectively.
The names are calixarene [5], calixarene [6], calixarene [7] and calixarene [8]. The numerical value in [] is the number of phenol units constituting the calixarene, and corresponds to n in the general formula (A). X-ray powder diffraction of calix arene [4] and calix arene [8] by CuKα radiation is shown in FIGS. 1 and 2, respectively. As is clear from FIGS. 1 and 2, both calixarenes have three strong lines in the range of 2θ ≦ 25 °.

A mixture containing a phenolic resin component and a crystalline component is usually obtained by adding a crystalline component to the phenolic resin component. However, when the crystalline component is a calixarene, the reaction conditions (for example, severe reaction conditions of high temperature and concentrated alkali) at which the calixarene is simultaneously generated during the synthesis of the phenol resin are adjusted, and thus the phenol resin is adjusted. And calixarenes can be obtained. The resulting mixture of phenolic resin and calixarenes is
It can be used as it is or purified for spinning.

By using a mixture of a phenolic resin component and a crystalline component and containing the crystalline component in an amount of 1 to 50% by weight, the desired properties of the phenolic resin fiber and carbon fiber can be effectively enhanced. it can. When the content of the crystalline component is less than 1% by weight, it may be difficult to effectively increase the strength and elastic modulus of the target phenol resin fiber and carbon fiber. Conversely, if it exceeds 50% by weight, drawbacks such as a decrease in spinning performance upon fiberization and a decrease in fiber strength after spinning occur.

The fineness, diameter, fiber length and the like of the phenolic resin fiber of the present invention are not particularly limited, and can be variously set according to the purpose of use of the phenolic resin fiber. The phenolic resin fiber of the present invention usually has about 1.5 times the strength and modulus of elasticity as compared with a phenolic resin fiber produced using a phenolic resin containing no crystalline component.

The phenolic resin fiber according to the present invention can be produced from a mixture containing the above-mentioned phenolic resin component and the above-mentioned crystalline component via a known spinning method. For example, a phenol resin fiber can be obtained by melt-spinning the mixture, stretching and post-treating the mixture as necessary. When a novolak resin is used as the phenol resin component, a curing agent is used to cure the phenol resin fibers after spinning. As a curing agent,
For example, resole resin, hexamethylenetetramine, paraformaldehyde, trioxane and the like can be used. In this case, a curable agent may be added in advance to the mixture containing the phenolic resin component (novolak resin) and the crystalline component by adding a curing agent before spinning, or the fiber obtained by melt spinning may be subjected to formaldehyde. May be immersed in an acid solution of the above for curing.

Phenolic resin-based carbon fiber The phenolic resin-based carbon fiber of the present invention is obtained by firing the above-mentioned phenolic resin fiber.
The phenol resin fiber is fired at 500 to 2800 ° C. in an atmosphere of an inert gas such as nitrogen or argon.
, Preferably in a temperature range of 800 to 1500 ° C, carbon fibers can be obtained efficiently. When the firing temperature is lower than 500 ° C., it is difficult to obtain performance as a carbon fiber. Conversely, if the temperature exceeds 2800 ° C., sublimation causes a decrease in the yield of carbon fibers and a decrease in strength.

By activating the phenolic resin-based carbon fiber of the present invention, an activated carbon fiber having excellent strength and elastic modulus can be obtained. Activation of the phenolic resin-based carbon fiber can be performed by a method similar to the activation method conventionally applied to carbon fibers. When activated carbon fibers obtained by baking phenolic resin fibers produced using a phenolic resin component to which metals such as yttrium and vanadium, metal salts, metal oxides, and organic metals are added before spinning, macropores are formed after activation. Thus, activated carbon fibers capable of adsorbing macromolecules such as humic acid can be obtained. In addition, when a carbon fiber obtained by firing a phenol resin fiber produced using a phenol resin component to which a metal such as silver, a metal salt, a metal oxide, and an organic metal has been added is activated, an antibacterial activated carbon fiber is obtained. be able to.

The fineness, diameter, fiber length and the like of the phenolic resin-based carbon fibers (including activated carbon fibers) of the present invention are not particularly limited, and can be variously set according to the purpose of use of the carbon fibers. it can. The carbon fiber of the present invention usually has about 1.8 times the strength and elastic modulus as compared with carbon fiber produced using a phenol resin fiber containing no crystalline component. Generally, when carbon fibers are activated, the strength decreases. However, the carbon fiber of the present invention can maintain required strength even when activated.

[0021]

EXAMPLES Production Example 1 (Production of novolak resin) 77% by weight of phenol, 8.7% by weight of formaldehyde
4880 g of a mixture consisting of water and 14.3% by weight of water was prepared, and 8 g of 95% sulfuric acid was added thereto. The mixture was heated to 70 ° C. to initiate a novolak resin formation reaction. A 37% formaldehyde aqueous solution 16 was added to the reaction system.
After adding 40 g over 15 minutes and refluxing for 3 hours, the solution was neutralized by adding a solution of 7 g of sodium hydroxide in 50 ml of water. Next, the reaction system was gradually heated to 150 ° C., and at the same time, water present in the reaction system was removed by vacuum distillation. As a result, a crude novolak resin was obtained.

In order to remove phenol, sodium sulfate and a low molecular weight novolak resin fraction contained in the obtained crude novolak resin, the crude novolak resin is vigorously stirred and washed in 2 liters of water. Was discarded. Such washing with water was repeated twice, and the novolak resin after washing was cooled to room temperature and solidified. This novolak resin had a number average molecular weight of about 850 and a viscosity at 130 ° C. of about 70,000 cps.

Production Example 2 (Production of Calixarene [6]
They were charged 37% formaldehyde phenol and 33.8ml of granulation) 15.7 g in the flask, to which was added rubidium hydroxide of 5.82 g. This at 80-90 ° C
The mixture was heated for 5 minutes, and then stirred for 2 hours while passing nitrogen through the reaction system while removing water and formaldehyde under heating. Next, 250 ml of xylene was added to the reaction system,
The reaction system was heated up to the reflux temperature at once in 10-15 minutes. When reflux was continued for 3 hours, calixarene [6] was precipitated in the reaction system during this time.

The reaction was cooled to room temperature, the solids were filtered and washed with xylene. This solid was suspended in chloroform, and the extraction operation was repeated three times using 1N hydrochloric acid. The organic layer was washed with distilled water until neutral, the organic layer was separated, and the solvent was distilled off. As a result, calixarene [6] crystals were obtained. The obtained calixarene [6] crystal was vacuum-dried at 150 ° C. for 24 hours. The yield was 36.3%.

Production Example 3 (containing calixarene [4])
Production of novolak resin) In a round bottom flask placed on a steam bath, 50 g of resorcinol was dissolved in 500 ml of 10% sulfuric acid.
Separately, 1 in 190 ml of 10% aqueous formaldehyde solution
110 ml of a 0% aqueous sulfuric acid solution was gradually added to obtain a diluted sulfuric acid solution of formaldehyde. The resulting diluted sulfuric acid solution of formaldehyde was cooled and added to the resorcinol solution in the flask at a rate of 5 ml every 5 minutes.

In the flask, the reaction immediately proceeded with the addition of a dilute sulfuric acid solution of formaldehyde, and a white precipitate which quickly turned dark red was formed. The reaction product thus obtained was filtered, washed and dried to obtain a mixture of a novolak resin and calixarene [4]. Calixarene in this mixture [4]
Was 25.4% by mass.

Example 1 (Production of phenol resin fiber) Production Example 2 was applied to 100 g of the novolak resin obtained in Production Example 1.
Was mixed with 15 g of the calixarene [6] obtained in the above. The mixture is melt spun at 140 ° C. and
m of fiber were obtained. Next, an aqueous solution (hardening agent for novolak resin) containing 18% by mass of hydrochloric acid and 18.5% by mass of formaldehyde was prepared, and the obtained fiber was immersed therein. The temperature of the aqueous solution was set to 40 ° C., and
After gradually increasing the temperature to 100 ° C, the temperature is further increased to 100 ° C for 1 hour.
Temperature. Next, the fiber was taken out from the aqueous solution, washed with water, and dried in air at about 100 ° C.

The obtained phenol resin fiber is 25 m long.
m, and the fiber pieces were examined for fiber diameter, tensile strength and tensile modulus.
4.2 .mu.m, strength 24.5kgf / mm ² (average value), the tensile elastic modulus was 620kgf / mm ² (average value). The fiber diameter was measured with a laser outer diameter measuring device M-550-A manufactured by Anritsu Corporation, and the tensile strength and tensile modulus were measured with a strength tester UTM-II-20 manufactured by Toyo Baldwin Co., Ltd.

Example 2 (Production of phenolic resin fiber) Production Example 3 was applied to 100 g of the novolak resin obtained in Production Example 1.
The calixarene [4] -containing novolak resin (50 g) obtained in (1) was mixed and melted at 135 ° C., and the melt was spun into a fiber having a diameter of about 14 μm. The obtained fiber was treated in the same manner as in Example 1 to obtain a phenol resin fiber.
This phenolic resin fiber is cut into many pieces with a length of 25 mm,
When the fiber diameter, strength and tensile modulus were examined in the same manner as in Example 1, the average fiber diameter was 13.8 μm and the strength was 2
8.6 kgf / mm ² (average value), tensile modulus is 642
kgf / mm ² (average value).

Comparative Example 1 (Production of Phenolic Resin Fiber) The novolak resin obtained in Production Example 1 was melted at 135 ° C., and this melt was spun into a fiber having a diameter of about 14 μm.
The obtained fiber was treated in the same manner as in Example 1 to obtain a phenol resin fiber. This phenolic resin fiber has a length of 2
Cut to a large number of 5 mm, the fiber diameter in the same manner as in Example 1,
When the strength and tensile modulus were examined, the average fiber diameter was 1
3.2 μm, strength was 18.2 kgf / mm ² (average value), and tensile modulus was 440 kgf / mm ² (average value).

Example 3 (Production of Carbon Fiber) The phenol resin fiber obtained in Example 1 was fired at 900 ° C. in a nitrogen atmosphere to obtain a carbon fiber. A large number of the obtained carbon fibers were cut into a length of 25 mm, and the fiber diameter, strength and tensile modulus were measured in the same manner as in Example 1. The average fiber diameter was 11.4 μm and the strength was 74 kgf / m.
m ² (average value), tensile modulus of elasticity is 3670 kgf / mm
² (average value).

Example 4 (Production of carbon fiber) The phenol resin fiber obtained in Example 2 was fired at 900 ° C. in a nitrogen atmosphere to obtain a carbon fiber. A large number of the obtained carbon fibers were cut into a length of 25 mm, and the fiber diameter, strength and tensile modulus were examined in the same manner as in Example 1. As a result, the average fiber diameter was 10.8 μm and the strength was 83.2 kgf.
/ Mm ² (average value), tensile modulus of elasticity is 4280 kgf / m
m ² (average value).

Comparative Example 2 (Production of Carbon Fiber) The phenolic resin fiber obtained in Comparative Example 1 was fired at 900 ° C. in a nitrogen atmosphere to obtain a carbon fiber. A large number of the obtained carbon fibers were cut into a length of 25 mm, and the fiber diameter, strength, and tensile modulus were measured in the same manner as in Example 1. As a result, the average fiber diameter was 10.5 μm, and the strength was 43.2 kgf.
/ Mm ² (average value), tensile modulus is 2340 kgf / m
m ² (average value).

Example 5 (Production of Activated Carbon Fiber) The carbon fiber obtained in Example 3 was activated by steam at 750 ° C. using a rotary kiln. This activated carbon fiber was cut into many pieces having a length of 25 mm, and the fiber diameter and tensile strength were examined in the same manner as in Example 1.
0.5 [mu] m, the strength degree of 41.6kgf / mm ² (average value)
Met.

Comparative Example 3 (Production of Activated Carbon Fiber) The carbon fiber obtained in Comparative Example 2 was activated in the same manner as in Example 5. A large number of the activated carbon fibers were cut into a length of 25 mm, and the fiber diameter and tensile strength were examined in the same manner as in Example 1. As a result, the average fiber diameter was 9.5 μm and the strength was 31.
It was 7 kgf / mm ² (average value).

[0036]

As described above, the phenolic resin fiber of the present invention contains a phenolic resin component and a crystalline component as described above, and therefore has higher strength and elastic modulus than conventional phenolic resin fibers. The phenolic resin-based carbon fiber of the present invention is manufactured using the phenolic resin fiber of the present invention, and has a higher strength and elastic modulus than conventional phenolic resin-based carbon fibers, so that it can be used in a wide range of applications. It is.

[Brief description of the drawings]

FIG. 1 is a diagram showing the results of X-ray powder diffraction of calixarene [4] by CuKα radiation.

FIG. 2 is a diagram showing the results of X-ray powder diffraction of calixarene [8] by CuKα radiation.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-117822 (JP, A) JP-A-2-221420 (JP, A) JP-A-50-158644 (JP, A) JP-A-50-158 123923 (JP, A) JP-A-50-31118 (JP, A) JP-A-49-71211 (JP, A) JP-A-48-72413 (JP, A) JP-A-48-77112 (JP, A) JP-A-48-93721 (JP, A) JP-A-48-9690 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 6/76 D01F 9/24 551

Claims (7)

(57) [Claims] 1. A phenolic resin component prepared using a phenol and an aldehyde, and a calixarene
Phenolic fibers containing a kind, the. 2. The phenolic resin fiber according to claim 1, wherein the phenolic resin component is a novolak resin. 3. In X-ray diffraction using CuKα ray, 2
3. The phenolic resin fiber according to claim 1, which has a peak in the range of θ ≦ 25 °. 4. A calixarene comprising 1 to 50% by weight.
The phenolic resin fiber according to any one of claims 1 to 3 , which contains the phenolic resin fiber. 5. A phenolic resin component prepared using a phenol and an aldehyde, and a calixarene.
Phenolic resin based carbon fiber obtained by firing a phenolic resin fiber containing a kind, the. 6. The phenolic fibers obtained by firing at 500 to 2,800 ° C. in an inert gas atmosphere according to claim 5
2. The phenolic resin-based carbon fiber according to item 1. 7. Activated carbon fibers obtained by activating the phenolic resin-based carbon fibers according to claim 5 or 6 .