JPS58214581A - Oil agent for producing acrylic carbon fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil agent for treating acrylic fibers used as a precursor in the production of carbon fibers.

More precisely, it is added to acrylic fibers in the process before flame-retardant treatment to give them excellent permeability through the process and prevent the fibers from fusing after the flame-retardant process, producing acrylic carbon fibers with excellent physical properties. The present invention relates to an oil agent containing an alkyl@■ or alkenylthio fatty acid ester.

When manufacturing carbon fiber using acrylic fiber as a raw material, the acrylic fiber called precursor is heated to 200 to 300°C.
A method is adopted in which the fibers are heated and fired in an oxidizing atmosphere of 300 to 1,700° C. to form flame-resistant fibers, and then heated and carbonized in an inert atmosphere at 300 to 1,700° C.

Conventionally, in the production of acrylic carbon fibers, it has been said that in order to obtain high-quality carbon fibers, it is important that K has good precursor splitting properties and little fusion during the flame-retardant process.

Therefore, the oil agent applied in the process of manufacturing acrylic carbon fiber precursors provides general smoothness, antistatic, and cohesive functions to the fibers, as well as excellent fiber splitting properties and fusion bonding properties. A function to prevent this is required.

However, in the precursor production process, process passability, fiber splitting property,
At present, there is currently no known oil agent that satisfies all of the requirements of improving cohesiveness, preventing fluff, and preventing fusion during the flame-resistant fiber production process.

In general, alkali metal phosphate salts, various cation activators, polyoxyalkylene ethers, etc. are mainly used as oils for treating acrylic fibers, but these oils have limited antistatic properties, focusing properties, and smoothness. However, it has been pointed out that these oils have poor fiber splitting properties due to decomposition of the oil. Also 2
In the flame-retardant fiber manufacturing process, which is carried out at temperatures between 00 and 300 degrees Celsius, tar is generated or most of the treated oil is volatilized during the initial heating stage, causing fusion between the fibers. It does not have sufficient performance as an oil agent for treating precursors.

Here, the present inventors have discovered that in the production of acrylic carbon fibers, the precursor production and flame resistant processes have excellent process passability (hereinafter referred to as smoothness) and splitting properties, and stable quality without problems such as fusion. The present invention was arrived at as a result of extensive research into oil agents for obtaining carbon fibers.

That is, the present invention relates to an ester obtained by reacting an alkyl or alkenylthio fatty acid represented by the following general formula with an aliphatic alcohol having 1 to 4 hydroxyl groups (hereinafter referred to as the ester of the present invention), and a nitrogen-containing surfactant. The present invention relates to an oil agent for producing acrylic carbon fibers, which is characterized by containing an agent as an important component.

General formula R8(CH2)ncOOH R: alkyl or alkenyl group of carbon a6-22 n: 1
An integer of ~3 The oil agent of the present invention can be applied to acrylic synthetic fibers before the flame-retardant treatment step to obtain high-quality carbon fibers.

The acrylic precursor tow used in the production of acrylic carbon fibers in the present invention is made from an acrylonitrile homopolymer or an acrylonitrile copolymer containing at least 85 moles of acrylonitrile, preferably 90 moles or more. It is manufactured.

Specific examples of alkyl or alkenylthio fatty acids used to obtain the esters of the invention include γ-octylthiobutanoic acid, β-laurylthiopropionic acid, β-myristylthiopropionic acid, β-cetylthiopropionic acid,
Examples include β-oleylthiopropionic acid and t-octylthioacetic acid.

Similarly, the aliphatic alcohols having 1 to 4 hydroxyl groups used in the present invention include lauryl alcohol, which is an aliphatic alcohol having an alkyl or alkenyl group having 6 to 24 carbon atoms, -tridecyl alcohol, Oleyl alcohol, l-stearyl alcohol, etc., aliphatic glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, etc., aliphatic glycols having an ether bond, such as diethylene glycol Examples include hetriethylene glycol and thiogetanol, which is an aliphatic glycol having a sulfide bond; trihydric alcohols, such as glycerin and trimethylolpropane; and quaternary alcohol, pentaerythritol.

The ester, which is an important component of the present invention, can be produced by various known methods. For example, an ester of an alkyl or alkenylthio fatty acid and an aliphatic alcohol can be prepared by mixing 1 mole of alkyl or alkenylthio fatty acid with 1 mole of fatty acid. Dehydration of K group alcohols under reduced pressure at 110 to 120°C in the presence of an acidic catalyst, such as p-)luenesulfonic acid.
Therefore, it is obtained.

The esters of the present invention include β-octylthiopropionate i-stearyl ester β-myristylthiopropionate i-stearyl ester β-oleylthiopropionate octyl ester β-stearylthiopropionate oleyl ester bis-(β
-myristylthiopropionic acid) ethylene glycol ester tri(β-stearylthiopropionic acid) pentaerythritol ester cap.

The above-mentioned ester of the present invention preferably has a molecular weight of 400 or more in order to prevent evaporation and diffusion during the flame resistance process at 200 to 300°C, and preferably has a molecular weight of 2.000 or less in terms of smoothness and emulsifying property. It is preferable that there be.

Next, in the present invention, the nitrogen-containing surfactant component contained together with the alkyl or alkenylthio fatty acid ester is obtained from an alkyl phosphate amine salt, a polyoxyethylene alkyl phosphate amine salt, an alkylimidacyline and a dialkyl sulfate. R1: Ca-22 alkyl group, alkenyl group or human, specific examples of which include lauryl phosphate ester, Jetanolamine salt, stearyl phosphate monoethanolamine salt, i-cetyl phosphate-diptylethanolamine salt, triethanolamine salt of polyoxyethylene stearyl ether phosphate, polyoxyethylene octyl ether phosphate jetanolamine salt, polyoxyethylene octylph x1 ζ′ laurylamine salt,
Examples include heptadecenyl ethyl imidazolinium ethyl sulfate, undecyl methyl imidazolinium methyl sulfate, dimethyl lauryl amine oxide, methyl octyl stearyl amine oxide, dioctyl oleyl amine oxide, and distearyl hydroxyethyl amine oxide. In particular, when tertiary amine oxide is used as the nitrogen-containing surfactant, the effect is remarkable.

The content of the ester of the present invention in the oil agent of the present invention is usually 40% by weight in order to sufficiently prevent fusion of fibers in the flameproofing process.
It is preferable that it is above.

Further, the content of the nitrogen-containing surfactant is preferably 3% by weight or more in order to sufficiently increase the adhesion resistance and antistatic properties of the oil agent of the present invention.

The oil solution of the present invention contains the above-mentioned two components as essential components, but it is necessary to improve the emulsifying properties of the ester of the present invention within a range that does not impair the effects of the present invention. Ethers, fatty acid EO adducts, etc., specifically 1-butylphenol,
Nonylphenol, benzylphenol, lauryl alcohol, stearyl alcohol, oleyl alcohol,
Nonionic surfactants such as behenyl alcohol, EO adducts of lauric acid, palmitic acid, oleic acid, behenic acid, etc. can be used.

Furthermore, in the present invention, in addition to the above ingredients, coconut oil, PoE (
2) Smoothing agents such as bisphenol A dilaurate, polydimethyl silicone, antioxidants, preservatives, etc. can also be used as appropriate.

When using the oil agent of the present invention, it is applied during or after the precursor manufacturing process by a known oiling method such as a water-based method, silicone or organic solvent solution, roller oiling, or dipping method.

The amount of oil applied to the breaker is 0.1 in terms of antistatic properties.
It is preferably at least 3% by weight, and preferably at most 3% by weight from the viewpoint of fusion resistance.

Examples of the present invention will be described below together with comparative examples, but the present invention is not limited thereto.

Examples and Comparative Examples Processing oils 1 to 10 of the present invention and processing oils 1 to 8 of comparative examples using the esters of the present invention shown in Table 1 were prepared. Their compositions are shown in Table-2.

(The numbers under the numbers 1 to 10 and 1 to 8 each indicate weight %.) The above treatment oil was applied in an amount of 0.5±0.
A sample thread was prepared using a roller oiling method so that the oil content was 1%, and the friction coefficient and generated electricity of the treatment system were measured using the methods described below.

Also, acrylic filament thread (16ρ00 denier/12
．． 000 filament) was applied with the above-mentioned processing oil to a coating amount of 0.5±0.1 inch by dipping method, and then dried using a dry heat roller at 115°C for 4 seconds to obtain the obtained precursor tow. was prepared, and its fibrillation properties were measured and evaluated using the method described below using nuclear precursor tow as a sample.

Further, the precursor tow after fiber splitting was treated as a sample in a forced circulation open condition at 250° C. for 60 minutes, and the fusion resistance was measured and evaluated using the method described below.

Friction coefficient and electricity generation A sample yarn was left for 24 hours in an atmosphere of 20°C and 65% RH, and under the same conditions, the initial tension was 202 and the yarn speed was 100 m/-i-.
Ting. The friction coefficient was measured using a µmeter (manufactured by Eiko Sokki) by running it in contact with a matte finish coated Epin. At the same time, the electricity generated at the point of contact with the chrome-plated satin finished bottle was measured using a Kasuga type current collector. All measured values (absolute values)
The smaller the value, the better.

Precursor tow as a splittable sample was cut into 2 cm pieces, lightly shaken on black paper, and the split line condition was evaluated using the following standard.

◎: Good splitting property △; Slightly poor ×: Significantly poor Fusing resistance The flame-resistant fiber of the sample was cut into 2 crn pieces and lightly shaken on white paper, and the fusing resistance was evaluated using the following standards. .

◎: No fusion ○：〃〃〃Very little Δ: Slightly present ×：〃Large ××: Significantly large The test results were as shown in Table-2.

From the results shown in Table 2, the oil agent of the present invention using the ester of the present invention has excellent performance in all aspects of fiber splitting properties, fusion resistance, smoothness, and antistatic properties required as an oil agent for carbon fiber production. It is clear to show.

In contrast, conventional silicon-based compounds (Comparative Examples 7.8)
The conventional polyether compound (Comparative Example 6) had good antistatic properties but poor fusion resistance and splitting properties, although it had good splitting properties. and poor smoothness. Therefore, with silicone-based and polyether-based oils, it is not possible to simultaneously obtain good results for the four items mentioned above, and it is clear that there is a clear difference in this respect compared to the oil of the present invention.

It is also clear from Comparative Examples 1 and 2 that even if the ester of the present invention is used, good results cannot be obtained in all of the above four items with an oil agent that does not contain a nitrogen-containing surfactant.

Furthermore, it is clear from Comparative Examples 3.4 and 5 that if the ester of the present invention is not used as a leveling agent, good results cannot be obtained even if a nitrogen-containing surfactant is contained.

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Claims (1)

[Scope of Claims] 1. An ester obtained by reacting an alkyl or alkenylthio fatty acid represented by the following general formula with an aliphatic alcohol having 1 to 4 hydroxyl groups, and a nitrogen-containing surfactant as important components. An oil agent for producing acrylic carbon fiber characterized by containing: General formula RS (CH2)n COOH E,: alkyl group or alkenyl group having 6 to 22 carbon atoms n
: An integer 2 from 1 to 3. The oil agent for producing acrylic carbon fibers according to claim 1, wherein the nitrogen-containing surfactant is a tertiary amine oxide represented by the following general formula. )