JPS6257743B2 - - Google Patents

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, and more specifically, it is applied to acrylic fibers in a process before flame-retardant treatment to give them excellent process passability, and The present invention relates to an oil agent that prevents subsequent fusion of fibers and thus produces acrylic carbon fibers with excellent physical properties. When manufacturing carbon fiber using acrylic fiber as raw material, acrylic fiber called precursor is used as raw material.
A method is adopted in which the fibers are heated and fired in an oxidizing atmosphere at 200 to 300°C to form flame-resistant fibers, and then heated and carbonized in an inert atmosphere at 300 to 1700°C. In the production of such acrylic carbon fiber,
In order to obtain high-quality carbon fibers, it is important that the precursor has good splitting properties and little fusion during the flame-retardant process. Therefore, the oil agent applied in the process of producing precursors for acrylic carbon fibers not only imparts general smoothness, antistatic properties, and cohesive properties to the fibers, but also improves the splitting properties of the fibers. An excellent function to prevent fusion is required. Conventionally, alkali metal salts of phosphates, various cation activators, polyoxyalkylene ethers, etc. have been mainly used as oils for treating acrylic fibers, but these oils have antistatic properties, focusing properties, and smoothness. Although these oils have a certain level of performance, they have poor fiber splitting properties due to decomposition of the oil, and the flame-resistant fiber manufacturing process, which is carried out at temperatures of 200 to 300°C, produces tar. Otherwise, most of the treated oil agent evaporates in the early stage of heating, causing fusion between fibers, and thus does not have sufficient performance as an oil agent for treating precursors for manufacturing carbon fibers. From the above-mentioned viewpoints, the inventors of the present invention have found that, in the production of acrylic carbon fibers, they have excellent process passability (hereinafter simply referred to as "smoothness") and splitting properties in the precursor production and flame-retardant processes, as well as fusion-bonding properties. As a result of intensive research into oil agents for obtaining carbon fibers with stable quality and free from such problems, it was discovered that oil agents containing specific esters and specific nitrogen-containing surfactants in specific ranges were sufficient. This finding led to the completion of the present invention. That is, the present invention provides an aliphatic polyhydric alcohol having 2 to 4 hydroxyl groups bonded to each of the two carboxyl groups of an aliphatic dibasic acid, and the free hydroxyl group of the aliphatic polyhydric alcohol has the following general 40% by weight or more of an ester bonded with thio fatty acids represented by the formula, alkyl phosphate amine salt, polyoxyethylene alkyl phosphate amine salt, polyoxyethylene alkyl phenyl phosphate amine salt, alkyl or alkenyl An acrylic system characterized by containing an imidazolinium alkyl sulfate salt and 3% by weight or more of one or more nitrogen-containing surfactants selected from tertiary amine oxides represented by the following general formula: Pertains to oil for carbon fiber manufacturing. General formula: RS(CH ₂ ) _o COOH (However, R is an alkyl group or alkenyl group having 6 to 22 carbon atoms. n is an integer of 1 to 3.) General formula:

[Formula] (However, R ₁ is an alkyl group, alkenyl group, or hydroxyethyl group having 8 to 22 carbon atoms.
R ₂ and R ₃ may be the same or different at the same time, and are an alkyl group or an alkenyl group having 1 to 22 carbon atoms. ) Aliphatic dibasic acids in the present invention include succinic acid, adipic acid, sebacic acid, azelaic acid,
These include α,ω-eicosane, dicarboxylic acid [HOOC(CH ₂ ) ₂₀ COOH], and thiodipropionic acid, which is an aliphatic dibasic acid having a sulfide bond. In addition, the aliphatic polyhydric alcohol having 2 to 4 hydroxyl groups in the present invention includes aliphatic glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol, and diethylene glycol. aliphatic glycols with ether bonds such as polyalkylene glycols such as triethylene glycol, aliphatic glycols with sulfide bonds such as thiodiethanol, trihydric alcohols such as glycerin and trimethylolpropane, and trihydric alcohols such as pentaerythritol and diglycerin. alcohol, etc. Furthermore, the thioaliphatic acids in the present invention include γ
-Octylthiobutanoic acid, β-laurylthiopropionic acid, β-myristylthiopropionic acid, β
-Cetylthiopropionic acid, β-oleylthiopropionic acid, t-octylthioacetic acid, etc. The ester in the present invention is synthesized from the above components by various known methods. For example, n
(However, 2 mols of aliphatic polyhydric alcohol having 2≦n≦4) hydroxyl groups and 2 (n-1) mols of alkyl or alkenylthio fatty acids are combined in the presence of a catalyst of p-toluenesulfonic acid, After dehydration under reduced pressure at 120°C and reaction, 1 mol of aliphatic dibasic acid is further added and dehydration under reduced pressure is performed again at 110 to 120°C to cause reaction. The ester in the present invention thus obtained is
The molecular weight is preferably 2000 or less in terms of smoothness and emulsifying properties. In the present invention, the nitrogen-containing surfactant component contained together with the ester described above includes alkyl phosphate ester amine salt, polyoxyethylene alkyl phosphate ester amine salt, polyoxyethylene alkyl phenyl phosphate ester amine salt, alkyl phosphate ester amine salt, or alkenylimidazolinium alkyl sulfate salts, and tertiary amine oxides represented by the above general formula. Specific examples of these include lauryl phosphate/diethanolamine salt, stearyl phosphate/monoethanolamine salt, i-cetyl phosphate/dibutylethanolamine salt,
Triethanolamine salt of polyoxyethylene stearyl ether phosphate, diethanolamine salt of polyoxyethylene octyl ether phosphate, laurylamine salt of polyoxyethylene octylphenyl phosphate, heptadecenyl ethyl imidazolinium ethyl sulfate ate, undecylmethylimidazolinium methylsulfate, dimethyllaurylamine oxide, methyloctylstearylamine oxide, dioctyloleylamine oxide or distearylhydroxyethylamine oxide. The effect is remarkable when used. In the present invention, the above-mentioned ester content is set at 40% in order to sufficiently prevent fiber fusion during the flameproofing process.
The above-mentioned nitrogen-containing surfactant content needs to be 3% by weight or more in order to sufficiently increase the adhesion resistance and antistatic properties of the oil agent. The oil agent according to the present invention contains each of the above-mentioned components as essential components, but POE alkyl phenyl ether is added in order to improve the emulsifying properties of the above-mentioned ester to the extent that the effects of the present invention are not impaired. , POE alkyl ether, fatty acid EO adducts, etc., specifically t-butylphenol, nonylphenol, benzylphenol, lauryl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lauric acid, palmitic acid, oleic acid, behenic acid, etc. Nonionic surfactants such as EO adducts can be used, and in addition, smoothing agents, antioxidants, or preservatives such as coconut oil, POE(2) bisphenol A dilaurate, and polydimethyl silicone can be used. etc. can also be used as appropriate. The specific use of the oil agent according to the present invention is to apply the oil as an aqueous emulsion or an organic solvent solution during or after the precursor manufacturing process by a known oiling method such as roller oiling or immersion method. At this time, the amount of oil applied to the precursor is 0.1 in terms of antistatic properties.
It is preferably 3% by weight or more in terms of fusion resistance.
The following are preferred. As explained above, by applying the oil agent according to the present invention to acrylic synthetic fibers before the flame-retardant treatment step, it is possible to ultimately produce high-quality carbon fibers. The acrylic precursor tow used in the production of acrylic carbon fibers in the present invention is a homopolymer of acrylonitrile or contains at least 85 mol% of acrylonitrile, more preferably
It is manufactured from an acrylonitrile copolymer containing 90 mol% or more. Test examples will be given below to make the structure and effects of the present invention more concrete. Using the ingredients (1) to (27) shown in the test example, oil agents (Category 1 to 8
(Examples (Examples) and Comparative Examples (Categories 9 to 24)) were prepared and tested using the oil agent. The results are shown in Table 2.・Test A sample yarn was prepared by applying each oil agent listed in Table 1 to an acrylic filament yarn (75 denier/40 filament) using a roller oiling method so that the adhesion amount was 0.5 ± 0.1%, and the treated yarn was The friction coefficient and generated electricity were measured by the methods described below. In addition, each oil agent listed in Table 1 was applied to acrylic filament yarn (16,000 denier/12,000 filament) by a dipping method to a coating amount of 0.5 ± 1%, and then heated at 115°C using a dry heat roller. The precursor tow obtained by drying for 4 seconds was prepared and used as a sample to evaluate its fibrillation property by the method described below. Furthermore,
After splitting, the precursor tow was processed in a forced circulation oven at 250°C for 60 minutes, and this was used as a sample to evaluate its fusion resistance using the method described below. ...Friction coefficient and generated electricity A sample yarn left in an atmosphere of 20℃ and 60% RH for 24 hours was run in contact with a chrome-plated satin finish pin under the same conditions at an initial tension of 20g and a yarn speed of 100m/min. was measured with a μmeter (manufactured by Eiko Sokki Co., Ltd.). At the same time, the electricity generated at the point of contact with the chrome plated satin finished pin was measured using a Kasuga type current collector. In both cases, the smaller the measured value (absolute value), the
It's good. ...Fiber splitting property The sample precursor tow was cut into 2 cm pieces, lightly shaken on black paper, and the splitting state was evaluated using the following standard. ◎: Good splitting property 〇: Good splitting property △: Slightly poor splitting property ×: Separating property is markedly poor...fusing resistance The flame-resistant fiber sample was cut into 2 cm pieces and lightly shaken on white paper. The fusion resistance state was evaluated using the following standards. ◎: No fusion 〇: Very slight fusion △: Slight fusion ×: Large fusion × ×: Significantly large fusion Component (1) (2) (3) (Four) (Five) (6) Liquid paraffin (120 seconds RW/30℃) (7) i-stearyl stearate (8) Rapeseed oil (9) Polyether (MW: 1000) (10) Polydimethylsiloxane (emulsion) (11) Amino modification Silicon (emulsion) (12) POE (10) Nonyl phenyl ether (13) POE (6) Lauryl ether (14) POE (8) Palmitate (15) POE (30) Hydrogenated castor oil (16) POE (22) Sorbitan triolate (17) i-cetylphosphate diethanolamine salt (18) POE (3) lauryl phosphate monoethanolamine salt (19) POE (2) octylphenol phosphate triethanolamine salt (20) stearyl ethyl imidazo Linium monoethyl sulfate (21) Dimethyl lauryl amine oxide (22) Dioctyl oleyl amine oxide (23) Distearyl hydroxyamine oxide (24) Potassium laurate (25) Sodium cetyl sulfonate (26) N-Oleoyl-N- Sodium methyltaurate (27) Sodium lauryl aminopropionate

【table】

【table】

[Table] From the results in Table 2, it is clear that the oil agent according to the present invention has excellent performance in fiber splitting properties and anti-fusing properties required for oil agents for producing acrylic carbon fibers, and has smoothness and antistatic property. It is clear that the characteristics are also good. In particular, in this test example, the results of Example 2 for Comparative Example 14 and the results of Example 2 for Comparative Example 10 demonstrate the mutual effect of the ester and nitrogen-containing surfactant in the present invention. The results of Example 2 for Example 3 demonstrate the effectiveness of tertiary amine oxide among the nitrogen-containing surfactants in the present invention.

Claims (1)

[Scope of Claims] 1. An aliphatic polyhydric alcohol having 2 to 4 hydroxyl groups is bonded to each of the two carboxyl groups of the aliphatic dibasic acid, and the free hydroxyl groups of the aliphatic polyhydric alcohol have the following properties: 40% by weight or more of an ester bound with thio fatty acids represented by the general formula;
Alkyl phosphate ester amine salts, polyoxyethylene alkyl phosphate ester amine salts, polyoxyethylene alkyl phenyl phosphate ester amine salts, alkyl or alkenylimidazolinium alkyl sulfate salts, and tertiary salts represented by the following general formula An oil agent for producing acrylic carbon fibers, characterized in that it contains 3% by weight or more of one or more nitrogen-containing surfactants selected from amine oxides. General formula: RS(CH ₂ ) _o COOH (However, R is an alkyl group or alkenyl group having 6 to 22 carbon atoms. n is an integer of 1 to 3.) General formula: [Formula] (However, R ₁ is an alkyl group, alkenyl group or hydroxyethyl group having 8 to 22 carbon atoms.
R ₂ and R ₃ may be the same or different at the same time, and are an alkyl group or an alkenyl group having 1 to 22 carbon atoms. )