Silicon-free oiling agent for carbon fiber precursor

Abstract

The invention discloses a silicon-free oiling agent for carbon fiber precursor. The silicon-free oiling agent comprises an aqueous emulsion prepared by dispersing aromatic ester compounds, aromatic polyoxyethylene ether and amine compounds, by the mass ratio of (50-80):(10-35):(1-5), in water; the aromatic ester compounds include one or more of benzene tricarboxylic acid esters, benzene dioctyl phthalate esters, hydroxy-benzoate esters and bisphenol ethoxide high-grade fatty acid esters; aromatic polyoxyethylene ether includes one or more of alkylphenol polyoxyethylene and bisphenol-A polyoxyethylene ether; the amine compounds include one or more of lauramide ethoxide, aliphatic long-chain quaternary ammonium; the survival rate of mass of the aromatic ester compounds is 80-98% at the temperature of 300 DEG C in the atmosphere of air, and the mass ratio of the aromatic ester compounds in involatile components of the oiling agent is 50-80%. Roll banding degree of the precursor in production can be reduced effectively, doubling and adhering of PAN filaments in the pre-oxidation process can be avoided, and the silicon-free oiling agent has certain hydrophilicity and heat resistance.

Description

technical field [0001] The invention relates to a silicone-free oil agent, in particular to a silicone-free oil agent for carbon fiber precursors, and belongs to the technical field of textile oil agents. Background technique [0002] Carbon fiber is widely used in the field of advanced composite materials as a reinforcing material due to its good specific strength and specific elastic modulus. The industrial production method of carbon fiber is to pre-oxidize polyacrylonitrile (PAN) fiber bundles in an oxidative atmosphere between 200-400°C to obtain non-combustible and non-melting pre-oxidized fibers, and then heat them at a high temperature of at least 1000°C , carbonized in an inert atmosphere such as nitrogen to obtain carbon fibers. [0003] In the pre-oxidation process, the process temperature exceeds the softening point of the PAN precursor. Under the action of heat, the PAN monofilament will soften and even melt, and adjacent monofilaments will stick to each other,...

AI Technical Summary

Problems solved by technology

[0013] In Documents 1, 2, and 3, silicon-based substances and non-silicon substances are used as the main active ingredients of the oil agent. Although the content of silicone oil in the non-volatile components is different, as long as it contains silicone oil, the aforementioned problems can be solved. be completely resolved, especially the ash content of fibers

In addition, the two-stage oiling method used in Document 1, compared with one-time oiling, additionally increases the equipment cost

In Document 3, the heat resistance of the aliphatic ester compound used is insufficient, and there is still room for improvement in the effect of preventing monofilament sticking

Both document 4 and document 5 use silicone-free oil agents, but the effective components in document 4 require several steps to be synthesized, and the production process is complicated; the aliphatic monobasic ester used in document 5 has the same problem as document 3, both Carbon fiber with excellent performance cannot be obtained

[0014] To sum up, the current technologies in this field either use silicone oil to ensure fiber performance and quality, but there are problems in sticking rolls, deposits in the furnace, and fiber ash, or use low-silicon or no-silicon oil agents, although it can solve the problem of silicon oil to a certain extent. It is the problem of oil agent, but the effect of preventing monofilament adhesion is poor, the performance of the obtained carbon fiber is not satisfactory, and it is impossible to achieve a perfect balance from two aspects

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