Silicon-free carbon fiber spinning oil and preparation method thereof

Abstract

The present invention belongs to the technical field of spinning oil, and is specifically related to silicon-free carbon fiber spinning oil and its preparation method. The spinning oil comprises the following components: 40-55 parts of ester smoothing agent, 10-15 parts of surfactant, 10-20 parts of composite antistatic agent, 4-8 parts of glycerol, 5-8 parts of clustering agent, 0.2-2 parts of antioxidant, 0.1-1 parts of defoaming agent, 0.5-2 parts of preservative and bactericidal agent, 0-6 parts of emulsifier, 100-150 parts of water, wherein the composite antistatic agent is composed of long carbon chain imidazoline quaternary ammonium salt and coconut oil methyl ammonium methyl sulfate. Using ester substances as smoothing agents solves the problem that silicone oil is easy to form impurities such as silicon-containing oxides and carbides during pre-oxidation and carbonization as carbon fiber spinning oil. Coconut oil methyl ammonium methyl sulfate and propylene glycol improve the dispersion properties of long-chain imidazoline quaternary ammonium salts. The prepared silicon-free carbon fiber spinning oil has excellent thermal stability, which solves the technical problems of existing carbon fiber oil products such as sticking to rollers, high fiber content and difficulty in taking into account antistatic properties.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning oils, and in particular relates to a silicon-free carbon fiber spinning oil and a preparation method thereof. Background Art

[0002] Carbon fiber is a new type of inorganic fiber material. It has many excellent properties such as corrosion resistance, radiation resistance, heat transfer, high temperature resistance, high specific modulus, conductivity, fatigue resistance, high specific strength, shock absorption, low relative density and noise reduction. It is a typical high-performance fiber. Due to its excellent properties, carbon fiber has been widely used in cutting-edge fields such as aerospace, space exploration, military defense, and artificial satellites. At the same time, it is also used in civil industries such as advanced sports goods, lightweight automobiles, medical equipment, and infrastructure due to its special properties. In 1959, the Osaka Industrial Test Institute in Japan invented the production technology route of polyacrylonitrile-based carbon fiber. The invention of this technology has promoted the development of the carbon fiber industry. So far, it has been the mainstream technology for producing carbon fiber.

[0003] Early researchers conducted a lot of research work. There are many raw materials used to produce carbon fiber. Early research work has shown that the known raw materials that can be used in the carbon fiber production process are PAN, asphalt, polyimide, viscose fiber, polybenzothiazole, etc. PAN-based, viscose-based and asphalt-based carbon fibers can meet the requirements of production development and the application of the carbon fiber industry chain. Asphalt-based carbon fibers have the advantages of wide material access and high yield, but due to its large number of impurities and unstable structure, there are many difficult to solve problems in the actual production process and they have not been mass-produced and applied. Viscose-based carbon fibers with low thermal conductivity, low density, easy purification and good biocompatibility are applied to some special aspects because of their many advantages, especially in medical and health applications. Certain components in viscose-based carbon fibers cause certain harm to the environment, and this disadvantage limits their use. Polyacrylonitrile fiber is a synthetic fiber made by weaving a high molecular polymer produced by copolymerizing the first monomer acrylonitrile and the second and third monomers. Because PAN-based fibers are easy to prepare, have low requirements for production conditions, and have little environmental pollution and low cost, they have become the most widely used fiber in the fiber industry chain.

[0004] Carbon fiber precursor oil has many functions to improve the processability of fiber: reduce friction static electricity, reduce friction coefficient; make the fiber surface smooth and soft; reduce defects on the fiber surface and improve fiber strength; act between monofilaments to add clustering, drafting and fiber separation to the tow. There are many defects on the surface of carbon fiber precursor, which are the main factors that cause carbon fiber breakage. Usually, various modified oils with different functional groups can be used to reduce the phenomenon of broken wires during carbonization caused by fiber surface defects and improve the application performance of carbon fiber. Therefore, the production of special oils for carbon fiber with excellent performance is an important prerequisite for the production of high-performance carbon fiber precursor. Summary of the invention

[0005] In view of the shortcomings of the prior art, the first object of the present invention is to provide a silicon-free carbon fiber spinning oil.

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned silicon-free carbon fiber spinning oil.

[0007] In order to achieve the above first purpose, the present invention is implemented by the following technical solutions:

[0008] Silicon-free carbon fiber spinning oil, which is particularly suitable for polyacrylonitrile carbon fiber spinning oil, comprises the following components in parts by weight:

[0009] 40-55 parts of ester smoothing agent, 10-15 parts of surfactant, 10-20 parts of composite antistatic agent, 4-8 parts of glycerol, 5-8 parts of sizing agent, 0.2-2 parts of antioxidant, 0.1-1 parts of defoaming agent, 0.5-2 parts of preservative and bactericidal agent, 0-6 parts of emulsifier and 100-150 parts of water, wherein the composite antistatic agent is composed of long-chain imidazoline quaternary ammonium salt and coconut oil methyl ammonium methyl sulfate, the amount of coconut oil methyl ammonium methyl sulfate is greater than that of long-chain imidazoline quaternary ammonium salt, and the amount of long-chain imidazoline quaternary ammonium salt is not 0.

[0010] The prior art generally uses silicone oil as the main component of carbon fiber spinning oil, which has the characteristics of good heat resistance, but this type of oil is prone to form impurities such as silicon-containing oxides and carbides during pre-oxidation and carbonization, affecting the performance of carbon fiber. The non-silicone oil currently used is not resistant to high temperatures, and has poor local compatibility, and is prone to microscopic phase separation. In order to solve this problem, the present invention uses ester substances as lubricants. Ester lubricants have good high temperature resistance, can reduce the friction coefficient between the fibers themselves and between the metal and the fibers, prevent fiber wear, maintain uniform and low tension, and protect the fiber surface.

[0011] Although the smoothing agent during the fiber pre-oxidation treatment has a certain bundling effect, it is easy to melt and stick together during the pre-oxidation treatment process. After the oil agent is dispersed, the bundling is disordered, and the dispersed fiber bundles are disconnected to produce lint, and are easily wound on the guide roller, making it difficult to operate normally. Although the addition of a water-soluble surfactant can improve the bundling effect, the surfactant may decompose or tar during pre-oxidation, which also makes the operation difficult. In addition, fibers such as polyacrylonitrile fibers are hydrophobic and non-hygroscopic. When the fibers are in contact with each other or with other materials (rollers), they may be electrostatically charged, and are easily wound on the guide roller to cause broken fibers. In order to improve the high temperature resistance of the oil agent and solve the problem of lint, the present invention adds a certain amount of long carbon chain imidazoline quaternary ammonium salt. The long carbon chain imidazoline quaternary ammonium salt used in the present invention is specifically VARISOFT3696. VARISOFT3696 is a long carbon chain imidazoline quaternary ammonium salt fabric treatment agent launched by Evonik. It has good hydrophilicity and has a good hydrophilic effect on various fibers. Long carbon chain imidazoline quaternary ammonium salt not only has excellent emulsifying properties, but can also be used as an antistatic agent. Compared with other antistatic agents, it has good thermal stability and greatly improves the high temperature resistance of carbon fiber spinning oil.

[0012] However, since the long carbon chain imidazoline quaternary ammonium salt has a long carbon chain structure, its viscosity is relatively large and it is easily unevenly dispersed in the emulsion. The present invention adds a certain amount of coconut oil base methyl ammonium methyl sulfate and glycerol to improve the dispersibility of the long carbon chain imidazoline quaternary ammonium salt. Coconut oil base methyl ammonium methyl sulfate also possesses certain emulsification and antistatic properties, and it contains a quaternary ammonium salt structure, has good compatibility with VARISOFT3696 long carbon chain imidazoline quaternary ammonium salt, and is conducive to improving the dispersibility of VARISOFT3696 long carbon chain imidazoline quaternary ammonium salt. Glycerol, as a small molecule compound of polyhydroxy, has excellent hygroscopicity, has good wettability to fibers such as polyacrylonitrile, and can improve the dispersibility of the long carbon chain imidazoline quaternary ammonium salt in the emulsion.

[0013] Further, the composite antistatic agent is composed of 1-7 parts of long carbon chain imidazoline quaternary ammonium salt and 9-13 parts of coconut oil methyl ammonium methyl sulfate. Further, the coconut oil methyl ammonium methyl sulfate used in the present invention is PEG-5 coconut oil methyl ammonium methyl sulfate.

[0014] Furthermore, the ester lubricant is one or more of pentaerythritol stearate, pentaerythritol tetraisostearate, and pentaerythritol oleate.

[0015] Furthermore, the surfactant is one or more of PEG400MO, PEG400DO, and PEG600MO.

[0016] Furthermore, the sizing agent is one or more of castor oil polyoxyethylene ether, polyoxyethylene laurate, and triethanolamine oleic acid soap.

[0017] Furthermore, the antioxidant is antioxidant 1010 or antioxidant 1790. Among them, antioxidant 1790 has excellent heat resistance and can effectively prevent the oil from oxidative deterioration.

[0018] Furthermore, the defoamer is tributyl phosphate; the preservative and bactericide is Dow Chemical KATHON LXE; and the emulsifier is Evonik TAGAT PD36. TAGAT PD36 has better antioxidant properties and higher thermal stability than ester substances, and has excellent emulsion stabilizing properties, and is used in ester oil emulsions to stabilize droplet size and improve lubrication performance.

[0019] Furthermore, the long carbon chain imidazoline quaternary ammonium salt is 2-4 parts; the emulsifier is 2-6 parts.

[0020] In order to achieve the above-mentioned second purpose, the present invention provides a method for preparing a silicon-free carbon fiber spinning oil, comprising the following steps: adding an ester smoothing agent, a surfactant, a composite antistatic agent, propylene glycol, a sizing agent, an antioxidant, a defoaming agent, a preservative and a bactericidal agent, and an emulsifier into a reaction kettle according to a proportion, stirring evenly, and then adding water dropwise for phase inversion emulsification to obtain a silicon-free carbon fiber spinning oil.

[0021] Furthermore, the stirring rate is 1000-2000 r / min.

[0022] Beneficial effects of the present invention:

[0023] (1) The silicon-free carbon fiber spinning oil of the present invention is mainly composed of a smoothing agent, a surfactant, a composite antistatic agent, glycerol, a sizing agent, etc. In the process of preparing the oil, several different types and models of quaternary ammonium salts and glycerol are compounded together to complement each other and exert their synergistic effect.

[0024] (2) The present invention uses ester substances as lubricants, thereby solving the problem that silicone oil used as a carbon fiber spinning oil easily forms impurities such as silicon oxides and carbides during the pre-oxidation and carbonization processes.

[0025] (3) The silicon-free carbon fiber spinning oil prepared by the present invention has good antistatic properties, excellent thermal stability, reduced friction coefficient, and greatly improved high temperature resistance of the carbon fiber spinning oil. DETAILED DESCRIPTION

[0026] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0027] The long carbon chain imidazoline quaternary ammonium salt used in the examples and comparative examples is VARISOFT3696; the antioxidant is antioxidant 1790; the defoaming agent is tributyl phosphate; the preservative and bactericide is Dow Chemical KATHON LXE; and the emulsifier is Evonik TAGAT PD36.

[0028] Example 1

[0029] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0030] 40 parts of ester smoothing agent, 10 parts of surfactant, 10 parts of composite antistatic agent, 4 parts of glycerol, 5 parts of sizing agent, 0.2 parts of antioxidant, 0.1 parts of defoaming agent, 0.5 parts of preservative and bactericidal agent, 2 parts of emulsifier, and 100 parts of water; the composite antistatic agent is composed of 1 part of long carbon chain imidazoline quaternary ammonium salt and 9 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0031] The ester smoothing agent is 20 parts of pentaerythritol tetraisostearate and 20 parts of pentaerythritol oleate; the surfactant is PEG400MO; the sizing agent is 3 parts of castor oil polyoxyethylene ether and 2 parts of polyoxyethylene laurate.

[0032] Example 2

[0033] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0034] 55 parts of ester smoothing agent, 15 parts of surfactant, 17 parts of composite antistatic agent, 8 parts of glycerol, 8 parts of sizing agent, 2 parts of antioxidant, 1 part of defoaming agent, 2 parts of preservative and bactericidal agent, 6 parts of emulsifier, and 150 parts of water. The composite antistatic agent is composed of 4 parts of long carbon chain imidazoline quaternary ammonium salt and 13 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0035] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is PEG400DO; the sizing agent is 3 parts of castor oil polyoxyethylene ether, 3 parts of lauric acid polyoxyethylene ester, and 2 parts of triethanolamine oleic acid soap.

[0036] Example 3

[0037] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0038] 40 parts of ester smoothing agent, 15 parts of surfactant, 17 parts of composite antistatic agent, 4 parts of glycerol, 8 parts of sizing agent, 0.2 parts of antioxidant, 1 part of defoaming agent, 1.5 parts of preservative and bactericidal agent, 5 parts of emulsifier, and 150 parts of water. The composite antistatic agent is composed of 4 parts of long carbon chain imidazoline quaternary ammonium salt and 13 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0039] The ester smoothing agent is 20 parts of pentaerythritol tetraisostearate and 20 parts of pentaerythritol oleate; the surfactant is PEG600MO; and the sizing agent is castor oil polyoxyethylene ether.

[0040] Example 4

[0041] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0042] 55 parts of ester smoothing agent, 10 parts of surfactant, 11 parts of composite antistatic agent, 8 parts of glycerol, 5 parts of sizing agent, 0.2 parts of antioxidant, 0.1 parts of defoaming agent, 0.5 parts of preservative and bactericidal agent, 1 part of emulsifier, and 100 parts of water. The composite antistatic agent consists of 2 parts of long carbon chain imidazoline quaternary ammonium salt and 9 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0043] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 5 parts of PEG400MO and 5 parts of PEG400DO; and the sizing agent is polyoxyethylene laurate.

[0044] Example 5

[0045] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0046] 45 parts of ester smoothing agent, 11 parts of surfactant, 13 parts of composite antistatic agent, 5 parts of glycerol, 7 parts of sizing agent, 0.8 parts of antioxidant, 0.8 parts of defoaming agent, 0.9 parts of preservative and bactericidal agent, 5 parts of emulsifier, 120 parts of water, wherein the composite antistatic agent is composed of 3 parts of long carbon chain imidazoline quaternary ammonium salt and 10 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0047] The ester smoothing agent is 20 parts of pentaerythritol tetraisostearate and 25 parts of pentaerythritol oleate; the surfactant is PEG400MO; the sizing agent is 3 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0048] Example 6

[0049] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0050] 52 parts of ester smoothing agent, 14 parts of surfactant, 17 parts of composite antistatic agent, 7 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 0.5 parts of defoaming agent, 1.8 parts of preservative and bactericidal agent, 3 parts of emulsifier, and 140 parts of water. The composite antistatic agent is composed of 4 parts of long carbon chain imidazoline quaternary ammonium salt and 13 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0051] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 6 parts of PEG400DO and 8 parts of PEG600MO; and the bundling agent is triethanolamine oleic acid soap.

[0052] Example 7

[0053] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0054] 48 parts of ester smoothing agent, 13 parts of surfactant, 13 parts of composite antistatic agent, 6 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 1 part of defoaming agent, 1 part of preservative and bactericidal agent, 3 parts of emulsifier, and 130 parts of water. The composite antistatic agent is composed of 3 parts of long carbon chain imidazoline quaternary ammonium salt and 10 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0055] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 10 parts of PEG400MO and 3 parts of PEG400DO; the sizing agent is 2 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0056] Example 8

[0057] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0058] 48 parts of ester smoothing agent, 13 parts of surfactant, 13 parts of composite antistatic agent, 6 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 1 part of defoaming agent, 1 part of preservative and bactericidal agent, 0 parts of emulsifier, and 130 parts of water. The composite antistatic agent is composed of 3 parts of long carbon chain imidazoline quaternary ammonium salt and 10 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0059] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 10 parts of PEG400MO and 3 parts of PEG400DO; the sizing agent is 2 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0060] Example 9

[0061] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0062] 48 parts of ester smoothing agent, 13 parts of surfactant, 17 parts of composite antistatic agent, 6 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 1 part of defoaming agent, 1 part of preservative and bactericidal agent, 3 parts of emulsifier, and 130 parts of water. The composite antistatic agent is composed of 7 parts of long carbon chain imidazoline quaternary ammonium salt and 10 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0063] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 10 parts of PEG400MO and 3 parts of PEG400DO; the sizing agent is 2 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0064] Comparative Example 1

[0065] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0066] 48 parts of ester smoothing agent, 13 parts of surfactant, 19 parts of composite antistatic agent, 0 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 1 part of defoaming agent, 1 part of preservative and bactericidal agent, 3 parts of emulsifier, and 130 parts of water. The composite antistatic agent consists of 3 parts of long carbon chain imidazoline quaternary ammonium salt and 16 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0067] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 10 parts of PEG400MO and 3 parts of PEG400DO; the sizing agent is 2 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0068] Comparative Example 2

[0069] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0070] 48 parts of ester smoothing agent, 13 parts of surfactant, 3 parts of composite antistatic agent, 16 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 1 part of defoaming agent, 1 part of preservative and bactericidal agent, 3 parts of emulsifier, and 130 parts of water. The composite antistatic agent consists of 3 parts of long carbon chain imidazoline quaternary ammonium salt and 0 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0071] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 10 parts of PEG400MO and 3 parts of PEG400DO; the sizing agent is 2 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0072] Comparative Example 3

[0073] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0074] 48 parts of ester smoothing agent, 13 parts of surfactant, 13 parts of composite antistatic agent, 2 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 1 part of defoaming agent, 1 part of preservative and bactericidal agent, 3 parts of emulsifier, and 130 parts of water. The composite antistatic agent is composed of 3 parts of long carbon chain imidazoline quaternary ammonium salt and 10 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0075] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 10 parts of PEG400MO and 3 parts of PEG400DO; the sizing agent is 2 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0076] Comparative Example 4

[0077] The silicon-free carbon fiber spinning oil comprises the following components in parts by weight:

[0078] 48 parts of ester smoothing agent, 13 parts of surfactant, 13 parts of composite antistatic agent, 12 parts of glycerol, 6 parts of sizing agent, 1 part of antioxidant, 1 part of defoaming agent, 1 part of preservative and bactericidal agent, 3 parts of emulsifier, and 130 parts of water. The composite antistatic agent consists of 3 parts of long carbon chain imidazoline quaternary ammonium salt and 10 parts of PEG-5 coconut oil methyl ammonium methyl sulfate.

[0079] The ester smoothing agent is pentaerythritol tetraisostearate; the surfactant is 10 parts of PEG400MO and 3 parts of PEG400DO; the sizing agent is 2 parts of castor oil polyoxyethylene ether and 4 parts of polyoxyethylene laurate.

[0080] The preparation methods of the silicon-free carbon fiber spinning oils in the above-mentioned embodiments and the comparative examples are the same, and specifically include the following steps: adding ester smoothing agents, surfactants, composite antistatic agents, propylene glycol, sizing agents, antioxidants, defoaming agents, preservatives and bactericides, and emulsifiers into the reactor in a proportion, stirring evenly at a stirring rate of 1500r / min, and then adding water dropwise for phase inversion emulsification to obtain the silicon-free carbon fiber spinning oil.

[0081] Performance Test:

[0082] 1. The silicon-free carbon fiber spinning oil prepared in the above examples and comparative examples was placed at 60° C. for 10 days to observe whether stratification or turbidity occurred.

[0083] 2. Prepare polyacrylonitrile precursor with the silicon-free carbon fiber spinning oil prepared in the above embodiment and comparative example, and prepare carbon fiber through pre-oxidation and carbonization process. Observe the degree of roller sticking (AD, the degree of roller sticking from A to D is gradually serious); evaluate the grade of carbon fiber hair (1-5, the higher the grade, the more serious the hair condition); test the strength, modulus, elongation, diameter unevenness of the precursor and the strength (MPa) of the carbon fiber.

[0084] Table 1: Properties of silicon-free carbon fiber spinning oils prepared in Examples 1 to 9

[0085]

[0086] Table 2: Properties of silicon-free carbon fiber spinning oils prepared in Comparative Examples 1 to 4

[0087]

[0088] As can be seen from Table 1, the present invention adds a certain amount of long carbon chain imidazoline quaternary ammonium salt, and the long carbon chain imidazoline quaternary ammonium salt not only has excellent emulsifying properties, but also can be used as an antistatic agent, greatly improving the high temperature resistance of carbon fiber spinning oil. A certain amount of PEG-5 coconut oil base methyl ammonium methyl sulfate and glycerol improve the dispersibility of long carbon chain imidazoline quaternary ammonium salt VARISOFT3696. As can be seen from Example 1-Example 7, Example 8-Example 9, an appropriate amount of long carbon chain imidazoline quaternary ammonium salt and emulsifier can make the fiber surface evenly adhere to the oil, protect its surface, make multi-filament bundles bundled, prevent broken wires, thereby improve its processing properties, make carbon fiber strength higher. Comparative Example 1-Comparative Example 2 shows that coconut oil base methyl ammonium methyl sulfate and glycerol improve the dispersibility of long carbon chain imidazoline quaternary ammonium salt together, prevent the long carbon chain imidazoline quaternary ammonium salt of long chain structure from agglomeration. Coconut oil base methyl ammonium methyl sulfate and glycerol improve the stability of the emulsion, can quickly leak the generated charge, so that there is a certain cohesion between the fiber filaments, and the effect of clustering is achieved. Comparative Examples 3-4 show that glycerol has excellent hydrophilicity, can improve the wetting properties of the oil agent, reduce the contact angle between the oil agent and the fiber, is conducive to the spreading and film formation of the oil agent on the fiber surface, protects its surface from damage during movement, and enables the production process to proceed smoothly. However, the amount of glycerol should not be too much, otherwise it will affect the flow of airflow between the individual fibers, so that the fiber surface during the carbonization process cannot fully contact the oxidizing medium and affect the mechanical properties of the carbon fiber.

[0089] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0090] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A silicon-free carbon fiber spinning oil, characterized in that: According to parts by weight, it includes the following components: 40-55 parts of ester smoothing agent, 10-15 parts of surfactant, 10-20 parts of composite antistatic agent, 4-8 parts of glycerol, 5-8 parts of sizing agent, 0.2-2 parts of antioxidant, 0.1-1 parts of defoaming agent, 0.5-2 parts of preservative and bactericidal agent, 0-6 parts of emulsifier and 100-150 parts of water. The composite antistatic agent is composed of 1-7 parts of long carbon chain imidazoline quaternary ammonium salt and 9-13 parts of coconut oil methyl ammonium methyl sulfate; the coconut oil methyl ammonium methyl sulfate is PEG-5 coconut oil methyl ammonium methyl sulfate; the long carbon chain imidazoline quaternary ammonium salt is VARISOFT3696 produced by Evonik.

2. The silicon-free carbon fiber spinning oil according to claim 1, characterized in that: The ester lubricant is one or more of pentaerythritol stearate, pentaerythritol tetraisostearate and pentaerythritol oleate.

3. The silicon-free carbon fiber spinning oil according to claim 1, characterized in that: The surfactant is one or more of PEG400MO, PEG400DO, and PEG600MO.

4. The silicon-free carbon fiber spinning oil according to claim 1, characterized in that The sizing agent is one or more of castor oil polyoxyethylene ether, polyoxyethylene laurate, and triethanolamine oleic acid soap.

5. The silicon-free carbon fiber spinning oil according to claim 1, characterized in that: The antioxidant is antioxidant 1010 or antioxidant 1790.

6. The silicon-free carbon fiber spinning oil according to claim 1, characterized in that: The defoaming agent is tributyl phosphate; the preservative and bactericide is Dow Chemical KATHON LXE; and the emulsifier is Evonik TAGAT PD36.

7. The silicon-free carbon fiber spinning oil according to claim 1, characterized in that: The long carbon chain imidazoline quaternary ammonium salt is 2-4 parts; the emulsifier is 2-6 parts.

8. The method for preparing a silicon-free carbon fiber spinning oil according to any one of claims 1 to 7, characterized in that: The following steps are involved: Ester lubricant, surfactant, composite antistatic agent, propylene glycol, sizing agent, antioxidant, defoaming agent, preservative and bactericidal agent, and emulsifier are added into the reaction kettle according to the proportion, stirred evenly, and then water is added dropwise for phase inversion emulsification to obtain silicon-free carbon fiber spinning oil.

9. The method for preparing a silicon-free carbon fiber spinning oil according to claim 8, characterized in that: The stirring rate is 1000-2000r / min.

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