Silicon-compound-free carbon fiber precursor oiling agent as well as preparation method and application thereof

Abstract

The invention relates to a silicon compound-free carbon fiber precursor oiling agent as well as a preparation method and application thereof. The silicon compound-free carbon fiber precursor oiling agent comprises the following components: oleate, alkynol ester, a polyoxyethylene ether derivative, an emulsifier, an antistatic agent and a defoaming agent. According to the oiling agent disclosed by the invention, the carbon fiber precursor has excellent lubricity, heat resistance and antistatic property, so that the carbon fiber obtained by pre-oxidizing and carbonizing the precursor has excellent mechanical property. The carbon fiber precursor oiling agent is simple in preparation process, has excellent film-forming property, heat resistance and stability, and can eliminate silicon powder pollution in the production process of polyacrylonitrile-based carbon fibers, prolong the running time of a carbon fiber production line and reduce the production cost.

Description

Technical Field

[0001] The present invention belongs to the field of carbon fiber finishing agents, and particularly relates to a carbon fiber precursor finishing agent without silicon compounds, a preparation method thereof, and an application thereof. Background Art

[0002] Carbon fiber is a fiber material with excellent properties such as high strength, high modulus, heat and corrosion resistance. It is widely used in fields such as aerospace, railway transportation, wind power generation, medical devices, and leisure and entertainment. Among them, polyacrylonitrile-based carbon fiber has the best performance and relatively low price, accounting for the largest proportion in the carbon fiber market.

[0003] Carbon fiber finishing agent is an important auxiliary agent used in the process of producing carbon fiber precursors and plays an important role in the production of high-performance carbon fibers. The carbon fiber finishing agent forms a uniform oil film on the surface of each single fiber. This oil film separates the single fibers from each other to prevent adhesion and filament merging; because the formed oil film has softness and self-lubricity, it can also prevent friction and wear between the filament bundle and the roller during the production process; it can prevent heat accumulation or overheating during the pre-oxidation process, resulting in local thermal adhesion or thermal filament merging between single fibers, which is helpful for forming homogeneous fibers; its oil film still has a protective effect on the fiber surface during low-temperature carbonization.

[0004] At present, most carbon fiber oils use silicon oils, because silicone oil has good performance and low price. However, there are some problems with silicon oils. The oils are pyrolyzed into SiO2 and other volatilizations, which cause dust and silicon pollution to the pre-oxidation furnace, carbonization furnace and supporting equipment; at the same time, the oils that penetrate into the fiber will generate silicides after pre-oxidation and carbonization and remain in the fiber, resulting in a decrease in the strength of the carbon fiber. Therefore, the research and development of low-silicon or non-silicon oils has become a research hotspot for oil development. Low-silicon oils are achieved by reducing the proportion of silicon in the overall oil to reduce dust and silicon pollution and reduce ash content. Although this type of oil can reduce the impact of silicon oils, silicon pollution still exists in the production process of carbon fibers using this type of oil. Non-silicon oils are mainly composed of polyesters of long-chain fatty acids and polyols and ethylene oxide adducts of long-chain fatty amides. This type of oil fundamentally solves the problem of silicon pollution in carbon fiber production. At present, patents for carbon fiber oils are mainly concentrated in silicon oils and low-silicon oils. For example: Chinese patent CN112778527A uses polyol fatty acid ester, phenyl and polyether co-modified silicone oil as the main components to obtain a low-silicone oil agent for carbon fiber; Chinese patent CN114539530A introduces long carbon chain modification on the basis of the original amino silicone oil, and uses alkane amino modified silicone oil to improve its temperature resistance, lubricity and anti-roller resistance. At the same time, due to the introduction of long carbon chains, the proportion of silicone is reduced. The active ingredients in the oils of the above patents are all modified silicone oils, which will not only cause silicon contamination of production equipment, but also reduce the performance of carbon fiber. If non-silicon components are used to prepare oils, various problems caused by silicon pollution will be fundamentally solved. Summary of the invention

[0005] In view of the defects of the prior art, the technical problem to be solved by the present invention is to provide a carbon fiber precursor oil agent that does not contain silicon compounds and a preparation method and application thereof. The oil agent has excellent lubricity, heat resistance and antistatic properties. At the same time, the use of the oil agent can eliminate silicon powder pollution in the carbon fiber production process and silicide residues inside the carbon fiber.

[0006] The present invention provides a carbon fiber precursor oil agent free of silicon compounds, which comprises the following components in parts by mass:

[0007] 20-50 parts of oleate;

[0008] 20-30 parts of acetylenic alcohol esters;

[0009] 20-50 parts of polyoxyethylene ether derivatives;

[0010] 1 to 5 parts of emulsifier;

[0011] 1 to 5 parts of antistatic agent;

[0012] 1 to 5 parts of defoaming agent;

[0013] 100 to 200 parts of deionized water.

[0014] Preferably, the oleate includes one or more of polyethylene glycol oleate, pentaerythritol oleate, glycerol oleate, sorbitan monooleate, glycerol trioleate, trimethylolpropane trioleate.

[0015] More preferably, the oleate is polyethylene glycol oleate and pentaerythritol oleate, and the mass ratio is 1:2 to 2:1.

[0016] Preferably, the structural formula of the alkynol ester is as follows:

[0017] wherein R is the remaining part after the carboxylic acid group of the organic acid is removed (i.e., the non-carboxyl part in the organic acid), and R1, R2 are C1-C 10 alkyl groups, and m, n are integers from 2 to 10.

[0018] Among them, the organic acid includes one or more of acetic acid, oxalic acid, benzoic acid, stearic acid, salicylic acid, lactic acid, adipic acid, terephthalic acid.

[0019] Preferably, the alkynol ester is obtained by reacting a raw material containing an organic acid and an alkynol polyoxyethylene ether under certain temperature and catalyst conditions.

[0020] Preferably, the structural formula of the alkynol polyoxyethylene ether is as follows:

[0021] ; wherein R1, R2 are C1-C 10 alkyl groups, and m, n are integers from 2 to 10.

[0022] Preferably, the organic acid includes one or more of acetic acid, oxalic acid, benzoic acid, stearic acid, salicylic acid, lactic acid, adipic acid, terephthalic acid.

[0023] Preferably, the catalyst is concentrated sulfuric acid.

[0024] Preferably, the molar ratio of the organic acid to the alkynol polyoxyethylene ether is 1:(0.5 to 3).

[0025] Preferably, the reaction temperature is 120 to 150 °C, and the reaction time is 3 to 5 h.

[0026] Preferably, the structural formula of the polyoxyethylene ether derivative: RCONH-(CH2CH2O) n -H; wherein R is selected from C 10 to C 20 alkyl groups, n is selected from integers from 2 to 20, and more preferably R is selected from C 17 to C20 The alkyl group has n being an integer selected from 10 to 20.

[0027] Preferably, the polyoxyethylene ether derivative is obtained by ethoxylation of a long-chain fatty amide with ethylene oxide.

[0028] Preferably, the emulsifier includes one or more of isomeric alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyvinyl alcohol, sodium dodecylbenzenesulfonate, and trihydroxymethane polyoxyethylene ether.

[0029] Preferably, the antistatic agent includes one or more of polyoxyethylene fatty alcohol phosphate, polyoxyethylene laurate, sorbitan fatty acid ester, and dodecyltrimethylammonium chloride.

[0030] Preferably, the defoamer includes one or more of ethylene glycol monostearate, isoamyl alcohol, diisobutyl carbinol, and trialkyl melamine.

[0031] The present invention provides a method for preparing a sizing agent for carbon fiber precursor without silicon compounds, comprising the following steps:

[0032] Weigh each component by mass fraction, mix the components evenly to form an emulsion, and obtain a sizing agent for carbon fiber precursor without silicon compounds.

[0033] Preferably, the average particle size of the sizing agent is 150 - 300 nm.

[0034] The present invention provides an application of a sizing agent for carbon fiber precursor without silicon compounds in the preparation of polyacrylonitrile-based carbon fibers.

[0035] Beneficial effects

[0036] The sizing agent of the present invention can endow the carbon fiber precursor with excellent lubricity, softness, fiber splitting property, heat resistance, etc., can effectively protect the fiber, and improve the performance of the fiber. By using oleate, alkynol esters, and polyoxyethylene ether derivatives as the main components of the sizing agent, the sizing agent of the present invention can solve the silicon powder pollution in the carbon fiber production process and improve the mechanical properties of the carbon fiber. Specific embodiments

[0037] The following combines specific embodiments to further illustrate the present invention. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0038] The conditions for pre-oxidation and carbonization in the examples are as follows:

[0039] Pre-oxidation is carried out in an air atmosphere, and it is kept at 240 °C, 250 °C, and 260 °C for 15 min respectively; carbonization is carried out in a nitrogen atmosphere, and the gradient heating method is adopted, in which the residence time in the low-temperature carbonization zone (400 °C, 500 °C, 600 °C, 700 °C, 800 °C) and the high-temperature carbonization zone (1000 °C, 1100 °C, 1200 °C, 1300 °C, 1400 °C) is 2 min each.

[0040] The test standards and characterization methods involved in the examples are as follows:

[0041] The particle size of the oil agent emulsion is tested by a particle size analyzer; the thermal residue rate is tested by a thermogravimetric analyzer, and the residue rate at 300 °C is taken for comparison; the mechanical properties are tested in accordance with the national standard GB / T 31290-2022.

[0042] The structural formula of the alkynol ester in the example:

[0043]

[0044] The structural formula of the alkynol polyoxyethylene ether:

[0045]

[0046] The structural formula of the polyoxyethylene ether derivative RCONH-(CH2CH2O) n -H.

[0047] Example 1

[0048] This example provides a carbon fiber precursor oil agent without silicon compounds. By mass, it includes the following components:

[0049] Polyethylene glycol oleate 20 parts;

[0050] Pentaerythritol oleate 10 parts;

[0051] Alkynol ester 20 parts;

[0052] Polyoxyethylene ether derivative 40 parts;

[0053] Nonylphenol polyoxyethylene ether 5 parts;

[0054] Polyoxyethylene laurate 3 parts;

[0055] Isoamyl alcohol 2 parts;

[0056] Deionized water 150 parts.

[0057] Among them, the preparation process of the alkynol ester is as follows:

[0058] Take 120 g of benzoic acid and 120 g of alkynol polyoxyethylene ether (both R1 and R2 are C1 alkyl groups, and both m and n are 2). The catalyst concentrated sulfuric acid is 10% of the total reactant mass. React at 150 °C for 4 h, neutralize with excessive anhydrous sodium bicarbonate, and obtain alkynol esterified product after centrifugal purification.

[0059] The polyoxyethylene ether derivative is a product obtained by the ethoxylation reaction of long-chain fatty amide and ethylene oxide. R is C 17 ~C 20 alkyl group, n is an integer between 10 and 20. In this example, R is C 17 and n is 15.

[0060] The preparation process and performance detection of the size for carbon fiber precursor are as follows:

[0061] Mix the above components evenly to obtain an emulsion with an average particle size of 194 nm. The emulsion has excellent stability and a thermal residue rate of 92% at 300 °C.

[0062] When preparing T700 grade carbon fiber precursor, using this size, the obtained carbon fiber precursor is smooth, soft, without hairiness and splicing; the carbon fiber obtained after pre-oxidation and carbonization treatment has a tensile strength of 5167 MPa.

[0063] Example 2

[0064] This example provides a size for carbon fiber precursor without silicon compounds. By mass, it includes the following components:

[0065] Polyethylene glycol oleate: 10 parts;

[0066] Pentaerythritol oleate: 20 parts;

[0067] Alkynol esterified product: 20 parts;

[0068] Polyoxyethylene ether derivative: 40 parts;

[0069] Nonylphenol polyoxyethylene ether: 5 parts;

[0070] Polyoxyethylene laurate: 3 parts;

[0071] Isoamyl alcohol: 2 parts;

[0072] Deionized water: 150 parts.

[0073] Among them, the alkynol esterified product and the polyoxyethylene ether derivative are the same as in Example 1.

[0074] The preparation process and performance detection of the size for carbon fiber precursor are as follows:

[0075] Mix the above components evenly to obtain an emulsion with an average particle size of 214 nm. The emulsion has excellent stability and a thermal residue rate of 94% at 300 °C.

[0076] When preparing T700 grade carbon fiber precursor filaments, using this sizing agent, the obtained carbon fiber precursor filaments are smooth, soft, without hairiness and splicing; the carbon fiber obtained after pre-oxidation and carbonization treatment has a tensile strength of 5057 MPa.

[0077] Example 3

[0078] This example provides a sizing agent for carbon fiber precursor filaments without silicon compounds. By mass, it includes the following components:

[0079] Polyethylene glycol oleate: 10 parts;

[0080] Pentaerythritol oleate: 10 parts;

[0081] Alkynol ester: 20 parts;

[0082] Polyoxyethylene ether derivative: 50 parts;

[0083] Nonylphenol polyoxyethylene ether: 5 parts;

[0084] Polyoxyethylene laurate: 3 parts;

[0085] Isoamyl alcohol: 2 parts;

[0086] Deionized water: 150 parts.

[0087] Among them, the alkynol ester and the polyoxyethylene ether derivative are the same as in Example 1.

[0088] The preparation process and performance testing of the sizing agent for precursor filaments are as follows:

[0089] Mix the above components evenly to obtain an emulsion with an average particle size of 227 nm. The emulsion has excellent stability and a thermal residue rate of 91% at 300 °C.

[0090] When preparing T700 grade carbon fiber precursor filaments, using this sizing agent, the obtained carbon fiber precursor filaments are smooth, soft, without hairiness and splicing; the carbon fiber obtained after pre-oxidation and carbonization treatment has a tensile strength of 4983 MPa.

[0091] Example 4

[0092] This example provides a sizing agent for carbon fiber precursor filaments without silicon compounds. By mass, it includes the following components:

[0093] Polyethylene glycol oleate: 30 parts;

[0094] Pentaerythritol oleate: 20 parts;

[0095] 20 parts of alkynol ester;

[0096] 20 parts of polyoxyethylene ether derivative;

[0097] 5 parts of nonylphenol polyoxyethylene ether;

[0098] 3 parts of polyoxyethylene laurate;

[0099] 2 parts of isoamyl alcohol;

[0100] 150 parts of deionized water.

[0101] Among them, the alkynol ester and the polyoxyethylene ether derivative are the same as in Example 1.

[0102] The preparation process and performance detection of the size for carbon fiber precursor are as follows:

[0103] Mix the above components evenly to obtain an emulsion with an average particle size of 239 nm. The emulsion has better stability, and the thermal residue rate at 300 °C is 94%.

[0104] When using this size in the preparation of T700 grade carbon fiber precursor, the obtained carbon fiber precursor is smooth, soft, without hairiness and splicing; the carbon fiber obtained after pre-oxidation and carbonization treatment has a tensile strength of 4927 MPa.

[0105] Example 5

[0106] This example provides a size for carbon fiber precursor without silicon compounds, including the following components by mass:

[0107] 10 parts of polyethylene glycol oleate;

[0108] 10 parts of pentaerythritol oleate;

[0109] 30 parts of alkynol ester;

[0110] 40 parts of polyoxyethylene ether derivative;

[0111] 5 parts of nonylphenol polyoxyethylene ether;

[0112] 3 parts of polyoxyethylene laurate;

[0113] 2 parts of isoamyl alcohol;

[0114] 150 parts of deionized water.

[0115] Among them, the alkynol ester and the polyoxyethylene ether derivative are the same as in Example 1.

[0116] The preparation process and performance detection of the size for carbon fiber precursor are as follows:

[0117] Mix the above components evenly according to the ratio to obtain an emulsion with an average particle size of 204 nm. The emulsion has excellent stability and a thermal residue rate of 90% at 300 °C.

[0118] When preparing T700 grade carbon fiber precursor filaments, using this sizing agent, the obtained carbon fiber precursor filaments are smooth, soft, without hairiness and splicing; the carbon fiber obtained after pre-oxidation and carbonization treatment has a tensile strength of 4895 MPa.

[0119] Comparative Example 1

[0120] This comparative example provides a sizing agent for carbon fiber precursor filaments without silicon compounds. By mass, it includes the following components:

[0121] Polyethylene glycol oleate: 30 parts;

[0122] Pentaerythritol oleate: 40 parts;

[0123] Alkynol esterified product: 20 parts;

[0124] Nonylphenol polyoxyethylene ether: 5 parts;

[0125] Polyoxyethylene laurate: 3 parts;

[0126] Isoamyl alcohol: 2 parts;

[0127] Deionized water: 150 parts.

[0128] Among them, the alkynol esterified product is the same as in Example 1.

[0129] The preparation process and performance detection of the sizing agent for precursor filaments are as follows:

[0130] Mix the above components evenly according to the ratio to obtain an emulsion with an average particle size of 346 nm. The emulsion has poor stability and a thermal residue rate of 96% at 300 °C.

[0131] When preparing T700 grade carbon fiber precursor filaments, using this sizing agent, the obtained carbon fiber precursor filaments are smooth, soft, with hairiness and splicing, and the carbon fiber obtained after pre-oxidation and carbonization treatment has a tensile strength of 4059 MPa.

[0132] Comparative Example 2

[0133] This comparative example provides a sizing agent for carbon fiber precursor filaments without silicon compounds. By mass, it includes the following components:

[0134] Alkynol esterified product: 40 parts;

[0135] Polyoxyethylene ether derivative: 50 parts;

[0136] Nonylphenol polyoxyethylene ether: 5 parts;

[0137] 3 parts of polyoxyethylene laurate;

[0138] 2 parts of isoamyl alcohol;

[0139] 150 parts of deionized water.

[0140] Among them, the alkynol ester and polyoxyethylene ether derivative are the same as in Example 1.

[0141] The preparation process and performance detection of the precursor sizing are as follows:

[0142] Mix the above components evenly to obtain an emulsion with an average particle size of 247 nm. The emulsion has excellent stability and a thermal residue rate of 81% at 300 °C.

[0143] When preparing T700 grade carbon fiber precursor, using this sizing, the obtained carbon fiber precursor is smooth, soft, without hairiness and splicing. After pre-oxidation and carbonization treatment, the obtained carbon fiber has a tensile strength of 3679 MPa.

[0144] Comparative Example 3

[0145] This comparative example provides a carbon fiber precursor sizing without silicon compounds. By mass fraction, it includes the following components:

[0146] 30 parts of polyethylene glycol oleate;

[0147] 40 parts of pentaerythritol oleate;

[0148] 40 parts of polyoxyethylene ether derivative;

[0149] 5 parts of nonylphenol polyoxyethylene ether;

[0150] 3 parts of polyoxyethylene laurate;

[0151] 2 parts of isoamyl alcohol;

[0152] 150 parts of deionized water.

[0153] Among them, the polyoxyethylene ether derivative is the same as in Example 1.

[0154] Mix the above components evenly to obtain an emulsion with an average particle size of 235 nm. The emulsion has excellent stability and a thermal residue rate of 95% at 300 °C.

[0155] When preparing T700 grade carbon fiber precursor, using this sizing, the obtained carbon fiber precursor is relatively rough, soft, with hairiness and splicing. After pre-oxidation and carbonization treatment, the obtained carbon fiber has a tensile strength of 3428 MPa.

[0156] Comparative Example 4

[0157] This comparative example provides a sizing agent for carbon fiber precursor filaments without silicon compounds, which, by mass fraction, comprises the following components:

[0158] 20 parts of polyethylene glycol oleate;

[0159] 10 parts of pentaerythritol oleate;

[0160] 20 parts of alkynol esterified product;

[0161] 40 parts of polyoxyethylene ether derivative;

[0162] 5 parts of nonylphenol polyoxyethylene ether;

[0163] 3 parts of polyoxyethylene laurate;

[0164] 2 parts of isoamyl alcohol;

[0165] 150 parts of deionized water.

[0166] Among them, the alkynol esterified product is prepared by reacting adipic acid with alkynol polyoxyethylene ether (both R1 and R2 are C1 alkyl groups, and both m and n are 2), and the specific steps are the same as those in Example 1.

[0167] Among them, the polyoxyethylene ether derivative is the same as that in Example 1.

[0168] The preparation process and performance detection of the sizing agent for precursor filaments are as follows:

[0169] Mix the above components evenly to obtain an emulsion with an average particle size of 217 nm. The emulsion has excellent stability and a thermal residue rate of 92% at 300 °C.

[0170] When preparing T700-grade carbon fiber precursor filaments and using this sizing agent, the obtained carbon fiber precursor filaments are smooth, soft, without hairiness and splicing. After pre-oxidation and carbonization treatment, the obtained carbon fiber has a tensile strength of 5037 MPa.

[0171] Comparative Example 5

[0172] This comparative example provides a sizing agent for carbon fiber precursor filaments without silicon compounds, which, by mass fraction, comprises the following components:

[0173] 20 parts of polyethylene glycol oleate;

[0174] 10 parts of pentaerythritol oleate;

[0175] 20 parts of alkynol esterified product;

[0176] 40 parts of polyoxyethylene ether derivative;

[0177] 5 parts of nonylphenol polyoxyethylene ether;

[0178] 3 parts of polyoxyethylene laurate;

[0179] 2 parts of isoamyl alcohol;

[0180] 150 parts of deionized water.

[0181] The acetylene alcohol ester is prepared by reacting benzoic acid and acetylene alcohol polyoxyethylene ether (R1 is a C3 alkyl group, R2 is a C5 alkyl group, m is 3, and n is 4), and the specific steps are the same as those in Example 1.

[0182] Wherein, the polyoxyethylene ether derivative is the same as that in Example 1.

[0183] The preparation process and performance test of the raw silk oil are as follows:

[0184] The above components were mixed uniformly according to the proportion to obtain an emulsion with an average particle size of 226 nm. The emulsion had excellent stability and a thermal residual rate of 93% at 300°C.

[0185] When preparing T700 grade carbon fiber precursor, the oil agent is used to obtain smooth, soft, hairless and parallel carbon fiber precursor. The carbon fiber obtained after pre-oxidation and carbonization treatment has a tensile strength of 4997MPa.

[0186] Comparative Example 6

[0187] This comparative example provides a carbon fiber precursor oil agent that does not contain silicon compounds, comprising the following components in parts by mass:

[0188] 20 parts of polyethylene glycol oleate;

[0189] 10 parts of pentaerythritol oleate;

[0190] 20 parts of acetylenic alcohol esters;

[0191] 40 parts of polyoxyethylene ether derivatives;

[0192] 5 parts of nonylphenol polyoxyethylene ether;

[0193] 3 parts of polyoxyethylene laurate;

[0194] 2 parts of isoamyl alcohol;

[0195] 150 parts of deionized water.

[0196] Wherein, the acetylene alcohol ester is the same as that in Example 1.

[0197] Among them, the polyoxyethylene ether derivative is a product obtained by the ethoxylation reaction of long-chain fatty amide and ethylene oxide, R is C 10 ~C 17 Alkyl, n is an integer between 2 and 10, in this example R is C 12 , n is 5.

[0198] The preparation process and performance detection of the sizing agent for carbon fiber precursor are as follows:

[0199] Mix the above components evenly to obtain an emulsion with an average particle size of 579 nm. The emulsion has poor stability and a thermal residue rate of 90% at 300 °C.

[0200] When preparing T700 grade carbon fiber precursor, using this sizing agent, the obtained carbon fiber precursor is smoother, softer, with hairiness and splicing. After pre-oxidation and carbonization treatment, the obtained carbon fiber has a tensile strength of 3894 MPa.

[0201] In summary, the present invention uses oleic acid esters, alkynol esters, and polyoxyethylene ether derivatives as the main components of the sizing agent, together with emulsifiers, antistatic agents, and defoamers to form a sizing agent for carbon fiber precursor without silicon compounds.

[0202] From Examples 1 to 5, it can be seen that the sizing agent for carbon fiber precursor of the present invention has excellent performance, can protect the fiber, and improve the performance of carbon fiber. By comparing the data of Examples 1 to 5 and Comparative Examples 1 to 3, it can be seen that the sizing agent prepared using oleic acid esters, alkynol esters, and polyoxyethylene ether derivatives has excellent heat resistance and stability, and the obtained carbon fiber precursor has excellent smoothness. By comparing the data of Examples 1 to 5 and Comparative Examples 4 to 5, it can be seen that when using different organic acids and alkynol polyoxyethylene ethers, the performance of the sizing agent does not change significantly. By comparing the data of Examples 1 to 5 and Comparative Example 6, it can be seen that when R of the polyoxyethylene ether derivative is C 17 -C 20 alkyl and n is an integer between 10 and 20, the performance of the sizing agent is better. The present invention proposes a new type of sizing agent for carbon fiber precursor without silicon compounds, which is of great significance for eliminating silicon powder pollution in the carbon fiber production process and improving the performance of carbon fiber.

Claims

1. A sizing agent for carbon fiber precursor filaments without silicon compounds, characterized in that, By mass, the components include: 20-50 parts of oleate; 20-30 parts of acetylenic alcohol esters; 20-50 parts of polyoxyethylene ether derivatives; 1 to 5 parts of emulsifier; 1 to 5 parts of antistatic agent; 1 to 5 parts of defoaming agent; 100-200 parts of deionized water.

2. The sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 1, characterized in that, The oleic acid ester includes one or more of polyethylene glycol oleic acid ester, pentaerythritol oleic acid ester, glycerol oleic acid ester, sorbitan monooleic acid ester, glycerol oleic acid ester, and trimethylolpropane trioleic acid ester.

3. The sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 1, characterized in that, The structural formula of the acetylenic alcohol ester is as follows: wherein R is the remainder after removing the carboxyl group from the organic acid, and R1, R2 are C1-C 10 alkyl groups, and m, n are integers from 2 to 10.

4. The sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 1, characterized in that, The acetylene alcohol ester is obtained by reacting raw materials containing organic acid and acetylene alcohol polyoxyethylene ether under catalyst conditions.

5. The sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 4, characterized in that, The structural formula of the acetylenic alcohol polyoxyethylene ether is as follows: ; wherein R1 and R2 are C1-C 10 alkyl groups, and m and n are integers from 2 to 10; The organic acid includes one or more of acetic acid, oxalic acid, benzoic acid, stearic acid, salicylic acid, lactic acid, adipic acid, and terephthalic acid; and the catalyst is concentrated sulfuric acid.

6. The sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 4, characterized in that, The molar ratio of the organic acid to the acetylene alcohol polyoxyethylene ether is 1:(0.5-3); the reaction temperature is 120-150° C., and the reaction time is 3-5 h.

7. The sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 1, characterized in that, Structural formula of the polyoxyethylene ether derivative: RCONH-(CH2CH2O) n -H; wherein R is selected from C 10 ~C 20 alkyl groups, and n is an integer selected from 2 to 20.

8. The sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 1, characterized in that, The emulsifier includes one or more of isomeric alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyvinyl alcohol, sodium dodecylbenzene sulfonate, and trihydroxymethane polyoxyethylene ether; The antistatic agent includes one or more of polyoxyethylene fatty alcohol phosphate, polyoxyethylene laurate, sorbitan fatty acid ester, and dodecyltrimethylammonium chloride; The defoaming agent includes one or more of ethylene glycol monostearate, isoamyl alcohol, diisobutyl carbinol, and trialkyl melamine.

9. A method for preparing the sizing agent for carbon fiber precursor filaments without silicon compounds according to any one of claims 1 to 8, comprising the following steps: The components are weighed according to their mass fractions, and the components are evenly mixed to form an emulsion, so as to obtain a carbon fiber precursor oil agent free of silicon compounds.

10. The method for preparing the sizing agent for carbon fiber precursor filaments without silicon compounds according to claim 9, characterized in that, The average particle size of the oil agent is 150-300 nm.

11. Application of the sizing agent for carbon fiber precursor filaments without silicon compounds according to any one of claims 1 to 8 in the preparation of polyacrylonitrile-based carbon fibers.

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