Alcohol modified organic silicon emulsion as well as preparation method and application thereof

Abstract

The invention discloses an alcohol modified organic silicon emulsion as well as a preparation method and application thereof. The alcohol modified organic silicon emulsion is prepared by mixing and reacting the following components in percentage by mass: 20%-30% of cyclic siloxane, 1%-3% of epoxy alkoxy silane, 0.5%-5% of a nonionic surfactant, 5%-10% of an anionic surfactant, 1%-2% of strong acid, 0.1%-0.5% of a chain end capping agent, 1%-5% of hydroxyl-terminated polydiorganosiloxane and the balance of water. The alcohol-modified organic silicon emulsion can be mixed with amino-modified silicon emulsion or epoxy-modified organic silicon emulsion in proportion for use and is moderately cross-linked, so that a film can be formed to play a better role in protecting fibers, and the phenomenon of roll sticking caused by excessive cross-linking of the traditional amino-epoxy-modified organic silicon emulsion in the heating process can be avoided; and the fiber quality and the manufacturability are greatly improved.

Description

Technical Field

[0001] The invention belongs to carbon fiber production technology and relates to an alcohol-modified organic silicon emulsion and a preparation method and application thereof. Background Art

[0002] Polyacrylonitrile (PAN) based carbon fiber is widely used in defense, aerospace, wind power generation and other fields due to its excellent properties such as light weight, high specific strength, high specific modulus, high temperature resistance and corrosion resistance. Carbon fiber oil is an indispensable and important auxiliary agent in the production process. It effectively protects the fiber during the spinning, pre-oxidation and low-temperature carbonization stages. High-quality oil is the key to the production of high-quality carbon fiber.

[0003] At present, the oils for carbon fiber are mainly modified organic silicone oil emulsions, among which amino-modified silicone oil is widely used in synthetic carbon fiber oils because of its excellent heat resistance, softness, and easy formation of strong hydrogen bonds with polar groups such as hydroxyl groups on the fiber. However, the uneven distribution of amino groups in the molecular structure of amino-modified silicone oil leads to poor hydrophilicity, making it difficult to obtain a uniform and stable emulsion; the degree of binding with the fiber is too low, making it difficult to spread evenly on the fiber surface and unable to play a good protective role. Therefore, amino-modified silicone oil is often used together with epoxy-modified silicone oil, but it is easy to cross-link and form a film during the drying process, causing the fiber to stick to the roller. Summary of the invention

[0004] In order to solve the problem that the existing amino-epoxy modified silicone emulsion is prone to excessive cross-linking to form a film, which causes the fiber to stick to the roller, resulting in many defects, poor hairiness and other processability problems, the present invention provides an alcohol modified silicone emulsion and its preparation method and application. The alcohol modified silicone emulsion of the present invention can improve the heat resistance and hydrophilicity of silicone oil, and can be mixed with amino modified silicone emulsion and epoxy modified silicone emulsion in a specific ratio, so as to achieve a film-forming effect without excessive cross-linking.

[0005] The technical solution of the present invention is as follows:

[0006] The alcohol-modified organic silicon emulsion is prepared by mixing and reacting the following components by mass fraction: 20% to 30% cyclic siloxane, 1% to 3% epoxy alkoxy silane, 0.5% to 5% nonionic surfactant, 5% to 10% anionic surfactant, 1% to 2% strong acid, 0.1% to 0.5% chain capping agent, 1% to 5% hydroxyl-terminated polydiorganosiloxane, and the balance is water. The cyclic siloxane is selected from hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), tetravinyltetramethylcyclotetrasiloxane ( V D4) and tetraphenyltetramethylcyclotetrasiloxane ( Ph D4), wherein the hydroxyl-terminated polydiorganosiloxane polymer has the structural formula HOCH3SiO(CH3SiO)20 SiCH3OH.

[0007] Further, the structural formula of epoxyalkoxysilane is Wherein X is methyl or ethyl, and n is 0 or 1. Preferably, X is methyl, and n=1, that is, β-glycidyl ether propyl trimethoxy silane.

[0008] Furthermore, the HLB value of the nonionic surfactant is 10 to 20, and is selected from polyoxyethylene nonylphenol ether, polyoxyethylene lauryl ether, C11-C15 secondary alkoxy polyoxyethylene ether, etc., preferably polyoxyethylene lauryl ether.

[0009] Furthermore, the anionic surfactant is dodecylbenzenesulfonic acid or its sodium salt.

[0010] Furthermore, the strong acid used as the condensation polymerization catalyst is selected from hydrochloric acid, sulfuric acid, nitric acid, etc., preferably hydrochloric acid.

[0011] Furthermore, the chain capping agent functions to stop the chain polymerization growth of the emulsion polymerization reaction, and is selected from hexamethyldisiloxane or tetramethyldivinylsiloxane, preferably hexamethyldisiloxane.

[0012] Furthermore, the alcohol-modified silicone emulsion is prepared by mixing and reacting the following components by mass fraction: 20% to 30% hexamethylcyclotrisiloxane or octamethylcyclotetrasiloxane, 1% β-glycidyl ether propyl trimethoxy silane, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid or its sodium salt, 2% hydrochloric acid, 0.1% hexamethyldisiloxane, 1% hydroxyl-terminated polydiorganosiloxane, and the balance is water.

[0013] The preparation method of the alcohol-modified silicone emulsion comprises the following specific steps:

[0014] According to the ratio, water, nonionic surfactant, anionic surfactant and strong acid are first mixed and heated and stirred to dissolve, then part of the cyclic siloxane is slowly added, and after stirring and mixing evenly, epoxyalkoxysilane and the remaining cyclic siloxane are added, and heating and stirring are continued. After cooling to room temperature, a chain capping agent and a hydroxyl-terminated polydiorganosiloxane polymer are added under stirring conditions, and finally an alkaline solution is used to neutralize excess acid to terminate the reaction to obtain an alcohol-modified silicone emulsion.

[0015] Furthermore, the heating temperature is 50-80°C.

[0016] The present invention also provides a carbon fiber oil agent, which is prepared by mixing an alcohol-modified organic silicon emulsion and an amino- or epoxy-modified organic silicon emulsion in a mass ratio of 1:4 to 1:25.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The present invention utilizes active groups to modify the organosilicon, which can improve its application effect. The alcohol-modified organosilicon emulsion can be mixed with the amino-modified silicone emulsion and the epoxy-modified organosilicon emulsion in a certain proportion and cross-linked appropriately, which can not only form a film to provide good protection for the fiber, but also avoid the sticking roller phenomenon caused by excessive cross-linking of the traditional amino-epoxy-modified organosilicon emulsion during the heating process, which greatly improves and enhances the fiber quality and processability. DETAILED DESCRIPTION

[0019] The content and technical solutions of the present invention are further described below in conjunction with specific embodiments, but should not be construed as limiting the present invention. Without departing from the concept of the present invention, simple modifications or replacements made to the method, steps or conditions of the present invention all fall within the scope of protection of the present invention.

[0020] In the following examples, the hydroxyl-terminated polydiorganosiloxane polymer used has the structural formula HOCH3SiO(CH3SiO) 20 SiCH3OH.

[0021] Example 1

[0022] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 15% D4, stir for a certain period of time, add 1% β-glycidyl ether propyl trimethoxysilane and 5% D4, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0023] Example 2

[0024] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 0.5% polyoxyethylene lauryl ether, 10% sodium dodecylbenzene sulfonate, and 2% hydrochloric acid according to the total amount of materials, heat and stir to dissolve, and slowly add 20% v D4, after stirring for a certain period of time, add 1% β-glycidyl ether propyl trimethoxysilane and 5% v D4, heating and stirring. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:25, a carbon fiber oil agent was prepared and the evaluation results are shown in Table 1.

[0025] Example 3

[0026] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 25% D3, stir for a certain period of time, add 1% β-glycidyl ether propyl dimethoxysilane and 5% D3, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:4, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0027] Example 4

[0028] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 2% polyoxyethylene lauryl ether, 7% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 15% D5, stir for a certain period of time, add 1% β-glycidyl ether propyl trimethoxysilane and 5% D5, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 2% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with epoxy-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0029] Example 5

[0030] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 5% polyoxyethylene lauryl ether, 5% sodium dodecylbenzene sulfonate, and 1% hydrochloric acid according to the total amount of materials, heat and stir to dissolve, and slowly add 15% Ph D4, after stirring for a certain period of time, add 1% β-glycidyl ether propyl trimethoxysilane and 5% D4, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with epoxy-modified silicone emulsion at a ratio of 1:5, a carbon fiber oil agent was prepared and the evaluation results are shown in Table 1.

[0031] Example 6

[0032] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 2% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 15% D4, stir for a certain period of time, add 3% β-glycidyl ether propyl trimethoxysilane and 5% D4, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 5% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0033] Example 7

[0034] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 2% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 15% D4, stir for a certain period of time, add 2% β-glycidyl ether propyl trimethoxysilane and 5% D4, heat and stir. After cooling, continue stirring, add 0.5% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0035] Comparative Example 1

[0036] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 15% dimethyl polysiloxane, stir for a certain period of time, add 1% β-glycidyl ether propyl trimethoxy silane and 5% dimethyl polysiloxane, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0037] Comparative Example 2

[0038] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 10% D4, stir for a certain period of time, add 1% β-glycidyl ether propyl trimethoxysilane and 5% D4, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0039] Comparative Example 3

[0040] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 15% D4, stir for a certain period of time, add 1% β-glycidyl ether propyl trimethoxysilane and 5% D4, heat and stir. After cooling, continue stirring, add 1% hydroxyl-terminated polydiorganosiloxane polymer, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0041] Comparative Example 4

[0042] In a stirred kettle equipped with a stirrer, reflux condenser, and thermometer, add water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid, and 2% hydrochloric acid according to the total amount of feed, heat and stir to dissolve, slowly add 15% D4, stir for a certain period of time, add 1% β-glycidyl ether propyl trimethoxysilane and 5% D4, heat and stir. After cooling, continue stirring, add 0.1% hexamethyldisiloxane, 1% hydroxyl-terminated polydiorganosiloxane polymer with R as ethyl and n=50, use alkaline solution to neutralize excess acid, terminate the reaction, and obtain alcohol-modified silicone emulsion. After compounding with amino-modified silicone emulsion at a ratio of 1:10, a carbon fiber oil agent is prepared and the evaluation results are shown in Table 1.

[0043] Table 1 Characteristics of carbon fiber oil obtained in the examples and comparative examples and the results of production line evaluation

[0044]

[0045]

[0046] As can be seen from Table 1, the oil emulsions obtained in Examples 1-7 are microemulsions or emulsions with an average particle size of 150-600nm. No sticking to the roller occurs during use, and the number of surface defects of the polyacrylonitrile precursor is small, and the precursor hairiness is good. Comparative Example 1 failed to obtain a conventional emulsion due to the use of dimethyl polysiloxane, indicating that cyclic siloxane is crucial in the preparation of alcohol-modified silicone emulsions. In Comparative Example 2, the mass fraction of cyclic siloxane was reduced, the quality of the emulsion decreased, and the use effect was poor. In Comparative Example 3, since a chain capping agent was not used, an alcohol-modified silicone oil emulsion was not obtained. In Comparative Example 4, since the main chain of the hydroxyl-terminated polydiorganosiloxane used was too long, an emulsion was also not obtained.

[0047] In summary, the alcohol-modified silicone emulsion of the present invention can be mixed with amino-modified silicone emulsion and epoxy-modified silicone emulsion in a certain proportion and used as a carbon fiber oil agent to achieve moderate cross-linking. It can not only form a film to provide good protection for the fiber, but also avoid the sticking to the roller caused by excessive cross-linking of the traditional amino-epoxy modified silicone emulsion during the heating process, which greatly improves and enhances the fiber quality and processability.

Claims

1. Alcohol-modified silicone emulsion, characterized in that: The following components are mixed and reacted by mass fraction: 20%-30% cyclic siloxane, 1%-3% epoxy alkoxy silane, 0.5%-5% nonionic surfactant, 5%-10% anionic surfactant, 1%-2% strong acid, 0.1%-0.5% chain capping agent, 1%-5% hydroxyl-terminated polydiorganosiloxane, and the balance is water. The cyclic siloxane is selected from one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tetravinyltetramethylcyclotetrasiloxane and tetraphenyltetramethylcyclotetrasiloxane. The structural formula of the hydroxyl-terminated polydiorganosiloxane polymer is HOCH3SiO(CH3SiO) 20 SiCH3OH.

2. The alcohol-modified silicone emulsion according to claim 1, characterized in that: The structural formula of epoxyalkoxysilane is , wherein X is methyl or ethyl, and n is 0 or 1.

3. The alcohol-modified silicone emulsion according to claim 1, characterized in that: The HLB value of the nonionic surfactant is 10-20, and is selected from polyoxyethylene nonylphenol ether, polyoxyethylene lauryl ether or C11-C15 secondary alkoxy polyoxyethylene ether.

4. The alcohol-modified silicone emulsion according to claim 1, characterized in that: The anionic surfactant is dodecylbenzenesulfonic acid or its sodium salt.

5. The alcohol-modified silicone emulsion according to claim 1, characterized in that: The strong acid is selected from hydrochloric acid, sulfuric acid or nitric acid.

6. The alcohol-modified silicone emulsion according to claim 1, characterized in that: The chain capping agent is selected from hexamethyldisiloxane or tetramethyldivinylsiloxane.

7. The alcohol-modified silicone emulsion according to claim 1, characterized in that: It is prepared by mixing and reacting the following ingredients by mass fraction: 20% to 30% hexamethylcyclotrisiloxane or octamethylcyclotetrasiloxane, 1% β-glycidyl ether propyl trimethoxy silane, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzene sulfonic acid or its sodium salt, 2% hydrochloric acid, 0.1% hexamethyldisiloxane, 1% hydroxyl-terminated polydiorganosiloxane, and the balance is water.

8. The method for preparing the alcohol-modified organosilicon emulsion according to any one of claims 1 to 7, characterized in that: The specific steps are as follows: According to the ratio, water, nonionic surfactant, anionic surfactant and strong acid are first mixed and heated and stirred to dissolve, then part of the cyclic siloxane is slowly added, and after stirring and mixing evenly, epoxyalkoxysilane and the remaining cyclic siloxane are added, and heating and stirring are continued. After cooling to room temperature, a chain capping agent and a hydroxyl-terminated polydiorganosiloxane polymer are added under stirring conditions, and finally an alkaline solution is used to neutralize excess acid to terminate the reaction to obtain an alcohol-modified silicone emulsion.

9. The preparation method according to claim 8, characterized in that The heating temperature is 50~80℃.

10. A carbon fiber oil agent, characterized in that: The alcohol-modified silicone emulsion according to any one of claims 1 to 7 is mixed with an amino- or epoxy-modified silicone emulsion in a mass ratio of 1:4 to 1:25.

Images