Alcohol-modified silicone emulsion and its preparation method and application

Abstract

The present invention discloses a kind of alcohol-modified organosilicon emulsion and its preparation method and application. The alcohol-modified organosilicon emulsion is formed by the mixed reaction of the following components by mass fraction: 20%~30% of cyclic siloxane, 1%~3% of epoxyalkoxysilane, 0.5%~5% of nonionic surfactant, 5%~10% of anionic surfactant, 1%~2% of strong acid, 0.1%~0.5% of chain capping agent, 1%~5% of hydroxyl-terminated polydiorganosiloxane, and the balance is water. The alcohol-modified organosilicon emulsion of the present invention can be mixed with amino-modified silicone emulsion or epoxy-modified organosilicon emulsion in proportion, and is moderately cross-linked. It can form a film to better protect the fiber, and can avoid the sticky roller phenomenon caused by excessive cross-linking of traditional amino-epoxy-modified organosilicon emulsion during heating, and fiber quality and processability are greatly improved and 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 fibers are widely used in defense, aerospace, wind power, and other fields due to their lightweight, high-specific strength, high-specific modulus, high-temperature resistance, and corrosion resistance. Carbon fiber lubricants are essential additives in the production process, effectively protecting the fibers during spinning, pre-oxidation, and low-temperature carbonization. High-quality lubricants are crucial for producing high-quality carbon fibers.

[0003] Currently, most carbon fiber lubricants are modified silicone oil emulsions. Amino-modified silicone oils are widely used in synthetic carbon fiber lubricants due to their excellent heat resistance, softness, and ability to form 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 oils results in poor hydrophilicity, making it difficult to obtain a uniform and stable emulsion. Furthermore, their low degree of binding to the fiber makes it difficult to spread evenly on the fiber surface, failing to provide adequate protection. Therefore, amino-modified silicone oils are often used together with epoxy-modified silicone oils. However, during the drying process, they are prone to cross-linking and forming films, which can cause the fibers to stick to the rollers. Summary of the Invention

[0004] To address the processability issues of existing amino-epoxy-modified silicone emulsions, such as excessive cross-linking leading to film formation, resulting in fiber sticking to rollers, numerous defects, and poor fiber quality, the present invention provides an alcohol-modified silicone emulsion, its preparation method, and applications. This alcohol-modified silicone emulsion improves the heat resistance and hydrophilicity of silicone oil and can be mixed with amino-modified silicone emulsions and epoxy-modified silicone emulsions in specific proportions to achieve film-forming properties without excessive cross-linking.

[0005] The technical solutions of the present invention are as follows:

[0006] The alcohol-modified organic silicone emulsion is prepared by mixing and reacting the following components by mass fraction: 20% to 30% of cyclic siloxane, 1% to 3% of epoxyalkoxysilane, 0.5% to 5% of nonionic surfactant, 5% to 10% of anionic surfactant, 1% to 2% of strong acid, 0.1% to 0.5% of chain capping agent, 1% to 5% of 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) one of the hydroxyl-terminated polydiorganosiloxane polymers having the structural formula HOCH3SiO(CH3SiO)20 SiCH3OH.

[0007] Furthermore, 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 propyltrimethoxysilane.

[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 propyltrimethoxysilane, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid or its sodium salt, 2% hydrochloric acid, 0.1% hexamethyldisiloxane, 1% hydroxyl-terminated polydiorganosiloxane, and the balance 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, stirred and mixed evenly, and 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. Finally, an alkaline solution is used to neutralize the 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] This invention utilizes active groups to modify silicone, enhancing its application effectiveness. Alcohol-modified silicone emulsions can be mixed with amino-modified silicone emulsions and epoxy-modified silicone emulsions in a certain proportion. Moderate crosslinking allows for film formation, providing excellent fiber protection, while also preventing the roller sticking caused by excessive crosslinking during heating of conventional amino-epoxy-modified silicone emulsions. This significantly improves fiber quality and processability. DETAILED DESCRIPTION

[0019] The following is a further description of the content and technical solutions of the present invention in conjunction with specific embodiments, but it should not be understood 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 fall within the scope of protection of the present invention.

[0020] In the following examples, the hydroxyl-terminated polydiorganosiloxane polymer used is structurally represented by HOCH3SiO(CH3SiO) 20 SiCH3OH.

[0021] Example 1

[0022] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 15% D4 was slowly added. After stirring for a period of time, 1% β-glycidyl ether propyltrimethoxysilane and 5% D4 were added, and heating and stirring were continued. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0023] Example 2

[0024] In a stirring 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 was heated and stirred. After cooling, stirring was continued. 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, yielding an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:25 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0025] Example 3

[0026] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 25% D3 was slowly added. After stirring for a period of time, 1% β-glycidyl ether propyl dimethoxysilane and 5% D3 were added, and heating and stirring were continued. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:4 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0027] Example 4

[0028] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 2% polyoxyethylene lauryl ether, 7% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 15% D5 was slowly added. After stirring for a period of time, 1% β-glycidyl ether propyl trimethoxysilane and 5% D5 were added, and heating and stirring were continued. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 2% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an epoxy-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0029] Example 5

[0030] In a stirring 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 was stirred for a period of time before adding 1% β-glycidyl ether propyl trimethoxysilane and 5% D4, followed by heating and stirring. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, yielding an alcohol-modified silicone emulsion. This was then compounded with an epoxy-modified silicone emulsion at a ratio of 1:5 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0031] Example 6

[0032] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 2% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 15% D4 was slowly added. After stirring for a period of time, 3% β-glycidyl ether propyltrimethoxysilane and 5% D4 were added, and heating and stirring were continued. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 5% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0033] Example 7

[0034] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 2% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 15% D4 was slowly added. After stirring for a period of time, 2% β-glycidyl ether propyltrimethoxysilane and 5% D4 were added, and heating and stirring were continued. After cooling and continued stirring, 0.5% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0035] Comparative Example 1

[0036] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 15% dimethylpolysiloxane was slowly added. After stirring for a period of time, 1% β-glycidyl ether propyl trimethoxysilane and 5% dimethylpolysiloxane were added, and the mixture was heated and stirred. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0037] Comparative Example 2

[0038] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 10% D4 was slowly added. After stirring for a period of time, 1% β-glycidyl ether propyltrimethoxysilane and 5% D4 were added, and the mixture was heated and stirred. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0039] Comparative Example 3

[0040] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total feed volume. Heat and stir to dissolve. 15% D4 was slowly added. After stirring for a period of time, 1% β-glycidyl ether propyltrimethoxysilane and 5% D4 were added, and the mixture was heated and stirred. After cooling, stirring was continued, and 1% hydroxyl-terminated polydiorganosiloxane polymer was added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0041] Comparative Example 4

[0042] In a stirred tank equipped with a stirrer, reflux condenser, and thermometer, water, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid, and 2% hydrochloric acid were added, based on the total amount of ingredients. Heat and stir to dissolve. 15% D4 was slowly added. After stirring for a period of time, 1% β-glycidyl ether propyltrimethoxysilane and 5% D4 were added, and heating and stirring were continued. After cooling and continued stirring, 0.1% hexamethyldisiloxane and 1% hydroxyl-terminated polydiorganosiloxane polymer (R is ethyl and n=50) were added. Excess acid was neutralized with an alkaline solution to terminate the reaction, resulting in an alcohol-modified silicone emulsion. This was then compounded with an amino-modified silicone emulsion at a ratio of 1:10 to produce a carbon fiber oil. The results of the evaluation are shown in Table 1.

[0043] Table 1 Properties of carbon fiber oils obtained in Examples and Comparative Examples and 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 dimethylpolysiloxane, 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, no chain capping agent was used, so an alcohol-modified silicone oil emulsion was not obtained. In Comparative Example 4, no emulsion was obtained because the main chain of the hydroxyl-terminated polydiorganosiloxane used was too long.

[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 better protection for the fiber, but also avoid the roller sticking phenomenon caused by excessive cross-linking of traditional amino-epoxy modified silicone emulsions during the heating process, thereby greatly improving the fiber quality and processability.

Claims

1. Alcohol-modified silicone emulsion, characterized in that: The present invention is prepared by mixing and reacting the following components by mass fraction: 20% to 30% cyclic siloxane, 1% to 3% epoxyalkoxysilane, 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 being 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, epoxyalkoxysilane is β-glycidyl ether propyltrimethoxysilane.

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

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

4. 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.

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

6. 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%~30% hexamethylcyclotrisiloxane or octamethylcyclotetrasiloxane, 1% β-glycidyl ether propyl trimethoxysilane, 0.5% polyoxyethylene lauryl ether, 10% dodecylbenzenesulfonic acid or its sodium salt, 2% hydrochloric acid, 0.1% hexamethyldisiloxane, 1% hydroxyl-terminated polydiorganosiloxane, and the balance is water.

7. The method for preparing the alcohol-modified organosilicon emulsion according to any one of claims 1 to 6, 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, stirred and mixed evenly, and 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. Finally, an alkaline solution is used to neutralize the excess acid to terminate the reaction to obtain an alcohol-modified silicone emulsion.

8. The preparation method according to claim 7, wherein The heating temperature is 50~80℃.

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

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