CN118773778A - Highly protective carbon fiber oil and preparation method thereof - Google Patents

Abstract

The invention discloses a highly protective carbon fiber oil and a preparation method thereof. The highly protective carbon fiber oil is composed of 20 to 25 parts of a low molecular weight polysiloxane with a molecular weight of 1000 to 10000 g/mol, 1 to 7 parts of a phosphate-modified polysiloxane, 2 to 7 parts of an emulsifier, 56 to 72 parts of pure water, and 5 parts of other auxiliary agents. The oil of the invention has excellent self-crosslinking and film-forming properties, and can effectively prevent defects caused by fiber sticking to a roller during densification and scratching of a metal roller.

Description

Highly protective carbon fiber oil and preparation method thereof

Technical Field

The invention belongs to the field of carbon fiber preparation and relates to a high-protective carbon fiber oil agent and a preparation method thereof.

Background Art

Polyacrylonitrile (PAN)-based carbon fibers are widely used in defense, aerospace, wind power and other fields due to their 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 of polyacrylonitrile carbon fiber. It effectively protects the fiber during spinning, pre-oxidation and low-temperature carbonization. Therefore, high-quality oil is the key to producing high-quality carbon fibers.

At present, carbon fiber oils are mainly divided into two categories: one is silicone oils, and the other is non-silicone oils. Among them, silicone oils have been widely used in carbon fiber production because of their high heat resistance and lubricity. The main function of carbon fiber oils is to protect the fibers during the spinning process, preventing the fibers from melting and spinning at high temperatures and being damaged by metals. Oils are often used to form films when heated to protect the fibers, but traditional oils use amino, epoxy, and polyether modified silicone oils as the main raw materials, which are difficult to form a uniform protective film on the surface of the single fibers inside the fiber bundle, and it is difficult to produce high-performance and stable carbon fibers, and this type of emulsion may cause hairy fibers and broken fibers. Chinese patent application CN13667127A discloses a method for preparing an oil, which can form a protective film on the surface of fiber precursors, and has the advantages of preventing fiber precursors from bonding, hairy fibers, and broken fibers, but its preparation method is relatively complicated. Chinese patent application CN1823117A discloses a method for producing polysiloxane modified with phosphonate. The synthesized phosphonate-modified organosiloxane can be used as an additive in elastomers, an additive in silicone elastomers or an antistatic additive in silicone elastomers.

Summary of the invention

In order to solve the problems that the existing carbon fiber oil is not easy to cross-link when heated to form a protective film, thereby causing sticking to the roller during the densification process, and scratches on the fibers and metal rollers to cause defects, the present invention provides a highly protective carbon fiber oil and a preparation method thereof, which can avoid the occurrence of process problems such as sticking to the roller and poor fiber quality to the greatest extent.

The technical solution of the present invention is as follows:

The highly protective carbon fiber oil comprises the following components by weight: 20 to 25 parts of low molecular weight polysiloxane with a molecular weight of 1000 to 10000 g/mol, 1 to 7 parts of phosphate modified polysiloxane, 2 to 7 parts of emulsifier, 56 to 72 parts of pure water, and 5 parts of other additives. The structural formula of the phosphate modified polysiloxane is , wherein x=10~25, and the emulsifier is sodium dodecyl sulfate, dodecylbenzene sulfonic acid or polyoxyethylene sodium dodecylbenzene sulfonate.

Furthermore, other auxiliary agents are fatty alcohol polyoxyethylene ether nonionic emulsifiers and preservatives.

Furthermore, the molecular weight of the low molecular weight polysiloxane is 1000-5000 g/mol.

Further, the low molecular weight polysiloxane is selected from dimethyl polysiloxane, dihydroxy dimethyl polysiloxane, dialkoxy dimethyl polysiloxane or cyclic dimethyl polysiloxane.

Furthermore, the mass of the phosphate-modified polysiloxane is 5% to 28%, preferably 20% to 28%, of the mass of the low molecular weight polysiloxane.

Furthermore, the mass of the emulsifier is 10% to 28% of the mass of the low molecular weight polysiloxane, preferably 20% to 28%.

Furthermore, the highly protective carbon fiber oil agent comprises the following ingredients, by weight: 25 parts of dialkoxydimethylpolysiloxane with a molecular weight of 5000 g/mol, 5 parts of phosphate-modified polysiloxane, 5 parts of emulsifier sodium polyoxyethylene dodecylbenzene sulfonate, 60 parts of pure water, and 5 parts of other additives.

The preparation method of the above-mentioned highly protective carbon fiber oil agent comprises the following steps:

According to the proportion, phosphate-modified polysiloxane is dissolved in low molecular weight polysiloxane, and the resulting mixture is added to an aqueous solution of an emulsifier, further emulsified using a colloid mill, reacted at a constant temperature of 30-50°C, and hydrochloric acid solution is added to accelerate the copolymerization reaction. After the reaction is completed, sodium carbonate solution is added to neutralize excess acid, and finally other additives are added to keep the emulsion stable to obtain a highly protective carbon fiber oil agent.

Furthermore, the mass fraction of the hydrochloric acid solution is 15%, and the amount of the hydrochloric acid solution added is 0.5 parts by weight; the mass fraction of the sodium carbonate solution is 10%.

Furthermore, the constant temperature reaction time is 5 to 10 hours.

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

The present invention uses phosphate-modified polysiloxane and low molecular weight polysiloxane as the main components of the oil agent. The composition of the two mixed in a specific ratio has excellent self-crosslinking and film forming properties, avoids the yellowing problem of amino-modified silicone, and solves the low reactivity and poor film forming properties of alkoxy silicones containing epoxy groups, as well as the reaction of epoxy groups of organic functional groups or hydrolysis polymerization of alkoxy groups, which leads to inappropriate gel formation. In addition, the side-end ionizable phosphate group provides excellent antistatic and wettability for the fiber, and changes the physical properties of the fiber surface by attaching to the fiber surface. The carbon fiber oil agent prepared by the present invention can effectively prevent the occurrence of defects caused by sticking to the roller during the densification process and scratches between the fiber and the metal roller, thereby optimizing the carbon fiber production process to the greatest extent.

DETAILED DESCRIPTION

The content and technical scheme of the present invention are further described below in conjunction with specific embodiments so that those skilled in the art can further understand the present invention, 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 all fall within the scope of protection of the present invention.

The preparation of the phosphate-modified polysiloxane described in the present invention is based on the literature [CN 1807437A: Preparation method of organosilicon phosphate ester], and the structural formula of the phosphate-modified polysiloxane is:

, x=10~25.

Example 1

1 part by weight of phosphate-modified polysiloxane is dissolved in 20 parts by weight of dimethylpolysiloxane with a molecular weight of 1000 g/mol to form a mixed solution, 2 parts by weight of sodium dodecyl sulfate are stirred and dissolved in 72 parts by weight of water, the mixed solution is added, further emulsified by a colloid mill, and reacted at a constant temperature of 40°C for 8 hours, and 0.5 parts by weight of a 15% hydrochloric acid solution is added to accelerate the copolymerization reaction. After the reaction, a 10% sodium carbonate aqueous solution is added to neutralize excess acid, and finally 5 parts by weight of a fatty alcohol polyoxyethylene ether nonionic emulsifier and a preservative are added to obtain a stable emulsion.

Example 2

5 parts by weight of phosphate-modified polysiloxane are dissolved in 25 parts by weight of dialkoxydimethylpolysiloxane with a molecular weight of 5000 g/mol to form a mixed solution, 5 parts by weight of sodium polyoxyethylene dodecylbenzene sulfonate are stirred and dissolved in 60 parts by weight of water, the mixed solution is added, further emulsified by a colloid mill, and reacted at a constant temperature of 40°C for 8 hours, and 0.5 parts by weight of a 15% hydrochloric acid solution is added to accelerate the copolymerization reaction, and after the reaction is completed, a 10% sodium carbonate aqueous solution is added to neutralize excess acid, and finally 5 parts by weight of a fatty alcohol polyoxyethylene ether nonionic emulsifier and a preservative are added to obtain a stable emulsion.

Example 3

7 parts by weight of phosphate-modified polysiloxane are dissolved in 25 parts by weight of dihydroxydimethylpolysiloxane with a molecular weight of 10000 g/mol to form a mixed solution, 7 parts by weight of sodium polyoxyethylene dodecylbenzene sulfonate are stirred and dissolved in 56 parts by weight of water, the mixed solution is added, further emulsified by a colloid mill, and reacted at a constant temperature of 40°C for 8 hours, and 0.5 parts by weight of a 15% hydrochloric acid solution is added to accelerate the copolymerization reaction. After the reaction, a 10% sodium carbonate aqueous solution is added to neutralize excess acid, and finally 5 parts by weight of a fatty alcohol polyoxyethylene ether nonionic emulsifier and a preservative are added to obtain a stable emulsion.

Example 4

3 parts by weight of phosphate-modified polysiloxane are dissolved in 21 parts by weight of cyclic dimethyl polysiloxane with a molecular weight of 5000 g/mol to form a mixed solution, 5 parts by weight of dodecylbenzenesulfonic acid are stirred and dissolved in 66 parts by weight of water, the mixed solution is added, further emulsified by a colloid mill, and reacted at a constant temperature of 40°C for 8 hours, and 0.5 parts by weight of a 15% hydrochloric acid solution is added to accelerate the copolymerization reaction. After the reaction, a 10% sodium carbonate aqueous solution is added to neutralize excess acid, and finally 5 parts by weight of a fatty alcohol polyoxyethylene ether nonionic emulsifier and a preservative are added to obtain a stable emulsion.

Example 5

This embodiment is substantially the same as embodiment 2, except that the molecular weight of the dialkoxydimethylpolysiloxane is 1000 g/mol.

Example 6

This embodiment is substantially the same as embodiment 2, except that the molecular weight of the dialkoxydimethylpolysiloxane is 10000 g/mol.

Example 7

This embodiment is substantially the same as Embodiment 2, except that sodium dodecyl sulfate is used as the emulsifier instead of sodium polyoxyethylene dodecylbenzene sulfonate.

Example 8

This embodiment is substantially the same as Embodiment 2, except that dodecylbenzene sulfonic acid is used as the emulsifier instead of sodium polyoxyethylene dodecylbenzene sulfonate.

Example 9

This embodiment is substantially the same as embodiment 2, except that the amount of phosphate-modified polysiloxane is 1 part by weight, the amount of dialkoxydimethyl polysiloxane is 20 parts by weight, the amount of polyoxyethylene dodecylbenzene sulfonic acid is 2 parts by weight, and the amount of water added is 72 parts by weight.

Example 10

This embodiment is substantially the same as embodiment 2, except that the amount of phosphate-modified polysiloxane is 7 parts by weight, the amount of dialkoxydimethyl polysiloxane is 25 parts by weight, the amount of polyoxyethylene dodecylbenzene sulfonic acid is 7 parts by weight, and the amount of water added is 56 parts by weight.

Comparative Example 1

This comparative example is substantially the same as Example 2, except that an alkylphenol polyoxyethylene ether emulsifier is used instead of sodium polyoxyethylene dodecylbenzene sulfonate as the emulsifier.

Comparative Example 2

This comparative example is substantially the same as Example 2, except that the amount of phosphate-modified polysiloxane added is 10 parts by weight, and the amount of water added is 55 parts by weight.

Comparative Example 3

This comparative example is substantially the same as Example 2, except that the amount of sodium polyoxyethylene dodecylbenzene sulfonate added is 10 parts by weight, and the amount of water added is 55 parts by weight.

Comparative Example 4

This comparative example is substantially the same as Example 2, except that the molecular weight of the dialkoxydimethylpolysiloxane is 20,000 g/mol.

Comparative Example 5

This comparative example is substantially the same as Example 2, except that the molecular weight of the dialkoxydimethylpolysiloxane is 500 g/mol.

The properties of the carbon fiber oil obtained in each embodiment and comparative example and the results of production line evaluation are shown in Table 1.

Table 1

The oil emulsions prepared in Examples 1 to 10 are stable and have a short film-forming time, indicating that they have excellent self-crosslinking and film-forming properties, so that no roller sticking occurs during the fiber operation, and the number of fiber defects is small, the friction coefficient is small, and the original silk wool is excellent. In Comparative Examples 1 to 5, due to the use of alkylphenol polyoxyethylene ethers as emulsifiers, the addition amount of phosphate-modified polysiloxane is too large, the amount of emulsifier is too much, and the molecular weight of organic silicon is too large or too small, which makes the oil emulsion extremely poorly stable and even cannot be used online. During use, there is a roller sticking phenomenon, an increase in the number of fiber defects, an increase in the friction coefficient, and the original silk wool is deteriorated.

In summary, the present invention uses phosphate-modified polysiloxane and low molecular weight polysiloxane as the main components of the oil agent. The composition mixed in a specific proportion has excellent self-crosslinking and film-forming properties, can effectively prevent the roller from sticking during the densification process, and prevent defects caused by scratches between the fiber and the metal roller, thereby optimizing the processability of carbon fiber production to the greatest extent.

Claims (10)

1. The high-protection carbon fiber oiling agent is characterized by comprising the following components in parts by weight: 20-25 parts of low molecular weight polysiloxane with molecular weight of 1000-10000 g/mol, 1-7 parts of phosphate modified polysiloxane, 2-7 parts of emulsifier, 56-72 parts of pure water and 5 parts of other auxiliary agents, wherein the structural formula of the phosphate modified polysiloxane is as followsWherein x=10-25, and the emulsifier is sodium dodecyl sulfate, dodecyl benzene sulfonic acid or polyoxyethylene sodium dodecyl benzene sulfonate.

2. The high protective carbon fiber oiling agent according to claim 1, wherein other auxiliary agents are fatty alcohol polyoxyethylene ether nonionic emulsifiers and preservatives.

3. The high protective carbon fiber oiling agent according to claim 1, wherein the molecular weight of the low molecular weight polysiloxane is 1000-5000 g/mol.

4. The high protective carbon fiber oil according to claim 1, wherein the low molecular weight polysiloxane is selected from the group consisting of dimethylpolysiloxane, dihydroxydimethylpolysiloxane, dialkoxydimethylpolysiloxane, and cyclic dimethylpolysiloxane.

5. The high protective carbon fiber oiling agent according to claim 1, wherein the mass of the phosphate modified polysiloxane is 5% -28% of the mass of the low molecular weight polysiloxane, and the mass of the emulsifier is 10% -28% of the mass of the low molecular weight polysiloxane.

6. The high protective carbon fiber oiling agent according to claim 1, wherein the mass of the phosphate modified polysiloxane is 20% -28% of the mass of the low molecular weight polysiloxane, and the mass of the emulsifier is 20% -28% of the mass of the low molecular weight polysiloxane.

7. The high-protection carbon fiber oiling agent according to claim 1, which is characterized by comprising the following components in parts by weight: 25 parts of dialkoxy dimethyl polysiloxane with molecular weight of 5000g/mol, 5 parts of phosphate modified polysiloxane, 5 parts of emulsifier polyoxyethylene dodecyl benzene sulfonate, 60 parts of pure water and 5 parts of other auxiliary agents.

8. The preparation method of the high-protection carbon fiber oiling agent according to any one of claims 1 to 7, which is characterized by comprising the following steps:

According to the proportion, the phosphate modified polysiloxane is dissolved in low molecular weight polysiloxane, the formed mixture is added into an aqueous solution of an emulsifier, the mixture is further emulsified by using a colloid mill, the mixture reacts at a constant temperature of 30-50 ℃, a hydrochloric acid solution is added to accelerate the copolymerization reaction, a sodium carbonate solution is added to neutralize redundant acid after the reaction is finished, and finally other auxiliary agents are added to keep the emulsion stable, so that the high-protection carbon fiber oiling agent is prepared.

9. The preparation method according to claim 8, wherein the mass fraction of the hydrochloric acid solution is 15%, and the addition amount of the hydrochloric acid solution is 0.5 parts by weight; the mass fraction of the sodium carbonate solution was 10%.

10. The method according to claim 8, wherein the constant temperature reaction time is 5 to 10 hours.