阅读说明：本技术 一种碳纤维原丝用油剂 (Oiling agent for carbon fiber precursor ) 是由 钱京 张淑斌 顾红星 张明 李国明 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种碳纤维原丝用油剂,为包括二甲基硅油、氨基硅油、聚醚硅油、脂肪族聚氧乙烯醚,分散在水中形成的水性乳液；在油剂的不挥发性组分中,二甲基硅油的质量占比为60~80%,氨基硅油的质量占比为1~10%,聚醚硅油的质量占比为1~10%,脂肪族聚氧乙烯醚的质量占比为15~35%。本发明通过使用占绝对量的二甲基硅油和少量的氨基硅油、聚醚硅油作为油剂的主要成分,并使用脂肪族聚氧乙烯醚作为乳化剂,可获得稳定的、平均粒径小的油剂乳液,实现油剂与原丝表面的亲和性、均匀的成膜性,解决改性硅油在使用过程中的粘辊现象,提高运行的稳定性,降低现场的劳动强度,获得高品质、高品位的PAN原丝和碳纤维产品。(The invention discloses an oiling agent for carbon fiber precursors, which comprises dimethyl silicone oil, amino silicone oil, polyether silicone oil and aliphatic polyoxyethylene ether, and is an aqueous emulsion formed by dispersing the dimethyl silicone oil, the amino silicone oil, the polyether silicone oil and the aliphatic polyoxyethylene ether in water, wherein in the non-volatile components of the oiling agent, the mass ratio of the dimethyl silicone oil to the amino silicone oil is 60 ~ 80%, the mass ratio of the amino silicone oil to the amino silicone oil is 1 ~ 10%, the mass ratio of the polyether silicone oil to the polyether silicone oil is 1 ~ 10%, and the mass ratio of the aliphatic polyoxyethylene ether to the aliphatic polyoxyethylene ether is 15 ~ 35%.)

1. An oiling agent for carbon fiber precursors is characterized by comprising dimethyl silicone oil, amino silicone oil, polyether silicone oil and aliphatic polyoxyethylene ether which are dispersed in water to form aqueous emulsion;

in the nonvolatile components of the emulsion, the mass ratio of the dimethyl silicone oil is 60 ~ 80%, the mass ratio of the amino silicone oil is 1 ~ 10%, the mass ratio of the polyether silicone oil is 1 ~ 10%, and the mass ratio of the aliphatic polyoxyethylene ether is 15 ~ 35%.

2. The oiling agent for carbon fiber precursors according to claim 1, wherein the sum of the mass ratios of the amino silicone oil and the polyether silicone oil is 5 ~ 15%.

3. An oiling agent for carbon fiber precursor according to claim 1, wherein the oiling agent is capable of imparting, at 25 ℃,

the kinematic viscosity of the dimethyl silicone oil is 100 ~ 1000mm and 1000mm²/s，

The kinematic viscosity of the polyether silicone oil is 10 ~ 500mm²/s，

The kinematic viscosity of the amino silicone oil is 50 ~ 750mm²/s，

The amino silicone oil had an ammonia equivalent of 1000 ~ 5000 g/mol.

4. An oiling agent for carbon fiber strands according to claim 1, further comprising an auxiliary additive, wherein the auxiliary additive is at least one of an antistatic agent, an antioxidant, an antibacterial agent, a pH adjusting agent, an antifoaming agent, a preservative, a penetrating agent and a stabilizer, and the sum of the mass ratios of the auxiliary additive in the nonvolatile components of the oiling agent is 0.1 ~ 5%.

5. An oiling agent for carbon fiber strands according to claim 1, wherein the content of nonvolatile components in the emulsion is 10 ~ 40 wt%.

6. An oiling agent for carbon fiber strands according to claim 1, wherein the emulsion has an average particle diameter of 200 ~ 500 nm.

Technical Field

The invention relates to an oiling agent, in particular to an oiling agent for carbon fiber precursors, and belongs to the technical field of textile oiling agents.

Background

Carbon fiber is an important reinforcing material. Industrially, a method for producing carbon fibers comprises pre-oxidizing Polyacrylonitrile (PAN) fiber bundles as precursor fibers at 200 to 400 ℃ in an oxidizing atmosphere to obtain pre-oxidized fibers, and then carbonizing the pre-oxidized fibers at a high temperature of at least 1000 ℃ in an inert atmosphere such as nitrogen to obtain carbon fibers.

In the pre-oxidation process, because the process temperature exceeds the softening point of the PAN precursor, the PAN monofilament can be softened or even melted under the action of heat, and adjacent monofilaments can be adhered to each other, so that the multi-monofilament fibers are combined together, and the phenomenon of adhesion and doubling is generated. The adhesion and doubling of PAN monofilaments can directly cause the increase of broken filaments, the performance and the grade of fibers are reduced, and severe fibers can even cause the breakage of the filaments, thereby influencing the normal operation of production.

In order to prevent the adhesion and doubling of the PAN monofilaments during the pre-oxidation process, a conventional solution is to treat the raw filaments with a special oil solution to form a protective film having good heat resistance on the surface layer of the PAN fibers, thereby separating the monofilaments and preventing the monofilaments from blocking at high temperature. The effective components in the carbon fiber precursor oiling agent are mainly various modified polysiloxanes, such as ammonia modified polysiloxane (amino silicone oil), polyether modified polysiloxane (polyether silicone oil, water-soluble silicone oil) and cyano modified polysiloxane, and the like, because the modified polysiloxanes have good film forming property, heat resistance, antistatic property and friction resistance, have good interface affinity with PAN precursor, can be uniformly attached and distributed on the surface of the fiber to form a protective film, and thus, the PAN fiber can be effectively prevented from being adhered and doubled in the pre-oxidation process.

The reason for selecting the modified silicone oil is that different properties can be given to the silicone oil due to different modified groups, for example, the amino group in the amino silicone oil can improve the affinity of the silicone oil and the fiber and the crosslinking property under the action of heat, so that an oil film with considerable strength is obtained and the fiber is better protected; the polyether chain segment in the polyether modified silicone oil can endow the silicone oil with strong hydrophilicity, so that the silicone oil has water solubility and the like, and the properties are favorable for better exerting effects.

However, in practical use, it has been found that modified silicone oils, particularly the oil agents mainly comprising amino silicone oils, which are most widely used at present, have a significant problem, namely the so-called roll sticking problem. In the production process of PAN protofilament, after the fiber is treated by using oil agent, the technological processes of drying densification, high-power drafting and the like are further carried out, the oil agent on the surface of the fiber can be partially dropped and adhered to the roller surface of a guide roller, and because modified silicone oil such as amino silicone oil has strong crosslinking property, crosslinking reaction is easy to occur under the action of heat, and a colloidal condensate with high viscosity is formed. Especially, when the equipment such as a yarn separating frame, a grooved roll and the like is used for controlling the yarn channel of the fiber in the production process, the accumulation of the oil agent is more obvious due to stronger friction and shearing action. The oil agent which is adhered to the equipment and is high in viscosity and partially solidified can adhere to the fiber in operation, if a small amount of monofilaments are adhered to the oil agent, broken filaments can be generated, and filament winding can be caused when the monofilaments are not cleaned in time; if the running tows take away the oil agent blocks, obvious defect points are generated on the tows, and the yarns are easy to break at the positions in the subsequent heat treatment process.

In order to solve the phenomenon that the modified silicone oil agent is stuck on the roller, other components are introduced to reduce the content of the modified silicone oil such as amino silicone oil in the oil agent, or the field inspection frequency is enhanced to clean the oil agent accumulated on the roller surface and other equipment in time.

Non-silicon substances are introduced into the oil agent, so that the content of amino silicone oil and the like is reduced, the phenomenon can be reduced to a certain extent, and the problem of roller sticking cannot be thoroughly solved. And the field inspection strength is enhanced, the workload of field personnel can be obviously increased, and for equipment such as a wire separating frame, if semi-solidified oil agent blocks are adhered to the equipment, the treatment is difficult in the fiber running process, and the forced treatment easily causes damage to fiber bundles and even production and safety accidents.

Disclosure of Invention

In order to solve the defects of the prior art, the invention aims to provide an oiling agent for carbon fiber precursors, which can solve the problem that a modified silicone oil agent sticks to a roller on the premise of not influencing the effect of the oiling agent.

In order to achieve the above object, the present invention adopts the following technical solutions:

an oiling agent for carbon fiber precursors comprises dimethyl silicone oil, amino silicone oil, polyether silicone oil and aliphatic polyoxyethylene ether, and is an aqueous emulsion formed by dispersing the dimethyl silicone oil, the amino silicone oil, the polyether silicone oil and the aliphatic polyoxyethylene ether in water.

In the non-volatile components of the emulsion, the mass ratio of the dimethyl silicone oil is 60-80%, the mass ratio of the amino silicone oil is 1-10%, the mass ratio of the polyether silicone oil is 1-10%, and the mass ratio of the aliphatic polyoxyethylene ether is 15-35%. The mass ratio of the amino silicone oil to the polyether silicone oil is 5-15%.

The mass ratio of the dimethyl silicone oil is 60-80%: if the content of the modified silicone oil in the oil agent is lower than 60 percent, the content of the modified silicone oil in the oil agent is too high, and a large number of modified groups with reactivity are crosslinked under the action of heat, so that the main purpose of the invention, namely solving the problem that the roll sticking phenomenon of the oil agent cannot be realized; if it exceeds 80%, it is difficult to obtain a stable aqueous emulsion having a sufficiently small particle diameter because of the poor hydrophilicity of the dimethylsilicone oil, and the affinity of the oil agent with the fiber is poor.

The mass ratio of the amino silicone oil is 1-10%: if the content of the amino silicone oil is less than 1%, the affinity of the finish oil with the fiber is too poor, and it is difficult to attach a sufficient amount to the surface of the fiber; if the content exceeds 10%, the main object of the present invention, i.e., the roll sticking phenomenon of the oil agent is reduced and eliminated.

The mass ratio of the polyether silicone oil is 1-10%: polyether silicone oil is water-soluble silicone oil, it can also function as a silicone oil emulsifier, if its content is less than 1%, it is difficult to obtain a stable aqueous emulsion with a sufficiently small particle size, and if it exceeds 10%, the effect of the present invention is also affected.

Aliphatic polyoxyethylene ethers are mainly used as emulsifiers. In order to obtain a stable emulsion having a small average particle diameter by achieving an optimum emulsification effect, it is preferable to use a mixture of two or more substances having different HLB values (hydrophilic-lipophilic balance value).

The mass ratio of the aliphatic polyoxyethylene ether is 15-35%: if the proportion thereof is less than 15%, it is difficult to obtain a stable emulsion; if the content exceeds 35 percent, the heat resistance of the whole oiling agent is influenced, and the prevention effect of the oiling agent on the adhesion and doubling of PAN fiber in the pre-oxidation process is reduced.

Besides the dimethyl silicone oil, amino silicone oil, polyether silicone oil, aliphatic polyoxyethylene ether and the like, on the premise of not influencing the effect of the invention, a small amount of auxiliary additives of various other components such as an antistatic agent, an antioxidant, an antibacterial agent, a pH regulator, a defoaming agent, a preservative, a penetrating agent, a stabilizer and the like can be added according to the requirement. The mass ratio of the auxiliary additive in the nonvolatile components of the emulsion is 0.1-5%.

At 25 ℃, the kinematic viscosity of the dimethyl silicone oil is 100-1000 mm²(ii) s, preferably 300 to 500mm²S; the lower the viscosity of the silicone oil, the higher the cost, if the viscosity exceeds 1000mm²The difficulty of emulsification increases, and a stable aqueous emulsion having a sufficiently small particle diameter cannot be obtained.

At 25 ℃, the kinematic viscosity of the polyether silicone oil is 10-500 mm²/s。

At 25 ℃, the kinematic viscosity of the amino silicone oil is 50-750 mm²(ii) s, preferably 100 to 250mm²Is between/s. If the viscosity is less than 50mm²S, insufficient heat resistance, easy decomposition by heating, poor effect of preventing monofilament adhesion in the pre-oxidation process, and failure to obtain high-quality carbon fibers; if the viscosity exceeds 750mm²The emulsion has poor stability, is easily gelled, affects uniform adhesion to the filaments, and has poor fiber distribution of the fiber bundle after oiling.

The amino silicone oil has an ammonia equivalent of 1000 to 5000 g/mol. The ammonia equivalent herein means the mass of the silicone oil containing 1mol of amino groups, and the larger the ammonia equivalent, the smaller the number of amino groups in the molecule. When the ammonia equivalent is less than 1000, the number of amino groups per silicone molecule is too large, and the amino groups are a main cause of crosslinking and curing of the silicone oil. When the ammonia equivalent exceeds 8000g/mol, the number of amino groups per siloxane molecule is too small, and the affinity of the silicone oil with the precursor is poor, which is not favorable for uniform adhesion of the silicone oil on the surface of the precursor.

The oil agent of the invention is aqueous emulsion, and the water used as a dispersion medium is preferably deionized water. The specific method of emulsification includes the equipment and specific process used, and is not particularly limited, and generally known emulsification methods such as a high shear emulsification method, an ultrasonic emulsification method, and a method of emulsification using equipment such as a homogenizer and a high pressure homogenizer may be used. Different emulsification methods are used, the particle size of the obtained emulsion can be different, and the emulsion is properly selected according to the comprehensive consideration of actual conditions, such as production cost, production efficiency, product performance requirements and the like.

The emulsion has an average particle diameter of 200 to 500 nm. In the case of a large proportion of the dimethylsilicone fluid, it is practically difficult to achieve an average particle diameter of less than 200nm, and an average particle diameter of more than 500nm is not good in emulsion stability, and affects uniform adhesion of the finish agent to the fiber surface.

The content (solid content) of nonvolatile components in the emulsion is 10-40 wt%; if the solid content is lower than 10%, the production and transportation cost of the oil agent is obviously increased, which is not beneficial to improving the production capacity; if the content exceeds 40 percent, the stability of the oil solution emulsion is poor, the long-term storage is not facilitated, demulsification with different degrees is easy to generate in the using process, and the phenomenon of nonuniform oiling is caused.

If the oil agent of the invention has high solid content, the oil agent can be diluted as required in actual use. Deionized water is used during dilution, a certain amount of deionized water is slowly added to dilute the oil solution to the required concentration while the oil solution is kept stirred, and then the stirring is continued for half an hour. The diluted oil agent can be used for oiling the PAN precursor fiber bundle by an immersion method, a spray method, or the like, and the immersion method is generally used in consideration of the oiling effect, the overall cost, and the like.

The invention has the advantages that:

the oiling agent for the carbon fiber precursor is characterized in that dimethyl silicone oil, a relatively small amount of amino silicone oil and polyether silicone oil which account for absolute advantages in mass ratio are used as main components of the oiling agent, and aliphatic polyoxyethylene ether is used as an emulsifier, so that stable oiling agent emulsion with small average particle size (nanometer level) can be obtained, the affinity between the oiling agent and the surface of the PAN precursor, uniform film forming property and the like can be well realized, the main component of the oiling agent is low in crosslinking degree under the action of heat, the degree of viscosity increase is small, roll sticking phenomenon basically cannot occur, the roll sticking phenomenon of the past oiling agent with modified silicone oil as a main component in the using process can be thoroughly solved, the long-term operation stability of PAN precursor production is improved, the field labor intensity is reduced, and high-quality and high-grade PAN precursor and carbon fiber products are obtained.

The oil agent of the invention has easily obtained raw materials, simple and easily operated synthesis steps, can be prepared based on the existing equipment, can be properly adjusted according to the actual use, comprises the components and the proportion of the oil agent, the viscosity range of the dimethyl silicone oil, the viscosity range and the ammonia equivalent range of the amino silicone oil, the viscosity range of the polyether silicone oil, the solid content range of the emulsion, the particle size range of the emulsion and the like, and has strong practicability and wide applicability.

Detailed Description

The present invention will be described in detail with reference to the following embodiments.