TWI642709B - Carbon fiber surface oil replacement method - Google Patents

Abstract

The carbon fiber surface oil agent replacement method of the invention basically comprises the steps of providing raw materials, desizing, dry plasma surface treatment, and sizing, etc.; mainly in the surface process of the dry plasma, through the physical flow of the plasma gas stream and Chemical reaction, molecularizing or even blowing impurities originally attached to the surface of the carbon fiber, roughening the surface of the carbon fiber, and increasing the functional group on the surface of the carbon fiber, contributing to the high quality of the carbon fiber and the matrix resin in the subsequent process of the carbon fiber. The interface is bonded to enhance the performance of the carbon fiber composite.

Description

Carbon fiber surface oil replacement method

The present invention relates to a surface treatment technology for carbon fibers, and aims to provide a method for replacing a carbon fiber surface oil agent which can effectively replace an oil agent on a surface of a carbon fiber.

Carbon fiber, also known as carbon fiber, can be widely used in various applications due to its excellent mechanical and electrical properties. At present, carbon fibers are often bundled with precursor fibers of carbon fibers such as polyacrylonitrile fibers. The resulting carbon fiber precursor fiber bundle is obtained by calcination.

The untreated carbon fiber has insufficient surface adhesion and has poor lateral properties such as separation strength and shear strength, so it is less directly used, and is usually formed into a carbon fiber composite material combined with a matrix resin according to the use; Because carbon fiber and graphite fiber are particularly hard, brittle, lack of adhesiveness, bending force and wear resistance, they will be coated with a layer of oil (sizing agent) on the surface before leaving the factory to protect the fiber from frictional fracture.

In the past, carbon fiber composite materials have excellent mechanical properties for the complete utilization of carbon fibers, and the matrix resin is mostly made of a thermosetting resin material, which is a so-called thermosetting carbon fiber composite material. The biggest difference from the thermoplastic carbon fiber composite material is that the conventional thermosetting type The long molding time of the carbon fiber composite material results in a low use rate of the mold and a relatively low production capacity.

However, most of the oil agents on the surface of commercially available carbon fiber raw materials are thermosetting resin oils designed according to the wettability of thermosetting resins, and further development of such carbon fiber raw materials into thermoplastic carbon fiber composite materials. The carbon fiber raw material and the resin may not form a complete bonding interface due to interface mismatch, and it is a major factor that cannot be applied to various electrical, electronic parts, mechanical parts, and automobile parts, which are mainly used for injection molding. .

In view of the above, the present invention provides a method for replacing a carbon fiber surface oil agent which can effectively replace an oil agent on a surface of a carbon fiber, and is a main object thereof.

In order to achieve the above object, the carbon fiber surface oil agent replacement method of the present invention basically comprises at least the following steps: a step of providing a raw material, providing a carbon fiber, the carbon fiber is covered with a first oil agent; The slurry step is to remove the first oil agent; a dry plasma surface treatment step is to provide a plasma gas flow to the carbon fiber; and a sizing step is to cover a carbon fiber with a second oil agent.

By using the above technical features, the carbon fiber surface oil agent replacement method of the present invention can replace the oil agent on the surface of the carbon fiber with a desired oil agent by a relatively more positive and reliable means; in particular, the carbon fiber can be surface treated by dry plasma treatment. The roughening of the surface, while increasing the functional groups on the surface of the carbon fiber, in the subsequent sizing process of the carbon fiber, contributes to the high-quality interface bonding between the carbon fiber and the intended oil agent, thereby improving the characteristic performance of the carbon fiber composite material formed by the subsequent process.

According to the above technical feature, the carbon fiber surface oil agent replacement method applies a plasma gas flow of 100 to 10000 watts (W) to the carbon fiber for 10 to 1000 milliseconds in the dry plasma surface treatment step ( Msec).

According to the above technical feature, the carbon fiber surface oil agent replacement method is applied to the carbon fiber 10 to 1000 milliseconds in the dry plasma surface treatment step by using an atmospheric plasma gas flow having a power of 100 to 10000 watts (W). (msec).

According to the above technical feature, the carbon fiber surface oil agent replacement method is applied to the carbon fiber 10~1000 in a low-pressure plasma airflow with a power of 100-10000 watts (W) in the dry plasma surface treatment step. Milliseconds (msec).

According to the above technical feature, the carbon fiber surface oil agent replacement method is applied to the carbon fiber 10 to 1000 milliseconds in the dry plasma surface treatment step by using a microwave plasma gas having a power of 100 to 10000 watts (W). (msec).

According to the above technical feature, the carbon fiber surface oil agent replacement method is applied to the carbon fiber 10 to 1000 milliseconds in the dry plasma surface treatment step by using a glow plasma flow having a power of 100 to 10000 watts (W). (msec).

The method for replacing the oil on the surface of the carbon fiber is carried out in the degreasing step at a high temperature of 250 to 650 ° C for 1 to 60 seconds (sec).

In the carbon fiber surface oil replacement method, in the degreasing step, the first oil agent is removed by an organic solvent.

The above organic solvent is acetone or chloroform.

In the carbon fiber surface oil replacement method, in the sizing step, the second oil agent is coated on the surface of the carbon fiber by a soaking method.

In the carbon fiber surface oil replacement method, in the sizing step, the second oil agent is coated on the surface of the carbon fiber by padding.

The first oil agent is a thermosetting resin oil agent.

The second oil agent is a thermosetting resin oil agent.

The second oil agent is a thermoplastic resin oil.

The second oil agent may be one of a PU (polyurethane), PE (polyethene, polyethylene), PP (polypropylene, polypropylene) or acrylic (acrylic) system.

The method for replacing the carbon fiber surface oil agent is to apply at least one drying step to the carbon fiber raw material having the second oil agent after the sizing step, and fix the second oil agent to the carbon fiber.

The carbon fiber surface oil agent replacement method disclosed in the invention is particularly suitable for replacing the existing thermosetting resin oil agent on the surface of the commercially available carbon fiber raw material into a thermoplastic resin oil agent, so that the injection molding can be applied as the main processing means. Various electrical, electronic parts, mechanical parts and auto parts; in particular, the surface of the carbon fiber can be roughened by the surface treatment of the plasma, and the functional groups of the surface of the carbon fiber are increased, which helps in the subsequent process of the carbon fiber. The carbon fiber and the thermoplastic resin oil achieve high-quality interface bonding, thereby improving the performance of the carbon fiber composite material formed by the subsequent process.

10‧‧‧Carbon fiber raw materials

11‧‧‧Carbon fiber

111‧‧‧ Plasma reforming structure

12‧‧‧First oil agent

13‧‧‧Second oil agent

Fig. 1 is a basic flow chart showing a method for replacing a carbon fiber surface oil agent according to a first embodiment of the present invention.

Fig. 2 is a schematic view showing the cross-sectional structure of the carbon fiber raw material in the step of supplying the raw material by using the carbon fiber surface oil replacement method of the present invention.

Fig. 3 is a schematic view showing the cross-sectional structure of the carbon fiber after the completion of the desizing step by using the carbon fiber surface oil replacement method of the present invention.

Fig. 4 is a schematic view showing the cross-sectional structure of carbon fibers after completion of the plasma surface treatment step by using the carbon fiber surface oil agent replacement method of the present invention.

Fig. 5 is a schematic view showing the cross-sectional structure of the carbon fiber raw material after the completion of the sizing step by using the carbon fiber surface oil replacement method of the present invention.

Fig. 6 is a basic flow chart showing a method for replacing a carbon fiber surface oil agent according to a second embodiment of the present invention.

The invention mainly provides a carbon fiber surface oil agent replacement method which can effectively replace the oil agent on the surface of the carbon fiber. As shown in FIG. 1, the carbon fiber surface oil agent replacement method of the present invention basically comprises the following steps in sequence: Providing a raw material step, a de-pulping step, a dry plasma surface treatment step, and a sizing step, etc., together with the figures of Figures 2 to 5, further illustrating the possible implementation of each step as follows: The carbon fiber 11 is mainly provided on a surface of a carbon fiber 11 covered with a first oil agent 12; the carbon fiber 11 may be made of ruthenium, polyvinyl alcohol, vinylidene chloride or polyacrylonitrile. A carbon fiber precursor fiber bundle obtained by bundling precursor fibers such as PAN) and pitch is obtained by calcination; in practice, the first oil agent 12 may be a thermosetting resin oil.

In the desizing step, the first oil agent 12 on the surface of the carbon fiber raw material 10 is removed (as shown in FIG. 3); in the implementation, the temperature may be between 250 and 650 ° C for 1 hour. Desizing is performed under conditions of 60 seconds (sec), or the surface of the carbon fiber raw material 10 is washed with an organic solvent. In the embodiment, the slurry is removed; in the embodiment in which the surface of the carbon fiber material 10 is washed with the organic solvent, the organic solvent may be acetone or chloroform.

In the dry plasma surface treatment step, a plasma gas stream having a predetermined power is applied to the carbon fiber 11 from which the first oil agent has been removed for a predetermined time to form a relatively roughened electricity on the surface of the carbon fiber 11. The slurry reforming structure 111 (as shown in Fig. 4).

In the sizing step, the surface of the carbon fiber 11 on which the plasma reforming structure 111 is formed is covered with a second oil agent 13 to obtain a carbon fiber raw material 10 having the second oil agent 13 on the surface (eg, In the embodiment, the second oil agent 13 may be covered on the surface of the carbon fiber 11 by immersion or padding; as for the second oil agent, it may be a thermosetting type. a resin oil agent, or a thermoplastic resin oil agent; in the embodiment where the second oil agent is a thermoplastic resin oil agent, the second oil agent may be PU, PE, PP Or one of the acrylic systems.

Accordingly, the carbon fiber surface oil agent replacement method of the present invention can replace the oil agent on the surface of the carbon fiber with the expected oil agent by a relatively more active and reliable means; it is particularly suitable for the heat setting of the surface of the commercially available carbon fiber raw material. The resin oil is replaced by a thermoplastic resin oil, and can be applied to various electrical and electronic parts, mechanical parts, and automobile parts, which are mainly processed by injection molding.

In the dry plasma surface treatment process, an atmospheric plasma gas stream having a power of between 100 and 10,000 watts (W), a low pressure plasma gas stream, a microwave plasma gas stream or a glow plasma gas stream may be used to act on the carbon fiber 10 ~1000 milliseconds (msec); because the plasma gas stream contains energy particles, the physical reaction (impact) and chemical reaction of the plasma gas stream can be used to molecularize or even blow impurities originally attached to the surface of the carbon fiber to make carbon fiber Surface roughening while increasing carbon fiber The functional group of the surface of the dimension, in the subsequent sizing process of the carbon fiber, contributes to the high-quality interface bonding between the carbon fiber and the thermoplastic resin oil, thereby improving the characteristic performance of the carbon fiber composite material formed by the subsequent process.

Furthermore, since the surface treatment of the plasma in the present invention is a dry surface treatment technology, it is possible to avoid not only generating extra impurities or deposits in the carbon fibers, but also to reduce the drying of the carbon fibers after completion of the plasma surface treatment step. Working time, process; of course, the carbon fiber surface oil agent replacement method of the present invention may also be applied to the carbon fiber raw material having the second oil agent at least one drying step after the sizing step, as shown in FIG. The second oil can be firmly attached to the surface of the carbon fiber by drying or air drying.

Specifically, the method for replacing the carbon fiber surface oil agent disclosed in the present invention is particularly suitable for replacing the existing thermosetting resin oil agent on the surface of the commercially available carbon fiber raw material with a thermoplastic resin oil agent, so that it can be applied to injection molding. The main processing means of various electrical, electronic parts, mechanical parts and automotive parts; in particular, the surface of the carbon fiber can be roughened by dry plasma surface treatment, while increasing the functional groups of the carbon fiber surface, in the subsequent process of carbon fiber In the middle, it helps the carbon fiber to achieve high-quality interface bonding with the thermoplastic resin oil, thereby improving the performance of the carbon fiber composite material formed by the subsequent process.

The embodiments described above are merely illustrative of the technical spirit and the features of the present invention, and the objects of the present invention can be understood by those skilled in the art, and the scope of the present invention cannot be limited thereto. That is, the equivalent variations or modifications made by the spirit of the present invention should still be included in the scope of the present invention.

Claims (15)

A method for replacing a carbon fiber surface oil agent, comprising at least the following steps: providing a raw material step, providing a carbon fiber, the carbon fiber is covered with a first oil agent; and a degreasing step is the first oil a dry plasma surface treatment step for providing a plasma gas flow to the carbon fiber; wherein, in the dry plasma surface treatment step, the microwave plasma having a power of between 100 and 10000 watts (W) is used. The gas stream acts on the carbon fiber for 10 to 1000 milliseconds (msec); in a sizing step, a second oil agent is applied to the carbon fiber. The carbon fiber surface oil agent replacement method according to claim 1, wherein in the dry plasma surface treatment step, the plasma gas having a power of 100 to 10000 watts (W) acts on the carbon fiber for 10 to 1000 milliseconds. (msec). The carbon fiber surface oil agent replacement method according to claim 1, wherein in the dry plasma surface treatment step, the atmospheric plasma gas flow having a power of 100 to 10000 watts (W) acts on the carbon fiber 10 to 1000. Milliseconds (msec). The carbon fiber surface oil agent replacement method according to claim 1, wherein in the dry plasma surface treatment step, the low-pressure plasma gas having a power of 100 to 10000 watts (W) acts on the carbon fiber 10~ 1000 milliseconds (msec). The method for replacing a carbon fiber surface oil agent according to claim 1, wherein in the dry plasma surface treatment step, a glow plasma flow having a power of 100 to 10000 watts (W) is applied to the carbon fiber 10 to 1000. Milliseconds (msec). The carbon fiber surface oil agent replacement method according to claim 1, wherein in the desizing step, the slurry is removed at 250 to 650 ° C for 1 to 60 seconds. The carbon fiber surface oil agent replacement method according to claim 1, wherein in the desizing step, the first oil agent is removed by an organic solvent. The carbon fiber surface oil agent replacement method according to claim 7, wherein the organic solvent is acetone or chloroform. The carbon fiber surface oil agent replacement method according to claim 1, wherein in the sizing step, the second oil agent is coated on the carbon fiber by a soaking method. The carbon fiber surface oil agent replacement method according to claim 1, wherein in the sizing step, the second oil agent is coated on the carbon fiber in a padding manner. The carbon fiber surface oil agent replacement method according to claim 1, wherein the first oil agent is a thermosetting resin oil agent. The carbon fiber surface oil agent replacement method according to claim 1, wherein the second oil agent is a thermosetting resin oil agent. The carbon fiber surface oil agent replacement method according to claim 1, wherein the second oil agent is a thermoplastic resin oil agent. The method for replacing a carbon fiber surface oil agent according to claim 1, wherein the second oil agent is one of a PU, PE, PP or acrylic system. The carbon fiber surface oil agent replacement method according to claim 1, wherein at least one drying step is performed after the sizing step to fix the second oil agent to the carbon fiber.