JP5651244B2 - Carbon fiber bundle manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a carbon fiber bundle, and more particularly, to an improvement in the strength of the carbon fiber bundle, prevention of dust during processing, improvement in heat resistance and fire resistance, prevention of peeling of the plating film, and improvement in surface appearance. Is.

Since carbon fiber has high heat resistance, many techniques relating to this have been proposed.
For example, Patent Document 1 discloses a composite process provided with a brush table in which brush hairs are made of carbon fiber having a high heat-resistant temperature in order to solve the problem that brush hairs near a laser or spark are burned, melted, or worn down. An apparatus is disclosed.
Further, Patent Documents 2 and 3 describe a carbon fiber bundle in which a nylon fiber is welded to a carbon fiber bundle and subjected to copper plating and nickel plating for the purpose of improving heat resistance and preventing the carbon fiber from being cut. A manufacturing method is disclosed.

Japanese Patent Laid-Open No. 9-327786 Japanese Patent No. 4135968 Japanese Patent No. 4521818

  However, the carbon fiber bundles disclosed in Patent Documents 1 to 3 improve the toughness of the carbon fiber bundle, prevent dust during processing, improve heat resistance and fire resistance, prevent peeling of the plating film, and have a surface appearance. There is room for improvement in terms of improvement. And the prior art which solved all of these is not yet known.

  The present invention has been made in view of the above circumstances, and its purpose is to improve the flexibility of the carbon fiber bundle, to prevent dust during processing, to improve heat resistance and fire resistance, to prevent the peeling of the plating film, and to the surface appearance. An object of the present invention is to provide a method of manufacturing a carbon fiber bundle that can improve the above.

In order to solve the above problems, a method for producing a carbon fiber bundle according to the present invention includes:
A twisting process of twisting a carbon fiber bundle in which a plurality of carbon fibers are bundled together;
A winding step of winding the first and second nylon yarns around the carbon fiber bundle A that has undergone the twisting step;
A heat treatment step of taking out a plurality of bundles of carbon fiber bundles B that have undergone the winding step and welding at least one of the first to third nylon yarns in a state of being twisted with a third nylon yarn sandwiched between them. When,
A copper plating step of applying copper plating to the carbon fiber bundle C that has undergone the heat treatment step;
A nickel plating step of applying nickel plating to the carbon fiber bundle D that has undergone the copper plating step;
The gist of the present invention is to provide an acrylic resin impregnation step of impregnating the carbon fiber bundle E that has undergone the nickel plating step with an acrylic resin.

  In this case, the acrylic resin is preferably a polymethyl methacrylate resin or a resin obtained by further adding a flame retardant.

  In this case, the acrylic resin impregnation step is a step of impregnating the carbon fiber bundle E into the acrylic resin at a temperature of 80 to 100 ° C. for 8 to 12 hours and then drying at a temperature of 50 to 80 ° C. Is preferred.

In this case, the copper plating step is
Immersing the carbon fiber bundle C in a colloidal solution of Pd and Sn, and applying a catalyst to adsorb Pd and Sn on the surface of the carbon fiber bundle C;
Among the Pd and Sn adsorbed on the carbon fiber bundle C in the catalyst application step, an accelerator treatment step in which Sn is dissolved and only Pd is adsorbed;
Copper that immerses the carbon fiber bundle C in a copper plating solution in which a reducing agent is added to a mixed solution of a mixed solution of a copper sulfate aqueous solution and potassium sodium tartrate, a mixed solution of a caustic soda aqueous solution and a stabilizer aqueous solution. It preferably comprises a plating solution immersion step.

In this case, the nickel plating step is
Dipping the carbon fiber bundle D in a colloidal solution of Pd and Sn, and applying a catalyst to adsorb Pd and Sn on the surface of the carbon fiber bundle D;
Among the Pd and Sn adsorbed on the carbon fiber bundle D in the catalyst application step, an accelerator treatment step in which Sn is dissolved and only Pd is adsorbed;
It is preferable to comprise a nickel plating solution immersing step of immersing the carbon fiber bundle D in a nickel plating solution obtained by adding sodium hypophosphite to a solution prepared by mixing a nickel sulfate aqueous solution and a sodium citrate aqueous solution and adjusting the pH.

  The carbon fiber bundle manufacturing method according to the present invention includes an acrylic resin impregnation step of impregnating an acrylic resin into the carbon fiber bundle E that has undergone a nickel plating step after performing a predetermined step. It has the effects of improving the flexibility of the carbon fiber bundle, preventing dust during processing, improving heat resistance and fire resistance, preventing peeling of the plating film, and improving the surface appearance.

It is sectional drawing of the carbon fiber bundle 10 which concerns on 1st embodiment of this invention. It is sectional drawing of the carbon fiber bundle 20 which concerns on 2nd embodiment of this invention. It is a flowchart for demonstrating a copper plating process and a nickel plating process. It is a figure for demonstrating the measuring method of surface frictional resistance.

1 Carbon fiber 2 Nylon resin 3 Copper plating film 4 Nickel plating film 5 Acrylic resin film 10, 20 Carbon fiber bundle

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view of the carbon fiber bundle 10. In the figure, a carbon fiber bundle 10 is formed by bundling a plurality of carbon fibers. The carbon fiber used here is not particularly limited and may be a commercially available one. The diameter and the number of carbon fibers constituting the carbon fiber bundle 10 are not particularly limited, but a carbon fiber bundle in which 1000 to 6000 carbon fibers of 0.001 to 0.030 mm are bundled is preferable. A carbon fiber bundle obtained by bundling 1000 to 5000, particularly 3000, carbon fibers of 007 mm is preferable.

  The nylon resin 2 only needs to adhere at least one of the carbon fibers constituting the carbon fiber bundle 10 to each other. The nylon resin 2 used here is not particularly limited as long as a commercially available fused yarn is melted by heat and / or 6,6-nylon is melted by heat. The nylon resin 2 enters between the carbon fibers constituting the carbon fiber bundle 10 and bonds the carbon fibers together. The degree of penetration of the nylon resin 2 may be anything that entangles at least part of the surface of each carbon fiber.

  The copper plating film 3 covers the carbon fiber bundle 10 in which at least one of the carbon fibers is bonded to each other with the nylon resin 2. The film thickness of the copper plating film 3 is not particularly limited. The composition of the copper plating film 3 is not particularly limited, but is preferably composed of 99.5 wt% or more of Cu and inevitable impurities.

  The nickel plating film 4 covers the carbon fiber bundle 10 on which the copper plating film 3 is formed. The film thickness of the nickel plating film 4 is not particularly limited. The composition of the nickel plating film 4 is not particularly limited, but is preferably composed of about 90 to 97 wt% Ni, about 3 to 10 wt% P and unavoidable impurities (almost negligible).

  The acrylic resin film 5 covers the carbon fiber bundle 10 on which the nickel plating film 4 is formed. The film thickness of the acrylic resin film 5 is not particularly limited, but is preferably 0.001 to 0.010 mm. The composition of the acrylic resin film 5 is not particularly limited, but is preferably made of a polymethyl methacrylate resin or further added with a flame retardant.

(Second embodiment)
FIG. 2 is a cross-sectional view of the carbon fiber bundle 20. As shown in the figure, the carbon fiber bundle 20 is coated with a nylon resin 2 on the entire surface of each carbon fiber 1 constituting the carbon fiber bundle 20, and the entire surface coated with the nylon resin 2 is a copper plating film 3. Further, the entire surface coated with the copper plating film 3 is coated with a nickel plating film 4, and the entire surface coated with the nickel plating film 4 is further coated with an acrylic resin film 5. is there. Although illustration is omitted, when the acrylic resin film 5 is formed, the carbon fiber on which the nickel plating film 4 is formed may be bundled.

  Carbon fiber bundles 10 and 20 have improved resilience, dust prevention during processing, improved heat resistance and fire resistance, and plating when applied to brush bristles, compared to the case where conventional acrylic resin film 5 is not formed. It is possible to prevent peeling of the film and improve the surface appearance.

(Method for producing carbon fiber bundle according to the first embodiment)
Next, a method for manufacturing the carbon fiber bundle 10 shown in FIG. 1 will be described.
The manufacturing method of the carbon fiber bundle 10 which concerns on one Embodiment of this invention is equipped with a twist process, a winding process, a heat treatment process, a copper plating process, a nickel plating process, and an acrylic resin impregnation process.

(1) Twisting process A carbon fiber bundle obtained by bundling a plurality of carbon fibers is twisted together. For example, about 3000 carbon fibers having a diameter of 0.007 mm are bundled, and the carbon fiber bundle is twisted so that the carbon fiber bundle can be twisted 180 ± 10 times at almost equal intervals within a unit length of 1 m. The number of carbon fibers and the number of twists are not particularly limited. The carbon fiber bundle that has undergone the twisting process is referred to as “carbon fiber bundle A”.

(2) Winding step The first and second nylon yarns are wound around the carbon fiber bundle A. 6,6-nylon yarn can be used as the first nylon yarn, and 6,6-nylon yarn can be used as the second nylon yarn, but is not limited thereto. Between the unit length of 1 m of the carbon fiber bundle A, the first and second nylon yarns (two nylon yarns in total) are wound 600 ± 10 times at almost equal intervals. Let the carbon fiber bundle which passed through the winding process be "carbon fiber bundle B".

(3) Heat treatment step Two bundles of carbon fiber bundles B are taken out, a third nylon thread is sandwiched between them and twisted. 6,6-nylon yarn can be used as the third nylon yarn. Then, the twisted carbon fiber bundle B is placed in an atmosphere of about 200 ° C. for about 10 seconds. Thereby, the first to third nylon yarns (nylon resin) are melted and the carbon fibers constituting the carbon fiber bundle are bonded to each other. Thereby, the intensity | strength of a carbon fiber bundle is raised and a carbon fiber bundle stands out. The carbon fiber bundle that has undergone the heat treatment step is referred to as “carbon fiber bundle C”.

(4) Copper Plating Step A procedure for applying copper plating to the carbon fiber bundle C will be described with reference to FIG. In addition, each process performed with respect to the carbon fiber bundle C is the carbon fiber bundle C made into soft winding (referring to the method of winding to the extent that a plating solution enters easily. Or by injecting each treatment liquid onto the substrate.
(Pretreatment of copper plating process)
As pre-processing, the processes (i) to (vi) shown in FIG. 3 are performed. In the degreasing process of FIG. 1 (i), residual oil on the surface of the carbon fiber bundle C is removed. And the water washing process of the figure (ii) is performed.
In the catalyst application process of FIG. 3 (iii), the carbon fiber bundle C is immersed in a colloidal solution of Pd and Sn, and Pd and Sn are adsorbed on the surface of the carbon fiber bundle C. And the water washing process of the same figure (iv) is performed.
In the accelerator process of FIG. 5 (v), Sn is dissolved out of the adsorbed Pd and Sn, and only Pd is adsorbed. And the water washing process of the figure (vi) is performed.

(Main treatment of copper plating process)
When the above is completed, the copper plating process (vii-1) shown in FIG. 3 is performed as the main process (electroless copper plating). The procedure of this process is as follows.
(A) Adjustment of copper plating solution The copper plating solution is adjusted according to the following procedures (a) to (f).
(A) 3 grams of copper sulfate is dissolved in 300 cc of water (solution A).
(B) Dissolve 30 grams of potassium sodium tartrate in 300 cc of water (Liquid B).
(C) Mix liquid A and liquid B (liquid C)
(D) A solution obtained by dissolving 10 grams of caustic soda in 100 cc of water and a solution obtained by dissolving 0.1 gram of a stabilizer (for example, thiourea) in 100 cc of water are mixed (liquid D).
(E) C liquid and D liquid are mixed (E liquid).
(F) Dissolve 10 grams of formaldehyde (reducing agent) in E solution and add water to make a total of 1 liter (F solution: copper plating solution).
(B) Immersion in copper plating solution (F solution) Next, the carbon fiber C subjected to the pretreatment of (A) is immersed in an F solution at 30 ° C. for 30 minutes. Then, pure Cu (purity 95 wt% or more) is deposited on the surface of the carbon fiber C, and copper plating is completed. The carbon fiber bundle that has undergone the copper plating step is referred to as “carbon fiber bundle D”.

(5) Nickel plating step The procedure for applying nickel plating to the carbon fiber bundle D will be described with reference to FIG. In addition, each process performed with respect to the carbon fiber bundle D is performed by immersing the carbon fiber bundle D softly wound in a liquid-permeable winding tube in each treatment tank, or spraying each treatment liquid on this.

(Pretreatment of nickel plating process)
As pre-processing, processing (viii) and processing (iii) to (vi) shown in FIG. 3 are performed. First, since it is after copper plating, the water washing process of FIG.
In the catalyst application process in FIG. 3 (iii), the carbon fiber bundle D is immersed in a colloidal solution of Pd and Sn, and Pd and Sn are adsorbed on the surface of the carbon fiber bundle D. And the water washing process of the same figure (iv) is performed.
In the accelerator process of FIG. 5 (v), Sn is dissolved out of the adsorbed Pd and Sn, and only Pd is adsorbed. And the water washing process of the figure (vi) is performed.

(Nickel plating process)
When the above is completed, the nickel plating process (vii-2) shown in FIG. 3 is performed as the main process (electroless nickel plating). The procedure of this process is as follows.
(A) Adjustment of nickel plating solution The nickel plating solution is adjusted according to the following procedures (a) to (f).
(A) Dissolve 20 grams of nickel sulfate in 300 cc of water (liquid a).
(B) 40 grams of sodium citrate is dissolved in 300 cc of water (liquid b).
(C) Mix liquid a and liquid b (liquid c)
(D) Ammonia is added to the liquid c to adjust the pH to 9 (liquid d).
(E) Dissolve 15 grams of sodium hypophosphite in d solution (e solution).
(F) Water is added to the solution e to make 1 liter as a whole (solution f: nickel plating solution).
(B) Immersion in nickel plating solution (f solution) Next, the carbon fiber D that has been subjected to the pretreatment of (A) is immersed in an f solution at 30 ° C. for 30 minutes. Then, an alloy of Ni and P (Ni is 95 wt%, P is 5 wt%) is deposited on the surface of the carbon fiber D, and nickel plating is completed. The carbon fiber bundle that has undergone the nickel plating step is referred to as “carbon fiber bundle E”.

(6) Acrylic resin impregnation step To improve the toughness of the obtained carbon fiber bundle E, to prevent dust during processing, to improve heat resistance and fire resistance, to prevent peeling of the plating film, and to improve the surface appearance, acrylic A step (binder processing step) of immersing in a system resin-containing solution is performed. The procedure of this process is as follows.
(A) An acrylic resin-containing solution (α liquid) containing polymethyl methacrylate resin (PMMA) and no flame retardant is prepared. Moreover, what contains polymethyl methacrylate resin and a flame retardant (beta liquid) is also produced.
(B) The acrylic resin-containing solution (α solution or β solution) is set to 90 ° C. The carbon fiber bundle E is immersed in this for 10 hours.
(C) After dipping for 10 hours, the carbon fiber bundle E is dried for 12 hours in a drying furnace whose temperature is adjusted to 50 ° C. to 80 ° C. Thereby, the “carbon fiber bundle F” in which the acrylic resin film 5 is formed is obtained.

(Examples 1 and 2)
As the acrylic resin-containing solution, a solution containing a polymethyl methacrylate resin and containing no flame retardant (the above α solution) and a solution containing a polymethyl methacrylate resin and a flame retardant (the above β solution) were prepared. . Then, the above-described (1) twisting step, (2) winding step, (3) heat treatment step, (4) copper plating step, (5) nickel plating step, and (6) acrylic resin impregnation step were performed. Example 1 uses the α liquid, and Invention 1 is the carbon fiber bundle F obtained in Example 1. Example 2 uses a β solution, and invention product 2 is the carbon fiber bundle F obtained in Example 2.
The conditions for the acrylic resin impregnation step are shown in Table 1.

(Comparative Example 1)
(1) Twisting step, (2) Winding step, (3) Heat treatment step, (4) Copper plating step, (5) Nickel plating step (Comparative Example 1), and carbon fiber obtained thereby The bundle E is the comparative product 1.

Next, since various measurements and various tests were carried out on Invention Products 1 and 2 and Comparative Product 1, it will be described. These results are shown in Table 1.
(Film thickness measurement)
The film thickness of the formed acrylic resin was measured by cutting Invention Products 1 and 2 and enlarging them with a microscope.

(Flexibility measurement)
The resilience was determined by measuring the deflection value (length) when the invention products 1, 2 and the comparative product 1 were each 1000 mm in length, supported at both ends, and a load of 1 g was applied to the center. .

(Dust scattering test during cutting)
The degree of dust scattering was confirmed by wiping the inventive products 1 and 2 and the comparative product 1 with a white waste and visually observing the degree of dirt on the waste. This confirmed also about peeling of a plating film.

(Heat resistance-flame spread)
The extent of the flame was confirmed by applying the flame of the burner to Inventions 1 and 2 and Comparative Product 1 for 10 seconds and observing the state of the flame.

(Heat resistance-Fire extinguishing)
The fire extinguishing property was confirmed by measuring the fire extinguishing time when the flame of the burner was moved away from the inventive products 1 and 2 and the comparative product 1 after applying for 10 seconds to observe the above-mentioned flame spread.

(Fire resistance (flame retardant))
The fire resistance (flame resistance) was confirmed by observing the states of the inventive products 1, 2 and the comparative product 1 by applying a flame of the burner to the inventive products 1, 2 and the comparative product 1 for 10 seconds.

(Surface friction resistance)
After the invention products 1 and 2 and the comparative product 1 were immersed in water for 1 minute, as shown in FIG. 4, these (test pieces) were placed on an aluminum plate coated with an automotive paint, and a 300 g weight was placed thereon. . In this state, each test piece was pulled horizontally. Then, the force when the test piece started to move was measured using a push-pull meter (manufactured by Imada Co., Ltd., model number: DPSH100) to obtain surface friction resistance.

(appearance)
The appearance was confirmed by shining light on the invention products 1 and 2 and the comparative product 1 to observe the gloss.

  From the above, carbon fiber bundles that have been formed into a film with an acrylic resin by immersing them in an acrylic resin-containing solution have improved flexibility (less deflection) than carbon fiber bundles that do not have an acrylic resin film. , Dust prevention during processing (wipe away with waste during cutting), heat resistance and fire resistance improved (flame does not spread easily, fire extinguishing time is short, does not melt), prevention of plating film peeling (cutting processing) It was found that the surface appearance was improved (glossy), and sometimes the surface was wiped off with a waste cloth so that no dirt adhered.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made.

  The method for producing a carbon fiber bundle according to the present invention contributes to improvement of the resilience of the carbon fiber bundle, prevention of dust during processing, improvement of heat resistance and fire resistance, prevention of peeling of the plating film, and improvement of the surface appearance. Therefore, the industrial utility value is extremely high.

Claims (5)

A twisting process of twisting a carbon fiber bundle in which a plurality of carbon fibers are bundled together;
A winding step of winding the first and second nylon yarns around the carbon fiber bundle A that has undergone the twisting step;
A heat treatment step of taking out a plurality of bundles of carbon fiber bundles B that have undergone the winding step and welding at least one of the first to third nylon yarns in a state of being twisted with a third nylon yarn sandwiched between them. When,
A copper plating step of applying copper plating to the carbon fiber bundle C that has undergone the heat treatment step;
A nickel plating step of applying nickel plating to the carbon fiber bundle D that has undergone the copper plating step;
A method for producing a carbon fiber bundle, comprising: an acrylic resin impregnation step of impregnating an acrylic resin into the carbon fiber bundle E that has undergone the nickel plating step.   The method for producing a carbon fiber bundle according to claim 1, wherein the acrylic resin is a polymethyl methacrylate resin or a resin obtained by further adding a flame retardant.   The acrylic resin impregnation step is a step of impregnating the carbon fiber bundle E into the acrylic resin at a temperature of 80 to 100 ° C. for 8 to 12 hours and then drying at a temperature of 50 to 80 ° C. The manufacturing method of the carbon fiber bundle of Claim 2. The copper plating step is
Immersing the carbon fiber bundle C in a colloidal solution of Pd and Sn, and applying a catalyst to adsorb Pd and Sn on the surface of the carbon fiber bundle C;
Among the Pd and Sn adsorbed on the carbon fiber bundle C in the catalyst application step, an accelerator treatment step in which Sn is dissolved and only Pd is adsorbed;
Copper that immerses the carbon fiber bundle C in a copper plating solution in which a reducing agent is added to a mixed solution of a mixed solution of a copper sulfate aqueous solution and potassium sodium tartrate, a mixed solution of a caustic soda aqueous solution and a stabilizer aqueous solution. A method for producing a carbon fiber bundle according to any one of claims 1 to 3, further comprising a plating solution immersion step. The nickel plating step is
Dipping the carbon fiber bundle D in a colloidal solution of Pd and Sn, and applying a catalyst to adsorb Pd and Sn on the surface of the carbon fiber bundle D;
Among the Pd and Sn adsorbed on the carbon fiber bundle D in the catalyst application step, an accelerator treatment step in which Sn is dissolved and only Pd is adsorbed;
A nickel plating solution dipping step of immersing the carbon fiber bundle D in a nickel plating solution obtained by adding sodium hypophosphite to a solution adjusted to pH by mixing a nickel sulfate aqueous solution and a sodium citrate aqueous solution. The method for producing a carbon fiber bundle according to any one of claims 1 to 4.

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