JPS62133193A - Carbon fiber cord and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a flexible carbon fiber cord that is easy to twist and twist and does not cause cord cracking, and a method for manufacturing the same.

More specifically, carbon fibers with good flexibility are obtained by binding 1 g of charcoal fiber bundles with a reaction product of butadiene-acrylonitrile copolymer (hereinafter referred to as rcTBNJ) having carboxyl groups at both ends and epoxy resin. Information on cords and their manufacturing methods. The carbon 1111i cord is used for offshore development or industrial cables, etc.

[Prior art]

Carbon fibers have excellent properties such as high specific strength, specific modulus, fatigue resistance, and heat resistance, so they have been widely used in fields related to space and aviation, automobiles, and sports and leisure.

However, carbon fibers with the above-mentioned characteristics have small fiber diameters and are brittle, so they are rarely used alone, and in most cases, they are shaped and assimilated using synthetic resin as a matrix.
It is used in a rigid state. Materials formed in this manner are inflexible and very hard, and are generally used in fields where little deformation is required.

On the other hand, material such as nylon or polyester fiber bundles
If cords with flexibility similar to those seen in cords and ropes made of fibers can be obtained using carbon bundles, cords, lobes, etc. with high performance can be realized by utilizing the excellent properties of carbon fibers mentioned above. However, this product can be expected to be used as a cable for offshore or construction work.

However, carbon fiber bundles have the disadvantage of low workability due to their characteristic high elastic modulus, and are susceptible to problems such as buckling and cord cracking.

For this reason, the original characteristics of carbon fiber bundles were not fully exhibited, making it difficult to develop applications in this field.

(Structure and Effects of the Invention) The present inventors have studied a carbon 111m cord that does not have such problems and has excellent workability and flexibility, and as a result, has arrived at the present invention.

That is, in the present invention, carbon fiber bundles are bundled with 925 to 50 wt. It is a carbon fiber cord with flexibility.

The present invention also provides a method for manufacturing such a cord, comprising:
5 to 50% by weight of a resin component consisting of a preliminary reaction product of CTBN and an epoxy resin or a mixture thereof (based on carbon jFill),
This method is characterized by applying and impregnating an epoxy resin curing agent to a carbon IIN bundle, and then heat-treating to harden the resin component.

The carbon mN cord of the present invention has good convergence, does not break even after repeated bending, has excellent workability, and exhibits particularly high knot strength.

Here, the carbon fiber bundle is a multifilament or interlaced bundle of 1,000 to 30,000 monofilaments with a diameter of 4 to 20 μm. Such carbon fiber bundles are classified into polyacrylonitrile type, rayon type, vidge type, etc. depending on the type of raw material precursor, but there is no particular restriction in the present invention, and commonly used fibers can be applied.

For example, the CTBN is Hiker C manufactured by Gutdrich.
TBN etc. are used.

The epoxy resin is not particularly limited, and bisphenol A epoxy resins such as Epicoat 828 and Epicoat 8
34 (both Shell Chemistry), DER332 (manufactured by Dow Chemical Company), and glycidylamine type epoxy resin,
For example, MY-720 (manufactured by Ciba Geigy), Evototo Y) 1434 (manufactured by Toto Kasei), etc. are suitable. As the epoxy resin curing agent, those commonly used can be used. In particular, imidazole-based and polyamide-based curing agents are suitable because the curing reaction is completed in a short time. Specifically, as the imidazole curing agent, for example, 2-ethyl-4-methylimidazole or the like is used, and as the polyamide curing agent, for example, Tomide (manufactured by Fuji Kasei Kogyo Co., Ltd.), Persamide (manufactured by Daiichi General Co., Ltd.), etc. are used.

The matrix whose resin component is a reaction product of CTBN and epoxy resin, etc. is obtained by reaction-curing a pre-reaction product of CTBN and epoxy resin or the same mixture on carbon fiber Tojo, and has a ratio of 5% to the weight of the carbon fiber cord. % between 50Φ and 50Φ. Particularly preferably 10 to 30% by weight
It is.

Strand prepreg is known as a carbon IAl fiber bundle to which a resin component is added, but in strand prepreg, the matrix resin is not hardened, and the matrix resin is hardened by heating etc. after shaping. In contrast, the carbon fiber cord of the present invention has a hardened matrix and is flexible, so it has good form stability and processability, and can be processed into textiles, braids, etc. Unyielding.

A viscosity modifier, a conductivity improver, a coloring agent, etc. can also be added as a third component to be adhered to or impregnated into the cord of the present invention.

The resin components are CTBN 100 parts and epoxy resin 5~
It is preferable to react with 60 parts by weight, particularly preferably 10 to 40 parts by weight. As the epoxy resin becomes more open, the cord becomes more likely to crack, buckle, and break at the buckling point during processing.

The method for manufacturing the carbon fiber cord of the present invention will be described.
1° (Adjustment of resin components) CTBN and epoxy resin are pre-reacted and then applied to and impregnated with the m-fiber bundle, or a mixture of CTBN and epoxy resin is applied and impregnated with the I-fiber bundle.

Preliminary reaction between CTBN and epoxy resin can be performed, for example, in 11
It is carried out under stirring at 0-120° C. for 1-2 hours. Trinoenylphosphine is usually used as a reaction catalyst.

An epoxy resin hardener is added to the premature ejaculation reactant or mixture. The curing agent is usually epoxy resin and CTBN.
For example, 2-ethyl-4-
In the case of methylimidazole, it is used in a range of 0.1 to 2% by weight, and in the case of Tomide 215x, it is used in a range of 3 to 50% by weight.

(Applying and impregnating the fiber bundle with the resin component) The resin component is dissolved in a single solution or a mixture of organic solvents such as acetone, methyl ethyl ketone, or methyl seosol to form a homogeneous solution, and the solution is applied by dipping, spraying, or drum contact. It is applied to the fiber bundle and impregnated by a method or the like.

The solution concentration varies depending on the impregnation method, but approximately 20% by weight is appropriate.

Although the temperature of the solution is preferably lower for reasons such as stability of the solution and stability of m degrees, it is usually used in the range of 10 to 30°C. Solvent removal is preferably carried out at 80 to 150°C.

(Heat treatment) Curing of the matrix resin consisting of CTBN and epoxy resin varies depending on the type of epoxy resin curing agent, etc., but it is usually heat treated at 150 to 230°C for 1 to 30 minutes, especially in a non-contact state. good.

If the cord is cured in a contact state, the cord will become flattened, which is not preferable. It is preferable to perform the heat treatment after complete solvent removal in order to prevent the generation of voids inside the cord and the generation of bliss on the surface.

This heat treatment cures the epoxy resin and completes the reaction between CTBN and the epoxy resin, and as a result, the resin becomes insoluble in the solvent before the reaction, such as methyl ethyl ketone.

The carbon fiber cord of the present invention produced as described above is a cord that is well bundled, hardly causes cord cracking, and has excellent mechanical properties such as strength and elastic modulus. It has particularly good flexibility and high knot strength.

The carbon mm cord of the present invention can be used alone or in combination or by twisting a plurality of cords.

〔Example〕

Example 1 Butadiene-acrylonitrile copolymer 1-1ycar CTBN1300 having carboxyl groups at both ends
x 13 (manufactured by Gutdrich) and 1 part of glycidylamine type epoxy resin MY-720 (manufactured by Ciba Geigy) > 20ff!
Preliminary reaction time! ,: Subsequently, this pre-reacted resin was dissolved in methyl ethyl ketone so that the resin concentration was 20. Furthermore, MY-72 was added to this resin solution.
3 parts by weight of the curing agent 2-ethyl-4-methylimidazole was added to 0.100 parts by weight and thoroughly stirred and mixed.

Next, a carbon fiber bundle (Besphite HTA-7-6000 manufactured by Toho Rayon Co., Ltd.) was continuously impregnated with this resin solution, dried at 120°C for 3 minutes, and cured at 200°C for 2 minutes.

4!7 The resin adhesion amount of the carbon fiber bundle cord is 23.5
% by weight. This carbon fiber cord was very thin, had good convergence, and was highly flexible.

Evaluation of the flexibility of the qed cord was performed by knot strength.

The measurement was carried out using an Instron testing machine at a tensile speed of 50 mm/
The load at the time of rupture at the node is H/v. As a result, the nodule strength was 8.3 klj.

Example 2 1-lycar CT B N 1300x 1
0.49 parts by weight of triphenylphosphine was added as a pre-reaction catalyst to 3100 parts by weight of ethophylphenol A resin and 20 parts by weight of Epicoat 828 (manufactured by Shell Chemical Co.), and pre-reaction was carried out at 120° C. for 2 hours. This preliminary reaction product was dissolved in a mixed solvent of methyl ethyl ketone and methyl cellosolve, and polyamide resin TOMIDE 21 was further added as a curing agent.
5X (manufactured by Fuji Kasei Kogyo Co., Ltd.) was added in the same amount as Epicote 828 to prepare a 20% by weight resin solution. The same carbon fiber bundle as in Example 1 was used, and impregnation, drying, and curing were performed in the same manner as in Example 1 to produce a carbon fiber cord.

This cord was very pliable, had good convergence, and was highly flexible.

The resin content of this cord was 20.3% by weight, and the knot strength was measured in the same manner as in Example 1 and was 9.5kO.
Met.

Example 3 Hyear CRB N 1300x 13 and M
Blend resin mixtures with different mixing ratios of Y-720 (7),
Without pre-reacting, the resin was dissolved in methyl ethyl ketone to a concentration of 2 to 1%, and 2-ethyl-4-methylimidazole was added as a curing agent to this resin solution.
3 small parts of the mixture was added to Y-720, 100 pieces of alcohol and mixed thoroughly with stirring. Next, the same carbon fiber bundle as in Example 1 was impregnated with these resin solutions in the same manner as in Example 1, and dried and hardened to produce a carbon fiber cord. The performance of the obtained carbon fiber cord was as shown in the table below.

As shown above, it can be seen that as the ratio of epoxy resin to CTBN increases, the cord becomes harder and more brittle.

Claims (4)

[Claims] (1) Flexibility obtained by bundling carbon fiber bundles in a matrix of 5 to 50% by weight whose resin component is a reaction product of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and an epoxy resin. Carbon fiber cord. (2) The flexible carbon according to claim (1), wherein the resin component is a reaction product of 100 parts by weight of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and 5 to 60 parts by weight of an epoxy resin. fiber cord. (3) 5 to 50% by weight (based on carbon fibers) of a resin component consisting of a pre-reacted product or a mixture of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and an epoxy resin, and an epoxy resin curing agent added to the carbon fibers. 1. A method for producing a flexible carbon fiber cord, which comprises impregnating a bundle with the resin component and then heat-treating the resin component to harden the resin component. (4) Flexibility according to claim (3), wherein the resin component is a preliminary reaction product or a mixture of 100 parts by weight of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and 5 to 60 parts by weight of an epoxy resin. A method for manufacturing carbon fiber cord with properties.