JPH02112454A - Production of braid made of carbon fiber - Google Patents

Abstract

PURPOSE:To easily produce the subject braid suitable as a reinforcing material for concrete, etc., in high productivity by applying a specific amount of a specific thermosetting resin or a thermoplastic resin to a pitch-based carbon fiber and knitting the coated fiber into a braid. CONSTITUTION:The objective braid is produced by knitting a pitch-based carbon fiber coated with 1-15wt.% of a thermosetting resin having a glass-transition temperature of -5 to +100 deg.C (e.g., phenolic resin, urea resin or epoxy resin) or a thermoplastic resin having a heat-deformation temperature of >=50 deg.C (e.g., PE, PP, PS, acrylic resin, polyethylene terephthalate or polyamide).

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing carbon fiber braid, and more specifically, to a method for producing carbon fiber braid, which is suitable for producing reinforcing materials such as concrete. This relates to a manufacturing method.

[Prior Art] Reinforcing bars and the like have been known as structural reinforcement materials for concrete and the like. However, when reinforcing bars are used as structural reinforcing materials, they not only rust and have insufficient durability, but also have insufficient workability, and it is important to reduce the weight of the enclosure.

In view of the above points, a structural reinforcing material made of thin wires made of a material with high tensile strength such as aromatic polyamide fibers knitted into a braided cord (Jikou No. 1!380-119853),
Structural material in which thin wires made of aromatic polyamide 411 fibers and other materials with high tensile strength are knitted into a braid shape, and the braid-like materials are bound together with a binder (Japanese Patent Laid-Open No. 61-29015
Publication No. 0) is employed.

Further, M strings made of polyacrylonitrile carbon fibers are known.

Problem to be Solved by the Invention M1] According to the above-mentioned structural reinforcing materials and structural materials, aromatic polyamide fibers and the like are used as materials with high tensile strength. It is easy to do.

However, when pitch-based carbon fibers with a large tensile modulus are used instead of the aromatic polyamide fibers and polyacrylonitrile-based carbon fibers, pitch-based carbon fibers tend to become fluffy, so when producing braids with a braiding machine, carbon There is a problem that the fibers easily break due to sliding contact with the guide, and the productivity of the carbon fiber braid is not sufficient.

Furthermore, although braided cord exhibits great strength against stress in the longitudinal direction, it easily distorts and widens against stress in the width direction, i.e., it has the property of becoming wider in response to shrinkage of concrete. Reinforcing materials in the form of licks and braids do not have a sufficient reinforcing effect. Therefore, in order to obtain a reinforcing material in the form of braids with excellent reinforcing effects, it is necessary to integrate thin wires with each other. In the case of braids made of carbon fibers, the pitch-based carbon fibers tend to fluff, tend to break during the production of the braids, and are difficult to fasten together.

The present invention has been made in view of the above-mentioned points, and provides a method for manufacturing carbon fiber braids that can easily and efficiently produce carbon fiber braids suitable for producing structural materials with excellent reinforcing effects. The purpose is to provide

[Means and effects for solving the problems] The present invention provides pitch-based carbon 1iI! Roughly, glass transition temperature -5 to 100
The above-mentioned problem is solved by a method for manufacturing a carbon fiber braid in which 1 to 15% by weight of a thermosetting resin or a thermoplastic resin having a heat distortion temperature of 50° C. or higher is attached and then knitted into a braid. .

According to the present invention having the above configuration, a specific thermosetting resin or thermoplastic a is added to the pitch-based carbon fiber that easily breaks during braid production.
Since the pitch-based carbon fibers are knitted into braided cords after adhering 1 to 15% of fat, the attached thermosetting resin or thermoplastic resin improves the slipperiness of the carbon fibers on the guide of the assembling machine. can do well.

In addition, in this specification, hardening is used not only to harden a thermosetting resin but also to include solidification of a thermoplastic resin.

Further, the glass transition temperature of the thermosetting resin means the glass transition temperature of the thermosetting resin in an uncured state without containing a curing agent.

The present invention will be explained in detail below.

The method for producing a carbon fiber braid of the present invention includes adding 1 to 15% of a thermosetting resin with a glass transition temperature of -5 to 100°C or a thermoplastic resin with a heat distortion temperature of 50°C or higher to pitch-based carbon fiber.
The process includes a resin adhesion step for adhering weight percent, and a knitting step for knitting into a braid.

Examples of the pitch-based carbon fiber used in the VA fat adhesion step include various carbon fibers made from pitch, liquid crystal pitch, and the like. The pitch may be either coal-based or petroleum-based. The above-mentioned carbon fiber is a concept that includes not only carbon fiber but also graphite. Carbon fibers, for example, have a fiber diameter of 5 to
A fiber having an appropriate fiber diameter such as 20u can be used.

Carbon fibers include high strength types, high elongation types,
Various types such as high elasticity type and general-purpose type can be used.
The carbon fiber usually has a tensile modulus of about 5 to 100 x 103h/n+-, but in order to enhance the reinforcing effect on treetop relics, the tensile modulus is increased to 15 x 103'J/n.
Carbon fibers with a diameter of lnJ or more are preferred.

Note that the carbon fibers may have an appropriate number, for example, 2 to 500.
It may be a strand in which about 0 carbon fiber filaments are tied together.

In the resin attachment step, in order to prevent thread breakage during braid production, a braid is produced using the pitch-based carbon fiber to which a predetermined amount of a specific thermosetting resin or a specific thermoplastic resin is attached.

Examples of the thermosetting resin include phenol resin, urea resin, epoxy resin, vinyl ester resin, diallyl phthalate resin, urethane resin, unsaturated polyester, and polyimide.

The above thermosetting resins may be used alone or in combination of two or more.

The thermosetting resin has a glass transition temperature of -5 to 100°C.
Use the one. If the glass transition temperature of the thermosetting resin is outside the above range, thread breakage will occur easily during knitting,
Weavability is not sufficient.

Examples of thermoplastic resins include polyethylene, polypropylene, polystyrene, acrylic resin, saturated polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides, polyacetals, polysulfones, polyethersulfones, polyphenylene sulfides, polyphenylene oxides, polyarylates, and polyethersundylenes. , polyetheretherketone, polyamideimide, polyetherimide, polyamino bismaleimide, aromatic polyamide, and the like. One or more types of the above thermoplastic resins may be used. Among the above-mentioned thermoplastic resins, polysulfone, which is used as an engineering plastic, is particularly excellent in not only heat resistance but also mechanical strength, and is therefore preferably used as a binder.

Further, as the thermoplastic resin, one having a heat deformation temperature of 50° C. or higher is used. If the heat deformation temperature of the thermoplastic resin is less than 50°C, thread breakage tends to occur during knitting of the braid, resulting in insufficient weavability.

In addition, upon impregnation with resin, the thermosetting resin and thermoplastic resin may be used together.

Further, among the thermosetting resins and thermoplastic resins, thermosetting resins are preferred in order to improve the integrity and reinforcing properties of the reinforcing material.

In the resin attachment step, 1 to 15% by weight of a thermosetting resin or thermoplastic resin is attached to the pitch-based carbon fiber. If the amount of resin attached is less than 1% by weight, not only will it not be possible to sufficiently suppress the fluffing of the pitch-based carbon fibers, but if it is outside the above range, the sanding effect will be small and yarn breakage will easily occur, resulting in insufficient weavability.

In addition, the thermosetting resin and thermoplastic resin in the above-mentioned resin adhesion step can be used in the Cl, solid state or heated molten state if the resin is in a liquid state, and if necessary, it can be used in a solution or emulsion dissolved in an organic solvent. It may also be used as a dispersion.

The amount of adhesion per tree finger can be controlled by various methods6.For example, when using a solvent-free liquid or heated molten resin, the viscosity of the resin and the application method such as dipping or squirting can be controlled. The amount of resin deposited can be controlled by adjusting the amount of deposited resin or by squeezing out excess resin with a roll or the like after the resin has been deposited. Further, when the resin is used as a solution or dispersion containing a melt, the amount of resin deposited can be controlled by adjusting the resin content plate, viscosity, etc.

Note that the resin attached to the pitch-based carbon fibers in the resin adhesion process may leak into the knitting process without drying.
Drying the resin before the knitting process, which is preferably dried, increases the integrity of the carbon fibers, thereby further preventing yarn breakage during knitting.

After the thermosetting resin or thermoplastic resin is attached to the pitch-based carbon fibers as described above, a braid is produced in a knitting process.

The above knitting process is usually carried out by winding a strand of bound carbon fibers around a bobbin winder and knitting the strand with an appropriate number of strokes using a braiding machine. At this time, by adjusting the tension and number of strokes applied to the carbon fibers during knitting, it is possible to control the pitch of the braid and the size of the uneven portions.

Furthermore, in the knitting process, by adjusting the number of strokes of the carbon fibers, various types of braids, such as flat braids, square braids, and round braids, can be produced. Also, the core of the braid may be hollow, but from the point of view of reinforcement,
It is preferable that the number of strokes is 3 to 8 and the core is solid.

According to the method described above, since the braid is produced in the knitting process after the resin adhesion process, even pitch-based carbon fibers that tend to fluff can be easily slipped on the guide of the braiding machine, and the carbon fibers Efficiently carbon M& while preventing thread breakage.
Fiber plastic braid can be manufactured.

The carbon fiber braid obtained as described above is suitable for manufacturing pitch-based carbon fiber structural materials. More specifically, since the carbon fiber braid contains a thermosetting resin or a thermoplastic resin, it has excellent affinity with resin, and the carbon fiber braid contains a thermosetting resin or a thermoplastic resin. It can be easily attached or impregnated with resin. Furthermore, by further adhering to or impregnating the vj41m fat, a void-free braid-like product in which air present in the voids in the braid is removed can be obtained. Therefore, in order to improve the integrity of the carbon fiber braid, by further adhering or impregnating a thermosetting resin or thermoplastic resin and curing it,
A structural material with excellent mechanical strength can be obtained.

The obtained structural material is integrated with the above-mentioned thermosetting resin or thermoplastic resin, and the uneven parts of the braid can improve adhesion to concrete structures, so it can be buried in structures such as concrete. However, the compressive stress of the structural material can prevent the structure from cracking, and it has an excellent reinforcing effect on concrete structures.

The amount of resin attached to or impregnated into the carbon fiber braid can be appropriately selected within a range that does not impair the integrity of the structural material and the reinforcing properties for concrete structures, but preferably the total amount of resin is 10 to 50 f. ! It is preferable to attach or impregnate the resin in an amount of 20 to 30% by weight, more preferably 20 to 30% by weight.

If the total amount of the resin is less than 1 of IL%, the integrity of the structural material will be insufficient, and if it exceeds 50% by weight, the proportion of braid will decrease and the reinforcing performance will be impaired.

Note that the structural material manufactured using the carbon fiber braid may be surface-treated with a silane coupling agent, a titanium coupling agent, etc. in order to improve its compatibility with concrete and the like.

Furthermore, according to such a structural material, the structural material may have an irregular cross-sectional shape with further unevenness formed on the surface.
Coupled with the reinforcing effect due to the uneven portions of the braid, the adhesion to the concrete structure can be increased, and the reinforcing effect can be further enhanced.

The above-mentioned structural reinforcing material may have an appropriate diameter depending on the desired reinforcing properties, but a diameter of 1 to 50 mm, preferably 2 to 25 mm is usually sufficient.

The structural material obtained as described above can be used as a substitute for main reinforcement buried in concrete, steel material for prestressed concrete, etc. Note that the structural reinforcing material may be cut into a predetermined length if necessary.

[Examples] The present invention will be described in more detail below based on Examples.

Pitch-based carbon fiber (tensile strength 3001q/+nn (, tensile modulus 20 x 1031q/n ()) consisting of 2000 filaments made from pitch, epoxy resin (
Manufactured by Yuka Shell ■, trade name Ebiko-1001, immersed in a 10% by weight methyl ethyl ketone solution with a glass transition temperature of 30''C), removed excess resin with a roll, and heated at 150°C.
Carbon fibers having 5% by weight of epoxy resin as a sizing agent attached thereto were produced by passing through a soot drying machine (C).

In addition, instead of the above epoxy resin, an epoxy resin having a glass transition temperature of -10°C shown in the table (manufactured by Yuka Shell Co., Ltd., trade name Epicote 828), an epoxy resin having a glass transition temperature of 120°C (Yuka Shell Co., Ltd. fM> Carbon fibers with different amounts of epoxy resin deposited were produced in the same manner as above.

Then, using braided cord l1l (manufactured by Kokubu Iron Works), make 8 strokes.
When the carbon la fibers were knitted into a braid under the following conditions, the results shown in the table were obtained.

(Hereafter, margin) Excellent: Weaving properties are good and thread breakage does not occur.

Unsatisfactory: indicates poor sintering and thread breakage.As is clear from Table 4, the glass transition temperature is -10℃ and 120℃.
℃ resin or resin adhesion amount is 0.5% by weight
and 20% by weight, yarn breakage occurred during braid production and the weavability was not sufficient, whereas carbon fibers with 1 to 15% by weight of epoxy resin with a glass transition temperature of 30°C were used. All of the fabrics had excellent weavability with no thread breakage.

[Effects of the Invention] As described above, according to the present invention, pitch-based carbon fiber has
Since 1 to 15% by weight of a specific thermosetting resin or thermoplastic resin is attached and then knitted into a braid, even pitch-based carbon fibers, which tend to break easily when making braids, can easily slide against the guide of the braiding machine. This makes it possible to easily and efficiently manufacture carbon fiber braids suitable for manufacturing structural materials.

Claims (1)

[Claims] Pitch-based carbon fiber has a glass transition temperature of -5 to 100℃
1. A method for producing a carbon fiber braid, which comprises depositing 1 to 15% by weight of a thermosetting resin or a thermoplastic resin having a heat deformation temperature of 50° C. or higher, and then knitting it into a braid.