JPS58208457A - Production of carbon fiber yarn strip material - 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 As one method for producing fiber reinforced plastics (hereinafter referred to as FRP), a fiber yarn woven fabric which is a constituent component of FRP,
For this purpose, there is a production method that uses an FRP intermediate (hereinafter referred to as textile prepreg) obtained by impregnating a resin (hereinafter referred to as matrix resin), which is another component of PR and P, in a liquid state by diluting it in a solvent or by heating and layer dissolving. One of the properties required of the textile prepreg used in such a method is the F of the fiber.
During RP, it is required to reduce the fabric thickness relative to the fiber weight in the fabric in order to increase the uniformity of the distribution and the packing density of the fibers in the FItP. In other words, the threads constituting the fabric are required to be as long as possible.

In addition, in the design of FIt P, various unit surfaces and loading materials immediately before the pickling are required.

Recently, 4J1. for reinforcing FRP. Carbon fiber has been used as fiber for a long time, but it is made of such a high-performance fiber material! The above-mentioned required performance is required to the maximum for the proboscis, but charcoal AJ fiber 2 (hereinafter referred to as CIi') made by the conventional method
) Since the threads are in a converged state, it is difficult to make ultra-thin carbon fiber fabrics. Furthermore, in carbon fiber fabrics made using these 01-tows, the warp and weft yarns are constrained by the threads during the manufacturing process, so CF) has no choice but to narrow the right bank of the fabric. There are many difficulties and problems involved in making the material thinner.

Therefore, the present inventor completed the present invention as a result of studies aimed at obtaining a thin carbon fiber yarn that can significantly reduce the thickness of a woven fabric compared to conventionally developed carbon fiber woven fabrics using CF'.

The gist of the present invention is to form a thin carbon fiber sheet by arranging and expanding a large number of carbon fibers in parallel, and after impregnating this thin carbon fiber sheet with a resin, A thin carbon fiber cloth characterized by being slit in the length direction of a sheet to a predetermined width, or splitting the thin carbon + R fiber aligned sheet into strip-like sheet and then impregnated with resin. It is in the manufacturing method of yarn products.

In carrying out the present invention, to make a thin carbon fiber sheet, a plurality of CF tows of 3,000 to 200,000 filaments are usually lined up and spread and expanded by sandwiching them between nip-meal-like expansion rolls. ! , or supplying a plurality of CF tows into a running water tray,
A thin carbon fiber sheet can be made by opening and expanding the CF tow using the power of running water.

The carbon fiber sheet obtained as described above was then impregnated with a resin, and then passed through a cutter (rad roll) as shown in FIG.
2) and a disc cutter (31) and slit it to a predetermined width to produce a thin carbon fiber aligned thin yarn material as the object of the present invention, or a thin carbon fiber aligned sheet material. After splitting the fibers to a predetermined width, the fibers are impregnated with a resin to form a thin, aligned carbon fiber filament.

The uniform used in carrying out the present invention is carbon #11.
Thermosetting resins used in making RP molded products, such as epoxy resins, unsaturated polyester resins; In addition to amide resins, polyester resins, polycarbonate resins, etc., water materials such as polyvinyl alcohol, sodium polyacrylate, polyacrylate ester, polyvinyl acetate, starch, and french, which are commonly used as sizing agents, may also be used. I can do it.

It is desirable to select these resins as appropriate depending on the intended use of the narrow carbon fiber aligned yarn of the present invention, and the amount of the resin adhered to the carbon fiber yarn in the form of a narrow tape is the same as that of the carbon fiber yarn of the present invention. It is necessary to have a sufficient amount of resin to maintain the shape without causing a large width change in the direction of force.

These resins may be removed by a method such as washing with water or baking to remove the sizing agent after the narrow thread of the present invention is woven into a woven fabric.

As mentioned above, when cutting a unidirectionally aligned carbon fiber sheet material or its resin-impregnated material in the longitudinal direction, the width of the cutting is generally the same as the length of thin thread that can be obtained when obtaining a thin or low basis weight fabric. is normally used, but in the case of the present invention,
Since the thread is sufficiently flattened, there is no need to cut it into smaller pieces than necessary. That is, when used for textiles, when the sheet-like material has a wide cut l], the basis weight of the textile can be adjusted by decreasing the warp or weft density per unit.

However, if the tape width is extremely wide, handling such as weaving becomes difficult, so the tape should be 5m++! The following degree is convenient.

Furthermore, thinner yarns can be easily obtained from low-cost thick carbon fiber yarns by cutting them into tapes having fewer yarns than the original yarn.

To summarize the above method, a large number of carbon fiber threads are arranged in parallel and each thread is expanded to form a sheet.
This is a method for producing yarn using, as a weaving raw material, a single yarn obtained by cutting a unidirectional preplex or unidirectional sheet obtained by impregnating IJ socks with resin or a removable resin in its longitudinal direction. .

When this method is used, it is possible to minimize the thickness of the carbon fiber yarn (strictly speaking, the thickness of the yarn relative to the weight per unit thickness of the yarn), and at the same time maximize the width. It is possible to obtain a yarn that is thinner than the thickness of the carbon fiber yarn (thickness and weight per unit length) of the carbon fiber yarn used when making the sheet-like product by pulling the yarn. Also, during weaving, it has the great feature that the fabric weight does not increase due to narrowing of the tow width, unlike when CF tow is used.

The method of the present invention will be explained in more detail below according to examples.

Example 1 A non-twisted yarn consisting of approximately 6,000 carbon fibers of 7 to 8 μm in diameter is arranged at a density of approximately 10 cm per 10 cIn, making it impossible to distinguish the width of each yarn from adjacent yarns. The epoxy resin prepared by adding a cross-linking agent and other additives was discharged to a sheet size of 7 ogyrtl, and the sheet was impregnated with a width of 30 cIn 175 cm.
A unidirectional prepreg of W was obtained.

This one-way prepreg is connected to a slitter T as shown in Fig. 1.
2 times wide in an atmosphere at 3℃ using
7) L□"°*07-pu"089' starvation 01' At the same time, it was wound into one beam and this was used as the warp.

Each tape-like thread wrapped around the beam weighs 0.35g.
It has a weight of 7 feet, and the amount of carbon fibers contained in the middle is 0.
21. ! It was about 1/2 the weight of the yarn electric switch with 6,000 filaments used in the production of the unidirectionally aligned prepreg with i'/fn.

On the other hand, make a unidirectional prepreg with a width of 5 crrL, slit it into a width of 2 mm to obtain four tape-like threads, wind these threads onto 20 bobbins one by one, and use this as a weft. And so. The yarn obtained was the same as that prepared for the warp.

Warp and weft of 1 warp/25In in an atmosphere of 5℃
Woven with a fabric density of 12 wefts/25 threads and 330g/rF?
Obtained a fabric prepreg prisoner. On the other hand, in order to compare the performance of this fabric, the CF tow consisting of 6,000 filaments used as the raw material for the unidirectionally aligned CF sheet was woven with a warp of 6/25m and a weft of 6/25 to have the same basis weight. A woven fabric was obtained, and the epoxy resin prepared by the method described above was soaked into the woven fabric to obtain a 320 g/m' woven prepreg (B).

Fabric prepregs (A) and (B) were tested under the same conditions/1i'! +11 pressure heating molding and calculating the thickness of one woven fabric, the fabric prepreg using yarn of the present invention (
A fabric prepreg using a CF of 6,000 filaments of 0.21 mm for comparison (0.28 mm thick was obtained from the uniform fabric), and the one according to the present invention was clearly superior.

Example 2 (1) Approximately 3,000 untwisted yarns of 7 to 8μ carbon fibers were gathered together at a density of water added per 10crrL, and the width of each yarn was adjusted until the boundaries between adjacent yarns could no longer be distinguished. The width was uniformly expanded to form a sheet, and this was impregnated with a water-soluble sizing agent mainly composed of sodium polyacrylate in an amount equivalent to approximately % weight of carbon fiber to create a unidirectionally aligned sheet with a width of 3 cTL. . This was slit into a width of 2++II+1 to obtain 12 tape-like threads, and 1 thread was placed on 812 bobbins.
I rolled up the books one by one. The yarn obtained was approximately 0.085 g/m.

(2) Five Gaos fibers No. 450 (11.2 tex count) were prepared as warp yarns at a density of 72.5 mm, and the aforementioned slit yarns were woven as weft yarns at a density of 12 yarns/25 mm using a rapier loom.

(3) After weaving, after removing the sizing agent, sodium polyacrylate, using a liquid flow machine, the resin used in Example 1-'Q was 359/rr? An epoxy prepreg was obtained by laminating a resin film that could be coated on a release paper so as to form a J/C pattern. The composition of the obtained prepreg was approximately 85 g/rF, consisting of approximately 45 carbon fibers, 13% glass, and 42% resin. It belonged to

On the other hand, threads consisting of 3,000 carbon fibers were woven as warps and wefts at a density of 5/25 in order of warp and weft under the conditions shown in (2) so that the structure was the same as that obtained in (3), and each under the same conditions. Calculating the thickness of a single woven fabric after lamination, pressure, and heat molding, the fabric using the yarn of the present invention has a thickness of 0.08 m.
yp, and was clearly superior to the conventional method, 2U, which was a woven fabric using threads consisting of 3,000 carbon fibers.

[Brief explanation of the drawing]

FIG. 1 shows an example of a method of cutting a unidirectional prepreg or a unidirectional sheet in its longitudinal direction, and (a) is a side view thereof, and (b) is a sectional view thereof. 1st Δ A゛(a) (b)

Claims (1)

[Claims] (1) A sheet is formed by arranging a large number of carbon fiber threads in parallel and uniformly expanding each core carbon fiber thread, and after impregnating the sheet with resin, the sheet is cut in the length direction. Alternatively, a method for producing a carbon fiber yarn strip, which comprises splitting the sheet into strips and then impregnating them with a resin.