JPH032225A - Hybrid prepreg - Google Patents

Abstract

PURPOSE:To obtain hybrid prepreg having increased compression strength in forming two kinds of fiber zones containing carbon fiber yarn and different fiber yarn in one layer into a layer state by impregnating a matrix resin into between the yarns. CONSTITUTION:A carbon fiber zone 2 which is prepared by using 100-150 pts.wt. based on 100 pts.wt. reinforcing fibers of preferably a thermosetting matrix resin 6 (e.g. bisphenol A, F or S-based epoxy resin), a curing agent (e.g. diaminodienyl sulfone) to make a curing temperature 50-150 deg.C and other additives and impregnating the matrix resin into between the reinforcing fibers comprising carbon fiber yarn 2a and one or more different fiber yarns 4a and a different fiber zone 4 are formed in one layer in a lamellar state to give the aimed prepreg.

Description

DETAILED DESCRIPTION OF THE INVENTION 1) The present invention relates to a hybrid type composite material (4), particularly a hybrid type carbon fiber formed of carbon fiber threads and different types of fiber threads. Prepreg (simply called “hybrid prepreg” in Honkawa MLA)
).

[Sugo 1j] In recent years, carbon fiber reinforced prepreg has attracted attention because it is lightweight, has excellent environmental resistance such as heat resistance and water resistance, and has good mechanical properties. Bathing.

However, high modulus carbon fibers, especially pitch-based high modulus carbon fibers, have high tensile strength and high tensile modulus, for example, tensile strength of 3.0 GPa or higher and tensile modulus of 450 GPa or higher. However, the compressive strength is low, and at most l
, is about 0 GPa.

Therefore, carbon fiber prepregs produced using high-modulus carbon m-fibers as reinforcing fibers have low compressive strength compared to their tensile strength and tensile modulus, and an increase in compressive strength is desired.

Hitherto, hybrid prepregs containing carbon fiber and axial embroidery have been proposed to increase compressive strength.
Currently, hybrid prepregs include interlayer hybrids formed by laminating carbon fiber prepregs and prepregs of different types of fibers, and interlayer hybrids formed by layering carbon fiber prepregs and different types of fibers in one layer. It is thought to be an intralayer hybrid.

Although the former interlayer hybrid is easy to manufacture, it cannot be said that the increase in compressive strength has improved yet.

In addition, although the latter intralayer hybrid has considerably increased compressive strength compared to the interlayer hybrid and ordinary carbon fiber prepreg, there is considerable variation in actual fiber strength, ranging from 1 weak fiber to 1 weak fiber. In order to cut in sequence, the degree of increase follows the hybrid compound rule and does not exceed the hybrid rule, so it cannot be said to be sufficient yet.

As a result of many studies and experiments on conventional hybrid prepregs, especially on intralayer hybrid prepregs, the present inventors have found that by increasing the contact area between the carbon fiber region and the 'AN fiber region as much as possible, In other words, by forming a layer of a charcoal We have found that the hybrid multi-constitution rule can increase the amount to an extent that exceeds the hybrid rule.

The reason why such a phenomenon occurs is not clear, but it is thought that the hybrid effect is improved more than expected by increasing the contact area between the carbon ##1 fiber region and the different fiber region.

This decision was made based on new knowledge that led to the one town not being exposed.

It is therefore an object of the present invention to provide a hybrid prepreg with increased compressive strength.

As shown in the first factor, the hybrid prepreg 1 of the present invention has carbon fiber threads 2a in one layer. a carbon Mll fiber region 2 containing carbon Mll fiber region 2 and one or more different types of m
A heterogeneous m-fiber region 4 including fiber threads 4a is formed in a layered manner,
The hybrid prepreg is characterized in that matrix resin 6 is impregnated between the fiber threads.

As the carbon fiber yarn 2a, pitch-based carbon fiber, PAN
Carbon fibers based on carbon X#a and rayon-based carbon fibers can be used, but carbon fibers with high tensile strength and high tensile modulus, such as a tensile strength of 2°0 GPa or more and an elastic modulus of 200 GPa or more, are preferably used. Ru. Further, the carbon fiber yarn generally has a diameter of 5 to 12. 100 um filament
A carbon fiber strand (tow) formed by collecting 0 to 24,000 fibers and plying them together is used.

As the dissimilar fiber yarn 4a, any fiber having a compressive strength greater than carbon m#l can be used. For example, silicon carbide yarn fiber: alumina fiber; titanium, steel, stainless steel, beryllium, tungsten. , metal #aM such as molybdenum; boron fiber, glass fiber, etc. Preferably, fibers with a compressive strength of 1.5 GPa or more are used, and the fiber yarn is generally made of filaments with a diameter of about 5 to 12) tm.
A strand formed by gathering ~24,000 yarns together is used.

The matrix 81 resin 6 impregnated into the reinforcing fibers made of the carbon fiber threads and different types of fiber threads may be a thermosetting matrix resin such as an epoxy resin, an unsaturated polyester resin, a polyurethane resin, a diallyl phthalate resin, or a phenol resin. It can be used, and the curing temperature is 50~1
A curing agent and other imparting agents, such as a buildable IJ agent, are added so as to obtain a hardening agent of 50".

To give a preferred example, epoxy resin is preferred as the matrix resin, and usable epoxy resins include (1) glycidyl ether epoxy resin (
(2) Cycloaliphatic epoxy resin; (3) Glycidyl ester epoxy resin; (4) Glycidyl amine epoxy Resin; (5) Heterocyclic epoxy resin; one or more selected from various other epoxy resins are used, and bisphenol A, F, and S glycidylamine-based epoxy resins are particularly preferably used. . In addition, as a curing agent, diaminosif-7nylsulfone (DD
S), diaminodiphenylmethane (DDM), etc. are preferably used.

For reinforced materials, it is manufactured by setting the weight of the standard matrix resin to 100-150 parts per 100 parts of the reinforcing fibers, or by mixing various matrix resins and adjusting the ratio appropriately. Ru.

Moreover, such a hybrid prepreg according to the present invention can be suitably manufactured by using drum wine goo and hot pressing in the same manner as ordinary carbon fiber prepreg, although it is not limited thereto.

To explain the manufacturing method, as shown in FIG. 2, first, a thermosetting matrix resin 6 having a viscosity of tooooo to 5ooooo poise is coated on a sheet of paper 6a to a thickness of 0.015 to 0.050 mm. The first resin-coated paper 10 coated with the above resin is wound and fixed around the drum D1.

Next, the long fiber carbon fiber region 2a is wound around -E of the resin-coated paper lO to form carbon m#I yarn J+1t2b, and then one or more types of The different types of fiber threads 4a are wound to form a different types of fiber thread layer 4b. As a result, the carbon m miscellaneous yarn layer 2b and the different types of fiber yarn layer 4b are arranged in parallel layers on the tree@elm paper IO.

Next, the first resin-coated paper 10 is coated with a viscosity of 10oooo to 50 to cover the Moeki different fiber yarn layer 4b.
A second resin coated paper 10' coated with a thermosetting matrix resin 6 of 0,000 poise to a thickness of 0.015 to 0.050 mm is wrapped around the coated paper 6a to form a front prepreg sheet 12. .

The front prepreg sheet 12 produced in this way is
It is peeled off from drum D and brought to a hot press 20 as shown in FIG.

According to this embodiment, the hot press 20 includes a base plate 21 and a press plate 22 that is disposed facing the base plate 21 and is movable up and down. The base plate 21 and press plate 22 are internally equipped with heating means (not shown) such as an electric heater to maintain a desired temperature.

The front prepreg sheet 12 is placed on the base plate 21E and pressed by the press plate 22. The front prepreg sheet 12 is heated under pressure by the base plate 21 and the press plate 22, and the matrix resin 6 is impregnated between the fiber threads 2a and 4a to form a prepreg.

Next, the base plate 21 and the press plate 22 are separated, the prepreg is taken out, and the prepreg is cooled to a predetermined temperature to produce the hybrid prepreg l according to the present invention as shown in FIG. 1. Usually, The hybrid prepreg l has a thickness t of 0.05 to 0.3 mm, and the thickness of the carbon fiber region 2 is 1.0 mm. is 0.025~0,
28 mm, and the thickness t2 of the different fiber region 8 is 0.025 to 0.
．． It is assumed to be 15mm.

According to the invention, the carbon fibers and dissimilar fibers used are
Various compressive strengths, tensile strengths, tensile modulus, and even inertia can be achieved by changing the physical properties and mixing ratio, as well as the impregnation ratio of the matrix resin, and by varying the composition ratio of the matrix resin used. The provided hybrid prepreg is produced.

4 and 5 are graphs showing hybrid composites of a hybrid prepreg made of carbon fiber/silicon carbide yarn fiber and a hybrid prepreg made of carbon fiber/alumina according to the present invention.

Referring to FIG. 4, the strength of carbon fiber is shown by line AB, and the strength of silicon carbide yarn fiber is shown by line CD. Therefore, the composite area, that is, the hybrid line is line A.
It is represented by ED.

It was impossible to achieve a strength higher than that of the hybrid line with the conventional hybrid prepreg made of carbon fiber/silicon carbide filament fibers, but according to the present invention, the compressive strength is equal to the line AED-2' enclosed diagonal line. It was possible to increase the size until it was located in the area.

The same was true for the hybrid composite of carbon fiber/alumina fiber hybrid prepreg shown in FIG.

As mentioned above, the reason for this is not necessarily clear, but it is thought that the hybrid effect is improved more than expected by increasing the contact area between the carbon fibers and the different fibers.

Next, the present invention will be explained with reference to examples.

The hybrid prepreg 1 according to the present invention was manufactured using the drum wine gourd and hot press described in connection with L2 FIGS. 2 and 3.

A strand (tow) made of 3,000 monofilaments with a diameter of 10 μm and woven together as carbon fiber yarn 2a.
The dissimilar fiber yarn 4a is silicon carbide fiber JIB (manufactured by Nippon Carbon Co., Ltd., trade name: 22 Kalon,
NL201) was used. The silicon carbide yarn fiber has a diameter of 1
5) It was a strand (tow) made of 500 i m monofilaments gathered together.

On the other hand, resin-coated paper 1 wrapped around the drum wine goo
The matrix resin 6 on 0 is bisphenol A-based resin EP828 (manufactured by Yuka Shell Epoxy Co., Ltd.).
Product name)/EP100I (product name) 50gr150g
r, f & dicyandiamide 4,2 g r as a converting agent
, DCMU (N -3,4dichlorophenylene N'-
It contained 4.2 gr of dimethylurea).

The carbon fiber yarn layer 2b was formed by winding the carbon fiber yarn 2a onto a resin-coated paper 10 whose matrix resin layer had a thickness of 0.025 mm, which was fixed on a drum wine gourd. The silicon carbide fiber yarn layer 4a was wound around the carbon fiber yarn layer 2b to form a silicon carbide fiber yarn layer 4b.

Next, a resin-coated L paper 10' having the same structure as the resin-coated paper 10 was wrapped around the silicon carbide-based m-thread layer 4b to produce a 0.15 mm thick prepreg sheet 12.

Next, the front prepreg sheet 12 was peeled off using a drum machine, and was placed in a hot press and heated under pressure. The pressing force of the hot press at this time was 20 Kg/c
rn', the temperature was lO5-''C.

The hybrid prepreg l manufactured in this way and having the configuration shown in FIG. 1 has a thickness t of 0.1 mm.
, the thickness t of the carbon fiber region 2 was 0.06 mm, and the thickness t2 of the dissimilar m-line region 4 was 0.04 mm.

Also, is the amount of reinforcing fiber in the matrix resin, that is, the impregnation rate, in the carbon fiber range? In the inner region of the different fiber region 4, the resin/fiber volume ratio was 40/60.

20 sheets of the hybrid prepreg L were used.

20 layer composition (7) 12.7 (width) Xl, 89 (thickness) X1
A test piece T for bending test having a length of 40 mm was prepared.

In the test, as shown in FIG. 6, the test piece T was supported at two places 30 at both ends, and a load P was applied from the central part Zflb to bend the test piece T. If an initial break occurs on the tension side of the test piece T, the tensile strength can be estimated, and if an initial break occurs on the compression side, the compressive strength can be estimated. The compressive strength is
Evaluation was made based on the bending strength at the point where a crack appeared on the compression side of the test piece and the stress decreased.

The test results showed that the initial failure occurred on the compression side and the final failure occurred on the tension side, but did not separate.

The breaking load on the contact compression side was 48 kg, the bending strength at this time was 85 kg/mm'te, and the strain was 0.
It was 60.

From FIG. 4, it can be seen that the hybrid prepreg of the present invention has a strength (point X) higher than the hybrid rule (line ED).

Lf20 As shown in FIG. 7, a hybrid prepreg 40 having a structure in which carbon fiber regions 2 and different types of fiber regions 4 are arranged alternately is made of the same material as in Example 1, using a drum wine goo and a hot press. Manufactured by

In other words, in the drum wine goo, instead of arranging the carbon fiber threads 2a and the different types of fiber threads 4a in a layered manner as shown in FIG. M conical point groups and silicon carbide #a conical point groups consisting of 500 silicon carbide fiber threads 4a are arranged alternately and adjacent to each other, and these fiber thread groups are arranged on both sides. This was then sandwiched between resin-coated papers to form a front prepreg sheet. The pre-prepreg sheet was then peeled off from the drum wine gourd, mounted on a hot press, and heated under pressure. The pressing force of the hot press at this time was 20 kg
/crn', the temperature was 105°C.

Hybrid prepreg 40 manufactured in this way
The thickness t is 0.1 mm, and the radius Wl of carbon fiber region 2 is 2.
．． 8mm, and the radius W2 of the different fiber region 4 was 1.9mm.Also, the amount of reinforcement m miscellaneous to the matrix resin, that is, the impregnation rate, was determined by the resin/fiber volume in the inner region of the carbon fiber region 2 and the different fiber region 4. The ratio was 40/60.

Using 20 sheets of the hybrid prepreg 40, a 20-layer structure of 12.7 (radius) XL, 89 (thickness) XL 40
(M) mm test piece T for bending test was prepared and tested in the same manner as in Example 1.

As a result of the test, a crack appeared on the compression side under a load of 40 kg and the product was separated. The bending strength at this time is 70 Kg/
There was mrn'te, and the distortion was 0.42.

From FIG. 4, the hybrid prepreg of this comparative example has a strength (point Y) below the hybrid 2 dollar rule (line ED).
It can be seen that it has

Compare the diameter of the reinforcing fiber with 10. un monofilament) 30
A carbon fiber prepreg was produced in the same manner as in Example 1 except that only carbon fiber strands (tow) in which 00 carbon fibers were bundled and spun were used, and tests were conducted in the same manner.

As a result of the test, a crack occurred on the compression side at a load of 46 kg and the product was broken into pieces. The bending strength at this time is 74Kg/mrn
', and the distortion was 0.21.

diameter 15. am monofilament 50
A silicon carbide fiber prepreg was produced in the same manner as in Example 1, except that a silicon carbide-based woven fabric (manufactured by Nippon Carbon Co., Ltd., trade name: 22 Calon, NL201) in which 0 fibers were bundled and spun was used. I did a test.

As a result of the test, a crack appeared on the tensile side under a load of 95 kg, but no breakage occurred. The bending strength at this time is 180
K g / m rn' was present, and the strain was 1.90.

Soil-Oasted Salmon A A hybrid prepreg was produced by forming a layer of the carbon fiber prepreg and silicon carbide fiber prepreg used in Comparative Examples 2 and 3.

Using 10 sheets of the hybrid prepreg, a 20-layer structure of 12.7 (width) Xl, 89 (thickness) X 140 (&) mm
A test piece T for bending test was prepared and tested in the same manner as in Example 1.

As a result of the test, a crack appeared on the compression side when the load was 128 kg, and the product was separated. The bending strength at this time is 50 Kg/
mm', and the strain was 0.26.

From Fig. 4, the hybrid prepreg of this comparative example has a strength (point Y') below the hybrid rule (line ED).
It can be seen that it has

The procedure was the same as in Example 1, except that alumina m miscellaneous (manufactured by Sumitomo Chemical Co., Ltd., trade name: 5N-10), which was made by bundling 1000 monofilaments with a diameter of 15 JJm, was used as the different fiber thread. A hybrid prepreg was produced and tested in the same manner.

As a result of the test, the initial fracture occurred on the compression side, and the final fracture occurred on the tension side, but it did not break even once.

The maximum compression side breaking load was 45 Kg, the bending strength at this time was 80 K g/mrn', and the strain was 0.55.

From FIG. 5, it can be seen that the hybrid Bripreg of the present invention has a strength (point X) greater than the hybrid rule (line ED).

Comparative Example A hybrid prepreg was produced in the same manner as in Comparative Example 1, except that the alumina fiber of Example 2 was used as the dissimilar fiber yarn 4a, and tested in the same manner as in Example 1.

As a result of the test, a crack appeared on the compression side with a load of 32 kg, and the product was separated. The bending strength at this time is 60 kg
/ m rn', and the strain was 0.36.

From FIG. 5, it can be seen that the hybrid prepreg of this comparative example has a strength (point Y) below the hybrid rule (line ED).

An alumina fiber prepreg was produced in the same manner as in Example 1, except that only the alumina fiber of Example 2 was used as the reinforcing fiber, and a test was conducted in the same manner as in Example 1.

As a result of the test, cracks appeared on the tensile side under a load of 78 kg, but no breakage occurred. The bending strength at this time is 154
K g / m rn' was present, and the strain was 1.33.

l\Ibrid prepreg was prepared by applying a rust layer to the carbon fiber prepreg and alumina #a #1 prepreg used in Comparative Example 2.6.

Using 10 sheets of the hybrid prepreg, a 20-layer structure of 12.7 (radius) XL, 89 (thickness) x 40 (length) m
A test piece T for bending test was prepared and tested in the same manner as in Example 1.

As a result of the test, a crack occurred on the compression side under a load of 24 Kg, resulting in one piece being broken. The bending strength at this time is 45K
g/m rn' and the strain was 0.25.

From FIG. 5, the hybrid prepreg of this comparative example has a strength (point Y') below the hybrid rule (line ED).
It can be seen that it has

The hybrid prepreg according to the present invention configured as described above has a feature of increased compressive strength.

4a: Different types of fiber yarn 6: Matrix resin

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a hybrid prepreg according to the present invention. FIGS. 2 and 3 are diagrams illustrating one method of manufacturing a hybrid prepreg according to the present invention. FIGS. 4 and 5 are graphs illustrating the hybrid compounding rule of the hybrid 7-doped prepreg according to the present invention. FIG. 6 is an explanatory diagram illustrating the test method. FIG. 7 is a schematic cross-sectional view of a conventional hybrid prepreg.

Claims (1)

[Claims] 1) a carbon fiber region containing carbon fiber threads in one layer;
A hybrid prepreg characterized in that a heterogeneous fiber region containing one or more types of different fiber threads is formed in a layered manner, and a matrix resin is impregnated between the fiber threads.