JP2944738B2 - Long fibrous alkali titanate and its composite material - Google Patents

Description

The present invention relates to alkali titanate fibers, particularly various synthetic resins,
The present invention relates to a long fiber alkali titanate suitable as a reinforcing material for a molding material such as a light alloy.

[Conventional technology]

Fibrous alkali titanate is conventionally known as a firing method, a flux method, a melting method, a hydrothermal method, etc., but the fiber length is 1 mm.
As mentioned above, there is no example of synthesizing a highly flexible alkali titanate having a length of more than 2 mm and a polycrystalline structure, and thus, an alkali titanate fiber having such properties has not yet been provided.

[Problems to be solved by the invention]

The conventional alkali titanate obtained by such a method has a very short fiber length, even though it is fibrous, and has a length of at most several tens of μm. Has a disadvantage that the strength is low and the reinforcing effect is inferior to that obtained by blending a continuous fiber material such as carbon fiber.

An object of the present invention is to remove such disadvantages of the conventional alkali titanate, and to provide a long-fiber-shaped alkali titanate fiber and a high-strength composite material utilizing the properties of the alkali titanate and having excellent reinforcing performance for the composite material. To offer.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve the above object.As a result, the fiber composed of a polycrystalline structure in which alkali titanate crystals are continuously arranged in one direction has a high flexibility, and is mixed with a composite material. The present inventors have found that the orientation in the material is facilitated, the reinforcing property is remarkably increased, and a high-strength composite material is obtained.

That is, the present invention is a long fiber-like alkali titanate rich in flexibility consisting of a polycrystalline structure continuously arranged in one direction, the fiber diameter is usually 50 μm or less, the fiber length is 1 mm or more long fiber. Things. Since what is generally called a whisker has a perfect crystal structure, it is easily broken at the time of compounding (at the time of kneading), and as a result, the strength of the composite material is reduced.

On the other hand, the fiber composed of the polycrystal of the present invention is:
It shows strong resistance to external stresses during kneading during the production of composite materials and during molding. This is presumably because the whiskers (grain boundaries) play a role of dispersing and relaxing the stress. In addition, the polycrystalline structure allows the fiber to exhibit flexibility, and thus has an effect that the fiber is less likely to be cut or damaged during compounding.

In producing a composite material using the long-fibrous alkali titanate of the present invention as a reinforcing material, the composite material, for example, a thermoplastic resin or a thermosetting resin is kneaded by ordinary means, or the composite material is kneaded. It can be easily manufactured by impregnating cloth or the like prepared in advance with the alkali titanate fiber of the present invention.

In the case of a light alloy, a melt forging method in which a preform made of the alkali titanate fiber of the present invention is impregnated with a molten metal under pressure or a powder metallurgy method is selected, and thereafter, plastic working such as extrusion is performed. It has features such as giving directionality to the fibers and improving the properties of the matrix.

The long-fibrous alkali titanate of the present invention is obtained by adding a mixture obtained by adding a carbon material and an alkali halide to a mixed material of a titanium source and an alkali source, for example, at a vapor pressure of an alkali halide in a range of 900 to 1200 ° C. By firing in the presence, it can be formed on the surface of the fired product.

FIG. 1 is a stereomicrograph of the long-filament alkali titanate of the present invention thus obtained, and FIG. 2 is a photograph further enlarged by a scanning electron microscope.

When the long-fibrous alkali titanate obtained in this example was identified by X-ray diffraction, it was confirmed that it was a single phase of K ₂ O · 6TiO ₂ .

As apparent from the photographs of FIGS. 1 and 2, the fiber diameter was 2 to 10 μm, the fiber length was 2 mm or more, and it was confirmed that the crystal structure was a polycrystalline structure arranged in one direction.

For comparison, conventional commercially available K ₂ O.6TiO ₂ fibers have a fiber diameter of 0.2 to 0.5 μm and a fiber length of 10 to 20 μm as shown in FIG.
And are fine needle-like crystals.

〔Example〕

(1) composite material polybutylene terephthalate resin mainly made of thermoplastic resin to (Polyplastics Co., Ltd., trade name DURANEX 2000) 70 parts by weight, K ₂ O · 6TiO ₂ long fibers (epoxysilane coupling of the present invention
30 parts by weight) were extruded with a KCK kneader manufactured by KCK, melt-kneaded at 250 ° C., and pelletized.

The obtained pellets were injection-molded by an injection molding machine (cylinder temperature 250 ° C, mold temperature 70 ° C), and ASTM, D638,
A No. 1 tensile strength test piece, ASTM, D790, and a bending strength test piece (12.7 mm × 127 mm × 3.2 mm strip) were prepared.

For comparison, a test piece was prepared in the same manner as above using the above-mentioned conventional K ₂ O · 6TiO ₂ . Table 1 shows the strength test results.
It is exactly as shown.

(2) Composite material mainly composed of thermosetting resin 38.8 parts by weight of unsaturated polyester resin (manufactured by Takeda Pharmaceutical Co., trade name: Polymer 9802), 12.9 parts by weight of calcium carbonate (manufactured by Shiraishi Calcium Co., trade name: Whiten SB) 2.6 parts by weight of zinc stearate (manufactured by Kokusan Chemical Co., Ltd.), 0.4 part by weight of t-butyl peroxybenzoate (manufactured by NOF CORPORATION, trade name: Barbutyl Z), 19.4 parts by weight of glass fiber (manufactured by Nitto Boseki Co., trade name: CS6E-227SB) Then, 25.9 parts by weight of the long-fiber K ₂ O.6TiO ₂ of the present invention was added to the mixture, kneaded with a desktop type kneader PNV-1 manufactured by Irie Trading Co., Ltd., and compression molded at 140 ° C. to produce a test piece. The dimensions of the test pieces are bending test pieces (JIS K7203)
Is 4 × 10 × 80 mm, and the tensile test piece is a (JIS K7113) No. 3 test piece.

For comparison, test pieces were prepared in the same manner as above using the above-mentioned conventional K ₂ O · 6TiO ₂ .

 The results of the strength test are as shown in Table-2.

(3) Composite material mainly composed of alloy After dispersing the long-fibrous K ₂ O · 6TiO ₂ obtained in the present invention in water, adding 5 parts by weight of silica sol to the fiber, filtering, pressing, After drying, a preform having a fiber content of 20 vol% was prepared.

The high-pressure casting temperature was 800 ° C, 800 ° C, and 250 ° C for the preform 6061 alloy melt and mold, respectively, and the pressing force was 100 kg / c.
The composite was rapidly cooled and solidified while applying a pressure of m ² to produce a composite material.

The composite material was cut into a prismatic shape with a cutting grindstone to prepare a tensile test piece equivalent to JIS No. 4, and was further solution-hardened at 520 ° C. for 30 minutes, then quenched in water, and subsequently subjected to aging treatment at 75 ° C. for 8 hours.

For comparison, test pieces were prepared in the same manner as described above using the above-mentioned conventional K ₂ O · 6TiO ₂ . Table 3 shows the strength test results.

[Effects of the Invention] The long-fibrous alkali titanate of the present invention has a polycrystalline structure arranged in one direction, and has a high fiber length and an aspect ratio that is extremely flexible. Not only is it particularly high, it is not only very suitable as a reinforcing material for various composite materials, but also the use of conventional alkali titanate fibers can be further expanded, and the effect is extremely large.

[Brief description of the drawings]

FIG. 1 is a photograph showing the shape of the alkali titanate fiber of the present invention, FIG. 2 is a photograph showing the crystal structure of the alkali titanate fiber of the present invention, and FIG. 3 is the crystal structure of the conventional alkali titanate fiber. It is a photograph showing.

Claims (3)

(57) [Claims] 1. A highly flexible long-fibrous alkali titanate comprising a polycrystalline structure continuously arranged in one direction. 2. A fiber having a fiber diameter of 50 μm or less and a fiber length of at least
The long-fibrous alkali titanate according to claim 1, which is 1 mm or more. 3. A composite material comprising the long-fibrous alkali titanate according to claim 1 or 2.