JPH03119036A - Production of composite material of inorganic fiber and polyether ether ketone - Google Patents

Abstract

PURPOSE:To readily obtain a composite material, having stabilized physical properties and bright color and suitable as filters, diaphragms, etc., of fuel cells by dissolving a polyether ether ketone in a solvent and applying the resultant solution to inorganic fiber. CONSTITUTION:A polyether ether ketone is dissolved in a ketonic solvent (e.g. acetone) and the resultant solution is then applied to inorganic fiber (e.g. carbon fiber, glass fiber, ceramic fiber or steel fiber) having <=15mu diameter, coagulated and subsequently heat-treated above the glass transition point of the polyether ether ketone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a composite consisting of inorganic fibers and polyetheretherketone.

More specifically, by dissolving polyetheretherketone in a solvent and applying the solution.

This invention relates to a method for making a composite of inorganic fiber and polyetheretherketone.

[Conventional technology]

Resin molded products using inorganic fibers such as carbon fibers as reinforcing fibers are widely used. This technology involves the molding of inorganic fibers (
(weaving, column, filament wrapping, etc.) and resin application technology.

The current mainstream technology for applying resin is mainly applying epoxy and curing it in the ninth stage.

However, such techniques have the disadvantages of difficult time and temperature control due to the reactivity of epoxy;
Since epoxy is basically a two-component product, there are problems such as imbalance in physical properties due to non-uniform mixing. For this reason, recent efforts have been made to utilize thermoplastic resins as resins for such composite materials. The flow of this technology can be roughly divided into (1) a technology in which thermoplastic fibers and inorganic fibers are mixed into a yarn, and the mixed yarn is used as a thermoplastic binder. Another technique is to melt thermoplastic resin,
This is a technology that is intended to be applied to inorganic fibers.

However, these techniques also have the following problems.

In the case of the former method, that is, the mixed fiber method, since the stiffness of inorganic fibers and organic fibers are different, it is difficult to uniformly process both at the same time, and as a result, the physical properties of the composite obtained by heat fusion are stable. There was a drawback to not doing so. On the other hand, the latter method, that is, it is very difficult to uniformly apply the molten polymer to the inside of the fiber aggregate, which has the drawback of high cost. For this reason, the epoxy impregnation method is still widely used today.

And when it comes to polyetheretherketone,
This resin has become a typical resin for the mixed yarn method and the hot melt bonding method.

Note that polyetheretherketone dissolves only in concentrated sulfuric acid at room temperature due to its heat resistance.

It's just that.

[Problem to be solved by the invention]

In view of the prior art as described above, an object of the present invention is to provide a method for producing a composite of inorganic fibers and polyetheretherketone by uniformly and easily applying polyetheretherketone to inorganic fibers. It's about doing.

[Means to solve the problem]

In view of the current situation, the inventors of the present invention have conducted extensive studies without being bound by conventional research concepts.

We have arrived at the present invention. In order to solve the above problems, the present invention has the following configuration.

That is, the method for producing an inorganic fiber and polyetheretherketone composite according to the present invention is characterized in that polyetheretherketone is dissolved in a ketone solvent, and then applied to the inorganic fiber and coagulated.

Furthermore, in the method of the present invention, preferably the ketone solvent is acetone.

Moreover, the method is one in which the inorganic fiber is any one of the following A to D.

A, carbon fiber, B, glass fiber, C, ceramic fiber,
D. Steel fiber It is also preferably a method in which the diameter of the inorganic fiber is 15μ or less, and preferably coagulation.

This method is dry coagulation.

Further, in the method of the present invention described above, preferably, the inorganic fiber to which polyetheretherketone has been added is heat-treated at a temperature equal to or higher than the glass transition point of the polyetheretherketone.

[Effect]

The present invention will be explained in more detail below.

According to the present invention, it is surprising that a composite consisting of polyetheretherketone and inorganic fibers with many characteristics can be easily produced.

The polyetheretherketone of the present invention refers to an aromatic resin having a structure represented by the following general formula as a unit.

Such resins are heat resistant, chemical resistant, and radiation resistant.

It is famous as a unique thermoplastic resin due to its H flammability.

First, in the present invention, a solution of polyetheretherketone is prepared. The solution can be made by the following method.

First, polyetheretherketone is dissolved in sulfuric acid.

In particular, if concentrated sulfuric acid, particularly preferably 98% or more concentrated sulfuric acid, is used, polyetheretherketone can be easily dissolved even at room temperature, and a solution of 20% by weight or more can be made. The sulfuric acid solution of polyetheretherketone thus obtained is coagulated in an aqueous system. Here, it is particularly preferable to leave the sulfuric acid solution at room temperature for some time. For example, more than half a day.

The solution is to store it. Alternatively, it can be dissolved in hot sulfuric acid. The solution is then solidified. li
The solid may be water at room temperature, high temperature water, steam, etc. In addition, various additives may be used to promote coagulation, and neutralizing agents such as sodium hydroxide may be used to remove sulfuric acid.

In addition, in order to facilitate the removal of sulfuric acid and to facilitate dissolution in the 9th order ketone solvent, it is preferable that the polyether ether ketone coagulate be fine particles or have a large surface area. .

A particularly preferred method is to perform coagulation while stirring the coagulation liquid.

Next, the wet coagulation thus obtained is dissolved in a ketone solvent.

Note that it is preferable that the wet coagulated product contains some water rather than being dry. It is easier to dissolve that way. The preferred water content is 10 to 200% by weight. Note that there is no problem even if sulfuric acid, sulfate ions, etc. are contained.

Various types of ketone solvents including acetone can be used, but acetone is particularly preferred. The solvent may be acetone alone or may contain other solvents. Also, water may be included, and water is 30%
% may be included. About 20% by weight of polyetheretherketone can be easily dissolved.

Next, the ketone solution of polyetheretherketone thus obtained is applied to the inorganic fibers.

In the present invention, polished inorganic fibers include ceramic fibers such as carbon fibers, glass fibers, alumina fibers, silicon carbide fibers, and tyranno fibers.

Furthermore, conventionally known inorganic fibers such as steel fibers can be widely used.

The fibers of the present invention include not only 1a fibers but also various types of u! fibers that are processed products thereof. Aa aggregate 2, for example, thread, string, robe, woven fabric, nonwoven fabric, filament winding product, and composites thereof are also collectively referred to as Aa aggregate 2.

Further, the fineness and fiber length are not particularly limited either. The fibers of the present invention include not only fibers with uniform thickness but also bifurcated fibers with whiskers. In order to further improve the adhesiveness with polyetheretherketone, it is also preferable to appropriately treat the surface of the fibers. One thing that particularly demonstrates the effects of the present invention is:
This is the case when such fibers are thin and have a certain number of fibers. It is not easy to impregnate polyetheretherketone into thin fibers and a large number of fibers by a melting method, but it is possible to easily impregnate polyetheretherketone with a single fiber method.

In the case of the melting method, the fibers were sometimes cut, but with the method of the present invention.

Such drawbacks can be significantly reduced. especially.

The method of the present invention is extremely effective when the fibers are 15 μm or less.

Next, methods for applying the polyether ether ketone solution to inorganic fibers include impregnation and coat spraying.

Conventionally known techniques can be widely used. The polyetheretherketone solution thus applied to the inorganic fibers is then coagulated. Coagulation is done by dry or wet methods.

Also, known techniques such as a combination of these can be used, and there are no particular limitations. Further, the application of the polyetheretherketone solution does not have to be carried out only in one stage, but may be applied in multiple stages. The coagulation method at this time should be determined as appropriate depending on the use and purpose.

When a composite with particularly high chemical resistance is desired, it is preferable to heat-treat the composite to which polyetheretherketone has been added at a temperature equal to or higher than the glass transition temperature of the polyetheretherketone. This greatly improves the chemical resistance of the polyetheretherketone component.

Note that, if necessary, it is also preferable to perform surface processing by hot pressing.

The ratio of the inorganic fibers and polyetheretherketone of the inorganic fiber and polyetheretherketone composite thus obtained should be determined as appropriate depending on the purpose and use, and is not particularly limited.

In particular, when a large amount of polyetheretherketone is added, the polyetheretherketone is thermally fused by heat press treatment, etc., so a polyetheretherketone composite reinforced with fibers can be made, and such a composite can be used as a material.
It is also possible to make processed products.

The composite of the present invention essentially contains inorganic fibers and polyetheretherketone, but it also contains polymers other than polyetheretherketone, plasticizers, light stabilizers, antistatic agents, terminal stoppers, and fluorescent brighteners. , a flame retardant, etc. may be contained. Further, inorganic substances such as titanium oxide, iron oxide, carbon black, lead fine particles, etc. may be contained.

It is also effective to provide these by adding them to the polyetheretherketone solution.

The composite made of inorganic fiber and polyether ether ketone obtained by the present invention can not only be widely used in the field of conventional composites made of polyether ether ketone and inorganic fiber, but also can be used to produce thinner molded products and porosity. It can also be applied to molded products with high quality.

Representative examples are shown below.

Namely, filters, heat-resistant filters, chemical-resistant filters, antistatic filters, conductive filters, fuel cell membranes, filtration base materials, and sealing materials.

Gaskets, packing, base materials for printed circuit boards, electrical insulation materials, nuclear power materials, radiation resistant materials, flame retardant insulation materials, electrical components, conductive materials, high dimensional stability mi first product. conveyor belts, resin belts, canvas, nets, molding chips, reinforcing materials, eyeglass frames, rods, plates, blinds, aircraft base materials, aircraft walls, aircraft ceilings, chairs, flame-retardant floors,
Concrete reinforcement materials, marine materials, helmets, protective clothing,
Fire uniforms, screen gauze, roofs, pipes, sail cloth.

Tire cords, strings, racket base materials, tensigon members, vehicle base materials, vehicle ceilings, laboratory ceilings, belts for continuously variable transmissions, timing belts.

Rust-proof base material, etc.

〔Example〕

Hereinafter, it will be explained in more detail with reference to Examples.

It goes without saying that the present invention is not limited to these Examples.

Example 1 An acetone solution of 25ffii% polyetheretherketone (15% by weight of polyetheretherketone dissolved in 98% concentrated sulfuric acid, A sulfuric acid solution of ether ketone was made. Next, the solution was left under a nitrogen seal for 1 day.
Next, it was wet coagulated in stirring water, washed with water to remove the sulfuric acid, and the water content of the wet coagulated polyetheretherketone was reduced to 100% using a dehydrator. I made an acetone solution. ) was extruded using a $1111f-7f, 11114t gear pump, and 250 parts of it was impregnated. Continue to 100℃
It was dried and further heat-treated at 200°C%.

Approximately 6 polyetheretherketones are applied per pair of fibers.
There were 3 parts. When the cross section of such fibers was observed, it was found that the polyetheretherketone had well penetrated into the aggregate of carbon fibers, and a composite consisting of the inorganic fibers and polyetheretherketone was formed. Note that this complex was no longer soluble in acetone.

The composite thus obtained could be used as a high-strength rod as it is. Moreover, when the rod was bent in air at 330° C. and then cooled, a bent rod was obtained. The rod was further cut to a length of 1cO1, resulting in a chip of polyetheretherketone reinforced with 1cI11 carbon fibers. The chip could also be used as a molding chip or a molding master chip. The color of the chip was a slightly yellowish color unique to polyetheretherketone, which made the carbon fibers look good.

Comparative Example 1 When molten polyetheretherketone was applied to the carbon fiber yarn of Example 1 at 400°C in the same manner as in Example 1,
Even when the carbon fiber feeding speed was set to 115 as in Example 1, the polyetheretherketone did not penetrate well into the fiber aggregate. It penetrated into the fiber aggregate for the first time when it was magnified to 1/8. In addition.

During this time, polyetheretherketone turns black,
Furthermore, the state of dispersion of carbon fibers in polyetheretherketone was slightly uneven.

Example 2 Polyether ether ketone was applied in the same manner as in Example 1 to a yarn made of 5,000 glass fibers of 15 μm and converged without twisting. When the rod was placed in cement and cured in an autoclave at 180° C., a cement board with a predetermined strength was obtained. As a comparative example, when 5,000 glass fiber threads were similarly tested, only a board with the same strength as a board made only of cement was obtained. In other words, it was found that the glass fibers did not reinforce the cement in any way.

Example 3 Carbon fibers were made into a 10n square 8-strand braided body using a braiding machine and firstly treated with high-temperature steam at 900° C. for 3 minutes to activate the carbon fibers. Next, 5 particles of tetrafluoroethylene were added to the string.
It was impregnated with a 10% by weight acetone solution of polyetheretherketone dispersed in % by weight to form a gland packing. Such a gland packing can be used not only for high-temperature steam but also as a gland packing for chemical plants. I investigated the breakage of this patch.

No problems were found even after 5 pressurization tests. That is,
There were no errors in the uh fibers or damage in the #a fibers, and the product could be used without any problems even after 5 tests.

In addition, when a breakability test was performed using a carbon fiber string coated with grease, the carbon fiber fell off from the packing and could only be used once.

[Effects of the present invention]

By adopting the configuration of the present invention, the following great effects are brought about.

■A composite consisting of inorganic fibers and polyetheretherketone can be easily obtained.

■A composite consisting of inorganic fiber and polyetheretherketone with stable physical properties can be obtained.

A composite consisting of brightly colored inorganic fibers and polyetheretherketone is obtained.

Claims (6)

[Claims] (1) A method for producing an inorganic fiber and polyether ether ketone composite, which comprises dissolving polyether ether ketone in a ketone solvent, then applying it to inorganic fibers, and coagulating. (2) The method for producing an inorganic fiber and polyetheretherketone composite according to claim 1, wherein the ketone solvent is acetone. (3) Claim 1 wherein the inorganic fiber is any of the following A to D.
Or the method for producing an inorganic fiber and polyetheretherketone composite according to 2. A, carbon fiber, B, glass fiber, C, ceramic fiber,
D. Steel fiber (4) Claims 1 to 3 wherein the inorganic fiber has a diameter of 15μ or less.
A method for producing an inorganic fiber and polyetheretherketone composite according to any one of the above. (5) The method for producing an inorganic fiber and polyetheretherketone composite according to any one of claims 1 to 4, wherein the coagulation is dry coagulation. (6) The inorganic fiber and polyetheretherketone according to any one of claims 1 to 5, characterized in that the inorganic fiber to which polyetheretherketone has been added is heat-treated at a temperature equal to or higher than the glass transition point of the polyetheretherketone. Method of manufacturing the complex.