JPH03234820A - hybrid fiber - Google Patents

Abstract

PURPOSE:To obtain the title yarn suitable as a reinforcing material for composite material, by using a yarn obtained from a silicon-containing polycyclic aromatic polymer and/or a polycyclic aromatic polymer containing one of Ti, Zr and Hf and silicon as the one component. CONSTITUTION:The objective hybrid yarn contains, as the one component, a yarn [containing carbonaceous substance in a crystal orientation state from a mesophase state and a crystalline substance in an amorphous state changed from an optically isotropic state and/or amorphous carbon and an Si-C-O substance having Si:C:O of (30-70):(20-60):(0.5-10)] obtained from a silicon-containing polycyclic aromatic polymer and/or a yarn [containing carbonaceous substance in a crystal orientation state changed from a mesophase state and carbonaceous substance in amorphous state changed from an optically isotropic state and an Si-M-C-O substance having Si:M:C:O of (5-70):(0.5-45):(20-40):(0.01-30) and M is Ti, Zr or Hf]. Carbon fibers, glass fibers and boron fibers, etc., are used as the other component.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a hybrid fiber suitable as a reinforcing material for composite materials.

(Conventional technology and its problems) Carbon fiber is lightweight, yet has high strength and high elasticity.
It is being used in a wide range of fields, including sports and leisure goods, aircraft, bicycles, and building materials.

As carbon fibers, PAN-based carbon fibers made from polyacrylonitrile and so-called pitch-based carbon fibers made from petroleum-based and coal-based pitches are known.

Pitch-based carbon fibers are generally inferior in strength to PAN-based carbon fibers, but since the raw materials are cheap, various studies have been conducted on ways to increase the strength.
No. 223316 discloses a method for effectively generating mesophase and orienting it during spinning.

However, since carbon fibers are basically crystalline fibers, they are hard, tend to fluff, and have poor wettability with a matrix when used as a composite material.

Therefore, various methods for surface treatment of carbon fibers have been devised, and the currently known methods use materials such as polyvinyl alcohol, unsaturated polyester resins, and epoxy resins to impart flexibility to the fibers and to suppress the generation of fuzz. There are methods such as applying a suitable sizing agent to the surface, and dry or wet oxidation treatment of the surface for the purpose of improving adhesion to the matrix.

Among these treatments, the method of providing a surface oxidation layer in particular damages the fibers during oxidation and thus tends to reduce physical properties. Furthermore, carbon fiber cannot be used in an oxidizing atmosphere at a temperature exceeding 500°C because it will burn.

Against this background, we are developing a new fiber that has high strength and high modulus, has good wettability and adhesion with the matrix, and is cheaper than the PAN-based carbon fiber that has been used in a wide range of fields. has been strongly requested.

Furthermore, it is strongly desired in various fields to improve the oxidation resistance of carbon fibers at higher temperatures.

As a method that does not meet this demand, for example, JP-A-61-2
The methods described in Japanese Patent Application Laid-open No. 09139 and Japanese Patent Application Laid-Open No. 62-215016 have been proposed.

In these publications, an organic solvent soluble component in a coal-based or petroleum-based pinch is mixed and heated to react with polysilane to synthesize olkaliboryarylsilane, which is then spun, infusible, and
A method for producing inorganic fibers having properties intermediate between silicon carbide fibers and carbon fibers by firing is described.

However, in the above method, pitch containing no organic solvent insoluble matter is selected as one of the starting materials, and the reaction is carried out under conditions in which the insoluble matter is not produced at all in the production of organopolyarylsilane.

Therefore, the resulting spinning material, which is a product, does not contain all of the above-mentioned insoluble matter including the mesophase state, which is said to be the most important component for developing the strength of carbon fibers.

Depending on the conditions, the inorganic fiber obtained by spinning, infusible, and firing the above-mentioned spinning raw material corresponds to graphite crystals of carbon (00
2) Although a diffraction line is obtained, the orientation peculiar to pitch fibers is not observed, and a product with a high elastic modulus cannot be obtained. Furthermore, the method disclosed in the above-mentioned publication has the problem that as the pinch component increases, the heat resistance in an inert gas improves, but the oxidation resistance decreases, and furthermore, the mechanical properties deteriorate significantly.

The present applicant has disclosed in Japanese Patent Application No. 1-206640 and Japanese Patent Application No. 1-224511 that the above-mentioned problems are solved, the wettability to the matrix for composite material is good, and it is much more effective than silicon carbide fiber. The present invention discloses a high-strength, high-modulus inorganic fiber that has a high elastic modulus and has improved oxidation resistance by 200 to 300''C compared to pitch-based and PAN-based carbon fibers.

(Means for Solving the Problems) An object of the present invention is to provide a hybrid fiber containing at least one of the above-mentioned proposed fibers.

Another object of the present invention is to provide a hybrid fiber suitable as a reinforcing material for producing fiber-reinforced composite materials with excellent mechanical properties.

Another object of the present invention is to provide a hybrid fiber suitable as a reinforcing material for producing fiber-reinforced composite materials that has excellent corrosion resistance, heat resistance, and oxidation resistance.

The hybrid fiber of the present invention includes inorganic fiber ①, inorganic fiber I
I, carbon fiber, glass fiber, boron fiber, alumina fiber, silicon nitride fiber, aramid fiber, silicon carbide fiber, aramid fiber, silicon carbide fiber with carbon core wire, and Si-
Consists of at least two types of fibers selected from the group consisting of M-C-〇 fibers (M represents Ti or Zr), and contains at least one of inorganic fibers I and inorganic fibers II as a constituent component of the fibers. The inorganic fiber I is an inorganic fiber obtained from a silicon-containing polycyclic aromatic polymer, the constituent components of which are i) a polycyclic aromatic compound in a mesophase state constituting the polymer; a carbon material exhibiting at least one type of crystal orientation selected from the group consisting of a radial structure, an onion structure, a random structure, a core radial structure, a skin onion structure, and a mosaic structure derived from Ii) an optical structure constituting the polymer; non-oriented crystalline carbon and/or amorphous carbon derived from a oriented polycyclic aromatic compound, and iii) an amorphous phase consisting essentially of Si, C and O and/or having a particle size of It is an aggregate consisting of crystalline ultrafine particles substantially consisting of βSiC of 500 Å or less and amorphous SiOx (0<x≦2), and the proportion of the constituent elements is Si; 30 to 70% by weight C; 20 to
5i-C which is 60% by weight and O; 0.5-10% by weight
-0 substance, and the inorganic fiber (2) is an inorganic fiber obtained from a polycyclic aromatic polymer containing silicon and at least one element selected from the group consisting of titanium, zirconium, and hafnium. and the constituent components thereof are a) from the group consisting of a radial structure, an onion structure, a random structure, a core radial structure, a skin onion structure, and a mosaic structure derived from a polycyclic aromatic compound in a mesophase state constituting the polymer. (b) A crystalline material in a non-oriented state derived from an optically isotropic polycyclic aromatic compound containing an organic solvent-insoluble component that constitutes the polymer. carbon and/or amorphous carbon, and c) (1) an amorphous substance consisting essentially of Si, M, C and O, and/or ■ substantially consisting of β-3i C, MC1 β-SiC and MC It is an aggregate of crystalline ultrafine particles having a particle size of 500 Å or less consisting of a solid solution and M C+-x, and amorphous 5iOy and MO, and the proportion of the constituent elements is Si: 5 to 70% by weight, M: 0. 5
~45% by weight, C, 20-40% by weight and O, 0,01
~30% by weight of SiM-C-0 material (in the above formula:
M is at least one element selected from Ti, Zr, and Hf, and O<x<1.0<y≦2.0<z0≦2. ) is an inorganic fiber consisting of

First, the inorganic fiber (1) and the inorganic fiber (H) in the present invention will be explained. All "parts" in the following explanations are "parts by weight."
and "%" is "% by weight".

The inorganic fibers (①) in the present invention are the above-mentioned constituents i), i)
Consisting of i) and iii), Si; 0.01 to 2
9% by weight, C: 70-99.9% by weight and O: 0.00
1-10% by weight, preferably S i ; 0.1-25
Weight: 74~99.8% by weight and O: 0°01~
Consisting essentially of 10% by weight.

The inorganic fiber (2) consists of the above-mentioned constituent components a), b) and C), S i ; 0.01-30%, M; 0.
01-10%, C; 65-99.9% and 0; 0.00
1-10%, preferably Si; 0.1-25%, M;
0.01-8%, C; 74-99.8% and O; 0.
01-8%.

Crystalline carbon, which is a component of inorganic fibers ■ and inorganic fibers II, has a crystallite size of 500 Å or less, and is oriented in the fiber axis direction under a high-resolution electron microscope with a resolution of 1.5 Å. It is an ultrafine graphite crystal in which a fine lattice image corresponding to the (002) plane of the graphite crystal can be observed. Crystalline carbon in inorganic fibers has radial structure, onion structure, random structure, core-radial structure,
It can have a random structure including a skin onion structure, a mosaic structure, and a partially radial structure. This is due to the presence of mesophase polycyclic aromatic compounds in the raw materials.

Sum of constituent components i) and ii) in inorganic fiber ■1,
The ratio of component iii) to O0 parts is 0.015
~200 parts, and the ratio of components l), ii) is 1:0.02-4.

If the ratio of component iii) to 100 parts of the total of components i) and ii) is less than 0.015, the oxidation resistance and interfacial adhesion with 71-rix carbon are almost the same as pitch fibers. No improvement in the elasticity can be expected, and if the above ratio exceeds 200 parts, fine crystals of Graphi [.

Total of constituent components a) and b) in inorganic fiber H: 100
The ratio of component C) to parts is 0.015 to 200 parts, and the ratio of components a) and b) is l:0.0
It is 2-4.

If the ratio of component C) to 100 parts of the total of components a) and b) is less than 0.015, the fibers are almost the same as pitch fibers, and no improvement in oxidation resistance or wettability can be expected. If the proportion exceeds 200 parts, fine graphite crystals will not be effectively generated and fibers with high elastic modulus will not be obtained.

In inorganic fibers ■ and inorganic fibers H, microcrystals with small interlayer spacing and three-dimensional arrangement are effectively generated, and silicon atoms are distributed very uniformly so as to wrap around the microcrystals. There is.

Furthermore, the distribution state of silicon can also be controlled by the atmosphere during firing and the size and concentration of mesophase in the raw material. For example, if the mesophase grows large,
The silicon-containing polymer is easily extruded into the fiber surface phase and can produce a silicon-rich layer on the fiber surface after firing.

Next, the manufacturing method of inorganic fiber (1) and inorganic fiber (II) in the present invention will be explained.

The inorganic fiber (1) can be manufactured in the following first to fourth steps.

First step: The organosilicon polymer, which is one of the starting materials, can be synthesized by a known method. For example, polymethylsilane obtained by the reaction of dimethyldichlorosilane and metal strium is synthesized in an inert gas. Obtained by heating to 400°C or higher.

The organosilicon polymer has a bonding unit (Si CH2),
Or the bonding unit (S 1-CH2) and the bonding unit (Si-3
i), and the ratio of the total number of bonding units (SiCH2) to the total number of bonding units (Si-3i) (D is 1:0 to 2
It is within the range of 0.

The weight average molecular weight (Mll) of the organosilicon polymer is 300 to 10oo for boat fishing, and those with M of 4oo to 800 are suitable as precursor polymers that are intermediate raw materials for obtaining excellent carbon-based inorganic fibers. Particularly preferred is 3 4 for preparing (1).

Another starting material, the polycyclic aromatic compound, is pitch obtained from petroleum and/or coal. Particularly preferable pitch is heavy oil obtained by fluid catalytic cracking of petroleum, or by distilling the heavy oil. These are the distillate components or residual oils obtained by the distillation process, and the pinch obtained by heat-treating them.

The above pitch contains benzene, I-luene, xylene,
5 to 5 components insoluble in organic solvents such as tetrahydrofuran
The content is preferably 98% by weight. When pitch containing less than 5% by weight of the above-mentioned insoluble components is used as a raw material, inorganic fibers with excellent strength and elastic modulus cannot be obtained;
If more than 8% by weight of pinch is used as a raw material, the molecular weight of the copolymer will increase sharply, and coking may occur in some cases, making spinning difficult.

The weight average molecular weight (M8) of this pinch is 100 to 30
It is 00.

The weight average molecular weight is a value determined as follows. That is, if the pitch does not contain organic solvent insoluble components for gel permeation chromatography (CPC) measurement, such as benzene, toluene, xylene, tetrahydrofuran, chloroform, and dichlorobenzene, it is directly measured by GPC, and the pitch is determined from the above organic solvent insoluble components. If it contains, it is hydrogenated under mild conditions to change the organic solvent-insoluble components to the organic solvent-soluble components, followed by GPC measurement. Below, the weight average molecular weight of the polymer containing the above organic solvent insoluble matter is:
This is a value obtained by performing the same processing as above.

Precursor polymer (1) is prepared by adding petroleum-based or coal-based pitch to an organosilicon polymer, and preparing the mixture preferably at 250% in an inert gas.
Eight rounds are produced by a force-n-thermal reaction at a temperature in the range of ~500°C.

The ratio of pitch used is 8 parts per 100 parts of organosilicon polymer.
It is preferable that it is 3-4900 parts.

If the ratio of pitch used is too small, the silicon carbide component in the resulting inorganic fiber will increase, making it impossible to obtain an inorganic fiber with a high modulus of elasticity. 5 6 , and it becomes impossible to obtain inorganic fibers with excellent interfacial adhesion with matrix carbon and oxidation resistance.

If the reaction temperature of the above reaction is too low, it will be difficult to form bonds between silicon atoms and aromatic carbon, and if the reaction temperature is too high, the resulting precursor polymer (1) will be violently decomposed and its molecular weight will increase. Undesirable.

The mesophase polycyclic aromatic compound (2) is, for example, petroleum-based or coal-based pitch heated to 300 to 500% in an inert gas.
It can be prepared by heating to °C and conducting polycondensation while removing the soft fraction produced.

If the temperature of the condensation polymerization reaction is too low, the growth of the condensed ring will not be sufficient, and if the temperature is too high, the formation of infusible substances will be intense due to coking.

The above mesophase polycyclic aromatic compound (2) has a melting point in the range of 200 to 400°C and a weight average molecular weight of 200 to 10,000.

Among the mesophase polycyclic aromatic compounds (2), 20
Those having an optical anisotropy of 100% to 100% and containing 30 to 100% insoluble matter in benzene, toluene, xylene or tetrahydrofuran are particularly preferred in order to obtain inorganic fibers with excellent mechanical performance.

In the first step, the precursor polymer (1) and the mesophase polycyclic aromatic compound (2) are heated and melted and/or reacted in a temperature range of 200 to 500°C to form a silicon-containing polycyclic aromatic polymer. A spun polymer is prepared.

The mesophase polycyclic aromatic compound (2) is preferably used in an amount of 5 to 50,000 parts per 100 parts of the precursor polymer (1). If it is less than 5 parts, the mesophase content in the product will be insufficient and the content will be high. An elastic fired yarn cannot be obtained, and if the amount exceeds 50,000 parts, an inorganic fiber with excellent interfacial adhesion with matrix carbon and oxidation resistance cannot be obtained due to a lack of silicon component.

The weight average molecular weight of the silicon-containing polycyclic aromatic polymer is 2
00-11000, and the melting point is 200-400°C.

2nd Step Near The spinning polymer, which is a silicon-containing polycyclic aromatic polymer obtained in the 1st step, is heated and melted, and in some cases, it is filtered to remove substances that are harmful during spinning, such as microgels and impurities. This is then spun using a commonly used synthetic fiber spinning device.

The temperature of the spinning dope during spinning varies depending on the softening temperature of the raw material polymer, but a temperature in the range of 220 to 420°C is advantageous.

In the spinning device, a spinning tube is attached as necessary,
After setting the atmosphere in the spinning tube to one or more atmospheres selected from the group consisting of air, inert gas, hot air, hot inert gas, steam, and ammonia gas, the winding speed is increased to create a thin diameter. fibers can be obtained. The spinning speed in the melt spinning is determined by the average molecular weight of the raw materials,
Although it varies depending on the molecular weight distribution and molecular structure, 50 to 500
A range of 0 m/min is preferable.

Third step: The spun fibers obtained in the second step are rendered infusible by applying tension or non-tension.

A typical infusibility method is to heat spun fibers in an oxidizing atmosphere. The infusibility temperature is preferably 50 to 4
The temperature is in the range of 00°C. If the infusibility temperature is too low, the polymers that make up the spinning filament will not form.
Also, if this temperature is too high, the polymer will burn.

The purpose of infusibility is to make the polymer that makes up the spun fibers into a three-dimensional structure that is infusible and insoluble, so that it does not melt during the next firing process and does not fuse with adjacent fibers. It is. Gases constituting the oxidizing atmosphere during infusibility include air, ozone, oxygen, chlorine gas, bromine gas, ammonia gas, and mixed gases thereof.

As an infusible method different from the above, spun fibers are infusible by T-ray irradiation or electron beam irradiation in an oxidizing or non-oxidizing atmosphere, under tension or no tension, while heating at a low temperature as necessary. method can also be adopted.

The purpose of irradiating with γ rays or electron beams is to further polymerize the polymer forming the spun fibers, thereby preventing the spun filaments from melting and losing their fiber shape.

The appropriate dose of gamma rays or electron beams is 106 to 1010 rand.

Irradiation can be carried out in a vacuum, an inert gas atmosphere, or an oxidizing gas atmosphere such as air, ozone, oxygen, chlorine gas, bromine gas, ammonia gas, and mixtures thereof.

Infusibility by irradiation can be carried out at room temperature, and if necessary, infusibility can be achieved in a shorter time by heating in the temperature range of 50 to 200°C.

If infusibility is carried out without tension, the spun fibers will shrink and take on a wavy shape, but this can sometimes be corrected in the next firing process, and tension is not necessarily required. In this case, good results can be obtained if the tension is greater than that which can at least prevent the spun fibers from shrinking and becoming wavy during infusibility.

The tension to be applied during infusibility is 1 to 500
A range of g 7 mm2 is preferable; even if a tension of Lg/mm2 or less is applied, it is not possible to apply tension that will not cause the fibers to slack, and if a tension of 500 g 7 mm2 or more is applied, the fibers may break. .

Fourth step: By firing the infusible yarn obtained in the third step at a temperature in the range of 800 to 3000°C in a vacuum or inert gas atmosphere, inorganic fibers mainly composed of carbon, silicon, and oxygen are obtained. It will be done.

In the firing process, it is not necessarily necessary to apply tension, but high-temperature firing while applying tension in the range of 0.001 to 100 kg/mm2 makes it possible to obtain high-strength inorganic fibers with less bending.

It is estimated that during the heating process, mineralization becomes intense from about 700°C and is almost completed at about 800°C. Therefore, the firing is preferably performed at a temperature of 800°C or higher. Moreover, since obtaining a temperature higher than 3000°C requires expensive equipment 1 2 , firing at a higher temperature than 3000°C is impractical from the viewpoint of cost I.

Inorganic fiber (1) can be produced in the following steps 1 to 4.

First step: A precursor polymer (1) is prepared from an organic silicon polymer and pitch in the same manner as the method for preparing the precursor polymer (1) in the first step of producing inorganic fiber I.

Next, the precursor polymer (1) and the transition metal compound represented by the formula MX are reacted at a temperature in the range of 100 to 500°C to prepare a random copolymer (2).

In the above MX4, M is at least one element selected from Ti, Zr, and Hf, and X is an element that can bond with silicon of the precursor polymer (1) directly or via an oxygen atom through condensation. Although there is no particular limitation, a halogen atom, an alkoxy group, or a complex-forming group such as β-diketone is preferable.

If the reaction temperature is too low, the precursor polymer (1) and the formula MX4
If the condensation reaction with M does not proceed and the reaction temperature is excessively high, M
The crosslinking reaction of the precursor polymer (1) may proceed excessively, resulting in gelation, or the precursor polymer (1) itself may condense and increase its molecular weight, or in some cases, MX4 may volatilize, which is undesirable.

- For example, when M is Ti and X is OC4Hq, a reaction temperature of 200 to 400°C is suitable.

Through this reaction, a random copolymer (3) in which at least some of the silicon atoms of the precursor polymer (1) are bonded to the metal M directly or via oxygen atoms is prepared.

The metal M can be bonded to the silicon atom of the precursor polymer (1) in the form of a side chain in a bonding manner such as -MX3 or -○-MX, or it can be bonded directly to the silicon atom of the precursor polymer (1) or A bonding mode in which the bond is cross-linked via oxygen may also be used.

In addition to the above-mentioned method, the random copolymer (3) can also be prepared by reacting an organosilicon polymer with MX4 and further reacting the resulting product with pitch.

In the first step, the random copolymer (3) 3 4 and the mesophase polycyclic aromatic compound (2) are finally reacted and/or heated and melted to prepare a metal-containing polycyclic aromatic polymer.

Mesophase polycyclic aromatic compound (2) is an inorganic fiber ■
It is prepared in the same manner as the preparation method described in the first step of production.

The mesophase polycyclic aromatic compound (2) has a melting point of 20
The temperature is in the range of 0 to 400°C, and the weight average molecular weight is in the range of 200 to 10,000.

Among mesophase polycyclic aromatic compounds, 20 to 10
0%, especially 40-100% optical anisotropy, 3
Those containing 0 to 100% of insoluble matter in benzene, toluene, xylene or tetrahydrofuran are preferred in order to obtain inorganic fibers (1) with excellent mechanical performance.

The usage ratio of the mesophase polycyclic aromatic compound (2) is 5 to 50,000 per 100 parts of the random copolymer (3).
parts, more preferably 5 to 10,000 parts; if it is less than 5 parts, the mesophase content in the product will be insufficient, making it impossible to obtain a highly elastic fired yarn; if it is more than 50,000 parts, the silicon component will be Due to the shortage, inorganic fibers with excellent matrix wettability and oxidation resistance cannot be obtained.

At least a portion of the random copolymer (3) is melted and/or heated and reacted with the random copolymer (3) and the mesophase polycyclic aromatic compound (2) in a temperature range of 200 to 500°C. A metal-containing polycyclic aromatic polymer in which is combined with the mesophase polycyclic aromatic compound (2) is obtained. However, the bond mentioned here refers to a chemical bond between silicon and carbon of a polycyclic aromatic compound, and/or a polycyclic aromatic ring moiety chemically bonded to silicon in the random copolymer (2) and a mesophase polycyclic aromatic compound. It means a physical bond such as a van der Waals bond between a group compound.

If the above melt-mixing temperature is lower than 200°C, unmelted portions will occur, making the yarn non-uniform and having a negative effect on the strength and elastic modulus of the inorganic fibers.If the melt-mixing temperature is higher than 500°C, the condensation reaction will occur. The process progresses violently, and the resulting polymer has a high melting point, making it extremely difficult to spin the polymer.

5 6 As a method for preparing a metal-containing polycyclic aromatic polymer,
In addition to the above-mentioned method, it is also possible to prepare a product by reacting an organosilicon polymer and pitch, adding mesophase pitch and MX simultaneously or sequentially to the resulting product, and further reacting.

The weight average molecular weight of the metal-containing polycyclic aromatic polymer is 200
~11,000 and a melting point of 200-400°C.

2nd step: The spinning polymer, which is a metal-containing polycyclic aromatic polymer obtained in the 1st step, is spun in the same manner as in the 2nd step of producing the inorganic fiber (1) described above.

Third step: The spun fiber obtained in the second step is made infusible in the same manner as in the third step of producing inorganic fiber I described above.

4th step: By firing the infusible system obtained in the 3rd step in the same manner as in the 4th step of producing inorganic fibers ① described above, inorganic fibers II mainly consisting of carbon, M, silicon, and oxygen are obtained. .

In addition, SiM-C-0, which is the constituent component C) of the inorganic fiber
The form of the substance is determined by the manufacturing conditions employed in the first to fourth steps. - In terms of boat fishing, if the firing temperature in the fourth step is lower than 1000°C, Si
, M, C, 0.

On the other hand, when the firing temperature in the fourth step is, for example, 1700°C or higher, particles with a diameter of 500 Å or less that are substantially composed of β-SiC, MC1, a solid solution of βSiC and MC, and MC, It is substantially composed of an amorphous aggregate consisting of ultrafine particles and 5iny (however, 0<y≦2), MO, (however, O<z≦2).

At an intermediate temperature, the system is composed of a mixed system of each aggregate. Further, the amount of oxygen in the inorganic fibers can be controlled, for example, by the addition ratio of MX4 in the first step or the infusibility conditions in the third step.

Furthermore, the distribution state of component C) can also be controlled by the atmosphere during firing and the size and concentration of mesophase in the raw material. For example, a thicker mesophase (constituent C when grown) is more likely to be extruded into the fiber surface phase.

In the present invention, the above-mentioned inorganic fiber I and/or inorganic fiber ■
The fibers that make up the hybrid fiber include carbon fiber, glass fiber, Holon fiber, alumina fiber, silicon nitride fiber,
Silicon carbide fibers, aramid fibers, silicon carbide fibers with a carbon core, and 51-MC-〇 fibers (M is Ti or Zr
).

The above Si-M-C-0 fibers are (i) amorphous consisting essentially of Si, M, C1 and O;
or (ii) substantially β-SiC, MC, β-SiC and MC
A solid solution of MC+-x, each crystalline ultrafine particle with a particle size of 500 Å or less, and an aggregate consisting of amorphous 5iOz and MC2, or (iii) the amorphous of (1) above and (ii) above. A mixed system of crystalline ultrafine particle aggregates, (where M in the above formula represents Ti or Zr, and 0<x<
1) is an inorganic fiber consisting of This inorganic fiber is disclosed in, for example, Japanese Patent Publication No. 60-1405, Japanese Patent Publication No. 58-5286,
Eight rounds can be produced by the method described in the specifications of Japanese Patent No. 60-20485 and Japanese Patent No. 5944403.

When the hybrid fiber of the present invention is used as a reinforcing material for a composite material, the fiber itself may be blended in a uniaxial or multiaxial direction, or it may be used in hand-woven, satin-woven, simulated-woven, twilled, leno-woven, spiral-woven, or three-dimensional woven fabrics. There are methods of using it in various woven fabrics, such as, and methods of using it as chopped fiber.

Inorganic fibers I and/or inorganic fibers in hybrid fibers■
The proportion of is 10% by volume or more, preferably 20-90% by volume.
It is. If it is less than 10% by volume, the effect of improving mechanical properties, which is the objective of the present invention, such as improving the bonding strength between the inorganic fibers and the matrix in the composite material and improving the reinforcing efficiency, is poor.

Looking at the hybrid state of hybrid fibers by form: (1) interlayer hybrid in which a layer of one type of fiber is laminated with a layer of another type of fiber (2) intralayer hybridization that has already been hybridized to 90 within one layer There are basically two types of hybrids, and (3) combinations of them. There are six main types of binding:

(a) Lamination of single-layer tape (layers of different fibers are alternately layered) (b) Sandwich type (layers of different fibers are layered in a sandwich) (c) Rib reinforcement (d) Mixed fiber tow (Hybrid of different fibers in single fiber units) (e) Lamination of mixed fiber tape (high printing of different fibers in each yarn layer) (f) Mixed fiber surface layer of the hybrid fiber of the present invention The content ratio in the composite material is 1
0 to 70% by volume is preferred. The above content is 10% by volume
If the amount is less than 70% by volume, the reinforcing effect of the high print fibers will not be sufficiently exhibited, and if it exceeds 70% by volume, the amount of matrix will be too small, making it impossible to sufficiently fill the gaps between the hybrid fibers with the matrix.

Compared to conventional carbon fibers, the use of the hybrid fiber of the present invention as a reinforcing material has the following advantages.

That is, when the use as a composite material requires excellent properties as a part or part, for example, when abrasion resistance of the composite material surface is required, inorganic fibers and/or inorganic fibers are used. It is advantageous to hybridize with boron fiber, alumina fiber, silicon nitride fiber, silicon carbide fiber, silicon carbide fiber with carphone core, or 51-MC-0 fiber, and on the contrary, lubricity is required. In this case, it is advantageous to hybridize inorganic fiber (1) and/or inorganic fiber (2) with carbon fiber. In addition, when tensile strength is required only in a certain direction, high strength carbon fibers can be arranged in the strength direction to increase the strength, and in other directions reinforced with inorganic fibers ■ and/or inorganic fibers ■ to prevent compression failure. It is also effective to prevent peeling between the eyebrows.

(Effects) The hybrid fiber of the present invention includes a fiber-reinforced plus 1 2 composite material, a fiber-reinforced metal composite material, a fiber-reinforced ceramic composite material (this fiber-reinforced ceramic composite material mainly includes fiber-reinforced carbonaceous materials having carbon as a matrix). Composite materials are also included.

) can be suitably used as a reinforcing material for composite materials such as

For example, fiber-reinforced plastic composite materials obtained using the hybrid fibers of the present invention have excellent glabella shear strength and bond strength between plastics and fibers, so they can be used for long periods in harsh environments. It can withstand

The fiber-reinforced carbonaceous composite material obtained using the hybrid fiber of the present invention has improved adhesion with the carbon matrix, so it is a carbonaceous composite material with high strength, high elasticity, and excellent toughness, as well as wear resistance. Practical mechanical properties such as wear resistance are also improved.

(Example) The present invention will be explained below with reference to Examples.

Reference Example 1 (Manufacture of inorganic fiber I) Anhydrous xylene 2.5 I! , and 400 g of sodium were added, heated to the boiling point of xylene under a nitrogen gas stream, and dimethyldichlorosilane 11 was added dropwise over 1 hour. After the dropwise addition was completed, the mixture was heated under reflux for 10 hours to form a precipitate. The precipitate was filtered and washed with methanol and then water to obtain 420 g of white powder polydimethylsilane.

400 g of this polydimethylsilane was transferred to a 3-unit system equipped with a gas introduction pipe, a stirrer, a cooler, and a distillation pipe. The mixture was placed in a three-ring flask and heated under a nitrogen flow of 50mff1/min while stirring.
After heat treatment at 20°C, 350 g of a colorless and transparent slightly viscous liquid was obtained in a distillation receiver.

The number average molecular weight of this liquid was 470 as measured by the Han pressure osmosis method.

When we measured the infrared absorption spectrum of this substance, we found that
5i for 650-900cm-' and 1250CT11-'
absorption of CH, absorption of 5i-II at 2100 cm-',
5i-CH near 102102O' and 1355cm-'
2S1 absorption, C at 2900 cm- and 2950 cm-'
11 absorption was observed, and when the far infrared 3 4 absorption spectrum of this material was measured, 5 at 380cnr1 was observed.
Since absorption of i-3t is observed, the obtained liquid material mainly consists of (Si CHz) bond units and (Si
-3i) It was found to be an organosilicon polymer consisting of bonding units and having a hydrogen atom and a methyl group in the silicon side chain.

According to the measurement results of nuclear magnetic resonance analysis and infrared absorption analysis, the ratio of the total number of (Si C142) bond units to the total number of (Si-3i) bond units in this organosilicon polymer is approximately 1:3.
It was confirmed that the polymer was

300 g of the above organosilicon polymer was treated with ethanol to remove low molecular weight substances to obtain 40 g of a polymer having a number average molecular weight of 1200.

When the infrared absorption spectrum of this substance was measured, absorption peaks similar to those above were observed, and this substance mainly consists of (S+ CHz) bond units and (Si-3i) bond units, and has hydrogen atoms and silicon side chains. It turned out to be an organosilicon polymer with methyl groups.

According to the measurement results of nuclear magnetic resonance analysis and infrared absorption analysis, this organosilicon polymer is a polymer in which the ratio of the total number of (Si CH2) bond units to the total number of (Si-3i) bond units is approximately 7:1. This was confirmed.

Among the petroleum fractions, high-boiling substances higher than light oil were subjected to fluid catalytic cracking and rectification at a temperature of 500'C in the presence of a silica-alumina cracking catalyst, and a residue was obtained from the bottom of the column. Hereinafter, this residue will be referred to as FCC slurry oil.

As a result of elemental analysis, this FCC slurry oil had an atomic ratio of carbon atoms to hydrogen atoms (C/H) of 0.75, and an aromatic carbon ratio of 0.55 as determined by nuclear magnetic resonance analysis.

200g of the above FCC slurry oil! Heating was performed at 450°C for 0.5 hour under a nitrogen gas flow of 1/2 min. After distilling off the distillate at the same temperature, the residue was filtered hot at 200°C to remove the infusible part at the same temperature. It was removed to obtain 57 g of light bone removed pitch.

This light bone removal pitch is 25% xylene insoluble 5 6 It was an optically isotropic pitch containing a minute.

The organic silicon polymer 25 was added to 57 g of this light bone removal pitch.
g and 20 g of xylene were added, the temperature was raised while stirring, the xylene was distilled off, and the mixture was reacted at 400°C for 6 hours.
A random copolymer of g was obtained.

As a result of infrared absorption spectrum measurement, this reaction product was found to be
As in Example 1, it was found that the organosilicon polymer was a random copolymer in which some of the silicon atoms were directly bonded to polycyclic aromatic rings.

Further, this copolymer contained no xylene-insoluble portion, had a weight average molecular weight of 1400, a melting point of 265°C, and a softening point of 310°C.

On the other hand, 180 g of the light bone removed pitch was heated at 400°C under a nitrogen stream while removing light components generated by the reaction.
Time-line polymerization was performed to obtain 97.2 g of heat-treated pitch.

This heat-treated pitch has a melting point of 263°C and a softening point of 308°C.
It was a mesophase polycyclic aromatic compound containing 77% xylene insoluble matter and 31% quinoline soluble matter, and had an optical anisotropy of 75% when observed with a polarizing microscope on the polished surface.

90 g of this mesophase polycyclic aromatic compound and 6.4 g of the random copolymer were mixed, and the mixture was heated to 380 g under a nitrogen atmosphere.
The mixture was melted and heated at °C for one hour to obtain a silicon-containing polycyclic aromatic polymer in a uniform state.

This polymer has a melting point of 267°C and a softening point of 315°C.
C and contained 70% xylene insoluble matter.

The above high molecular weight material is used as the raw material for spinning, and the nozzle diameter is 0°15m.
Melt spinning was carried out at 360°C using a metal nozzle of 300°C, and the obtained spun yarn was oxidized and made infusible at 300°C in air, and then fired at 1300°C in an argon atmosphere. , an inorganic fiber with a diameter of 8 μm was obtained.

This fiber had a tensile strength of 320 Kg/mm 2 and a tensile modulus of 26 t 7 mm 2 , and it clearly had a radial structure from observation of the fracture surface.

After pulverizing this inorganic fiber, it is melted with alkali and treated with hydrochloric acid to form an aqueous solution, which is then subjected to high-frequency plasma emission spectrometry (TCP).
), the silicon content was found to be 0.95%.

7 8 Reference Example 2 (Production of Inorganic Fiber II) Reference Example 1 was added to 57 g of the light bone removal pitch obtained in Reference Example 1.
Add 25 g of the organosilicon polymer obtained above and 20 m2 of xylene, raise the temperature while stirring, distill off the xylene, and heat to 400°
The mixture was reacted at C for 4 hours to obtain 57.4 g of precursor polymer (1).

As a result of infrared absorption spectrum measurement, this precursor polymer (1) was found to contain 5i-H bonds (I R
: 2100 cnr') and new 5i-C (
The formation of Hensen ring carbon) bonds (TR: 1135 cm-') indicates that the organosilicon polymer has a portion in which some of the silicon atoms are directly bonded to the carbon of a polycyclic aromatic ring. I understand.

A xylene-soluble solution (25% xylene solution 15.5 g) of 3.87 g of tetraoctoxytitanium (Ti (OCa H1J4)) was added to 57.4 g of precursor polymer (1), and after the xylene was distilled off, the mixture was heated at 340°. C for 1 hour to obtain 56 g of random copolymer (2).

This polymer contained no xylene-insoluble portion, had a weight average molecular weight of 1580, a melting point of 258°C and a softening point of 292°C, and was soluble in xylene.

6.4 g of the above random copolymer (2) and 90 g of the mesophase polycyclic aromatic compound (2) obtained in Reference Example 1
g were mixed and melted and heated at 380° C. for 1 hour under a nitrogen atmosphere to obtain a metal-containing polycyclic aromatic polymer in a uniform state.

The melting point of this polymer is 264°C and the softening point is 307°C.
It contained 68% xylene insoluble matter.

The above high molecular weight material is used as the raw material for spinning, and the nozzle diameter is 0°15m.
Melt spinning was carried out at 360°C using a metal nozzle of 300°C, and the obtained spun yarn was oxidized and made infusible at 300°C in air, and then fired at 1300°C in an argon atmosphere. , an inorganic fiber with a diameter of 7.5 μm was obtained.

This fiber has a tensile strength of 358 kg/m2 and a tensile modulus of 32 t/7 mm2, and observation of the fractured surface using a scanning electron microscope reveals that it has a coral-like random radial mixed structure with many overlapping crystal layers. Ta.

After pulverizing this inorganic fiber, it was subjected to alkali melting and hydrochloric acid treatment to form an aqueous solution and then subjected to high frequency plasma emission spectroscopy (ICP). As a result, the silicon content was 0.95% and the titanium content was 0.95%. It was 0.6%.

Reference Example 3 (Production of Si-Ti-C-0 fiber) Polyborosiloxane was added at a ratio of 3 parts to 100 parts of polydimethylsilane synthesized by dechlorination condensation of dimethyldichlorosilane with metallic sodium, and nitrogen The polycarbosilane having a main chain skeleton mainly composed of carbosilane units of the formula (SiCH2) and having a hydrogen atom and a methyl group on the silicon atom of the carbosilane unit was thermally condensed at 350'C. Manufactured. Titanium alkoxide was added to this polycarbosilane and cross-linked polymerized at 340'C in nitrogen to form 100 parts of carbosilane units and 2 (Ti
A polytitanocarbosilane consisting of 210 parts of titanoxa-0) was obtained. This polymer was melt-spun and
Infusible treatment at 90°C followed by 13
Sintered at 00°C, fiber diameter 13μ, tensile strength 310
An inorganic fiber containing 3% of the titanium element mainly consisting of silicon, titanium, carbon and oxygen and having an elastic modulus of 16 t and 7 mm2 (monofilament method) was obtained. The obtained inorganic fiber is amorphous consisting of Si-, Ti, C and O;
β-3ic, TiC1β-SiC and Tic solid solution and T
5iTi- consisting of a mixed system with an aggregate consisting of iOz
It was C-0 fiber.

Example 1 Bisphenol A epoxy resin (Ciba Geigy X)
B2879A) 100 parts and dicyandiamide curing agent (
After uniformly mixing 20 parts of XB2879B (manufactured by Ciba Geigy), the mixture was dissolved in a mixed solvent of methyl cellosolve and acetone at a weight ratio of 1:1, and 28 parts of the above mixture was dissolved.
% solution was prepared.

After the inorganic fiber I obtained in Reference Example 1 was impregnated with the above solution, it was pulled in one direction using a drum winder and heated in a heat circulation oven at 100°C for 14 minutes to make it in a semi-cured state in one direction. A prepared inorganic fiber prepreg sheet was prepared.

Similarly, surface-treated carbon fiber (polyacrylonitrile type, fiber diameter 7μ, tensile strength 300Kg/mm2,
Using a tensile modulus of elasticity of 24 t (7 mm2), a semi-cured carbon fiber prepreg sheet aligned in one direction was produced eight times.

After the inorganic fibers and carbon fiber prepreg sheets obtained in this way were laminated alternately with the same axis direction, the
A hybrid I-fiber (inorganic fiber/carbon fiber) reinforced epoxy composite material was produced by pressing.

The fiber content of this composite material was 30% by volume of inorganic fibers and 30% by volume of carbon fibers, 60% by volume in total.

The tensile strength and tensile modulus of the obtained composite material in the 0 degree direction were each 185 Kg/mm2.16.3t.

/ m+n 2, and the bending strength in the 0 degree direction is 185K
g/mm2, and the bending strength in the 90 degree direction is 7.3
K g/mm2, interlaminar shear strength is 8.1 K g 7
mm2, and the bending impact value was 228 Kg-cm/c.

Comparative Example 1 Using only the carbon fibers used in Example 1 (polyacryliconi-1-lyl, fiber diameter 7μ), a semi-cured carbon fiber prepreg sheet aligned in one direction was prepared in the same manner as in Example 1. Prepared.

These prepreg sheets were laminated with the same fiber axis and then hot pressed to produce a carbon fiber reinforced epoxy composite material. The fiber content of this composite material is 60% by volume
It is. The tensile strength and tensile modulus of the obtained composite material in the 0 degree direction are 150 K g 7 mm2 and 14, respectively.
t is 7mm2, and the bending strength in the 0 degree direction is 172
Kg/mm”, bending strength in 90 degree direction is 6.2 K
g 7mm2, interlaminar shear strength is 8゜1K g 7mm
2. The bending impact value was 150 Kg-crn/crR.

Example 2 A 34 composite material with a fiber content of 30% by volume of inorganic fibers and 30% by volume of carbon fibers, 60% by volume in total, was prepared in the same manner as in Example 1 except that inorganic fibers (■) were used instead of inorganic fibers (I). Manufactured. The tensile strength and tensile modulus of the obtained composite material in the 0 degree direction were 197 Kg/mm, respectively.
, 16.8t 7mm2, the bending strength in the 0 degree direction is 199Kg/mm2, the bending strength in the 90 degree direction is 8.0Kg 7mm2, and the interlaminar shear strength is 9.1Kg
/mm2, and the bending impact value was 235 Kg-cm/c111.

Example 3 Inorganic fiber I obtained in Reference Example 1 and 5i-Ti obtained in Reference Example 3
-Mixed fiber tow with C-0 fiber (inorganic fiber I and 5i-Ti
The volume ratio with -C-0 fibers was 8:2. ) was soaked in a methanol solution of Resul type phenolic resin (MRW3000 manufactured by Meisho Kasei ■) and pulled up, the methanol was removed, and the fabric was dried to obtain a prepreg sheet. A square sheet with 5 marks on one side was cut out from this prepreg sheet, stacked in a mold, and heated to 20'C.
The -y/-el resin was cured by pressing at 50 kg/cm2 to obtain a molded body. This compact was buried in carbon powder and heated to 1000°C at a heating rate of 5°C/h in a nitrogen stream.
An inorganic fiber-reinforced carbon composite material was obtained.

Powder of the mesophase polycyclic aromatic compound (2) described in Reference Example 1 was added to this composite material, heated to 350°C in a nitrogen atmosphere in an autoclave, and after melting, the pressure was reduced, and the mesophase polycyclic aromatic compound (2) was added into the pores. After being impregnated with the aromatic compound (2), the material was impregnated under pressure at 100 kg/cm2, heated to 300°C at a heating rate of 5°C/h in air, and then infusible to 1300°C. Carbonized at °C. Impregnation and carbonization with the mesophase polycyclic aromatic compound (2) were repeated three more times.

The bulk density of the obtained composite material was 1.75 g/cry,
The bending strength was 28 kg/mm2, and the fiber volume content was 60%.

The friction coefficient and wear amount of this composite material were measured, and the results are shown in Table 1.

Comparative Example 2 Tensile strength: 300 kg/mmz, tensile modulus: 24 t/
A C/C composite was produced in the same manner as in Example 3, except that polyacrylonitrile carbon fiber of mm2 was used as the reinforcing material. The properties of this composite are shown in Table 1.

Comparative Example 3 5iTi-C-0/C
produced a composite. The properties of this composite are shown in Table 1.

Table 1 Initial sliding speed 10~20rn/sec Pressing pressure
5-10kg/c As is clear from Table 1,
The coefficient of friction of the composite material obtained in Example 3 is 0.4 to 0.6
, the amount of wear is 0.6 to 1. OX 10-'mm/5to
p/5urf, and has excellent abrasion resistance compared to the C/C composite of Comparative Example 2.

In addition, the composite obtained in Comparative Example 3 has a large friction coefficient of 0.8 to 1.0, and has inferior sliding properties (self-lubricating properties) compared to the C/C composite. The friction coefficient of the composite material was comparable to that of the C/C composite.

Claims (1)

[Claims] Inorganic fibers I, inorganic fibers II, carbon fibers, glass fibers, boron fibers, alumina fibers, silicon nitride fibers, silicon carbide fibers, aramid fibers, silicon carbide fibers with a carbon core, and Si-M- C-O fiber (M represents Ti or Zr)
consisting of at least two types of fibers selected from the group consisting of inorganic fibers I, inorganic fibers as constituent components of the fibers;
In a hybrid fiber containing at least one of II, the inorganic fiber I is an inorganic fiber obtained from a silicon-containing polycyclic aromatic polymer, and the constituent components thereof are i) in a mesophase state constituting the polymer; ii) a carbon material exhibiting at least one type of crystal orientation state selected from the group consisting of a radial structure, an onion structure, a random structure, a core radial structure, a skin onion structure, and a mosaic structure derived from a polycyclic aromatic compound; ii) the polymer; non-oriented crystalline carbon and/or amorphous carbon derived from the constituent optically isotropic polycyclic aromatic compound, and iii) an amorphous phase consisting essentially of Si, C and O; /Or an aggregate consisting of crystalline ultrafine particles substantially made of β-SiC with a particle size of 500 Å or less and amorphous SiO_x (0<x≦2), where the proportion of the constituent elements is Si;30~ 70% by weight C; 20~
Si-C which is 60% by weight and O; 0.5-10% by weight
-O substance, wherein the inorganic fiber II is an inorganic fiber obtained from a polycyclic aromatic polymer containing at least one element selected from the group consisting of titanium, zirconium, and hafnium and silicon. , the constituent components of which are selected from the group consisting of a) a radial structure, an onion structure, a random structure, a core radial structure, a skin onion structure, and a mosaic structure derived from a polycyclic aromatic compound in a mesophase state constituting the polymer; b) non-oriented crystalline carbon and/or amorphous carbon derived from an optically isotropic polycyclic aromatic compound constituting the polymer; and c) (1) an amorphous material consisting essentially of Si, M, C and O, and/or (2) consisting essentially of β-SiC, MC, a solid solution of β-SiC and MC, and MC_1_-_x crystalline ultrafine particles with a particle size of 500 Å or less, and amorphous SiO_y and MO_z
The proportion of the constituent elements is Si: 5-70% by weight, M: 0.5-70% by weight.
45% by weight, C: 20-40% by weight and 0: 0.01-
30% by weight of Si-M-C-O material (in the above formula:
M is at least one element selected from Ti, Zr, and Hf, and satisfies 0<x<1, 0<y≦2, and 0<z≦2. ) A hybrid fiber characterized by being an inorganic fiber consisting of.