JPH03103452A - Inorganic fiber reinforced plastic composite material - Google Patents

Abstract

PURPOSE:To obtain the subject economical composite material excellent in mechanical strength and bond strength between a matrix and a reinforcing material by using an inorganic fiber mainly composed of C, Si and O as the reinforcing material and a plastic as the matrix. CONSTITUTION:An objective composite material composed of (A) an inorganic fiber as an reinforcing material and (B) a plastic as a matrix. In the above mentioned composite material, the component (A) is contained in an amount of 10-80vol.%. The above mentioned inorganic fiber used as the above mentioned component (A) is produced from a silicon-containing polycyclic aromatic polymer and composed of a carbonaceous material showing a crystalline orientation state selected from a radical structure, an anion one, etc., derived from a mesophase-state polycyclic aromatic compound constituting the above mentioned structural material, a non-orientated (non)crystalline carbon derived from an organic solvent-insoluble component-containing optically isotropic polycyclic aromatic compound constituting the above mentioned polymer, an amorphous phase composed of Si: 30-70wt.%, C: 20-60wt.% and D: 0.5-10wt.% and an aggre gate composed of a crystalline ultrafine particle consisting of beta-SiC and having <=500Angstrom particle size and an amorphous material.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an inorganic fiber-reinforced plastic composite material (hereinafter referred to as This relates to composite materials (hereinafter abbreviated as composite materials).

(Prior Art and its Problems) Carbon fibers have been widely used as fibers for reinforcing plastics such as epoxy resins, modified epoxy resins, polyester resins, and polyimide resins. However, when carbon fibers are used, surface treatment of the fibers is required due to poor wettability with resin. However, even with plastic composite materials that use surface-treated carbon fibers as reinforcement, the glabellar shear strength is at most about 8 kg/mm, and the tensile strength in the direction perpendicular to the fibers is about 4.5 kg/mm.
In other words, the bonding strength between the resin and the fibers is weak, and the fibers are likely to peel off from the resin.For this reason, for example, the fibers may peel off from the resin due to long-term use, or the bending impact value may be low. This poses a practical problem of destruction due to instantaneous impact.

In addition, silicon carbide fiber obtained by spinning, infusible, and burning an organic silicon polymer called polycarbosilane has good wettability with resin in composite materials with resin, and can be used as a reinforcing material without surface treatment. What can be done is JP-A-52-146
It is disclosed in Publication No. 87. However, the above-mentioned inorganic fibers are expensive, and this is one of the obstacles to their use in composite materials.

(Means for Solving the Problems) An object of the present invention is to solve the above problems and provide a composite material that has excellent mechanical properties and is inexpensive.

Another object of the present invention is to provide a composite material with excellent bonding strength between a plastic matrix and inorganic fibers serving as reinforcing materials.

Another object of the present invention is to provide a composite material with excellent compatibility between a matrix and inorganic fibers and with excellent reinforcement efficiency by the inorganic fibers.

Another object of the present invention is to provide a composite material with a low rate of decrease in fatigue strength.

Another object of the present invention is to provide a composite material that is inexpensive and suitable for mass production.

Furthermore, the present invention has an interlaminar shear strength of up to about 8.5 kg.
/ mm" or more, the tensile strength and bending strength in the direction perpendicular to the fibers are about 6 kg/mm" or more and about 8 kg/mm" or more, respectively, and the dt + impact value is 200 kg -
To provide an inorganic fiber-reinforced plastic composite material having a hardness of at least cm/cni.

The composite material of the present invention uses inorganic fibers as a reinforcing material and plastic as a matrix, and a) the inorganic fibers are inorganic fibers obtained from a silicon-containing polycyclic aromatic polymer, and a part of the composition thereof is i) 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 in a mesophase state constituting the polymer. ii) non-oriented crystalline carbon and/or amorphous carbon derived from an optically isotropic polycyclic aromatic compound containing an organic solvent insoluble component constituting the polymer; and iii) an amorphous phase consisting essentially of Si, C and x≦2), and the proportions of the constituent elements are Si: 30 to 70% by weight, C: 2
0-60% by weight and O; 0. 5 to 10% by weight of a high-strength, high-elasticity inorganic fiber made of a Si-C-○ substance, b) The content of the inorganic fiber in the composite material is 10 to 80% by volume. It is an inorganic fiber reinforced plastic composite material.

First, the inorganic fiber in the present invention will be explained.

In addition, in the following description, all "parts" are "parts by weight."
, and all "%" are "% by weight".

The inorganic fibers in the present invention are the above-mentioned constituent components i) and ii.
) and city), Si; 0.01 to 29%,
C: 70-99.9% and o. o. o o1～1
0%, preferably Si; 0.1-25%, C; 74-9
9.8% and O. 0. 0.01 to 8%.

1 of this inorganic fiber. ': The constituent crystalline carbon is 50
A fine lattice image corresponding to the (002) plane of 3.2 people oriented in the fiber axis direction was observed using a high-resolution electron microscope with a crystallite size of 0 or less and a resolution of 1.5 people. It is an ultrafine graphite crystal that can be The crystalline carbon in the inorganic fibers can have a radial structure, an onion structure, a random structure, a core radial structure, a skin onion structure, a mosaic structure, a random structure including a partial radial structure, and the like. This is due to the presence of the mesophase polycyclic aromatic compound (2) in the raw material.

The sum of structural precepts i) and ii) in this inorganic fiber 1
The ratio of component iii) to 00 parts is 0.015~
200 copies, and the ratio of constituent precepts i) and ii) is 1:0.02-4.

The ratio of component iii) to the total of 100 copies of component i) and ii) is 0. If it is less than 0.15, it is almost the same as pitch fiber, and no improvement in oxidation resistance or wettability can be expected, and if the above ratio exceeds 200 parts, graphite fine crystals cannot be effectively prevented. , fibers with high elastic modulus cannot be obtained.

In this inorganic fiber, microcrystals with a small interlayer spacing and three-dimensional arrangement are effectively preserved.

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 is greatly elongated,
The silicon-containing polymer tends to be extruded into the fiber surface phase, resulting in a silicon-rich layer on the fiber surface after sintering.

The inorganic fiber in the present invention mainly consists of i) a bonding unit (S i CHz ), or a bonding unit (Si-CH2) and a bonding unit (St-Si), and has hydrogen atoms, lower alkyl groups, It has a side chain group selected from the group consisting of a phenyl group and a silyl group, and the ratio of the total number of bonding units (S i C Hz ) to the total number of bonding units (Si-Si) is in the range of 120 to 20. Random copolymer (1) in which at least a portion of the silicon atoms of an organosilicon polymer are bonded to an aromatic ring of petroleum-based or coal-based pitch or a heat-treated product thereof via a silicon-carbon linking group (1) 100 weight and ii) a mesophase state obtained by heat-treating petroleum-based or coal-based pitch, or a polycyclic aromatic compound consisting of both mesophase and optically isotropic phases (hereinafter both are collectively referred to as mesophase polycyclic aromatic Sometimes referred to as compound (2)) 5-500
A first step of obtaining a silicon-containing polycyclic aromatic polymer by heat-reacting and/or heat-melting 00 parts by weight at a temperature in the range of 200 to 500'C, the silicon-containing polycyclic aromatic polymer described above. A second step of preparing a spinning dope and spinning the yarn, and a third step of infusibleizing the spinning yarn under tension or without tension.
and a fourth step of firing the infusible spun fibers at a temperature in the range of 800 to 3000° C. in vacuum or in an inert gas atmosphere.

Each of the above steps will be explained.

First step: bonding unit (St CHz), which is one of the starting materials, or bonding unit (St CHz) and bonding unit (Si-S
The organosilicon polymer consisting of i) can be obtained, for example, by heating polymethylsilane obtained by the reaction of dimethyldichlorosilane and metallic sodium to 400° C. or higher in an inert gas. The weight average molecule i (M,) of this organosilicon polymer is generally 300 to 1000, and M
, of 400 to 800 is particularly preferred for preparing the random copolymer (1), which is an intermediate raw material for obtaining excellent carbon-based inorganic fibers.

Another starting material, a polycyclic aromatic compound, is pitch obtained from petroleum and/or coal, especially heavy oil obtained by fluid catalytic cracking of petroleum, and pitch obtained by distilling the heavy oil. Preferred are distillate fractions or residual oils and pitch obtained by heat treating them.

The above pitch contains 5 to 9 compounds that are insoluble in organic solvents such as benzene, toluene, xylene, and tetrahydrofuran.
Preferably contains 8%, less than 5%
- When used as a raw material, an inorganic fiber with excellent strength and elastic modulus cannot be obtained, and when more than 98% pitch is used as a raw material, the molecular weight of the copolymer increases sharply, and some Coking may occur, making spinning difficult.

The weight average molecular weight (M,) of this pitch is 100 to 30
It is 00.

The weight average molecular weight is a value determined as follows. In other words, if the pitch does not contain organic solvent-insoluble matter, it is directly measured by gel pernation chromatography (GPC), and if it contains organic solvent-insoluble matter, it is hydrogenated under mild conditions to remove the organic solvent-insoluble matter. After changing the components to organic solvent-soluble components, GPC measurement is performed. The weight average molecular weight of the polymer containing organic solvent insoluble matter is a value obtained by performing the same treatment as above.

Random copolymer (1) is prepared by adding petroleum-based or coal-based pitch to an organosilicon polymer and subjecting it to a heating reaction in an inert gas, preferably at a temperature in the range of 250 to 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 proportion 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. As a result, inorganic fibers with excellent matrix wettability and oxidation resistance cannot be obtained.

If the reaction temperature of the above reaction is too low, the bond between silicon atoms and aromatic carbon will be difficult to form, and if the reaction temperature is too high, the random copolymer (1) formed will decompose and increase its molecular weight. This is a severe occurrence and is 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 condensation polymerization while removing a soft fraction.

If the temperature of the condensation polymerization reaction is too low, the length of the condensed ring will not be sufficient, and if the temperature is too high, the formation of infusible products will increase 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 (M, ) of 200 to 10000 te.
! >ru.

Among the mesophase polycyclic aromatic compounds (2), 20
An inorganic fiber with excellent mechanical performance can be obtained by having an optical anisotropy of ~100%, especially 40 to 100%, and containing 30 to 100% of insoluble matter in benzene, toluene, xylene, or tetrahydrofuran. preferred for.

In the first step, the random copolymer (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 usage ratio of the mesophase polycyclic aromatic compound (2) is 5 to 500 parts per 100 parts of the random copolymer (1).
00 parts is preferable; if it is less than 5 parts, the mesophase content in the raw material will be insufficient, making it impossible to obtain a highly elastic sintered yarn; if it is more than 50,000 parts,
Due to a certain lack of silicon, inorganic fibers with excellent wettability and oxidation resistance to the matrix of the burned yarn cannot be obtained.

The weight average molecular weight (M
) is 200-11000, and the melting point is 200-40
0'C.

2nd step: 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 harmful substances during spinning, such as 5 clogel and impurities. This is then spun using a commonly used 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 process: The spun fibers obtained in the second step are rendered infusible by the action of 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 process of burning and does not fuse with adjacent fibers. That's true. Examples of gases that prevent an oxidizing atmosphere during infusibility include air, osone, oxygen, chlorine gas, bromine gas, ammonia gas, and mixed gases thereof.

As an infusibilization method different from the above, the spun fibers are infusibilized by irradiation with gamma rays or electron beams in an oxidizing or non-oxidizing atmosphere, under tension or without tension, while heating at a low temperature as necessary. method can also be adopted.

The purpose of irradiating with gamma rays or electron beams is to further polymerize the polymer that forms the spun fibers.
The purpose is to prevent the spun yarn from melting and losing its 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, or if necessary, infusibility can be achieved in a shorter time by heating at a temperature in the 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. When applied, 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 50
A range of 0 g/mm2 is preferable; even if a tension of Ig/mm or less is applied, it is not possible to apply tension that will not cause the fibers to sag, and if a tension of 500 g/mm or more is applied, Fibers may break.

4th process: By baking the infusible yarn obtained in the 3rd 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 produced. is obtained.

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/sha2 makes it possible to obtain high-strength inorganic fibers with less bending.

In the heating process, it is estimated that mineralization becomes intense from about 700'C and is almost completed at about 800C. Therefore, it is preferable to perform baking at a temperature of 800° C. or higher. Furthermore, since obtaining a temperature higher than 3000"C requires expensive equipment, baking at a higher temperature than 3000"C is not practical from a cost standpoint.

The above inorganic fibers can be produced by blending the fibers themselves in uniaxial or multiaxial directions, or by plain weaving, satin weaving, mock-satin weaving, twill weaving,
There are methods of using it in various fabrics such as leno weave, spiral weave, and three-dimensional fabric, and methods of using it as chopped fiber.

The plastic in the present invention includes epoxy resin,
Polyester resin, phenolic resin, polyester resin,
Polyurethane resin, polyamide resin, polycarbonate resin, silicone resin, fluororesin, nylon 1M resin, polyphenylene sulfide, polybutylene terephthalate, ultra-high molecular weight polyethylene, polypropylene, modified polyphenylene oxide, polynarene, ABS resin,
Vinyl chloride resin, polyether/etherketone resin,
Examples include bismaleid resin and the like.

These plastic composite materials can be manufactured by methods known per se, such as (1) hand lay-up method, (2) matched metal die method, (3) play-away method, (4) filament winding method, (5)
Methods such as a hot press method, (6) an autoclave method, and (7) a continuous drawing method can be employed.

(1) According to the hand lay-up method, first the inorganic fibers are cut and laid on a mold, then the plastic containing the catalyst is applied onto it using a brush or roller, and then allowed to harden naturally.
It can be demolded and made into a composite material.

(2) According to the matched metal die method, a composite material can be obtained by pre-impregnating inorganic fibers with plastic, a hardening agent, a filler, and a thickening agent, and then forming the fibers under heat and pressure. The SMC method (Shee
t Moldiiig Compound), B M
C method (Bulk Mold Compound
d) can be selected and used.

(3) According to the play-away method, a sheet of inorganic fiber is pre-impregnated with plastic to create a pre-cured prepreg, which is wrapped around a tapered mandrel, and after curing is extracted and used as a composite material. can do. Complex hollow products are made in this way.

(4) According to the filament winding method, inorganic fibers impregnated with a thermosetting resin such as epoxy resin or unsaturated polyester resin are wound around a mandrel, and after the resin is cured, the mold is removed and made into a composite material. can do. This method includes a wet method and a dry method (method using Bripreg tape).

(5) According to the hot press method, after laminating buri preg sheets in one direction or at an arbitrary angle, they can be pressed and heated with a hot press to form a plate-shaped composite material.

(6) According to the autoclave method, Buripreg is laminated in a mold, wrapped in a special rubber, placed in a vacuum state, placed in a high-pressure cooker, and cured by heating and pressurizing to form a composite material. Suitable for complex precepts.

(7) According to the continuous pultrusion method, inorganic fibers and plastic are separated separately, fed to a molding machine, mixed before the molding mold, and passed through a heating furnace midway through the process. It can be made into a long composite material.

The tensile strength (σC) of a composite material made from inorganic fibers and a plastic matrix is expressed by the following formula.

(lc = (11 Vf+ σ MV MσC = Tensile strength of composite material σf: Tensile strength of inorganic fiber σH = Tensile strength of plastic matrix f: Volume percentage of inorganic fiber v8: Volume percentage of plastic matrix As shown in the above formula The strength of a composite material increases as the volume ratio of inorganic fibers in the composite material increases. Therefore, in order to produce a composite material with high strength, the volume ratio of inorganic fibers to be composited must be increased. However, if the volume percentage of inorganic fiber exceeds 80%, the amount of plastic matrix will be small.
Since the gaps between the inorganic fibers cannot be sufficiently filled with the plastic matrix, even if a composite material is manufactured, it will not exhibit the strength shown by the above formula. In addition, as the volume ratio of fibers is lowered, the strength of the composite material decreases as shown in 2 above, so in order to make a practical composite material, it is necessary to combine 10% or more of inorganic fibers. is necessary.

Therefore, in producing the inorganic fiber-reinforced plastic composite material of the present invention, the volume ratio of the inorganic fibers to be composited is 10 to 10.
The best effect can be obtained by setting it to 80%, more preferably 30 to 60%.

Various mechanical properties in the specification were determined according to the following measurement methods.

(a) Interlaminar shear strength A test method for determining interlaminar shear stress, 10 x 12 x 2 mm was placed on two pins (length 20 mm) with a radius of curvature of 6 φ.
A composite material in which inorganic fibers are uniaxially oriented is placed, and the tip radius of curvature is 3. The test is performed by compression using a 5 mm R indenter and a so-called three-point bending method, and the interlaminar shear stress is measured. It is expressed in shear stress (kg/mm").

(b) Tensile strength and tensile modulus in the fiber vertical direction Thickness 2m
A uniaxial fiber-reinforced composite material of
Take a 7mm test piece. The thickness of the test piece is 2 mm, and a curvature of 125 R is applied in the thickness direction of the center part, so that the thickness is approximately 1 mark. The tensile speed was 1 mm/min. It is expressed by tensile strength (kg/mm") and tensile modulus (t/mm").

(c) Fiber perpendicular bending strength and bending modulus thickness 2n
A uniaxial fiber-reinforced composite material of
．． A test piece of 7 x 8 5 + nm is taken. The thickness of the test piece is 2M, with a curvature of 125mmR in the thickness direction at the center, and the thickness is about IIl! Finish to In. The test is conducted using a three-point bending method, and is expressed in terms of bending strength (kg/mm") and bending modulus (t/mm").

Interlaminar shear strength, tensile strength in the direction perpendicular to the fibers, and bending strength in the direction perpendicular to the fibers are indicators of the strength of the bond between the matrix and the fibers.

(d) Tensile strength and tensile modulus A uniaxial fiber-reinforced composite material with a thickness of 2 degrees is manufactured, and the axial direction of the test piece is 12 times perpendicular to the fiber arrangement direction.
．． Take a 7x85mm test piece. The thickness of the test piece is 2
Add a curvature of 125mmR in the thickness direction at the center using ribs, and finish to a thickness of about 1mm. The tensile strength was measured at a tensile speed of 1 mm/min. It is expressed by tensile strength (kg/mad") and tensile modulus (t/mm").

(e) Bending strength and flexural modulus A uniaxial fiber-reinforced composite material with a thickness of 2 [lm] was produced, and the axial direction of the test piece was set perpendicular to the fiber arrangement direction. Take a 7 x 8 5 mm test piece.

The thickness of the test piece is 2IIIl1, and the thickness of the test piece is 1 in the thickness direction at the center.
Add a 25mm RO curvature and finish to a thickness of approximately III1. The test was conducted using a three-point bending method, and the bending strength (kg/m"
) and flexural modulus (t/mm").

(f) Bending impact value Charpy test method using 3-point bending (JIS K71i
i) The bending impact value was measured. Bending impact value (kg
- cm/cm”).

The bending impact value is an index that indicates the strength of the bond between the plastic and the fibers, and is particularly an index that indicates the strength of resistance to instantaneous impact. If the bending impact value is low, the resin and fibers are likely to separate and breakage due to instantaneous impact is likely to occur.

The plastic composite material of the present invention has: a) interlaminar shear strength of 8.5 kg/mm2 or more; b
) The tensile strength in the fiber vertical direction is 6 kg/elm" or more, C) The bending strength in the fiber vertical direction is 8 kg/elm" or more, and d) The bending impact value is 200 kg-cm/cm" or more. be.

(Effects of the Invention) In the inorganic fiber reinforced plastic composite material of the present invention, since the i1ftN fibers used in the present invention have excellent wettability to plastics, there is no need to particularly surface treat the inorganic fibers, and furthermore, the inorganic fibers do not need to be surface treated Excellent bond strength between. Therefore, the present invention provides a composite material that is excellent in interlaminar shear strength, tensile strength and bending strength in the direction perpendicular to the fibers, and bending impact value.

On the other hand, since the inorganic fiber in the present invention contains carbon in a crystalline alignment state, it has higher elasticity than an amorphous inorganic fiber. Therefore, the inorganic fiber-reinforced plastic composite material of the present invention exhibits excellent values in tensile modulus and flexural modulus.

Furthermore, the inorganic fibers of the present invention can be manufactured at a lower cost than conventional silicon carbide fibers because the use of expensive organic silicon compounds is reduced.

As described above, the inorganic fibers used in the present invention have excellent reinforcing efficiency in plastic composite materials, and the resulting plastic composite materials have excellent various mechanical properties and are suitable for long-term use in harsh environments. It is something that can be endured. Therefore, it can be used in various fields where conventional inorganic fiber reinforced plastic composite materials could not be used satisfactorily. For example, materials for Hewei textiles, materials for Hekai chemicals, materials for machinery industry, materials for construction machinery, materials for ocean development (including space), materials for automobiles, materials for food, electrical materials, sporting goods, and audio equipment. This is a field that requires excellent mechanical properties in various fields such as materials.

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

Reference example 1 (method for producing organosilicon polymer) 51. 2.5 liters of anhydrous xylene and 400 g of sodium were placed in a three-necked flask, heated to the boiling point of xylene under a nitrogen gas stream, and dimethyldichlorosilane lffi was added dropwise over 1 hour. After the 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 boridimethylsilane was charged into a 3-liter three-necked flask equipped with a gas inlet tube, a stirrer, a condenser, and a distillation tube, and heated at 420°C under a nitrogen flow of 50 d/min while stirring.
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 vapor pressure osmosis.

When the infrared absorption spectrum of this substance was measured, it was found that 6
Absorption of Si-CH, at 50 to 900 cm-' and 1250 cm-', Si-H at 2100C1+1-'
absorption, around 1020 cm-' and 1 3 5 5 cm-
Si CHZ-St absorption was observed at 2900 cm-' and 2950 cm-', and when the far-infrared absorption spectrum of this material was measured, 38
Since absorption of St-Si is observed at 0 cm-',
The obtained liquid substance mainly has (S i CHz )
It turned out to be an organosilicon polymer consisting of bond units and (Si-Si) bond units and having hydrogen atoms and methyl groups in silicon side chains.

From 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 CHz) bond units to the total number of (Si-Si) bond units is approximately 1:3. This was confirmed.

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 (Si CH2) bond units and (Si-St) bond units, and contains hydrogen atoms and hydrogen atoms in the 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-Si) bond units is approximately 7:1. This was confirmed.

Reference Example 2 (Production method of inorganic fiber I) Fluid catalytic cracking and rectification of petroleum fractions with a higher boiling point than light oil in the presence of a silica/alumina cracking catalyst at a temperature of 500°C. A residue was obtained from the bottom. 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.

130 g of the above FCC slurry oil was heated at 450"C for 1 hour under a nitrogen gas flow of if/min, and after distilling off the distillate at the same temperature, the residue was filtered while hot at 200°C. The infusible part is removed, and the light matter removal pitch is 5.
7g was obtained.

This light fraction removed pitch contained 60% xylene insoluble matter.

25 g of the organosilicon polymer obtained in Reference Example 1 and 20 mfl of xylene were added to 57 g of this light fraction removed pitch, the temperature was raised while stirring, the xylene was distilled off, and the mixture was reacted at 400°C for 6 hours to produce 46 g of random copolymer. Obtained union.

As a result of infrared absorption spectrum measurement, this reaction compound was found to be the Si-H bond (IR: 210
0CII1-') and the formation of new Si-C (benzene ring carbon) bonds (IR: 1135 cm-'), some of the silicon atoms in the organosilicon polymer are polycyclic aromatic. It turned out to be a copolymer with a part directly bonded to the ring.

Further, this copolymer did not contain any xylene-insoluble parts, had a weight average molecular weight of 1400, and a melting point of 265°C.

This was heated and melted at 300'C and left to stand, to obtain 40 g of the remainder from which light parts were removed due to the difference in specific gravity. This is called a polymer (a).

In parallel with this, 400 g of FCC slurry oil was heated to 450"C under a nitrogen gas stream, and after distilling off the distillate at the same temperature, the residue was filtered while hot at 200°C, and the residual fraction at the same temperature was removed. Pitch 180g to remove fused parts and remove light components
I got it. 180 g of the resulting pitch from which light components had been removed was subjected to condensation polymerization at 400° C. for 8 hours under a nitrogen stream to remove light components produced by reaction, to obtain 80.3 g of heat-treated pitch.

This heat-treated pitch has a melting point of 310°C and a xylene insoluble content of 9.
It was a mesophase polycyclic aromatic compound (2) containing 7% and 20% of quinoline insoluble matter, and an optical anisotropy of 95% when observed with a polarized light microscope on the polished surface.

This was heated and melted at 350° C. and left to stand again, and light components were separated and removed based on the difference in specific gravity to obtain 80 g of the remainder.

This and 30 g of polymer (a) were mixed and melted and heated at 350"C for one hour in a nitrogen atmosphere to obtain a silicon-containing polycyclic aromatic polymer in a uniform state. This polymer had a melting point of At 290°C, it contained 70% xylene insoluble matter.

Using the above-mentioned high molecular weight material as a raw material for spinning, melt spinning was performed at 360"C using a metal nozzle with a nozzle diameter of 0.15mm, and the resulting spun yarn was heated in air at 300°COO"C.
The inorganic fiber I with a diameter of 10 μm was obtained.

This inorganic fiber (1) had a tensile strength of 300 kg/am'' and a tensile modulus of 30 t/mmz, and was clearly of a radial structure from observation of the fracture surface.

Reference Example 3 (Production method of inorganic fiber ■) 200g of FCC slurry oil obtained in Reference Example 2
0.0 at 450°C under nitrogen gas flow for 17 minutes. After heating for 5 hours and distilling off the distillate at the same temperature, the residue was filtered while hot at 200''C to remove the infusible portion at the same temperature to obtain 57 g of light fraction removed pitch.

This light-removed pitch contained 25% xylene insolubles.

To 57 g of this light fraction removed pitch, 25 g of the organosilicon polymer obtained in Reference Example 1 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 to produce 51 g of random copolymer. Polymer (1) was obtained.

As a result of infrared absorption spectrum measurement, this reaction compound was found to be the Si-H bond (IR: 210
0cm-') and the new St-C<carbon of benzene ring) bond (IR: 1135cm-') were observed, indicating that some of the silicon atoms in the organosilicon polymer are polycyclic aromatic. It turned out to be a copolymer with a part directly bonded to the ring.

In addition, this copolymer does not contain xylene-insoluble parts, has a weight average molecular weight of 1400, a melting point of 265°C, and a softening point of 31°C.
It was 0°C.

On the other hand, 180 g of the pitch from which light components were removed was heated at 400"C for 8 hours under a nitrogen stream while removing light components that were trapped in the reaction.
Time-condensation 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.
, contains 77% xylene insoluble matter and 3 l% quinoline insoluble matter, and when observing the polished surface with a polarizing microscope, 90 g of this mesophase polycyclic aromatic compound (2) and 6.4 g of the random copolymer (1) were used. were mixed and heated under nitrogen atmosphere for 38 hours.
The mixture was melted and heated at 0°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, a softening point of 315°C,
It contained 70% xylene insoluble matter.

The above high molecular weight material is used as the raw material for spinning, and the nozzle diameter is 0.15 m.
Melt spinning was performed at 360° C. using a metal nozzle of 1.0 m, and the obtained spun yarn was oxidized and made infusible at 300° C. in air, and then burned at 1300° C. in an argon atmosphere.
Inorganic fibers (■) with a diameter of 8 μm were obtained.

This inorganic fiber ■ has a tensile strength of 320 kg/1111
It had a tensile modulus of elasticity of 11" and a tensile modulus of 26 t/mad", and from observation of the fracture surface, it was clearly a radial structure.

This inorganic fiber (1) was pulverized, then melted with alkali and treated with hydrochloric acid to form an aqueous solution, and then subjected to high frequency plasma emission spectrometry analysis. As a result, the silicon content in this inorganic fiber (1) was found to be 0.95%.

Reference Example 4 (Production method of inorganic fiber ■) The same procedure as Reference Example 3 was carried out except that 97 g of mesophase polycyclic aromatic compound (2) and 3 g of random copolymer (1) were mixed and melted and heated at 400°C. A silicon-containing polycyclic aromatic polymer was obtained. This polymer has a melting point of 372°C,
It had a softening point of 319°C and contained 71% xylene insoluble matter.

The above-mentioned high molecular weight material is used as a raw material for spinning, and the nozzle diameter is 0. 15
Melt spinning was performed at 360"C using a metal nozzle of 1III1, and the obtained spun yarn was oxidized and made infusible at 300°C in air, and further calcined at 2000°C in an argon atmosphere. Inorganic fibers (■) with a diameter of 7.3 μm were obtained.

This inorganic fiber ■ has a tensile strength of 325kg/1111
11'' and a tensile modulus of 41 t/mm''.

This inorganic fiber (1) was pulverized, then melted with alkali and treated with hydrochloric acid to form an aqueous solution, and then subjected to high frequency plasma emission spectrometry analysis. As a result, the silicon content in this inorganic fiber (1) was found to be 0.47%.

Example l Amide curing agent (XB2879B manufactured by Ciba Geigy) 20
After uniformly mixing the mixture, the mixture was dissolved in a mixed solvent of methyl cellosolve and acetone at a weight ratio of 1:1 to prepare a 28% solution of the above mixture.

After impregnating the inorganic fiber I obtained in Reference Example 2 with the above solution, it was pulled in one direction using a drum wine gourd and heated at 100"C for 14 minutes in a heat circulation oven to obtain a semi-cured fiber. An inorganic fiber prepreg that was aligned in one direction was prepared.The fiber content of this prepreg was 60% by volume, and the thickness was 0.15 mm.

Layer the 10 sheets of Buri Preg above with the fiber direction aligned, and
A unidirectionally reinforced epoxy resin composite material with a size of 250 mm x 250 (1) was obtained by pressing at 70'C and 7 kg/C1a for 4 hours.

Width 1 from the above composite material 2. 7 rIa, length 85m
m, cut out a sample for bending strength measurement with a thickness of 2M,
Three-point bending test with span/width = 32 at test speed 2ITII
It was performed at Il/min. The mechanical properties of the above composite material are shown below.

Tensile strength (kg/ffR2) 1
6 0 tensile modulus (mm/mm”)
1 8 bending strength (kg/kaku”)
220 Flexural modulus (1/Kaku2) 17
Fiber vertical tensile strength (kg/mm”) 6.3
Fiber perpendicular tensile modulus (t/mm”) 5.
1 fiber vertical bending strength (kg/on”) 8
．． 9 Fiber vertical bending modulus (t/mm2) 5.
0 interlayer shear strength (kg/IIIm”)
8.6 Bending impact value (kg-cm/ffI1”)
2 4 0 Comparative Example 1 Instead of the inorganic fiber used in the present invention, tensile strength 2 8
0kg/mm", tensile modulus 55t, /an
A carbon fiber-reinforced epoxy composite material was produced in the same manner as in Example 1, except that high-modulus pitch-based carbon fibers with a fiber diameter of 10 μm were used. The fiber content of this composite material was 60% by volume.
The mechanical properties of the obtained composite material are shown below.

Tensile strength (kg/Kaku”) 150)
Tensile modulus (1/ga) 28 Bending strength (kg/mm2) 1 0
0 Bending elastic modulus (1/Kaku2) l2 Fiber vertical tensile strength (kg/mm”) 3.0 Fiber vertical tensile modulus (t/mm2) 0.5 Fiber vertical bending strength t;= (kg/ mm”) 3.
5-fiber vertical bending modulus (t/ffIII1”)
0.5 interlayer shear strength (kg/cm”)
7.5 Bending impact value (kg-1/W”)
70 Comparative Example 2 Instead of inorganic fiber I, tensile strength 300 kg/mmχ,
A carbon fiber-reinforced epoxy composite material was produced in the same manner as in Example 1, except that surface-treated polyacrylonitrile-based high-strength carbon fibers having a tensile modulus of elasticity of 21 t/mII12 and a fiber diameter of 1.5 a were used. The fiber content of this composite material is 6
The mechanical properties of the resulting composite material are shown below.

Tensile strength (kg/Kaku M 172
Tensile modulus (t/mm”) 14 Bending strength (kg/man”) 1 7 0 Bending modulus (1
/ Theory 2) 13 fiber vertical tensile strength (kg/am+") 4.5 fiber vertical tensile modulus (t/mm") 0.88m fiber vertical bending V strength (kg/mm") 6. 2 fiber Vertical bending modulus (t/m+++2) 0.8 7 interlayer shear strength (kg/kaku”) 8.1 Bending impact value (k
g-crn/rM1”) 1 5
0 Example 2 An inorganic fiber-reinforced polyester composite material with a fiber content of inorganic fibers (■) of 58% by volume was produced in the same manner as in Example 1 except that a commercially available unsaturated polyester resin was used instead of the epoxy resin as the matrix. .

The mechanical properties of the above composite material are shown below.

Tensile strength (kg/mm”) 1
5 0 tensile modulus (1/Peng2) 18
Bending strength (kg/kaku”) 21B
Flexural modulus (1/mm) 16.8 Fiber perpendicular tensile strength (kg/mm) 6.
0 fiber perpendicular tensile modulus (t/ilm”) 4.
8 fiber vertical bending strength (kg/mm”) 8
．． 7 Fiber vertical bending modulus (t/mm”) 8
．． 5 interlayer shear strength (kg/mII1”)
8.6 Bending impact value (kg-cm/mo+”)
2 3 8 Example 3 An inorganic fiber with a fiber content of 60% by volume of inorganic fiber I was prepared in the same manner as in Example 1 except that polyimide resin C (M) manufactured by Ube Industries, Ltd. was used as the matrix instead of the epoxy resin. A reinforced polyamide composite material was produced.

The mechanical properties of the manufactured composite material are shown below.

Tensile strength (kg/mm) 151 Tensile modulus (t/mm") 18 Bending strength (kg/instant") 217 Flexural modulus (t/mm2) 16.6 Tensile strength in the vertical direction of the fiber (kg/mn+") 6 .1 Fiber vertical tensile modulus (t/mmz) 4.9 Fiber vertical bending strength (kg/mm”) 8.8
Fiber vertical bending modulus (t/['') 5.0 Interlaminar shear strength (kg/mm2)' 8.
6 Bending impact value (kg-cn+/mm”)
2 3 B Example 4 Bisphenol A type epoxy resin (X manufactured by Ciba Geigy)
82879A) and dicyandiamide curing agent (
After uniformly mixing 20 parts of X82879B (manufactured by Jiba 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 fibers obtained in Reference Example 3 were impregnated with the above solution, they were pulled in one direction using a drum winder and heated in a heat circulation oven at 100'C for 14 minutes to form a semi-cured unidirectional fiber. Inorganic fiber prepregs were prepared. The fiber content of this Bripreg was 60% by volume and the thickness was 0.15 mm.

Layer the 10 sheets of prepreg above with the fiber directions aligned, and
A unidirectionally reinforced epoxy resin composite material with a size of 250 marks x 250 mm was obtained by pressing at 70'C and 7 kg/ci for 4 hours.

Width 1 from the above composite material 2. 7mm, length 85mm
A sample with a thickness of 2 mm for bending strength measurement was cut out, and a three-point bending test was performed at a speed of 2 nm/width = 32.
I went in minutes. The a-mechanical properties of the above composite material are shown below.

Tensile strength (kg/mm”) 1
7 0 tensile modulus (1/Shizu2) l6
Bending strength (kg/mm”) 2
3 2 Flexural modulus (t/mm”)
16 Fiber vertical tensile strength (kg/mm”) 6
．． 7 Fiber perpendicular tensile modulus (t/mm”) 5.
1 fiber vertical bending strength (kg/mm”) 9
．． 2-fiber vertical bending modulus (t/mm”) 5.
0 interlayer shear strength (}Cg/11+11”)
9.0 bending force wi value (kg-cm/mm”)
2 5 5 Example 5 A fiber with a fiber content of 58% by volume was prepared in the same manner as in Example 4, except that inorganic fiber ■ was used instead of inorganic fiber ■, and commercially available unsaturated polyester resin was used instead of epoxy resin. An inorganic fiber reinforced polyester composite material was manufactured. The mechanical properties of the above composite material are shown below.

Tensile strength (kg/2) 161 Tensile modulus (t/mm") 21 Bending strength (kg/mm") 234 Bending modulus (t/1111") 20.5 Tensile strength in the fiber vertical direction (kg/IIIm") ) 6.2 Fiber vertical tensile modulus (t,/m") 5.5 Fiber vertical bending strength (kg/mm") 9. 1
Fiber vertical bending modulus (t/mm") 8.7 Interlaminar shear strength (kg/mm") 9.0 Bending impact value (kg-Cm/an") 2 5
1 Example 6 Polyimide resin [Ube Industries Co., Ltd.] was used instead of epoxy resin.
An inorganic fiber-reinforced polyimide composite material having a fiber content of 60% by volume of the inorganic fiber (1) was produced in the same manner as in Example 4, except that the inorganic fiber (2) was used.

The mechanical properties of the manufactured composite material are shown below.

Claims (1)

[Scope of Claims] An inorganic fiber-reinforced plastic composite material comprising inorganic fiber as a reinforcing material and plastic as a matrix, comprising: a) the inorganic fiber is an inorganic fiber obtained from a silicon-containing polycyclic aromatic polymer; The constituent components are: i) at least one 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 in a mesophase state constituting the polymer; carbonaceous material exhibiting a kind of crystalline alignment; ii) crystalline carbon in a non-oriented state derived from an optically isotropic polycyclic aromatic compound containing an organic solvent-insoluble component constituting the polymer; crystalline carbon, and iii) an amorphous phase consisting essentially of Si, C and O and/or crystalline ultrafine particles consisting essentially of β-SiC with a particle size of 500 Å or less and amorphous SiO_x(0 <x≦2), and the proportions of the constituent elements are Si; 30 to 70% by weight; C; 20% by weight.
~60% by weight and O; 0.5-10% by weight Si-
An inorganic fiber-reinforced plastic composite material, characterized in that it is a high-strength, high-modulus inorganic fiber made of a C-O substance, and b) the content of the inorganic fiber in the composite material is 10 to 80% by volume.