JP2597186B2 - Imide resin matrix composite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention uses a specific heat-resistant inorganic fiber as a reinforcing material,
The present invention relates to a composite material having a cured layer of an imide resin matrix prepreg having an imide resin composition containing a terminal-modified imide oligomer as a main component as a matrix.

The imide resin matrix prepreg of the present invention can be cured at a relatively low temperature and in a short period of time, and can be easily laminated because of good tackiness and drapability. Excellent workability.

And the composite material having a cured layer obtained by curing the prepreg in the present invention by heating or the like has mechanical strength, elastic modulus,
It is extremely excellent in heat resistance and can be used for a wide range of applications such as aircraft and space industry equipment.

[Description of the Prior Art] Carbon fiber reinforced resin composite material (CFRP) is widely used in sports, leisure, general industrial and aerospace industries due to its high specific strength and specific elastic modulus.

However, CFRP has particularly disadvantageous properties such as insufficient compression and bending properties compared to its excellent tensile strength properties, and furthermore has serious drawbacks such as easy oxidation in air at high temperatures. It does not have sufficient suitability as a structural material in fields where properties are required.

As one material for solving this CFRP problem,
There is a "plastic composite material reinforced with inorganic fibers" described in JP-A-62-57427. In particular, a composite material using a polyimide resin as a plastic matrix is considered to be suitable as a heat-resistant structural material.

However, polyimides used as a matrix for composite materials which are generally known at present have many problems particularly in workability such as tackiness and curing temperature, and have poor properties (heat resistance, strength, etc.). In most cases, the workability was not balanced.

Recently, the present applicant has disclosed an invention relating to a terminal-modified imide oligomer capable of solving the above-mentioned problem.
We filed applications as Japanese Patent Application Nos. 62-297668 and 63-73194.

However, when the terminal-modified imide oligomer of the invention according to the above-mentioned application is used as a matrix resin such as a prepreg, it has excellent tackiness and blade properties, but has a long gelation time, or after heat curing. However, uncrosslinked terminal groups are liable to remain, and a cured product having sufficient strength may not be obtained, which is not always satisfactory.

[Problems to be solved by the invention]

An object of the present invention is to provide an imide containing a reinforcing fiber having good workability and workability, and capable of producing a composite material having excellent mechanical properties and heat resistance required for a structural material. An object of the present invention is to provide a composite material having a cured layer of a resin-based matrix prepreg.

[Means for solving the problem]

The invention of this application uses silicon Si, titanium
Metal M which is Ti or zirconium Zr, carbon C and oxygen O
And a reaction of 2,3,3 ', 4'-biphenyltetracarboxylic acids, an aromatic diamine compound and a monoamine compound having a carbon-carbon triple bond in a solvent as a matrix. Which has an unsaturated terminal group at the oligomer terminal and an imide bond inside the oligomer, and has a logarithmic viscosity at 30 ° C. (concentration: 0.5 g / 100 m 1 -solvent, solvent: N-methyl-2-pyrrolidone) Is a composite material having a thermosetting layer of an imide resin matrix prepreg containing an imide resin composition mainly composed of a terminal-modified imide oligomer imide having 0.1-1.

The inorganic fibers used in the prepreg of the present invention include, for example, i) an amorphous substance substantially consisting of M, C and O which are Si, Ti or Zr; ii) substantially β-SiC, MC, β -Solid solution of SiC and MC and
Crystalline fine particles of MC _1-X having a particle size of 500 ° or less, and an aggregate of amorphous SiO ₂ and MO ₂ , or iii) an aggregate of the above i) amorphous substance and the above ii) It is preferably a Si-MCO fiber composed of a substance mixed with the body (x is 0 <x <1). For example, Japanese Patent Publication No. 60-1405, Japanese Patent Publication No. 58-5286,
It can be produced according to the methods described in JP-B-60-20485 and JP-B-59-44403.

The ratio of each element in the Si-MCO fiber is Si: 3
It is preferably 0 to 60% by weight, Ti or Zr: 0.5 to 35% by weight, particularly preferably 1 to 10% by weight, C: 25 to 40% by weight, and O: 0.01 to 30% by weight. As the Si-MCO fiber, Tyranno fiber (registered trademark) manufactured and sold by Ube Industries, Ltd. is suitable.

The Si-MCO fibers used in the present invention are:
Those that have been bundled and / or treated with a known heat-resistant sizing agent and / or surface treatment agent are desirable, but not necessary.

As the sizing agent or the surface treatment agent, a silane coupling agent is most suitable, and those described in the application specification of Japanese Patent Application No. 1-328030 can be mentioned as a typical example.

Examples of the imide resin composition used in the present invention include: i) biphenyltetracarboxylic acids, an aromatic diamine compound, and a carbon-carbon triple bond, as described in the specification of Japanese Patent Application No. 63-213732. Which has an unsaturated terminal group at the oligomer terminal and an imide bond inside the oligomer, and has a logarithmic viscosity at 30 ° C. of 0.1 to 1, preferably 0.2 to 1. 100 parts by weight of a terminal-modified imide oligomer having a relatively high molecular weight of about 0.8, particularly preferably about 0.03 to 0.7, and ii) a biphenyltetracarboxylic acid and a monoamine compound having a carbon-carbon triple bond in a solvent. In an unsaturated imide compound having an unsaturated terminal group at the terminal and an imide bond at the end of the compound. Parts, preferably may be mentioned the imide resin composition containing 1 to 10 parts by weight Preferably, only the terminal-modified imide oligomer may be a imide resin contained primarily as the resin component.

The terminal-modified imide oligomer has a melting point of 100
It is preferably 300 to 300 ° C., preferably 150 to 270 ° C., and is preferably a terminal-modified imide oligomer which is excellent in solubility in an organic solvent and is solid (powder) at ordinary temperature.

The biphenyltetracarboxylic acids are 2,3,3 ',
4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (a-BPDA), or an acid derivative such as a lower alcohol ester or a salt of the acid compound, In particular, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride is most suitable.

The 2,3,3 ', 4'-biphenyltetracarboxylic acids are partially (for example, 30 mol% or less, particularly 20 mol% or less, and further 10 mol% or less), and other aromatic tetracarboxylic acids, for example, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA), pyromellitic dianhydride (PMDA), 2,2-bis (3', 4'-dicarboxyphenyl) propane Anhydride, bis (3,4-dicaroxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) thioether dianhydride, bis ( It may be substituted with 3,4-dicarboxyphenyl) phosphine dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, or the like.

Examples of the aromatic diamine compound include: [A] a diamine compound having one aromatic ring; i) a phenylenediamine diamine compound; ii) a xylylene diamine compound; iii) a trialkylbenzene diamine compound; Diamine compound i) benzidine diamine compound ii) diphenyl ether diamine compound iii) diphenyl thioether diamine compound iv) benzophenone diamine compound v) diphenyl sulfine diamine compound vi) diphenyl sulfide diamine compound vii) diphenyl sulfone diamine compound viii) Diphenylalkane diamine compound [C] Diamine compound having three aromatic rings i) Bis (phenoxy) benzene diamine compound [D] Diamine compound having four aromatic rings ) Bis [(phenoxy) phenyl] propane based diamine compound ii) bis (phenoxy) diphenyl sulfone diamine compounds can be exemplified, can be used as they alone or as a mixture.

As the aromatic diamine compound, in particular, 4,4 '
Diamino diphenyl ethers (DADE), 3,4'-diamino diphenyl ether, diphenyl ether diamine compounds such as 3,3'-diamino diphenyl ether,
3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminenodiphenylmethane, bis (2,6-diethyl-4-aminophenyl) methane, bis (2-ethyl-6-methyl- 4-aminophenyl) methane, 2,2-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2-
Bis (3-chloro-4-aminophenyl) propane, 2,
Diphenylalkane based diamine compounds such as 2-bis (4-amino-3-hydroxyphenyl) hexafluoropropane, 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,3-bis (3- Aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene (T
Bis- (phenoxy) benzene-based diamine compounds such as PE-Q) and 1,4-bis (3-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), 2 , 2-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane (BAFP)
Bis [4- (phenoxy) phenyl] propane-based diamine compound, 4,4'-bis (4-aminophenoxy) diphenylsulfone, bis [4- (4-aminophenoxy) phenyl] sulfone (4-BAPS), Screw [4-
(3-Aminophenoxy) phenyl] sulfone (3-BA
Preferred examples include bis (phenoxy) diphenylsulfone-based diamine compounds such as PS).

Further, as a diamine component for producing the terminal-modified imide oligomer used in the present invention, a polymer diamine such as α, ω-polysiloxane diamine, polyoxypropylene diamine, polyethylene glycol dianiline, etc. Some alternatives can be used.

The monoamine compound having a carbon-carbon triple bond includes an unsaturated group (crosslinking group) composed of a carbon-carbon triple bond (acetylene group) and a monoamino group (primary amino group).
And a reactive unsaturated monoamine compound capable of reacting with a pair of adjacent carboxyl groups to form an imide bond.

Examples of the monoamine compound having a carbon-carbon triple bond include: (a) propargylamine (PA), 3-aminobutyne, 4-aminobutyne, 5-aminopentin, 6-aminohexyne, 7-aminoheptin, 4-amino-3- Preferred are aliphatic monoamino compounds such as methylbutyne and 4-aminopentin, and (b) aromatic monoamino compounds such as (b) 3-aminophenylacetylene and 4-aminophenylacetylene. A monoamine compound having a carbon triple bond may be used alone, or a plurality of such monoamino compounds may be used in combination.

Examples of the organic solvent used for producing the terminal-modified imide oligomer include, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-
Amide solvents such as 2-pyrrolidone (NMP) and N-methylcaprolactam; solvents containing sulfur atoms such as dimethyl sulfoxide, hexamethylphosphoramide, dimethyl sulfone, tetramethylene sulfone, and dimethyltetramethylene sulfone; cresol; phenol; And other solvents such as phenolic solvents, pyridine, ethylene glycol, and tetramethylurea.

As a method for producing the terminal-modified imide oligomer used in the present invention, for example, 2,3,3 ', 4'-
Biphenyltetracarboxylic acids (especially, these acid dianhydrides), an aromatic diamine compound, and a monoamine compound having a carbon-carbon triple bond are equivalent to acid anhydride groups (or adjacent dicarboxylic acid groups) of all components. Are used in a proportion such that the total amount of the amino groups of all the components and the total amount of the equivalents of the amino groups of all the components are substantially equivalent.
The reaction is carried out at a reaction temperature of 0 ° C. or lower, particularly 80 ° C. or lower to produce “oligomer having an amide-acid bond”, and then the amide-acid oligomer (also referred to as amic acid oligomer) is heated to about 0 to 140 ° C. Dehydration and imide cyclization by a method of adding an imidizing agent at a low temperature or a method of heating to a high temperature of 140 to 250 ° C. to form an imide oligomer having an addition-polymerizable unsaturated group at a terminal. Examples of the production method include:

The terminal-modified imide oligomer produced as described above may be isolated as a powdery product by pouring the reaction solution into water or the like.

In the present invention, unsaturated imide compounds that can be used as a resin component together with the above-mentioned terminal-modified imide oligomer include biphenyltetracarboxylic acids and a monoamine compound having a carbon-carbon triple bond, and an acid anhydride group ( Or an unsaturated imide compound obtained by reacting in an organic solvent such that the sum of equivalents of two adjacent carboxyl groups) and the sum of equivalents of amino groups of each component become approximately equivalent. I just need.

The unsaturated imide compound is an unsaturated imide compound having an unsaturated terminal group having an addition-polymerizable triple bond such as a propargyl group at a terminal, and having at least one, particularly a plurality of imide bonds therein.

The unsaturated imide compound has a logarithmic viscosity at 30 ° C. (concentration;
0.5 g / 100 ml solvent, solvent; N-methyl-2-pyrrolidone)
However, it has a relatively low molecular weight of 0.005 to 0.09, particularly preferably about 0.01 to 0.08, and more preferably about 0.01 to 0.05, and has excellent solubility in organic solvents. ) Is preferable.

"Biphenyltetracarboxylic acids", "monoamine compound having a carbon-carbon triple bond", and "organic solvent for reaction" used in the production of the unsaturated imide compound are used in the production of the above-mentioned terminal-modified imide oligomer. Exactly the same as "biphenyltetracarboxylic acids", "monoamine compounds having a carbon-carbon triple bond", and "organic solvents for reaction", which have been specifically exemplified, can be used.

The reaction method and reaction conditions in the production of the unsaturated imide compound may be almost the same as those used in the production of the above-mentioned terminal-modified imide oligomer.

In the present invention, if the content of the unsaturated imide compound in the imide resin composition is too large relative to the terminal-modified imide oligomer, the cured product obtained from such a composition may have many large voids on its surface. , Blisters and the like are formed, and the mechanical properties of the cured product are remarkably deteriorated, which is not preferable.If the content of the unsaturated imide compound is too small, the curing takes a long time, and In some cases, the physical properties are also deteriorated, so that it may not be practical.

The imide resin composition of the terminal-modified imide oligomer and the unsaturated imide compound used in the present invention comprises: i) mechanically uniformly mixing powders of the terminal-modified imide oligomer and the unsaturated imide compound in the above-mentioned mixing ratio. Ii) The terminal-modified imide oligomer and unsaturated imide compound are uniformly dissolved in an organic solvent having a boiling point of about 100 to 250 ° C. at normal pressure in the above-mentioned mixing ratio, and then the organic solvent is removed. It can be prepared by a method or the like.

The prepreg of the present invention is generally impregnated with an imide resin solution dissolved in a molten resin or a solvent, or an inorganic fiber or an inorganic fiber woven fabric arranged on one side, or an inorganic imide resin previously impregnated with an imide resin. After winding the fiber on the drum, by heating to remove volatiles, the imide resin is prepared to have a sticky state,
It is manufactured.

When impregnating the solution of the imide resin composition described above, the reinforcing fibers may be used in the form of a strip or a bundle of yarns arranged in one direction in a plane, and further,
It may be used in the form of a nonwoven fabric or a woven fabric made of reinforcing fibers.

As a method for producing a prepreg, specifically, after impregnating the above imide resin solution with Si-MCO fibers,
The solvent is substantially evaporated off (dried) in an oven at a temperature of about 50 to 200 ° C., and the thickness is about 10 to 300 μm,
In particular, it is preferably obtained as a sheet-shaped prepreg having a size of 50 to 200 μm.

The imide resin solution has a total concentration of the terminal-modified imide oligomer and the unsaturated imide compound of about 20 to 60% by weight, particularly 30 to 50% by weight, and has a solution viscosity at 25 ° C. (Brookfield-type rotational viscometer). The polymer concentration (20% by weight), which is the rotational viscosity measured in the above, is 0.1 to 200 poise, particularly preferably 0.5 to 100 poise, and more preferably 5 to 80 poise.
It is preferably about poise from the viewpoint of the operation of impregnating the reinforcing inorganic fibers and the like.

The amount of the residual solvent in the prepreg (% by weight in the prepreg) is 1 to 20% by weight, particularly preferably 5 to 15%.
Wt%, more preferably in the range of 7 to 12 wt%, such as workability such as tackiness and drape,
Fluidity of the imide resin during molding to form a composite,
It is suitable from the viewpoint of the void content ratio in the cured molded article (composite material) and the like.

In the prepreg of the present invention, the content ratio of the imide resin is 100 times the value obtained by the ratio [ _Wr / ( _Wr + _Wf )]. W _r and W _f indicates the weight of the imide resin composition component and the inorganic fibers present in each prepreg] is
It is preferably in the range of 20 to 50% by weight, especially 25 to 45% by weight.

The prepreg prepared by impregnating the reinforcing fibers with the imide resin composition as described above has a plurality of layers,
Vacuum backing / autoclave hardening method, hot press molding method, laminating by a known method such as sheet winding method, and the laminate is heated to 200 ° C. to 300 ° C. under a pressure of about 3 to 15 kg / cm ^2. By heating and molding, a “fiber-reinforced imide resin composite material” in which the imide resin composition is cured can be manufactured.

If necessary, the composite material produced as described above can be further post-cured in a heating oven.

The volume fiber content of the composite material comprising the cured product of the fiber-reinforced imide resin is about 30 to 80% by volume, particularly 40 to 70% by volume.
It is preferred that it is about.

The composite material of the present invention has excellent heat resistance because the cured imide resin composition has a thermal decomposition onset temperature of 400 ° C. or higher and a secondary transition temperature (Tg) of 250 ° C. or higher. In addition, it has excellent mechanical strength because it is reinforced with Si-MCO fibers.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

First, methods for measuring various physical properties shown in Examples and the like are described below.

(A) Prepreg curing time (gel time) JIS K7
According to the specification of 071, the prepreg formed from the composition is pressed out to flow out the resin, and the resin is heated.
The gel time was determined from the change in threadiness.

(B) Tackiness of prepreg A prepreg (length; 7.6 cm and width; 7.6 cm) is laminated and pasted on an iron plate with a width of 10.1 cm and a length of 20.3 cm. Attach another prepreg and place the resulting laminate upright, at 23 ° C, humidity: 50% R
At H, it was left for 30 minutes and judged whether it could be maintained.
(AMS 3894) (c) Drapability of prepreg At 23 ° C, prepreg was placed on a semi-cylindrical surface (diameter: 2.54c
m) and placed on top of it under its own weight. (A
MS 3894) using (d) is the thermal decomposition characteristics DTA · TG analyzer (Co. Second Seikosha), in air, Atsushi Nobori rate; measured at 20 ° C. / min, 5 wt% decomposition temperature (T _D ). Further, the weight loss rate (ΔW) when left in the air at 700 ° C. for 5 minutes was determined.

(E) Mechanical properties Measuring machine; Instron 1185 manufactured by Instron i) Bending test: 3-point bending method ・ Span / thickness ratio; 32 ・ Crosshead speed; 2 mm / min ・ Measurement temperature; 23 ° C. ・ Measurement Humidity: 50 RH (ASTM 790) ii) Interlaminar shear strength: short beam method ・ Span / thickness ratio; 4 ・ Crosshead speed; 2 mm / min ・ Measurement temperature; 23 ° C. ・ Measurement humidity; 50 RH (ASTM D2344) (f) ) Volume fiber content (Vol%) (V _f ) The matrix of the composite material was dissolved in concentrated sulfuric acid, the weight content of the reinforcing fiber was determined, and the density of the composite material was measured and calculated. (ASTM D3171) (g) volume void content the sum of (Vol%) (V _v) volume fiber content and volume resin content calculated therefrom was calculated subtracted from 100. (ASTM D2734) Example 1 i) Preparation of terminal-modified imide oligomer (A) In a 500 ml flask, (a) 105.92 g of 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA) (B) 87.70 g of 1,3-bis (4-aminophenoxy) benzene (TPE-R) (c) 6.67 g of propargylamine (PA) and (d) 240 g of N-methyl-2-pyrrolidone (NMP) The mixture was stirred at 50 ° C. for 1 hour in a nitrogen stream to produce an amic acid oligomer, and then the reaction solution was heated to 185 ° C. and stirred at that temperature for 1 hour to form a terminal-modified imide oligomer. .

After cooling the reaction solution to room temperature (about 25 ° C.), it is poured into water to precipitate a powdery imide oligomer, and the precipitated imide oligomer is separated by filtration and washed twice with methanol at 25 ° C. After drying under reduced pressure, a powder of a terminal-modified imide oligomer (logarithmic viscosity at 25 ° C .; 0.134) was obtained.

ii) Production of unsaturated imide compound (B) In a 100 ml flask, (a) 105.92 g of 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA) (b) propargylamine (PA) ) 39.66 g and (d) 582 g of N-methyl-2-pyrrolidone (NMP) were charged and stirred at 50 ° C. for 1 hour in a nitrogen stream to produce an amic acid compound. , And stirred at that temperature for 1 hour to produce an unsaturated imide compound.

After the reaction solution was cooled to room temperature (about 25 ° C.), it was poured into water to precipitate a powdery unsaturated imide compound, and the precipitated unsaturated imide compound was separated by filtration and then separated at 25 ° C.
Was washed twice with methanol and dried under reduced pressure to obtain a powder of an unsaturated imide compound (logarithmic viscosity at 25 ° C .; 0.02).

iii) Preparation of solution of imide resin composition Terminal-modified imide oligomer (powder) (A) (166 g) and unsaturated imide compound (B) 9.
27 g was dissolved in N, N-dimethylacetamide (DMAc) to obtain an imide resin composition solution (25%) having a total concentration of the terminal-modified imide oligomer (A) and the unsaturated imide compound (B) of 30% by weight. ° C solution viscosity; 2 poise).

iv) Production of Inorganic Fiber Reinforced Prepreg Next, the terminal-modified imide oligomer solution prepared as described above was mixed with an amorphous Si-MCO inorganic fiber mainly at a temperature of 25 ° C. and a humidity of 50% RH. (Ube Industries, Ltd.)
(Trade name: Tyranno fiber, 1600 filaments), wound using a drum winder, aligned in one direction (UD), and dried at 180 ° C. for 1.5 hours to produce a prepreg.

In the production of the prepreg, the state in which the imide resin composition solution was impregnated into the inorganic fibers was good.

The prepreg obtained as described above has a volatile content of 8.
It was 0% by weight, the resin content was 27.0% by weight, and the gel time was 25 minutes. And the tackiness and doping property of the prepreg were extremely good.

Example 2 An imide resin composition solution was prepared and used in the same manner as in Example 1 except that the amount of the unsaturated imide compound used in the preparation of the imide resin composition solution was changed to 18.2 g. A prepreg was produced in the same manner as in Example 1.

The resulting prepreg had a gel time of 17 minutes. Further, the tackiness and doping properties of the prepreg were extremely good.

Example 3 An imide resin composition solution was prepared and used in the same manner as in Example 1 except that the amount of the unsaturated imide compound used in preparing the imide resin composition solution was changed to 27.3 g. A prepreg was produced in the same manner as in Example 1.

The resulting prepreg had a gel time of 16 minutes. Further, the tackiness and doping properties of the prepreg were extremely good.

Example 4 An imide resin composition solution was prepared in the same manner as in Example 1 except that no unsaturated imide compound was used in the preparation of the imide resin composition solution. A prepreg was produced in the same manner.

The resulting prepreg had a gel time of 35 minutes.

Further, the tackiness and doping properties of the prepreg were extremely good.

Example 5 Production of Composite Material (Cured Laminate) The prepreg (thickness: 260 μm) obtained in Example 1 was
Cut into a rectangle having a length of 260 mm and a width of 90 mm, stack eight sheets in the same direction (0 ° direction) and press-bond, and heat the laminate to 180 ° C. in an autoclave and hold at that temperature for 2 hours. Then, the temperature was further raised to 250 ° C. and maintained at that temperature for 4 hours. Finally, after cooling to 80 ° C., the pressure was released to produce a laminated composite material molded article. In the molding of the composite material described above, the maximum value of the molding pressure is 8.
It was 5 kg / cm ² . The inside of the bag was kept under reduced pressure (5 mmHg or less) until the inside of the autoclave can reached 250 ° C.

Further, the molded article of the composite material molded as described above was heated at 300 ° C. for 2 hours to perform post cure.

From the obtained molded product (composite material), a bending test piece (length in the fiber direction; 85 mm, width; 12.7 mm) and a test piece for interlayer shearing (length in the fiber direction; 28 mm, width; 12.7 mm) I cut it out.

Using these test pieces, pyrolysis properties, bending strength,
The flexural modulus, interlaminar shear strength, volume fiber content, and volume void content were measured, and the results are shown in Table 1.

In addition, the composite material molded as described above was
After heating at 0 ° C. for 5 minutes, the surface was observed with a scanning electron microscope (SEM). As a result, slight decomposition of the imide resin composition as the matrix was observed, but no damage to the inorganic fibers was observed. Was.

Example 6 A composite material was produced in the same manner as in Example 5, except that the prepreg obtained in Example 4 was used.

The obtained composite was subjected to the same physical property tests as in Example 5, and the results are shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated, except that the carbon fiber (Vesfight HTA, 3000 filament, manufactured by Toho Rayon Co., Ltd.) was used instead of the Tyranno fiber.
Prepreg was created.

A composite material was formed in the same manner as in Example 5 except that the prepreg was used. Table 1 shows the physical properties of the composite material.

The composite material produced as described above was heated in the same manner as in Example 5, and the surface thereof was observed by SEM. As a result, remarkable thermal decomposition of the carbon fibers was observed together with the imide resin composition.

[Function and effect of the present invention] The imide resin matrix prepreg of the present invention has excellent tackiness and drape properties, and as a result,
Since the prepreg is easily laminated and cured at a low temperature in a short time, the curing operation can be easily performed.

Further, the composite material produced by curing the prepreg of the present invention uses a specific inorganic fiber as a reinforcing material, and therefore has higher heat resistance and bending strength than a conventional carbon fiber reinforced composite material. It is the most excellent material as a heat-resistant structural material.

Claims (1)

(57) [Claims] An inorganic fiber consisting essentially of a metal M which is silicon Si, titanium Ti or zirconium Zr, carbon C and oxygen O as a reinforcing material, and a matrix as a matrix.
2,3,3 ', 4'-biphenyltetracarboxylic acids and an aromatic diamine compound and a monoamine compound having a carbon-carbon triple bond are obtained by reacting in a solvent,
It has an unsaturated terminal group at the oligomer end and an imide bond inside the oligomer, and has a logarithmic viscosity at 30 ° C. (concentration: 0.5
g / 100m1-solvent, solvent; N-methyl-2-pyrrolidone)
A composite material having a thermosetting layer of an imide resin matrix prepreg containing an imide resin composition mainly composed of a terminal-modified imide oligomer imide having 0.1-1.