JPS6198741A - Production of prepreg sheet - Google Patents

Abstract

PURPOSE:To produce a prepreg sheet, by impregnating a fibrous reinforcing material with a solution of a polyamic acid in an organic solvent, extracting the solvent with an extracting solvent, drying the material under heating to eliminate the remaining solvent and extracting solvent, and imidating the polyamic acid under heating. CONSTITUTION:3,3'-Diaminobenzophenone is reacted with 3,3', 4,4'-benzophe nonetetracarboxylic acid dianhydride in an organic solvent to give a polyamic acid having a repeating unit shown by the formula I (R1 and >=2 are >=2C aliphatic group or alicyclic group; Y is H, alkyl, or aryl). A solution of the polyamic acid in an organic solvent having 2-20 wt.% resin content is impreg nated into a fibrous reinforcing material, the solvent is extracted with an extracting solvent (water >=1C organic solvent having a lower boiling point than that of the solvent), the material is then dried under heating to remove the unextracted solvent and extracting solvent, the polyamic acid is imidated under heating to give a polyimide having a repeating unit shown by the formula II, to give a prepreg sheet.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing a prepreg sheet useful as a heat-resistant adhesive, a heat-resistant composite material, etc., and a laminate molded product made from the obtained prepreg sheet. The present invention relates to a manufacturing method and an adhesion method using a prepreg sheet.

[Conventional technology]

In the fields of electronics, aerospace equipment, transportation equipment, etc., there is a demand for materials with better high-temperature properties in order to improve the performance and reduce the weight of various industrial materials.

Resins such as epoxy, modified epoxy, and phenolic resins conventionally used as structural adhesives or prepregs for laminated molded bodies have a significant drawback of low heat resistance.

Furthermore, epoxy resins and the like have problems in storage stability and have the disadvantage of requiring storage at low temperatures. Polyimide resins are used as materials that have improved these drawbacks (I).

However, once the polyimide resin in the hole is completely cyclized and becomes a polyimide, its melt fluidity becomes extremely poor, making it difficult to use. On the other hand, if the solvent or polyamic acid remains, although the melt fluidity improves, voids may occur in the molded product or adhesive layer due to the residual solvent or moisture generated during cyclization of the amic acid group during processing. 3 as a polyimide resin with improved melt fluidity, which is preferable because it reduces physical properties.
A polyamic acid obtained by reacting a tetracarboxylic dianhydride such as ゜3',4,4'-benzophenonetetracarboxylic dianhydride with a diamine such as 3゜3'-diaminohensiphenone in an organic solvent. A polyimide resin obtained by heat imidization was developed by the National Aeronautics and Space Administration (NASA). (For example, U.S. Pat. No. 4.065,345 and U.S. Pat. No. 4.094.862.) However, although this polyimide resin has good properties, no processing method has been provided to fully bring out its performance. Not yet.

[Problem that the invention seeks to solve]

The present invention has been made based on the above-mentioned viewpoints, and an object of the present invention is a method for producing a material that can provide a processing method that does not impair the good properties of polyimide resin developed by NASA. The object of the present invention is to provide a method for producing a heat-resistant laminate molded article using the same, and a method for adhering the same.

(Means for Solving the Problems) The present inventors have made extensive studies to achieve the above object, and as a result, have finally arrived at the present invention.

That is, the present invention provides formula (I) [wherein R1 is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or an aromatic nucleus] Represents a divalent group selected from the group consisting of non-fused polycyclic aromatic groups and heterocyclic groups interconnected by a bridge member, R
2 is an aliphatic group having 2122 carbon atoms, a cyclic aliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-fused polycyclic aromatic group in which aromatic nuclei are interconnected by a crosslinking member. 41i1 [i represents a group selected from the group consisting of group groups and heterocyclic groups, Y
represents a group selected from the group consisting of a hydrogen atom, an alkyl group and an aryl group. ] After impregnating a fibrous reinforcing material with an organic solvent solution of a polyamic acid having a repeating unit represented by the formula, the contained solvent is extracted with an extraction solvent, and the remaining volatile matter is removed by heating and drying. is heated and imidized to essentially form the formula (
It) (In the formula, R1 and R2 are the same as R1 and R2 in formula (I).) A method for producing a prepreg sheet characterized by making it from a polyimide having a repeating unit represented by the following: A method for producing a laminate molded article, characterized in that the obtained prepreg sheets are laminated and heated to a temperature above the glass transition point of polyimide under pressure, and the prepreg sheet obtained by this method is inserted between adherends. , is an adhesion method characterized by heating polyimide to a temperature higher than its glass transition point under pressure.

In the present invention, first, polyamic acid is synthesized.

Polyamic acid can be synthesized by a known method. Generally, it is synthesized by reacting a tetracarboxylic dianhydride and a diamine compound in an organic solvent. Specifically, for example, by dissolving or suspending a diamine compound in an organic solvent and gradually adding tetracarboxylic dianhydride under a stream of dry nitrogen, or vice versa, diamine is added to a tetracarboxylic dianhydride solution. Gradually adding the compound
Synthesize from this.

As the tetracarboxylic dianhydride to be used, for example, the following are desirable.

Pyromellitic anhydride, 3.3', 4.4'-benzophenonetetracarboxylic dianhydride, 2,3°3', 4'-benzophenonetetracarboxylic dianhydride, 2.2', 3
．． 3'-benzophenonetetracarboxylic dianhydride, 4
．． 4', 5.5'.

6.6'-hexafluorobenzophenone-2゜2',
3.3'-tetracarboxylic dianhydride, 3°3', 4.
4'-biphenyltetracarboxylic dianhydride, 2+2'
+3+37-biphenyltetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride,
Bis(3,4-dicarboxyphenyl)methanihydride, bis(2゜5.6L trifluoro-3,4-dicarboxyphenyl)methanihydride, 1,1-bis(3,4
-dicarboxyphenyl)ethanihydride, 2゜2-bis(3,4-dicarboxyphenyl)brovanhydride, 2.2-bis(2,3-dicarboxyphenyl)propannihydride, bis(3,4 -dicarboxyphenyl)
Ether dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,5,rotrifluoro-3゜4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl) Sulfone dianhydride, bis(2,5,6-1lifluoro-3゜4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-
dicarboxyphenyl)-phenylphosphonate(-dianhydride, bis(3,4-dicarboxyphenyl)-phenylphosphine oxide dianhydride, N,N-(3,4-dicarboxyphenyl)-N-methylamine dianhydride 3.3'.

4.47-Titracarpoxybenzoyloxybenzene dianhydride, 1,4,5.8-naphthalenetetracarboxylic dianhydride, 2,3,6.7-naphthalenetetracarboxylic dianhydride, 1,2, 5゜6-naphthalenetetracarboxylic dianhydride, 2.6-cyclonaphthalene-1.4
, 5.8-Tetracarboxylic dianhydride, 2,7-cyclonaphthalene-1.4,5.8-tetracarboxylic dianhydride, 2,3,6.7-titrachloronaphthalene-1.
4,5.8-f tracarboxylic dianhydride, 1°4.5.
8-tetrafluoronaphthalene-2,3゜6.7-tetracarboxylic dianhydride, 1,8.9゜10-phenanthrenetetracarboxylic dianhydride, 3.4,9.10-perylenetetracarboxylic dianhydride Anhydride, 2,3,4.5-thiophenetetracarboxylic acid dianhydride, 2,3,5.6
-Pyridinetetracarboxylic dianhydride, 2,3,5.6
-Pyridinetetracarboxylic dianhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride, 3
．． 3',4.4'-Azobenzenetetracarboxylic dianhydride, 3.3',4.4'-azoxybenzenetetracarboxylic dianhydride, 1,2,3゜4-cyclobencunetetracarboxylic acid These include dianhydride, ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, and the like. Particularly preferred tetracarboxylic dianhydrides are 3.3', 4.
It is 4'-benzophenone tetracarboxylic dianhydride (hereinafter abbreviated as BTDA). These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

Further, as the diamine compound, the following are preferable.

o-lm- and p-phenylenediamine, 2°4-diaminotoluene, 1,4-diamino-2-methoxybenzene, 2,5-diaminoxylene, 1,3-diamino-4
-chlorobenzene, 1,4-diamino-2,5-dichlorobenzene, l,4-diamino-2-bromobenzene,
1,3-diamino-4-isopropylbenzene, 2.2
-bis(4-aminophenyl)propane, 3□ 3'-
or 4.47-diaminodiphenylmethane, 3.4'-
Diaminodiphenylmethane, 2,2'- is 4゜4'-
Diaminostilbene, 4,4'-diamino-2,2',
3.3', 5.5', 6.6'-octafluorodiphenylmethane, 3,3'- is 4,4'-diaminodiphenyl ether, 3.4'-diaminodiphenyl ether, 4,4'-diamino-2 ,2',3,3. ',,5.
5',6.6'-octafluorodiphenyl ether,
3,4'-diaminodiphenylthioether, 3.3'
- or 4,4'-diaminodiphenylthioether, 4
．． 4'-diaminodiphenylsulfone, 3,37-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4-aminobenzoic acid 4'-aminophenyl ester, 2.2'-13,3'- or 4.4 '-Diaminobenzophenone, 3°47-diaminobenzophenone, 2,3'-diaminoanthraquinone, 4,4'-diaminobenzyl, 4-(4-aminophenylcarbamoyl)aniline, bis(4-aminophenyl)-phosphine.

bis(4-aminophenyl)-methylphosphine oxide, bis(4-aminophenyl)-cyclohexylphosphine oxide, bis(4-aminophenyl)-cyclohexylphosphine oxide, N,N-bis(4-
aminophenyl)-N-phenylamine, N,N-bis(4-aminophenyl)-N-methylamine, 2.2'
-,3゜3'- or 4,4'-diaminoazobenzene,
4゜4'-diaminodiphenylurea, 1,8 or 1゜5
-diaminonaphthalene, 1,5-diaminoanthraquinone, diaminofluoranthene, 3,9-diaminochrysene, diaminopyrene, bis(4-aminophenyl)-diethylsilane, bis(4-aminophenyl)-dimethylsilane, bis( 4-aminophenyl)-tetramethyldisiloxane, 2.6-diaminochrysene, 2,4-diaminopyrimidine, 3.6-diaminochrysene, 2.4-
Diamino-8-triazine, 2,7-diamituzodihenzofuran, 2,7-cyamitsucarbazole, 3,7-cyamitsuphenothiazine, 5,6-diamitsu-1,3-dimethyluracil, 2,5- Diamino-1,3,4-thiadiazole, dimethylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine,
Nonamethylene diamine, decamethylene diamine, 2.2
-dimethylpropylenediamine, 2.5-dimethylhexamethylenediamine, 2.5-dimethylhexamethylenediamine, 4.4-dimethylhexamethylenediamine,
3-Methylhebutamethylenediamine, 3-methoxyhexamethylenediamine, 5-methylnonamethylenediamine, 2,11-diaminododecane, 1,12-diaminooctadecane, 1,2-bis(3-aminopropoxy)-
Ethane etc. Among them, a particularly preferred diamine compound is 3.3'-diaminobenzophenone (hereinafter referred to as 3.3'-diaminobenzophenone).
It is abbreviated as DABP. ).

These diamine compounds may be used alone or in combination of two or more.

In addition, N,N'-dialkyl or diaryl-substituted diamine compounds, such as N,N'-diethylethylenediamine, N,N'-diethyl-1°3-diaminoflopane, within a range that does not significantly affect the physical properties of the polyimide resin. N
, N'-dimethyl-1゜6-diamithexane, N,N
'-Diphenyl-1,4-phenylenediamine etc. can be used in combination.

The organic solvent used is N,N-dimethylacetamide,
N~methyl-2-pyrrolidone, N,N-dimethylformamide, N-acetyl-2-pyrrolidone, sulfolane,
Dimethyl sulfoxide, diethylene glycol dimethyl ether, etc. These solvents may be used alone or in combination.

The obtained polyamic acid solution usually contains 2 to 50% resin, and the viscosity of the solution is 10 to 50% as measured by a Brookfield viscometer.
, ooo centipoise range is preferred from the viewpoint of ease of handling the solution and ease of impregnating the reinforcing material.

° The intrinsic viscosity of polyamic acid itself is 0.2
~2. A range of Oa/g is preferred from the viewpoint of mechanical strength, melt flowability, heat resistance, etc. of the polyimide resin obtained.

Note that the intrinsic viscosity is calculated using the following formula.

ηinh = (I/C) ・j! n (η/77
o) (In the above formula, In = natural logarithm η = N, viscosity of a solution of 0.5 g of polyamic acid dissolved in 100 ml of N-dimethylacetamide (35°C
) 70 = Viscosity of N,N-dimethylacetamide (35℃
) C=polymer solution concentration in g of polyamic acid per 100 ml of solvent. ) Typical fibrous reinforcing materials used in the present invention include glass fibers, carbon fibers, aromatic polyamide fibers, aromatic polyamide nonwoven fabrics, boron fibers, etc., and these fibers may be used alone or in combination.

Further, if necessary, other reinforcing materials such as silicon carbide fibers, mica, calcium silicate, silica, alumina, etc. can also be used in combination with the fibers.

The simplest impregnation method is to immerse the fibrous reinforcing material in a polyamic acid solution. Of course, other methods of impregnation may also be used.

In the present invention, first, the solvent contained in the impregnated polyamic acid solution is extracted with an extraction solvent.

Examples of extraction solvents used here include the following:

Pentane, isopentane, hexane, cyclohexane,
Aliphatic hydrocarbons such as heptane and otane, aromatic hydrocarbons such as benzene, toluene, 0-xylene, m-xylene, p-xylene, mixed xylene, and ethylbenzene, dichloromethane, chloroform, carbon tetrachloride, ethyl chloride, 1 , 1-dichloroethane, 1,2-dichloroethane, l.

1.1-) Aliphatic chlorides such as dichloroethane and tetrachloroethane, cis-dichloroethylene, trans
- Unsaturated chlorides such as dichloroethylene and trichloroethylene, aromatic halogen compounds such as chlorobenzene, 0-dichlorobenzene, bromobenzene, bromonaphthalene, and iodobenzene, methyl iodide, methane niodide,
Aliphatic iodo compounds such as ethyl iodide, methanol, 1
, 3-butanediol, ethanol (99.9%), methyl cellosolve, n-propatol, n-butanol,
Isobutanol, n-amyl alcohol, n-hexanol, 2-ethylbutanol, n-heptatool, n-
Hydroxyl compounds such as octatool, carboxylic acids such as acetic acid, formic acid, butyric acid, γ-butyrolactone, acetone, methyl ethyl ketone, diethyl ketone, dibutyl ketone, methyl propyl ketone, methyl isobutyl ketone, methyl butyl ketone and other ketones, methylal, diethyl ether ,
Ethers such as furan, diisopropyl ether, methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, ethyl propionate, amyl formate, cellosolve acetate, butyl acetate, esters such as ethyl butyrate, diethylamine, dibutylamine, etc. amines, amides such as formic acid amide, acetic acid amide, dimethylformamide, dimethylacetamide, acetonitrile,
Nitriles such as probiononitrile and butyronitrile, nitromethane, nitroethane, l-nitropropane, 2-
These include nitro compounds such as nitropropane and nitroenzene, sulfur compounds such as carbon disulfide, ethyl mercaptan, and dimethyl sulfide, and water.

These extraction solvents may be used alone or in combination. Note that the extraction solvent used has a boiling point lower than that of the solvent contained in the polyamic acid solution.

The simplest extraction method is to immerse a fibrous reinforcing material impregnated with a polyamic acid solution in an extraction solvent.

Of course, other methods of extraction may be used. The extraction temperature is preferably from -10°C to the boiling point of the extraction solvent at normal pressure.

The prepreg sheet from which as much as possible of the solvent in the polyamic acid solution has been extracted by the extraction operation is further heated and dried to remove volatile components such as unextracted solvent and extraction solvent, and heated to be imidized. Volatile matter in the prepreg sheet causes blisters to occur during the subsequent product N operation or bonding operation, so it is preferable to remove it as much as possible, and the volatile matter should be 10% by weight or less of the entire prepreg sheet. is desirable. In addition, the resin content of the entire prepreg sheet is 20~
The content is preferably 80% by weight.

One of the features of the present invention is that when manufacturing a polyimide resin-impregnated prepreg sheet, the solvent present in the polyamic acid solution is first extracted with a low boiling point solvent, but this method has not been commonly performed in the past. Compared to a method in which the solvent in a fibrous reinforcing material impregnated with a polyamic acid solution is removed only by heating and drying, the high boiling point solvent can be quickly removed at a low temperature without rapid temperature rise.

Since there is no need to dry the prepreg sheet at high temperatures for long periods of time, there is almost no deterioration of the resin, and it is an energy-saving process. Moreover, the polyimide in the obtained prepreg sheet has excellent melt fluidity and is suitable as a material for a laminate molded product or as an adhesive.

The laminated molded product is obtained by laminating the prepreg sheets obtained as described above and heating and pressing them. The heating temperature during lamination is higher than the glass transition point of the polyimide resin contained in the prepreg sheet, preferably 240 to 360.
It is ℃. Also, the pressure applied varies depending on the shape, but it is 1 to 50.
0 kg/cm2 is desirable. The prepreg sheet of the present invention can be stored indoors at room temperature. In addition, molding is easy and a molded product of a desired shape can be obtained using a conventional molding machine such as a heat press or an autoclave.

The prepreg sheet is also useful as an adhesive sheet.

When bonding, place the prepreg sheet 1 between the adherends.
・This is done by inserting and heating under pressure. Adhesion pressure is 0~500kg70m2, especially 0.1~20kg
/ cm2 range is desirable. Further, the adhesion temperature is higher than the glass transition point of the polyimide contained in the prepreg sheet, preferably 240 to 360°C. Heating and pressing methods include heat press, heat roll, induction heating using high frequency,
Known methods such as double belt press and autoclave are possible.

The adhesive obtained by the above procedure shows excellent adhesive strength even at high temperatures.

〔Example〕

The present invention will be specifically explained with reference to Examples and Comparative Examples.

Example-1 (a) Polymerization N,N-dimethylacetamide 3001.3. 3'-DABP31.85g
(0.15 mol) at 15°C under a stream of dry nitrogen.
While stirring, 48.33 g (0.15 mol) of BTDA powder was gradually added. The viscosity of the solution increases as it is added. After the addition was completed, stirring was continued for another 4 hours to complete the reaction.

The obtained polyamic acid was light brown and transparent, and had an intrinsic viscosity of 0.
74J/g (0.5g/100mlN, N-
Dimenano-acetamitone vehicle, 35°C).

tbl Impregnation and extraction (After diluting the polyamic acid solution obtained with al with N,N-dimedelacetamide so that the resin content was 8% by weight, a glass fiber cloth (WF-230 manufactured by Nittobo Co., Ltd.) was immersed. The taken out polyamic acid solution-containing glass fiber cloth was immersed in an ethanol bath for 30 minutes to extract N,N-dimethylacetamide.After air-drying, the above operation was repeated once again to obtain a polyamic acid-impregnated prepreg sheet.

(C1 Dry and imidize the obtained prepreg sheet at 60°C for 30 minutes, 120
The mixture was dried by heating at 180°C for 30 minutes, 180°C for 30 minutes, and 220°C for 2 hours to imidize and remove volatile components, thereby obtaining a prepreg sheet impregnated with a polyimide resin. The resin content of this prepreg sheet was 40%.

(d) The prepreg sheets obtained by molding are laminated and molded using a compression molding machine for 3
It was molded at 50°C and 100kg/cm2.

The obtained molded product was brown and strong.

The tensile strength of this molded body is 12.2 kg/mm2 (23℃
) (ASTM D-638), bending strength is 13.5
kg/Tsuru2 (23℃) (ASTM D-790)
, Izotsu impact strength (with notch) is 4.9kg-c
m/cm2 (23°C) (ASTM D-256).

Adhesion test (The prepreg sheet obtained in C1 was inserted between two cold rolled steel plates (JI 5-G3141.5PCC-SD D size 1.6X25X Room) and heated at 355°C 15kIr/cI112 using a heat press. Glue Lf.

The tensile shear adhesive strength was 210 kg/cm2 at room temperature. (Measurement method is JIS K-6848 and K
- Based on 6850. ) Comparative Example-1 3.3'-DABP and BTDA under the same conditions as Example-1
The intrinsic viscosity is 0.75 dl/g (0.5 g/
100 o+j? A polyamic acid solution of 31) in N,N-dimethylacetamide solvent was obtained. This solution was diluted with N.

After diluting the resin with N-dimethylacetamide to a resin content of 8% by weight, a glass fiber cloth was immersed. The glass fiber cloth was air dried after soaking. This operation was repeated three times to obtain a polyamic acid-containing prepreg sheet.

The obtained prepreg sheet was heated at 100°C for 1 hour, 15
A polyimide resin-containing prepreg sheet was obtained by heating and drying at 0°C for 1 hour, 180°C for 1 hour, and 220°C for 3 hours to imidize and remove volatile components.

ta) The prepreg sheets obtained by molding were laminated, and Example-1(d)
It was molded in the same way.

The tensile strength of this molded body is 6.1 kg/B2 (23℃)
, d10 strength is 7.0 kg/Ryu2 (23℃), Izotsu impact strength (with notch) is 2.4 kg-cm/
cm2 (23°C), which was inferior to Example-1fd).

(b) Adhesion test Using the obtained prepreg sheet, adhesion was performed under the same conditions as in Example 1(e). The tensile shear adhesive strength of the obtained adhesive was 101 kg/cm2 at room temperature, and
It was less than half that of 1(e).

Examples 2 to 6 Various diamine compounds and tetracarboxylic dianhydrides were prepared in the same manner as in Example 1, and glass fibers were further impregnated, extracted, dried, and imidized to produce prepreg sheets. . Molding and adhesion tests were conducted using the obtained prepreg sheet, and the results shown in Table 1 were obtained.

Example-7 (a) Polymerization In the same reaction apparatus as in Example-1, BTD A 4B
, 33 g (0.15 mol) and 300 raβ of N,N-dimethylacetamide and 3.3
'-Diaminodiphenyl ether 30.04 g (0
, 15 mol) was added and reacted, and the intrinsic viscosity was 0.7.
2d! /g of polyamic acid solution is i'4. Add more N to this solution.

N-dimethylacetamide was added to bring the resin concentration to 8% by weight.

(bl Impregnation and extraction (al) A carbon fiber cloth (Torayca cloth #6343 manufactured by Toshi Co., Ltd.) was impregnated with the solution obtained in al.The taken out polyamic acid solution impregnated carbon fiber cloth was immersed in a water tank for 30 minutes, then N,N −
Dimethylacetamide extraction was performed.

After air drying, the above operation was repeated once again to obtain a polyamic acid-impregnated prepreg sheet.

(C) Drying and imidization The obtained prepreg sheet was heated at 80°C for 1 hour. 11
()Q'1 A prepreg sheet impregnated with polyimide was obtained by heating and drying at 50° C. for 30 minutes and at 220° C. for 2 hours to imidize and remove volatile components.

(dl The prepreg sheets obtained in molding (C) were laminated, and Example-
It was molded under the same conditions as 1(d).

The tensile strength of this molded body is 67 kg / 2 (23°
C1 fiber direction), bending strength is 71 kg/m” (
The Izo impact strength (notched) was 48 kg-cm/cII+2 (23°C, fiber direction).

tel Adhesion test (The prepreg sheet obtained in C1 was inserted between two cold rolled steel plates (JIS-G3141.5PCC-SD D size 0.5x25x150m) and heated at 355°C with a heat press of 5kg/ It was glued with Cm2.

180° peel adhesive strength is 9,8 kg/2 at room temperature
It was 5+am. (The measurement method is JIS K-684.
8 and -6854. ) Examples 8 to 10 Polymerization was carried out in the same manner as in Example 7(a) using various diamine compounds and tetracarboxylic dianhydride, and carbon Impregnated with fiber cloth (Traca cloth #6343), extracted from water, dried,
A prepreg sheet was produced by imidization. Molding and adhesion were performed using this prepreg sheet, and the results shown in Table 2 were obtained.

〔Effect of the invention〕

Since the present invention is constructed as described above, the present invention provides a novel method for manufacturing a prepreg sheet that exhibits particularly excellent strength even at high temperatures, and a laminate molding method using this prepreg sheet with excellent heat resistance. It is possible to provide a method for manufacturing the prepreg sheet and an adhesion method with excellent heat resistance using this prepreg sheet.

Claims (1)

[Claims] 1) Formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (I) [In the formula, R_1 is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, or a monocyclic aromatic group. represents a divalent group selected from the group consisting of a group group, a fused polycyclic aromatic group, a non-fused polycyclic aromatic group in which aromatic nuclei are interconnected by a bridge member, and a heterocyclic group,
R_2 is an aliphatic group having 2 or more carbon atoms, a cyclic aliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-fused polycyclic aromatic group in which aromatic nuclei are interconnected by a crosslinking member. represents a tetravalent group selected from the group consisting of a group group and a heterocyclic group, and Y represents a group selected from the group consisting of a hydrogen atom, an alkyl group, and an aryl group. ] After impregnating a fibrous reinforcing material with an organic solvent solution of a polyamic acid having a repeating unit represented by the formula, the contained solvent is extracted with an extraction solvent, and then the remaining solvent is removed by heating and drying, and the polyamic acid is removed. After heating imidization, the formula (I
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) [In the formula, R_1 and R_2 are the same as R_1 and R_2 in formula (I). ] A method for producing a prepreg sheet, characterized in that it is made of polyimide having a repeating unit represented by: 2) Claim 1, wherein the polyamic acid is obtained by reacting 3,3'-diaminobenzophenone and 3,3',4,4'-benzophenonetetracarboxylic dianhydride in an organic solvent. A method for producing a prepreg sheet as described in Section 1. 3) Claim 1 or 2 in which the extraction solvent is water
A method for producing a prepreg sheet as described in Section 1. 4) The method for producing a prepreg sheet according to claim 1 or 2, wherein the extraction solvent is an organic solvent having one or more carbon atoms and has a boiling point lower than the solvent contained in the polyamic acid solution. 5) Formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, R_1 is an aliphatic group with 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, or a fused polycyclic group. represents a divalent group selected from the group consisting of an aromatic group, a non-fused polycyclic aromatic group and a heterocyclic group in which aromatic nuclei are interconnected by a bridge member,
R_2 is an aliphatic group having 2 or more carbon atoms, a cyclic aliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-fused polycyclic aromatic group in which aromatic nuclei are interconnected by a crosslinking member. represents a tetravalent group selected from the group consisting of a group group and a heterocyclic group, and Y represents a group selected from the group consisting of a hydrogen atom, an alkyl group, and an aryl group. ] After impregnating a fibrous reinforcing material with an organic solvent solution of a polyamic acid having a repeating unit represented by the formula, the contained solvent is extracted with an extraction solvent, and then the remaining solvent is removed by heating and drying, and the polyamic acid is removed. After heating imidization, the formula (I
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) [In the formula, R_1 and R_2 are the same as R_1 and R_2 in formula (I). ] A method for producing a laminate molded product, which comprises laminating prepreg sheets obtained as a polyimide having a repeating unit represented by the formula and heating the prepreg sheets under pressure to a temperature higher than the glass transition point of the polyimide. 6) Claim 5, wherein the polyamic acid is obtained by reacting 3,3'-diaminobenzophenone and 3,3',4,4'-benzophenonetetracarboxylic dianhydride in an organic solvent. A method for producing a laminate molded product as described in . 7) Claim 5 or 6 in which the extraction solvent is water
A method for producing a laminate molded product as described in . 8) The method for producing a laminate molded article according to claim 5 or 6, wherein the extraction solvent is an organic solvent having one or more carbon atoms and has a boiling point lower than the solvent contained in the polyamic acid solution. 9) Formula (I) ▲Mathematical formulas, chemical formulas, tables, etc. are available▼(I) [In the formula, R_1 is an aliphatic group with 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, or a fused polycyclic group. represents a divalent group selected from the group consisting of an aromatic group, a non-fused polycyclic aromatic group and a heterocyclic group in which aromatic nuclei are interconnected by a bridge member,
R_2 is an aliphatic group having 2 or more carbon atoms, a cyclic aliphatic group, a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-fused polycyclic aromatic group in which aromatic nuclei are interconnected by a crosslinking member. represents a tetravalent group selected from the group consisting of a group group and a heterocyclic group, and Y represents a group selected from the group consisting of a hydrogen atom, an alkyl group, and an aryl group. ] After impregnating a fibrous reinforcing material with an organic solvent solution of a polyamic acid having a repeating unit represented by the formula, the contained solvent is extracted with an extraction solvent, and then the remaining solvent is removed by heating and drying, and the polyamic acid is removed. After heating imidization, the formula (I
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) [In the formula, R_1 and R_2 are the same as R_1 and R_2 in formula (I). ] An adhesion method characterized by inserting a prepreg sheet obtained as a polyimide having a repeating unit represented by the following between adherends and heating the prepreg sheet under pressure to a temperature equal to or higher than the glass transition point of the polyimide. 10) Claim 9, wherein the polyamic acid is obtained by reacting 3,3'-diaminobenzophenone and 3,3',4,4'-benzophenonetetracarboxylic dianhydride in an organic solvent. Adhesion method described in section. 11) The bonding method according to claim 9 or 10, wherein the extraction solvent is water. 12) The bonding method according to claim 9 or 10, wherein the extraction solvent is an organic solvent having one or more carbon atoms and has a boiling point lower than that of the solvent contained in the polyamic acid solution.