ES2352507T3 - COMPOSITION AND PREPREG OF THERMOENDURECIBLE SOLUTION. - Google Patents

Abstract

A thermosetting solution composition comprising a biphenyltetracarboxylic acid compound containing at least 15 mol% of a lower partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or a lower partial aliphatic acid alkyl ester 2,2 ', 3,3'-biphenyltetracarboxylic, an aromatic diamine compound in a molar amount greater than a molar amount of the biphenyltetracarboxylic acid compound, a lower partial aliphatic alkyl ester of a 4- (2-phenylethynyl acid compound) ) phthalic in a molar amount as much as 1.8-2.2 times a molar amount corresponding to a difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound, and an organic solvent comprising an alcohol lower aliphatic.

Description

FIELD OF THE INVENTION

 The present invention relates to a thermosetting solution composition, a prepreg using the same, and a method of manufacturing an aromatic polyimide resin article from the prepreg. In particular, the invention relates to a thermosetting solution composition that can be favorably employed for the manufacture of a prepreg and subsequently an aromatic polyimide resin article.

 BACKGROUND OF THE INVENTION

 It is known that an aromatic polyimide resin article exhibits very favorable physical and chemical characteristics such as high mechanical strength, high thermal resistance, and high resistance to chemical compounds. Accordingly, the aromatic polyimide resin has been widely used to manufacture motherboards of electronic devices. The favorable physical and chemical characteristics of the aromatic polyimide resin have recently received increased attention, and as a consequence the aromatic polyimide resin has been studied for use in the manufacture of various aircraft and spacecraft constituent units. In fact, some articles of aromatic polii-20 resin are used in these technical fields.

 An aromatic polyimide article such as an aromatic polyimide sheet is generally manufactured by first preparing a solution of a polyamic acid (i.e. polyamide acid) by the reaction between a tetracarboxylic aromatic acid derivative and an aromatic diamine in a solvent, spreading the polyamic acid solution onto a temporary support to prepare a polyamic acid sheet, and finally heating the polyamic acid sheet to form the polyimide sheet by drying and cyclization reaction.

 An aromatic polyimide article having a thick thickness or an aromatic polyimide article other than a sheet is generally manufactured using a plurality of prepregs. A plurality of the prepregs are stratified over each other and then heated under pressure to give an aromatic polyimide article. The prepreg is prepared by impregnating a sheet matrix of a reinforcing fiber with a thermosetting polymer solution composition.

 Japanese publication PCT 2002-511902 describes a method of preparing a prepreg from a precursor solution of polyimide having a concentration of 35 solids from 50 to 80% by weight, a concentration of volatile materials not greater than 35% by weight , and a Brookfield viscosity of 4000 to 10,000 cP. The typical precursor solution of

Polyimide is prepared from oxydifthalic dianhydride, phthalic acid and 3,4'-oxidianiline. The solvent in the solution is typically a mixture of N-methyl-2-pyrrolidone and ethanol.

 Japanese Provisional Patent Publication 2000-219741 A describes a terminal modified imide oligomer solution (thermosetting solution composition) which is obtained by the reaction of 2,3,3 ', 4'-biphenyltetracarboxylic acid with a compound of 5 aromatic diamine and 4- (2-phenylethynyl) phthalic anhydride, and further describes that the composition of the solution can be used for the manufacture of a prepreg and subsequently an article of aromatic polyimide (i.e., a cured article). The publication describes a list of solvents that can be used for the preparation of the solution composition that includes N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-10 diethylacetamide, and N-caprolactam.

 Japanese Provisional Patent Publication 2004-331801 A describes that 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride can be used for the preparation of an aromatic polyimide as the aromatic tetracarboxylic acid compound, and further describes that the dianhydride be reacts with an aromatic diamine compound in the presence of a reactive crosslinking agent to give a polyamic acid oligomer.

 The thermosetting solution composition comprising the terminal modified imide oligomer solution prepared by the reaction of 2,3,3 ', 4'-biphenyltetracarboxylic acid with an aromatic diamine compound and 4- (2-phenylethynyl) phthalic anhydride in a solvent it is valuable to prepare an aromatic polyimide article 20 (ie, a cured article) having excellent physical and chemical properties. However, all the solvents described in the publication as solvents that can be used for the preparation of the imide, that is, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N , N-diethylacetamide, and N-caprolactam, have a high boiling point. Therefore, removal of the solvent from the evaporation solution composition requires high temperatures and long periods of time. These evaporation conditions are not favorable from the point of view of industrial preparation.

 SUMMARY OF THE INVENTION

 Accordingly, it is an object of the present invention to provide a thermosetting solution composition that is easily removed by distillation in the process of preparing a prepreg for the use of manufacturing an aromatic polyimide article (it is that is, a cured article) and subsequently in the manufacturing process of the cured article and which, moreover, is easily manipulated in the industrial process.

 Another object of the invention is to provide a prepreg that can be favorably used for the manufacture of an aromatic polyimide article (ie, a square article) by pressure heating from the viewpoint that the solvent used,

as well as the water and alcohol that are obtained as by-products in these processes are easily separated by evaporation.

 The authors of the present invention have observed and studied the composition of the thermosetting solution described in Japanese Provisional Patent Publication 2000-219741 A. As a result of the studies, they have discovered that when di-5 anhydride is dissolved 2,3,3 ', 4'-Biphenyltetracarboxylic and 4- (2-phenylethynyl) phthalic anhydride in a lower aliphatic alcohol such as methanol or ethanol and heated, a lower partial aliphatic alkyl ester of 2,3,3', 4 'acid is produced -biphenyltetracarboxylic acid and a lower partial aliphatic alkyl ester of 4- (2-phenylethynyl) phthalic acid, both of which are soluble in the alcohol used, and which a solution composition comprising the resulting solution and an aromatic mine dia-10 compound exhibits a stable viscosity in solution. The inventors have further discovered that the resulting solution composition can be favorably used to prepare a prepreg and additionally that the prepreg easily converts into a cured polyimide article. The lower aliphatic alcohol used as a solvent of the thermosetting solution composition is advantageous in that its boiling point is low, that is to say that it is easily removed by evaporation, that it is easily handled, and that the cost is low. Accordingly, the use of the lower aliphatic alcohol as the solvent of the thermosetting solution composition is very advantageous, particularly from the point of view of the industrial preparation of the composition of the thermosetting solution and the prepreg. twenty

 The present invention resides in a thermosetting solution composition comprising a biphenyltetracarboxylic acid compound containing at least 15 mol% of a lower partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or an alkyl ester Lower partial aliphatic of 2,2 ', 3,3'-biphenyltetracarboxylic acid, an aromatic diamine compound in a molar amount greater than a molar amount of the compound of biphenyltetracarboxylic acid, a lower partial aliphatic alkyl ester of a compound of 4- acid (2-phenylethynyl) phthalic in a molar amount as much as 1.8-2.2 times a molar amount corresponding to a difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound, and a Organic solvent comprising a lower aliphatic alcohol. 30

 The lower aliphatic alcohol employed in the invention includes a mono-valent aliphatic alcohol having 1 to 6 carbon atoms. Representative examples of lower aliphatic alcohols include methanol and ethanol. The lower aliphatic alkyl ester includes an ester with a monovalent aliphatic alkyl alcohol having 1 to 6 carbon atoms. Representative examples include methyl ester and ethyl ester. The lower partial aliphatic alkyl ester 35 means that 1 to 3 carboxyl groups (generally two carboxyl groups) of the biphenyltetracarboxylic acid form ester bonds with the lower aliphatic alcohol, and that a carboxyl group of the 4- (2-phenylethynyl) phthalic acid forms a ester bond with lower aliphatic alcohol.

 The present invention further resides in a thermosetting solution composition comprising a compound of biphenyltetracarboxylic acid containing at least 15 molar% of a partial methyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or a Partial methyl ester of 2,2 ', 3,3'-biphenyltetracarboxylic acid. an aromatic diamine compound in a molar amount greater than a molar amount of the biphenylte-5 tracarboxylic acid compound, a partial methyl ester of a 4- (2-phenylethynyl) phthalic acid compound in a molar amount as much as 1 , 8-2.2 times a molar amount corresponding to a difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound, and an organic solvent comprising ethanol.

 Preferred embodiments of the thermosetting solution compositions of the invention are indicated below.

 (1) The lower aliphatic alcohol is methanol, ethanol, or a mixture of these alcohols.

 (2) The lower aliphatic alkyl ester is methyl ester, ethyl ester, or a mixture of methyl ester and ethyl ester.

 (3) The molar amount of lower partial aliphatic alkyl ester of the 4-15 (2-phenylethynyl) phthalic acid compound is as much as 1.95-2.05 times a molar amount corresponding to the difference of the molar amount of the diamine compound aromatic and the molar amount of the biphenyltetracarboxylic acid compound.

 (4) a total amount of the biphenyltetracarboxylic acid compound, the aromatic polyimide compound, and the 2- (2-phenylethynyl) phthalic acid compound is in the range of 30 to 80% by weight, based on the amount of The solution composition.

 (5) The biphenyltetracarboxylic acid compound comprises at least 50 mol% of 2,3,3 ', 4'-biphenyltetracarboxylic acid compound comprising a lower partial aliphatic alkyl ester of 2,3,3', 4'- biphenyltetracarboxylic.

 (6) The aromatic diamine compound comprises at least 50 mol% of an aromatic diamine having an aromatic ring in a molecular structure thereof.

 (7) The aromatic diamine compound comprises p-phenylene diamine, 1,3-bis (4-aminophenoxy) benzene, or a mixture thereof.

 (8) An imidazole compound is contained.

 The present invention further resides in a thermosetting powder composition comprising a compound of biphenyltetracarboxylic acid containing at least 15 mol% of a lower partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or a Lower partial aliphatic alkyl ester of 2,2 ', 3,3'-biphenyltetracarboxylic acid, an aromatic diamine compound in a molar amount greater than the molar amount of the biphenyltetracarboxylic acid compound, and a lower partial aliphatic alkyl ester of compound of acid 4 - (2-phenylethynyl) phthalic in a molar amount as much as 1.8-2.2 times a molar amount corresponding to a difference between the amount

molar of the aromatic diamine compound and the molar amount of the bife-nyltetracarboxylic acid compound.

 In the thermosetting powder composition mentioned above, the lower partial alkyl ester is preferably a partial methyl ester.

 The present invention further resides in a prepreg comprising a sheet of a reinforcing fiber impregnated with the thermosetting solution composition of the invention.

 The present invention further resides in a method of manufacturing a resin article comprising stratifying a plural number of the prepregs of the invention over each other and heating the resulting laminate. 10

 The thermosetting solution composition of the invention exhibits a high stability of solution regardless of whether or not an easily volatile solvent is used. Therefore, the solvent is easily removed by evaporation and easily manipulated when preparing a prepreg using the solution composition. In other words, since the lower aliphatic alcohol used as a solvent has a low boiling point, solvent removal as well as water and compounds formed as a byproduct are easily removed by distillation in the prepreg procedures and the article of cured polyimide

 Particularly, when the acidic components of the composition of the thermosetting solution are in the form of methyl esters, the resulting prepreg easily provides a cured polyimide article having a desired shape since the prepreg prepared using the thermosetting solution composition that buy-of the methyl esters hardly deforms in its preparation process and exhibits satisfactory moldability.

 Additionally, when the solvent of the thermosetting solution composition 25 is ethanol, the ambient atmosphere formed in the prepreg preparation process and subsequently in the process of the cured polyimide article worsens less, as compared to the use of methanol as a solvent . Accordingly, it is very preferred that the acid components of the thermosetting solution composition be in the form of methyl esters and additionally that the solvent is ethanol. 30

 BRIEF DESCRIPTION OF THE DRAWINGS

 Fig. 1 is a graph showing the results of dynamic viscoelasticity measurements (indicating relationships between temperature and complex viscosity).

 Fig. 2 is a 1H-NMR spectrum of the thermosetting solution composition of Example 10 (1). 35

 Fig. 3 is a 1H-NMR spectrum of the thermosetting solution composition of Example 15 (1).

 Fig. 4 illustrates an example for the process of manufacturing an article cured from a prepreg.

 Fig. 5 illustrates a stepped heating pattern used in the manufacturing process of a cured article from a vacuum prepreg which is carried out by modifying the heating temperature and the degree of vacuum. 5

 Fig. 6 illustrates a stepped vacuum pattern used in the manufacturing process of a cured article from a vacuum prepreg that is performed by varying the temperature and the degree of vacuum.

 Fig. 7 illustrates a stepped pressure pattern used in the manufacturing process of a cured article from a vacuum prepreg that is made by modifying the heating temperature and the degree of vacuum.

 Fig. 8 illustrates another stepped heating pattern used in the manufacturing process of a cured article from a vacuum prepreg which is carried out by modifying the heating temperature and the degree of vacuum.

 Fig. 9 illustrates another stepped vacuum pattern employed in the process of manufacturing a cured article from a vacuum prepreg that is made by varying the heating temperature and the degree of vacuum.

 Fig. 10 illustrates another stepped pressure pattern employed in the manufacturing process of a cured article from a vacuum prepreg that is performed by modifying the heating temperature and the degree of vacuum. twenty

 DETAILED DESCRIPTION OF THE INVENTION

 The monomer compounds required for the preparation of the thermosetting solution composition of the invention are described below:

 (1) a compound of biphenyltetracarboxylic acid containing at least 15 molar% of a lower partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or a lower partial aliphatic al-25 kyl ester of 2,2 ', 3,3'-biphenyltetracarboxylic;

 (2) an aromatic diamine compound in a molar amount greater than a molar amount of the biphenyltetracarboxylic acid compound; Y

 (3) a lower partial aliphatic alkyl ester of a 4- (2-phenylethynyl) phthalic acid compound (a portion less than 50 mol% may not be in the form of the alkyl ester) in a molar amount as much as 1.8-2 , 2 times a molar amount corresponding to the difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound.

 The biphenyltetracarboxylic acid compound contains at least 15 mol% (preferably, at least 30 mol%, more preferably, at least 50 mol%, most preferably at least 80 mol%) of a partial aliphatic alkyl ester of acid 2 , 3,3 ', 4'-biphenyltetracarboxylic acid and / or a partial aliphatic alkyl ester of 2,2', 3,3'-

biphenyltetracarboxylic. More preferably, the biphenyltetracarboxylic acid compound comprises a partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid.

 The partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid can be prepared by placing 2,3,3', 4'-biphenyltetracarboxylic dianhydride in a lower aliphatic alcohol and heating the resulting mixture to form a solution . The heating is preferably carried out at a temperature between 40 ° C and the boiling temperature of the alcohol, at reflux. 2,3,3 ', 4'-Biphenyltetracarboxylic dianhydride is known as the starting compound for the preparation of an aromatic polyimide resin. The partial aliphatic alkyl ester of 2,2 ', 3,3'-biphenyltetracarboxylic acid can be prepared by placing 2,2', 3,3'-biphenyltetracarboxylic dianhydride in a lower aliphatic alcohol and heating the resulting mixture 10 to give a solution . The 2,2', 3,3'-biphenyltetracarboxylic dianhydride is described in detail in Japanese Provisional Patent Publication 2004-331801 A, mentioned above.

 In the composition of the thermosetting solution, a portion (not greater than 10 mol%) of the lower partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or a portion (not greater than 10 mol%) of the lower partial aliphatic alkyl ester of 2,2 ', 3,3'-biphenyltetracarboxylic acid can be replaced with a lower partial aliphatic alkyl ester of another tetracarboxylic acid. Examples of the lower partial aliphatic alkyl esters of other tetracarboxylic acids include a lower partial aliphatic alkyl ester of the compound 3,3 ', 4,4'-biphenyltetracarboxylic acid, a lower partial aliphatic alkyl ester of a compound of 3,3', 4 acid, 4, 4'-benzophenonatetracarboxylic acid, a lower partial aliphatic alkyl ester of a pyromellitic acid compound, and a lower partial aliphatic alkyl ester of bis (3,4-dicarboxyphenyl) ether.

 Examples of aromatic diamine compounds include p-phenylene diamine, m-phenylene diamine, 1,3-bis (4-aminophenoxy) benzene, and mixtures thereof. It is also possible to use aromatic diamine compounds known to be used for the preparation of aromatic polyimide resins. These aromatic diamine compounds are described in detail in Japanese Provisional Patent Publication 2000-219741 A, mentioned above. Very preferred aromatic diamine compounds are p-phenylene diamine and a mixture of p-phenylene diamine and 1,3-bis (4-aminophenoxy) benzene, which are advantageous in the preparation of a thermosetting solution composition film having a satisfactory stability.

 The aromatic diamine compounds are used in an oral amount greater than the molar amount of the biphenyltetracarboxylic acid compound. For example, the aromatic diamine compound is used in an amount of 1.1 to 2.0 moles, preferably 1.15 to 35.30 moles, per mole of the biphenyltetracarboxylic acid compound.

 When a mixture of p-phenylene diamine and 1,3-bis (4-aminophenoxy) benzene is used as the aromatic diamine compound, the mixture is preferably used in a

an amount of 1.15 to 1.30 moles per mole of the biphenyltetracarboxylic acid compound, and p-phenylene diamine is preferably used in an amount of 50 to 70 mol% based on the total amount of p-phenylene diamine and 1,3-bis (4-aminophenoxy) benzene, whereby the resulting cured polyimide article may exhibit sufficient thermal resistance and satisfactory molding characteristics. 5

 The thermosetting solution composition of the invention further comprises a lower partial aliphatic alkyl ester of 4- (2-phenylethynyl) phthalic acid in a molar amount as much as 1.8-2.2 times, preferably as much as 1.95-2 , 05 times, a molar amount corresponding to the difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound. 10

  The thermosetting solution composition of the invention further comprises an organic solvent comprising a lower aliphatic alcohol (monovalent aliphatic alcohol having 1 to 6 carbon atoms) as the main component. Methanol and ethanol are preferred. A mixture of lower aliphatic alcohols can be used. However, if the mixture is used, the mixture preferably contains at least 50% by volume, more preferably at least 80% by volume, of methanol or ethanol. Other low boiling solvents may also be used in combination with the lower aliphatic alcohol. However, the other low boiling solvents in the combination are preferably in an amount of 30% by volume or less.

 The thermosetting solution composition of the invention can be easily prepared by the step comprising the following three steps:

 (1) putting a biphenyltetracarboxylic acid compound containing at least 15 mol% of 2,3,3 ', 4'-biphenyltetracarboxylic and / or 2,2', 3,3'-biphenyltetracarboxylic dianhydride, and 4- ( 2-phenylethynyl) phthalic in an organic solvent comprising a lower aliphatic alcohol, to form a suspension; 25

 (2) heating the suspension to give a solution in which a lower aliphatic alkyl-ter of the biphenyltetracarboxylic acid compound and a lower aliphatic alkyl ester of 4- (2-phenylethynyl) phthalic acid are dissolved;

 Y

 (3) Mix an aromatic diamine compound with the solution obtained above in (2).

 It has been observed that a thermosetting solution composition comprises methyl esters of the biphenyl tetracarboxylic acid compound and 4- (2-phenylethynyl) phthalic acid, a prepreg prepared from the solution composition exhibits satisfactory stability in the process of manufacturing a cured polyimide article under high temperature pre-35 sion. Accordingly, the lower aliphatic alkyl esters in the thermosetting solution composition are preferably methyl esters. However, in the event that environmental pollution caused by the evaporation of

Methanol in the manufacture of an aromatic polyimide article from the prepreg, the free methanol can be removed from the prepreg by the following method:

 first preparation of a thermosetting solution composition using methanol;

 drying of the thermosetting methanolic solution composition prepared to give a thermosetting powder composition;

 ethanol solution of the thermosetting powder composition, to give a thermosetting ethanolic solution composition; Y

 Preparation of a prepreg from the composition of thermosetting ethanolic solution. 10

 In the method indicated above, the thermosetting powder composition is preferably prepared by heating the thermosetting methanolic solution composition at a temperature not exceeding 60 ° C. The thermosetting powder composition may contain a small amount of methanol.

 The prepreg preferably contains a volatile component that includes a lower aliphatic alcohol in an amount of 18 to 25% by weight, more preferably in an amount of 20 to 22% by weight.

 The thermosetting solution composition of the invention additionally preferably contains an imidazole compound in an amount of 0.01 to 3% by weight, based on the total volume of the reactive compounds (ie, biphenyl-20 acid compound tetracarboxylic, 4- (2-phenylethynyl) phthalic acid compound, and aromatic diamine compound). In the preparation of the thermosetting solution composition, the imidazole compound serves to accelerate the dissolution of the incorporated acid components, such that the solution can be completed within a short period of time. Additionally, the imidazole compound serves to accelerate the thermosetting of prepreg 25 in the process in which the prepreg is heated under pressure to manufacture a cured polyimide article. There is no specific limitation with respect to imidazole compounds. Examples of the imidazole compounds include known imidazole catalysts such as 2-methylimidazole and 1,2-dimethylimidazole.

 In the thermosetting solution composition of the invention, the total amount of the reactive compounds mentioned above (i.e., biphenyl tetracarboxylic acid compound, 4- (2-phenylethynyl) phthalic acid compound and aromatic diamine compound) preferably it is 30 to 80% by weight, more preferably 35 to 75% by weight, more preferably 40 to 75% by weight, and most preferably 45 to 75% by weight.

 A prepreg is prepared by impregnating a matrix sheet of high strength fibers with the thermosetting solution composition of the invention and heating the impregnated matrix sheet to remove a portion of the solvent by evaporation.

 The prepreg should contain an appropriate amount of a volatile component and an appropriate amount of a resin component so that it can be easily handled during the manufacture of the cured polyimide article. Handling features include susceptibility of draping and stickiness. Accordingly, the matrix sheet can be impregnated with the thermosetting solution composition by immersion method or casting method, and then heated in a dry air oven to remove an excessive volatile component, in order to prepare an appropriate prepreg having a resin content (Rc) of 35 to 55% by weight and a volatile content (Vc) of 10 25% by weight. The heating process is generally carried out at a temperature in the range of 40 to 150 ° C, for 0.5 to 30 minutes. 10

 The matrix sheet comprises known high strength fibers such as carbon fibers, aramid fibers, glass fibers, and ceramic fibers such as titanium dioxide fibers.

 The prepreg of the invention can be heated to give a cured polyimide article that has Tg greater than 300 ° C (or that does not exhibit any Tg at temperatures of 300 ° C or below).

 The prepreg is preferably in the form of a coil and is preferably coated on both surfaces with a cover sheet such as a poly (ethylene terephthalate) sheet and a paper sheet for storage and transport.

 The prepreg can be processed to give a resin article cured by a variety of known methods. For example, a prepreg coil is cut to give plural sheets having the desired size. The plural prepreg sheets (for example, from several sheets to more than a hundred sheets) are stratified on top of each other, and the formed prepreg laminate is heated under pressure by means of a hot press. In the pressure heating process, the thermosetting composition gives an article of aromatic polii-25 measured by thermal imitation reaction and curing reaction.

 For example, the prepregs laminate is heated under pressure as illustrated in Fig. 4. In more detail, the prepregs laminate 11 is placed between a pair of air permeable sheets (such as poly (terephthalate sheets). ethylene) and glass sheets) 12a, 12b. On each of the air permeable sheets 12a, 12b a separating film 30 13a, 13b is placed. The laminate thus prepared is placed between a pair of heat-resistant nonwoven fabrics (sponge materials) 14a, 14b, and then enclosed in a heat resistant bag 15. The heat resistant bag 15 is then sealed at the open end 16, for example, by heat seal. The inner space of the bag 15 is evacuated by extracting the air through the evacuation tube 17 by means of a vacuum pump, while the enclosed laminate is heated under pressure. In the process of evacuation and heating under pressure, it is preferred to vary the degree of vacuum and the temperature according to the patterns illustrated in Figures 5 to 10.

 The present invention is further described by the following non-limiting examples.

 In the following examples, the measured values and the calculated values are obtained as follows.

 (1) Total content of reactive components in solution 5

 Total content of reactive components (%) = 100 x [quantities (g) of the reactive components used] / [quantities (g) of the reactive components used + quantity (g) l solvent]

 (2) Solution viscosity

 The viscosity in solution is determined at 25 ° C by means of an E 10 type viscometer (available from Tokyo Measuring Apparatus Co., Ltd.).

 (3) Glass transition temperature (Tg) of the cured resin article.

 For measurement, the cured resin article is heated in gaseous nitrogen by means of SSC5200-DSC-3200 (available from Seiko-Instrument Co., Ltd.) at a temperature rise rate of 20 ° C / min. fifteen

 (4) Linear expansion coefficient of the cured resin article

 For measurement, the cured resin article is heated from 50 ° C to 250 ° C in a nitrogen atmosphere by means of TMA-50 (available from Shimazu Seisakusho Co., Ltd.) at a temperature rise rate of 5 ° C / min.

 (5) Volatile content (Vc) and resin content (Rc) 20

 Vc (%) = 100 x [amount (g) of uncured prepreg - amount (g) of prepreg after heating at 370 ° C for one hour] / [amount (g) of uncured prepreg]

 Rc (%) = 100 x [amount (g) of prepreg after heating at 370 ° C for one hour - amount (g) of matrix sheets] / [amount (g) of prepreg after heating at 370 ° C for one hour ] 25

 (6) Complex viscosity of prepreg

 A dynamic viscoelasticity in a nitrogen atmosphere is measured by means of a dynamic fusion viscoelastometer (available from T.A. Instrument Japan Co., Ltd.) at a temperature rise rate of 2 ° C / min.

 (7) Thermal decomposition temperature of resin article 30

 The heat treated resin article is heated in TG / DTA 6300 (available from S.I.I. Nanotechnology Co., Ltd) at a temperature rise rate of 5 ° C / min. The temperature at which a weight loss of 5% by weight is observed is recorded as the temperature of thermal decomposition.

 (8) Determination of the 1H-NMR spectrum 35

 The 1H-NMR spectrum was measured at a resonance frequency of 400 MHz in deuterated methanol by means of an EX-400 nuclear magnetic spectrometer, FT-NMR (available from JEOL, Ltd.).

 In the examples that follow, the following monomer components (ie reactive components) were used:

 a-BPDA: 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride

 s-BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride

 PEPA: 4- (2-phenylethynyl) phthalic anhydride 5

 TPE-R: 1,3-bis (4-aminophenoxy) benzene

 PPD: p-phenylene diamine

 MPD: m-phenylenediamine

[Example 1]

(1) Preparation of the thermosetting solution composition 10

 In a separable flask of 100 ml capacity with 4 mouths equipped with agitator, reflux condenser and nitrogen inlet, 11.77 g (0.0400 mol) of a-BPDA, 4.97 g (0.0200 mol) were placed of PEPA, and 13.54 g of ethanol in a stream of nitrogen gas. The resulting mixture was stirred at reflux for 5 hours to give a homogeneous solution. The solution was then cooled to room temperature. 6.58 g (0.025 mol) of TPE-R and 2.97 g (0.0275 mol) of PPD were added to the solution under stirring. The resulting mixture was heated at 60 ° C for 60 minutes to give a homogeneous solution (thermosetting solution composition).

 The homogeneous solution was spread on a polyimide film (Upilex 125S, available from Ube Industries, Ltd.) and treated successively at 80 ° C for 30 minutes, 20 135 ° C for 30 minutes, 180 ° C for 30 minutes, 250 ° C for 30 minutes, 300 ° C for 30 minutes, and 370 ° C for 60 minutes, in order to give a clear resin film having a thickness of approximately 0.1 mm.

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1. 25

(2) Prepreg preparation

 The homogenous solution mentioned above (thermosetting solution composition) was spread on a poly (ethylene terephthalate) (PET) film to form a solution film. A carbon fiber cloth (FAW 198 g / m2, plain cloth, T300-3K, available from Toray Corp.) having dimensions of 80 30 mm x 100 mm was placed on the solution film. The laminate thus prepared was placed on a hot plate heated at 40 ° C under such conditions that the PET film was in contact with the hot plate. In the hot plate, the upper surface of the carbon fiber fabric was slightly pressed onto the PET film so that the fabric could be impregnated with the solution. Subsequently, the carbon cloth impregnated with the solution was stopped from the PET film, and dried by keeping it suspended for 3 minutes in a hot air oven heated at 100 ° C. The dried carbon cloth was removed from the oven, placed between a pair of PET films (thickness: 25 μm), and pressed at a pressure of 0.1

MPa for one minute by means of a hot press heated to 80 ° C. In this way a prepreg was obtained.

(3) Cured resin sheet manufacturing

 The prepreg was successively heated at 135 ° C for 30 minutes, 180 ° C for 30 min, 250 ° C for 30 min, 300 ° C for 30 min, and 370 ° C for 60 min, to make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc and Rc values are indicated in Table 2.

[Example 2] 10

(1) Preparation of the thermosetting solution composition

 The procedures of Example 1- (1) were repeated except that TPE-R, PPD and ethanol were used in amounts of 4.39 g (0.0150 mol), 3.78 g (0.0350 mol), and 11, 72 g, respectively, to give a homogeneous solution (thermosetting solution composition). Subsequently, the homogeneous solution was processed in the same manner as in Example 15 1- (1) to give a clear resin film (thickness: approximately 0.1 mm).

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

(2) Prepreg preparation

 The procedures of Example 1- (2) were repeated using the homogeneous solution 20 prepared above in (1), to prepare a prepreg.

 The prepreg was subjected to dynamic viscoelasticity. The measured viscoelasticity is shown in Fig. 1.

(3) Cured resin sheet manufacturing

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc and Rc values are indicated in Table 2.

[Example 3] 30

(1) Preparation of the thermosetting solution composition

 The procedures of Example 1- (1) were repeated except that a-BPDA, s-BPDA, PEPA and ethanol were used in amounts of 5.89 g (0.0200 mol), 5.98 g (0.0200 mol) , 4.97 g (0.0200 mol), and 12.37 g, respectively, to give a homogeneous solution (thermosetting solution composition). Additionally, the homogeneous solution 35 was processed in the same manner as in Example 1- (1), to give a clear resin film (thickness: approx. 0.1 mm).

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

(2) Prepreg preparation

 The procedures of Example 1- (2) were repeated using the homogeneous solution prepared above in (1), to prepare a prepreg. 5

(3) Cured resin sheet manufacturing

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 Volatile content (Vc) and resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from 10 prepreg. The determined Vc and Rc values are indicated in Table 2.

[Example 4]

(1) Preparation of the thermosetting solution composition

 The procedures of Example 1- (1) were repeated except that a-BPDA, s-BPDA, PEPA and ethanol were used in amounts of 3.53 g (0.0120 mol), 8.24 g (0.0280 mol) , 4.97 g (0.0200 mol), and 11.27 g, respectively, to give a homogeneous solution (thermosetting solution composition). Subsequently, the homogeneous solution was processed in the same manner as in Example 1- (1) to give a clear resin film (thickness: approx. 0.1 mm).

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

(2) Prepreg preparation

 The procedures of Example 1- (2) were repeated using the homogeneous solution prepared in (1) above, to prepare a prepreg.

(3) Manufacture of the cured resin sheet 25

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The Vc and Rc values determined are indicated in Table 2. 30

[Example 5]

(1) Preparation of the thermosetting solution composition

 The procedures of Example 1- (1) were repeated except that TPE-R, MPD (instead of PPD) and ethanol were used in amounts of 2.07 g (0.0070 mol), 4.66 g (0.0430 moles), and 12.64 g, respectively, to give a homogeneous solution (composition of thermosetting solution). Additionally, the homogeneous solution was processed in the same manner as in Example 1- (1), to give a clear resin film (thickness: approx. 0.1 mm).

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

(2) Prepreg preparation

 The procedures of Example 1- (2) were repeated using the homogeneous solution prepared above in (1), to prepare a prepreg. 5

(3) Cured resin sheet manufacturing

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 Volatile content (Vc) and resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from 10 prepreg. The determined Vc and Rc values are indicated in Table 2.

 In this example, the next cured resin sheet was subsequently manufactured.

(4) Cured resin sheet manufacturing

 A carbon fiber cloth (FAW 198 g / m2, plain cloth, T300-3K, available from Toray Corp.) was placed in a dry air oven purged with gaseous nitrogen and heated at 15 350 ° C for 30 minutes. By measuring the weight loss of the carbon fiber fabric after heat treatment, it was confirmed that 0.7% of a sizing agent had been removed.

 The procedures of Example 5- (2) and 5- (3) were repeated using the heat treated carbon fiber cloth and the homogeneous solution of Example 5- (1), to prepare a prepreg and then make a resin sheet cured

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc value was 15% by weight, and the Rc value was 39% by weight.

(5) Manufacture of cured resin sheet 25

 The procedures of Example 5- (2) and 5- (3) were repeated using the Tirano fiber cloth (titanium dioxide fiber cloth, FAW 328 g / m2, plain cloth, TM-S17E08PX, available from Ube Industries, Ltd.) and the homogeneous solution of Example 5- (1), to prepare a prepreg and then make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the 30 data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc value was 16% by weight, and the Rc value was 39% by weight.

(6) Cured resin sheet manufacturing

 Ten g (10 g) of the homogeneous solution prepared in Example 5- (1) was diluted with 2.5 g of methyl ethyl ketone. The resulting solution was a homogeneous solution. 35

 The procedures of Example 5- (2) and 5- (3) were repeated using the homogenous solution mentioned above, to prepare a prepreg and then make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc value was 15% by weight, and the Rc value was 39% by weight.

[Example 6]

(1) Preparation of the thermosetting solution composition 5

 The procedures of Example 1- (1) were repeated using 11.06 g (0.0376 mol) of a-BPDA, 16.55 g (0.0667 mol) of PEPA, 10.38 g (0.0355 mol) of TPE-R, 3.84 g (0.0355 mol) of MPD and 17.9 g of ethanol, to give a homogeneous solution (thermosetting solution composition). Additionally, the homogeneous solution was processed in the same manner as in Example 1- (1) to give a clear resin film (thickness: approx. 0.1 mm).

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

(2) Prepreg preparation

 The procedures of Example 1- (2) were repeated using the homogeneous solution 15 prepared above in (1), to prepare a prepreg.

(3) Cured resin sheet manufacturing

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the 20 data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc and Rc values are indicated in Table 2.

[Example 7]

(1) Preparation of the thermosetting solution composition

 The procedures of Example 1- (1) were repeated using 15.59 g (0.0530 mol) of a-BPDA, 23.33 g (0.0940 mol) of PEPA, 14.62 g (0.0500 mol ) of TPE-R, 2.70 g (0.0250 mol) of PPD, 2.70 g (0.0250 mol) of MPD, and 25.26 g of ethanol, to give a homogeneous solution (thermosetting solution composition ). Subsequently, the homogeneous solution was processed in the same manner as in Example 1- (1) to give a clear resin film (thickness: approx. 0.1 mm). 30

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

 (2) Prepreg preparation

 The procedures of Example 1- (2) were repeated using the homogeneous solution prepared above in (1), to prepare a prepreg. 35

 (3) Cured resin sheet manufacturing

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc and Rc values are indicated in Table 2.

[Example 8]

(1) Preparation of the thermosetting solution composition 5

 The procedures of Example 1- (1) were repeated except that TPE-R was not used, and that PPD and ethanol were used in amounts of 5.41 g (0.0500 mol) and 14.46 g, respectively, to give a homogeneous solution (thermosetting solution composition). Additionally, the homogeneous solution was processed in the same manner as in Example 1- (1) to give a clear resin film (thickness: approx. 0.1 mm). 10

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

(2) Prepreg preparation

 The procedures of Example 1- (2) were repeated using the homogeneous solution prepared above in (1), to prepare a prepreg. fifteen

(3) Cured resin sheet manufacturing

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 Volatile content (Vc) and resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from prepreg. The determined Vc and Rc values are indicated in Table 2.

[Example 9]

(1) Preparation of the thermosetting solution composition

 In a 2000 ml separable flask with 4 mouths, equipped with stirrer, reflux condenser and gaseous nitrogen inlet, 294.22 g (1,000 25 moles) of a-BPDA, 124.12 g (0.500 moles) ) of PEPA, and 415.06 g of methanol in a stream of gaseous nitrogen. The resulting mixture was stirred at reflux for 5 hours to give a homogeneous solution (the mixture became a homogeneous solution in the course of approximately 3 hours, but stirring at reflux was continued for a further 2 hours. The solution was cooled. then at room temperature, 109.63 g (0.375 mol) of TPE-R and 94.62 g (0.875 mol) of PPD were added to the solution with stirring, the resulting mixture was heated at 60 ° C for 60 minutes to give a homogeneous solution (composition of the thermosetting solution.) Subsequently, the homogeneous solution was processed in the same manner as in Example 1- (1) to give a clear resin film (thickness: approx. 0.1 mm ) .35

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

(2) Prepreg preparation

 The homogenous solution mentioned above (composition of the thermosetting solution) was spread on a film of poly (ethylene terephthalate) (PET) to form a solution film. A carbon fiber cloth (FAW 320 g / m2, plain cloth, T800-12K, available from Toray Corp.) having dimensions of 320 mm x 320 mm was placed on the solution film. The laminate thus prepared was placed on a hot plate 5 heated to 40 ° C under such conditions that the PET film was in contact with the hot plate. In the hot plate, the upper surface of the carbon fiber fabric was lightly pressed onto the PET film so that the fabric could be impregnated with the solution. Subsequently, the carbon cloth impregnated with the solution was separated from the PET film, and dried by keeping it suspended for 3 minutes in a hot air oven heated at 90 ° C. The dried carbon cloth was removed from the oven, placed between a pair of PET films (thickness: 25 μm), and pressed at a pressure of 0.1 MPa for one minute by means of a hot press heated to 80 ° C. In this way a prepreg was obtained.

 The prepreg thus prepared exhibited satisfactory adhesiveness and susceptibility to draping.

 The prepreg was subjected to dynamic viscoelasticity. The measured viscoelasticity is shown in Fig. 1.

 (3) Cured resin sheet manufacturing

 The prepreg was successively heated at 135 ° C for 30 min, 180 ° C for 30 min, 20 250 ° C for 30 min, 300 ° C for 30 min, and 370 ° C for 60 min, to make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined Vc and Rc values are indicated in Table 2. 25

[Example 10]

(1) Preparation of a thermosetting solution composition

 In the same separable flask described in Example 9- (1) 294.22 g (1,000 moles) of a-BPDA, 124.12 g (0.500 moles) of PEPA, 1.25 g of 2-methylimidazole were placed, and 415.06 g of methanol in a stream of gaseous nitrogen. The resulting mixture was stirred at reflux for 3 hours to give a homogeneous solution (the mixture became a homogeneous solution over the course of about 1 hour, but stirring was continued at reflux for a further 2 hours). The solution was then cooled to room temperature. 109.63 g (0.375 mol) of TPE-R and 94.62 g (0.875 mol) of PPD were added to the solution under stirring. The resulting mixture was heated at 60 ° C for 60 minutes to give a homogeneous solution (thermosetting solution composition).

 The homogeneous solution was subjected to the determination of the 1H-NMR spectrum. The 1H-NMR spectrum is shown in Fig. 2.

 Additionally, the homogeneous solution was processed in the same manner as in Example 1- (1), to give a clear resin film (thickness: approx. 0.1 mm).

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

 The other physical characteristics of the resin film are indicated below:

 Tensile strength: 127 MPa (at 23 ° C, according to ASTM D 882)

 Tensile modulus: 2.8 GPa (at 23 ° C, in accordance with ASTM D 882)

 Breaking extent: 13% (at 23 ° C, according to ASTM D 882)

 Water absorption: 2.2% (at 23 ° C, saturation absorption, according to ASTM D 570) 10

 Thermal decomposition temperature: 563ºC

 Linear expansion coefficient: 51 ppm

 (2) Preparation of a prepreg

 The procedures of Example 1- (2) were repeated using the homogeneous solution prepared above in (1), to prepare a prepreg. fifteen

 (3) Cured resin sheet manufacturing

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet.

 Volatile content (Vc) and resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from prepreg. The determined values of Vc and Rc are indicated in Table 2.

 [Example 11]

 (1) Preparation of the thermosetting solution composition

 In the same separable flask described in Example 9- (1) 294.22 g (1,000 moles) of a-BPDA, 124.12 g (0.500 moles) of PEPA, 1.25 g of 2-methylimidazole were placed, and 415.06 g of n-propanol in a stream of gaseous nitrogen. The resulting mixture was stirred at reflux for 3 hours to give a homogeneous solution (the mixture became a homogeneous solution over the course of about 1 hour, but stirring was continued under reflux for an additional 2 hours. The solution was then cooled to ambient temperature 109.63 g (0.375 mol) of TPE-R and 94.62 g 30 (0.875 mol) of PPD were added to the solution with stirring. The resulting mixture was heated at 60 ° C for 60 minutes to give homogeneous solution (thermosetting solution composition) Additionally, the homogeneous solution was processed in the same manner as in Example 1- (1), to give a clear resin film (thickness: approx. 0.1 mm).

 The viscosity of the homogeneous solution and the Tg value of the resin film are indicated in Table 1.

 (2) Preparation of a prepreg

 The procedures of Example 9- (2) were repeated except that the homogeneous solution prepared above in (1) was used, and the drying procedure was performed at 100 ° C for 15 minutes, to prepare a prepreg.

 The prepreg thus prepared exhibited satisfactory stickiness and susceptibility to draping. 5

 The prepreg was subjected to dynamic viscoelasticity. The measured viscoelasticity is shown in Fig. 1.

 (3) Manufacture of a cured resin sheet

 The procedures of Example 9- (3) were repeated using the prepreg prepared above in (2), to make a cured resin sheet. 10

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. The determined values of Vc and Rc are indicated in Table 2.

 Table 1

 Monomer content (% p) Solution viscosity (poise) Tg of the cured sheet (ºC)

 fifteen

Example 1 66 105 323

Example 2 68 112 365

Example 3 68 107 319

Example 4 70 106 321

Example 5 65 107 342 20

Example 6 71 115 317

Example 7 70 110 336

Example 8 60.5 106 * 1

Example 9 60 2.0 357

Example 10 60 2.2 357 25

                     Example 11 60 113 357_____

 Remarks: The monomer content means the concentration of the reactive components in the thermosetting solution composition.

 * 1 means that no clear Tg value was observed at temperatures below 30 400 ° C.

Table 2

 Homogeneous Solution

 Vc (% weight) Rc (% weight)

 Example 1

 16 39

 Example 2

 15 39

 Example 3

 16 40

 Example 4

 15 39

 Example 5

 15 38

 Example 6

 15 39

 Example 7

 16 39

 Example 8

 15 39

 Example 9

 13 41

 Example 10

 13 41

 Example 11

 14 36

 Examples 12 and 13 below describe the preparation of the cured resin article in the manner illustrated in Fig. 4.

[Example 12] 5

 The prepreg prepared in Example 5- (2) was cut to give 16 sheets of prepreg, each of which had dimensions of 50 mm x 60 mm. The 16 hours of prepreg were stratified over each other, and the laminate thus prepared was introduced into the heat-resistant bag (as illustrated in Fig. 4). The open end of the bag was tightly sealed by heat sealing, and the bag was placed in a hot press. The laminate contained in the bag was thus heated under pressure, under such conditions of degree of vacuum in the bag and heating temperature that the historical curve indicated in Figs. 5 to 7. In this way a cured resin article was manufactured.

 The cured resin article was subjected to measurement of interlaminar shear strength at 23 ° C cure with ASTM D2344, to give a shear strength 15 of 60 MPa. The cured resin article was subsequently subjected to defect detection by means of an ultrasonic defenses detector. No significant defect was detected.

[Example 13]

 The prepreg prepared in Example 9- (2) was cut to give 12 sheets of prepreg, each of which had dimensions of 300 mm x 300 mm. The 12 prepreg sheets were stratified on top of each other, and the laminate thus prepared was placed in the heat-resistant bag (as illustrated in Fig. 4). The open end of the bag was tightly sealed by heat sealing, and the bag was placed in a hot press. Stratified

The contents of the bag were heated under pressure, under conditions of degree of vacuum in the bag and heating temperature such that the historical curve of Figs. 8 to 10. Thus a cured resin article was manufactured.

 The cured resin article contained the 59% vol carbon fiber matrix and an empty volume of 0.5% vol. The carbon fiber matrix content and the empty volume 5 were determined in accordance with ASTM D3171.

 Next, the cured resin article was subjected to defect detection by means of an ultrasonic defect detector. No significant defect was detected.

 The physical characteristics of the cured resin article are indicated below:

 Flexural strength (according to ASTM D790): 10

 815 MPa (at 23 ° C), 479 MPa (at 288 ° C)

 Flexural modulus (according to ASTM D790):

 61.9 GPa (at 23 ° C), 62.0 GPa (at 288 ° C)

 Interlaminar shear strength (according to ASTM D2344):

 68.8 MPa (at 23 ° C), 38.2 MPa (at 288 ° C) 15

 The cured resin article was further heated at 357 ° C for 6 hours in a hot air oven. The article so heated was subjected to a measure of the interlaminar shear strength. The results are indicated below:

 Interlaminar shear strength (according to ASTM D2344):

 49.6 MPa (at 23 ° C), 33.9 MPa (at 288 ° C). twenty

 Examples 14 and 15 below describe the preparation of a thermosetting powder composition, the preparation of a thermosetting solution composition from the powder composition, the preparation of a prepreg from the prepared thermosetting solution composition, and the manufacture of a cured resin article.

[Example 14] 25

(1) Preparation of the thermosetting powder composition

 40.00 g of the homogeneous solution (thermosetting solution composition) pre-stopped in Example 10- (1) were placed in a 500 ml capacity flask, of the be-renjena type. The flask was immersed in a water bath heated to 40 ° C, and the flask was evacuated for 3 hours by means of an evaporator to remove methanol. In this way a powder composition (thermosetting powder solution composition) was obtained.

 The powder composition was examined as follows.

 A polyimide film having dimensions of 300 mm x 300 mm and an air-permeable tetrafluoroethylene / glass sheet having the same dimensions and a thickness of 2 mm were arranged neatly on a stainless steel plate having the same dimensions. An stainless steel frame (width 50 mm, length 100 mm, thickness 3 mm) was placed on the air permeable sheet. The powder composition was placed in the frame. The same sheet of paper was placed neatly on the frame

Tetrafluoroethylene / air-permeable glass, polyimide film and stainless steel plate to cover the frame. The frame with the coating sheets was placed in a high temperature vacuum press (KVHC-PRESS, available from Kitagawa Seiki Co., Ltd.) and heated from room temperature to 250 ° C for 3 hours and subsequently to 250 ° C for 2 hours. The vacuum press was evacuated until a vacuum of 2 Torr was established in the internal space for 30 minutes. The powder composition was then heated in the frame at 370 ° C for 24 minutes under 5 MPa, and maintained under these conditions for one hour. The composition was then cooled under vacuum at 30 ° C under pressure (sic), to give a resin plate (width 50 mm, length 100 mm, thickness 3 mm).

 The resin plate was cut into a 50 mm x 50 mm piece, and subjected to the following measure of heat loss:

  Weight loss after heat treatment:

   0.60% (300ºC, 500 hours, in air)

   0.15% (275 ° C, 500 hours, in air)

[Example 15] 15

(1) Preparation of a thermosetting powder composition

 20.00 g of the homogeneous solution (thermosetting solution composition) pre-stopped in Example 10- (1) were placed in an eggplant-type flask of 300 ml capacity. The flask was immersed in a water bath heated to 40 ° C, and the flask was evacuated for 3 hours by means of an evaporator to remove methanol. In this way, 14.2 g of a powder composition (thermosetting powder composition) were obtained.

 The homogeneous solution was subjected to the determination of the 1H-NMR spectrum. The 1H-NMR spectrum is shown in Fig. 3.

 (2) Preparation of the thermosetting solution composition from the thermosetting powder composition 25

 13.78 g of the powder composition (thermosetting powder composition) obtained above in (1) was dissolved in 4.59 g of ethanol to give a homogenous solution (thermosetting solution composition).

 (3) Preparation of prepreg

 A prepreg was prepared in the manner described in Example 1- (2) using the ethanolic solution composition prepared above in (2).

 The prepreg thus prepared exhibited stickiness and susceptibility of satisfactory draping factories.

 The prepreg was subjected to the measure of dynamic viscoelasticity. The measured viscoelasticity is shown in Fig. 1. 35

 (4) Manufacture of a cured resin sheet

 The procedures of Example 1- (3) were repeated using the prepreg prepared above in (3), to make a cured resin sheet.

 The volatile content (Vc) and the resin content (Rc) were determined from the data measured in the manufacturing process of the cured resin sheet from the prepreg. Vc was determined to be 15% and Rc was 41%.

 (5) Concentration dependence and temperature dependence of the solution viscosity of the thermosetting solution composition 5

 The thermosetting powder composition in Example 14- (1) was dissolved in ethanol to give homogeneous solutions having different concentrations. The relationship between the concentration of the solution and the viscosity of the solution is indicated below.

  10

 Dust concentration (% weight)

 Viscosity of the solution (30ºC, poise) Imide content (% weight)

 fifty

 0.3 40

 62.5

 1.9 50

 75

 54 60

 Remarks: The imide content was determined by the following method: The powder composition (thermosetting powder composition) was processed to give a fully imitated product which was then heated at 250 ° C for 30 minutes to completely remove methanol; The weight of the imitated product was determined, and a weight loss ratio of the powder composition to the imitated product was calculated. The imide content was calculated by the following equation:

 Imide content (%) = dust concentration (%) x (1-weight loss ratio)

 The thermosetting solution composition (concentration of 62.5% by weight in 20 ethanol) prepared from the thermosetting powder composition of Example 14- (1) was measured as the viscosity dependence of the solution with respect to temperature. The results are indicated below:

 Temperature (ºC)

 Viscosity of the solution (poise, 30ºC)

 twenty

 4,5

 30

 1.9

 40

 1.0

 fifty

 0.6

 25

[Comparative Example 1]

 The procedures of Example 1- (1) were repeated except that a-BPDA (0.0400 mol) was replaced with s-BPDA (11.77 g, 0.0400 mol), to prepare a homogenous solution. A portion of the homogeneous solution was spread on a polyimide film in the same manner as in Example 1- (1) and heated at 80 ° C for 30 min, 135 ° C for 30 min, 180 ° C for 30 min, 250 ° C for 30 min, 300 ° C for 30 min, and 370 ° C for 60 min. In the course of the treatment, the solution film became an opaque and brittle film.

Claims (17)

 1. A thermosetting solution composition comprising a biphenyltetracarboxylic acid compound containing at least 15 mol% of a lower partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or an infectious partial aliphatic alkyl ester Rior of 2,2 ', 3,3'-biphenyltetracarboxylic acid, an aromatic diamine compound in a molar amount greater than a molar amount of the biphenyltetracarboxylic acid compound, a lower partial aliphatic alkyl ester of a 4- acid compound (2-phenylethynyl) phthalic in a molar amount as much as 1.8-2.2 times a molar amount corresponding to a difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound, and an organic solvent comprising a lower aliphatic alcohol.  2. The thermosetting solution composition of claim 1, wherein the lower aliphatic alcohol is methanol or ethanol.  3. The thermosetting solution composition of claim 1, wherein each of the lower partial aliphatic alkyl esters is a partial methyl ester or a partial ethyl ester.  4. The thermosetting solution composition of claim 1, wherein the molar amount of the lower partial aliphatic alkyl ester of the compound 4- (2-phenylethynyl) phthalic acid is as much as 1.95-2.05 times a corresponding molar amount unlike the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound.  5. The thermosetting solution composition of claim 1, wherein a total amount of the biphenyltetracarboxylic acid compound, the aromatic diamine compound, and the phthalic 2- (2-phenylethynyl) acid compound is in the range of 30 to 80% by weight, based on the amount of the solution composition. 25  6. The thermosetting solution composition of claim 1, wherein the biphenyltetracarboxylic acid compound comprises at least 50% molar of 2,3,3 ', 4'-biphenyltetracarboxylic acid compound comprising a partial aliphatic alkyl ester compound lower 2,3,3 ', 4'-biphenyltetracarboxylic acid.  7. The thermosetting solution composition of claim 1, wherein the aromatic diamine compound comprises at least 50 mol% of an aromatic diamine having an aromatic ring in a molecular structure thereof.  8. The thermosetting solution composition of claim 1, wherein the aromatic diamine compound comprises p-phenylenediamine, 1,3-bis (4-aminophenoxy) benzene, or a mixture thereof. 35  9. The thermosetting solution composition of claim 1, which additionally comprises an imidazole compound.  10. A thermosetting solution composition comprising a compound of biphenyltetracarboxylic acid containing at least 15 mol% of a partial methyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or a partial methyl ester of acid 2 , 2 ', 3,3'-biphenyltetracarboxylic acid, an aromatic diamine compound in a molar amount greater than a molar amount of the biphenyltetracarboxylic acid compound, a partial methyl ester 5 of a 4- (2-phenylethynyl) phthalic acid compound in a molar amount as much as 1.8-2.2 times a molar amount corresponding to the difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound, and an organic solvent comprising ethanol.  11. A thermosetting powder composition comprising a compound of 10 biphenyltetracarboxylic acid containing at least 15 mol% of a lower partial aliphatic alkyl ester of 2,3,3 ', 4'-biphenyltetracarboxylic acid and / or a partial aliphatic alkyl ester infe - 2,2 ', 3,3'-biphenyltetracarboxylic acid, an aromatic diamine compound in a molar amount greater than the molar amount of the biphenyltetracarboxylic acid compound, and a lower partial aliphatic alkyl ester of a compound of 4- (2 -phenylethynyl) phthalic in a molar amount as much as 1.8-2.2 times a molar amount corresponding to the difference between the molar amount of the aromatic diamine compound and the molar amount of the biphenyltetracarboxylic acid compound.  12. The thermosetting powder composition of claim 11, wherein each of the lower partial aliphatic alkyl esters is a partial methyl ester. twenty  13. A prepreg comprising a sheet matrix of a reinforcing fiber impregnated with the thermosetting solution composition of claim 1.  14. A prepreg comprising a sheet matrix of a reinforcing fiber impregnated with the thermosetting solution composition of claim 10.  15. A method of manufacturing a resin article comprising stratifying a plural number of the prepregs defined in claim 13 over each other and heating the resulting laminate under pressure.  16. A method of manufacturing a resin article comprising stratifying a plural number of the prepregs defined in claim 14 over each other and heating the resulting laminate under pressure. 30