JP2015059147A - Heat-curable solution composition, cured product using the same, prepreg, and fiber-reinforced composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-curable solution composition which has excellent oxidation resistance and provides an imide group-containing molded body having a high glass transition temperature (Tg).SOLUTION: The heat-curable solution composition is obtained by mixing: (A) an aromatic tetracarboxylic acid component containing a 2,3,3',4'-biphenyltetracarboxylic acid compound and a 3,3',4,4'-biphenyltetracarboxylic acid compound, each in the amount of 20 mol% or more; (B) an aromatic diamine component having no oxygen atom in the molecule, containing an aromatic diamine having no oxygen atom in the molecule, having two carbon-nitrogen bond axes positioned on the same straight line and an aromatic diamine having no oxygen atom in the molecule, having two carbon-nitrogen bond axes not positioned on the same straight line, each in the amount of 20 mol% or more; and (C) an end-capping agent having a phenylethynyl group.

Description

The present invention relates to a thermosetting solution composition that gives an imide oligomer having an addition-reactive functional group at its terminal by heating and a cured product thereof, a cured product using the same, a prepreg, and a fiber-reinforced composite material.

  Oligomers in which both ends of polyimide are sealed with addition-reactive functional groups are conventionally known as matrix resins for molded products and fiber-reinforced composite materials because their cured products have excellent heat resistance. Among them, an imide oligomer whose terminal is sealed with 4- (2-phenylethynyl) phthalic anhydride is considered to have an excellent balance of moldability, heat resistance, and mechanical properties. For example, Patent Document 1 discloses curing. An object of the present invention is to provide a terminal-modified imide oligomer having excellent heat resistance and mechanical properties and a highly practical product and a cured product thereof, and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, A terminal-modified imide oligomer obtained by reacting an aromatic diamine compound and 4- (2-phenylethynyl) phthalic anhydride and having a logarithmic viscosity of 0.05-1 and a cured product thereof are disclosed.

  Patent Document 2 discloses a thermosetting solution composition that does not use a high-boiling solvent such as N-methyl-2-pyrrolidone and N, N-dimethylacetamide in order to facilitate removal of the solvent in the step of forming a cured product, and For the purpose of providing an uncured resin composite impregnated with a fibrous reinforcing material, 2,3,3 ′, 4′-biphenyltetracarboxylic acid and / or 2,2 ′, 3,3′- Partially lower aliphatic alkyl ester of aromatic tetracarboxylic acid compound mainly composed of biphenyltetracarboxylic acid, aromatic diamine compound and partially lower aliphatic alkyl ester of 4- (2-phenylethynyl) phthalic acid as lower aliphatic A thermosetting solution composition dissolved in an organic solvent containing alcohol as a main component and an uncured resin composite using the same are disclosed.

JP 2000-219741 A JP 2007-308519 A

The hardened | cured material of patent document 1 and 2 has the outstanding physical property and chemical property. However, there is room for further improvement in oxidation resistance. In particular, when an diamine having an ether bond such as 1,3-bis (4-aminophenoxy) benzene or 4,4′-diaminodiphenyl ether is used as an aromatic diamine component, a problem that good oxidation resistance cannot be obtained. There is.
An object of the present invention is to provide a thermosetting solution composition that provides a cured product having excellent oxidation resistance and a high glass transition temperature (Tg).
Another object of the present invention is to provide a thermosetting solution composition suitable for use in the production of a fiber-reinforced composite material, in which no reaction failure is observed during curing.
Still another object of the present invention is to provide a cured product, a prepreg, and a fiber-reinforced composite material using the above-mentioned thermosetting solution composition.

In order to achieve the above object, the present inventors have intensively studied. As a result, by using a specific aromatic diamine having no oxygen atom in the molecule as an aromatic diamine component, the present invention has excellent oxidation resistance and a glass transition. A thermosetting solution composition that can give a cured product having a high temperature (Tg) and that does not exhibit a reaction failure during curing and is suitable for use in the production of a fiber-reinforced composite material, and a cured product using the same The present inventors have found that a prepreg and a fiber-reinforced composite material can be obtained, and have reached the present invention.
According to the first aspect of the present invention, (A) 2,3,3 ′, 4′-biphenyltetracarboxylic acid compound and 3,3 ′, 4,4′-biphenyltetracarboxylic acid compound are each 20 An aromatic tetracarboxylic acid component containing at least mol%, (B) an aromatic diamine in which two carbon-nitrogen bond axes derived from an amino group are located on the same straight line and has no oxygen atom in the molecule, and an amino group An aromatic diamine having no oxygen atom in the molecule, wherein the two derived carbon-nitrogen bond axes are not located on the same straight line and each contains 20 mol% or more of an aromatic diamine having no oxygen atom in the molecule. There is provided a heat-curable solution composition obtained by mixing a component and an end-capping agent having (C) a phenylethynyl group.

In the above thermosetting solution composition, aromatic diamines having two carbon-nitrogen bond axes derived from the amino group (B) on the same straight line and having no oxygen atom in the molecule, -Diaminobenzene, an aromatic diamine that does not have two carbon-nitrogen bond axes derived from an amino group on the same straight line and has no oxygen atom in the molecule can be 1,3-diaminobenzene .
Moreover, the terminal blocker which has the said phenylethynyl group of (C) can be made into a 4- (2-phenylethynyl) phthalic acid compound.
The molar ratio of the aromatic diamine component to the aromatic tetracarboxylic acid component (number of moles of aromatic diamine component / number of moles of aromatic tetracarboxylic acid component) can be 1.067 to 1.125.

  According to the 2nd aspect of this invention, the hardened | cured material obtained by heat-curing the said thermosetting solution composition is provided.

  According to a third aspect of the present invention, there is provided a prepreg characterized in that a fibrous reinforcing material is impregnated with the thermosetting solution composition.

  According to a fourth aspect of the present invention, there is provided a fiber-reinforced composite material obtained by heat-curing the prepreg.

  As described above, according to the present invention, a cured product having excellent oxidation resistance and a high glass transition temperature (Tg) can be provided, and no reaction failure is observed at the time of curing, thereby producing a fiber-reinforced composite material. A thermosetting solution composition suitable for use in the present invention, a cured product using the composition, a prepreg, and a fiber-reinforced composite material can be provided.

Hereinafter, suitable embodiment is described in detail about the thermosetting solution composition of this invention.
The heat-curable solution composition of this embodiment is a solution composition that gives an imide oligomer having an addition-reactive functional group at the terminal and a cured product thereof by heating. The imide oligomer is an aromatic tetracarboxylic acid containing at least 20 mol% of 2,3,3 ′, 4′-biphenyltetracarboxylic acid compound and 3,3 ′, 4,4′-biphenyltetracarboxylic acid compound. An acid component and two carbon-nitrogen bond axes derived from an amino group are located on the same straight line, an aromatic diamine having no oxygen atom in the molecule, and two carbon-nitrogen bond axes derived from an amino group Is composed of an aromatic diamine component that does not have an oxygen atom in the molecule, each containing 20 mol% or more of an aromatic diamine that is not located on the same straight line and does not have an oxygen atom in the molecule. Having a phenylethynyl group which is a functional group. If the composition of the aromatic tetracarboxylic acid component and the aromatic diamine component is outside the above range, imidization and / or addition reaction does not proceed sufficiently during curing, and the toughness of the cured product may not be sufficient. In such a case, it is difficult to obtain a fiber reinforced composite material having good physical properties.

  The aromatic tetracarboxylic acid component which is the component (A) of the thermosetting solution composition according to the present embodiment includes 2,3,3 ′, 4′-biphenyltetracarboxylic acid compound, 3,3 ′, 4, The 4'-biphenyltetracarboxylic acid compound is contained, and the content thereof is preferably 20 mol% or more in the component (A), particularly preferably 30 mol% or more. If the content of these biphenyltetracarboxylic acid compounds is low, the glass transition temperature (Tg) of the resulting cured product will be low, and the toughness may not be sufficient. The aromatic tetracarboxylic acid component may contain other biphenyltetracarboxylic acid compounds. Examples of other biphenyltetracarboxylic acid compounds include 2,2 ′, 3,3′-biphenyltetracarboxylic acid compounds. Can be mentioned.

2,3,3 ′, 4′-biphenyltetracarboxylic acid compounds include 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (A-BPDA), an ester or salt of 2,3,3 ′, 4′-biphenyltetracarboxylic acid.
Similarly, 3,3 ′, 4,4′-biphenyltetracarboxylic acid compounds include 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid. Dianhydrides (s-BPDA), esters or salts of 3,3 ′, 4,4′-biphenyltetracarboxylic acid are included, and 2,2 ′, 3,3′-biphenyltetracarboxylic acid compounds include 2 , 2 ′, 3,3′-biphenyltetracarboxylic acid, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, ester or salt of 2,2 ′, 3,3′-biphenyltetracarboxylic acid Is included.

In the aromatic diamine component having no oxygen atom in the molecule as the component (B) of the thermosetting solution composition according to the present embodiment, the two carbon-nitrogen bond axes derived from the amino group are located on the same straight line. And an aromatic diamine having no oxygen atom in the molecule and an aromatic diamine in which the two carbon-nitrogen bond axes derived from the amino group are not located on the same straight line and have no oxygen atom in the molecule. . In the present embodiment, these aromatic diamines are preferably contained in the component (B) in an amount of 20 mol% or more, particularly preferably 30 mol% or more, respectively. Here, having no oxygen atom in the molecule means having no ether bond, carbonyl group or the like in the molecule.
As aromatic diamines in which two carbon-nitrogen bond axes derived from an amino group are located on the same straight line and have no oxygen atom in the molecule, 1,4-diaminobenzene (PPD), 2,5-diaminotoluene, 2,2′-bis (trifluoromethyl) benzidine, 2,2′-dimethylbenzidine, 3,3′-dimethylbenzidine, 3,3 ′, 5,5′-tetramethylbenzidine, 4,4-diaminooctafluoro Biphenyl and the like can be mentioned. These may be used alone or in combination.
Further, as an aromatic diamine in which two carbon-nitrogen bond axes derived from an amino group are not located on the same straight line and do not have an oxygen atom in the molecule, 1,3-diaminobenzene (MPD), 2,4- Diaminotoluene, 2,6-diaminotoluene, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) Examples include propane and 9,9′-bis (4-aminophenyl) fluorene. These may be used alone or in combination.

  In the present embodiment, 1,4-diaminobenzene (paraphenylenediamine, PPD) and 1,3-diaminobenzene (metaphenylenediamine, MPD) are used as aromatic diamine components having no oxygen atom in the molecule. It is suitable to use together.

  As an end-capping agent used for introducing an addition-reactive functional group at the end which is the component (C) of the thermosetting solution composition according to this embodiment, one having an ethynyl group is preferable, and in particular, phenylethynyl. Those having a group are preferred. Further, the end to be sealed may be either an amine end or a carboxylic acid end, but those that react with the amine end to form an imide group are preferred. Examples of such a terminal blocking agent include 4- (2-phenylethynyl) phthalic acid compounds. 4- (2-Phenylethynyl) phthalic acid compounds include 4- (2-phenylethynyl) phthalic anhydride and esters or salts of 4- (2-phenylethynyl) phthalic acid.

  Moreover, the component which has the effect | action which accelerates | stimulates imidation reaction may contain in the thermosetting solution composition of this embodiment. The content is preferably in the range of 0.01 to 3% by mass relative to the amount of all components. For example, an imidazole compound has an action of promoting dissolution when preparing a solution composition, and can shorten the dissolution time. Furthermore, it has the effect of accelerating curing when an uncured molded body is heated under pressure to produce a cured product (cured molded body), and a cured molded body with excellent characteristics can be easily obtained. become. Examples of the imidazole compound include known compounds as polyimide imidation catalysts such as 2-methylimidazole and 1,2-dimethylimidazole.

  In order to obtain an imide oligomer having an amine terminal blocked, the aromatic diamine component is preferably used in a stoichiometrically excess molar amount with respect to the aromatic tetracarboxylic acid component. The amount of the aromatic diamine component to be used is appropriately adjusted so that the resulting imide oligomer has a desired molecular weight, but the aromatic diamine component is used in an amount of 1.067 to 1. It is preferably used in an amount in the range of 167 mol, and particularly preferably in an amount in the range of 1.083 to 1.125 mol. Further, the end-capping agent is 1.8 to 2.2 times the molar amount corresponding to the difference between the molar amount of the aromatic diamine component and the molar amount of the aromatic tetracarboxylic acid component, preferably 1.95 to It is preferable to use a 2.0 times molar amount. In the present embodiment, imide oligomers having different molecular weights produced individually can be mixed and used.

  The thermosetting solution composition of the present embodiment can be obtained by mixing the aromatic tetracarboxylic acid component, the aromatic diamine component and the terminal blocking agent by a known method. For example, as a first method, aromatic tetracarboxylic dianhydride, aromatic diamine and 4- (2-phenylethynyl) phthalic anhydride are substantially equal in the total amount of acid anhydride groups and the total amount of amino groups. Can be prepared by mixing each component in a solvent at a temperature of about 100 ° C. or lower, particularly 80 ° C. or lower.

  As the solvent used in the above method, N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide, N, N-dimethylacetamide (DMAc), N, N-diethylacetamide, N-methylcaprolactam, γ -Butyrolactone (GBL), cyclohexanone, etc. are mentioned. These solvents may be used alone or in combination of two or more. With respect to the selection of these solvents, a known technique of a polyimide precursor solution composition can be applied.

  The obtained solution can be used as it is or after being appropriately concentrated or diluted. Further, if necessary, this solution is poured into water or the like and isolated as a powder product, and the powder product is appropriately dissolved in a solvent and used as the thermosetting solution composition of the present embodiment. it can.

  In addition, the thermosetting solution composition of the present embodiment includes, for example, aromatic tetracarboxylic dianhydride and 4- (2-phenylethynyl) phthalic anhydride, lower aliphatic alcohol as the second method. It can also be prepared by adding to the containing solution, converting the resulting suspension to a partially lower aliphatic alkyl ester by heating and dissolving it, and then adding an aromatic diamine to the solution. The obtained solution can be used as it is or after being appropriately concentrated or diluted.

  Examples of the solution used in the above method include an organic solvent containing a lower aliphatic alcohol (a monovalent aliphatic alcohol having 1 to 6 carbon atoms) as a main component. In particular, the lower aliphatic alcohol is preferably methanol or ethanol. A mixture of lower aliphatic alcohols may be used, but the mixture preferably contains 50% by volume or more of methanol or ethanol, and particularly preferably contains 80% by volume or more of methanol or ethanol. Here, a low-boiling solvent other than the lower aliphatic alcohol (eg, ketone) can be used in combination, and the amount of the low-boiling solvent other than the lower aliphatic alcohol in that case is 30% by volume or less. desirable.

  Methanol is particularly preferred as the lower aliphatic alcohol used for obtaining the partial lower aliphatic alkyl ester. When methyl ester is used as the lower aliphatic alkyl ester, excellent shape maintainability is exhibited when a cured product is produced using the heat curable solution composition.

  When it is desired to avoid environmental pollution caused by methanol generated when evaporating and removing a solvent from an uncured body using the above-mentioned heat curable solution composition and heating at a high temperature to obtain a subsequent cured body, After manufacturing a thermosetting solution composition using methanol, the solution composition is dried once to obtain a thermosetting powder composition, and this powder composition is dissolved in a solvent with low environmental impact such as ethanol. Then, a method of preparing a heat-curable solution composition again and preparing an uncured body using the composition can be used.

  The temperature at which the solvent is removed by evaporation to obtain the heat-curable powder composition is preferably 60 ° C. or lower. A small amount of solvent may remain in the heat curable powder composition, but the volatile component composed of the remaining solvent or alcohol generated when heated at a high temperature to obtain a cured product is in the range of 18 to 25%. Are preferable, and the thing of 20 to 22% of range is still more preferable.

  The heat curable solution composition obtained as described above is a cured product obtained by heating in the presence or absence of a curing catalyst, either alone or as a composite material obtained by impregnating a fibrous reinforcing material. It can be. For example, a film is obtained by apply | coating a thermosetting solution composition to a support body, and heat-hardening at 260-500 degreeC for 5-200 minutes. Further, the above thermosetting powder composition is filled in a mold, heated and imidized at 10 to 260 ° C. for about 1 to 240 minutes under normal pressure or reduced pressure, and 260 under normal pressure or 0.1 to 20 MPa pressure. A molded body can be produced by heating at about 500 ° C. for about 10 minutes to 40 hours. By using the thermosetting solution composition of this embodiment, a cured product (imide group-containing molded product) in which Tg cannot be confirmed at Tg of 340 ° C. or higher or 340 ° C. or lower can be obtained.

  In order to obtain a fiber reinforced composite material using the heat curable solution composition of the present embodiment, first, a sheet-like matrix material of high-strength fibers is impregnated with the heat curable solution composition and, if necessary, a solvent. An uncured fiber reinforced composite material (prepreg) is prepared by evaporating and removing a part of the material by heating or the like. The prepreg has an appropriate volatile content for ensuring good handleability (drapability and tackiness) when producing a fiber-reinforced composite material by heating under pressure, and an obtained fiber-reinforced composite material. In order to have a good resin content, an appropriate adhesion amount of the component forming the resin is required. For this purpose, a high-strength fiber sheet-like matrix material is impregnated with a thermosetting solution composition containing a component that forms an appropriate amount of resin by a method such as a dipping method or a casting method, and then in a hot air oven or the like. It is preferable to evaporate and remove excess volatile components by heating and drying. Usually, a high-strength fiber sheet matrix material is impregnated with a predetermined amount of a thermosetting solution composition, and is heated and dried. Temperature range: 40 to 150 ° C., time range: 0.5 to 30 minutes A prepreg having a preferable resin content (Rc) of 30 to 50% by mass and a volatile content (Vc) of 10 to 30% by mass can be suitably prepared.

  As a sheet-like matrix material made of high-strength fibers used for producing a prepreg, those made of known high-strength fibers used for producing a fiber-reinforced composite material can be suitably used. Preferred high-strength fibers are carbon fibers, aramid fibers, glass fibers, and ceramic fibers such as Tyranno fibers (titanium dioxide fibers).

  The obtained prepreg is preferably stored and transported in a state where each of both surfaces thereof is covered with a resin sheet such as polyethylene terephthalate (PET) or a covering sheet such as paper. The prepreg in such a covering state is Usually, it is stored and transported in a roll state.

  As a method for producing a fiber reinforced composite material (cured body) from a prepreg, a known method may be applied. For example, after cutting a roll-shaped prepreg to a desired size and laminating a plurality of cut uncured fiber reinforced composite material pieces (from several to 100 or more), using a heating press or an autoclave, 140 After drying and imidization by heating at ˜310 ° C. for 5 to 270 minutes under normal pressure or reduced pressure, at a temperature of 250 to 500 ° C. under normal pressure or 0.1 to 20 MPa for 1 second to 240 minutes. By heating to a certain extent, a fiber reinforced composite material is obtained.

  A fiber reinforced composite material obtained by heat curing an uncured fiber reinforced composite material (prepreg) in which a fibrous reinforcing material is impregnated with the heat curable solution composition of the present embodiment is excellent in mechanical properties and the like. It is suitable for applications such as space industry equipment.

  Hereinafter, the present invention will be described with reference to specific examples. First, each measured value is based on the following method.

(1) Thermal oxidation stability (TOS)
For resin film, based on the weight after drying at 270 ° C. for 4 hours, the weight loss after exposure to flowing air at 350 ° C. for 100 hours using inert gas oven INH-21CD-S (Koyo Thermo System Co., Ltd.) Expressed in percent by weight relative to the reference weight. The measurement was performed on three samples at the same time, and the average value of these was taken as the TOS value.
For the CFRP plate, the TOS value was calculated in the same manner as above except that the conditions were 274 ° C., 1000 hours or 3000 hours.

(2) Glass transition temperature (Tg)
For the resin film, a DSC curve was measured using a differential scanning calorimeter Q100 series manufactured by TA Instruments Japan Co., Ltd. while raising the temperature at 20 ° C./min in a nitrogen atmosphere (20 ml / min). . The temperature at the intersection of tangents at the inflection point of the DSC curve was defined as the glass transition temperature.
For the CFRP plate, the viscoelasticity was measured in a three-point bending mode while increasing the temperature in nitrogen at a frequency of 10 Hz and 10 ° C./min using a solid viscoelasticity analyzer RSAIII manufactured by TA Instruments Japan. . A tangent line was drawn at the inflection point of the graph in which the storage elastic modulus was plotted against the temperature, and the temperature at the intersection was taken as the glass transition temperature. Further, Tg obtained from the temperature at the peak top of tan δ was defined as Tg (tan δ).
(3) Tensile strength, tensile modulus, elongation at break A universal testing machine (model number 5582) manufactured by Instron was used for measurement. The test piece was made of a resin film with a standard IEC-540 punching blade. The pulling speed is 2 mm / min. The test was performed at room temperature.

(4) Interlaminar shear strength (SBS)
The CFRP plate was measured according to ASTM D2344. A universal testing machine (model number 5582) manufactured by Instron was used for the measurement.
(5) Measurement of carbon fiber content (Vf) and porosity (Vv) With respect to the CFRP plate, the carbon fiber content (Vf) and the porosity (Vv) were measured by the sulfuric acid decomposition method according to ASTM D3171.

Moreover, in the Example described below, each monomer component was shown by the following display.
a-BPDA: 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride s-BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PPD: 1,4-diaminobenzene (Paraphenylenediamine)
MPD: 1,3-diaminobenzene (metaphenylenediamine)
PEPA: 4- (phenylethynyl) phthalic anhydride TPE-R: 1,3-bis (4-aminophenoxy) benzene 2-Mz: 2-methylimidazole

[Comparative Example 1]
A separable flask was charged with 47.08 g (0.16 mol) of a-BPDA as an acid component, 9.93 g (0.04 mol) of PEPA and 63.50 g of methanol as a solvent, and 2-Mz. 1529 g was added and stirred under reflux conditions to dissolve uniformly. After cooling the solution to room temperature, 13.63 g (0.126 mol) of PPD, which is a diamine component, and 5.84 g (0.054 mol) of MPD were added and stirred to obtain a uniform thermosetting solution composition. This solution was placed in a container made of polyimide film and placed in an oven maintained at 80 ° C. The oven was heated to 260 ° C. at 2 ° C./min and held for 3 hours, and the resulting solid content was pulverized to obtain a heat curable powder composition. This thermosetting powder composition is pressed with a press machine heated to 260 ° C., then heated up to 370 ° C. in about 20 minutes, heat-treated at 370 ° C. for 60 minutes, and a resin film having a thickness of about 0.15 mm Got. The properties of the film are shown in Table 1.

[Comparative Example 2]
As an acid component, 47.08 g (0.16 mol) of a-BPDA, 9.93 g (0.04 mol) of PEPA, and 63.50 g of methanol as a solvent were added, and 0.1529 g of 2-Mz as a catalyst was added to reflux conditions. The mixture was stirred and dissolved uniformly. After the solution was cooled to room temperature, the thermosetting solution composition and the resin were the same as in Example 1 except that 9.73 g (0.09 mol) of PPD and 9.73 g (0.09 mol) of MPD were used as diamine components. A film was obtained. The properties of the film are shown in Table 2.

[Comparative Example 3]
28.25 g (0.096 mol) of s-BPDA, 18.83 g (0.064 mol) of a-BPDA and 9.93 g (0.04 mol) of PEPA as the acid component, 73.44 g of methanol as the solvent, and 2- A thermosetting solution composition and a resin film were prepared in the same manner as in Example 1 except that 0.172 g of Mz was used and 13.63 g (0.126 mol) of PPD and 15.79 g (0.054 mol) of TPE-R were used as diamine components. Got.

[Example 1] PPD / MPD (50/50)
In a separable flask, 14.12 g (0.048 mol) of s-BPDA as an acid component, 32.95 g (0.112 mol) of a-BPDA, 9.93 g (0.04 mol) of PEPA, and 63.50 g of methanol as a solvent. Was added, and 0.152 g of 2-Mz as a catalyst was added and stirred under reflux conditions to be uniformly dissolved. After cooling the solution to room temperature, 9.73 g (0.09 mol) of PPD as a diamine component and 9.73 g (0.09 mol) of MPD were added and stirred to obtain a uniform thermosetting solution composition. This solution was placed in a container made of polyimide film and placed in an oven maintained at 80 ° C. The oven was heated to 260 ° C. at 2 ° C./min and held for 3 hours, and the resulting solid content was pulverized to obtain a heat curable powder composition. This thermosetting powder composition is pressed with a press machine heated to 260 ° C., then heated up to 370 ° C. in about 20 minutes, heat-treated at 370 ° C. for 60 minutes, and a resin film having a thickness of about 0.15 mm Got. The properties of the film are shown in Table 2.

[Example 2]
Heat curing as in Example 1 except that 18.83 g (0.064 mol) of s-BPDA, 28.25 g (0.096 mol) of a-BPDA and 9.93 g (0.04 mol) of PEPA were used as the acid component. Solution composition and resin film were obtained. The properties of the film are shown in Table 2.

[Example 3]
Heat curing as in Example 1 except that 23.54 g (0.08 mol) of s-BPDA, 23.54 g of a-BPDA (0.08 mol) and 9.93 g of PEPA (0.04 mol) were used as the acid component. Solution composition and resin film were obtained. The properties of the film are shown in Table 2.

[Example 4]
Heat curing as in Example 1 except that 28.25 g (0.096 mol) of s-BPDA, 18.83 g (0.064 mol) of a-BPDA and 9.93 g (0.04 mol) of PEPA were used as the acid component. Solution composition and resin film were obtained. The properties of the film are shown in Table 2.

[Example 5]
Heat curing as in Example 1 except that 32.95 g (0.112 mol) of s-BPDA, 14.12 g (0.048 mol) of a-BPDA and 9.93 g of PEPA (0.04 mol) were used as the acid component. Solution composition and resin film were obtained. The properties of the film are shown in Table 2.

[Example 6] s-BPDA / a-BPDA (60/40)
28.25 g (0.096 mol) of s-BPDA as an acid component, 18.83 g (0.064 mol) of a-BPDA and 9.93 g (0.04 mol) of PEPA, and 3.89 g (0.036 mol) of PPD as a diamine component A thermosetting solution composition and a resin film were obtained in the same manner as in Example 1 except that 15.57 g (0.144 mol) of MPD was used. The properties of the film are shown in Table 3.

[Example 7]
A thermosetting solution composition and a resin film were obtained in the same manner as in Example 6 except that 11.68 g (0.108 mol) of PPD and 7.79 g (0.072 mol) of MPD were used as the diamine component. The properties of the film are shown in Table 3.

[Example 8]
A thermosetting solution composition and a resin film were obtained in the same manner as in Example 6 except that 13.63 g (0.126 mol) of PPD and 5.84 g (0.054 mol) of MPD were used as the diamine component. The properties of the film are shown in Table 3.

[Example 9] s-BPDA / a-BPDA (50/50)
23.54 g (0.08 mol) of s-BPDA, 23.54 g (0.08 mol) of a-BPDA and 9.93 g (0.04 mol) of PEPA as acid components, and 11.68 g (0.108 mol) of PPD as diamine components And 7.79 g (0.072 mol) of MPD were used in the same manner as in Example 1 to obtain a thermosetting solution composition and a resin film. Table 4 shows the characteristics of the film.

[Example 10]
A thermosetting solution composition and a resin film were obtained in the same manner as in Example 9 except that 13.63 g (0.126 mol) of PPD and 5.84 g (0.054 mol) of MPD were used as the diamine component. Table 4 shows the characteristics of the film.

[Example 11] s-BPDA / a-BPDA (60/40), PPD / MPD (50/50)
As the acid component, 28.42 g (0.0966 mol) of s-BPDA, 18.95 g (0.0644 mol) of a-BPDA and 11.42 g (0.046 mol) of PEPA, 65.42 g of methanol as a solvent, and 2- A thermosetting solution composition and a resin film were obtained in the same manner as in Example 1 except that 0.1574 g of Mz was used and 9.95 g (0.092 mol) of PPD and 9.95 g (0.092 mol) of MPD were used as the diamine component. It was. Table 5 shows the characteristics of the film.

[Example 12]
30.19 g (0.1026 mol) of s-BPDA, 20.12 g (0.0684 mol) of a-BPDA and 9.43 g (0.038 mol) of PEPA as the acid component, 66.60 g of methanol as the solvent, and 2- A thermosetting solution composition and a resin film were obtained in the same manner as in Example 1 except that 0.1606 g of Mz was used and 10.27 g (0.095 mol) of PPD and 10.27 g (0.095 mol) of MPD were used as diamine components. It was. Table 5 shows the characteristics of the film.

[Example 13]
As an acid component, 35.31 g (0.12 mol) of s-BPDA, 23.54 g (0.08 mol) of a-BPDA, 9.93 g (0.04 mol) of PEPA, 76.71 g of methanol as a solvent, and 2- A thermosetting solution composition and a resin film were obtained in the same manner as in Example 1 except that 0.1851 g of Mz was used and 11.90 g (0.11 mol) of PPD and 11.90 g (0.11 mol) of MPD were used as diamine components. It was. Table 5 shows the characteristics of the film.

[Example 14] s-BPDA / a-BPDA (50/50), PPD / MPD (50/50)
25.01 g (0.085 mol) of s-BPDA, 25.01 g (0.085 mol) of a-BPDA and 8.44 g (0.034 mol) of PEPA as an acid component, 65.20 g of methanol as a solvent, and 2- A thermosetting solution composition and a resin film were obtained in the same manner as in Example 1 except that 0.1574 g of Mz was used, and 10.11 g (0.0935 mol) of PPD and 10.11 g (0.0935 mol) of MPD were used as diamine components. It was. Table 6 shows the characteristics of the film.

[Example 15]
26.48 g (0.09 mol) of s-BPDA, 26.48 g (0.09 mol) of a-BPDA and 7.45 g (0.03 mol) of PEPA as the acid component, 67.44 g of methanol as the solvent, and 2- A thermosetting solution composition and a resin film were obtained in the same manner as in Example 1 except that 0.1630 g of Mz was used and 10.54 g (0.0975 mol) of PPD and 10.54 g (0.0975 mol) of MPD were used as diamine components. It was. Table 6 shows the characteristics of the film.

[Example 16] s-BPDA / a-BPDA (50/50), PPD / MPD (60/40)
25.01 g (0.085 mol) of s-BPDA, 25.01 g (0.085 mol) of a-BPDA and 8.44 g (0.034 mol) of PEPA as an acid component, 65.20 g of methanol as a solvent, and 2- A thermosetting solution composition and a resin film were obtained in the same manner as in Example 1 except that 0.1574 g of Mz was used and 12.13 g (0.1122 mol) of PPD and 8.09 g (0.0748 mol) of MPD were used as the diamine component. It was. Table 7 shows the characteristics of the film.

[Example 17]
A thermosetting solution composition having a solid content concentration of 40 to 60% by weight was prepared in the same manner as in Example 1 with the composition shown in Table 7. This heat curable solution composition was impregnated in a carbon fiber fabric (HTS40 3K 8 satin weave, weight per unit weight 378 g / m ² ) manufactured by Toho Tenax Co., Ltd. and dried in an oven at 80 to 100 ° C. for 10 to 30 minutes. Got. The drying conditions were adjusted so that the volatile content after drying was about 15% by weight. The volatile content was calculated from the weight loss after heating at 250 ° C. for 1 hour. The obtained prepreg was cut into 100 × 140 mm, stacked in 12 pieces, placed in an autoclave molding machine, heated at 370 ° C. for 1 hour under a pressure of 1.38 MPa, and a 4.3 mm thick carbon fiber reinforced plastic (CFRP ) Obtained a board. The obtained CFRP plate was found to be a non-defective product from which almost no voids were observed from an ultrasonic flaw detection test and cross-sectional observation with a stereomicroscope. Table 8 shows the properties of the obtained CFRP plate.

[Example 18]
A CFRP plate was obtained in the same manner as in Example 17 except that a thermosetting solution composition was prepared with the composition shown in Table 8. Table 8 shows the properties of the obtained CFRP plate.

[Comparative Example 4]
A CFRP plate was obtained in the same manner as in Example 19 except that a thermosetting solution composition was prepared with the composition shown in Table 8. Table 8 shows the properties of the obtained CFRP plate.

[Example 19]
A thermosetting solution composition having a solid content concentration of 40 to 60% by weight was prepared in the same manner as in Example 1 with the composition shown in Table 8. This heat curable solution composition is impregnated into a carbon fiber fabric (T650 / 35 3K 8 satin weave, weight per unit weight 375 g / m ² ) manufactured by Cytec, and dried in an oven at 80 to 100 ° C. for 10 to 30 minutes. A prepreg was obtained. The drying conditions were adjusted so that the volatile content after drying was about 15% by weight. The volatile content was calculated from the weight loss after heating at 250 ° C. for 1 hour. The obtained prepreg was cut into 100 × 140 mm and stacked in 6 sheets, placed in an autoclave molding machine, heated at 370 ° C. for 1 hour under a pressure of 1.38 MPa, and a 2.4 mm thick carbon fiber reinforced plastic (CFRP ) Obtained a board. The obtained CFRP plate was found to be a non-defective product from which almost no voids were observed from an ultrasonic flaw detection test and cross-sectional observation with a stereomicroscope. Table 9 shows the properties of the obtained CFRP plate.

[Example 20]
A CFRP plate was obtained in the same manner as in Example 21 except that a thermosetting solution composition was prepared with the composition shown in Table 9. Table 9 shows the properties of the obtained CFRP plate.

[Example 21]
A CFRP plate was obtained in the same manner as in Example 21 except that a thermosetting solution composition was prepared with the composition shown in Table 9. Table 9 shows the properties of the obtained CFRP plate.

[Example 22]
A CFRP plate was obtained in the same manner as in Example 21 except that a thermosetting solution composition was prepared with the composition shown in Table 9. Table 9 shows the properties of the obtained CFRP plate.

[Comparative Example 5]
A CFRP plate was obtained in the same manner as in Example 21 except that a thermosetting solution composition was prepared with the composition shown in Table 9. Table 9 shows the properties of the obtained CFRP plate.

Claims (7)

  (A) Aromatic tetracarboxylic acid component containing 20 mol% or more of 2,3,3 ′, 4′-biphenyltetracarboxylic acid compound and 3,3 ′, 4,4′-biphenyltetracarboxylic acid compound, respectively (B) the two carbon-nitrogen bond axes derived from the amino group are located on the same straight line, the aromatic diamine having no oxygen atom in the molecule, and the two carbon-nitrogen bond axes derived from the amino group An aromatic diamine component not having an oxygen atom in the molecule, and (C) a phenylethynyl group, each containing 20 mol% or more of an aromatic diamine that is not located on the same straight line and does not have an oxygen atom in the molecule; A heat-curable solution composition obtained by mixing an end-capping agent having the composition.   An aromatic diamine in which two carbon-nitrogen bond axes derived from the amino group in (B) are located on the same straight line and has no oxygen atom in the molecule is 1,4-diaminobenzene, 2. The heating according to claim 1, wherein the two derived carbon-nitrogen bond axes are not collinear and the aromatic diamine having no oxygen atom in the molecule is 1,3-diaminobenzene. Curable solution composition.   The thermosetting solution composition according to claim 1 or 2, wherein the end-capping agent having a phenylethynyl group (C) is a 4- (2-phenylethynyl) phthalic acid compound.   The molar ratio of the aromatic diamine component to the aromatic tetracarboxylic acid component (number of moles of aromatic diamine component / number of moles of aromatic tetracarboxylic acid component) is 1.067 to 1.167, Item 5. The thermosetting solution composition according to any one of items 1 to 4.   A cured product obtained by heat-curing the thermosetting solution composition according to claim 1.   A prepreg comprising a fibrous reinforcing material impregnated with the thermosetting solution composition according to any one of claims 1 to 4.   A fiber-reinforced composite material obtained by heat-curing the prepreg according to claim 6.