JPH03258828A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To provide a resin composition suitable for impregnating highly elongated carbon fibers to give cured composite materials having good heat resistance, impact resistance and high strength by compounding a resin comprising cyanic acid ester and bismaleimide, an epoxy resin and a specific reaction product. CONSTITUTION:(A) A resin composed of a cyanic acid component and bismaleimide component, (B) an epoxy resin and (C) a reaction product synthesized from norbornenediol of the formula and terephthalic dichloride and having a number-average mol.wt. of 200-20000 and hydroxyl groups at both the molecular ends thereof are compounded in amount of 50-94wt.% 4-48wt.% and 2-30wt.%, respectively, per 100wt.% of the sum of A+B+C to provide the objective composition.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thermosetting resin composition suitable as a resin composition for impregnating prepreg that can be used as a structural material. More specifically, the present invention relates to a thermosetting resin composition that, when used as a resin composition for impregnating prepreg, provides a composite material that has appropriate tackiness, high strength, high toughness, and excellent water resistance.

<Prior Art> In recent years, a so-called prepreg, which is a heterogeneous material made by impregnating reinforcing fibers with a matrix resin composition, has come to be used in various structures as an advanced composite material.

Since this prepreg is a non-uniform material as mentioned above,
There is a large difference in physical properties such as strength and impact resistance between the long axis direction of the fiber, which is one of its constituent components, and the other directions.

In order to further reduce the difference in physical properties depending on the direction, various techniques have been proposed, such as a method in which a film is sandwiched between layers, a method in which chopped fibers are placed between layers.

As a method of sandwiching a film between the eyebrows, there is a method of sandwiching various thermosetting films (U.S. Patent No. 3.472.731i).
US Pat. No. 4,539,253) and methods of sandwiching various thermoplastic films (US Pat. No. 4,604)
, No. 319 specification, etc.). However, with the method of sandwiching a thermosetting film, it is not possible to obtain a product that satisfies both impact resistance and heat resistance, while on the other hand, with the method of sandwiching a thermoplastic film, there is no tack and the dryability is not achieved. There was a problem in that it was difficult to use as a prepreg because the characteristics of the thermoplastic film, such as the absence of porosity, were strongly exhibited.

In addition, as a method for placing chopped fibers between the eyebrows, methods using chopped short fibers, chopped strands, milled fibers, etc. have been proposed (Japanese Patent Application Laid-Open No.
No. 4-3879, No. 56-115216, No. 6044334, etc.), when chopped fibers were used, the problem of thickening between the eyebrows was solved.

On the other hand, epoxy resin compositions are mainly used as resin compositions for impregnating such prepregs.
In particular, when aiming for a product with high heat resistance, tetraglycidyldiaminodiphenylmethane (
Epoxy resin compositions containing diaminodiphenylsulfone (DDS) and diaminodiphenylsulfone (DDS) as a curing agent have been widely used. Although this TGDDM/DDS-based epoxy resin composition has excellent initial heat resistance and good adhesion to reinforcing fibers such as carbon fiber, its heat resistance deteriorates significantly due to moisture absorption and after impact. Shortcomings such as low compressive strength were eliminated.

In this way, when an epoxy resin composition is used as a resin composition for impregnating prepreg, it cannot be used sufficiently for applications that require high heat resistance and i-impact resistance, such as secondary structural materials for aircraft. Ta.

In addition, a thermosetting resin composition whose main component is a resin composed of a cyanate ester component and a bismaleimide component has also been proposed as a resin composition for impregnating prepreg (
(See Japanese Patent Publication No. 52-31279 and Japanese Patent Publication No. 54-30440). Although this material exhibits excellent heat resistance after curing, it does not have sufficient impact resistance and is still suitable for aircraft use.
It was not able to adequately respond to applications that require high heat resistance and impact resistance, such as secondary structural materials.

Furthermore, as a resin composition for impregnating prepreg, a long-chain bisphenol A type epoxy resin is blended with a thermosetting resin composition whose main component is a resin composed of the cyanate ester component and bismaleimide component. is also known. However, this resin composition is difficult to mix with long-chain bisphenol A type epoxy resin, and heating for a long time is required to obtain a uniform resin composition. Prepregs made by impregnating fibers do not exhibit sufficient adhesion.

<Problem to be solved by the invention> As mentioned above, various properties of prepreg after curing, namely,
There is no known prepreg that satisfies heat resistance, impact resistance, high strength, etc. at the same time.

The present invention aims to improve various properties of prepreg after curing from the viewpoint of a resin composition for impregnating prepreg, and in particular, it aims to improve various properties of prepreg after curing from the viewpoint of a resin composition for impregnating prepreg. It is suitable as a resin composition for impregnation of
The object of the present invention is to provide a thermosetting resin composition that has appropriate adhesiveness itself and provides a composite material that has excellent heat resistance, water resistance, and impact resistance after curing.

Means for Solving the Problems> The present invention provides a resin (A) composed of a cyanate ester component and a bismaleimide component, an epoxy resin (B), and the following formula! A reaction product synthesized from norbornene diol and terephthalic acid chloride shown in
C), containing (A) + (B) + (C) at 100
When expressed as weight%, the content of (A) is 50 to 94% by weight
, the content of (B) is 4 to 48% by weight, and the content of (C) is 2 to 30% by weight.

The present invention will be explained in detail below.

First, the resin (A) composed of a cyanate ester component and a bismaleimide component will be explained.

As the cyanate ester component constituting the resin (A),
Examples include polyfunctional cyanate esters, cyanate ester prepolymers, and prepolymers composed of the cyanate esters and diamines.

Examples of the polyfunctional cyanate ester component include any organic compound having two or more cyanate ester groups, especially aromatic compounds, and among them, the following - narrowing [II] formula [II] R'% 0-CxN)n (In the above formula [II], n is a number of 2 or more and usually 5 or less, R1 is an aromatic organic group, and the cyanate ester group is the organic group R1 is bonded to the aromatic ring of ) are preferred.

Here, the organic group R1 is a group derived from an aromatic hydrocarbon having 1 to 16 carbon atoms such as benzene, naphthalene, anthracene, and pyrene; Organic groups bonded through biphenyl, diphenylmethane, 2,2-diphenylpropane, diphenyl ether, dibenzyl ether, diphenylthioether, diphenyl ketone, diphenylamine, diphenyl sulfoxide, diphenyl sulfone, triphenyl phosphite, tri- Preferred examples include a group derived from phenyl phosphate and the like; a group derived from a novolac type phenol resin; and the like.

Note that the aromatic ring of these aromatic organic groups may be substituted with a substituent unrelated to the reaction.

Such polyfunctional cyanate ester components generally include:
The corresponding polyhydric phenols can be obtained in a manner known per se by reacting with cyanogen halides, in particular symmetric and condensed phenols such as bisphenol A [2,2-bis(4-hydroxyphenyl)propane]. Preferred are cyanate ester components obtained by reaction of ring-free dihydric phenols and cyanogen halide; reaction of an initial condensate of phenol and formaldehyde with cyanogen halide; and the like.

Cyanate ester prepolymer is produced by polymerizing the above-mentioned polyfunctional cyanate ester in the presence of a catalyst such as a mineral acid, a Lewis acid, a salt such as sodium carbonate or lithium chloride, or a phosphate ester such as tributylphosphine. can get. These prepolymers generally have a triazine ring in the molecule, which is formed by trimerization of the cyano group in the cyanate ester. In the present invention, it is preferable to use a prepolymer having an average molecular weight of 400 to 6,000.

In addition, a prepolymer composed of a polyfunctional cyanate ester and a diamine is a polyfunctional cyanate ester and a diamine.
Following - Refinement [III] Formula [m] H, N-R2-NH.

(In the above formula [III], R2 is a divalent aromatic or alicyclic organic group.) It is obtained by reacting diamines represented by the following formula. That is, a cyanate ester and a diamine, particularly preferably 0.1 to 1 equivalent of amine per cyanate ester, are mixed in an organic solvent such as a ketone at a temperature of 0 to 100°C for 1 minute to 1 minute.
Allow the reaction to occur for a relatively short period of time, such as one hour.

In addition, as diamines, metaphenylenediamine,
meta- or para-xylylenediamine, 1,4-cyclohexanediamine, hexahydroxylylenediamine,
Bis(4-aminophenyl)methane, bis(4-aminophenyl)sulfone, bis(4-amino-3-methylphenyl)methane (MDT), bis(4-amino-3,5
-dimethylphenyl)methane (MDX), bis(4-aminophenyl)cyclohexane, bis(4-aminophenyl)ether, 2,2-bis(4'-aminophenyl)propane, bis(4-amino-3-methyl) phenyl)
Examples include methane, bis(4-aminophenyl)phenylmethane, etc., and aromatic diamines are preferable from the viewpoint of heat resistance after curing, but alicyclic diamines are preferable from the viewpoint of flexibility and pliability after curing. Group diamines may be used alone or in combination. Further, from the viewpoint of reactivity, the diamines are preferably primary amines, but may be secondary amines.

The above-mentioned cyanate ester component, which is a component of the resin (A) used in the present invention, may be used alone or 2f!
The above may be used in combination.

The bismaleimide component constituting the resin (A) is composed of any organic metal compound having two maleimide groups derived from maleic anhydride and diamine, a bismaleimide prepolymer, and the bismaleimide and diamine. Examples include prepolymers.

In the present invention, the bismaleimide component contains 2 maleimide groups derived from maleic anhydride and diamine.
Any organic compound having the same characteristics can be applied, but in particular, the following narrowing [IV] formula [IVco(in the above formula [TVl], R3 is a divalent aromatic or alicyclic organic group The compound represented by these is preferable.

Here, the organic group R3 is a phenylene group, a naphthylene group,
Aromatic or alicyclic hydrocarbons having 6 to 16 carbon atoms, such as xylylene groups, cyclohexylene groups, and hexahydroxylylene groups; organics in which multiple aromatic rings are bonded directly or through bridging atoms or bridging groups. Groups: and the like are preferably exemplified.

Note that the aromatic ring of these aromatic organic groups may be substituted with a substituent unrelated to the reaction.

Such bismaleimide can be obtained by a method known per se, in which bismaleamic acid is prepared by reacting maleic anhydride with diamines, and then this bismaleamic acid is cyclodehydrated. Note that specific examples of the diamines used are as shown in the section of the prepolymer of polyfunctional cyanate ester and diamine.

The bismaleimide prepolymer is derived from any organic compound having two maleimide groups derived from the above-mentioned maleic anhydride and diamine by a known method.

Further, a prepolymer composed of bismaleimide and diamine can be obtained by reacting bismaleimide with the diamines shown in the section of the prebolymer of polyfunctional cyanate ester and diamine in the following manner.

That is, bismaleimide and diamines, particularly preferably diamine in an amount of 1/2 to 1 mole per mole of bismaleimide, are mixed in a suitable solvent such as a ketone at a temperature of, for example, about 40 to 250°C. , the reaction may be carried out for 5 minutes to 5 hours.

The above-mentioned bismaleimide component, which is a constituent component of the resin (A) used in the present invention, may be used alone or 2f! The above may be used in combination.

The resin (A) contains the cyanate ester component and the bismaleimide component in a ratio of 1:99 to 99:1. Preferably 5
:95 to 95:5 weight ratio was used to carry out the preliminary reaction.

This quantitative ratio is appropriately selected depending on the properties desired for the resin (A). For example, when various properties such as electrical properties such as dielectric properties, adhesiveness, and adhesion are desired, the cyanate ester component is increased, If heat resistance is desired, increase the bismaleimide component.

In addition, there are various commercial products such as BT resin (manufactured by Mitsubishi Gas Chemical Co., Ltd.) that correspond to the resin (A), and these may be used.

In addition, a resin composed of such a cyanate ester component and a bismaleimide component is disclosed in Japanese Patent Publication No. 52-3132.
79 and No. 54-30440.

Next, the epoxy resin (B) will be explained.

The thermosetting resin composition of the present invention contains the resin (A) composed of the cyanate ester component and bismaleimide component described above, but the resin (A) has no adhesive properties. Since it is small, when the thermosetting resin composition of the present invention is used as a resin composition for impregnating prepreg, it may be difficult to fit it into the shape of a jig for lamination molding of prepreg.

The epoxy resin (B) reacts with the components in the resin (A), increases its tackiness, and exhibits the effect of shortening the curing time. Therefore, the thermosetting resin composition of the present invention also contains an epoxy resin (B).

The epoxy resin (B) includes widely used glycidyl ether epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, novolak epoxy resin, and brominated epoxy resin, as well as cycloaliphatic epoxy resins, There are special epoxy resins such as glycidyl ester epoxy resins, glycidyl amine epoxy resins, and heterocyclic epoxy resins.

Furthermore, epoxy resins include those that are liquid at room temperature, those that are semi-solid, and those that are solid.

The epoxy resin (B) used in the present invention is not particularly limited and may be any epoxy resin, but preferably an epoxy resin having a number average molecular weight of 500 or less and an epoxy equivalent of 300 or less is used. As an example of such an epoxy resin, the following bisphenol type epoxy resin can be exemplified.

Yuka Shell Epoxy Company: Epikote 801,8
02.807.808.815,819,827.82
8,834.871゜Dow Chemical Company: D, E, R, 3] 7.330.33
1.332.333.337.383.824.825
．． 361.365゜Ciba Geigy: ^raJdHe
GY 250.250.2BO Sumitomo Chemical: EL
Item A 5.117.121.127.128, 34 Furthermore, in order to improve the heat resistance after curing, it is preferable to use a novolac type epoxy resin or a nitrogen-containing epoxy resin.

Novolac type epoxy resins include Epikote 152.154 (Yuka Shell Epoxy Co., Ltd.), ESCN 220 series (Sumitomo Chemical Industries, Ltd.), and nitrogen-containing epoxy resins include MY.
? 20, Fu21 (Ciba Geigy), ELM 43
4.12o (Sumitomo Chemical Industries, Ltd.) etc. are exemplified.

Next, the reaction product (C) synthesized from norbornenediol and terephthalic acid chloride will be explained.

It is synthesized from norbornene diol and terephthalic acid chloride, has hydroxyl groups at both ends, and has a number average molecular weight of 200.
The reaction product (C) of ~20,000 is a type of polyester. Furthermore, norbornenediol is
This is a compound represented by the following formula I.

By the way, it is known that when a saturated polyester such as Vylon 300 (manufactured by Toyobo ■) is blended into a resin composition for prepreg, the toughness increases after curing.

However, when saturated polyester is blended, water resistance after curing is poor. Therefore, the present invention aims to improve water resistance by introducing an aromatic group into polyester. Therefore, terephthalic acid chloride was used as one of the synthetic raw materials for polyester. Furthermore, by using terephthalic acid chloride, the molecular weight of the reaction product can be kept low and the heat resistance after curing can be increased. Further, considering the flexibility and water resistance after curing, norbornene diol was used as the other synthetic raw material for polyester.

The reaction product (C) synthesized from norbornene diol and terephthalic acid chloride can be easily mixed with other resins used in the present invention.

Moreover, by containing this reaction product (C), the thermosetting resin composition of the present invention comes to have appropriate tack.

By the way, the synthesis of polyester from norbornene diol and terephthalic acid chloride can be carried out rapidly at room temperature or high temperature by using an appropriate solvent. The presence of hydroxyl groups at both ends of this reaction product is confirmed by the infrared absorption spectrum. The solvent to be used may be any solvent as long as norbornene diol and terephthalic acid chloride can be dissolved therein, but preferred examples include chlorine-containing solvents such as chloroform, N-methylpyrrolidone, dimethylformamide, and dimethylsulfoxide.

In the present invention, the reaction product (C) synthesized from norbornene diol and terephthalic acid chloride has a number average molecular weight of 200 to 20,000. 20
Anything less than 0 is a mixture of the two, rather than a reaction product of norbornene diol and terephthalic acid chloride. Since a mixture of monomers does not exhibit the effect of a polyester, a monomer having a number average molecular weight of 200 or more is used. On the other hand, if it exceeds 20,000, the solubility in the resin composition is poor, the viscosity of the system is high even after dissolution, and proper tack cannot be obtained when made into a prepreg. Therefore, the number average molecular weight is 200
Use a value of 00 or less.

The thermosetting resin composition of the present invention contains the above components in the following proportions.

That is, the total of the resin (A) composed of a cyanate ester component and a bismaleimide component, the epoxy resin (B), and the reaction product (C) synthesized from norbornene diol and terephthalic acid chloride is 100% by weight. In this case, the content of (A) is 50 to 94% by weight, the content of (B) is 4 to 48% by weight, and the content of (C) is 2 to 30% by weight.

If the resin (A) is less than the above range, the heat resistance after curing will be insufficient, while if it exceeds the above range, it will become brittle.

If the epoxy resin (B) is less than the above range, curing will be slow, and if it is more than the above range, the heat resistance after curing will be insufficient.

In addition, if the reaction product (C) is less than the above range, the effect of its addition, that is, the effect of improving toughness and water resistance after curing, cannot be obtained, while if it exceeds the above range, the properties after curing will not be obtained. becomes soft, making it undesirable as a matrix for composite materials.

In addition to the above-mentioned essential components, the thermosetting resin composition of the present invention usually contains a curing agent and a curing catalyst. However, in such a case, the content of the essential components is such that the total content of the essential components is 100% by weight.

As curing agents, in addition to the diamines exemplified in the section of the prepolymer obtained from cyanate ester and amine in the explanation of resin (A), triethylenediamine, imidazole, 2-methyl Imidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 2-phenylimidazole, 2-ethyl-4
-methylimidazole, 1-benzyl-2-methylimidazole, 1-pro-2-methylimidazole, 1
-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-guanamineethyl-2-methylimidazole and Examples include trimellitic acid adducts of these imidazoles.

Curing catalysts include organic bases such as N,N-dimethylaniline, N,N-dimethyltoluidine, N,N-dimethyl-p-anisidine, P-halogeno-N,N-dimethylaniline, 2-N-dityl. Anilinoethanol, trilobylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, N,N-dimethylbenzylamine, N,N,N
',N'-Tetramethylbutanediamine and other tertiary amines: imidazole, benzimidazole, 2-methylimidazole, 2-andecylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole and other imidazoles ; Phenols such as phenol, cresol, xylenol, resorcinol, phloroglucin; Organic peroxides such as dicumyl peroxide, benzoyl peroxide, 7-butyl hydroperoxide, cyclohexanone peroxide, decanoyl peroxide E1 diisopropyl peroxydicarbonate; Materials: Organometallic salts such as zinc octylate, tin octylate,
Lead naphthenate, lead stearate, zinc naphthenate, tin oleate, dibutyltin maleate, manganese naphthenate, cobalt naphthenate, lead resinate, iron acetylacetone, copper acetylacetone, butyl titanate, propyl aluminum, etc., 5nCA4, ZnCA2 A
Examples include chlorides such as flCls, FeCJ12, and FeCJZ3; metal powders such as iron and zinc;

The thermosetting resin composition of the present invention may further contain the following components for the purpose of improving various properties, within a range that does not impair the gist of the present invention. However, in such a case, the content ratio of essential components shall be determined by adding up the total amount of essential components to 100%.
Weight%.

One of the ingredients to improve various properties is various natural,
Semi-synthetic or synthetic resins.

Such resins include oleoresins such as drying oils and non-drying oils, rosins, shellac, copal, oil-modified rosins, phenolic resins, alkyd resins, urea resins, melamine resins, polyester resins, vinyl butyral resins, and vinyl acetate resins. , vinyl chloride resin, acrylic resin, silicone resin, etc., and 1 fi or a combination of two or more types can be used.

Furthermore, the thermosetting resin composition of the present invention can further contain a reinforcing agent in the form of fiber or powder.

As reinforcing agents, inorganic powders such as various carbon blacks, finely powdered silica, fired clay, basic magnesium silicate, diatomaceous earth powder, alumina, calcium carbonate, magnesium carbonate, magnesia, kaolin, sericite, ceramic fibers, asbestos, rock wool, glass fiber,
Inorganic fibers such as slag wool, carbon fiber,
Examples include various synthetic fibers such as polyimide fibers.

Furthermore, for the purpose of coloring the composition, it contains white pigments such as titanium dioxide, coloring pigments such as yellow lead, carbon black, iron black, molybdenum red, sulfur, cadmium yellow, cadmium red, etc., or various organic dyes. can be done.

In addition, anti-sag agents such as colloidal silica and carbon black, various rubbers, polythiols, polycarboxyl compounds, flexibility agents such as urethane prepolymers, fillers such as silica, calcium carbonate, and whiskers, antimony trioxide, etc. Various known additives such as flame retardants may also be included.

The thermosetting resin composition of the present invention is as described above,
Here, the production of prepreg using the composition will be described.

Prepreg is obtained by impregnating organic or inorganic reinforcing fibers with a thermosetting resin composition.

Organic or inorganic fibers refer to fibers commonly used in prepregs. Specifically, there are polyamide fibers, polyester fibers, carbon fibers, glass fibers, silicon carbide fibers, alumina fibers, polyethylene fibers, silicon carbide-titanium fibers, and the like. It is particularly suitable for the thermosetting resin composition of the present invention to be combined with high elongation and medium elongation carbon fibers.

In addition, the composition of prepreg consists of 3 organic or inorganic fibers.
It is preferable to bind 0 to 70% by weight and make the remainder a thermosetting resin composition. Outside this range, it may become unsuitable as a prepreg.

The temperature for curing the thermosetting resin composition in the prepreg varies depending on the presence or absence of a curing agent and catalyst, the types of composition components, etc., but is usually selected within the range of 150 to 300°C. During heat curing, it is preferable to apply pressure, and the pressure may be appropriately selected within the range of 0.1 to 500 kg/cm'.

<Example> The present invention will be specifically explained below by showing Examples and Comparative Examples.

First, the synthesis of the reaction product (C) synthesized from norbornene diol and terephthalic acid chloride will be described.

(Synthesis Example 1) 60.0 g of norbornene diol and 79.0 g of terephthalic acid chloride were placed in a 3-day flask with a capacity of 2 liters, and 100,100 O of chloroform was added thereto and dissolved. This mixture was heated to 70°C and reacted. The generated hydrogen chloride gas was neutralized by introducing it into an aqueous sodium hydroxide solution. After 10 hours, the reaction mixture solution was poured into methanol to precipitate the produced polymer.
It was dried and collected (yield: 94, 0 g).

The infrared absorption spectrum of this polymer is shown in Figure 1, and
The 'H-NMR spectrum is shown in FIG.
In addition, 'H-NMR is 27℃, CD Cfl
Measured in 3. As is clear from both spectra,
A polyester having hydroxyl groups at both ends was synthesized.
As a result of GPC measurement, its number average molecular weight is 3000.
Met.

(Synthesis Example 2) 60.0 g of norbornene diol and 79.0 g of terephthalic acid salt were placed in a 30 flask with a capacity of 2 liters, and 250 mJ2 of N-methylpyrrolidone was added thereto and dissolved. 40 g of pyridine was added dropwise to this mixture and reacted at room temperature. After 100 hours, the reaction mixture solution was poured into methanol, and the produced polymer was precipitated, dried, and collected (yield: 96.0 g).

The infrared absorption spectrum and NMR spectrum of this polymer were similar to each spectrum of the polymer obtained in Synthesis Example 1. Further, as a result of measurement by GPC, the number average molecular weight was 3,500.

(Synthesis example 3) 60 g of norbornene diol and 7 g of terephthalic acid chloride
9 g was placed in a 3-day flask with a capacity of 2 liters, and 250 mJZ of DMSO was added thereto to dissolve it. This mixture was reacted at 180°C. After 10 hours, the reaction mixture solution was poured into methanol, and the produced polymer was precipitated, dried, and collected (yield: 80 g). This polymer was treated again at 250°C for 10 hours.

The infrared absorption spectrum and NMR spectrum of this polymer were similar to each spectrum of the polymer obtained in Synthesis Example 1. Further, as a result of measurement by GPC, the number average molecular weight was 40,000.

(Examples 1 to 3, Comparative Examples 1 to 3) Thermosetting resin compositions were prepared with the blending amounts (% by weight) shown in Table 1.

Regarding this, the glass transition temperature (Tg) was measured using a thermomechanical device, and the results are shown in Table 1. Note that WET is data measured after immersion in boiling water for 48 hours.

In addition, after coating each thermosetting resin composition on a film,
A prepreg was obtained by impregnating unidirectional carbon fibers.

These prepregs were evaluated for tack and ease of handling, and are shown in Table 1 as good (0) or bad (×).

Furthermore, this prepreg was laminated and cured in an autoclave at 177° C. for 2 hours. The properties of this laminate were measured by the following method, and the results are shown in Table 1.

(Test method) ■0° compressive strength and elastic modulus: ASTM D 341
Measured according to 0.

■Interlaminar shear strength: Measured according to ASTM D 2344.

■ Compressive strength after impact: 15
A load of 00 bond is dropped from 1 inch above (1500
1b-in/in) After the impact, the compressive strength was measured. Compressive strength was measured in accordance with JIS K 6911.

As is clear from Table 1, in all Examples, the glass transition temperature of the thermosetting resin composition was around 200°C,
Since the prepared prepreg had a suitable tack and was easy to handle, the prepreg could be easily laminated. Moreover, the laminate after curing had excellent compressive strength and impact strength.

Comparative Example 1, in which the thermosetting resin composition lacks polyester,
The glass transition temperature (DRY) of the resin composition was 209°C, but the tack of the prepared prepreg was very strong.
It was difficult to handle. In addition, the laminate after curing is
Compressive strength after impact was low.

Comparative Example 2 using a polyester with too large a molecular weight,
Although the glass transition temperature of the resin composition was high, the resin composition was hard and could not be coated successfully. The prepared prepreg had no tack at all and was difficult to handle, so the prepreg could not be laminated and the physical properties of the laminate after curing could not be measured.

In Comparative Example 3 using saturated polyester, the glass transition temperature (DRY) of the resin composition was 180°C, and the prepared prepreg had good tack and ease of handling. As is clear from the fact that the temperature was 140°C, the water resistance of the laminate after curing was particularly poor.

<Effects of the Invention> According to the present invention, it is suitable as a resin composition for impregnating prepreg, and it has moderate adhesiveness itself, and after curing, it has high strength, high toughness, heat resistance, and water resistance together with reinforcing fibers. , a thermosetting resin composition that provides a composite material with excellent impact resistance is provided.

The properties of the prepreg using the thermosetting resin composition of the present invention after curing satisfy the properties required in the aircraft-related field, so the uses of the prepreg are widened.

[Brief explanation of drawings]

FIG. 1 is an infrared absorption spectrum of a reaction product synthesized from norbornene diol and terephthalic acid chloride used in Examples. Figure 2 shows the reaction product synthesized from norbornene diol and terephthalic acid chloride used in the examples.
This is an H-N HR spectrum.

Claims (1)

[Claims] (1) Synthesized from a resin (A) composed of a cyanate ester component and a bismaleimide component, an epoxy resin (B), and norbornene diol and terephthalic acid chloride represented by the following formula I, with hydroxyl groups at both ends. and a number average molecular weight of 200 to 20,000 (C
) and 100% by weight of (A) + (B) + (C)
When, the content of (A) is 50 to 94% by weight, (B
) content is 4 to 48% by weight, (C) content is 2 to 3
A thermosetting resin composition characterized in that the content is 0% by weight. ▲There are mathematical formulas, chemical formulas, tables, etc.▼... I