JPH0678422B2 - Thermosetting resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermosetting resin composition having excellent storage stability, impact resistance, moist heat resistance and mechanical properties.

[Prior art]

Conventionally, various resin compositions have been used as a matrix of a composite material, but particularly in the field of thermosetting resins, in addition to excellent mechanical properties, good adhesiveness with a reinforcing material, Epoxy resins have been widely used because of their excellent strength development compared to other thermosetting resins.
In recent years, there has been a strong demand for higher performance of composite materials, in particular, improvement in impact resistance, wet heat resistance and the like. As one of the methods, a polyfunctional maleimide as a matrix, a polyfunctional cyanate ester, an oligomer thereof and a pre-reacted product thereof have been investigated. However, the impact resistance was low and it was still insufficient for use as a matrix for composite materials.

[Object of the Invention]

The present inventors, in view of the present situation, excellent storage stability,
The present invention has been achieved as a result of intensive studies to develop a thermosetting resin composition having moist heat resistance and impact resistance.

[Structure of Invention]

The present invention is selected from the group consisting of a polyfunctional maleimide (I), a polyfunctional cyanate ester, an oligomer thereof or a prepolymer (II) of this ester and an amine and a pre-reactant of (I) and (II). (A), at least one kind (A), a pre-reaction product (B) of an epoxy compound having two or more epoxy groups in the molecule and a diamine, and a urea compound (C), and (B) with respect to the component (A) Component ratio is B / A = 1 / 4〜
The thermosetting resin composition is characterized in that it is in the range of 9/1.

The polyfunctional maleimide (I) used in the present invention is a compound having two or more maleimide groups and has a general formula: (In the formula, R ₁ represents an aromatic or alicyclic divalent organic residue)
In addition to the bismaleimide represented by, a prepolymer obtained by reacting these bismaleimides with a diamine can be mentioned.

Bismaleimide can be produced by a known method in which maleic anhydride is reacted with a diamine to prepare bismaleamic acid, and then dehydration cyclization. The diamine may be either an aromatic diamine or an alicyclic diamine,
For example, the following compounds are used. m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone Ether, 2,2-bis (4-aminophenoxyphenyl) propane, bis (4-aminophenoxyphenyl) sulfone, bis (4-aminophenoxyphenyl) sulfide, 1,4-bis (4- Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, trimethylene-bis (4-aminobenzoate), 1,4-cyclohexanediamine, hexahydroxylylenediamine and the like. These diamines can be used alone or in combination.

The polyfunctional cyanate ester used in the present invention is represented by the general formula R ₂ OCN) n (2) (wherein R ₂ is an aromatic organic residue, and n is an integer of 2 to 5). An organic compound having two or more cyanate ester groups, and examples of the compound of formula (2) include 1,3 or 1,4-dicyanate benzene, 4,4'-dicyanate biphenyl, bis ( 4-cyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) ethane,
2,2-bis (4-cyanatophenyl) propane, bis (4-cyanatophenyl) sulfone and the like can be mentioned.
Examples of the polyfunctional cyanate ester oligomer include a triazine oligomer obtained by trimerization of cyanate. A prepolymer obtained by reacting a cyanate ester with an amine can also be used. Examples of the amine used for producing the prepolymer include those used for the synthesis and modification of the above polyfunctional maleimide.

As the component (A) of the present invention, the polyfunctional maleimide (I), the polyfunctional cyanate ester, the oligomer thereof or the prepolymer (II) of the ester and the amine and / or the (I) ( A preliminary reaction product obtained by preliminarily reacting II) in the absence of a catalyst or in the presence of a catalyst is used.

Examples of the epoxy compound having two or more epoxy groups in the molecule for producing the preliminary reaction product (B) used in the present invention include, for example, glycidyl ether type, glycidyl ester type, glycidyl amine type, and chain aliphatic. Known epoxy compounds such as epoxide type and alicyclic epoxide type are included. Examples of the diamine include the diamines used in the synthesis and modification of the above polyfunctional maleimide. The diamine preferably has a pkb of 7 or more. p
When the kb is 7 or less, it is difficult to control the preliminary reaction, and the storage stability may decrease. Examples of the diamine having a pkb of 7 or more include 4,4'-diaminodiphenyl sulfone,
1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, trimethylenebis (4-aminobenzoate) and the like can be mentioned.

Preliminary reaction product (B) of the aforementioned epoxy compound and diamine
Can be obtained by reacting an epoxy compound with a diamine at an equivalent ratio of amino group / epoxy group = 1/10 to 8/10, preferably 2/10 to 5/10. Reaction temperature is 50
~ 250 ° C, preferably 100-200 ° C, and the reaction is completed in 1 minute to 10 hours. The pre-reactant obtained is preferably reacted so that its viscosity is at least 50 times greater than that of a simple mixture.

The urea compound (C) used in the present invention is added as a catalyst of a preliminary reaction product of an epoxy compound and a diamine, and is necessary for improving impact resistance. Imidazole, carboxylic acid adducts thereof, tertiary amines, and the like not only lack storage stability but also have insufficient improvement in impact resistance.

Examples of the urea compound (C) include N- (3-chloro-
4-methoxyphenyl) -N ', N'-dimethylurea, N
-(4-chlorophenyl) -N ', N'-dimethylurea,
N- (3-chloro-4-ethylphenyl) -N ', N'-
Dimethylurea, N- (3-chloro-4-methylphenyl) -N ', N'-dimethylurea, N- (3,4-dichlorophenyl) -N', N'-dimethylurea, N- (4- Methyl-3-nitrophenyl) -N ', N'-dimethylurea,
1,1 '-(4-methyl-m-phenylene) -bis (3,3-
Dimethylurea) and the like. These may be used alone or in combination of two or more.

The amount of the urea compound (C) used is 1 to 10 parts by weight, preferably 2 to 5 parts by weight, based on 100 parts by weight of the component (B). Further, a catalyst other than the urea compound may be added for the purpose of accelerating the curing or imparting desired characteristics to the cured product. Examples of such catalysts include latent curing catalysts such as boron trifluoride amine complex compounds, organic peroxides such as benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, zinc octylate, and the like. Examples thereof include organic acid metal salts such as tin octylate, zinc naphthenate, and cobalt naphthenate. The amount of these used is sufficient in the range of the catalyst amount in the general sense, and may be, for example, 5% by weight or less based on the total resin composition.

In order for the resin composition of the present invention to have excellent impact resistance and wet heat resistance, the components (A) and (B) should be B / A = 1/4 to 9 /.
It is necessary to use it in a composition ratio range of preferably 1 to 9/1. When the B / A is less than 1/4, the wet heat resistance is excellent, but the impact resistance is low. When the B / A exceeds 9/1, the impact resistance is excellent, but sufficient moist heat resistance cannot be obtained, and the mechanical properties of the composite material are insufficient.

By impregnating the reinforcing material with the thermosetting resin composition of the present invention, an intermediate material for a composite material is obtained. As the reinforcing material, in addition to inorganic fibers such as glass fiber, carbon fiber, boron fiber, silicon carbide, and fiber, a chop shape made of organic fiber such as poly-p-phenylene terephthalamide, poly-p-benzamide, polyamide hydrazide, Examples thereof include yarn, tape, sheet, knitted fabric, mat, paper, glass powder, glass sphere, mica, talc, asbestos, aluminum, iron and copper. These may be used alone or in combination of two or more. Depending on the application, flow regulators such as fine powder of silicon oxide, additives such as pigments, dyes, stabilizers and plasticizers may be used in appropriate combination.

The thermosetting resin composition and the intermediate material for a composite material of the present invention,
It has excellent storage stability, workability and processability, and its cured product has excellent impact resistance. Further, the thermosetting resin composition of the present invention has extremely excellent water resistance as compared with conventional epoxy resins.

Parts in the following Examples and Comparative Examples mean parts by weight.

Example 1 50 parts of bis (4-maleimidophenyl) methane and 450 parts of 2,2-bis (4-cyanatophenyl) propane at 120 ° C.
Preliminary reaction was performed for 20 minutes to obtain a preliminary reaction product. Epicoat 834 (Okaka Ciel Co., Ltd., epoxy equivalent 250) was added to this for 4,4 '
-Diaminodiphenyl sulfone and amino group / epoxy group = 1/4 equivalent ratio were reacted at 160 ° C for 4 hours, and Epicoat 80
2000 parts of a pre-reacted substance diluted to 80% with 7 (Okaka Shell Co., Ltd., epoxy equivalent 170) was added and uniformly mixed for 30 minutes at 70 ° C., and further N- (3,4-dichlorophenyl) -N. ′, N′−
Dimethyl urea 100 parts, dicumyl peroxide 1 part and silicon oxide fine powder Aerosil 380 (manufactured by Nippon Aerosil Co., Ltd.) 2
5 parts were added and mixed uniformly at 70 ° C. for 1 hour. This resin composition is sandwiched between glass plates to a predetermined thickness, 180
Curing was carried out for 2 hours at a temperature to obtain a resin plate. Further, this resin composition was formed into a film by a hot melt method, and a unidirectional prepreg (fabric weight 145 g / m ² , resin content 34.0%) was prepared using Pyrofil T-3 (manufactured by Mitsubishi Rayon Co., Ltd.).
This prepreg was laminated on [0 °] ₁₆ and “+ 45 ° / 0 ° / −45 ° / + 90 °” _4S and cured at 180 ° C. for 2 hours to obtain a composite material.

Various tests were carried out on the resin plate and the composite material. The results are shown in the table below. The glass transition point (Tg) in the table is Rheo
tanδmax temperature measured by a dynamics mechanical spectrometer manufactured by metrics Inc. Moisture and heat resistance of composites is [0 °] ₁₆ laminated plate composites in water at 71 ° C.
After soaking for 14 days, it was measured by performing a compression test in the 0 ° direction at 82 ° C. according to ASTM D695. The impact resistance is "+ 45 ° / 0 ° / -45 ° / + 90 °" _4S laminated plate composite is cut out into a size of 4 x 6 inches and fixed on steel with holes of 3 x 5 inches. Drop a 4.9 kg weight with a 0.5 inch R nose in the center to reduce the plate thickness to 1
It was measured by performing a compression test after applying an impact of 1500 lb-in per inch.

Example 2 Epicoat 828 (produced by Yuka Shell Co., Ltd., epoxy equivalent 189) was used as a pre-reactant of an epoxy compound and a diamine.
A resin plate and a composite material were obtained in the same manner as in Example 1 except that 4'-diaminodiphenyl sulfone was reacted with an amino group / epoxy group = 3/10 equivalent ratio at 160 ° C. for 4 hours. . The test results are shown in the table below.

Example 3 A resin plate and a composite material were obtained in the same manner as in Example 1, except that the amount of the pre-reacted product of the epoxy compound and diamine of Example 1 diluted to 80% with Epicoat 807 was changed to 1000 parts. It was The test results are shown in the table below.

Example 4 Epicoat 152 (produced by Yuka Shell Co., Ltd., epoxy equivalent: 177) was used as a pre-reaction product of an epoxy compound and a diamine.
A resin plate and a composite material were obtained in the same manner as in Example 1 except that 4'-diaminodiphenyl sulfone was reacted with an amino group / epoxy group = 3/10 at an equivalent ratio of 160 ° C. for 3 hours. It was The test results are shown in the table below.

Example 5 As a pre-reaction product of an epoxy compound and a diamine, a product obtained by reacting Epikote 834 with 1,4-bis (4-aminophenoxy) benzene under the same conditions as in Example 1 was used, and otherwise the same as in Example 1. To obtain a resin plate and a composite material. The test results are shown in the table below.

Example 6 As a pre-reactant of an epoxy compound and a diamine, a resin obtained by reacting epicote 834 with trimethylenebis (4-aminobenzoate) under the same conditions as in Example 1 was used, and otherwise the same as in Example 1. Plates and composites were obtained.
The test results are shown in the table below.

Example 7 2,2-bis (4-cyanatophenyl) propane and 4,4'-diaminodiphenylmethane were used as a pre-reaction product of a polyfunctional maleimide and a cyanate ester, and amino groups / cyanate groups = 1 / To 450 parts of a prepolymer of cyanate ester and amine pre-reacted at 70 ° C. for 10 minutes at an equivalent ratio of 5,
Add 50 parts of bis (4-maleimidophenyl) methane, add 12
A resin plate and a composite material were obtained in the same manner as in Example 1 except that the material preliminarily reacted at 0 ° C. for 20 minutes was used. The test results are shown in the table below.

Comparative Example 1 A resin plate and a composite material were obtained in the same manner as in Example 1 except that N- (3,4-dichlorophenyl) -N ', N'-dimethylurea was not added. The test results are shown in the table below.

Comparative Example 2 When a resin composition was prepared in the same manner as in Example 1 except that the epoxy compound and the diamine were used without preliminary reaction, the resin had poor storage properties and could not be formed into a prepreg.

Comparative Example 3 The amount of the pre-reacted product of the epoxy compound and diamine of Example 1 diluted with Epicoat 807 was changed to 100 parts,
Others were the same as in Example 1 to obtain a resin plate and a composite material. The test results are shown in the following method.

Claims (4)

[Claims] 1. A group consisting of a polyfunctional maleimide (I), a polyfunctional cyanate ester, an oligomer thereof, or a prepolymer (II) of this ester and an amine and a pre-reactant of (I) and (II). At least one (A) selected from
Preliminary reaction product (B) of urea compound with epoxy compound having two or more epoxy groups in the molecule and diamine (C)
And the ratio of component (B) to component (A) is B / A
= 1 / 4-9 / 1, The thermosetting resin composition characterized by the above-mentioned. 2. The thermosetting material according to claim 1, wherein the pre-reaction product of the epoxy compound and the diamine is obtained by the equivalent ratio of amino group / epoxy group = 1/10 to 8/10. Resin composition. 3. The diamine is 4,4'-diaminodiphenyl sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene or trimethylene bis (4-aminobenzoate). ) Is the thermosetting resin composition according to claim 1. 4. The thermosetting resin composition according to claim 1, wherein the urea compound is N- (3,4-dichlorophenyl) -N ', N'-dimethylurea.