JPH03258819A - Curable resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition having excellent low temperature curability and giving cured products having excellent heat resistance and mechanical properties, especially toughness, by compounding a maleimide group- containing compound with a specific compound. CONSTITUTION:The objective composition comprises (A) a compound having one or more maleimide groups in the molecule (e.g. N,N'-phenylene bismaleimide) and (B) a compound having two or more vinylbenzyl ether groups bonded to a benzene nucleus or naphthalene nucleus and prepared by elongating the molecular chain of a polyhydric phenol or naphthol with an epoxy resin (e.g. a bisepoxy resin having an epoxy equivalent of 170-500) in an equivalent ratio of 1:0.05-0.5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a curable polymaleimide resin composition. In particular, the present invention provides a curable resin composition that has excellent low-temperature curability, and the cured product thereof has excellent heat resistance and mechanical properties, particularly toughness.

[Conventional technology]

Curable resin can be used for adhesion, casting, coating, impregnation, MW
It is widely used as a molding compound in paints, insulating materials, composite structural materials, etc. However, in recent years, their uses have become diverse, and depending on the environment and conditions of use, conventionally known curable resins are no longer satisfactory. Among these, it is particularly insufficient for use at high temperatures, and development in this aspect is desired.

Among these, polyimide resin is one of the most excellent materials, and various developments are underway. For example, JP-A-8
No. 2-53319 discloses a composition of a polymaleimide compound and a reactive oligomer having an alkenyl ether at the end of the molecule. However, this resin composition has a high curing temperature and a long curing time, and in terms of workability including these, it is still not advantageous compared to existing general-purpose curable resins. This is true even for the most typical compositions, such as the combination of bismaleimide and aromatic amine, and the combination of bismaleimide, aromatic amine, and epoxy resin, which have been known for a long time. A material with excellent physical properties and low-temperature curability has not been provided.

[Problem to be solved by the invention]

In view of these current circumstances, some of the inventors of the present invention have conducted intensive research in order to provide a polyimide resin composition that has a low curing temperature, short curing time, excellent heat resistance and thermal stability, and excellent mechanical properties. As a result of stacking, a curable resin composition consisting of a maleimide compound and a polyhydric phenol divinyl benzyl ether compound having one or more substituents represented by methylhydroquinone divinyl benzyl ether, and a curable resin composition consisting of a maleimide compound and 1,4 naphthalene We have discovered a curable resin composition consisting of a polyvalent naphthol divinyl benzyl ether compound represented by divinyl benzyl ether,
I proposed it earlier (Japanese Patent Application No. 1-153898,
No. 3-241231), although both exhibited excellent heat resistance, the cured products tended to be somewhat brittle, so improvement in toughness was required.

As a result of further research, the present inventors found that using a vinyl benzyl ether compound with a partially extended molecular chain using an epoxy resin improves toughness without impairing heat resistance, and also has excellent physical properties. It was discovered that a polyimide resin composition can be obtained, and the present invention was achieved.

[Means to solve the problem]

That is, the present invention uses 0.05 equivalent to 0.5 equivalent of epoxy resin per equivalent of a compound (^) having one or more maleimide groups in the molecule and polyhydric phenol or polyhydric naphthol. Regarding a curable composition comprising a compound (B) having two or more vinylbenzyl ether groups bonded to a benzene nucleus or naphthalene nucleus whose molecular chain has been extended by The object of the present invention is to provide a curable composition that takes a short time and exhibits not only excellent thermal stability but also greatly improved toughness of the cured product.

Details of the present invention are shown below.

The compound (^) having a maleimide group used in the present invention includes N, N' phenylene bismaleimide, N, N' xylene bismaleimide, N, N' tolylene bismaleimide, N, N' diphenylmethane bismaleimide,
N, N' diphenyl ether bismaleimide, N, N
' Diphenylsulfone bismaleimide, N,N'diphenylmethane and smethylmaleimide, N,N'diphenyl ether and smethylmaleimide, N,N'hydrogenated diphenylmethane bismaleimide, and further, these bismaleimides and, for example, diaminodiphenylmethane, diaminodiphenylsulfone, Examples include amino compounds such as diaminodiphenyl ether and adducts with amino compounds modified with epoxy resins that still have maleimide groups. Examples of monofunctional maleimides include aromatic maleimides represented by phenylmaleimide, alkylmaleimides represented by laurylmaleimide, and alicyclic maleimides represented by cyclohexylmaleimide.

For each equivalent of polyhydric phenol or polyhydric naphthol used in the present invention, 0.05 to 0.5 equivalents of epoxy resin are used to extend the molecular chain of two or more benzene nuclei or naphthalene nuclei. The compound (B) having a vinylbenzyl ether group (hereinafter referred to as a vinylbenzyl ether compound) is a compound having at least two hydroxyl groups directly bonded to benzene, such as 2,3-dioxytoluene, 3,4-dioxy Toluene, 4-ter-
Butylcatechol, cresircine, orcine, β-orcine, m-xylorcine, 4-n-hexylresolun, 2-methylhydroquinone, tar-butylhydroquinone, 2.5-di-ter-acylhydroquinone,
2,5-jethoxyhydroquinone, 2,3.6-)
Limethylhydroquinone, pyrogallol, pyrogallol-2-methyl ether, pyrogallol monoacetate,
1,3.5-) Compounds having at least two or more hydroxyl groups directly bonded to polyhydric phenols such as lyoxybenzene or naphthalene, such as 1.2 dihydroxynaphthalene,
], 3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, I,
6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-
Dihydroxynaphthalene, 2.6-dihydroxynaphthalene, 2.7-dihydroxynaphthalene, 1.2.3-trihydroxynaphthalene, 1,2.4-)dihydroxynaphthalene, 1.4.5-trihydroxynaphthalene, 1.2. 3.4-tetrahydroxynaphthalene, 1.
2.3.4,5.8-hexahydroxynaphthalene, etc.
Epoxy resin in an amount of 0.05 to 0.5 equivalent per equivalent, such as a bis-based epoxy resin with an epoxy equivalent of 170 to 500, a novolac type epoxy resin with an epoxy equivalent of 190 to 250, and an epoxy equivalent of 140 to 200
naphthalene skeleton type epoxy resin, epoxy equivalent: 100
~200 aromatic amine type epoxy resin etc. in the presence of an amine catalyst such as triethylamine, if necessary using a solvent such as dioxane or dimethyl sulfoxide, and then elongating the molecular chain with halomethylstyrene such as chloromethylstyrene, alcohol, It can be easily synthesized by dehydrochlorination with caustic potash or caustic soda using a solvent such as dioxane or dimethyl sulfoxide.

Furthermore, when extending the molecular chain with an epoxy resin, if the number of equivalents of the epoxy resin is 0.05 equivalent or less for 1 equivalent of polyhydric phenol or polyhydric naphthol, the toughness effect cannot be obtained; If the viscosity is higher than that, the viscosity will be too high and the workability will be poor, and the heat resistance will also be reduced.

The component ratio in the composition of the maleimide compound (A) and the vinylbenzyl ether compound (B) in the present invention can be varied widely depending on the purpose of use, but when expressed in terms of the respective unsaturated group equivalent ratios, A/ B-100
/30 to 1/100, more preferably 100150 to
1/30, and in these ranges, it can be easily thermally cured without intentionally adding a radical initiator necessary for curing, and it can be cured at a much lower temperature and in a shorter time compared to thermal curing alone. The reaction proceeds. Moreover, in the case of these ranges, the thermal decomposition initiation temperature in air is high and the decomposition loss is small.

In the curable composition of the present invention, in addition to the components (A) and (B), other known monomers such as styrene, vinyltoluene, allylphenol, allyloxybenzene, diallyl phthalate, acrylic acid It is possible to incorporate monofunctional maleimide compounds such as esters, methacrylic esters, vinylpyrrolidone, phenylmaleimide, and alkylmaleimides without departing from the spirit of the present invention. Hydroquinone, benzoquinone, copper salts, tetramethylthiuram compounds, for curing adjustment
It goes without saying that known and publicly available compounds such as nitrosophenyl hydroxyl compounds may be blended, and that radical initiators may be blended to accelerate curing.

The curable composition of the present invention can be mixed with various other fillers and reinforcing fibers using a kneader, blender, roll, etc. to be used as a molding material or composite material, or dissolved in a solvent to be used as a varnish, paint, or adhesive. It can also be impregnated into reinforcing fibers such as glass fibers, carbon fibers, aromatic polyamide fibers, silicon carbide fibers, and alumina fibers to produce useful molding and structural materials as prepregs and filament windings. .

Next, reference examples and examples are shown to explain the present invention in detail, but the scope of the present invention is not limited thereto. In addition, unless otherwise specified, parts in the examples are parts by weight.

Reference Example 1 Synthesis of methylhydroquinone divinylbenzyl ether with extended molecular chain using bisphenol A epoxy resin 62 parts (1.0 equivalents) of 2-methylhydroquinone and 47.3 parts (0
, 25 equivalents), triethylamine 0.1 as a reaction catalyst
1 part was charged, the temperature was raised to 150°C, and after about 1 hour of reaction, 120 parts of dimethyl sulfoxide, 42.1 parts (0.75 equivalents) of potassium hydroxide, and 30 parts of water were dissolved, and commercially available chloro 114.4 parts of methylstyrene (0.75 parts
equivalent) in 25 parts of dimethyl sulfoxide was added dropwise at 70 to 80°C over 1 hour, and then
The reaction was continued for 2 hours at °C. Next, a large excess of water was added to the system, and after stirring, an oily substance was extracted with benzene. The benzene layer is 5
% caustic potash, water washing was repeated until the pH of the aqueous layer became 7, and the benzene layer was dried with anhydrous sodium sulfate. The reaction product was an oil with a yield of 94% after removal of benzene, and was soluble in various organic solvents (hereinafter referred to as 0.25 equivalent bisA).
(abbreviated as epoxy-modified MHQDVBE).

Reference Example 2 Synthesis of naphthalene divinyl benzyl ether with extended molecular chain using naphthalene skeleton type epoxy resin 1.4 dihydroxynaphthalene 80 parts (1.0 equivalent) and 1.6 diglycidyloxynaphthalene 37 parts (0.25
(1) was dissolved in 100 parts of dimethyl sulfoxide, 0.12 parts of triethylamine was added as a reaction catalyst, the temperature was raised to 130°C, and after about 2 hours of reaction, 50 parts of dimethyl sulfoxide and 42.1 parts of potassium hydroxide (0.1 parts of potassium hydroxide) were dissolved. , 75 equivalents) was dissolved in 30 parts of water, and 114.4 parts (0.75 equivalents) of commercially available chloromethylstyrene dissolved in 25 parts of dimethyl sulfoxide was added dropwise over 1 hour at 70 to 80°C. Then, the reaction was further continued at 70 to 80°C for 2 hours. Next, a large excess of water was added to the system, and after stirring, an oily substance was extracted with benzene. The benzene layer was washed with 5% caustic potassium, water washing was repeated until the pll of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The reactant is an oil and the yield is 9
3%, and was soluble in various organic solvents (hereinafter referred to as 0.
25 equivalent naphthalene type epoxy modified 1.4N DV
(abbreviated as B E).

Reference example 3 TE with extended molecular chain using aromatic amine type epoxy resin
Synthesis of r-butylhydroquinone divinylbenzyl ether 83 parts (1.0 equivalents) of ter-butylhydroquinone and 11.5 parts (0.1 equivalents Jl) of tetraglycidyldiaminodiphenylmethane were dissolved in 100 parts of dimethyl sulfoxide, and triethylamine was added as a reaction catalyst. .1 part of dimethyl sulfoxide was added, the temperature was raised to 130°C, and after about 2 hours of reaction, 50 parts of dimethyl sulfoxide and 50.5 parts of potassium hydroxide (0.9
g equivalent), dissolved in 30 parts of water, to which 113 parts (01 g equivalent) of commercially available chloromethylstyrene dissolved in 30 parts of dimethyl sulfoxide was added dropwise at 70 to 80°C over 1 hour, and further 70 to 80 parts of The reaction was continued for 2 hours at °C.

Next, a large excess of water was added to the system, and after stirring, an oily substance was extracted with benzene. The benzene layer was washed with 5% caustic potassium, water washing was repeated until the pll of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The reactant is an oil and the yield is 93
% and was soluble in various organic solvents (hereinafter 0.1
equivalent TGDDM modified t-BHQDVBE).

In the same way, epoxy effi ig9 bis-type epoxy resin 0.1 equivalent modified MHQDVBE, tetraglycidyldiaminodiphenylmethane 0.1 equivalent modified MHQDVB
E, x boxy hit! 1189 bis-type epoxy 0.25 equivalent modified 1.4 naphthalene divinyl benzyl ether (hereinafter each 0.1 equivalent bis-A type epoxy-modified M
HQDVBE, 0.1 equivalent TGDDM modified MHQDVB
E, 0.25 equivalent bis A epoxy modified 1.4NDVBE
).

Table 1 shows the properties of each divinylbenzyl ether modified with an epoxy resin.

Table 1 Reference Example 4 Synthesis of diaminodiphenylmethane bismaleimide by reaction of bismaleimide and diaminodiphenylmethane 358 parts of N,N'-diphenylmethane bismaleimide (
1,0 mol), 99 parts of diaminodiphenylmethane (0,
17 mol) was thoroughly ground and mixed in a ball mill
The mixture was melted and stirred for 10 minutes in a container at 0° C., and the container was immediately cooled with water to obtain a solid material. This reaction product was soluble in solvents such as N-methylpyrrolidone and dimethylformamide, and also soluble in low-boiling point solvents such as acetone and methyl ethyl ketone (hereinafter abbreviated as DDM modified MI).

Reference example 5 Methylhydroquinone divinylbenzyl ether (MH
Synthesis of QDvBE) 62 parts (1.0 equivalents) of 2-methylhydroquinone and 56.1 parts (1.0 equivalents) of potassium hydroxide were dissolved in 120 parts of dimethyl sulfoxide and 30 parts of water. A solution of 152.5 parts (1.0 equivalents) of methylstyrene dissolved in 50 parts of dimethyl sulfoxide was added dropwise at 70°C over 1 hour, and the reaction was further continued at 70°C for 2 hours.

Next, a large excess of water was added to the system, the water was stirred, the dimethyl sulfoxide was removed, and the oil was extracted with benzene. The benzene layer was washed with 5% caustic potassium, repeated washing with water until the pH of the aqueous layer became 7, and the benzene layer was dried with anhydrous sodium sulfate. The reaction product was an oil with a yield of 98% after removal of benzene, and was soluble in various organic solvents (hereinafter referred to as MHQDVB).
(abbreviated as E).

Example 1 Six kinds of divinylbenzyl ethers (0,
25 equivalent bis-A engineered poxy modified MHQDVBE.

0.25 equivalent naphthalene type epoxy modification 1. ANDV
B.E.

0.1 equivalent fiTGDDM modified t-BHQDVBE.

0.1 Ett's A modified MHQDVBE.

0.1 ffiTGDDM modified MHQDVBES0.2
5 equivalent bis A epoxy modified 1. diphenylmethane bismaleimide (
(manufactured by Civer Geigy) were mixed to prepare a sample. These were placed on a hot plate at 120°C and gelation was examined. For comparison, VBE and bismaleimide were similarly tested and the results are summarized in Table 2.

Next, each composition was molded for 30 minutes at 120°C, and after being removed from the mold, it was subsequently post-cured at 250°C for 5 hours, and the thermal decomposition initiation temperature in air was measured, and the results are shown in Table 3.

Example 2 0,25 equivalent bis-A-engineered poxy-modified MH synthesized in Reference Example
QDVBE, 0.25 equivalent naphthalene type epoxy modified 1
．． 4NDVBE, 0.1 melon TGDDM modified t-BH
For each 100 parts of QDVBE, 10 parts of DDM-modified BMI or phenylmaleimide synthesized in Reference Example 4
A sample containing 0 parts was molded at 120°C for 30 minutes, and after demolding, it was subsequently cured at 250°C for 5 hours, and the thermal decomposition initiation temperature in air was measured. The results are shown in Table 4.

Example 3 Six kinds of divinylbenzyl ethers (0,
25 equivalent bis-A engineered poxy modified MHQDVBE (a), 0
．． 25 equivalent naphthalene type epoxy modified 1,4N DV
B E @, 0.1 TGDDM modified tBHQDV
BE (c), 0.1 bis A-engineered poxy modified MHQDV
BE (→, 0.1 f: LTGDDM modified MHQDVB
E(, t9.0.25 equivalent m Bis A epoxy modified 1.4N
100 parts of diphenylmethane bismaleimide (manufactured by Civer Geigy) or DDM-modified BM synthesized in Reference Example 4.
A sample containing 100 parts of I was molded at 120°C for 30 minutes, removed from the mold, and then cured at 250°C for 5 hours.The bending strength, bending elastic modulus, and bending maximum at room temperature and hot according to JIS K 13911 were determined. The amount of deflection was determined to be 1ill, and the results are shown in Table 5.

Comparative Example 0, 25 equivalent bis A-modified poxy MH in Example 3
MHQDVB synthesized in Reference Example 5 instead of QDVBE
The bending strength characteristics of the cast cured product were measured in the same manner as in Example 3, except that E was used, and the results are shown in Table 6.

The amount of deflection of the specimen when the stress reaches its maximum during the bending test is 1
Indicated by m.

〔Effect of the invention〕

The curable resin composition according to the present invention exhibits excellent curability due to the above-mentioned structure, and the cured product exhibits excellent heat resistance and even more excellent mechanical strength, especially toughness, so that it has excellent adhesive properties. It can be widely used in industry as a casting, coating, impregnating, laminating molding compound, or as a paint, insulating material or composite structural material.

Claims (1)

[Claims] (1) Compound (A) having one or more maleimide groups in the molecule and 1 equivalent of polyhydric phenol or polyhydric naphthol,
A compound having two or more vinylbenzyl ether groups bonded to a benzene nucleus or naphthalene nucleus whose molecular chain has been extended using an epoxy resin of 0.05 equivalent to 0.5 equivalent (
A curable resin composition consisting of B).