JPH04164909A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain a curable resin composition which can be cured at low temperatures and has a short curing time and excellent heat stability and mechanical properties, especially hot strength, by mixing a maleimide compound with a divinylbenzyl ether. CONSTITUTION:A curable resin composition is obtained by mixing a compound having a maleimide group in the molecule (e.g. a bismaleimide such as N,N'- phenylenebismaleimide or a compound derived by modifying a bismaleimide with an amino compound such as diaminodiphenylmethane and still having two maleimide groups in the molecule) with divinylbenzyl ether. This composition excels in workability because it is amorphous and lowly viscous, and it can be extensively used as a bonding, casting, coating, impregnation or lamination molding compound, a coating material, an insulation material or a composite structural material because it is excellent in low-temperature curability, heat resistance and mechanical strengths.

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 relates to a curable resin composition that is excellent in low-temperature curing, heat resistance, and mechanical properties.

[Conventional technology]

Curable compositions are widely used as adhesives, castings, coatings, impregnations, laminations, molding compounds, etc. in paints, insulating materials, composite structural materials, and the like.

Among these, polyimide resin is one of the most excellent materials, and various developments are being promoted.

For example, a composition of a polymaleimide compound and a reactive oligomer having an alkenyl ether at the end of the molecule is known from JP-A-62-53319.

[Problem to be solved by the invention]

However, the above-mentioned resin composition has a high curing temperature,
The curing time is long, and in terms of workability including this,
It still cannot be said to be advantageous compared to existing general-purpose curable resins.

In addition, in recent years, curable resins have been used for a wide variety of purposes, so the curable resin compositions that have been used traditionally are
It is not possible to be completely satisfied under various usage environments or usage conditions. In particular, the heat resistance and hot strength when used at high temperatures are insufficient, and even the most typical compositions, such as the combination of bismaleimide, aromatic amine, and epoxy resin, are
Sufficient materials were not yet available.

Therefore, the present invention solves the above-mentioned problems of conventional curable resin compositions, and has a low curing temperature, short curing time, excellent heat resistance and thermal stability, and excellent mechanical properties. The purpose is to provide a polyimide resin composition.

The present inventors have discovered that a curable resin composition consisting of a maleimide compound and a vinylbenzyl ether compound bonded to an aromatic residue is effective, and has already been published in JP-A-64
-65110, but after further research,
We have discovered a curable resin composition that has excellent heat resistance such as hot strength.

[Means to solve the problem]

That is, the present invention provides a curable resin composition consisting of a compound having a maleimide group in the molecule and divinylbenzyl ether, which can be cured at a similar low temperature as the invention of JP-A No. 64-65110, and has a high cure rate. The time is short,
Furthermore, the present invention provides a curable resin composition characterized by excellent thermal stability and mechanical properties, particularly excellent hot strength.

The present invention will be explained in more detail below.

(Compound having a maleimide group in the molecule) A compound having a maleimide group in the molecule, which is a component of the composition of the present invention, is, for example, 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 bismethylmaleimide, N,N
'-Diphenyl ether and bismaleimides such as smethylmaleimide, or adducts of the above-mentioned bismaleimides with amino compounds such as diaminodiphenylmethane, diaminodiphenyl sulfone, and diaminodiphenyl ether, or amino compounds modified with epoxy resins. A typical example is a compound having two maleimide groups in the molecule.

Furthermore, monofunctional maleimide compounds such as aromatic maleimides such as phenylmaleimide, alicyclic maleimides such as cyclohexylmaleimide, and alkylmaleimides such as laurylmaleimide can also be used, but they are preferably used in place of a part of the bismaleimide compound. be able to.

(Divinylbenzyl ether) Divinylbenzyl ether, which is another component of the composition of the present invention, is represented by the following general formula % Formula % Divinylbenzyl ether represented by the above general formula:
It can be easily synthesized by dehydrochlorinating a commercially available chloromethylstyrene monomer with an aqueous inorganic alkali solution.

(Composition) The composition ratio of the maleimide compound and divinylbenzyl ether in the present invention can be varied widely depending on the purpose of use. When expressed as the equivalent ratio of each unsaturated group,
Maleimide compound/divinylbenzyl ether = 10
0/30 to 1/100, preferably 100150 to 1/
30 is good. Within this range, thermal curing is easy even without intentionally adding a radical initiator necessary for curing, and the reaction proceeds at a much lower temperature and in a shorter time than in the case of thermal curing alone. The initiation temperature of thermal decomposition in air is high and the decomposition loss is small.

The curable resin composition of the present invention combines the maleimide compound and divinylbenzyl ether with known monomers such as styrene, vinyltoluene, allylphenol, allyloxybenzene, diallyl phthalate, acrylic ester, methacrylic ester, or epoxy resin. and (meth)acrylic acid, vinyl pyrrolidone, vinyl benzyl ether compounds obtained by reacting phenols with chloromethylstyrene, and vinyl benzyl ether compounds obtained by reacting amines with chloromethylstyrene. Vinylbenzylamine compounds and the like can be blended. To prepare for curing, hydroquinone, benzoquinone, copper salt, ammonium salt or aluminum salt of N-nitronphenylhydroxylamine, etc. may be blended, and to further accelerate curing, known and publicly available radical initiators, such as Organic peroxides or an organic peroxide and its decomposition accelerator (REDOX) can also be blended.

Furthermore, the curable resin composition of the present invention can be cured with active energy rays, such as ultraviolet rays and laser beams, and can also be easily cured with electron beams by incorporating a publicly known photoinitiator.

The curable resin composition of the present invention can be used in kneaders, blenders,
Using a roll or the like, various other fillers and reinforcing fibers can be mixed to form a molding material or a composite material. It can also be dissolved in solvents to make varnishes, paints, and adhesives.
In addition, by impregnating reinforcing fibers such as glass fiber, carbon fiber, aromatic polyamide fiber, silicon carbide fiber, alumina fiber, etc., it can be used as a useful molding material and structural material for hand lay molding, prepreg, and filament winding. You can also do that.

〔Example〕

The present invention will be further explained below with reference to Examples.

In addition, unless otherwise specified, parts in the examples are parts by weight.

11" Synthesis of Nidivinyl Benzyl Ether (hereinafter abbreviated as DVBE) 1525 parts (1.0 equivalents) of commercially available chloromethylstyrene to which 300 ppm of aluminum salt of N-nitron phenylhydroxylamine was added was mixed with 150 parts of dimethyl sulfoxide (DMSO). 60 parts of potassium hydroxide aqueous solution [3 parts (1.2 equivalents) of potassium hydroxide, 35 parts of water] was added dropwise to the solution at 2°C over 40 minutes, and then 60 parts were reacted at 2°C for 4 hours. continued.

Next, a large excess of water was added to the system, and after stirring, water-DMSO was removed and an oily substance was extracted with benzene.

The benzene layer was washed repeatedly with water until the pH of the aqueous layer became 7, and the benzene was removed under reduced pressure to reduce the viscosity to 0, 1 (ps/25
DVBE was obtained with a yield of 98%. Also, dioxane or N was used here instead of DMSO.

Similar synthesis was possible using N-dimethylformamide.

11" Synthesis of diaminodiphenylmethane-modified bismaleimide by reaction of ubismaleimide and diaminodiphenylmethane 358 parts of N,N'-diphenylmethane bismaleimide (
1.0 mol) and 99 parts of diaminodiphenylmethane (
0.5 mol) was thoroughly ground and mixed in a ball mill, melted and stirred in a container at 170° C. for 10 minutes, and the container was immediately cooled with water to obtain a solid. This reactant is soluble in solvents such as N-methylpyrrolidone and dimethylformamide,
Furthermore, it was also soluble in low boiling point solvents such as acetone and methyl ethyl ketone (hereinafter referred to as DDM-modified BMI).

Dog 1 A sample was prepared by mixing 1 equivalent of DVBE synthesized in Reference Example 1 with 1 equivalent of diphenylmethane bismaleimide manufactured by Mitsui Toatsu (hereinafter abbreviated as BMI), and the mixture was heated at 120°C.
gelation was examined by placing it on a hot plate. For comparison, DVBE and BMI were also tested in the same manner. The results are shown in Table-1.

[Dog] L animals - A sample in which 10 equivalents of BM r was blended with respect to DVBEl and O equivalent, and 1.0 equivalent theoretical equivalent of DDM modified BMI synthesized in Reference Example 2 were blended and molded at 120 ° C. for 30 minutes. .

After demolding, thermal decomposition onset temperature in air for products subsequently cured at 250°C for 5 hours, JIS K 6911
The bending strength and bending elastic modulus at room temperature and hot conditions were measured. The results are shown in Table-2 and Table-3.

Table 2 Temperature m As a comparison, a curable composition made of a vinylbenzyl ether compound in which a maleimide compound and an aromatic residue are bonded together, which was previously proposed by the present inventors (Japanese Patent Laid-Open No. 64-6511
As an example of No. 0), for 1 equivalent of bisphenol A divinylbenzyl ether (BADVBE), Example 1
The BMI used in Example 2 or the DDM-modified BMI synthesized in Reference Example 2 were each mixed in an amount of 1.0 equivalent theoretically.
Molding was carried out at 80°C for 30 minutes. Subsequently, the material was post-cured at 250° C. for 5 hours, and its bending strength and bending elastic modulus at room temperature and hot temperature were measured according to JIS K 6911.

The results are also shown in Table 3.

Table 3 [Effects of the Invention] Due to the above-mentioned structure, the curable resin composition of the present invention is amorphous and has a low viscosity, so it has excellent workability, and also has excellent low-temperature curability and heat resistance. and mechanical strength, it can be used extensively in industry as adhesive, casting, coating, impregnated, laminated molding compounds, or as paints, insulation materials or composite structural materials.

Patent applicant: Showa Kobunshi Co., Ltd.

Claims (1)

[Claims] A curable resin composition comprising a compound having a maleimide group in the molecule and divinylbenzyl ether.