JPS61272227A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:The titled composition, consisting essentially of a previous reaction product of a polyamino compound with an unsaturated bismaleimide compound under specific conditions, epoxy group-containing vinyl compound, etc., usable as a solvent-free type and having improved operability, heat resistance, etc. CONSTITUTION:A thermosetting resin composition obtained by preparing (A) a previous reaction product of (A) a polyamino compound, e.g. 4,4'- diaminodicyclohexylmethane, with an unsaturated bismaleimide compound, e.g. N,N'-phenylenebismaleimide, in the absence of (B) an epoxy group-containing vinyl compound, e.g. glycidyl acrylate, and incorporating the component (A) with the component (B), (C) an aliphatic epoxy compound containing no vinyl group, e.g. ethylene glycol diglycidyl ether, (D) an epoxy hardener and, (E) a radical polymerization initiator. Specifically, the component (A) is preferably dissolved in the component (B) and the components (C)-(E) are added to the resultant solution.

Description

[Detailed Description of the Invention] 1 Presentation of raw elbows! The present invention relates to a thermosetting resin composition based on an unsaturated bismaleimide compound, and more particularly to a thermosetting resin composition that has excellent workability and heat resistance, and has a sufficiently low curing shrinkage rate.

In general, the heat-cured products of unsaturated bismaleimide compounds obtained by reacting amines with maleic anhydride not only have excellent heat resistance, but also because the curing polymerization reaction described above is an addition reaction. Since no volatile components are generated during curing, it has the advantage of forming a dense cured product.

However, unsaturated bismaleimide compounds have low solubility in general battering machine solvents, so in order to make this compound a solution, highly polar dimethylformamide,
Requires the use of high boiling point solvents such as N-methylpyrrolidone. In addition, in order to compensate for such low solubility, unsaturated bismaleimide compounds have been modified by adding, for example, epoxy resins, but this generally results in precipitation at room temperature or excessively high viscosity. Therefore, it is currently difficult to use this type of thermosetting resin composition as a non-dissolving type.

An object of the present invention is to provide an unsaturated bismaleimide compound-based thermosetting resin composition that can be used as a solvent-free type.

Another object of the present invention is to provide a thermosetting resin composition having excellent properties such as workability and heat resistance.

Still another object of the present invention is to provide a thermosetting resin composition which has a sufficiently low curing shrinkage rate and which makes it possible to obtain cured molded products with excellent dimensional stability and appearance characteristics.

(a) Pre-reaction product of polyamino compound and unsaturated bismaleimide compound, (b) Vinyl compound containing epoxy group, (b') Aliphatic epoxy compound having no vinyl group, (c) Epoxy curing agent, (d ) a radical polymerization initiator as an essential component, and the pre-reacted product of the component (a) is substantially formed by pre-reacting in the absence of the epoxy group-containing vinyl compound of the component (b). A thermosetting resin composition (n) is provided.

One plan and one dish The components used in the second invention are as follows.

The component (a) consists of a preliminary reaction product of a polyamino compound and an unsaturated bismaleimide compound.

Examples of the polyamino compound include, but are not limited to, the following general formula: R-+-NH2), ...(1), where R is 2 such as an alkylene group, a cycloalkylene group, an arylene group, etc. These organic groups have higher valences and may be bonded to each other directly or through other bonding groups.

m represents an integer of 2 or more.

An amino compound represented by is used.

Specifically, for example, the following compounds are used.

4.4'-diaminodicyclohexylmethane, ■, 4-
Diaminocyclohexane, 2,6-diamitupyridine,
m-phenylenediamine, p-phenylenediamine, 4
．． 4'-Diaminodiphenylmethane J4,4'-Diaminodiphenyl ether, 2,2-bis(4-aminophenyl)propane, benzidine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, bis(4- aminophenyl) methylphosphine, m-xylylene diamine, 1,5-diaminonaphthalene, p-xylylene diamine, hexamethylene diamine, 1,4'-diaminobenzophenone, 2,5-bis(
m-aminophenyl)-1,3,4-oxadithiazole, 2,5-bis(p-1 aminophenyl') -1,
3,4-oxadithiazole, 4,4'-bis(p-aminophenyl)-2,2'-dithiazole, 3,4'-
Diaminobenzanilide, 2,2'-bis(m-aminophenyl)-5,5'-dibenzimidazole, N,N
Cyamino compounds such as '-bis(p-aminobenzoyl)-4,4'-diaminodiphenylmethane.

1.2.4-) riaminobenzene, 1.3.5=triaminobenzene, 2.4.6-triaminotoluene, 2.
4.6-1 riamino-1,3,5-trimethylbenzene, 1.3.7-triaminonaphthalene, 2,4.4'-
Triaminodiphenyl, 2.4.6-triaminopyridine, 2,4゜4'-triaminodiphenylmethane, p-
Aminophenyl-4,4'-diphenylmethane, tri(
4-aminophenyl)methane, 2.4.4'-triaminobenzophenone, 3.5.4'-)lyaminobenzanilide, melamine-1,2,4°5-tetraaminobenzene, 2.3,6 .7-tetraaminonaphthalene, 3.
3',4.4'-tetraaminodiphenyl ether, 3
．． 3', 4゜4'-tetraaminodiphenylmethane, 3
．． 5-bis(3,4'-diaminophenyl)pyridine,
General formula (where R1 is an organic group having 1 to 8 carbon atoms, X is 0.1 to
A compound having three or more amino groups, such as a compound represented by (2).

Examples of the unsaturated bismaleimide compound used with the above polyamino compound include those represented by the following general formula.

In the formula, R is an alkylene group having 2 or more carbon atoms, a cycloalkylene group, an arylene group, or an organic group consisting of two or more bonds thereof, and R3 is a divalent organic group having a carbon-carbon double bond. shows.

Specifically, for example, the following compounds are used.

N,N'-phenylene bismaleimide, N,N'-hexamethylene bismaleimide, N,N'-methylene-di-
p-phenylene bismaleimide, N.

N'-oxy-di-p-phenylene bismaleimide, N
, N'-4,4'-benzophenone-bismaleimide,
N, N'-p-diphenylsulfone bismaleimide, N
, N'-(3,3'-dimethyl)-methylene-p-phenylenebismaleimide, N,N'-4,4'-dicyclohexylmethane-bismaleimide, N,N'-m-xylylene-bisma, leimide , N,N'-p-xylylene-bismaleimide, N,N'-(3,'3'-diethyl)-methylene-p-phenylenebismaleimide, N,N'-m-toluylene-cimaleimide, aniline-formalin reaction reaction product between maleic anhydride and maleic anhydride.

These unsaturated bismaleimide compounds can be substituted with monomaleimide compounds such as N-allylmaleimide, N-propylmaleimide, N-hexylmaleimide, and N-phenylmaleimide up to about 60% by weight. .

These polyamino compounds and unsaturated bismaleimide compounds are generally mixed in an amount of about 0.1 g equivalent of the former to 1 g equivalent of the latter.
A proportion of ~10 g equivalents, preferably about 0.5-5 g equivalents, is used in the form of a pre-reactant.

To prepare the preliminary reaction product, in the absence of the epoxy group-containing vinyl compound as component (b), for example, both of these are kneaded using a roll or the like while heating to a temperature of about 70 to 170°C. to form a prepolymer. Both of these can form polyamino bismaleimide by Michael addition of the amino group of the polyamino compound to the unsaturated bond of the bismaleimide compound.

In the present invention, since the curing polymerization reaction of component (a) is an addition reaction, volatile components are not generated during curing and a dense cured product can be formed. It can be uniformly dissolved in component (b) even at room temperature.

The following compounds are used as the epoxy group-containing vinyl compound as component (b).

glycidyl acrylate, glycidyl methacrylate,
Vinyl monomers such as allyl glycidyl ether and allyl oxide.

The epoxy group-containing vinyl compound used as component (b) acts as a diluent for component (a), that is, the (
It enables component a) to be uniformly dissolved even at room temperature, and as a result, a curable resin composition obtained without the use of a special solvent is formed as a low-viscosity solution, resulting in improved workability.

In addition, since this vinyl compound contains an epoxy group, when the resin composition is impregnated into fibers, etc. by using it together with a specified curing agent, the viscosity increases rapidly, and this thickening reaction Another advantage is that it does not involve gelation. That is, since the obtained thickened product does not increase in viscosity over time, the effect of improving the storage stability of molding materials such as SMC and pre-plugs, which must be in the stage before complete curing, can be achieved. Ru.

Component (b) is added in an amount that does not substantially inhibit the solubility of the prepolymer at room temperature.
It may contain styrenic monomers such as α-methylstyrene, vinyltoluene, and divinylbenzene. The upper limit is usually set to 0.1 to 10 moles, preferably 0.1 to 3 moles, per mole of component (b). This further improves the strength of the cured product.

Examples of aliphatic epoxy compounds without vinyl groups used as the single-layer trowel-laying (b') component include aliphatic epoxy resins such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and pentaerythritol polyglycidyl ether. , an epoxy resin obtained by the reaction of an aliphatic carboxylic acid with epichlorohydrin is used.

Among these epoxy resins, those having an epoxy equivalent of 20 to 1,000, especially 50 to 300, and a viscosity of 1 to 30,000 cps at 25°C, especially 5 to 10,000
Those in the cps range are particularly preferably used from the viewpoint of obtaining a solution-like resin composition that is excellent in workability.

That is, by using this aliphatic epoxy compound that does not have a vinyl group, the curing shrinkage rate is significantly suppressed, as shown in the examples described later.

Any known epoxy curing agent can be used as long as it does not substantially inhibit radical polymerization.

Specific examples include aliphatic amines, acid anhydrides, dicyandiamide, hydrazines, imidazoles, and amine complex compounds of boron trifluoride.

For example, the following radical polymerization initiators are used.

(1) Isopropyl hydroperoxide, tertiary butyl hydroperoxide, cumyl hydroperoxide, perbenzoic acid, etc., in which -0-H is bonded to a secondary or tertiary carbon atom (2) Diisopropyl peroxide, ditertiary Butyl peroxide, dicumyl peroxide etc. have two secondary or tertiary carbon atoms.
(3) 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 2,5-dimethyl-2°5-bis(tert-butylperoxy)hexene-3,2,5 -dimethyl-2,5-bis(tert-butylperoxy)hexyne-3,1,3-bis(tert-butylperoxyisopropyl)bisperoxides containing two peroxy groups in one molecule, such as benzene; Bisperoxides are particularly advantageous due to their peroxy value.

(4) Organic azo compounds having at least one -0-N-N- bond in the molecular structure represented by azobisalkanonitrile such as azobisisobutyronitrile and azobiscarbonamide.

The thermosetting composition of the present invention is composed of the above components (a) and (b) as essential components.

Of course, in addition to the above ingredients, imidazoles,
Epoxy curing accelerators such as boron trifluoride amine complex compounds, tertiary amines, quaternary ammonium salts, urea compounds, internal mold release agents such as higher fatty acid metal salts, etc. may be blended in amounts known per se. is also possible.

In the resin composition of the present invention, each component is generally as follows: component (b), the epoxy group-containing vinyl compound, is 2 to 140 parts by weight, particularly 5 to 70 parts by weight, per 100 parts by weight of component (a); The epoxy compound of component (b') is 100% of component (b).
4 to 100 parts by weight, especially 8 to 50 parts by weight, the epoxy cured product of component (c) contains (a), (b) and (b).
') 0.01 to 100 per 100 parts by weight of the resin component
Parts by weight, especially 0.05 to 50 parts by weight, of the radical polymerization initiator of component (d) are 10 parts by weight of the resin components (a) to (c).
0.01 to 10 parts by weight, especially 0.05 parts by weight
It is used in a weight ratio of 5 parts by weight.

During this preparation, component (a) is prepared as a solution of component (b).

In addition, in the formation of the preliminary reaction product, component (a) is replaced with component (b).
In the substantial absence of components, e.g.
While heating to a temperature of 170°C, the (a) component (b)
Preliminary reaction is carried out to the extent that it dissolves in the components at room temperature and does not precipitate even if left at room temperature.

To the thus formed homogeneous solution consisting of components (a) and (b), component (c) and an epoxy curing accelerator as necessary are added under room temperature conditions, and further component (d) and internal mold release as necessary. A thermosetting composition can be obtained by adding an agent or the like.

The thermosetting resin composition of the present invention thus obtained has the following characteristics.

(Since the 11-unsaturated bisimide compound is dissolved in a low-viscosity epoxy group-containing vinyl compound at room temperature as a preliminary reaction product with a polyamino compound, it is formed as a low-viscosity ?8 liquid, and therefore has excellent workability. Not only that, but the viscosity increases rapidly after impregnation, and this thickening reaction does not involve gelation, so the resulting thickened product does not increase in viscosity over time and remains in the stage before complete curing. must be S
Improves storage stability of molding materials such as MO and prepreg.

Here, the pre-reactant (prepolymer) is 1 g of component (a)
Component (b) is mixed at a ratio of usually 1.5 to 3 geq to eq.
It is usually obtained by reacting 2 to 15 m1n at a temperature of ~170°C, and its curing point is usually 60 to 110
It is prepared so that it reaches ℃.

To measure the softening point of the preliminary reactant, the sample was heated under a microscope at a heating rate of 2.
This is done by observing while heating at °C/min.

(2) By using a radical polymerization initiator, the resin composition of the present invention cures in a short time of several minutes or less even at temperatures below 200°C, and the resulting thermoset has excellent mechanical strength. , heat resistance is also good.

(3) Since the prepared resin composition is a low-viscosity liquid material, it has many uses as a material for molding such as impregnation, casting, and lamination. In particular, it easily penetrates into reinforcing materials such as glass fibers, aromatic polyamide fibers, aromatic polyester fibers, carbon fibers, silicon carbide fibers, alumina fibers, etc., and impregnated products thereof can be obtained. If this is completely impregnated using a press or roll at room temperature with a release film interposed, sheet molding composite
A material called SMC) prepreg is obtained, which is reacted under pressure and heat, and further post-cured.
It can be molded into various molded products.

(4) Furthermore, in the thermosetting resin composition of the present invention, since the curing shrinkage rate is significantly suppressed, it has the remarkable advantage that the dimensional stability and appearance stability of the cured molded product are not impaired as a result. achieved.

Example I 82 parts by weight of N,N'-4,4'-diphenylmethane bismaleimide and 18 parts by weight of 4,4'-diaminodiphenylmethane were pre-reacted by heating at 130°C for 15 minutes with a roll, and 100 parts by weight A prepolymer was obtained.

55 parts by weight of this prepolymer and 35 parts by weight of glycidyl methacrylate were heated in a glass reaction vessel at room temperature for 30 minutes.
After mixing for a minute to dissolve the prepolymer, ethylene glycol diglycidyl ether 1 is added as the epoxy compound.
0 parts by weight, 2 parts by weight of dicyandiamide as an epoxy curing agent, 0.5 parts by weight of 2-ethyl-4-methylimidazole as an epoxy curing accelerator, 1 part by weight of dicumyl peroxide (hereinafter abbreviated as DCP) as a radical polymerization initiator.
Parts by weight and 2 parts by weight of zinc stearate as an internal mold release agent were mixed to prepare a thermosetting resin composition.

The viscosity of this resin composition at 25°C was 6.800 cps as measured with an E-type viscometer.

This thermosetting resin composition was impregnated into 8 layers of chopped glass fiber mat (chop length: 50 g/m, area weight: 300 g/m) at room temperature. This impregnated material was pressed at room temperature, and the glass fiber content was approximately 60 wt. % SMC (approximately 3 mm thick) was prepared.A polyethylene film with a thickness of 50 μm was used as a release film for the overcoat.

This SMC was left at room temperature for several days to become tack-free, and then a curing reaction was performed at 160° C. for 3 minutes.

Thereafter, a post-curing reaction was performed in an air oven at 200° C. for 24 hours to obtain a plate-shaped compression molded product.

The following various properties of the above SMC and the obtained molded article were evaluated. The results obtained are shown in Table 1.

Viscosity of thermosetting resin composition: Measured at 25°C using an E-type viscometer Impregnation of resin composition into chopped glass fiber mat:
Visually determined SMC tackiness: Visually determined SMC drapeability: Visually determined Bending strength and flexural modulus of molded product: Measured at 20°C, 200°C, and 250°C in accordance with JIS K-6911 Molded product Tensile strength: According to JIS K-6911, at 20°C and 200°C
Water absorption rate of molded product measured at ℃: Measured at 20℃ for 24 hours in accordance with JIS K-6911 Storage stability: SMC was stored at 20℃, and maintenance of drapability was visually determined. .

Curing shrinkage rate: SMC was compression molded using a mold with a marker for measuring curing shrinkage rate, and calculated from the dimensional difference between the mold and the SMC molded product.

Example 2 S was prepared in the same manner as in Example 1 except that the amount of glycidyl methacrylate used was 25 parts by weight and the amount of ethylene glycol glycidyl ether was 20 parts by weight.
MC and plate-shaped compression molded products were obtained.

Various properties are shown in Table 1.

Example 3 S was produced in the same manner as in Example 1 except that the amount of glycidyl methacrylate used was 15 parts by weight and the amount of ethylene glycol glycidyl ether was 30 parts by weight.
MC and plate-shaped compression molded products were obtained.

Various properties are shown in Table 1.

Claims (4)

[Claims] (1) (a) Preliminary reaction product of polyamino compound and unsaturated bismaleimide compound, (b) Vinyl compound containing epoxy group, (b') Aliphatic epoxy compound without vinyl group, (c) Epoxy curing agent , (d) a radical polymerization initiator, as an essential component, and the pre-reacted product of the component (a) is formed by pre-reacting substantially in the absence of the epoxy group-containing vinyl compound of the component (b). A thermosetting resin composition characterized by: (2) The epoxy group-containing vinyl compound as the component (b) is one or a combination of two or more selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. The thermosetting resin composition described. (3) Each of the above components contains 2 to 1 component (b) per 100 parts by weight of component (a).
40 parts by weight, component (b') is 4 to 100 parts by weight per 100 parts by weight of component (b), component (c) is per 100 parts by weight of the resin components (a), (b) and (b'). 0.01 to 100 parts by weight, (d) resin component 1 whose components are (a), (b) and (b')
The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition is contained in a proportion of 0.01 to 10 parts by weight per 0.00 parts by weight. (4) The thermosetting resin composition according to claim 1, wherein in the component (a), the unsaturated bismaleimide compound is used in an amount of 0.1 to 10 g equivalent per 1 g equivalent of the polyamino compound.