JPH01146922A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which gives a molded article having excellent heat aging resistance and weatherability, by mixing a specified pre- reaction product, a vinyl compound containing epoxy groups, a triallyl compound, a curing agent for epoxy, and a radical-polymerization initiator. CONSTITUTION:A polyamino compound (a) and 0.1-10 gram equivalent, per gram equivalent of component (a), of an unsaturated bismaleimide compound (b) are heated and kneaded together at 70-170 deg.C for 2-15min to give a pre- reaction product (A) having a softening point of 60-110 deg.C. 100 pts.wt. component A is mixed with 1-100 pts.wt. component (B) comprising a vinyl compound containing epoxy groups and, if required, an aliphatic epoxy compound which has a viscosity of 1-30,000cps and an epoxy equivalent of 20-1,000 and does not contain a vinyl group; 2-100 pts.wt. triallyl compound (C) capable of dissolving component A; 0.01-100 pts.wt., based on 100 pts.wt. components A and B in total, curing agent (D) for epoxy resin; and 0.01-10 pts.wt., based on 100 pts.wt. components A-C in total, radical-polymerization initiator (E).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a thermosetting resin composition based on an unsaturated bismaleimide compound, and more specifically, a thermosetting resin composition that is solvent-free and
The present invention relates to a thermosetting resin composition that is in a liquid form that is easy to handle and that can provide molded products with excellent heat aging characteristics and weather resistance.

(Prior art) In general, a thermosetting product of an unsaturated bismaleimide compound obtained by reacting an amine with maleic anhydride not only has excellent heat resistance, but also the above-mentioned curing polymerization reaction is an addition reaction. Therefore, since volatile components are not produced during curing, it has the advantage of forming a dense cured product.

However, unsaturated bismaleimide compounds have low solubility in general organic solvents, so in order to make this compound a solution, it is necessary to use 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 are modified by adding eboshiki resin, etc., but in general, precipitation occurs at room temperature or the viscosity becomes too high. Therefore, it has been difficult to use this type of thermosetting resin composition as a non-dissolving type.

Therefore, in JP-A No. 11-272227, the present inventors proposed that (a) a preliminary reaction product of a polyamino compound and an unsaturated bismaleimide compound be used as a pre-reactant of (b) an epoxy group-containing vinyl compound and/or (b) ) Successful solvent-free liquefaction was achieved by dissolving it in an aliphatic epoxy compound that does not have a vinyl group.

(Problems to be Solved by the Invention) The thermosetting resin composition of the prior art is in a liquid form that is solvent-free and easy to handle, and has a high curing shrinkage rate due to both the epoxy curing reaction and the radical polymerization reaction. It has the advantage of providing a cured molded product with low heat resistance and relatively excellent heat resistance. However, this cured molded product has a tendency to heat aging, resulting in a decrease in bending strength and flexural modulus and weight loss in a high-temperature atmosphere. In addition, it has poor weather resistance and is prone to a decrease in strength and poor appearance.

Therefore, an object of the present invention is to improve the solvent-free liquid curable resin composition, and in particular to provide a composition with improved heat aging resistance and weather resistance of molded articles.

(Means for Solving the Problems) According to the present invention, (a) a preliminary reaction product of a polyamino compound and an unsaturated bismaleimide compound, (b) an epoxy group-containing vinyl compound, or a vinyl compound containing no vinyl group therein; A thermosetting resin composition is provided, which contains as essential components a combination with an aliphatic epoxy compound (c) a triallyl compound, (d) an epoxy curing agent, and (e) a radical polymerization initiator.

(Function) Similar to the prior art, the present invention utilizes the effect that component (a) dissolves in component (b) even in the absence of a solvent to provide a liquid curable resin composition. However, it is characterized by the use of a triallyl compound as component (c) in addition to these components, and its use can significantly improve the heat aging resistance and weather resistance of the cured molded product.

In the present invention, the components (a) and (b) are involved in the curing reaction by the epoxy curing agent (d), while the components involved in the curing reaction by the radical polymerization initiator (e) are They are (a) component, (b) component, and (c) component.

Component (a) used in the present invention consists of a pre-reacted product (prepolymer) of a polyamino compound and an unsaturated bismaleimide compound. It can be used in the form of a solution dissolved in components (b) and (c). This component (a) reacts with the epoxy group due to the amino group contained in its molecule, and undergoes radical polymerization with components (b) and (c) due to the remaining ethylenic unsaturation.

The component (b) used in the present invention acts as a solvent for the component (a), and under the curing conditions, an epoxy curing reaction occurs due to the presence of an epoxy group (oxirane ring), and a radical polymerization curing reaction occurs due to the presence of a vinyl group. Contributes to curing through both reactions.

Component (c) used in the present invention is a gold compound with three allyl groups ((:H2=CH-C)Iz) in the molecule,
It is polymerized in the presence of a radical initiator to give a highly reticulated cured molded body.

In the present invention, it is also important to use the above components (b) and (c) in combination; if only component (b) is used, the heat aging resistance of the cured molded product may be unsatisfactory. On the other hand, if only component (c) was used,
After all, the heat aging resistance of the molded product is insufficient, and the viscosity of the composition becomes high, resulting in decreased workability.
Alternatively, it takes a long time to harden, resulting in poor moldability. By using both in combination, it becomes possible to improve the heat aging resistance and weather resistance of the cured molded product while controlling the viscosity and curing rate of the composition within a range that is easy to handle.

(Preferred embodiment of the invention) Each component used in the present invention is 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 formula: The above organic groups, these groups are:
They may be bonded to each other directly or via 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, 1.4-
Diaminocyclohexane, 2,6-riamitubiridine,
m-phenylenediamine, p-phenylenediamine, 4
．． 4°-diaminodiphenylmethane, 4.4°-diaminodiphenyl ether, 2.2-bis(4-aminophenyl)propane, benzidine, 4.4″-diaminodiphenyl sulfone, 4.4°-diaminodiphenyl sulfide, bis(4 -aminophenyl)methylphosphine, m-xylylenediamine, 1,5-diaminonaphthalene, p-xylylenediamine, hexamethylenediamine, 1,4°-diaminobenzophenone, 2,5-bis(
m-doaminophenyl)-1,3,4-oxadithiazole, 2,5-bis(p-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'-
Diamino compounds such as bis(p-aminobenzoyl)-4,4°-diaminodiphenylmethane.・ 1.2.4-) riaminobenzene, 1,3.5-triaminobenzene, 2,4.6-) riaminotoluene, 2,
4.6-Triamino-1,3,5-trimethylbenzene, 1,3.7-)-riaminonaphthalene, 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°-triaminobenzanilide, 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 (however, R1 is an organic group having 1 to 8 carbon atoms, and X is 0.1 to 8.
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, R2 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. and two carbonyl groups (=CO) are bonded to adjacent carbon atoms of the double bond.

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
°-henzophenone-bismaleimide, N, N'-p
-diphenylsulfone bismaleimide, N, N' -(
3,3°-dimethyl)-methylene-p-phenylenebismaleimide, N,N'-4,4'-dicyclohexylmethane-bismaleimide, N',N'-m-xylylene-bismaleimide, N,N'- p-xylylene-
Bismaleimide, N, N'-(3,3'-diethyl)-methylene-di-p-phenylenebismaleimide, N
, N'-m-)-lylene dimaleimide, aniline-
Reaction product of formalin reactant and maleic anhydride.

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

These polyamino compounds and unsaturated bismaleimide compounds are generally used in an amount of about 0.1 g equivalent of the latter to 1 g equivalent of the former.
It is used in the form of a pre-reactant in a proportion of ~10 g equivalents, preferably about 0.5-5 g equivalents and most preferably 1.5-3 g equivalents. In order to prepare the pre-reactant, for example, both of these are stirred into a prepolymer state using a roll or the like while being heated to a temperature of about 70 to 170° C., usually for 2 to 15 minutes. 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. It is generally desirable that this pre-reactant has a softening point of 60 to 110°C, and this softening point is determined by observing the sample under a microscope while heating it at a heating rate of 2°C/min.

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.

Component (b) As the epoxy group-containing vinyl compound of component (b), the following compounds are used.

glycidyl acrylate, glycidyl methacrylate,
Vinyl compounds such as allyl glycidyl ether, allyl oxide, etc. The epoxy group-containing vinyl compound used as the component (b) acts as a diluent for the 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 aggregate 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, is achieved. .

Component (b) is added in an amount that does not substantially inhibit the solubility of the prepolymer at room temperature.
It may contain styrenic compounds such as α-methylstyrene, vinyltriene, and divinylbenzene. The upper limit is usually 0.1 to 10 times the mole of component (b),
Preferably it is set to 0.1 to 3 times the mole. This results in
The strength of the cured product is further improved.

Examples of aliphatic epoxy compounds without vinyl groups used in combination with the above components include aliphatic epoxy resins such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and pentaerythritol polyglycidyl ether, and aliphatic carboxylic acids. Epoxy resins obtained by reaction with epichlorohydrin are used.

Among these epoxy resins, those having an epoxy equivalent of 20 to 1000, especially 50 to 3001, and a viscosity of 1 to 30000 cps at 25°C, especially 5 to 1000
Those in the range of 0 cps are particularly preferably used from the viewpoint of obtaining a resin composition in the form of a solution that is excellent in workability.

As the triallyl compound for component (c), any of the well-known compounds can be used as long as it dissolves the preliminary reaction product of component (a), the polyamino compound and the unsaturated bismaleimide compound.

Specific examples include triallyl isocyanurate, triallyl cyanurate, and triallyl trimellitate.

As the component (tl), 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.

As the radical polymerization initiator (e), for example, the following can be used.

(1) Isopropyl hydroperoxide, tert-butyl hydroperoxide, cumyl hydroperoxide, barbenzoic acid, etc., in which 10-0-H is bonded to a secondary or tertiary carbon atom; (2) Diisopropyl peroxide, (3) 2,5-dimethyl-2,5-bis(tert-butyl peroxy)hexane, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexene-3,2,5-dimethyl-2,5-bis(tert-butylperoxy)hexene-3,1,3- Bisperoxides containing two peroxy groups in one molecule, such as bis(tert-butylperoxyisopropyl)benzene: These bisperoxides are particularly advantageous in terms of peroxy value.

(4) Organic azo compounds having at least one 10-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) to (e) 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 metal salts, etc. may be blended in amounts known per se. is also possible.

Bean 1 In the resin composition of the present invention, each component is generally as follows: (b) the epoxy group-containing vinyl compound is 1 to 100 parts by weight, particularly 2 to 30 parts by weight, per 100 parts by weight of component (a); The vinyl group-free epoxy compound in component b) is
(b) 0 to 100 parts by weight per 100 parts by weight of component;
In particular, 4 to 30 parts by weight, the triallyl compound (c) is 2 to 100 parts by weight, especially 10 to 70 parts by weight, per 100 parts by weight of component (a), and the cured epoxy product (d) is comprised of (a) and ( 0.01 to 100 parts by weight per 100 parts by weight of the resin component b),
In particular, 0.05 to 50 parts by weight of the radical polymerization initiator (e) as component (a), (b)
and (c) in a weight ratio of 0.01 to 10 parts by weight, particularly 0.05 to 5 parts by weight, per 100 parts by weight of the resin component.

In this preparation, (a) component is (b) component and (c)
Prepared as a solution of ingredients.

In addition, in the formation of the preliminary reaction product, component (a) is replaced with component (b).
(a) in the substantial absence of component and (c), e.g., while heating in a reaction vessel to a temperature of about 70-170°C.
) component in component (b) and component (c) from room temperature to 100%
Preliminary reaction is carried out to such an extent that the mixture dissolves at a temperature of .degree. C. and does not precipitate even if left at room temperature.

Components (a), (b), and (c) thus formed
Component (d) and, if necessary, an epoxy curing accelerator, etc. are added to a homogeneous solution consisting of component (e) and, if necessary, an internal template agent, etc., at a temperature between room temperature and 100°C. A curable composition is obtained.

(Effects of the Invention) The thus obtained thermosetting resin composition of the present invention has the following characteristics.

(1) Since the unsaturated bisimide compound is dissolved in the low-viscosity epoxy group-containing vinyl compound and triallyl compound as a preliminary reaction product with the boriamic compound at room temperature to 100°C, it can be mixed with reinforcing fibers or fillers, etc. is easy and has excellent workability.

(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. , good heat resistance and weather resistance.

If the resin composition does not contain an epoxy group-containing vinyl compound, the curing of the resin composition will be extremely slow, lasting several tens of minutes or more.

(3) Since the prepared resin composition is a liquid substance with low viscosity at a temperature of room temperature to 100° C., it has many uses as a material for molding such as impregnation, casting, or lamination. In particular, it can be easily impregnated into reinforcing materials such as glass fibers, aromatic polyamide fibers, aromatic polyester fibers, carbon fibers, silicon carbide fibers, and alumina fibers to obtain impregnated products thereof. When this is completely impregnated using a press or roll at room temperature with a release film interposed, a material called sheet molding compound (SMC) or prepreg is obtained, which is reacted under pressure and heat.
By further performing post-curing, it can be molded into various molded products.

(4) Since the thermosetting resin composition of the present invention contains an epoxy group-containing vinyl compound, the curing rate is 20%.
It can be applied quickly in a few minutes at temperatures below 0°C, and because it contains a triallyl compound, it has excellent heat aging properties, and also has good weather resistance and appearance.

(Example) Example I 82 parts by weight of N,pJ'-4,4°-diphenylmethane bismaleimide and 18 parts by weight of 4.4°-diaminodiphenylmethane were heated for 15 minutes at 130 t: for a preliminary reaction. A prepolymer having two parts of ioo was obtained.

65 parts by weight of this prepolymer, 5 parts by weight of glycidyl methacrylate, and 30 parts by weight of triallyl isocyanurate were mixed at 80°C for 30 minutes in a stainless steel reaction vessel to dissolve the prepolymer. - 0.5 parts by weight of ethyl-4-methylimidazole,
Dicumyl peroxide as a radical polymerization initiator (
(hereinafter abbreviated as DCP) were mixed to prepare a thermosetting resin composition. The viscosity of this resin composition at 80°C was 4500 c, p, s as measured with an E-type viscometer.

This resin composition was heated to a thickness of about 0.5n+m (5nm) at 80°C.
40 g/m2) on a release film.

Sandwich chopped glass fiber (chop length 172 inches) with the coating film, and
The impregnation was carried out at 0°C, and the glass fiber content was approximately 60% by weight.
A MC was fabricated (thickness: approximately 2 mm 1°; this SMC was 200 mm thick).
The curing reaction was carried out at .degree. C. for 10 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.

(1) Viscosity of the resin composition = Measured at 80°C using an E-type viscometer (2) Impregnation of the resin composition into chopped glass fibers:
Visual judgment (3) Tackiness of SMC: Visual judgment (4) Drapability of SM: Visual judgment (5) Formability: The end point of curing at 200°C was evaluated using a curelastometer.

(6) Storage stability: SMC was stored at 20°C, and retention of drapability was visually determined.

(7) Bending strength and bending modulus of molded product: JIS K
-20℃, 200℃ and 250℃ according to 6911
Measured at ℃ (8) Tensile strength of molded product: 20℃ and 200℃ according to JIS K-6911
Measurement at °C (9) Heat Aging Characteristics of Molded Articles The molded articles were left in an air oven at 250°C for 1000 hours, and then the bending strength, flexural modulus, and weight loss rate at 20°C were evaluated.

(10) Weather resistance of molded product: The molded product was left in a sunshine weather meter for 1000 hours, and its appearance, bending strength, and flexural modulus were evaluated.

Example 2 SMC and plate-shaped compression molded products were obtained in the same manner as in Example 1 except that the amount of glycidyl methacrylate used was 10 parts by weight and the amount of triallyl isocyanurate was 25 parts by weight.

Various properties are shown in Table 1.

Example 3 SMC and plate-shaped compression molded products were obtained in the same manner as in Example 1 except that 30 parts by weight of triallyl trimellitate was used instead of triallyl isocyanurate-1.

Various properties are shown in Table 1.

Example 4 In Example 1, the resin coat thickness was changed to approximately 0.1 mm (12
0g/n+2), a prepreg with a carbon ta II content of 65 wt% was prepared using carbon fiber cloth instead of chopped glass fiber (thickness: approximately 0.3 m).
m). A plate-shaped compression molded product was obtained in the same manner except that.

Various properties are shown in Table 1.

Comparative Example 1 SMC and plate-shaped compression molded products were obtained in the same manner as in Example 1 except that the entire amount of glycidyl methacrylate was changed to triallyl isocyanurate.

Various properties are shown in Table 1.

Comparative Example 2 SMC and plate-shaped compression molded products were obtained in the same manner as in Example 1 except that the entire amount of triallylisocyanurate was changed to glycidyl methacrylate.

Various properties are shown in Table 1.

Claims (6)

[Claims] (1) (a) Preliminary reaction product of a polyamino compound and an unsaturated bismaleimide compound, (b) An epoxy group-containing vinyl compound, or a combination thereof with an aliphatic epoxy compound having no vinyl group, (c) Triallyl compound , (d) an epoxy curing agent, and (e) a radical polymerization initiator as essential components. (2) A thermosetting resin composition, characterized in that the pre-reacted product of component (a) is formed by pre-reacting substantially in the absence of components (b) and (c). (3) The thermosetting according to claim 1, wherein 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 methacrylate and allyl glycidyl ether. resin composition. (4) Claim 1, wherein the triallyl compound as the component (c) is one or a combination of two or more selected from the group consisting of triallyl isocyanurate, triallyl cyanurate, and triallyl trimellitate. The thermosetting resin composition described in . (5) Each of the above components contains 1 to 1 component (b) per 100 parts by weight of component (a).
00 parts by weight, component (c) is 2 to 10 parts by weight per 100 parts by weight of component (a)
0 parts by weight, component (d) is 0.01 to 100 parts by weight per 100 parts by weight of the total amount of components (a) and (b), component (e) is the amount of components (a), (b) and (c). Total amount 1
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 00 parts by weight. (6) In the component (a), the unsaturated bismaleimide compound is reacted at a rate of 0.1 to 10 g equivalent per 1 g equivalent of the polyamino compound.
The thermosetting resin composition described in .