JPH08134351A - Heat-resistant resin composition - Google Patents

Abstract

PURPOSE: To obtain a heat-resistant resin composition composed of a specific polyimide, a resol type phenolic resin and a novolak type phenolic resin, not requiring long time or high temperature for curing, excellent in moldability and mechanical strength and useful for laminated sheets, etc. CONSTITUTION: This heat-resistant resin composition is composed of (A) a polyimide having a phenolic hydroxyl group in the molecule and obtained by reacting (i) an aromatic diamine such as diaminodiphenylmethane with (ii) a bismaleimide such as N,N'-diphenylmethanebismaleimide and (iii) aminophenols having both of an amino group and a phenolic hydroxyl group in one molecule, e.g. paraaminophenol, (B) a resol-type phenolic resin and (C) a novolak type phenolic resin. Furthermore, the compounds A to C are preferably used in amounts of 10-90wt.% of the component A and 90-10wt.% of total amount of the components B and C, and the components B and C are preferably used in amounts of 30-90wt.% of the component B and 70-10wt.% of the component C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant resin composition which is curable and has good physical properties and heat resistance, and which is useful in various fields such as molding materials, laminated plates, grindstones and brakes. Is.

[0002]

2. Description of the Related Art It is well known that a heat-resistant resin is obtained by reacting a bismaleimide with an aromatic diamine.
However, this heat-resistant resin requires high temperature for a long time for curing, and the products are mainly liquid (solvent-soluble type).

[0003]

DISCLOSURE OF THE INVENTION The present invention does not require a high temperature for a long time for curing, and is a curable and useful as a molding material mainly for liquid type resins and mainly for applications using powdered resins. An object of the present invention is to provide a heat resistant resin composition which is excellent in moldability, heat resistance and mechanical strength.

[0004]

Means for Solving the Problems As a result of various investigations for solving the above problems, the present inventors have found that when a bismaleimide and an aromatic diamine are reacted with each other, a third component in one molecule is used. Aminophenols that share a phenolic hydroxyl group and a primary amino group are co-reacted with each other to synthesize a polyimide having a phenolic hydroxyl group at the end, and a resole-type phenolic resin and a novolac-type phenolic resin are used in combination therewith. It was found that the resin composition thus obtained can improve the moldability and the mechanical strength without impairing the heat resistance, and was able to complete the present invention.

That is, the present invention relates to [I] (1) aromatic diamine, (2) bismaleimide and
(3) A polyimide having a phenolic hydroxyl group in the molecule, which is obtained by reacting aminophenols sharing an amino group and a phenolic hydroxyl group in one molecule, [II] a resole type phenolic resin and [III] novolak The present invention relates to a heat resistant resin composition which is used in combination with a type phenolic resin.

The term "combined" as used herein means that the polyimide as the component [I], the resol type phenolic resin as the component [II], and the novolac type phenolic resin as the component [III] may be simply mixed and used. Or a polyimide as the component [I], a resol-type phenolic resin as the component [II], and a novolac-type phenolic resin as the component [III],
The polyimide of the component [I] may be preheated or kneaded at a temperature such that the resol type phenolic resin of the component [II] and the novolac type phenolic resin of the component [III] are not completely crosslinked. Means

In order to facilitate understanding of the present invention, an example of a polyimide having a phenolic hydroxyl group in the molecule, which is synthesized by using paraaminophenol, N, N'-diphenylmethane bismaleimide and diaminodiphenylmethane, is shown below. As indicated.

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The model of the cured resin when the resol type phenolic resin and the novolac type phenolic resin are reacted with the polyimide of the above formula is as follows.

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[0009] The properties of the heat-resistant resin composition according to the present invention include the ratio of bismaleimide and aromatic diamine, and the type of aromatic diamine, the amount of aminophenols, the type and amount of resol-type phenolic resin, and the novolac-type phenolic type. It can be greatly changed depending on the type and amount of resin used, and can be used for a variety of applications.

In the present invention, it is used to synthesize a polyimide having a phenolic hydroxyl group in the molecule,
Examples of aromatic diamines include the following. Diaminodiphenylmethane, diaminodiphenyl sulfone, 2,4-tolylenediamine, 2,6-tolylenediamine, and mixed amines thereof, metaphenylenediamine, paraphenylenediamine, naphthylenediamine and the like.

Examples of the bismaleimide capable of reacting with these aromatic diamines to form a polyimide include N, N '.
-Diphenylmethane bismaleimide, N, N'-diphenyl ether bismaleimide, N, N'-paraphenylene bismaleimide, N, N '-(2-methylmetaphenylene) bismaleimide, N, N'-metaphenylene bismaleimide, N , N '-(3,3-dimethyldiphenylmethane) bismaleimide, N, N'-(3,3-diphenylsulfone) bismaleimide and the like.

Further, as aminophenols sharing a primary amino group and a phenolic hydroxyl group in one molecule which imparts a phenolic hydroxyl group to a polyimide, para-aminophenol, ortho-aminophenol, 4-amino-
4'-Hydroxyphenylpropane and the like are mentioned, and para-aminophenol is preferable from the viewpoint of availability and cost and other practical use.

The use ratios of the aromatic diamine, the bismaleimide and the aminophenols vary depending on the required physical properties, but the aromatic diamine and the bismaleimide are used in an amount of 3 mol or more and 30 mol or more per 1 mol of the aminophenol. The following is suitable for use.

The reaction of the aromatic diamine, the bismaleimide and the aminophenol can be carried out in the required organic solvent or without solvent.

The present invention is to use a polyimide having a phenolic hydroxyl group in the molecule, a resol type phenolic resin and a novolac type phenolic resin, and react them to obtain a cured resin having a crosslinked structure. The role of novolac type phenolic resin is to react with the methylol group of methylolphenol as shown in the following formula when methylolphenol is used as the resol type phenolic resin to form a crosslinked structure by a heat-resistant methylene bond. Especially.

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The role of the novolac type phenolic resin is to play a role of the methylene ether bond having poor heat resistance formed by the reaction between the resol type phenolic resins.

[Chemical 4] It is also to minimize the generation of.

Resol-type phenolic resins used in combination with a polyimide having a phenolic hydroxyl group in the molecule generally include phenols (including polyphenols), alkali metals such as caustic soda, caustic potash, calcium hydroxide and barium hydroxide, It can be obtained by reacting an aldehyde (generally, formalin, which is an aqueous solution of formaldehyde) with an alkaline earth metal hydroxide, ammonia, a tertiary amine, a quaternary ammonium or the like as a catalyst. The catalyst is selected and used according to the purpose.

The phenols used for producing the resol type phenolic resin are preferably trifunctional or higher functional ones from the point of the present invention. For example, phenol, m
-Cresol, 3,5-xylenol, resorcin, hydroquinone, bisphenol A, bisphenol F,
Examples thereof include biphenol, and these can be used alone or as a mixture of two or more kinds.

The aldehydes include formaldehyde, paraformaldehyde, polyoxymethylene, trioxane and the like.

The resol type phenolic resin used in the present invention is not particularly required to specify its production method and structure, but it is desirable that the aldehydes are used in a large amount relative to the phenols. When phenol is used as the phenols, it can be obtained by reacting 1 mol of phenol with 1.5 mol or more and 3 mol or less of formaldehyde. Further, when the phenols are bisphenol F, it is a type obtained by using 3 mol or 4 mol of formaldehyde for 1 mol of bisphenol F.

The novolac type phenolic resin used in combination with the resol type phenolic resin is not particularly limited, but it is preferable that it has reactivity with the methylol group of the resol type phenolic resin, and it is trifunctional or higher functional. The melting point is 60 to 150 ° C and the molecular weight is 300, which is produced by using phenols (including polyhydric phenols) and aldehydes (generally, formalin which is an aqueous solution of formaldehyde) in combination with an acidic catalyst such as oxalic acid and sulfuric acid. Approximately 1500 types are preferable. It is desirable that the novolac type phenolic resin is a type containing as few free phenols as possible.

The phenols and aldehydes used to produce the novolac type phenolic resin are
It is the same as that used for producing the resol-type phenolic resin.

The proportion of the resol type phenolic resin and the novolac type phenolic resin used is preferably 30 to 90% by weight of the resol type phenolic resin and 70 to 10% by weight of the novolac type phenolic resin. If the proportion of the novolac type phenolic resin used is less than 10% by weight, gas generation during molding is conspicuous and molding tends to be difficult. Further, when the proportion of the novolac type phenolic resin used is more than 70% by weight, the crosslinking with the resol type phenolic resin becomes rough and the heat resistance is lowered.

The proportions of the polyimide of the component [I], the resol type phenolic resin of the component [II], and the novolac type phenolic resin of the component [III] are changed depending on the purpose of use, but 10 to 90% by weight of the component,
The total amount of the [II] component and the [III] component is preferably 90 to 10% by weight, and more preferably the [I] component 30.
˜70% by weight, the total amount of [II] component and [III] component 7
It consists of 0 to 30 weight. When the total amount of the [II] component and the [III] component is less than 10% by weight, the crosslinking becomes poor and the heat resistance becomes poor. On the other hand, if it is more than 90% by weight, the polyimide alone is not thermosetting, and the heat resistance is reduced as in the above case.

The polyimide having a phenolic hydroxyl group in the molecule of the present invention, the resol type phenolic resin and the novolac type phenolic resin are prepared by simply mixing three components,
The composition may be used as is, or polyimide,
Resole type phenolic resin and novolac type phenolic resin may be used by heating or heating and kneading at a temperature at which the polyimide is not completely crosslinked with the resole type phenolic resin and the novolac type phenolic resin. When the powder resin is used, the latter method is preferable because it is easy to handle and has good moldability.

In the latter method, the temperature for heating or kneading by heating is preferably 80 to 130 ° C. By heating or kneading with heat, a heat resistant resin composition having a required softening point and heat fluidity can be obtained.

Further, the molding of the heat resistant resin composition is carried out at a temperature of 150 to 200 ° C. and 50 to 2 in the same manner as general phenol resin.
It is carried out under a pressure of 00 kg / cm ² .

The heat-resistant resin composition of the present invention, when put into practical use, is an organic or inorganic filler, a fiber reinforcing material,
Needless to say, a release agent, a colorant, a thermoplastic polymer, a coupling agent and the like can be used in combination.

[0029]

The heat-resistant resin composition of the present invention has a long-term heat resistance of the polyimide having a phenolic hydroxyl group in the molecule, an antioxidant action of the resol-type phenolic resin, and a heat resistance having resistance to short-term temperature rise. Show.

[0030]

EXAMPLES In order to facilitate understanding of the present invention, examples will be shown below.

Example 1 Polyimide (I) having a phenolic hydroxyl group in the molecule
In a 1-liter four-necked separable flask equipped with a stirrer, a reflux condenser, and a thermometer, 149 g of diaminodiphenylsulfone, 11 g of paraaminophenol, and 0.5 g of phenothiazine were charged, and the contents were melted at 150 to 160 ° C. After that, 358 g of N, N'-diphenylmethane bismaleimide was added every 5 minutes in 3 portions. After the addition, the reaction was carried out at 170 to 175 ° C for 60 minutes to obtain a polyimide (I) having a dark yellowish brown color and a phenolic hydroxyl group having a melting point of 130 to 140 ° C.

Production of molding material (A) and physical properties A mixture comprising the following components was kneaded with a roll at 110 to 120 ° C. for about 6 minutes. Polyimide (I) 100 parts by weight Resol type phenolic resin (solid content) ^*) 60 parts by weight Novolac type phenolic resin 40 parts by weight (Showa Polymer Co., Ltd.'s show containing 0.1% by weight or less of free phenol) Nol BRG-558) Milled fiber 400 parts by weight Zinc stearate 6 parts by weight (Note) *) Resol type phenolic resin is a tetramethylol compound of bisphenol F manufactured by Showa Polymer Co., Ltd. Shownor BLS-455N. (Solid content about 75%, ethyl acetate solution).

The obtained molding material (A) was crushed to 170
After heating and pressurizing at ~ 175 ℃, 70kg / cm ² for 5 minutes,
After curing at 0 ° C. for 12 hours and at 180 ° C. for 6 hours, a test piece was prepared. The physical properties of the obtained test piece are
As shown in Table 1, it was extremely excellent.

[0034]

[Table 1] Bending strength (kg / mm ² ) 16.9 Bending elastic modulus (kg / mm ² ) 1690 Heat distortion temperature (℃) 231 Charpy impact value (kg · cm / cm ² ) 11.4 Barcol hardness ( 934-1) 94 90% weight retention temperature (° C) 398 500 ° C weight retention rate (%) 71

Example 2 Polyimide (II) having phenolic hydroxyl group in the molecule
In a 1-liter 4-neck separable flask equipped with a stirrer, a reflux condenser, and a thermometer, 122 g of mixed tolylenediamine (2,4 bodies 65%, 2,6 bodies 35%), 22 g of para aminophenol, After weighing 0.5 g of phenothiazine and 270 g of dimethylformamide, the temperature was adjusted to 115
At ˜120 ° C., 322 g of N, N′-diphenylmethane bismaleimide was added every 10 minutes in 3 portions. After the addition, the reaction was continued for another 2 hours, and it was confirmed that almost no free diamine was present. Next, 200 g of dimethylformamide was added, and a polyimide varnish (II) (solid content: about 50% by weight) was obtained as a blackish brown liquid.

Production of Resole-type Phenolic Resin (a) A composition of 1 mol of phenol, 2 mol of formaldehyde and 0.2 mol of ammonia is reacted at 80 ° C., depressurized at about 100 ° C. and dehydrated to promote condensation and softening. The thing which made the point 55-60 degreeC was used.

Production of varnish for prepreg and preparation of prepreg
Production A prepreg varnish was produced with the following formulation. Polyimide varnish (II) 240 parts by weight (solid content ≈120 parts by weight) Resol type phenolic resin (a) 60 parts by weight Novolac type phenolic resin 20 parts by weight (Showanol BRG-manufactured by Showa Polymer Co., Ltd.) 558) 80 parts by weight of dimethylformamide

The thickness of the prepreg varnish was set to 0.06.
m / m (Nitobo Co., Ltd., WEA 05E 106BY
After impregnating the glass cloth of (5HN), it was dried at 100 to 105 ° C., and the B-stage was proceeded.

Manufacture of Laminated Plate and Physical Properties 36 sheets of the obtained prepreg are stacked, and 160 to 165 ° C.
Heat and pressurize at 50 kg / cm ² for 30 minutes, then at 150 ℃ for 12
The post-curing was performed at 180 ° C. for 6 hours. The physical properties of the obtained blackish brown laminate having a thickness of 1.2 m / m are as shown in Table 2.

[0040]

[Table 2] Bending strength (kg / mm ² ) 54.1 Bending elastic modulus (kg / mm ² ) 2300 Glass transition temperature (° C) 267 Bending strength after heating at 200 ° C for 1000 hours (kg / mm ² ) 64.4

[0041]

Since the present invention is constructed as described above,
The resin composition gives a cured product excellent in moldability, heat resistance and mechanical strength, and is useful as a molding material, a laminated plate, a grindstone, a brake, and the like.

Claims (2)

[Claims] 1. In the molecule, obtained by reacting [I] (1) aromatic diamine, (2) bismaleimide and (3) aminophenols sharing an amino group and a phenolic hydroxyl group in one molecule. A heat-resistant resin composition comprising a combination of a polyimide having a phenolic hydroxyl group, [II] a resole type phenolic resin and [III] a novolac type phenolic resin. 2. The proportion of the component (I) polyimide, the component (II) resol-type phenolic resin, and the component (III) novolac-type phenolic resin used is 10 to 90% by weight of the component (I). The total amount of the [II] component and the [III] component is 90 to 10% by weight, and the [II] component and the [II] component
The ratio of the component (I) used is 30 to 90% by weight of the component (II) and 70 to 10% by weight of the component (III).
The heat resistant resin composition as described in 1.