JPS6254339B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heat-resistant resin molded product containing a metal insert, and more specifically, a heat-resistant resin molded product containing a metal insert molded from a thermosetting resin composition that has good workability and mechanical properties, and particularly excellent long-term heat deterioration characteristics. Regarding plastic molded products. As is well known, resin molded products in which metal inserts are penetrated or embedded using various thermoplastic or thermosetting resins are widely used as insulating parts and mechanical parts of electrical equipment, electronic equipment, office equipment, transportation equipment, etc. ing. The conditions under which these parts are used tend to become stricter year by year, and this is particularly evident in the demand for heat deterioration resistance of the resins used. Furthermore, in order to make devices smaller and lighter, parts that used to be made of metal are now being replaced with plastic, and this requires materials with excellent mechanical properties and heat deterioration resistance at high temperatures. ing. As described above, the problem of heat resistance has attracted attention from various quarters, and improvements in resin materials are constantly being made. On the other hand, requirements for workability and properties vary depending on the application, and the standards tend to increase gradually, making it difficult to meet all of these requirements with a specific material. In particular, unlike general thermosetting molding materials, a large amount of granular,
When a metal insert is molded from a material containing various fillers such as flakes or fibers, and the molded product is left at high temperatures, or when a heating element is attached to the insert and the insert is exposed to high temperatures, Thermal deterioration of the material occurs from the surface of the molding material and the interface between the molding material and the insert.
In particular, thermal deterioration tends to progress near the interface between the metal insert and the molding material, and as a result, for example, the heat-resistant life of the insert's pull-out strength is extremely shorter than the heat-resistant life evaluated for the molding material alone, and the long-term thermal deterioration characteristics are excellent. It was difficult to obtain molded products. That is, materials using maleimide compounds or polyamino bismaleimide compounds as resin components are widely known as heat-resistant thermosetting molding materials.
When a part containing a metal insert was molded using these materials and the insert was heated to a high temperature of 200°C or higher, the heat-resistant life of the insert's pull-out strength was significantly shorter than that of the molding material alone. Therefore, the present inventors conducted a detailed study on the thermal deterioration mechanism of composite materials, and found that the heat resistance of the resin component is necessary to obtain a heat-resistant molded product containing a metal insert with excellent long-term thermal deterioration characteristics. Needless to say, we have discovered that the filler of the resin component, the adhesion to metal, the toughness after curing, etc. have a great influence, leading to the present invention. The resin molded article of the present invention is a heat-resistant resin molded article containing a metal insert, in which the resin is (a) an epoxy resin, (b) an alkenylphenol polymer, and (c) a latent curing accelerator represented by the following general formula. Agent: (Here, R ₁ is halogen, R ₂ and R ₃ are hydrogen,
(representing an alkyl group, alkoxy group, cycloalkyl group or substituted cycloalkyl group, n is 0, 1 or 2), or ammonium, phosphonium, arsonium and imidazolium compounds, pyridine, piperidine and morpholine It is characterized in that it is one or more compounds selected from the group consisting of tetra-substituted boron salts of type compounds, and (d) it is a cured product of a resin composition containing a filler. In the present invention, metal inserts include copper or its alloy, aluminum or its alloy, steel,
Common metal materials such as stainless steel. The insert can be used in any shape, and examples of its molding are shown in Figures 1-3. In addition, the insert includes
For example, they are used for various purposes such as supporting and fixing parts that generate heat such as heaters and rolls, as well as various electrical parts, mechanical parts, and structural parts, and are subjected to direct or indirect heating. Figure 4 shows an example in which a heater is installed. The epoxy resin used in the present invention refers to all well-known epoxy resins, but in consideration of workability when producing a molding composition, the epoxy resin should be in a liquid or semi-solid state with a softening temperature of 80°C or lower, preferably at room temperature. A low viscosity resin is desirable. Specifically, bisphenol-based epoxy resin obtained from bisphenol A and epichlorohydrin, novolak-based epoxy resin obtained by reacting novolac resin with epichlorohydrin, and xylene obtained by reacting xylene and formalin or toluene and paraformaldehyde. Polyphenolic epoxy resins obtained by reacting epichlorohydrin with resins or condensates of toluene resins and phenols, resols, and polyhydroxy resins obtained by reacting epichlorohydrin with phenolic resins using polyhydric phenols such as hydroquinone. Benzene-based epoxy resins, epoxy resins obtained by reacting aromatic or aliphatic carboxylic acids with epichlorohydrin, epoxy resins obtained from vinyl polymers, epoxy resins obtained from polyhydric alcohols such as glycerin, cyclohexene, cyclopentadiene, Epoxy resins obtained from alicyclic compounds such as cyclopentadiene, epoxy resins obtained from natural products such as starch or unsaturated higher fatty acids, nitrogen-containing epoxy resins obtained from aniline or aliphatic amines, and epoxy resins obtained from isocyanuric acid. Epoxy resins having nitrogen-containing heterocycles, silicon-containing epoxy resins obtained by reacting epoxy resins with silanol, silicon-containing epoxy resins obtained by oxidizing silicon compounds having carbon-carbon double bonds, olefinic unsaturation These include epoxy resins containing heavy alloys other than phosphorous acid, silicon, and phosphorus in the form of chelates, and these can be used alone or in combination of two or more. May be used. Furthermore, alkenylphenol polymers are polymers obtained by thermal polymerization, ionic polymerization, or radical polymerization of vinylphenol, n-propenylphenol, isopropenylphenol, n-butenylphenol, or derivatives thereof. . The polymer ranges from a few polymers to tens of thousands of polymers, but in consideration of handling workability, moldability as a molding material, and various properties of molded products, in the present invention, the polymerization degree is about 20 to 80 (average molecular weight 3000). ~
8000) is preferable. Since the polymer requires a high temperature to melt and has a high melt viscosity, it is desirable to disperse and mix it in the epoxy resin in the form of a fine powder. The resin composition comprising the epoxy resin and alkenylphenol polymer is cured when heated at a temperature of about 150 to 250°C for 0.5 to 4 hours. moreover,
A curing accelerator can also be added to the composition, thereby shortening the curing (molding) time and increasing the working efficiency of the forming process. 103599, 55−36212,
Various tertiary amines described in Publication No. 56-34724, etc.
Polyamine, urea, dicyandiamide, dimethylformamide, pyridine, imidazole or these compounds and boron trifluoride complexes, Lewis acids,
At least one kind such as a complex with Brønsted acid is used. In the present invention, particularly useful curing accelerators have the following general formula: (Here, "in the present invention, particularly useful curing accelerators have the following general formula: (Here, R ₁ is halogen, R ₂ and R ₃ are hydrogen,
represents an alkyl group, alkoxy group, cycloalkyl group or substituted cycloalkyl group, n is 0,1
or 2) or tetra-substituted boron salts of ammonium, phosphonium, arsonium, imidazolium, pyridine, piperidine, and morpholine compounds that do not exhibit curing accelerating properties at low temperatures but have high curing accelerating properties at high temperatures. It is a so-called latent curing accelerator. A specific example is 3-(parachlorophenyl)-1,1-
Dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3,4-
dichlorophenyl)-1-methoxy-1-methylurea, 3-(3,4-dichlorophenyl)-
1,1-diethylurea, 1-(2-methylcyclohexyl)-3-phenylurea, trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, triphenylammonium tetraphenylborate, diethylmethylammonium tetraphenylborate, Tetrabutylammonium tetrabutylborate, tetrabutylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrabutylborate, tetrabutylphosphonium tetrabutylborate, tetramethylarsonium tetraphenylborate, tetraphenylborate enylarsonium tetraphenylborate, dimethyldiethylarsonium tetraphenylborate or imidazolium tetraphenylborate, 2-
Ethyl-4-methylimidazolium tetraphenylborate, 2-ethyl-1,4-dimethylimidazolium tetraphenylborate, 1-cyanoethyl-2-phenylimidazolium tetraphenylborate, 1-allyl-2-methyl Examples include imidazolium tetraphenylborate, viridium tetraphenylborate, morpholinium tetraphenylborate, methylmorpholium tetraphenylborate, and at least one of these is used. The blending ratio of the components of the resin composition is not particularly limited, but in general, (a) the epoxy resin and (b) the alkenylphenol polymer have the epoxy group in (a). /(b) hydroxyl group (molar ratio) = 0.8
~1.2 Furthermore, the latent curing accelerator/epoxy resin (weight ratio) is preferably in the range of 0.01 to 0.05. Next, fillers include glass fiber, carbon fiber, potassium titanate fiber, wollastonite fiber, alumina fiber, zirconia fiber, ceramic fiber, copper, metal fiber such as aluminum and stainless steel, cellulose, nylon, Kevlar, etc. organic fibers, calcium carbonate, magnesium carbonate, zircon, mica, clay, kaolin, aluminum hydroxide, magnesium hydroxide, alumina, silica, fused silica glass, glass beads, titanium white,
At least one of gypsum, barium sulfate, graphite, carbon black, graphite fluoride, molybdenum disulfide, boron nitride, beryllium oxide, various metal powders, and the like is used. The above fibers and granular fillers are useful for resin molded products (resin cured products) by reducing molding shrinkage and thermal expansion coefficient, improving thermal conductivity, abrasion resistance, mechanical strength and creep resistance, and improving conductivity and It is blended for the purpose of imparting or improving various properties that cannot be obtained with the resin component alone, such as imparting antistatic properties, and generally 50 parts by weight is added to 100 parts by weight of the resin component. ~500 parts by weight, more preferably 200-400
Used in parts by weight. In addition, the resin composition of the present invention may contain other resin components such as various bismaleimide compounds, polyaminobismaleimide compounds, and polybutadiene resins, as well as an organic superoxide for promoting the curing reaction thereof, within a range that does not impair the purpose. Oxides, pigments, dyes, mold release agents, coupling agents, etc. can be added. In the present invention, the above-mentioned resin composition is prepared by, for example, dispersing and mixing the alkenylphenol polymer as a fine powder into an epoxy resin that is liquid or semi-solid at room temperature at a temperature of about 40 to 80 degrees Celsius together with fillers, etc. This can be done by a method such as When the alkenylphenol polymer is divided into powders of 200 mesh (particle size: about 74 μm) or less, it can be dispersed fairly uniformly, which is advantageous in terms of the properties of the molded product. For kneading, devices such as a heating kneader, roll, mixer, extruder, etc. can be used. The resin composition produced as described above is generally cured and molded at a temperature of about 160 to 200°C, a pressure of 150 to 500 kg/cm ² , and a time of 0.5 to 3 minutes. For molded products that require mechanical properties at high temperatures, it is desirable to further post-cure at 180-230°C for about 1-5 hours. The molded part of the present invention is not limited in its manufacturing method, and may be manufactured by a casting method or an impregnation method using a composition containing the resin component and filler component. 1 to 3 show the shape and molding example of a metal insert to which the present invention is applied, and FIG. 4 is a sectional view of a molded product showing an example in which a heater is attached to the insert. 3 is a resin layer (cured product), 3 is a heater, and 4 is a nut for fixing the heater. Note that the shape and molding method of the insert are not limited to these methods, and
The insert may contain heating elements other than heaters,
Various electrical and mechanical parts can be attached. Examples 1 to 8 DER-332 (bisphenol A type semisolid epoxy resin manufactured by Dow Chemical Company,
(Epoxy equivalent: 175) and DEN-438 (manufactured by Dow Chemical Co., Ltd.) novolac-type epoxy resin, epoxy equivalent: 180, softening temperature: 38℃) Resin M (Maruzen Oil Co., Ltd. Polymer) with a particle size of 200 mesh (74 μm) or less as an alkenylphenol-based polymer p-vinylphenol, hydroxyl equivalent weight 120, average molecular weight 6000) and poly p-isopropenylphenol (hydroxyl equivalent weight 120, average molecular weight 6000)
135, average molecular weight 5500), 3-(parachlorophenyl)-1,1-dimethylurea (LCA-), triethylammonium tetraphenylborate (LCA-), 2-ethyl-4-methyl as latent curing accelerators. Imidazolium tetraphenylborate (LCA-), tetraphenylphosphonium tetraphenylborate (LCA-), methylmorpholinium tetraphenylborate (LCA-)
) was used to produce molding materials having the compositions shown in Table 1. A pressure kneader was used to knead each component. First, the alkenylphenol polymer, filler, and mold release agent were added for about 5 minutes, then the epoxy resin was added for about 5 minutes.
Kneading was carried out for 15 minutes. In this case, the kneading tank is 40 to 60
Warmed to ℃. Using each of the above molding materials, a molded product including the brass insert 1 shown in Fig. 1 was molded at a mold temperature of 180°C.
Transfer molding was carried out at a temperature of 150 kg/cm ² at a molding pressure of 150 kg/cm 2 for a molding time of 3 minutes. 2 is a resin layer. 200 after molding
The initial pull-out strength of the insert was measured for the molded product that was post-cured for 5 hours at ℃, and the change in strength (25℃) over time was measured when the insert was heated to 270℃ at room temperature. I measured it. The results are shown in Table 1. Examples 9 to 11 In addition to DER-332 and Resin M, N,N'-4,4'-diphenylmethane bismaleimide (BMI) was used as the resin component, and dicumyl peroxide (DCPO) was used as the curing catalyst. In combination, the above Example 1
In the same manner as above, the molding materials shown in Table 2 were prepared,
A molded product containing a brass insert was made, and a pullout test was conducted on the initial stage of the insert and after it had deteriorated due to heat. The results are shown in Table 2. Comparative Example 1 4 moles of N,N'-4,4'-diphenylmethane bismaleimide and 1 mole of 4,4'-diaminodiphenylmethane were thoroughly mixed, and then this mixture was heated at 150°C.
heated for 30 minutes. After cooling, it is crushed to a softening temperature of approx.
A polyamino bismaleimide prepolymer (hereinafter abbreviated as PABMI) at 95°C was obtained. Using this PABMI, a molding material having the composition shown in Table 3 was kneaded with a heated roll. Comparative Example 2 Using the above PABMI, DEN-438, and a novolak type phenolic resin (average degree of polymerization 4, softening temperature 80°C), a molding material having the composition shown in Table 3 was kneaded with a heated roll. Comparative Example 3 The above BMI, terephthalic acid-based unsaturated polyester (terephthalic acid 0.45 mol, maleic acid 0.55 mol,
Condensate obtained from 0.45 mol of ethylene glycol and 0.55 mol of propylene glycol, softening temperature 90
℃) and N-vinyl-2-pyrrolidone, a molding material having the composition shown in Table 3 was kneaded with a heated roll. Using the molding materials obtained in Comparative Examples 1 to 3 above,
A molded article containing the same metal insert as in the example was molded, and changes over time in the initial pullout strength of the insert and the insert pullout strength when the insert portion was heated to 270°C were investigated. The results are shown in Table 3.

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[Table] As is clear from these results, the molded product of the present invention has a strong metal insert pull-out strength at high temperatures, and the strength decreases little due to heat deterioration, so it can be applied to various uses as a heat-resistant component.
What is particularly interesting is that it has better thermal deterioration characteristics than maleimide resin molded products, which are known to have better heat resistance than epoxy resins.

[Brief explanation of the drawing]

1 to 4 are partial cross-sectional views showing the structure of a heat-resistant resin molded product including a metal insert according to an embodiment of the present invention. 1...Metal insert, 2...Resin layer, 3...Heater, 4...Nut.

Claims (1)

[Scope of Claims] 1. A heat-resistant resin molded article containing a metal insert, wherein the resin is (a) an epoxy resin, (b) an alkenylphenol polymer, and (c) a latent curing accelerator represented by the following general formula. : (Here, R ₁ is halogen, R ₂ and R ₃ are hydrogen,
(representing an alkyl group, alkoxy group, cycloalkyl group or substituted cycloalkyl group, n is 0, 1 or 2), or ammonium, phosphonium, arsonium and imidazolium compounds, pyridine, piperidine and morpholine A heat-resistant resin molding containing a metal insert, which is a cured product of a resin composition containing one or more compounds selected from the group consisting of tetra-substituted boron salts of type compounds, and (d) a filler. Goods. 2. The heat-resistant resin molded article according to claim 1, wherein the metal insert is heated to a high temperature by an adjacent or contacting heating element.