JP2688692B2 - Epoxy resin composition containing metal powder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is useful for adhesives, molding materials, jigs and tools, for example, resin molds, and the like. The present invention relates to a resin composition.

In particular, the epoxy resin composition of the present invention is useful as a material for a resin mold which requires severe conditions such as reduction of internal stress, high thermal shock resistance and accuracy.

[Conventional technology]

Epoxy resins have excellent adhesiveness, mechanical strength and chemical resistance, and are therefore used in a wide range of applications such as paints, electrical insulating materials, adhesives and jigs.

Epoxy resin adhesives bond a wide range of materials such as metals, plastics, wood, glass and concrete. This is because the epoxy resin wets the surface of the adherend well and has a low shrinkage ratio upon solidification.

However, when a high degree of adhesion performance is required for metal materials with different linear expansion coefficients, or when severe environmental resistance such as repeated heating and cooling after adhesion is required, ordinary epoxy resin compound products cannot handle it. .

Further, the epoxy resin molding material is used for manufacturing mechanical parts such as tools and jigs by utilizing its excellent mechanical strength.
In particular, as a replacement for parts that have traditionally used metallic materials,
It is used as a high-strength, high-modulus material by combining it with various fibers such as glass and carbon fibers, and metals such as iron and aluminum. In that case as well, the adhesiveness to various fibers and metals is required similarly to the adhesive.

There are many factors that contribute to such adhesiveness, but the most important are the internal stress of the epoxy resin, the rheology and the morphology of the adhesive joint, and the most important is the internal stress. By reducing this stress, the adhesive strength can be improved.

At the same time, improvement of thermal shock resistance can be achieved by reducing internal stress.

Conventionally, various methods have been studied in order to reduce the internal stress of the epoxy resin. For example, the internal stress can be reduced by increasing the flexibility of the cured product by using a flexible epoxy resin, a curing agent and an auxiliary material. However, in this case, the heat resistance of the cured product is significantly impaired.

It is also effective to reduce the internal stress due to the sea-island structure with the recently developed rubber blend, but it is inevitable that the mechanical properties will drop significantly.

It is also known to add a filler to reduce internal contraction by curing shrinkage and thermal expansion coefficient.

However, it is also said that the addition of a certain amount of filler or more has a negative effect on the internal stress. In addition, the addition of the filler increases the viscosity of the blended product, resulting in poor workability.

JP-B-62-54822 describes that in an epoxy resin composition containing an alumina powder, there is a critical particle size distribution width of the alumina powder for preventing sedimentation and improving workability. No mention is made of the stress reduction effect.

(Problems to be Solved by the Invention) The present inventor aims to reduce the internal stress of the cured product without impairing the workability of the epoxy resin compounded product, the mechanical performance and the thermal performance of the cured product. The present invention has been achieved as a result of extensive studies on the problem of improving the thermal shock resistance.

(Means for Solving the Problems) The present invention includes: (A) an epoxy resin and a curing agent, and (B).
In a composition containing a metal powder as an essential component, the metal powder (B) has a powder (a) having an average particle diameter of 50 to 60 μm and 8 to
It is composed of powder (b) having an average particle size of 10 μm, the weight ratio of the metal powders is 10/90 to 90/10, and the thermal shock resistance by the washer test method is two times or more. An epoxy resin composition containing a metal powder for a resin mold.

Epoxy resins that can be used in the present invention include bisphenol A, bisphenol F, novolac resin, brominated bisphenol A, etc. described in "New Epoxy Resins" (Kakiuchi, Hiroshi, Shokoido, 1985). Glycidyl ethers of various phenols, cycloaliphatic epoxy resins,
Examples thereof include glycidyl ester resin, glycidyl amine resin, and heterocyclic epoxy resin.

Preferably, the bisphenol A type epoxy resin has a balanced performance.

The curing agent that can be used in the present invention is a primary amine,
Amines such as secondary amines and tertiary amines, and acid anhydrides.

Primary amines can be classified into aliphatic primary amines, cycloaliphatic primary amines and aromatic primary amines.

Examples of the aliphatic primary amine include ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, hexaethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, aminoethylethanolamine, diethyleneglycol.
Examples thereof include bispropylenediamine, adipic acid dihydrazide, sebacic acid dihydrazide and the like.

Examples of the alicyclic primary amine include menthenediamine, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane, bis (4-aminocyclolhexyl) methane and the like.

Examples of aromatic primary amines include m-xylenediamine, m-phenylenediamine, diaminediphenylmethane, and diaminodiphenylsulfone.

Examples of the heterocyclic primary amine include N-aminoethylpiperazine, 3,9-bis (3-aminopropyl) -2,
4,8,10-tetraspiro [5,5] undecane and the like can be mentioned.

Further, a polyamide of the above-mentioned primary amine and various acids,
Mention may be made of adducts with various epoxy compounds and AN adducts.

Examples of the secondary amine and tertiary amine include piperidine, N, N-dimethylpiperazine, triethylenediamine, pyridine, picoline, 2- (dimethylaminomethyl) phenol, benzyldimethylamine, dicyandiamide and the like.

As the acid anhydride, an aliphatic acid anhydride, an alicyclic acid anhydride and an aromatic acid anhydride can be used. Further, from the number of functional groups, monofunctional, difunctional and polyfunctional ones can be used.

Examples of monofunctional acid anhydrides include phthalic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, methyl nadic acid anhydride, alkenyl succinic anhydride and the like. To be

As the bifunctional acid anhydride, pyromellitic dianhydride,
Examples thereof include benzophenone tetracarboxylic acid anhydride and ethylene glycol bis (anhydrotrimellitate).

Examples of polyfunctional acid anhydrides include glycerose tris (anhydrotrimellitate) and polyazeline polyanhydride. Metal powder that can be used in the present invention, for example, aluminum, iron, copper,
Examples thereof include nickel, tin, silver and gold.

The type of preferable metal powder varies depending on the use, but in the case of jigs and tools, aluminum and iron are preferable.

These metal powders can be powdered by various methods. The most general-purpose production method is the atomization method, and other methods such as an electrolysis method and a reduction method can be mentioned. The most preferable one is a metal powder produced by the atomizing method, and it is said that it suppresses an increase in internal stress when it is highly filled in a compounded product because it is almost spherical.

In the present invention, the average particle size refers to the particle size on a 50% sieve in the particle size distribution represented by the Stokes size.
That is, it means that the cumulative fraction is 50% by volume.

The metal powder used in the present invention is a mixture of powder (a) having an average particle size of 50 to 60 μ and powder (b) having an average particle size of 8 to 10 μ, and the weight ratio thereof is 10/90 to. It is necessary to have a ratio of 90/10.

When the powder (a) having an average particle diameter of 50 to 60 μ is used, the internal stress reducing effect is overwhelmingly superior to the case where powder having a particle diameter smaller than that is used.

However, when the powder (a) having an average particle diameter of 50 to 60 μ is used alone, the metal powder is settled between the production of the compounded product and the curing, and only a non-uniform cured product is obtained. In order to cause a defect, in the present invention, the metal powder (a) having an average particle diameter of 50 to 60 µ is used in combination with the powder (b) having an average particle diameter of 8 to 10 µ.

When the metal powder (b) is 10 μm or more, the effect of preventing sedimentation is small.

In the present invention, powder (a) having an average particle size of 50 to 60 μm
And powder (b) having an average particle size of 8-10 μm in 10 / 90-90 /
Used in a ratio of 10 weight ratio.

If the ratio of both powders is 10/90 or less, the effect of reducing internal stress is low, and if it is 90/10 or more, the effect of preventing sedimentation is small. A ratio of 50/50 to 90/10 weight ratio is preferable.

If necessary, a metal powder having a particle size other than that may be added within a range not exceeding 50% of the metal powder used. Depending on the case, not only one kind of metal powder but also two or more kinds of metal powder may be used together.

The ratio of the epoxy resin and the curing agent used in the present invention is generally blended so that the functional group of the curing agent is almost equivalent to the epoxy group, but the ratio is determined as necessary. Good.

On the other hand, the addition amount of the metal powder can be used in the range of 5 to 90% by weight in the composition. If it is less than 5% by weight, the effect of reducing internal stress is low, and if it is more than 90% by weight, workability is poor. Preferably 40
~ 90% by weight.

If necessary, a curing accelerator, a diluent, a flexibility-imparting agent, a filler other than metal powder, various additives and a solvent can be added to the composition of the present invention.

As the diluent, a reactive diluent such as monoglycidyl ether or diglycidyl ether or a non-reactive diluent can be used. Examples of the flexibility-imparting agent include long-chain diglycidyl ether. Fillers other than metal powders include oxides of silica, alumina, magnesia, talc, mica, kaolin and the like; metal carbonates such as calcium carbonate; carbon black; glass fiber,
Fibers such as carbon fibers; and especially silane-based, titanium-based, and aluminum-based coupling agents can be mentioned.

Examples of the solvent include alcohol-based, ketone-based, ester-based, and hydrocarbon-based solvents.

The composition of the present invention can be used as an adhesive, a casting material, an injection material, a jig tool material and the like. Especially when it is used for adhesion to a metal, it can maintain excellent adhesion performance and has good performance against thermal shock.

 This will be described in detail in the following examples.

(Example 1) Bisphenol A type epoxy resin AER331 30 parts by weight,
To 10 parts by weight of Laromin C-260 (manufactured by BASF), 50 parts by weight of Al powder having an average particle size of 60μ and 10 parts of Al powder having an average particle size of 10μ.
A blended product 1 was prepared by adding parts by weight and stirring the mixture uniformly. The viscosity of the compound 1 at 60 ° C. was about 2500 cps, and at this temperature, precipitation of Al powder was not desired to be seen. Blend 1 to 60
Molded at ℃ / 3 hours + 150 ℃ / 5 hours, the characteristics were examined.
Table 1 shows the results.

(Examples 2 to 5) Blended products 2 to 5 were prepared by changing the blending amount of the Al powder used in Example 1 as shown in Table 2, and the performance of the cured product measured is shown in Table 3.

(Examples 6 and 7) In Example 1, the compounded amount was changed as shown in Table 4 to prepare compounded products 6 and 7, and the measured performance of the cured product is shown in Table 5.

(Example 8) 100 parts by weight of AER331 was added to HN-2200 (manufactured by Hitachi Chemical Co., Ltd.,
Methyl tetrahydrophthalic anhydride) 80 parts by weight, benzyldimethylamine 0.5 parts by weight, silane coupling agent 0.1 parts by weight, Crystallite A (manufactured by Tatsumori Co., Ltd., silica powder) 50
A blended product 8 consisting of 180 parts by weight of Al powder having an average particle size of 50μ and 20 parts by weight of iron powder having an average particle size of 8μ is uniformly mixed in parts by weight and molded at 100 ° C / 3 hours + 180 ° C / 3 hours. Got Table 6 shows the physical properties of the molded product.

(Comparative Examples 1 to 3) Instead of the Al powder used in Example 1, Al powders having average particle diameters of 60 μ, 30 μ, and 10 μ were used alone, and 60 parts by weight were used to prepare blended products 9 to 11. Table 7 shows the measured performance of the cured product.

When the compound 9 was left at 60 ° C. for about 30 minutes, Al powder was settled, and formation of a clear layer of about 5% was observed on the upper part.

(Summary) Table 8 below summarizes the average particle size, the type of metal powder, the addition amount, the weight ratio of the metal powder, and the physical properties of the blended products used in the above Examples and Comparative Examples.

Claims (1)

(57) [Claims] 1. An epoxy resin and a curing agent (A) and (B).
In a composition containing metal powder as an essential component, the metal powder (B) and powder (a) having an average particle diameter of 50 to 60 μm and 8
Composed of a powder (b) having an average particle size of ˜10 μm,
Moreover, the metal powder-containing epoxy resin for a resin mold is characterized in that the weight ratio of the metal powders is 10/90 to 90/10 and the thermal shock resistance by the washer test method is two times or more. Composition.