JPH0892353A - Epoxy resin and its cured product - Google Patents

Abstract

PURPOSE: To provide an epoxy resin composition capable of giving a cured product having small cure shrinkage, excellent thermal shock resistance and especially high mechanical strength such as tensile strength and flexural strength. CONSTITUTION: This epoxy resin composition contains (A) a low-viscosity epoxy resin containing a trifunctional or tetrafunctional liquid epoxy resin and having a viscosity of <=100 poise at 25 deg.C, (B) a liquid alicyclic amine mixture (hardener) produced by adding at least one kind of amine selected from menthenediamine and (4-amino-3-methylcyclohexyl)methane to isophorone diamine and containing 10-90wt.% of isophorone diamine in the mixture, (C) an imidazole compound and (D) metal powder having an average particle diameter of <=100μm. The amount of the component C is >=0.1 pts.wt. based on 100 pts.wt. of the component A and that of the component D is >=200 pts.wt. based on 100 pts.wt. of the sum of the components A, B and C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an epoxy resin composition containing a large amount of metal powder and a cured product of the same. Since the epoxy resin composition of the present invention provides a cured product having excellent durability, small curing shrinkage, particularly high mechanical strength, and high thermal shock resistance, it can be used for various moldings such as resin molds and jigs. It can be advantageously used for manufacturing.

[0002]

2. Description of the Related Art Epoxy resin compositions containing metal powder such as aluminum powder are known. For example, Japanese Examined Patent Publication (Kokoku) No. 50-38606 discloses a resin material obtained by mixing 40 to 60 parts by weight of 200 to 500 mesh aluminum powder and 10 to 20 parts by weight of a curing agent with 100 parts by weight of an epoxy resin. It is described that a resin model for casting is manufactured by molding into an appropriate shape. However, in this resin model, the upper limit of the amount of aluminum powder compounded is at most 60 parts by weight with respect to 100 parts by weight of the epoxy resin, so the curing shrinkage of the resin mold is large, and the master mold cannot be faithfully transferred. That was the problem.

Further, Japanese Patent Application Laid-Open No. 60-137623 describes a method of manufacturing a resin mold for injection molding composed of an epoxy resin, which compares metal powder such as aluminum powder or iron powder as a filler. It is described that the composition is added in an extremely large amount to improve the curing shrinkage of the resin mold. However, since this resin type uses an amine type curing agent as a curing agent and uses a bisphenol A type epoxy resin or the like as an epoxy resin, the composition viscosity is high, and the metal powder as a filler is relatively high. Had to use a large particle size. Moreover, the resin mold obtained by using a filler having a large particle size not only has a difficulty in the finish of the mold, but the filler does not uniformly disperse, so that the resin composition has a drawback of causing the separation of the filler. there were.

Further, in Japanese Patent Laid-Open No. 2-53850,
To a low-viscosity epoxy resin containing an alicyclic epoxy resin and having a viscosity of 50 poise or less, 50 fine particles having a particle size of 44 μm or less are added.
It is described that by adding 100 parts by weight or more of the metal powder containing at least wt% to 100 parts by weight of the total amount of the epoxy resin and the curing agent, a cured product having a small curing shrinkage and good thermal conductivity can be obtained. There is. However, in this case, satisfactory results cannot be obtained in terms of thermal shock resistance.

In addition, the present inventors have previously mentioned (a) a low-viscosity epoxy resin containing a trifunctional or tetrafunctional liquid epoxy resin, (b) mensendiamine, isophoronediamine or (4-amino-3). -Methylcyclohexyl) methane and other amine-based curing agents, (C) imidazole compounds,
And (d) contains metal powder having an average particle size of 100 μm or less, and (c) component is 0.1 per 100 parts by weight of (a) component.
% By weight, and the total amount of components (a) to (c) is 1
Regarding the epoxy resin composition in which the component (d) is 200 parts by weight or more with respect to 00 parts by weight, a patent application as an epoxy resin composition which gives a cured product having small curing shrinkage, high strength and high thermal shock resistance. (JP-A-6-56
965), a cured product of the epoxy resin composition is
It was found that the mechanical strength was not sufficiently satisfactory.

[0006]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the conventional epoxy resins described above, and in particular, the cured product of the epoxy resin composition of the present inventors of the present invention has a mechanical strength. It is possible to give a cured product that has a small curing shrinkage, excellent thermal shock resistance and remarkably high mechanical strength, overcoming the disadvantage of being insufficient, and therefore manufactures resin molds and various cast products. Another object of the present invention is to provide an epoxy resin composition that can be advantageously used for the above, and a cured product of the epoxy resin composition.

[0007]

As a result of various studies to solve the above-mentioned problems, the present inventors have found that isophoronediamine and mensendiamine and / or (4-amino-3-methyl) as a curing agent. It was found that by adding a liquid alicyclic amine mixture in which cyclohexyl) methane is mixed in a specific ratio, a cured product having remarkably large mechanical strength such as tensile strength and bending strength can be provided, and the present invention has been reached. I did.

That is, the epoxy resin composition of the present invention comprises the following components (a), (b), (c), and (d), and is added to 100 parts by weight of the (a) component. On the other hand, the component (c) is 0.1 part by weight or more, and (b)
The composition is characterized in that the amount of the component (d) is 200 parts by weight or more based on 100 parts by weight of the total amount of the component, the component (b) and the component (c). Component (a): A low-viscosity epoxy resin containing a trifunctional or tetrafunctional liquid epoxy resin and having a viscosity at 25 ° C. of 100 poise or less. Component (b): a mixture of isophoronediamine and at least one amine selected from menthenediamine and (4-amino-3-methylcyclohexyl) methane, the content of isophoronediamine in the mixture. Is 1
A liquid cycloaliphatic amine mixture which is 0 to 90% by weight. (C) Component: Imidazole compound. (D) Component: Metal powder having an average particle size of 100 μm or less.

The epoxy resin cured product of the present invention is a cured product obtained by curing the above epoxy resin composition.

The low-viscosity epoxy resin as the component (a) used in the present invention contains a trifunctional or tetrafunctional liquid epoxy resin and has a viscosity at 25 ° C. of 100 poise or less. When a trifunctional or tetrafunctional epoxy resin is used, a cured product having a higher strength than that when a bifunctional epoxy resin is used can be obtained.

Preferred as the trifunctional to tetrafunctional liquid epoxy resin used in the present invention are trifunctional triglycidylaminophenol, triglycidylaminocresol, tetrafunctional tetraglycidyl xylene diamine, and 1,3-bis ( N, N′-diglycidylaminomethyl) cyclohexane, tetraglycidylaminodiphenylmethane and the like. These trifunctional or tetrafunctional liquid epoxy resins may be used alone or in combination of two or more as appropriate. Further, these trifunctional to tetrafunctional liquid epoxy resins may be used alone, or if they are alone, the viscosity at 25 ° C. is about 10 to 10.
70 poise. If necessary, an aromatic liquid epoxy resin such as bisphenol A diglycidyl ether or bisphenol F diglycidyl ether can be used in combination with these trifunctional or tetrafunctional liquid epoxy resins. Since the low-viscosity epoxy resin as the component) needs to have a viscosity at 25 ° C. of 100 poise or less, the combined amount thereof is up to about 20% by weight. When its viscosity becomes higher than 100 poise,
The viscosity of the composition becomes high and the workability becomes poor, which is not preferable.

(B) as a curing agent component in the present invention
The component is a mixture of isophoronediamine and at least one amine selected from mensendiamine and (4-amino-3-methylcyclohexyl) methane, and the content of isophoronediamine in the mixture is 10 ~
90% by weight, preferably 30-70% by weight, liquid alicyclic amine mixture. By using such a specific liquid alicyclic amine mixture as a curing agent, it is possible to greatly improve the mechanical strength of the cured product, particularly the tensile strength and bending strength (see each Example). .

The above alicyclic amines, that is, isophoronediamine, menthenediamine and (4-amino-3-methylcyclohexyl) methane, are used alone, and mesenediamine and (4-amino) are used. −
When it is used as a mixture with 3-methylcyclohexyl) methane, and even when it is used as a mixture with isophoronediamine and mensendiamine and / or (4-amino-3-methylcyclohexyl) methane, the mixture thereof. When the content of isophoronediamine in the compound is outside the above-mentioned specific range, any of (a)
Ingredients, i.e. isophoronediamine and mensendiamine and / or (4-amino-3-methylcyclohexyl)
Compared with the case where methane is used as a mixture within the above-mentioned specific range, the effect of improving the mechanical strength of the cured product is reduced (see each comparative example).

Thus, the reason why the effect of greatly improving the mechanical strength of the cured product can be obtained only when the specific liquid alicyclic amine mixture of the present invention is used is not clear, but it is not clear. On the other hand, there is little steric hindrance due to the adjacent group, and isophoronediamine that is easily three-dimensionally crosslinked, and steric hindrance of the adjacent group is large, and mensendiamine that hardly causes three-dimensional crosslinking at the initial stage of curing, It is speculated that the combination with (methylcyclohexyl) methane produces a cured product having a unique three-dimensional network structure, and as a result, a significant improvement in mechanical strength may be obtained.

Even in the case of the mixture of the specific alicyclic amine used as the component (b), the content of isophoronediamine is within the specific range described above (that is, 10 to 90% by weight, preferably 30 to 70% by weight). ), The effect of improving the mechanical strength due to the combined use of both amines decreases (see Comparative Examples 4 and 6).

Further, the compounding amount of the liquid alicyclic amine mixture as the component (b) in the composition of the present invention is such that the active hydrogen of the amine mixture / the epoxy equivalent ratio of the epoxy resin is 5 /.
It is about 10 to 12/10.

The imidazole compound as the component (c) in the present invention has the functions of improving the thermal shock resistance of the cured product and reducing the curing shrinkage. The compounding amount of the compound is 0.1 parts by weight or more, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the epoxy resin of component (a). If the content is too small, the effect of improving the thermal shock resistance and the effect of reducing the curing shrinkage cannot be sufficiently obtained, and if it is too large, the viscosity of the composition becomes high and the workability deteriorates.

As the imidazole compound, all imidazole compounds that are commonly used can be used. Specific examples thereof include 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-ethyl-4.
(Or 5) -Methylimidazole, 1-benzyl-
2-methylimidazole, 1-isobutyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 2-methylimidazole azine, 1-cyanoethyl-2-ethyl-4 (or 5) -methylimidazole, 1-cyanoethyl- 2-methylimidazole, 1-
Examples thereof include cyanoethyl-2-isopropylimidazole, 1-cyanoethyl-2-phenylimidazole, and modified products of these various imidazole compounds.

The metal powder as the component (d) in the present invention has an average particle size of 100 μm or less, preferably 80 μm or less. Specific examples thereof include various metal powders such as aluminum powder, copper powder, iron powder, nickel powder, and chromium powder. When the particle size of the metal powder is large, not only the finish of the casting surface is deteriorated when used as a resin mold, but also the filler (that is, the metal powder) is not uniformly dispersed in the resin composition, Storage stability becomes poor, and physical properties of the cured resin also deteriorate.

The mixing ratio of the resin component [the total amount of the components (a), (b) and (c)] and the component (d) in the epoxy resin composition of the present invention is 100 parts by weight of the former resin component. On the other hand, the latter filler component is adjusted to 200 parts by weight or more, preferably 230 to 300 parts by weight. When the ratio of the component (d) is less than 200 parts by weight, the thermal expansion of the cured product becomes large, so that the mold is likely to be damaged when the resin mold is repeatedly used.

Various additives may be added to the epoxy resin composition of the present invention, if necessary, in addition to the components (a) to (d). For example, (d) component metal powder is prevented from settling, composition fluidity is improved,
Various inorganic fillers other than the metal powder of component (d) can be added for the purpose of adjusting thermal conductivity.

Further, a curing accelerator, a flame retardant, a thixotropy imparting agent, a reactive diluent, a leveling agent, a defoaming agent, a coupling agent, a pigment, a rust preventive agent and various other additives can be added. Since the addition of these additives is a known technique, detailed description thereof will be omitted.

The preparation of the epoxy resin composition of the present invention is carried out by appropriately mixing and kneading the above-mentioned essential components (a) to (d) and the additives to be added if necessary. For the kneading, for example, a kneader, roll, mixer or the like is appropriately used. In some cases, it may be preferable to mix only the amine curing agent as the component (b) and the imidazole compound as the component (c) immediately before using the resin composition. In addition, the epoxy resin composition of the present invention can be cured by using various methods, which results in a small thermal expansion, good dimensional stability and surface characteristics, and a cured product having high strength. It has excellent performance as a molded product for jigs and other articles including resin molds.

[0024]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples.

Example 1 A composition prepared by mixing the following samples with a kneader was first prepared at 45 ° C.
It was cured by heating for 10 hours at 130 ° C. for 5 hours. The measurement results of cure shrinkage, thermal shock resistance test, tensile strength, and bending strength of the obtained cured product are shown in Table 1.

Triglycidyl aminophenol 105 g Isophorone diamine 20 g (4-amino-3-methylcyclohexyl) methane 28 g 1-isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 380 g

Example 2 A composition obtained by mixing the following sample in the same manner as in Example 1 was similarly heated and cured, and the same test was conducted. The results are shown in Table 1.

Triglycidylaminophenol 100 g Isophoronediamine 18 g (4-amino-3-methylcyclohexyl) methane 15 g Mensendiamine 5 g 1-Benzyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 360 g

Example 3 A composition obtained by mixing the following sample in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidyl aminocresol 100 g Isophorone diamine 20 g Mensendiamine 20 g 2-Ethyl-4-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 370 g

Example 4 A composition obtained by mixing the following sample in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidylaminophenol 80 g 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane 20 g Isophoronediamine 18 g (4-amino-3-methylcyclohexyl) methane 30 g 1-Cyanoethyl-2-methylimidazole 2 g Aluminum powder (average particle size 50 μm) 380 g

Example 5 A composition prepared by mixing the following samples in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Tetraglycidyl xylylenediamine 100 g Isophorone diamine 20 g (4-amino-3-methylcyclohexyl) methane 28 g 1-isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 360 g

Example 6 A composition prepared by mixing the following samples in the same manner as in Example 1 was heated and cured in the same manner, and the same test was performed. The results are shown in Table 1. Tetraglycidyl diaminodiphenylmethane 100 g Isophoronediamine 20 g (4-amino-3-methylcyclohexyl) methane 28 g 1-Cyanoethyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 360 g

Example 7 A composition obtained by mixing the following samples in the same manner as in Example 1 was heated and cured in the same manner, and the same test was performed. The results are shown in Table 1.

1,3-Bis (N, N′-diglycidylaminomethyl) cyclohexane 110 g Isophoronediamine 22 g (4-amino-3-methylcyclohexyl) methane 24 g 1-Cyanoethyl-2-methylimidazole 1 g Aluminum powder (average particle size) Diameter 50μm) 360g

Comparative Example 1 A composition prepared by mixing the following samples in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidyl aminophenol 100 g Isophorone diamine 22 g 1-isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 350 g

Comparative Example 2 A composition obtained by mixing the following sample in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidyl aminophenol 100 g Mensendiamine 38 g 1-Isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 350 g

Comparative Example 3 A composition obtained by mixing the following sample in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidyl aminophenol 100 g (4-amino-3-methylcyclohexyl) methane 53 g 1-isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 385 g

Comparative Example 4 A composition obtained by mixing the following sample in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidylaminophenol 100 g Isophoronediamine 36 g Mensendiamine 3 g 1-isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 375 g

Comparative Example 5 A composition obtained by mixing the following sample in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidylaminophenol 105 g Isophoronediamine 4 g (4-amino-3-methylcyclohexyl) methane 54 g 1-isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 380 g

Comparative Example 6 A composition prepared by mixing the following samples in the same manner as in Example 1 was heated and cured in the same manner, and the same test was conducted. The results are shown in Table 1.

Triglycidyl aminophenol 105 g Mensendiamine 20 g (4-amino-3-methylcyclohexyl) methane 28 g 1-isobutyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 380 g

Comparative Example 7 A composition prepared by mixing the following sample in the same manner as in Example 1 was heated and cured in the same manner, and the same test was performed. The results are shown in Table 1.

Triglycidylaminophenol 100 g Isophoronediamine 15 g Tetraethylenepentamine 18 g 1-Cyanoethyl-2-methylimidazole 1 g Aluminum powder (average particle size 50 μm) 360 g

Comparative Example 8 A composition prepared by mixing the following samples in the same manner as in Example 1 was heated and cured in the same manner, and the same test was performed. The results are shown in Table 1.

Triglycidyl aminophenol 100 g Isophorone diamine 18 g (4-amino-3-methylcyclohexyl) methane 33 g Aluminum powder (average particle size 50 μm) 370 g

[0054]

[Table 1]

Note in Table 1: * 1 ... {(dimension of casting mold)-(dimension of cured product)}
/ Dimensions of mold to be cast * 2: 2 pieces of 300g cylindrical (φ50mm) cured product
After being heated to 00 ° C and put into water at 0 ° C and cooled,
Judging by whether or not cracks occur in the cured product ◯: No crack occurs ×: Crack occurs * 3 ・ ・ ・ Compliant with ASTM D-790 * 4 ・ ・ ・ Compliant with ASTM D-790

[0056]

The epoxy resin composition of the present invention has a small curing shrinkage, an excellent thermal shock resistance, and a mechanical strength,
For example, since it gives a cured product having extremely high tensile strength and bending strength, it is advantageously used for the production of resin molds and various cast products.

Claims (4)

[Claims] 1. The following (a) component, (b) component, and (c)
And (d) component, and (a) component 10
Component (c) is 0.1 parts by weight or more with respect to 0 parts by weight,
An epoxy resin composition characterized in that the amount of the component (d) is 200 parts by weight or more based on 100 parts by weight of the total amount of the components (a), (b) and (c). Component (a): A low-viscosity epoxy resin containing a trifunctional or tetrafunctional liquid epoxy resin and having a viscosity at 25 ° C. of 100 poise or less. Component (b): a mixture of isophoronediamine and at least one amine selected from menthenediamine and (4-amino-3-methylcyclohexyl) methane, the content of isophoronediamine in the mixture. Is 1
A liquid cycloaliphatic amine mixture which is 0 to 90% by weight. (C) Component: Imidazole compound. (D) Component: Metal powder having an average particle size of 100 μm or less. 2. The component (a) comprises triglycidylaminophenol, triglycidylaminocresol, tetraglycidylxylenediamine, tetraglycidyldiaminodiphenylmethane, and 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane. 2 which is mainly composed of at least one selected epoxy resin
The epoxy resin composition according to claim 1, which is a low-viscosity epoxy resin having a viscosity at 100C of 5 poise or less. 3. The epoxy resin composition according to claim 1 or 2, wherein the liquid alicyclic amine mixture as the component (b) has an isophoronediamine content of 30 to 70% by weight. 4. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 1, claim 2, or claim 3.