JPH06263840A - Epoxy resin composition for casting and cast epoxy resin article - Google Patents

Abstract

PURPOSE:To improve the storage stability and compression strength of an epoxy resin compsn. and the durability in pressing by compounding a specific low-viscosity epoxy resin, a room-temp.-curing liq. epoxy hardener, an iron powder, and an inorg. filler. CONSTITUTION:This resin compsn. is prepd. by compounding 100 pts.wt. low- viscosity epoxy resin having a viscosity (25 deg.C) of 80 P or lower and contg. at least 30wt.% epoxy resin comprising either bisphenol F glycidyl ether or bisphenol AD glycidyl ether, 5-100 pts.wt. room-temp.-curing liq. epoxy hardener mainly comprising a polyamide compd. or a heterocyclic amine compd., and 170-300 pts.wt. mixture comprising an iron powder having a mean particle size of 5-100mm and an inorg. filler having a mean particle size not lower than 0.1mum and not higher than one half of that of the iron powder and in an amt. less than that of the iron powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting epoxy resin composition containing iron powder, and a casting product obtained by casting and curing the same epoxy resin composition. Specifically, an epoxy resin composition used for repairing various jigs and metal equipment / parts, or for molding resin molds for manufacturing various metal parts, and cast-curing this Regarding cast products.

[0002]

2. Description of the Related Art Heretofore, an epoxy resin composition containing a metal such as iron powder has been known. For example, it is used to manufacture a zinc alloy / resin combination type (see Japanese Examined Patent Publication No. 58-151925), which is used as a die for trial production of parts such as automobile doors and bonnets, or for small-scale production for special specifications. As the casting resin, an epoxy resin composition containing iron powder is generally used. As such an epoxy resin composition, one having particularly good storage stability and excellent press durability of a cured product is required.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to improve the storage stability and the durability of a cured casting resin composition in an epoxy resin composition for casting which contains such iron powder. Thus, the present invention is intended to provide a cast epoxy resin composition containing iron powder, which gives a cast product having excellent compression strength and particularly excellent press durability.

[0004]

The cast epoxy resin composition of the present invention contains the following (a) component, (b) component, (c) component, and (d) component in addition to the (b) component: The amount is 5 to 100 parts by weight with respect to 100 parts by weight of the component (a), and the total amount of the components (c) and (d) is 100 parts by weight with respect to the total amount of the components (a) and (b). 170 to 300 parts by weight, and the weight of the component (d) is less than the weight of the component (c),
It is a cast epoxy resin composition which is contained in the following ratio. (A) Component: Viscosity (25 ° C.) containing 30% by weight or more of an epoxy resin selected from bisphenol F diglycidyl ether and bisphenol AD diglycidyl ether
Is a low-viscosity epoxy resin having a poise of 80 poise or less (b) component: room temperature curable liquid epoxy curing agent (c) component: iron powder having an average particle size of 5 to 100 μm (d) component: average particle size of 0.1 μm or more And an inorganic filler which is 1/2 or less of the average particle size of the iron powder of (C) component.

The component (a) in the present invention, that is, bisphenol F diglycidyl ether used in a low-viscosity epoxy resin having a viscosity (25 ° C.) of 80 poise or less is
It is a compound represented by the following formula (1), and bisphenol AD diglycidyl ether is a compound represented by the following formula (2).

[0006]

[Chemical 1]

[0007]

[Chemical 2]

As the epoxy resin having a viscosity of 80 poise or less used in the present invention, one of the above bisphenol F diglycidyl ether (viscosity 30 poise at 25 ° C.) and bisphenol AD diglycidyl ether (viscosity 30 poise at 25 ° C.) or It may be composed of only two kinds, or may be an epoxy resin obtained by mixing these with another epoxy resin. Other epoxy resins that can be mixed include, for example, bisphenol A diglycidyl ether, tetraglycidyl aminodiphenylmethane, tetraglycidyl-bis (4-aminocyclohexyl) methane, tetraglycidyl xylene diamine, tetraglycidyl cyclohexyl dimethylamine, triglycidyl metaaminophenol. , Triglycidyl aminocresol, triglycidyl paraaminophenol, triglycidyl metaaminoalkylphenol, triglycidyl paraaminoalkylphenol, diglycidyl phthalate and other glycidyl ester type liquid epoxy resins, diglycidyl aniline, 1,6-hexamethylene glycol diglycidyl ether, neo Pentyl glycol diglycidyl ether, polyethylene glycol di Glycidyl ether, polypropylene diglycidyl ether, and novolac epoxy resins.

When a low-viscosity epoxy resin is used, the viscosity of the composition can be kept low enough not to impair workability even if a filler, especially iron powder, is contained in a high concentration, but bisphenol F diglycidyl ether is used. When the content of bisphenol AD diglycidyl ether is less than 30% by weight, the press durability of the cured product is reduced.

As the room temperature curable liquid epoxy curing agent (B), various types can be used. For example, aliphatic polyamines such as triethylenetetramine and tetraethylenepentamine, cycloaliphatic amines such as N-aminoethylpiperazine, aromatic amines such as m-xylylenediamine, polyaminoamide compounds (also referred to as polyamide resins), and , And heterocyclic amines. Particularly preferred curing agents are polyaminoamide compounds and heterocyclic amines, especially diamines of the formula:

[0011]

[Chemical 3]

(In the formula, n represents an integer of 2 to 4.) These epoxy curing agents can be used in combination of two or more kinds. The component (b) is usually added at the time of casting to a mixture in which the component (a), the component (c) and the component (d) are mixed in advance. The blending amount of the component (b) is in the range of 5 to 100 parts by weight with respect to 100 parts by weight of the component (a).

The iron powder having an average particle size of 5 to 100 μm, which is added as the component (c), improves the wear resistance (press durability, etc.) of the cured resin. As the iron powder, iron powder such as sponge iron powder (reduced iron powder) or steel powder is further pulverized into fine powder so that the content of fine powder having a particle size of 44 μm or less is 50% by weight or more. Those are preferable. When the particle size of iron powder becomes large, it becomes easy for sedimentation separation to occur,
The storage stability of the mixture of the (a) component, the (c) component, and the (d) component pre-blended becomes poor, and, for example, when the resin composition is used for producing a metal casting mold, The casting surface of the cast metal is poorly finished.

The inorganic filler of the component (d) has an average particle size of
The average particle size is 0.1 μm or more and 1/2 or less of the average particle size of the iron powder of the component (c). If the average particle size is larger than 1/2 of the average particle size of the iron powder, the close packing effect is reduced and the viscosity decreasing effect of the system is reduced, and if the average particle size is less than 0.1 μm, the system viscosity is reduced. It is not preferable because it rises. Examples of the inorganic filler of component (d) include inorganic fillers such as aluminum hydroxide, alumina, silica powder, glass powder, magnesium hydroxide and calcium carbonate, and metals such as copper powder, aluminum powder and iron powder. Powder. The average particle diameter of finely divided silica, which is generally known as an anti-settling agent, is 0.
Those smaller than 1 μm are not used as the component (d) of the present invention.

As for the blending amounts of the (c) component and the (d) component, the total amount of the two components is 100: the total amount of the (a) component and the (b) component.
It is in the range of 170 to 300 parts by weight with respect to parts by weight. If the blending amount is too small, the abrasion resistance of the cured resin cannot be sufficiently improved, and if the blending amount is too large, the fluidity of the resin composition is deteriorated and the workability is deteriorated. (D)
The amount of the component is less than the amount of the component (c) by weight, and preferably in the range of 0.01 to 0.25 times the amount of the component (c). If the amount of the component (d) is too large, the close-packing effect of the filler decreases, which is not practical.

The resin composition of the present invention includes the above (a) to
In addition to the component (d), various additives such as defoaming agents, anti-settling agents, coupling agents, reactive diluents, leveling agents, lubricants, flame retardants, dispersants, and adhesion, as required. Additives, wetting agents, dyes, pigments, rust preventives and the like can be added.

The composition of the present invention comprises the above (a) to (d).
It is prepared by appropriately mixing the components and additives to be added as necessary, and kneading them using, for example, a kneader roll or a mixer. Usually, (a) in advance,
A mixture obtained by kneading the components (c) and (d) is prepared, and at the time of casting, the component (b) is added to this and kneaded uniformly. The epoxy resin cast product of the present invention is obtained by pouring the composition obtained as described above into an appropriate mold and allowing it to stand at room temperature for about one day to cure, thereby obtaining a cast product.

[0018]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples. Example 1 Bisphenol F diglycidyl ether 100 parts by weight Iron powder (average particle size 30 μm) 360 parts by weight Aluminum hydroxide powder (average particle size 3 μm) 23 parts by weight Storage of a mixture obtained by mixing the above components with a kneader The stability was as shown in Table 1.

To 100 parts by weight of this mixture, 13 parts by weight of a commercially available liquid polyaminoamide (Trademark 2500, Fuji Kasei Kogyo Co., Ltd.) as a curing agent was added and uniformly mixed to obtain an epoxy resin composition. This composition was applied to a hardness measuring flat plate mold having a depth of 5 mm, a JIS compressive strength testing mold, and a model molding mold for press evaluation having a diameter of 8 cm and a thickness of 1 cm (R value of corner portion: 2.25 mm). After injection, the mixture was allowed to stand at room temperature for 2 days to be cured, and used as a test cast sample. The obtained cast products were evaluated by the following methods. The results are shown in Table 1.

Hardness Test Method The surface hardness of the mold is measured with a Shore D hardness meter. Test method of compressive strength JIS K-6911 conformity test method of press durability A steel plate having a thickness of 0.8 mm is pressed and the wear of the corner portion of the model die is measured with an R-gauge to obtain an initial R value of 2.25 m.
The number of presses until m changes to 2.50 mm is measured.

Example 2 An epoxy resin mixture and composition were prepared in the same manner as in Example 1 except that the same amount of alumina powder having the same average particle size was used instead of the aluminum hydroxide powder. The mixture and composition were also tested as in Example 1.

Example 3 An epoxy resin mixture and a composition were prepared in the same manner as in Example 1 except that the same amount of bisphenol AD diglycidyl ether was used instead of bisphenol F diglycidyl ether in Example 1, and this was used. The same test as in Example 1 was performed.

Example 4 Example 1 was repeated except that the curing agent used in Example 1 was 13 parts by weight of a commercially available liquid heterocyclic modified amine (Yukaka Shell Epoxy Co., Ltd., trade name Epomate B-002). Epoxy resin mixtures and compositions were prepared in the same manner, and the same tests as in Example 1 were conducted using the same.

Comparative Example 1 An epoxy resin mixture and composition were prepared in the same manner as in Example 1 except that the aluminum hydroxide powder was not used, but the same amount of iron powder was added instead. The same test as in Example 1 was carried out.

Comparative Example 2 An epoxy resin mixture and composition were prepared in the same manner as in Example 1 except that the same amount of fine powder silica powder having an average particle size of 0.02 μm was used instead of the aluminum hydroxide powder. Then, using this, the same test as in Example 1 was performed. still,
The press durability test was not conducted because the composition had poor fluidity and could not be cast into a model mold for press evaluation.

Comparative Example 3 An epoxy resin mixture and a composition were prepared in the same manner as in Example 1 except that the amounts of the respective components were changed as follows, and the epoxy resin mixture and composition were prepared in the same manner as in Example 1. I did a test.
The press durability test was not conducted because the composition had poor fluidity and could not be cast into a model mold for press evaluation.

Bisphenol F diglycidyl ether 100 parts by weight Iron powder (average particle size 30 μm) 360 parts by weight Aluminum hydroxide powder (average particle size 3 μm) 23 parts by weight The results of the tests of Examples and Comparative Examples are summarized below. Shown in the table.

[0028]

[Table 1]

[0029]

The cast epoxy resin composition of the present invention can provide a cured product having high hardness and good press durability.

Claims (3)

[Claims] 1. The following (a) component, (b) component, and (c)
Ingredients and (d) component, (b) component content (a)
5 to 100 parts by weight based on 100 parts by weight of the components, and the total amount of the components (c) and (d) is (a) and (b).
170 to 300 parts by weight based on 100 parts by weight of the total amount of the components, and the weight of the component (d) is less than the weight of the component (c),
Cast epoxy resin composition containing at a ratio of (a): 30% by weight or more of an epoxy resin selected from bisphenol F diglycidyl ether and bisphenol AD diglycidyl ether, viscosity (25 ° C.)
Is a low-viscosity epoxy resin having a poise of 80 poise or less (b) component: room temperature curable liquid epoxy curing agent (c) component: iron powder having an average particle size of 5 to 100 μm (d) component: average particle size of 0.1 μm or more And an inorganic filler which is 1/2 or less of the average particle size of the iron powder of (C) component. 2. The composition according to claim 1, wherein the curing agent as the component (b) contains as a main component a compound selected from a polyamide compound and a heterocyclic amine compound. 3. An epoxy resin casting product obtained by casting and curing the casting epoxy resin composition according to claim 1 or 2.