JPH1036764A - Epoxy resin coating material and epoxy resin coated iron alloy material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject coating material capable of comfortably coating on the desired surface of an iron alloy material and forming a cured coated film without generating any repelling, and useful for an iron alloy material such as a material for a gasket in an automotive cylinder head by containing inorganic fine powder in an epoxy resin. SOLUTION: This coating material contains (A) an epoxy resin (e.g. an epoxy resin having a liquid state at a room temperature, especially having >=1,000cp, preferably 1,200-50,000cp viscosity at 25 deg.C) and (B) inorganic powder such as talc, clay, molybdenum disulfide, silica, calcium carbonate, mica or alumina (e.g. powder material having a particle size 100% passing through a Tyler screen having 300 mesh, a long particle or a platy particle having 1.5-1,000 aspect ratio and 0.1-80μm, especially 1-40μm length of the longest part under a visual field of a microscope). Preferably, a using amount of the component B is 10-50 pts.wt., especially 15-40 pts.wt. per 100 pts.wt. of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin paint for an iron alloy such as stainless steel, and an iron alloy having a cured coating film of the epoxy resin paint.

[0002]

2. Description of the Related Art Two-layer metal gaskets for automobiles are:
As shown in FIG. 1, an example of a cross section around the cylinder bore is shown in FIG.
A stainless steel plate 1 having a folded portion 11 and a stainless steel plate 2 having a bead 21 around the cylinder bore CB. In the bead portion 21 and the vicinity thereof, the stainless steel plate 1 has the fluoro rubber layer 12 on one outer surface, while the stainless steel plate 2
It has fluoro rubber layers 22 and 22 'and fluoro rubber layers on both surfaces. The fluoro rubber layer 22 ′ inside the stainless steel plate body 2 may be provided not inside the stainless steel plate body 2 but inside the stainless steel plate body 1. In the cross-sectional example of FIG. 1, a hard organic polymer layer 24 is provided inside the bead portion 21. Such a hard organic polymer layer 24 is not yet provided on the metal gasket in use. However, in order to further improve the sealing function of the metal gasket, the hard organic polymer layer 24 is replaced with the folded portion 11 described above or folded as shown in FIG. Recently, its installation in combination with the unit 11 has been considered. In any case, the bead portion 21 in the peripheral portion of the cylinder bore is provided to enhance the sealing function of the metal gasket. However, since the tightening pressure during the use of the metal gasket gradually causes a set, the set is reduced. In order to prevent this, the folded portion 11 is provided on the stainless steel plate body 1 to prevent the bead portion 21 from being bent completely.

[0003] The height of the bead portion 21 is usually 0.1 to
On the other hand, the thickness of the stainless steel plate 1 is, for example, about 0.10 to 0.15 mm, and generally, the height of the bead portion 21 is greater than the thickness of the stainless steel plate 1, In other words, it is larger than the gap width between the two steel plates 1 and 2. Therefore, the bead portion 21 has a cushioning effect and thereby achieves a sealing function. However, there is a case where the folded portion 11 alone does not sufficiently prevent the set, and in such a case, the bead portion is not provided. The hard organic polymer layer 24 inside the inside 21 functions as a stopper for setting the bead portion 21. The hard organic polymer layer such as the layer 24 is placed in the cylinder 23 from the position outside the bead portion 21, for example, around the position shown in FIG. Bore CB
There are also proposals to provide them at various locations such as on the inner surface of the stainless steel plate body 2 or on the inner surface of the stainless steel plate body 1 at a position close to. In general, the thickness and width of the hard organic polymer layer, including the layer 24, can be freely set, so that the design of the bead portion 21 and the folded portion 11 itself can be made.
Furthermore, it plays a role in giving great freedom to the design of the vicinity thereof. For the above reasons, a technique for forming a hard organic polymer layer inside and outside the bead portion 21 and its vicinity is important.

[0004] The inventors of the present invention have first studied on the selection of the constituent materials of the hard organic polymer layer such as the hard organic polymer layer 24 and found that an epoxy resin having excellent compression stress relaxation characteristics is particularly excellent. Obtained. By the way, according to a subsequent experiment by the present inventors, it is considered that the epoxy resin paint has poor wettability to the iron alloy. However, when the epoxy resin paint is applied to the surface of the iron alloy, particularly to a curved surface such as the bead portion 21, And it is difficult to form a continuous coating film due to repelling. Epoxy resin paints with high viscosity at room temperature have a stronger shape retention force based on high viscosity than repellency, so it is possible to apply a uniform thickness at room temperature. When heated to a temperature, there is a problem in that the viscosity of the coating material decreases due to a high temperature prior to curing, so that the continuous coating film also contracts due to repelling, causing uneven swelling and numerous wrinkles.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an epoxy resin paint having improved applicability to an iron alloy body, particularly a stainless steel body. Another object of the present invention is to provide an epoxy resin-coated iron alloy body having a cured coating of an epoxy resin paint on a desired surface of the iron alloy body.

[0006]

The present invention has the following features. 1. An epoxy resin paint for applying an iron alloy body, comprising an epoxy resin containing an inorganic fine body. 2. 2. The epoxy resin paint according to the above 1, which contains 10 to 50 parts by weight of inorganic fine particles per 100 parts by weight of the epoxy resin. 3. 3. The epoxy resin paint according to 1 or 2, wherein the inorganic fine particles are at least one selected from the group consisting of talc, clay, molybdenum disulfide, silica, calcium carbonate, mica, and alumina. 4. An epoxy resin-coated iron alloy body having a cured coating of the epoxy resin paint according to any one of the above items 1 to 3 on a desired surface of the iron alloy body. 5. 5. The epoxy resin-coated iron alloy according to the item 4, wherein the iron alloy is a stainless steel. 6. The above 4 wherein the iron alloy body is a plate material for a metal gasket.
Or the epoxy resin-coated iron alloy according to 5. 7. The epoxy according to any of 4 to 6, wherein the iron alloy body is a stainless steel gasket plate material having a bead portion, and having a cured coating film of an epoxy resin paint at least inside and / or outside the bead portion. Resin coated iron alloy body.

[0007]

The epoxy resin coating composition of the present invention contains inorganic fine particles, so that the wettability to the iron alloy body is improved and the epoxy resin coating composition maintains a high apparent viscosity even at a high temperature during heat curing. For this reason, at room temperature, it is possible to satisfactorily apply to desired surfaces of various iron alloy bodies,
Further, even if the coating film is heated to a high temperature at the time of curing, a high apparent viscosity is maintained, so that repelling does not occur. Since the epoxy resin-coated iron alloy body of the present invention has a cured coating film of the above-described epoxy resin paint, the cured coating film has substantially no shrinkage and can have good continuity in film thickness and film shape. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
Examples of the epoxy resin serving as a base of the epoxy resin paint in the present invention include bisphenol A, novolak, cycloaliphatic, long-chain aliphatic, hydantoin,
Various epoxy resins such as an isocyanurate type can be used. Among them, those which are liquid at room temperature, particularly those having a viscosity at 25 ° C. of at least 1,000 centipoise, and more preferably 1,200 to 50,000 centipoise, are preferred from the viewpoint of applicability. Examples of the curing agent include diethylenetriamine, triethylenetetramine, diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylenediamine, polyamideamine and derivatives thereof, amines such as dicyandiamide and melamine, hydrazines such as isophthalohydrazine, and boron trifluoride. -Complexes of boron trifluoride and amine such as monoethylamine complex, acid anhydrides such as phthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, One or more kinds of epoxy resin curing agents such as imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole are used.

Among these various curing agents, a latent curing agent having a long pot life and capable of withstanding a long continuous application operation in a factory is particularly preferable. Examples of such latent curing agents include complexes of boron trifluoride and amine such as dicyandiamide, melamine, isophthalohydrazine and boron trifluoride-monoethylamine complex, and various curing agents described above, for example, diethylene triamine. And molecular sieve type hardeners adsorbing the above, and microcapsules of the above various hardeners. The microencapsulated product is usually used by crushing the microcapsule with pressure or heat at the time of use.

Regarding the chemical species of the inorganic fine particles used in the present invention, those that are chemically inert to epoxy resins, for example, glass powder such as quartz glass and silicate glass, natural and synthetic ceramics, etc. Powders, powders of metals and alloys such as iron, copper, nickel, stainless steel and brass, powders of metal oxides such as alumina, silica, zinc oxide, iron oxide and copper oxide, talc, clay, mica, vermiculite, Examples thereof include rubber and plastic fillers such as calcium carbonate and carbon black, and other inorganic substances such as molybdenum disulfide. Of these, one or more of talc, clay, molybdenum disulfide, silica, calcium carbonate, mica, and alumina are preferred. Regarding the shape of such inorganic fine particles, spherical, various square, or other irregularly shaped powders, whiskers, needles, fibers,
Or a plate-like body such as mica or expanded vermiculite fragments. Regarding the inorganic fine particles of powders, those having a particle size that passes 100% through a 100-mesh Tyler sieve, particularly, a particle size that passes 100% through a 300-mesh Tyler sieve are preferable. The aspect ratio of the inorganic fine body of a long body or a plate-like body is 1.
Those having a length of about 5 to 1000 and a longest part by a microscope observation of 0.1 to 80 μm, particularly 1 to 40 μm are preferable.

When the amount of the inorganic fine particles used is too small, the above-mentioned effects are poor even with the use of the inorganic fine particles. On the other hand, when the amount is too large, the mixture of the obtained epoxy resin and the inorganic fine particles has fluidity. And poor applicability. The amount of the inorganic fine particles to be used is preferably 10 to 50 parts by weight, particularly preferably 15 to 40 parts by weight, per 100 parts by weight of the epoxy resin.

The epoxy resin paint of the present invention comprises the above-mentioned epoxy resin and inorganic fine particles, or other components which can be added as required, such as antioxidants, coloring agents, plasticizers, acrylonitrile-butadiene rubber, etc. And a conventional mixer such as a sand mill. In order to further facilitate the mixing or to improve the coating properties, it is possible to add and dilute an appropriate solvent as needed.

The epoxy resin-coated iron alloy body of the present invention is obtained by applying the above-described epoxy resin paint of the present invention to a desired portion of the iron alloy body at room temperature or an appropriate temperature, and then heating and curing the applied layer of the epoxy resin paint. It can be manufactured by the following. Examples of the iron alloy constituting the iron alloy body include Fe-C alloys such as iron and steel, stainless steels such as ferritic stainless steel, martensitic stainless steel, and austenitic stainless steel, ferromanganese, ferrosilicon, ferronickel, ferrochrome, and others. Is a ferroalloy containing iron as a main component, particularly having an iron content of at least 80% by weight. Among such iron alloys, stainless steel, particularly SUS301-CSP, SUS304-C
SP, SUS420J2-CSP, SUS631-CS
Stainless steels such as P, SUS304 and SUS430 are preferred.

Iron alloy bodies having various shapes and dimensions can be used as the material of the epoxy resin-coated iron alloy body of the present invention. For example, it is a flat plate, a corrugated plate, a round bar, a square bar, a block, or the like. Among them, a punched plate having a textured portion such as a bead portion, such as a metal gasket plate material, and particularly a plate made of stainless steel is difficult to apply with a conventional epoxy resin paint, and the present invention An epoxy resin paint is particularly preferable because a good cured coating layer can be formed for the first time. The size of the above-mentioned concavo-convex processed portion is, for example, the height of the protruded portion in the case of a protruded processed portion that is raised on one side of the plate body, such as a bead portion 21 formed in the stainless steel plate body 2 in FIG. Is about 0.1 to 0.4 mm, and the width is about 1.0 to 4.0 mm. The hard organic polymer layer 24 in the bead portion 21 formed on the stainless steel plate 2 of FIG. 1 is made of the cured epoxy resin of the present invention. Becomes

The epoxy resin-coated iron alloy according to the present invention, which is a stainless steel plate body having at least one bead portion having the above-mentioned dimensions, and having a cured coating of an epoxy resin paint inside and / or outside the bead portion. The body is particularly suitable as a plate material for metal gaskets, especially as a material for cylinder head gaskets in motor vehicles.

[0016]

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

Example 1 Bisphenol A type epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd., viscosity at 25 ° C .:
100 parts by weight of about 1,350 cp), 5 parts by weight of 2-ethyl-4-methylimidazole (trade name: Epicure EMI-24 manufactured by Yuka Shell Epoxy Co., Ltd.), and talc (trade name: talc SWB manufactured by Nippon Talc Co., particle size) : 15 parts by weight of 325 mesh of Tyler sieve and 99.8% or more were mixed with a mixer (ACE HOM (trade name, manufactured by Nippon Seiki Seisakusho)
Epoxy resin paint manufactured by mixing uniformly at room temperature with OGENIZER AM-10).

Example 2 The amount of talc was 2 per 100 parts by weight of epoxy resin.
An epoxy resin paint different from that of Example 1 only in that the amount was 5 parts by weight.

Example 3 The amount of talc was 3 per 100 parts by weight of epoxy resin.
An epoxy resin paint different from that of Example 1 only in that the amount was 5 parts by weight.

Example 4 100 parts by weight of a phenol novolak type epoxy resin (Epicoat 154, trade name, manufactured by Yuka Shell Epoxy Co., Ltd., viscosity at 52 ° C .: about 5,100 cp), dicyandiamide (Epicure, tradename, manufactured by Yuka Shell Epoxy Co., Ltd.) DIC
Y-7) 5 parts by weight and 20 parts by weight of clay (Neocarrier K, trade name, manufactured by Asada Flour Milling Co., Ltd., particle size: 97% or more passing through 325 mesh of a Tyler sieve) at room temperature in the same manner as in Example 1. Epoxy resin paint manufactured by mixing uniformly with.

Example 5 Commercial one-part epoxy resin (trade name: 2212B, manufactured by Three Bond Co., viscosity at 25 ° C .: about 25,000 c)
p) 100 parts by weight and 20 parts by weight of talc (talc SWB, trade name, manufactured by Nippon Talc, particle size: 99.8% or more passing through 325 mesh of a Tyler sieve) at room temperature in the same manner as in Example 1. Epoxy resin paint manufactured by mixing evenly.

Comparative Example 1 An epoxy resin paint different from Example 1 only in that talc was not added.

Comparative Example 2 The amount of talc was 3 per 100 parts by weight of the epoxy resin.
Epoxy resin paint different from Example 1 only in parts by weight.

Comparative Example 3 An epoxy resin paint different from Example 5 only in that talc was not added.

Examples 6 to 10 and Comparative Examples 4 to 6 A metal gasket plate made of SUS301-CSP3 / 4H having a thickness of 0.25 mm has an inner diameter of 55 mm and an outer diameter of 7 mm.
A 5 mm ring-shaped sample was punched out, and was 3.4 mm in width and 0.30 in height over the entire circumference in the center in the width direction of the ring-shaped sample.
mm bead was provided. The entire surface of the beaded sample was cleaned by blasting. Next, the epoxy resin paints of Examples 1 to 5 and Comparative Examples 1 to 3 were applied at 25 ° C. from the concave side surface of the bead to the concave portion by screen printing so as to have an application width of 1.0 mm. Further, another ring-shaped sample was applied by screen printing to a flat portion near the convex portion from the convex side surface of the bead so as to have an application width of 1.5 mm. Next, for the purpose of heat curing, the epoxy resin paint was cured by heating in a thermostat with the respective application surfaces facing upward, thus obtaining the epoxy resin-coated iron alloy bodies of Examples 6 to 10 and Comparative Examples 4 to 6, respectively. The heating conditions of Examples 6, 7, 8 and Comparative Examples 4 and 5 were 150 ° C. for 30 minutes, Example 9 was 160 ° C. for 60 minutes, and Example 10 and Comparative Example 6 were different. 20 minutes at 100 ° C.

In each of the epoxy resin-coated iron alloy bodies of Examples 6 to 10 using the epoxy resin paints of Examples 1 to 5, even when applied in the concave portion of the bead portion, it was applied to the flat portion near the convex portion. Also in this case, a cured epoxy resin layer having good uniformity in both width and thickness was formed. In contrast, Comparative Examples 4 to 4 using the epoxy resin paints of Comparative Examples 1 to 3
In each epoxy resin-coated iron alloy body of No. 6, the epoxy resin paint is repelled, and the cured epoxy resin layer is
Both width and thickness became extremely uneven.

[0027]

The epoxy resin coating composition of the present invention exhibits good applicability to various iron alloy bodies, especially stainless steel bodies, and repels even at a high temperature during heat curing after application. Cures without Therefore, it is suitable for applying iron alloy bodies of various shapes such as a flat plate, corrugated plate, round bar, square bar, block and the like. Further, the epoxy resin-coated iron alloy body of the present invention has a cured layer of the epoxy resin paint having a uniform layer without a repellent portion. Among the epoxy resin-coated iron alloy bodies, a stainless steel body having a cured coating of an epoxy resin paint inside and / or outside a bead portion is particularly suitable as a metal gasket plate material, particularly a material for a cylinder head gasket of an automobile. It is.

[Brief description of the drawings]

FIG. 1 is an example of a sectional view of a two-layer metal gasket for an automobile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stainless steel body 11 Folding part 2 Stainless steel body 21 Bead part 24 Hard organic polymer layer

Claims (7)

[Claims] 1. An epoxy resin paint for applying an iron alloy body, comprising an epoxy resin containing an inorganic fine body. 2. 10 to 100 parts by weight of epoxy resin
The epoxy resin paint according to claim 1, which contains 50 parts by weight of inorganic fine particles. 3. The epoxy resin coating according to claim 1, wherein the inorganic fine particles are at least one selected from the group consisting of talc, clay, molybdenum disulfide, silica, calcium carbonate, mica, and alumina. 4. The method according to claim 1, wherein a desired surface of the iron alloy body is provided.
An epoxy resin-coated iron alloy body having a cured coating of the epoxy resin paint according to any one of the above. 5. The iron alloy body coated with an epoxy resin according to claim 4, wherein the iron alloy body is a stainless steel body. 6. The epoxy resin-coated iron alloy according to claim 4, wherein the iron alloy is a metal gasket plate. 7. The stainless steel gasket plate having a bead portion, wherein the iron alloy body has a cured coating film of an epoxy resin paint at least inside and / or outside the bead portion. The epoxy resin-coated iron alloy according to any one of the above.