JPH09176609A - Adhesive composition for heavy-duty corrosionproof coated steel product and heavy-duty corrosionproof coated steel product prepared using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive compsn. for a heavy-duty corrosionproof coated steel product which compsn. can strongly bond a steel product to a polyolefin resin and is prevented from the degradation with time in adhesive strength. SOLUTION: This adhesive compsn. contains 100 pts.wt. glycidylamine-type epoxy resin, 5-45 pts.wt. latent curative for an epoxy resin, and if necessary a glycidyl ether-type epoxy resin. A primer layer formed from the adhesive compsn., a modified polyolefin layer, and a polyolefin layer are formed successively in this order on a steel product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Heavy-corrosion-coated steel material coats the surface of steel material with polyethylene, polyurethane, etc. The present invention relates to an adhesive for adhering plastics such as polyolefin or polyurethane to steel material, and heavy-corrosion protection using the same. The present invention relates to coated steel materials.

[0002]

BACKGROUND OF THE INVENTION The present invention relates to a polyolefin coating, a polyurethane coating, as a corrosion prevention measure against the corrosive environment of steel materials,
In particular, the present invention relates to an adhesive used for coating a chemically stable polyolefin such as polyethylene or polypropylene, and a heavy anticorrosion coated steel material using the same.

The polyolefin resin is a versatile resin that is easy to process by heat fusion and has excellent water resistance, moisture resistance, and hygienic properties, and is a relatively inexpensive resin. However, since the polyolefin resin has poor polarity, it is inferior in adhesiveness to a metal and has a drawback that it is immediately peeled from the metal even if it is once adhered. Therefore, it has been conventionally known to improve the adhesiveness by introducing a polar group into a polyolefin resin, for example, a polyolefin resin is graft-modified with an unsaturated carboxylic acid such as maleic anhydride or an anhydride thereof, It is known to use this for coating or thermal bonding to metal substrate surfaces.

[0004] For example, in Japanese Patent Publication No. 56-10184, a polyolefin grafted with an unsaturated carboxylic acid or an anhydride thereof and a metal fitting are used, and a hydroxyl group or a hydrolyzable group and an acid-reactive group are present at their interfaces. It is disclosed that an organosilicon compound having and is disposed and thermally bonded. Further, Japanese Patent Publication No. 58-12299 discloses that a composition of 70 to 95 parts by weight of acid-modified polyethylene and 5 to 30 parts by weight of polypropylene is used for laminating with a metal. The official gazette discloses the use of a composition containing 99 to 70 parts by weight of an acid-modified polyolefin as an adhesive agent when adhering the polyolefin and the metal foil.

However, most of the laminates of the polyolefin resin and the base metal exhibit high adhesive strength in the initial stage, but most of them show deterioration in adhesive strength due to aging, especially under environmental conditions in which water is present. This tendency is remarkable below. For example, the above-mentioned acid-modified polyolefin-based resin has a considerably high initial adhesive strength to a metal, but also the adhesive strength deteriorates significantly with time under environmental conditions in which water is present.

This tendency of deterioration of the adhesive strength over time is similarly recognized when the metal surface is treated with an epoxy primer prior to the adhesion.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to coat a steel material with a polyolefin resin and heat-bond it to produce a laminate, in which a steel material and a polyolefin resin are combined. It is an object of the present invention to provide an adhesive composition for a heavy anticorrosion coated steel material capable of improving the adhesive strength and further preventing deterioration of the adhesive strength over time, and a heavy anticorrosion coated steel material using the same.

[0008]

A first invention is a heavy anticorrosion coating characterized by containing 5 to 45 parts by weight of a latent curing agent for an epoxy resin with respect to 100 parts by weight of a glycidylamine type epoxy resin. It is an adhesive composition for steel materials. A second invention comprises a latent curing agent for an epoxy resin in an amount of 5 to 45 parts by weight based on 100 parts by weight of the total amount of the glycidyl amine type epoxy resin and the glycidyl ether type epoxy resin, and the glycidyl amine type epoxy resin. 100 parts by weight of the total amount of resin and glycidyl ether type epoxy resin is composed of (1) 10 parts by weight or more of glycidyl amine type epoxy resin and less than 100 parts by weight, and (2) 90 parts by weight or less of glycidyl ether type epoxy resin. An adhesive composition for heavy-duty anticorrosion coated steels, which is characterized in that:

A third aspect of the present invention is a heavy anticorrosion coated steel material in which a primer layer made of an epoxy resin adhesive, a modified polyolefin resin layer, and a polyolefin layer are sequentially laminated on the surface of a steel material, wherein the epoxy resin adhesive is used. Is an epoxy resin-based adhesive containing 5 to 45 parts by weight of a latent curing agent for an epoxy resin with respect to 100 parts by weight of a glycidyl amine type epoxy resin.

Further, a fourth invention is a heavy anticorrosion coated steel material in which a primer layer made of an epoxy resin adhesive, a modified polyolefin resin layer and a polyolefin layer are sequentially laminated on the surface of a steel material, wherein the epoxy resin adhesive is used. But,
The glycidyl amine type epoxy resin and the glycidyl ether type epoxy resin are contained in an amount of 5 to 45 parts by weight with respect to 100 parts by weight of the total amount of the glycidyl amine type epoxy resin and the glycidyl amine type epoxy resin and the glycidyl ether type epoxy resin. The total amount of 100 parts by weight is (1) 10 parts by weight or more of glycidyl amine type epoxy resin and less than 100 parts by weight,
(2) A heavy anticorrosion coated steel material, which is an epoxy resin adhesive composed of 90 parts by weight or less of a glycidyl ether type epoxy resin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In order to achieve the above-mentioned object, the present inventors have earnestly studied, and as a result, an epoxy resin-based adhesive composition comprising at least a glycidylamine type epoxy resin and a latent curing agent for an epoxy resin, in an environment where water is present or It has a very high adhesiveness even in an environment of salt water, and by using the adhesive composition as a primer and coating the surface of the steel material with a polyolefin resin, the polyolefin resin in the environment in the presence of water can be changed over time. It was found that deterioration of the adhesive strength can be prevented.

Examples of the glycidylamine type epoxy resin used in the present invention include a glycidylamine compound which is a condensation product of an aliphatic diamine such as xylylenediamine and epichlorohydrin, and a condensation product of an aromatic diamine such as diaminodiphenylmethane and epichlorohydrin. One or more kinds of glycidylamine compounds such as glycidylamine compounds, which are condensates of monoamine compounds such as 3-aminophenol, aniline, and toluidine, and glycidylamine compounds, which are epichlorohydrin, are preferably exemplified. It is not limited.

Commercial products that can be used as the glycidyl amine type epoxy resin include, for example, Epicron 421L, Epicron 430 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), Epicoat 604 (trade name, Yuka Shell Co., Ltd. Made),
GOT, GAN (: trade name, manufactured by Nippon Kayaku Co., Ltd.), TETRAD
-X, TETRAD-D, and TETRAD-C (: trade name, manufactured by Mitsubishi Gas Chemical Co., Inc.).

The glycidylamine type epoxy resin is a rubber-modified epoxy resin such as TSR 960 or TSR 93.
0 (: Product name, manufactured by Dainippon Ink and Chemicals, Inc.), EP
4032, EP 4026 (: trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), EPU 6 (: trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), which is a urethane-modified epoxy resin, and Polybd R-45EP.
I (: trade name, manufactured by Idemitsu Petrochemical Co., Ltd.) and the like can also be preferably used.

Next, as the glycidyl ether type epoxy resin used in the present invention, for example, one or more selected from glycidyl ethers such as phenol novolac type glycidyl ether and bisphenol A, AD and F diglycidyl ether. Are preferably exemplified, but not limited thereto. As commercially available products that can be used as phenol novolac type glycidyl ether, Epicoat 152, Epicoat 15
4 (: Product name, Yuka Shell Epoxy Co., Ltd.), Epotote
YDPN 638, YDPN 601, YDPN 602 (: trade name, manufactured by Tohto Kasei Co., Ltd.), DEN431, DEN 438, DEN 439, DEN 485 (:
Product name, manufactured by Dow Chemical Japan), EPN 1138, EPN 113
9, XPY 307 (trade name, manufactured by Ciba Geigy) and the like.

Commercial products usable as the diglycidyl ether of bisphenol A include Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1007, Epicoat 1009 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.), Epomic R140, Epomic R144, Epomic R301
, Epomic R302, Epomic R304, Epomic R
307, Epomic R309 (trade name, manufactured by Mitsui Petrochemical Industries, Ltd.), DER 317, DER 330, DER 331, DER 33
3, DER 383, DER 387, DER 662, DER 664, DER 667
(: Product name, manufactured by Dow Chemical Japan Co., Ltd.) and the like.

Commercially available products that can be used as the diglycidyl ether of bisphenol AD include Epomic
R710, Epomic R710H (: trade name, manufactured by Mitsui Petrochemical Industry Co., Ltd.) and the like. Further, examples of commercially available products that can be used as the diglycidyl ether of bisphenol F include Epicoat 806 and Epicoat 807 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.).

These epoxy resins, particularly glycidyl amine type epoxy resins, are used to maintain the adhesion between steel materials and anticorrosion coating materials such as polyolefin resins and polyurethane resins under a long-term wet environment or salt water environment. Required. In the second invention and the fourth invention, the total amount of the glycidyl amine type epoxy resin and the glycidyl ether type epoxy resin is 100 parts by weight, and (1) the glycidyl amine type epoxy resin is 10 parts by weight or more and less than 100 parts by weight, 2)
It is preferable that the amount of the glycidyl ether type epoxy resin is 90 parts by weight or less.

When the glycidyl amine type epoxy resin is less than 10 parts by weight and the glycidyl ether type epoxy resin is more than 90 parts by weight, the initial adhesive strength of the polyolefin-coated steel material,
The decrease in adhesive strength over time in an environment where water is present becomes large. When the epoxy resin has a high viscosity or a solid state at room temperature, for example, when using Epicoat 1007, it is preferable to use a low viscosity epoxy resin by diluting with a reactive diluent.

Furthermore, an epoxy resin called a reactive diluent can be blended in some cases.
Further, as the curing agent for the epoxy resin, which is a component of the adhesive composition in the present invention, it is preferable to blend a latent curing agent that acts as a curing agent when heated.

Examples of the latent curing agent for epoxy resin used in the present invention include dicyanodiamide, adipic acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide and other hydrazide derivatives, imidazole derivatives, fenuron, monuron, duron,
One or more selected from latent curing agents such as urea derivatives such as dimethylurea, tolylene diisocyanate and an adduct of dimethylamine and the like are preferably exemplified, but not limited thereto.

Commercially available products that can be used as a latent curing agent for epoxy resins include Amicure (PN 23, MY 24, VD
H, LDH, UDH) (trade name, Ajinomoto Co., Inc.), Novacure (HX 3612, HX 3613, HX 3721, HX 3722, HX)
3741, HX 3742, HX 3871, HX 3891, HX 3921HP, H
X 3951HP) (: Product name, manufactured by Asahi Kasei Corporation), A
CR Hardener (H 3615, H 3809, H 3731, H 3293, H
3366, H 3842, H 3849S, H 3670S, H 3636) (trade name, manufactured by AC R Co., Ltd.) and the like.

The latent hardener may be used alone, or two or more kinds of latent hardeners may be mixed and used. The blending amount of these latent curing agents depends on the required curing rate, but is preferably 5 to 45 parts by weight with respect to 100 parts by weight of the total amount of the epoxy resin. this is,
If the compounding amount is less than 5 parts by weight, the curing speed will be slow and it will not be compatible with the speed of the coating material laminating line, and if it exceeds 45 parts by weight, it will foam depending on the type of curing agent, or stability as an adhesive agent. This is because there is a possibility that the

Further, additives such as glass flakes which are scaly pigments having a corrosion factor permeation inhibiting effect, mica, talc which is an extender pigment, and color pigments may be added to the adhesive composition of the present invention. Good. Further, it is preferable to add an appropriate amount of an anti-sedimentation agent such as fumedricica or colloidal silica for the purpose of preventing sedimentation of the latent curing agent, the filler and the pigment in the adhesive composition of the present invention.

Examples of the steel material in the present invention include steel pipes, low-alloy steels such as carbon steel and stainless steel, high-alloy steels, shaped steels, steel plates, steel bars, and steel molded products and structures. , It is a general term for those widely used in the ground, ground, and seabed. Further, on the surface of the steel material, a plated layer of zinc, aluminum, chromium, nickel, etc., an alloy plated layer of zinc-iron, zinc-nickel-cobalt, etc., and further silica, alumina, titanium oxide, silicon in these plated layers. A steel material having a dispersed plating layer in which inorganic fine particles such as carbide and boron nitride are dispersed is also preferably used.

The steel material is preferably preliminarily subjected to rusting treatment such as pickling and blasting, and may be further subjected to chemical conversion treatment such as phosphate and chromate. Examples of the chemical conversion treatment method include coating methods such as dip coating, brush coating and spray coating, and electrolytic methods such as electrolytic chromate.
As the modified polyolefin resin in the present invention, polyethylene, polyolefin such as polypropylene, polyolefin copolymer resin such as ethylene-propylene copolymer, maleic acid, acrylic acid, unsaturated carboxylic acid such as methacrylic acid, or those Examples thereof include those modified with an acid anhydride or a mixture of these modified polyolefin resins.

In the present invention, by forming the polyolefin layer on the modified polyolefin resin layer, the adhesion between the primer layer and the polyolefin layer can be further improved, and more preferable results can be obtained. Examples of the polyolefin in the present invention include polyolefins such as polyethylene and polypropylene, polyolefin copolymer resins such as ethylene-propylene copolymer, and mixtures thereof.

Further, in the present invention, at least one of the modified polyolefin resin layer and the polyolefin layer.
The layer may optionally contain a pigment. As the pigment, silica, alumina, titania, talc, silicate,
Examples include general extender pigments such as zinc white, aluminum phosphate, carbon black, red iron oxide, aniline black, azo pigments, and phthalocyanines, and coloring pigments.

The heavy anticorrosion coated steel material of the present invention was able to extremely suppress the amount of corrosion on the steel surface.

[0030]

The present invention will be described below in more detail with reference to examples. As a glycidyl diether type epoxy resin, Epicoat 828 (manufactured by Yuka Shell Epoxy Co., Ltd.): 26 parts by weight,
As a latent curing agent for epoxy resin, dicyanodiamide (DICY): 8 parts by weight and Amicure PN23 (Ajinomoto Co., Inc.): 3 parts by weight were blended, and the blended mixture had an average particle size of 20 μm or less on a paint roll. Crushed to become.

The formulation is then further subjected to Epicoat 82.
8:54 parts by weight and Epicoat 604 (produced by Yuka Shell Epoxy Co., Ltd.) as a glycidyl diamine amine type epoxy resin: 20
An epoxy resin adhesive was produced as a trial by adding parts by weight and stirring and defoaming. Next, the trial epoxy resin adhesive
SS41 steel plate (thickness 3m
m) was applied with a bar coater to a thickness of 35 μm.

The coated steel sheet is heated to 120 ° C. to cure the adhesive, and then a polyethylene sheet grafted with maleic anhydride and polyethylene are superposed in this order, and rolled down by a hot press at 220 ° C. A coated steel material laminated with polyethylene was obtained (Example 1). Further, in the same manner as in Example 1, the epoxy resin adhesives shown in Examples 2 to 9 in Table 1 and Comparative Examples 1 to 9 in Table 2 were experimentally produced, and polyethylene was produced using them. A coated steel material was prototyped.

The test pieces of the obtained epoxy resin adhesive and polyethylene-coated steel material were evaluated for performance by the following test method. [Initial bond strength:] The initial bond strength was judged by performing a 90-degree peeling test on a trial coated steel material test piece. The 90 degree peeling test was performed by the peel test method. That is, the coating of coated steel is peeled off with a width of 1.0 cm, peeling angle: 90 degrees, peeling speed: 10 mm / m
The peel strength when peeling the coating with in was measured.

[Adhesive Strength After Hot Water Test:] The coated steel test piece was immersed in hot water at 60 ° C. for 120 days, and then a 90 ° peel test was performed on the test piece for judgment. [Adhesive strength after salt water test:] The coated steel test piece was
After 120 days of immersion in an aqueous solution of NaCl, a 90-degree peel test was conducted on the test piece for judgment.

The obtained results are also shown in Tables 1 and 2.

[0036]

[Table 1]

[0037]

[Table 2]

From the results shown in Tables 1 and 2, the coated steel material using the adhesive composition of the present invention has a large initial adhesive strength, and both the adhesive strength after the hot water test and the adhesive strength after the salt water test. It turns out to be great.

[0039]

The adhesive composition of the present invention improves the adhesive strength between a steel material and a resin such as a polyolefin resin, and the coated steel material using the adhesive composition of the present invention has the presence of water. It is possible to prevent a decrease in the adhesive strength over time even in an environment where it is used or in an environment of salt water, and the present invention has an excellent effect.

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Claims (4)

[Claims] 1. An adhesive composition for heavy anticorrosion coated steel, comprising 5 to 45 parts by weight of a latent curing agent for an epoxy resin with respect to 100 parts by weight of a glycidyl amine type epoxy resin. 2. A latent curing agent for an epoxy resin in an amount of 5 to 45 parts by weight per 100 parts by weight of the total amount of the glycidyl amine type epoxy resin and the glycidyl ether type epoxy resin, and the glycidyl amine type epoxy resin. And the total amount of glycidyl ether type epoxy resin is 100 parts by weight,
(1) Glycidylamine type epoxy resin 10 parts by weight or more, 10
Less than 0 parts by weight, (2) glycidyl ether type epoxy resin
An adhesive composition for heavy anticorrosion coated steel, which is composed of 90 parts by weight or less. 3. A heavy anticorrosion coated steel material in which a primer layer made of an epoxy resin adhesive, a modified polyolefin resin layer and a polyolefin layer are sequentially laminated on the surface of a steel material, wherein the epoxy resin adhesive is a glycidyl amine type epoxy. A heavy anticorrosion coated steel material, which is an epoxy resin-based adhesive containing 5 to 45 parts by weight of a latent curing agent for epoxy resin with respect to 100 parts by weight of resin. 4. A heavy anticorrosion coated steel material comprising a primer layer made of an epoxy resin adhesive, a modified polyolefin resin layer and a polyolefin layer, which are sequentially laminated on the surface of a steel material, wherein the epoxy resin adhesive is a glycidyl amine type epoxy. The total amount of the resin and the glycidyl ether type epoxy resin is 100 parts by weight, and the latent curing agent for the epoxy resin is 5 to 45 parts by weight, and the total amount of the glycidyl amine type epoxy resin and the glycidyl ether type epoxy resin is 100 parts by weight. Parts by weight are (1) glycidyl amine type epoxy resin
A heavy corrosion resistant coated steel material, which is an epoxy resin adhesive composed of 10 parts by weight or more and less than 100 parts by weight and (2) 90 parts by weight or less of a glycidyl ether type epoxy resin.