JPH03281668A - Primer composition and resin-coated metal body - Google Patents

Abstract

PURPOSE:To enhance the adhesion between a coating layer and the surface of a metal body by coating the surface with a primer comprising a titanate coupling agent and a polyphenylene sulfide resin powder and then with a polyphenylene sulfide resin to form the coating layer. CONSTITUTION:A primer compsn. comprising a titanate coupling agent and a polyphenylene sulfide resin powder is used to enhance the adhesion between a polyphenylene sulfide resin coating layer and the surface of a metal body. The coupling agent and the resin powder are compounded pref. in a wt. ratio of the former to latter of (98:2) to (20:80).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a primer composition for coating a metal body surface with a polyphenylene sulfide resin and a metal body coated with a polyphenylene sulfide resin.

(Prior art) Polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) has excellent heat resistance, hot water resistance, chemical resistance, mechanical strength, etc., and has good fluidity during melt molding, and is easy to form on metal surfaces. It is used as a coating resin.

When coating the metal surface with this PPS resin, in order to obtain excellent coating performance, it is necessary to
It is necessary to bake at a high temperature of about 00°C to allow the curing reaction to proceed sufficiently. Furthermore, in order to strengthen the adhesion between the resin coating layer and the metal surface, it is necessary to use a primer with excellent heat resistance.

As a primer for this type of PPS resin, for example, Japanese Patent Publication No. 5B-50147 discloses a primer composition consisting of aluminum powder, zinc powder, and an initial condensate of an alkyl silicate whose alkyl group has 1 to 4 carbon atoms. has been disclosed.

(Problem to be Solved by the Invention) However, although the PPS resin-coated metal body using the above primer composition has good adhesion to the metal body surface, the PPS resin coating layer has an anchoring effect due to the unevenness of the interface. It's just that they're in close contact. Therefore, there is a problem in that when used for a long period of time, especially under hot water, the adhesion decreases and the coating becomes prone to blistering and peeling.

The present invention is intended to solve the above conventional problems, and its purpose is to provide a primer composition and a resin coating that have excellent heat resistance and excellent adhesion between both the PPS resin coating layer and the metal body. The objective is to provide a metal body.

(Means for Solving the Problems) The primer composition of the present invention is a primer composition for coating a metal body surface with a PPS resin, and is composed of a titanate coupling agent and a PPS resin powder. Further, the resin-coated metal body of the present invention has a primer layer formed of the primer composition of the present invention on the surface of the metal body, and a PPS resin is coated thereon.

With the above configuration, the object of the present invention is achieved.

The titanate coupling agent used in the present invention includes an organic group that binds to an inorganic substance (e.g., a hydrolyzable group such as isopropyl group) and an organic group that has an affinity for organic substances (e.g., stearoyl group, N-aminoethyl group). It is an organic titanate compound having an organic group such as -aminoethyl group, dodecylbenzenesulfonyl group, or dioctyl phosphate group), and for example, "Prenact" manufactured by Ajinomoto Co., Ltd. and "Titacoat" manufactured by Nippon Soda Co., Ltd. are commercially available.

Typical examples of such titanate coupling agents include isopropyl (N-aminoethyl-aminoethyl) titanate, ethyltri(N-aminoethyl-aminoethyl) titanate, and diisopropyldii(N-aminoethyl-aminoethyl) titanate. ethyl) titanate, butyl tri(N
Examples include aminoethyl-aminoethyl) titanate, dibutyl di(N-aminoethyl-aminoethyl) titanate, and the like.

In addition, isopropyl triisostearoyl titanate, tetraoctyl bis(didodecyl) phosphite titanate, isopropyltrioctanoyl titanate, isopropyl dimethacrylylisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tricumylphenyl titanate,
Isopropyl tris (dioctyl pyrophosphate)
Titanate, tetraisopropyl bis(dioctyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl) bis(ditridecyl) phosphite titanate, bis(dioctyl pyrophosphate)
Representative examples include oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyl tris(dioctyl phosphate) titanate, and isopropylisostearoyl diacryl titanate.

The PPS resin used in the present invention has alternating benzene-sulfur bonds and may be partially oxidized, branched, or crosslinked. Examples of such PPS resins include Rydon'l-1 manufactured by Phillips Vetroleum and T-4 manufactured by Torbren. Such PPS resin is used as a powder, and its particle size is preferably 300 μm or less, more preferably 100 μm or less.

If the particle size is as large as 300 μM or more, good dispersion in the primer composition may not be obtained and adhesion may decrease.

Therefore, in the present invention, the titanate coupling agent and PPS resin powder are blended. The blending ratio of the titanate coupling agent and PPS resin powder is preferably in the range of 98:2 to 20:80 by weight. If the amount of PPS resin powder is too large, the adhesion between the primer layer and the PPS resin coating layer will improve, but the adhesion between the primer layer and the metal surface will decrease.

Since the titanate coupling agent is a liquid, the primer composition consisting of the above titanate coupling agent and PPS resin powder can be used by simply mixing the two uniformly. It is used by dissolving the agent in an organic solvent and uniformly mixing and dispersing the PPS resin powder therein.

As such an organic solvent, a @solvent that is compatible with the titanate coupling agent and does not show corrosivity to metals is used. For example, benzene, toluene, xylene,
Ethyl ether, hexyl ether, methyl ethyl ketone, normal hexane, ethanol, methanol, isopropyl ether, methyl isobutyl ketone, diethylhexanol, isopropanol, etc. are used.

Incidentally, an inorganic filler may be added to the primer composition of the present invention, if necessary. This inorganic filler has the function of reducing residual stress in the primer layer and preventing cracks from forming. Examples of such inorganic fillers include metals, metal oxides, glass, carbon, and ceramic inorganic salts.

Examples of metals include zinc, nickel alloy, stainless steel, and cast iron. Examples of metal oxides include alumina, iron oxide, titanium oxide, zirconium oxide, chromium oxide, nickel oxide, potassium titanate, talc, kaolin, clay, and mica. This includes potassium titanate. In addition to those included in metal oxides, ceramics include silicon nitride, titanium nitride, boron carbide, silicon carbide, and the like. Inorganic salts include barium sulfate.

These inorganic fillers are preferably contained in the form of fibrous, granular, or flake-like fine powder, and the average particle size is 1
The mesh is adjusted to ~100 μm, preferably 5 to 30 μm.

This inorganic filler is preferably contained in an amount of 10 to 800 parts by weight, more preferably 25 to 400 parts by weight, based on 100 parts by weight of the primer composition. If it is less than 10 parts by weight, the effect of the inorganic filler will be small; if it is more than 800 parts by weight, the binder ability of the primer composition will decrease, and the adhesion to the metal body will decrease.

The primer composition of the present invention is applied to the surface (surface or inner surface) of a metal body such as iron, aluminum, stainless steel, various alloys, etc., and is then generally heated and so-called baked. As a result, the titanate coupling agent in the composition reacts and the PPS resin powder is melted and hardened to form a primer layer.

The metal body is previously subjected to appropriate pretreatment such as sandblasting, degreasing, and chemical conversion treatment. The baking temperature is usually 300°C or higher, preferably 350 to 420°C. The thickness of the primer layer is in the range of 5-1OOp, preferably 10-30μ. When the gloss is less than 5μ, the primer layer is not formed uniformly, and pinholes and cracks are likely to occur. Conversely, when it exceeds 100 Bm, the adhesion between the primer layer and the metal body decreases.

The metal body surface (surface or inner surface) on which the primer layer is formed is coated with PPS resin. As this PPS resin, the same PPS resin as used in the above primer composition is used.

As the coating method, an electrostatic powder coating method using PPS resin powder is suitably employed.

After powder coating, the painted surface is baked, and the PPS resin is melted and hardened to form a resin coating layer. The baking temperature is preferably 300 to 450''C.

The thickness of the resin coating layer is 50 to 2000 μm, preferably 25 μm.
The range is 0 to 1000μ. If it is less than 50 μl, the resin coating layer will not be formed uniformly, and pinholes and cranks will likely occur. On the other hand, if it exceeds 2000 μm,
Baking takes time and foaming occurs, making it impossible to obtain a dense resin coating layer. After baking, it may be annealed or cooled.

(Function) Since the primer composition of the present invention is composed of a titanate coupling agent and PPS resin powder, the primer layer formed thereby has excellent heat resistance and is composed of a titanate coupling agent and PPS resin powder. This primer layer is formed by the action of the organic groups that bond with the inorganic substances in the molecules of the titanium coupling agent (
(hydrolysis), good adhesion to the metal surface is developed. In addition, due to the action (reaction) of organic groups in the molecule that have an affinity for organic substances, it adheres well to the PPS resin in the primer layer.

Furthermore, due to the action of the PPS resin contained in the primer layer, the adhesion of the PPS resin to the coating layer is further strengthened. Therefore, it has excellent hot water resistance and the decrease in adhesion under hot water is significantly reduced.

(Example) Examples and comparative examples of the present invention are shown below.

l Kadokado titanate coupling agent (Titako) S-581=
(manufactured by Nippon Soda Co., Ltd.) "Isopropyl group and -0COR' group (
R1 is an unsaturated hydrocarbon)" 90 parts by weight and a particle size of 90 μ-
10 parts by weight of the following PPS resin powder (Rydon v-1, manufactured by Phillips Vetroleum) and 1 part by weight of isopropanol
80 parts by weight were blended and mixed uniformly to obtain a primer composition.

After grid blasting an iron plate of 100m x 100cm x 3cm thick, it was cleaned by blowing compressed air, the above primer composition was applied with a brush to one side of the iron plate, and this was baked at 380°C for 30 minutes. Ta. The thickness of the obtained primer layer was 25 μI on average. On this primer layer, PPS resin powder (T-4:)-manufactured by Bren Co., Ltd.) was electrostatically powder coated, and then this was baked at 380°C for 60 minutes, and then poured into water and rapidly cooled to form a PPS resin-coated iron plate. I got it. The thickness of the resulting coating layer was approximately 700 μm.

The thus obtained PPS resin-coated iron plate was subjected to a normal adhesion test and a hot water adhesion test using the following test methods. The results are shown in Table 1.

(1) Normal adhesion test Make a 10m wide cut in the coating film on a PPS resin-coated iron plate with a sharp knife so that the cut reaches the iron plate, peel off one end, and peel it off at room temperature (23°C). speed 10 kaku 7
The peel strength was measured by pulling in a 90 degree direction for 1 minute. Note that the * mark in the table indicates that the PPS resin coating layer was broken.

(2) Heat-resistant water adhesion test After immersing the PPS resin-coated iron plate in hot water at 95°C for 100 hours, cut the coating with a sharp knife to a width of 10 m so that the cut reaches the iron plate, and cut one end of the plate. Peel off the
This was pulled in a 90 degree direction at room temperature (23° C.) at a peeling rate of 10-71 minutes, and the peel strength was measured.

1 Lit Titanate coupling agent of Example 1 (Titako) S
-581: manufactured by Nippon Soda Co., Ltd.) to 15 parts by weight, PPS
The same procedure as in Example 1 was carried out except that the resin (Rydon ■-1: manufactured by Philips Vetroleum Co., Ltd.) was changed to 85 parts by weight.

1 Cliff 11 Titanate coupling agent of Example 1 (Chikucoat S
-581: manufactured by Nippon Soda Co., Ltd.) 90 parts by weight of titanate coupling agent (Chikukoat S-152: manufactured by Nippon Soda Co., Ltd.) [isopropyl group and -0C0R2 group (R1 is an unsaturated hydrocarbon)'' The same procedure as in Example 1 was carried out except for the changes.

Titanate coupling agent (Titako) S of Disaster soil Example 1
-581: manufactured by Nippon Soda Co., Ltd.) was changed to 90 parts by weight of a titanate coupling agent (Blenact KR12: manufactured by Ajinomoto Co., Ltd.) "isopropyl tri(dioctyl phosphate) titanate". I did the same.

The titanate coupling agent of Example 1 (Titacoat S)
-5817 Nippon Soda Co., Ltd.) 90! The same procedure as in Example 1 was carried out, except that part iii was changed to 190 parts by weight of a titanate coupling agent (Chikukoat S-161, manufactured by Nippon Soda Co., Ltd.) "having an isopropyl group and an N-amino-amino group". Ta.

Fusemastan titanate coupling agent (Chikucoat S-581:
90 parts by weight of titanate coupling agent (Blenact KR9S: manufactured by Ajinomoto Co., Ltd.) "Isopropyl tridodecylbenzenesulfonyl titanate" 90 parts by weight
The same procedure as in Example 1 was carried out except that parts by weight were changed.

Indigo soil Example 1 was carried out in the same manner as in Example 1 except that the primer composition was not applied.

The same procedure as in Example 1 was carried out, except that 90 parts by weight of a titanate coupling agent (Chikukoat S-581, manufactured by Nippon Soda Co., Ltd.) was not blended into the primer composition. .

Comparison 1 In Example 1, PPS resin powder (Rydon v-1: manufactured by Phillips Veterolium) was added to the primer composition.
The same procedure as in Example 1 was carried out except that 0 parts by weight was not blended.

(The following is a blank space) Table 1 (Effects of the Invention) As mentioned above, the primer composition of the present invention consists of a titanate coupling and PPS resin powder. By coating, a resin-coated metal body can be obtained which has excellent heat resistance, excellent adhesion between the coated PPS resin and the metal body, and particularly good hot water resistance.

Therefore, the resin-coated metal body of the present invention can be suitably used for corrosion protection of metal surfaces that come into contact with hot water, such as vibrators and joints for hot water supply, and pipes and joints for chemical plants.

Claims (1)

[Scope of Claims] 1. A primer composition for coating a metal body surface with polyphenylene sulfide resin, the primer composition comprising a titanate coupling agent and polyphenylene sulfide resin powder. 2. A resin-coated metal body, in which a primer layer made of the primer composition according to claim 1 is formed on the surface of the metal body, and a polyphenylene sulfide resin is coated thereon.