JPH0488066A - Primer composition and resin-coated metal - Google Patents

Abstract

PURPOSE:To provide the subject composition composed of a metallic titanium alkoxide (precondensate) and a titanate-based coupling agent, having excellent heat-resistance and exhibiting excellent adhesivity between a metal and a coated polyphenylene sulfide resin, excellent hot-water resistance and corrosion resistance. CONSTITUTION:The objective composition is composed of metallic titanium alkoxide [e.g. Ti(OCH3)4)] or its precondensate and a titanate-based coupling agent [e.g. isopropyl (N-aminoethyl-aminoethyl) titanate]. A layer of the primer is formed on the surface of a metal and a polyphenylene sulfide resin is applied to the primer layer to obtain a metal coated with polyphenylene sulfide resin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a primer composition for coating the surface of a metal body mainly 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, making it suitable for forming into metal objects. 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 0.000°C to allow the hardening reaction to proceed sufficiently. In addition, the adhesion between the PPS resin coating layer and the metal surface is poor, so in order to strengthen the adhesion,
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. 61-2706 specifically describes 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. Disclosed.

(Problems to be Solved by the Invention) A PPS resin-coated metal body using the above primer composition has relatively excellent adhesion between the metal body surface and the primer layer. However, the primer layer and the PPS resin coating layer are only in close contact with each other due to the anchoring effect of the unevenness of the interface, and the level of adhesion is not sufficient, especially when used for a long time under hot water. Adhesion may decrease and the film may blister or peel.

The present invention is intended to solve these problems, and its purpose is to provide a primer composition and resin that have excellent heat resistance and excellent adhesion between both the PPS resin coating layer and the metal surface. An object of the present invention is to provide a coated metal body.

(Means for Solving the Problems) The primer composition of the present invention comprises a metal titanium alkoxide or its initial condensate, and a titanate coupling agent. Another primer composition of the present invention is
It consists of a metal titanium alkoxide or its initial condensate, a titanate coupling agent, and polyphenylene sulfide resin powder.

Further, the resin-coated metal body of the present invention has a primer layer made of any of the primer compositions of the present invention formed 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 alkoxide of metallic titanium used in the present invention has the formula T
It is represented by i(OR') (OR2) (OR3) (OR').

Here, R1, R2, R3, and R4 represent the same or different alkyl groups, and particularly preferred are alkyl groups having 1 to 18 carbon atoms. If the number of carbon atoms in the alkyl group exceeds 18, it will be easily decomposed by heat. Note that the alkoxide of titanium metal also includes acid forms of titanium metal.

Specific examples of such metal titanium alkoxides include T
i (OCH3) a, Ti (OC2H5) 4,
Ti (OC31i7) 4, C3H70(Ti (Q
C, +H7) 20) l oc: +H7, C4H90
Examples include (T i (OC3H7) zo)+oCtHq. Further, the initial condensate of titanium metal alkoxide can be obtained by partially hydrolyzing and polycondensing the alkoxide of titanium metal as described above. The degree of polycondensation (n) is generally 10 or less.

The titanate coupling agent used in the present invention includes an ionic group that binds to an inorganic substance (e.g., a hydrolyzable group such as an isopropyl group) and an organic group that has an affinity for organic substances (e.g., a stearoyl group, an N-amino group). It is an organic titanate compound having an organic group (such as an ethyl-aminoethyl group, a dodecylbenzenesulfonyl group, or a dioctylphosphate-1 group), such as "Plenact" manufactured by Ajinomoto Co., Ltd. and "Chikukoat" manufactured by Nippon Soda Co., Ltd. is commercially available.

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

In addition, isopropyl triisostearoyl titanate, tetraoctyl bis(didodecyl) phosphite titanate, isopropyl trioctanoyl titanate, isopropyl dimethacrylic isostearoyl titanate
1~, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tricumylphenyl titanate, isopropyl tris(dioctylpyrophosphate) tichnate, tetraisopropyl bis(dioctyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis( Typical examples include ditridecyl) phosphite titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene thicnate, isopropyl tris(dioctyl phosphate) titanate, and isopropylisostearoyldiacryl titanate. Can be mentioned.

The primer composition made of the alkoxide of metallic titanium or its initial condensate used in the present invention can be used as it is if it is in liquid form, but generally the alkoxide of metallic titanium or its initial condensate is dissolved in an organic solvent. It is used as As the organic solvent, methanol, ethanol, isopropanol, butanol, hexane, Hensen, toluene, xylene, etc. are used.

In addition, since the tikunate coupling agent is a liquid,
Although it can be used as it is by simply mixing it with a solution of metal titanium alkoxide or its initial condensate, titanate coupling agents are also generally used by dissolving the same as above in an organic solvent.

Therefore, in the present invention, the alkoxide of metallic titanium or its initial condensate and a titanate coupling agent are blended. The blending ratio is 95:5 to 95:5 by weight.
A range of 70:30 is preferred. In particular, in the present invention, if PPS resin powder is blended and dispersed in the primer composition consisting of the alkoxide of metal titanium or its initial condensate and a titanate coupling agent, PPS
Adhesion with the PS resin coating layer is further improved.

The PPS resin used in the present invention has alternating Hensen-sulfur bonds and may be partially oxidized, branched, or crosslinked. Examples of such PPS resins include Rydon I-1 manufactured by Phillips Vetroleum and T-4 manufactured by Topren. The PPS resin is used as a powder, and the 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.

The blending ratio of the mixture of metal titanium alkoxide or its initial condensate and titanate coupling agent and PPS resin powder is preferably in the range of 100:0 to 30:0 by weight. If the amount of PPS resin powder blended is too large, the adhesion between the formed primer layer and the metal surface will decrease.

Incidentally, in order to further improve the adhesion, an inorganic filler may be added to the above primer composition as necessary. The inorganic filler is preferably contained in the form of fibrous, granular, or flake-like fine powder, and the average particle size is 1 to 1.
The thickness is adjusted to 100 μm, preferably 5 to 30 μm. Such inorganic fillers include, for example, metals, metal oxides,
Glass, carbon, ceramic inorganic salts, etc. are used.

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.

The primer composition of the present invention is applied to the surface (surface or inner surface) of metal bodies such as iron, aluminum, stainless steel mesh, and various alloys. Then, baking is performed, thus forming a primer layer on the surface of the metal body.

The metal body is previously subjected to appropriate pretreatment such as sandblasting, degreasing, and pickling. 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 to 100 μm, preferably 10 to 40 μm. When it is less than 5μm,
If the primer layer is not formed uniformly and the thickness exceeds 100 μm, the adhesion between the primer layer and the metal body may deteriorate.

The surface of the metal body on which the primer layer is formed is coated with PPS resin. This PPS resin is the same PPS resin used in the primer composition for forming the primer layer.
PS resin 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 2
The range is 50 to 2000 μm. If it is less than 50 μm, the resin coating layer will not be formed uniformly, and pinholes and cracks will easily occur. On the other hand, if it exceeds 2000 μm, it takes time to bake, etc., and foaming occurs, making it impossible to obtain a dense resin coating layer. After baking, it may be annealed or cooled.

(Function) The primer layer formed by the primer composition consisting of the alkoxide of metal titanium or its initial condensate and a titanium coupling agent has a structure in which the alkoxide of metal titanium or its initial condensate in the primer composition is free from moisture in the air. This results in crosslinking and hardening, resulting in excellent adhesion to the metal surface.

Furthermore, when a titanium coupling agent is blended into this composition, good adhesion to the metal surface is developed due to the action (hydrolysis) of the organic group that bonds with the inorganic substance in the molecule of the titanium coupling agent. do. In addition, due to the action (reaction) of the organic group that has affinity with the organic group in the molecule, it adheres well to the PPS resin coating layer.

In particular, if PPS resin is blended into the primer layer,
20 Due to the action of the PPS resin, the adhesion with the PPS resin coating layer is further improved. Furthermore, the primer layer has excellent heat resistance and is resistant to hot water. 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.

Gas flow side J Initial condensate of titanium alkoxide (B-io: manufactured by Nippon Soda Co., Ltd.) (10-molecule condensate of tetrabutyl titanate)
'Cd(qO(Ti (OC4tl,)0) +.C
90 parts by weight of 5Hq J and a titanate coupling agent (Plenact KR-44: manufactured by Ajinomoto Co., Ltd.) r C
3H70Ti (OC2H4NllCzH4NHz)
3. 10 parts by weight of "isopropyl tri(N-aminoethyl-aminoethyl) titanate" and 1 part by weight of isopropyl tri(N-aminoethyl-aminoethyl) titanate.
00 parts by weight and mixed uniformly to obtain a primer composition.

After grid blasting a 100 mm x 100 mm x 3 mm thick iron plate, it was cleaned by blowing with compressed air, the above primer composition was applied with a brush to one side of the iron plate, and it was heated at 380°C for 30 minutes. Bake for a minute. The thickness of the obtained primer layer was 25 μm on average.

PPS resin powder (manufactured by T4 Nidoprene Co., Ltd.) was electrostatically powder coated on this primer layer, and then this was heated at 380°C.
Bake it for 60 minutes, then put it in water and cool it down quickly to make PPS.
A resin-coated iron plate was obtained. The thickness of the obtained coating layer was approximately 70
It was 0 μm.

Regarding the PPS resin-coated iron plate obtained in this way,
A normal adhesion test, a hot water resistant adhesion test, and a hot water resistant test were conducted using the following test methods.

The results are summarized in Table 1.

(1) Normal adhesion test Make a 10 mm wide cut in the coating on the 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
The peel strength was measured by pulling in a 90 degree direction at mm/1 minute. Note that the * mark in the table indicates that the PPS resin coating layer was broken.

(2) Hot water adhesion test After immersing a PPS resin-coated iron plate in hot water at 95°C on the coating layer side and 65°C on the iron plate side for 200 hours, cut the coating film with a sharp knife so that the cut reaches the iron plate. Make a 10mm wide cut in the paper, peel off one end, and store it at room temperature (23°C).
C), the film was pulled in a 90 degree direction at a peeling speed of 10 mm/1 minute, and the peel strength was measured.

(3) Hot water resistance test After immersing a PPS resin-coated iron plate in hot water with the coating layer side at 95°C and the iron plate side at 65°C for 200 hours, the occurrence of blisters on the coating layer side was determined. Shown as area percentage.

Practical properties 1 60 parts by weight of an initial condensate of titanium alkoxide (B-10: manufactured by Nippon Soda Co., Ltd.), 40 parts by weight of a titanate coupling agent (Plenact KR-44: manufactured by Ajinomoto Co., Ltd.), and 100 parts by weight of isopropasol. A primer composition was obtained by blending and mixing uniformly. Other than that, the same procedure as in Example 1 was carried out.

- Initial condensate of titanium alkoxide (A-10: manufactured by Nippon Soda Co., Ltd.) rc+to0 (Ti(OCsl17)0) +
90 parts by weight of oCiHq J and a titanate coupling agent (Accoat S-581: manufactured by Nippon Soda Co., Ltd.) 't
? +0Ti(OCORz)3, R1: isopropyl group,
10 parts by weight of "R2; unsaturated hydrocarbon group" and 100 parts by weight of isopropasol were blended and mixed uniformly to obtain a primer composition. Other than that, the same procedure as in Example 1 was carried out.

Titanium alkoxide (TST: manufactured by Nippon Soda Co., Ltd.) 'Ti (
OC+aH3t) aJ 90 parts by weight and a titanate coupling agent (Plenact KR-44: manufactured by Ajinomoto Co., Ltd.)
10 parts by weight and 100 parts by weight of isoprobanol were blended and mixed uniformly to obtain a primer composition. Other than that, the same procedure as in Example 1 was carried out.

Enyaku J- 90 parts by weight of an initial condensate of titanium alkoxide (B-10: manufactured by Nippon Soda Co., Ltd.), 10 parts by weight of a titanate coupling agent (Plenact KR-44: manufactured by Ajinomoto Co., Ltd.), and 100 parts by weight of isoprobanol and 10 parts by weight of PPS resin powder having a particle size of 90 μm or less (Rydon V-1, manufactured by Phillips Petroleum) were mixed uniformly to obtain a primer composition. Other than that, the same procedure as in Example 1 was carried out.

60 parts by weight of an initial condensate of titanium alkoxide (B-1 (1: manufactured by Nippon Soda Co., Ltd.) and a thicnate coupling agent (
Plainact KR-44 (manufactured by Ajinomoto Co.) 40 parts by weight,
100 parts by weight of isopropasol and 10 parts by weight of PPS resin powder having a particle size of 90 μm or less (Rydon V-1; manufactured by Phillips Petroleum) were blended and mixed uniformly to obtain a primer composition. Other than that, the same procedure as in Example 1 was carried out.

90 parts by weight of an initial condensate of actual leakage former yutitan alkoxide (A-10: manufactured by Nippon Soda Co., Ltd.), 10 parts by weight of a titanate coupling agent (Plenac) KR-44: manufactured by Ajinomoto Co., Ltd., and 100 parts by weight of isopropasol. parts by weight and 10 parts by weight of PPS resin powder having a particle size of 90 μm or less (Rydon V-1, manufactured by Phillips Veterolium) were mixed uniformly to obtain a primer composition. Other than that, the same procedure as in Example 1 was carried out.

90 parts by weight of an initial condensate of titanium alkoxide (A-10: manufactured by Nippon Soda Co., Ltd.), 10 parts by weight of a chicknate coupling agent (Chikukoat S-581: manufactured by Nippon Soda Co., Ltd.), and 100 parts by weight of isoprobanol. and 10 parts by weight of PPS resin powder having a particle size of 90 μm or less (Rydon V-1: manufactured by Phillips Veterolium) were mixed uniformly to obtain a primer composition. Other than that, the same procedure as in Example 1 was carried out.

Upper U special ↓ The same procedure as in Example 1 was carried out except that the primer composition was not applied.

15±l In Example 1, a titanate coupling agent (Plenact KR44: manufactured by Ajinomoto Co., Ltd.) was added to the primer composition.
The same procedure as in Example 1 was carried out except that .

Comparison Example 1 The same procedure as in Example 5 was carried out except that the titanate coupling agent (Plenac 1 to KR44: manufactured by Ajinomoto Co., Ltd.) was not blended into the primer composition.

Example 6 was carried out in the same manner as in Example 6, except that a titanate coupling agent (Plenac I-KR44: manufactured by Ajinomoto Co., Ltd.) was not blended into the primer composition.

Comparison 1 In Example 8, a titanate coupling agent (Chikucoat 5-58, manufactured by Nippon Soda Co., Ltd.) was added to the primer composition.
The same procedure as in Example 8 was carried out except that .

(Margins below) Table 1 (Effects of the Invention) As mentioned above, the primer composition of the present invention consists of a metal titanium alkoxide or its initial condensate and a titanate coupling agent, or it further includes PPS resin powder. If you use these primer compositions and coat the metal surface with PPS resin, it will have excellent heat resistance.
A resin-coated metal body having excellent adhesion between the coated PPS resin and the metal body, and particularly excellent hot water resistance and corrosion resistance, can be obtained.

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)

[Claims] 1. An alkoxide of metallic titanium or an initial condensate thereof;
A primer composition comprising a titanate coupling agent. 2. Metallic titanium alkoxide or its initial condensate;
A primer composition comprising a titanate coupling agent and polyphenylene sulfide resin powder. 3. A metal body coated with a polyphenylene sulfide resin, wherein a primer layer made of the primer composition according to claim 1 or 2 is formed on the surface of the metal body, and a polyphenylene sulfide resin is coated thereon.