JPH0486254A - Resin coated metallic body - Google Patents

Abstract

PURPOSE:To manufacture a resin coated metallic body of superior resistance to hot water and resistance to corrosion by forming a primer layer of a primer composition composed of metallic alcoxide or its precondensate body on a metallic body surface, over which a specified thermoplastic resin such as nylon is applied for coating. CONSTITUTION:A primer composition composed of metallic alcoxide or its precondensate is applied to a metallic body surface such as iron or aluminum. Then, baking is performed and the metallic alcoxide or its precondensate is crosslinking cured to form a heat-resistant primer layer. The baking temperature of the primer composition is usually l00 deg.C or over and the thickness of the primer layer is in the range of 5-100mum. Then, at least one kind of thermoplastic resin selected out of nylon, polyphenylene oxide, polysulfone, polyether sulfone, polyether ketone, polyether imide and the like is applied on the primer layer formed on the metallic body surface for coating. As for the coating method, the electrostatic powder coating method using said resin powder is suitable, and baking is performed on the coated surface after powder coating, and resin is melt cured to form a resin coated layer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resin-coated metal body particularly excellent in hot water resistance and corrosion resistance.

(Conventional technology) Nylon, polyphenylene oxide, polysulfone,
polyether sulfone, polyether ether ketone,
Polyetherimide is a thermoplastic resin that has excellent heat resistance, chemical resistance, water resistance, mechanical strength, etc., and also has good melt processability. Therefore, it is expected that by coating the surface of a metal body with this resin, a resin-coated metal body particularly excellent in hot water resistance and corrosion resistance can be obtained.

However, when such a resin is used as a coating material for a metal body, its adhesion to the metal body is poor. In order to improve the adhesion to the metal body and the corrosion resistance, a method of chemically treating the surface of the metal body with zinc phosphate or the like is generally used.

(Problems to be Solved by the Invention) However, in this method, the chemical conversion treated layer lacks heat resistance. Therefore, when coating the surface of a metal body that has undergone chemical conversion treatment with the above-mentioned thermoplastic resin, which has a relatively high heating temperature during baking, the chemical conversion treatment layer deteriorates due to this heating, and the adhesion with the metal body is substantially reduced. does not improve.

Therefore, if such a resin-coated metal body is used for a long period of time, especially under hot water, a large number of blisters (
There are problems such as blistering (blister) and peeling.

The present invention is intended to solve these problems, and its purpose is to provide a resin-coated metal body that has excellent adhesion between the resin coating layer and the metal body, and has excellent hot water resistance and corrosion resistance. There is a particular thing.

(Means for Solving the Problems) The PPS resin-coated metal body of the present invention has a primer layer formed on the surface of the metal body using a primer composition made of a metal alkoxide or an initial condensate thereof, and a primer layer made of a primer composition made of a metal alkoxide or an initial condensate thereof, and a layer of nylon, polyphenylene oxide, etc. , polysulfone, polyethersulfone, polyetheretherketone, and polyetherimide, and is coated with at least one thermoplastic resin selected from polysulfone, polyethersulfone, polyetheretherketone, and polyetherimide, thereby achieving the above object.

In the present invention, in the primer composition comprising a metal alkoxide or an initial condensate thereof used to form a primer layer, the metal alkoxide has the general formula M (OR
') (OR”) (OR3) [(OR')] [(O
R5)]. Here, gate represents a trivalent to pentavalent metal, and includes Ti, Zr, Ga, In, Si, and G.
A metal selected from e, Sn, and Nb is preferable, and R1,
RZ, R3, R4, and R5 represent the same or different alkyl groups, and preferably have 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 metal alkoxide also includes a metal matrix.

Specific examples of such metal alkoxides include Δl (O
CH3)3, Al(OC2H5)3, 8l (is
o-QC,,R7)3,Ga(OCH3)3,Ga
(OCzt15) 3, Ga (OC3117) 3,
Ge (OCtls) 3, Ge (OCzHs) 4
, ce (oc3H7) 4, In (OCI+3) 3
, In(OCzHs) 3, In(iso-OC3t
17) 3, Nb(OCI+,)S, Nb(OCzHs
) s, Nb (OC311?) s, Si (OCI
(3) a, Si (OCzHs) 4.5i(is
o-OCsTo), CH30(Si(OCL)zO)
4CL, Ti (OCH3) 4, Ti (OCzHs
) 4, Ti (OC3117) 4, C3H90 (T
i (OC3117) zo) l 0C3H7, CJq
O(Ti(OCI7)zO)+oC411q,5n(O
CH+)4.5n(OCzHs)4, Sn(iso-
OC3t17) 4, Zr (OCHs”) 4, Zr
(OC2115) 4, Zr (OC3H7) 4, and the like.

Further, the initial condensate of metal alkoxide can be obtained by partially hydrolyzing and polycondensing the above metal alkoxide. The degree of polycondensation (n) is generally 10 or less.

The above-mentioned metal alkoxides or initial condensates thereof can be used not only alone, but also as a mixture of two or more kinds. A primer composition composed of such a metal alkoxide or its initial condensate can be used as it is if it is in liquid form, but it is generally used by dissolving the metal alkoxide or its initial condensate in a suitable organic solvent.

As the organic solvent, methanol, ethanol, isopropanol, butanol, hexane, benzene, toluene, xylene, etc. are used.

Incidentally, in order to further improve the adhesion, an inorganic filler may be added to the above-mentioned primer composition forming the primer layer, if necessary. The inorganic filler is fibrous,
It is preferably contained in the form of granular or flake-like fine powder, with an average particle size of 1 to 100 μm, preferably 5 to 3 μm.
Adjusted to 0 μm. 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.

In the present invention, first, a primer composition consisting of a metal alkoxide or an initial condensate thereof is applied to the surface (surface or inner surface) of a metal body such as iron, aluminum, stainless steel, various alloys, etc. Next, baking is performed, and the metal alkoxide or its initial condensate is crosslinked and hardened by moisture in the air, forming a heat-resistant primer layer.

The metal body is previously subjected to appropriate pretreatment such as sandblasting, degreasing, and pickling. The baking temperature of the primer composition is usually 100°C or higher, preferably 200 to 400°C.
It is. The thickness of the primer layer is in the range of 5 to 100 μm, preferably 10 to 30 μm. If it is less than 5 μm, the primer layer will not be formed uniformly, and pinholes and cracks will easily occur. On the other hand, if the thickness exceeds 100 μm, the adhesion between the primer layer and the metal body may deteriorate.

Next, the primer layer formed on the surface of the metal body is coated with at least one thermoplastic resin selected from nylon, polyphenylene oxide, polysulfone, polyethersulfone, polyetheretherketone, and polyetherimide. As the coating method, an electrostatic powder coating method using these resin powders is suitably employed. Other methods such as sheet pressure bonding method and melt extrusion method can also be adopted.

After powder coating, the painted surface is baked to melt and harden the resin, forming a resin coating layer.

The baking temperature varies depending on the type of thermoplastic resin being coated. 200-250°C for nylon, 300-400°C for polyphenylene oxide, 300-400°C for polysulfone, 380°C for polyethersulfone.
~420”C, 380 for polyetheretherketone
~420°C, 300-400 for polyetherimide
°C is preferred.

The thickness of the resin coating layer is generally in the range of 50 to 200011 m, preferably 250 to 1000 m. 50μm
If it is lower than that, the resin coating layer will not be formed uniformly, and pinholes and cranks are likely to occur. On the other hand, if the thickness exceeds 2000 μm, it takes time for baking, etc., and foaming occurs, making it impossible to obtain a dense resin coating layer. After baking, annealing treatment or rapid cooling may be performed.

Note that the thermoplastic resin for coating may contain a metal alkoxide or an initial condensate thereof used in the primer composition. When such a metal alkoxide or its initial condensate is blended, adhesion with the primer is improved, rigidity is imparted to the resin coating layer, and deterioration resistance is also improved.

(Function) A primer layer formed from a primer composition made of a metal alkoxide or an initial condensate thereof has excellent heat resistance and hot water resistance due to crosslinking and curing, and also has excellent adhesion to the surface of a metal body. Moreover, it adheres well to a coating layer of at least one thermoplastic resin selected from nylon, polyphenylene oxide, polysulfone, polyethersulfone, polyetheretherketone, and polyetherimide.

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

Scrap■↓ Initial condensate of metal alkoxide (B-10: manufactured by Nippon Soda Co., Ltd.) (10-molecule condensate of tetrabutyl titanate-1)
r C4H90(Ti(OC4H9)0) + o
A 60% by weight isopropanol solution of c4Hq J was used as a primer composition.

After grid blasting a 100mm x 100mm x 3mm thick iron plate, it was cleaned by blowing compressed air, the primer composition was applied to one side of the iron plate with a brush, and it was heated at 380″C for 30 minutes. After drying and baking, the resulting primer layer had an average thickness of 30 μm.

Next, on this primer layer, polyetheretherketone powder (PEIEK) with a particle size of 100 μm or less (15
0PF (manufactured by IC1) was electrostatically powder coated, then baked at 380° C. for 30 minutes, and then put into water and rapidly cooled to obtain a resin-coated iron plate. The thickness of the obtained coating layer is
It was about 700 um.

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

(1) Normal adhesion test Make a 1 cm cut in the coating film of a 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). 10 nun
/ ] minutes in a 90 degree direction to measure the peel strength. Note that the * mark in the table indicates that the resin coating layer was broken.

(2) Hot water adhesion test Resin-coated iron plate is heated at 95°C on the coating layer side and 75°C on the iron plate side.
After soaking in hot water of C for 100 hours, make a 1 cm wide cut in the coating film with a sharp knife so that the cut reaches the iron plate, peel off one end, and leave it at room temperature (23°C). The peel strength was measured by pulling in a 90 degree direction at a peel rate of 10 mm/min.

(3) Hot water resistance test Resin-coated iron plate is heated at 95°C on the coating layer side and 75°C on the iron plate side.
After being immersed in hot water of C for 100 hours, the occurrence of blisters on the coating layer side was expressed as the area ratio where blisters were generated.

Punishment M↓ Initial condensate of metal alkoxide (zirconium butyrate 2 manufactured by Nippon Soda Co., Ltd.) 'Zr (OCal19) 4
A 60% by weight solution of isopropanol was used as a primer composition. Other than that, the same procedure as in Example 1 was carried out.

Actual creation 1-↓- Initial condensate of metal alkoxide (aluminum isopropyl 1: manufactured by Nippon Soda Co., Ltd.) 'Al(is.

A 60% by weight isofurobanol resin solution of 0CJ7) 3j was used as a primer composition. Other than that, Example 1
I did the same thing.

! IL! L Obium propylate (manufactured by Nippon Soda Co., Ltd.) 'Nb (QC: +H7) sJ 6 in the initial condensate of metal alkoxide
A 0% by weight isopropanol solution was used as a primer composition. Other than that, the same procedure as in Example 1 was carried out.

X, Plum - Example i Polyetheretherketone powder of Example 1 (PEI'
5l (), polyphenylene oxide (Pro) (
Noryl (manufactured by Japan GE Plastics Co., Ltd.) was used, and the baking conditions were changed to 300°C for 30 minutes. Other than that, the same procedure as in Example 1 was carried out.

Disaster Example-6- Polyetheretherketone powder (PIEE) of Example 1
K) with polyether sulfone (
PES) (5003P: manufactured by ICI). Other than that, the same procedure as in Example 1 was carried out.

Polyether ether ketone powder (PEER) of Example 1
) was replaced with polyetherimide (PEI) (Ultem: manufactured by Japan GE Plastics Co., Ltd.). Other than that, the same procedure as in Example 1 was carried out.

Copying l Polyetheretherketone powder (PEEK) of Example 1
) was replaced with polysulfone (PSF) (manufactured by Amoco Japan). Other than that, the same procedure as in Example 1 was carried out.

The baking conditions for the primer composition of Example 1 were set at 230"C.
The baking temperature was changed to 230°C for 60 minutes, the polyetheretherketone powder (PEEK) was changed to nylon 11 (ES: manufactured by Nippon Rilsan Co., Ltd.), and the baking conditions were changed to 230°C for 60 minutes. Other than that, the process was carried out in the same manner as in Example 1.

3(]b扼ノ1fil.

Nylon 11 (ES: manufactured by Nippon Rilsan Co., Ltd.) in Example 1 was replaced with filler-added grade nylon 11 (FP840: manufactured by Nippon Rilsan Co., Ltd.). Other than that, the same procedure as in Example 1 was carried out.

Comparative Edition 1 Example 1 was carried out in the same manner as in Example 1, except that the primer composition was not applied.

Comparative Example 5 was carried out in the same manner as in Example 5, except that no primer composition was applied.

1 Comparison side l The same procedure as in Example 6 was carried out except that the primer composition was not applied.

The same procedure as in Example 7 was performed except that the primer composition was not applied.

Example 8 was carried out in the same manner as in Example 8, except that the primer composition was not applied.

Northern Comparative Example The same procedure as in Example 9 was carried out except that the primer composition was not applied.

■" Example 10 was carried out in the same manner as in Example 10, except that the primer composition was not applied.

(Blanks below) (Effects of the Invention) As described above, the resin-coated metal body of the present invention has a primer layer formed on the surface of the metal body using a primer composition made of a metal alkoxide or an initial condensate thereof, and a primer layer made of nylon, polyphenylene It is coated with at least one type of thermoplastic resin selected from oxide, polysulfone, polyethersulfone, polyetheretherketone, and polyetherimide, and this structure has excellent heat resistance, and the coated resin and metal A resin-coated metal body having excellent adhesion to the body and particularly excellent hot water resistance and corrosion resistance can be obtained.

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

Claims (1)

[Claims] 1. A primer layer made of a primer composition made of metal alkoxide or its initial condensate is formed on the surface of the metal body, and on top of that, nylon, polyphenylene oxide,
A resin-coated metal body characterized by being coated with at least one thermoplastic resin selected from polysulfone, polyethersulfone, polyetheretherketone, and polyetherimide.