JPH0196261A - Coated metallic material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a coated metal body coated with a resin composition, particularly to a coated metal body having excellent hot water resistance and chemical resistance.

(Prior Art) Coated metal bodies whose surfaces are coated with resin compositions are manufactured for the purpose of preventing rust and improving hot water resistance and chemical resistance of various metal products. As a resin used for such a coated metal body.

For example, polyphenylene sulfide can be mentioned.

Polyphenylene sulfide is an aromatic linear crystalline polymer compound with a Tg of about 95°C and is heat resistant.

Excellent water and chemical resistance. It also has excellent mechanical properties. Therefore, this resin is considered to be advantageously used, for example, for coating the inner walls of clean pipes and plant piping. but.

For example, when the surface of the coating layer comes into contact with a chemical solution such as hot water or an acid, it is necessary to increase the crystallinity of the resin. When the degree of crystallinity is increased, residual stress is generated due to crystallization shrinkage, which tends to cause peeling and cracking of the coating layer. Even if a crystallization step is not provided in the manufacturing process of the metal coating, crystallization may proceed naturally depending on the usage conditions (for example, when used at a temperature of 100°C or higher), and the coating layer This may cause peeling or cracking.

On the other hand, as resins having heat resistance and corrosion resistance, polyarylsulfones (for example, polyethersulfones (P
ES), Tg approximately 225°C; polysulfone (PSF
).

Tg approximately 190°C). Polyarylsulfone is chemically stable in the temperature range from room temperature to the glass transition point, and has excellent mechanical properties such as abrasion resistance and impact resistance. Furthermore, since it is a non-grade polymer, it has the advantage that when used as a coating material, no internal residual stress is generated due to crystallization of the coating layer. However, since polyarylsulfone has relatively high water absorption, infiltration of water and chemical solutions is unavoidable.

The disadvantage is that the coating layer is prone to blistering and peeling.

JP-A-54-34335 discloses a powder coating method using an aromatic polyethersulfone resin. In this method, the resin coating layer is treated at a predetermined temperature and then baked, thereby improving the adhesion of the resin to the base material. Therefore, blistering and peeling are relatively less likely to occur. but.

Aromatic polyether sulfone is woody and has water-absorbing properties, so it is inadequate for applications where it comes into contact with high-temperature steam or acids.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and its purpose is to provide a coated metal body with excellent hot water resistance and chemical resistance. .

(Means for Solving the Problems) The coated metal body of the present invention is a coated metal body in which a metal base material subjected to an undercoat treatment or a thermal spray treatment is coated with a resin composition containing polyphenylene sulfide and polyaryl sulfone. As a base material used in the coated metal body of the present invention, the above object is achieved.

Single metals such as iron and aluminum, or various alloys such as stainless steel are used. The shapes of these base materials are not particularly limited. Flat, tubular.

Various shapes such as irregular shapes are used.

The polyphenylene sulfide (PPS) contained in the resin composition used in the coated metal body of the present invention is as follows.

It is a compound composed of repeating units represented by the following formula (I): An example of such a compound is Rydon P-6 manufactured by Philips. This compound has a melting point (
Tm) is 280°C, glass transition point (Tg) is approximately 95°
It is a crystalline polymer compound of C.

On the other hand, the polyarylsulfone contained in the resin composition is a polyarylene compound containing an arylene repeating unit having both an ether bond and a sulfone bond. Examples include compounds mainly composed of repeating units represented by any of the following formulas (II) to [X■].

+CJ40 C6H45oz-3-(U)-(-C
hH,-0-C,l+,-5o□-C611,-C,O
,-3O□← [■]-(-5Oz C&+1
4 0-Ci, IL S(h C61+4 CH
2CbHs + (Vl)CH3 ■ I-cbHa CCJn OC6H45o2C6H
40→ [■]C8゜CH3 +OC61+4 CC61140CJL So□
-C6H4-)-CbIIs
(■]-(-0-C6H50C611
4-302C6H4÷ (X) (70-C6
1+4 CC61140CbHa SO□-C6)
+4-)-(XI)÷o -C,H4-C-C6H4-
0-C,,H,-SO□-C6114+ (X II
)C, +15 +-OC6tla OC6114-OC6114SO
2CbHa+(XI[[)-(-0-CbHa SO
□-CbHa OC6H4Cc6na-)-(XTV
)4-o-so□-C6114C6++4 SO□-
C611,-0-C611,-0-■ CH.

-(-C,11,-SO□-CbHa OC6Ha
So□-C6H,-0-C,H4-+CJ4-SOz
C6++4 0 C6H4SO2CbHa +
(X■) (hereinafter blank) Among the above formulas, polyarylsulfone mainly composed of repeating units represented by formula (II), (I [[) or [■]) has various properties such as heat resistance, strength, rigidity, etc. It is preferable because it has excellent physical properties and good processability and provides a uniform coating layer.Polyarylsulfone having a reduced viscosity in the range of 0.3 to 0.6 is more preferable.Here, 5M element The viscosity was measured at 25°C by dissolving 1.0 g of polyarylsulfone in 100 mf of dimethylformamide.

Among the compounds mainly composed of repeating units represented by formulas (II) to [X■] above, a general-purpose compound is polyether sulfone (PES), which is composed only of repeating units of formula (n). , and polysulfone (PSF) composed only of repeating units of formula [■]. As for PES.

For example, Victrex PIES 5 manufactured by IC1
003P (Tm, 325"C; Tg, approximately 225°C
). As for PSF.

For example, needle polysulfone (Tm, 300°C, Tg, about 190°C) manufactured by Union Carbide Co., Ltd. is exemplified.

The polyphenylene sulfide and the polyaryl sulfone have a ratio of 10:90 to 90:10. Preferably 3
They are mixed at a weight ratio of 0:70 to 70:30.

If polyphenylene sulfide is in excess, the resin coating layer tends to crack or peel due to shrinkage due to crystallization. On the other hand, if polyarylsulfone is present in excess, the water absorption of the coating layer will increase.

Blisters are more likely to occur.

The resin composition may contain an inorganic filler if necessary. This inorganic filler increases the thermal conductivity and elastic modulus of the coating layer. Furthermore, it also has the effect of reducing residual stress inside the coating layer.

Therefore, the inorganic filler increases the strength of the coating layer and prevents the occurrence of cranks in the coating layer due to shrinkage due to crystallization.

As an inorganic filler, it has excellent water resistance and chemical resistance.

A material that is stable even at high temperatures of 400°C is used. Examples include metal oxides, glass, carbon, and ceramics. Metal oxides include alumina, iron oxide, titanium oxide, and zirconium oxide.

Examples include chromium oxide and nickel oxide. 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. It is preferable that these fillers are contained in the form of fibrous particles or flake-like fine powder.

The amount of inorganic filler in the composition is 40% by weight or less, preferably 1
It is contained in a range of 0 to 30% by weight. When the weight exceeds 40 weight, the bonding force of the coating layer with the resin component is inhibited, and thus the adhesion of the coating layer to the metal body decreases.

In the present invention, the surface treatment of the metal base is performed by, for example, one method.

This is done by undercoating using an undercoat composition or thermal spraying by thermally spraying a thermal spraying material onto a metal base material. As the undercoat composition, a composition containing a thermosetting resin and an inorganic filler, or a composition containing an inorganic binder and an inorganic filler is used. Examples of thermosetting resins include imide resins, epoxy resins, phenol resins, and amide-imide resins.

There is furan resin. In particular, imide resins are preferred because they have excellent heat resistance. One example is imide resin.

Prepolymer containing bismaleimide and diamine as polymerization components; Contains a prepolymer of polyfunctional cyanate ester or polyfunctional cyanate ester and amine, and a prepolymer of bismaleimide or bismaleimide and amine. Resin composition; polyfunctional amine, polyanhydride.

Examples include imide prepolymers containing nadic anhydride as polymerization components; resin compositions containing resins containing bismaleimide and alkenylphenol as polymerization components. When a thermosetting resin is used, a network structure is formed by baking after applying the undercoat composition.

Adhesion between the resin composition layer and the metal base material, which will be described later, is improved.

The adhesive strength of the thermosetting resin also provides good adhesion between the metal base material and the undercoat layer.

The inorganic filler contained in the undercoat composition has a function of preventing peeling and cracking of the undercoat layer formed by the undercoat composition. Such inorganic fillers include, for example, metals, metal oxides, and glasses.

Examples include carbon, ceramics, and inorganic crystals.

Examples of metals include aluminum, zinc, nickel alloy, stainless steel, and cast iron. metal oxide.

As the glass and ceramics, any of the materials used in the resin composition can be used.

All metals, metal oxides, glass, carbon, and ceramics are preferably in the form of fine powder.

The average particle size is adjusted to 1 to 100 μm, preferably 5 to 30 μm. This inorganic filler is added in an amount of 10 to 800 parts by weight, preferably 25 to 400 parts by weight, per 100 parts by weight of the resin used in the undercoat composition. 10
If the amount is less than parts by weight, the effect of adding the inorganic filler cannot be obtained. If it exceeds 800 parts by weight, the bonding strength of the thermosetting resin will decrease, and the adhesion between the resin coating layer and the metal base material will deteriorate.

Inorganic binders contained in the undercoat composition include lithium polysilicate, amine silicate, alkyl silicate, silicon dioxide colloid, and the like.

When thermal spraying is performed as a base treatment for metal substrates,
The thermal spraying material used in the thermal spraying process is as follows.

Metals, ceramics, etc. are used. In particular, it is preferable to use metal in order to improve the adhesion between the resin coating layer and the metal base material. Metals used as thermal spray materials include nickel alloys, stainless steel, and cast iron.

These include aluminum and zinc. Formation of sprayed layer.

It is done by arc spraying or plasma spraying.

When producing the coated metal body of the present invention, the metal base material to be coated is first subjected to appropriate pretreatment such as sandblasting degreasing and chemical conversion treatment as necessary.

Next, surface treatment is performed. When performing an undercoat treatment as a base treatment, apply the above undercoat composition (
(containing an appropriate solvent if necessary) is applied, heated and baked to form an undercoat layer. The thickness of the undercoat layer is in the range of 5 to 100 μm, preferably 10 to 30 μm. If it is less than 5 μm, the undercoat layer will not be formed uniformly, and pinholes and cracks will likely occur. 100μ
When it exceeds m, the adhesion between the undercoat layer and the metal decreases. When thermal spraying is performed, a thermal spray layer is formed by arc spraying or plasma spraying, for example, the above-mentioned metal for thermal spraying on the surface of a metal base material. The layer thickness of the sprayed layer is 20
The thickness is adjusted to ~200 μm, preferably 30 to 80 μm.

A coating layer made of a resin composition containing the polyphenylene sulfide, polyaryl sulfone, and optionally the inorganic filler is formed on the surface of the metal body that has been subjected to the base treatment as described above.

This coating layer is formed by, for example, making the above-mentioned composition into a suspension using an appropriate solvent, or coating it in powder form on the surface of a metal body that has been subjected to surface treatment, and then baking it at, for example, around 400°C. be done. The thickness of the coating layer is 50 to 20
00 μm, preferably in the range of 250 to 2000 μm. If it is less than 50 μm, the coating layer will not be formed uniformly and pinholes and cracks will easily occur. 2000μ
If it exceeds m, it takes a long time for baking, etc., and bubbling occurs, making it impossible to obtain a dense resin coating layer.

A metal body on which a coating layer of the resin composition is formed.

After cooling or quenching, the coating layer is crystallized by heat treatment at an appropriate temperature (for example, 200° C.), if necessary. Chemical resistance due to crystallization.

Improves hot water resistance, etc.

According to the present invention, a coated metal body in which a coating layer made of a composition containing the polyphenylene sulfide and polyaryl sulfone is formed is thus obtained. Polyphenylene sulfide is heat resistant.

Corrosion Resistance 1 Excellent mechanical properties and moldability, and polyarylsulfone has excellent chemical stability, abrasion resistance, and impact resistance. The coating layer of the coated metal body of the present invention has both of these characteristics.

For example, there is almost no peeling or cracking due to crystallization, which is a disadvantage of polyphenylene sulfide. and.

Since the water absorption caused by polyarylsulfone is reduced, there is almost no blistering or peeling caused by infiltration of hot water or chemical solutions. Furthermore, when the coating layer contains a material, the thermal conductivity of the coating layer increases. Generally, the greater the temperature difference between the surface of the coating layer and the portion where the coating layer contacts the metal body that is the substrate, the easier it is for hot water or chemical solutions (acids, etc.) to penetrate into the coating layer. Therefore, if the thermal conductivity of the coating layer is high, it becomes very difficult for hot water or chemical solutions to penetrate and diffuse into the coating layer. Furthermore, the filler increases the elastic modulus of the coating layer. Therefore, even if moisture or a chemical solution were to enter the coating layer, lifting of the coating layer from the substrate by the moisture or chemical solution, that is, the occurrence of blisters, is suppressed. In this way, a metal body coated with a resin composition is obtained which does not cause cranking or peeling, and furthermore, the infiltration of hot water and chemicals is suppressed, and almost no blistering occurs.

(Example) Examples of the present invention will be described below.

(A) Formation of base treatment layer: 3,3",4,4"-benzophenonetetracarboxylic acid (anhydride) 3.222g,
3゜3''-diaminodiphenylsulfone 3.725
g and 1.642 g of 5-norbornene-2,3-dicarboxylic acid (anhydride) were dissolved in 30 g of N-methyl-2-pyrrolidone dried with molecular sieves. This solution was stirred at room temperature for 6 hours to carry out 9 reactions. To this solution, 25.8 g of 5US304 stainless steel powder (average particle size: 40 μm or less) was added as an inorganic filler and mixed uniformly to prepare an undercoat composition.

A 100n+m x 100mm x 3mm iron plate was grid blasted and then cleaned by blowing compressed air.

The above-mentioned undercoat composition was applied with a brush to one side of this iron plate, and the coated surface was dried at 250° C. for 30 minutes to complete the baking process. The average layer thickness of the obtained undercoat layer was 25 μm.

(B) Formation of coating layer: Approximately 10 to 20
80 g of polyphenylene sulfide (Rydon P-6, manufactured by Phillips) micronized to μm, and polyether sulfone (Victrex PES 5003P, IC) micronized in the same way as polyarylsulfone.
(manufactured by one company) 80 g, and glass fiber powder (diameter 9 μm, length approximately 15-100 am) as an inorganic filler 4
A resin composition was prepared by mixing 0 g of powder. The iron plate on which the undercoat layer obtained in section (A) was formed was further heated for 40"
After baking at C for 30 minutes, this resin composition was powder-coated in four parts at an electrostatic voltage of 60 kV using an electrostatic powder coating method. Each step included a 5 minute flowout at 400°C. After the iron plate coated and baked with the resin composition is placed in water and rapidly cooled.

Further, heat treatment was performed at 200°C for 1 hour. The resulting resin coating layer had an average thickness of 500 μm.

(C) Performance evaluation of coated metal body: Performance evaluation of the coated iron plate obtained in section (B) was performed using the following test method.

The respective results are shown in the table below. The results of Examples 2 to 10 and Comparative Examples 1 to 4 are also shown in the table below.

(1) Peeling Test After cutting the resin coating layer of the coated metal body into the metal body in the shape of base lines at 1 mm intervals using a knife, the state of the resin coating layer was observed.

(2) Steam test The coated metal body is exposed to steam at 120°C in an autoclave.
After 00 hours of exposure, the state of the resin coating layer was observed.

In the table below, the numbers in the steam test results section indicate the degree of blistering that occurs in the resin coating layer. The area where blisters were generated was measured and expressed as a percentage.

"100%" indicates a state in which the coating film (coating layer and undercoat layer) is completely lifted off the base material due to blistering.

The procedure was the same as in Example 1 except that the weight of polyphenylene sulfide (PPs) was 100 g, and the weight of polyether sulfone (PES) was 60 g.

1 kg of actual coal-based polyphenylene sulfide and 1 kg of polyether sulfone (PES) were mixed into 400 kg by a kneader.
The mixture was melt-kneaded at °C and pelletized. The obtained pellets were freeze-pulverized to form a fine powder of about 10 to 20 μm. The procedure was the same as in Example 1, except that 40 g of glass fiber powder (about 9 pm in diameter, about 15 to 1100 zz in length) was pulverized and mixed as an inorganic filler to prepare a resin composition.

KERIMID 601
, manufactured by Rhone-Poulenc) was dissolved in 15 g of N-methyl-2-pyrrolidone. To this solution, 15 g of S[JS304 stainless steel powder similar to that in Example 1 was added and mixed uniformly to obtain an undercoat composition. The procedure was the same as in Example 1 except that this undercoat composition was used.

Example 1 is the same as Example 1 except that the inorganic filler (glass fiber powder) in the resin coating layer is not used.

Carbon fiber powder (approximately 7 mm in diameter) was used as an inorganic filler for the resin coating layer.
．． It is the same as Example 1 except that 30 g of 5 μm and length of about 20 to 100 μm (111) was used.

Freeze-pulverized polysulfone (PSF) (needle polysulfone, manufactured by Union Carbide) was used as the polyaryl sulfone, and the resin coating layer was baked at 170°C after painting. The rest is the same as in Example 1.

As the resin contained in the undercoat layer, an ethyl silicate condensate was prepared by the following method. first.

Ethyl silicate I40 (ethyl silicate monomer 5
Condensation product of molecules, content calculated as SiO□ is 40
100 parts by weight) and 40 parts by weight of ethyl alcohol were placed in a glass reactor, and while stirring and stirring, IN
1 part by weight of hydrochloric acid and 9 parts by weight of water were continuously added dropwise over 2 hours. After the completion of the addition, stirring was continued for 3 hours, and then 20
After standing for a while, an ethyl silicate condensate solution was obtained. This ethylsilicate condensate solution contained 50% by weight of ethylsilicate condensate.

The procedure was the same as in Example 1 except that the following formulation was blended and mixed to obtain an undercoat composition.

Ethyl silicate condensate solution 15 parts by weight Aluminum powder (particle size 40 μm or less) 30 parts by weight Butyl cellosolve 5 parts by weight A sprayed metal layer was formed by arc spraying 5US306 stainless steel onto a steel plate. The layer thickness of the sprayed metal layer was fairly uniform and approximately 50-60 μm.

Other than forming a coating layer on the surface of this base treatment layer,
This is the same as in Example 1.

Implementation ± polyphenylene sulfide (PPS) 4 in dish basecoat composition
．． 3g, polyether sulfone (PES) 4.3g
, and 10 g of N-methyl-2-pyrrolidone were added.

Shangbian coal soil Does not use polyphenylene sulfide (PPS).

The process was the same as the example except that the weight of polyether sulfone (PES) was 160 g.

Comparison I Except that no polyaryl sulfone was used and the weight of polyphenylene sulfide was 160 g.

This is the same as in Example 1.

It is suitable for use without using polyphenylene sulfide and with polysulfone (
except that the weight of PSF) was 160 g.

This is the same as in Example 1.

This is the same as in Example 1, except that instead of the dark soil undercoating treatment, a chemical conversion treatment using phosphoric acid was applied to the metal base material.

From Table 1, it can be seen that the adhesion between the coated metal body coating layer obtained by the method of the present invention and the metal base material is good, and the coating layer does not peel off, blister, or crack due to hot water or steam. Steam Although slight blisters or peeling occurred in some areas during the test, the water resistance under high temperatures was sufficiently satisfactory. On the other hand, the coating layer is formed on a coated metal body in which a coating layer is formed on a metal base material that has been subjected to chemical conversion treatment with phosphoric acid as a base treatment, or on a resin composition using polyphenylene sulfide or polyaryl sulfone alone. It is clear that in coated metal bodies, hot water or steam tends to cause peeling of the coating layer, blistering, and cracking of the coating film.

(Effects of the Invention) According to the present invention, a coating layer is formed using a resin composition containing a polyphenylene sulfide resin and a polyaryl sulfone resin on the surface of a metal substrate that has been subjected to an undercoating treatment or a thermal spraying treatment. Therefore, a coated metal body with excellent coating properties can be obtained. This coated metal body is prone to peeling and cracking of the coating layer.

It also prevents the coating from cracking and has excellent resistance to hot water and chemicals. Such coated metal bodies are used in various applications such as coating the inner walls of pipes that transport acids and acid-containing vapors in areas exposed to heat and chemical solutions at high temperatures in chemical plants and equipment for the chemical and food industries. It is suitably used for.

that's all

Claims (1)

[Scope of Claims] 1. A coated metal body in which a metal base material subjected to undercoating treatment or thermal spraying treatment is coated with a resin composition containing polyphenylene sulfide and polyaryl sulfone. 2. The resin composition contains the polyphenylene sulfide and the polyaryl sulfone in a ratio of 10:90 to 90:10.
The coated metal body according to claim 1, which contains the coated metal body in a weight ratio of . 3. The coated metal body according to claim 1, wherein the resin composition contains an inorganic filler. 4. Claim 1, wherein the undercoating treatment is performed using an undercoat composition containing a thermosetting resin and an inorganic filler, or an undercoat composition containing an inorganic binder and an inorganic filler. The coated metal body described in . 5. The undercoat composition contains a thermosetting resin, an inorganic filler,
The coated metal body according to claim 4, which contains polyphenylene sulfide and polyaryl sulfone.