JP3007222U - Steel material with low temperature spray coating - Google Patents

Abstract

(57) [Summary] [Purpose] The drawbacks of conventional arc-type or gas-type thermal spray coatings were solved, and even if the conventional thermal spray coating was present, the rust of the iron base material was generated from the pinholes. Prevented,
A steel material having a low temperature sprayed coating is provided. [Structure] An iron material 1 and a low temperature sprayed coating 2 of a metal or its alloy which is sprayed on the surface and has a greater ionization tendency than iron.
And the amount of adhesion applied to this surface after drying is 10 to 5
And silane coupling agent coating 3 of 30,000 mg / m ² .

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steel material having a low temperature sprayed coating, in which a coating for protecting the metal sprayed coating is formed on the metal sprayed coating.

[0002]

[Prior art]

 It has long been known that the surface of iron is electrochemically protected by coating the surface of iron with a metal having a greater ionization tendency than iron or an alloy thereof. For example, by coating the surface of steel material with zinc or its alloy, the potential difference between iron and zinc is used to protect the steel by using zinc as a sacrificial anode. One of the methods for coating the surface of steel with zinc or its alloy is a metal spraying method. In this metal spraying, a linear or powdered coating material is melted and sprayed at a high speed to form a coating film of fine particles laminated on the surface of the base material. Conventionally, a heat source for melting the material is used. , Gas type, arc type, plasma type, explosion type, etc. For general rust prevention, arc type or gas type using wire was used.

In any of the thermal spraying methods, a coating obtained from a metal that is baser than iron, such as zinc or its alloy, serves as a sacrificial anode for iron and protects the iron surface. However, since zinc or its alloy, in particular, serves as a sacrificial anode, it corrodes before iron, resulting in white rust on the surface, which is very aesthetically unsightly. Generally, the life of steel is considered to be proportional to the film thickness of the coated zinc or zinc alloy coating, but in reality, the thermal spray coating has severe irregularities and has air permeability (pinholes), so Even if it exists, red rust of iron base material is generated from the pinhole part. Much research has been done to solve these problems. For example, after spraying, a method has been proposed in which epoxy resin, phenolic resin, silicone resin paint, etc. are diluted with thinner and painted, and the pores are sealed (Jundo Hasui, Yokendo Publishing: "Spraying Engineering").

In addition, it is known to perform chromate treatment on the thermal spray coating (Japanese Patent Publication No. 62-35831).

[0005]

[Problems to be solved by the device]

 However, in arc-type or gas-type thermal spraying using wire rods that have been generally used for rust prevention, molten metal particles adhere at high temperature, so thin steel plates and their molded products are deformed by strain. Could occur. Further, there are problems such as a decrease in coating efficiency due to the diffusion of the metal held at a high temperature, a problem of fumes, and an oxidation of the metal due to a state of being exposed to a high temperature.

[0006] Furthermore, conventional epoxy resin, phenolic resin, and silicone resin coating films have the appearance that the pinholes are sealed and the thermal spraying is performed against the problem that the rust of the iron base material is generated from the pinholes even if the thermal sprayed coating is present. Although the coating seems to be uniformly coated, it has the drawback that the sealing effect rapidly diminishes over time because the coating is thin and the coating is not durable. Especially, there was a problem that white rust remarkably occurred in a short time.

Further, the chromate treatment on the thermal spray coating has a problem of safety and hygiene of chromium, and the corrosion resistance in a short time is excellent, but the durability is insufficient in a long time. Further, with respect to the chromate treatment, some effects were not observed unless baking was performed at a high temperature of 150 to 180 ° C.

The present invention has been made in view of the above circumstances, and is protected by a low temperature sprayed coating of a metal or its alloy having a greater ionization tendency than iron and a silane coupling agent coating applied to this surface. And a steel material having a low temperature sprayed coating.

[0009]

[Means for Solving the Problems]

The present invention is an iron material, a low temperature sprayed coating of a metal or its alloy that is sprayed on the surface of the iron material and has a greater ionization tendency than iron, and the amount of adhesion after drying is 10 to 50,000 mg. / M ² of silane coupling agent coating.

[0010]

[Action]

 The low temperature sprayed coating serves as a sacrificial iron anode and protects the surface of the steel material.

Further, the silane coupling agent coating prevents the generation of red rust from the pinhole portion of the low temperature sprayed coating and the generation of white rust from the low temperature sprayed coating itself.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is a steel plate (iron material), 2 is a low temperature spray coating of a metal or its alloy having a greater ionization tendency than iron, and 3 is a silane coupling agent coating. In addition to steel plates, 1 includes round steel, shaped steel and other shapes of steel materials. 2 is, for example, a zinc-aluminum alloy or a zinc-titanium alloy. The low-temperature spray coating of the present invention is a low pressure arc type, for example, one wire is a zinc wire, the other is an aluminum wire, and two wires are sprayed at the same time. However, if the formed alloy has a greater ionization tendency than iron, it is naturally included in the scope of the present invention. In this case, the ratio of the two kinds of metals can be arbitrarily changed by changing the thickness of the wire. Further, the silane coupling agent coating 3 of the present invention generally has the structural formula shown below,

[0013]

[Chemical 1]

Depending on the type of A, it is classified into vinyl type, methacrylic type, amine type, epoxy type, mercapto type and the like. Further, the alkoxy group represented by OR is hydrolyzed by water in an aqueous solution or in the air to form a silanol group, which brings the binding property to the material. Specific examples of the silane coupling agent include, for example, vinyl-based silane coupling agents such as vinyltriethoxysilane and vinyltris (2-methoxyethoxy) silane; methacryl-based silan couplings such as 3-methacryloxypropyltrimethoxysilane. Agents; amine-based silanes such as N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopromylmethyldimethoxysilane, and 3-aminopropyltriethoxysilane Coupling agent: Epoxy-based silane coupling agent such as 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; Mercapto-based agent such as 3-mercaptopropyltrimethoxysilane Silane coupling agent, etc. And the like.

In the present invention, it is natural that a commercially available silane coupling agent other than the above can be used. The silane coupling agent can be applied as it is or by diluting it with water or an organic solvent, but it is preferable to dilute and apply it in order to form a uniform film on the sprayed surface and to control the adhesion amount. The silane coupling agent has an adhesion amount after drying of 10 to 50,000 mg / m 2. ² , Preferably 100-1,000 mg / m²Is applied onto the surface of the sprayed coating by a usual coating method such as dipping, air spraying, brush coating.

When the adhesion amount of the silane coupling agent after drying is less than 10 mg / m ² , the convex surface of the sprayed coating surface is not completely covered, and white rust is generated from that portion, which is an object of the present invention. If the effect is difficult to obtain and if the amount of adhesion is more than 50,000 mg / m ^{2, the} inside of the silane coupling agent coating may peel off during processing, or the silanol groups produced by hydrolysis due to water may be insufficient. Therefore, the adhesiveness to the sprayed coating is lowered, and the effect of increasing the amount of adhesion and the economical efficiency cannot be balanced, which is not preferable. The steel material after applying the silane coupling agent may be left to dry at room temperature as it is, or may be forcedly dried at 80 to 180 ° C. for about 2 to 30 minutes.

The details of the present invention will be described below with reference to examples. "Part" or "%" means "part by weight" or "% by weight". Inventive Example 1 On a 10 cm × 10 cm sandblasted steel plate (surface roughness R _Z ≈40 μm), an arc-sprayed coating 50 μm of zinc was manufactured by a conventional method, and an amine-based silane coupling agent [N-2- ( Aminoethyl) -3-aminopropyltrimethoxysilane (trade name A-1120 manufactured by Nippon Unicar Co., Ltd.)] and a mixed solution of 97 parts of methyl alcohol. The above-mentioned sprayed steel plate was dipped and dried at room temperature. The amount of the amine-based silane coupling agent attached after drying was 150 mg / m ² . This steel sheet was subjected to a comparative test.

Inventive Example 2 On a 10 cm × 10 cm grit blasted steel plate (surface roughness R _Z ≈70 μm), a zinc-aluminum pseudo-alloy sprayed coating of 50 μm was prepared by reduced pressure internal arc spraying, and further vinyl-based silane. Coupling agent [vinyl-tris- (β-methoxy-ethoxy) silane (trade name A-172 manufactured by Nippon Unicar)] was sprayed as an undiluted solution and air-sprayed so that the adhesion amount after drying was 4500 mg / m ² for comparison. It was submitted to the test.

Inventive Example 3 A zinc-titanium alloy sprayed coating of 50 μm was formed on a 10 cm × 10 cm grit blasted steel plate (surface roughness R _Z ≈70 μm) by a reduced pressure arc spraying method. 1 part of a coupling agent [3-methacryloxy-propylmethoxysilane (trade name A-174 manufactured by Nippon Unicar Co., Ltd.)] and 99 parts of ethyl alcohol was taken out in a mixed solution after 1 minute and dried. The amount of the silane coupling agent attached after drying was 15,000 mg / m ² . This steel sheet was subjected to a comparative test.

Conventional Example 1 In Invention Example 1, the same treatment as in Invention Example 1 was performed except that the amount of the amine-based silane coupling agent attached after drying was 7 mg / m ² . This steel sheet was subjected to a comparative test.

Conventional Example 2 The same thermal spray coating as in Invention Example 3 was prepared, and the epoxy resin having the following formulation was diluted by 50% with a solvent without silane coupling treatment so that the dry film thickness was 20 to 30 μm. Air sprayed. This plate was subjected to the test. (Epoxy resin coating) A Main agent Epoxy resin 15 parts Xylol 25 Methyl isoptyl ketone 22.5 Titanium oxide 5 Calcium carbonate 7.5 B Hardener Polyamide resin 10 Xylol 10 Isobutanol 5 The epoxy resin is a shell science ( Trade name Epicoat # 1001 (epoxy equivalent 450-520) manufactured by Fuji Kasei Co., Ltd. trade name Thomade # 210 was used as the polyamide resin. Immediately before use, 75 parts of the main agent was mixed with 25 parts of a curing agent to obtain an epoxy resin coating material.

Conventional Example 3 On a 10 cm × 10 cm grit blasted steel plate (surface roughness R _Z ≈70 μm), a gas sprayed coating of zinc 50 μm was formed by a conventional method, and a silane coupling agent coating was not formed. It was submitted to the test.

Conventional Example 4 A zinc gas sprayed coating of 50 μm was formed on a 10 cm × 10 cm sandblasted steel plate (surface roughness R _Z ≈40 μm), the surface of which was coated with a chromate solution and dried at 150 ° C. for 15 minutes. It was The amount of the chromate film deposited after drying was 500 mg / m ² . This steel sheet was subjected to a comparative test.

Conventional Example 5 The same thermal spray coating was formed on the same steel sheet as in Conventional Example 4, and an amine-based silane coupling agent [3-aminopropyl-triethoxysilane (Nippon Unicar Co., Ltd., trade name A-1100)] 3 was formed on the surface. A mixed solution of 100 parts of methyl alcohol and 97 parts of methyl alcohol was applied by brushing so that the adhesion amount after drying was 65,000 mg / m ² to form a silane coupling agent film. Further, it was dried at 110 ° C. for 20 minutes and subjected to a comparative test.

The results obtained in Examples 1 to 3 of the present invention and Conventional Examples 1 to 5 are shown in Tables 1 and 2.

[0026]

[Table 1]

[0027]

[Table 2]

Notes 1 to 4 in Tables 1 and 2 are as follows. Note 1) Corrosion resistance (SST500H) According to JIS-K-5400, a razor was used to insert a different cut into the base material, and a salt spray test was conducted. After spraying salt water for 500 hours, the area occupied by white rust on the surface was observed. [Evaluation] ◎ No white rust at all ○ White rust area within 5% △ White rust area 5 to 50% × Total white rust

Note 2) Corrosion resistance (SST1000H) By the same test method as in Note 1), after spraying salt water for 1000 hours, the state of red rust on the surface was observed. [Evaluation] ◎ No red rust at all ○ Red rust area within 5% △ Red rust area 5-10% × Full red rust

Note 3) Hot water resistance (50 ° C. × 10 days) A test plate was cut with a razor to reach the substrate, and immersed in deionized water at 50 ° C. for 10 days to observe the surface condition. [Evaluation] ◎ Completely good with neither white rust nor red rust ○ Spotted white rust (within 5%) △ White rust occupancy rate 5 to 50% × Full white rust, red rust, or blistering

Note 4) Okinawa exposure test (1 year) A test plate was cut with a razor for the base material and exposed to the coastal area of Okinawa for 2 years, and then the surface condition was observed. Evaluation criteria are the same as Note 3).

[0032]

[Effect of device]

 According to the present invention, it is clear from the test results of Tables 1 and 2 that not only the surface of the iron substrate is protected but also red rust is generated from the pinholes of the thermal spray coating, as compared with those obtained by the conventionally known examples. It is extremely effective in the prevention and prevention of white rust on the thermal spray coating.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Steel plate (iron material) 2 Low temperature spray coating 3 Silane coupling agent coating

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B32B 27/00 101 8413-4F

Claims (1)

[Scope of utility model registration request] 1. A low-temperature sprayed coating of an iron material, a metal or an alloy thereof, which is sprayed on the surface of the iron material and has a greater ionization tendency than iron, and an adhesion amount after drying applied to this surface is 10
A steel material having a low temperature sprayed coating, characterized in that it comprises a silane coupling agent coating of 50,000 mg / m ² .