JPS6068933A - Thermo-setting resin coated metallic pipe having excellent shock resistance - 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 [Technical Field of the Invention] The present invention relates to a thermosetting resin-coated metal tube with excellent impact resistance.

[Technical background of the invention and its problems]

Typical examples of conventional thermosetting resin externally coated steel pipes include those coated with epoxy powder nuclide, tar urethane coating, and tar epoxy coating. During manufacturing, the surface of the raw pipe must be cleaned by blasting or pickling.
After purification, preheat to an appropriate temperature using a hot air oven or induction heating, and then use an electrostatic powder spray method or an airless spray method. It can be obtained by coating with J resin.

Incidentally, this manufacturing process is shown in Table 1.

Table 1 However, because the anticorrosion coating of this stem is fragile, it must be packed tightly or used as cushioning material from old tires during shipping and transportation.Also, when burying pipes, it is used as backfilling soil. Instead of using sand that does not contain large rocks, special measures are taken to prevent large impact deposits from forming on the coating.

However, with t, a great deal of work is required to protect the coating, and this remains a major problem in terms of economic efficiency.

[Purpose of the invention]

An object of the present invention is to solve the above-mentioned conventional problems and provide a thermosetting resin-coated metal tube whose coating itself has excellent impact resistance, thereby eliminating the need for special protective work for the handler. .

[Structure of the invention]

In order to achieve this object, the present invention forms a coating layer of 30μ or more of a thermosetting resin such as epoxy, tar urethane, or cool epoxy on the outer surface of the metal tube, and the coating layer is coated with the thermosetting resin. It is characterized by forming a mask coating layer in which rubber powder having a diameter of 0.1 to 50 mm is mixed.

[Specific examples of the invention]

Next, the structure of the 1% gold tube according to the present invention will be explained using the eleventh column.

Reference numeral 1 denotes a metal tube, such as an eg, on the surface of which a thermosetting resin coating layer 2 with a thickness of 30 μm or more is formed, and furthermore, a mastic covering layer 3 is formed thereon. Note that the interface between the stiff layers is usually rough due to the manufacturing method described below.

The material 1 for forming the thermally ignited resin coating layer 2 is coated with epoxy powder paint, tar urethane paint, tar epoxy paint, or the like.

The mastic coating layer 3 has a diameter of 0.1 to 5.0 mm.
% preferably O,1~2.0; nm rubber ω3A,
For example, old tires are crushed by grinding them at room temperature or low temperature.
) The composition is 7:ll'l, in which pulverized resin 3B and thermofabrication resin 3B of the same kind as the covering layer 2 are mixed. In addition, if the uppermost layer 3C made of only a thermosetting resin is formed on the mastic layer 3, the coating surface will be finished smoothly and the appearance will be improved.Here, it is preferable that the roughness of the coating layer 20 is 30μ or more.
If it is less than 30μ, the adhesion of the rubber powder 3A to the coating layer 2 will be completely reduced, and the rubber powder will be present at the adhesive interface with the metal tube 1, resulting in a decrease in adhesion. In addition, the rubber powder diameter should preferably be within the above range; if the powder is too fine, the impact absorption ability of the rubber will not be sufficient, and the coarse powder and rubber powder will not mix properly in the resin, resulting in a noticeable impact resistance improvement effect. This is because they will no longer do so.

The coated metal tube thus obtained has excellent impact resistance, as will be shown in the Examples below.

Next, an example of the method for manufacturing a metal tube according to the present invention is shown in FIG. 2. The metal tube 1 to be skew-fed is first subjected to a blasting treatment 1o for cleaning, and then preheated 11, and then coated with a coating layer. In order to form No. 2, a thermally imageable resin is sprayed using a resin spray 12A such as an ordinary electrostatic powder spray or an airless hot spray, and then sieved on the downstream side. Rubber powder 3A is sprayed onto the rubber powder by a rubber powder spraying device 13 using a powder spray method or the like. In this case, it is preferable to spray the rubber powder 3A uniformly over the entire surface of the coating layer 2 to the extent that the rubber powder 3A no longer adheres. Furthermore, after that, resin spray 12B
spray the thermosetting resin.

Here, spraying of the rubber powder 3A and spraying of the thermosetting resin using the anti-greasy spray 12B (f) may be repeated multiple times.

Once the encapsulation is completed, it is cooled by cooling device 1/I.
After that, it is transferred to the product production process.

〔Example〕

Next, Examples and Comparative Examples will be shown to clarify the effects of the present invention.

The outer surface was blasted to remove rust by 4 tons, 32”OD・5
A liquid-temperature steel pipe made of WT arc welded carbon steel was prototyped as shown below, and is widely used in the impact resistance of steel pipe outer coating. A falling head impact test was conducted with f?L.

(Example 1) The steel pipe was heated to 230°C by induction heating and then coated with epoxy powder coating [Sco, Chiko] 206NJ.
(manufactured by aMCa), and when this coating film is still uncured, spray rubber powder with a particle size of 0.3 mm or less uniformly over the entire surface using an air spray method. A powder coating was applied to give a total film thickness of 400 μm, and after the epoxy resin was completely cured, it was cooled with water to obtain Example 1.

(Example 2) The steel pipe was heated to 60°C in a hot air oven, and then tar urethane paint [Grotegor 32-IOJ (T,
1. After painting 100μ of B chemie),
When this coating film is in an uncured state, the particle size is 1. Ovrm
The following rubber powder was sprayed uniformly on the entire surface using an air spray method, and the same tar urethane paint was further applied 49 times to give a total film thickness of 1.8 trim, and the tar urethane resin was completely cured to form Example 2.

(Example 3) Tar urethane paint [Sumitar+1000] was applied to this steel pipe.
After applying 30 μm of J (manufactured by Dainippon Toyo Co., Ltd.), immediately spray rubber powder with a particle size of 0.3 arm or less evenly over the entire surface using the air spray method, and then apply the same tar epoxy/paint 9 times to reduce the total film thickness. Example 3 was prepared by drying and curing at 0.6 na and 1 room temperature for 3 days.

(Comparative Example 1) The same coating process as in Example 1 was used, but the film thickness of the a4 resin layer was set to 02 mm. (Comparative Example 2) Same as Example 2. However, when the thickness of the first porcelain layer is 0.
021 m, and Comparative Example 2 was adopted.

(Comparison/Example 3) Same as Example 1, but with comb flour menarche crab Q, 1.
Comparative Example 3 was defined as less than 1 □ Buhi O (Comparative Example 4) Same as Example 1, but Comparative Example 4 was defined as rubber powder particle size exceeding 501 ○ (ratio 11 bites 1 row) 5, 6.7) Without using any rubber examples, the actual coating was the same as the coating used in 11 cases 1, 2 and 3, the composition σ) was coated with wood/powder-coated wood, tar urethane paint and tar /Reepo・Vnax p+
Please use the conventional product coated with
6 and 7 O or above, using the ASTM standard commonly used to evaluate the impact strength of steel pipe outer coatings
) The results of the tests conducted in accordance with the IN standard are shown in Table 2. The results show that the thermosetting resin-coated steel pipes on which the masticating layer is formed using the rubber powder of the present invention have excellent resistance to corrosion. It was found to have impact properties.

〔Effect of the invention〕

As described above, according to the present invention, a mastic layer containing a mixture of thermosetting resin and rubber powder is formed on the thermosetting resin coating layer, so that impact resistance is significantly improved due to the inclusion of rubber powder. Improved design, freeing you from the protective work that was previously required during shipping.

[Brief Description of the Drawings] Fig. 1 is a partial sectional view showing the structure of a metal tube according to the present invention;
FIG. 2 is a schematic diagram showing an example of the manufacturing method. ■...Metal tube 2...Wandering layer 3...Masty layer 3A...Rubber powder 3B...Thermosetting resin 3C...Top layer 12A, 12B...Resin spray 13...Rubber powder spraying device No. Figure 1

Claims (1)

[Claims] (1) A coating layer of thermosetting resin such as epoxy, tar urethane or tar epoxy is formed on the outer surface of the metal tube with a coating layer of 30μ or more, and on this coating, the thermosetting resin and powder with a diameter of 01 to 5
．． A thermosetting resin-coated metal tube with excellent impact resistance, characterized by forming a mastic coating layer mixed with 0 mm rubber powder.