KR102082963B1 - A partial inhibitor of hot dip galvanizing and method of hot dip galvanizing using the same - Google Patents

Abstract

The present invention relates to a partial preventive agent for hot dip galvanizing, which comprises: 15 to 35 wt% of a polyester resin; 40 to 60 wt% of a solvent mixed with toluene and xylene; 10 to 40wt% of a high melting point inorganic filler containing at least one of calcium carbonate (CaCO_3), TiO_2, SiO_2, Al_2O_3, and tar; and 5wt% or less of an additive containing a dispersant and an antifoaming agent. According to the present invention, plating is prevented more effectively than conventional technologies even in the case of complicated parts such as a bolt with a thread, as well as a simple flat plate when hot dip galvanizing.

Description

Hot dip galvanizing and method of hot dip galvanizing using the same}

The present invention relates to a hot-dip galvanized partial preventive agent comprising a polyester as a main component and a method for manufacturing the same, and more particularly, in order to prevent zinc from being plated on a part to be welded in the plated body during hot-dip galvanized. It relates to a coating agent for preventing plating applied in a manner to apply to and a method for producing the same.

When steel is placed in the air, oxidized and rust occurs, various techniques have been developed to prevent this.

At this time, one of the techniques for preventing rust from the steel material is zinc molten plating, zinc molten plating refers to the process of dipping the steel material in the molten zinc bath, zinc zinc plating with zinc galvanized layer and steel material Also called steel. One of the problems of galvanized steel sheet is that when welding in the state of galvanized steel, very toxic gas and odor which is difficult for the worker to perform welding work are harmful to the human body, and the boiling point of the product is low due to the low boiling point of zinc. This point is rising.

Due to these problems, conventionally, the part to be welded is used by peeling off the zinc-plated part with a grinder, but this is a costly and labor-intensive work process and cannot be applied to precision-processed products such as flanges.

In addition, another method for peeling the galvanized layer of the site where the welding of the galvanized steel is to be performed, by placing an intermediate layer of tape or paint between the steel and the galvanized layer of the galvanized steel, the peeled zinc plated layer on the intermediate layer simply peeled off In the case of manufacturing galvanized steel, the tape or paint that forms the intermediate layer in the process of immersing the steel in a zinc-melted bath may be separated from the steel without being able to withstand the temperature (about 430 to 500 degrees) of the zinc-melted bath. There was a problem of disassembly.

In order to solve this problem, Korean Patent No. 10-0956026, in the laser welding method of galvanized steel sheet, the galvanized layer with the laser beam of the conduction welding zone along the welding line on each galvanized steel sheet to be overlapped welding A first step of forming a plating removal surface by burning and removing a second step, a second step of loading each zinc plated steel sheet on a jig so that the plating removal surfaces of the respective galvanized steel sheets correspond to each other, and overlapping each other in the second step. A laser welding method of a galvanized steel sheet is disclosed, comprising a third step of performing a laser welding operation with a laser beam of a keyhole welding section along the weld line of the galvanized steel sheet.

However, in the prior art, by removing the galvanized layer of the site where the welding of the galvanized steel sheet is to be carried out with a laser beam, the by-product of which the galvanized layer is burned in the steel of the site where the welding of the galvanized steel sheet is to be performed removes these by-products. There was a problem that the process should be carried out further.

In addition, a method is characterized in that the polytetrafluoroethylene and Molybdenum Disulphide-based composites are composed of a release agent in a polycarbonate urethane binder. However, in this case, polytetrafluoroethylene and Molybdenum Disulphide are very expensive raw materials, which are difficult to use publicly, and have the disadvantage of low plating prevention rate for bolts and composite moldings.

Republic of Korea Patent No. 10-0956026 (2010.04.27.)

The present invention has been made to solve the problems of the prior art as described above, it is an object of the present invention to provide an anti-plating coating agent in the form of a coating that can prevent the plating in the weld portion during the hot dip galvanizing and its manufacturing method.

In particular, in contrast to the prior art of the present applicant, it provides a plating preventing agent having a high plating preventing effect not only on a flat plate but also on a complicated structure such as a threaded bolt.

In order to achieve the above object, the hot-dip galvanizing part inhibitor according to the present invention, polyester resin 15 to 35wt%; 40 to 60 wt% of a mixture of toluene and xylene; 10 to 40 wt% of a high melting inorganic filler including at least one of calcium carbonate (CaCO 3), TiO 2, SiO 2, Al 2 O 3, and tar; 5 wt% or less of an additive including a dispersant and an antifoaming agent.

At this time, the toluene is characterized in that 30 to 70wt% with respect to the total weight of the solvent.

Method for producing a hot-dip galvanized portion inhibitor according to the present invention, the first step of stirring 15 to 35wt% of the polyester resin with respect to 40 to 60wt% of toluene and xylene mixed solvent with respect to the total weight; A second step of adding 5 wt% or less of the additive to the material of the first step; And a third step of adding 10 to 40 wt% of a high melting inorganic filler including at least one of CaCO 3, TiO 2, SiO 2, Al 2 O 3, and tar to the material of the second step.

The hot-dip galvanized part preventive agent according to the present invention and a method for manufacturing the same have an effect of effectively preventing plating even in a complicated structure such as a bolt having a thread as well as a simple flat plate during hot-dip galvanizing.

1 is a flow chart showing a method for producing a hot dip galvanized part inhibitor according to the present invention.
Figure 2 is a photograph showing the result of galvanizing after the hot-dip galvanized partial inhibitor treatment according to Comparative Example 1 on the flange.
Figure 3 is a photograph showing the result of zinc plating after the hot-dip galvanized partial inhibitor treatment according to Example 1 on the flange.
Figure 4 is a photograph showing the result of zinc plating after the hot-dip galvanized partial inhibitor treatment according to Example 2 on the screw.
Figure 5 is a photograph showing the result of zinc plating after the hot-dip galvanized partial inhibitor treatment according to Example 3 on the flange.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings refer to like elements.

The hot-dip galvanized part preventive agent according to the present invention is a high melting point inorganic filler including at least one of a polyester resin, a solvent in which toluene and xylene are mixed, calcium carbonate (CaCO 3), TiO 2, SiO 2, Al 2 O 3, tar and It is prepared by including an additive including a dispersant and an antifoaming agent.

Each component will be described in detail. First, polyester, which is a resin applied in the present invention, is dehydrated by water (H 2 O) by a condensation reaction between a carboxyl group (-COOH) and an alcohol group (-OH). Having a structure to be connected, not only an aliphatic ester resin but also an aromatic ester resin is applicable. The polyester resin is preferably applied at 15 to 35wt% with respect to the total weight of the hot dip galvanized portion inhibitor. As a result of the experiment, when the content of the polyester resin is 15wt% or less, the coating film is too thin, so that the acid resistance in the pickling process, which is a pretreatment process of the hot dip galvanizing process, is weak. There was a problem that the viscosity of the inhibitor was too high and uniform application was difficult.

As a result of performing a number of experiments, it was confirmed that the hot-dip galvanized partial preventive agent applying the polyester resin of 15 to 35wt% strongly adhered to the metal surface to be plated to prevent the penetration of the pickling solution and the hot-dip galvanization was effectively prevented. .

The solvent serves to melt the polyester resin, and in the present invention, a mixed solvent obtained by mixing toluene and xylene is used. When toluene alone is used as the solvent, the coating film agglomerates when the coating is evaporated too quickly during application, and a toluene-xylene mixed solvent is applied to improve the coating. At this time, when the toluene content is 30wt% or less, the drying rate is too slow during application, and when the toluene content is 70wt% or more, the drying rate is too fast, and the content of the toluene is preferably 30 to 70wt% with respect to the total mixed solvent.

The weight ratio of the solvent to the total weight of the hot-dip galvanized partial preservative in consideration of the viscosity of the hot-dip galvanized partial preservative is preferably 40 to 60%.

The inorganic filler is composed of high melting point inorganic materials such as calcium carbonate (CaCO 3), titanium dioxide (TiO 2), silicon dioxide (SiO 2), aluminum oxide (Al 2 O 3), talc, and the like to interact with the polyester resin to form a composite material. The hot dip galvanizing part prevents the hot dip galvanizing portion inhibitor of the present invention from being rapidly decomposed by hot dip zinc during plating. At this time, the weight ratio of each material constituting the inorganic filler can be variously applied as necessary.

When the content of the inorganic filler is less than 10wt%, the manufacturing cost of the hot-dip galvanized part preventive agent is not only higher than necessary, but the coating object which is coated with the hot-dip galvanized part preventive agent does not endure the high temperature when the hot-dip zinc deposit is deposited. This problem has been raised. On the other hand, when the content of the inorganic filler is more than 40wt%, the coating film is not dense, causing problems in acid resistance. Therefore, the inorganic filler is most preferably applied at 10 to 40wt% based on the total weight of the hot-dip galvanized portion inhibitor.

In describing the characteristics of representative materials that can be applied as an inorganic filler, the calcium carbonate is separated into heavy calcium carbonate obtained by crushing and pulverizing carbonate minerals and hard (precipitated) calcium carbonate obtained through chemical precipitation reactions. Its low cost makes it widely used in the plastics processing industry and the chemical industry. In the present invention, precipitated calcium carbonate was applied for cost competitiveness inventory.

Titanium dioxide, expressed as TiO2, is used as a sunscreen and cosmetics, and is widely used as a white paint. High hiding power, insoluble in almost all solvents and very stable. Aluminum oxide is a material having a high melting point of 2,072 degrees and is distributed at a relatively low cost.

Additionally, the inorganic filler may include ammonium polyphosphate, which is a non-halogen flame retardant, to prevent instantaneous ignition during deposition of molten zinc bath. That is, by including the ammonium polyphosphate, the zinc coating agent film is ignited instantaneously ignited when deposited in the molten zinc bath to prevent the zinc layer of the area to be blackened to be burned can be applied more stably. .

The additive may include a dispersant, an antifoaming agent, a leveling agent, and the like, and the type and weight ratio of the dispersant, the antifoaming agent, and the leveling agent may be optionally controlled according to required physical properties, but may be 5 wt% based on the total weight of the hot dip galvanizing agent. It is preferable to apply below.

1 is a flow chart showing a method for producing a hot dip galvanized part inhibitor according to the present invention.

Referring to FIG. 1, a method of manufacturing a hot dip galvanized part preventive agent including the above-described materials is sequentially described. A total of 15 to 35 wt% of a polyester resin is added to 40 to 60 wt% of a solvent in which toluene and xylene are mixed. A first step (S1) of stirring, a second step (S2) of adding an additive of 5 wt% or less to the material of the first step, and an inorganic filler of 10 to 40 wt% to the material of the second step, It consists of a third step S3 of stirring.

In the following, each of the melts produced by the flange and the structure having the unevenness of the surface having a flat surface and the repetition of the uneven structure and the screw having the thread of the uneven structure are manufactured by the comparative example and the manufacturing method of the present invention. With reference to the drawings showing the experimental results of applying the galvanized partial inhibitor will be described.

2 is a photograph showing the result of galvanizing after the hot-dip galvanized partial inhibitor treatment according to Comparative Example 1 on the flange, Figure 3 is a photograph showing the result of galvanizing after the hot-dip galvanized partial inhibitor treatment according to Example 1 on the flange 4 is a photograph showing the result of zinc plating after the treatment of the hot dip galvanized partial inhibitor according to Example 2 on the screw, and FIG. 5 is a result of galvanizing after the hot dip galvanizing partial preservative treatment according to Example 3 on the flange. The picture shown.

Comparative Example 1

18 g of the acrylic resin was dissolved in a solvent mixed with toluene and xylene in a 7: 3 weight ratio, and a small amount of an additive including a dispersant and an antifoam was added thereto, and 30 g of CaCO 3 was added to prepare a hot dip galvanizing agent.

The upper part of the flange was coated on the hot dip galvanized part preventive agent prepared in Comparative Example 1 and dried at room temperature. Thereafter, the flange coated with the hot-dip galvanized part preventive agent of Comparative Example 1 was washed with water, washed with water, treated with a flux solvent for dissolution or removal of foreign matters, and then completely charged into a hot-dip zinc bath and then taken out. The hot dip galvanizing process was performed.

As a result of observing the surface of the flange subjected to the hot dip galvanizing process after coating the hot dip galvanized partial preventive agent prepared in Comparative Example 1, as shown in FIG. 2, the hot dip galvanized partial inhibitor was prepared using an acrylic resin. It was confirmed that the zinc plated part was not completely prevented from galvanizing the part coated with.

Example 1

18 g of polyester resin was dissolved in a solvent in which toluene and xylene were mixed at a 7: 3 weight ratio, and a small amount of an additive including a dispersant and an antifoam was added thereto, and 30 g of CaCO 3 was added to prepare a hot dip galvanizing agent.

The hot dip galvanizing partial prevention agent prepared in Example 1 was coated by dipping the upper part of the flange and dried at room temperature, and then the hot dip galvanizing process was performed.

As a result of observing the surface of the flange subjected to the hot dip galvanizing process after coating the hot dip galvanizing partial inhibitor of the present invention prepared in Example 1, the hot dip galvanizing partial inhibitor was coated as shown in FIG. Successful results have been obtained in which the galvanizing of the top of the flange is completely prevented.

Example 2

As a result of coating the hot-dip galvanized part preventive agent in the same process as in Example 1 on the lower surface of the thread of the screw having a concave-convex shape and performing hot-dip galvanizing on the whole screw, as shown in FIG. Successful results have been obtained in which the zinc plating on the bottom of the thread coated with a hot dip galvanizing agent is completely prevented.

Example 3

20 g of polyester resin was dissolved in a solvent in which toluene and xylene were mixed at a 5: 5 weight ratio, and a small amount of an additive including a dispersant and an antifoam was added thereto, and 20 g of TiO 2 was added to prepare a hot dip galvanizing agent.

As a result of observing the surface of the flange subjected to the hot dip galvanizing process after coating the hot dip galvanized partial preventive agent prepared in Example 3, the flange is coated with the hot dip galvanized partial inhibitor as shown in FIG. It was confirmed that the zinc plating of the lower part of the was completely prevented.

Although the configuration and operation of the hot-dip galvanized part inhibitor according to the present invention and a method for producing the same are shown in the above description and drawings, these are merely examples and the spirit of the present invention is not limited to the above description and the drawings. Of course, various changes and modifications are possible without departing from the technical spirit of the.

S1: first stage
S2: second stage
S3: third stage

Claims (3)

In order to prevent zinc from being plated on a part of the plated body during the hot dip galvanizing process, it is coated on a part of the plated body in the previous step of the hot dip galvanizing process,
15 to 35 wt% polyester resin;
40 to 60 wt% of a mixture of toluene and xylene;
10 to 40 wt% of a high melting inorganic filler including at least one of CaCO 3, TiO 2, SiO 2, Al 2 O 3, and tar;
5 wt% or less of an additive including a dispersing agent and an antifoaming agent.
delete Preparing a hot-dip galvanized portion inhibitor;
Coating a portion of the body to be coated with the hot dip galvanizing agent;
Including the hot-dip galvanized coating agent to be coated in the hot dip galvanizing bath and take out;
When hot-dip galvanizing, characterized in that the zinc plating is prevented in the portion coated with the hot-dip galvanized part preventive agent,
Preparing the hot-dip galvanized part preventive agent,
A first step of stirring 15 to 35 wt% of the polyester resin in 40 to 60 wt% of a solvent in which toluene and xylene are mixed with respect to the total weight;
A second step of adding 5 wt% or less of the additive to the material of the first step;
And a third step of adding 10 to 40 wt% of a high melting inorganic filler including at least one of CaCO 3, TiO 2, SiO 2, Al 2 O 3, and tar to the material of the second step, and stirring the molten zinc. Hot-dip galvanizing method using plating inhibitor.

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