KR102392986B1 - Corrugated steel pipe coating layer repair material and corrugated steel pipe repaired using the same - Google Patents

Abstract

The present invention relates to a material for repairing a coating layer that repairs a damaged portion of a coating layer adhered to inner and outer walls of the corrugated profile a corrugated steel pipe. More specifically, the present invention provides a material for repairing a coating layer of a corrugated steel pipe consisting of a mixture of a mixed powder of polyethylene (PE) powder, polypropylene (PP) powder, and glass fiber powder, and one paint among urethane paint, epoxy paint, and enamel paint.

Description

Corrugated steel pipe coating layer repair material and corrugated steel pipe repaired using the same { Corrugated steel pipe coating layer repair material and corrugated steel pipe repaired using the same }

The present invention relates to a corrugated steel pipe coating layer repair agent and a corrugated steel pipe repaired using the same, and more particularly, to a corrugated steel pipe coating layer repair agent for repairing a coating layer of a corrugated steel pipe coated with high-strength PE (polyethylene). Corrugated steel pipe coating layer repair agent that can prevent corrosion of the inner steel sheet layer through the damaged part of the coating layer by repairing the damaged part of the coating layer by adding a coating layer repair agent that is chemically bonded to form an integrated surface, and to the corrugated steel pipe repaired using the same it's about

In general, drainage structures buried underground to treat rainwater and sewage mainly use concrete Hume pipes, concrete pipes, PC BOX, etc. In order to solve the problems, galvanized steel sheets are manufactured and replaced with spiral corrugated steel pipes. there is.

Accordingly, we are producing PE-coated corrugated steel sheets and PE-coated corrugated steel pipes made by laminating and bonding high-strength PE (polyethylene) films to the inner and outer peripheral surfaces of galvanized steel sheets using a high-frequency induction heating method. Because it has chemical properties, it is economical because it can be constructed in areas with severe soil pollution, reclaimed land, and salty areas such as ports.

However, the coated corrugated steel pipe coated with high-strength PE (polyethylene) film has a problem in that it cannot be partially repaired for parts where the coating layer is damaged, cracked, peeled, etc. during transportation and construction of the finished product.

For partial repair work, simple methods include spraying organic compound-based repair agents (oil-based repair agents, liquid repair agents, and other compound repair agents), heat sealing, and painting. Since the surface of the PE (polyethylene) film has a stable molecular structure, chemical bonding and adhesion between the film outer layer and the repair agent did not occur, causing a problem of easy peeling even after repair work.

In addition, when the peeled part of the PE-coated corrugated steel pipe is used without repair, the galvanized layer corrosion progresses and the service life of the PE-coated corrugated steel pipe is significantly reduced compared to that of the non-peeled PE-coated corrugated steel pipe, so repair or replacement is necessary. .

In particular, in the case of replacement, since it is difficult to replace only the peeled part due to the characteristics of the corrugated steel pipe formed in a spiral shape by corrugation of the steel sheet, it may cause economic loss.

1, the corrugated steel pipe coating layer repair agent and the corrugated steel pipe manufacturing method repaired using the same according to the present invention pass through the surface treatment device (A) horizontally while removing impurities on the surface and releasing a steel sheet wound in a roll shape and forming the roughness of the surface to improve adhesion to the surface of the steel sheet,

The surface-treated steel sheet is heated while passing through the high-frequency induction heating device (B), and the multilayer film 100 on both sides of the heated iron sheet is coated on the upper and lower surfaces of the steel sheet by the coating device (C) and is formed integrally while being laminated and supplied. , the steel sheet coated with the multilayer film 100 is cooled while passing through the cooling device (D), the cooled coated steel sheet is corrugated, and then the steel sheet is rolled in a spiral while passing through the pipe making device (E) It is molded to complete a corrugated steel pipe coated with a multi-layer film on the inner and outer surfaces.

Corrugated steel pipe coated with a multi-layer film finished through such a process is damaged, cracked, peeled, etc. of the coating layer during the pipe making process, transportation, and construction process.

Korean Patent Publication No. 10-1894590 Korean Patent Publication No. 10-2075320 Korean Patent Publication No. 10-1653972 Korean Patent Publication No. 10-0467895

Therefore, the present invention has been devised to solve the problems of the prior art as described above, and the film coating layer of the coated corrugated steel pipe to prevent damage to the galvanized layer of the corrugated steel pipe before and after production and construction can be repaired on site. To provide a corrugated steel pipe coating layer repair agent and a corrugated steel pipe repaired using the same.

In addition, it is to provide a corrugated steel pipe coating layer repair agent capable of easily forming a repair layer repairing a damaged portion of the film coating layer of the corrugated steel pipe to have a thickness equal to or thicker than that of the film coating layer, and a corrugated steel pipe repaired using the same.

The present invention for achieving the above object is a coating layer repair agent for repairing the damaged portion of the coating layer adhered to the inner and outer walls of the corrugated steel pipe, polyethylene [polyethylene; hereinafter PE] powder, polypropylene [polypropylene; Hereinafter PP] powder, glass fiber (Glass Wool) powder, mixed powder, urethane paint, epoxy paint, or any one of enamel paint is a corrugated steel pipe coating layer repair agent, characterized in that it is composed by mixing the paint.

To explain this in more detail, the size of the particles of the PE powder and PP powder is 350 microns or more and 800 microns or less, and the size of the particles of the glass fiber powder is 350 microns or more and 500 microns or less, and the PE powder by volume ratio is 40%, It is composed by mixing the mixed powder mixed with 40% PP powder and 20% glass fiber powder and one of the urethane paints, epoxy paints, or enamel paints in a volume ratio of 1: 1.

In addition, after diluting the paint mixed with the paint and powder mixture with a diluent, it is applied to the damaged part of the coating layer adhered to the corrugated steel pipe, and then subjected to a natural drying step and then cured by heating at 350°C.

The urethane paint comprises a prepolymer main part and a curing agent part; Here, the prepolymer main part is characterized in that it is obtained by polymerizing a polyisocyanate as 5 to 31% by weight of a high equivalent polyol, 5 to 60% by weight of a low equivalent polyol and the balance.

In addition, the epoxy paint includes a urethane epoxy resin obtained by reacting an epoxy compound with an isocyanate prepolymer obtained by reacting a polyol and a diisocyanate compound, and a hydroxyl group equivalent (molecular weight/number of hydroxyl groups) of the polyol is 200 to 3500, and an isocyanate equivalent weight The urethane epoxy resin obtained by making this 70-140 diisocyanate compound react is included.

In addition, the enamel paint is mixed with an additive containing a small amount of water in an organic polar solvent such as dimeltyl sulfoxide (DMSO) to a conventional paint or enamel made using organic montmorillonite.

In addition, the damaged portion of the corrugated steel pipe having the coating layer adhered to the corrugated inner and outer walls is formed as a corrugated steel pipe repaired using the corrugated steel pipe coating layer repair agent presented above.

The coated corrugated steel pipe coated with PE (polyethylene) film by providing the corrugated steel pipe coating layer repair agent that can repair the damaged part of the film coating layer of the coated corrugated steel pipe of the present invention on site, and the corrugated steel pipe repaired using the same, is a finished product. It has the advantage of improving the durability of the coated corrugated steel pipe by making it possible to easily repair the parts where the coating layer is damaged, cracked, or peeled during transportation and construction.

In addition, the corrugated steel pipe coating layer repair agent of the present invention has the advantage of being able to form the repair layer at the damaged portion of the film coating layer of the corrugated steel pipe to have a thickness equal to or thicker than that of the undamaged film coating layer.

1 is a manufacturing process diagram of a corrugated steel pipe according to the prior art of the present invention.
2 is a schematic view of a corrugated steel pipe showing a repair part to be repaired with the corrugated steel pipe coating layer repair agent of the present invention.
3 is a flowchart of repairing with a corrugated steel pipe coating layer repair agent according to the present invention

Hereinafter, the corrugated steel pipe coating layer repair agent according to the present invention and the corrugated steel pipe repaired using the same will be described in detail with reference to the accompanying drawings.

In the following description, only the parts necessary to understand the corrugated steel pipe coating layer repair agent according to the present invention and the corrugated steel pipe repaired using the same will be described, and descriptions of other parts may be omitted so as not to obscure the gist of the present invention.

In addition, the terms or words used in the present specification and claims described below should not be construed as being limited to conventional or dictionary meanings, and meanings consistent with the technical spirit of the present invention so that the present invention can be most appropriately expressed. and should be interpreted as a concept.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated. In addition, terms such as "... unit" and "... group" described in the specification mean a unit that processes at least one function or operation.

In various embodiments, the same reference numerals are used for components having the same configuration in one embodiment, and configurations different from the one embodiment will be described in other embodiments.

2 is a schematic view of a corrugated steel pipe showing a repair part to be repaired with the invention corrugated steel pipe coating layer repair agent according to the present invention.

Referring to Figure 2, the corrugated steel pipe coating layer repair agent according to the present invention and the corrugated steel pipe repaired using the same are multilayer films 100 formed on the inner and outer walls of the corrugated steel pipe 10 having corrugated inner and outer surfaces, and the multilayer film ( 100) is to be coated on the surface of the corrugated steel pipe 10 for a corrosion-resistant function, and the steel sheet adhesive layer 110 having excellent adhesion to the steel sheet and the upper surface layer 120 with enhanced corrosion resistance and wear resistance to protect the steel sheet is a composition comprising

In the multilayer film 100 as described above, there are repair parts 200 that require repair such as damage, cracks, peeling, etc. to be explained.

As a coating layer repair agent for repairing a damaged portion of the coating layer adhered to the inner and outer walls of the corrugated steel pipe, polyethylene [polyethylene; hereinafter PE] powder, polypropylene [polypropylene; Hereinafter PP] powder, glass fiber (Glass Wool) powder, mixed powder, urethane paint, epoxy paint, or any one of enamel paint is a corrugated steel pipe coating layer repair agent, characterized in that it is composed by mixing the paint.

As described above, the corrugated steel pipe coating layer repair agent according to the present invention is made of PE and PP powder, which are the main members forming the coating layer, so that it can be easily dissolved in the solvent provided in the urethane paint, epoxy paint, or enamel paint, which is a paint. It is formed so that it can be dissolved by mixing the paint.

As such, in order to increase abrasion and coatability in the paint containing PE and PP, glass wool is included.

To explain this in more detail, the size of the particles of the PE powder and PP powder is 350 microns or more and 800 microns or less, and the size of the particles of the glass fiber powder is 350 microns or more and 500 microns or less, and the PE powder by volume ratio is 40%, It is composed by mixing the mixed powder mixed with 40% PP powder and 20% glass fiber powder and one of the urethane paints, epoxy paints, or enamel paints in a volume ratio of 1: 1.

When the particle size of the PE powder and PP powder is less than 350 microns, they dissolve too easily in the mixed paint and cannot affect the mechanical properties. There is a problem with this.

When the particle size of the glass fiber powder is 350 microns or less, when the coating layer repair agent is applied, it is not laminated and spreads widely, and when it is 500 microns or more, there is a problem that air bubbles are contained inside.

In addition, after diluting the paint mixed with the paint and powder mixture with a diluent, it is applied to the damaged part of the coating layer adhered to the corrugated steel pipe, and then subjected to a natural drying step and then cured by heating at 350°C.

That is, after diluting the paint mixed with the paint and powder mixture with a diluent, it is applied to the damaged part of the coating layer adhered to the corrugated steel pipe, and after natural drying, it is heated to 250~350℃ to increase the hardness of the outer surface and heat-cured. .

If it is used at less than 250°C based on the heating temperature, there may be a problem that the hardness of the product does not exceed the lower limit of hardness of 50. Conversely, when used above 350°C, the mixed powder is oxidized or bubbles There may be problems with this occurring.

In addition, the composition of the diluent includes acetone and toluene, and the diluent is 40-50 wt% of the mixed powder, 15-25 wt% of acetone, 5-15 wt% of toluene, and methyl ethyl ketone (METHYL ETHYL KETONE) ) 1 to 5 wt% is additionally included.

The diluent composition is preferably 15 to 25 wt% of acetone, 5 to 15 wt% of toluene, and 1 to 5 wt% of methyl ethyl ketone (METHYL ETHYL KETONE). If the sum of the contents of acetone, toluene, and methyl ethyl ketone is less than 20% by weight, the surface layer of the cured coating layer does not melt, and if it is 50% by weight or more, the surrounding coating layer is excessively melted and the coating layer of the steel sheet is eroded and durability is reduced. there is a problem.

In addition, the urethane paint comprises a prepolymer main part and a curing agent part; Here, the prepolymer main part is characterized in that it is obtained by polymerizing a polyisocyanate as 5 to 31% by weight of a high equivalent polyol, 5 to 60% by weight of a low equivalent polyol and the balance.

As described above, the urethane paint according to the present invention comprises a two-component thermosetting polyurethane resin capable of obtaining a polyurethane resin constituting the solid content of the paint by reacting the prepolymer main part with a curing agent.

The prepolymer main part constituting a part of the two-part type together with the curing agent part is obtained by polymerizing 5 to 31% by weight of a high equivalent polyol, 5 to 60% by weight of a low equivalent polyol, and a polyisocyanate as the remainder. That is, it is characterized in that the hardness of the polyurethane resin finally obtained is controlled by adjusting the ratio of the high equivalent polyol to the low equivalent polyol of the polyol constituting the prepolymer by reacting with the polyisocyanate. That is, when synthesizing the prepolymer, the polyurethane resin finally obtained by adjusting the ratio of the high equivalent polyol and the low equivalent polyol within the range such that the content of unreacted free isocyanate is within the range of 9 to 20 wt %. hardness can be adjusted.

When the high equivalent polyol used in the preparation of the prepolymer main part is used in an amount of less than 5% by weight based on the total weight of the prepolymer, there may be a problem that there is no effect on elongation among mechanical properties, and conversely, 31% by weight When used in excess of %, there may be a problem that does not exceed the lower limit hardness of 70 of the required product.

In addition, when the low equivalent polyol used in the preparation of the prepolymer main part is used in an amount of less than 5% by weight based on the total weight of the prepolymer, there may be a problem in that the hardness of the product does not exceed the lower hardness limit of 70, and conversely, 60% by weight When used in excess of %, there may be problems in that control of reaction temperature and viscosity of usable products cannot be obtained.

In addition, the epoxy paint includes a urethane epoxy resin obtained by reacting an epoxy compound with an isocyanate prepolymer obtained by reacting a polyol and a diisocyanate compound, and a hydroxyl group equivalent (molecular weight/number of hydroxyl groups) of the polyol is 200 to 3500, and an isocyanate equivalent weight The urethane epoxy resin obtained by making this 70-140 diisocyanate compound react is included.

The polyol may include at least one selected from the group consisting of polypropylene glycol, polyethylene glycol, polytetrahydrofuran glycol, polycaprolactone polyol, and polybutadiene glycol.

In addition, the epoxy compound is a glycidyl ether epoxy compound obtained from at least one selected from the group consisting of ethylene glycol, propylene glycol, butanediol, 2-methyl propanediol, neopentyl glycol, 1,6-hexanediol and trimethylol propane, A glycidyl ester epoxy compound obtained from at least one selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, adipic acid, tetrahydrophthalic acid, and hexahydrophthalic acid, a bisphenol A type epoxy compound, and a bisphenol F type epoxy compound selected from the group consisting of It may include at least one.

In addition, the corrugated steel pipe repaired using the corrugated steel pipe coating layer repair agent described above is formed.

In addition, Figure 3 is a procedure diagram for repairing the corrugated steel pipe coating layer repair agent according to the present invention.

The procedure for repairing the damaged part of the film coating layer of the coated corrugated steel pipe is explained.

As step S100, it is a step of removing foreign substances from the damaged part of the film coating layer of the coated corrugated steel pipe (hereinafter; the repair part),

In step S200, after the foreign substances in the repair part are removed, the corrugated steel pipe coating layer repair agent (PE powder, PP powder particle size is 350 microns or more and 800 microns or less, and the size of glass fiber powder particles is 350 microns or more and 500 microns) or less, mixed powder mixed with 40% PE powder, 40% PP powder, and 20% glass fiber powder in a volume ratio and a paint of either urethane paint, epoxy paint, or enamel paint in a volume ratio of 1: 1 applying a repair agent)

In step S200, it is applied so that it can be formed higher than the outer surface of the coating layer in anticipation of shrinkage during drying.

In step S300, the repair agent applied to the repair part is naturally dried,

In step S400, it is a step of thermosetting by heating to 250 ~ 350 ℃ in a naturally dried repair agent.

After these steps, a corrugated steel pipe repaired using a corrugated steel pipe coating layer repair agent is formed.

Although the present invention has been described in detail through specific examples, it is intended to describe the present invention in detail, and the present invention is not limited thereto. It is clear that the modification or improvement is possible.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be clarified by the appended claims.

A : Surface treatment device B : High frequency induction heating device
C: Multi-layer film coating device D: Cooling device
E: Pipe making device 10: Corrugated steel pipe
100: multi-layer film 110: steel plate adhesive layer
120: upper surface layer 200: repair part

Claims (5)

As a coating layer repairing agent for repairing damaged parts of the coating layer attached to the corrugated steel pipe,
polyethylene [polyethylene; hereinafter PE] powder, polypropylene [polypropylene; Hereinafter PP] powder and glass fiber (Glass Wool) powder mixed powder,
It is composed by mixing any one of urethane paint, epoxy paint, or enamel paint,
In addition, after diluting the paint mixed with paint and powder with a diluent, it is applied to the damaged part of the coating layer adhered to the corrugated steel pipe, and then subjected to a natural drying step and then cured by heating at 250~350℃.
The size of the particles of the PE powder and PP powder is 350 microns or more and 800 microns or less, and the size of the particles of the glass fiber powder is 350 microns or more and 500 microns or less, and the PE powder 40%, PP powder 40%, glass fiber by volume ratio It is composed by mixing the mixed powder mixed with powder 20% and the paint of any one of urethane paint, epoxy paint, or enamel paint in a volume ratio of 1: 1,
In addition, the diluent is 40 to 50 wt% of the mixed powder, 15 to 25 wt% of acetone, 5 to 15 wt% of toluene, and 1 to 5 wt% of methyl ethyl ketone (METHYL ETHYL KETONE) Corrugated steel pipe coating layer repair agent. A corrugated steel pipe in which the damaged part of a corrugated steel pipe having a coating layer is repaired using the corrugated steel pipe coating layer repair agent of claim 1.
delete delete delete

Images