KR101557685B1

KR101557685B1 - Complex waterproof structure and constructing method using rubberized asphalt sheet and aqueous waterproofing material

Info

Publication number: KR101557685B1
Application number: KR1020150115113A
Authority: KR
Inventors: 강충모; 손문세
Original assignee: 강충모
Priority date: 2015-08-17
Filing date: 2015-08-17
Publication date: 2015-10-06

Abstract

The present invention relates to a complex waterproof structure using a rubberized asphalt sheet and a liquid waterproofing material and a construction method thereof, complementing each disadvantage of a sheet waterproofing method and a liquid waterproofing method and maximizing advantages thereof, thereby allowing an easy construction joint of a jointed part, which is a very important construction point in the complex waterproof structure and has high frequency of generation of a deficiency, and forming a watertight jointed part. The complex waterproof structure using the rubberized asphalt sheet and the liquid waterproofing material is a complex waterproof structure where waterproof sheets are installed on the upper part of a concrete foundation surface, and a urethane waterproofing material is applied on entire supper surfaces of the waterproof sheets to form a waterproof layer. The jointed part where the waterproof sheets are connected to each other comprises: a primer layer; a lower polyurethane layer; the waterproof sheets; a reinforcing member; and the upper polyurethane layer. The primer layer is applied to the concrete foundation layer. The lower polyurethane is applied to the upper part of the primer layer. The waterproof sheets have lower edges attached to the upper part of the lower polyurethane layer to be spaced from each other. The reinforcing member is attached on both upper parts of the waterproof sheets aligned and spaced from each other. The upper polyurethane layer is applied to the upper part of the reinforcing member and is charged into a gap between the waterproof sheets to be formed integrally with the lower polyurethane layer.

Description

Technical Field The present invention relates to a composite waterproof structure using a modified asphalt sheet and a liquid type coating material,

The present invention relates to a composite waterproof structure and a method of constructing the waterproof structure. More particularly, the present invention relates to a composite waterproof structure and a method of constructing the same. More particularly, Which is capable of forming a watertight junction between the modified asphalt sheet and the liquid-phase coating material, and a method of constructing the composite waterproof structure.

The waterproofing method can be broadly divided into a sheet waterproofing method, a film waterproofing method, and a composite waterproofing method in which these are mixed. The sheet waterproofing method is a method of forming a waterproof layer by using an adhesive agent or fusing the factory-produced waterproof sheet. Since the product is standardized, the thickness of the waterproof layer is uniform, the finish is good, the construction is quick, The occurrence rate of defects is high at the joint portions between the sheets and it is difficult to work the complicated construction site and there is a possibility that the wall and parapet portions are peeled and sagged due to the temperature change after the construction. Further, since the sheet material is sensitive to temperature, it is influenced by work in the winter or summer season, and waterproof performance is deteriorated due to partial joining failure and insufficient stability.

In addition, the coating film waterproofing method is a method in which a waterproofing material is applied a plurality of times to a base surface to form a waterproof film. Since a waterproof layer is formed by simply transporting a material and applying a liquid state material, Although it is possible to easily perform construction even if it is applied to the base surface, there is a problem that the thickness of the coating film is unevenly formed along the irregularities of the base surface because the concrete base surface can not be raised irregularly even if the construction is well done. There is a problem in that a part of the waterproof membrane may be swollen due to the water vapor pressure generated on the concrete base surface or pinholes may be generated due to pores on the surface of the concrete and a phenomenon such as poor curing due to erroneous mixing of materials may occur have.

Meanwhile, in order to overcome the disadvantages of the waterproofing method and the waterproofing method, Patent No. 238994 entitled " Combined waterproof structure and construction method ", patent registration No. 1015120 "Waterproof coating material for desk adjustment and self- Various composite waterproofing methods such as a waterproof structure using a sheet and a composite waterproofing method for constructing the same, and a patented Korean Patent No. 1173410 "combined waterproofing method and a composite waterproofing structure implemented thereby" have been developed and applied in the field.

The waterproofing is directly connected to the water leakage even if any part of the waterproofing area is defective after construction. Especially, the part where the water leakage occurs is a joint part where the sheet and the sheet are connected to each other. However, in the combined waterproofing method, there is a problem that the sheet is dissolved by the organic solvent contained in the coating material, which causes defects such as a lack of waterproofing performance, as well as a leakage of the dissolved material through the cracked portion of the structure, Due to the lack of interlayer integrity between the two materials due to the use of different heterogeneous materials, the problem of breaking the joint between sheets due to delamination and lack of flexibility is still a problem, and adhesion at the interface The watertightness is rapidly deteriorated, and the sheet is repeatedly shrunk and expanded according to the outside air temperature, so that cracks or breakage of the joint portion coating film occurs and leakage occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an asphalt sheet which can improve compositional composition of an asphalt sheet to improve joint performance, By using a polyurethane coating material that can be applied without adding an organic solvent, it compensates for the shortcomings of sheet waterproofing and film waterproofing respectively and makes full use of the advantages to make it a very important construction point in complex waterproofing. And to provide a composite waterproof structure using the modified asphalt sheet and the liquid phase coating material, which can form a joint between the construction joint and the watertight joint, and a method of construction thereof.

In order to solve the above problems, the composite waterproofing structure using the modified asphalt sheet and the liquid film material according to the present invention is characterized in that a waterproof sheet is provided on the top of the concrete base and a polyurethane coating material is applied on the entire upper surface of the waterproof sheet Wherein the waterproof sheet and the waterproof sheet are connected to each other by a composite waterproof structure comprising a primer layer applied on a concrete base surface, A lower polyurethane layer applied over the primer layer; A waterproof sheet having a lower edge attached to an upper portion of the lower polyurethane layer and spaced apart from each other at a predetermined interval; A stiffener installed at an upper portion of the waterproof sheet that is spaced apart at a predetermined interval and is installed so as to cover both of the waterproof sheets; And an upper polyurethane layer which is applied to the upper portion of the reinforcing member and is integrated with the lower polyurethane layer by being filled in the gap between the waterproof sheets by penetrating into the reinforcing member, the waterproof sheet comprising: a modified asphalt compound layer; An insulation yarn attached to a lower portion of the compound layer; Wherein the composite long layer fiber is impregnated into the compound layer and the long fiber bundle is laminated on the top of the compound layer with the long fibers protruding from the top, 35 to 50 parts by weight; 5 to 10 parts by weight of synthetic rubber (SBS) which is a synthetic rubber; 10 to 15 parts by weight of butyl rubber; 5 to 10 parts by weight of a process oil; 10 to 15 parts by weight of polybutene; 2 to 5 parts by weight of an oil absorbent; 5 to 10 parts by weight of a filler (dolomite); 2 to 5 parts by weight of aluminum stearate; 2 to 4 parts by weight of an antioxidant; And 1 to 3 parts by weight of a special additive are mixed.

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Preferably, the insulator is a basalt or calcite particle coated with a liquid resin, the liquid resin is a mixture of polysilicon and silicate, and the reinforcing material is a lattice-shaped glass fiber.

Preferably, the polyurethane used in the waterproof layer and the bonding portion is a low viscosity polyurethane which minimizes the organic solvent content by using a hydrocarbon solvent in the non-aromatic solvent.

The method for constructing a composite waterproof structure using the modified asphalt sheet and the liquid coating material of the present invention comprises the steps of applying a primer at a predetermined interval on a concrete base surface; Applying a polyurethane on top of the primer after curing; Before the applied polyurethane is cured, installing a waterproof sheet at a predetermined interval above the polyurethane application surface; Installing a stiffener on the abutment between the waterproof sheet and the waterproof sheet opposed to each other; Applying polyurethane to the upper portion of the reinforcing material, filling the gap between the waterproof sheets with the polyurethane penetrating into the reinforcing material to form a joint by integrating both sheets; And coating a polyurethane coating material on the entire upper surface of the waterproof sheet to form a coating waterproof layer.

The modified asphalt sheet used in the composite waterproofing structure and the construction method according to the present invention having the above-mentioned characteristics is characterized in that the modified asphalt sheet having the above-mentioned characteristics is made by adding SBS and butyl rubber, which are synthetic rubber, to process oil and polybutene, It is possible to secure the stability of the construction quality under any climatic conditions because there is no damage or deformation of the sheet surface and there is no lifting with the base surface. Further, since the polyurethane coating material is a low-viscosity polyurethane which is formed by a reaction between the subject of polyol component and a curing agent of polyisocyanate component and which uses a non-aromatic solvent to minimize the organic solvent content, Not only the layer is not dissolved, but also easily spreads (spreads) on the nonwoven fabric upper surface of the sheet and is wetted automatically and self-leveled, so that the construction is efficient and can be used without adding organic solvent (diluent) in the field.

The composite waterproofing structure and method of the present invention as described above complements the disadvantages of sheet waterproofing and film waterproofing respectively and maximally improves joint performance with a high frequency of occurrence of defects, It is possible to form an easy-to-connect joint and a watertight joint at the joint.

1 is a cross-sectional view of a composite waterproof structure according to the present invention.
2 is a view for explaining the structure of the modified asphalt sheet of the present invention.
3 is a flow chart for explaining a composite waterproofing method according to the present invention.

The most significant technical feature of the composite waterproofing structure using the modified asphalt sheet and the liquid film material according to the present invention and the construction method thereof is that the compound composition of the asphalt sheet is changed and the composition of the polyurethane film material is changed to secure the stability of the construction quality, It is a very important construction point in waterproofing, and it makes it possible to form an easy joint and a watertight joint of a joint having a high frequency of defects.

The composite waterproof structure according to the present invention is characterized in that a waterproof sheet 20 is provided on an upper surface of a concrete base 10 and a polyurethane coating material is applied to the entire upper surface of the waterproof sheet 20 to form a coating layer 40 The characteristic constitution of the present invention is a joint portion (30) to which a waterproof sheet and a waterproof sheet are connected. The most important technical problem to be solved by the present invention is that the joining portion where the sheet and the sheet are connected in waterproof is the region where the occurrence frequency of the defect is the highest, so that the joining portion can be easily constructed and the joining portion of watertightness can be formed.

The structure of the joint 30 in which the waterproof sheet and the waterproof sheet are connected includes a primer layer 31, a lower polyurethane layer 32, a waterproof sheet 20, a reinforcing material 33, an upper polyurethane layer 34, And a coating layer 40 applied over the entire surface is formed thereon.

The primer layer 31 is a kind of adhesive applied to the concrete base surface 10 and the primer layer 31 is not applied to the entire base surface but is applied only to a certain width of a portion where the edge of the waterproof sheet 20 is to be located . The lower polyurethane layer 32 is a portion which is applied to the top of the primer layer 31 and adhered to the waterproof sheet 20.

The asphalt waterproofing sheet used for composite waterproofing is formed by overlapping the sheet and the sheet at a predetermined interval or by overlapping the edge of the sheet when the sheet is installed on the base surface and applying the coating material on the upper part of the sheet- I have installed. However, since the sheet is not in close contact with the base surface, a part of the applied coating material penetrates into the lower portion of the sheet, and a proper amount of the coating on the upper portion of the joint is not applied.

The waterproof sheet (10) of the present invention solves the above problems. The waterproof sheet (10) of the present invention has the above-mentioned problems, and it is made to increase the content of SBS and butyl rubber, which are synthetic rubbers, Even if the surface of the sheet is not damaged or deformed, it is a modified asphalt sheet that ensures the stability of the quality of the construction under any weather conditions at the time of construction.

The waterproof sheet 20 of the present invention, which is a modified asphalt sheet, is attached to the upper portion of the lower polyurethane layer 32 at its lower edge, and adjoining sheets are spaced apart from each other at a predetermined interval. The waterproof sheet 20 has a structure in which an insulating yarn 22 is sprayed and attached to the lower part of the modified asphalt compound layer 21 and a long fibrous nonwoven fabric 23 is laminated on the upper part. The long fibers protruding to the lower portion of the long fibrous nonwoven fabric 23 are impregnated into the compound layer 21 and the long fibers protruding upward are directly protruded to the upper portion of the sheet to strengthen the binding force with the coating material .

The long fibrous nonwoven fabric layer 23 is laminated on top of the compound layer 21 to improve the physical performance of the sheet and improve the dimensional stability and mechanical properties of the sheet when the sheet is spread in the field so as to prevent the sheet from being bent I can do it. Preferably, the long fibrous nonwoven fabric 23 has a nonwoven fabric of 70 to 200 g / m < 2 >. When the nonwoven fabric is laminated using 200 g / There is a problem that the coating material is excessively applied and over-applied, and when the nonwoven fabric is used at 70 g / m 2 or less, the weight of the compound in the lower portion of the nonwoven fabric can not be pulled. There is a problem that when the seat is raised and stored, the compound moves to the lower portion of the seat and the lower portion of the seat is bent.

The compound constituting the compound layer 21 is composed of 35 to 50 parts by weight of straight asphalt, 5 to 10 parts by weight of synthetic rubber SBS, 10 to 15 parts by weight of butyl rubber, 5 to 10 parts by weight of process oil, 10 to 15 parts by weight of butene, 2 to 5 parts by weight of an oil absorbent, 5 to 10 parts by weight of a filler (dolomite), 2 to 5 parts by weight of aluminum stearate, 2 to 4 parts by weight of an antioxidant and 1 to 3 parts by weight of a special additive It is made.

Polybutene imparts adhesion and flexibility and helps disperse the filler to improve workability and cohesion. That is, polybutene used for imparting tackiness to butyl rubber and improving plasticity is not only a polymer substance, but also chemically stable, exhibits excellent stability to heat or ultraviolet rays, and has a function of improving adhesion to a waterproof sheet. In addition, polybutene improves the melt index, facilitates processing, improves low-temperature flexibility, flexibility and cold resistance, and prevents sheet breakage even at a low temperature of -30 ° C or lower, which is the limit of use of butyl rubber.

The filler (dolomite) is used to reinforce the compound surface and reinforce the strength. The aluminum stearate is used for strengthening the cohesion and for stabilizing the heat stabilizer. do. The antioxidant for preventing oxidation and cracking of the sheet is a mixture of PA (phenyl-α-naphthylamine), DCD (Substituted diphenylamine) and RD (trimethyl dihydroquinoline) in the same ratio. Use gum roots to prevent spillage.

The reinforcing member 33 is provided to reinforce the strength of the joint portion 30 and is attached to the upper portion of the waterproof sheet 20 which is spaced apart at a predetermined interval so as to cover both the waterproof sheets 20, Shaped glass fiber is preferably used.

The upper polyurethane layer 34 is formed on the upper surface of the reinforcing member 33. When the liquid polyurethane is applied on the upper surface of the reinforcing member 33, the liquid polyurethane penetrates into the reinforcing member 33, (Gap) between the sheet 20 and the waterproof sheet 20 to be integrated with the lower polyurethane layer 31 while filling the gaps.

The sheet with three sand on the bottom of the waterproof sheet that has appeared so far has poor adhesion to the three sand and compound layers. Therefore, there are various problems. Firstly, since the waterproof sheet is stored and transported in a roll state, the three sands are not able to function because of the problem of falling off from the compound layer. Second, In addition, there is a problem in that a large amount of three sands are separated from the compound layer due to the impact due to the fact that the sheet is thrown during the time and the construction process. Third, the sheet is shrunk or expanded according to the outside temperature, There is a problem that three sands attached to the edge portion of the sheet can not withstand the tensile force due to deformation of the sheet and are detached from the compound layer. Fourth, the organic solvent contained in the polyurethane dissolves the compound of the sheet, There is a problem that three sands can not function.

In the present invention, the insulating yarn 22 is applied to the lower part of the compound mixture to increase the adhesion with the underlying polyurethane at the time of application. Basalt or calcareous particles coated with the liquid resin are used as the insulating yarn 22, Is a mixture of polysilicon and silicate. The insulation yarn 22 is obtained by mixing inorganic materials such as inorganic pigment (mineral inorganic pigment) with basalt or calcite particles and baking the mixture at a high temperature of about 800 to 900 ° C in a rotary kiln, It is. In addition, when the baked insulating yarn is cured by coating a liquid resin mixed with polysilicon and silicate, the silylgate remains on the surface of the insulating yarn and the surface becomes rough, thereby increasing the adhesion to the compound and the adhesion with the polyurethane do.

Since the insulation yarn 22 of the present invention has a very strong adhesive force with the compound layer 21 and the lower polyurethane 32, even if the sheet shrinks or expands according to the outside air temperature, the insulation yarn does not come off, Since the insulating yarn remains bonded to the lower part of the compound layer even in the remaining part not bonded to the lower polyurethane, the sheet is insulated from the base surface and the sheet is partially bulged by the water vapor pressure generated on the concrete base surface. So that the entire surface of the sheet can be absorbed.

The polyurethane used in the waterproof layer and the joint is an improved polyurethane having a low viscosity which is obtained by reacting a polyol component with a curing agent of a polyisocyanate component and minimizing an organic solvent content during mixing by using a non- By significantly lowering the viscosity than ordinary polyurethane, it is easily spread (spread) on the long fiber nonwoven fabric on the top of the modified asphalt sheet and is self-leveling automatically by wetting, so that the construction is efficient and can be used in the field without any additional diluent Feature. In general polyurethane, since the content of the organic solvent is 5 parts by weight or more, various problems as mentioned above arise. However, the polyurethane used in the present invention has a content of organic solvent remarkably reduced to less than 2.5 parts by weight, It is one of the features that it solves the problem which it did.

Typical polyurethane waterproofing agents include 20 to 35 parts by weight of polypropylene glycol, 10 to 25 parts by weight of toluene diisocyanate, 2 to 8 parts by weight of amine (MBOCA), 30 to 40 parts by weight of extender pigment, 1 to 10 parts by weight of plasticizer, And 1 to 10 parts by weight of an aromatic solvent (Xylene, Toluene, etc.). (Urethane thinner) is additionally added in order to facilitate workability in the field of construction. However, the polyurethane used in the present invention is not limited to aromatic solvents used in general polyurethanes, but hydrocarbon solvents such as hydrocarbons hydrocarbons based solvent to minimize the organic solvent content.

The composite waterproofing method according to the present invention comprises the steps of (S1) applying a primer on a concrete base surface after arranging a base surface, (S2) applying a polyurethane onto the primer after curing the primer, A step (S3) of placing a waterproof sheet at a predetermined interval on the upper surface of the polyurethane coated surface before the applied polyurethane is cured, a step (S4) of installing a stiffener on the joint between the waterproof sheet and the waterproof sheet, A step (S5) of applying a polyurethane to fill the gaps between the waterproof sheets with the polyurethane penetrating into the reinforcing material so as to form the joints by integrating the two sheets (S5), applying the polyurethane coating material to the entire upper surface of the waterproof sheet A step S6 of forming a coating waterproof layer, and a step (S7) of coating a top coating layer at a portion where the coating waterproof layer is exposed after the coating waterproof layer is formed It is possible.

Since the width of the waterproof sheet is usually 1 m, a bonding portion is formed every 1 m. The primer is applied to a portion where the edge of the waterproof sheet is to be positioned at a width of about 100 to 300 mm. The polyurethane applied on the primer layer has a width of 100 to 200 mm Lt; / RTI > When a reinforcing material is provided on the abutting portion between the sheet and the sheet and polyurethane is applied to the abutting portion between the sheet and the sheet, the polyurethane penetrates into the reinforcing material, which is glass fiber, And the two sheets are integrated with the coating film to form a stable joint, thereby ensuring the watertightness of the joint having the highest frequency of occurrence of defects.

Polyurethane may be applied to the entire upper surface of the sheet 1 to several times after the completion of the joint application, and silica sand may be sprayed simultaneously if necessary. The polyurethane used for the joint portion may be a general polyurethane, but it is preferable to use a water-hardened urethane or a water-soluble urethane. Such a water-hardened urethane or a water-soluble urethane can be produced by a process in which a compound layer of a waterproof sheet is dissolved in an organic solvent The breakage of the joint portion can be fundamentally prevented.

Although only polyurethane is used as a coating material so far, the liquid coating material may be polyurethane, acrylic rubber, polyurea, cement-incorporated polymer, rubberized asphalt, epoxy, FRP, have.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Various modifications and variations will be possible without departing from the spirit of the invention. Therefore, the scope of the present invention should be construed as being covered by the scope of the appended claims, and technical scope within the scope of equivalents thereof should be construed as being included in the scope of the present invention.

10: Concrete base
20: waterproof sheet 21: compound layer
22: insulating yarn 23: long-fiber nonwoven fabric
30: bonding portion 31: primer layer
32: Lower polyurethane 33: Stiffener
34: Upper polyurethane
40: Coating layer

Claims

A composite waterproof structure in which a waterproof sheet is provided on an upper surface of a concrete base and a polyurethane coating material is applied on the entire upper surface of the waterproof sheet to form a waterproof layer,
The joining portion, to which the waterproof sheet and the waterproof sheet are connected,
A primer layer applied to the concrete base;
A lower polyurethane layer applied over the primer layer;
A waterproof sheet having a lower edge attached to an upper portion of the lower polyurethane layer and spaced apart from each other at a predetermined interval;
A stiffener installed at an upper portion of the waterproof sheet that is spaced apart at a predetermined interval and is installed so as to cover both of the waterproof sheets;
An upper polyurethane layer coated on the upper surface of the reinforcing member and integrated with the lower polyurethane layer by being filled in the gap between the waterproof sheets by penetrating into the reinforcing member;
Wherein the waterproof sheet comprises:
Modified asphalt compound layer;
An insulation yarn attached to a lower portion of the compound layer;
A long fibrous nonwoven fabric impregnated with the projected long fibers, and laminated on the top of the compound layer with the long fibers projecting from the top;
Wherein the composition of the compound layer is composed of:
35 to 50 parts by weight of straight asphalt;
5 to 10 parts by weight of synthetic rubber (SBS) which is a synthetic rubber;
10 to 15 parts by weight of butyl rubber;
5 to 10 parts by weight of a process oil;
10 to 15 parts by weight of polybutene;
2 to 5 parts by weight of an oil absorbent;
5 to 10 parts by weight of a filler (dolomite);
2 to 5 parts by weight of aluminum stearate;
2 to 4 parts by weight of an antioxidant;
1 to 3 parts by weight of a special additive;
Wherein the modified asphalt sheet is a modified asphalt sheet in which the modified asphalt sheet is mixed with the modified asphalt sheet.

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The method according to claim 1,
Wherein the insulation yarn is basalt or calcareous particles coated with a liquid resin, and the liquid resin is a mixture of polysilicon and silicate. The composite waterproof structure using the modified asphalt sheet and the liquid phase coating material.

The method according to claim 1,
Wherein the reinforcing material is a glass fiber, and the composite waterproof structure using the modified asphalt sheet and the liquid phase coating material.

The method according to claim 1,
Wherein the polyurethane used in the waterproof layer and the joint portion is a low viscosity polyurethane using a hydrocarbon solvent in a non-aromatic solvent, and a composite waterproof structure using the modified asphalt sheet and the liquid film material.

A composite waterproofing method for constructing a waterproofing layer by providing a waterproof sheet on an upper surface of a concrete base and applying a polyurethane coating material to the entire upper surface of the waterproof sheet,
The method includes:
Applying a primer to the concrete surface at a predetermined interval;
Applying a polyurethane on top of the primer after curing;
Before the applied polyurethane is cured, installing a waterproof sheet at a predetermined interval above the polyurethane application surface;
Installing a stiffener on the abutment between the waterproof sheet and the waterproof sheet opposed to each other;
Applying polyurethane to the upper portion of the reinforcing material, filling the gap between the waterproof sheets with the polyurethane penetrating into the reinforcing material to form a joint by integrating both sheets;
Coating a polyurethane coating material on the entire upper surface of the waterproof sheet to form a coating waterproof layer;
Wherein the waterproof sheet comprises a waterproof sheet,
Modified asphalt compound layer;
An insulation yarn attached to a lower portion of the compound layer;
A long fibrous nonwoven fabric wherein the projected fibers are impregnated into the compound layer and the upper part is laminated on the compound layer with the fibers protruding;
Wherein the composition of the compound layer is a modified asphalt sheet having a composition ratio
35 to 50 parts by weight of straight asphalt;
5 to 10 parts by weight of synthetic rubber (SBS) which is a synthetic rubber;
10 to 15 parts by weight of butyl rubber;
5 to 10 parts by weight of a process oil;
10 to 15 parts by weight of polybutene;
2 to 5 parts by weight of an oil absorbent;
5 to 10 parts by weight of a filler (dolomite);
2 to 5 parts by weight of aluminum stearate;
2 to 4 parts by weight of an antioxidant;
1 to 3 parts by weight of a special additive;
Wherein the modified asphalt sheet and the liquid phase coating material are mixed.

The method according to claim 6,
Wherein the step of applying a top coat is applied to a portion where the water-repellent layer is exposed after the formation of the water-repellent layer, so that the water-repellent layer is formed.

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