KR20140066313A - Embossed color steel sheet and manufacturing method thereof - Google Patents

Abstract

According to the present invention, a colored steel sheet having an embossed film can be obtained by forming an embossment onto an upper film layer coated with either a fluoride resin paint or a polyester resin paint, and by coating a clearance layer to prevent the elastic fluorine resin paint from being restored, while minimizing a roll separating force applied when forming the embossment and still realizing beautiful appearances such as hologram patterns.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an emboss color steel sheet,

The present invention relates to a coated emboss color steel sheet and a method of manufacturing the same, and more particularly, to a method for manufacturing a coated emboss color steel sheet by embossing an embossed color film on a top surface coated with a fluororesin coating or a polyester resin coating, The present invention relates to a coated film emboss color steel sheet and a method of manufacturing the same.

Generally, as a method of forming a hologram pattern on the surface of a workpiece, a method of forming an emboss on a film or thin film containing a polymer or a resin and bonding it to the surface of the workpiece using an adhesive or the like is used, The process of coating the steel sheet, and the process of joining the film and the steel sheet are separated, which complicates the manufacturing process and increases the cost.

On the other hand, a PCM (Pre-Coated Metal) color steel sheet in which an emboss pattern can be embodied and a method of manufacturing the same are commonly used in which an emboss is formed on a base steel sheet and then a coating film is sequentially formed. It is impossible to realize a fine pattern and a relatively large pressure is required.

In addition, although there is a method of forming an emboss in the coating film by thickening the coating film, it is difficult to form a fine emboss for realizing a hologram pattern and the like due to the restoring force due to the elasticity of the coating, There is a problem that it must be done.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and it is an object of the present invention to provide a method of forming an emboss on an upper coating layer coated with a fluororesin coating or a polyester resin coating, Color coated steel sheet which can realize a beautiful appearance such as a hologram pattern while minimizing a pressing force applied when forming an embossment.

Preparing a base steel sheet selected from a sheet metal body and a coated steel sheet; Treating non-chromate or chromate to form a pretreatment layer; Treating the toxic or non-toxic anticorrosive pigment to form an anticorrosive primer coat layer; Coating a fluororesin coating or a polyester resin coating to form an upper coating layer; Forming an emboss using an embossing roll; And coating a clear paint to form a clear layer under a predetermined condition in a continuous process, thereby reducing the cost of the coating film emboss color steel sheet.

In order to achieve the above-mentioned object, there is provided a steel sheet comprising: a base steel sheet selected from a metal sheet body and a coated steel sheet; Pretreatment layer; Anticorrosive primer coating layer; An upper coating layer having an embossed upper surface; And a clear layer sequentially on the surface of the coated film.

In one embodiment of the present invention, a print layer may be further included on the top coat layer.

In one embodiment of the present invention, the top coat layer may be formed by coating a fluororesin coating material including a main resin made of a fluororesin, a thermoplastic acrylic resin or a thermoplastic resin including a thermosetting acrylic resin, a solvent, and a pigment have.

In one embodiment of the present invention, the top coat layer comprises a modified polyester compound having a number average molecular weight of 8,000 to 20,000, a glass transition temperature (Tg) of 20 ° C to 45 ° C and an OH value of 15 to 40, , And a solvent-containing polyester resin paint.

In one embodiment of the present invention, the fluororesin coating material may further include a storage stabilizer composed of an alkoxy compound having a molecular weight of 100 to 1,000.

In one embodiment of the present invention, the fluororesin coating material may further include a neutral dispersant having both an acid value and an amine value.

According to an aspect of the present invention, there is provided a method of manufacturing a steel sheet, comprising the steps of: preparing a base steel sheet selected from a sheet metal plate and a coated steel sheet; Forming a pretreatment layer; Forming an anticorrosive primer coat layer; Coating a fluororesin coating or a polyester resin coating to form an upper coating layer; Forming an emboss using an embossing roll; And coating a clear paint to form a clear layer. A method for manufacturing a coated film emboss color steel sheet is provided.

In one embodiment of the present invention, the method may further include the step of forming a print layer by performing a print print process after forming the embossment using the embossing roll.

In one embodiment of the present invention, the fluororesin coating material may include a main resin made of a fluororesin, a thermoplastic acrylic resin, or an auxiliary resin including a thermosetting acrylic resin, a solvent, and a pigment.

In one embodiment of the present invention, the polyester resin paint is a modified polyester resin having a number average molecular weight of 8,000 to 20,000, a glass transition temperature (Tg) of 20 to 45 占 폚, and an OH value of 15 to 40 , Additives, and solvents.

In one embodiment of the present invention, the fluororesin coating material may further include a storage stabilizer composed of an alkoxy compound having a molecular weight of 100 to 1,000.

In one embodiment of the present invention, the fluororesin coating material may further include a neutral dispersant having both an acid value and an amine value.

In one embodiment of the present invention, the embossing roll may include an upper roll and a lower roll.

In one embodiment of the present invention, the lower roll may be a rubber lower roll.

According to an embodiment of the present invention, an emboss is formed on a top coat layer coated with a fluororesin paint or a polyester resin paint, and a clear layer is coated to prevent the coating paint from being restored by elasticity, It is possible to obtain a coated emboss color steel sheet in which a beautiful appearance such as a hologram pattern and the like can be realized while minimizing the pressing force applied at the time of emboss formation.

According to an embodiment of the present invention, there is also provided a method of manufacturing a steel sheet, comprising: preparing a base steel sheet selected from a sheet metal plate and a coated steel sheet; Forming a pretreatment layer using non-chromate or chromate; Forming an anticorrosive primer coating layer using a toxic or non-toxic anticorrosive pigment; Coating a fluororesin coating or a polyester resin coating to form an upper coating layer; Forming an emboss using an embossing roll; And a step of forming a clear layer by coating a clear paint is performed in a continuous process under a predetermined condition, so that the process cost can be reduced.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a cross-sectional view of a coated embossment color steel sheet in which an emboss is formed on an upper surface of a top coat layer according to an embodiment of the present invention.
2 is a cross-sectional view of a coated embossment color steel sheet including a print layer according to an embodiment of the present invention.
3 is a schematic view illustrating a method of manufacturing a coated emboss color steel sheet by a continuous process according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view of a coated-film embossed-color steel sheet according to an embodiment of the present invention, which includes a step of forming a print layer by a print-printing process after forming an emboss using an embossing roll, And the manufacturing method is schematically shown.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "indirectly connected" . Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a layer structure of a coated film emboss color steel sheet 100 according to an embodiment of the present invention.

A top coat layer 140 formed with an embossment 170 on an upper side and a top coat layer 140 formed on an upper side of the top coat layer 130 and a clear layer 150, Coated steel sheet is provided.

As the base steel sheet 110 according to an embodiment of the present invention, for example, a metal plate itself or a base plate having a known plating layer formed thereon such as a zinc-aluminum-silica alloy hot dip galvanizing, , Aluminum, copper, and a stainless steel base plate, but the present invention is not limited thereto.

A known pretreatment coating layer 120 such as a phosphate coating, a chromate, a non-chromate coating or the like is included to ensure interlayer adhesion and basic corrosion resistance between the backing steel sheet 110 and the anti-corrosive primer coating layer 130 .

As used herein, the term " chromate film " refers to a thin film composed mainly of chromium chromate formed on a metal such as zinc by chromate treatment.

On the other hand, an environmentally friendly non-chromate film treatment is preferable for good film adhesion, but there is a problem that the corrosion resistance is somewhat lower than that of conventional chromate film treatment, and a known chromate or chromate film having a composition of trivalent chromium Processing may be performed.

The anti-corrosive primer coating layer 130 according to an embodiment of the present invention can improve the interlayer bonding force, chemical resistance, and corrosion resistance between the surface of the base steel sheet 110 and the top coat layer 140.

As the paint for coating the anti-corrosive primer coat layer 130, epoxy paints, epoxy-modified polyester paints, and other polyester paints for commercial PCM (Pre-Coated Metal) may be used.

Conventional chromium-based anticorrosive pigments or lead-based anticorrosive pigments may be used as the pigments for forming the anticorrosive primer coating layer 130. However, in order to meet the flow of the use of environmentally controlled substances worldwide, Non-toxic anti-corrosive pigments may be used.

As used herein, the term " anticorrosive pigment " refers to a pigment that prevents pigment from reacting with the oil in the vehicle to form a metallic soap, or is decomposed by moisture to become alkali-alkali, The pigment is generally referred to as a pigment which exhibits the effect of a method such as making or increasing a vent resistance.

Conventional anticorrosive pigments include lead and chromium-containing Red Leed, Zinc Potassium Chromate, Zinc Tetraoxy Chromate, and Strontium Chromate. no.

Examples of non-toxic anti-corrosive pigments include borate-based barium metaborate, molybdate-based zinc molybdate, calcium zinc molybdate, zinc phosphate (Zinc phosphate), aluminum triphosphate (Aluminum Triphosphate), silicate-based calcium borosilicate, phosphosilicate, calcium ion-exchanged silicate, and magnesium ion-exchanged silicate. But is not limited thereto.

The dry film thickness of the anticorrosive primer coating layer 130 may be 3 탆 to 20 탆. When the dry film thickness of the anticorrosive primer coating layer is less than 3 탆, the anticorrosion property and adhesion may be deteriorated. If the anticorrosive primer coating film thickness is more than 20 탆, the workability may be deteriorated due to thickening and may be disadvantageous in terms of economy.

Since the top coat layer 140 is formed on the top surface of the anticorrosive primer coat layer 130, the dry coat layer 140 of the anticorrosive primer coating layer may be formed in consideration of workability and economical efficiency depending on the paint used for forming the top coat layer 140. [ The thickness may be varied from 4 탆 to 6 탆 when a fluororesin paint is used, and from 10 탆 to 15 탆 when a polyester resin paint is used.

The top coat layer 140 providing the hologram pattern by forming the embossment 170 on the color steel sheet of the present invention will be described in detail.

The top coat layer 140 according to an embodiment of the present invention may be formed using a fluororesin paint, a polyester resin paint, a silicone paint, an acrylic resin paint, a urethane resin paint, an alkyd paint, But is not limited thereto.

It is preferable to use a fluororesin paint or a polyester resin paint softened to be suitable for a continuous process.

The top coat layer 140 in the present invention may be a fluororesin coating material containing a fluororesin in order to exhibit stable physical properties without discoloring or deteriorating the color of the coating film even when used for a long time in an external environment.

The fluororesin is a thermoplastic or crystalline polymer containing two fluorine (F) atoms in a molecule constituting the resin, and the vinylidene fluoride is a resin having a molecular weight of And has a stable structure which is excellent in solvent resistance and does not easily dissolve in a solvent at room temperature.

In the present invention, since the fluororesin is a main resin having basic properties such as weather resistance and chemical resistance, it is used without any change and has excellent color stability and excellent durability even by long-term external exposure.

Since the fluororesin paint has a relatively soft nature compared to a paint comprising a polyester as a main resin, it is possible to form an embossing which gives a fine downward load to the surface of the steel sheet while giving a beautiful appearance.

When the total solid content corresponding to the sum of the content of the fluororesin and the acrylic auxiliary resin is 100% by weight, the content of the fluororesin is preferably 70% by weight or more in order to exhibit long-term weatherability or other basic properties, It is impossible to exert the weather resistance and solvent resistance expected for the fluororesin as described above.

An example of a fluororesin coating that can be used for application to the fluororesin coating of the present invention is KYNAR 500 from Pennant, USA.

On the other hand, since the fluororesin coating is chemically inert and has a limit of film adhesion due to non-tackiness, an auxiliary resin can be used to improve such adhesiveness.

As the auxiliary resin, thermoplastic acrylic resin or thermosetting acrylic resin may be alternatively used, or a thermosetting acrylic resin having reactivity with a thermoplastic acrylic resin in use may be used, Self-cleaning may also be implemented.

The total amount of the two acrylic resins is preferably 30 wt% or less so as not to deteriorate the weather resistance of the fluororesin.

As a pigment, ceramic coloring pigments having excellent heat resistance, chemical resistance, weather resistance and corrosion resistance can be used to ensure long-term weatherability for more than 20 years. Metallic and mica pigments may be used alone or in combination of two or more thereof depending on the color selection.

Since the fluororesin coating material has a limited solubility, it can be produced with a solvent-dispersed coating material. The fluororesin coating material can be easily melted so as to complete an excellent coating film upon baking, and a high boiling point An ester type solvent, and a low boiling point solvent which is advantageous in viscosity adjustment and coating operation can be mixed and used.

On the other hand, the reaction of the methoxysilyl groups (SiOMe) is stable when there is relatively no moisture, but the reaction is rapid in the presence of the hydroxyl group (-OH) of the resin in the presence of water, Shield the locks or design the moisture content to a minimum.

Therefore, in the present invention, an alkoxy compound may be added as a storage stabilizer in order to shield the hydroxyl group (-OH) contained in the main resin and the hydroxyl group (-OH) contained in the other composition components.

The alkoxy compound preferably has a mass average molecular weight of 100 to 1000. When the weight average molecular weight is less than 100, the storage stability is lowered. When the weight average molecular weight is more than 1000, A defective defect is generated.

Examples of the alkoxy compounds that can be used in the present invention include KBM 13 manufactured by Shinnitsu of Japan, trimethyl orthoformate of HULS, triethyl orthoformate, trimethyl orthoacetate, edited by BAYER, (ADDITIVE TI).

Meanwhile, a dispersant may be used in the present invention in order to complement color separation and painting workability by introducing a special thermosetting acrylic resin as an auxiliary resin.

As a suitable dispersing agent, Disperbyk-140, Disperbyk-142, Disperbyk-145 and similar grades of BYK Co. can be used as neutral dispersants having an acid value (unit mgKOH / g) and an amine value (unit mgKOH / g) , And the amount used is suitably from 0.2 to 0.5% by weight.

On the other hand, when the top coat layer 140 is formed by coating a fluororesin paint, the dry coat thickness is preferably 10 to 30 占 퐉, more preferably 15 to 25 占 퐉. When the dry film thickness of the upper coat layer is less than 15 탆, the hiding power is poor, and when it exceeds 25 탆, the workability and economy are inferior.

When the top coat layer 140 is formed by coating a polyester resin paint rather than a fluororesin paint, the effect of embossing may be realized more remarkably.

The polyester resin coating material according to one embodiment of the present invention is characterized by having an oil-free polyester having a number average molecular weight of 8,000 to 20,000, a glass transition temperature (Tg) of 20 to 45 占 폚, an OH value of 15 to 40, , A modified oil-free polyester compound, an additive, and a solvent.

The polyester resin coating material for general building materials has a network structure such as a hydroxyl group and a carboxyl group in the main chain of the polyester resin and has a network structure when formed with a melamine resin used as a crosslinking resin (curing agent) of the coating film, Elongation of the coating film after formation was extremely limited. On the other hand, since the main chain of the water-based polyester resin has a linear structure, the elongation of the coating film is very excellent, but it is weak in corrosion resistance and stain resistance.

In order to compensate for these disadvantages, the polyester main resin according to one embodiment of the present invention has an average molecular weight of 8,000 to 20,000, May be a modified oil-free polyester compound obtained by reacting an oil-free polyester having a glass transition temperature (Tg) of 20 ° C to 45 ° C and an OH value of 15 to 40 with melamine.

If the average molecular weight is less than 8,000, the durability of the coating film may be deteriorated. If the average molecular weight is more than 20,000, the number of functional groups may become too small and the curing reactivity may be deteriorated.

If the glass transition temperature (Tg) is lower than 20 캜, the viscosity of the coating film may become excessively high. If the glass transition temperature (Tg) is higher than 45 캜, the resin may not melt easily. Therefore, It is preferable to maintain the temperature at 20 캜 to 45 캜.

On the other hand, if the OH value is less than 15, the number of functional groups may become too small, and the curing reactivity may deteriorate. If the OH value is more than 40, the durability of the coating film may be deteriorated.

When melamine is used alone or in a mixture of methoxy melamine and butoxy melamine, compatibility with melted melamine is remarkably reduced and melamine is transferred to the upper layer of the paint to cause paint failure. Therefore, Is preferably an alkylated form of hexamethoxymethyl melamine having a number average molecular weight of 300 to 1,000 and a slightly alkylated form of methoxybutoxy type melamine.

Resinine 757 (SOLUTIA), RESIMINE 751 (SOLUTIA), CYMEL 1168 (CYTEL), CYMEL 1170 (CYTEL), CYMEL 232 (CYTEL) and the like are commercially available melamine .

The additive is a curing accelerator for promoting crosslinking between a polyester resin as a main resin and a melamine resin as a crosslinking resin to improve a coating film density and stain resistance.

Toluenesulfonic acid (PTSA), dinonylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid (DDBSA) and the like as the masked acid by blocking with an amine. In addition, epoxy-masked sulfonic acid or organic resin-masked sulfonic acid can be used, but PTSA having a high degree of low-temperature dissociation is preferred in order to achieve maximum coating density at a predetermined baking time.

In addition to the popping property of the embossed uneven parts, the solvent may be selected from the group consisting of hydrocarbons, esters, ethers, and acetates in consideration of the interlocking property with the printing ink film, the ink film permeability, And the like.

The dry film thickness of the top coat layer is preferably from 10 탆 to 40 탆, more preferably from 20 탆 to 40 탆. When the film thickness of the upper coat layer 140 is less than 10 탆, the film is excessively thinned, which may restrict the pattern formation. If it is more than 40 탆, the film is excessively thickened, The application of colored steel sheets may be extremely limited.

Table 1 shows that when the top coat layer is formed using the fluororesin paint according to one embodiment of the present invention, the texture of the pattern according to the dry film thickness of each of the anticorrosive primer coat layer 130 and the top coat layer 140 Respectively.

Dry film thickness (unit: 탆) Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 primer 5 5 10 15 20 normal course 20 25 15 10 10 Pattern formation texture Xx × × △ ○

(?: Very good,?: Good,?: Fair, X: poor)

In the case of a technique of directly forming an emboss pattern on the surface of a steel sheet by the formation of concavities and convexities of the conventional ground steel sheet, the embossing pattern formed on the base steel sheet by the restoring force due to the elasticity of each coating layer coating material formed on the base steel sheet There is a problem that it is difficult to realize a beautiful appearance such that the pattern is not implemented as it is, or the emboss pattern is blurred.

The emboss pattern 170 according to an embodiment of the present invention has a shape in which indentations are grabbed on the upper flat surface of the upper coat layer 140, .

The clear layer 150 according to an embodiment of the present invention will be described in detail.

The clear layer 150 serves to visually maintain the texture of the embossment 170 formed on the top coat layer 140 and to make the surface of the finished color steel sheet high-gloss.

The clear layer 150 may be formed as a single layer on the upper surface of the top coat layer 140 on which the embossment 170 is formed and may be formed in a multi-layer structure according to the demand of the customer. When the clear layer 150 is formed in multiple layers, the linearity, smoothness, corrosion resistance, moisture resistance, and the like of the color steel sheet can be further improved as compared with the case of a single layer.

As a clear paint that can be used when a product that is stabilized in a clear and physically stable state is required, there is a UV curable paint or EB (Electro-Beam) curable paint.

When oil-based thermosetting paints are used, the visual effect may be deteriorated due to restoration of the pattern. On the other hand, a low temperature curing type paint or a natural curing type paint can be used, which is very difficult to apply to a continuous process.

The UV curable coating material or the EB curable coating material is cured at a low temperature and cured by light rather than heat. Since the heat is not generated, the embossed texture of the top coating layer can be maintained as it is, The effect of the emboss can be maximized.

Examples of the coloring pigment contained in the clear paint composition include azo pigments such as beta-naphthols (insoluble), naphthol AS (insoluble), condensed azo pigments, phthalocyanine pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, A tint dye system, a philocholine system, a fluorovinyl system, a quinophthalone system, a metal complex, and the like can be used.

On the other hand, it is more preferable to use a pigment of the nano-pigment concept in order to express a clearer color. In this case, since the particle size during dispersion is tens to hundreds of nanometers, the particle size is smaller than that of an ordinary oil / There is an advantage of sharpness of color. It is preferable to use Chromatic Color Pigments of various colors of PNC corporation as a kind of usable pigment.

In addition, silicone oil, waxes, and the like are added to the clear paint in accordance with functional needs such as lubricity, cleansing properties, antibacterial property, etc. to facilitate processing and handling of the material, and hydrophilicity is imparted to the final coating film component, Cleanliness may be imparted, and general and specific antibacterial additives may be added to the coating material to impart antibacterial functionality.

2 is a cross-sectional view showing a coat layer structure of a coated film emboss color steel sheet including a print layer according to another embodiment of the present invention.

The print layer 160 may be formed on the top coat layer 140 on the cross-sectional structure of the coat layer, but may not be included according to the needs of the consumer. By forming the print layer, a more colorful appearance can be realized.

The print ink constituting the print layer 160 may be any of known PCM print inks. However, in addition to the quick drying property and the adhesion to the top or bottom of the ink, the printability at the concavo-convex interface should be considered .

In the case of pearl and metal in the pigment used for the PCM print ink, the particle size is preferably set to a maximum of 60 mu m or less. When particles exceeding 60 mu m are used, the linearity of the surface may be deteriorated due to the protrusion of the particles, and the printing property of the mesh interface may be poor, and when the clear coat is roll coated on the printing layer, It can cause the coating failure.

By applying the PCM printing ink having the above-mentioned physical properties to the continuous process, besides the three-dimensional feeling due to the basic unevenness of the embossing, the color difference (hiding power) of uneven irregularities can be reduced by expressing various additional textures and colors It is possible to provide a coated film emboss color steel sheet having a three-dimensional and colorful appearance.

3 is a schematic view illustrating a method of manufacturing a coated-film emboss color steel sheet by a continuous process according to an embodiment of the present invention.

Preparing a base steel sheet selected from a sheet metal body and a coated steel sheet (S1); Forming a pretreatment layer (S2); Forming an anti-corrosive primer coat layer (S3); (S4) coating a fluororesin paint or a polyester paint to form an upper coat layer; (S5) forming an emboss using an embossing roll; And a step (S6) of coating a clear paint to form a clear layer. A method for manufacturing a coated film emboss color steel sheet by a continuous process is provided.

In the step (S1) of preparing a base steel sheet selected from a sheet metal body and a coated steel sheet according to an embodiment of the present invention, the base steel sheet may be a sheet metal body or a zinc- , Electric and hot dip galvanizing, and known metallic / non-metallic substrates such as copper, aluminum, copper, and stainless steel disks can be used, but the present invention is not limited thereto.

In the step S2 of forming the pretreatment layer according to an embodiment of the present invention, the non-chromate or chromate may be treated and dried at 50 DEG C to 100 DEG C to form the pretreatment layer.

The environmentally friendly non-chromate film treatment is preferable for good coating film adhesion, but it has a disadvantage in that the corrosion resistance is somewhat lower than that of the conventional chromate film treatment, so that a chromate film treatment of known chromate or trivalent chromium is performed You may.

According to an embodiment of the present invention, the step S3 of forming an anti-corrosive primer coating layer may be performed by treating a toxic or nontoxic anti-corrosive pigment and heating and cooling the anti-corrosive primer coating layer at PMT (Peak Metal Temperature) .

The coating method of the anticorrosive primer coating is not limited to the roll coating method but may be applied to a curtain flower method used in a PCM (Pre-Coated Metal) steel sheet, but the present invention is not limited thereto.

The baking conditions after coating are preferably such that the peak metal temperature (PMT) in the continuous line is 170 ° C to 240 ° C, and more preferably the peak metal temperature (PMT) is 180 ° C to 210 ° C.

(S4) of forming a top coating layer by coating and heating a fluororesin coating or a polyester resin coating according to an embodiment of the present invention will be described.

The composition of the fluororesin coating material or the polyester resin coating material used in the above step is as described above.

The coating method of the fluororesin coating material or the polyester resin coating material is not limited to the roll coating method but may be applied to a curtain flower method used in a PCM (Pre-Coated Metal) steel sheet. But is not limited thereto.

The baking conditions after coating are preferably such that the peak metal temperature (PMT) in the continuous line is 200 ° C to 300 ° C, and more preferably the peak metal temperature (PMT) is 210 ° C to 250 ° C.

(S5) of forming an emboss using an embossing roll according to an embodiment of the present invention will be described in detail.

As a method for forming embosses and imparting a texture to them, a method of laminating an embossed steel plate to an original plate before coating, a method of laminating a vinyl chloride resin film, and a method of pressing a steel sheet coated with a thermoplastic paint A method of forming embosses, and the like are known.

According to the embossing method of the present invention, the upper coating layer is formed by coating the fluororesin coating or the polyester resin coating, and the emboss pattern is formed so that the indentation of the emboss pattern is formed on the upper coating layer A single-sided emboss pattern can be formed on the top coat layer by passing the sandwiched between the stamped top roll and the bottom roll supporting the steel sheet to form concavities and convexities and then cooling the single-sided emboss pattern.

That is, when the steel sheet passes between the upper roll (embossing roll) and the lower roll, the embossing pattern can be formed by applying a downward force.

As shown in Table 2, when the lower roll is made of metal in the configuration of the upper roll and the lower roll, it is very unstable in the process. It is very difficult to form the emboss having the same depth in both the right and left directions. Therefore, it is preferable to use rubber roll as the lower roll.

Since the elasticity of the rubber can relieve pressure deviations at the time of pressing (pushing down) due to the elasticity of the rubber, the depth of the embossing can be made even and the breaking force can be excessively prevented and the coating film can be prevented from being broken.

Lower roll type Metal bottom roll Rubber bottom roll Exterior Uneven depth in left and right Uniform depth to left and right When pressurized There is paint film breakdown No film destruction

(S6) of forming a clear layer by coating a clear paint according to an embodiment of the present invention will be described in detail.

The clear layer functions to visually maintain the texture of the emboss formed on the top coat layer and to make the surface of the finished color steel sheet high-gloss.

The clear layer may be formed as a single layer on the upper surface of the upper coating layer on which the emboss is formed, and may be additionally formed in a multi-layer according to the demand of the customer. In the case where the clear layer is formed in multiple layers, the linearity, smoothness, and the like of the color steel sheet can be improved as compared with the case of a single layer.

As a clear paint that can be used when a product that is stabilized in a clear and physically stable state is required, there is a UV curable paint or EB (Electro-Beam) curable paint.

When oil-based thermosetting paints are used, the visual effect may be deteriorated due to restoration of the pattern. On the other hand, a low temperature curing type paint or a natural curing type paint can be used, which is very difficult to apply to a continuous process.

The UV curable coating material or the EB curable coating material is cured at a low temperature and cured by light rather than heat. Since the heat is not generated, the embossed texture of the top coating layer can be maintained as it is, The effect of the emboss can be maximized.

Examples of the coloring pigment contained in the clear paint composition include azo pigments such as beta-naphthols (insoluble), naphthol AS (insoluble), condensed azo pigments, phthalocyanine pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, A tint dye system, a philocholine system, a fluorovinyl system, a quinophthalone system, a metal complex, and the like can be used.

On the other hand, it is more preferable to use a pigment of the nano-pigment concept in order to express a clearer color. In this case, since the particle size during dispersion is tens to hundreds of nanometers, the particle size is smaller than that of an ordinary oil / There is an advantage of sharpness of color. It is preferable to use Chromatic Color Pigments of various colors of PNC corporation as a kind of usable pigment.

In addition, silicone oil, waxes, and the like are added to the clear paint in accordance with functional needs such as lubricity, cleansing properties, antibacterial property, etc. to facilitate processing and handling of the material, and hydrophilicity is imparted to the final coating film component, Cleanliness may be imparted, and general and specific antibacterial additives may be added to the coating material to impart antibacterial functionality.

The clear layer may be formed using a clear paint as described above, but it is preferable to use a UV curable paint or an EB curable paint.

The UV curable coating material or the EB curable coating material is cured at low temperatures and is cured by light rather than heat. Since the heat is not generated, the embossed texture of the top coating layer can be maintained as it is, The effect of the emboss can be maximized. The coating method is not limited to a roll coating method, but a curtain flower method used in a PCM (Pre-Coated Metal) steel sheet may be applied, but is not limited thereto.

FIG. 4 is a cross-sectional view of an embossing embossing process according to an embodiment of the present invention, which further comprises a step (S7) of forming a print layer by printing and printing processing after embossing using an embossing roll, And a method of manufacturing a colored steel sheet is schematically shown.

The method may further include a step (S7) of forming a print layer by a print-printing process after forming the top coat layer on which the emboss has been formed. This is a step of further forming a print layer using a PCM print ink having the above-described characteristics on the top surface of the top coat layer formed with the embossing.

The print layer may be formed by any one of a printing ink printing process on a PCM line, a transfer method, an offset method, and a silk-screen method.

Meanwhile, each step of the method for manufacturing a coated embossment color steel sheet according to an embodiment of the present invention is characterized by a continuous process.

In the case of a discontinuous process such as a conventional sheet process, a plate-like base steel sheet having a predetermined size is arranged in a coating process line using a conveyor system, and the plate-like base steel sheet is coated and dried at each process step, sheet type color steel sheets could be manufactured. The discontinuous process has a problem in that the productivity is decreased in proportion to the interval between the sheets and the color steel sheet in the sheet form produced by the discontinuous process has a problem that the storage efficiency at the time of product storage and the transportation efficiency at the time of product shipment are inferior .

On the other hand, in the case of the continuous process, the base steel sheet continuously passing continuously without separation is passed through each process step of the continuous line so as to have a certain size, and the finished product is not a sheet but a roll Wound and stored. Therefore, the continuous process is excellent in productivity compared to the conventional discontinuous process, and the color steel sheet produced by the continuous process can greatly improve the storage efficiency, transportation efficiency, and the like.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: Coating emboss color steel plate
110:
120: Pre-treatment layer
130: anticorrosive primer coating layer
140: top coat layer
150: clear layer
160: Printed layer
170: emboss

Claims (14)

A ground steel plate selected from a metal plate body and a plated steel plate; Pretreatment layer; Anticorrosive primer coating layer; An upper coating layer having an embossed upper surface; And a clear layer in this order.
The method according to claim 1,
Further comprising a print layer on the top coat layer. 3. The method according to claim 1 or 2,
Wherein the upper coating layer is formed by coating a fluororesin coating material comprising a main resin made of a fluororesin, a thermoplastic acrylic resin, or an auxiliary resin including a thermosetting acrylic resin, a solvent, and a pigment. 3. The method according to claim 1 or 2,
Wherein the top coat layer comprises a polyester resin comprising a modified polyester compound having a number average molecular weight of 8,000 to 20,000, a glass transition temperature (Tg) of 20 ° C to 45 ° C and an OH value of 15 to 40, Coated embossed steel sheet, which is formed by coating a paint. The method of claim 3,
Wherein the fluororesin coating further comprises a storage stabilizer composed of an alkoxy compound having a molecular weight of 100 to 1,000. The method of claim 3,
Wherein the fluororesin coating further comprises a neutral dispersant having both an acid value and an amine value. Preparing a base steel sheet selected from a metal sheet body and a coated steel sheet; Forming a pretreatment layer; Forming an anticorrosive primer coat layer; Coating a fluororesin coating or a polyester resin coating to form an upper coating layer; Forming an emboss using an embossing roll; And coating a clear paint to form a clear layer. 8. The method of claim 7,
Further comprising the step of forming a print layer by a print-printing process after forming the embossment using the embossing roll. 9. The method according to claim 7 or 8,
Wherein the fluororesin coating material comprises a main resin made of a fluororesin, a thermoplastic acrylic resin, or an auxiliary resin comprising a thermosetting acrylic resin, a solvent, and a pigment. 9. The method according to claim 7 or 8,
The polyester resin paint includes a modified polyester compound having a number average molecular weight of 8,000 to 20,000, a glass transition temperature (Tg) of 20 ° C to 45 ° C and an OH value of 15 to 40, an additive, and a solvent In method. 10. The method of claim 9,
Wherein the fluororesin coating further comprises a storage stabilizer composed of an alkoxy compound having a molecular weight of 100 to 1,000. 10. The method of claim 9,
Wherein the fluororesin coating further comprises a neutral dispersant having both an acid value and an amine value. 8. The method of claim 7,
Wherein the embossing roll comprises an upper roll and a lower roll. 14. The method of claim 13,
Wherein the lower roll is a rubber material lower roll.

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