JP5680721B2 - PCM color steel plate having a three-dimensional pattern and method for producing the same - Google Patents

Description

  The present invention relates to a PCM color steel plate and a method for manufacturing the same, and more specifically, rotary screen printing technology is applied to a continuous painting process of a color steel plate to improve productivity and form various patterns or patterns. The present invention relates to a rotary screen PCM (Pre-Coated Metal) color steel plate and a method of manufacturing the same.

  Conventional painting process of PCM color steel sheet is generally performed by Gravure Offset method. In the offset method, a pattern is printed on a steel plate to be coated using a printing roll or transfer roll on which a pattern or pattern is formed.

  The gravure offset method has a problem that the resolution of the pattern printed on the steel sheet is low due to a defect in the mold that occurs in the stage of forming the pattern or pattern on the printing roll or transfer roll.

  On the other hand, print printing and silk screen printing techniques have been used to print various patterns on color steel plates that are generally used for building materials and home appliances.

  However, since the pattern formed by the print printing has a thin film thickness, it does not meet the needs of consumers for the three-dimensional effect or the high-class feeling. In the case of the silk screen printing, the three-dimensional effect is not achieved. However, there is a problem that the manufacturing cost of the sheet type is high due to the fact that it cannot express or implement delicate patterns such as holograms.

  Therefore, there is a need for technical development regarding PCM color steel sheets with various three-dimensional patterns, and methods for manufacturing PCM color steel sheets that can be realized and have improved productivity and workability.

  The present invention is for solving the above-mentioned problems of the prior art, and in the present invention, a photocurable coating composition or a thermosetting coating composition is used using a rotary screen printing method. We provide PCM color steel plates with various three-dimensional patterns.

  In addition, the present invention can introduce the rotary screen printing method into the continuous coating process of PCM color steel sheet to optimize the usage environment of the coating composition, and can implement various three-dimensional patterns with a certain thickness, The present invention provides a method for producing a PCM color steel sheet that can improve workability and workability.

To achieve the above object, an embodiment of the present invention includes a base steel plate; a pretreatment layer; a rust preventive primer coating layer; a base coating layer; a rotary screen that forms a three-dimensional pattern or pattern. It includes a print layer sequentially the rotary screen printing layer provides a photocurable coating composition or Ranaru PCM (Pre-Coated Metal) color steel plate.

  In one embodiment, the photocurable coating composition comprises 40 to 75 wt% urethane (meth) acrylate prepolymer and 20 to 45 wt% (meth) acrylate monomer based on the total weight of the photocurable coating composition. , Photoinitiator 3.5 to 8% by weight, and the remaining content of additives.

  In one embodiment, the photocurable coating composition may further include 0.1 to 35% by weight of pigment based on the total weight of the photocurable coating composition.

  In one embodiment, a print layer may be further included on the base coating layer.

  In one embodiment, the rotary screen printing layer may have a thickness of 1 μm to 40 μm.

  In one embodiment, a clear layer may be further included on the rotary screen printing layer.

  In one embodiment, the rotary screen printing layer may be formed by one or more rotary screen printing machines.

  In one embodiment, the rotary screen printing machine may include a rotary press including a squeegee and a screen, and an impression roller.

  In one embodiment, the rotary screen printing machine may further include a tension leveler, and tension bridle rolls may be provided before and after the rotary screen printing machine.

In order to achieve the above object, another aspect of the present invention includes a step of preparing a base steel plate made of a metal plate or a plated steel plate; a step of forming a pretreatment layer on the base steel plate; Forming a base coat layer on the rust preventive primer coat layer; coating a base coating composition on the rust preventive primer coat layer; and forming the base coat layer; Forming a rotary screen printing layer on the layer using a rotary screen printing method to form a three-dimensional pattern or pattern , each step comprising a continuous process, wherein the rotary screen printing layer is photocured. A method for producing a PCM color steel sheet obtained by printing a conductive coating composition is provided.

  In one embodiment, the photocurable coating composition comprises 40 to 75 wt% urethane (meth) acrylate prepolymer and 20 to 45 wt% (meth) acrylate monomer based on the total weight of the photocurable coating composition. , Photoinitiator 3.5 to 8% by weight, and the remaining content of additives.

  In one embodiment, the photocurable coating composition may further include 0.1 to 35% by weight of pigment based on the total weight of the photocurable coating composition.

  In one embodiment, the method may further include forming a printed layer after forming the base coating layer.

  In one embodiment, the rotary screen printing layer may have a thickness of 1 μm to 40 μm.

  In an embodiment, the method may further include forming a clear layer after forming the rotary screen printing layer.

  In one embodiment, the step of forming the rotary screen printing layer comprises using a rotary press including a squeegee and a screen, and one or more rotary screen printers including an impression roller to form a desired pattern on the screen. A step in which the material to be coated on which the base coating layer is formed is advanced between the rotary press rotating at the same speed and the impression roller; and the pattern is the base coating layer. A step of printing on can be included.

  In one embodiment, the rotary screen printing machine may further include a tension leveler, and tension bridle rolls may be provided before and after the rotary screen printing machine.

According to one aspect of the present invention, it is possible by using a rotary screen printing method, to obtain an implementation has been PCM color steel various solid pattern using the photocurable coating composition.

  In addition, according to another aspect of the present invention, a rotary screen printing method can be introduced into the continuous coating process of PCM color steel sheet to optimize the usage environment of the coating composition, and various three-dimensional patterns can be obtained with a certain thickness. Therefore, productivity and workability can be greatly improved.

  The effects of the present invention are not limited to the effects described above, but are understood to include all effects that can be inferred from the detailed description of the present invention or the structure of the invention described in the claims. Should.

It is sectional drawing of the PCM color steel plate which concerns on one Example of this invention. It is sectional drawing of the PCM color steel plate which concerns on another one Example of this invention. It is sectional drawing of the PCM color steel plate which concerns on another one Example of this invention. It is a figure which shows the principle of operation of the rotary screen printing machine which concerns on this invention. It is a figure which shows the step which forms the rotary screen printing layer which concerns on this invention. 1 is a surface photograph of a PCM color steel plate manufactured by rotary screen printing of a photocurable coating composition according to an embodiment of the present invention. The thermosetting coating composition is a surface photograph of the PCM color steel sheet produced by rotary screen printing.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented or embodied in various different forms and is not limited to the embodiments described herein. In order to clearly describe the present invention in the drawings, parts not related to the description are omitted, and like parts are given like reference numerals throughout the specification.

  Throughout the specification, when a part is “connected” to another part, this is not only “directly connected”, but via another member in the middle. This includes cases where they are indirectly linked. Also, when a part “includes” a component, this means that it does not exclude another component, unless it is stated to the contrary, it may have another component. .

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

PCM color steel plate 1 is a cross-sectional view of a PCM color steel sheet according to an embodiment of the present invention.

  According to one embodiment of the present invention, a base steel plate (110); a pretreatment layer (120); a rust preventive primer coating layer (130); a base coating layer (140); a rotary screen printing layer ( 150), and the rotary screen printing layer (150) provides a PCM (Pre-Coated Metal) color steel plate made of a photocurable coating composition or a thermosetting coating composition.

  The base steel plate (110) may be, for example, a metal plate itself or a plate on which a known plating layer is formed such as zinc-aluminum-silica alloy hot-plated, electric and hot-dip galvanized, or copper, aluminum , And a known metal / non-metal substrate such as a stainless steel plate can be used, but is not limited thereto.

  In order to ensure interlayer adhesion and basic corrosion resistance between the base steel plate (110) and the rust preventive primer coating layer (130), known chemical conversions such as phosphate coating, chromate, non-chromate, etc. It is preferable to include a pretreated layer (120) subjected to a film treatment.

  The pre-treatment layer (120) is preferably an environmentally friendly non-chromate film treatment for good coating adhesion, but may have a somewhat lower corrosion resistance than the existing chromate film treatment. Therefore, it was also possible to carry out a chromate film treatment with a known chromate or trivalent chromium composition according to the needs of customers.

  The antirust primer coating layer (130) has a structure that affects the interlaminar bonding strength, coating hardness, chemical resistance, corrosion resistance, etc. between the base steel plate (110) and the base coating layer (140). In view of such interconnected physical properties, epoxy-based or epoxy-modified polyester-based paints, polyester-based paints for PCM (Pre-Coated Metal), or modified paints can be used, but for home appliances and building materials, etc. A paint for PCM (Pre-Coated Metal) that is commercially available depending on the application and application base can be appropriately selected and used.

  As for the pigment contained in the paint forming the antirust primer coating layer (130), ordinary chromium and lead antirust pigments are used in consideration of corrosion resistance. Correspondingly, non-toxic anti-corrosion pigments free from lead and chromium can be used according to the needs of customers.

  Existing anti-corrosion pigments include Red Leed, Zinc Potassium Chromate, Zinc Tetraoxy Chromate, and Strontium Chromate containing lead and chromium. It is not limited to these.

  Non-toxic anticorrosive pigments include typical borate barium metaborate, molybdate zinc zinc molybdate, calcium zinc zinc molybdate, Phosphate Zinc Phosphate, Aluminum Triphosphate, Silicate Calcium Borosilicate, Phosphosilicate, Calcium Ion Exchanged Silicate ), Magnesium ion-exchanged silicate, but not limited thereto.

  The dry coating thickness of the anticorrosive primer coating layer (130) is preferably 3 μm to 10 μm, more preferably 4 μm to 6 μm. If the thickness of the dry coating film of the rust preventive primer is less than 3 μm, the rust preventive property and adhesive strength may be reduced, and if it exceeds 10 μm, the surface appearance may be poor and the economy may be reduced.

  The base coating layer (140) is formed on the rust-preventing primer coating layer (130) in a layered structure of the coating, and the photocurable coating composition or the thermosetting coating composition is adsorbed thereon. As a result, the adhesion, drying and absorption properties of the coating composition and the resolution of the pattern embodied by the rotary screen printing layer 150 may be affected.

  The main resin of the base coating composition forming the base coating layer (140) includes polyester resin, urethane resin, modified polyester resin, acrylic resin, silicon modified polyester resin, alkyd resin, fluororesin, polypropylene resin, polyvinyl acetate. Resins and polyalkyd resins are included, but not limited to these.

  Examples of the auxiliary resin for the base coating composition include, but are not limited to, melamine resin, isocyanate resin, acrylic resin, and urethane resin.

  When excessive urethane resin is used as a conventional auxiliary resin, yellowing may occur in the high-temperature baking type curing method. Use melamine resin or a mixture of urethane resin and melamine resin. It is preferable.

  In addition, the base coating composition may further include pigments, solvents, and additives such as leveling agents, antifoaming agents, and quenching agents.

  When the dry coating thickness of the base coating layer (140) is less than 10 μm, the photocurable coating composition or the thermosetting coating composition may be inferior in adhesion and adsorptivity, 30 μm If it exceeds 1, the base coating composition may be excessively consumed and the cost may increase. Therefore, the dry coating thickness of the base coating layer 140 is preferably 10 μm to 30 μm, more preferably 15 μm to 20 μm. Is preferred.

  The rotary screen printing layer (150) of the PCM color steel sheet according to the present invention, and the photocurable coating composition and the thermosetting coating composition for forming the same will be described in detail.

  Using the rotary screen printer, a PCM color steel plate in which various three-dimensional patterns are embodied can be obtained using the photocurable coating composition or the thermosetting coating composition.

Photo-curable coating composition
In one embodiment, the rotary screen printing layer (150) may be made of a photocurable coating composition.

  In one embodiment, the photocurable coating composition comprises 40 to 75 wt% urethane (meth) acrylate prepolymer and 20 to 45 wt% (meth) acrylate monomer based on the total weight of the photocurable coating composition. , Photoinitiator 3.5 to 8% by weight, and the remaining content of additives.

  The urethane (meth) acrylate prepolymer can be produced by copolymerizing a hydroxyl group-containing (meth) acrylate with a mixture of a diisocyanate compound, a diol compound and a polyol.

  There are various methods for introducing double bonds at both ends of a urethane prepolymer substituted with diisocyanate. Among them, 2 moles of hydroxyl group-containing (meth) acrylate per mole of urethane prepolymer. It is preferable to use a prepolymer method in which is reacted.

  The hydroxyl group-containing (meth) acrylate used at this time has 2 to 6 carbons in the alkyl group, and includes 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy Butyl (meth) acrylate or a mixture thereof can be used, but is not limited thereto.

  The urethane (meth) acrylate prepolymer has a weight average molecular weight of 3000 to 50000, and an urethane (meth) acrylate prepolymer having an average urethane bond per molecule of 7 to 50. If the weight average molecular weight is less than 3000, the cured film has high tensile strength and hardness and low elongation, and the desired adhesion and workability cannot be obtained. May result.

  As the diisocyanate compound, any of aliphatic, alicyclic and aromatic diisocyanate compounds can be used.

  For example, isophorone diisocyanate, 2,4-toluene diisocyanate and its isomer, 1,6-hexamethylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, 2,2-bis-4'-propane isocyanate, 6-isopropyl-1, 3-phenyl diisocyanate, bis (2-isocyanatoethyl) -fumarate, 1,6-hexane diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dimethylphenylene diisocyanate, 3,3′-dimethyl-4,4 ′ -Diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,4-xylene diisocyanate, 1,3-xylene diisocyanate DOO, or mixtures thereof can be used, but is not limited thereto.

  Among these, 2,4-toluene diisocyanate and its isomer, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or a mixture thereof is preferable.

  As the diol compound, a single molecule having a weight average molecular weight of less than 200 can be used. For example, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, bisphenol A, bisphenol F, dicyclopentanediol , Or mixtures thereof, but are not limited to these.

  As the polyol, those having a weight average molecular weight of 500 to 3000 can be used. If the weight average molecular weight is less than 500, the hardness of the coating film becomes too high and the adhesion is lowered, and if it exceeds 3000, the coating film may become too brittle.

  As the polyol, polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol, or a mixture thereof may be used, but the polyol is not limited thereto.

  For example, polyethylene glycol, 1,2-polypropylene glycol, polytetramethylene glycol, 1,2-polybutylene glycol and copolymerized forms thereof can be used as the polyether polyol. Can be used.

  Examples of the polyester polyol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, polytetramethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. , Neopentyl glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,8-octanediol and phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, sebacic acid, azelaic acid A polyester polyol or a copolymer thereof in a form reacted with an acid such as can be used.

  Further, 1,6-hexane polycarbonate can be used as the polycarbonate polyol, and ε-caprolactone and ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butanediol, 1,4 can be used as the polycaprolactone polyol. A form in which a diol such as butanediol, polytetramethylene glycol, 1,2-polybutylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol is reacted can be used.

  The content of the urethane (meth) acrylate prepolymer may be 40 to 75% by weight, preferably 50 to 65% by weight, based on the total weight of the photocurable coating composition. If the content of the urethane (meth) acrylate prepolymer is less than 40% by weight, the strength of the coating film is too strong to obtain the desired processability, and the adhesion is lowered. The film becomes excessively flexible and the desired hardness and scratch resistance cannot be obtained.

  A urethane (meth) acrylate prepolymer synthesized by copolymerizing a hydroxyl group-containing (meth) acrylate with a mixture of the diisocyanate compound, a diol compound having a weight average molecular weight of less than 200, and a polyol having a weight average molecular weight of 500 to 3000 is included. By using a photo-curable coating composition, a color steel plate having excellent adhesion, hardness and workability can be produced.

  As the (meth) acrylate monomer, a monofunctional monomer and a polyfunctional monomer can be used.

  Monofunctional monomers of the (meth) acrylate include diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, t-octyl (meth) acrylate, N, N-dimethyl (meth) acrylate, N-vinylcaprolactam , N-vinylpyrrolidone, isobutoxy (meth) acrylamide, diacetone (meth) acrylamide, bonyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclo Pentadiene (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, polypropylene Glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, phenoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, epoxydiethylene glycol (meth) acrylate, butoxyethyl (meth) acrylate, tetrahydrofur Furyl (meth) acrylate, stearyl (meth) acrylate, octadecyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, isodecyl (meth) acrylate, nonyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Isoamyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, butyl (meth) acrylate, isopropyl (meth) acrylate, propyl (meth) acrylate Rate, ethyl (meth) acrylate, methyl (meth) acrylate, or mixtures thereof can be used, but are not limited thereto.

  The polyfunctional monomer of the (meth) acrylate includes trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 1,6 -Hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, or mixtures thereof can be used. It is not limited to.

  The content of the (meth) acrylate monomer may be 20 to 45% by weight, preferably 25 to 35% by weight, based on the total weight of the photocurable coating composition. If the content of (meth) acrylate monomer is less than 20% by weight, the coating film becomes excessively soft and the desired hardness and scratch resistance cannot be obtained. If it exceeds 45% by weight, the coating film strength is too strong. Therefore, the desired processability cannot be obtained, and the adhesive force may be reduced.

  The photopolymerization initiator means a substance that can start a polymerization reaction by absorbing energy from an ultraviolet light source.

  For example, photopolymerization initiators include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenyl-acetophenone, benzaldehyde, anthraquinone, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone. , Benzoinpropyl ether, benzoin ethyl ether, 1- (4-isopropyl-phenol) -2-hydroxy-2-methylpropan-1-one, thioxanthone, benzophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine, or these Mixtures can be used, but are not limited to these.

  Commercially available photopolymerization initiators include Irgacure 184, 651, 500, 819, 907, 1800 (Ciba Geigy), Darocure 1116, 1173 (Merck), Lucirine LR8728 (BASF), Micure HP -8, TPO, CP-4, BK-6 (MIWON Shoji) etc. can be used.

  The photopolymerization initiator may be contained in an amount of 3.5 to 8% by weight, preferably 5 to 7% by weight, based on the total weight of the photocurable coating composition. When the content of the photopolymerization initiator is less than 3.5% by weight, curing may not occur sufficiently, and when it exceeds 8% by weight, adhesion and workability decrease due to yellowing and temporary curing of the coating film. Sometimes.

  In addition, the photocurable coating composition may further include a remaining content of the additive.

  The additive means a substance that can improve or enhance the properties of the photocurable coating composition for rotary screen printing.

  The additive may be an adhesion promoter, an antioxidant, a light absorber, a light stabilizer, a silane coupling agent, a thermal polymerization inhibitor, an organic pigment, an inorganic pigment, a smoothing agent, a dispersant, an antifoaming agent, or a mixture thereof. However, it is not limited to these.

  In particular, the adhesion promoter means a substance that can improve the adhesion of an ultraviolet curable film.

  For example, the adhesion promoter may be phosphoric acid acrylate, non-reactive acrylic resin, and a mixture thereof, but is not limited thereto.

  The content of the additive is not particularly limited, and takes into consideration the hue, transparency or steric effect of the pattern to be embodied by an engineer having ordinary knowledge in this field, and does not impair the effects of the invention. Thus, the content of the components can be selected appropriately.

  In one embodiment, the photocurable coating composition may further include 0.1 to 35% by weight pigment based on the total weight of the photocurable coating composition.

  When the composition of the pigment is less than 0.1% by weight, it is difficult to realize a vivid hue, and when it exceeds 35% by weight, it may not be cured or the curing rate may be very slow, resulting in poor adhesion. Manufacturing costs may rise excessively.

  The pigment is a component that enables various hues to be realized on the surface of the final product. In order to guarantee a long-term weather resistance of 20 years or more, a ceramic having excellent heat resistance, chemical resistance, weather resistance and corrosion resistance is used. Color pigments are recommended, but one or more selected from metallic and mica pigments can be used alone or in combination depending on the hue.

  Ceramic pigments are inorganic pigments produced by plasticizing metal oxides at high temperatures, and they form a coating film with a basic resin to give a hue. Examples include titanium dioxide and cobalt aluminate. , Copper chromite, cobalt chromite, chromium antimony titanium, lead chromate, etc. can be used, but are not limited thereto.

  An aluminum paste can be used for the metallic pigment, and colored mica, iriidine, etc. can be used for the mica pigment, but it is not limited thereto.

  The pigment may be a fine particle, preferably a nanoparticle. In this case, the pigment may be processed and used in a dispersed form in a photocurable coating composition.

  According to the photocurable coating composition, it is possible to produce a three-dimensional color steel plate having excellent chemical, physical and mechanical properties. Specifically, it is excellent in high definition, high hardness, and workability, and it is not necessary to have a baking furnace for curing after painting, so it is environmentally friendly and economical.

In one embodiment of the thermosetting coating composition , the rotary screen printing layer 150 may be composed of a thermosetting coating composition.

  In one embodiment, the thermosetting coating composition comprises a polyester main resin in an amount of 5 to 45% by weight, a melamine auxiliary resin in an amount of 0.5 to 10% by weight, and a pigment 1 to 1, based on the total weight of the thermosetting coating composition. It may contain 35% by weight, 0.5-10% by weight additive, and 30-90% by weight solvent.

  The polyester main resin may include 5 to 45% by weight based on the total weight of the thermosetting coating composition. If the composition of the polyester main resin is less than 5% by weight, It is difficult to realize spreadability, adsorptivity, and sharpness of the pattern, and when it exceeds 45% by weight, drying of the rotary screen printing layer 150 may be delayed.

  Auxiliary resins that can be used in the thermosetting coating composition include, but are not limited to, melamine resins, isocyanate resins, acrylic resins, and urethane resins.

  When excessive urethane resin is used as a conventional auxiliary resin, yellowing may occur in the high-temperature baking type curing method. Use melamine resin or a mixture of urethane resin and melamine resin. It is preferable.

  Among the melamine resins, amino group or butoxy group-containing melamine resins are advantageous in terms of the hardness of the coating film, etc., but when used with an acid catalyst, the curing reaction rate is fast and the coating film has excellent curing properties. It is preferable to use a melamine resin containing a methoxy group.

  The melamine auxiliary resin may be included in an amount of 0.5 to 10% by weight based on the total weight of the thermosetting coating composition. If the composition of the melamine auxiliary resin is less than 0.5% by weight, Although the processability is good, the surface hardness of the coating film may be reduced, and when it exceeds 10% by weight, the adhesion with the clear layer (170) may be reduced.

  The pigment may be included in an amount of 1 to 35% by weight based on the total weight of the thermosetting coating composition. However, if the pigment composition is less than 1% by weight, it is difficult to realize a clear hue, and 35% by weight. If it exceeds 1, it is difficult to realize the spreadability, adsorbability, and sharpness of the desired thermosetting coating composition.

  As the pigment, ceramic color pigments with excellent heat resistance, chemical resistance, weather resistance, and corrosion resistance are recommended to ensure long-term weather resistance of 20 years or more. One or more selected from pigments can be used alone or in combination.

  Ceramic pigments are inorganic pigments produced by plasticizing metal oxides at high temperatures, and they form a coating film with a basic resin to give a hue. Examples include titanium dioxide and cobalt aluminate. , Copper chromite, cobalt chromite, chromium antimony titanium, lead chromate, etc. can be used, but are not limited thereto.

  An aluminum paste can be used for the metallic pigment, and colored mica, iriidine, etc. can be used for the mica pigment, but it is not limited thereto.

  The additive may be included in an amount of 0.5 to 10% by weight based on the total weight of the thermosetting coating composition. However, when the additive composition is less than 0.5% by weight, May occur, the flowability of the paint may deteriorate, and the sharpness of the surface may deteriorate. If the amount exceeds 10% by weight, the concentration of ink may occur due to the surface floating of the additive. And the absorbency may also be reduced.

  In one embodiment, the additive may include one or more selected from the group consisting of a leveling agent, an antifoaming agent, and a dispersing agent.

  Examples of the leveling agent and antifoaming agent include, but are not limited to, Disparon L-1980, Disparon L-1984, Disparon AP-30, BYK356 manufactured by BYK, and the like.

  As the dispersant, Disperbyk-140, Disperbyk-142, Disperbyk-145 and similar grades of BYK may be used, but are not limited thereto.

  The solvent should be a mixture of ester, ether, alcohol, and ketone solvents as the active solvent for directly dissolving the polyester main resin, and petroleum solvent as a cosolvent for diluting the dissolved molecules. Can do.

  Examples of the ester solvent include, but are not limited to, ethyl acetate, n-butyl acetate, cellosolve acetate, propylene glycol monomethyl acetate, and 3-methoxybutyl acetate manufactured by Union Carbide.

  Examples of the ether solvent include, but are not limited to, methyl cellosolve, ethyl cellosolve, ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, and diethylene glycol butyl ether manufactured by Union Carbide.

  Examples of the alcohol solvent include, but are not limited to, ethanol, isopropanol, n-butanol, methyl alcohol, amyl alcohol, and cyclohexanol.

  Examples of the ketone solvent include, but are not limited to, cyclohexanone, methyl amyl ketone, diisobutyl ketone, and methyl ethyl ketone.

  Examples of the petroleum-based co-solvent include, but are not limited to, Oil Corporation's Cocosol # 100 and Cocosol # 150.

  The solvent may be included in an amount of 30 to 90% by weight based on the total weight of the thermosetting coating composition, but if the solvent is used at less than 30%, the downward effect on the viscosity of the coating may be reduced. , If it exceeds 90%, workability such as paintability may be deteriorated.

  The thermosetting coating composition may optionally further include 0.1 to 10% by weight of a UV stabilizer based on the total weight of the thermosetting coating composition. May include one or more selected from the group consisting of phenyl salicylate, benzophenone, benzotriazole, nickel derivatives, and HALS (hindered amine light stabilizer).

  When the composition of the UV stabilizer is less than 0.1% by weight, the coating film may be modified or discolored by UV and the weather resistance and light resistance may be deteriorated. Therefore, the coating film may not be dried quickly, and the denseness of the coating film may decrease.

  Table 1 shows a comparison of the compositions of the photocurable coating composition and the thermosetting coating composition according to one example.

  Table 2 shows the physical property test results of the photocurable coating composition and the thermosetting coating composition according to the composition shown in Table 1.

  The photocurable coating composition and the thermosetting coating composition each show excellent adhesion, but in the case of the photocurable coating composition, the photopolymerization initiator contained therein It can be seen that the weather resistance and heat resistance are somewhat low due to the double bond of the main resin.

  On the other hand, in the case of a thermosetting coating composition containing a polyester resin as a main resin according to one embodiment, the coating film has a high density due to a chemical reaction between the polyester main resin and the melamine auxiliary resin, and thus has good weather resistance and heat resistance. Indicates that

  Also, by using both coating compositions, a three-dimensional pattern can be realized on the surface of the color steel plate.

  In the case of the photo-curable coating composition, when it is colored, it does not cure or is somewhat delayed, but it has an advantage that a clear three-dimensional pattern can be realized very delicately.

  In the case of the thermosetting coating composition, the resolution of the three-dimensional pattern embodied is somewhat lower than that of the photo-curable coating composition, but not only the clear form but also the colored form, that is, the three-dimensional pattern having various hues. There is an advantage that can be realized.

  FIG. 2 is a cross-sectional view of a PCM color steel plate according to another embodiment of the present invention.

  In one embodiment, the base coating layer may further include a print layer (160).

  The printed layer 160 means a coating layer for embodying a plane or a three-dimensional pattern on the surface of the coating film. When the printing layer 160 is further included, the rotary screen printing layer ( 150) and a variety of patterns can be realized on the surface of the color steel plate, so that a color steel plate having a more brilliant and beautiful appearance can be provided.

  At this time, the ink for forming the print layer 160 is acrylic resin, urethane resin, silicon resin, fluorine resin, EDPM (Ethylene Propylene Diene Monomer), polypropylene, polyethylene, polyvinyl chloride, chlorinated polyethylene, PVDF (Polyvinylidenefluoride). ), Polyester, polyamide, polymethylmethacrylate, and the like, but is not limited thereto.

  The ink may further include an additive such as a leveling agent for adjusting the surface tension of the coating film, a pigment for adjusting the popping property and thixotropic property, a wax, an organic solvent, and a filler. It is not limited to.

  In one embodiment, the rotary screen printing layer 150 may have a thickness of 1 μm to 40 μm.

  When the dry screen thickness of the rotary screen printing layer (150) is less than 1 μm, the adhesiveness, adsorptivity and solvent resistance of the thermosetting coating composition may be reduced, In some cases, the resolution of the pattern may be reduced, and if it exceeds 40 μm, the thermosetting coating composition may be used excessively, the drying of the rotary screen printing layer 150 may be delayed, and the cost may increase.

  FIG. 3 is a cross-sectional view of a PCM color steel plate according to another embodiment of the present invention.

  In one embodiment, a clear layer (170) may be further included on the rotary screen printing layer (150).

  The clear layer (170) protects the rotary screen printing layer (150) formed on the base coating layer (140), thereby maintaining the hue, pattern, texture, etc. embodied on the surface of the steel plate. The surface of the finished color steel sheet plays a role of high definition.

  The clear layer 170 may be formed as a single layer or multiple layers on the rotary screen printing layer 150 according to the needs of the customer.

  The main resin of the clear paint used to form the clear layer 170 is polyester resin, urethane resin, modified polyester resin, acrylic resin, silicon modified polyester resin, alkyd, fluorine resin, urethane acrylate resin, epoxy acrylate. Resins, polyester acrylate resins, polyacryl acrylate resins, silicon acrylate resins, and the like may be mentioned, but are not limited thereto.

  FIG. 4 is a schematic diagram illustrating the operating principle of the rotary screen printing machine according to the present invention.

  In one embodiment, the rotary screen printing layer 150 may be formed using one or more rotary screen printers.

  The rotary screen printing refers to a system in which ink is discharged into a cylindrical screen having a pattern formed thereon, and then the ink is discharged through a mesh portion formed on the screen to continuously transfer the pattern. .

  Referring to FIG. 4, a squeegee (E) is disposed inside a screen (F) on a rotary press (H). The steel plate (A) travels at a constant speed between the screen (F) and the impression roller (impression roller, G) immediately below the screen, and the steel plate (A) moves the rotary screen printing machine. When passing, the screen (F) also rotates at a constant speed due to the moving speed of the steel plate (A). At this time, the position of the squeegee (E) on the rotary press (H) is fixed by the tip at the position where the screen (F), the steel plate (A) and the impression roller (G) face each other.

  Thereafter, ink (ink, D) is automatically fed into the center of the screen (F), and the wedge-shaped formed by the leading side of the squeegee (E) and the inner surface of the screen. It will be gathered in a well. The movement of the screen (F) causes the ink (D) to hang down, so that even if there is no flood bar, the ink spills from the screen (F) and ink is supplied to the stencil (B). The After that, the squeegee (E) cuts the ink so that the ink is transferred or deposited on the steel plate (ink deposit, C).

  In general, the rotary screen printing method has been frequently used in other existing fields, for example, the production of interior wallpaper and flooring. However, when applied to continuous production color steel plate manufacturing, because of the characteristics of the steel plate material, it is difficult to perform stable printing due to material deformation such as WAVE deformation and recursion. It has been considered impossible to produce colored steel plates with patterns.

  When manufacturing a steel plate by the rotary screen printing method, the thickness variation in the width direction (20-30 μm) existing in the existing steel plate material and the uneven surface shape (WAVE) and recursion (camber) that occur occasionally Due to the defect, a gap is generated between the material and the contact boundary surface of the rotary press (H), and the ink transfer for forming the three-dimensional pattern is not properly performed in this gap, and the gap is stable. There is a problem that consistent print processing is difficult.

  In addition, the rotary press (H) is affected by printing defects due to the difference in rotational speed between the steel plate and the rotary press (H), and the position change of the central contact surface due to the elasticity of the impression roll diameter and the thickness of the steel plate material. There is a problem that the contact surface becomes wider and it is difficult to delicately reproduce the desired pattern and pattern on the steel plate.

  In contrast, according to one embodiment, the rotary screen printing machine may include a rotary press (H) including a squeegee (E) and a screen, and an impression roller (G). Leveler) may be included, and a tension bridle roll may be provided before and after the rotary screen printing machine.

  The tension leveler and the tension bridle roll are provided in the width direction of the steel plate at the closest front position of the rotary screen printing machine to prevent printing defects by minimizing deformation of the steel plate material. be able to.

  On the other hand, printing failure may occur due to the difference in rotational speed between the steel plate and the rotary press (H). If the rotational speed of the rotary press (H) is faster than the traveling speed of the steel plate, the pattern has the desired thickness. On the contrary, when the rotational speed of the rotary press (H) is slower than the traveling speed of the steel sheet, the printed pattern may spread or stretch.

  Such a problem can be solved by controlling the rotational speed of the rotary press (H) and the traveling speed of the steel sheet to be the same.

  In addition, the central position of the printing contact surface is variably designed so that the central printing point, which changes depending on the elasticity of the steel sheet, is grasped according to the thickness of the steel sheet, and the rotary press (H) can be moved vertically. Thus, a stable printing process is possible, and thereby, a delicate and three-dimensional color steel plate can be manufactured.

  Therefore, the distance between the rotary screen printing machine and the upper deflecting roll located between the upper and lower deflecting rolls (Deflect Roll) of the portion where the rotary screen printing machine is provided, and the rotary screen The distance between the printing press and the lower deflecting roll is controlled to have a specific ratio, and the position of the upper deflecting roll in the front-rear direction is changed to change the angle with the rotary screen printing press. Thus, a stable printing angle was found, thereby determining the center position of the printing contact surface due to the change in the thickness of the steel sheet.

  As an example, the rotary screen printing machine is disposed at a point where the distance from the upper and lower deflector rolls is about 3: 1, and the upper deflector roll is arranged according to the shape and / or precision of the pattern. After determining the appropriate position by moving and adjusting in the front-rear direction, the position of the central printing contact surface was determined based on the position change due to the thickness of the steel plate.

  For example, by changing the position of the upper deflector in the front-rear direction, the value of the middle contact angle formed between the impression roll and the contact surface also changes, and at this time, the changed rotary screen is changed. Considering the position of the center of the printing machine, the position of the rotary screen printing machine can be moved up and down and brought into contact with the center so as to enable stable and delicate printing. .

  At this time, in order to control the change in tension of the raw steel plate due to the movement of the impression roll at a point immediately before the rotary screen printer is pulled in, the lower deflector roll and the rotary roll are offset in order to cancel out the bending of the raw steel plate as much as possible. A stabilizer roll can be further provided between the press (H).

  According to the above description, the rotary screen printer is installed and applied in the vertical type due to the structure of the process line. However, the present invention is not limited to this, and if there is no restriction in the line space, the horizontal (horizontal) ) Type can also be applied.

  In the case of the horizontal type, a stabilizer roll that plays a role of tension stabilization and anti-curvature cancellation may be omitted depending on the situation. In this case, a fixed impression roll is applied so that the rotary screen part is converted into a forward / backward movement type.

Method for Producing PCM Color Steel Plate According to another aspect of the present invention, a step of preparing a base steel plate (110) made of a metal plate or a plated steel plate; forming a pretreatment layer (120) on the base steel plate (110) Forming a rust-preventing primer coating layer on the pretreatment layer 120; coating a base coating composition on the rust-preventing primer coating layer 130; Forming a coating layer; and forming a rotary screen printing layer (150) on the base coating layer (140) using a rotary screen printing method, each step from a continuous process. Thus, the rotary screen printing layer (150) provides a method for producing a PCM color steel plate by printing a photocurable coating composition or a thermosetting coating composition.

  In the stage of preparing the base steel plate (110), the base steel plate (110) is known as, for example, a metal plate itself or an alloy hot-dip plating of zinc-aluminum-silica, electric and hot-dip galvanizing. A known metal / nonmetal substrate such as copper, aluminum, and stainless steel plate can be used, but is not limited thereto.

  In the step of forming the pretreatment layer (120), the non-chromate or chromate can be treated and dried at 50 to 100 ° C. to form the pretreatment layer (120). Environmentally friendly non-chromate film treatment is preferred for film adhesion, but it has some disadvantages in corrosion resistance compared to existing chromate film treatment, and it is known that it is a known chromate or trivalent depending on customer needs. Chromate film treatment with chromium as a composition can also be performed.

  In the step of forming the rust preventive primer coating layer (130), the rust preventive primer paint is treated with a toxic or non-toxic rust preventive pigment, and heated and cooled at a PMT (Peak Metal Temperature) of 150 ° C to 300 ° C. Thus, the antirust primer coating layer (130) can be formed.

  The composition of the antirust primer coating composition is as described above.

  The coating method of the rust preventive primer paint is not limited to the roll-coating method, but the curtain flower method used for PCM (Pre-Coated Metal) steel plate can also be applied, but is not limited to these. Is not to be done. Further, the baking condition after coating is preferably PMT (Peak Metal Temperature) 150 ° C. to 300 ° C., more preferably PMT (Peak Metal Temperature) 180 ° C. to 210 ° C. in a continuous line. Is preferred.

  In the step of forming the base coating layer (140), the base coating layer (140) can be formed by coating a base coating composition containing a polyester resin as a main resin.

  The composition of the base coating composition is as described above.

  The coating method of the base paint composition may be roll coating, curtain flower coating, spray coating or the like, but is not limited thereto. The baking condition is preferably PMT (Peak Metal Temperature) 180 ° C. to 245 ° C., more preferably PMT 185 ° C. to 200 ° C. in a continuous line. If the temperature is too low, the coating film may be damaged by roll touch during operation, and if it is too high, the adhesive property of the photocurable coating composition or the thermosetting coating composition forming the rotary screen printing layer (150). In addition, transferability may be reduced.

  In the step of forming the rotary screen printing layer (150), one or more rotary screen printers that print a photocurable coating composition or a thermosetting coating composition on the base coating layer (140) are used. can do.

  FIG. 5 shows a step of forming the rotary screen printing layer 150 according to the present invention.

  In one embodiment, the step of forming the rotary screen printing layer (150) includes one or more rotary screen printers including a squeegee (E) and a rotary press (H) including a screen, and an impression roller (G). A step of forming a desired pattern on the screen using the rotary press (H) for rotating the material on which the base coating layer (140) is formed at the same speed, and the impression roller. Proceeding with (G); and printing the pattern onto the base coating layer (140).

  In one embodiment, the rotary screen printing machine may further include a tension leveler, and may include tension bridle rolls before and after the rotary screen printing machine.

  Referring to FIG. 5, a desired pattern is first formed on a blank rotary screen. The pattern is not particularly limited, and can include any pattern to be embodied.

  Then, the said pattern is printed on a coating-film layer using the said rotary screen printing machine in which the desired pattern was engraved. This is because the screen (2) on which the desired pattern is formed is mounted on the rotary screen printer, and then the squeegee (1) is inserted inside the mesh, and the coating composition (2) for rotary screen printing is placed inside the mesh. When the squeegee (1) applies pressure to the net (3), the coating composition (2) is printed on the surface of the steel plate (4) through the handle formed on the screen mesh. it can.

The rotary screen printing layer made of the photocurable coating composition (150) is formed by irradiation of ultraviolet light of energy density 500mJ / cm ² ~3,000mJ / cm ² with respect to the light curable coating composition can do.

When the energy density of the ultraviolet rays is less than 500 mJ / cm ² , the surface appearance of the coating film may be deteriorated. When it exceeds 3,000 mJ / cm ² , the top coating layer is excessively cured and attached. Adhesion may be reduced or the coating may be destroyed.

  The baking condition of the rotary screen printing layer (150) made of the thermosetting coating composition is preferably PMT 220 ° C. to 245 ° C., more preferably 225 ° C. to 235 ° C.

  Each step of the manufacturing method of the PCM color steel sheet according to an embodiment is performed by a continuous process. In particular, the rotary screen printing method is introduced into the continuous process to produce a color steel sheet with various three-dimensional patterns. And workability can be greatly improved.

  In one embodiment, the photocurable coating composition comprises 40 to 75 wt% urethane (meth) acrylate prepolymer and 20 to 45 wt% (meth) acrylate monomer based on the total weight of the photocurable coating composition. , Photoinitiator 3.5 to 8% by weight, and the remaining content of additives.

  In one embodiment, the photocurable coating composition may further include 0.1 to 35% by weight of pigment based on the total weight of the photocurable coating composition.

  In one embodiment, the thermosetting coating composition comprises a polyester main resin in an amount of 5 to 45% by weight, a melamine auxiliary resin in an amount of 0.5 to 10% by weight, and a pigment 1 to 1, based on the total weight of the thermosetting coating composition. It may contain 35% by weight, 0.5-10% by weight additive, and 30-90% by weight solvent.

  In one embodiment, the additive may include one or more selected from the group consisting of a leveling agent, an antifoaming agent, and a dispersing agent.

  In addition, the thermosetting coating composition may optionally further include 0.1 to 10 wt% of a UV stabilizer based on the total weight of the thermosetting coating composition. The agent may include one or more selected from the group consisting of phenyl salicylate, benzophenone, benzotriazole, nickel derivatives, and HALS (hindered amine light stabilizer).

  When the composition of the UV stabilizer is less than 0.1% by weight, the coating film may be modified or discolored by UV and the weather resistance and light resistance may be deteriorated. Therefore, the coating film may not be dried quickly, and the denseness of the coating film may decrease.

  In this way, the rotary screen printing method can be introduced into the continuous coating process of PCM color steel sheet to optimize the usage environment of the paint composition, and three-dimensional patterns with various hues can be realized at a certain thickness, producing And workability can be greatly improved.

  In one embodiment, the method may further include forming a print layer (160) after forming the base coating layer (140).

  At this time, the ink for forming the print layer 160 is acrylic resin, urethane resin, silicon resin, fluorine resin, EDPM (Ethylene Propylene Diene Monomer), polypropylene, polyethylene, polyvinyl chloride, chlorinated polyethylene, PVDF (Polyvinylidenefluoride). ), Polyester, polyamide, polymethylmethacrylate, and the like, but is not limited thereto.

The ink may further contain additives such as a leveling agent for adjusting the surface tension of the coating film, a pigment for adjusting the popping property and thixotropic property, a wax, an organic solvent and a filler. In an embodiment, the rotary screen printing layer 150 may have a thickness of 1 μm to 40 μm.

  In an exemplary embodiment, the method may further include forming a clear layer 170 after forming the rotary screen printing layer 150.

  The clear layer 170 may be formed in a single layer or multiple layers on the rotary screen printing layer 150 according to the needs of the customer.

  The main resin of the clear paint used to form the clear layer 170 is polyester resin, urethane resin, modified polyester resin, acrylic resin, silicon modified polyester resin, alkyd, fluorine resin, urethane acrylate resin, epoxy acrylate. Resins, polyester acrylate resins, polyacryl acrylate resins, silicon acrylate resins, and the like may be mentioned, but are not limited thereto.

  FIG. 6 is a surface photograph of a PCM color steel plate manufactured by rotary screen printing of a photocurable coating composition according to an embodiment of the present invention.

  On the other hand, FIG. 7 is a surface photograph of a PCM color steel plate produced by rotary screen printing of a thermosetting coating composition according to an embodiment of the present invention.

  The above description of the present invention is for illustrative purposes only, and those having ordinary knowledge in the technical field to which the present invention pertains will not be able to change the technical idea or essential features of the present invention. It should be understood that changes can be easily made in a typical form. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not limiting. For example, each component described as a single unit or a single component can be implemented in a distributed manner, and similarly, components described as being distributed may be implemented in a combined form. Can do.

The scope of the present invention is represented by the following claims, and all modifications or variations derived from the meaning and scope of the claims and equivalents thereof are included in the scope of the present invention. Should be interpreted.

Claims (17)

A base steel sheet; a pretreatment layer; a rust preventive primer coating layer; a base coating layer; and a rotary screen printing layer forming a three-dimensional pattern or pattern ,
The rotary screen printing layer, or a light curable coating composition Ranaru PCM (Pre-Coated Metal) color steel plate.   The photocurable coating composition comprises 40 to 75% by weight of urethane (meth) acrylate prepolymer, 20 to 45% by weight of (meth) acrylate monomer based on the total weight of the photocurable coating composition, a photopolymerization initiator. The PCM color steel sheet according to claim 1, comprising 3.5 to 8% by weight, and the remaining content of the additive.   The PCM color steel sheet according to claim 2, wherein the photocurable coating composition further comprises 0.1 to 35% by weight of a pigment based on the total weight of the photocurable coating composition.   The PCM color steel sheet according to claim 1, further comprising a printed layer on the base coating layer.   The PCM color steel plate according to claim 1, wherein the rotary screen printing layer has a thickness of 1 μm to 40 μm.   The PCM color steel plate according to claim 1, further comprising a clear layer on the rotary screen printing layer.   The PCM color steel sheet according to claim 1, wherein the rotary screen printing layer is formed using one or more rotary screen printing machines. The PCM color steel plate according to claim 7 , wherein the rotary screen printing machine includes a rotary press including a squeegee and a screen, and an impression roller. The PCM color steel plate according to claim 8 , wherein the rotary screen printing machine further includes a tension leveler, and includes tension bridle rolls before and after the rotary screen printing machine. Preparing a base steel plate made of a metal plate or a plated steel plate;
Forming a pretreatment layer on the base steel sheet;
Forming a rust preventive primer coating layer on the pretreatment layer;
Coating a base coating composition on the rust preventive primer coating layer to form a base coating layer; and
Forming a rotary screen printing layer on the base coating layer to form a three-dimensional pattern or pattern using a rotary screen printing method;
Wherein each step is made from a continuous process, the rotary screen printing layer is formed by printing the photocurable coating composition, method for producing a PCM color steel plate. The photocurable coating composition comprises 40 to 75% by weight of urethane (meth) acrylate prepolymer, 20 to 45% by weight of (meth) acrylate monomer based on the total weight of the photocurable coating composition, a photopolymerization initiator. The manufacturing method of the PCM color steel plate of Claim 10 containing 3.5 to 8 weight% and an additive of the remaining content. The method for producing a PCM color steel sheet according to claim 11 , wherein the photocurable coating composition further comprises 0.1 to 35% by weight of a pigment based on the total weight of the photocurable coating composition. The method of manufacturing a PCM color steel sheet according to claim 10 , further comprising a step of forming a printed layer after the step of forming the base coating layer. The method for producing a PCM color steel sheet according to claim 10 , wherein the rotary screen printing layer has a thickness of 1 µm to 40 µm. The method of manufacturing a PCM color steel sheet according to claim 10 , further comprising a step of forming a clear layer after the step of forming the rotary screen printing layer. Forming the rotary screen printing layer comprises:
Forming a desired pattern on the screen by means of a rotary press including a squeegee and a screen, and one or more rotary screen printers including an impression roller;
A step of causing the material to be coated on which the base coating layer is formed to advance between the rotary press rotating at the same speed and the impression roller; and
The manufacturing method of the PCM color steel plate of Claim 10 including the step in which the said pattern is printed on the said base coating film layer. The method of manufacturing a PCM color steel sheet according to claim 16 , wherein the rotary screen printer further includes a tension leveler, and includes tension bridle rolls before and after the rotary screen printer.