WO2017111472A1

WO2017111472A1 - Color ink composition having excellent adhesiveness for steel material, method for manufacturing printed steel plate using same, and printed steel plate manufactured according to same

Info

Publication number: WO2017111472A1
Application number: PCT/KR2016/015039
Authority: WO
Inventors: 이정환; 유경표; 송연균; 이광진; 김진태; 최하나
Original assignee: 주식회사 포스코; 주식회사 잉크테크
Priority date: 2015-12-23
Filing date: 2016-12-21
Publication date: 2017-06-29
Also published as: CN108603061A; KR20170075932A; JP6684912B2; KR101858796B1; JP2019507203A

Abstract

The present invention relates to: a color ink composition for printed steel plates, the color ink composition having excellent adhesiveness, processability, and solvent resistance and the like with respect to steel plates; a method for manufacturing a printed steel plate using the color ink composition; and a printed steel plate manufactured according to the method. Specifically, the present invention relates to a color ink composition for steel material, the color ink composition comprising: 10 to 30 parts by weight of a mixture of a urethane acrylate oligomer and a different acrylate oligomer other than the urethane acrylate oligomer; 50 to 80 parts by weight of a photocurable monomer, which is a mixture of a monofunctional photocurable monomer and a difunctional or higher photocurable monomer; 5 to 20 parts by weight of a photoinitiator; 0.1 to 10 parts by weight of a pigment; and, in terms of dispersant solid content per 100 parts by weight of the pigment, 3 to 300 parts by weight of the dispersant, wherein the urethane acrylate oligomer and the different acrylate oligomer are mixed in a 1:1 to 10:1 weight ratio, and the monofunctional photocurable monomer and the difunctional or higher photocurable monomer are mixed in a 5:1 to 100:1 weight ratio. Moreover, the present invention specifically relates to a method for manufacturing a printed steel plate, the method comprising: a step for jetting, onto a steel plate, a color ink composition for steel plates; and a step for curing to form a print layer. Furthermore, the present invention specifically relates to a printed steel plate comprising: a steel plate; and a print layer formed on the steel plate using the color ink composition for steel plates according to the present invention.

Description

Color ink composition for steel materials with excellent adhesion, printed steel sheet manufacturing method using same and printed steel sheet manufactured accordingly

The present invention relates to a color ink composition, a method for producing a printed steel sheet using the same, and a printed steel sheet produced accordingly. More specifically, the present invention relates to a color ink composition for a printed steel sheet, a method for manufacturing a printed steel sheet using the same, and a printed steel sheet manufactured according to the same, which have excellent adhesion to steel, workability, solvent resistance, and the like.

Conventionally, a printed steel sheet having a pattern on the steel sheet has been produced by a silk screen or roll print method. However, when the printed steel sheet is manufactured by the silk screen method, it is manufactured by a printing process on a sheet rather than a coil by an intermittent batch type process. In the case of manufacturing a printed steel sheet by a roll printing method, the printed steel sheet is manufactured by etching a printed pattern on the roll, and then coating the steel sheet with ink or paint on the etched roll.

As such, the conventional printed steel sheet has been produced through silk screen, roll printing, or laminating, but such a conventional printing method is impossible to print patterns of high resolution. In addition, the manufacturing costs are increased due to screen or roll production, low error rate, it is impossible to produce a variety of color products. To solve this problem, the inkjet printing method is applied to steel to compensate for the shortcomings of the conventional printing steel plate manufacturing method.

However, when the color ink composition is directly jetted onto a steel material, it is difficult to secure adhesion between the ink and the material due to the absorbing layer member and thus cannot be utilized as a product. In addition, there is a limit to replace the conventional printed steel sheet because it must satisfy not only the adhesion but also the processability, solvent resistance and the like.

An object of the present invention is to provide a color ink composition having excellent adhesion to steel materials. Moreover, an object of this invention is to provide the color ink composition for steel materials excellent in the jetting property, workability, processability, and solvent resistance in a head.

An object of the present invention is to provide a method for producing a printed steel sheet having excellent jetting property and workability by applying a color ink composition to the steel sheet by an inkjet method, and excellent adhesion, processability and solvent resistance of the print layer to the steel sheet.

An object of the present invention is to provide a printed steel sheet having a print layer formed of a color ink composition having excellent adhesion to a steel sheet, workability and solvent resistance.

The present invention, 10 parts by weight to 30 parts by weight of a mixture of a hetero acrylate oligomer other than the urethane acrylate oligomer and the urethane acrylate oligomer,

50 parts by weight to 80 parts by weight of a photocurable monomer which is a mixture of a monofunctional photocurable monomer and a bifunctional or higher photocurable monomer;

5 to 20 parts by weight of the photoinitiator;

0.1 to 10 parts by weight of the pigment; And

Dispersant solids content per 100 parts by weight of pigment, 3 to 300 parts by weight of dispersant

Include,

The urethane acrylate oligomer and the hetero acrylate oligomer are 1: 1 to 10: 1 by weight, and the monofunctional photocurable monomer and the bifunctional or more functional photocurable monomer are mixed in a 5: 1 to 100: 1 weight ratio. A color ink composition is provided.

The urethane acrylate oligomer may be a urethane acrylate oligomer having a weight average molecular weight of 500 to 12,000.

Aliphatic urethane acrylate may be used as the urethane acrylate oligomer.

The urethane acrylate oligomer may be used that has three or less functional groups.

The hetero acrylate oligomer is preferably selected from the group consisting of polyester acrylate oligomers, and epoxy acrylate oligomers.

As the polyester acrylate oligomer, one having 4 or less functional groups may be used.

As the polyester acrylate oligomer, a weight average molecular weight of 500 to 3,000 may be used.

As the epoxy acrylate oligomer, one having two or less functional groups may be used.

As the epoxy acrylate oligomer, one having a weight average molecular weight of 500 to 2,000 may be used.

The monofunctional photocurable monomer is isooctyl acrylate, cyclic trimethylolpropane formal acrylate (cyclic trimethylolpropane formal acrylate), phenoxy benzyl acrylate, trimethyl cyclohexyl acrylate, isobornyl acrylate, benzyl acrylate, lauryl Acrylates, isodecyl acrylate, phenoxyethyl acrylate, tetrahydroperfuryl acrylate, ethoxy ethoxy ethyl acrylate, stearyl acrylate, hydroxy ethyl acrylate, hydroxy propyl acrylate, acrylic morpholine, Preference is given to using at least one or more selected from the group consisting of vinyl ethers, vinyl esters, N-vinyl-2-pyrrolidone, and N-vinylcaprolactam.

The photocurable monomer of the bifunctional group or more is ethylene glycol diacrylate, hexanediol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, tetraethylene glycol diacrylate, neopentyl With glycol diacrylate, tricyclodecane dimethanol diacrylate, polyethylene glycol 400 diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, glycerol triacrylate and pentaerythritol triacrylate It is preferable to use at least 1 sort (s) or more chosen from the group comprised.

It is preferable that the color ink composition for steel materials has a viscosity of 40 cps or less at room temperature.

The color ink composition for steel materials may have a surface tension of 20 to 50 dyne / cm.

The present invention comprises the steps of jetting a color ink composition for a steel sheet of the present invention to a steel sheet; And

It provides a method for producing a printed steel sheet comprising the step of curing the jetted color ink composition to form a printed layer.

The present invention, a steel sheet; And it provides a printed steel sheet comprising a printed layer formed on the steel sheet of the color ink composition for a steel sheet of the present invention.

The printed steel sheet may include at least one pretreatment layer selected from the group consisting of a color coating layer, a chromium layer, and a chromium free layer between the steel sheet and the print layer.

The color ink composition for steel materials of this invention is excellent in adhesiveness with respect to the steel of the printed layer formed by this. In addition, the print layer has excellent processability, solvent resistance, strength, and color, and the printed steel sheet on which the print layer is formed is used as a high quality printed steel sheet. In addition, the color ink composition for a steel material of the present invention can be applied to the steel material by inkjet low enough viscosity at room temperature.

1 shows a side cross-sectional view of a printed steel sheet having a steel sheet and a printed layer formed on the steel sheet.

Fig. 2 shows a side cross-sectional view of a printed steel sheet having a print layer formed on a steel sheet provided with a pretreatment layer of chromium treatment or chromium free treatment.

Fig. 3 shows a side cross-sectional view of a printed steel sheet having a print layer formed on a steel sheet on which a pretreatment layer and a color coating layer are formed.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

According to one embodiment of the present invention, 10 parts by weight to 30 parts by weight of a mixture of a hetero acrylate oligomer other than the urethane acrylate oligomer and the urethane acrylate oligomer,

5 to 20 parts by weight of the photoinitiator;

0.1 to 10 parts by weight of the pigment; And

Include,

The urethane acrylate oligomer and the hetero acrylate oligomer are 1: 1 to 10: 1 by weight, and the monofunctional photocurable monomer and the bifunctional or more functional photocurable monomer are mixed in a 5: 1 to 100: 1 weight ratio. A color ink composition (hereinafter also referred to as 'color ink composition of one embodiment') is provided. Hereinafter, the composition of the color ink composition for steel materials of this invention is demonstrated.

The color ink composition for steel materials of this invention contains a urethane acrylate oligomer as a main body. In general, a polyester acrylate oligomer, epoxy acrylate oligomer, urethane acrylate oligomer is used for the UV curable resin composition. However, polyester acrylate oligomers have good solvent resistance and scratch resistance but poor processability. Epoxy acrylate oligomer is excellent in hardness and solvent resistance, but there is a problem that yellowing occurs. Urethane acrylate oligomer satisfies most of the physical properties required in the printed layer of the printed steel sheet, such as workability, solvent resistance, hardness, adhesiveness, and particularly has an excellent effect on workability. Thus, urethane acrylate oligomers are used as the main material.

It is preferable that the said urethane acrylate oligomer is an aliphatic urethane acrylate oligomer which does not contain a benzene ring in terms of adhesiveness, curability, hardness, and the like.

The urethane acrylate oligomer may be used that has three or less functional groups, preferably 1 to 3 functional groups. When the number of functional groups of the urethane acrylate oligomer exceeds three, the flexibility of the coating film may be insufficient, resulting in poor workability. You must have at least one functional group to form a coating film by hardening reaction.

It is preferable to use the urethane acrylate oligomer whose weight average molecular weight (Mw) is 500-12,000. If the weight average molecular weight is less than 500, the crosslinking density may be high, resulting in poor workability. If the weight average molecular weight is more than 12,000, the viscosity of the material is generally high, so that it is difficult to implement the jettable viscosity of the ink composition. Low crosslinking density may weaken solvent resistance.

Non-limiting examples of the urethane oligomer, Miwon's Miramer PU210, Miramer PU2034C, Miramer PU2100, Miramer PU2200, Miramer PU330, Miramer PU340, Miramer PU3200, Miramer PU2560, Cytec's EBECRYL 244, EBECRYL 245, EBECRYL 254, EBECRYL 264, EBECRYL 265 , EBECRYL 270, EBECRYL 280, EBECRYL 284, EBECRYL 285, EBECRYL 294, EBECRYL 1259, EBECRYL 1290, EBECRYL 4830, EBECRYL 4835, EBECRYL 4883, EBECRYL 8296, EBECRYL 8402, EBECRYL 8465, EBECRYL 8800 , EBECRYL 8806, EBECRYL 9215, EBECRYL 9216, EBECRYL 9259, EBECRYL 9260, EBECRYL 9270, EBECRYL 9370, UA 7933, UP 112, UP 136, UP 137. These urethane acrylate oligomer can select and use 1 or more types as needed. These may be used alone or in combination of two or more as necessary.

The urethane acrylate oligomer is used together with other hetero acrylate oligomers other than the urethane acrylate oligomer. That is, from the viewpoint of controlling the required physical properties, the urethane acrylate oligomer may be used in combination with the hetero acrylate oligomer to suitably control physical properties such as adhesion, hardness, solvent resistance, processability, and viscosity.

The content of the mixture of the urethane acrylate oligomer and the hetero acrylate oligomer in the composition of the present invention is based on the weight of the color ink composition, with respect to the content of other components of the color ink composition according to one embodiment, from 10 to 30 It may be part by weight. When the content of the mixture of the urethane acrylate oligomer and the hetero acrylate oligomer is less than 10 parts by weight, adhesiveness, processability, solvent resistance, and the like become weak. If the content exceeds 30 parts by weight, the viscosity becomes so high that spraying becomes difficult, thus making it impossible to use in an inkjet system.

As the hetero acrylate oligomer, one selected from the group consisting of polyester acrylate oligomer, and epoxy acrylate oligomer may be used. These may be used alone or in combination of two or more.

As the polyester acrylate oligomer, those having 4 or less functional groups, preferably 1 or more functional groups and 4 or less functional groups may be used. When the number of functional groups of the polyester acrylate oligomer exceeds 4, the crosslinking density may be high, resulting in poor workability. At least one functional group must have at least one functional group to form a printed layer by a polymerization reaction.

The polyester acrylate oligomer preferably has a weight average molecular weight of 500 to 3,000. If the weight average molecular weight is less than 500 or more than 3,000, physical properties may be difficult to control effectively.

Non-limiting examples of the polyester acrylate oligomer include Miramer PS4040, Miramer PS420, CYTEC EBECRYL 80, EBECRYL 81, EBECRYL 84, EBECRYL 452, EBECRYL 657, EBECRYL 800, EBECRYL 810, EBECRYL 851, EBECRYL 852, EBECRYL 884, EBECRYL 1657, EBECRYL 1810, UP 039, etc. are mentioned. These may be used alone or in combination of two or more as necessary.

The epoxy acrylate oligomer may be two or less functional groups, preferably one or more and two or less functional groups. If the number of functional groups of the epoxy acrylate oligomer exceeds two, workability may be inferior. At least one functional group must have at least one functional group to form a printed layer by a polymerization reaction.

The epoxy acrylate oligomer preferably has a weight average molecular weight of 500 to 2,000. If the weight average molecular weight is less than 500 or more than 2,000, it may be difficult to satisfy the required physical properties.

Examples of the epoxy acrylate oligomers include, but are not limited to, bisphenol A type, bisphenol F type, novolac type, and the like. Miwon's Miramer EA2235, Miramer EA2255, Miramer EA2259, Miramer EA2280, Cytec's EBECRYL 600, EBECRYL 604, EBECRYL 605, EBECRYL 606, EBECRYL 608, EBECRYL 629, EBECRYL 645, EBECRYL 648, EBECRYL 1608, EBECRYL 1940, EBECRYL 2959, EBECRYL 3105, EBECRYL 3200, EBECRYL 3201, EBECRYL 3500, EBECRYL 3600, EBECRYL 3600 , EBECRYL 3701, EBECRYL 3702, EBECRYL 3703, EBECRYL 3708, EBECRYL 3720, EBECRYL 6040, EBECRYL 9686, EBECRYL 9706, EBECRYL 9704 and the like. These may be used alone or in combination of two or more as necessary.

The urethane acrylate oligomer and the hetero acrylate oligomer are used in a mixture of 1: 1 to 10: 1 weight ratio, preferably 1.2: 1 to 7: 1 weight ratio, and more preferably 1.2: 1 to 5: 1 weight ratio. It is preferable. It is preferable to use a mixture of the urethane acrylate oligomer and hetero acrylate oligomer in the mixing ratio range in terms of balanced physical properties.

The color ink composition of the present invention contains a photocurable monomer as a diluent of a mixture of the urethane acrylate oligomer and the hetero acrylate oligomer. As the photocurable monomer, a monofunctional photocurable monomer and a photocurable monomer having a bifunctional group or more are used together. By using together a monofunctional photocurable monomer and the photocurable monomer more than bifunctional group, adhesiveness, workability, solvent resistance, and surface hardness improve at the time of print layer formation.

The content of the photocurable monomer in the ink composition of the present invention may be 50 parts by weight to 80 parts by weight based on the content of the other components of the color ink composition according to one embodiment, based on the weight of the color ink composition. If the content of the photocurable monomer is less than 50 parts by weight, the viscosity becomes high, and application of the ink composition to the steel material using the inkjet system is impossible. On the other hand, when the content of the photocurable monomer exceeds 80 parts by weight, it adversely affects the overall coating film properties.

The monofunctional photocurable monomer makes the color ink composition of the present invention have a low viscosity and improves the adhesion and processability of the print layer formed from the color ink composition of the present invention. Non-limiting examples of monofunctional photocurable monomers are isooctyl acrylate, cyclic trimethylolpropane foam acrylate, phenoxy benzyl acrylate, trimethyl cyclohexyl acrylate, isobornyl acrylate, benzyl acrylate, lauryl acrylate Isodecyl acrylate, phenoxyethyl acrylate, tetrahydroperfuryl acrylate, ethoxy ethoxy ethyl acrylate, stearyl acrylate, hydroxy ethyl acrylate, hydroxy propyl acrylate, acrylic morpholine, vinyl ether , Vinyl esters, N-vinyl-2-pyrrolidone, N-vinyl caprolactam and the like. These monofunctional photocurable monomer can select and use 1 or more types as needed. These may be used alone or in combination of two or more as necessary.

The photocurable monomer having a bifunctional group or more improves solvent resistance and surface strength of the print layer formed from the color ink composition of the present invention. Non-limiting examples of photocurable monomers having at least two functional groups include ethylene glycol diacrylate, hexanediol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, tetraethylene glycol diacryl Latex, neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate, polyethylene glycol 400 diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, glycerol triacrylate pentaerythritol tri Acrylates and the like. These bifunctional group photocurable monomers can select and use 1 or more types as needed. These may be used alone or in combination of two or more as necessary. In the photocurable monomer having two or more functional groups, the functional group may be a maximum of 6 functional groups. This is because the maximum number of functional groups that the photocurable monomer can have is six.

The monofunctional photocurable monomer and the bifunctional or more photocurable monomer are mixed in a weight ratio of 5: 1 to 100: 1, preferably 5: 1 to 90: 1 weight ratio, and more preferably 6: 1 to 90: 1 weight ratio. It is preferable to use. It is preferable to mix the monofunctional photocurable monomer and the bifunctional or higher photocurable monomer in the above ratio in terms of controlling the viscosity and controlling the physical properties of the overall coating film effectively.

The color ink composition of the present invention includes a photoinitiator to induce polymerization of the mixture of the urethane acrylate oligomer and the hetero acrylate oligomer and the photocurable monomer using ultraviolet rays. As the photoinitiator, any photoinitiator capable of inducing a photopolymerization reaction of the color ink composition according to the present invention may be used.

Specific examples of the photoinitiator include, but are not limited to, the following compounds or combinations thereof. Examples of photoinitiators include benzophenones and substituted benzophenones, thioxanthones such as 1-hydroxycyclohexyl phenyl ketone, isopropyl thioxanthone, 2-hydroxy-2-methyl-1-phenylpropane-1- On, 2-benzyl-2-dimethylamino- (4-morpholinophenyl) butan-1-one, benzyl dimethyl ketal, bis (2,6) -dimethylphenzoyl) -2,4,4-trimethylpentyl force Pin oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl-2,4,6-trimethylbenzoylphenylphosphinate, 2-methyl-1- [4 (methylthio) phenyl] -2-mo Polynopropane-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, 5,7-dioodo-3-butoxy-6-fluorone, diphenyliodonium flo Lide, triphenylsulfonium hexafluorophosphate, and the like. These may be used alone or in combination of two or more as necessary.

Non-limiting examples of photoinitiators usable in the color ink compositions of the present invention also include Irgacure® 184, 500, 369, 379, 907, 819, Darocur® 1173, MBF, TPO, BP, ITX, and the like. These photoinitiators can be used 1 or more types as needed. These may be used alone or in combination of two or more as necessary.

The content of the photoinitiator in the color ink composition of the present invention may be 5 parts by weight to 20 parts by weight based on the content of the other components of the color ink composition according to one embodiment, based on the weight of the color ink composition. When the photoinitiator is less than 5 parts by weight, the print layer may not be sufficiently cured and the performance of the print layer may not be properly implemented. On the other hand, if it exceeds 20 parts by weight, yellowing occurs in the print layer or the storage stability of the composition is lowered.

The color ink composition of the present invention contains a pigment for imparting color to a steel material. The content of the pigment may be 0.1 part by weight to 10 parts by weight with respect to the content of other components of the color ink composition according to one embodiment, based on the weight of the color ink composition. When the content of the pigment is less than 0.1 part by weight, the coloring power is lowered. When the content of the pigment is more than 10 parts by weight, the dispersibility is lowered and the ink stability is lowered.

As the pigment, an organic pigment, an inorganic pigment, or the like may be used.

Non-limiting examples of the inorganic pigments include carbon black, titanium oxide, zinc oxide, zinc sulfur, red oxide, cadmium, ultramarine blue, rust. Non-limiting examples of the organic pigments include insoluble azo pigments, soluble azo pigments, phthalocyanine organic pigments, quinacridone organic pigments, perylene organic pigments, isoindolinone organic pigments, pyrantrone organic pigments, thioindigo organic Pigments, condensed azo-based organic pigments, benzimidazolone-based organic pigments, quinophthalone-based organic pigments, isoindolin-based organic pigments, nickel azo yellow, dioxazine violet and the like. The pigments may be used alone or in combination of two or more as necessary.

The pigment may be cyan, magenta, yellow, black, white, red, green, blue, orange, violet, brown color, mixtures thereof, and the like.

Illustrating organic pigments with color index (CI) numbers, CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 73, 74, 75, 83, 93, 95, 97 , 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, 213 , 214; CI Pigment Red 5, 7, 9, 12, 48, 49, 52, 53, 57, 97, 112, 122, 123, 149, 168, 177, 180, 184, 192, 202, 206, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254; C. I. Pigment Green 7, 36, 58; C. I. Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64; C. I. Pigment Orange 16, 36, 43, 51, 55, 59, 61; C. I. Pigment Violet 19, 23, 29, 30, 37, 40, 50; C. I. pigment brown 23, 25, 26 etc. are mentioned.

The color ink composition of the present invention includes a dispersant to disperse the pigment. Polymeric dispersants may be used as the dispersant, and the types of the dispersants are not particularly limited. Non-limiting examples of polymer dispersants that can be used include SOLSPERSE dispersants from Lubrizol, DISPERBYK dispersants from BYK, EFKA dispersants from BASF, and the like. These may be used alone or in combination of two or more as necessary.

The content of the dispersant in the color ink composition usually depends on the kind and concentration of the pigment. The dispersant preferably has a dispersant solid content of 3 to 300 parts by weight, preferably 5 to 200 parts by weight, per 100 parts by weight of pigment, in terms of dispersibility and dispersion stability.

The average particle size of the pigment in the color ink composition of the present invention is one of the important features in the jetting property. The pigment particles should be small enough to allow jetting through the inkjet head and not to cause nozzle clogging. In addition, it is preferable that the average particle size of the pigment is 10 to 500 nm, preferably 50 to 300 nm, depending on the kind of the pigment, in order to have good dispersibility and dispersion stability of the pigment and to express sufficient color. When the average particle size of the pigment is less than 10 nm, the light fastness may be lowered, and when the average particle size is larger than 500 nm, the head nozzle of the inkjet system may be clogged by the large particles, which may cause a decrease in the jetting stability. The average particle size of the pigment was measured using a Microtrac Nanotrac 250 Particle Size Analyzer.

In the color ink composition of the present invention, the pigment is very small in particle size and difficult to evenly disperse in the composition. Therefore, a color ink composition is prepared by preparing a pigment dispersion in which the pigment is first dispersed separately in the dispersant, and then blending with other components of the color ink composition.

On the other hand, the average particle size of the desired pigment can be obtained by wetting, pulverizing and dispersing the pigment in a dispersion medium together with a dispersant. The production method of the pigment dispersion is not particularly limited, and for example, the pigment may be prepared by adjusting the particle size to a desired size through a grinding technique such as bead milling, ball milling, and three roll milling.

If necessary, the color ink composition of the present invention may be included in a leveling agent, an antifoaming agent, an antioxidant, a light stabilizer, an ultraviolet absorber, an adhesion promoter, and the like within a range not deteriorating the required physical properties.

The color ink composition of the present invention has a lower viscosity than the composition of the conventional silkscreen or roll printing method for forming a print layer through an inkjet system. Specifically, the color ink composition of the present invention has a viscosity of 40 cps or less, preferably 30 cps or less, and more preferably 20 cps to 30 cps at room temperature (eg, 15 to 25 ° C.). Color ink compositions in the above viscosity range may be suitably applied to form a coating film on a steel material with an inkjet system. As described above, the color ink composition of the present invention has a viscosity applicable to a target material by jetting with an inkjet system, and thus, may be applied to a steel material with an inkjet system. The color ink composition of the present invention has an advantage that the level of viscosity that can be used in an inkjet system is secured without using an organic solvent.

The color ink composition of the present invention is a solvent-free system containing no solvent, but before curing, it has a viscosity low enough to form a print layer on a material using an inkjet system, and the cured print layer formed on the steel material is a steel material. It has a satisfactory level of adhesion, processability, solvent resistance, and hardness.

In addition, the color ink composition preferably has a suitable surface tension for jetting in an inkjet system to be applied to a steel material. The color ink composition of the present invention has a surface tension of 20 to 50 dyne / cm, preferably 22 to 40 dyne / cm at room temperature (eg, 15 to 25 ° C). When the surface tension is less than 20 dyne / cm, ink may form on the head nozzle area of the inkjet system to block the nozzle and prevent the jetting, or the nozzle may be dropped, and ink leakage may occur at the nozzle part. If the surface tension exceeds 50 dyne / cm, ink supply to the inkjet print head may not be smooth, which may cause difficulty in continuous jetting or when jetting to steel materials, resulting in poor leveling on the surface of the material, making it difficult to achieve a desirable coating film. It may be difficult to satisfy the required physical properties.

The said steel material is not specifically limited, For example, a steel plate is mentioned. As the steel sheet, a steel sheet which does not have a separate pretreatment coating on the surface, and a coated steel sheet which has a separate pretreatment coating on the surface may be used. The type of steel sheet to which the color ink composition of the present invention can be applied is not particularly limited, but non-limiting examples thereof include cold rolled steel sheet, hot rolled steel sheet, galvanized steel sheet, aluminum plated steel sheet, stainless steel sheet, magnesium steel sheet, aluminum steel sheet, Zinc steel sheet, titanium steel sheet, color coated steel sheet, anti-fingerprint steel sheet and the like. The ink composition of the present invention is applied to the surface of the steel sheet, and the thickness of the steel sheet to which the ink composition is applied is not particularly limited. Generally 0.1 mm to 10 mm thick steel sheet may be used.

According to another embodiment of the present invention, the method comprises: jetting a color ink composition for steel sheet of the present invention to a steel sheet; And curing the jetted color ink composition to form a printed layer. The matters described in the color ink composition are equally applied to the method of manufacturing a printed steel sheet.

The print layer formed of the color ink composition of the present invention is excellent in adhesion to steel materials, and may be applied by jetting a steel sheet with an inkjet system to have a low viscosity at room temperature as described above.

The color ink composition of the present invention on the steel material, specifically the steel sheet, is applied by jetting with an inkjet system. Printheads, which are widely used for inkjet printing systems, are mainly applied to the thermal jet method of forming ink through instantaneous heat generation in the heating plate in the head and jetting ink, and applying piezoelectric ceramic converters in the printhead. The piezoelectric head may be classified into a piezoelectric head that fills and jets the ink by changing the shape of the ink into a plurality of types. In the present invention, a piezoelectric head is used as the head for the inkjet printing system, but the present invention is not limited thereto, and the heads of the various types may be used.

Inkjet print heads are typically at most 65 ° C., preferably at most 50 ° C., more preferably at most 50 ° C. to room temperature (eg, 15) due to the potential volatility and reactivity of one or more components of the color ink composition, head durability, and the like. To 25 ° C.). The moving speed of the jetted droplets has a speed of 4 m / s to 15 m / s, and the distance between the steel material and the head is 1 mm to 10 mm, preferably 1 mm to 7 mm, which is advantageous for proper image realization. Can be.

The thickness of the coating film formed through the jetted droplets may vary depending on the resolution of the image to be implemented or the number of printing layers, but forming a thickness of 5 μm to 50 μm, preferably 5 μm to 30 μm It may be advantageous to secure.

Thereafter, the jetted color ink composition is irradiated with ultraviolet rays to cure to form a coating film. The curing means may be arranged in combination with the printer head of the inkjet printer to move together with the print head to irradiate the ultraviolet light, or the ultraviolet light may be irradiated through the static fixed curing means. These may be used in one kind or two or more kinds together.

Ultraviolet rays irradiated through the curing means may be generally classified into UV-A in a 400 nm to 320 nm region, UV-B in a 320 nm to 290 nm region, and UV-C in a 290 nm to 100 nm region. In the case of mercury lamps, metal-halide lamps and gallium lamps, ultraviolet rays are radiated from the entire wavelength range of the ultraviolet rays. In the case of LED lamps, ultraviolet rays of a specific wavelength range can be irradiated depending on the configuration of the LED module.

UV-curable lamps are classified into mercury lamps, metal-halide lamps, and gallium lamps according to the type of luminescent materials in the lamp.The UV-curable lamps are classified into H-bulbs, D-bulbs, and A-bulbs depending on the wavelength to be irradiated. Can be classified.

The ink composition according to the present invention uses an H-Bulb UV lamp of Integration Company as a curing means, but is not particularly limited thereto, and any kind of lamp may be used.

The ink composition of the present invention may be jetted to a steel material from an inkjet printer head, and then cured by ultraviolet curing means to form a coating film. The amount of curing energy is determined by many factors such as the amount and type of reactants involved, the energy source, the distance from the energy source, and the thickness of the coating film that is cured.Usually, the amount of UV radiation is about 0.1J / cm ² to 10J / cm ^2. The exposure time to ultraviolet rays may be less than about 1 second to 10 minutes or less. In addition, irradiation of ultraviolet rays may occur in the air or in an inert environment such as nitrogen. By curing with the ultraviolet irradiation amount and exposure time, a coating film of a desired physical property can be formed.

In addition, a color coating layer, a chromium layer or a chromium free layer may be formed on the steel sheet to which the color ink composition of the present invention is applied, before the color ink composition is applied. By applying the color ink composition of the present invention to a steel sheet on which a color coating layer is formed, a desired color print layer may be realized in vivid colors and / or patterns by color contrast. Moreover, the adhesiveness of a color coat layer or a print layer can be improved by forming a chromium layer or a chromium free layer. Furthermore, a clear top coat layer, an ultraviolet cured coating film layer, etc. can be further formed as needed on the printed layer formed from the color ink composition of this invention. The color coating layer, the chromium layer, the chromium free layer, the clear top coat layer, the ultraviolet curing coating layer, and the like correspond to the general steel sheet treatment in the art, and thus do not limit the present invention, and a person skilled in the art needs It can be applied in combination as appropriate.

According to still another embodiment of the present invention, a steel sheet; And a printed steel sheet having a printed layer formed of the color ink composition of the present invention on a steel sheet. The matters described in the above-described color ink composition and printed steel sheet manufacturing method are equally applied to the printed steel sheet of the present invention. 1 is a side cross-sectional view of a printed steel sheet having a steel sheet and a printed layer formed on the steel sheet. Fig. 2 shows a side cross-sectional view of a printed steel sheet having a printed layer formed on a steel sheet with a pretreatment layer formed by chrome treatment or chrome free pretreatment. 3 shows a side cross-sectional view of a printed steel sheet having a print layer formed on the steel sheet on which the pretreatment layer and the color coating layer are formed.

As described above, the print layer formed of the color ink composition of the present invention is not only excellent in adhesion to the steel sheet, but also excellent in solvent resistance, hardness, color, and the like of the print layer. Therefore, the printed steel sheet of the present invention comprising the same also satisfies the physical properties required for the printed steel sheet.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples are merely examples to help understanding of the present invention, but the scope of the present invention is not limited thereto.

1. Preparation of Color Ink Composition

(Example 1)

Black pigment (Carbon Black, Degussa Co.) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Example 2)

Black pigment (Carbon Black, Degussa) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, epoxy acrylate oligomer (EBECRYL 3200, Cytec, bifunctional, Mw 500) 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate ( HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) 0.5 An ink composition was prepared by mixing 2 parts by weight of dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Example 3)

Blue pigment (PB15: 3, Clariant) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, tetrafunctional, Mw 1,800) 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Example 4)

Violet pigment (PV19, Clariant) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, tetrafunctional, Mw 1,800 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) ) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) 0.5 parts by weight 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol) was prepared to prepare an ink composition. The composition of the components used is shown in Table 1 below.

(Example 5)

Yellow pigment (PY155, Clariant) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, tetrafunctional, Mw 1,800 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) ) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) 0.5 parts by weight 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol) was prepared to prepare an ink composition. The composition of the components used is shown in Table 1 below.

(Example 6)

Black pigment (Carbon Black, Degussa Co.) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 5 parts by weight, 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), 24.5 parts by weight of hydroxy propyl acrylate (2-HPA), hexanediol diacrylate (HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Example 7)

Black pigment (Carbon Black, Degussa Co.) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of isobornyl acrylate (IBOA), 20 parts by weight of ethoxy ethoxy ethyl acrylate (EOEOEA), hexanediol diacryl Rate (HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Example 8)

Black pigment (Carbon Black, Degussa Co.) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), dipropylene glycol diacryl Rate (DPGDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Comparative Example 1)

Black pigment (Carbon Black, Degussa Co.) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 5 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 10 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Comparative Example 2)

Black pigment (Carbon Black, Degussa) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 14 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 1 part by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Comparative Example 3)

Black pigment (Carbon Black, Degussa Co.) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 5 parts by weight, 24.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 15 parts by weight of tetrahydrofurfuryl acrylate (THFA), 15 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) 15 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Comparative Example 4)

Black pigment (Carbon Black, Degussa Co.) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 10 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 5 parts by weight, phenoxy ethyl acrylate (2-PEA) 29 parts by weight, 20 parts by weight of tetrahydrofurfuryl acrylate (THFA), 20 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) 0.5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

(Comparative Example 5)

Black pigment (Carbon Black, Degussa) 3 parts by weight, urethane acrylate oligomer (Miramer PU2560, Miwon, bifunctional, Mw 10,400) 25 parts by weight, polyester acrylate oligomer (Miramer PS420, Miwon, 4-functional, Mw 1,800) 10 parts by weight, 14.5 parts by weight of phenoxy ethyl acrylate (2-PEA), 15 parts by weight of tetrahydrofurfuryl acrylate (THFA), 15 parts by weight of isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA) 5 parts by weight, photoinitiator Irgacure 184 (BASF) 2 parts by weight, photoinitiator Irgacure 369 (BASF) 3 parts by weight, photoinitiator Darocur TPO (BASF) 5 parts by weight, leveling agent (BYK-UV3510, BYK) An ink composition was prepared by mixing 0.5 parts by weight and 2 parts by weight of a dispersant (Solsperse 35000, Lubrizol). The composition of the components used is shown in Table 1 below.

TABLE 1

(* The surface tensions of the color ink compositions of Examples 1-8 and Comparative Examples 1-5 were 25-30 dyne / cm, and the pigments were first formulated into a pigment dispersion by controlling the particle size with a bead-milling agent. In combination with other ingredients)

2. Fabrication of Specimen

The color ink compositions of Examples 1 to 8, and Comparative Examples 1 to 5 were jetted using UVT printer JETRIX KX6SD, manufactured by InkTec, and UV cured onto a white coated steel sheet coated with 10 to 15 μm, thereby printing 5 to 10 μm thick. A layer was formed to prepare a specimen. Specific printing conditions are as follows.

Equipment: InkTec JETRIX KX6SD

Head: Konica Minolta KM1024SHB

Head temperature: 45 ℃

Image resolution: 1440 x 720 dpi

Output mode: Fine art (12pass)

UV light source: Integration Subzero Lamp 170mm H-bulb

Curing Mode: Normal Full Cure

UV irradiation light quantity: EIT's UV Power Puck Ⅱ measurement, cumulative light quantity of about 2J / ㎠

UV irradiation time: 3 seconds

Coating thickness: 7㎛

Distance between material and print head: 2 mm

Droplet moving speed: 4 m / sec to 15 m / sec

3. Evaluation method

The specimens and color ink compositions prepared as described above were evaluated for viscosity, adhesion (adhesion), processability, solvent resistance, and pencil hardness in the following manner, and the results are shown in Table 2.

(1) viscosity

The viscosity of the ink composition was measured and evaluated at 25 ° C. using BrookField viscometer DV II + CPE-40 chiffins.

(2) average particle size

Average particle size was measured using a Microtrac Nanotrac 250 Particle Size Analyzer as the average particle size of the pigment.

(3) Adhesiveness (adhesiveness)

Adhesion is made by cutting 10 lines with a cutter so that the interval between the specimens is 1 mm, making 100 pieces, attaching a cellophane adhesive tape on it, and then peeling off to evaluate the adhesion of the print layer.

(◎: No abnormality (no drop out), ○: Fall out of 10, △: Fall out of 50, Χ: Complete drop out)

(4) processability

Machinability was confirmed by the crack after the 3T (three sheet thickness) 180 ° bend processing of the specimen.

(◎: No abnormality (no cracking), Χ: Cracking)

(5) solvent resistance

Solvent resistance was measured by applying MEK (methyl ethyl ketone) to the gauze, applying a constant force, rubbing in a reciprocating manner and observing a good state of the print layer. The number of times the coating film was peeled off or damaged in the solvent was evaluated separately.

(◎: 50 or more times, ○: less than 20 times, △: less than 10 times, Χ: less than 5 times)

(6) pencil hardness

Pencil hardness was measured according to JIS K5600-5-4KS. Here, the pencil hardness was measured sequentially from 9B to 9H, the closer to 9B the hardness is weaker, the closer to 9H the hardness is stronger.

[Table 2] Property Evaluation

As shown in Table 2, all of Examples 1 to 8, which are color ink compositions satisfying the composition of the color ink composition of the present invention, secured a viscosity and an average particle size without great difficulty in jetting. In addition, the print layer formed therefrom exhibited excellent adhesion, processability, solvent resistance and pencil hardness.

The print layers formed of Comparative Examples 1 and 2 in which the mixing ratio of the urethane acrylate oligomer and the hetero acrylate oligomer outside the scope of the present invention could not satisfy the balanced physical properties. It can be seen that Comparative Examples 3 and 4 in which the mixing ratio of the monofunctional monomer and the monomer of the bifunctional group or more out of the scope of the present invention have the deterioration of the opposite physical properties. Comparative Example 5 in which the total content of the urethane acrylate oligomer and the hetero acrylate oligomer exceeds 30 parts by weight and the photocurable monomer is less than 50 parts by weight, it was confirmed that the jetting is difficult due to the high viscosity.

Claims

10 parts by weight to 30 parts by weight of a mixture of a urethane acrylate oligomer and a hetero acrylate oligomer other than the urethane acrylate oligomer,

50 parts by weight to 80 parts by weight of a photocurable monomer which is a mixture of a monofunctional photocurable monomer and a bifunctional or higher photocurable monomer;

5 to 20 parts by weight of the photoinitiator;

0.1 to 10 parts by weight of the pigment; And

Dispersant solids content per 100 parts by weight of pigment, 3 to 300 parts by weight of dispersant

Include,

The urethane acrylate oligomer and the hetero acrylate oligomer are 1: 1 to 10: 1 by weight, and the monofunctional photocurable monomer and the bifunctional or more functional photocurable monomer are mixed in a 5: 1 to 100: 1 weight ratio. Color ink composition.
The method of claim 1,

The urethane acrylate oligomer has a weight average molecular weight of 500 to 12,000 color ink composition for steel materials.
The method of claim 1,

The urethane acrylate oligomer is an aliphatic urethane acrylate color ink composition.
The method of claim 1,

The urethane acrylate oligomer is a color ink composition for steel materials having 3 or less functional groups.
The method of claim 1,

The hetero acrylate oligomer is selected from the group consisting of a polyester acrylate oligomer, and an epoxy acrylate oligomer.
The method of claim 5,

The polyester acrylate oligomer is a color ink composition for steel materials having 4 or less functional groups.
The method of claim 5,

The polyester acrylate oligomer is a color ink composition for a steel material having a weight average molecular weight of 500 to 3,000.
The method of claim 5,

The epoxy acrylate oligomer is a color ink composition for steel materials having a functional number of two or less.
The method of claim 5,

The epoxy acrylate oligomer has a weight average molecular weight of 500 to 2,000 color ink composition for steel materials.
The method of claim 1,

The monofunctional photocurable monomer is isooctyl acrylate, cyclic trimethylolpropane foam acrylate, phenoxy benzyl acrylate, trimethyl cyclohexyl acrylate, isobornyl acrylate, benzyl acrylate, lauryl acrylate, isodecyl acryl Latex, phenoxyethyl acrylate, tetrahydroperfuryl acrylate, ethoxy ethoxy ethyl acrylate, stearyl acrylate, hydroxy ethyl acrylate, hydroxy propyl acrylate, acrylic morpholine, vinyl ether, vinyl ester, Color ink composition for steel materials selected from the group consisting of N-vinyl-2-pyrrolidone, and N-vinyl caprolactam.
The method of claim 1,

The photocurable monomer of the bifunctional group or more is ethylene glycol diacrylate, hexanediol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, tetraethylene glycol diacrylate, neopentyl With glycol diacrylate, tricyclodecane dimethanol diacrylate, polyethylene glycol 400 diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, glycerol triacrylate and pentaerythritol triacrylate Color ink composition for steel materials selected from the group consisting of.
The method of claim 1,

The color ink composition for steel materials is a color ink composition for steel materials having a viscosity of 40 cps or less at room temperature.
The method of claim 1,

The color ink composition for steel materials has a surface tension of 20 to 50 dyne / cm color ink composition for steel materials.
Jetting the steel sheet with the color ink composition for steel materials according to any one of claims 1 to 13; And

Curing the jetted color ink composition to form a printed layer.
Steel plate; And a print layer formed on the steel sheet with the color ink composition for steel materials according to any one of claims 1 to 13.
The method of claim 15,

The printed steel sheet includes at least one pretreatment layer selected from the group consisting of a color coating layer, a chromium layer and a chromium free layer between the steel sheet and the print layer.