KR102762855B1 - Ultraviolet curable black ink composition for printing on 3d curved glass and a method for forming a bezel pattern - Google Patents

Abstract

The present invention relates to an ultraviolet-curable high-light-blocking black ink composition that can be printed on curved tempered glass (3D) and a bezel pattern printing method using the same. More specifically, the black ink composition for printing on curved tempered glass of the present invention can be printed by an inkjet process without ink sagging on an inclined surface of 3D curved glass.

Description

{ULTRAVIOLET CURABLE BLACK INK COMPOSITION FOR PRINTING ON 3D CURVED GLASS AND A METHOD FOR FORMING A BEZEL PATTERN}

The present invention relates to an ultraviolet-curable high-light-blocking black ink composition that can be printed on curved tempered glass (3D) and a bezel pattern printing method using the same. More specifically, the black ink composition for printing on curved tempered glass of the present invention can be printed by an inkjet process without ink sagging on an inclined surface of curved glass.

With the upward standardization of smartphone specifications, there is almost no difference in hardware, and curved displays have become a differentiated form factor for flagship smartphones. 3D curved glass with a curvature molding is also being applied to tempered glass that protects the display panel. Previous 2D tempered glass mostly had a bezel printed using screen printing, but 3D tempered glass cannot be printed using screen printing due to its curved surface. Since curved tempered glass is formed using flat glass at a high temperature of 800℃ in a metal mold, problems such as discoloration and peeling occur due to the high temperature when printing and molding 2D tempered glass with existing ink. Therefore, decorative films were mainly used for the bezel of curved tempered glass, but they are expensive and difficult to attach to the glass chamfer surface, causing light leakage. Currently, it is mainly printed using pad printing, but in order to exhibit light-blocking properties, 4-5 degrees of printing is required, which causes yield and process cost issues, so a new printing process is needed.

Inkjet printing can print bezels of O.D. 5 or larger at 1 degree and UV cure them at once, but because it prints in a 2D state, there are limitations to the curvature of curved glass, and there is the challenge of preventing ink sagging on inclined surfaces.

Korean Patent Application No. 2015-0084409 Korean Patent Application No. 2018-0095806

In order to solve the problems of the above-mentioned prior art, the present invention aims to provide a composition capable of preventing curvature and ink sagging of curved glass printable by inkjet.

In order to solve the above problems, the present invention provides an ultraviolet-curable black ink composition comprising a black pigment, a dispersant, an oxetane compound, a trifunctional or higher epoxy compound, an adhesion promoter, a photopolymerization initiator, a photosensitizer, and a surfactant, wherein the ink contact angle of the ink composition is 10° or more and 40° or less on a glass substrate, and an ultraviolet-curable black ink composition for forming a bezel pattern on a curved tempered glass (3D curved glass) substrate is provided.

In addition, the present invention provides a method for printing a bezel pattern on curved tempered glass (3D, Curved glass) using the above-described ultraviolet-curable high-light-blocking black ink composition.

By using the ultraviolet-curable light-blocking black ink composition according to the present invention, a bezel having an O.D. of 5 or more can be printed on curved tempered glass using an inkjet printing technique without ink sagging on the curved surface.

Figure 1 shows the glass curvature measurement of 3D curved glass (in the case of 63° curvature).
Figure 2 shows the contact angle measurement according to the Sessile Drop Method.

Hereinafter, the present invention will be described in more detail.

The present invention relates to an ultraviolet-curable black ink composition comprising a black pigment, a dispersant, an oxetane compound, an epoxy compound, an adhesion promoter, a photopolymerization initiator, a photosensitizer, and a surfactant.

The above epoxy compound may be a trifunctional or higher epoxy compound. Examples of the above trifunctional or higher epoxy compound include glycerol propoxylate triglycidyl ether, trimethylolpropane triglycidyl ether, tris(4-hydroxyphenyl)methane triglycidyl ether, pentaerythritol polyglycidyl ether, castor oil polyglycidyl ether, sorbitol polyglycidyl ether, and the like.

The content of the epoxy compound may be 5 to 30 wt%, or 10 to 20 wt%, based on the total weight of the ink composition. If the content is less than 5 wt%, hardness may be reduced, and if the content exceeds 30 wt%, there is a problem that viscosity increases.

Additionally, the ink composition according to the present invention may include an oxetane monomer.

Oxetane monomer is a compound having a four-membered cyclic ether group in its molecular structure and can act to lower the viscosity of a cationic cured ink composition (for example, less than 50 cPs at 25°C).

Specifically, examples thereof include 3-ethyl-3-hydroxymethyl oxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, bis[1-(ethyl(3-oxetanyl))methyl ether, 3-ethyl-3-(phenoxymethyl)oxetane, di[(3-ethyl-3-oxetanyl)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-cyclohexyloxymethyl oxetane, or phenolnovolac oxetane. As the oxetane compound, for example, “Alonoxetane OXT-101”, “Alonoxetane OXT-121”, “Alonoxetane OXT-211”, “Alonoxetane OXT-221” or “Alonoxetane OXT-212” manufactured by Toagosei Co., Ltd. can be used. These can be used alone or in combination of two or more types.

The content of the oxetane monomer may be 20 to 60 wt%, or 35 to 55 wt%, based on the total weight of the ink composition. If the content is less than 20 wt%, viscosity may increase and coatability may deteriorate, and if the content exceeds 60 wt%, the degree of curing may be insufficient.

The ink composition of the present invention contains, as a cationic photopolymerization initiator, a compound that produces cationic species or Bronsted acid upon irradiation with ultraviolet light, such as an iodonium salt or a sulfonium salt, but is not necessarily limited thereto.

The above iodonium salt or sulfonium salt causes a curing reaction in which a monomer having an unsaturated double bond contained in the ink reacts to form a polymer during the ultraviolet curing process, and a photosensitizer may also be used depending on the polymerization efficiency.

For example, the photopolymerization initiator may have an anion represented by SbF ₆ -, AsF ₆ -, BF ₆ -, (C ₆ F ₅ ) ₄ B-, PF ₆ -, or RfnF _6-n , but is not necessarily limited thereto. According to one embodiment of the present invention, the photopolymerization initiator may use a triarylsulfonium salt having excellent high-temperature stability for the storage stability of the ink.

The above photopolymerization initiator may be included in an amount of 1 to 10 wt%, or 2 to 6 wt%, based on the total weight of the ultraviolet-curable ink composition. If the content is less than 1 wt%, the curing reaction is not sufficient, and if the content is more than 10 wt%, it may not dissolve at all or the viscosity may increase, resulting in reduced coatability.

The above ink composition may contain a colorant.

The above coloring agent may be one or more pigments, dyes or mixtures thereof, and is not particularly limited as long as it can express a color as required.

As a specific example of the present invention, carbon black, graphite, metal oxide, organic black pigment, etc. can be used as the black pigment.

Additionally, the colorant used in the present invention may be a combination of a coloring pigment, a black or color dye, or a combination of organic color pigments such as red, blue, yellow, and green.

Examples of carbon black include Cysto 5HIISAF-HS, Cysto KH, Cysto 3HHAF-HS, Cysto NH, Cysto 3M, Cysto 300HAFLS, Cysto 116HMMAF-HS, Cysto 116MAF, Cysto FMFEF-HS, Cysto SOFEF, Cysto VGPF, Cysto SVHSRF-HS and Cysto SSRF (Donghae Carbon Co., Ltd.); Diagram Black II, Diagram Black N339, Diagram Black SH, Diagram Black H, Diagram LH, Diagram HA, Diagram SF, Diagram N550M, Diagram M, Diagram E, Diagram G, Diagram R, Diagram N760M, Diagram LR, #2700, #2600, #2400, #2350, #2300, #2200, #1000, #980, #900, MCF88, #52, #50, #47, #45, #45L, #25, #CF9, #95, #3030, #3050, MA7, MA77, MA8, MA11, MA100, MA40, OIL7B, OIL9B, OIL11B, OIL30B and OIL31B (Mitsubishi Chemical Corporation); PRINTEX-U, PRINTEX-V, PRINTEX-140U, PRINTEX-140V, PRINTEX-95, PRINTEX-85, PRINTEX-75, PRINTEX-55, PRINTEX-45, PRINTEX-300, PRINTEX-35, PRINTEX-25, PRINTEX-200, PRINTEX-40, PRINTEX-30, PRINTEX-3, PRINTEX-A, SPECIAL BLACK-550, SPECIAL BLACK-350, SPECIAL BLACK-250, SPECIAL BLACK-100, and LAMP BLACK-101 (Degusa Co., Ltd.); RAVEN-1100ULTRA, RAVEN-1080ULTRA, RAVEN-1060ULTRA, RAVEN-1040, RAVEN-1035, RAVEN-1020, RAVEN-1000, RAVEN-890H, RAVEN-890, RAVEN-880ULTRA, RAVEN-860ULTRA, RAVEN-850, RAVEN-820, RAVEN-790ULTRA, RAVEN-780ULTRA, RAVEN-760ULTRA, RAVEN-520, RAVEN-500, RAVEN-460, RAVEN-450, RAVEN-430ULTRA, RAVEN-420, RAVEN-410, RAVEN-2500ULTRA, RAVEN-2000, RAVEN-1500, Examples thereof include RAVEN-1255, RAVEN-1250, RAVEN-1200, RAVEN-1190ULTRA, and RAVEN-1170 (Colombia Carbon Co., Ltd.) or mixtures thereof.

The above organic black pigment may include, but is not limited to, aniline black, lactam black, or perylene black.

In the present invention, the ink composition is characterized in that it is cured by irradiation with long-wavelength ultraviolet rays (e.g., 365 or 395 nm) and has a certain level of OD (optical density) at a film thickness of 5 to 15 μm.

For this purpose, the content of the colorant may be 5 to 30 wt%, or 5 to 15 wt%, based on the total weight of the ink composition. When the content of the colorant is less than 5 wt%, a desired level of OD may not be achieved, and when the content exceeds 30 wt%, an excessive amount of the colorant may not be dispersed in the ink and a sediment may be formed, and the inkjet process performance may be significantly deteriorated.

When the content of the colorant is within the above range, the composition can achieve an O.D. of 5.0 or more at a film thickness of 5 to 15 μm after curing.

Next, the dispersant is used to make the black pigment into particles of uniform size, and also to shorten the ink manufacturing time. The dispersant may be a polymeric, nonionic, anionic or cationic dispersant, and examples thereof include acrylic series, polyalkylene glycol and its esters, polyoxyalkylene polyhydric alcohols, ester alkylene oxide adducts, alcohol alkylene oxide adducts, sulfonic acid esters, sulfonate salts, carboxylic acid esters, carboxylates, alkylamide alkylene oxide adducts and alkylamines, and may be used alone or in combination of two or more, and among these, it is preferable to use an acrylic series dispersant which has excellent ink storability, etc.

The content of the dispersant is 0.5 to 5 wt%, preferably 1 to 3 wt%, and more preferably about 2 wt%, based on the entire ink composition. If the content of the dispersant is less than 0.5 wt% based on the entire ink composition, there is a risk that the pigment may not be evenly dispersed, and if it exceeds 5 wt%, there is a risk that the pigment may aggregate or the curing sensitivity may be reduced.

The ink composition according to the present invention may contain an adhesion promoter.

The above adhesion promoter can improve the adhesion between the substrate and the printing layer, and can be used at least one selected from the group consisting of an alkoxy silane compound and a phosphate-based acrylate such as a phosphate acrylate. Examples of the alkoxy silane compound include 3-glycidoxypropyl trimethoxysilane (KBM-403 (Shin-Etsu, USA)), 3-glycidoxypropyl methyldimethoxysilane (KBM-402), 2-(3,4 epoxycyclohexyl) ethyltrimethoxysilane (KBM-303), 3-glycidoxypropyl methyldiethoxysilane, Examples thereof include 3-glycidoxypropyl triethoxysilane (KBE-402), 3-methacryloxypropyl trimethoxysilane (KBE-403), and 3-methacryloxypropyl trimethoxysilane (KBM-503), and more than one type may be used.

According to one embodiment of the present invention, excellent adhesion is achieved between a bezel pattern and a substrate by using an epoxy silane compound, for example, 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by ShinEtsu Co., Ltd.), as an adhesion promoter.

The content of the adhesion promoter may be 5 to 20 wt%, or 10 to 15 wt%, based on the total weight of the ink composition. When the content of the adhesion promoter is less than 5 wt%, the adhesion performance of the bezel on the tempered glass may deteriorate, and when the content exceeds 20 wt%, the curing sensitivity of the ink may deteriorate.

Additionally, the ink composition according to the present invention may contain a surfactant.

As the above surfactant, one having a low surface tension reducing effect can be used, and specifically, a fluorinated surfactant and a silicone surfactant can be used. In addition, a surfactant that enables precise pattern printing, has excellent leveling, and can suppress ink flow in curved areas can be used, and commercially available products include, for example, F-477 (manufactured by DIC), BYK-373 (manufactured by BYK), RAD2200N, and Glide 450 (manufactured by TEGO).

The content of the surfactant may be 0.05 to 5 wt%, or 0.1 to 2 wt%, based on the total weight of the ink composition. When the content of the surfactant is less than 0.05 wt%, the spreadability of the ink is not controlled to a desired level, which makes it difficult to print a precise pattern, and when the content exceeds 5 wt%, the surfactant is used in an excessive amount, which causes a problem in that the compatibility and antifoaming properties of the composition are reduced.

The ink composition according to the present invention may contain a photosensitizer.

The above photosensitizers include anthracene compounds such as anthracene, 9,10-dibutoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 2-ethyl-9,10-dimethoxyanthracene; benzophenone compounds such as benzophenone, 4,4-bis(dimethylamino)benzophenone, 4,4-bis(diethylamino)benzophenone, 2,4,6-trimethylaminobenzophenone, methyl-o-benzoylbenzoate, 3,3-dimethyl-4-methoxybenzophenone, and 3,3,4,4-tetra(t-butylperoxycarbonyl)benzophenone; acetophenone; ketone compounds such as dimethoxyacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and propanone; Perylene; 9-fluorenone compounds, such as 2-chloro-9-fluorenone, and 2-methyl-9-fluorenone; thioxanthone compounds, such as thioxanthone, 2,4-diethyl thioxanthone, 2-chloro thioxanthone, 1-chloro-4-propyloxy thioxanthone, isopropylthioxanthone (ITX), and diisopropylthioxanthone; xanthone compounds, such as xanthone and 2-methylxanthone; anthraquinone compounds, such as anthraquinone, 2-methyl anthraquinone, 2-ethyl anthraquinone, t-butyl anthraquinone, and 2,6-dichloro-9,10- anthraquinone; Acridine compounds such as 9-phenylacridine, 1,7-bis(9-acridinyl)heptane, 1,5-bis(9-acridinylpentane), and 1,3-bis(9-acridinyl)propane; dicarbonyl compounds such as benzyl, 1,7,7-trimethyl-bicyclo[2,2,1]heptane-2,3-dione, and 9,10-phenanthrenequinone; phosphine oxide compounds such as 2,4,6-trimethylbenzoyl diphenylphosphine oxide and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide; benzoate compounds such as methyl-4-(dimethylamino)benzoate, ethyl-4-(dimethylamino)benzoate, and 2-n-butoxyethyl-4-(dimethylamino)benzoate; Amino synergists such as 2,5-bis(4-diethylaminobenzal)cyclopentanone, 2,6-bis(4-diethylaminobenzal)cyclohexanone, 2,6-bis(4-diethylaminobenzal)-4-methyl-cyclopentanone; Coumarin compounds such as 3,3-carbonylvinyl-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-benzoyl-7-(diethylamino)coumarin, 3-benzoyl-7-methoxy-coumarin, and 10,10-carbonylbis[1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-C1]-benzopyrano[6,7,8-ij]-quinolizin-11-one; It may be at least one selected from the group consisting of chalcone compounds such as 4-diethylamino chalcone, 4-azidebenzalacetophenone; 2-benzoylmethylene; and 3-methyl-b-naphthothiazoline.

The content of the photosensitizer may be 2 to 4 wt% based on the total weight of the ink composition.

If the content of the above-mentioned sensitizer is less than 2 wt%, the curing sensitivity is reduced and surface wrinkles occur during UV curing, resulting in poor bezel coating properties. If it exceeds 4 wt%, the sensitizer may be precipitated without being diluted, thereby lowering the stability of the ink.

The ink composition according to the present invention may have an ink contact angle of 10° or more and 40° or less, or 15° or more and 30° or less, for a droplet of 10 picoliter to 1 microliter. If it is less than 10°, ink sagging occurs on the glass surface, weakening the light-shielding property, and if it exceeds 40°, the ink spreads poorly, making it difficult to obtain a bezel film of uniform thickness.

In the present invention, the ink contact angle can be measured using the Sessile Drop method. Fig. 2 shows the ink contact angle measurement using the Sessile Drop method.

According to one embodiment of the present invention, the ink composition can form a printing layer on curved glass without ink sagging up to a glass curvature of 80°.

The ultraviolet-curable ink composition used in the present invention spreads within a short period of time immediately after inkjet printing, exhibits excellent film properties, and is cured to exhibit excellent adhesive properties. Therefore, when applying the ultraviolet-curable ink composition, it is preferable to install a UV lamp immediately behind the inkjet head so that curing can be performed simultaneously with inkjet printing.

The above ultraviolet-curable ink composition has a curing dose of 1 to 10,000 mJ/cm2, preferably 1,000 to 7,000 mJ/cm2.

The above ultraviolet curable ink composition is cured by absorbing radiation in a wavelength range of 250 nm to 450 nm, preferably 360 nm to 410 nm.

The above UV-curable ink composition has a viscosity of, for example, 1 to 30 mPa·s, or 10 to 20 mPa·s at 25°C, and is thus suitable for an inkjet process. The UV-curable ink composition having the above viscosity range has good discharge at the process temperature. The process temperature refers to a temperature at which the curable ink composition is heated to lower its viscosity. The process temperature may be 10°C to 100°C, and preferably 20°C to 70°C.

The present invention also provides a method for printing a bezel pattern on 3D curved glass using the ink composition. Specifically, the method for printing a bezel pattern on 3D curved glass according to the present invention comprises the steps of: a) forming a bezel pattern on 3D curved glass by inkjet printing using the ultraviolet-curable black ink composition; and b) photocuring the bezel pattern.

As a method for forming a bezel pattern on the above substrate, an inkjet printing method using ultraviolet curable resin can be used instead of photolithography, screen, gravure, or reverse offset printing.

When forming a printing layer on a curved substrate, the problem of ink sagging may occur. When forming a printing layer on curved glass having a glass curvature of 80° or less using the ink composition according to the present invention, the problem of ink sagging can be minimized and curved light leakage can be blocked.

As a light source for curing the ultraviolet-curable ink composition of the present invention, examples thereof include, but are not necessarily limited to, a mercury vapor arc emitting light having a wavelength of 250 to 450 nm, a carbon arc, a Xe arc, an LED curing device, etc.

The following specific examples of the invention will explain the operation and effects of the invention in more detail. However, these are presented as examples of the invention and the scope of the invention's rights is not limited in any way by these.

Example

(Example 1)

A pigment dispersion (9 parts by weight of carbon black, 2 parts by weight of an acrylic dispersant, and 51 parts by weight of OXT-221 as an oxetane monomer), 15 parts by weight of YH-300 as a trifunctional epoxy compound, 10 parts by weight of KBM-403 as an adhesion promoter, 10 parts by weight of Speedcure992 as a photoinitiator, 2.5 parts by weight of DBA as a sensitizer, and 0.5 parts by weight of F-477 as a surfactant were stirred and mixed for 6 hours to produce an ultraviolet-curable ink composition of the present invention.

(Examples 2 to 4)

An ultraviolet-curable ink composition was prepared using the same method as in Example 1 with the composition described in Table 1 below.

Example 1 Example 2 Example 3 Example 4 (A) Carbon black 9 9 9 9 Acrylic dispersant 2 2 2 2 OXT-221 51 51 51 51 (B) YH-300 15 15 15 15 (C) KBM-403 10 10 10 10 (D) Speedcure992 (50% solution in PC) 10 10 10 10 (E) DBA 2.5 2.5 2.5 2.5 (F) F-477 0.5 BYK-373 0.5 RAD2200N 0.5 Glide450 0.5 F-554 BYK-399 RAD2100 Glide100 (A) Pigment dispersion: manufactured by Tokushiki (dispersed in OXT-221 (manufactured by Toagosei))
(B) Epoxy compound: YH-300 (trifunctional epoxy compound, manufactured by Kukdo Chemical)
(C) Adhesion promoter: KBM-403, manufactured by Shin-Etsu
(D) Initiator: Cationic polymerization initiator (Speedcure992 is dissolved in propylene carbonate at 50%, and the actual solid content is 50%, manufactured by Lambson)
(E) Sensitizer: 9,10-Dibutoxyanthracene, manufactured by Kawasaki, ANTHRACURE™ UVS-1331
(F) Surfactant: (F-477, F-554) DIC manufacturing
(BYK-373, BYK-399) Manufactured by BYK
(RAD2200N, RAD2100, Glide450, Glide100) TEGO Manufacturing

(Comparative Example 1)

A pigment dispersion (9 parts by weight of carbon black, 2 parts by weight of an acrylic dispersant, and 51 parts by weight of OXT-221 as an oxetane monomer), 15 parts by weight of YH-300 as a trifunctional epoxy compound, 10 parts by weight of KBM-403 as an adhesion promoter, 10 parts by weight of Speedcure992 as a photoinitiator, 2.5 parts by weight of DBA as a sensitizer, and 0.5 parts by weight of F-554 as a surfactant were stirred and mixed for 6 hours to prepare an ultraviolet-curable ink composition.

(Comparative examples 2 to 4)

An ultraviolet-curable ink composition was prepared using the same method as in Comparative Example 1 with the composition described in Table 2 below.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 (A) Carbon black 9 9 9 9 Acrylic dispersant 2 2 2 2 OXT-221 51 51 51 51 (B) YH-300 15 15 15 15 (C) KBM-403 10 10 10 10 (D) Speedcure992 (50% solution in PC) 10 10 10 10 (E) DBA 2.5 2.5 2.5 2.5 (F) F-477 BYK-373 RAD2200N Glide450 F-554 0.5 BYK-399 0.5 RAD2100 0.5 Glide100 0.5 (A) Pigment dispersion: manufactured by Tokushiki (dispersed in OXT-221 (manufactured by Toagosei))
(B) Epoxy compound: YH-300 (trifunctional epoxy compound, manufactured by Kukdo Chemical)
(C) Adhesion promoter: KBM-403, manufactured by Shin-Etsu
(D) Initiator: Cationic polymerization initiator (Speedcure992 is dissolved in propylene carbonate at 50%, and the actual solid content is 50%, manufactured by Lambson)
(E) Sensitizer: 9,10-Dibutoxyanthracene, manufactured by Kawasaki, ANTHRACURE™ UVS-1331
(F) Surfactant: (F-477, F-554) DIC manufacturing
(BYK-373, BYK-399) Manufactured by BYK
(RAD2200N, RAD2100, Glide450, Glide100) TEGO Manufacturing

<Manufacturing Example 1>

The ink compositions manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 were inkjet-printed on a glass substrate using an inkjet printer Omnijet300 (manufactured by Unijet) at 600 DPI conditions so that the OD was 5. The optical density (OD) was measured using X-rite 341C. The printed layer was cured using a 395 nm UV LED lamp at a light amount of 5000 mJ/cm ² to produce a sample. The thickness of the sample was measured using Alpha step D-600 (manufactured by KLA tencor).

<Property Evaluation>

1) Ink contact angle measurement

Drop shape analysis system DSA100 (Kruss) was used to form a 0.1 μl drop and measure it according to the sessile drop method.

2) Curved light leak evaluation

The light source on the curved surface was visually observed and evaluated using a three-wavelength lamp.

The results of the property evaluation according to the above property evaluation method are shown in Table 3 below.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Ink contact angle 15.4 26.7 16.8 17.4 6.8 8.8 8.5 7.4 Curved light source Curvature (63°) OK OK OK OK NG NG NG NG Curvature (75°) OK OK OK OK NG NG NG NG Curvature (88°) NG NG NG NG NG NG NG NG

It can be seen that the ink compositions of Examples 1 to 4 according to the present invention have an ink contact angle of 10° or more. In addition, no curved light leakage occurred at glass curvatures of 63° and 75°, and curved light leakage occurred at glass curvatures of 88°.

Meanwhile, it can be seen that the ink compositions of Comparative Examples 1 to 4 have ink contact angles of less than 10°. In addition, curved light leakage already occurred at glass curvatures of 63° and 75°.

As described above, specific parts of the present invention have been described in detail. It will be obvious to those skilled in the art that such specific descriptions are merely preferred embodiments and that the scope of the present invention is not limited thereby. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (18)

A UV-curable black ink composition comprising a black pigment, a dispersant, an oxetane compound, a trifunctional or higher epoxy compound, an adhesion promoter, a photopolymerization initiator, a photosensitizer, and a surfactant,
The above surfactant is selected from the group consisting of fluorine-based surfactants and silicone-based surfactants,
The ink composition comprises 5 to 30 wt% of the black pigment, 0.5 to 5 wt% of the dispersant, 20 to 60 wt% of the oxetane compound, 5 to 30 wt% of the trifunctional or higher epoxy compound, 5 to 20% of the adhesion promoter, 1 to 10 wt% of the photopolymerization initiator, 2 to 4 wt% of the photosensitizer, and 0.05 to 5 wt% of the surfactant, based on the total weight of the ink composition.
An ultraviolet-curable black ink composition for forming a bezel pattern on a curved tempered glass (3D curved glass) substrate, wherein the ink contact angle of the ink composition is 10° to 40° on a glass substrate for a droplet of 10 picoliter to 1 microliter. An ultraviolet-curable black ink composition in claim 1, wherein the glass curvature of the curved glass is 80° or less. delete delete An ultraviolet-curable black ink composition in claim 1, wherein the oxetane compound is selected from the group consisting of 3-ethyl-3-hydroxymethyl oxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]benzene, bis[1-(ethyl(3-oxetanyl))methyl ether, 3-ethyl-3-(phenoxymethyl)oxetane, di[(3-ethyl-3-oxetanyl)methyl]ether, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-cyclohexyloxymethyl oxetane, and phenol novolac oxetane. delete An ultraviolet-curable black ink composition in claim 1, wherein the trifunctional or higher epoxy compound is selected from the group consisting of glycerol propoxylate triglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol polyglycidyl ether. delete In claim 1, the adhesion promoter is an alkoxy silane compound selected from the group consisting of 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, and 3-methacryloxypropyl trimethoxysilane, and a group consisting of phosphate-based acrylates. delete In the first paragraph, the photosensitizer is an anthracene-based compound such as anthracene, 9,10-dibutoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 2-ethyl-9,10-dimethoxyanthracene; a benzophenone-based compound such as benzophenone, 4,4-bis(dimethylamino)benzophenone, 4,4-bis(diethylamino)benzophenone, 2,4,6-trimethylaminobenzophenone, methyl-o-benzoylbenzoate, 3,3-dimethyl-4-methoxybenzophenone, and 3,3,4,4-tetra(t-butylperoxycarbonyl)benzophenone; anthracene; Ketone compounds such as dimethoxyacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and propanone; perylene; fluorenone compounds such as 9-fluorenone, 2-chloro-9-fluorenone, and 2-methyl-9-fluorenone; thioxanthone compounds such as thioxanthone, 2,4-diethyl thioxanthone, 2-chloro thioxanthone, 1-chloro-4-propyloxy thioxanthone, isopropylthioxanthone (ITX), and diisopropylthioxanthone; xanthone compounds such as xanthone and 2-methylxanthone; anthraquinone compounds such as anthraquinone, 2-methyl anthraquinone, 2-ethyl anthraquinone, t-butyl anthraquinone, and 2,6-dichloro-9,10- anthraquinone; Acridine compounds such as 9-phenylacridine, 1,7-bis(9-acridinyl)heptane, 1,5-bis(9-acridinylpentane), and 1,3-bis(9-acridinyl)propane; dicarbonyl compounds such as benzyl, 1,7,7-trimethyl-bicyclo[2,2,1]heptane-2,3-dione, and 9,10-phenanthrenequinone; phosphine oxide compounds such as 2,4,6-trimethylbenzoyl diphenylphosphine oxide and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide; benzoate compounds such as methyl-4-(dimethylamino)benzoate, ethyl-4-(dimethylamino)benzoate, and 2-n-butoxyethyl-4-(dimethylamino)benzoate; Amino synergists such as 2,5-bis(4-diethylaminobenzal)cyclopentanone, 2,6-bis(4-diethylaminobenzal)cyclohexanone, 2,6-bis(4-diethylaminobenzal)-4-methyl-cyclopentanone; Coumarin compounds such as 3,3-carbonylvinyl-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-benzoyl-7-(diethylamino)coumarin, 3-benzoyl-7-methoxy-coumarin, and 10,10-carbonylbis[1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-C1]-benzopyrano[6,7,8-ij]-quinolizin-11-one; An ultraviolet-curable black ink composition, wherein the composition is selected from the group consisting of chalcone compounds such as 4-diethylamino chalcone, 4-azidebenzalacetophenone, 2-benzoylmethylene, and 3-methyl-b-naphthothiazoline. delete An ultraviolet-curable black ink composition in claim 1, wherein the photopolymerization initiator comprises at least one of an iodonium salt and a sulfonium salt. delete delete delete a) forming a bezel pattern on a 3D curved glass by inkjet printing using the ultraviolet curable black ink composition according to claim 1; and
b) A method for printing a bezel pattern on a 3D curved glass, comprising the step of photo-curing the bezel pattern. A method for printing a bezel pattern on a 3D curved glass, wherein in claim 17, the bezel pattern has a film thickness of 5 to 15 μm and exhibits a light-blocking property of OD 5 or greater.