阅读说明：本技术 可膜印刷的可紫外线固化的油墨组合物、边框图案的制造方法、边框图案和显示基板 (Film-printable ultraviolet-curable ink composition, method for producing frame pattern, and display substrate ) 是由 俞在贤 郑赫 于 2019-08-13 设计创作，主要内容包括：本发明涉及：一种用于形成边框图案的可膜印刷的可紫外线固化的油墨组合物,所述边框图案具有减小的厚度和优异的光屏蔽性能,从而防止诸如移动设备的可折叠显示器的面板图案可见并且防止漏光；使用所述油墨组合物制造边框图案的方法；根据所述方法制造的边框图案；和包括所述边框图案的显示基板。(The present invention relates to: a film-printable ultraviolet-curable ink composition for forming a bezel pattern having a reduced thickness and excellent light shielding properties, thereby preventing a panel pattern of a foldable display such as a mobile device from being visible and preventing light leakage; a method of manufacturing a frame pattern using the ink composition; a bezel pattern manufactured according to the method; and a display substrate including the bezel pattern.)

1. An ultraviolet-curable ink composition for forming a bezel pattern of a foldable display substrate, comprising: a black pigment, a dispersant, an alicyclic epoxy compound, an oxetane compound, a photosensitizer, a photopolymerization initiator and an organic solvent,

wherein the photosensitizer: the photopolymerization initiator is in a weight ratio of 1:1 to 1:2, and the sum of the photosensitizer and the photopolymerization initiator is 13 to 21 parts by weight based on 100 parts by weight of the sum of the alicyclic epoxy compound and the oxetane compound.

2. The ultraviolet-curable ink composition according to claim 1, wherein the alicyclic epoxy compound: the weight ratio of the oxetane compound is 1:4 to 1: 8.

3. The ultraviolet-curable ink composition according to claim 1, wherein the organic solvent has a boiling point of 200 ℃ or more and a viscosity of 1 to 5cP at 25 ℃.

4. The ultraviolet-curable ink composition according to claim 1, wherein the organic solvent is at least one selected from the group consisting of diethylene glycol dibutyl ether, dipropylene glycol methyl ether acetate, ethylene glycol dibutyrate, diethyl succinate, γ -butyrolactone, and ethyl decanoate.

5. The ultraviolet-curable ink composition according to claim 1, wherein the black pigment is a carbon black pigment, a lactam black pigment, a perylene black pigment, or a combination thereof.

6. The ultraviolet-curable ink composition according to claim 1, wherein the content of the black pigment is 5 to 25% by weight based on the entire ink composition.

7. The ultraviolet-curable ink composition according to claim 1, wherein the dispersant is contained in an amount of 0.5 to 5% by weight, based on the entire ink composition.

8. The ultraviolet-curable ink composition according to claim 1, wherein the alicyclic epoxy compound is contained in an amount of 2 to 15% by weight based on the entire ink composition.

9. The ultraviolet-curable ink composition according to claim 1, wherein the oxetane compound is contained in an amount of 25 to 50% by weight based on the entire ink composition.

10. The ultraviolet-curable ink composition according to claim 1, wherein the content of the organic solvent is 20 to 25% by weight based on the entire ink composition.

11. The uv-curable ink composition according to claim 1, wherein the dispersant is selected from the group consisting of acrylic resins, polyalkylene glycols and esters thereof, polyoxyalkylene polyols, ester alkylene oxide adducts, alcohol alkylene oxide adducts, sulfonic acid esters, sulfonic acid salts, carboxylic acid esters, carboxylic acid salts, alkylamide alkylene oxide adducts, and alkylamine, and mixtures thereof.

12. The UV-curable ink composition according to claim 1, wherein the alicyclic epoxy compound is selected from dicyclopentadiene dioxide, limonene dioxide, (3, 4-epoxycyclohexyl) methyl-3, 4-epoxycyclohexanecarboxylate, 3-vinylcyclohexene oxide, bis (2, 3-epoxycyclopentyl) ether, bis (3, 4-epoxycyclohexylmethyl) adipate, bis (3, 4-epoxy-6-methylcyclohexylmethyl) adipate, (3, 4-epoxycyclohexyl) methyl alcohol, (3, 4-epoxy-6-methylcyclohexyl) methyl-3, 4-epoxy-6-methylcyclohexanecarboxylate, ethyleneglycol bis (3, 4-epoxycyclohexyl) ether, ethylene glycol bis (2, 3-epoxycyclopentyl) ether, and ethylene glycol bis (3, 4-epoxycyclohexyl) ether, 3, 4-epoxycyclohexenecarboxylic acid ethylene glycol diester and (3, 4-epoxycyclohexyl) ethyltrimethoxysilane.

13. The ultraviolet-curable ink composition according to claim 1, wherein the oxetane compound is selected from the group consisting of 3-ethyl-3-hydroxymethyloxetane, 1, 4-bis [ (3-ethyl-3-oxetanyl) methoxymethyl ] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, bis [ (3-ethyl-3-oxetanyl) methyl ] ether, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3-cyclohexyloxymethyloxetane and phenol novolac oxetane.

14. The ultraviolet-curable ink composition according to claim 1, wherein the photopolymerization initiator is a sulfonium salt.

15. The ultraviolet-curable ink composition according to claim 14, wherein the photopolymerization initiator is a triarylsulfonium salt.

16. The uv-curable ink composition according to claim 1, further comprising 1 to 5 wt% of an adhesion promoter, based on the entire ink composition.

17. The ultraviolet-curable ink composition according to claim 16, wherein the adhesion promoter is at least one selected from the group consisting of an alkoxysilane compound selected from the group consisting of 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-methacryloxypropyltrimethoxysilane, and a phosphate acrylate.

18. The ultraviolet-curable ink composition according to claim 1, wherein the curing dose of the ultraviolet-curable ink composition is 100mJ/cm²To 5,000mJ/cm²And is cured by absorption of radiation in the wavelength range of 250nm to 410 nm.

19. The ultraviolet-curable ink composition according to claim 1, wherein the ultraviolet-curable ink composition has an adhesion to the substrate of 4B or more in a cross-cut test, and does not crack when folded 100,000 times with a folding radius of 2.5R after curing.

20. The uv-curable ink composition according to claim 1, wherein the uv-curable ink composition is used to form a bezel pattern of a foldable display substrate.

21. A manufacturing method of a frame pattern of a foldable display substrate comprises the following steps:

a) inkjet printing the ultraviolet-curable ink composition according to claim 1 on a substrate to form a frame pattern; and

b) and solidifying the frame pattern.

22. The method of claim 21, wherein the cured frame pattern has a thickness of 1 μm to 5 μm and an OD of 4 or more.

23. A frame pattern formed from the ultraviolet-curable ink composition according to claim 1.

24. A foldable display substrate comprising the bezel pattern as claimed in claim 23.

25. The foldable display substrate of claim 24, wherein the foldable display substrate comprises a foldable display film.

Technical Field

The present invention relates to a film-printable ultraviolet curable ink composition, a method of manufacturing a bezel pattern using the same, a bezel pattern manufactured thereby, and a display substrate including the bezel pattern.

Background

The flexible display market is gradually evolving from flat products and curved products to foldable products that can be folded and unfolded freely. As with other display devices, the foldable display device requires a bezel pattern that displays colors and the pattern in the non-display area of the panel is not visually visible. The mobile device is close to the human eye due to its characteristics, and therefore, in order to prevent light leakage and the panel pattern from being visible, a bezel having high light shielding characteristics should be formed. If the bezel is thick, there is a problem in that the bezel step is visually visible on the screen and bubbles are not released when the Optically Clear Adhesive (OCA) is attached. Therefore, a frame pattern having a low thickness and excellent light shielding characteristics is required. In addition, in order to reduce the process cost, an ink composition capable of forming a frame pattern by single-layer printing of a high light-shielding black ink is required.

[ Prior art documents ]

[ patent document ]

(patent document 1) KR 10-2016-0147535A

Disclosure of Invention

Technical problem

An object of the present invention is to provide a film-printable ultraviolet curable ink composition capable of forming a bezel pattern having a low thickness and excellent light shielding properties so that a panel pattern of a foldable display device such as a mobile device is not visually visible and light leakage does not occur, a method of manufacturing the bezel pattern using the same, a bezel pattern manufactured thereby, and a display substrate including the bezel pattern.

Another object of the present invention is to provide a film-printable ultraviolet curable ink composition capable of forming a bezel pattern by single-layer printing of a high-shielding black ink so as to reduce process costs, a method of manufacturing a bezel pattern using the same, a bezel pattern manufactured thereby, and a display substrate including the bezel pattern.

Technical scheme

In order to achieve the above object, the present invention provides an ultraviolet curable ink composition for forming a bezel pattern of a display substrate, comprising: a black pigment, a dispersant, an alicyclic epoxy compound, an oxetane compound, a photosensitizer, a photopolymerization initiator, and an organic solvent, wherein the photosensitizer: the photopolymerization initiator is in a weight ratio of 1:1 to 1:2, and the sum of the photosensitizer and the photopolymerization initiator is 13 to 21 parts by weight based on 100 parts by weight of the sum of the alicyclic epoxy compound and the oxetane compound.

In addition, the invention provides a manufacturing method of a frame pattern of a display substrate, comprising the following steps:

a) printing the ultraviolet-curable ink composition on a substrate to form a frame pattern; and

b) and solidifying the frame pattern.

In addition, the present invention provides a bezel pattern manufactured according to the method of manufacturing a bezel pattern.

In addition, the present invention provides a display substrate including the bezel pattern.

Advantageous effects

The film-printable ultraviolet curable ink composition according to the present invention may be applied to a method of manufacturing a bezel pattern of a foldable display device. In addition, high light shielding inks (e.g., o.d.) are printed in a single layer on various films.>4) The resulting structure is formed with a low thickness (e.g.,<5 μm) can be used with a low uv dose(for example,<2,000mJ/cm²) Cured and has excellent frame properties (folding, adhesion, patterning).

Detailed Description

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

Since various modifications and changes can be made in the present invention, specific embodiments are shown in the drawings and will be described in detail in the detailed description. It should be understood, however, that the intention is not to limit the invention to the particular embodiments, but to include all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. In the following description of the present invention, a detailed description of known functions will be omitted if it is determined that the gist of the present invention will be obscured.

The present invention provides an ultraviolet-curable ink composition comprising: a black pigment, a dispersant, an alicyclic epoxy compound, an oxetane compound, a photosensitizer, a photopolymerization initiator, and an organic solvent, wherein the photosensitizer: the photopolymerization initiator is in a weight ratio of 1:1 to 1:2, and the sum of the photosensitizer and the photopolymerization initiator is 13 to 21 parts by weight based on 100 parts by weight of the sum of the alicyclic epoxy compound and the oxetane compound.

In addition, in one embodiment of the present invention, the weight ratio of the alicyclic epoxy compound to the oxetane compound may be 1:4 to 1: 8.

The ultraviolet-curable ink composition includes a black pigment as a colorant.

In one embodiment of the present invention, carbon black, graphite, metal oxide, organic black pigment, or the like may be used as the black pigment.

Examples of Carbon black include Cisto 5HIISAF-HS, Cisto KH, Cisto 3HHAF-HS, Cisto NH, Cisto 3M, Cisto 300 HAF-L S, Cisto 116HMMAF-HS, Cisto 116MAF, Cisto FMFEF-HS, Cisto SOFF, Cisto VGPF, Cisto SVHSRF-HS and Cisto SSRF (Donghae Carbon Co., L td.),. Diagcrambrank II, Diagcram black N339, Diagcram black SH, Diagcram black H, Diagcram L0H, Diagcram HA, Diagcram SF, Diagcram N550M, Diagcram M, Diagcram E, Diagcram G, Diagcram R, Diagcram N760, 760M, PLAN M-M, INTRAV # 3675-M-3651-M, INTRAV-M-M, INTRAV-3655-3651-M, INTRAV-M-3655-M, INTRAV-3675-3651-M, INTRAN-M, INTRAV-M-M-3695-3675-3651-3695-7H, INTRAN-3632-7H, INTRAN-3632-7H, INTRAV-7H, INTRAV-7, INTRAV-7-INTRAV-7, INTRAV-7, INTRAV-7H, INTRAV-7H, INTRAV-7, INTRAV-7, INTRAV-7, INTRAV-7, INTRAV-7, INTRAV-7, INTRAV-7, INTRAV-7, INTRAV-.

The organic black pigment includes carbon black, lactam black, perylene black, etc., but is not limited thereto.

The black pigment is contained in an amount of 5 to 25 wt% or 10 to 20 wt%, based on the total weight of the ultraviolet curable ink composition. If the content of the black pigment is less than 5% by weight, an Optical Density (OD) level suitable for the frame pattern cannot be obtained. If the content exceeds 25% by weight, the viscosity of the ink becomes too high or an excessive amount of black ink cannot be dispersed in the ink, so that a precipitate may be formed.

The ultraviolet-curable ink composition includes a dispersant.

The dispersant serves to make the particle size of the black pigment uniform and shorten the production time of the ink. The dispersant may be a polymer, a nonionic, anionic or cationic dispersant, and examples thereof include: acrylic resins, polyalkylene glycols and esters thereof, polyoxyalkylene polyols, ester alkylene oxide adducts, alcohol alkylene oxide adducts, sulfonic acid esters, sulfonic acid salts, carboxylic acid esters, carboxylic acid salts, alkylamide alkylene oxide adducts, alkylamines, and the like, which may be used alone or in combination of two or more of them. It is preferable to use an acrylic resin dispersant having excellent ink storage properties.

The dispersant is present in an amount of 0.5 wt% to 5 wt%, or 2 wt% to 4 wt%, or about 3 wt%, based on the total ink composition. If the content of the dispersant is less than 0.5% by weight based on the entire ink composition, the pigment cannot be uniformly dispersed. If the content exceeds 5% by weight, the pigment may aggregate, or curing sensitivity may be reduced.

The ultraviolet-curable ink composition includes a cycloaliphatic epoxy compound.

The alicyclic epoxy compound is a cationically polymerizable compound, and may be one or a mixture of two selected from alicyclic epoxy compounds containing a cationically polymerizable alicyclic epoxy monomer. Such cycloaliphatic epoxy compounds may contain one or two epoxidized cycloaliphatic groups. The epoxidized alicyclic group may be a compound having an epoxy group bonded to an alicyclic ring, and a hydrogen atom of the alicyclic ring may be substituted with a substituent such as an alkyl group.

The alicyclic epoxy compounds, i.e., epoxy compounds include, but are not limited to, dicyclopentadiene dioxide, limonene dioxide, (3, 4-epoxycyclohexyl) methyl-3, 4-epoxycyclohexanecarboxylate, 3-vinylcyclohexene oxide, bis (2, 3-epoxycyclopentyl) ether, bis (3, 4-epoxycyclohexylmethyl) adipate, bis (3, 4-epoxy-6-methylcyclohexylmethyl) adipate, (3, 4-epoxycyclohexyl) methyl alcohol, (3, 4-epoxy-6-methylcyclohexyl) methyl-3, 4-epoxy-6-methylcyclohexanecarboxylate, ethylene glycol bis (3, 4-epoxycyclohexyl) ether, ethylene glycol diester of 3, 4-epoxycyclohexenecarboxylate and (3, 4-epoxycyclohexyl) ethyltrimethoxysilane.

The cycloaliphatic epoxy compound may be present in an amount of from 2 wt% to 15 wt%, or from 3 wt% to 10 wt%, or about 6 wt%, based on the total ink composition. If the content of the alicyclic epoxy compound is less than 2% by weight based on the entire ink composition, curing sensitivity may be reduced. If the content exceeds 15 wt%, surface wrinkles may be generated after the ultraviolet curing, causing a reduction in bezel performance.

The ultraviolet-curable ink composition contains an oxetane compound as another cationically polymerizable monomer.

Examples thereof include 3-ethyl-3-hydroxymethyl OXETANE, 1, 4-bis [ (3-ethyl-3-oxetanyl) methoxymethyl ] benzene, 3-ethyl-3- (phenoxymethyl) OXETANE, bis [ (3-ethyl-3-oxetanyl) methyl ] ether, 3-ethyl-3- (2-ethylhexyloxymethyl) OXETANE, 3-ethyl-3-cyclohexyloxymethyl OXETANE and phenol novolak OXETANE, and commercially available products thereof include "ARON oxtane-101", "ARON oxtane-121", "ARON oxtane-221", and "ARON oxtane-212" from toagoseo co, &ttt translation = L "&l &/t &ttttgtd, and" ARON oxtane-101 "," ARON oxtane-121 "," ARON oxtane-221 ", and" these two or more kinds of these can be used alone or in combination.

The oxetane compound is contained in an amount of 25 to 50% by weight, or 30 to 45% by weight, or 34 to 42% by weight, based on the entire ink composition. If the content of the oxetane compound is less than 25% by weight based on the entire ink composition, the viscosity of the ink composition may increase, thereby deteriorating the inkjet processability. If the content exceeds 50% by weight, curing sensitivity may be reduced.

In addition, in the composition according to the invention, the cycloaliphatic epoxy compound: the weight ratio of the oxetane compounds can be from 1:4 to 1:8, in another embodiment from 1:4.5 to 1:7 or from 1:5 to 1: 6.8. If the ratio of the epoxy compound to the oxetane compound exceeds 1:8, the composition will be excellent in inkjet processability due to the low viscosity of the composition, but curing sensitivity will be reduced. If the ratio is less than 1:4, inkjet processability may be deteriorated due to high viscosity of the composition, and surface wrinkles may occur in the coating film after ultraviolet curing.

The uv-curable ink composition includes a photosensitizer.

The photosensitizer may be at least one compound selected from the group consisting of anthraquinones such as anthracene, 9, 10-dibutoxyanthracene, 9, 10-dimethoxyanthracene, 9, 10-diethoxyanthracene and 2-ethyl-9, 10-dimethoxyanthracene, benzophenones such as benzophenone, 4, 4-bis (dimethylamino) benzophenone, 4, 4-bis (diethylamino) benzophenone, 2,4, 6-trimethylaminobenzophenone, methyl-o-benzoylbenzoate, 3-dimethyl-4-methoxybenzophenone and 3,3,4, 4-tetra (tert-butylperoxycarbonyl) benzophenone, ketones such as acetophenone, dimethoxyacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one and acetone, benzophenones such as 9-fluorenone, 2-chloro-9-fluorenone and 2-methyl-9-fluorenone, thioxanthone compounds such as 9-fluorenone, 2-chloro-9-fluorenone and 2-methyl-9-fluorenone, 7-methyl-7- (2, 7-methyl-1-ethyl-7-methyl-1, 7-ethoxybenzophenone, 2, 3-di-o-4-benzoylenebenzophenones such as benzophenone, 2,3, 4-tetra (tert-butyl-ethyl-1-ethyl-4-benzoylbenzophenone, 7-ethyl-7-methyl-ethyl-7-methyl-1-ethyl-4-methyl-benzophenone, 2-ethyl-5-ethyl-4-benzophenone, 2-ethyl-5-methyl-ethyl-methyl-4-ethyl-methyl-benzophenone, 3-ethyl-4-ethyl-4-methyl-benzophenone, 3-ethyl-4-ethyl-benzophenone, 3-ethyl-4-benzophenone and acetone, and-diethyl-ethyl-7-diethyl-ethyl-4-benzophenone, 3, and-ethyl-7-ethyl-benzophenone, 3, benzophenone, and-ethyl-7-ethyl-7-ethyl-7-ethyl-7-ethyl-7-ethyl-2-ethyl-2-7-ethyl-7-2-ethyl-7-ethyl-2-ethyl-2-7-2-ethyl.

The photosensitizer is present in an amount of 1 to 5 wt%, and in another embodiment 2 to 4 wt%, based on the total weight of the uv-curable ink composition. If the content of the photosensitizer is less than 1% by weight, the synergistic effect of curing sensitivity at a desired wavelength cannot be achieved. If it exceeds 5% by weight, the photosensitizer cannot be dissolved and the adhesive strength and crosslinking density of the pattern may be reduced.

The ultraviolet-curable ink composition includes a photopolymerization initiator.

The photopolymerization initiator is a compound that generates a cationic substance or a bronsted acid by irradiation with ultraviolet rays, and for example, may include an iodonium salt and a sulfonium salt, but is not limited thereto.

The iodonium salt or sulfonium salt may cause a curing reaction in which monomers having an unsaturated double bond contained in the ink react during an ultraviolet curing process to form a polymer, and a photosensitizer may be used according to polymerization efficiency.

For example, the photopolymerization initiator may include a photopolymerization initiator having a structure of SbF₆ ^-、AsF₆ ^-、BF₆ ^-、(C₆F₅)₄B^-、PF₆ ^-Or Rf_nF_6-nThe anionic compounds are shown, but are not necessarily limited thereto.

In one embodiment of the present invention, for the storage stability of the ink, a triarylsulfonium salt having excellent high-temperature stability may be used, and for example, triarylsulfonium hexafluorophosphate may be used.

The photopolymerization initiator may be contained in an amount of 1 to 15% by weight, and in another embodiment, 2 to 10% by weight, or 3 to 5% by weight, relative to the total weight of the ultraviolet-curable ink composition. If the content of the photopolymerization initiator is less than 1% by weight, the curing reaction may be insufficient, and if the content exceeds 15% by weight, it may not be completely dissolved, or the viscosity may increase, and the coating property may be lowered.

In the composition according to the present invention, the higher the light-shielding property due to the difference in curing rate, the higher the possibility of occurrence of surface wrinkles due to the nature of the black pigment. Therefore, by optimizing the content ratio of the photopolymerization initiator and the photosensitizer which absorb light, it is possible to use a low ultraviolet dose (for example,<2,000mJ/cm²) A frame is formed. Thus, the photosensitizer: the photopolymerization initiator may be in a weight ratio of 1:1 to 1:2 or 1:1.5 to 1:1.8, and the sum of the photosensitizer and the photopolymerization initiator may be 13 to 21 parts by weight or 15 to 20 parts by weight, based on 100 parts by weight of the sum of the alicyclic epoxy compound and the oxetane compound.

The ultraviolet-curable ink composition includes an organic solvent.

The organic solvent is an essential component of the ink composition according to the present invention to maintain a low thickness while exhibiting high light-shielding properties after curing. An organic solvent may be used without particular limitation so long as it has excellent curing sensitivity even after a frame pattern is printed on a display substrate using the ink composition according to the present invention. However, in order to improve inkjet processability, it is preferable to use an organic solvent having a boiling point of 200 ℃ or more and a viscosity of 1cP to 5cP, or 1cP to 3cP at 25 ℃.

When the black pigment according to the present invention is contained at a low content of less than 10% (particularly 7% or less) in the entire ink composition, the inkjet processability is not greatly problematic even if an organic solvent having a boiling point of less than 200 ℃ such as ethylene glycol monobutyl ether acetate (BCsA) is used. However, when the black pigment is contained at a relatively high content of 10% or more, the inkjet processability is reduced.

Accordingly, organic solvents satisfying such conditions should be used, for example, diethylene glycol dibutyl ether (or dibutyl ether), dipropylene glycol methyl ether acetate, ethylene glycol dibutyrate, diethyl succinate, γ -butyrolactone (GB L), and ethyl decanoate, and diethylene glycol dibutyl ether and diethyl succinate are preferably used.

The organic solvent is present in an amount of 10 to 40 wt%, or 15 to 30 wt%, or 20 to 25 wt%, based on the total ink composition. If the content of the organic solvent is less than 10% by weight, the viscosity of the ink may increase or the thickness of the frame layer may become thick. If the content exceeds 40% by weight, curing sensitivity may be reduced.

Meanwhile, the ink composition according to the present invention may further include any one or more of a reactive diluent, an adhesion promoter, a surfactant, and a photopolymerization initiator solvent, as necessary.

Reactive diluents may be included to reduce the viscosity of the ink, thereby improving inkjet processability, and cationically polymerizable glycidyl ether epoxy compounds and vinyl epoxy compounds may be used, examples of the glycidyl ether epoxy compounds include N-butyl glycidyl ether, neopentyl glycol diglycidyl ether (L D203), aliphatic glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, tolyl glycidyl ether, benzyl glycidyl ether, 1, 4-butanediol glycidyl ether, ethylene glycol diglycidyl ether, 1, 6-hexanediol glycidyl ether, 1, 4-cyclohexanedimethanol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, examples of the vinyl epoxy compounds include 1, 4-cyclohexanedimethanol divinyl ether, triethylene glycol divinyl ether (DVE-3), and hydroxybutyl vinyl ether.

The content of the reactive diluent is preferably 0 to 10% by weight, more preferably 1 to 7% by weight, based on the total weight of the ultraviolet-curable ink composition. If it exceeds 10% by weight, surface wrinkles may be generated in the coating film after ultraviolet curing.

Examples of the alkoxysilane compound include 3-glycidoxypropyltrimethoxysilane (KBM-403(Shin-Etsu chemical Co., and &ttttranslation = L "&tttL &/T &ttt td., USA)), 3-glycidoxypropylmethyldimethoxysilane (KBM-402), 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane (KBM-303), 3-glycidoxypropylmethyldiethoxysilane (KBE-402), 3-glycidoxypropyltriethoxysilane (KBE-403), 3-methacryloxypropyltrimethoxysilane (KBM-503), and the like, which may be used alone or in combination of two or more.

In the case of using the adhesion promoter, the content thereof is 1 to 5% by weight, or 2 to 4% by weight, based on the entire ink composition. If the content of the adhesion promoter is less than 1 wt%, the adhesion between the substrate and the printed layer may be reduced. If it exceeds 5% by weight, the curing sensitivity may be reduced and the stability of the ink may be reduced.

As said surfactant, commercially available products may be used, for example, selected from Megafack F-444, F-475, F-478, F-479, F-484, F-550, F-552, F-553, F-555, F-570 and RS-75 from DIC (DaiNippon Ink & Chemicals), or Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141 and S-145 from Asahi Glass Co., L td., or Fluoron FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430 and S-145 from Sumitomo 3M Co., L td., or BYK-306, BYK-354, BYK-3532-430 and BYK-310 from DuPont, BYK-300, FSN, BYN-100 and FSO from BYK, BYK-3N, BYK, BYK-306, BYK-354, BYK-35K-310, BYK-35, BYK-150, BYK-310, BYK-35, BYK-310, BYK-35, BYK-310, BYK-150, BYK-35, BYK-150, BYK-310, BYK-35, B.

The surfactant may be present in an amount of 0.01 wt% to 2.0 wt%, or 0.1 wt% to 1.0 wt%, based on the total weight of the uv-curable ink composition. If the content of the surfactant is less than 0.01 wt%, the effect of reducing the surface tension of the composition is insufficient, so that coating failure occurs when the composition is coated on a substrate. If the content exceeds 2.0% by weight, the surfactant is used in an excessive amount, and there is a problem that compatibility and defoaming of the composition are rather reduced.

The photopolymerization initiator solvent may be used without limitation as long as it is a solvent capable of dissolving the initiator due to high solubility, and is at least one selected from propylene carbonate, γ -butyrolactone (GB L), and N-ethylpyrrolidone (NEP), but is not necessarily limited thereto.

The content of the photopolymerization initiator solvent may be 50 to 150% by weight, or 75 to 125% by weight, based on the content of the photopolymerization initiator. If the content is less than 50 wt%, the photopolymerization initiator cannot be dissolved, and thus precipitates may be formed. If the content exceeds 150% by weight, curing sensitivity is reduced.

The UV-curable ink composition (or ink) according to the present invention has a curing dose of 100mJ/cm²To 5,000mJ/cm²Or 200mJ/cm²To 3,000mJ/cm²And cured by absorption of radiation in the wavelength range 250nm to 410nm, preferably 360nm to 410 nm. Further, in order to be suitable for use in an inkjet process, its viscosity is, for example, 1cP to 30cP at 25 ℃, or 2cP to 20cP at a process temperature. In the cross-cut test, the adhesive force to the substrate without post-treatment (heat treatment) is 4B or more or 5B or more, and with respect to foldingPerformance, after uv curing, no cracks occurred when folded 100,000 times or more at a folding radius of 2.5R.

In addition, the ultraviolet-curable ink composition (or ink) according to the present invention exhibits excellent storage stability in which the time point at which the viscosity increases by 10% or more after storage at 40 ℃ is 20 days or more, preferably 40 days or more, and more preferably 60 days or more. It achieves such excellent ink stability that no photopolymerization initiator precipitates after ink preparation.

The ultraviolet-curable ink composition forms a frame pattern on a cover window film or a polarizing film layer. Even in a film having low heat resistance, even if a low ultraviolet dose (for example,<2,000mJ/cm²) Can also be made to have high light shielding performance (e.g., OD)>4) The pattern of (2) is cured without surface wrinkling, thereby enabling ultraviolet curing without film deformation. Further, due to the excellent light shielding property at a low thickness, there is no problem that the pattern of the panel is visible and the step is visible, and no bubble is generated after the OCA is adhered. In addition, the folding (e.g., folding radius of 2.5R, 100,000 or more) and adhesion (e.g., cross-cut of 5B) characteristics applied to the foldable device are excellent.

The top of the frame pattern formed by the ultraviolet curable ink composition may be adhered to the upper substrate through an adhesive layer for the upper substrate. The ultraviolet-curable ink composition has excellent adhesion to an adhesive for an upper substrate, such as an acrylic adhesive, a styrene-butadiene rubber adhesive, an epoxy adhesive, a polyvinyl alcohol adhesive, or a polyurethane-based adhesive. The ultraviolet-curable ink composition can improve the adhesion between the frame pattern and the upper substrate.

The method for manufacturing a bezel pattern for a foldable display film according to the present invention uses the above ultraviolet-curable ink composition.

Specifically, the method for manufacturing a bezel pattern for a foldable display film according to the present invention includes the steps of: a) printing the ultraviolet-curable ink composition on a substrate to form a frame pattern; and b) curing the frame pattern.

Here, the thickness of the frame pattern after curing may be 1 to 5 μm or 2 to 4 μm.

In one embodiment of the present invention, the foldable display substrate may be a foldable display film.

In one embodiment of the present invention, the foldable display substrate may comprise a foldable display film.

In addition, the method for manufacturing a bezel pattern for a display film of the present invention may further include a step of cleaning the film before the step a) of forming the bezel pattern. This is to selectively perform surface treatment according to the surface energy of the substrate to improve the coating performance of the ink and remove stains caused by foreign substances.

Specifically, the surface treatment may be performed by treatment with atmospheric pressure plasma, corona, or the like.

The bezel pattern is characterized by a taper angle of greater than 0 ° and 30 ° or less, and a thickness of 0.1 μm to 20 μm, measured after curing. Further, the taper angle may be preferably more than 0 ° and 10 ° or less. Further, the thickness may preferably be 0.5 μm to 5 μm. Since the frame pattern of the present invention has the above characteristics, short circuits due to large steps, bubble generation, and deterioration of visual quality due to film peeling are not exhibited.

The optical density of the bezel pattern may be 4 to 5.5, or may be 4.5 to 5, based on a film thickness of 4.0 μm, as necessary. In this case, there is an advantage that the shielding performance of the frame pattern is excellent. If the optical density exceeds 5.5, the content of the pigment to be added becomes very high, which may adversely affect the production of the ink and the ink jet process, and may inhibit the ultraviolet-curable ink composition from being cured by radiation.

The composition of the present invention can form a frame having high light-shielding properties (o.d. >4) at a low ultraviolet dose by single-layer printing on various substrates (films, glass, plastics, etc.) and does not require alignment required for two-layer printing, so that process time and cost (yield) can be improved.

The invention provides a frame pattern for a display substrate manufactured by the method. In the present invention, a bezel pattern refers to a pattern formed at the edge of various devices such as a watch, a display device, and the like.

In one embodiment of the present invention, the display substrate may be a foldable display film.

In one embodiment of the present invention, the display substrate may include a foldable display film.

The bezel pattern is characterized by a taper angle of greater than 0 ° and 30 ° or less, and a thickness of 0.1 μm to 20 μm, measured after curing. Further, the taper angle may be preferably more than 0 ° and 10 ° or less. Further, the thickness may preferably be 0.5 μm to 5 μm. Since the frame pattern of the present invention has the above characteristics, short circuits due to large steps, bubble generation, and deterioration of visual quality due to film peeling are not exhibited.

The optical density of the bezel pattern may be 4 to 5.5, or may be 4.5 to 5, based on a film thickness of 4.0 μm, as necessary. In this case, there is an advantage that the shielding performance of the frame pattern is excellent. If the optical density exceeds 5.5, the content of the pigment to be added becomes very high, which may adversely affect the production of the ink and the ink jet process, and may inhibit the ultraviolet-curable ink composition from being cured by radiation.

In addition, the present invention provides a foldable display substrate including the bezel pattern.

The foldable display substrate may be a foldable display film.

The foldable display substrate may include a foldable display film.

The display substrate may be used for an organic light emitting diode (O L ED).

Hereinafter, preferred examples are provided to aid understanding of the present invention. However, it will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention as set forth in the appended claims. Such changes and modifications are intended to fall within the scope of the appended claims.