KR102171285B1 - Method for evaluating reliable of ink jet printing - Google Patents

Abstract

The present application relates to a method for evaluating the reliability of an inkjet process and a substrate for evaluating the same. In forming a thin film layer through an inkjet process, the reliability of the inkjet process can be intuitively confirmed with the naked eye, thereby improving the efficiency and economic efficiency of the process. It relates to a method for evaluating the reliability of an inkjet process that can be made and a substrate for evaluating it.

Description

Reliability evaluation method of inkjet process{METHOD FOR EVALUATING RELIABLE OF INK JET PRINTING}

The present application relates to a method for evaluating the reliability of an inkjet process and a substrate for evaluating the same.

In the industry related to inkjet printing, where the recent growth is remarkable, high performance of inkjet printers, improvement of ink, and the like are rapidly progressing.

[0003] The ink is required to have various performances year by year along with the high performance of inkjet printers and the like. For example, the ink ejection stability does not cause clogging of the ink ejection nozzles constituting the inkjet printer over time, and does not cause ink ejection defects or abnormal ejection directions over a long period of time.

Accordingly, there is a need for a method of intuitively checking the ejection stability of the ink before proceeding with the inkjet process.

The present application provides a method for evaluating the reliability of an inkjet process and a substrate for evaluating the reliability of the inkjet process, which improves the efficiency and economy of the process by intuitively checking the reliability of the inkjet process in forming a thin film layer through an inkjet process. .

The present application relates to a method for evaluating the reliability of an inkjet process. The evaluation method is not an inkjet printing method, but provides a method for intuitively determining the reliability of an inkjet process prior to the printing process.

The inkjet process can be applied to encapsulating or encapsulating an organic electronic device such as an OLED, for example. In one example, the reliability evaluation method of the present application may be a reliability evaluation method for the process before the process of encapsulating or encapsulating the entire surface of the organic electronic device. After the ink composition is applied to encapsulation, it may exist in the form of an organic layer sealing the entire surface of the organic electronic device. In addition, the organic layer may be stacked on an organic electronic device together with an inorganic layer to be described later to form an encapsulation structure.

In the present specification, the term ``organic electronic device'' refers to an article or device having a structure including an organic material layer that generates an exchange of electric charges using holes and electrons between a pair of electrodes facing each other. Examples include, but are not limited to, a photovoltaic device, a rectifier, a transmitter, and an organic light-emitting diode (OLED). In one example of the present application, the organic electronic device may be an OLED.

An exemplary method for evaluating the reliability of an inkjet process may include discharging an ink composition using an inkjet apparatus having two or more nozzles on a substrate having a surface energy in the range of 40 to 70 mN/m. The surface energy of the substrate may be, for example, in the range of 41 to 78 mN/m, 44 to 73 mN/m, 48 to 68 mN/m, or 53 to 63 mN/m. The reliability evaluation method may evaluate whether or not the ink jet device ejects ink to a desired position without clogging a nozzle through the above step. Specifically, in the evaluation method of the present application, a gap exists between the ejected ink composition droplets, and accordingly, the number of ink compositions ejected with the naked eye and the number of nozzles can be compared, and accordingly, ejection stability can be evaluated. Therefore, in this specification, reliability may mean the same as discharge stability.

In one example, in the reliability evaluation method, the ratio (S/I) of the surface energy (S) of the substrate to the surface energy (I) of the ink composition is 1.1 to 5, 1.2 to 4.8, 1.7 to 4.3, 2.3 to 3.8 Or it may be in the range of 2.8 to 3.2. Specifically, the reliability evaluation method includes the step of discharging the ink composition using an inkjet device having two or more nozzles on the substrate, and the ratio of the surface energy (S) of the substrate to the surface energy (I) of the ink composition (S/I) may be an evaluation method in the range of 1.1 to 5. That is, the surface energy of the substrate is not limited to the above-described range, and may vary depending on the surface energy of the ink composition. Accordingly, the evaluation can be performed by adjusting the surface energy of the substrate according to the surface energy of the ink composition. In the evaluation method of the present application, by adjusting the surface energy ratio, the spreadability of the ink composition discharged on the substrate is limited so that the discharged ink and the ink do not contact each other, thereby evaluating the discharge stability.

In the specific example of the present application, the surface energy (γ ^surface , mN/m) may be calculated as γ ^surface = γ ^dispersion + γ ^polar . In one example, the surface energy may be measured using a drop shape analyzer (DSA100 manufactured by KRUSS). For example, as for the surface energy, the average value of the five contact angle values obtained by dropping deionized water with known surface tension to the substrate to be measured and obtaining the contact angle is repeated five times, is obtained, Similarly, diiodomethane, which has a known surface tension, is dropped and the process of obtaining the contact angle is repeated five times to obtain the average value of the five contact angle values obtained. Thereafter, the surface energy can be calculated by substituting a value (Strom value) about the surface tension of the solvent by the Owens-Wendt-Rabel-Kaelble method using the obtained average value of the contact angle for deionized water and diiodomethane.

In one example, the ink composition has a surface energy of 20 mN/m to 40 mN/m, 23 mN/m to 39 mN/m, 28 mN/m to 35 mN/m or 31 mN/m to 33 after curing. It may be within the range of mN/m. The present application may implement excellent coating properties within the surface energy range. The measurement of the surface energy may be measured by a method known in the art, for example, it may be measured by the Ring Method method. In one example, the surface energy may be measured by the same method as the method of measuring the surface energy of the substrate. For example, the ink composition to be measured was applied to a SiNx substrate with a thickness of about 50 μm and a coating area of 4 cm ² (width: 2 cm, length: 2 cm) to form an encapsulation film (spin coater), at room temperature under a nitrogen atmosphere. after about 10 minutes through the dried light amount of 4000mJ / cm ² at an intensity of 1000mW / cm ² after UV curing in curing it can measure the surface tension of the film.

In one example, the reliability evaluation method may include that the number of ejected ink composition droplets is 90% or more of the number of nozzles. The number of ink compositions may refer to the form of droplets discharged through a nozzle. The evaluation method may be determined to be excellent in reliability when the number of ejected ink composition droplets is 90% or more compared to the number of nozzles. In one example, since the ejection stability is excellent when droplets of the ink composition ejected by the number of nozzles are observed, the upper limit is not limited and may be 100%.

In a specific example of the present application, the reliability evaluation method includes the step of discharging an ink composition, as described above, and a gap may exist between droplets of the discharged ink composition. In a general inkjet process, inkjet printing proceeds while forming a coating film in contact with other neighboring ink due to the spread of the ejected ink, but the reliability evaluation method of the present application is the number of ejected ink droplets due to the existence of a gap between the ink and the ink. To be able to grasp.

In one example, the distance between the discharged ink composition droplets may be in the range of 1 μm to 170 μm, 4 μm to 150 μm, 11 μm to 120 μm, or 28 μm to 100 μm. In the present application, by adjusting the distance between the discharged ink and the ink within the above range, it is possible to intuitively determine the discharge stability with the naked eye.

In addition, in the specific example of the present application, the reliability evaluation method may make the diameter of the discharged ink composition droplet smaller than the distance between the nozzle and the nozzle. In the reliability evaluation method, the diameter of the discharged ink composition droplet may be in the range of 30 μm to 200 μm, 45 μm to 180 μm, 68 μm to 130 μm, or 77 μm to 120 μm. In addition, the interval between the nozzle and the nozzle may be in the range of 200㎛ to 350㎛, 230㎛ to 330㎛, 243㎛ to 322㎛, or 252㎛ to 312㎛. In the present application, by adjusting the diameter of the ejected ink droplet and the distance between the nozzle and the nozzle within the above range, it is possible to intuitively determine the ejection stability with the naked eye, thereby promoting the efficiency and economic efficiency of the process.

In the specific example of the present application, the reliability evaluation method may repeat the step of discharging the ink composition at least once, at least 2 times, or at least 3 times. The upper limit is not particularly limited, but may be 20 times in terms of process efficiency. In the above method, the discharging step is repeated one or more times to evaluate the clogging of the nozzle of the inkjet apparatus in advance, thereby preventing process defects in the actual inkjet process.

The present application also relates to a substrate capable of the above reliability evaluation. That is, the present application provides a substrate for evaluating the reliability of an inkjet process and having a surface energy in the range of 40 to 70 mN/m. The surface energy may be in the range of 41 to 78 mN/m, 44 to 73 mN/m, 48 to 68 mN/m, or 53 to 63 mN/m.

In addition, the present application is a substrate for evaluating the reliability of an inkjet process, wherein the ratio (S/I) of the surface energy (S) of the substrate to the surface energy (I) of the ink composition discharged in the inkjet process is 1.1 to 5 It relates to a description within the range. The ratio (S/I) may be in the range of 1.1 to 5, 1.2 to 4.8, 1.7 to 4.3, 2.3 to 3.8, or 2.8 to 3.2.

The substrate may be in the form of a film or sheet. The material of the substrate is not limited as long as it satisfies the surface energy. For example, the substrate may include a polymer resin, and in one embodiment, the polymer resin is polyethylene terephthalate, polytetrafluoroethylene, polyethylene, polypropylene, polybutene, polybutadiene, vinyl chloride copolymer, poly Urethane, ethylene-vinyl acetate, ethylene-propylene copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, or polyimide.

The present application also provides an ink composition applied to the evaluation method. In one example, the above-described reliability evaluation method may be applied to an ink jet process of an ink composition described below.

An exemplary ink composition may include an epoxy compound and a compound having an oxetane group. The epoxy compound may be a photocurable or thermosetting compound. The compound having an oxetane group may be included in the range of 45 parts by weight to 145 parts by weight, 48 parts by weight to 143 parts by weight, or 63 parts by weight to 132 parts by weight based on 100 parts by weight of the epoxy compound. In this application, by controlling the above specific composition and its content range, an organic layer can be formed on an organic electronic device by an inkjet method, and the applied ink composition has excellent spreadability within a short time, and excellent curing sensitivity after curing. It is possible to provide an organic layer having. In addition, the ink composition may include a photoinitiator. The ink composition may realize excellent adhesion strength and curing sensitivity as well as fairness as an ink composition together with the above-described epoxy compound and oxetane group-containing compound.

In one example, the epoxy compound may be at least bifunctional or higher. That is, two or more epoxy functional groups may be present in the compound. The epoxy compound implements an appropriate degree of crosslinking in the sealing material to realize excellent heat resistance and durability at high temperature and high humidity.

In the embodiments of the present application, the epoxy compound may include a compound having a cyclic structure and/or a linear or branched aliphatic compound in the molecular structure. That is, the ink composition of the present application may include, as an epoxy compound, at least one of a compound having a cyclic structure and a linear or branched aliphatic compound in a molecular structure, or may be included together. In one example, the compound having a cyclic structure in the molecular structure may have 3 to 10, 4 to 8, or 5 to 7 cyclic atoms in the molecular structure, and two or more cyclic structures may exist in the compound. When the compound having the cyclic structure and the linear or branched aliphatic compound are included together, the linear or branched aliphatic compound is 20 parts by weight to 200 parts by weight, 23 parts by weight based on 100 parts by weight of the compound having a cyclic structure To 190 parts by weight, 25 parts by weight to 180 parts by weight, 29 parts by weight to 175 parts by weight, or 32 parts by weight to 173 parts by weight may be included in the ink composition. By controlling the content range, the present application provides suitable physical properties for sealing the entire surface of the organic electronic device by ink jetting the ink composition, has excellent curing sensitivity after curing, and also realizes excellent moisture barrier properties. To be.

In one example, the linear or branched aliphatic compound may have an epoxy equivalent of 120 g/eq to 375 g/eq or 120 g/eq to 250 g/eq. In the present application, by controlling the epoxy equivalent of the aliphatic compound within the above range, it is possible to prevent the viscosity of the composition from becoming too high, making the inkjet process impossible while improving the degree of completion of curing after curing the sealing material.

In one example, the epoxy compound may have an epoxy equivalent in the range of 50 to 350 g/eq, 73 to 332 g/eq, 94 to 318 g/eq, or 123 to 298 g/eq. In addition, the compound having an oxetane group may have a weight average molecular weight of 150 to 1,000 g/mol, 173 to 980 g/mol, 188 to 860 g/mol, 210 to 823 g/mol, or 330 to 780 g/mol. The present application provides excellent printability when applied to inkjet printing by controlling the epoxy equivalent of the epoxy compound to be low or controlling the weight average molecular weight of the compound having an oxetane group to be low, while simultaneously providing moisture barrier properties and excellent curing sensitivity. can do. In the present specification, the weight average molecular weight may mean a value converted to standard polystyrene measured by GPC (Gel Permeation Chromatograph). In addition, in the present specification, the epoxy equivalent is the number of grams (g/eq) of a resin containing 1 gram equivalent of an epoxy group, and can be measured according to the method specified in JIS K 7236.

In addition, the compound having an oxetane group may have a boiling point in the range of 90 to 300 °C, 98 to 270 °C, 110 to 258 °C, or 138 to 237 °C. The present application is a sealing material capable of preventing damage to the device by controlling the boiling point of the compound within the above range, implementing excellent printability even at high temperatures in the inkjet process, excellent moisture barrier properties from the outside, and suppressing outgassing It is possible to provide. In the present specification, the boiling point may be measured at 1 atmosphere unless otherwise specified.

In one example, the compound having a cyclic structure in the molecular structure may be an alicyclic epoxy compound. For example, the compound is 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate (EEC) and derivatives, dicyclopentadiene dioxide and derivatives, vinylcyclohexene dioxide and derivatives, 1,4 -Cyclohexanedimethanol bis (3,4-epoxycyclohexanecarboxylate) and derivatives may be exemplified, but are not limited thereto.

In one example, the structure of the compound containing the oxetane group is not limited as long as it has the oxetane functional group, for example, TOAGOSEI's OXT-221, CHOX, OX-SC, OXT101, OXT121, OXT221 or OXT212 , Or ETERNACOLL's EHO, OXBP, OXTP or OXMA may be exemplified. In addition, the linear or branched aliphatic epoxy compound is aliphatic glycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, 1,6-hexanediol digly Cidyl ether, propylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether or neopentyl glycol diglycidyl ether Can, but is not limited thereto.

In the embodiment of the present application, the ink composition may further include a photoinitiator. The photoinitiator may be a cationic photopolymerization initiator. In addition, the photoinitiator may be a compound that absorbs a wavelength in the range of 200nm to 400nm.

Can be used a known material in the art for cationic photo-polymerization initiator, for example, aromatic sulfonium, aromatic iodonium, aromatic dia cation portion containing jonyum or aromatic ammonium and _{^{AsF 6 -, SbF 6 -,}} PF 6 ^- , or a compound having an anion moiety including tetrakis (pentafluorophenyl) borate. In addition, as the cationic photopolymerization initiator, an onium salt or an organometallic salt based ionized cationic initiator or an organic silane or latent sulfonic acid based or non-ionized cationic photopolymerization initiator may be used. Examples of the onium salt-based initiator include a diaryliodonium salt, a triarylsulfonium salt, or an aryldiazonium salt. Initiation of an organometallic salt series Examples of zero may be iron arene, and the like, and examples of the organosilane-based initiator include o-nitrobenzyl triaryl silyl ether, triaryl silyl peroxide. Alternatively, acyl silane may be exemplified, and the latent sulfuric acid-based initiator may include α-sulfonyloxy ketone or α-hydroxymethylbenzoin sulfonate, but is not limited thereto. .

In one example, the sealing material composition of the present application may include a photoinitiator including an iodonium salt or a sulfonium salt as a photoinitiator in the specific composition described above so as to be suitable for use in sealing an organic electronic device in an inkjet manner. Although the sealing material composition according to the above composition is directly sealed on the organic electronic device, the amount of outgassing is small, so that chemical damage to the device can be prevented. In addition, the photoinitiator has excellent solubility and can be suitably applied to an inkjet process.

In a specific example of the present application, the photoinitiator may be included in an amount of 1 to 15 parts by weight, 2 to 13 parts by weight, or 3 to 11 parts by weight based on 100 parts by weight of the epoxy compound.

In a specific example of the present application, the ink composition may further include a surfactant. The ink composition may be provided as a liquid ink with improved spreadability by including a surfactant. In one example, the surfactant may include a polar functional group. The polar functional group may include, for example, a carboxyl group, a hydroxy group, a phosphate, an ammonium salt, a carboxylate group, a sulfate or sulfonate. In addition, in the embodiment of the present application, the surfactant may be a non-silicone surfactant or a fluorine surfactant. The non-silicone-based surfactant or the fluorine-based surfactant is applied together with the above-described epoxy compound and the compound having an oxetane group to provide excellent coating properties on an organic electronic device. On the other hand, in the case of a surfactant including a polar reactive group, since it has high affinity with other components of the ink composition, it is possible to participate in the curing reaction, and thus an excellent effect in terms of adhesion can be realized. In the specific example of the present application, a hydrophilic fluorine-based surfactant or a non-silicone-based surfactant may be used to improve coating properties on the substrate.

Specifically, the surfactant may be a polymeric or oligomeric fluorine-based surfactant. The surfactant may be a commercial product, for example, TEGO's Glide 100, Glide110, Glide 130, Glide 460, Glide 440, Glide450 or RAD2500, DIC (DaiNippon Ink & Chemicals) Megaface F-251, F-281, F-552, F554, F-560, F-561, F-562, F-563, F-565, F-568, F-570 and F-571 or Surflon S-111, S-112 from Asahi Glass , S-113, S-121, S-131, S-132, S-141 and S-145 or Sumitomo SriM's Fluorad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430 and FC-4430 or Zonyl FS-300, FSN, FSN-100 and FSO from DuPont and BYK-350, BYK-354, BYK-355 from BYK, BYK-356, BYK-358N, BYK -359, BYK-361N, BYK-381, BYK-388, BYK-392, BYK-394, BYK-399, BYK-3440, BYK-3441, BYKETOL-AQ, BYK-DYNWET 800, etc. Can be used.

The surfactant is 0.1 to 10 parts by weight, 0.05 to 10 parts by weight, 0.1 to 10 parts by weight, 0.5 to 8 parts by weight, or 1 to 4 parts by weight based on 100 parts by weight of the curable compound. Can be included. Within the above content range, the present application allows the ink composition to be applied to an ink jet method to form a thin organic layer.

In the specific example of the present application, the ink composition may further include a photosensitizer to supplement curability in a long wavelength active energy ray of 300 nm or more. The photosensitizer may be a compound that absorbs a wavelength in the range of 200 nm to 400 nm.

The photosensitizers include anthracene compounds such as anthracene, 9,10-dibutoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 2-ethyl-9,10-dimethoxyanthracene; Benzophenone, 4,4-bis(dimethylamino)benzophenone, 4,4-bis(diethylamino)benzophenone, 2,4,6-trimethylaminobenzophenone, methyl-o-benzoylbenzoate, 3,3 -Benzophenone compounds such as 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; Fluorenone compounds such as 9-fluorenone, 2-chloro-9-prorenone, and 2-methyl-9-fluorenone; Thioxanthone, 2,4-diethyl thioxanthone, 2-chloro thioxanthone, 1-chloro-4-propyloxy thioxanthone, isopropyl thioxanthone (ITX), diisopropyl thioxanthone, etc. Thioxanthone compounds; 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; 9-phenylacridine, 1,7-bis(9-acridinyl)heptane, 1,5-bis(9-acridinylpentane), 1,3-bis(9-acridinyl)propane, etc. Acridine compounds; 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; 2,5-bis(4-diethylaminobenzal)cyclopentanone, 2,6-bis(4-diethylaminobenzal)cyclohexanone, 2,6-bis(4-diethylaminobenzal)-4- Amino synergists such as methyl-cyclopentanone; 3,3-carbonylvinyl-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-benzoyl-7-(diethylamino)coumarin, 3 -Benzoyl-7-methoxy-coumarin, 10,10-carbonylbis[1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-C1]-benzo Coumarin compounds such as pyrano[6,7,8-ij]-quinolizin-11-one; Chalcone compounds such as 4-diethylamino chalcone and 4-azidebenzalacetophenone; 2-benzoylmethylene; And it may be one or more selected from the group consisting of 3-methyl-b-naphthothiazoline.

The photosensitizer may be included in the range of 28 parts by weight to 40 parts by weight, 31 parts by weight to 38 parts by weight, or 32 parts by weight to 36 parts by weight, based on 100 parts by weight of the photoinitiator described later. In the present application, by adjusting the content of the photosensitizer, while implementing the effect of increasing the curing sensitivity at a desired wavelength, it is possible to prevent the photosensitizer from deteriorating the adhesion due to not being dissolved.

The ink composition of the present application may further include a coupling agent. The present application can improve the adhesion of the ink composition to the adherend of the cured product or the moisture permeability of the cured product. The coupling agent may include, for example, a titanium-based coupling agent, an aluminum-based coupling agent, and a silane coupling agent.

In a specific example of the present application, as the silane coupling agent, specifically, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl (dime Epoxy-based silane coupling agents such as oxy)methylsilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; Mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 11-mercaptoundecyltrimethoxysilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, Amino-based silane coupling agents such as N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and N-(2-aminoethyl)-3-aminopropyldimethoxymethylsilane; Ureide-based silane coupling agents such as 3-ureidepropyltriethoxysilane, vinyl-based silane coupling agents such as vinyl trimethoxysilane, vinyl triethoxysilane, and vinylmethyldiethoxysilane; styryl-based silane coupling agents such as p-styryltrimethoxysilane; Acrylate-based silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; Isocyanate-based silane coupling agents such as 3-isocyanate propyltrimethoxysilane, bis(triethoxysilylpropyl) disulfide, and sulfide-based silane coupling agents such as bis(triethoxysilylpropyl)tetrasulfide; Phenyl trimethoxysilane, methacryloxypropyl trimethoxysilane, imidazole silane, triazine silane, etc. are mentioned.

In the present application, the coupling agent may be included in an amount of 0.1 parts by weight to 10 parts by weight or 0.5 parts by weight to 5 parts by weight based on 100 parts by weight of the epoxy compound. The present application may implement an effect of improving adhesion by adding a coupling agent within the above range.

The ink composition of the present application may include a moisture adsorbent, if necessary. The term “moisture adsorbent” may be used as a generic term for a component capable of adsorbing or removing moisture or moisture introduced from the outside through a physical or chemical reaction. That is, it means a moisture-reactive adsorbent or a physical adsorbent, and a mixture thereof may also be used.

The specific types of moisture adsorbents that can be used in the present application are not particularly limited, and for example, in the case of a moisture-reactive adsorbent, one or more mixtures of metal oxides, metal salts, or phosphorus pentoxide (P ₂ O ₅ ) may be mentioned. And, in the case of a physical adsorbent, zeolite, zirconia, montmorillonite, etc. are mentioned.

The ink composition of the present application may contain a moisture adsorbent in an amount of 5 parts by weight to 100 parts by weight, 5 to 80 parts by weight, 5 parts by weight to 70 parts by weight, or 10 to 30 parts by weight based on 100 parts by weight of the epoxy compound. have. In the ink composition of the present application, by controlling the content of the moisture adsorbent to be preferably 5 parts by weight or more, the ink composition or a cured product thereof may exhibit excellent moisture and moisture barrier properties. In addition, the present application may provide a thin film encapsulation structure by controlling the content of the moisture adsorbent to 100 parts by weight or less.

In one example, the ink composition may further include an inorganic filler, if necessary. The specific type of the filler that can be used in the present application is not particularly limited, and for example, one type of clay, talc, alumina, calcium carbonate, or silica, or a mixture of two or more types may be used.

The ink composition of the present application may include 0 to 50 parts by weight, 1 to 40 parts by weight, 1 to 20 parts by weight, or 1 to 10 parts by weight of an inorganic filler based on 100 parts by weight of the epoxy compound. have. The present application may provide a sealing structure having excellent moisture or moisture barrier properties and mechanical properties by controlling the inorganic filler to preferably 1 part by weight or more. In addition, the present invention can provide a cured product exhibiting excellent moisture barrier properties even when formed as a thin film by controlling the inorganic filler content to 50 parts by weight or less.

In addition to the above-described configuration, the ink composition according to the present application may contain various additives within a range that does not affect the effects of the above-described invention. For example, the ink composition may contain a defoaming agent, a tackifier, an ultraviolet stabilizer, or an antioxidant in an appropriate range depending on the desired physical properties.

In one example, the ink composition may be liquid at room temperature, for example, 15 °C to 35 °C or about 25 °C. In the specific example of the present application, the ink composition may be a liquid in a solvent-free form. The ink composition may be applied to encapsulating an organic electronic device, and specifically, the ink composition may be an ink composition applicable to encapsulating the entire surface of an organic electronic device. In the present application, since the ink composition has a liquid form at room temperature, the composition may be encapsulated on the side of the organic electronic device in an inkjet manner.

In addition, in a specific example of the present application, the ink composition has a viscosity of 50 cPs or less, 1 to 46 cPs, 3 to 25 °C, a torque of 90%, and a shear rate of 100 rpm, as measured by Brookfield's DV-3. 44 cPs, 4 to 38 cPs, 5 to 33 cPs or 14 to 24 cPs. The present application can provide a thin film encapsulant by controlling the viscosity of the composition within the above range, thereby improving coating properties at the time of application to an organic electronic device.

Further, in the specific example of the present application, the ink composition may have a light transmittance of 90% or more, 92% or more, or 95% or more in a visible light region after curing. Within the above range, the present application provides an organic electronic device with high resolution, low power consumption and long life by applying an ink composition to a top emission type organic electronic device.

In one example, the ink composition of the present application may have an amount of volatile organic compounds measured after curing of less than 50 ppm. In the present specification, the volatile organic compound may be expressed as an out gas. The volatile organic compound can be measured after curing the ink composition, and then holding the cured product sample at 110°C for 30 minutes using a purge & trap-gas chromatography/mass spectrometry method. The measurement may be measured using a Purge&Trap sampler (JAI JTD-505Ⅲ)-GC/MS (Agilent 7890b/5977a).

In one example, the ink composition of the present application may have a contact angle with respect to glass of 30° or less, 25° or less, 20° or less, or 12° or less. The lower limit is not particularly limited, but may be 1° or 3° or more. According to the present application, by adjusting the contact angle to be 30° or less, spreadability can be secured within a short time in inkjet coating, and thus a thin organic layer can be formed. In the present application, the contact angle may be measured by applying a drop of the ink composition on the glass using the Sessile Drop measurement method, and may be measured by measuring an average value after applying 5 times.

The present application also relates to an organic electronic device. The organic electronic device may include an organic film formed by inkjet coating after performing the above-described reliability evaluation. An exemplary organic electronic device includes a substrate; An organic electronic device formed on the substrate; And an organic layer that encapsulates the entire surface of the organic electronic device and includes the ink composition described above.

In a specific example of the present application, the organic electronic device may include a first electrode layer, an organic layer formed on the first electrode layer and including at least an emission layer, and a second electrode layer formed on the organic layer. The first electrode layer may be a transparent electrode layer or a reflective electrode layer, and the second electrode layer may also be a transparent electrode layer or a reflective electrode layer. More specifically, the organic electronic device may include a reflective electrode layer formed on a substrate, an organic layer formed on the reflective electrode layer and including at least a light emitting layer, and a transparent electrode layer formed on the organic layer.

In the present application, the organic electronic device may be an organic light emitting diode.

In one example, the organic electronic device according to the present application may be a top emission type, but is not limited thereto, and may be applied to a bottom emission type.

The organic electronic device may further include an inorganic layer protecting the electrode and the light emitting layer of the organic electronic device. The inorganic layer may be an inorganic protective layer. The inorganic layer may be a protective layer by chemical vapor deposition (CVD), and the material may be a known inorganic material.

In the specific example of the present application, the organic electronic device may further include an inorganic layer formed on the organic layer. In one example, the inorganic layer may be one or more metal oxides, nitrides, or oxynitrides selected from the group consisting of Al, Zr, Ti, Hf, Ta, In, Sn, Zn, and Si. The thickness of the inorganic layer may be 0.01 μm to 50 μm, or 0.1 μm to 20 μm, or 1 μm to 10 μm. In one example, the inorganic layer of the present application may be an inorganic material without a dopant or an inorganic material including a dopant. The dopant that can be doped is one or more elements selected from the group consisting of Ga, Si, Ge, Al, Sn, Ge, B, In, Tl, Sc, V, Cr, Mn, Fe, Co, and Ni, or the element It may be an oxide of, but is not limited thereto.

In one example, the thickness of the organic layer may be in the range of 2㎛ to 20㎛, 2.5㎛ to 15㎛, 2.8㎛ to 9㎛. The present application may provide a thin organic electronic device by providing a thin organic layer.

The organic electronic device of the present application may include an encapsulation structure including the aforementioned organic layer and an inorganic layer, and the encapsulation structure includes at least one organic layer and at least one inorganic layer, and an organic layer and an inorganic layer are repeatedly stacked. Can be. For example, the organic electronic device may have a structure of a substrate/organic electronic device/inorganic layer/(organic layer/inorganic layer) n, and n may be a number in the range of 1 to 100.

In one example, the organic electronic device of the present application may further include a cover substrate present on the organic layer. The material of the substrate and/or the cover substrate is not particularly limited, and a material known in the art may be used. For example, the substrate or cover substrate may be a glass, a metal substrate, or a polymer film. Polymer films are, for example, polyethylene terephthalate film, polytetrafluoroethylene film, polyethylene film, polypropylene film, polybutene film, polybutadiene film, vinyl chloride copolymer film, polyurethane film, ethylene-vinyl acetate film, ethylene -A propylene copolymer film, an ethylene-ethyl acrylate copolymer film, an ethylene-methyl acrylate copolymer film, or a polyimide film can be used.

In addition, the organic electronic device of the present application may further include an encapsulant that exists between the cover substrate and the substrate on which the organic electronic device is formed. The encapsulant may be applied to attach a substrate on which an organic electronic device is formed and the cover substrate, and may be, for example, an adhesive film or an adhesive film, but is not limited thereto. The encapsulant may seal the entire surface of the organic layer and inorganic layer structure stacked on the organic electronic device.

In addition, the present application relates to a method of manufacturing an organic electronic device. The manufacturing method may be to manufacture an organic electronic device by performing the above-described reliability evaluation and then ink jet coating.

In one example, the manufacturing method may include forming an organic layer by applying the above-described ink composition to seal the entire surface of the organic electronic device on a substrate on which the organic electronic device is formed.

In the above, the organic electronic device is a substrate, for example, a reflective electrode or a transparent electrode is formed on a substrate such as glass or a polymer film by vacuum deposition or sputtering, and an organic material layer is formed on the reflective electrode. It can be manufactured. The organic material layer may include a hole injection layer, a hole transport layer, an emission layer, an electron injection layer and/or an electron transport layer. Subsequently, a second electrode is further formed on the organic material layer. The second electrode may be a transparent electrode or a reflective electrode.

The manufacturing method of the present application may further include forming an inorganic layer on the first electrode, the organic material layer, and the second electrode formed on the substrate. Then, the above-described organic layer is applied on the substrate to cover the entire organic electronic device. At this time, the step of forming the organic layer is not particularly limited, and inkjet printing (Inkjet), gravure coating (Gravure), spin coating, screen printing or reverse offset coating, etc. of the above-described ink composition on the entire surface of the substrate The process of can be used.

The manufacturing method is also; It may further include the step of irradiating light to the organic layer. In the present invention, a curing process may be performed on the organic layer encapsulating the organic electronic device, such a curing process) may be performed in, for example, a heating chamber or a UV chamber, and preferably may be performed in a UV chamber.

In one example, after the above-described ink composition is applied to form the front organic layer, crosslinking may be induced by irradiating light to the composition. Irradiating the light may include irradiating light having a wavelength range of 250 nm to 450 nm or 300 nm to 450 nm at a light amount of 0.3 to 6 J/cm ² or 0.5 to 5 J/cm ² .

In addition, the manufacturing method of the present application may further include forming an inorganic layer on the organic layer. In the forming of the inorganic layer, a method known in the art may be used, and may be formed by chemical vapor deposition (CVD) as described above.

The present application provides a method for evaluating the reliability of an inkjet process and a substrate for evaluating the reliability of the inkjet process, which improves the efficiency and economy of the process by intuitively checking the reliability of the inkjet process in forming a thin film layer through an inkjet process. .

1 to 5 are diagrams showing a reliability evaluation process according to Examples and Comparative Examples.

Hereinafter, the present invention will be described in more detail through examples according to the present invention and comparative examples not according to the present invention, but the scope of the present invention is not limited by the examples presented below.

Example One

Photoinitiator containing an alicyclic epoxy compound (Celloxide 2021P from Daicel), an aliphatic epoxy compound (HAJIN CHEM TECH, DE200), an oxetane group-containing compound (OXT-221 from TOAGOSEI), and an iodonium salt as an epoxy compound at room temperature ( Tetrachem's TTA-UV694, hereinafter, UV694) and a fluorine-based surfactant (DIC's F552), respectively, in a mixing container in a weight ratio of 23.8:28.7:37.5:5.0:1.0 (Celloxide2021P:DE200:OXT-221:UV694:F552). Was put in.

The mixing vessel was prepared with a uniform ink composition ink using a Planetary mixer (Kurabo, KK-250s).

The prepared ink composition was ink-jetted on a polyethylene substrate (PE, DIAFOIL from Mitsubishi) using Unijet UJ-200 (Inkjet head-Dimatix 10Pl 256) to conduct reliability evaluation. The ejection stability was evaluated by comparing the number of ejected ink composition droplets to the number of nozzles of the inkjet device.

Example 2

Reliability evaluation was performed in the same manner as in Example 1, except that a polyethylene terephthalate substrate (PET, SKC's SG31) was used as the substrate.

Comparative example One

Reliability evaluation was performed in the same manner as in Example 1, except that a polyethylene terephthalate substrate (PET, ARflow 92804 of Adhesive Research Corporation) was used as the substrate.

Comparative example 2

Reliability evaluation was performed in the same manner as in Example 1, except that a polyethylene substrate (PE, HHNW of Coveme) was used as the substrate.

Comparative example 3

Reliability evaluation was performed in the same manner as in Example 1, except that a polyethylene substrate (PE, 3M9971 from PRONAT) was used as the substrate.

Physical properties in Examples and Comparative Examples were evaluated in the following manner.

1. Surface energy of substrate

For the substrates in Examples and Comparative Examples, surface energy was measured as follows using DSA manufactured by KRUSS.

Deionized water, whose surface tension is known, is dropped on the substrate to be measured and the process of obtaining the contact angle is repeated five times to obtain the average value of the five contact angle values obtained, and the same, the surface tension is known. Diiodomethane is dropped and the process of obtaining the contact angle is repeated five times, and the average value of the five contact angle values obtained is obtained. Thereafter, the surface energy was obtained by substituting a value (Strom value) about the surface tension of the solvent by the Owens-Wendt-Rabel-Kaelble method using the obtained average value of the contact angle for deionized water and diiodomethane.

2. Ejected ink Droplet size

For the ink droplets discharged on the substrate in Examples and Comparative Examples, the diameter was measured using an OLYMPUS BX51 optical microscope (digital microscope). Measured five times and recorded the average value.

3. Visual inspection

For the ink discharged on the substrate in Examples and Comparative Examples, when a surface was formed due to spreading between the discharged ink and the ink, it was classified as X because visual inspection was impossible, and the gap between the discharged ink and the ink was If present, it was classified as O. 1 to 5 are views taken using an OLYMPUS BX51 optical microscope (digital microscope) of the ink discharged in Examples 1 to 2 and Comparative Examples 1 to 3, respectively.

Surface energy of substrate Ink droplet size Visual inspection Example 1 42.5mN/m 70㎛ O Example 2 65.5 mN/m 140㎛ O Comparative Example 1 72.1 mN/m - X Comparative Example 2 81.9 mN/m - X Comparative Example 3 38.4 mN/m - X

Claims (15)

Including the step of discharging the ink composition using an inkjet apparatus having two or more nozzles on a substrate having a surface energy in the range of 40 to 70 mN/m ,
A method for evaluating the reliability of an inkjet process, which is judged to have excellent reliability when the number of discharged ink composition droplets is 90% or more compared to the number of nozzles . delete The method of claim 1, wherein the ink composition has a surface energy of 20 to 40 mN/m. delete The method for evaluating the reliability of an inkjet process according to claim 1, wherein a gap exists between the discharged ink composition droplets. The method for evaluating the reliability of an inkjet process according to claim 5, wherein the interval between the discharged ink composition droplets is within a range of 1 µm to 170 µm. The method of claim 1, wherein a diameter of the discharged ink composition droplet is smaller than a gap between the nozzle and the nozzle. The method for evaluating the reliability of an inkjet process according to claim 1, wherein the discharged ink composition droplet has a diameter within a range of 30 µm to 200 µm. The method of claim 1, wherein the distance between the nozzle and the nozzle is in a range of 200 µm to 350 µm. The method of claim 1, wherein the step of discharging the ink composition is repeated one or more times. delete A substrate for evaluating the reliability of the inkjet process according to claim 1, wherein the substrate has a surface energy in the range of 40 to 70 mN/m. delete The substrate according to claim 12, comprising a polymer resin. The method of claim 14, wherein the polymer resin is polyethylene terephthalate, polytetrafluoroethylene, polyethylene, polypropylene, polybutene, polybutadiene, vinyl chloride copolymer, polyurethane, ethylene-vinyl acetate, ethylene-propylene copolymer, ethylene- A substrate comprising an ethyl acrylate copolymer, an ethylene-methyl acrylate copolymer, or a polyimide.

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