Curable high refractive index ink compositions with water chelating agents

Abstract

A curable ink composition comprising a (meth) acrylate-based component and a water chelating component, the (meth) acrylate-based component forming a matrix when cured. The water chelating component is an epoxy group / anhydride reaction pair. At least one of the reaction pairs is co-curable with the (meth) acrylate component. The reaction pair chelates the water by a 2-step mechanism, the water reacts with the anhydride to form an acid, and the acid reacts with the epoxy group. The reaction causes the matrix to irreversibly absorb water as at least one of the epoxy group and the anhydride is bonded to the (meth) acrylate matrix. The ink composition is inkjet printable, has a refractive index of 1.55 or greater, and is optically clear. After 7 days of exposure to 85 DEG C / 85% relative humidity, the cured substrate has a water absorption of at least 2% by weight.

Description

Summary of the invention

[0001] Disclosed herein are curable high refractive index compositions containing a water chelating agent. The water chelating agent helps prevent the migration of water through the curable ink composition. Also disclosed are articles containing a layer prepared from the curable high refractive index ink composition.

[0002] In some embodiments, the curable ink composition comprises: a (meth)acrylate-based component that is capable of curing to form a (meth)acrylate-based matrix; and a water chelating component. The curable (meth)acrylate-based component comprises: at least one aromatic (meth)acrylate; at least one multifunctional (meth)acrylate, the at least one multifunctional (meth)acrylate having a heteroaromatic group, a fused aromatic group, a heteroalkylene group, or a group containing both a heteroalkylene group and an aromatic group; and a photoinitiator. The water chelating component is a reactive pair of an epoxy functional portion and an anhydride functional portion. The water chelating component comprises: at least one co-curable portion, the at least one co-curable portion comprising an epoxy functional (meth)acrylate, an anhydride functional ethylenically unsaturated compound, or both; and an optional non-curable epoxy portion, a non-curable anhydride portion, or both. After curing, the ink composition forms a (meth)acrylate matrix having an epoxy functional group, an anhydride functional group, or both. The matrix is ​​capable of water chelation, whereby the anhydride groups are attached to the matrix or do not react with water, thereby forming an acid that reacts with the epoxy functional groups. As described above, one or both of the epoxy groups and the anhydride groups are attached to the matrix. Therefore, the reaction produces irreversible water absorption through the (meth)acrylate-based matrix. The ink composition is inkjet printable, has a viscosity of 30 centipoise or less at a temperature of room temperature to 35°C, and is solvent-free. The ink composition has a refractive index of 1.55 or greater and is optically clear when set and cured, and has an irreversible water absorption of at least 2 weight percent after exposure to 85°C / 85% relative humidity for 7 days.

[0003] In some embodiments, the article of the present disclosure includes a substrate and a cured organic layer, the substrate having a first major surface and a second major surface, the cured organic layer being adjacent to at least a portion of the second major surface of the substrate, wherein the cured organic layer comprises a cross-linked (meth) acrylate-based layer, and has a refractive index of 1.55 or greater and is optically clear, the cross-linked (meth) acrylate-based layer containing epoxy functional groups, anhydride functional groups, or both. The cured organic layer may contain a non-curable epoxy portion, a non-curable anhydride portion, or both, such that the cured organic layer has a water chelating component. The water chelating component is a reaction pair, the reaction pair being an epoxy functional portion and an anhydride functional portion. As described above, the water chelating component produces irreversible water absorption through the (meth) acrylate matrix. After exposure to 85°C / 85% relative humidity for 7 days, the irreversible water absorption is at least 2% by weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The present application may be more fully understood by referring to the following detailed description of various embodiments of the present disclosure in conjunction with the accompanying drawings.

[0005] Figure 1 is a cross-sectional view of an article of the present disclosure.

[0006] Figure 2 is a cross-sectional view of the test article used in the Examples section.

[0007] In the following description of the illustrated embodiments, reference is made to the accompanying drawings and various embodiments in which the present disclosure may be practiced are shown in these drawings by way of example. It should be understood that the embodiments may be utilized and structural changes may be made without departing from the scope of the present disclosure. The figures are not necessarily drawn to scale. Like numbers used in the figures refer to like parts. However, it should be understood that the use of numbers to refer to parts in a given figure is not intended to limit the parts marked with the same numbers in another figure. DETAILED DESCRIPTION

[0008] Optical devices are becoming increasingly complex, which affects the materials that can be used therein. In particular, organic polymer materials have been widely used in optical devices, however, they still have to meet the stringent requirements and demands required for performance.

[0009] For example, thin organic polymer films are desired for a wide range of uses in optical devices as adhesives, protective layers, spacers, etc. As articles become more complex, the physical demands on these layers increase. For example, as optical devices become more compact, they often include additional layers, resulting in a growing need for thinner layers. At the same time, as the layers are thinner, there is also a need for the layers to be more precise. For example, a thin spacer (1 micron thick) needs to be flat and free of gaps and holes in order to provide the proper spacing function. This requires the organic layers to be deposited in a precise and consistent manner.

[0010] In addition, these layers must not only fulfill their physical role (adhesion, protection, spacing, etc.), but must also provide the desired optical properties. Among the properties that are becoming increasingly important is the refractive index. When light passes through the layers of a multilayer article, it encounters the interfaces between the layers. If the refractive indices of the layers are different, the light can be refracted. Therefore, in order to minimize this refraction, matching of the refractive indices of the layers within the multilayer article is desirable.

[0011] An example of an optical device that utilizes a thin film layer is an OLED (organic light emitting diode) device. Specifically, organic light emitting devices are susceptible to degradation due to the penetration of certain liquids and gases, such as water vapor and oxygen. In order to reduce the permeability of these liquids and gases, barrier coatings are applied to OLED devices, which is known in the art as thin film encapsulation. Typically, these barrier coatings require a high refractive index to match the other layers in the device.

[0012] Typically, the organic film layer is a solidified organic matrix. Because these layers are very thin, it may be difficult for the barrier layer to prevent water from being transmitted through the barrier layer, particularly, for example, in a humid environment. Water may be harmful to devices (such as OLEDs), so it is desirable that the barrier layer has an enhanced ability to prevent water migration. One method is to make the organic matrix absorb water. Various techniques can be used to make the organic film layer have water absorption to prevent water from passing through the organic film layer. However, many of these techniques can change the desired properties and necessary properties of the organic film layer, such as optical properties. In addition, many materials (commonly referred to as water scavengers) that are commonly used to absorb water in the organic matrix can release small molecules that are harmful to the organic layer and / or the device. For example, oxazolidine or alkoxysilane can be used as water scavengers, but these molecules form ketones and alcohols respectively, and these small molecules are problematic materials produced in the organic film layer. Therefore, there is still a need for a method for removing water in the organic film layer.

[0013] In the present disclosure, a water removal method, i.e., a water chelation method, is described. This chelation method is a two-step method involving an anhydride / epoxy reaction pair. The method utilizes an anhydride functional group, which reacts with water to form an acid group, and the acid group reacts with an epoxy group. At least one of the anhydride and epoxy groups is cured into a (meth)acrylate matrix, so the result of the 2-step reaction is that water is trapped or chelated in the matrix without generating any small molecules.

[0014] The term "(meth)acrylate" refers to monomeric acrylate or methacrylate esters of alcohols. Acrylate and methacrylate monomers or oligomers are collectively referred to herein as "(meth)acrylates". Materials referred to as "(meth)acrylate functional" are materials that contain one or more (meth)acrylate groups. The term "(meth)acrylate-based" refers to a composition or layer that contains (meth)acrylates and may contain additional (meth)acrylate co-reactive materials.

[0015] The terms "room temperature" and "ambient temperature" are used interchangeably and refer to temperatures in the range of 20°C to 25°C.

[0016] As used herein, the term "adjacent" when referring to two layers means that the two layers are adjacent to each other without an intervening open space between them. They can be in direct contact with each other (eg, laminated together) or there can be intervening layers.

[0017] As used herein, the terms "polymer" and "macromolecule" are consistent with their common usage in chemistry. Polymers and macromolecules are composed of many repeating subunits. As used herein, the term "macromolecule" is used to describe a group attached to a monomer that has multiple repeating units. The term "polymer" is used to describe the resulting material formed by a polymerization reaction.

[0018] The term "alkyl" refers to a monovalent group that is an alkane radical, which is a saturated hydrocarbon. The alkyl group may be linear, branched, cyclic, or a combination thereof, and typically has 1 to 20 carbon atoms. In some embodiments, the alkyl group contains 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, and ethylhexyl.

[0019] The term "aryl" refers to a monovalent group that is aromatic and carbocyclic. The aryl group may have one to five rings connected or fused to the aromatic ring. Other ring structures may be aromatic, non-aromatic, or a combination thereof. Examples of aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, anthryl, naphthyl, acenaphthenyl, anthraquinone, phenanthrenyl, anthracenyl, pyrenyl, perylenyl, and fluorenyl.

[0020] The term "alkylene" refers to a divalent group that is a radical of an alkane. An alkylene group may be linear, branched, cyclic, or a combination thereof. An alkylene group typically has 1 to 20 carbon atoms. In some embodiments, an alkylene group contains 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. The radical centers of an alkylene group may be on the same carbon atom (i.e., an alkylidene group) or on different carbon atoms.

[0021] The term "heteroalkylene" refers to a divalent group comprising at least two alkylene groups connected by a thiol group, an oxy group, or -NR-, wherein R is an alkyl group. The heteroalkylene group can be linear, branched, cyclic, substituted with alkyl groups, or a combination thereof. Some heteroalkylene groups are polyoxyalkylenes in which the heteroatom is oxygen, such as, for example

[0022] -CH2CH2(OCH2CH2) n OCH2CH2-.

[0023] The terms "free radical polymerizable" and "ethylenically unsaturated" are used interchangeably and refer to reactive groups containing carbon-carbon double bonds capable of polymerizing via a free radical polymerization mechanism.

[0024] Unless otherwise indicated, "optically clear" refers to a layer, film or article having high light transmittance over at least a portion of the visible spectrum (about 400 nm to about 700 nm). Typically, an optically clear layer, film or article has a light transmittance of at least 80%.

[0025] Unless otherwise indicated, "optically clear" means that the layer, film or article has high light transmittance over at least a portion of the visible spectrum (about 400 nm to about 700 nm) and exhibits low haze. Typically, an optically clear layer, film or article has a visible light transmittance value of at least 80%, usually at least 90%, and a haze value of 5% or less, usually 2% or less.

[0026] Disclosed herein is a curable composition that is printable and therefore described as ink. Curable compositions are not necessarily used as inks, that is, they are not necessarily printed and then cured, and curable compositions can be delivered to substrate surfaces in a wide variety of ways, but they can be printed. The terms "curable composition" and "ink" are used interchangeably in the present disclosure. Specifically, the printable compositions of the present disclosure are generally capable of inkjet printing, which means that they have appropriate viscosity and other properties in order to be inkjet printed. The term "inkjet printable" is not a process description or restriction, but a material description, meaning that the curable composition can be inkjet printed, rather than that the composition must have been inkjet printed. This is similar to the statement "hot melt processable", meaning that the composition can be hot melt processed, but does not mean that the composition has been hot melt processed.

[0027] The curable ink composition comprises: a (meth)acrylate-based component capable of curing to form a (meth)acrylate-based matrix; and a water chelating component. The (meth)acrylate-based component comprises: at least one aromatic (meth)acrylate; at least one multifunctional (meth)acrylate, wherein the multifunctional (meth)acrylate comprises a heteroaromatic group, a fused aromatic group, a heteroalkylene group, or a group containing both a heteroalkylene group and an aromatic group; and a photoinitiator. The (meth)acrylate-based component forms a crosslinked matrix when cured.

[0028] The water chelating component comprises a reaction pair, which is an epoxy functional part and an anhydride functional part. The water chelating component comprises: at least one co-curable part, which comprises an epoxy functional (meth) acrylate, an anhydride functional ethylenically unsaturated compound or both; and an optional non-curable epoxy part, a non-curable anhydride part or both. In this way, at least one of the reaction pair (anhydride or epoxy group) is cured into a (meth) acrylate matrix. As described above, water chelation of the reaction pair occurs by reacting water with anhydride groups to form an acid, wherein the anhydride groups are either cured into a (meth) acrylate matrix or not cured. The acid then reacts with the epoxy groups. Similarly, the epoxy groups can be cured into a (meth) acrylate matrix or not cured, as long as at least one of the anhydride groups or the epoxy groups is cured into a (meth) acrylate matrix. In this way, water is irreversibly connected to the (meth) acrylate matrix and no small molecule byproducts are produced. This process is called water chelation because free water molecules are incorporated into the matrix through it, resulting in irreversible water absorption.

[0029] The ink composition has a variety of desirable properties, including being solvent-free and inkjet printable, having a viscosity of 30 centipoise or less at temperatures between room temperature and 35°C, and when set and cured, forming an organic layer having a refractive index of 1.55 or greater and being optically clear. Additionally, the cured organic layer has an irreversible water absorption of at least 2 wt% after exposure to 85°C / 85% relative humidity for 7 days.

[0030] The curable ink composition comprises a (meth)acrylate-based component and a water-chelating component. As described above, the (meth)acrylate-based component comprises: at least one aromatic (meth)acrylate; at least one multifunctional (meth)acrylate, wherein the multifunctional (meth)acrylate comprises a heteroaromatic group, a fused aromatic group, a heteroalkylene group, or a group containing both a heteroalkylene group and an aromatic group; and a photoinitiator. A wide variety of aromatic (meth)acrylate monomers are suitable for use in the curable ink composition of the present disclosure. Typically, these aromatic (meth)acrylate monomers are monofunctional. A single monofunctional (meth)acrylate monomer may be used or a mixture of monofunctional (meth)acrylate monomers may be used. Generally, at least one monofunctional (meth)acrylate comprises a compound of Formula I (as shown below):

[0031]

[0032] wherein at least one R1 comprises an aromatic substituent, t is an integer from 1 to 4, and R2 is hydrogen or methyl.

[0033] A wide variety of aromatic substituents are suitable for one or more R1 groups. Typically, at least one aromatic substituent R1 comprises a substituted or unsubstituted aromatic group of the type -CH2-Ar, or a heteroatom-linked aromatic group of the type -X-Ar, wherein X is S or O, and each Ar is independently a substituted or unsubstituted phenyl group, a fused aromatic group, or a phenyl or substituted phenyl group to which two or more alkyl groups are linked.

[0034] Thus, one or more R1 groups may include various aromatic substituents such as:

[0035]

[0036] or * -S-Ar.

[0037] The aromatic substituent R1 is typically bonded to the aromatic ring of the benzyl group through at least one divalent (e.g., alkylene or ether) linking group. In some embodiments, the aromatic substituent R1 is bonded to the aromatic benzyl ring through two or more divalent (e.g., alkylene or ether) linking groups. Each * represents the point(s) of attachment to the aromatic ring of Formula I; and Ar is a substituted or unsubstituted phenyl group, a fused aromatic group, or a phenyl or substituted phenyl group to which 2 or more alkyl groups are attached.

[0038] In some advantageous embodiments, t is 1. Representative structures of Formula I thus include:

[0039]

[0040] Where t is 1 and the R1 group is * In some embodiments of -S-Ar, the compound may have the general structure of Formula IA:

[0041]

[0042] wherein R2 is H or CH3, X is O, S or a single bond, Q is O, S, SiR2 (wherein R is an alkyl group), a carbonyl group (C=O), an amino group NR (wherein R is hydrogen or an alkyl group), or a SO2 group, n is in the range of 0 to 10 (for example, n is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10), and L is an alkylene group having 1 to 5 carbon atoms, optionally substituted by a hydroxyl group.

[0043] A particularly suitable monomer of formula IA is one in which R2 is hydrogen, n is 1, L is a -CH2- group, X is a single bond, and Q is sulfur. This monomer is shown below as formula IB:

[0044]

[0045] Although compounds similar to this monomer have been reported in the literature, such as in Korean Patent Publication No. 101,254,325B1, this monomer has been found to have particularly desirable viscosity and refractive index characteristics. Specifically, the monomer of Formula III has been found to have a viscosity of less than 40 centipoise at 25°C, even a viscosity of 13 centipoise at 25°C, and a refractive index of less than 1.630, or even less than 1.620 when uncured.

[0046] In other embodiments of the monomer of formula I, t is greater than 1. In one embodiment, t is 3. A representative structure is:

[0047]

[0048] Various aromatic alcohols available from Sigma-Aldrich are available as starting materials that can be converted to (meth)acrylates by reacting such materials with (meth)acrylic acid or (meth)acrylic acid derivatives. Particularly suitable monofunctional (meth)acrylate monomers include biphenyl methyl acrylate (wherein R1 is a phenyl group), which is commercially available as MIRAMER M1192 or MIRAMER M1192H from Miwon Specialty Chemicals, Exton, PA, and monomers of Formula III, the synthesis of which is given in the Examples section.

[0049] The amount of aromatic (meth)acrylate monomers used in the curable ink composition can vary. By "aromatic (meth)acrylate monomers" is meant all aromatic (meth)acrylate monomers present when more than one aromatic (meth)acrylate monomer is used. In some embodiments, the curable ink composition comprises at least 20 wt % or more of aromatic (meth)acrylate monomers. In other embodiments, the curable ink composition comprises up to 65 wt % of aromatic (meth)acrylate monomers. As described above, typically, the aromatic (meth)acrylate monomer is a monofunctional (meth)acrylate.

[0050] In some embodiments, the aromatic (meth)acrylate monomer has a refractive index greater than 1.50 (e.g., at least 1.51 or 1.52), and may have a refractive index greater than 1.60. Generally, these aromatic (meth)acrylate monomers are non-halogenated (e.g., non-brominated). In some embodiments, the aromatic (meth)acrylate monomer has a refractive index of at least 1.53, 1.54, 1.55, 1,56, 1,57, 1.58, 1.59, 1.60, or 1.61 and typically no greater than 1.65.

[0051] The curable ink composition of the present disclosure further comprises at least one multifunctional (meth)acrylate of the following general formula II:

[0052] (H2C=CR2-(CO)-O-) n A

[0053] Formula II

[0054] Wherein R2 is hydrogen or methyl, (CO) is a carbonyl group C=O, A is an n-valent group including a heteroaromatic group, a fused aromatic group, or a group containing both a heteroalkylene group and an aromatic group, and n is an integer of 2 or greater. In some embodiments, the multifunctional (meth)acrylate is difunctional (n=2), and in other embodiments, the multifunctional (meth)acrylate is trifunctional (n=3). Higher functional multifunctional (meth)acrylates are also possible.

[0055] The example of heteroaromatic group includes thiadiazole group, thiazole group and thiophene group.The example of condensed aromatic group includes naphthyl group, anthracene group and fluorenyl group.The example of heteroalkylene group includes polyethylene oxide group, polypropylene oxide group, polythioether group etc.The example of the group containing heteroalkylene group and aromatic group includes the group with the difunctional alkylene group containing 2-10 carbon atoms, and has 1-10 repeating units, and contains difunctional aromatic group, such as phenylene, benzylidene or benzylidene group connected.

[0056] In some embodiments, it may be desirable to use a multifunctional (meth)acrylate monomer having a functionality greater than 2. One particularly suitable trifunctional (meth)acrylate is TMPTA (trimethylolpropane triacrylate), which is commercially available under the trade name "MIRAMER M300" from Miwon Specialty Chemical Co., Ltd. Yongin, Korea.

[0057] Since the multifunctional (meth)acrylate monomers have a functionality of 2 or more, these monomers act as crosslinking agents and crosslink the formed polymer. The amount of the multifunctional (meth)acrylate monomers is controlled to prevent the polymer from becoming rigid. Typically, the curable ink composition comprises less than 65% by weight of one or more multifunctional (meth)acrylate monomers, and at least 10% by weight of one or more multifunctional (meth)acrylate monomers. In some embodiments, the one or more multifunctional (meth)acrylate monomers are present in an amount of 15% to 35% by weight.

[0058] The (meth)acrylate component also includes at least one photoinitiator, which means that the initiator is activated by light, typically ultraviolet (UV) light, but other light sources may also be used with appropriate selection of initiators (such as visible light initiators, infrared photoinitiators, etc.). Typically, UV photoinitiators are used. Photoinitiators are well known to those skilled in the art of (meth)acrylate polymerization. Examples of suitable free radical photoinitiators include IRGACURE 4265, IRGACURE 184, IRGACURE 651, IRGACURE 1173, IRGACURE 819, IRGACURE TPO, IRGACURE TPO-L, which are commercially available from BASF, Charlotte, NC.

[0059] Generally, the photoinitiator is used in an amount of 0.01 to 10 parts by weight, more typically 0.1 to 2.0 parts by weight, relative to 100 parts by weight of the total reaction components.

[0060] The curable ink composition also includes a water chelating component. As mentioned above, the water chelating component is an anhydride / epoxy group reaction pair. At least one of the components of the reaction pair can be co-cured with the above-mentioned (meth) acrylate component. This means that at least one of the reaction pair is a compound with an ethylenically unsaturated group, so that it is co-cured with the (meth) acrylate component and becomes a part of the (meth) acrylate matrix. The water chelating component may also include non-curable epoxy or anhydride functional parts. If the two reaction pair components are co-curable, non-curable epoxy or anhydride functional parts are not required. In many embodiments, non-curable epoxy or anhydride functional parts.

[0061] The reactive pair of water chelating components comprises at least one epoxy functional moiety. At least one epoxy functional moiety may comprise a co-curable epoxy functional moiety, a non-curable epoxy functional moiety, or a combination thereof. In many embodiments, the epoxy functional moiety is a co-curable moiety. Epoxy functional (meth) acrylates are particularly suitable co-curable epoxy moieties. Suitable epoxy (meth) acrylates include those described by Formula III:

[0062] H2C=CR2-(CO)-O-CH2-B

[0063] Formula III

[0064] Wherein R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and B is a divalent group containing an epoxy-functional alkylene or heteroalkylene group. Examples of suitable epoxy (meth)acrylates include 3,4-epoxycyclohexylmethyl methacrylate TTA-15, which is commercially available from Jiangsu Tetra New Material Technology Co., Ltd.

[0065] The reactive pair of water-chelating components also comprises at least one anhydride functional moiety. The at least one anhydride may comprise a co-curable anhydride, a non-curable anhydride, or a combination thereof.

[0066] In some embodiments, the anhydride is a copolymerizable anhydride comprising a (meth)acrylate functional anhydride of Formula IV:

[0067] H2C=CR2-(CO)-O-(CO)-R2C=CH2

[0068] Formula IV

[0069] wherein R2 is hydrogen or methyl; (CO) is a carbonyl group C=O. Examples of such anhydrides include methacrylic anhydride. In other embodiments, the copolymerizable anhydride comprises an ethylenically unsaturated anhydride, such as maleic anhydride.

[0070] In some embodiments, the anhydride is a non-curable anhydride. Examples of non-curable anhydrides include aromatic anhydrides and aliphatic anhydrides. Aromatic anhydrides are particularly suitable because they generally have a higher refractive index than aliphatic anhydrides. Higher refractive index synthons are ideal for forming a higher refractive index matrix, and since the anhydride is incorporated into the matrix, a higher refractive index anhydride may be more ideal. Suitable aromatic anhydrides include benzoic anhydride and phthalic anhydride. Aliphatic anhydrides include NBA (5-norbornene-2,3-dicarboxylic anhydride).

[0071] In some particularly suitable curable ink compositions, the water chelating component comprises a co-curable epoxy functional (meth)acrylate and a non-curable anhydride. Without wishing to be bound by theory, it is believed that the use of a non-curable anhydride provides increased mobility within the (meth)acrylate matrix to allow the anhydride to more easily access any water that enters the matrix.

[0072] The amount of each part of the water chelating component can vary widely. Typically, in embodiments containing epoxy (meth)acrylate moieties, the epoxy (meth)acrylate is present in an amount of 0.075 wt % to 45 wt % of the total weight of the curable ink composition. In these embodiments, the non-curable anhydride comprises 0.005 wt % to 18 wt % of the total weight of the curable ink composition.

[0073] Articles are also disclosed herein. In some embodiments, the article includes: a substrate having a first major surface and a second major surface; and a cured organic layer, the cured organic layer being adjacent to at least a portion of the second major surface of the substrate. The cured organic layer comprises a cross-linked (meth) acrylate base layer having a refractive index of 1.55 or greater and being optically clear, the cross-linked (meth) acrylate base layer containing epoxy functional groups, anhydride functional groups, or both. The cured organic layer optionally comprises a non-curable epoxy portion, a non-curable anhydride portion, or both, such that the cured organic layer has a water chelating component. The water chelating component has been described above and is a reaction pair, the reaction pair being an epoxy functional portion and an anhydride functional portion. The anhydride group that is cured into a (meth) acrylate matrix or a non-curable portion forms an acid functional group when reacting with water, and the acid functional group reacts with the epoxy functional group that is cured into a (meth) acrylate matrix or a non-curable portion. At least one of the epoxy functional groups or the anhydride functional groups cures into a (meth)acrylate matrix to produce an irreversible water absorption of the (meth)acrylate based matrix, wherein the irreversible water absorption is at least 2 wt% after exposure to 85°C / 85% relative humidity for 7 days.

[0074] The cured organic layer is formed by curing a curable ink composition that has been disposed and cured on at least a portion of the second major surface of the substrate. The curable ink composition has been described above and comprises: a (meth)acrylate-based component that is capable of curing to form a (meth)acrylate-based matrix; and a water chelating component. As described above, the (meth)acrylate-based component comprises: at least one aromatic (meth)acrylate; at least one multifunctional (meth)acrylate, the at least one multifunctional (meth)acrylate having a heteroaromatic group, a fused aromatic group, a heteroalkylene group, or a group containing both a heteroalkylene group and an aromatic group; and a photoinitiator. Each of these components is described in detail above. The water chelating component comprises a reaction pair that is an epoxy functional portion and an anhydride functional portion. The water chelating component comprises: at least one co-curable portion comprising an epoxy-functional (meth)acrylate, an anhydride-functional ethylenically unsaturated compound, or both; and optionally a non-curable epoxy portion, a non-curable anhydride portion, or both. The curable ink composition is inkjet printable, has a viscosity of 30 centipoise or less at a temperature of room temperature to 35°C, and is solvent-free.

[0075] The cured organic layer can have various thicknesses. Typically, the cured organic layer is a thin layer. As mentioned above, the curable ink composition can be arranged on the substrate using a variety of techniques, including but not limited to printing techniques, wherein inkjet printing is particularly suitable for forming a thin layer. In some embodiments, the thickness of the cured organic layer is 1 micron to 16 microns.

[0076] As mentioned above, the cured organic layer is adjacent to the second major surface of the substrate. A variety of substrates are suitable. In some embodiments, the article includes an electronic device, and the substrate includes an optical electronic component. The example of a suitable optical electronic component includes at least one of an organic light emitting diode, a quantum dot light emitting diode, a micro light emitting diode, or a quantum nanorod electronic device. The example of a particularly suitable optical electronic component is an organic light emitting diode (OLED). The cured organic layer may be disposed on the optical electronic component, or one or more intermediate layers may be present.

[0077] Also disclosed herein are methods for preparing articles, particularly optical articles. These methods include: providing a substrate having a first major surface and a second major surface; providing a curable ink composition; disposing the curable ink composition on the second major surface of the substrate to form a curable layer; and curing the curable layer to form a cured organic layer. The cured organic layer has a refractive index of 1.55 or greater and is optically clear. Typically, the cured organic layer has a thickness of 1 micrometer to 16 micrometers.

[0078] In many embodiments, disposing the curable ink composition on the second major surface of the substrate to form a curable layer comprises printing, especially inkjet printing. As described above, inkjet printing has a variety of desirable features that make it particularly suitable for preparing curable layers, including the ability to deposit precise patterns on complex substrates and form uniform coatings.

[0079] The curable ink composition used in the method is the curable ink composition described above. Since the curable ink composition contains a photoinitiator, the curing of the curable layer includes photocuring. The nature of the photoinitiator determines the curing conditions, i.e. the wavelength of the radiation used, the duration of exposure to the radiation, etc.

[0080] exist Figure 1 An example of an article of manufacture of the present disclosure is shown in FIG. Figure 1 An OLED device is shown. The OLED device has a base layer 110 with an OLED 120 disposed thereon, an inorganic barrier layer (typically aluminum oxide) 130 , a cured organic layer of the present disclosure 140 , and another inorganic barrier layer (typically aluminum oxide) 150 .

[0081] Example

[0082] These examples are for illustrative purposes only and are not intended to limit the scope of the appended claims. Unless otherwise indicated, all parts, percentages, ratios, etc. in the examples and the remainder of the specification are by weight. The following abbreviations are used: mm = millimeter; cm = centimeter; nm = nanometer; mL = milliliter; RPM = revolutions per minute; sec = second; min = minute; J = joule; W = watt CTH = controlled temperature and humidity. The terms "weight %, "by weight %" and "wt %" are used interchangeably.

[0083] Materials used in the examples

[0084]

[0085]

[0086] Test Method

[0087] Test Method 1: Film Preparation and Weight Change Test

[0088] A hexagonal groove (20 mm high x 5 mm wide x 2 mm thick) was carved into a Teflon block. The groove was filled with approximately 0.2 mL of the Example composition or the Comparative Example composition. The Teflon block was placed in a small chamber connected to nitrogen. The top side of the chamber was clear glass. The chamber was purged with nitrogen for 2 minutes. A 395 nm FJ800 UV LED lamp (Phoseon, OR, USA) was then placed on the top glass side of the chamber and the sample was exposed to 0.5 W / cm 2 Lasts for 20 seconds (total dose 10J / cm 2 ). Use a rod or needle to peel the cured film off the Teflon block. Repeat this process to prepare 5 samples.

[0089] The cured film was baked at 85°C for 2 days to remove residual monomers or moisture and weighed (A). The film was kept in an oven set at 85°C and 85% relative humidity for 7 days and weighed (B). The film was baked at 85°C for another 2 days to remove physically adsorbed moisture and weighed (C). The water absorption was calculated according to the following equation:

[0090] Maximum water absorption % = (BA) / A×100

[0091] Irreversible water absorption % = (CA) / A×100

[0092] Test Method 2: pH Measurement of Liquid Samples

[0093] Fill a 50 mL glass bottle (30 mm in diameter, 110 mm in height) with about 30 mL of freshly prepared Examples or Comparative Examples. Measure the pH of the liquid using an S400 pH meter (Mettler Toledo, OH, USA) equipped with a DGI116 organic solvent probe. Immerse the probe in the vial, wait 2 minutes and record the pH value.

[0094] To another 50 mL glass bottle, add about 30 mL of the Example or Comparative Example and 1.5 mL of distilled water. Place the vial in a water bath set at 50° C. for 7 days. Measure the pH of the aged sample in the same manner.

[0095] Test method 3: FT-IR

[0096] The chemical groups of the cured film were identified by attenuated total reflectance on a Thermo iS50 FT-IR (Thermo Fisher, MA, USA). The cured film before and after the water absorption chamber test of test method 1 was pressed on a diamond prism and scanned 32 times at a resolution of 4 nm to obtain an IR spectrum. A drop of the liquid sample before and after the water absorption test of test method 2 was dropped on a diamond prism and its IR spectrum was obtained in the same way.

[0097] Test Method 4: Refractive Index

[0098] About 0.2 mL of the example was dropped onto a clean glass substrate. A doctor blade was used to obtain a film about 5 μm thick. The film was cured under 395 nm LED light (0.6 W / cm 2 5 seconds = 3J / cm 2 The refractive index of the cured films was measured at a wavelength of 450 nm on a 2010M prism coupler (Metricon, NJ, USA).

[0099] Test Method 5: Viscosity

[0100] About 20 mL of the example was used to fill the cylinder maintained at 25° C. A Brookfield viscometer LV-1 spindle (Ametek, PA, USA) was immersed in the cylinder and rotated at 6 rpm to obtain the viscosity of the liquid.

[0101] Test method 6: OLED life test

[0102] Strong cavity top emitting blue OLED samples were fabricated using a SUNIC deposition system (SUNIC, Suwon, Korea). All layers in the OLED stack were thermally evaporated under vacuum. Figure 1 As shown, the thin film encapsulation structure consists of a bottom Al2O3 film, an organic ink layer, and a top Al2O3 film. The Al2O3 layer was RF sputtered using a SUNIC deposition system, and the organic ink was inkjet printed in a nitrogen-filled glove box (thickness 5 μm).

[0103] exist Figure 1 In the embodiment, the OLED 120 is located on the base layer 110 and has an Al 2 O 3 film 130 , an organic ink layer 140 and a top Al 2 O 3 film 150 .

[0104] The OLED performance was first characterized before the life test. The current-voltage-brightness characteristics were recorded using a computer-controlled Keithley 2400 source meter and a calibrated PR650 spectrophotometer. Each OLED sample had 4 active areas (or pixels) where light emission was measured. Images of the pixels were taken using a Nikon microscope. Pixel images were taken for the first time before the life test and accelerated reliability test.

[0105] The OLED samples were then loaded into a life tester. Life tests were performed in an OLA300 life tester (S-fac, Daejon, Korea) at room temperature and relative humidity. Each OLED sample was loaded into a test cell that applied a constant current to all four pixels during the entire test and measured the voltage and light output simultaneously. The current was selected and applied to the OLED sample so that the initial brightness of all pixels was about 100 cd / m 2 Monitor the brightness decay of each pixel and record the time required for the brightness to drop to a certain percentage of the initial brightness. For example, LT 90 = The time it takes for the brightness to drop by 10% or to reach 90% of the initial brightness. LT 70 = The time it takes for the brightness to drop by 30% or to reach 70% of the initial brightness.

[0106] After the 7-day life test, the sample was removed from the tester. Images of all pixels were taken a second time. Then, the sample was immediately placed in a humidity chamber with a preset temperature of 85°C and a relative humidity of 85%. After 24 hours, the sample was removed from the chamber and an image of the pixels was taken for the last time.

[0107] Test Method 7: Calcium WVTR Test

[0108] like Figure 2A similar sample is prepared as shown. On a glass plate 210, metallic calcium 220 is vapor deposited under vacuum to a thickness of 100 nanometers. Then, aluminum oxide 130, a cured organic layer 140 of the present disclosure, and another aluminum oxide layer 150 are deposited or printed. The sample is placed in a CTH chamber (85°C, 85% RH). The optical density is measured periodically. The water vapor transmission rate (WVTR) is calculated from this.

[0109] Example

[0110] A mixture of BPMA, TMPTA, BAPO and getter components indicated in Table 1 was stirred at 300 rpm for 10 minutes at room temperature in a polyethylene bottle placed under sodium light or white LED light, rather than under a fluorescent lamp emitting UV light. Unless otherwise stated, all parts in the examples and the rest of the specification are in grams.

[0111] Table 1 .

[0112]

[0113]

[0114] Water absorption and pH measurements were performed according to the test methods described above. The results are shown in Table 2 below.

[0115] Table 2

[0116]

[0117] Comparative Example

[0118] The mixture of BPMA, TMPTA, BAPO and getter components indicated in Table 3 was stirred at room temperature at 300 rpm for 10 minutes in a polyethylene bottle placed under sodium light or white LED light, rather than under a fluorescent lamp emitting ultraviolet light. Unless otherwise stated, all parts in the examples and the rest of this specification are in grams.

[0119] Table 3

[0120]

[0121]

[0122] Water absorption and pH measurements were performed according to the test methods described above. The results are shown in Table 4 below.

[0123] Table 4

[0124]

[0125] Predictive Embodiments

[0126] The mixture of BPMA, TMPTA, BAPO and moisture sequestering component indicated in Table 5 was stirred at room temperature at 300 rpm for 10 minutes in a polyethylene bottle placed under sodium light or white LED light, not under fluorescent light emitting ultraviolet light. Unless otherwise stated, all parts in the examples and the rest of this specification are in grams.

[0127] Material Description

[0128]

[0129] Table 5

[0130] Hypothetical example BPMA TMPTA BAPO MAAH ECHMMA A-1 A-2 E-1 E-2 E-3 E-4 sum P1 25.3 25.0 2.0 0 29.4 20.3 0 0 0 0 0 102.0 P2 12.3 25.0 2.0 0 29.4 0 33.3 0 0 0 0 102.0 P3 39.7 25.0 2.0 11.6 0 0 0 23.7 0 0 0 102.0 P4 41.9 25.0 2.0 11.6 0 0 0 0 21.5 0 0 102.0 P5 42.5 25.0 2.0 11.6 0 0 0 0 0 20.9 0 102.0 P6 44.4 25.0 2.0 11.6 0 0 0 0 0 0 19.0 102.0

Claims

1. A curable ink composition, comprising: A (meth)acrylate-based component, the (meth)acrylate-based component being capable of curing to form a (meth)acrylate-based matrix, the (meth)acrylate-based component comprising: at least one aromatic (meth)acrylate; at least one multifunctional (meth)acrylate having a heteroaromatic group, a condensed aromatic group, a heteroalkylene group, or a group containing both a heteroalkylene group and an aromatic group; and a photoinitiator; and A water chelating component, the water chelating component is a reactive pair, the reactive pair is an epoxy functional portion and an anhydride functional portion, wherein The water chelating component comprises: at least one co-curable moiety comprising an epoxy-functional (meth)acrylate, an anhydride-functional ethylenically unsaturated compound, or both; and optional non-curable epoxy moieties, non-curable anhydride moieties, or both; Such that upon curing, the ink composition forms a (meth)acrylate matrix, wherein the (meth)acrylate matrix comprises epoxy functional groups, anhydride functional groups, or both, and wherein the (meth)acrylate matrix is ​​capable of water chelation, whereby anhydride groups from the co-curable portion or the non-curable portion, upon reaction with water, form acid functional groups, which react with epoxy functional groups from the co-curable portion or the non-curable portion, thereby producing irreversible water absorption of the (meth)acrylate-based matrix, wherein the ink composition is inkjet printable, has a viscosity of 30 centipoise or less at a temperature between room temperature and 35° C., and is solvent-free, and wherein the ink composition, when set and cured, has a refractive index of 1.55 or greater, is optically clear, and has an irreversible water absorption of at least 2 wt. % after exposure to 85° C. / 85% relative humidity for 7 days.

2. The curable ink composition according to claim 1, wherein the at least one aromatic (meth)acrylate comprises a monofunctional (meth)acrylate compound of Formula I: wherein at least one R1 comprises an aromatic substituent; t is an integer from 1 to 4; and R2 is hydrogen or methyl.

3. The curable ink composition according to claim 2, wherein the at least one R1 group include: or * -S-Ar, Each of these * represents the point of attachment to the aromatic ring of Formula I; and Ar is a substituted or unsubstituted phenyl group, a condensed aromatic group, or a phenyl group or a substituted phenyl group or a substituted phenyl group to which two or more alkyl groups are linked.

4. The curable ink composition of claim 1, wherein the at least one multifunctional (meth)acrylate comprises a compound of Formula II: (H 2 C=CR2-(CO)-O-) n A Formula II Wherein R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and A is an n-valent group, including a heteroaromatic group, a condensed aromatic group, a heteroalkylene group, or a group containing both a heteroalkylene group and an aromatic group; and n is an integer of 2 or more.

5. The curable ink composition of claim 1 , wherein at least a portion of the epoxy-functional moieties of the reactive pair of the water-chelating component comprises an epoxy-functional (meth)acrylate of Formula III: H 2 C=CR2-(CO)-O-CH 2 -B Formula III Wherein R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and B is a divalent group comprising an epoxy-functional alkylene or heteroalkylene group.

6. The curable ink composition of claim 1 , wherein at least a portion of the anhydride functional portion of the reactive pair of the water chelating component comprises an anhydride functional ethylenically unsaturated group comprising: (Meth)acrylate functional anhydride of formula IV: H 2 C=CR2-(CO)-O-(CO)-R2C=CH 2 Formula IV Wherein R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; or Maleic anhydride.

7. The curable ink composition of claim 1, wherein the water-chelating component further comprises a non-curable anhydride, the non-curable anhydride comprising an aromatic anhydride or an aliphatic anhydride.

8. The curable ink composition of claim 1, wherein the water chelating component comprises a co-curable epoxy functional (meth)acrylate and a non-curable anhydride.

9. The curable ink composition according to claim 8, wherein the epoxy functional (meth)acrylate comprises 0.075 wt% to 45 wt% of the total weight of the curable ink composition.

10. The curable ink composition according to claim 8, wherein the non-curable anhydride comprises 0.005 wt% to 18 wt% of the total weight of the curable ink composition.

11. A product, wherein the product include: a substrate having a first major surface and a second major surface; a cured organic layer adjacent to at least a portion of the second major surface of the substrate, wherein the cured organic layer comprises a cross-linked (meth)acrylate-based matrix, has a refractive index of 1.55 or greater, and is optically clear, the cross-linked (meth)acrylate-based matrix containing at least one of epoxy functional groups, anhydride functional groups, or both; and wherein the cured organic layer optionally comprises a non-curable epoxy portion, a non-curable anhydride portion, or both, such that the cured organic layer has a water chelating component, the water chelating component is a reactive pair, the reactive pair is an epoxy functional portion and an anhydride functional portion, whereby the anhydride groups cured into the (meth)acrylate matrix or the non-curable portion form acid functional groups when reacting with water, and the acid functional groups react with the epoxy functional groups cured into the (meth)acrylate matrix or the non-curable portion, wherein at least one of the epoxy functional groups or the anhydride functional groups is cured into the (meth)acrylate matrix, thereby producing an irreversible water absorption of the (meth)acrylate-based matrix, wherein the irreversible water absorption is at least 2 weight percent after exposure to 85°C / 85% relative humidity for 7 days.

12. The article of claim 11, wherein the cured organic layer comprises a curable ink composition that has been disposed and cured on at least a portion of the second major surface of the substrate, The curable ink composition comprises: A (meth)acrylate-based component, the (meth)acrylate-based component being capable of curing to form a (meth)acrylate-based matrix, the (meth)acrylate-based component comprising: at least one aromatic (meth)acrylate; at least one multifunctional (meth)acrylate having a heteroaromatic group, a fused aromatic group, a heteroalkylene group, or a group containing both a heteroalkylene group and an aromatic group; and a photoinitiator; and A water chelating component, the water chelating component being a reactive pair, the reactive pair being an epoxy functional moiety and an anhydride functional moiety, wherein the water chelating component comprises: at least one co-curable moiety comprising an epoxy-functional (meth)acrylate, an anhydride-functional ethylenically unsaturated compound, or both; and optional non-curable epoxy moieties, non-curable anhydride moieties, or both; The curable ink composition is inkjet printable, has a viscosity of 30 centipoise or less at a temperature of room temperature to 35° C., and contains no solvent.

13. The article of claim 11, wherein the cured organic layer has a thickness of 1 micrometer to 16 micrometers.

14. The article of claim 11, wherein the article comprises an electronic device and the substrate comprises an optical electronic component.

15. The article of claim 14, wherein the optical electronic component comprises an organic light emitting diode (OLED), a quantum dot light emitting diode, a micro light emitting diode, or a quantum nanorod electronic device.

16. The article of claim 12, wherein at least a portion of the epoxy-functional moieties of the reactive pair of the water-chelating component comprises an epoxy-functional (meth)acrylate of Formula III: H 2 C=CR2-(CO)-O-CH 2 -B Formula III Wherein R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and B is a divalent group comprising an epoxy-functional alkylene or heteroalkylene group.

17. The article of claim 12, wherein the anhydride functional portion of the reactive pair of the water chelating component comprises an anhydride functional ethylenically unsaturated group comprising: (Meth)acrylate functional anhydride of formula IV: H 2 C=CR2-(CO)-O-(CO)-R2C=CH 2 Formula IV Wherein R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; or Maleic anhydride; or A non-curable anhydride, wherein the non-curable anhydride comprises an aromatic anhydride or an aliphatic anhydride.

18. The article of claim 12, wherein the water chelating component comprises a co-curable epoxy functional (meth)acrylate and a non-curable anhydride.

19. The article of claim 18, wherein the epoxy-functional (meth)acrylate comprises 0.075 wt% to 45 wt% of the total weight of the curable ink composition.

20. The article of claim 18, wherein the non-curable anhydride comprises 0.005 wt% to 18 wt% of the total weight of the curable ink composition.

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