Curable ink composition with water chelating agent

Abstract

A curable ink composition includes a (meth) acrylate-based component and a water chelating component. The ink composition is ink jet printable. The (meth) acrylate-based component includes an aliphatic (meth) acrylate, an aromatic (meth) acrylate or combination, a multifunctional (meth) acrylate, and a photoinitiator. The water chelating component is a reaction pair that is a co-curable epoxy functional moiety and a co-curable anhydride functional moiety. After curing, the ink forms a matrix having an epoxy functional group and an anhydride functional group. The ink composition is optically clear when set and cured and has an irreversible water absorption of at least 2 wt% after exposure to 85 DEG C / 85% relative humidity for 7 days.

Description

Summary of the Invention

[0001] This document discloses a curable ink composition having a water-chelating agent. When cured to form an organic layer, the water-chelating agent polymerizes into the matrix of the organic layer. Articles formed by disposing of the curable ink composition on a substrate and curing the ink to form an organic layer are also disclosed.

[0002] In some embodiments, 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 ink composition is inkjet printable, has a viscosity of 30 centipoise or less at temperatures from room temperature to 35°C, and is solvent-free. The (meth)acrylate-based component comprises at least one aliphatic (meth)acrylate, at least one aromatic (meth)acrylate, or a combination thereof, at least one polyfunctional (meth)acrylate, and a photoinitiator. The water-chelating component is a reaction pair consisting of a co-curable epoxy functional portion and a co-curable anhydride functional portion, wherein the co-curable anhydride functional portion comprises a co-curable aromatic anhydride, a co-curable aliphatic anhydride, or a combination thereof.

[0003] Upon curing, the ink composition forms a (meth)acrylate matrix comprising epoxy and anhydride functional groups, enabling the (meth)acrylate matrix to chelate water. The anhydride functional groups, upon reaction with water, form acid functional groups, which then react with the epoxy functional groups, resulting in irreversible water absorption of the (meth)acrylate-based matrix. The ink composition is optically clear when set and cured and exhibits at least 2% by weight of irreversible water absorption after exposure to 85°C / 85% relative humidity for 7 days.

[0004] Articles formed using the above-described curable ink composition are also disclosed. In some embodiments, the article includes a substrate and a cured organic layer having a first main surface and a second main surface, the cured organic layer being adjacent to at least a portion of the second main surface of the substrate, wherein the cured organic layer comprises a crosslinked (meth)acrylate-based matrix and is optically clear, and is formed by curing the above-described curable ink composition, the crosslinked (meth)acrylate-based matrix containing epoxy functional groups and anhydride functional groups. Attached Figure Description

[0005] This application can be more fully understood by referring to the following detailed description of various embodiments of this disclosure in conjunction with the accompanying drawings.

[0006] Figure 1 This is a cross-sectional view of the article disclosed herein. Detailed Implementation

[0007] Optical devices are becoming increasingly complex, which affects the materials that can be used in them. Specifically, organic polymer materials have been widely used in optical devices; however, they still need to meet stringent requirements and demands for performance.

[0008] For example, thin organic polymer films are desirable for a wide range of applications in optical devices, such as adhesives, protective layers, and spacers. As products become more complex, the physical requirements for these layers increase. For instance, as optical devices become more compact, they often include additional layers, leading to a growing need for thinner layers. Simultaneously, the thinner layers also require greater precision. For example, thin spacers (1 micrometer thick) need to be flat and free of gaps and pores to provide proper spacing. This necessitates depositing organic layers in a precise and consistent manner.

[0009] In addition, these layers must not only fulfill their physical functions (adhesion, protection, spacing, etc.) but also provide the required optical properties. Among these properties, refractive index is becoming increasingly important. 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, then the light can be refracted. Therefore, to minimize this refraction, matching the refractive indices of the layers within a multilayer article is desirable.

[0010] An example of an optical device utilizing thin-film layers is an OLED (Organic Light-Emitting Diode) device. Specifically, organic light-emitting devices are susceptible to degradation due to the permeation of certain liquids and gases, such as water vapor and oxygen. To reduce the permeability of these liquids and gases, a barrier coating is applied to the OLED device; this 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.

[0011] Typically, organic thin film layers are solidified organic substrates. Because these layers are very thin, barrier layers can be difficult to prevent water transport through them, especially in humid environments, for example. Water can be harmful to devices such as OLEDs, so it is desirable for barrier layers to have enhanced water migration prevention capabilities. One approach is to make the organic substrate absorb water. Various techniques can be used to make organic thin film layers water-absorbing to prevent water from passing through them. However, many of these techniques can alter the desired and necessary properties of the organic thin film layer, such as optical properties. Additionally, many materials commonly used to absorb water in organic substrates (often referred to as water scavengers) can themselves release small molecules that are harmful to the organic layer and / or the device. For example, oxazolidine or alkoxysilanes can be used as water scavengers, but these molecules form ketones and alcohols, respectively, and these small molecules are problematic materials generated within the organic thin film layer. Other water scavenging techniques use particulate particles as desiccants to absorb water, such as calcium oxide or nanoclay, as described in U.S. Patent Publication No. 2020 / 0181460. However, these particles are often large enough to scatter light, i.e., the particles are larger than the wavelength of visible light. These particulate methods are not suitable for layers used in display products where light needs to pass through, thus requiring the layer to be optically transparent. Therefore, methods for removing water from organic thin film layers are still necessary.

[0012] Previously, a water removal method, specifically a water-chelating method, was described in U.S. Serial No. 63 / 336363, filed April 29, 2022, entitled "Curable High Refractive Index Ink Compositions With Water-Sequestration Agents." This chelation method involves a two-step process involving an anhydride / epoxy reaction pair. The method utilizes an anhydride functional group that reacts with water to form an acid group, and this acid group reacts with an epoxy group. At least one of the anhydride and epoxy groups is cured into a (meth)acrylate matrix, thus the result of this two-step reaction is the trapping or chelation of water within the matrix without the formation of any small molecules.

[0013] This disclosure uses a similar method, but in the current water chelation system, both the epoxy functional portion and the anhydride functional portion of the reaction pair are co-curable, and the co-curable anhydride functional portion comprises co-curable aromatic anhydrides, co-curable aliphatic anhydrides, or combinations thereof. Co-curable monomers are advantageous for a variety of reasons. Ideal characteristics of using co-curable monomers include minimizing degassing of the cured layer while maximizing the mechanical properties of the cured layer.

[0014] The term "(meth)acrylate" refers to an acrylate or methacrylate monomer of an alcohol. Acrylates and methacrylate monomers or oligomers are collectively referred to herein as "(meth)acrylate". Materials referred to as "(meth)acrylate functionalized" are materials containing one or more (meth)acrylate groups. The term "(meth)acrylate-based" refers to a composition or layer containing (meth)acrylate and may contain additional (meth)acrylate co-reacting materials.

[0015] The terms “room temperature” and “ambient temperature” are used interchangeably, referring to temperatures in the range of 20°C to 25°C.

[0016] As used in this article, the term "adjacent" in the context of two floors means that the two floors are adjacent to each other and there is no intervening opening space between them. They may be in direct contact with each other (e.g., stacked together) or there may be an intervening floor.

[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 having multiple repeating units attached to a monomer. The term “polymer” is used to describe the material obtained by a polymerization reaction.

[0018] The term "alkyl" refers to a monovalent group that is an alkane group, where the alkane is a saturated hydrocarbon. Alkyl groups can be straight-chain, branched, cyclic, or combinations thereof, and typically have 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 consisting of an aromatic ring and a carbocyclic ring. An aryl group can have one to five rings attached to or fused with an aromatic ring. Other ring structures can be aromatic, non-aromatic, or combinations thereof. Examples of aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, anthryl, naphthyl, acenaphthenic, anthraquinone, phenanthryl, anthracenyl, pyrene, peryl, and fluorenyl.

[0020] The term "alkylene" refers to a divalent group that is a group of an alkane. Alkylenes can be straight-chain, branched, cyclic, or a combination thereof. Alkylenes typically have 1 to 20 carbon atoms. In some embodiments, alkylenes contain 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. The center of the alkylene group can 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 linked by a thio group, an oxygen group, or -NR-, wherein R is an alkyl group. Heteroalkylene groups can be straight-chain, branched, cyclic, substituted with alkyl groups, or combinations thereof. Some heteroalkylene groups are polyoxyethylenes, wherein the heteroatom is an oxygen atom, such as, for example... .

[0022] The terms “free radical polymerizable” and “olefinic unsaturated” are used interchangeably and refer to reactive groups containing carbon-carbon double bonds that can be polymerized via a free radical polymerization mechanism.

[0023] Unless otherwise specified, "optically transparent" means a layer, film, or article that has high light transmittance over at least a portion of the visible spectrum (about 400 nm to about 700 nm). Typically, optically transparent layers, films, or articles have a light transmittance of at least 80%.

[0024] Unless otherwise specified, "optically clear" means a layer, film, or article that has high transmittance and exhibits low haze 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 visible light transmittance of at least 85%, usually at least 90%, and a haze of 5% or less, usually 2% or less.

[0025] This document discloses curable compositions that are printable and are therefore described as inks. Curable compositions are not necessarily used as inks; that is, they are not necessarily printed and then cured. Curable compositions can be delivered to a substrate surface in a variety of ways, but they are capable of being printed. The terms "curable composition" and "ink" are used interchangeably in this disclosure. Specifically, the printable compositions of this disclosure are generally capable of being inkjet printed, meaning they have suitable viscosity and other properties for inkjet printing. The term "inkjet printable" is not a process description or limitation but a material description, meaning that the curable composition can be inkjet printed, not that the composition must have been inkjet printed. This is similar to the expression "thermally melt processable," meaning that the composition can be thermally melt processable, but not that the composition has been thermally melt processable.

[0026] 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 aliphatic (meth)acrylate, at least one aromatic (meth)acrylate, or both; at least one polyfunctional (meth)acrylate; and a photoinitiator. The (meth)acrylate-based component facilitates the formation of a crosslinked matrix.

[0027] The water-chelating component comprises a reaction pair having an epoxy functional moiety and an anhydride functional moiety. The water-chelating component comprises a co-curable epoxy functional moiety and a co-curable anhydride functional moiety, wherein the co-curable anhydride functional moiety comprises a co-curable aromatic anhydride, a co-curable aliphatic anhydride, or a combination thereof. As described above, the water chelation of the reaction pair occurs through the reaction of water with the anhydride group to form an acid, wherein the anhydride group is cured into a (meth)acrylate matrix. The acid can then react with the epoxy group to form additional crosslinking sites and secondary hydroxyl groups. Since the epoxy group is also cured into the (meth)acrylate matrix, water is chemically converted into a chemical substance bound to the (meth)acrylate matrix without generating small molecule byproducts. This process is called water chelation because free water molecules are incorporated into the matrix through a chemical reaction within the cured film, resulting in irreversible water absorption.

[0028] The ink composition possesses a variety of desired properties, including solvent-free and inkjet printability, a viscosity of 30 centipoise or less at temperatures ranging from room temperature to 35°C, and the formation of an optically clear organic layer upon setting and curing. Additionally, the cured organic layer exhibits an irreversible water absorption rate of at least 2% by weight after exposure to 85°C / 85% relative humidity for 7 days. In some embodiments, the cured ink may possess other desired properties, such as a refractive index of 1.50 or greater.

[0029] The curable ink composition comprises a (meth)acrylate-based component and a water-chelating component. As mentioned above, the (meth)acrylate-based component comprises: at least one aliphatic (meth)acrylate, at least one aromatic (meth)acrylate, or a combination thereof; at least one polyfunctional (meth)acrylate; and a photoinitiator. The selection of these components depends on the desired properties of the organic layer formed from the curable composition. In some embodiments, a high refractive index may be desired, while in other embodiments, the refractive index may be less important. In embodiments where a high refractive index is required, aromatic monomers are typically particularly suitable.

[0030] A wide range of aliphatic (meth)acrylates are suitable. If used, in some embodiments, at least one aliphatic (meth)acrylate comprises a monofunctional (meth)acrylate compound of formula I:

[0031] Wherein R3 is an alkyl group having 2 to 32 carbon atoms, and R2 is hydrogen or methyl. Examples of suitable aliphatic (meth)acrylates include butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, benzyl (meth)acrylate, stearyl (meth)acrylate, hexadecyl (meth)acrylate, and heptadecanyl (meth)acrylate. Particularly suitable aliphatic (meth)acrylates are lauryl acrylates.

[0032] A wide variety of aromatic (meth)acrylate monomers are suitable for use in the curable ink compositions disclosed herein. Typically, these aromatic (meth)acrylate monomers are monofunctional. A single monofunctional (meth)acrylate monomer or a mixture of monofunctional (meth)acrylate monomers may be used. Generally, at least one monofunctional (meth)acrylate comprises a compound of formula II (as shown below):

[0033] Formula II

[0034] At least one of R1 includes an aromatic substituent, t is an integer from 1 to 4, and R2 is hydrogen or methyl.

[0035] A wide variety of aromatic substituents are applicable to 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 linked to two or more alkyl groups.

[0036] Therefore, one or more R1 groups may include various aromatic substituents, such as:

[0037] Aromatic substituent R1 is typically bonded to the aromatic ring of the benzyl group via at least one divalent (e.g., alkylene or ether) linking group. In some embodiments, aromatic substituent R1 is bonded to the aromatic benzyl ring via two or more divalent (e.g., alkylene or ether) linking groups. Indicates the attachment point to the aromatic ring of Formula II; and Ar is a substituted or unsubstituted phenyl group, a fused aromatic group, or a phenyl or substituted phenyl group connected to two or more alkyl groups.

[0038] In some advantageous embodiments, t is 1. The representative structure of Equation II therefore includes:

[0039] Where t is 1 and R1 group In some embodiments of -S-Ar, the compound may have the general formula structure of formula IIA:

[0040] Wherein R2 is H or CH3, X is O, S or a single bond, Q is O, S, SiR2 (where R is an alkyl group), carbonyl group (C=O), amino group NR (where R is hydrogen or alkyl), or SO2 group, n is in the range of 0 to 10 (e.g., 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 with a hydroxyl group).

[0041] Various aromatic alcohols obtained from Sigma-Aldrich can be used as starting materials, which can be converted into (meth)acrylates by reacting such materials with (meth)acrylic acid or (meth)acrylic acid derivatives. Particularly suitable monofunctional (meth)acrylate monomers include biphenyl methacrylate (where R1 is a phenyl group), which is commercially available as MIRAMER M1192 or MIRAMER M1192H from Miwon Specialty Chemicals, Columbia, SC, South Carolina.

[0042] The amount of (meth)acrylate monomers used in the curable ink composition can vary. "(meth)acrylate monomer" refers to all aliphatic and / or aromatic (meth)acrylate monomers present if more than one aliphatic (meth)acrylate, more than one aromatic (meth)acrylate monomer, or a combination of aliphatic and aromatic monomers is used. In some embodiments, the curable ink composition contains at least 20% by weight or more of (meth)acrylate monomers. In other embodiments, the curable ink composition contains up to 65% by weight of (meth)acrylate monomers. As mentioned above, typically, the (meth)acrylate monomers are monofunctional (meth)acrylates.

[0043] As mentioned above, a high refractive index may be a desirable feature in some embodiments. In these embodiments, the (meth)acrylate monomers are typically aromatic (meth)acrylate monomers with 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 monomers have 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 not greater than 1.65.

[0044] The curable ink compositions disclosed herein also comprise at least one polyfunctional (meth)acrylate of the following general formula III:

[0045] Wherein R2 is hydrogen or methyl, (CO) is a carbonyl group C=O, A is an n-valent group comprising an alkylene group, 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 polyfunctional (meth)acrylate is bifunctional (n=2), and in other embodiments, the polyfunctional (meth)acrylate is trifunctional (n=3). Higher functional polyfunctional (meth)acrylates are also possible.

[0046] Examples of heteroaromatic groups include thiadiazole, thiazolium, and thiophene groups. Examples of fused aromatic groups include naphthyl, anthracene, and fluorenyl groups. Examples of heteroalkylene groups include polyoxyethylene, polyoxypropylene, and polysulfide groups. Examples of groups containing both heteroalkylene and aromatic groups include groups having a bifunctional alkylene group with 2 to 10 carbon atoms and 1 to 10 repeating units, and containing a bifunctional aromatic group such as phenylene, benzylidene, or linked benzylidene groups.

[0047] Examples of usable multifunctional (meth)acrylates include, but are not limited to, di(meth)acrylates, tri(meth)acrylates, and tetra(meth)acrylates. Usable di(meth)acrylates include, for example, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, alkoxylated 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, cyclohexanediol di(meth)acrylate, alkoxylated cyclohexanediol diacrylate, ethoxylated bisphenol A di(meth)acrylate, neopentyl glycol diacrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and urethane di(meth)acrylate. Available tri(meth)acrylates include, for example, trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, tri(2-hydroxyethyl) isocyanurate triacrylate, and pentaerythritol triacrylate.

[0048] In some implementations, it may be desirable to use polyfunctional (meth)acrylate monomers with a functionality greater than 2. A 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.

[0049] Because polyfunctional (meth)acrylate monomers have a functionality of 2 or greater, these monomers are used as crosslinking agents to crosslink the resulting polymer. The amount of polyfunctional (meth)acrylate monomers is controlled to prevent the polymer from becoming rigid. Typically, curable ink compositions contain less than 65% by weight of one or more polyfunctional (meth)acrylate monomers and at least 10% by weight of one or more polyfunctional (meth)acrylate monomers. In some embodiments, one or more polyfunctional (meth)acrylate monomers are present in an amount from 15% by weight to 35% by weight.

[0050] The (meth)acrylate component also contains at least one photoinitiator, meaning the initiator is activated by light, typically ultraviolet (UV) light, but other light sources may also be used with appropriate selection of the initiator (such as visible light initiators, infrared light initiators, etc.). UV photoinitiators are typically 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, and IRGACURE TPO-L, commercially available from BASF, Charlotte, NC, North Carolina.

[0051] Generally speaking, the photoinitiator is used in amounts of 0.01 to 10 parts by weight, and more typically 0.1 to 2.0 parts by weight, relative to 100 parts by weight of the total reaction components.

[0052] The curable ink composition also contains a water-chelating component. As described above, the water-chelating component is an anhydride / epoxy group reaction pair. The components of the reaction pair can be co-cured with the aforementioned (meth)acrylate component. This means that each of the anhydride / epoxy group reaction pairs is a compound having an olefinically unsaturated group, such that it co-cures with the (meth)acrylate component and becomes part of the (meth)acrylate matrix.

[0053] The reaction pair of the water-chelated component contains at least one epoxy functional portion. The epoxy functional portion is a co-curable portion. Epoxy-functionalized (meth)acrylates are particularly suitable co-curable epoxy portions. Suitable epoxy (meth)acrylates include those described by Formula IV:

[0054] Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and B is a divalent group containing an epoxy-functionalized alkylene or heteroalkylene group. Examples of suitable epoxy (meth)acrylates include 3,4-epoxycyclohexylmethyl methacrylate TTA-15, commercially available from Jiangsu Tetra New Material Technology Co., Ltd. Oxybutanes are also suitable monomers, such as those from Tronly, Jiangsu, China. An example of a suitable oxybutane-functionalized monomer is 3-ethyl-3-methacryloyloxymethyloxybutane.

[0055] The reaction pair of the water-chelated component also includes at least one anhydride functional moiety. This at least one anhydride functional compound is a co-curable anhydride.

[0056] In some embodiments, the anhydride is a copolymerizable anhydride containing an aromatic (meth)acrylate functional anhydride of formula V:

[0057] Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; L 1 It is a divalent linker containing an alkylene group having at least 3 carbon atoms; and PA is a substituted or unsubstituted phthalic anhydride group. Phthalic anhydrides have the following general formula:

[0058] In some embodiments, the aromatic anhydride (meth)acrylate comprises the aromatic anhydride (meth)acrylate of formula V:

[0059] Where R2 is hydrogen; (CO) is a carbonyl group C=O; L 1 It is a divalent linker containing a branched alkylene group having 3 carbon atoms or a straight-chain alkylene group having 4 carbon atoms; and PA is an unsubstituted phthalic anhydride group.

[0060] Particularly suitable examples of aromatic anhydride (meth)acrylates include the compounds APTA and ABDA shown below:

[0061]

[0062] In other embodiments, at least a portion of the co-curable anhydride functional portion of the water-chelating component comprises an aliphatic anhydride (meth)acrylate of formula VI:

[0063] Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; each L 2 It is a divalent linker containing an alkylene group or a heteroalkylene group linked by an ester bond.

[0064] In other embodiments, the aliphatic anhydride (meth)acrylate comprises the aliphatic anhydride (meth)acrylate of formula VI:

[0065] Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; each L 2It is a divalent linker containing two alkylene groups having at least two carbon atoms linked by an ester bond.

[0066] A particularly suitable example of an aliphatic anhydride (meth)acrylate is the compound AHDA shown below:

[0067] The amount of each component of the water-chelated component can vary widely. Typically, the co-curable epoxy functional portion is present in an amount of 0.075% to 45% by weight of the total weight of the curable ink composition, and the co-curable anhydride functional portion is present in an amount of 0.075% to 45% by weight of the total weight of the curable ink composition.

[0068] Curable ink compositions may contain additional reactive or non-reactive components, but such components are not essential and should be used with care to ensure they do not impair the final properties of the resulting (meth)acrylate-based polymer. As mentioned above, curable ink compositions are substantially solvent-free or solvent-free. Ink formulations may also contain polymerization inhibitors, light stabilizers (e.g., hindered amines), synergists, antioxidants, catalysts, dispersants, leveling agents, etc., as needed or desired.

[0069] This document also discloses an article of manufacture. In some embodiments, the article of manufacture comprises: a substrate having a first main surface and a second main surface; and a cured organic layer adjacent to at least a portion of the second main surface of the substrate. The cured organic layer comprises a crosslinked (meth)acrylate-based layer and is optically clear, the crosslinked (meth)acrylate-based layer containing epoxy functional groups and anhydride functional groups. A water-chelating component, as described above, is a reaction pair consisting of an epoxy functional portion and an anhydride functional portion. The anhydride groups cured into the (meth)acrylate matrix form acid functional groups upon reaction with water, the acid functional groups reacting with the epoxy functional groups cured into the (meth)acrylate matrix. Because the epoxy and anhydride functional groups are cured into the (meth)acrylate matrix, the above reaction sequence results in an irreversible water absorption rate in the (meth)acrylate-based matrix. In some embodiments, the irreversible water absorption rate is at least 2 wt% after exposure to 85°C / 85% relative humidity for 7 days.

[0070] The cured organic layer is formed by curing a curable ink composition that has been applied and cured on at least a portion of a second primary surface of a substrate. The curable ink composition, as described above, comprises: a (meth)acrylate-based component capable of curing to form a (meth)acrylate-based matrix; and a water-chelating component. As mentioned above, the (meth)acrylate-based component comprises at least one aliphatic (meth)acrylate, at least one aromatic (meth)acrylate, or both; at least one polyfunctional (meth)acrylate; and a photoinitiator. Each of these components is described in detail above. The water-chelating component comprises a reaction pair consisting of an epoxy functional portion and an anhydride functional portion. The water-chelating component comprises epoxy-functionalized (meth)acrylate and anhydride-functionalized (meth)acrylate compounds. The curable ink composition is inkjet printable, has a viscosity of 30 centipoise or less at temperatures from room temperature to 35°C, and is solvent-free.

[0071] The cured organic layer can have various thicknesses. Typically, the cured organic layer is a thin layer. As mentioned above, a variety of techniques can be used to apply the curable ink composition to the substrate, including but not limited to printing techniques, with inkjet printing being particularly suitable for forming thin layers. In some embodiments, the thickness of the cured organic layer ranges from 1 micrometer to 16 micrometers.

[0072] As described above, the cured organic layer is adjacent to the second main surface of the substrate. Various substrates are suitable. In some embodiments, the article of manufacture includes an electronic device, and the substrate includes an optoelectronic component. Examples of suitable optoelectronic components include at least one of organic light-emitting diodes (OLEDs), quantum dot OLEDs, micro OLEDs, or quantum nanorod electronic devices. A particularly suitable example of an optoelectronic component is an organic light-emitting diode (OLED). The cured organic layer may be disposed on the optoelectronic component, or one or more intervening layers may be present.

[0073] This document also discloses methods for preparing articles, particularly optical articles. These methods include: providing a substrate having a first main surface and a second main surface; providing a curable ink composition; disposing the curable ink composition on the second main surface of the substrate to form a curable layer; and curing the curable layer to form a cured organic layer. Typically, the cured organic layer has a thickness of 1 micrometer to 16 micrometers.

[0074] In many embodiments, setting a curable ink composition on a second primary surface of a substrate to form a curable layer includes printing, particularly inkjet printing. As mentioned above, inkjet printing has several desirable characteristics that make it particularly suitable for preparing curable layers, including the ability to deposit precise patterns on complex substrates and form a uniform coating.

[0075] The curable ink composition used in this method is the aforementioned curable ink composition. Since the curable ink composition contains a photoinitiator, the curing of the curable layer includes photocuring. The properties of the photoinitiator determine the curing conditions, namely the wavelength of radiation used, the duration of exposure to radiation, etc.

[0076] exist Figure 1 Examples of articles of the present disclosure are shown in the figure. Figure 1 An OLED device 100 is shown. The OLED device has a base layer 110, on which an OLED 120 is disposed. An inorganic barrier layer (typically alumina) 130, a cured organic layer 140 of this disclosure, and another inorganic barrier layer (typically alumina) 150 are also shown.

[0077] Example

[0078] These embodiments are for illustrative purposes only and are not intended to limit the scope of the appended claims. Unless otherwise specified, all parts, percentages, ratios, etc., in the embodiments and the remainder of the specification are by weight. The following abbreviations are used: cm = centimeter; mm = millimeter; nm = nanometer; mL = milliliter; RPM = revolutions per minute; g = gram; mTorr = millitor; Pa = Pascal; MPa = megapascal; min = minute; s = second; sccm = standard cubic centimeters per minute; W = watt; J = joule; Hz = hertz; RH = relative humidity. The terms "weight%", "by weight%", and "wt%" are used interchangeably.

[0079]

[0080] Test methods

[0081] Viscosity measurement

[0082] The viscosity of the ink was measured using a Brookfield DV2T viscometer. First, the graduated cylinder and mandrel were cleaned with acetone and isopropanol (IPA), then dried with nitrogen. Approximately 17 mL of the ink formulation was filtered through a 1 μm filter and loaded into the cylinder. The shear rate was set to 10 Hz, and the temperature to 25 °C. Viscosity measurements were repeated multiple times, and the average and standard deviation of all data points were recorded in centipoises.

[0083] Glass transition temperature (Tg) and modulus

[0084] The Tg and modulus of the ink were measured using dynamic mechanical analysis (DMA). The ink formulation was UV-cured within a silicone mold (2-inch (5 cm) × 3-inch (8 cm) mold with a 5 mm × 2-inch (5 cm) cutout in the center). The width and thickness of the resulting ink sample strip were measured and recorded using calipers before loading it into the TA Instruments Q800 DMA. The sample was ramped from 25 °C to 150 °C at a rate of 2 °C / min, with a strain of 0.1%. Tg and modulus were extracted from the peak value of the tanδ curve in °C and the storage modulus at 25 °C in MPa, respectively.

[0085] Plasma-enhanced chemical vapor deposition (PECVD) stability

[0086] Used for SiO x The preparation of cured film samples for PECVD stability testing followed the same procedures described in previous chapters. The cured film samples were loaded into the PECVD system chamber within a circle of constant radius from the chamber center, with the film sides facing upwards. The following process parameters were used for all depositions: Tetramethylsilane (TMS) and O2 flow rates were maintained at 100 sccm and 500 sccm, respectively. A plasma Rf power of 1500 W was used, and the deposition pressure was kept constant at 100 mTorr (13 Pa). Deposition time was controlled to vary the layer thickness. Deposition was typically performed for 4 minutes, resulting in a SiO layer 1 ± 0.1 μm thick. A Si wafer was included in each run for later thickness measurement of the SiO layer using an ellipticity meter. The chamber plate temperature was measured using an infrared thermometer prior to deposition. A starting plate temperature of 40 °C was used. After PECVD deposition, the transmittance and haze of the ink samples were characterized using a Haze-gard (BYK-Gardner haze-gard plus) instrument. Ink samples with a haze of <2% passed the test, while samples with a haze of >10% failed.

[0087] Water absorption test

[0088] Cured specimens were prepared according to the description in the section titled "Glass Transition Temperature (Tg) and Modulus" above. First, these specimens were baked at 85°C for 2 days to remove residual moisture and convert any unreacted monomers. Each specimen was weighed (A). Then, the specimens were kept in an oven set at 85°C and 85% relative humidity for 7 days. They were immediately weighed again (B). Finally, the specimens were baked again at 85°C for at least 2 days to remove physically adsorbed moisture, and then weighed (C).

[0089]

[0090] FT-IR measurement

[0091] All cured and liquid samples were measured on a Thermo iS50 FT-IR in attenuated total reflection mode.

[0092] Refractive index measurement

[0093] Approximately 0.2 mL of the sample was dropped onto a clean glass substrate. A film of approximately 5 micrometers was obtained using a wire-wound rod. The film was cured in a nitrogen chamber under 395 nm LED light (0.6 W / cm²) as described in Test Method 1. 2 5 seconds = 3J / cm 2 The refractive index of the cured film at a wavelength of 450 nm was measured on a 2010M prism coupler (Metricon, NJ, USA).

[0094] Synthesis example

[0095] Preparation of acid anhydride monomers

[0096] SE-1: Preparation of Acryloyloxybutyltriphenyltriglyceridyl anhydride (ABTA)

[0097] A solution of 50.00 g (0.24 mol) trimellitic anhydride chloride in 200 mL dichloromethane was cooled in an ice bath. A solution of 34.225 g (0.24 mol) 4-hydroxybutyl acrylate, 20 g pyridine, and 250 mL dichloromethane was added dropwise to the flask over 1 hour. The mixture was stirred overnight at room temperature. After 17 hours, the mixture was washed with 1.0 M HCl and water. 0.05 g phenothiazine was added to the solution, and the solution turned deep orange. The organic phase was concentrated to give an oily substance that crystallized into a solid. The product was recrystallized using a mixture of toluene and hexane. Recrystallization was repeated four times to obtain most of the color from the product. The final product was separated as a gray / white solid (46.28 g).

[0098] SE-2: Preparation of Acryloyloxypropyltriphenyltriglyceridyl anhydride (APTA)

[0099] A solution of 12.36 g (9.5 mmol) hydroxypropyl acrylate (a mixture of isomers), 8.00 g (0.10 mol) pyridine, and 100 mL dichloromethane was cooled in an ice bath. A solution of 20.00 g (9.5 mmol) trimellitic anhydride chloride in 125 mL dichloromethane was added dropwise to the flask over 1 hour. The mixture was stirred overnight at room temperature. After 17 hours, the mixture was filtered and then concentrated under vacuum. Ethyl acetate (150 mL) was added and the mixture was washed with 1.0 M HCl and water. The organic phase was concentrated to give an oil. The crude oil was purified by column chromatography on silica gel using a gradient of 12% to 80% ethyl acetate in heptane. The product was separated as a heavy oil (13.49 g).

[0100] Preparation of SE-3: Acryloyloxyethyl succinic anhydride (AHDA)

[0101] A mixture of 25.00 g (0.116 mol) acryloyloxyethyl succinate, 47.22 g (0.463 mol) acetic anhydride, and 20 mg 2,6-di-tert-butyl-4-methylphenol (BHT) was heated to 110 °C for 90 minutes. The mixture was cooled and then concentrated under vacuum. The crude liquid was purified by column chromatography on silica gel using a gradient of ethyl acetate in hexane. The product was separated as a colorless oil (12.90 g).

[0102] Examples E1-E6 and Comparative Examples CE1-CE7

[0103] Preparation of ink compositions

[0104] Stir the components shown in Tables 1 and 2 in amber glass vials at 300 rpm for 10 minutes. The tables show the relative amounts of each component in parts by weight.

[0105]

[0106] Curing process

[0107] Unless otherwise specified, all ink samples were tested using a 395nm UV lamp (Phoseon Technology) at 0.24W / cm². 2 Cured for 30 seconds in a custom-made box filled with N2 at high power (dosage equal to 7.2 J / cm²). 2 ).

[0108] Characteristics of ink and cured layer

[0109] After mixing, the ink compositions were classified as either soluble "good" or insoluble "insoluble". Insoluble compositions were not further tested. Viscosity was measured as described in the test methods above. PECVD testing was performed, and cured samples were reported as "pass" or "fail". Modulus and Tg were measured as described in the test methods above. Refractive index (RI) was measured as described in the test methods above. The results are shown in Tables 3 and 4 below.

[0110]

[0111] Water absorption rate

[0112] The maximum absorption rate was measured by weight after 7 days at 85°C and 85% RH. The irreversible absorption rate was measured by weight after drying at 85°C for another 2 days.

[0113] An acid anhydride captures one water molecule, and the molecular weight remains unchanged thereafter. Therefore, according to the following equation, the weight increases proportionally to the amount of acid anhydride:

[0114] The results are reported in Table 5 below.

[0115]

[0116] ATR-FTIR measurement

[0117] The ATR-FTIR spectra of samples E1 and E5 were obtained using the above testing method. For E1, the anhydride C=O stretching is located at 1822 cm⁻¹. -1 Upon exposure to moisture, the peak disappeared, and a broadening of the carbonyl stretching was observed (1680 cm⁻¹). -1 Up to 1750cm -1 This indicates that the anhydride group dissociates into a carboxylic acid group. A similar trend was observed in E5. The C=O stretching of the ABTA anhydride lies at 1780 cm⁻¹. -1 After exposure to moisture, the peak disappeared, and broadening of the carbonyl stretching was observed again (1680 cm⁻¹). -1 Up to 1750cm -1 This indicates that the anhydride group dissociates into a carboxylic acid group.

Claims

1. A curable ink composition, said curable ink composition comprising: The (meth)acrylate-based component, which is capable of curing to form a (meth)acrylate-based matrix, comprises: At least one aliphatic (meth)acrylate, at least one aromatic (meth)acrylate, or a combination thereof; At least one polyfunctional (meth)acrylate; and Photoinitiators; and A water-chelated component, wherein the water-chelated component is a reaction pair, wherein the reaction pair is a co-curable epoxy functional portion and a co-curable anhydride functional portion, wherein the co-curable anhydride functional portion comprises a co-curable aromatic anhydride, a co-curable aliphatic anhydride, or a combination thereof. Upon curing, the ink composition forms a (meth)acrylate matrix, wherein the (meth)acrylate matrix comprises epoxy functional groups and anhydride functional groups, and wherein the (meth)acrylate matrix is ​​capable of water chelation, whereby the anhydride functional groups react with water to form acid functional groups, which react with the epoxy functional groups to produce an irreversible water absorption rate in the (meth)acrylate-based matrix. The ink composition is inkjet printable, has a viscosity of 30 centipoise or less at temperatures from room temperature to 35°C, and is solvent-free. Furthermore, the ink composition is optically clear when set and cured, and has an irreversible water absorption rate of at least 2% by weight 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 aliphatic (meth)acrylate comprises a monofunctional (meth)acrylate compound of formula I: Wherein R3 is an alkyl group having 2 to 32 carbon atoms; and R2 is hydrogen or methyl.

3. 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: At least one of R1 includes an aromatic substituent; t is an integer from 1 to 4; and R2 is hydrogen or methyl.

4. The curable ink composition according to claim 1, wherein the at least one polyfunctional (meth)acrylate comprises a compound of formula II: Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and A is an n-valent group, which includes an alkylene group, a heteroaromatic group, a fused 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 greater.

5. The curable ink composition of claim 1, wherein at least a portion of the co-curable epoxy functional portion of the reaction pair of the water-chelating component comprises an epoxy-functionalized (meth)acrylate of formula IV: Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and B is an epoxy-functional alkyl or heteroalkyl group.

6. The curable ink composition of claim 1, wherein at least a portion of the co-curable anhydride functional portion of the reaction pair of the water-chelating component comprises an aromatic anhydride (meth)acrylate of formula V: Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; L 1 It is a divalent linker containing an alkylene group having at least 3 carbon atoms; and PA represents substituted or unsubstituted phthalic anhydride groups.

7. The curable ink composition according to claim 6, wherein the aromatic anhydride (meth)acrylate comprises an aromatic anhydride (meth)acrylate of formula V: Where R2 is hydrogen; (CO) is a carbonyl group C=O; L 1 It is a divalent linker comprising a branched alkylene group having 3 carbon atoms or a straight-chain alkylene group having 4 carbon atoms; and PA is an unsubstituted phthalic anhydride group.

8. The curable ink composition of claim 1, wherein at least a portion of the co-curable anhydride functional portion of the reaction pair of the water-chelating component comprises an aliphatic anhydride (meth)acrylate of formula VI: Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; Each L 2 It is a divalent linker containing an alkylene group or a heteroalkylene group linked by an ester group.

9. The curable ink composition according to claim 8, wherein the aliphatic anhydride (meth)acrylate comprises an aliphatic anhydride (meth)acrylate of formula VI: Where R2 is hydrogen; (CO) is a carbonyl group C=O; Each L 2 It is a divalent linker comprising an alkylene group having at least two carbon atoms and an ester group.

10. The curable ink composition of claim 1, wherein the co-curable epoxy functional portion comprises 0.075% to 45% by weight of the total weight of the curable ink composition.

11. The curable ink composition according to claim 1, wherein the co-curable anhydride functional portion accounts for 0.075% to 45% by weight of the total weight of the curable ink composition.

12. An article comprising: A substrate having a first main surface and a second main surface; A cured organic layer adjacent to at least a portion of the second main surface of the substrate. A substrate, wherein the cured organic layer comprises a cross-linked (meth)acrylate-based matrix and is optically clear, the cross-linked (meth)acrylate-based matrix containing epoxy functional groups and anhydride functional groups; such that the cured organic layer has a water-chelating component, the water-chelating component being a reaction pair consisting of an epoxy functional portion and an anhydride functional portion, wherein the (meth)acrylate matrix is ​​capable of water chelation, thereby the anhydride functional groups forming acid functional groups upon reaction with water, the acid functional groups reacting with the epoxy functional groups, thereby causing the (meth)acrylate-based matrix to have an irreversible water absorption rate, wherein the irreversible water absorption rate is at least 2 wt% upon exposure to 85°C / 85% relative humidity for 7 days.

13. The article of claim 12, wherein the cured organic layer comprises a curable ink composition disposed and cured on at least a portion of the second main surface of the substrate. The curable ink composition comprises: The (meth)acrylate-based component, which is capable of curing to form a (meth)acrylate-based matrix, comprises: At least one aliphatic (meth)acrylate, at least one aromatic (meth)acrylate, or a combination thereof; At least one polyfunctional (meth)acrylate; and Photoinitiators; and A water-chelated component, wherein the water-chelated component is a reaction pair, wherein the reaction pair is a co-curable epoxy functional portion and a co-curable anhydride functional portion, wherein the co-curable anhydride functional portion comprises a co-curable aromatic anhydride, a co-curable aliphatic anhydride, or a combination thereof. The curable ink composition described herein is inkjet printable, has a viscosity of 30 centipoise or less at temperatures ranging from room temperature to 35°C, and is solvent-free.

14. The article of claim 12, wherein the thickness of the cured organic layer is from 1 micrometer to 16 micrometers.

15. The article of claim 12, wherein the article of claim 12 comprises an electronic device, and the substrate comprises an optoelectronic component.

16. The article of claim 15, 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.

17. The article of claim 13, wherein at least a portion of the co-curable epoxy functional portion of the reaction pair of the water-chelating component comprises an epoxy-functionalized (meth)acrylate of formula IV: Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; and B is an epoxy-functional alkyl or heteroalkyl group.

18. The article of claim 13, wherein at least a portion of the co-curable anhydride functional portion of the reaction pair of the water-chelating component comprises an aromatic anhydride (meth)acrylate of formula V: Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; L 1 It is a divalent linker comprising a branched alkylene group having 3 carbon atoms or a straight-chain alkylene group having 4 carbon atoms; and PA is an unsubstituted phthalic anhydride group.

19. The article of claim 13, wherein at least a portion of the co-curable anhydride functional portion of the reaction pair of the water-chelating component comprises an aliphatic anhydride (meth)acrylate of formula VI: Where R2 is hydrogen or methyl; (CO) is a carbonyl group C=O; L 2 It is a divalent linker containing two alkylene groups having at least two carbon atoms linked by an ester bond.

20. The article of claim 13, wherein the co-curable epoxy functional portion comprises 0.075% to 45% by weight of the total weight of the curable ink composition.

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