Ink composition and film product and application thereof

Abstract

The invention relates to the field of organic materials, in particular to an ink composition and a film product and application thereof. The ink composition comprises a thianthrene photocuring monomer and a free radical photoinitiator, the thianthrene light-cured monomer is a compound shown in a formula I in the specification. The ink composition provided by the invention is a pure organic high-refractive-index light-curable ink composition based on a thianthrene light-curable monomer, has the advantages of high refractive index, high light transmittance, high curing rate and the like, and can be prepared into products such as display semiconductors, optical devices and the like through light curing; and the material can be well applied to the fields of OLED display devices and the like.

Description

Technical Field

[0001] The present invention relates to the field of organic materials, in particular to an ink composition and a film product and application thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs) offer all-solid-state, active luminescence, high brightness, high contrast, ultra-thinness and lightness, low cost, low power consumption, no viewing angle restrictions, and a wide operating temperature range. They can be fabricated on flexible plastic substrates to enable flexible displays. OLEDs are considered the third generation of flat-panel display technology. As OLEDs for next-generation flat-panel display applications, organic optoelectronic semiconductor materials must meet the following requirements: 1. High luminous efficiency; 2. Excellent electron and hole stability; 3. Suitable emission color; and 4. Excellent processability. Currently used OLEDs primarily include small molecule organic light-emitting diodes (SMLEDs), polymer organic light-emitting diodes (POLEDs), organic phosphorescent light-emitting diodes (PHOLEDs), and thermally activated delayed luminescence (TADF) materials. Organic phosphorescent light-emitting diodes (OLEDs) utilize both singlet excited states (fluorescence) and triplet excited states (phosphorescence) for luminescence, achieving quantum efficiency and luminous efficiency three to four times that of fluorescent OLED materials. Phosphorescent materials, therefore, offer significantly higher luminous efficiency than small-molecule fluorescent materials while also generating less heat, increasing the competitiveness of OLED display panels. This makes it possible for OLED displays or lighting to surpass LCDs and traditional light sources overall.

[0003] Due to the demand for high luminous efficiency and long lifespan in OLED devices, thin-film encapsulation has become a current trend. Thin-film encapsulation involves growing a single or multilayer thin film on a pre-fabricated OLED device substrate to achieve a water vapor barrier. Research on OLED thin films typically utilizes organic-inorganic composite thin film approaches. Inorganic thin films effectively block water vapor and oxygen, but they suffer from poor film-forming properties, poor interfacial compatibility, and the formation of defects. Organic thin films, due to their large free volume and average chain freedom, offer excellent flexibility, film-forming properties, and smoothness. These organic thin films can also mask the defects of inorganic thin films. Leveraging the high barrier properties of inorganic films to water vapor and oxygen and the excellent surface morphology of organic films, an alternating deposition of organic and inorganic films can achieve satisfactory encapsulation results. To address the low light extraction efficiency of OLED devices, a capping layer (CPL), a light extraction material, is required on the cathode surface of top-emitting devices to adjust the optical interference distance, suppress external light emission, and mitigate extinction caused by surface plasmon migration. Based on the principles of optical absorption and refraction, the refractive index of this surface capping layer should be as high as possible.

[0004] Thin-film encapsulation, exemplified by a three-layer structure (PECVD-Flatness-PECVD), has become the mainstream method for flexible OLED encapsulation due to its excellent performance. This three-layer structure consists of a smooth first inorganic layer (SiNX) on which an organic polymer buffer layer is inkjet-printed and then cured. The third inorganic layer (SiNX) serves as the final inorganic layer. Organic polymer buffer layers (organic UV-curable resins) are considered a common and effective encapsulation material due to their excellent curing characteristics, stability, bonding strength, optical transparency, and high purity. Common organic polymer buffer layers include mixtures of two or more of acrylic resins, methacrylic resins, isoprene resins, vinyl resins, epoxy resins, polyurethane resins, cellulose resins, perylene resins, and imide resins. When the refractive index of the ink used for OLED encapsulation is low, total internal reflection (TIR) ​​within the OLED reduces light extraction efficiency. Increasing the refractive index of the encapsulation ink reduces TIR, thereby improving light extraction efficiency. The key to developing high-refractive-index ink compositions is how to maximize light extraction efficiency while ensuring effective encapsulation. High-refractive-index films can achieve higher light extraction efficiency. However, current high-refractive-index ink compositions are rarely used in OLED displays and struggle to simultaneously meet the performance requirements of high refractive index, high transmittance, and high photocuring efficiency, which are increasingly demanded by thin-film encapsulation.

[0005] With the continuous development of science and technology, the demand for high refractive index inks is increasing. High refractive index inks can be widely used in optical lenses, electronic components, biomedicine, photovoltaics and other fields, especially in the optoelectronics field, where they play an important role. Existing high refractive index inks often have problems such as low refractive index, poor stability or complex preparation process, which makes it difficult to meet market demand. The development of a new type of high refractive index ink composition to improve product quality and stability is an urgent problem to be solved in the current field. The development of pure organic high refractive index ink compositions has largely overcome the risks of instability and easy precipitation of inorganic filler-type ink compositions, and has also improved the stability of inkjet printing. However, there are still problems such as low refractive index, large curing shrinkage, and low transmittance. The development of a new stable pure organic high refractive index ink composition is becoming increasingly important. Summary of the Invention

[0006] To address the above-mentioned technical problems, the present invention provides an ink composition, film products, and applications thereof. The present invention provides a purely organic, high-refractive-index, UV-curable ink composition based on thianthrene monomers, which exhibits advantages such as high refractive index, high transmittance, and high curing rate. It can be photocured to produce products such as display semiconductors and optical devices, finding promising applications in fields such as OLED displays.

[0007] In a first aspect, the present invention provides an ink composition comprising a thianthrene-based photocurable monomer and a free radical photoinitiator; the thianthrene-based photocurable monomer is a compound represented by Formula I: Formula I Among them, group A is , group B is , the C group is , the D group is , at least one of A, B, and D groups exists, and C group exists simultaneously with A, B, or D groups; a, b, and c are each independently 0 or 1; R1 is a single bond, oxygen, sulfur, substituted or unsubstituted C1~C 20 Alkylene or substituted or unsubstituted C7~C 20 R2 is oxygen or sulfur; R3 is hydrogen, substituted or unsubstituted C1~C 20 Alkyl or substituted or unsubstituted C1~C 20 R4 is benzene, naphthalene or fluorene.

[0008] In the present invention, a high-refractive-index ink composition based on a thianthrene-based photocurable monomer represented by Formula I having an optimized branched structure can be obtained. The composition has advantages such as high refractive index, high transmittance, and high curing rate, and can be photocured to prepare products such as display semiconductors and optical devices. The ink composition can be well applied in the fields of high-frequency communication equipment, polymer optical materials, optical fibers, and the like, especially in the field of organic light-emitting OLED devices.

[0009] Preferably, the thianthrene-based photocurable monomer is selected from monomers of formulas 1-1 to 1-28: .

[0010] Further preferably, the thianthrene-based photocurable monomer is a first thianthrene-based photocurable monomer, a second thianthrene-based photocurable monomer, and a third thianthrene-based photocurable monomer in a mass ratio of 0-10:0-10:0-10; the first thianthrene-based photocurable monomer, the second thianthrene-based photocurable monomer, and the third thianthrene-based photocurable monomer are not all 0. The first thianthrene-based photocurable monomer is selected from one or more monomers of Formulas 1-1 to 1-6, the second thianthrene-based photocurable monomer is one or more monomers of Formulas 1-7 to 1-10, and the third thianthrene-based photocurable monomer is one or more monomers of Formulas 1-11 to 1-28. The present invention uses a specific combination of the first thianthrene-based photocurable monomer, the second thianthrene-based photocurable monomer, and the third thianthrene-based photocurable monomer to work synergistically, significantly improving the refractive index, curing performance, and light transmittance of the ink, and reducing the curing shrinkage of the ink. The formed film can effectively block water and oxygen, ensuring the performance of the product, thereby significantly improving the performance of the light extraction layer of optical components and optoelectronic devices.

[0011] Further preferably, the thianthrene-based photocurable monomer is a first thianthrene-based photocurable monomer and a second thianthrene-based photocurable monomer in a mass ratio of 1~10:1~10, or a first thianthrene-based photocurable monomer and a third thianthrene-based photocurable monomer in a mass ratio of 1~10:1~10, or a second thianthrene-based photocurable monomer and a third thianthrene-based photocurable monomer in a mass ratio of 1~10:1~10, or a first thianthrene-based photocurable monomer, a second thianthrene-based photocurable monomer and a third thianthrene-based photocurable monomer in a mass ratio of 1~10:1~10:1~10.

[0012] Further preferably, the composition also includes a non-thianthrene photocurable monomer. The inventors have discovered that when thianthrene photocurable monomers are used in combination with other non-thianthrene photocurable monomer components, such as aromatic, multifunctional, and monofunctional, the resulting film has a higher refractive index, cure rate, transmittance, and low cure shrinkage, making it more effectively suitable for inkjet printing and rapid curing. Preferably, the non-thianthrene photocurable monomer is present in an amount of 1 to 140 parts by weight, and the thianthrene photocurable monomer is present in an amount of 10 to 30 parts by weight. Controlling the mass ratio of the specific thianthrene photocurable monomer within the above range has a significant effect on reducing the viscosity of the ink, increasing the refractive index, improving the cure rate, increasing the hardness, and reducing the cure shrinkage. If the amount of thianthrene photocurable monomer is too small, the refractive index of the ink composition will be too low. If the amount of thianthrene photocurable monomer is too large and the amount of non-thianthrene photocurable monomer is too small, the viscosity of the ink composition will be too high, making it unsuitable for inkjet printing.

[0013] More preferably, the non-thianthianthrene photocurable monomer includes one or more of a first non-thianthianthrene monomer, a second non-thianthianthrene monomer, and a third non-thianthianthrene monomer.

[0014] According to the present invention, the first non-thianthrenthrene monomer can be a non-thianthrenthrene aromatic monomer comprising C1 to C30; the second non-thianthrenthrene monomer can be one or more of a C2 to C30 difunctional (meth)acrylate or a C3 to C30 multifunctional (meth)acrylate, for example, a glycol diacrylate such as ethylene glycol diacrylate, propylene glycol diacrylate, or other glycol diacrylates; and the third non-thianthrenthrene monomer can be a C1 to C30 monofunctional (meth)acrylate, for example, an alkyl acrylate, a hydroxy (meth)acrylate, or a (meth)acrylate monomer with a cyclic structure or a benzene ring. The inventors have discovered that a higher number of carbon atoms increases the viscosity of the monomer, significantly impacting the overall viscosity of the ink. A higher number of carbon atoms in a linear chain can also affect the barrier properties of the resulting film.

[0015] In the present invention, by optimizing the branched structure of a specific thianthrene-based high-refractive-index monomer and synergizing it with several other non-thianthrene monomers in a specific ratio, a high-refractive-index ink composition is achieved with a further enhanced refractive index, maximizing light extraction efficiency, while also possessing suitable viscosity and improved hardness. Furthermore, the present invention is free of issues such as poor film color, oxidation, or odor, and the synthesis process is simple. Since it contains no solvent, drying after spray coating does not affect the uniformity of film thickness or surface smoothness. The present invention achieves the above-mentioned excellent film by compounding a thianthrene-based photocurable monomer with three non-thianthrene monomers to achieve a synergistic effect. Among the non-thianthrene monomers, aromatic monomers have a higher refractive index than conventional aliphatic monomers and alkane monomers, and their use can further enhance the refractive index of the ink composition. Monofunctional monomers have a lower viscosity and can be used to adjust the viscosity of the entire ink. Excessive addition of monofunctional monomers results in a weaker film with a lower degree of curing, affecting its performance; insufficient addition results in an ink system with excessively high viscosity, making it unsuitable for spray coating. Multifunctional monomers are used to adjust the degree of curing of the film layer and the hardness of the film. If too much multifunctional monomer is added, the viscosity of the ink system will be high and the film will be too hard and brittle; if too little is added, the film will not be hard enough and the Tg will be too low, affecting the performance in the use scenario.

[0016] Preferably, the first non-thianthrene monomer is selected from 3-phenoxybenzyl acrylate, phenyl acrylate thioester, methylphenyl acrylate thioester, ethylphenyl acrylate thioester, propylphenyl acrylate thioester, diphenyl acrylate thioester, triphenyl acrylate thioester, 2-phenoxyethyl acrylate, 2-phenylthioethyl acrylate, 4-methylthiophenyl thioacrylate, diethyl phthalate diacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-phenylethyl acrylate, 2-phenylethyl methacrylate, 4-phenylbutyl ... One or more of butyl acrylate, 2-phenylpropyl acrylate, 2-phenylpropyl methacrylate, 3-phenylpropyl acrylate, 3-phenylpropyl methacrylate, 4-phenylbutyl acrylate, 4-phenylbutyl methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-phenylethyl acrylate, and 2-phenylethyl methacrylate, preferably one or more of 3-phenoxybenzyl acrylate, 2-phenoxyethyl acrylate, 2-phenylthioethyl acrylate, 4-methylthiophenylthioacrylate, and 3-phenylpropyl methacrylate.

[0017] Preferably, the second non-thianthrene monomer is selected from diethylene glycol diacrylate, diethylene glycol di(meth)acrylate, triethylene glycol diacrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, ethylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, neopentyl glycol diacrylate, propoxy neopentyl glycol diacrylate, 1,6 -Hexanediol diacrylate, 1,6-hexanediol di(meth)acrylate, 1,4-butanediol diacrylate, 1,4-butanediol di(meth)acrylate, 20(ethoxy)bisphenol A diacrylate, glycerol diacrylate, octanediol di(meth)acrylate, nonanediol di(meth)acrylate, decanediol di(meth)acrylate, undecanediol di(meth)acrylate, dodecanediol di(meth)acrylate, 1,4-dipropylene glycol diacrylate, 1,4-butanediol diacrylate, 2,4-diol bisphenol A diacrylate, 1,4-dipropylene glycol diacrylate, 1,4-diol bisphenol A ...acrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4- Benzyl thioacrylate, 4,4-[isopropylidenebis(p-phenyloxy)]diethanol methacrylate, 2,4,6-trithio-1,3-dimethyl diacrylate, 2-(1,3-disulfanyl)-1,3-dithio-1,4-dimethacrylate, 1,9-nonanediacrylate benzyl thioester, 3,7-dithia-1,9-nonanediacrylate thioester, cyclohexanedimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, trimethylolpropane The present invention further comprises one or more of alkyl triacrylate, pentaerythritol triacrylate, trihydroxymethylpropane triol triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol tripropylene glycol ester and propoxylated pentaerythritol propylene glycol ester, di(trimethylolpropane) tetraacrylate, preferably one or more of triethylene glycol diacrylate, diethylene glycol diacrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate and ethylene glycol diacrylate.

[0018] Preferably, the third non-thianthrene monomer is selected from the group consisting of dodecyl acrylate, ethoxyethoxyethyl acrylate, butyl acrylate, hydroxyethyl acrylate and isobornyl acrylate, ethoxylated tetrahydrofuran acrylate, methacrylate phosphate and isobornyl methacrylate, phenyl thioacrylate, methylphenyl thioacrylate, ethylphenyl thioacrylate, propylphenyl thioacrylate, diphenyl thioacrylate, triphenyl thioacrylate, 2-phenoxyethyl acrylate, 2-phenylthioethyl acrylate, 4-methylthiophenyl thioacrylate, 1-bicyclo[2.2.1]heptane-2,5-di(methylthio)-4-methacrylate, 2-phenylmethylthioacrylate, 2-phenylmethylthioethyl acrylate, methyl (meth)acrylate, (methyl The invention also includes one or more of ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, glycidyl (meth)acrylate, dicyclopentadiene (meth)acrylate, dicyclopentyl (meth)acrylate, isobornyl (meth)acrylate, and 1-adamantane (meth)acrylate, preferably one or more of dodecyl acrylate, diethylene glycol diacrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and ethylene glycol diacrylate. The first to third non-thianthrene monomers used in the present invention, when used in combination with the thianthrene photocurable monomer of the present invention in a certain proportion, can provide a high refractive index ink composition with better overall performance.

[0019] More preferably, the mass ratio of the first non-thianthrene monomer, the second non-thianthrene monomer, and the third non-thianthrene monomer is 1-50:1-40:1-50, preferably 20-40:20-30:1-20, and more preferably 25-40:20-26:10-15. The preferred ratios provide better effects.

[0020] Preferably, the composition comprises, by mass, 10 to 30 parts of a thianthrene-based photocurable monomer, 1 to 50 parts of a first non-thianthrene-based monomer, 1 to 40 parts of a second non-thianthrene-based monomer, 1 to 50 parts of a third non-thianthrene-based monomer, 0.1 to 10 parts of a free radical photoinitiator and 0 to 5 parts of an auxiliary agent.

[0021] More preferably, the composition comprises, by weight, 15-30 parts of a thianthrene-based photocurable monomer, 20-40 parts of a first non-thianthrene-based monomer, 20-30 parts of a second non-thianthrene-based monomer, 1-20 parts of a third non-thianthrene-based monomer, 3-8 parts of a free radical photoinitiator, and 0.1-1 parts of an auxiliary agent. More preferably, the ink composition comprises, by weight, 20-25 parts of a thianthrene-based photocurable monomer, 25-40 parts of a first non-thianthrene-based monomer, 20-26 parts of a second non-thianthrene-based monomer, 10-20 parts of a third non-thianthrene-based monomer, 3.5-8 parts of a free radical photoinitiator, and 0.1-0.5 parts of an auxiliary agent. By optimizing the amounts of each component, the present invention can better leverage the interactions between the components and improve the various properties of the ink composition.

[0022] Preferably, the free radical photoinitiator includes one or more of benzoin and its derivatives initiators, benzil and its derivatives initiators, acetophenone derivatives initiators, α-hydroxyketone derivatives initiators, α-aminoketone derivatives initiators, benzoylformate initiators, acylphosphine oxide initiators, benzophenone initiators, and thioxanthone initiators.

[0023] More preferably, the benzoin and its derivatives initiator is selected from one or more of benzoin, benzoin methyl ether, benzoin isopropyl ether, 4-phenylbenzoin, 4,4'-dimethoxybenzoin, and benzoin acetate; the benzil and its derivatives initiator is selected from one or more of benzil (diphenylethylenedione), 4,4'-dimethoxybenzil, 4,4'-dimethylbenzil, benzil dimethyl ketal, 4-hydroxybenzil, benzil diethyl ester, and α-naphthol; the acetophenone derivative initiator is selected from one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl One or more of 2-hydroxy-1-[4-(methylthio)phenyl]-2-morpholinyl-1-propanone, methyl benzoylformate, 4-phenylbenzophenone, and 2-isopropylthioxanthone; the α-hydroxyketone derivative initiator is selected from one or more of 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, 2-hydroxy-2-methyl-1-(4-isopropenylphenyl)-1-propanone, 2-hydroxy-2-methyl-1-(1-methylvinylphenyl)-1-propanone, 2-hydroxy-2-methyl-1-(4-tert-butylphenyl)-1-propanone, and 2-hydroxy-2-methyl-1-(4-benzoylphenyl)-1-propanone; The α-aminoketone derivative initiator is selected from one or more of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone, 2-(4-methylbenzyl)-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone, and 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl)phenyl]-1-butanone; the benzoylformate initiator is selected from one or more of methyl benzoylformate, isopropyl benzoylformate, phenyl benzoylformate, 2-ethylhexyl benzoylformate, glycidyl benzoylformate, and methyl 2-naphthoylformate. The acylphosphine oxide initiator is selected from one or more of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzoylbis(2,6-dimethoxyphenyl)phosphine oxide, 2,4,6-trimethylbenzoylbis(4-methoxyphenyl)phosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, and bis(2,6-dichlorobenzoyl)phenylphosphine oxide; the benzophenone initiator is selected from one or more of benzophenone, 4-methylthiobenzophenone, 4-aminobenzophenone, and 4-hydroxybenzophenone;The thioxanthone initiator is selected from one or more of 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 1-chloro-4-propoxythioxanthone, 2-dodecylthioxanthone, and thioxanthone-2-carboxylic acid ethyl ester.

[0024] Preferably, the free radical photoinitiator is an acylphosphine oxide initiator, and more preferably, the free radical photoinitiator is selected from one or more of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and methyl o-benzoylbenzoate. Using these initiators, the photocuring efficiency of the acrylate free radical system of the present invention is relatively high.

[0025] Preferably, the auxiliary agent includes one or more of a substrate wetting agent, a defoaming agent and a leveling agent.

[0026] Preferably, the substrate wetting agent is selected from one or more of BASF Byclear 900, BASF BYK-348, BASF BYK-349, Clariant Genapol X-080, Clariant Genapol PF-40, Clariant Genapol PF-80, Dow Corning 7920, Dow Corning 7921, Ethyl Acetate, Butyl Acetate, Evonik Tegostab B 8411, and Evonik Tegostab B 8412.

[0027] Preferably, the defoaming agent is selected from one or more of BASF Basf NXZ, BASF Basf 2190, BASF Basf 2410, Dow Corning 5566 Antifoam, Dow Corning 5525, Evonik DegussaSilicone Antifoam AEROSIL 200, Evonik Degussa Antifoam Concentrate, BYK-024, BYK-028, Rohm and Haas Rohm and Haas Antifoam AE-1, Rohm and Haas Rohm and Haas Antifoam AE-3, Wacker Antifoam Silicone 300, and Wacker Antifoam Silicone 310.

[0028] Preferably, the leveling agent is selected from one or more of BYK-337, BYK-358N, BYK-310, TEGO 450, TEGO 410, TEGO 430, Evonik Vestosint 8100, Evonik Vestosint 8300, Rohm and Haas Rhoplex Flow Aid, Dow Corning 5200 Silicone Flow Control Additive, BASF Efka 4046, and BASF Efka 4059.

[0029] In the present invention, by optimizing the monomer structure and its combination, and under the interaction of each component, the comprehensive performance of the high refractive index ink composition and its product can be significantly improved.

[0030] Preferably, the viscosity of the photocurable high refractive index ink composition is 19 to 965 cP, preferably 20 to 24.8 cP, for example, 20.1, 20.3, 20.5, 20.8, 21.4, 21.5, 21.7, 21.9, 22.5, 22.7, 23.5, 23.8, 24.3, 24.5, 24.8 cP, etc.

[0031] Some embodiments of the present invention also provide a method for preparing the high-refractive index ink composition, comprising mixing a thianthrene-based photocurable monomer and other monomers, a free radical initiator, and an auxiliary agent under light-proof conditions, preferably using ultrasonic mixing for 0.1 to 2 hours and stirring for 0.1 to 2 hours, which can better prepare the high-refractive index ink composition.

[0032] In a second aspect, the present invention provides a film product, which is prepared by photocuring the above-mentioned high refractive index ink composition.

[0033] Preferably, the preparation of the film product comprises spraying or inkjet printing the high refractive index ink composition on a substrate, and curing the substrate by UV irradiation to obtain the film product.

[0034] Preferably, the refractive index (550nm) of the film product is ≥1.55, preferably ≥1.62, and more preferably 1.63-1.7. For example, 1.63, 1.64, 1.65, 1.66, 1.67, etc. The hardness of the film product is ≥2H, preferably >2H, for example, 3H, 4H, etc. The photocuring rate is ≥91.5%, preferably 91.5%-92.8%. For example, 91.56%, 91.65%, 92.15%, 92.31%, 92.45%, 92.55%, 92.65%, 92.68%, etc. The average transmittance at 400-800nm ​​is ≥96%, preferably 96%-98.5%. For example, 96.1%, 96.12%, 96.8%, 97.5%, 98%, 98.21%, 98.34%, 98.36%, 98.42%, 98.45%, 98.48%, etc.

[0035] In a third aspect, the present invention provides applications of the high refractive index ink composition or the film product, including applications in OLED display devices, photovoltaic films, optical sensors, integrated optical devices, and high-precision optical coatings. In the present invention, the application scenarios of high refractive index inks are very broad. In addition to OLED displays and optical films, they can also play an important role in the fields of photovoltaic films, laser displays, optical sensors, integrated optical devices, high-precision optical coatings, etc. For example, they can be used as light extraction layers on OLED devices, and can also be used to make optical glass, hollow optical fibers, high-refractive index couplers, nano-gratings, etc. in the optical field. And other applications, for example, are characterized by the need to precisely control the refraction, reflection or propagation path of light, thereby improving optical performance or energy conversion efficiency.

[0036] The present invention provides at least the following beneficial effects: The purely organic high-refractive-index ink composition employs a thianthrene-based high-refractive-index monomer, wherein the thianthrene-sulfur bond increases the sulfur content of the polymer repeating unit, resulting in a high molar refractive index and a low dispersion coefficient. Furthermore, by optimizing the selection and ratio of the monomers, the refractive index can be increased, viscosity improved, and film hardness enhanced, resulting in excellent overall performance and significantly improving the overall product value. The use of a purely organic ink composition avoids the risks of precipitation associated with inorganic filler systems. The high-refractive-index film prepared from this composition can improve the light extraction efficiency of optical components, maintaining performance while effectively blocking water and oxygen, making it suitable for use in optical components and optoelectronic devices. Furthermore, the ink composition is simple to prepare, low-cost, and conducive to large-scale production. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0038] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed in the present invention.

[0039] If no specific techniques or conditions are specified in the examples of the present invention, the techniques or conditions described in the literature in this field or the product instructions shall be followed. The devices, instruments, reagents, etc. used, for which the manufacturers are not specified, are all conventional products that can be purchased through regular channels. The experimental reagents and raw materials involved are all commercially available products, and the reagents are all analytically pure products.

[0040] In the following examples, the specific components used are as follows: (A) Thianthracene-based photocurable monomers: (A1) Monomers of formula 1-4 were purchased from Hangzhou Yuhao Chemical Technology Co., Ltd.; (A2) Monomers of formula 1-8 were purchased from Hangzhou Yuhao Chemical Technology Co., Ltd.; (A3) Monomers of formula 1-18 were purchased from Hangzhou Yuhao Chemical Technology Co., Ltd.; (A4) Monomers of formula 1-1 were purchased from Hangzhou Yuhao Chemical Technology Co., Ltd.; and (A5) Monomers of formula 1-9 were purchased from Hangzhou Yuhao Chemical Technology Co., Ltd. The thianthracene-based photocurable monomers used in the embodiments of the present invention were all custom-made by the above-mentioned manufacturers.

[0041] (B) Non-thianthrene photocurable monomers: (B1) 3-phenoxybenzyl acrylate was purchased from Zhide Chemical, (B2) triethylene glycol diacrylate was purchased from Sartomer Chemical, and (B3) dodecyl acrylate was purchased from Sartomer Chemical.

[0042] (C) Free radical initiator: TPO was purchased from Kain Chemical.

[0043] (D) Leveling agent: BYK-310 was purchased from BYK Chemicals.

[0044] Example 1 This embodiment provides a high refractive index ink composition, including the following components (in percentage by mass) as shown in Table 1: (A) a thianthrene-based photocurable monomer (10 wt % of a monomer of Formula 1-4 and 10 wt % of a monomer of Formula 1-18), (B) a non-thianthrene-based photocurable monomer (40 wt % of 3-phenoxybenzyl acrylate, 26 wt % of triethylene glycol diacrylate, and 10 wt % of dodecyl acrylate), (C) 3.5 wt % of TPO as a free radical initiator, and (D) 0.5 wt % of BYK-310 as a leveling agent.

[0045] The preparation method of the high refractive index ink composition provided in this embodiment is as follows: (A) thianthrene-based photocurable monomer, (B) non-thianthrene-based photocurable monomer, (C) free radical initiator and (D) leveling agent are placed in a brown polypropylene bottle in the amounts listed in Table 1, followed by ultrasonic mixing for 0.5 h and stirring for 0.5 h to prepare the ink composition.

[0046] Example 2-19 The same as Example 1, except that the selection and dosage of each component used are different, as shown in Table 1.

[0047] Comparative Example 1 The same as Example 1, except that the selection and dosage of each component used are different, as shown in Table 1.

[0048] Table 1

[0049] Experimental Example 1 The performance of the compositions prepared in the examples and comparative examples was evaluated using the following test methods. The performance results are shown in Table 2.

[0050] 1. Transmittance test: UV-visible spectrophotometer test system (Carry 5000, manufactured by Agilent Technologies, Inc., USA) was used. The photocurable composition was sprayed or inkjet printed on a glass substrate and the light transmittance was measured at 200 mW / cm 2 The film was subjected to UV curing by UV irradiation for 10 seconds under UV conditions to produce a cured specimen having a 10 μm thick layer. The light transmittance of the film was measured in the range of 400 to 800 nm using a UV-visible spectrophotometer testing system.

[0051] 2. Photocuring rate: FT-IR (Nicolet iS10, Thermo) at 1635cm -1 (C=C) and 1720cm -1 The absorption peak intensity of the photocurable composition was measured near (C=O). First, the photocurable composition was sprayed or inkjet printed on a glass substrate and the absorption peak intensity was measured at 200 mW / cm 2The film was subjected to UV curing for 180 seconds by UV irradiation to produce a sample having a size of 20 cm × 20 cm × 3 μm (width × length × thickness). The cured film was cut into samples, and the FT-IR was used to measure the spectral distribution of the film at 1635 cm -1 (C=C) and 1720cm -1 The absorption peak intensity of (C=O). The photocuring rate is calculated by formula 1: Photocuring rate (%) = |1-(A / B)| × 100 Formula 1 Where A is the cured film at 1635cm -1 The absorption peak intensity near 1720 cm -1 The ratio of the absorption peak intensities near 1635 cm and B is the absorption peak intensity of the photocurable composition at 1635 cm -1 The absorption peak intensity near 1720 cm -1 The ratio of the absorption peak intensities near

[0052] 3. Hardness: The composition was coated onto a glass substrate using a wire rod, and then heated to 150 mW / cm 2 UV curing was performed by irradiating with a UV lamp for 10 seconds. Tested according to GB / T 6739-2006.

[0053] 4. Viscosity: The viscosity of the composition at 25°C was tested using a TA Discovery HR-1 rheometer with 60 mm parallel plates.

[0054] 5. Refractive Index: The refractive index of the liquid ink composition is tested using an Abbe refractometer. An appropriate amount of liquid ink is evenly applied to the surface of an observable prism. Illuminated with a white light source, the corresponding value in the readable area is the refractive index of the liquid at 589 nm.

[0055] The cured layer film is tested using an ellipsometer. First, the liquid ink composition is evenly spread on the smooth surface of a silicon wafer or optical frosted glass with a thickness of 1 to 10 nm. After the film is cured, the full-band refractive index is tested on the ellipsometer to obtain the refractive index of the full band (210 to 1690 nm).

[0056] Table 2

[0057] As can be seen from the above, compared with the comparative examples, the compositions of the various embodiments of the present invention have more suitable viscosities and higher refractive indices. The polymer films formed from the compositions of the various embodiments have comprehensive advantages such as better hardness and higher refractive indices, which enable them to better meet the requirements of the light extraction layer. The ink compositions provided by the embodiments of the present invention have excellent overall properties, enabling them to better meet the requirements of the light extraction layer.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An ink composition, characterized in that It includes a thianthrene-based photocurable monomer and a free radical photoinitiator; the thianthrene-based photocurable monomer is a compound represented by formula I: Formula I Among them, group A is , group B is , the C group is , the D group is , at least one of A, B, and D groups exists, and C group exists simultaneously with A, B, or D groups; a, b, and c are each independently 0 or 1; R1, R7, and R 11 Can be independently a single bond, oxygen, sulfur, substituted or unsubstituted C1~C 20 Alkylene or substituted or unsubstituted C7~C 20 Arylalkylene; R2, R5, R8, R 12 R3, R6, R9, R 13 Can be independently hydrogen, substituted or unsubstituted C1~C 20 Alkyl or substituted or unsubstituted C1~C 20 Alkoxy; R4 and R 10 It is benzene, naphthalene or fluorene.

2. The ink composition according to claim 1, wherein The thianthrene-based photocurable monomer is selected from monomers of formulas 1-1 to 1-28: 。 3. The ink composition according to claim 2, characterized in that The thianthrene-based photocurable monomers are a first thianthrene-based photocurable monomer, a second thianthrene-based photocurable monomer, and a third thianthrene-based photocurable monomer in a mass ratio of 0~10:0~10:0~10; wherein the first thianthrene-based photocurable monomer is selected from one or more monomers of formula 1-1 to formula 1-6, the second thianthrene-based photocurable monomer is one or more monomers of formula 1-7 to formula 1-10, and the third thianthrene-based photocurable monomer is one or more monomers of formula 1-11 to formula 1-28.

4. The ink composition according to any one of claims 1 to 3, characterized in that The composition further includes a non-thianthrene photocurable monomer; Preferably, in parts by mass, the non-thianthrene photocurable monomer is 1 to 140 parts, and the thianthrene photocurable monomer is 10 to 30 parts.

5. The ink composition according to claim 4, characterized in that The non-thianthianthrene photocurable monomer includes one or more of a first non-thianthianthrene monomer, a second non-thianthianthrene monomer, and a third non-thianthianthrene monomer; Preferably, the first non-thianthrene monomer is selected from 3-phenoxybenzyl acrylate, phenyl acrylate thioester, methylphenyl acrylate thioester, ethylphenyl acrylate thioester, propylphenyl acrylate thioester, diphenyl acrylate thioester, triphenyl acrylate thioester, 2-phenoxyethyl acrylate, 2-phenylthioethyl acrylate, 4-methylthiophenyl thioacrylate, diethyl phthalate diacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-phenylethyl acrylate, 2-phenylethyl methacrylate, 2-phenylethyl methacrylate, 4-phenylbutyl methacrylate, 4-phenylbutyl methacrylate. one or more of acrylate, 2-phenylpropyl acrylate, 2-phenylpropyl methacrylate, 3-phenylpropyl acrylate, 3-phenylpropyl methacrylate, 4-phenylbutyl acrylate, 4-phenylbutyl methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-phenylethyl acrylate, and 2-phenylethyl methacrylate, preferably one or more of 3-phenoxybenzyl acrylate, 2-phenoxyethyl acrylate, 2-phenylthioethyl acrylate, 4-methylthiophenylthioacrylate, and 3-phenylpropyl methacrylate; And / or, the second non-thianthrene monomer is selected from diethylene glycol diacrylate, diethylene glycol di(meth)acrylate, triethylene glycol diacrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, ethylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, neopentyl glycol diacrylate, propoxy neopentyl glycol diacrylate, 1,6 -Hexanediol diacrylate, 1,6-hexanediol di(meth)acrylate, 1,4-butanediol diacrylate, 1,4-butanediol di(meth)acrylate, 20(ethoxy)bisphenol A diacrylate, glycerol diacrylate, octanediol di(meth)acrylate, nonanediol di(meth)acrylate, decanediol di(meth)acrylate, undecanediol di(meth)acrylate, dodecanediol di(meth)acrylate, 1,4-dipropylene glycol diacrylate, 1,4-butanediol diacrylate, 2,4-diol bisphenol A diacrylate, 1,4-dipropylene glycol diacrylate, 1,4-diol bisphenol A ...acrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4-diol bisacrylate, 1,4- Benzyl thioacrylate, 4,4-[isopropylidenebis(p-phenyloxy)]diethanol methacrylate, 2,4,6-trithio-1,3-dimethyl diacrylate, 2-(1,3-disulfanyl)-1,3-dithio-1,4-dimethacrylate, 1,9-nonanediacrylate benzyl thioester, 3,7-dithia-1,9-nonanediacrylate thioester, cyclohexanedimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, trimethylolpropane one or more of alkane triacrylate, pentaerythritol triacrylate, trimethylolpropane triol triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol tripropylene glycol ester and propoxylated pentaerythritol propylene glycol ester, di(trimethylolpropane) tetraacrylate, preferably one or more of triethylene glycol diacrylate, diethylene glycol diacrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate and ethylene glycol diacrylate; And / or, the third non-thianthrene monomer is selected from lauryl acrylate, ethoxyethoxyethyl acrylate, butyl acrylate, hydroxyethyl acrylate and isobornyl acrylate, ethoxylated tetrahydrofuran acrylate, methacrylate phosphate and isobornyl methacrylate, phenyl thioacrylate, methylphenyl thioacrylate, ethylphenyl thioacrylate, propylphenyl thioacrylate, diphenyl thioacrylate, triphenyl thioacrylate, 2-phenoxyethyl acrylate, 2-phenylthioethyl acrylate, 4-methylthiophenyl thioacrylate, 1-bicyclo[2.2.1]heptane-2,5-di(methylthio)-4-methacrylate, 2-phenylmethylthioacrylate, 2-phenylmethylthioethyl acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, ( One or more of butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, glycidyl (meth)acrylate, dicyclopentadiene (meth)acrylate, dicyclopentyl (meth)acrylate, isobornyl (meth)acrylate and 1-adamantane (meth)acrylate, preferably one or more of dodecyl acrylate, butyl acrylate, hydroxyethyl acrylate and isobornyl acrylate, ethoxylated tetrahydrofuran acrylate, ethyl (meth)acrylate, butyl (meth)acrylate and hexyl (meth)acrylate.

6. The ink composition according to claim 5, characterized in that The composition comprises, by mass, 10 to 30 parts of a thianthrene-based photocurable monomer, 1 to 50 parts of a first non-thianthrene-based monomer, 1 to 40 parts of a second non-thianthrene-based monomer, 1 to 50 parts of a third non-thianthrene-based monomer, 0.1 to 10 parts of a free radical photoinitiator, and 0 to 5 parts of an auxiliary agent; Preferably, the composition comprises, by mass, 15 to 30 parts of a thianthrene-based photocurable monomer, 20 to 40 parts of a first non-thianthrene-based monomer, 20 to 30 parts of a second non-thianthrene-based monomer, 1 to 20 parts of a third non-thianthrene-based monomer, 3 to 8 parts of a free radical photoinitiator and 0.1 to 1 part of an auxiliary agent.

7. The ink composition according to any one of claims 1 to 6, characterized in that: The free radical photoinitiator includes one or more of benzoin and its derivatives initiators, benzil and its derivatives initiators, acetophenone derivatives initiators, α-hydroxyketone derivatives initiators, α-aminoketone derivatives initiators, benzoylformate initiators, acylphosphine oxide initiators, benzophenone initiators, thioxanthone initiators, anthraquinone and anthraquinone derivatives initiators.

8. The ink composition according to claim 6, wherein The auxiliary agent includes one or more of a substrate wetting agent, a defoaming agent and a leveling agent.

9. A membrane product, characterized in that The film product is prepared by photocuring the ink composition according to any one of claims 1 to 8.

10. Use of the ink composition according to any one of claims 1 to 8 or the film product according to claim 9, characterized in that: These include applications in OLED displays, photovoltaic films, optical sensors, integrated optical devices, or high-precision optical coatings.

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