Photocurable encapsulation composition, encapsulation film layer and display

Abstract

This invention discloses a photocurable encapsulation composition, comprising a photocurable monomer, a silicon-containing monomer, and an initiator; the photocurable monomer is an epoxy compound containing an oxocyclic alkyl group without silicon in its molecule; the silicon-containing monomer comprises the structures shown in formulas (1) and (2); in formula (1), R1-R9 are each independently an aliphatic hydrocarbon substituted or unsubstituted with an oxocyclic alkyl group, Z1 is a chain or cyclic alkane group with 1-15 carbon atoms substituted with an oxocyclic alkyl group, n+m+p>0; in formula (2), R 10 Z1 is a C1-C6 alkane group, Z2 is a chain or cyclic alkane group with 1-15 carbon atoms substituted by an oxocyclic alkyl group, and q is an integer greater than 1. The photocurable encapsulation composition generated by this invention has a low dielectric constant, solving the problem of touch performance delay when encapsulating OLED devices with thin films.

Description

Technical Field

[0001] This invention relates to the field of electrical device packaging materials. More specifically, this invention relates to a photocurable packaging composition, a packaging film, and a display. Background Technology

[0002] Organic light-emitting diodes (OLEDs), also known as organic light-emitting semiconductor materials, are devices that generate electroluminescence using a multilayer organic thin-film structure. They are easy to fabricate and require only low driving voltages, making OLEDs particularly outstanding for flat panel display applications. OLED displays are thinner, lighter, brighter, consume less power, have faster response times, higher resolution, better flexibility, and higher luminous efficiency than traditional LCDs, meeting consumers' evolving demands for display technology.

[0003] In recent years, OLEDs have received widespread attention from major international display manufacturers. However, the performance and lifespan of organic light-emitting diodes (OLEDs) are susceptible to external moisture and oxygen. When water vapor and oxygen enter the organic light-emitting material layer, they can easily react chemically with small molecules, causing dark spots to appear at the locations where water molecules and oxygen come into contact with the OLED element, leading to the failure of the entire OLED device. Therefore, how to better ensure the stability of OLEDs has become an important issue in the current fabrication of OLED devices. To overcome this problem, many methods have been proposed, among which thin-film encapsulation technology is a relatively good solution.

[0004] While utilizing thin-film encapsulation for OLED devices, it has been found that reducing the dielectric properties of thin-film encapsulation materials can effectively improve the touch performance of the devices during use. Encapsulation materials with low dielectric constants can effectively reduce touch delay. Although there are some reports on photocurable encapsulation compositions with low dielectric constants, their dielectric constants still do not meet the requirements. Summary of the Invention

[0005] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0006] Another objective of this invention is to provide a photocurable encapsulation composition that combines a silicon-containing monomer with an oxygen-containing heterocyclic alkyl group and a silicon-free alkane photocurable monomer with an oxygen-containing heterocyclic alkyl group, and generates a photocurable encapsulation composition with a low dielectric constant under the action of an initiator, thereby solving the problem of touch performance delay when encapsulating OLED devices in thin films.

[0007] To achieve these and other advantages according to the present invention, a photocurable encapsulation composition is provided, comprising a photocurable monomer, a silicon-containing monomer, and an initiator;

[0008] The photocurable monomer is an epoxy compound containing oxygen-containing heterocyclic alkyl groups that does not contain silicon in its molecule;

[0009] The silicon-containing monomer includes the structures shown in formulas (1) and (2) below;

[0010]

[0011] In formula (1), R1-R9 are each an alkane group that is substituted with or unsubstituted with an oxocyclic alkyl group, Z1 is a chain or cyclic alkane group with 1-15 carbon atoms substituted with an oxocyclic alkyl group, n+m+p>0, and n,m,p are natural numbers.

[0012]

[0013] In equation (2), R 10 Z1 is a C1 to C6 alkane group, Z2 is a chain or cyclic alkane group with 1 to 15 carbon atoms substituted by an oxocyclic alkyl group, and q is an integer greater than 1.

[0014] Preferably, R1, R5, and R8 are each independently an alkane group substituted with or unsubstituted with an oxocyclic alkyl group, and R2, R3, R4, R6, R7, and R9 are each independently a C1 to C6 alkane group.

[0015] Preferably, the oxocyclic alkyl groups in Z1 and Z2 are each independently selected from one of formula (3) and formula (4);

[0016]

[0017]

[0018] The wavy lines represent the locations of chemical bonds.

[0019] Preferably, the photocurable monomer is an epoxy compound substituted with ethylene oxide and / or oxetyl and / or cyclohexyl oxide;

[0020] The photocurable monomer is at least one of monofunctional epoxy compounds, difunctional epoxy compounds, and polyfunctional epoxy compounds.

[0021] Preferably, the content of monofunctional silicon-containing monomers and monofunctional epoxy compounds in the encapsulation composition is 15 wt% or more.

[0022] Preferably, the content of the monofunctional epoxy compound in the encapsulation composition is 15 wt% or more.

[0023] Preferably, the content of the photocurable monomer is 30-80 wt%, the content of the silicon-containing monomer is 10-70 wt%, and the content of the initiator is 0.5-5 wt%.

[0024] Preferably, the encapsulation composition further includes a leveling agent, wherein the leveling agent content is 0.05-1 wt%.

[0025] Specifically, the solid dielectric constant of the encapsulation composition at 23±2°C is below 2.6.

[0026] The present invention provides an encapsulation film layer, which is formed by curing the aforementioned photocurable encapsulation composition for encapsulating OLEDs.

[0027] The present invention provides an OLED display, including the aforementioned encapsulation film layer.

[0028] The present invention has at least the following beneficial effects:

[0029] By combining silicon-containing monomers with oxygen-containing heterocyclic alkyl groups and silicon-free alkane photocurable monomers with oxygen-containing heterocyclic alkyl groups, a photocurable encapsulation composition with a low dielectric constant is generated under the action of an initiator, thereby improving the touch performance of thin-film encapsulated OLED devices.

[0030] The higher the proportion of monofunctional silicon-containing monomers and monofunctional epoxy compounds in the encapsulation composition, the greater the elongation at break of the encapsulation film formed by the photocurable encapsulation composition, and the better the softness and elasticity of the encapsulation film.

[0031] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0032] Before the detailed description of this disclosure that follows, it should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not limited to the appended claims. Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0033] Furthermore, the terms or words used in this specification and claims are intended to be understood based on the principle that the inventors may appropriately define the concepts of the terms in order to best describe the invention, and are to have meanings and concepts consistent with the technical concept of this disclosure as described in this specification, and are not limited to the conventional meaning.

[0034] In the technical solutions disclosed in this invention, the present invention relates to an encapsulation composition, encapsulation film layer and display that can be printed and photocured on a substrate.

[0035] The term "printing" can refer to any type of coating, including inkjet printing. The encapsulation composition is capable of forming an encapsulation film layer that encapsulates the organic light-emitting material layer, thereby reducing or preventing damage to the organic light-emitting material layer of the organic light-emitting device from physical shocks or foreign substances such as oxygen or moisture.

[0036] Furthermore, the photocurable encapsulation composition disclosed in this invention is configured to perform the function of protecting the light-emitting device, which is an inherent function of the encapsulation composition. In addition, the encapsulation composition of this invention has a low dielectric constant, which can effectively solve the problem of touch performance delay when encapsulating OLED devices in thin films.

[0037] As used herein, the term "photocurable encapsulation composition" refers to a composition that can be cured by free radical polymerization using light irradiation. Photocuring can be performed, for example, by irradiation with electromagnetic waves such as microwaves, infrared rays, ultraviolet rays, and gamma rays; or by particle beams such as electron beams including alpha particles, proton beams, and neutron beams.

[0038] There are no particular restrictions on the specific conditions for photocuring. However, for example, when using ultraviolet light for photocuring, the wavelength can be in the range of 290 nm to 400 nm.

[0039] Unless otherwise stated, the term "dielectric constant" as used herein refers to the dielectric constant of a solid. Specific measurement methods are disclosed in the experimental examples described later.

[0040] 1. A photocurable encapsulation composition

[0041] Specifically, it includes a photocurable monomer, a silicon-containing monomer, and an initiator, wherein the silicon-containing monomer has the structure shown in formula (1) and formula (2) below;

[0042]

[0043] In formula (1), R1-R9 are each an alkane group that is substituted with or unsubstituted with an oxocyclic alkyl group, Z1 is a chain or cyclic alkane group with 1-15 carbon atoms substituted with an oxocyclic alkyl group, and n+m+p>0, where n,m,p are natural numbers.

[0044]

[0045] In equation (2), R 10 Z1 is a C1 to C6 alkyl group, Z2 is a chain or cyclic alkane group with 1 to 15 carbon atoms substituted by an oxocyclic alkyl group, and q is an integer greater than 1.

[0046] The photocurable monomer is an epoxy compound containing ethylene oxide and / or oxobutyric and / or cyclohexyl oxide, which does not contain silicon in its molecule.

[0047] The following section provides a more detailed description of photocurable monomers, silicon-containing monomers, and initiators.

[0048] A) Photocurable monomers

[0049] The photocurable monomer is an epoxy compound containing oxygen-containing heterocyclic alkyl groups that does not contain silicon in its molecule.

[0050] The type of epoxy monomer in the epoxy compound of this invention is not particularly limited. For example, it can be classified as having an ethylene oxide group at the end, an oxetyl group on the aliphatic chain, and an cyclohexyl oxide group at the end, and used according to the desired performance. That is, the photocurable monomer is an epoxy compound substituted with ethylene oxide and / or oxetyl and / or cyclohexyl oxide.

[0051] Compounds containing ethylene oxide in their molecules include aromatic epoxy compounds, aliphatic epoxy compounds, and alicyclic epoxy compounds.

[0052] Examples of aromatic epoxy compounds include compounds such as phenyl glycidyl ether; bisphenol type epoxy compounds such as bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol AD ​​type epoxy compounds, and bisphenol S type epoxy compounds; naphthalene type epoxy compounds; phenolic varnish type epoxy compounds such as phenolic varnish type epoxy compounds and cresol varnish type epoxy compounds; and alcohol type epoxy compounds such as hydrogenated bisphenol A type epoxy compounds.

[0053] Examples of aliphatic epoxy compounds include polyglycidyl ethers of polyols or their olefinic oxygen adducts. Specific examples include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,9-nonanediol diglycidyl ether, 1,12-dodecanediol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, and polyethylene glycol diglycidyl ether.

[0054] Examples of alicyclic epoxides include hydrogenated aromatic epoxides, cyclohexanes, cyclohexylmethyl esters, cyclohexylmethyl ethers, spirocyclic epoxides, and tricyclic decane epoxides.

[0055] Specific examples of compounds having an oxetane group in their molecule include 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-[[(2-ethylhexyl)oxy]methyl]oxetane, 2-isopropyloxetane, 3-methoxy-3-phenyloxetane, 3-ethyl-3-methyloxetane, 3,3'-[oxybismethylene]bis[3-ethyl]oxetane, 3-ethyl-3-(phenoxymethyl)oxetane, and 3-ethyl-3-phenoxymethyloxetane.

[0056] Preferably, the epoxide having an oxetyl group can be selected from compounds with the structure shown below;

[0057]

[0058] Specific examples of compounds having an epoxide cyclohexyl group in their molecule may include 3,4-epoxide cyclohexylmethyl 3,4-epoxide cyclohexyl carbamate, 1,2-epoxide-4-vinylcyclohexane, (R)-limonene oxide, and 1,2-epoxide-4-hydroxymethylcyclohexane.

[0059] The content of the photocurable monomer is 40-80 wt%, for example, it can be 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55 wt%, 56 wt%, 57 wt%, 58 wt%, 59 wt%, 60 wt%, 61 wt%, 62 wt%, 63 wt%, 64 wt%, 65 wt%, 66 wt%, 67 wt%, 68 wt%, 69 wt%, 70 wt%, 71 wt%, 72 wt%, 73 wt%, 74 wt%, 75 wt%, 76 wt%, 77 wt%, 78 wt%, 79 wt%, or 80 wt%.

[0060] Furthermore, the photocurable monomer can be classified into at least one of monofunctional epoxy compounds, difunctional epoxy compounds, and polyfunctional epoxy compounds.

[0061] The content of monofunctional silicon monomers and monofunctional epoxy compounds in the encapsulation composition is 15 wt% or more; preferably, the content of monofunctional epoxy compounds in the encapsulation composition is 15 wt% or more.

[0062] Monofunctional epoxy compounds are epoxy compounds containing a single oxoheterocyclic structure, such as epoxy compounds containing a single ethylene oxide, epoxy compounds containing a single oxocyclic butyl, and epoxy compounds containing a single cyclohexane oxide.

[0063] The monofunctional epoxy compound is one or more of the following: 1,2-epoxyhexane, benzyl glycidyl ether, phenyl glycidyl ether, n-butyl glycidyl ether, neodecanoic acid glycidyl ester, octyl / decyl glycidyl ether, dodecyl glycidyl ether, tetradecyl glycidyl ether, octyl glycidyl ether, o-toluene glycidyl ether, 4-tert-butylphenyl glycidyl ether, and 3-ethyl-3-[[(2-ethylhexyl)oxy]methyl]oxetane.

[0064] The bifunctional epoxy compound is one or more of the following: ethylene glycol glycidyl ether, glyceryl diglycidyl ether, diglycidyl ether, 1,5-hexadiene diepoxide, 3,3'-[oxydimethylene]bis[3-ethyl]oxetane, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 3-ethyl-3-[[(2-ethylhexyl)oxy]methyl]oxetane, and 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarbamate.

[0065] The multifunctional epoxy compound is trimethylolpropane triglycidyl ether and / or glycerol triglycidyl ether.

[0066] B) Silicon-containing monomers

[0067] The organosilicon compound is preferably an organosilicon compound having a cationic curable functional group, and is particularly preferred to be an alicyclic epoxy organosilicon compound and an aliphatic epoxy organosilicon compound.

[0068] As organosilicon compounds with cationic curable functional groups, compounds with structures composed of formulas (1) and (2) are preferred. Both organosilicon compounds represented by formulas (1) and (2) can reduce the dielectric constant of the curing encapsulation composition.

[0069] The silicon-containing monomer includes the structures shown in formulas (1) and (2) below;

[0070]

[0071] In formula (1), R1-R9 are each an alkane group that is substituted with or unsubstituted with an oxocyclic alkyl group, and Z1 is a chain or cyclic alkane group with 1-15 carbon atoms substituted with an oxocyclic alkyl group, where n+m+p>0.

[0072] The structure of equation (2) is shown below;

[0073]

[0074] In equation (2), R 10Z1 is an alkyl group of C1 to C6, Z2 is a chain or cyclic alkane group with 1 to 15 carbon atoms substituted by an oxocyclic alkyl group, and q is an integer greater than 1, preferably an integer greater than 3, and more preferably an integer of 4.

[0075] Preferably, R1, R5, and R8 are each independently an alkane group substituted with an oxocyclic alkyl group; R2, R3, R4, R6, R7, and R9 are each independently a C1-C6 alkane group; the C1-C6 alkyl groups can be straight-chain or branched, and can be methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, n-heptyl, or n-hexyl, etc.

[0076] The oxecycloalkyl groups of Z1 and Z2 are preferably ethylene oxide, 3,4-epoxycyclopentyl or 3,4-epoxycyclohexyl, or oxecyclobutyl.

[0077] Preferably, Z1 has the structure shown in equation (5), -Y1-X1(5)

[0078] Z2 is the structure shown in equation (6), -Y2-X2(6)

[0079] Y1 and Y2 are each an alkane group with 1-6 carbon atoms, and X1 and X2 are each selected from one of formula (3) and formula (4).

[0080] The structures of equations (3) and (4) are shown below:

[0081]

[0082] The preferred structural formula of the compound represented by formula (1) is as follows:

[0083]

[0084] The preferred structural formula of the compound represented by formula (2) is as follows:

[0085]

[0086] The silicon monomer content in the encapsulation composition is 10-70 wt%; preferably, the silicon monomer content can be 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, or 37 wt%. %, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54 wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%.

[0087] Monofunctional silicon-containing monomers are compounds composed of formulas (1) and (2) containing a single oxygen heterocyclic structure as shown in formula (3) or (4), for example:

[0088]

[0089] (C) Initiator

[0090] The initiator of this invention belongs to the category of cationic photoinitiators. Cationic photoinitiators are another very important class of photoinitiators. After absorbing light energy and reaching an excited state, they undergo a photolysis reaction to produce a superacid, namely a superprotic acid or Lewis acid, thereby initiating cationic polymerization. Cationic photoinitiators can be classified into onium salts, organometallic compounds, and organosilanes. In this invention, onium salt cationic photoinitiators are preferred, specifically iodonium salts and thiodonium salts.

[0091] Examples of iodonium salts include compounds represented by the following formula (8);

[0092] Ar 1 -I + -Ar 2 ·X1 - (8)

[0093] In equation (8), Ar 1 and Ar 2 Independently substituted or unsubstituted aryl; X1 - It is an anion.

[0094] In formula (8), “aryl” refers to an aromatic hydrocarbon group having 6 to 18 carbon atoms, preferably phenyl or naphthyl. The aryl group may be unsubstituted or substituted with one or more optional substituents, including straight-chain or branched alkyl groups having 1 to 18 carbon atoms, straight-chain or branched alkoxy groups having 1 to 18 carbon atoms, straight-chain or branched alkoxy carbonyl groups having 2 to 18 carbon atoms, straight-chain or branched acyloxy groups having 2 to 18 carbon atoms, halogen atoms, cyano, nitro, hydroxyl, etc.

[0095] The anion portion X1 in formula (8) - As Cl - ,Br - ,SbF 6- ,PF 6- BF 4- .

[0096] Examples of thioonium salts include compounds represented by the following formula (9);

[0097]

[0098] In equation (9), Ar 3 and Ar 4 Independently substituted or unsubstituted aryl group; X2 - It is an anion.

[0099] In formula (9), “aryl” refers to an aromatic hydrocarbon group having 6 to 18 carbon atoms, preferably phenyl or naphthyl. The aryl group may be unsubstituted or substituted with one or more optional substituents, including straight-chain or branched alkyl groups having 1 to 18 carbon atoms, straight-chain or branched alkoxy groups having 1 to 18 carbon atoms, straight-chain or branched alkoxy carbonyl groups having 2 to 18 carbon atoms, straight-chain or branched acyloxy groups having 2 to 18 carbon atoms, halogen atoms, cyano, nitro, hydroxyl, etc.

[0100] The anion portion X2 in equation (9) - As Cl - ,Br - ,SbF 6- ,PF 6- BF 4- .

[0101] In some instances, the initiator may be selected from: aryl diazonium salts, diaryl iodonium salts, bis(dodecylbenzene)iodonium salts, long-chain alkoxydiphenyliodonium salts, triaryl iodonium salts, triphenylthionium salts, phenylthiophenyl diphenylthionium salts, phenylthiophenyl-diphenylthionium hexafluoroantimonate, and Irgacure 261 (isopropylbenzene ferrocene hexafluorophosphate).

[0102] The initiator may be selected from one or more of the above substances. Preferably, the initiator is selected from at least one compound of iodonium salts and at least one compound of thiodonium salts.

[0103] The initiator content in the composition is 0.5-5 wt%, for example, it can be 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2.0 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%. wt%, 2.9wt%, 3.0wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4.0wt%, 4.1wt%, 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%, 5.0wt%; in some embodiments, 2-5wt% is further preferred; more preferably 3-5wt%.

[0104] (D) Leveling agent

[0105] Leveling agents are commonly used additives that promote the formation of a smooth, uniform coating during the encapsulation process. They effectively reduce the surface tension of the encapsulation composition and improve its leveling and uniformity. The leveling agent content is 0.05-1 wt%. In some embodiments of the present invention, the leveling agent used is selected from the UNIQ FLOW series of Yuka Chemicals, particularly preferred are 360S, 361S, 362S, 372S, 375S, 376S, 380S, 384S, 392S, 400U, 415U, etc., with 362S being the most preferred.

[0106] 2. Synthesis method of photocurable encapsulation composition

[0107] The resin composition can be produced by a method comprising mixing the above-mentioned components, including a photocurable monomer, a silicon-containing monomer, a leveling agent, and an initiator.

[0108] 3. An encapsulation film layer

[0109] The encapsulation film includes an organic layer, and the raw material forming the organic layer contains the photocurable encapsulation composition described in the above-mentioned technical solution.

[0110] 4. An OLED display

[0111] OLED displays, or organic light-emitting diode displays, include the encapsulation film layer of this invention.

[0112] As one embodiment of the present invention, the light-emitting diode display of the present invention includes a substrate, an organic light-emitting diode fixed on the substrate, an inorganic layer encapsulating the organic light-emitting diode, and an encapsulation film layer stacked on the inorganic layer. The encapsulation film layer and the inorganic layer are stacked alternately to form a thin film encapsulation structure. The multi-layer stacked thin film encapsulation structure can effectively prevent water and oxygen from passing through the thin film layer and protect the device.

[0113] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0114] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0115] In the following examples and comparative examples, the abbreviations for each substance are as follows:

[0116] A) Photocurable monomers

[0117] A1: Epoxy compound 1, purchased from Hubei Gurun Technology Co., Ltd.

[0118]

[0119] A2: Epoxy compound 2, purchased from Hubei Gurun Technology Co., Ltd.

[0120]

[0121] A3: Epoxy compound 3, purchased from Shanghai Aladdin Reagent Co., Ltd.

[0122]

[0123] A4: Epoxy compound 4, purchased from Shanghai Aladdin Reagent Co., Ltd.

[0124]

[0125] B) Silicon-containing monomers

[0126] B1: Silicon-containing monomer 1

[0127]

[0128] Add 240g of D4H (2,4,6,8-tetramethylcyclotetrasiloxane, purchased from Shanghai Aladdin Reagent Co., Ltd.) to a 1500ml round-bottom flask, then add 500ml of toluene as a solvent, followed by 2ml of platinum solution (1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum ~ 2% xylene solution, CAS No. 68478-92-2, Shanghai Aladdin Reagent Co., Ltd.). Finally, add 496g of 1,2-epoxy-4-vinylcyclohexane (CAS No.: 106-86-5, Shanghai Aladdin Reagent Co., Ltd.) dropwise at 50℃. After the addition is complete, react at 50℃ for 24h, then remove the solvent toluene under reduced pressure to obtain silicon-containing monomer B1, with a purity greater than 99% as determined by NMR.

[0129] B2: Contains silicon monomer 2, purchased from Changzhou Qiangli Electronic New Materials Co., Ltd.

[0130]

[0131] B3: Contains silicon monomer 3, purchased from Hubei Gurun Technology Co., Ltd.

[0132]

[0133] B4: Contains silicon monomer 4, purchased from Hubei Gurun Technology Co., Ltd.

[0134]

[0135] B5: Contains silicon monomer 5, purchased from Shanghai Aladdin Reagent Co., Ltd.

[0136]

[0137] C) Initiator

[0138] C1: Iodonium diphenyltetrafluoroborate salt, purchased from Shanghai Laohan Chemical Technology Co., Ltd.

[0139] C2: Triphenylthionium hexafluoride phosphate, purchased from Shanghai Aladdin Reagent Co., Ltd.

[0140] D) Leveling agent

[0141] D1: Leveling agent (362s), purchased from Yoka Chemicals (Shanghai) Co., Ltd.

[0142] [Examples 1-16, Comparative Examples 1-6]

[0143] Synthesis method of photocurable encapsulation composition

[0144] At room temperature, in a 500ml round-bottom bottle, add photocurable monomer A, silicon-containing monomer B, leveling agent D and photoinitiator C according to the mass ratios listed in Examples 1-16 and Comparative Examples 1-6 in Table 1, respectively. After stirring evenly, filter with a 0.1µm filter to obtain a photocurable encapsulation composition.

[0145] [Evaluation Items]

[0146] <Dielectric constant of solids>

[0147] The dielectric constant was measured at 100 kHz using a precision impedance analyzer. The test results are shown in Table 1.

[0148] The solid dielectric constant sample was prepared as follows: the composition was inkjet printed onto a glass substrate coated with silver electrodes using an LP50 inkjet printer, and then cured (thickness 10.0 μm, exposure dose 2,000 mJ / cm). 2 Then, a top silver electrode (circular electrode, about 6 mm in diameter) is deposited on the organic curing film. The capacitance of the circular electrode is then tested, and the dielectric constant of the material is calculated using the relationship between capacitance and dielectric constant.

[0149] Elongation at break

[0150] A 30 μm thick adhesive film was prepared and punched into test specimens 10 mm wide and 30 μm long. The test specimens were then fixed on the test fixture of an electronic universal testing machine to test their tensile strength. The tensile speed of the testing machine was 12.5 mm / min. The initial force when clamping the sample should be less than 1 N. The tensile strength and displacement curves were recorded, and the displacement point L at which the specimen fractured was recorded. 断 As the fracture displacement point, the elongation at break ε = L 断 / 100×100%. The test results are shown in Table 1.

[0151] Table 1

[0152]

[0153] As can be seen from the comparison of Examples 1-15 and Comparative Examples 1-4, only by using the silicon-containing monomers shown in Formula (1) and Formula (2) can a packaging composition with a lower dielectric constant be prepared, which can improve the touch performance of thin-film encapsulated OLED devices.

[0154] As can be seen from the comparison of Examples 1-15 and Comparative Examples 5-6, only by combining the silicon-containing monomers shown in Formula (1) and Formula (2) with the photocurable epoxy monomers can a packaging composition with a lower dielectric constant be obtained. Only by combining the silicon-containing monomers shown in Formula (1) and Formula (2) with the photocurable epoxy monomers can a film with a higher elongation at break be obtained, making the film more flexible and elastic.

[0155] As can be seen from Examples 2-16, when the content of monofunctional silicon-containing monomers and monofunctional epoxy compounds is 15 wt% or more, the elongation at break of the membrane can improve the membrane's softness and elasticity.

[0156] A comparison of Examples 4 and 5, Examples 11-13, Examples 7, 9, and 14-15 shows that, with the same proportion of monofunctional silicon-containing monomers and monofunctional epoxy compounds, the higher the proportion of monofunctional epoxy compounds, the greater the elongation at break of the membrane, and the better the membrane's softness and elasticity.

[0157] As can be seen from the comparison between Examples 1-15 and Example 16, the leveling agent has almost no effect on the dielectric constant and almost no effect on the elongation at break of the film in the encapsulation composition.

[0158] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A photocurable encapsulation composition, characterized in that, Includes photocurable monomers, silicon-containing monomers, and initiators; The photocurable monomer is an epoxy compound containing oxygen-containing heterocyclic alkyl groups that does not contain silicon in its molecule; The silicon-containing monomer includes the structures shown in formulas (1) and (2) below; In formula (1), R1-R9 are each an alkane group that is substituted with or unsubstituted with an oxocyclic alkyl group, Z1 is a chain or cyclic alkane group with 1-15 carbon atoms substituted with an oxocyclic alkyl group, n+m+p>0, and n,m,p are natural numbers. In equation (2), R 10 Z1 is a C1 to C6 alkane group, Z2 is a chain or cyclic alkane group with 1 to 15 carbon atoms substituted by an oxocyclic alkyl group, and q is an integer greater than 1.

2. The photocurable encapsulation composition as described in claim 1, characterized in that, R1, R5, and R8 are each independently an alkane group substituted or unsubstituted with an oxocyclic alkyl group, and R2, R3, R4, R6, R7, and R9 are each independently a C1 to C6 alkane group.

3. The photocurable encapsulation composition as described in claim 1, characterized in that, The oxocyclic alkyl groups in Z1 and Z2 are each independently selected from one of formulas (3) and (4); The wavy lines represent the locations of chemical bonds.

4. The photocurable encapsulation composition as described in claim 1, characterized in that, The photocurable monomer is an epoxy compound substituted with ethylene oxide and / or oxobutyl and / or cyclohexyl oxide; The photocurable monomer is at least one of monofunctional epoxy compounds, difunctional epoxy compounds, and polyfunctional epoxy compounds.

5. The photocurable encapsulation composition as described in claim 4, characterized in that, The content of monofunctional silicon-containing monomers and monofunctional epoxy compounds in the encapsulation composition is 15 wt% or more.

6. The photocurable encapsulation composition as described in claim 5, characterized in that, The content of monofunctional epoxy compounds in the encapsulation composition is 15 wt% or more.

7. The photocurable encapsulation composition as described in claim 1, characterized in that, The content of the photocurable monomer is 30-80 wt%, the content of the silicon-containing monomer is 10-70 wt%, and the content of the initiator is 0.5-5 wt%.

8. The photocurable encapsulation composition as described in claim 1, characterized in that, The encapsulation composition further includes a leveling agent, wherein the leveling agent content is 0.05-1 wt%.

9. The photocurable encapsulation composition according to any one of claims 1-8, characterized in that, The solid dielectric constant of the encapsulation composition is below 2.6 at 23±2°C.

10. An encapsulation film layer, characterized in that, The encapsulation film layer is formed by curing the photocurable encapsulation composition for encapsulating OLEDs according to any one of claims 1-9.

11. An OLED display, characterized in that, Includes the encapsulation film layer as described in claim 10.

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