A compound for encapsulating a thin film, a composition comprising the same, and a method of preparing an encapsulating thin film

Abstract

The application discloses a kind of compound for encapsulation film, the preparation method of composition and encapsulation film comprising it, belong to involve the technical field of film encapsulation.The compound general structure is as follows:Wherein, X1 and X2 are same or different, selected from C3~C20 alkyl chain or C2~C20 alkoxy chain;R1 and R2 are selected from hydrogen atom, mono-substituted C1~C20 alkyl or mono-substituted C1~C20 alkoxy;R3 can be mono-substituted, di-substituted, tri-substituted, tetra-substituted or penta-substituted;Wherein at least one substitution position is fluorine group or trifluoromethyl;R4 is selected from hydrogen, substituted or unsubstituted C1~C20 alkyl.Application of the compound described in the application can reduce the permeability of water vapor and oxygen, prolong the service life of display device, and the shrinkage stress of the composition after curing is low, so that any deviation can be realized.

Description

Technical Field

[0001] This invention relates to the field of thin film encapsulation technology, and more specifically to a compound for encapsulating thin films, a composition comprising the same, and a method for preparing the encapsulated thin film. Background Technology

[0002] With the rapid development of science and technology, flexible, foldable, and even rollable electronic devices are gaining increasing market attention, especially smart devices based on flexible organic light-emitting diodes (OLEDs), such as televisions, computers, mobile phones, and smartwatches, which are increasingly favored by consumers. In the use of these products, besides display quality, one of the most critical indicators is their reliable and stable lifespan. However, to achieve these flexible, foldable, and rollable characteristics, organic molecular materials are used within the devices, which are susceptible to corrosion from moisture and oxygen in the air. Therefore, the lifespan of these devices is greatly affected by the effectiveness of the encapsulation in preventing water and oxygen penetration. To extend their lifespan, it is essential to effectively prevent moisture and oxygen from entering the device and causing harmful corrosion to the organic molecular materials; thus, proper encapsulation is necessary.

[0003] Currently, commonly used encapsulation materials are inorganic, and while their flexibility and water / oxygen protection capabilities are continuously improving, they still cannot achieve completely satisfactory results. Organic encapsulation materials possess intrinsic flexibility, making them highly suitable for fabricating flexible devices. Furthermore, their molecular structures are diverse, resulting in a rich variety of material systems, a wide range of raw material sources, and lower manufacturing costs, effectively compensating for the shortcomings of inorganic encapsulation materials. Summary of the Invention

[0004] In view of this, the present invention provides a compound for encapsulating films, a composition comprising the same, and a method for preparing the encapsulating film, which can reduce the permeability of water vapor and oxygen, thereby extending the service life of the display device. Furthermore, the composition has low shrinkage stress after curing, thus achieving the goal of not producing any displacement.

[0005] To achieve the above objectives, the present invention first provides a compound for encapsulating thin films, the compound for encapsulating thin films being shown in structural formula I:

[0006]

[0007] Formula I; Wherein, X1 and X2 may be the same or different, and are selected from alkyl chains of C3 to C20 or alkoxy chains of C2 to C20; R1 and R2 are selected from hydrogen atoms, alkyl groups of C1 to C20 or alkoxy groups of C1 to C20; R3 may be monosubstituted, disubstituted, trisubstituted, tetrasubstituted or pentasubstituted, and R3 may be selected from alkyl groups of C1 to C20, alkoxy groups of C1 to C20, fluorogroups, trifluoromethyl groups, aryl groups of C3 to C30, wherein at least one substitution position is a fluorogroup or a trifluoromethyl group; R4 is selected from hydrogen, substituted or unsubstituted alkyl groups of C1 to C20.

[0008] Preferably, the compound used for encapsulating the film is selected from the following chemical formulas:

[0009]

[0010] .

[0011] The present invention also provides a photocurable composition for encapsulation, the composition comprising the following raw materials in weight percentages: component A 9.5-90%, component B 9.5-90%, and component C 0.5-10%; wherein component A is the above-mentioned compound for encapsulating films; component B is any one or a combination of several of the following: photocurable monofunctional methacrylates of C1-C30 monohydric or polyhydric alcohols, photocurable difunctional methacrylates of C2-C30 monohydric or polyhydric alcohols, and photocurable polyfunctional methacrylates of C3-C30 monohydric or polyhydric alcohols; and component C is a photocrosslinking initiator.

[0012] Preferably, the photocurable C1-C30 monohydric or polyhydric monohydric alcohol monofunctional methacrylate is any one or a combination of several of lauryl acrylate, ethoxyethyl acrylate, butyl acrylate, hydroxyethyl acrylate, isobornyl acrylate, tetrahydrofuran acrylate, methacrylate phosphate, and isobornyl methacrylate.

[0013] Preferably, the photocurable C2-C30 monohydric or polyhydric difunctional methacrylate is any one or a combination of several of the following: diethylene glycol diacrylate, triethylene glycol diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, propoxy neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, 20(ethoxy)bisphenol A diacrylate, and glycerol diacrylate.

[0014] Preferably, the photocurable C3-C30 monohydric or polyhydric alcohol polyfunctional methacrylate is any one or a combination of several of the following: trimethylolpropane triacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol tripropylene acrylate, propoxylated pentaerythritol propylene acrylate, di(trimethylolpropane)tetraacrylate, triethylene glycol dimethacrylate, long-chain aliphatic hydrocarbon glycidyl ether acrylate, dipentaerythritol hexaacrylate, tripropylene glycol diacrylate, phthalic acid diethanolate diacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, and ethoxylated neopentyl glycol methoxy monoacrylate.

[0015] Preferably, the photocrosslinking initiator is any one or a combination of several of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine ester.

[0016] The present invention also provides a method for preparing the above-mentioned photocurable composition for encapsulation, comprising the following steps: (1) Weigh each raw material according to the weight percentage of the photocurable composition for encapsulation, and set aside; (2) After mixing components A, B and C, the mixture is stirred under vacuum and filtered to obtain the photocurable composition for encapsulation.

[0017] Preferably, the vacuum stirring temperature is 50°C and the time is 80 hours.

[0018] The present invention also provides an encapsulation film, which is formed by laminating an inorganic layer and an organic layer 1 to 5 times, with the outermost layer being an inorganic layer; wherein the material of the organic layer is the above-mentioned photocurable composition for encapsulation.

[0019] Preferably, the inorganic layer material is selected from any one or a combination of several of silicon nitride, silicon oxynitride, silicon oxide, aluminum oxide, zirconium oxide, titanium oxide and zinc oxide, and has a thickness of 8~12μm.

[0020] The present invention also provides a method for preparing the encapsulation film as described above, comprising the following steps: the inorganic layer is prepared by coating an inorganic layer material onto the surface of the object to be encapsulated by chemical vapor deposition to form an inorganic layer; an organic layer is deposited on the inorganic layer by inkjet printing; and then an organic layer is obtained by UV curing. This process is repeated, with the outermost layer being an inorganic layer, to obtain the encapsulation film.

[0021] Compared with existing technologies, this invention provides a compound for encapsulating films, a composition containing the compound, and a method for preparing the encapsulating film. After adding the encapsulating film compound of this invention, the water vapor transmission rate of the encapsulating film is significantly reduced, and the dielectric constant is also decreased. Encapsulating organic light-emitting devices with the aforementioned encapsulating film can effectively isolate moisture and extend the service life of the organic light-emitting devices. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 Mass spectrum of compound G-1. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 Preparation of compound G-1

[0026] Step 1: Weigh tetrabromophenylsilane (CAS: 18733-98-7, 1 eq), 4-fluorophenylboronic acid (CAS: 1765-93-1, 2.05 eq), anhydrous potassium carbonate (3 eq), tetrahydrofuran (10 eq), and water (10 eq) and add them to the reactor. Purge with nitrogen twice. Under a nitrogen atmosphere, add tetratetra(triphenylphosphine)palladium (symbol: Pd(PPh3)4, 0.03 eq) to the reaction system. React at 75°C for 12 hours until the reaction is complete. Add ethyl acetate (5 eq) to the phase system, stir for 5 minutes, allow to stand, and separate the phases. Extract the aqueous phase twice with ethyl acetate. Combine the organic phases, concentrate, and perform column chromatography using petroleum ether and ethyl acetate as eluents to obtain intermediate S1 in 45% yield.

[0027] HPLC: ≥99.4%.

[0028]

[0029] Step 2: Under a nitrogen atmosphere, intermediate S1 (1 eq), ethylene glycol (1 eq), anhydrous potassium carbonate (2 eq), and copper acetate (0.05 eq) were added to the reaction flask. The mixture was heated to 130°C and reacted for 24 hours until the reaction was complete. After cooling to room temperature, water (5 eq) and dichloromethane (5 eq) were added to the system. The mixture was stirred for 10 minutes, allowed to stand, and separated. The aqueous phase was extracted twice with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, concentrated, and subjected to column chromatography. Petroleum ether and ethyl acetate were used as eluents. The mixture was then concentrated to obtain intermediate S2 in 53% yield.

[0030] HPLC: ≥99%.

[0031]

[0032] Step 3: Under a nitrogen atmosphere, intermediate S2 (1 eq), methacryloyl chloride (2 eq), and pyridine (8.5 eq) were reacted at room temperature for 24 hours. The mixture was then concentrated and subjected to column chromatography with petroleum ether and ethyl acetate as eluents to obtain the target product G-1 in 35.7% yield.

[0033] HPLC: ≥96%.

[0034] See NMR data Figure 1 .

[0035] Preparation of photocurable compositions for encapsulation (1) Mix 20g of component A (G-1), 70g of component B (trimethylolpropane triacrylate) and 10g of component C (2,4,6-trimethylbenzoyl diphenylphosphonite) under vacuum at 50°C for 80h until homogeneous.

[0036] (2) Then filter with a syringe filter and use a particle counter to detect. When the number of particles with a diameter greater than 0.5 μm is no more than 50, the processed photocurable composition for encapsulation is obtained.

[0037] Preparation of encapsulation film (1) Silicon nitride is selected as the inorganic layer material and the above-mentioned photocurable composition for encapsulation is selected as the organic layer material. (2) Preparation of inorganic layer: An inorganic layer is formed by coating the surface of the object to be encapsulated with inorganic layer material by CVD, with a thickness of 10 μm. (3) Preparation of the organic layer: The organic layer material is sprayed onto the surface of the inorganic layer using an inkjet printer to form the organic layer. A 100mW / cm² inkjet printer is used. 2 Each 10-second exposure to ultraviolet light causes the organic layer to harden; (4) The encapsulation film is formed by depositing three layers on the surface of the object to be encapsulated in an alternating manner of inorganic and organic layers, with the outermost layer being an inorganic layer. The final encapsulation film consists of inorganic and organic layers deposited on the surface of the object to be encapsulated.

[0038] Example 2 Preparation of compound G-2 By replacing 4-fluorophenylboronic acid with 3,4-difluorophenylboronic acid, and using the same conditions as compound G-1, compound G-2 was prepared.

[0039] Preparation of photocurable compositions for encapsulation By replacing component A with G-2 and component B with triethylene glycol dimethacrylate, and keeping everything else the same as in Example 1, a photocurable composition for encapsulation was prepared.

[0040] Preparation of encapsulation film Same as Example 1.

[0041] Example 3 Preparation of compound G-3 By replacing 4-fluorophenylboronic acid with 3,4,5-trifluorophenylboronic acid and using the same conditions as compound G-1, compound G-3 was prepared.

[0042] Preparation of photocurable compositions for encapsulation By replacing component A with G-3 and component B with propoxylated glycerol triacrylate, and keeping everything else the same as in Example 1, a photocurable composition for encapsulation was prepared.

[0043] Preparation of encapsulation film Same as Example 1.

[0044] Example 4 Preparation of compound G-4 By replacing 4-fluorophenylboronic acid with 2,3,4,5,6-pentafluorophenylboronic acid, and using the same conditions as compound G-1, compound G-4 was prepared.

[0045] Preparation of photocurable compositions for encapsulation By replacing component A with G-4 and component B with propoxylated glycerol triacrylate, and keeping everything else the same as in Example 1, a photocurable composition for encapsulation was prepared.

[0046] Preparation of encapsulation film Same as Example 1.

[0047] Example 5 Preparation of compound G-5 By replacing methacryloyl chloride with acryloyl chloride and using the same conditions as compound G-1, compound G-5 was prepared.

[0048] Preparation of photocurable compositions for encapsulation By replacing component A with G-5 and component B with propoxylated glycerol triacrylate, and keeping everything else the same as in Example 1, a photocurable composition for encapsulation was prepared.

[0049] Preparation of encapsulation film Same as Example 1.

[0050] Example 6 Preparation of compound G-6 By replacing 4-fluorophenylboronic acid with 3,4-difluorophenylboronic acid and methacryloyl chloride with acryloyl chloride, and using the same conditions as compound G-1, compound G-6 was prepared.

[0051] Preparation of photocurable compositions for encapsulation By replacing component A with G-6 and component B with propoxylated glycerol triacrylate, and keeping everything else the same as in Example 1, a photocurable composition for encapsulation was prepared.

[0052] Preparation of encapsulation film Same as Example 1.

[0053] Example 7 The difference from Example 1 is that 20g of component A's composition monomer G-1 is replaced with 30g, and 70g of component B's trimethylolpropane triacrylate is replaced with 60g.

[0054] Example 8 The difference from Example 2 is that 20g of component A's composition monomer G-2 is replaced with 30g, and 70g of component B's triethylene glycol dimethacrylate is replaced with 60g.

[0055] Example 9 The difference from Example 3 is that 20g of component A's composition monomer G-3 is replaced with 30g, and 70g of component B's propoxylated glycerol triacrylate is replaced with 60g.

[0056] Example 10 The difference from Example 4 is that 20g of component A's composition monomer G-4 is replaced with 30g, and 70g of component B's propoxylated glycerol triacrylate is replaced with 60g.

[0057] Example 11 The difference from Example 5 is that 20g of component A's composition monomer G-5 is replaced with 30g, and 70g of component B's propoxylated glycerol triacrylate is replaced with 60g.

[0058] Example 12 The difference from Example 6 is that 20g of component A's composition monomer G-6 is replaced with 30g, and 70g of component B's propoxylated glycerol triacrylate is replaced with 60g.

[0059] Comparative Example 1 In the preparation of the photocurable composition for encapsulation, component A was replaced with the following compound, and the rest was the same as in Example 1, to obtain the photocurable composition for encapsulation and to prepare an encapsulation film.

[0060] .

[0061] Comparative Example 2 In the preparation of the photocurable composition for encapsulation, component A was replaced with the following compound, and the rest was the same as in Example 1, to obtain the photocurable composition for encapsulation and to prepare an encapsulation film.

[0062] .

[0063] Performance testing experiment Water vapor transmission rate was tested on the encapsulation films of Examples 1-12, Comparative Examples 1 and 2. The testing instrument was a high-precision water vapor transmission rate tester (model AQUARAN2) manufactured by MOCON (USA). Testing conditions were: temperature 85℃, relative humidity 85%, and testing duration 24 hours. Dielectric constant was measured using an HP4194A dielectric spectrum analyzer. Water contact angle was measured using a DSA25 fully automatic video contact angle measuring instrument manufactured by Krüss (Germany), and the average value of three parallel tests was taken. Tensile modulus was tested according to GB / T1040-92.

[0064] The experimental results are shown in Table 1 below:

[0065] The difference between Examples 1-12 and Comparative Examples 1 and 2 is that Component A created in this invention was added in Examples 1-12. The comparison shows that the water vapor transmission rate of the encapsulation film after adding Component A created in this invention is significantly lower than that of the encapsulation film without Component A created in this invention, and the dielectric constant is also reduced. By encapsulating organic light-emitting devices with the above encapsulation film, water vapor can be effectively isolated, and the service life of organic light-emitting devices can be extended.

[0066] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0067] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A compound for encapsulating thin films, characterized in that, The compound used for encapsulating the thin film is shown in structural formula I: Formula I; Wherein, X1 and X2 may be the same or different, and are selected from alkyl chains of C3 to C20 or alkoxy chains of C2 to C20; R1 and R2 are selected from hydrogen atoms, C1~C20 alkyl groups, or C1~C20 alkoxy groups; R3 can be monosubstituted, disubstituted, trisubstituted, tetrasubstituted, or pentasubstituted. R3 can be selected from C1 to C20 alkyl, C1 to C20 alkoxy, fluoro, trifluoromethyl, and C3 to C30 aryl, wherein at least one substitution position is fluoro or trifluoromethyl. R4 is selected from hydrogen, substituted or unsubstituted C1 to C20 alkyl groups.

2. The compound for encapsulating thin films according to claim 1, characterized in that, The compound used for encapsulating the film is selected from the following chemical formulas: 。 3. A photocurable composition for encapsulation, characterized in that, The composition comprises the following raw materials in weight percentages: component A 9.5-90%, component B 9.5-90%, component C 0.5-10%; Component A is the compound for encapsulating films as described in claim 1; Component B is any one or a combination of several of the following: monofunctional methacrylates of C1-C30 monohydric or polyhydric alcohols that can be cured by light; difunctional methacrylates of C2-C30 monohydric or polyhydric alcohols that can be cured by light; and polyfunctional methacrylates of C3-C30 monohydric or polyhydric alcohols that can be cured by light. Component C is a photocrosslinking initiator.

4. The photocurable composition for encapsulation according to claim 3, characterized in that, The photocurable C1~C30 monohydric or polyhydric monofunctional methacrylate is any one or a combination of several of lauryl acrylate, ethoxyethyl acrylate, butyl acrylate, hydroxyethyl acrylate, isobornyl acrylate, tetrahydrofuran acrylate, methacrylate phosphate, and isobornyl methacrylate. The photocurable C2-C30 monohydric or polyhydric difunctional methacrylate is any one or a combination of several of the following: diethylene glycol diacrylate, triethylene glycol diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, propoxy neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, 20(ethoxy)bisphenol A diacrylate, and glycerol diacrylate. The photocurable C3-C30 monohydric or polyhydric alcohol polyfunctional methacrylate is any one or a combination of several of the following: trimethylolpropane triacrylate, pentaerythritol triacrylate, trimethylolpropane triol triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol tripropylene acrylate, propoxylated pentaerythritol propylene acrylate, di(trimethylolpropane)tetraacrylate, triethylene glycol dimethacrylate, long-chain aliphatic hydrocarbon glycidyl ether acrylate, dipentaerythritol hexaacrylate, dipropylene glycol diacrylate, phthalic acid diethanolate diacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, and ethoxylated neopentyl glycol methoxy monoacrylate.

5. The photocurable composition for encapsulation according to claim 3, characterized in that, The photocrosslinking initiator is any one or a combination of several of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, and 2,4,6-trimethylbenzoyl-diphenylphosphine ester.

6. A method for preparing the photocurable composition for encapsulation as described in claim 3, characterized in that, Includes the following steps: (1) Weigh each raw material according to the weight percentage of the photocurable composition for encapsulation, and set aside; (2) After mixing components A, B and C, the mixture is stirred under vacuum and filtered to obtain the photocurable composition for encapsulation.

7. The preparation method according to claim 6, characterized in that, The vacuum stirring temperature is 50℃ and the time is 80h.

8. An encapsulation film, characterized in that, The encapsulation film is formed by stacking inorganic and organic layers 1 to 5 times, with the outermost layer being inorganic. The organic layer is made of the photocurable composition for encapsulation as described in claim 3.

9. The encapsulation film according to claim 8, characterized in that, The inorganic layer material is selected from any one or a combination of several of silicon nitride, silicon oxynitride, silicon oxide, aluminum oxide, zirconium oxide, titanium oxide and zinc oxide, and has a thickness of 8~12μm.

10. A method for preparing an encapsulation film as described in claim 8, characterized in that, Includes the following steps: The inorganic layer is prepared by chemical vapor deposition, in which an inorganic layer material is coated onto the surface of the object to be encapsulated to form an inorganic layer. An organic layer is deposited on the inorganic layer by inkjet printing, and then cured by ultraviolet light to form an organic layer. This process is repeated, with the outermost layer being an inorganic layer, to obtain the encapsulation film.

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