Light-cured resin composition with low refractive index

Abstract

The invention discloses a light-cured resin composition, which comprises an acrylate copolymer containing a Si-O chain segment, and an organic film formed after the composition is subjected to UV light curing has low refractive index, high weather resistance and high adhesive force, can be used as a surface organic packaging layer of an organic light-emitting diode, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of photocurable resin technology, and relates to a low refractive index photocurable resin, and more particularly to a photocurable resin composition for preparing a low refractive index, high weather resistance and high adhesion organic light-emitting diode (OLED) surface encapsulation layer. Background Technology

[0002] Organic light-emitting diode (OLED) technology is widely used in advanced display devices and other fields due to its self-emissive, wide-viewing-angle, and full-color characteristics. To prevent the internal components of an OLED from being degraded by moisture, oxygen, carbon dioxide, and other corrosive chemicals in the air, a protective encapsulation layer is typically placed above the light-emitting layer. Inorganic materials such as silicon nitride (SiN) have good water and oxygen barrier properties, and a layer of SiN can be deposited above the light-emitting layer using vapor-phase chemical deposition. To further improve the toughness of the encapsulation layer, an organic encapsulation layer is sprayed onto the SiN layer using inkjet printing, followed by UV curing.

[0003] One performance requirement for this encapsulation layer is a low refractive index to ensure the brightness of the display panel. Patent documents published with CN119842348A and WO2021 / 187861A report a low-refractive-index epoxy resin filler for coating between the OLED light-emitting layer and the glass cover of the display panel, but it is not very suitable as a surface encapsulation material on SiN layers or silicon oxynitride layers.

[0004] Currently, the main material for this organic encapsulation layer is polyacrylate polymer, which generally suffers from problems such as high curing shrinkage and poor adhesion. Furthermore, it is also important to further improve the moisture barrier properties and weather resistance of this organic encapsulation layer.

[0005] Existing polyacrylate polymers, such as the fluorinated polyacrylate polymers incorporating inorganic nanoparticles reported in patent document WO2017 / 021785A and the fluorinated polyacrylate resin reported in patent document CN115403716A, although having low refractive index, either have insufficient adhesion or poor water resistance, are easily affected by moisture and chemicals in the ambient air, and have poor weather resistance, making them unsuitable for use as OLED surface encapsulation layers.

[0006] We previously developed an organic film formed by curing polyacrylate resin that has properties such as low curing shrinkage, strong adhesion, and high refractive index (see patent document CN119798531A), but it is not suitable for use as an OLED surface encapsulation layer. Summary of the Invention

[0007] To meet the requirements of low refractive index, high weather resistance, and high adhesion for the surface encapsulation layer of organic light-emitting diodes (OLEDs), we designed the molecular structure based on existing acrylate resins, conceiving a novel structure that introduces organosilicon segments (Si-O segments) into the acrylate polymer. After multiple experimental comparisons, we developed a novel acrylate copolymer and a photocurable resin composition containing this acrylate copolymer. This composition, after UV curing, forms a high-performance organic film, which is well-suited for use as an OLED surface encapsulation layer. Specifically, this invention includes the following technical solutions.

[0008] Another aspect of the present invention is to provide an acrylate copolymer comprising Si-O segments, characterized in that its molecular structure is as shown in general formula (1):

[0009] (1)

[0010] R1 and R2 are each independently an alkyl chain such as methyl or ethyl, or a fluorinated alkoxy chain such as trifluoromethyl; n is a repeating unit of the Si-O chain segment, and the value of n ranges from 6 to 50.

[0011] If n < 6, the film formed after photocuring of the photocurable resin composition containing the acrylate copolymer of general formula (1) has too high a refractive index; if n > 50, the photocurable resin composition containing the acrylate copolymer of general formula (1) has poor solubility and compatibility, and too high viscosity, making it difficult to process.

[0012] Preferably, in the above-mentioned acrylate copolymer molecular structure formula, n is 10, and the molecular structure formula is as shown in general formula (1-1):

[0013] (1-1)

[0014] Where R1 and R2 are as defined above; or

[0015] When n is 16, the molecular structure is shown in general formula (1-2):

[0016] (1-2)

[0017] Where R1, R2, R3, and R4 are as defined above; or

[0018] When n is 22, the molecular structure is shown in general formula (1-3):

[0019] (1-3)

[0020] R1 and R2 are defined as described above.

[0021] In one embodiment, the weight-average molecular weight Mw (mol / g) of the above-mentioned acrylate copolymer is 400-9100.

[0022] A second aspect of the invention is to provide the use of the acrylate copolymer containing Si-O segments as described above in the preparation of photocurable resins.

[0023] A third aspect of this invention provides a method for preparing the acrylate copolymer containing Si-O segments as described above. The reaction principle is as follows: the polymer is prepared by hydrosilylation reaction of a hydrogen-containing silicone oil with an unsaturated acrylate (such as allyl acrylate, butyl acrylate, or other acrylates with allyl / vinyl groups). This reaction adds Si-H bonds to the C=C double bond, forming Si-CH2-CH2-acrylate side chains. The hydrogen-containing silicone oil is selected as a side-chain type polymethylhydrosiloxane with a hydrogen content of 0.1wt% to 1.6wt% (commonly 0.5wt% to 1.0wt%). The molecular weight is adjusted according to the target molecular weight (Momentive, Shin-Etsu, Wacker, Hesheng, and Xin'an have relevant products available). For high molecular weights, choosing a low hydrogen content is beneficial for synthesizing the target product.

[0024] The synthesis method specifically includes the following steps: The reactor is thoroughly dried, and nitrogen is introduced to replace the air; terminal hydrogen silicone oil (hydrogen content 0.1wt%–1.6wt% (commonly 0.5wt%–1.0wt%), selecting hydrogen-containing silicone oils with Si numbers of 12 / 18 / 24 (Momentive, Shin-Etsu, Wacker, Hosun, and Shin-An offer relevant products), solvent (toluene or xylene), and polymerization inhibitor (approximately 100-700 ppm) are added to the reactor, stirred, and heated to 60℃–85℃; a catalytic amount of Karstedt catalyst (Pt content typically 5-20%) is added. The unsaturated acrylate monomer (BASF, Arkema, Wanhua, Satellite Chemicals, Changxing Materials, Zhanxin, etc., have relevant materials available) is slowly added to the system, for example, dropwise, while controlling the allyl C=C:Si-H molar ratio at 1.1-1.2:1. The reaction temperature is controlled below 85°C during the dropwise addition. After the dropwise addition is complete, the reaction is carried out at 60-85°C, preferably around 80°C, for 4-6 hours. The temperature is then raised to 90-110°C, for example, about 100°C. A vacuum is turned on to remove excess unsaturated acrylate monomer (e.g., allyl methacrylate AMA monomer) and solvent (if necessary, a small amount of polymerization inhibitor is added and a small amount of air is introduced during the solvent removal process) to obtain the product.

[0025] A fourth aspect of the present invention is to provide a photocurable resin composition comprising, by weight percentage, the following components:

[0026] A, 5 to 50% of acrylate copolymers containing Si-O segments as shown in general formula (1) as described above;

[0027] B, 10-40% of photocurable compounds of general formula (2) containing Si-O segments:

[0028] (2),

[0029] In general formula (2), R1 and R2 are each independently alkyl chains such as methyl and ethyl or fluorinated alkoxy chains such as trifluoromethyl; R3 and R4 are each independently photocurable groups, selected from epoxy, oxetyl, acryloyl, and methacryl; n is a repeating unit of Si-O chain segment, with an n value ranging from 0 to 4, in order to improve the compatibility of the resin composition;

[0030] Preferably, in the photocurable compound containing Si-O segments of general formula (2), m is 2, and the molecular structure is as shown in general formula (2-1):

[0031] (2-1)

[0032] Where R1, R2, R3, and R4 are as defined above; or

[0033] In the photocurable compound containing Si-O segments of general formula (2), m is 3, and the molecular structure is shown in general formula (2-2):

[0034] (2-2)

[0035] R1, R2, R3, and R4 are as defined above;

[0036] C, 20-55% of one or more of monofunctional acrylate monomers, difunctional acrylate monomers, trifunctional acrylate monomers, or four or more functional acrylate monomers, wherein the molecular structure of the monofunctional acrylate monomer is shown in general formula (3):

[0037] (3),

[0038] In general formula (3), Y is selected from hydrogen atoms and substituted or unsubstituted alkyl or alkoxy groups with a carbon chain length of 1-30; Q is selected from alkyl chains or alkoxy chains with a carbon chain length of 1-30 or alkyl chains containing heteroatoms or alkyl chains containing aromatic rings or alkyl chains containing aromatic heterocycles.

[0039] The molecular structure of the bifunctional acrylate monomer is shown in general formula (4):

[0040] (4),

[0041] In general formula (4), Y is selected from hydrogen atoms and substituted or unsubstituted alkyl or alkoxy groups with a carbon chain length of 1-30; Q is selected from alkyl chains or alkoxy chains with a carbon chain length of 1-30 or alkyl chains containing heteroatoms or alkyl chains containing aromatic rings or alkyl chains containing aromatic heterocycles.

[0042] The molecular structure of the trifunctional acrylate monomer is shown in general formula (5):

[0043] (5),

[0044] In general formula (5), K is selected from hydrogen atoms, substituted or unsubstituted alkyl or alkoxy groups with a carbon chain length of 1-30; G is an alkyl chain or alkoxy chain with a carbon chain length of 1-30, or an alkyl chain containing heteroatoms, or an alkyl chain containing aromatic rings, or an alkyl chain containing aromatic heterocycles.

[0045] The functionality of the unsaturated double bonds in the four or more functional acrylate monomers is 4-10;

[0046] D, 0.1-5% of photoinitiator, wherein the photoinitiator is selected from one or more of alkyl phenyl ketones, acyl phosphooxides, benzophenones, xanthraphenones, diacene, and thioonium salts.

[0047] Furthermore, the above-mentioned photocurable resin composition also includes 0.1-5% of additives, wherein the additives are selected from one or more mixtures of leveling agents, defoamers, coupling agents, wetting and dispersing agents, adhesion promoters, and matting agents.

[0048] The additive constitutes 0.1-5.0% of the resin composition by mass, for example, 0.1%, 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5%, or any combination thereof.

[0049] Preferably, in the above-mentioned photocurable resin composition, the monofunctional acrylate monomer is selected from one or more of the following compounds: cycloaliphatic methacrylate, dicyclopentadiene methacrylate, tetrahydrofuran methacrylate, alicyclic acrylate, dodecyl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, and isobornyl acrylate.

[0050] The difunctional acrylate monomer is selected from one or more of the following compounds: dipropylene glycol diacrylate, butanediol diacrylate, hexanediol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, bisphenol A diacrylate, tetraethylene glycol diacrylate, dodecanediol dimethacrylate, tripropylene glycol diacrylate, and neopentyl glycol diacrylate.

[0051] The trifunctional acrylate monomer is selected from one or more mixtures of the following compounds: trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propionyl methacrylate, pentaerythritol triacrylate, propionyl methacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, cyanurate triacrylate; and / or

[0052] The four or more functional acrylate monomers are selected from one or more of the following groups of compounds: trimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaerythritol tetraacrylate alkyl oxyalkylene tetraacrylate, and dipentaerythritol pentaacrylate.

[0053] Optionally, in the above-mentioned photocurable resin composition, the leveling agent is selected from one or a mixture of two or more of the following compounds: commercially available BYK-300 (Shin-Etsu, Japan), BYK-310 (BYK, Germany), BYK-307 (BYK, Germany), BYK-333 (BYK, Germany), BYK-370 (BYK, Germany), R-08 (manufactured by DIC), R-475 (manufactured by DIC), R-30 (manufactured by DIC), BM-1000 (manufactured by BMCHEMIE), BM-1100 (manufactured by BMCHEMIE), FLUORADE FC-135 (manufactured by Sumitomo 3M Co., Ltd.), FLUORADE FC-170C (manufactured by Sumitomo 3M Co., Ltd.), FLUORADE FC-430 (manufactured by Sumitomo 3M Co., Ltd.), FLUORADE... FC-431 (manufactured by Sumitomo 3M Co., Ltd.), SAFLON S-112 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-113 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-131 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-141 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-145 (manufactured by Asahi Glass Co., Ltd.), SAFLON S-382 (manufactured by Asahi Glass Co., Ltd.), SAFLON SC-101 (manufactured by Asahi Glass Co., Ltd.), SAFLON SC-102 (manufactured by Asahi Glass Co., Ltd.), SAFLON SC-103 (manufactured by Asahi Glass Co., Ltd.), SAFLON SC-104 (manufactured by Asahi Glass Co., Ltd.), SAFLON SC-105 (manufactured by Asahi Glass Co., Ltd.), SAFLON SC-106 (manufactured by Asahi Glass Co., Ltd.), SH-28PA (manufactured by Toray Silicone Co., Ltd.), SH-190 (manufactured by Toray Silicone Co., Ltd.), SH-193 (manufactured by Toray Silicone Co., Ltd.), SZ-6032 (manufactured by Toray Silicone Co., Ltd.), SF-8428 (manufactured by Toray Silicone Co., Ltd.), DC-57 (manufactured by Toray Silicone Co., Ltd.), DC190 (manufactured by Toray Silicone Co., Ltd.);

[0054] In one embodiment, the leveling agent accounts for ≤1% of the resin composition.

[0055] The defoamer is selected from one or more of the following compounds: commercially available products KS-66 (Shin-Etsu, Japan), KS-69 (Shin-Etsu, Japan), KS-108 (Shin-Etsu, Japan), BYK-070 (BYK, Germany), BYK-011 (BYK, Germany), BYK-012 (BYK, Germany), and BYK-057 (BYK, Germany).

[0056] In one embodiment, the defoamer accounts for ≤2% of the resin composition.

[0057] The coupling agent is selected from one or more of the following compounds: commercially available KBM-403 (Shin-Etsu, Japan), KBM-503 (Shin-Etsu, Japan), and KBM-603 (Shin-Etsu, Japan).

[0058] In one embodiment, the coupling agent accounts for ≤2% of the resin composition.

[0059] The wetting and dispersing agent is selected from one or more of the following compounds: commercially available BYK-111 (BYK, Germany), BYK-142 (BYK, Germany), and BYK-145 (BYK, Germany).

[0060] In one embodiment, the wetting and dispersing agent accounts for ≤1% of the resin composition.

[0061] The adhesion promoter is selected from one or more of the following compounds: commercially available BYK-4511 (BYK, Germany), BYK-4510 (BYK, Germany), BYK-4509 (BYK, Germany), and BYK-4512 (BYK, Germany).

[0062] In one embodiment, the adhesion promoter accounts for ≤1% of the resin composition.

[0063] The matting agent is selected from one or more of the following compounds: commercially available ACEMATT HK125 (Evonik), ACEMATT HK400 (Evonik), ACEMATT HK440 (Evonik), ACEMATT OP278 (Evonik), and ACEMATT HK450 (Evonik).

[0064] In one embodiment, the matting agent accounts for ≤1% of the resin composition.

[0065] Optionally, in the above-described photocurable resin composition, the photoinitiator is selected from one or more mixtures of the following groups: commercially available Omnirad 1173 (IGM, Japan), Omnirad 184 (IGM, Japan), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, 4-phenylbenzophenone, Omnirad ITX (IGM, Japan), Omnirad DETX (IGM, Japan), and Omnirad 784 (IGM, Japan).

[0066] A fifth aspect of the present invention is to provide the use of the photocurable resin composition described above in the preparation of an organic light-emitting diode (OLED) surface encapsulation layer.

[0067] In one embodiment, the photocurable resin composition described above is sprayed onto the surface of the SiN layer and / or silicon oxynitride layer of an organic light-emitting diode (OLED) by inkjet printing, and then cured by UV irradiation to form an organic encapsulation layer.

[0068] A sixth aspect of the present invention is to provide an organic film, which is obtained by UV curing the photocurable resin composition as described above.

[0069] A seventh aspect of the present invention is to provide an electronic device comprising an organic light-emitting diode (OLED), characterized in that the surface of the organic light-emitting diode (OLED) comprises an organic encapsulation layer formed by curing a photocurable resin composition as described above by UV irradiation.

[0070] This invention develops a novel acrylate copolymer containing Si-O segments and a photocurable resin composition containing the acrylate copolymer. The organic film formed by UV curing of the photocurable resin composition has low refractive index, excellent weather resistance and high adhesion, and can be used as a surface organic encapsulation layer for organic electroluminescent devices such as OLEDs, with broad application prospects. Attached Figure Description

[0071] Figure 1-5 The Fourier transform infrared (FT-IR) spectra of the Si-O chain acrylate copolymers prepared by Synthesis Examples 1-5 of the present invention are shown respectively.

[0072] Figure 6-10 The gel permeation chromatograms (GPCs) of the weight-average molecular weight of the Si-O chain acrylate copolymers prepared in Synthesis Examples 1-5 of the present invention are shown respectively, with dimethyl sulfoxide (DMSO) as the mobile phase. Detailed Implementation

[0073] The photocurable resin composition developed in this invention produces an organic film with low refractive index and high adhesion after UV curing, while also exhibiting good water, moisture, and chemical corrosion barrier properties, i.e., good weather resistance; and low curing shrinkage. This photocurable resin composition comprises an acrylate compound containing organosilicon segments as shown in general formula (1). The Si-O segments in its structure have very low polarizability, a loose packing structure with low packing density, and low polarizability side chains, resulting in an organic film with a low refractive index after UV curing. Simultaneously, the high chemical stability and high hydrophobic shielding effect of Si-O provide good water, moisture, and chemical corrosion barrier properties for the organic film, thereby improving weather resistance. Furthermore, the low surface tension of general formula (1) imparts excellent wettability to the resin composition, thereby improving the adhesion of the organic film material. Further, the highly flexible Si-O bonds also endow the resin composition with good flexibility and low curing shrinkage. Therefore, the introduction of general formula (1) is key to imparting excellent properties to the organic film.

[0074] In this document, for the sake of simplicity, the names or designations of the photocurable resin composition and the organic film formed after curing are sometimes used interchangeably. Those skilled in the art should understand that these designations represent different types of substances in different descriptive contexts. Their meanings are readily understood by those skilled in the art based on the context.

[0075] As used in this article, the term "low refractive index" refers to an organic film with a refractive index not exceeding 1.50, preferably not exceeding 1.45. The refractive index can be measured using commonly used refractive index analysis instruments such as the HORIBA ellipsometry. Low-refractive-index surface encapsulation layers have a relatively small impact on the optical performance of OLEDs, which is beneficial for improving OLED display brightness. Some literature also mentions that low-refractive-index encapsulation layers may reduce surface plasmon loss.

[0076] The term "high weather resistance" refers to the high barrier function of organic membranes against water vapor, oxygen, carbon dioxide, and other corrosive chemical substances in ambient air. When characterized by water vapor transmission rate, the water vapor transmission rate of a 5μm thick organic membrane, measured by a water vapor transmission rate tester at 38.7℃ and 100% RH, should not exceed 3.5 g / m². 2 / 24h, preferably not exceeding 3.4 g / m 2 / 24h, preferably not exceeding 3.3 g / m 2 / 24h.

[0077] Preferably, the organic film formed by the photocurable resin composition of the present invention after photocuring, in addition to having a low refractive index, also possesses heat resistance and excellent mechanical properties. For example, the glass transition temperature (Tg) of the organic film is not lower than 100°C, preferably not lower than 110°C, and more preferably not lower than 120°C; the tensile strength of the organic film is not higher than 28 MPa, preferably not higher than 25 MPa, and more preferably not higher than 24 MPa; the elastic modulus is not higher than 500 MPa, preferably not higher than 480 MPa, and more preferably not higher than 450 MPa; the elongation at break is not lower than 23%, preferably not lower than 24%, and more preferably not lower than 25%; and the curing shrinkage is not higher than 5%, preferably not higher than 6%, and more preferably not higher than 7%.

[0078] The aforementioned excellent optical and physical / mechanical properties demonstrate the improvement effect of this invention on the chemical composition of prior art photocurable resin compositions.

[0079] Those skilled in the art will readily understand that, based on its low refractive index, high weather resistance against air erosion, adhesion to substrates, and heat resistance, the photocurable resin composition of the present invention is not only suitable for organic light-emitting diodes (OLEDs), but also for surface protective films of various other electroluminescent devices with display interfaces.

[0080] Furthermore, the substrate to which the organic film formed after the photocurable resin composition of the present invention is attached is not limited to the SiN layer and / or silicon oxynitride layer, but can also be other organic or inorganic materials, including but not limited to glass, semiconductors, transparent resins such as plexiglass, etc.

[0081] To make the present invention more apparent and understandable, the technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0082] Example

[0083] The embodiments involve the addition amount, content and concentration of various substances. Unless otherwise specified, the "parts" mentioned therein refer to "parts by weight"; unless otherwise specified, the percentage content refers to the mass percentage content.

[0084] In the embodiments described herein, unless otherwise specified, the temperature generally refers to room temperature (15-35°C).

[0085] Performance evaluation of organic films formed after UV curing of photocurable resin compositions:

[0086] 1. Group conversion rate

[0087] Fourier transform infrared spectroscopy was used to test the curing process at a depth of 1635 cm before and after curing.-1 The peak intensity of the C=C stretching vibration at point C characterizes the group conversion rate, and the specific calculation method is shown in formula a:

[0088]

[0089] Where C is the group conversion rate;

[0090] V1 is 1635cm before curing. -1 The corrected peak intensity;

[0091] V2 is 1635cm after curing. -1 The corrected peak intensity.

[0092] 2. Adhesion Test

[0093] Use a cross-cutting tool to cut the organic film perpendicular to each other until the glass substrate is exposed. Then use a soft brush to remove the cutting debris from the surface. Next, apply 3M Scotch 610 tape to the cross-cut pattern, press it firmly with your fingers, and then peel the tape off the layer. Observe the degree of peeling of the organic film at the cross-cut pattern to determine its adhesion level.

[0094] The judgment criteria are as follows: 5B - The cut edge is clear and smooth, and no part of the grid is missing; 4B - The area of ​​missing part within the grid is ≤5%; 3B - The area of ​​missing part within the grid is 5-15%; 2B - The area of ​​missing part within the grid is 15-35%; 1B - The area of ​​missing part within the grid is 35-65%; 0B - The area of ​​missing part within the grid is greater than 65%.

[0095] 3. Refractive index test

[0096] The refractive index of the organic film was characterized using a HORIBA ellipsometry.

[0097] 4. Water vapor transmission rate test

[0098] The water vapor transmission rate was tested on a 5μm thick organic membrane using a water vapor transmission rate tester (Permatran-W 3 / 33, Mocon Co.. Ltd.) at 38.7℃ and 100% RH.

[0099] 5. Mechanical property testing

[0100] The tensile strength, elastic modulus, and elongation at break of the organic film were tested using a DMA850 (TA Instrument) dynamic mechanical analyzer. The cured organic film was cut into rectangular strips with a length of 50 mm and a width of 5 mm, fixed on a tensile fixture, and stretched at a constant speed until the strips broke. The tensile strength, elastic modulus, and elongation at break values ​​were then recorded.

[0101] 6. Heat resistance test

[0102] The glass transition temperature (Tg) of the organic film was tested using a TA DMA850 (TA Instrument) dynamic mechanical analyzer. The cured organic film was cut into rectangular strips with a length of 50 mm and a width of 5 mm, fixed on a tensile fixture, and the Tg was tested at a heating rate of 1 Hz, 125% amplitude, and 10 °C / min.

[0103] 7. Curing shrinkage rate test

[0104] The density of the resin composition before curing is measured by a hydrometer and recorded as P1. The density of the cured organic film is measured by an analytical balance and recorded as P2. The curing yield K is calculated using formula b.

[0105] .

[0106] Synthesis example 1

[0107] This embodiment provides a method for synthesizing an acrylate compound containing Si-O segments as shown in general formula (1-1), where R1 is methyl and R2 is methyl. The method includes the following steps:

[0108] The reactor was thoroughly dried and nitrogen was introduced to replace the air. Hydrogen-terminated silicone oil (0.8 wt% hydrogen content, 12 Si number hydrogen-containing silicone oil, XHG-202, Xin'an Chemical), solvent toluene (Sinopharm), and polymerization inhibitor (MEHQ, Solvay) (approximately 500 ppm) were added to the reactor. The mixture was stirred and heated to 80°C. A trace amount of Karstedt catalyst (Shin-Etsu Chemical) (13 ppm Pt content) was added. Allyl methacrylate (AMA) monomer (BASF) was slowly added dropwise to the system, controlling the allyl C=C:Si-H molar ratio at 1.1:1. The reaction temperature was controlled below 85°C during the dropwise addition. After the dropwise addition was complete, the reaction was carried out at approximately 80°C for 4-6 hours. The temperature was then raised to 100°C, and a vacuum was applied to remove excess allyl methacrylate (AMA) monomer and solvent, yielding the final product.

[0109] The infrared spectrum (FT-IR) of general formula (1-1) is as follows: Figure 1 As shown; the gel permeation chromatogram (GPC) for molecular weight determination is as follows. Figure 6 As shown.

[0110] The molecular weight Mn (mol / g) of the general formula (1-1) is 1436.

[0111] Synthesis example 2

[0112] The acrylate compound containing Si-O segments, as shown in general formula (1-2), was synthesized according to a method substantially the same as that used in Example 1, wherein the number of Si segments in the hydrosilicone oil is 18. In general formula (1-2), R1 is methyl and R2 is methyl.

[0113] The infrared spectrum (FT-IR) of general formula (1-2) is as follows: Figure 2 As shown; the gel permeation chromatogram (GPC) for molecular weight determination is as follows. Figure 7 As shown.

[0114] The molecular weight Mn (mol / g) of the general formula (1-2) is 2231.

[0115] Synthesis example 3

[0116] Acrylate compounds containing Si-O segments, as shown in general formula (1-3), were synthesized using a method substantially the same as that in Example 1, wherein the number of Si segments in the hydrosilicone oil is 24. In general formula (1-3), R1 is methyl and R2 is methyl.

[0117] The infrared spectrum (FT-IR) of general formula (1-3) is as follows: Figure 3 As shown; the gel permeation chromatogram (GPC) for molecular weight determination is as follows. Figure 8 As shown.

[0118] The molecular weight Mn (mol / g) of the general formula (1-3) is 2936.

[0119] Synthesis example 4

[0120] The photocurable compound containing Si-O segments, as shown in general formula (2-1), was synthesized using a method substantially the same as that in Example 1, wherein the number of Si in the hydrogen-containing silicone oil is 4. In general formula (2-1), R1 is methyl, R2 is methyl, and R3 and R4 are residual groups after the reaction of allyl acrylate.

[0121] The infrared spectrum (FT-IR) of general formula (2-1) is as follows: Figure 4 As shown; the gel permeation chromatogram (GPC) for molecular weight determination is as follows. Figure 9 As shown.

[0122] The molecular weight Mn (mol / g) of the general formula (2-1) is 556.

[0123] Synthesis example 5

[0124] The photocurable compound containing Si-O segments, as shown in general formula (2-2), was synthesized according to a method substantially the same as that used in Example 1, wherein the number of Si in the hydrogen-containing silicone oil is 5. In general formula (22), R1 is methyl, R2 is methyl, and R3 and R4 are residual groups after the reaction of allyl acrylate.

[0125] The infrared spectrum (FT-IR) of general formula (2-2) is as follows: Figure 5 As shown; the gel permeation chromatogram (GPC) for molecular weight determination is as follows. Figure 10 As shown.

[0126] The molecular weight Mn (mol / g) of the general formula (2-2) is 765.

[0127] Example 1

[0128] Ten parts by mass of an acrylate compound containing Si-O segments as shown in general formula (1-1), 15 parts by mass of a photocurable compound containing Si-O segments as shown in general formula (2-1), 15 parts by mass of trimethylolpropane triacrylate (Sartoma) (general formula (5)), 10 parts by mass of bisphenol A diacrylate ethoxylate (Sartoma), 10 parts by mass of dipentaerythritol pentaacrylate (Sartoma), 5 parts by mass of photoinitiator TPO, 1 part by mass of leveling agent BYK-307, 2 parts by mass of coupling agent KBM-403, and 2 parts by mass of adhesion promoter BYK-4511 were added to a reaction vessel and stirred at room temperature for 5 hours. After filtration, resin composition 1 was obtained. A 20 μm thick coating of resin composition 1 was printed on ordinary glass by inkjet printing and further cured in an ultraviolet curing chamber at 1500 mJ / cm 2 Under certain conditions, the organic film 1 is formed by UV curing.

[0129] Example 2

[0130] Ten parts by mass of an acrylate compound containing Si-O segments as shown in general formula (1-2), 15 parts by mass of a photocurable compound containing Si-O segments as shown in general formula (2-1), 15 parts by mass of trimethylolpropane triacrylate, 10 parts by mass of bisphenol A diacrylate ethoxylate (general formula (4)), 10 parts by mass of dipentaerythritol pentaacrylate, 5 parts by mass of TPO, 1 part by mass of BYK-307, 2 parts by mass of KBM-403, and 2 parts by mass of BYK-4511 were added to a reaction vessel and stirred at room temperature for 5 hours. After filtration, resin composition 2 was obtained. A 20 μm thick coating of resin composition 2 was printed on ordinary glass by inkjet printing and further cured in a UV curing chamber at 1500 mJ / cm 2 Under certain conditions, ultraviolet light is used for curing to form an organic film 2.

[0131] Example 3

[0132] Ten parts by mass of an acrylate compound containing Si-O segments as shown in general formula (1-3), 15 parts by mass of a photocurable compound containing Si-O segments as shown in general formula (2-1), 15 parts by mass of trimethylolpropane triacrylate (general formula (5)), 10 parts by mass of bisphenol A diacrylate ethoxylate (general formula (4)), 10 parts by mass of dipentaerythritol pentaacrylate, 5 parts by mass of TPO, 1 part by mass of BYK-307, 2 parts by mass of KBM-403, and 2 parts by mass of BYK-4511 were added to a reaction vessel and stirred at room temperature for 5 hours. After filtration, resin composition 3 was obtained. A 20 μm thick coating of resin composition 3 was printed on ordinary glass by inkjet printing and further cured in a UV curing chamber at 1500 mJ / cm 2 Under certain conditions, ultraviolet light is used for curing to form an organic film 3.

[0133] Example 4

[0134] Ten parts by mass of an acrylate compound containing Si-O segments as shown in general formula (1-1), 15 parts by mass of a photocurable compound containing Si-O segments as shown in general formula (2-2), 15 parts by mass of trimethylolpropane triacrylate (general formula (5)), 10 parts by mass of bisphenol A diacrylate ethoxylate (general formula (4)), 10 parts by mass of dipentaerythritol pentaacrylate, 5 parts by mass of TPO, 1 part by mass of BYK-307, 2 parts by mass of KBM-403, and 2 parts by mass of BYK-4511 were added to a reaction vessel and stirred at room temperature for 5 hours. After filtration, resin composition 4 was obtained. Resin composition 4 was printed into a 20 μm thick coating on ordinary glass by inkjet printing and further cured in a UV curing chamber at 1500 mJ / cm 2 Under certain conditions, ultraviolet light curing is performed to form an organic film 4.

[0135] Example 5

[0136] Ten parts by mass of an acrylate compound containing Si-O segments as shown in general formula (1-1), 15 parts by mass of a photocurable compound containing Si-O segments as shown in general formula (2-2), 15 parts by mass of trimethylolpropane triacrylate (general formula (5)), 30 parts by mass of bisphenol A diacrylate ethoxylate (general formula (4)), 30 parts by mass of dipentaerythritol pentaacrylate, 5 parts by mass of TPO, 1 part by mass of BYK-307, 2 parts by mass of KBM-403, and 2 parts by mass of BYK-4511 were added to a reaction vessel and stirred at room temperature for 5 hours. After filtration, resin composition 5 was obtained. A 20 μm thick coating of resin composition 5 was printed on ordinary glass by inkjet printing and further cured in a UV curing chamber at 1500 mJ / cm 2Under certain conditions, ultraviolet light curing is performed to form an organic film 5.

[0137] Comparative Example 1

[0138] 30 parts by weight of pentaerythritol triacrylate, 30 parts by weight of pentaerythritol pentaacrylate, 20 parts by weight of bisphenol A diacrylate ethoxylate, 10 parts by weight of trimethylolpropane triacrylate, 5% Omnirad 819, 1 part by weight of BYK-307, 2 parts by weight of KBM-403, and 2 parts by weight of BYK-4511 were added to a reaction vessel and stirred at room temperature for 5 hours. After filtration, the comparative resin composition 1 was obtained. The comparative resin composition was then used to print a 20 μm thick coating on ordinary glass using inkjet printing. The coating was further cured in a UV curing chamber at 1500 mJ / cm². 2 Under certain conditions, ultraviolet light is used for curing to form an organic film.

[0139] Comparative Example 2

[0140] 20 parts by weight of pentaerythritol triacrylate, 40 parts by weight of pentaerythritol pentaacrylate, 40 parts by weight of bisphenol A diacrylate ethoxylate, 5% Omnirad 819, 1 part by weight of BYK-307, 2 parts by weight of KBM-403, and 2 parts by weight of BYK-4511 were added to a reaction vessel and stirred at room temperature for 5 hours. After filtration, the comparative resin composition 1 was obtained. The comparative resin composition was then used to print a 20 μm thick coating on ordinary glass using inkjet printing. The coating was further cured in a UV curing chamber at 1500 mJ / cm². 2 Under certain conditions, ultraviolet light is used for curing to form an organic film.

[0141] The organic films prepared in Examples 1-5 and the organic films prepared in Comparative Examples 1-2 were subjected to performance tests. The evaluation items included: group conversion rate, adhesion, refractive index, water vapor transmission rate, mechanical properties including tensile strength, elastic modulus and elongation at break, heat resistance, and curing shrinkage rate. The results are listed in Table 1.

[0142] Table 1. Performance comparison of organic membranes in Examples 1-5 and Comparative Examples 1-2

[0143] Resin Composition 1 Resin Composition 2 Resin Composition 3 Resin Composition 4 Resin composition 5 Comparative Example 1 Comparative Example 2 Acrylate compounds containing Si-O segments (1-1) 10 10 10 Acrylate compounds containing Si-O segments (1-2) 10 Acrylate compounds containing Si-O segments (1-3) 10 Photocurable compounds containing Si-O segments (2-1) 15 15 15 Photocurable compounds containing Si-O segments (2-2) 15 15 Trimethylolpropane triacrylate 15 15 15 15 15 10 Ethylene oxide bisphenol A diacrylate 10 10 10 10 30 20 40 Dipentaerythritol pentaacrylate 10 10 10 10 20 20 30 Pentaerythritol triacrylate 10 10 Pentaerythritol tetraacrylate TPO 5 5 5 5 5 5 5 BYK-307 1 1 1 1 1 1 1 BYK-4511 2 2 2 2 2 2 2 KBM-403 2 2 2 2 2 2 2 Tg (°C) 122 120 115 110 127 74 71 Strength (MPa) 22 20 19 17 23 75 81 Modulus (MPa) 440 427 411 403 435 907 926 Elongation at break (%) 24 27 31 35 27 22 19 Curing shrinkage rate (%) 4 4 3 3 4 9 11 Group conversion rate (%) 97 96 98 97 97 96 97 Refractive index 1.44 1.42 1.42 1.41 1.43 1.51 1.52 Adhesion 5B 5B 5B 5B 5B 4B 3B Water vapor transmission rate (g / m2 24h) 3.3 3.1 3.1 3.1 3.2 5.3 5.5

[0144] The results in Table 1 show that, compared with Comparative Examples 1-2 which belong to the prior art, the organic films 1-5 formed by the photocurable resin composition of the present invention containing acrylate compounds with Si-O segments have lower curing shrinkage and water vapor transmission rate, better adhesion, mechanical properties and heat resistance, and a lower refractive index.

[0145] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Based on the above embodiments, any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An acrylate copolymer comprising Si-O segments, characterized in that, The molecular structure is shown in general formula (1): （1） wherein R1, R2 are each independently methyl, ethyl or trifluoromethyl; n is a repeating unit of Si-O segment, and n is in the range of 6-50.

2. The acrylate copolymer of claim 1, wherein, n is 10, and the molecular structure is shown in general formula (1-1): （1-1）， wherein R1, R2 are as defined above; or n is 16, and the molecular structure is shown in general formula (1-2): （1-2）， wherein R1, R2 are as defined above; or n is 22, and the molecular structure is shown in general formula (1-3): （1-3）， wherein R1, R2 are as defined above.

3. A process for the preparation of an acrylate copolymer comprising Si-O segments according to claim 1 or 2, characterized in that, The method comprises the following steps: thoroughly drying a reaction kettle, and replacing air with nitrogen; adding end-hydrogen silicone oil (XHG-202, Xin'an Chemical), a solvent (toluene, National Pharmaceutical Group), and a polymerization inhibitor (MEHQ, Solvay) into the kettle, stirring, and heating to 60-85°C; adding a catalytic amount of Karstedt catalyst (Shin-Etsu Chemical); adding unsaturated acrylate monomers to the system, controlling the molar ratio of allyl C=C:Si-H to be 1.1-1.2:1, and controlling the reaction temperature to be below 85°C during feeding; after feeding is completed, reacting at 60-85°C, preferably at about 80°C, for 4-6 hours, heating to 90-110°C, for example, about 100°C, opening a vacuum, and removing excess unsaturated acrylate monomers and solvents to obtain the product.

4. A photocurable resin composition, characterized by, The composition comprises the following components in percentage by mass: A, 5-50% of the Si-O segment-containing acrylate copolymer shown in general formula (1) according to claim 1 or 2; B, 10-40% of the Si-O segment-containing photocurable compound of general formula (2): （2）， In general formula (2), R1, R2 are each independently methyl, ethyl or trifluoromethyl; R3, R4 are each independently a photocurable group, and are selected from an epoxy group, an oxetane group, an acryloyl group, and a methacryloyl group; and n is a repeating unit of Si-O segment, and n is in the range of 0-4. C, 20-55% of a single-functional acrylate monomer, a dual-functional acrylate monomer, a triple-functional acrylate monomer, or a mixture of two or more of the above four or more functional acrylate monomers, wherein the molecular structure of the single-functional acrylate monomer is shown in general formula (3): （3）， In general formula (3), Y is selected from a hydrogen atom, a substituted or unsubstituted alkyl or alkoxy group with a carbon chain length of 1-30; and Q is selected from an alkyl chain or an alkoxy chain with a carbon chain length of 1-30, or a heteroatom-containing alkyl chain, or an aromatic ring-containing alkyl chain, or an aromatic heterocycle-containing alkyl chain. The molecular structure of the dual-functional acrylate monomer is shown in general formula (4): （4）， In general formula (4), Y is selected from a hydrogen atom, a substituted or unsubstituted alkyl or alkoxy group with a carbon chain length of 1-30; and Q is selected from an alkyl chain or an alkoxy chain with a carbon chain length of 1-30, or a heteroatom-containing alkyl chain, or an aromatic ring-containing alkyl chain, or an aromatic heterocycle-containing alkyl chain. The molecular structure of the triple-functional acrylate monomer is shown in general formula (5): （5）， In the general formula (5), K is selected from a hydrogen atom, a substituted or unsubstituted alkyl group or alkoxy group having a carbon chain length of 1-30; G is an alkyl chain or alkoxy chain having a carbon chain length of 1-30, or an alkyl chain containing a heteroatom, or an alkyl chain containing an aromatic ring, or an alkyl chain containing an aromatic heterocyclic ring; The functionality of the unsaturated double bond in the four or more functional acrylate monomers is 4-10; D, 0.1-5% of a photoinitiator selected from one or a mixture of two or more of an alkyl phenone, an acyl phosphine oxide, a benzophenone, a thioxanthone, a titanocene, a sulfonium salt.

5. The photocurable resin composition according to claim 4, wherein In the Si-O chain-containing photocurable compound of general formula (2), m is 2, and the molecular structure is shown in general formula (2-1): （2-1）， wherein R1, R2, R3, R4 are as defined above; or In the Si-O chain-containing photocurable compound of general formula (2), m is 3, and the molecular structure is shown in general formula (2-2): （2-2）， wherein R1, R2, R3, R4 are as defined above.

6. The photocurable resin composition according to claim 4, wherein Further comprising 0.1-5% of an auxiliary agent selected from one or a mixture of two or more of a leveling agent, a defoaming agent, a coupling agent, a wet dispersant, an adhesion promoter, a matting agent.

7. The photocurable resin composition according to claim 4, wherein The monofunctional acrylate monomer is selected from one or a mixture of two or more of the following compounds: a cycloaliphatic methacrylate, a dicyclopentadiene methacrylate, a tetrahydrofurfuryl methacrylate, an alicyclic acrylate, a dodecyl acrylate, a 2-phenoxyethyl acrylate, a 2-phenoxyethyl methacrylate, an isobornyl acrylate; The difunctional acrylate monomer is selected from one or a mixture of two or more of the following compounds: a dipropylene glycol diacrylate, a butanediol diacrylate, a hexanediol diacrylate, a diethylene glycol dimethacrylate, a polyethylene glycol diacrylate, an ethoxylated bisphenol A diacrylate, a tetraethylene glycol diacrylate, a dodecanediol dimethacrylate, a tripropylene glycol diacrylate, a neopentyl glycol diacrylate; The trifunctional acrylate monomer is selected from one or a mixture of two or more of the following compounds: a trimethylolpropane triacrylate, an ethoxylated trimethylolpropane triacrylate, a propoxylated trimethylolpropane triacrylate, a pentaerythritol triacrylate, a propoxylated glycerol triacrylate, a tri(2-hydroxyethyl) isocyanurate triacrylate, a cyanuric acid triacrylate; and / or The four or more functional acrylate monomer is selected from one or a mixture of two or more of the following compounds: a trimethylolpropane tetraacrylate, a pentaerythritol tetraacrylate, an alkoxylated pentaerythritol tetraacrylate, a dipentaerythritol pentaacrylate.

8. Use of the photocurable resin composition according to any one of claims 5-7 in the preparation of an organic light-emitting diode (OLED) surface encapsulation layer.

9. An organic film having low refractive index, high weather resistance, and high adhesion, characterized in that, obtained by UV photocuring of the photocurable resin composition according to any one of claims 6-8.

10. An electronic device comprising an organic light emitting diode (OLED), characterized in that, The organic light-emitting diode (OLED) surface comprises an organic encapsulation layer formed by curing using UV irradiation of the photocurable resin composition according to any one of claims 6-8.

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