Photosensitive resin composition for optoelectronic component packaging and use method thereof

Abstract

The present invention belongs to the field of organic thin-film encapsulation materials and specifically discloses a photosensitive resin composition for encapsulating optoelectronic components and its use method. The photosensitive resin composition comprises, by weight, 20 to 50 parts of a UV-curable monomer, 2 to 8 parts of a photocrosslinking initiator, and 5 to 30 parts of a functional dispersion. The UV-curable monomer is a mixture of a (meth)acrylate containing a long carbon chain and a bridged ring photocurable monomer in a specific mass ratio. The functional dispersion comprises a monofunctional reactive monomer and hollow microspheres, the surfaces of which are connected to organic modifying groups. The photosensitive resin composition of the present invention exhibits excellent overall performance. Its viscosity and surface tension meet the requirements of inkjet printing. It has a high cure rate, transmittance, and refractive index. In particular, its dielectric constant can be controlled below 2. It also possesses excellent mechanical properties and the ability to isolate water and oxygen, providing material support for the encapsulation of related electronic components.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic thin films, and in particular relates to a photosensitive resin composition for encapsulating optoelectronic components and a method for using the same. Background Art

[0002] As semiconductor technology continues to make progress, organic light-emitting diodes (OLEDs), a device that uses a multi-layer organic thin film structure to generate electroluminescence, have been widely used in the field of flexible displays. They have a series of significant advantages, such as easy production, low driving voltage, light weight and portability, wide color gamut, excellent brightness, low power consumption, fast response, high clarity, excellent flexibility and high luminous efficiency. They are one of the display technologies with the most development potential at present and can greatly meet consumers' new demands for display technology.

[0003] However, current OLED technology still faces several challenges, such as short lifespan, insufficient brightness, and poor reliability. These issues primarily stem from the susceptibility of OLED devices to the adverse effects of external water, oxygen, and outgassing, which can lead to oxidation of the organic and electrode layers, resulting in defective pixels and ultimately significantly reduced device performance and lifetime. Currently, to protect organic molecular materials from water and oxygen damage, a common approach is to inkjet-print thin-film encapsulation compositions to create an organic encapsulation layer. This effectively isolates the organic molecules from the air and creates a tight encapsulation system. This process requires excellent spreadability to avoid negatively impacting the inkjet printing process. Furthermore, the organic encapsulation layer must possess a low dielectric constant and dielectric loss to effectively reduce the device's signal-to-noise ratio and signal latency. Therefore, the development of thin-film encapsulation compositions with low dielectric constants has become crucial in the field of flexible OLED encapsulation technology.

[0004] At present, the commonly used method includes adding substances with low dielectric constant properties, such as fluorinated monomers, but generally large-volume fluorinated monomers tend to have low reactivity, which not only causes the thermal and mechanical properties of the material to be lost during use, but also comes with high costs. In addition, another method is to introduce air micropores into the resin, using the low dielectric constant properties of air to reduce the average dielectric constant of the material, but this method has obvious drawbacks. The introduction of air micropores will cause the stability of the thin film packaging material to deteriorate, and it is very easy to cause other problems such as pore blocking or phase separation during the inkjet printing process. Therefore, such materials are currently not applicable to inkjet printing processes. In addition, the introduction of excessive cavities will also cause serious obstacles to the mechanical properties and water and oxygen barrier properties of the film material. For example, a low dielectric constant hollow carbon sphere / epoxy resin composite material disclosed in China Publication No. CN103756253B has the advantages of light weight, low dielectric constant, and good thermal conductivity, dimensional stability and chemical stability, but its surface tension and viscosity cannot meet the requirements of the inkjet printing process, and the mechanical properties and water and oxygen barrier properties are also difficult to be effectively guaranteed.

[0005] In view of this, this invention is proposed. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a photosensitive resin composition for encapsulating optoelectronic components and a method for using the same, which are mainly used to solve a series of problems existing in existing thin film encapsulation materials in actual application scenarios, specifically manifested in a high dielectric constant, frequent pore clogging and phase separation during inkjet printing, and poor mechanical properties and water and oxygen barrier properties.

[0007] The purpose of the present invention is to solve the problem through the following technical solutions:

[0008] In a first aspect, the present invention provides a photosensitive resin composition for encapsulating optoelectronic components, comprising the following raw materials in parts by mass: 20 to 50 parts of a UV-curable monomer, 2 to 8 parts of a photocrosslinking initiator, and 5 to 30 parts of a functional dispersion;

[0009] Wherein, the functional dispersion includes monofunctional reactive monomers and hollow microspheres.

[0010] Note: The hollow microspheres of the present invention refer to spherical structures with a cavity inside.

[0011] Preferably, the formulation of the photosensitive resin composition for encapsulating optoelectronic components is: 25 to 45 parts of UV-curable monomer, 2 to 5 parts of photocrosslinking initiator, and 14 to 21 parts of functional dispersion.

[0012] Furthermore, the mass ratio of the monofunctional reaction monomer to the hollow microspheres is (2-3):1.

[0013] Preferably, the mass ratio of the monofunctional reactive monomer to the hollow microspheres is (2.4-2.6):1.

[0014] Furthermore, the monofunctional reactive monomer is an acrylate monomer, and has a viscosity of 2 cps to 10 cps.

[0015] Specifically, the acrylate monomer includes any one of lauric acid acrylate, isodecyl acrylate, isooctyl acrylate, isononyl acrylate, lauric acid methacrylate and 2-ethylhexyl methacrylate.

[0016] Furthermore, the surface of the hollow microspheres is connected with an organic modification group, and the organic modification group is an acrylate group or a methacrylate group;

[0017] The hollow microspheres include hollow silica microspheres;

[0018] The particle size of the hollow microspheres is 10nm to 100nm, preferably 20nm to 50nm;

[0019] The wall thickness of the hollow microspheres is 2nm to 6nm.

[0020] Furthermore, the monofunctional reactive monomer and the surface-modified hollow microspheres are mixed in the above-mentioned mass ratio to obtain a functional dispersion.

[0021] Specifically, the method for preparing surface-modified hollow microspheres of the present invention comprises the following steps:

[0022] Step 1: first, cetyltrimethylammonium bromide (surfactant) and tetraethyl orthosilicate are mixed in a molar ratio of (0.1-0.5):1, then added to an ammonia solution and stirred to dissolve, and then the mixed solution is reacted at a constant temperature of 30°C to 80°C for 5h to 10h, the obtained reaction product is centrifuged, the supernatant is removed, and the residue is dried to obtain a white powder, and finally the obtained white powder is calcined at a temperature of 600°C to 650°C for 0.5h to 1h to remove the surfactant, thereby obtaining mesoporous spherical silica microspheres, that is, hollow microspheres;

[0023] Step 2: adding an organic substance for treating the surface of the hollow microspheres obtained in step 1, so that the surface of the hollow microspheres is connected with an organic modification group, wherein the organic modification group is an acrylate group or a methacrylate group.

[0024] Wherein, in step 2, the mass ratio of the hollow microspheres to the organic substance is (1-2): (1-2); the organic substance includes any one of 3-(methacryloyloxy)propyltrimethoxysilane, 3-(acryloyloxy)propyltrimethoxysilane or 3-(isomethacryloyloxy)propyltrimethoxysilane.

[0025] It should be noted that the present invention first mixes hollow microspheres (with modified groups attached to their surfaces) with monofunctional reactive monomers in proportion to obtain a functional dispersion, which is then added to the system to prepare a photosensitive resin composition. Compared with directly adding the hollow microspheres to the system, the present invention has the following effects:

[0026] (1) Interaction between the modifying group and the monofunctional reactive monomer: There is a chemical affinity between the modifying group (acrylate or methacrylate) on the surface of the hollow microspheres and the monofunctional reactive monomer (acrylate monomer). This affinity enables the hollow microspheres to form a stable mixture with the acrylate monomer, thereby improving the solubility of the hollow microspheres in the UV-curable monomer.

[0027] (2) Regulating the viscosity of the system: The interaction between the modified groups on the surface of the hollow microspheres and the acrylic monomers reduces the viscosity of the system. At the same time, the acrylic monomers have a low viscosity and can help regulate the distribution of the hollow microspheres in the system, thereby improving the fluidity of the mixture and effectively reducing the overall viscosity of the system. When the hollow microspheres are mixed with acrylic monomers, they can fill the gaps between the monomers, further reducing the viscosity of the system.

[0028] (3) Preventing aggregation of nanoscale hollow microspheres: Hollow microspheres generally have low solubility, especially nanoscale hollow microspheres, which have high surface energy and are prone to aggregation, thus affecting the performance of the photosensitive resin composition. Monofunctional acrylate monomers have strong surface activity and can be adsorbed on the surface of hollow microspheres. They interact with the surface of hollow microspheres through physical adsorption or chemical reaction. This surface modification reduces the surface energy of the hollow microspheres, thereby reducing their aggregation tendency.

[0029] (4) Enhanced system stability: Photocurable monomers usually have low polarity and high viscosity. Direct addition of hollow microspheres may cause microsphere aggregation. By first mixing with acrylate monomers, the hollow microspheres are well dispersed in the lower viscosity acrylate monomers. When the UV-curable monomers are added, the hollow microspheres are already in a uniformly dispersed state and are less likely to aggregate, thereby improving the uniformity and stability of the mixed system.

[0030] Furthermore, adding hollow microspheres can reduce the density of the material, but adding too much can reduce the mechanical and barrier properties of the material. To overcome this problem, the present invention prefers hollow microspheres with a particle size of 20nm to 50nm and a wall thickness of 2nm to 6nm, and the addition amount of the functional dispersion is 5 to 30 parts. At the same time, by properly adjusting the ratio of monofunctional reactive monomers to UV-curable monomers, a balance between tensile strength and elongation at break can be achieved, while also improving the barrier properties of the film, thereby effectively blocking the penetration of water and oxygen.

[0031] Furthermore, the UV-curable monomer is a mixture of a (meth)acrylate containing a long carbon chain and a bridged ring photocurable monomer.

[0032] Furthermore, the mass ratio of the monofunctional reactive monomer, the (meth)acrylate containing a long carbon chain and the bridged ring photocurable monomer is (10-15): (15-30): (10-15).

[0033] Among them, (meth)acrylates containing long carbon chains can give the material flexibility and fluidity, which helps achieve high-quality printing effects and can effectively reduce the surface tension of the material, thereby improving the fluidity of the material. At the same time, (meth)acrylates containing long carbon chains can produce cross-linking reactions with bridge-ring monomers, thereby building a three-dimensional network structure and strengthening the strength of the material. In addition, the introduction of bridge-ring photocurable monomers can help increase the cross-linking density, enhance the barrier properties of the material, and reduce the water and oxygen permeability. The functional dispersion works synergistically with the (meth)acrylates containing long carbon chains and bridge-ring photocurable monomers, which can not only balance the cross-linking density, flexibility and photocuring properties of the material, but also effectively reduce the dielectric constant and dielectric loss of the material, and improve the transmittance of the cured film.

[0034] Furthermore, the (meth)acrylate containing a long carbon chain includes one or more of 1,6-hexanediol diacrylate, 2-methyl-2-acrylate-1,10-decanediol, 2-methyl-2-acrylate-1,9-nonanediol dimethacrylate, 1,5-pentanediol dimethacrylate, 1,11-undecanediol dimethacrylate, 1,12-dodecanediol di(meth)acrylate, 1,13-tridecanediol dimethacrylate, 1,14-tetradecanediol di(meth)acrylate or 1,18-octadecanediyl dimethacrylate;

[0035] The bridged ring photocurable monomer includes a bridged ring diacrylate monomer containing six to twenty-five carbon atoms, specifically one or more of biscyclopentenyl acrylate, isobornyl acrylate, cyclohexyl methacrylate, isobornyl methacrylate, biscyclopentyl methacrylate, tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate, biscyclopentenyl ethoxylated acrylate, biscyclopentenyl ethoxylated methacrylate, isobornyl (meth)acrylate, or biscyclopentenyl (meth)acrylate.

[0036] The glass transition temperature (Tg) of the bridged ring photocurable monomer is 80°C to 170°C.

[0037] Furthermore, the photocrosslinking initiator includes one or more of TPO, TEPO, 1173, 184, 819, 4-methoxybenzaldehyde, 4,4'-bis(dimethylamino)benzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, bisbenzoylphenylphosphine oxide or benzoyldiphenylphosphine oxide.

[0038] After actual testing, the photosensitive resin composition formed by the present invention has a surface tension of 27 dyne / cm to 30 dyne / cm and a viscosity of 21 cps to 24 cps at a temperature of 25±5°C, is suitable for inkjet printing, and has a dielectric constant of only 1.9 to 22.

[0039] In a second aspect, the present invention provides a method for using the above-mentioned photosensitive resin composition for encapsulating optoelectronic components, the specific steps of which are as follows:

[0040] Step 1: firstly attach the photosensitive resin composition to the surface of the optoelectronic component to be packaged by spin coating, doctor blade coating, screen printing or inkjet printing;

[0041] Step 2: Next, the photosensitive resin composition is irradiated with ultraviolet light having a wavelength between 250 nm and 400 nm for 30 seconds to 600 seconds, and finally the photosensitive resin composition is cured to form an organic film having a thickness of 5 μm to 50 μm.

[0042] Furthermore, the optoelectronic components include light emitting diodes, photosensors, photovoltaic devices, etc.

[0043] Taking flexible OLED devices as an example, they include an ITO substrate, an organic light-emitting diode, an inorganic encapsulation film layer and an organic encapsulation film layer stacked in sequence.

[0044] Among them, the organic encapsulation film layer uses the photosensitive resin composition of the present invention and is formed by inkjet printing; the inorganic encapsulation film layer is a film layer of silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, indium oxide, silicon nitride, etc., and is formed by chemical vapor deposition or atomic deposition.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The present invention premixes hollow microspheres with surface-modifying groups with an acrylate monomer, then adds a UV-curable monomer and a photocrosslinking initiator to produce a photosensitive resin composition. This significantly improves the solubility of the hollow microspheres, regulates the viscosity of the system, and effectively curbs the aggregation of the nanoscale hollow microspheres. This premixing mechanism not only optimizes the processing performance of the system but also fundamentally enhances the stability and overall performance of the photosensitive resin composition, laying a solid foundation for its reliable operation in practical applications.

[0047] 2. The functional dispersion of the present invention incorporates hollow microspheres filled with gas. When the hollow microspheres are evenly dispersed in the system, they form a multiphase system containing air. The low dielectric properties of the gas reduce the polarization ability of the composite material under the action of an electric field, thereby significantly reducing the overall dielectric constant of the composite material. At the same time, the outer shell of the hollow microspheres acts as a shield, effectively hindering the transfer of charge in the medium. Furthermore, their presence reduces the density of polar molecules within the resin, further reducing the polarization effect and further reducing the dielectric constant, thus meeting the stringent requirements of packaging materials for low dielectric properties.

[0048] 3. The present invention regulates the mass ratio of the monofunctional reactive monomer, the (meth)acrylate containing a long carbon chain and the bridged ring photocurable monomer within the range of (10-15): (15-30): (10-15), and controls the amount of the functional dispersion added, thereby achieving the following effects: First, in terms of inkjet printing performance, the surface tension and viscosity can be adjusted to a suitable range, thereby improving the printing quality; second, in terms of material performance, the toughness of the material can be effectively improved, the brittleness can be significantly reduced, and the durability and reliability of the film can be greatly enhanced, so that the film can still maintain excellent performance in complex environments; third, in terms of barrier performance, the penetration of water and oxygen can be effectively blocked, providing a long-lasting and stable protective barrier for electronic components, thereby extending the service life of electronic components. DETAILED DESCRIPTION

[0049] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention described in detail in the appended claims.

[0050] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with relevant experiments.

[0051] Preparation Example 1

[0052] The functional dispersion in the embodiment of the present invention uses surface-modified hollow microspheres, and the preparation process is as follows:

[0053] 1) Hexadecyltrimethylammonium bromide and tetraethyl orthosilicate were mixed in a molar ratio of 0.3:1, added to an aqueous ammonia solution, stirred and dissolved, and the mixed solution was reacted at 60°C for 6 hours. The resulting reaction product was centrifuged, the supernatant was removed, and the residue was dried to obtain a white powder. Finally, the obtained white powder was calcined at 600°C for 1 hour to remove the surfactant, thereby preparing mesoporous spherical silica microspheres, i.e., hollow microspheres with a particle size of 50 nm and a wall thickness of 3 nm.

[0054] 2) 3-(methacryloyloxy)propyltrimethoxysilane was added to the above hollow microspheres at a mass ratio of 1:1 for surface treatment, thereby obtaining surface-modified hollow microspheres with a particle size of 50 nm (in the present invention, the particle size of the hollow microspheres refers to the average particle size).

[0055] Preparation Example 2

[0056] The functional dispersion in the embodiment of the present invention uses surface-modified hollow microspheres, and the preparation process is as follows:

[0057] 1) Hexadecyltrimethylammonium bromide and tetraethyl orthosilicate were mixed in a molar ratio of 0.3:1, added to an aqueous ammonia solution, stirred and dissolved, and the mixed solution was reacted at 60°C for 6 hours. The resulting reaction product was centrifuged, the supernatant was removed, and the residue was dried to obtain a white powder. Finally, the obtained white powder was calcined at 600°C for 1 hour to remove the surfactant, thereby preparing mesoporous spherical silica microspheres, i.e., hollow microspheres with a particle size of 50 nm and a wall thickness of 3 nm.

[0058] 2) 3-(acryloyloxy)propyltrimethoxysilane was added to the above hollow microspheres at a mass ratio of 1:2 for surface treatment, thereby obtaining surface-modified hollow microspheres with a particle size of 50 nm.

[0059] Preparation Example 3

[0060] The functional dispersion in the embodiment of the present invention uses surface-modified hollow microspheres, and the preparation process is as follows:

[0061] 1) Hexadecyltrimethylammonium bromide and tetraethyl orthosilicate were mixed in a molar ratio of 0.3:1, added to an aqueous ammonia solution, stirred and dissolved, and the mixed solution was reacted at 60°C for 6 hours. The resulting reaction product was centrifuged, the supernatant was removed, and the residue was dried to obtain a white powder. Finally, the obtained white powder was calcined at 600°C for 1 hour to remove the surfactant, thereby preparing mesoporous spherical silica microspheres, i.e., hollow microspheres with a particle size of 50 nm and a wall thickness of 3 nm.

[0062] 2) 3-(Isomethylacryloyloxy)propyltrimethoxysilane was added to the above hollow microspheres at a mass ratio of 2:1 for surface treatment, thereby obtaining surface-modified hollow microspheres with a particle size of 50 nm.

[0063] Preparation Example 4

[0064] The functional dispersion in Comparative Example 3 of the present invention uses surface-modified hollow microspheres, and the preparation process is as follows:

[0065] 1) Hexadecyltrimethylammonium bromide and tetraethyl orthosilicate were mixed in a molar ratio of 0.2:3, added to an aqueous ammonia solution, stirred and dissolved, and then the mixed solution was reacted at a constant temperature of 60°C for 6 hours. The obtained reaction product was centrifuged, the supernatant was removed, and the residue was dried to obtain a white powder. Finally, the obtained white powder was calcined at 600°C for 1 hour to remove the surfactant, thereby preparing mesoporous spherical silica microspheres, i.e., hollow microspheres with a particle size of 200 nm.

[0066] 2) 3-(methacryloyloxy)propyltrimethoxysilane was added to the above hollow microspheres at a mass ratio of 1:1 for surface treatment, thereby obtaining surface-modified hollow microspheres with a particle size of 200 nm. Example 1

[0067] The photosensitive resin composition provided in the present embodiment comprises, by weight, 14.5 parts of a functional dispersion, 25 parts of a UV-curable monomer, and 5 parts of a photocrosslinking initiator. The mass ratio of the monofunctional reactive monomer to the hollow microspheres in the functional dispersion is 10:4.5. The UV-curable monomer is a mixture comprising 15 parts of a long-chain (meth)acrylate and 10 parts of a bridged ring photocurable monomer.

[0068] Specifically, the monofunctional reactive monomer is lauric acid acrylate, and the hollow microspheres are prepared according to Preparation Example 1 to finally obtain surface-modified hollow microspheres with a particle size of 50 nm.

[0069] The (meth)acrylate containing a long carbon chain is selected from 1,6-hexanediol diacrylate.

[0070] The bridged ring photocurable monomer is isobornyl acrylate.

[0071] TPO was selected as the photocrosslinking initiator.

[0072] When preparing the photosensitive resin composition, at room temperature and in a dark environment, 10 parts of lauric acid acrylate and 4.5 parts of the surface-modified hollow microspheres with a particle size of 50 nm obtained in Preparation Example 1 were pre-mixed to obtain 14.5 parts of a functional dispersion, and then 15 parts of 1,6-hexanediol diacrylate, 10 parts of isobornyl acrylate and 5 parts of TPO were added thereto. The mixture was mixed and stirred until the initiator was completely dissolved, and the photosensitive resin composition was obtained after standing. Example 2

[0073] The photosensitive resin composition provided in the present embodiment comprises, by weight, 14.3 parts of a functional dispersion, 25 parts of a UV-curable monomer, and 2 parts of a photocrosslinking initiator. The mass ratio of the monofunctional reactive monomer to the hollow microspheres in the functional dispersion is 10:4.3. The UV-curable monomer is a mixture comprising 15 parts of a long-chain (meth)acrylate and 10 parts of a bridged ring photocurable monomer.

[0074] Specifically, the monofunctional reactive monomer is isooctyl acrylate, and the hollow microspheres are prepared according to Preparation Example 1 to obtain surface-modified hollow microspheres with a particle size of 50 nm.

[0075] The (meth)acrylate containing a long carbon chain is selected from 1,6-hexanediol diacrylate.

[0076] The bridged ring photocurable monomer is isobornyl methacrylate.

[0077] TPO was selected as the photocrosslinking initiator.

[0078] When preparing the photosensitive resin composition, at room temperature and in a dark environment, 10 parts of isooctyl acrylate and 4.3 parts of the surface-modified hollow microspheres with a particle size of 50 nm obtained in Preparation Example 1 were pre-mixed to obtain 14.3 parts of a functional dispersion, and then 15 parts of 1,6-hexanediol diacrylate, 10 parts of isobornyl acrylate and 5 parts of TPO were added thereto. The mixture was stirred until the initiator was completely dissolved, and the photosensitive resin composition was obtained after standing. Example 3

[0079] The photosensitive resin composition provided in this embodiment of the present invention comprises, by weight, 14 parts of a functional dispersion, 30 parts of a UV-curable monomer, and 3 parts of a photocrosslinking initiator. The mass ratio of the monofunctional reactive monomer to the hollow microspheres in the functional dispersion is 10:4. The UV-curable monomer is a mixture comprising 20 parts of a long-chain (meth)acrylate and 10 parts of a bridged ring photocurable monomer.

[0080] Specifically, the monofunctional reactive monomer is isononyl acrylate, and the hollow microspheres are prepared according to Preparation Example 2 to finally obtain surface-modified hollow microspheres with a particle size of 50 nm.

[0081] The (meth)acrylate containing a long carbon chain is 1,11-undecanediol dimethacrylate.

[0082] The bridged ring photocurable monomer is dicyclopentenyl ethoxylated acrylate.

[0083] 4-methoxybenzaldehyde was selected as the photocrosslinking initiator.

[0084] When preparing the photosensitive resin composition, at room temperature and in a dark environment, 10 parts of isononyl acrylate and 4 parts of the surface-modified hollow microspheres with a particle size of 50 nm obtained in Preparation Example 2 were pre-mixed to obtain 14 parts of a functional dispersion, and then 20 parts of 1,11-undecanediol dimethacrylate, 10 parts of dicyclopentenyl ethoxylated acrylate and 3 parts of 4-methoxybenzaldehyde were added thereto, and the mixture was stirred until the initiator was completely dissolved. After standing, the photosensitive resin composition was obtained. Example 4

[0085] The photosensitive resin composition provided in this embodiment of the present invention comprises, by weight, 18 parts of a functional dispersion, 40 parts of a UV-curable monomer, and 5 parts of a photocrosslinking initiator. The mass ratio of the monofunctional reactive monomer to the hollow microspheres in the functional dispersion is 13:5. The UV-curable monomer is a mixture comprising 25 parts of a long-chain (meth)acrylate and 15 parts of a bridged ring photocurable monomer.

[0086] Specifically, the monofunctional reactive monomer is 2-ethylhexyl methacrylate, and the hollow microspheres are prepared according to Preparation Example 2 to finally obtain surface-modified hollow microspheres with a particle size of 50 nm.

[0087] The (meth)acrylate containing a long carbon chain is 1,11-undecanediol dimethacrylate.

[0088] The bridged ring photocurable monomer is dicyclopentenyl acrylate.

[0089] The photocrosslinking initiator used is 819.

[0090] When preparing the photosensitive resin composition, at room temperature and in a dark environment, 13 parts of 2-ethylhexyl methacrylate and 5 parts of the surface-modified hollow microspheres with a particle size of 50 nm obtained in Preparation Example 2 were pre-mixed to obtain 18 parts of a functional dispersion, and then 25 parts of 1,11-undecanediol dimethacrylate, 15 parts of dicyclopentenyl acrylate and 5 parts of TPO were added thereto. The mixture was stirred until the initiator was completely dissolved, and the photosensitive resin composition was obtained after standing. Example 5

[0091] The photosensitive resin composition provided in this embodiment of the present invention comprises, by weight, 21 parts of a functional dispersion, 45 parts of a UV-curable monomer, and 5 parts of a photocrosslinking initiator. The mass ratio of the monofunctional reactive monomer to the hollow microspheres in the functional dispersion is 15:6. The UV-curable monomer is a mixture comprising 30 parts of a long-chain (meth)acrylate and 15 parts of a bridged ring photocurable monomer.

[0092] Specifically, the monofunctional reactive monomer is isodecyl acrylate, and the hollow microspheres are prepared according to Preparation Example 3 to finally obtain surface-modified hollow microspheres with a particle size of 50 nm.

[0093] The (meth)acrylate containing a long carbon chain is 1,18-octadecanediyl dimethacrylate.

[0094] The bridged ring photocurable monomer is dicyclopentenyl (meth)acrylate.

[0095] The photocrosslinking initiator used is 819.

[0096] When preparing the photosensitive resin composition, at room temperature and in a dark environment, 15 parts of isodecyl acrylate and 6 parts of the surface-modified hollow microspheres with a particle size of 50 nm finally obtained in Preparation Example 3 were pre-mixed to obtain 21 parts of a functional dispersion, and then 30 parts of 1,18-octadecanediyl dimethacrylate, 15 parts of dicyclopentenyl (meth)acrylate and 5 parts of 819 were added thereto, and the mixture was stirred until the initiator was completely dissolved. After standing, the photosensitive resin composition was obtained.

[0097] Comparative Example 1

[0098] The only difference between this comparative example and Example 1 is that no functional dispersion liquid is added to the photosensitive resin composition of this comparative example.

[0099] Comparative Example 2

[0100] The only difference between this comparative example and Example 1 is that no monofunctional reactive monomer is added to the functional dispersion of this comparative example.

[0101] Comparative Example 3

[0102] The only difference between this comparative example and Example 1 is that the particle size of the hollow microspheres added to the functional dispersion of this comparative example adopts the particle size of Preparation Example 4 to finally obtain surface-modified hollow microspheres with a particle size of 200 nm, that is, the particle size of the hollow microspheres in the functional dispersion of this comparative example is not in the range of 10 nm to 100 nm.

[0103] Comparative Example 4

[0104] The only difference between this comparative example and Example 1 is that the amount of the functional dispersion added in this comparative example is 40 parts, that is, the amount of the functional dispersion added to the photosensitive resin composition in this comparative example is too much.

[0105] Comparative Example 5

[0106] The only difference between this comparative example and Example 1 is that the mass ratio of the monofunctional reactive monomer, the long carbon chain (meth)acrylate and the bridged ring photocurable monomer in the photosensitive resin composition of this comparative example is 20:10:20, that is, it is not within the ratio range of (10-15): (15-30): (10-15).

[0107] Comparative Example 6

[0108] The only difference between this comparative example and Example 1 is that in this comparative example, 15 parts of butyl methacrylate and 10 parts of isobornyl acrylate are added as the UV-curable monomers, that is, the photosensitive resin composition of this comparative example does not contain (meth)acrylate containing a long carbon chain.

[0109] Comparative Example 7

[0110] The only difference between this comparative example and Example 1 is that in this comparative example, 15 parts of 1,6-hexanediol diacrylate and 10 parts of dodecafluoroheptyl methacrylate are added as the UV-curable monomer, that is, the photosensitive resin composition of this comparative example does not contain a bridged ring photocurable monomer.

[0111] The raw material ratios of Examples 1 to 5 and Comparative Examples 1 to 7 are shown in Table 1 below:

[0112] Table 1 Raw material ratios of Examples 1 to 5 and Comparative Examples 1 to 7

[0113]

[0114] In order to verify the efficacy of the present invention, the applicant used 30mW / cm 2 The film was cured by irradiation with UV light for 600s to obtain a 30μm thick cured film for performance testing. The specific aspects include the following:

[0115] (1) Surface tension: The surface tension was tested using a surface tension meter (QBZY-2 surface tension meter). The test was conducted at 25°C. Defoaming and centrifugation were performed before the test. Each sample was tested 5 times, and the final data were averaged.

[0116] (2) Viscosity: The viscosity of the high-refractive precursor liquid was tested using a rotational rheometer (EVO type rotational viscometer). The test was performed at 25°C, using a 20 mm diameter conical rotor, and setting the shear rate to 0.01 s. -1 ~500s -1 , and select 10s -1 The viscosity of the samples under different shear rates was compared, and each sample was tested 5 times, and the final data was averaged.

[0117] (3) Refractive index: Pure organic inkjet printing with high refractive index ink was printed on a glass substrate and heated to 30 mW / cm2 in a nitrogen atmosphere. 2 The film was subjected to UV curing by UV irradiation under UV conditions to produce a cured film layer having a size of 5 mm×15 mm×0.1 mm (width×length×thickness), which was then tested using an Abbe refractometer.

[0118] (4) Light transmittance: The samples were prepared according to the method for forming the cured pattern except that the mask was not used. The light transmittance of the cured film in the visible light range of 400 nm to 800 nm was measured using a UV-visible spectrophotometer (U-3900 Hitachi).

[0119] (5) Photocuring rate: The encapsulation ink composition was inkjet printed on a glass substrate and the curing rate was 30 mW / cm 2 The encapsulant was subjected to UV curing for 120 s by UV irradiation to produce a sample with a size of 3 cm × 7.5 cm × 18 μm (width × length × thickness), and then the encapsulant before curing and the film after curing were measured using FT-IR (Nicolet iS50, Thermo-Fisher) at 1635 cm -1 (C=C) and 1720cm -1 Absorption peak intensity near (C=O).

[0120] Photocuring rate (%) = |1-(F / S)| × 100;

[0121] Wherein, F is the cured film at 1635cm -1 The absorption peak intensity near 1720 cm -1 The ratio of the absorption peak intensities near 1635cm -1 The absorption peak intensity near 1720 cm -1 The ratio of the absorption peak intensities near

[0122] (6) Dielectric constant: The dielectric constant of the composition was tested under the test conditions of 10 GHz using GB / T 1693-2007.

[0123] (7) Water vapor transmission rate: The water vapor transmission rate was measured using a water vapor transmission rate tester (PERMATRAN-W3 / 33, manufactured by MOCON) at 85° C. and 85% relative humidity for 24 hours.

[0124] The final test results are shown in Table 2 below:

[0125] Table 2 Test results of Examples 1 to 5 and Comparative Examples 1 to 7

[0126]

[0127] The test results in Table 2 show that the photosensitive resin compositions formed by specific proportions of UV-curable monomers, photocrosslinking initiators, and functional dispersions in Examples 1 to 5 of the present invention have excellent comprehensive performance. Among them, the viscosity and surface tension meet the requirements of inkjet printing, and have high curing rates, transmittances, and refractive indices. In particular, the dielectric constant is significantly reduced and can be controlled below 2. In addition, the photosensitive resin composition also has excellent mechanical properties and the ability to isolate water and oxygen, and the water vapor permeability is less than or equal to 2.8g / m 2 24 hours, can provide reliable performance guarantee for related applications, effectively meet the stringent requirements of various complex application scenarios for comprehensive material performance.

[0128] However, the test results of Comparative Example 1 show that if the functional dispersion is not added to the formula, the dielectric lowering effect cannot be achieved; the test results of Comparative Example 2 show that without using a monofunctional reactive monomer for mixing pretreatment, the dielectric is difficult to further reduce; the test results of Comparative Example 3 show that the particle size of the hollow microspheres is too large and easy to agglomerate, which will affect the transmittance and photocuring rate; the test results of Comparative Example 4 show that if the amount of functional dispersion added is too much, the water vapor permeability is significantly increased, which is not conducive to isolating water and oxygen; the test results of Comparative Example 5 show that the mass ratio of the monofunctional reactive monomer, the long carbon chain (meth)acrylate and the bridged ring photocurable monomer is not within the ratio range given in the present invention, and the viscosity of the formed photosensitive resin composition is not within the appropriate range, and is not suitable for inkjet printing; the test results of Comparative Examples 6 and 7 show that when short carbon chain (meth)acrylate and dodecafluoroheptyl methacrylate are used in the UV curable monomer, the surface tension and viscosity are not within the appropriate range, which is not suitable for inkjet printing, and a printing ink with low dielectric properties cannot be obtained, and the water vapor permeability is also high.

[0129] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present 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 present invention.

[0130] It should be understood that the present invention is not limited to the above description and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A photosensitive resin composition for encapsulating optoelectronic components, characterized in that: The method comprises the following raw materials in parts by weight: 20 to 50 parts of an ultraviolet light curable monomer, 2 to 8 parts of a photocrosslinking initiator, and 5 to 30 parts of a functional dispersion; The functional dispersion comprises a monofunctional reactive monomer and hollow microspheres, wherein the mass ratio of the monofunctional reactive monomer to the hollow microspheres is (2-3):1, the hollow microspheres have a particle size of 20 nm to 50 nm, a wall thickness of 2 nm to 6 nm, and the monofunctional reactive monomer comprises one of lauric acid acrylate, isodecyl acrylate, isooctyl acrylate, isononyl acrylate, lauric acid methacrylate, and 2-ethylhexyl methacrylate; The ultraviolet light-curable monomer is a mixture of a (meth)acrylate containing a long carbon chain and a bridged ring photocurable monomer, and the mass ratio of the monofunctional reactive monomer, the (meth)acrylate containing a long carbon chain and the bridged ring photocurable monomer is (10-15): (15-30): (10-15); The (meth)acrylate containing a long carbon chain includes one or more of 1,6-hexanediol diacrylate, 2-methyl-2-acrylate-1,10-decanediol, 2-methyl-2-acrylate-1,9-nonanediol dimethacrylate, 1,5-pentanediol dimethacrylate, 1,11-undecanediol dimethacrylate, 1,12-dodecanediol di(meth)acrylate, 1,13-tridecanediol dimethacrylate, 1,14-tetradecanediol di(meth)acrylate or 1,18-octadecanediyl dimethacrylate; The bridged ring photocurable monomer includes a bridged ring diacrylate monomer containing six to twenty-five carbon atoms.

2. The photosensitive resin composition for encapsulating optoelectronic components according to claim 1, wherein The viscosity of the monofunctional reactive monomer is 2 cps to 10 cps.

3. The photosensitive resin composition for encapsulating optoelectronic components according to claim 1, wherein The hollow microspheres include hollow silica.

4. The photosensitive resin composition for encapsulating optoelectronic components according to claim 1, wherein The photocrosslinking initiator includes one or more of TPO, TEPO, 1173, 184, 819, 4-methoxybenzaldehyde, 4,4'-bis(dimethylamino)benzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-methoxybenzophenone, hydroxybenzophenone, bisbenzoylphenylphosphine oxide or benzoyldiphenylphosphine oxide.

5. A method for using the photosensitive resin composition for encapsulating optoelectronic components according to any one of claims 1 to 4, characterized in that: The specific steps include: Step 1: firstly attach the photosensitive resin composition to the surface of the optoelectronic component to be packaged by spin coating, doctor blade coating, screen printing or inkjet printing; Step 2: Next, the photosensitive resin composition is irradiated with ultraviolet light having a wavelength between 250 nm and 400 nm for 30 seconds to 600 seconds, and finally the photosensitive resin composition is cured to form an organic film having a thickness of 5 μm to 50 μm.

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