Packaging composition, packaging layer and electrophoretic display

Abstract

The invention provides a packaging composition, a packaging layer and an electrophoretic display, and belongs to the technical field of display device packaging. The packaging composition comprises the following components in parts by weight: 50 to 80 parts of polyurethane acrylate, 10 to 40 parts of a reactive diluent, 0.5 to 3 parts of a photoinitiator, 0.5 to 5 parts of a coupling agent, 0.1 to 2 parts of an additive containing disulfide bonds and 0.1 to 1 part of an additive containing polyethylene glycol, wherein the reactive diluent comprises 1-10 parts of an acrylate monomer with a refractive index of less than or equal to 1.45. The packaging composition not only has good water and oxygen resistance, but also has excellent cohesiveness, high bonding strength with the cofferdam and lower refractive index, and can increase the overall transmittance of an upper cover plate of a product.

Description

Technical Field

[0001] The invention belongs to the technical field of display device packaging, and in particular relates to a packaging composition, a packaging layer and an electrophoretic display. Background Art

[0002] Electronic Paper Display (EPD) is an important category of paper-like display technology. Unlike conventional TFT-LCD (Thin film transistor liquid crystal display) and OLED (Organic Light Emitting Device) self-luminous display technologies, electronic paper display technology mainly relies on ambient light reflection to display patterns. It is lighter and consumes less energy. There are six different types of electronic paper technology, including E-Ink microcapsule technology, SiPix microcup technology, Bridgestone electronic liquid powder technology, cholesterol liquid crystal display technology, micro-electromechanical system technology and electrowetting technology.

[0003] Electronic paper displays will be corroded and damaged by water vapor and oxygen, so they need to be protected from water and oxygen. Flexible packaging technology is a new type of packaging technology that uses flexible materials for packaging, which can effectively protect electronic paper from the influence of the external environment, improve the durability and reliability of electronic paper, and has high flexibility and adaptability to meet the needs of different application scenarios. However, the existing structure and process technology of flexible packaging are relatively complex, and the bonding strength of flexible packaging glue is low, the bonding force to the cofferdam is weak, and the weather resistance is poor; at the same time, the refractive index of the current flexible packaging material is too high, which is not conducive to the display of electronic paper. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide an encapsulation composition, an encapsulation layer and an electrophoretic display. The encapsulation composition has good water and oxygen barrier properties, excellent adhesion, high bonding strength with the cofferdam, and a low refractive index, which can increase the overall transmittance of the upper cover of the product.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides an encapsulation composition, wherein the components of the encapsulation composition include, by weight:

[0007] 50-80 parts of polyurethane acrylate, 10-40 parts of reactive diluent, 0.5-3 parts of photoinitiator, 0.5-5 parts of coupling agent, 0.1-2 parts of disulfide bond-containing additive, 0.1-1 parts of polyethylene glycol-containing additive;

[0008] Wherein, the active diluent comprises 1-10 parts of acrylic acid ester monomers with a refractive index of ≤1.45.

[0009] In a second aspect, the present invention provides an encapsulation layer obtained from the encapsulation composition described in the first aspect.

[0010] In a third aspect, the present invention provides a use of the encapsulation composition as described in the first aspect or the encapsulation layer as described in the second aspect in encapsulation of an electrophoretic display.

[0011] In a fourth aspect, the present invention provides an electrophoretic display, comprising a substrate, an electrophoretic filling layer located on the substrate, and an encapsulation layer as described in the second aspect and covering the electrophoretic filling layer.

[0012] Compared with the related art, the present invention has at least the following beneficial effects:

[0013] The embodiment of the present invention can control the refractive index of the encapsulation composition by introducing an acrylate monomer with a low refractive index into the active diluent, so that when it is applied to the encapsulation layer, the refractive index of the encapsulation layer can be lower and the transmittance can be higher, that is, the transmittance of the product can be improved. The dynamic disulfide bond contained in the disulfide bond-containing additive has a certain self-repairing function, which can improve the bending performance of the encapsulation layer; the polyethylene glycol segment in the polyethylene glycol-containing additive is a soft segment structure, which helps to improve the bending performance of the encapsulation layer, and the hard segment structure can enhance the bonding performance of the encapsulation layer. Therefore, the introduction of additives such as disulfide bond-containing additives and polyethylene glycol-containing additives into the encapsulation composition, and the use of polyurethane acrylates as the main material can make up for the disadvantage of low bonding strength caused by low refractive index acrylate monomers, and can make the obtained encapsulation composition The encapsulation layer formed has excellent flexibility and bonding strength, so that it can fully meet the requirements of flexible packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the structure of an electrophoretic display is provided for some embodiments of the present invention;

[0015] Among them, 1-cover assembly; 2-packaging layer; 3-electrophoretic filling layer; 4-substrate. DETAILED DESCRIPTION

[0016] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0017] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0019] In a first aspect, an embodiment of the present invention provides a packaging composition, wherein the components of the packaging composition include, in parts by weight:

[0020]

[0021] In the present invention, the reactive diluent includes 1-10 parts of an acrylic acid ester monomer having a refractive index of ≤1.45, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0022] When the encapsulation composition provided by the present invention is applied to the encapsulation layer, the refractive index of the encapsulation layer can be reduced and the reflectivity of the encapsulation layer can be increased; at the same time, it has high peel strength and holding force, and has certain bending properties, which can improve the bonding strength of the encapsulation glue to the cofferdam and the barrier performance to water vapor, thereby improving the sealing and reliability of the encapsulation layer; specifically:

[0023] The embodiment of the present invention can control the refractive index of the encapsulation composition by introducing an acrylate monomer with a low refractive index into the active diluent, so that when it is applied to the encapsulation layer, the refractive index of the encapsulation layer can be lower and the transmittance can be higher, that is, the transmittance of the product can be improved.

[0024] The dynamic disulfide bonds contained in the disulfide bond-containing additive introduced in the embodiment of the present invention have a certain self-repairing function, which can improve the bending performance of the encapsulation layer; the polyethylene glycol segment in the polyethylene glycol-containing additive is a soft segment structure, which helps to improve the bending performance of the encapsulation layer, and the hard segment structure can enhance the bonding performance of the encapsulation layer. Therefore, the introduction of additives such as disulfide bond-containing additives and polyethylene glycol-containing additives into the encapsulation composition, and the use of polyurethane acrylates as the main material can make up for the disadvantage of low bonding strength caused by low refractive index acrylate monomers, and can make the encapsulation layer formed by the obtained encapsulation composition have excellent flexibility and bonding strength, so that it can fully meet the requirements of flexible packaging.

[0025] In the embodiment of the present invention, the bonding strength of the encapsulation layer can reach above 20N / 25mm through the synergistic effect of polyurethane acrylate and additives.

[0026] The polyurethane acrylate used in the embodiment of the present invention is a reaction product of polyurethane and acrylic monomers, which contains both an urethane structure and a double bond structure. It is combined with a coupling agent, an additive containing a disulfide bond, an additive containing polyethylene glycol, etc. to balance the flexibility of the encapsulation layer obtained from the encapsulation composition and the bonding strength to the cofferdam.

[0027] In some specific embodiments of the present invention, the method for preparing the polyurethane acrylate comprises:

[0028] The polyester polyol reacts with isocyanate to obtain a polyurethane prepolymer;

[0029] The polyurethane prepolymer reacts with a hydroxyl-containing acrylic monomer to obtain polyurethane acrylate.

[0030] The polyurethane acrylate in the embodiment of the present invention is 50-80 parts, for example, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed in the range are also applicable.

[0031] The active diluent in the embodiment of the present invention is 10-40 parts, for example, it can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed in the range are also applicable.

[0032] The photoinitiator in the embodiment of the present invention is 0.5-3 parts, for example, it can be 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed in the range are also applicable.

[0033] The coupling agent in the embodiment of the present invention is 0.5-5 parts, for example, it can be 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed in the range are also applicable.

[0034] The disulfide bond-containing additive described in the embodiment of the present invention is 0.1-2 parts, for example, it can be 0.1 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed in the range are also applicable.

[0035] The additive containing polyethylene glycol in the embodiment of the present invention is 0.1-1 part, for example, it can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc. However, the present invention is not limited to the listed values, and other values ​​not listed in the range are also applicable.

[0036] In some embodiments of the present invention, the encapsulation composition further comprises 5-15 parts of hollow microspheres, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0037] In some embodiments of the present invention, the particle size D50 of the hollow microspheres is ≤100 nm, for example, 100 nm, 95 nm, 90 nm, 85 nm, 80 nm, 75 nm, 70 nm, 65 nm, 60 nm, etc. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0038] Introducing nano hollow microspheres into the encapsulation composition can further reduce the refractive index of the encapsulation layer obtained from the encapsulation composition and improve its transmittance. When the encapsulation layer is applied to an electrophoretic display, the transmittance of the upper cover plate of the electrophoretic display can be increased by 1-10%.

[0039] In some embodiments of the present invention, the acrylic monomer with a refractive index of ≤1.45 includes one or more of trifluoroethyl acrylate, trifluoroethyl methacrylate, pentafluoroethyl acrylate, pentafluoroethyl methacrylate, octafluoropentyl methacrylate, heptafluorobutyl acrylate, dodecafluoroheptyl acrylate, tridecafluorooctyl acrylate, tridecafluorooctyl methacrylate, pentafluorooctyl acrylate, lauric acid, methyl acrylate, methyl methacrylate or hydroxyethyl methacrylate. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0040] In some embodiments of the present invention, the reactive diluent further comprises 10-30 parts of a monofunctional acrylic monomer, for example, 10 parts, 12 parts, 15 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0041] In some embodiments of the present invention, the disulfide bond-containing additive is selected from one or more of diallyl disulfide, diallyl disulfide, methyl allyl disulfide or allyl propyl disulfide. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0042] In some embodiments of the present invention, the polyethylene glycol-containing additive is polyethylene glycol diacrylate, and the molecular weight of the polyethylene glycol is 200-800, for example, 200, 300, 400, 500, 600, 700, 800, etc. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0043] In some embodiments of the present invention, the disulfide bond-containing additive and the polyethylene glycol-containing additive both contain double bonds, and the double bonds contained in the polyurethane acrylate and the double bonds contained in the additive can undergo double bond polymerization reaction, so that the dynamic disulfide bonds and the polyethylene glycol fragments are linked to the polyurethane acrylate in the form of chemical bonds, wherein the dynamic disulfide bonds have a certain self-repairing function, and the polyethylene glycol fragments have a certain bending performance. At the same time, since the several form a form of mutual cross-linking between polymer chains, the bonding performance of the encapsulation layer obtained from the encapsulation composition is improved.

[0044] In some embodiments of the present invention, the composition of the encapsulation composition further includes 0.5-5 parts of a conductive material, for example, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0045] In some embodiments of the present invention, the conductive material is selected from nanomaterials, conductive polymers or antistatic agents. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0046] Since the conductivity of the encapsulation composition also needs to be considered, a conductive material may be introduced into the encapsulation composition provided in the embodiment of the present invention to reduce the volume resistivity of the encapsulation composition, and the volume resistivity of the encapsulation layer obtained by the encapsulation composition may be controlled to be less than 10 10 Ω·cm.

[0047] In some embodiments of the present invention, the nanomaterial is selected from one or more of carbon nanotubes, nanosilver wires, graphene and fullerene. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0048] In some embodiments of the present invention, the conductive polymer is selected from one or more of polyaniline, polypyrrole, polythiophene or polyacrylamide polymers. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0049] In some embodiments of the present invention, the photoinitiator is selected from free radical photoinitiators.

[0050] In some embodiments of the present invention, the photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone (photoinitiator 184), (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide (photoinitiator TPO), phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide (photoinitiator 819) or 4-acryloylhydroxybenzoic acid benzophenone (photoinitiator ABP).

[0051] In the embodiment of the present invention, the photoinitiator can initiate a free radical reaction to cause a polymerization reaction of double bonds. Since a cross-linking reaction occurs, the sealing composition provided by the present invention will be cross-linked and cured under the action of the photoinitiator to obtain an encapsulation layer.

[0052] In some embodiments of the present invention, the coupling agent is selected from silane coupling agents.

[0053] In some embodiments of the present invention, the silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane (KH550), γ-glycidyloxypropyltrimethoxysilane (KH560) or γ-methacryloxypropyltrimethoxysilane (KH570).

[0054] In a second aspect, the present invention provides an encapsulation layer obtained from the encapsulation composition described in the first aspect.

[0055] In some embodiments of the present invention, the thickness of the encapsulation layer is 5-15 μm, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, etc. However, the present invention is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0056] In some embodiments of the present invention, the refractive index of the encapsulation layer is less than 1.47, which is close to the refractive index of the electrophoretic fluid (1.4), and can effectively reduce reflection and refraction losses and improve the overall transmittance of the structure.

[0057] In a third aspect, the present invention provides a use of the encapsulation composition as described in the first aspect or the encapsulation layer as described in the second aspect in encapsulation of an electrophoretic display.

[0058] The sealing composition provided in the embodiment of the present invention can be used for encapsulating electrophoretic liquid, and the formed encapsulation layer has a high bonding strength to the cofferdam and has excellent water vapor barrier properties; not only that, the encapsulation layer formed by the sealing composition provided in the embodiment of the present invention is a flexible encapsulation layer, which has excellent reliability.

[0059] In a fourth aspect, the present invention provides an electrophoretic display, comprising a substrate, an electrophoretic filling layer located on the substrate, and an encapsulation layer as described in the second aspect and covering the electrophoretic filling layer.

[0060] In some embodiments of the present invention, a cover plate assembly is further included, and the cover plate assembly is located on a side of the packaging layer away from the electrophoretic filling layer.

[0061] like Figure 1 As shown, in some specific embodiments of the present invention, the electrophoretic display includes a substrate 4, an electrophoretic filling layer 3 located on the substrate 4, and an encapsulation layer 2 and a cover plate assembly 1 as described in the second aspect covering the electrophoretic filling layer 3.

[0062] The cover plate assembly provided by the embodiment of the present invention may be a transparent cover plate assembly. When the sealing composition or sealing layer provided by the embodiment of the present invention is applied to an electrophoretic display, the transmittance of the product cover plate assembly can be increased by 1-10%.

[0063] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its applications. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0064] If no specific techniques or conditions are specified in the examples, the conventional techniques or conditions in the art, or the techniques or conditions described in the literature, or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0065] Example 1

[0066] This embodiment provides a packaging composition as follows:

[0067] 60 parts of polyurethane acrylate, 40 parts of active diluent, 3 parts of photoinitiator, 5 parts of coupling agent, 2 parts of disulfide bond-containing additive, and 1 part of polyethylene glycol-containing additive.

[0068] in:

[0069] Polyurethane acrylate was purchased from CN9010 NS (Sartomer), the active diluent included 10 parts of an acrylate monomer with a refractive index ≤1.45 and 30 parts of a monofunctional acrylic monomer, the acrylate monomer with a refractive index ≤1.45 was trifluoroethyl acrylate, the monofunctional acrylic monomer was isobornyl acrylate (IBOA), the photoinitiator was photoinitiator 184, the coupling agent was KH550, the disulfide bond-containing additive was diallyl disulfide, and the polyethylene glycol-containing additive was polyethylene glycol (400) diacrylate.

[0070] Example 2

[0071] This embodiment provides a packaging composition.

[0072] The difference from Example 1 is that in this example, 10 parts of hollow microspheres are further included, and the particle size D50 of the hollow microspheres is 50 nm, which are purchased from Nouryon.

[0073] Example 3

[0074] This embodiment provides a packaging composition.

[0075] The difference from the embodiment 1 is that, in this embodiment, two portions of conductive material are further included, wherein the conductive material is carbon nanotubes.

[0076] Example 4

[0077] This embodiment provides a packaging composition as follows:

[0078] 80 parts of polyurethane acrylate, 20 parts of active diluent, 0.5 parts of photoinitiator, 0.5 parts of coupling agent, 0.1 parts of disulfide bond-containing additive, 0.1 parts of polyethylene glycol-containing additive, 5 parts of hollow microspheres, and 0.5 parts of conductive material.

[0079] in:

[0080] Polyurethane acrylate was purchased from CN9010 NS (Sartomer), the active diluent included 10 parts of acrylate monomers with a refractive index of ≤1.45 and 10 parts of monofunctional acrylic monomers, the acrylate monomers with a refractive index of ≤1.45 were tridecafluorooctyl acrylate, the monofunctional acrylic monomer was isobornyl acrylate (IBOA), the photoinitiator was photoinitiator 184, the coupling agent was KH570, the additive containing a disulfide bond was methyl allyl disulfide, the additive containing polyethylene glycol was polyethylene glycol (600) diacrylate, the particle size D50 of the hollow microspheres was 50 nm, which were purchased from Nouryon, and the conductive material was a silver nanowire dispersion.

[0081] Example 5

[0082] This embodiment provides a packaging composition as follows:

[0083] 65 parts of polyurethane acrylate, 35 parts of active diluent, 1.5 parts of photoinitiator, 2.5 parts of coupling agent, 1.5 parts of disulfide bond-containing additive, 0.8 parts of polyethylene glycol-containing additive, 8 parts of hollow microspheres, and 2 parts of conductive material.

[0084] in:

[0085] Polyurethane acrylate was purchased from CN9010 NS (Sartomer), the active diluent included 15 parts of acrylate monomers with a refractive index of ≤1.45 and 20 parts of monofunctional acrylic monomers, the acrylate monomers with a refractive index of ≤1.45 were pentadecafluorooctyl acrylate, lauric acid, the monofunctional acrylic monomer was isobornyl acrylate (IBOA), the photoinitiator was photoinitiator 819, the coupling agent was KH560, the additive containing a disulfide bond was diallyl disulfide, the additive containing polyethylene glycol was polyethylene glycol (400) diacrylate, the particle size D50 of the hollow microspheres was 50 nm, which were purchased from Nouryon, and the conductive material was an antistatic agent.

[0086] Example 6

[0087] This embodiment provides a packaging composition as follows:

[0088] 50 parts of polyurethane acrylate, 11 parts of active diluent, 0.5 parts of photoinitiator, 0.5 parts of coupling agent, 0.1 parts of disulfide bond-containing additive, 0.1 parts of polyethylene glycol-containing additive, 5 parts of hollow microspheres, and 0.5 parts of conductive material.

[0089] in:

[0090] Polyurethane acrylate was purchased from CN9010 NS (Sartomer), the active diluent included 1 part of acrylate monomer with a refractive index ≤1.45 and 10 parts of monofunctional acrylic monomer, the acrylate monomer with a refractive index ≤1.45 was 15fluorooctyl acrylate, lauric acid, the monofunctional acrylic monomer was isobornyl acrylate (IBOA), the photoinitiator was photoinitiator 819, the coupling agent was KH560, the additive containing disulfide bonds was diallyl disulfide, the additive containing polyethylene glycol was polyethylene glycol (400) diacrylate, the particle size D50 of the hollow microspheres was 50 nm, purchased from Nouryon, and the conductive material was an antistatic agent.

[0091] Example 7

[0092] This embodiment provides a packaging composition.

[0093] The difference from Example 5 is that in this example, the disulfide bond-containing additive is dibutyl disulfide.

[0094] Example 8

[0095] This embodiment provides a packaging composition.

[0096] The difference from Example 5 is that in this example, the polyethylene glycol-containing additive is polyethylene glycol 400 (PEG-400).

[0097] Comparative Example 1

[0098] This comparative example provides a packaging composition.

[0099] The difference from Example 1 is that in this comparative example, the reactive diluent does not include an acrylic ester monomer having a refractive index of ≤1.45, that is, the reactive diluent is 40 parts of a monofunctional acrylic monomer.

[0100] Comparative Example 2

[0101] This comparative example provides a packaging composition.

[0102] The difference from Example 1 is that in this comparative example, the encapsulation composition does not include a disulfide bond-containing additive.

[0103] Comparative Example 3

[0104] This comparative example provides a packaging composition.

[0105] The difference from Example 1 is that in this comparative example, the encapsulation composition does not include an additive containing polyethylene glycol.

[0106] Comparative Example 4

[0107] This comparative example provides a packaging composition.

[0108] The difference from Example 1 is that in this comparative example, polyurethane acrylate is replaced by polyurethane.

[0109] The comparative example could not complete polymerization and curing, and therefore, no subsequent testing was performed.

[0110] Performance Testing

[0111] The encapsulation compositions provided in Examples 1-8 and Comparative Examples 1-4 were mixed and cured to obtain an encapsulation layer with a thickness of 10 μm, and a performance test was performed as follows:

[0112] (1) Refractive index: tested using an Abbe refractometer;

[0113] (2) Bond strength: tested according to ASTM international standard D3330 method A;

[0114] (3) Bending performance: The encapsulation layer was placed between 50 μm CPI sheets to form a three-layer structure, and then the laminate was cut into 5 cm long × 1 cm wide; in a similar manner, a five-layer structure consisting of CPI / encapsulation layer / CPI / encapsulation layer / CPI was prepared using a 25 μm thick adhesive layer and 50 μm CPI; the sample was installed in a dynamic folding device with two folding stages, which rotated from 180 degrees (sample not bent) to 90 degrees (sample folded) and was tested at a rate of about 40 cycles / minute.

[0115] (4) Water vapor barrier performance: tested using a water vapor transmission meter;

[0116] (5) Volume resistivity: tested using high resistance meter SM7120;

[0117] The test results are shown in Table 1:

[0118] Table 1

[0119]

[0120]

[0121] It can be seen from the embodiments and performance tests that when the encapsulation composition provided by the present invention is applied to the encapsulation layer, it can reduce the refractive index of the encapsulation layer and improve the reflectivity of the encapsulation layer; at the same time, it has high peel strength and holding force, and has certain bending properties, which can improve the bonding strength of the encapsulation glue to the cofferdam and the barrier performance to water vapor, thereby improving the sealing and reliability of the encapsulation layer.

[0122] From the comparison between Example 1 and Example 2, it can be seen that the introduction of hollow microspheres into the encapsulation composition can further reduce the refractive index of the encapsulation layer and improve the reflectivity of the encapsulation layer.

[0123] From the comparison between Example 5 and Examples 7-8, it can be seen that the disulfide bond-containing additive and the polyethylene glycol-containing additive contain double bonds, and the disulfide bond-containing additive can be linked to polyurethane acrylate in the form of a chemical bond, which can improve the bending performance of the encapsulation layer and improve the bonding performance of the encapsulation layer.

[0124] From the comparison between Example 1 and Comparative Examples 1-3, it can be seen that the introduction of a disulfide bond-containing additive and a polyethylene glycol-containing additive into the encapsulation composition helps to improve both the bending performance and the bonding performance of the encapsulation layer.

[0125] From the comparison between Example 1 and Comparative Example 4, it can be seen that the polyurethane acrylate used in the encapsulation composition contains double bonds, which can be cured and formed into an encapsulation layer by cooperating with the double bonds of other additives.

[0126] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be 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 disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A packaging composition, characterized in that In parts by weight, the components of the encapsulation composition include: 50-80 parts of polyurethane acrylate, 10-40 parts of reactive diluent, 0.5-3 parts of photoinitiator, 0.5-5 parts of coupling agent, 0.1-2 parts of disulfide bond-containing additive, 0.1-1 parts of polyethylene glycol-containing additive; Wherein, the active diluent comprises 1-10 parts of acrylic acid ester monomers with a refractive index of ≤1.

45.

2. The encapsulation composition according to claim 1, characterized in that The encapsulation composition also includes 5-15 parts of hollow microspheres.

3. The encapsulation composition according to claim 2, characterized in that The particle size D50 of the hollow microspheres is ≤100 nm.

4. The encapsulation composition according to claim 1 or 2, characterized in that: The acrylic ester monomer with a refractive index of ≤1.45 includes one or more of trifluoroethyl acrylate, trifluoroethyl methacrylate, pentafluoroethyl acrylate, pentafluoroethyl methacrylate, octafluoropentyl methacrylate, heptafluorobutyl acrylate, dodecafluoroheptyl acrylate, tridecafluorooctyl acrylate, tridecafluorooctyl methacrylate, pentafluorooctyl acrylate, lauric acid, methyl acrylate, methyl methacrylate or hydroxyethyl methacrylate.

5. The encapsulation composition according to claim 1 or 2, characterized in that: The disulfide bond-containing additive is selected from one or more of diallyl disulfide, diallyl disulfide, methyl allyl disulfide or allyl propyl disulfide.

6. The encapsulation composition according to claim 1 or 2, characterized in that: The additive containing polyethylene glycol is polyethylene glycol diacrylate, and the molecular weight of the polyethylene glycol is 200-800.

7. The encapsulation composition according to claim 1 or 2, characterized in that: The packaging composition also includes 0.5-5 parts of conductive material.

8. The encapsulation composition according to claim 7, characterized in that The conductive material is selected from nanomaterials, conductive polymers or antistatic agents.

9. The encapsulation composition according to claim 1 or 2, characterized in that: The photoinitiator is selected from free radical photoinitiators; And / or, the coupling agent is selected from silane coupling agents.

10. An encapsulation layer obtained from the encapsulation composition according to any one of claims 1 to 9.

11. The encapsulation layer according to claim 10, characterized in that: The thickness of the encapsulation layer is 5-15 μm.

12. Use of the encapsulation composition according to any one of claims 1 to 9 or the encapsulation layer according to claim 10 or 11 in encapsulation of an electrophoretic display.

13. An electrophoretic display, characterized in that: The electrophoretic display comprises a substrate, an electrophoretic filling layer located on the substrate, and an encapsulation layer as claimed in claim 10 or 11 covering the electrophoretic filling layer.

14. The electrophoretic display according to claim 13, characterized in that: It also includes a cover plate assembly, which is located on a side of the packaging layer away from the electrophoretic filling layer.

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