A uv precurable epoxy sealant and electronic ink screen

Abstract

This application provides a UV-precurable epoxy sealant and an electronic ink screen, relating to the field of epoxy sealants. The UV-precurable epoxy sealant, by weight, comprises: 25%-50% epoxy resin, 10%-30% amine curing agent, 10%-40% free radical reactive crosslinking agent, 10%-30% filler, 0.1%-2% coupling agent, 0.1%-5% photoradical polymerization initiator, and 0%-5% catalyst; the free radical reactive crosslinking agent includes free radical reactive epoxy resin and / or free radical reactive amine curing agent. The free radical reactive crosslinking agent introduced in this application (a type of epoxy resin and amine curing agent capable of participating in free radical reactions) can simultaneously participate in epoxy ring-opening polymerization and free radical double bond polymerization, further increasing the crosslinking density and improving moisture barrier efficiency; achieving a high glass transition temperature (Tg) to meet reliability requirements.

Description

Technical Field

[0001] This application relates to the field of epoxy sealants, and more particularly to a UV-precurable epoxy sealant and an electronic ink screen. Background Technology

[0002] E-ink displays, also known as electronic paper, are a reflective display technology that mimics the display effect of traditional paper. They display text and images by reflecting ambient light, offering significant advantages such as low power consumption and a reading experience close to that of printed books. In recent years, with the continuous evolution of display technology, the application scenarios of e-ink displays have gradually expanded from the single field centered on reading to a wider range of industrial and consumer electronics fields.

[0003] Traditional electronic paper display modules are typically composed of the following core materials: Electronic paper film: As the core functional layer of the display module, it undertakes the key task of image display and is a display interface that can be directly observed by the human eye.

[0004] Substrate: Used as the pixel electrode (i.e., lower electrode) of electronic paper, responsible for controlling the switching of the black and white state of each pixel unit. Different types of substrates can be selected according to application requirements, such as TFT glass or flexible substrates such as PET. The electronic paper film is laminated to the substrate through a lamination process.

[0005] Transparent protective film: A high-performance polymer composite film with excellent water and oxygen barrier properties. Through lamination, it is tightly coated over the electronic paper film and substrate, effectively preventing moisture intrusion and subsequent moisture absorption and performance degradation.

[0006] Edge sealing adhesive: A liquid adhesive is used to evenly coat the edges of the transparent protective film to fill the gap between the protective film and the base plate. After curing, it forms a dense moisture barrier layer to prevent moisture from seeping through the edges and eroding the electronic paper film.

[0007] Driver chip: Generates corresponding logic levels based on control commands and timing signals, precisely controls the driving timing and working state of each pixel (or segment code) on the baseboard, thereby achieving stable display of the required content.

[0008] Currently, e-ink technology is experiencing rapid development, especially in the field of color e-ink displays, where significant breakthroughs have been achieved. The emergence of color e-paper has enabled e-ink displays to overcome the limitations of traditional black-and-white displays, possessing the potential to penetrate into diverse scenarios. Although the overall market share of color products is still smaller than that of traditional black-and-white products, its growth momentum is rapid, and its market erosion effect is becoming increasingly significant, marking the accelerated arrival of the era of color e-paper applications.

[0009] From the perspective of device stability, electronic paper films are extremely sensitive to water vapor and oxygen. When the internal moisture balance of the display device is disrupted, the display performance will drop sharply, the device will age faster, and abnormal phenomena such as edge damage and uneven display (MURA) may occur, which can lead to display failure in severe cases. Therefore, in the packaging process of electronic paper display modules, sealing materials with high water and oxygen barrier properties must be used to effectively seal the bezel area.

[0010] Currently, most mainstream frame sealants on the market use thermosetting systems, which have high requirements for curing temperature and time, typically requiring curing at temperatures above 70°C for about 60 minutes. However, with the advancement of color e-ink screen technology, the temperature sensitivity of e-paper films has significantly increased, and their tolerance temperature has dropped to 60°C or even lower. Under these low-temperature conditions, traditional thermosetting adhesives struggle to achieve full curing, resulting in a significant reduction in encapsulation effectiveness. Simultaneously, the 60-minute curing cycle also restricts production efficiency, making it difficult to meet the urgent needs of next-generation color e-paper module manufacturing processes for low-temperature, rapid curing. Summary of the Invention

[0011] The purpose of this application is to provide a UV-precurable epoxy sealant and an electronic ink screen to solve the above-mentioned problems.

[0012] To achieve the above objectives, the first aspect of this application provides a UV-precurable epoxy sealant, the raw materials of which, based on a total mass of 100%, comprise: 25%-50% epoxy resin, 10%-30% amine curing agent, 10%-40% free radical reactive crosslinking agent, 10%-30% filler, 0.1%-2% coupling agent, 0.1%-5% photoradical polymerization initiator, 0%-5% catalyst; The free radical reactive crosslinking agent includes a free radical reactive epoxy resin and / or a free radical reactive amine curing agent.

[0013] Optionally, the epoxy resin includes one or more of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, naphthalene ring structure epoxy resin, glycidylamine type epoxy resin, hydantoin epoxy resin, dicyclopentadiene dimethyl epoxy resin, polyphenol type glycidyl ether epoxy resin, phenolic epoxy resin, and allylphenol type epoxy resin. And / or, the amine curing agent includes one or more of polyether amines, aliphatic amines, cycloaliphatic amines, and aryl amines; And / or, the filler includes organic fillers and / or inorganic fillers; And / or, the coupling agent comprises one or more of γ-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-aminoethyl-3-aminopropylmethyldimethoxysilane; And / or, the photoradical polymerization initiator includes one or more of benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, diacetic titanium compounds, oxime ester compounds, benzoin ether compounds, and thioxanone compounds; And / or, the catalyst comprises one or more of an acid or a compound that can be hydrolyzed to an acid, a tertiary amine compound, and a phenolic compound.

[0014] Optionally, the amine curing agent includes one or more of the following: aliphatic primary amines, alicyclic primary amines, and aromatic aliphatic primary amines containing ether groups; And / or, the inorganic filler includes at least one or more of limestone, zeolite, bentonite, washed kaolin, talc, titanium dioxide, alumina, quartz, surface-treated and / or untreated silica, nano silica, flint and mica; And / or, the organic filler includes one or more of carbon black, graphite, graphene, organoclay, polyacrylonitrile powder, polyethylene powder, polypropylene powder, polytetrafluoroethylene powder, poly(meth)acrylate powder, and core-shell rubber. And / or, the photoradical polymerization initiator includes 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropanone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2,2-dimethoxy-2-phenylacetophenone, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, 2 The following are one or more of the following: 4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine acid, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propane-1-one, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] acetophenone-1-(O-acetoxy oxime), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; And / or, the acid or the compound that can be hydrolyzed to an acid includes one or more of salicylic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonate, calcium trifluoromethanesulfonate, diethylamine trifluoromethanesulfonate complex, boron trifluoride ethylamine complex, and ammonium hexafluoroantimonate. And / or, the tertiary amine compound includes one or more of 1,4-diazabicyclo[2.2.2]octane, N,N-dimethylbenzylamine, triethanolamine, 3-dimethylaminopropylamine, N,N-dimethyldipropyltriamine, 1-methylimidazole, 1-vinylimidazole, 1,2-dimethylimidazole, 2-dimethylaminomethylphenol, and 2,4,6-tris(dimethylaminomethyl)phenol; And / or, the phenolic compounds include one or more of phenol, tert-butylphenol, nonylphenol, dodecylphenol, cashew phenol, styrylated phenol, bisphenol A, bisphenol F, resorcinol, diallyl bisphenol A, diallyl bisphenol F, magnolol, and honokiol.

[0015] Optionally, the raw materials of the UV-precurable epoxy sealant may further include additives; the additives include one or more of the following: stabilizers, antioxidants, polymerization inhibitors, sensitizers, rheology modifiers, wetting and dispersing agents, leveling agents, defoamers, anti-exudants, colorants, reactive diluents, and plasticizers.

[0016] Optionally, the free radical reactive epoxy resin contains free radical reactive -C=C- and epoxy groups; And / or, the free radical reactive amine curing agent contains C=C- and -NH.

[0017] Optionally, the free radical reactive epoxy resin includes one or more of glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, (meth)acrylate modified epoxy resin, allylphenol type epoxy resin, and triallyl isocyanurate epoxidation products. And / or, the general structural formula of the free radical reactive amine curing agent is: Wherein, R0 includes the residues of a diamine after removing the -NH2 functional group; R1 includes the residues of a difunctional (meth)acrylate after removing the (meth)acryloyloxy functional group; and R2 includes -H and / or -CH3.

[0018] Optionally, the diamine includes one or more of the following: aliphatic diamines with ether groups, aliphatic diamines, alicyclic diamines, and aryliphatic diamines; And / or, the difunctional (meth)acrylates include one or more of bisphenol A dimethacrylate, ethoxylated bisphenol A dimethacrylate, propoxylated bisphenol A dimethacrylate, tricyclodecane dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, honokiol dimethacrylate, and honokiol dimethacrylate.

[0019] Optionally, the diamine includes aryl aliphatic diamines; And / or, the general structural formula of the difunctional (meth)acrylate includes: Among them, R3 and R4 in different positions each independently include -H or -CH3; R5, R6, R7 and R8 in different positions each independently include any one of -H, -CH3 and -CH2-CH=CH2; R9 and R... 10 Each can be independently represented by any one of -H, -CH3, and -C6H5, with m+n=1-4.

[0020] Optionally, the arylita-based primary amine includes 1,3-diaminomethylbenzene; And / or, the difunctional (meth)acrylate includes , , and One or more of them.

[0021] A second aspect of this application provides an electronic ink screen, the raw material of which includes the aforementioned UV-precurable epoxy sealant.

[0022] Compared with the prior art, the beneficial effects of this application include: The UV-precurable epoxy sealant provided in this application, through the selective addition of epoxy resin, amine curing agent, free radical reactive crosslinking agent, filler, coupling agent, photoradical polymerization initiator, and catalyst, allows for control over the sealant's flowability, working time, curing efficiency, and reliability. This results in a UV-precurable epoxy sealant with low viscosity, long working time, UV precurability, and room temperature curing characteristics. The cured product exhibits good substrate adhesion strength and excellent moisture barrier properties. Furthermore, by introducing both epoxy ring-opening polymerization crosslinking and free radical double bond crosslinking, along with free radical reactive crosslinking... The agent allows for a further combination of the two curing methods; in addition, to a certain extent, the amine curing agent can accelerate the free radical double bond polymerization, further accelerating the curing rate and efficiency; furthermore, the multifunctional epoxy resin introduced in this application can also further increase the crosslinking density during curing; in addition, the free radical reactive crosslinking agent (a type of epoxy resin that can participate in free radical reaction and an amine curing agent that can participate in free radical reaction) introduced in this application can simultaneously participate in epoxy ring-opening polymerization and free radical double bond polymerization, further increasing the crosslinking density and improving the water vapor barrier efficiency; achieving a high glass transition temperature (Tg) to meet reliability requirements.

[0023] The electronic ink screen provided in this application fills the gap between the transparent protective film and the base plate with a UV-precurable epoxy sealant. After curing, the UV-precurable epoxy sealant has strong water vapor barrier properties, which can prevent water vapor from penetrating from all sides of the transparent protective film and damaging the electronic paper film, thereby increasing reliability. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0025] Figure 1 A physical image of the UV-precurable epoxy sealant provided in Example 1. Detailed Implementation

[0026] First, the solution provided in this application will be explained in more detail as follows: The first aspect of this application provides a UV-precurable epoxy sealant, the raw materials of which, based on a total mass of 100%, include: 25%-50% epoxy resin, 10%-30% amine curing agent, 10%-40% free radical reactive crosslinking agent, 10%-30% filler, 0.1%-2% coupling agent, 0.1%-5% photoradical polymerization initiator, 0%-5% catalyst; Optionally, the raw materials of the UV-precurable epoxy sealant, based on a total mass of 100%, include: epoxy resin (any value between 25%, 30%, 35%, 40%, 45%, 50% or 25-50%), amine curing agent (any value between 10%, 15%, 20%, 25%, 30% or 10-30%), free radical reactive crosslinking agent (any value between 10%, 15%, 20%, 25%, 30%, 35%, 40% or 10-40%), filler (any value between 10%, 15%, 20%, 25%, 30% or 10-30%), coupling agent (any value between 0.1%, 0.5%, 1%, 1.5%, 2% or 0.1-2%), photoradical polymerization initiator (any value between 0.1%, 1%, 2%, 3%, 4%, 5% or 0.1-5%), and catalyst (any value between 0%, 0.1%, 1%, 2%, 3%, 4%, 5% or 0-5%).

[0027] The free radical reactive crosslinking agent includes a free radical reactive epoxy resin and / or a free radical reactive amine curing agent.

[0028] It should be noted that interpenetrating polymer networks (IPNs) are polymer blends formed by the interpenetration and entanglement of two or more cross-linked polymers. The mechanical properties of the system that generates an interpenetrating polymer network are improved. In the UV-curable epoxy sealant of this application, the double bonds in the raw materials are cross-linked by a photoradical initiator, and the free radical polymerization part is cross-linked with the main chain by a free radical reactive crosslinking agent. The interpenetrating network structure formed with the epoxy resin can significantly improve the toughness of the cured product and increase the Tg and heat resistance of the cured product. The overall cross-linking density is improved, thereby improving the water vapor barrier performance.

[0029] In some embodiments, the epoxy resin includes one or more of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, naphthalene ring structure epoxy resin, glycidylamine type epoxy resin, hydantoin epoxy resin, dicyclopentadiene dimethyl epoxy resin, polyphenol type glycidyl ether epoxy resin, phenolic epoxy resin, and allylphenol type epoxy resin. Optionally, bisphenol A epoxy resins include DER.332 (from DOW), EPICLON EXA-850CRP (from DIC Corporation), YD-8125 (from Tohto Kasei Co. Ltd.), and jER YL6810 (from Mitsubishi); bisphenol F epoxy resins include EPICLON EXA-830CRP (from DIC Corporation), YDF-8170 (from Tohto Kasei Co. Ltd.), and jER 1750 (from Mitsubishi); phenolic epoxy resins include EPICLON N-730A (from DIC Corporation); and glycidylamine epoxy resins include Araldite MY 0510 (from Huntsman), jER630LSD (from Mitsubishi), and ELM-434VL (from SUMITOMO). CHEMICAL and GA-240 (from Huntsman); naphthalene ring structure epoxy resins include EPICLON HP-4032D (from DIC Corporation); dicyclopentadiene dimethyl ether type epoxy resins include ADEKA EP-4088L (from ADEKA); polyphenol type glycidyl ether epoxy resins include EPICLONEXA-7250 (from DIC Corporation); diallyl bisphenol A type epoxy resins include RE-810NM (from Nippon Kayaku Co. Ltd). And / or, the amine curing agent includes one or more of polyether amines, aliphatic amines, cycloaliphatic amines, and aryl amines; It should be noted that polyetheramines include aliphatic primary amines containing ether groups, exemplary of which include 4,9-dioxadodecane-1,12-diamine (TTD), 4,7,10-trioxatridecane-1,13-diamine (DODA), alicyclic ether-containing diamines obtained by amination of 1,4-dihydroxymethylcyclohexane after propoxylation (Jeffamine RFD-270), and polyoxyethylene diamines / triamines (available from Huntsman under the trade names Jeffamine D-205, Jeffamine D-230, Jeffamine D-400, Jeffamine D-600, Jeffamine T-403). For example, aliphatic, alicyclic, and aryliphatic primary amines include 1,6-hexanediamine, 1,9-nonanediamine, (1,2-)diaminocyclohexane, (1,3-)diaminocyclohexane, (1,4-)diaminocyclohexane, (2- / 4-)methyl-1,3-diaminocyclohexane (MCDA), 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (IPDA), 4,4'-diaminodicyclohexylmethane (DC), 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (DMDC), 1,3-diaminomethylcyclohexane (1,3-BAC), 1,3-diaminomethylbenzene (MXDA), and dimeramines (available from Croda under the trade names Priamine 1073, Priamine 1074, and Priamine 1075). And / or, the filler includes organic fillers and / or inorganic fillers; And / or, the coupling agent comprises one or more of γ-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-aminoethyl-3-aminopropylmethyldimethoxysilane; It should be noted that the above-mentioned silane coupling agent has the effect of improving the adhesion of the UV-precurable epoxy sealant of this application. And / or, the photoradical polymerization initiator includes one or more of benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, diacetic titanium compounds, oxime ester compounds, benzoin ether compounds, and thioxanone compounds; And / or, the catalyst comprises one or more of an acid or a compound that can be hydrolyzed to an acid, a tertiary amine compound, and a phenolic compound.

[0030] In some embodiments, the amine curing agent comprises one or more of the following: ether-containing aliphatic primary amines, aliphatic primary amines, alicyclic primary amines, and aryliphatic primary amines; And / or, the inorganic filler includes at least one or more of limestone, zeolite, bentonite, washed kaolin, talc, titanium dioxide, alumina, quartz, surface-treated and / or untreated silica, nano silica, flint and mica; Preferably, the inorganic filler includes a large-layer structure filler, including but not limited to: bentonite, washed kaolin, talc, and mica; And / or, the organic filler includes one or more of carbon black, graphite, graphene, organoclay, polyacrylonitrile powder, polyethylene powder, polypropylene powder, polytetrafluoroethylene powder, poly(meth)acrylate powder, and core-shell rubber (CSR). It should be noted that the aforementioned core-shell rubber (CSR) consists of a core containing an elastomer or rubbery polymer and a shell formed by grafting a polymer onto the core. The core of the core-shell rubber can be selected from acrylate rubbers, silicone rubbers, and diene rubbers, and the shell of the core-shell rubber can be selected from acrylate polymers, acrylate copolymers, styrene polymers, and styrene copolymers. The median primary particle size D50 of the core-shell rubber CSR is 10-300 nm. For example, the core-shell rubber is obtained from Arkema Inc.'s Clearstrength XT-100 and Kaneka Corp.'s Kaneka Ace MX series, particularly MX-125, MX-139, MX-150, MX-160, MX-416, and MX-451. And / or, the photoradical polymerization initiator includes 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropanone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2,2-dimethoxy-2-phenylacetophenone, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, 2 The following are one or more of the following: 4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine acid, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propane-1-one, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] acetophenone-1-(O-acetoxy oxime), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; Preferably, the photoradical polymerization initiator acylphosphine oxide compound includes at least one of bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, and phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide; And / or, the acid or the compound that can be hydrolyzed to an acid includes one or more of salicylic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonate, calcium trifluoromethanesulfonate, diethylamine trifluoromethanesulfonate complex, boron trifluoride ethylamine complex, and ammonium hexafluoroantimonate. And / or, the tertiary amine compound includes one or more of 1,4-diazabicyclo[2.2.2]octane, N,N-dimethylbenzylamine, triethanolamine, 3-dimethylaminopropylamine, N,N-dimethyldipropyltriamine, 1-methylimidazole, 1-vinylimidazole, 1,2-dimethylimidazole, 2-dimethylaminomethylphenol, and 2,4,6-tris(dimethylaminomethyl)phenol; And / or, the phenolic compounds include one or more of phenol, tert-butylphenol, nonylphenol, dodecylphenol, cashew phenol, styrylated phenol, bisphenol A, bisphenol F, resorcinol, diallyl bisphenol A, diallyl bisphenol F, magnolol, and honokiol.

[0031] In some embodiments, the raw materials of the UV-precurable epoxy sealant further include additives; the additives include one or more of stabilizers, antioxidants, polymerization inhibitors, sensitizers, rheology modifiers, wetting and dispersing agents, leveling agents, defoamers, anti-exudants, colorants, reactive diluents, and plasticizers.

[0032] In some embodiments, the radical-reactive epoxy resin contains radical-reactive -C=C- and epoxy groups; And / or, the free radical reactive amine curing agent contains C=C- and -NH.

[0033] It is important to note that during the free radical-initiated polymerization stage, under given photopolymerization conditions, the degree of double bond reaction is often less than 100%. Although the double bond can undergo aza-Michael addition reaction with amine groups, this process takes a considerable amount of time. The reaction becomes even more difficult when the crosslinking density of the epoxy and amine groups increases, leading to greater steric hindrance. It is necessary to introduce other groups that participate in the epoxy / amine reaction, such as epoxy groups / amine groups. For free radical reactive epoxy resins, those with benzene ring structures generally have higher viscosity, while low-viscosity resins do not have benzene ring structures. When selecting raw materials based on low viscosity, free radical reactive amine curing agents offer better viscosity.

[0034] In some embodiments, the free radical reactive epoxy resin includes one or more of glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, (meth)acrylate modified epoxy resin, allylphenol type epoxy resin, and triallyl isocyanurate epoxidation products. It should be noted that the (meth)acrylate modified epoxy resin is obtained by reacting (meth)acrylic acid with epoxy resin with a functionality ≥2 at an epoxy / carboxyl ratio of 1:0.25-0.75. And / or, the general structural formula of the free radical reactive amine curing agent is: Wherein, R0 includes the residues of a diamine after removing the -NH2 functional group; R1 includes the residues of a difunctional (meth)acrylate after removing the (meth)acryloyloxy functional group; and R2 includes -H and / or -CH3.

[0035] In some embodiments, the precursor of R1 also includes (The product of esterification of magnolol and methacrylic anhydride) and (and the product of esterification of magnolol with methacrylic anhydride).

[0036] It is important to note that the Aza-Michael reaction is carried out by controlling the molar ratio of amine hydrogen to (meth)acrylate double bond in the diamine to be less than 1, so that the product retains some unreacted -C=C- double bonds while introducing active amine hydrogen -NH. The specific preparation steps are as follows: + .

[0037] It should be noted that R0 and R1 contain planar aromatic ring structures, benzene rings, naphthalene rings, and anthracene rings; these can form effective steric hindrance and extend the water vapor permeation channel; furthermore, for viscosity considerations, benzene ring structures are preferred. In some embodiments, the diamine includes one or more of the following: aliphatic diamines with ether groups, aliphatic diamines, alicyclic diamines, and aryliphatic diamines; And / or, the difunctional (meth)acrylates include one or more of bisphenol A dimethacrylate, ethoxylated bisphenol A dimethacrylate, propoxylated bisphenol A dimethacrylate, tricyclodecane dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, honokiol dimethacrylate, and honokiol dimethacrylate.

[0038] In some embodiments, the diamine includes an arylita-based diamine; And / or, the general structural formula of the difunctional (meth)acrylate includes: Among them, R3 and R4 in different positions each independently include -H or -CH3; R5, R6, R7 and R8 in different positions each independently include any one of -H, -CH3 and -CH2-CH=CH2; R9 and R... 10 Each can be independently represented by any one of -H, -CH3, and -C6H5, with m+n=1-4.

[0039] Optionally, m+n can be 1, 2, 3, 4 or any value between 1 and 4.

[0040] In some embodiments, the arylita-based primary amine includes 1,3-diaminomethylbenzene; And / or, the difunctional (meth)acrylate includes (2EO modified bisphenol A dimethacrylate) (Product of diallylbisphenol F esterified with methacrylic anhydride) (The product of the reaction of diallylbisphenol F with ethylene oxide and subsequent esterification with methacrylic anhydride) and One or more of the following: (the product obtained by esterification of diallyl bisphenol A with ethylene oxide and methacrylic anhydride).

[0041] in, The main structure of MXDA (1,3-diaminomethylbenzene) reacting with the double bond in equal proportions with active hydrogen is as follows: .

[0042] A second aspect of this application provides an electronic ink screen, the raw material of which includes the aforementioned UV-precurable epoxy sealant.

[0043] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0044] It should also be noted that the raw materials used in the examples and comparative examples are as follows: EPICLON EXA-850CRP is a liquid / crystalline bisphenol A epoxy resin with an epoxy equivalent weight (EEW) of 168~178 g / equivalent, purchased from DIC Corporation.

[0045] EPICLON EXA-830CRP is a liquid / crystalline bisphenol F epoxy resin with an epoxy equivalent weight (EEW) of 156~168 g / equivalent, purchased from DIC Corporation.

[0046] EPICLON HP-4032D is a liquid / crystalline 1,6-bis(2,3-epoxypropoxy)naphthalene epoxy resin with an epoxy equivalent weight (EEW) of 136~150 g / equivalent, purchased from DIC Corporation.

[0047] jER 630LSD is a triglycidyl p-aminophenol epoxy resin with an epoxy equivalent weight (EEW) of 90-100 g / equivalent, purchased from Mitsubishi Chemical.

[0048] ERISYS RDGE is a resorcinol diglycidyl ether epoxy resin with an epoxy equivalent weight (EEW) of 120-135 g / equivalent, purchased from Huntsman.

[0049] Jeffamine D230 is a polyetheramine with an amine hydrogen equivalent weight (AHEW) of ~60 g / equivalent, purchased from Huntsman.

[0050] Jeffamine T403 is a polyetheramine with an amine hydrogen equivalent weight (AHEW) of ~80 g / equivalent, purchased from Huntsman; Baxxodur EC130 is a 4,7,10-trioxatridecane-1,13-diamine with an amine hydrogen equivalent weight (AHEW) of ~56 g / equivalent, purchased from BASF.

[0051] MXDA is m-phenylenediamine with an amine hydrogen equivalent weight (AHEW) of ~34 g / equivalent, purchased from Mitsubishi Gas Chemical.

[0052] TS720, polydimethylsiloxane-treated fumed silica, purchased from Cabot.

[0053] Steashield 10, large-layer ultra-thin talc powder, 15-micron top cut, purchased from Imerys.

[0054] Clearstrength XT100, purchased from Arkema.

[0055] Silquest A187, a silane coupling agent, was purchased from Momentive.

[0056] Silquest A174, a silane coupling agent, was purchased from Momentive.

[0057] Omnirad 819, a photoradical polymerization initiator, purchased from IGM.

[0058] DABPA, 2,2'-diallylbisphenol A, purchased from aladdin.

[0059] SR 348 NS, Chinese name is (2) bisphenol A dimethacrylate, purchased from Sartomer.

[0060] Example 1 The first aspect of this embodiment provides a UV-precurable epoxy sealant, the raw materials of which include epoxy resin, amine curing agent, free radical reactive crosslinking agent, filler, coupling agent, photoradical polymerization initiator, and catalyst, the specific types and amounts of which are shown in Table 1.

[0061] Among them, the free radical reactive crosslinking agent is the free radical reactive epoxy resin RE-810NM (a diallyl diglycidyl ether epoxy resin with an epoxy equivalent weight (EEW) of 230 g / equivalent, purchased from Nippon Kayaku Co. Ltd.) and acrylate epoxy crosslinking agent 1, the structural formula of which is: The specific preparation method is as follows: In a 250mL three-necked flask equipped with a thermocouple, a mechanical stirrer and a nitrogen inlet, add (2) ethoxylated bisphenol A methacrylate (SR 348 NS, 135.6 g, 0.3 mol), add m-xylylenediamine (MXDA) (20.4 g, 0.15 mol), replace the air in the flask with nitrogen, and stir mechanically at 35°C for 72 hours to obtain acrylate epoxy crosslinking agent 1.

[0062] The second aspect of this embodiment provides a method for preparing a UV-precurable epoxy sealant, the specific steps of which are as follows: S1: Weigh the epoxy resin, coupling agent, and photoradical polymerization initiator according to the weight percentage of each raw material in Table 1 and put them into the reactor. Stir and mix for 30 minutes. S2. Weigh the packing material and add it to the reactor in S1 in batches at intervals. After the addition is complete, stir and mix for 60 minutes, and then cool down to below 20°C. S3. Weigh the catalyst, amine curing agent, and free radical reactive crosslinking agent and add them to the reactor in S2. Stir for 30 minutes at a speed of 100~1000 r / min, a temperature below 20℃, and a vacuum degree of 0.05~0.08MPa to obtain a UV-precurable epoxy sealant.

[0063] Actual photos of the UV-precurable epoxy sealant are shown below. Figure 1 As shown.

[0064] This application also provides Examples 2-8, which differ in principle, type, and dosage of UV-precurable epoxy sealant; and this application also provides Comparative Example 1, which differs from Example 3 in that the free radical reactive crosslinking agent provided in Example 3 is replaced with SR 348-NS and MXDA (which are precursors of free radical reactive crosslinking agent 1), as detailed in Table 1.

[0065] The structural formula of the acrylate epoxy crosslinking agent 2 used in Example 7 is as follows: The preparation method is as follows: In a 2L three-necked flask equipped with a thermocouple, magnetic stirrer, and reflux device, purified diallyl bisphenol F (280.37 g, 1.0 mol), triethylamine (111.31 g, 1.1 mol), 4-dimethylaminopyridine (12.22 g, 0.1 mol), 2,6-di-tert-butyl-p-cresol (4.4 g, 0.02 mol), and toluene (200 mL) were added. After the bottom liquid was mixed evenly, methacrylic anhydride (316.05 g, 2.05 mol) was added dropwise. After all the addition was completed, the temperature was raised to reflux with toluene and maintained for 3 hours. After completion, the mixture was cooled to room temperature and washed successively with equal volumes of saturated sodium bicarbonate solution, 1M dilute hydrochloric acid, and deionized water. The organic phase was dried with anhydrous magnesium sulfate. After filtration, the solvent was removed by vacuum distillation to obtain diallyl bisphenol F dimethacrylate (yield 90%). In a 250 mL three-necked flask equipped with a thermocouple, a mechanical stirrer, and a nitrogen inlet, purified diallyl bisphenol F dimethacrylate (125 g, 0.3 mol) and m-xylylenediamine (MXDA) (20.4 g, 0.15 mol) were added. The air in the flask was replaced with nitrogen, and the mixture was stirred mechanically at room temperature for 72 hours to obtain acrylate epoxy crosslinking agent 2.

[0066] Table 1. Raw material composition of Examples 1-8 and Comparative Example 1

[0067] The UV-precurable epoxy sealants provided in the above embodiments and comparative examples were subjected to the following performance tests, and the evaluation results are shown in Table 1: 1. Viscosity: Tested using a rotational viscometer at 25°C according to the ASTM D2393 standard test method.

[0068] 2. Water vapor barrier performance test: A 100mm×100mm×1mm test piece was prepared using a flat mold, at 1000mW / cm². 2 The LED (center wavelength 395nm) light source was cured for 20 seconds, followed by UV curing and then room temperature curing for 7 days at 25℃ / 50% RH. The water vapor transmission rate was tested according to ASTM F1249 using a water vapor transmission rate tester under the following conditions: 50℃ / 100%RH. The unit is g / m². 2 ·day·mm.

[0069] 3. Peel strength test: Using the transparent protective film of the e-ink screen as the test substrate, with a width of 25mm and an adhesive layer thickness controlled at 0.15mm, a peel strength test was conducted at 1000mW / cm². 2 Pre-curing with an LED (center wavelength 395nm) light source eliminates the UV blocking effect of the film material itself, ensuring that the adhesive layer receives a light intensity of 20000mJ / cm². 2 After UV curing, it was cured at room temperature for 7 days at 23±2℃ / 50%RH and tested according to ASTM D1786.

[0070] 4. Pot life test: The prepared product is packaged in a 30CC syringe and frozen at -40℃ for 24 hours. Then it is warmed at 23±2℃ / 50%RH for 1 hour. The viscosity is tested at 23±2℃ / 50%RH every hour. The viscosity growth rate after 4 hours is less than 50%. The growth rate is calculated as 100% × (measured viscosity - initial viscosity) / initial viscosity. The product is considered qualified.

[0071] 5. Reliability Test: Apply sealant evenly to the bezel of the electronic paper screen and use 1000mW / cm² pressure. 2 Pre-curing with an LED (center wavelength 395nm) light source eliminates the UV blocking effect of the film material itself, ensuring that the adhesive layer receives a light intensity of 20000mJ / cm². 2 After UV curing, it is cured at room temperature for 7 days at 23±2℃ / 50% RH, and then put into reliability testing. High temperature and high humidity: 500hrs@60℃&80%RH, high temperature and low humidity: 500hrs@60℃&35%RH, both tests are conducted in parallel. If one of the environmental test conditions fails, it is judged as a failure. Reliability judgment: edge damage of the electronic ink screen display area (electronic paper film) <6 grids; no obvious MURA, then it is judged as OK.

[0072] Table 1 Performance Tests

[0073] analyze: As can be seen from the above tests, the acrylate epoxy crosslinking agent provided in Comparative Example 1 was not prepolymerized. The incomplete double bond portion of the simple difunctional acrylate could not form an effective crosslink with the system during the curing stage, resulting in low crosslink density and thus insufficient reliability.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0075] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A UV-precurable epoxy sealant, characterized in that, Its raw materials, calculated on a 100% basis by total mass, include: 25%-50% epoxy resin, 10%-30% amine curing agent, 10%-40% free radical reactive crosslinking agent, 10%-30% filler, 0.1%-2% coupling agent, 0.1%-5% photoradical polymerization initiator, 0%-5% catalyst; The free radical reactive crosslinking agent includes a free radical reactive epoxy resin and / or a free radical reactive amine curing agent.

2. The UV-precurable epoxy sealant according to claim 1, characterized in that, The epoxy resin includes one or more of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, naphthalene ring structure epoxy resin, glycidylamine type epoxy resin, hydantoin epoxy resin, dicyclopentadiene dimethyl methanol type epoxy resin, polyphenol type glycidyl ether epoxy resin, phenolic epoxy resin and allylphenol type epoxy resin. And / or, the amine curing agent includes one or more of polyether amines, aliphatic amines, cycloaliphatic amines, and aryl amines; And / or, the filler includes organic fillers and / or inorganic fillers; And / or, the coupling agent comprises one or more of γ-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-aminoethyl-3-aminopropylmethyldimethoxysilane; And / or, the photoradical polymerization initiator includes one or more of benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, diacetic titanium compounds, oxime ester compounds, benzoin ether compounds, and thioxanone compounds; And / or, the catalyst comprises one or more of an acid or a compound that can be hydrolyzed to an acid, a tertiary amine compound, and a phenolic compound.

3. The UV-precurable epoxy sealant according to claim 2, characterized in that, The amine curing agent includes one or more of the following: aliphatic primary amines, alicyclic primary amines, and aromatic aliphatic primary amines containing ether groups; And / or, the inorganic filler includes at least one or more of limestone, zeolite, bentonite, washed kaolin, talc, titanium dioxide, alumina, quartz, surface-treated and / or untreated silica, nano silica, flint and mica; And / or, the organic filler includes one or more of carbon black, graphite, graphene, organoclay, polyacrylonitrile powder, polyethylene powder, polypropylene powder, polytetrafluoroethylene powder, poly(meth)acrylate powder, and core-shell rubber. And / or, the photoradical polymerization initiator includes 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropanone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2,2-dimethoxy-2-phenylacetophenone, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, 2 The following are one or more of the following: 4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphine acid, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propane-1-one, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] acetophenone-1-(O-acetoxy oxime), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; And / or, the acid or the compound that can be hydrolyzed to an acid includes one or more of salicylic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonate, calcium trifluoromethanesulfonate, diethylamine trifluoromethanesulfonate complex, boron trifluoride ethylamine complex, and ammonium hexafluoroantimonate. And / or, the tertiary amine compound includes one or more of 1,4-diazabicyclo[2.2.2]octane, N,N-dimethylbenzylamine, triethanolamine, 3-dimethylaminopropylamine, N,N-dimethyldipropyltriamine, 1-methylimidazole, 1-vinylimidazole, 1,2-dimethylimidazole, 2-dimethylaminomethylphenol, and 2,4,6-tris(dimethylaminomethyl)phenol; And / or, the phenolic compounds include one or more of phenol, tert-butylphenol, nonylphenol, dodecylphenol, cashew phenol, styrylated phenol, bisphenol A, bisphenol F, resorcinol, diallyl bisphenol A, diallyl bisphenol F, magnolol, and honokiol.

4. The UV-precurable epoxy sealant according to claim 1, characterized in that, The raw materials of the UV-precurable epoxy sealant also include additives; the additives include one or more of the following: stabilizers, antioxidants, polymerization inhibitors, sensitizers, rheology modifiers, wetting and dispersing agents, leveling agents, defoamers, anti-exudants, colorants, reactive diluents, and plasticizers.

5. The UV-precurable epoxy sealant according to claim 1, characterized in that, The free radical reactive epoxy resin contains free radical reactive -C=C- and epoxy groups; And / or, the free radical reactive amine curing agent contains C=C- and -NH.

6. The UV-precurable epoxy sealant according to claim 5, characterized in that, The free radical reactive epoxy resin includes one or more of glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, (meth)acrylate modified epoxy resin, allylphenol type epoxy resin, and triallyl isocyanurate epoxidation products. And / or, the general structural formula of the free radical reactive amine curing agent is: Wherein, R0 includes the residues of a diamine after removing the -NH2 functional group; R1 includes the residues of a difunctional (meth)acrylate after removing the (meth)acryloyloxy functional group; and R2 includes -H and / or -CH3.

7. The UV-precurable epoxy sealant according to claim 6, characterized in that, The diamine includes one or more of the following: aliphatic diamines with ether groups, aliphatic diamines, alicyclic diamines, and aryliphatic diamines; And / or, the difunctional (meth)acrylates include one or more of bisphenol A dimethacrylate, ethoxylated bisphenol A dimethacrylate, propoxylated bisphenol A dimethacrylate, tricyclodecane dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, honokiol dimethacrylate, and honokiol dimethacrylate.

8. The UV-precurable epoxy sealant for electronic ink screens according to claim 7, characterized in that, The primary diamine includes aryl aliphatic primary diamines; And / or, the general structural formula of the difunctional (meth)acrylate includes: Among them, R3 and R4 in different positions each independently include -H or -CH3; R5, R6, R7 and R8 in different positions each independently include any one of -H, -CH3 and -CH2-CH=CH2; R9 and R... 10 Each can be independently represented by any one of -H, -CH3, and -C6H5, with m+n=1-4.

9. The UV-precurable epoxy sealant according to claim 8, characterized in that, The aryl aliphatic diamine includes 1,3-diaminomethylbenzene; And / or, the difunctional (meth)acrylate includes , , and One or more of them.

10. An electronic ink screen, characterized in that, Its raw materials include the UV-precurable epoxy sealant as described in any one of claims 1-9.

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