Antistatic photocurable adhesive composition

Abstract

The present invention provides an antistatic photocurable adhesive composition comprising: (A) at least one acrylic oligomer having repeating units - (C4H8O) n - in the main chain, wherein n is a number greater than 2; (B) at least one monofunctional (meth)acrylate monomer; (C) at least one photoinitiator; and (D) at least one carbon nanotube.

Description

Technical Field

[0001] This invention relates to antistatic photocurable adhesive compositions and their uses, and particularly to antistatic photocurable adhesive compositions comprising carbon nanotubes, which exhibit optimal antistatic properties and excellent adhesive strength after curing. Background Technology

[0002] Traditional antistatic adhesive compositions typically employ thermosetting methods, requiring a silver powder content exceeding 70% by weight based on the total weight of the adhesive composition. However, thermosetting methods necessitate high temperatures (no less than 60°C), which are unsuitable for temperature-sensitive devices in electronics. Moisture curing methods, on the other hand, typically take 3 to 7 days to achieve complete curing, which is time-consuming. Photopolymerization, due to its higher production efficiency, is a more suitable alternative. However, challenges arise when adding large amounts of silver powder, leading to reduced light transmittance and rendering photopolymerization impractical.

[0003] To address this issue, alternative antistatic agents (such as graphene or carbon nanotubes) have been considered. However, using too little graphene results in insufficient conductivity, while excessive amounts can cause agglomeration and hinder the curing process. Summary of the Invention

[0004] According to a first aspect of the present invention, an antistatic photocurable adhesive composition is disclosed herein, the antistatic photocurable adhesive composition comprising: (A) At least one repeating unit – (C4H8O) in the main chain n – acrylic oligomers, where n is a number greater than 2. (B) At least one monofunctional (meth)acrylate monomer, (C) At least one photoinitiator, and (D) At least one carbon nanotube.

[0005] According to a second aspect of the present invention, a method for curing the antistatic photocurable adhesive composition is provided herein, the method comprising: (1) Applying the antistatic photocurable adhesive composition according to the invention to at least one of the substrates, and (2) Expose to photochemical radiation until the adhesive composition is cured, wherein the photochemical radiation is selected from ultraviolet light, visible light, electron beam radiation, or a combination thereof.

[0006] According to a third aspect of the invention, an article is provided herein comprising a substrate and a cured adhesive on the surface of the substrate, wherein the cured adhesive is formed by curing an antistatic photocurable adhesive composition according to the invention, and the substrate is selected from glass, polymer film, metal, and combinations thereof.

[0007] According to a fourth aspect of the invention, an electronic device is provided herein, the electronic device comprising articles of the invention or prepared using an antistatic photocurable adhesive composition according to the invention.

[0008] According to a fifth aspect of the invention, this document provides the use of the antistatic photocurable adhesive composition or article according to the invention in the manufacture of electronic devices.

[0009] Other features and aspects of the subject matter are described in more detail below. Detailed Implementation

[0010] Those skilled in the art will understand that this invention is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the invention. Unless explicitly stated otherwise, each aspect thus described may be combined with any other one or more aspects. In particular, any feature indicated as preferred or advantageous may be combined with any other one or more features indicated as preferred or advantageous.

[0011] In the context of this invention, unless otherwise specified, the terminology used shall be interpreted according to the following definitions.

[0012] Unless otherwise specified, the terms “a / an” and “the” as used herein include both the singular and plural references.

[0013] As used herein, the term “comprising / comprises” is synonymous with “including / includes” or “containing / contains”, and is inclusive or open-ended, and does not exclude additional undescribed members, elements, or method steps.

[0014] The terms “at least one” or “one or more” used in this document to define components refer to the type of component, not the absolute number of molecules. For example, “one or more polyols” means a type of polyol or a mixture of several different polyols.

[0015] As used herein, the term "photocurable" refers to the property of a material or composition to be cured or hardened by exposure to one or more types of ultraviolet light, visible light, electron beam radiation, or a combination thereof.

[0016] As used in this article, the term "curing" refers to a polymerization or addition reaction that exceeds the gelation point. The gelation point is the point at which the storage modulus G' becomes equal to the loss modulus G''.

[0017] As used in this article, "(meth)acrylates" or "(meth)acrylates" refers to both acrylates and methacrylates.

[0018] As used in this article, the term "oligomer" refers to a low molecular weight polymer containing more than two repeating units of at least 500 identical or different types.

[0019] The term "polymer" refers to a macromolecular compound composed of repeating units of the same or different types. The term "polymer" includes homopolymers and copolymers. The term "copolymer" should be understood as a polymer derived from two or more monomers; that is, the term "copolymer" includes binary copolymers, ternary copolymers, tetrary copolymers, etc.

[0020] As used herein, the term "monomer" refers to a substance that can undergo polymerization to provide structural units for the chemical structure of a polymer. Furthermore, according to this disclosure, the term "monomer" is distinguished from polymers or oligomers and refers to compounds with a weight-average molecular weight (Mw) of 1000 or less.

[0021] The term "monofunion" refers to having one aggregateable part, and the term "multifunctional" refers to having more than one aggregateable part.

[0022] The term "alicyclic group" as used in this article refers to saturated hydrocarbons with closed rings (such as cyclopropane, cyclobutene, and cyclopentane).

[0023] The term "heterocyclic group" as used herein refers to a 4- to 8-membered saturated alkylene group having at least one nitrogen atom and optionally one or more oxygen or sulfur atoms to form a heterocycle (such as a morpholine ring, piperidine ring, or piperazine ring).

[0024] As used herein, the term "room temperature" refers to a temperature of about 20°C to about 25°C, preferably about 25°C.

[0025] Unless otherwise specified, the definition of numerical endpoints includes all numbers and fractions falling into their respective ranges, as well as the listed endpoints.

[0026] All references cited in this specification are hereby incorporated in their entirety by reference.

[0027] Unless otherwise specified, molecular weight is exponential average molecular weight (Mn). Unless otherwise specified, all molecular weight data refer to values ​​obtained, for example, by gel permeation chromatography (GPC) according to DIN 55672.

[0028] Unless otherwise defined, all terms used in this invention (including technical and scientific terms) have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] In one aspect, this disclosure generally relates to antistatic photocurable adhesive compositions comprising: (A) At least one repeating unit in the main chain - (C4H8O) n – acrylic oligomers, where n is a number greater than 2. (B) At least one monofunctional (meth)acrylate monomer, (C) At least one photoinitiator, and (D) At least one carbon nanotube.

[0030] The adhesive composition is characterized by effective antistatic properties, resulting in a static charge of less than 1 × 10⁻⁶. 4 The volume resistivity in Ω·cm; the good bond strength after curing; and the desired elongation to resist deformation under applied force.

[0031] (A) Acrylic oligomers According to the present invention, the antistatic photocurable adhesive composition comprises at least one repeating unit – (C4H8O) in the main chain. n – An acrylic oligomer is used as the first essential component, where n is a number greater than 2. Component (A) is the main reactant that undergoes free radical polymerization in the presence of a photoinitiator (C) to form the acrylic polymer.

[0032] Regarding the main chain, component (A) has a repeating unit – (C4H8O). n – where n is a number greater than 2, preferably greater than 4, more preferably 6 to less than 500. Acrylic oligomers having this type of main chain structure impart moderate polarity to acrylic polymers upon curing. The inventors unexpectedly discovered that if the polarity of the acrylic polymer is too high (e.g., polymers made from acrylic oligomers with benzene rings), it exhibits low volume resistivity but poor adhesive strength and elongation. Conversely, if the polarity is too low (e.g., polymers made from aliphatic acrylic polymers without any ether or ester groups), it can have good flexibility and elongation but insufficient adhesive strength. Component (A) having such a main chain effectively balances the elongation and adhesive strength of the cured product with the antistatic properties of the composition after curing.

[0033] In a preferred embodiment, the acrylic oligomer (A) that can be used in the present invention is a polytetramethylene glycol di(meth)acrylate oligomer.

[0034] In a preferred embodiment, the molecular weight (Mw) of the acrylic oligomer (A) used in this invention is from 1,000 to 40,000 g / mol.

[0035] In a preferred embodiment, the aliphatic urethane diacrylate oligomers used in this invention have a viscosity of 60,000 to 90,000 mPa·s at 50°C. The viscosity values ​​described herein can be determined using any suitable viscosity measurement method conventionally used in the art.

[0036] It is worth noting that the compositions of the present invention preferably do not contain any acrylic oligomers other than component (A).

[0037] Commercially available compounds suitable for use as component (A) are products available under the following trade names: GRE2060 from Gubang (Shanghai) New Material Technology Co., Ltd; A-PTMG650 from Xinzhongcun Chemical Co., Ltd; ADT250 manufactured by NOF Corporation; DR-U247 from EternalSpecialty Materials (Zhuhai) Co., Ltd; CN996A NS from Sartomer (Guangzhou) Chemicals Ltd; and EB8807 from Allnex USA INC.

[0038] Particularly preferably, based on the total weight of the adhesive composition, the amount of component (A) may be from 8% to 86% by weight, preferably from 13% to 75% by weight, such as 15% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, or 73% by weight.

[0039] (B) Monofunctional (meth)acrylate monomers According to the present invention, the antistatic photocurable adhesive composition comprises at least one monofunctional (meth)acrylate monomer (B) as a second essential component in order to reduce viscosity and provide adhesive strength to the composition upon curing.

[0040] Useful monofunctional (meth)acrylate monomers may contain one or more aliphatic, aromatic, alicyclic, aryl-aliphatic, heterocyclic groups, and combinations thereof. Examples include acrylic acid, n-butyl (meth)acrylate, 2-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, amyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-methylbutyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, isopentyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, 4-methyl-2-pentyl (meth)acrylate, dodecyl (meth)acrylate, and methyl (meth)acrylate. Cinnamyl acrylate, 2-ethoxyethyl acrylate, 2-methoxyethyl acrylate, allyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, and hydroxyalkylene glycol (having 2-4 carbon atoms) diol (meth)acrylates (e.g., 2-hydroxyethylene glycol acrylate and 2-hydroxypropylene glycol acrylate), dicyclopentenyl acrylate, dicyclopentyl acrylate, dicyclopentenyloxyethyl acrylate, 4-tert-butylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, acryloylmorpholine, isobornyl acrylate, tetrahydrofurfuryl acrylate, 2-phenoxyethyl acrylate, and combinations thereof.

[0041] In a preferred embodiment, the monofunctional (meth)acrylate monomer used in this invention contains alicyclic groups and / or heterocyclic groups.

[0042] Preferred examples include acryloylmorpholine (ACMO), isobornyl acrylate (IBOA), dicyclopentyl acrylate, cyclohexyl (meth)acrylate (CHMA), tetrahydrofurfuryl acrylate (THFA), dicyclopentenyloxyethyl acrylate, 4-tert-butylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, and combinations thereof.

[0043] The above-mentioned monofunctional (meth)acrylate monomers can be used alone or in combination of two or more of them.

[0044] The composition preferably does not contain any polyfunctional (meth)acrylate monomers, because polyfunctional (meth)acrylate monomers increase the crosslinking content and make the composition too rigid and difficult to dispense.

[0045] Examples of commercially available products of component (B) may include: ACMO from KJ Chemicals; SR506 NS, SR531 NS and SR339 NS from Sartomer; Etermer 70 from Eternal Specialty Materials (Zhuhai) Co., Ltd; and IBXA from Osaka Organic Chemical Industry Limited.

[0046] Particularly preferably, based on the total weight of the adhesive composition, the amount of component (B) may be from 10% to 80% by weight, preferably from 20% to 70% by weight, such as 23% by weight, 27% by weight, 31% by weight, 35% by weight, 39% by weight, 43% by weight, 47% by weight, 51% by weight, 55% by weight, 59% by weight, 65% by weight, or 68% by weight.

[0047] The combination of components (A) and (B) together forms a resin base for incorporating carbon nanotubes and imparts mechanical properties to the adhesive composition of the present invention.

[0048] (C) Photoinitiator According to the present invention, the antistatic photocurable adhesive composition comprises at least one photoinitiator (C) as a third essential component.

[0049] A photoinitiator is a component that enables the adhesive composition to fully cure, and therefore its type or variety is not particularly limited. Commonly known photoinitiators can be used in this invention.

[0050] "Photoinitiator" refers to an initiator that can initiate a photopolymerization reaction under the action of light radiation.

[0051] Examples of photoinitiators include, but are not limited to: benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, hydroxydimethyl acetophenone, dimethylaminoacetophenone, dimethoxy-2-phenylacetophenone, 3-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 4-chloroacetophenone, 4,4-dimethoxyacetophenone, 2-hydroxy-2 1-Methyl-1-phenylpropane-1-one, 4-hydroxycyclophenyl one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propane-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)one, benzophenone, p-phenylbenzophenone, 4,4-diaminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-Aminoanthraquinone, β-chloroanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, benzophenone benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, fluorene, triphenylamine, carbazole, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, or (2,4,6-trimethyl... Examples of photoinitiators include ethyl benzoylphenylphosphinate, 1-hydroxycyclohexylphenyl ketone, 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl oxyphenylacetic acid, 2-[2-hydroxy-ethoxy]-ethyl oxyphenylacetic acid, 2-hydroxy-2-methyl-1-phenyl-1-propanone, phosphine bis(2,4,6-trimethylbenzoyl), and iodonium (4-methylphenyl)[4-(2-methylpropyl)phenyl]-hexafluorophosphate (1-), etc. These photoinitiators can be used alone or in combination.

[0052] Suitable commercially available components (C) are derived from IGM using Omnirad TPO-L and R-Gen. TM 261 and R-Gen TM 262 is sold by Chitec Technology.

[0053] Particularly preferably, based on the total weight of the adhesive composition, the amount of component (C) can be from 0.1 wt% to 10 wt%, preferably from 0.3 wt% to 5 wt%, more preferably from 0.5 wt% to 4.5 wt%, such as 0.2 wt%, 0.4 wt%, 0.7 wt%, 1.0 wt%, 1.3 wt%, 1.7 wt%, 2.1 wt%, 2.3 wt%, 2.5 wt%, 2.7 wt%, 2.9 wt%, 3.1 wt%, 3.4 wt%, 3.7 wt%, 4.0 wt%, 4.2 wt%, 4.4 wt%. The percentages by weight are as follows: 4.6 wt%, 4.8 wt%, 5.0 wt%, 5.2 wt%, 5.4 wt%, 5.6 wt%, 5.8 wt%, 6.0 wt%, 6.2 wt%, 6.4 wt%, 6.6 wt%, 6.8 wt%, 7.0 wt%, 7.2 wt%, 7.4 wt%, 7.6 wt%, 7.8 wt%, 8.0 wt%, 8.2 wt%, 8.4 wt%, 8.6 wt%, 8.8 wt%, 9.0 wt%, 9.2 wt%, 9.4 wt%, 9.6 wt%, 9.8 wt%. When the photoinitiator content is less than 0.1 wt%, the curing rate will decrease and oxygen inhibition will be severe, resulting in a very slow curing speed. On the other hand, when the photoinitiator content is greater than 10 wt%, this will reduce the curing depth.

[0054] (D) Carbon nanotubes According to the present invention, the antistatic photocurable adhesive composition comprises at least one carbon nanotube (D) as an antistatic agent.

[0055] Carbon nanotubes are cylindrical, hollow, fibrous materials composed of individual carbon atoms.

[0056] The useful carbon nanotubes used in this invention can be single-walled carbon nanotubes (SWCNTs). SWCNTs are cylindrical nanostructures composed of a single layer of graphene (a single-atom-thick sheet of carbon atoms arranged in a hexagonal lattice). Compared to multi-walled carbon nanotubes (MWCNTs), SWCNTs are more suitable for use in this invention from the viewpoint of achieving advantageous electrical properties and higher purity. This is because SWCNTs have a higher aspect ratio and a larger surface area than MWCNTs, making it easier for them to contact each other to form electrical paths.

[0057] The surface area of ​​carbon nanotubes (D) is preferably greater than 300 m². 2 / g, more preferably greater than 500 m 2 / g. When the surface area of ​​carbon nanotubes is greater than 300 m² 2 At / g, they are more likely to come into contact with each other to form electrical paths, thus achieving better electrical properties.

[0058] The average diameter of the carbon nanotubes (D) is preferably from 1 nm to 10 nm, more preferably from 1 nm to less than 5 nm, and even more preferably from 1 nm to 3 nm. When the average diameter of the carbon nanotubes is 1 nm or greater, the carbon nanotubes are easily incorporated into the resin. When the average diameter of the carbon nanotubes is from 1 nm to 3 nm, the antistatic properties of the adhesive composition are further improved.

[0059] The average length of the carbon nanotubes (D) is preferably greater than 1 μm to 800 μm, more preferably 1 μm to 650 μm, and even more preferably 1 μm to 200 μm. When the average length of the carbon nanotubes (D) is greater than 800 μm, they cannot be properly dispersed in the resin and will have more defects on the surface, resulting in unsatisfactory volume of the cured adhesive.

[0060] The aspect ratio of the carbon nanotubes (D) is preferably from 1,000 to 50,000, more preferably from 1,000 to 10,000.

[0061] Preferably, the carbon nanotube (D) is a SWCNT with an average diameter of 1 nm to 10 nm and an average length of greater than 1 μm to 800 μm. In this embodiment, a more preferred range for each of the average diameter and average length is as described above. The average diameter of the carbon nanotube (D) is determined by observing the carbon nanotube (D) using an electron microscope (scanning electron microscope (SEM) or transmission electron microscope (TEM)) and measuring the diameter of the carbon nanotube, and calculating the arithmetic mean of the measured diameters. The average length of the carbon nanotube (D) is determined by observing the carbon nanotube (D) using an electron microscope (scanning electron microscope (SEM) or transmission electron microscope (TEM)) and measuring the length of the carbon nanotube, and calculating the arithmetic mean of the measured lengths. The term "aspect ratio" as used herein refers to the calculated value of the length value obtained above and the diameter value obtained above.

[0062] Carbon nanotubes (D) can be prepared by methods such as arc discharge, chemical vapor deposition (CVD), and laser ablation. Furthermore, commercially available carbon nanotubes can be used as carbon nanotubes (D). Examples of commercially available carbon nanotubes used in this invention include pre-dispersion materials in resins, such as TUBALL from OCSiAl. TM MATRIX204 (containing 10% carbon nanotubes with diameters of 1.5 nm to 2.0 nm and lengths greater than 5 μm); and 100% carbon nanotube powder, such as ZEONANO from Zeon Corporation. TMSG101 (with a diameter of 3 nm to 5 nm and a length of 100 μm to 600 μm) and NG01SW0301 from Nanografi Nano technology (with a diameter of 1 nm to 2 nm and a length of 5 μm to 35 μm).

[0063] It is also feasible to use a combination of at least two of the above-mentioned carbon nanotubes in this invention.

[0064] It is worth noting that the adhesive composition of the present invention preferably does not contain any other antistatic agents other than component (D).

[0065] Particularly preferably, based on the total weight of the adhesive composition, the amount of component (D) can be from 0.01 wt% to 2 wt%, preferably from 0.01 wt% to 1 wt%, more preferably from 0.01 wt% to 0.8 wt%, such as 0.03, 0.05, 0.07, 0.09, 0.11, 0.13, 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.27, 0.29, 0.31, 0.33, 0.35, 0.37, 0 0.39, 0.41, 0.43, 0.45, 0.47, 0.49, 0.51, 0.53, 0.55, 0.57, 0.59, 0.61, 0.63, 0.65, 0.67, 0.69, 0.71, 0.73, 0.75, 0.79, 0.81, 0.83, 0.85, 0.89, 0.91, 0.93, 0.95, 0.97, 0.99, 1.01, 1.1, 1.3, 1.5, 1.7, 1.9 wt%. When the carbon nanotube content is less than 0.01 wt%, the electrical properties are insufficient for applications. On the other hand, when the carbon nanotube content is greater than 2 wt%, the black carbon nanotubes affect photocuring, are difficult to disperse completely, and have poor processability.

[0066] (E) Additives The compositions of the present invention may further comprise silane coupling agents, adhesion promoters, thixotropic agents, surfactants, preservatives, plasticizers, lubricants, light stabilizers, defoamers, and combinations thereof.

[0067] Examples of silane coupling agents include, but are not limited to, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane. Suitable commercial products are: SH6062 and SZ6030, available from Toray-Dow CorningSilicone Inc.; KB E903, KBM-5103, and KBM803, available from Shin-Etsu Silicone Inc.; and Sliquest A-187, available from Momentive. The amount of silane coupling agent present can be from 0% to 15% by weight, preferably from 1% to 10% by weight, based on the total weight of the adhesive composition.

[0068] Examples of adhesion promoters include, but are not limited to, di(methacryloyloxyethyl) hydrogen phosphate. A suitable commercial product is Kayamer PM-2 from Nippon Kayaku.

[0069] It is worth noting that the compositions of the present invention preferably do not contain any epoxy resins used for thermosetting.

[0070] Preparation method and curing properties The antistatic, light-curable adhesive composition according to the present invention can be prepared by a method comprising the following steps: (i) Mix all components according to the invention except for component (D), and (ii) Add component (D) and mix at 1000 rpm to 2000 rpm for at least 30 minutes until a homogeneous composition is formed.

[0071] There are no particular limitations on the equipment used for these mixing, stirring, and dispersing processes. Automatic mortars, Henschel mixers, three-roll mills, ball mills, planetary mixers, bead mills, etc., equipped with stirrers and heaters can be used. Appropriate combinations of these devices can also be used. There are no particular limitations on the preparation method of the antistatic photocurable adhesive composition, as long as it is a composition in which the above-mentioned components are uniformly mixed.

[0072] According to a second aspect of the present invention, a method for curing an antistatic photocurable adhesive composition is provided herein, the method comprising: (1) Applying the antistatic photocurable adhesive composition according to the invention to at least one of the substrates, and (2) Expose to photochemical radiation until the adhesive composition is cured, wherein the photochemical radiation is selected from ultraviolet light, visible light, electron beam radiation, or a combination thereof.

[0073] The aforementioned substrate may be selected from glass, polymer film, metal, and combinations thereof.

[0074] According to the present invention, the antistatic photocurable adhesive composition can be cured by exposure to photochemical radiation sufficient to polymerize or crosslink the composition, wherein the photochemical radiation is selected from ultraviolet light, visible light, electron beam radiation, or combinations thereof.

[0075] In one embodiment, the photochemical radiation has a wavelength range of 200 nm to 500 nm, preferably 300 nm to 465 nm, and an intensity of 50 mW / cm². 2 Up to 5000 mW / cm 2 .

[0076] In a preferred embodiment, the exposure time can be as short as 1 second to as long as 120 seconds, preferably 1 second to 60 seconds.

[0077] Preferably, the photochemical radiation source is an LED light source. A commercially available LED light source, such as the UVEC-100*100WII from Heraeus, has a maximum emission at 365 nm and an intensity ranging from 50 to 5000 mW / cm². 2 .

[0078] As should be understood, the time and temperature curing properties of various light-curable adhesive compositions will differ, and different compositions can be designed to provide curing properties suitable for specific industrial manufacturing processes.

[0079] Products, electronic devices and applications According to a third aspect of the invention, an article is provided herein comprising a substrate and a cured adhesive on the surface of the substrate, wherein the cured adhesive is formed by curing an antistatic photocurable adhesive composition according to the invention, and the substrate is selected from glass, polymer film, metal, and combinations thereof.

[0080] In another embodiment, two substrates can be bonded together using the antistatic, light-curable adhesive composition of the present invention. The method includes applying the adhesive composition of the present invention to at least one of the substrates, then mating the substrates together, and then exposing them to photochemical radiation until the adhesive composition cures. In such cases, at least one substrate may include a light-transmitting portion, or at least one substrate may be light-transmitting. In another embodiment, at least one substrate may include a plastic or glass material that is transparent to ultraviolet or visible light.

[0081] The adhesive composition can be applied to a substrate using any suitable application method, including, for example, automated fine-line dispensing, jet dispensing, slot die coating, roller coating, patterned coating, screen printing, spraying, filament coating, air knife, drag knife, brush coating, dip coating, doctor blade coating, and combinations thereof. The adhesive composition can be applied as a continuous or discontinuous coating in single or multiple layers, and combinations thereof.

[0082] According to a fourth aspect of the invention, an electronic device is provided herein, the electronic device comprising articles of the invention or prepared using an antistatic photocurable adhesive composition according to the invention.

[0083] The adhesive compositions of the present invention can be used in a variety of electronic devices, including, for example: wearable electronic devices (e.g., wristwatches and glasses), handheld electronic devices (e.g., telephones (e.g., cellular phones and cellular smartphones), cameras, tablet computers, e-readers, monitors (e.g., monitors used in hospitals and by healthcare workers, athletes, and individuals), watches, calculators, mice, touchpads, and joysticks), computers (e.g., desktop computers and laptop computers), computer monitors, televisions, media players, home appliances (e.g., refrigerators, washing machines, dryers, ovens, and microwave ovens), light bulbs (e.g., incandescent bulbs, light-emitting diodes, and fluorescent lamps), and articles comprising visible transparent or transparent components, glass housing structures, protective transparent covers for displays or other optical components.

[0084] According to a fifth aspect of the invention, this document provides the use of the antistatic photocurable adhesive composition or article according to the invention in the manufacture of electronic devices.

[0085] Suitable electronic devices include, but are not limited to, wearable electronic devices (e.g., wristwatches and glasses), handheld electronic devices (e.g., telephones (e.g., cellular phones and cellular smartphones), cameras, tablet computers, e-readers, monitors (e.g., those used in hospitals and by healthcare workers, athletes, and individuals), watches, calculators, mice, touchpads, and joysticks), computers (e.g., desktop computers and laptop computers), computer monitors, televisions, media players, or other electronic components, preferably camera modules.

[0086] Example The following examples are intended to help those skilled in the art better understand and implement the present invention. The scope of the invention is not limited by the examples, but is defined in the appended claims. Unless otherwise stated, all parts and percentages are based on weight.

[0087] raw material: CN 9014 NS is a polybutadiene acrylate oligomer available from Sartamomer.

[0088] EB3700 is an acrylate oligomer based on bisphenol A epoxy resin, available from Allnex.

[0089] GRE2060 is a repeating unit – (C4H8O) available from Gubang (Shanghai) New Material Technology Co., Ltd. n – an acrylic oligomer, where n is 420.

[0090] ACMO is an acryloylmorpholine available from KJ Chemicals.

[0091] SR506 NS is an isobornyl acrylate monomer available from Sartomer.

[0092] Omnirad TPO-L is an ethyl 2,4,6-trimethylbenzoyl)phenylphosphine ester available from IGM.

[0093] EA-0295 is a silver filler available from Metalor.

[0094] SE1233-S is graphene available from SIX Element.

[0095] TUBALL MATRIX 204 is a blend of triethylene glycol dimethacrylate, which is available from OCSiAl, and ammonium salts based on polyolefin derivatives, containing 10% by weight single-walled carbon nanotubes with a diameter of 1.5 to 2.0 nm and a length of 5 μm.

[0096] Kayamer PM-2 is a di(methacryloyloxyethyl) ester of hydrogen phosphate, available from Nippon Kayaku.

[0097] KBM-5103 is a silane coupling agent available from Shin-Etsu.

[0098] Test method: Curing depth The compositions of each comparative example and the invention were injected into an opaque container (with dimensions of 1 cm in diameter and 5 mm in depth), and then subjected to a wavelength of 365 nm and an intensity of 2 W / cm² on the top of the sample. 2The sample was cured by emitting LED light (UVEC-100*100WII manufactured by Heraeus) for 2 seconds. Then, the cured portion of the sample was removed to measure the curing depth.

[0099] Compositions with a curing depth of not less than 50 μm are acceptable. The results are recorded in Table 1.

[0100] Volume resistivity The volume resistivity of the comparative examples and invention examples was measured using an Agilent 34401A instrument based on ASTM D991. The upper limit of the volume resistivity that can be detected on this instrument is 1.00 × 10⁻⁶. 10 Ω·cm.

[0101] Volume resistivity less than 1 × 10 4 The composition with Ω·cm is desirable. The results are recorded in Table 1.

[0102] Adhesion strength on glass The adhesive strength of Comparative Examples 1, 6, and 7, as well as all inventive examples, was determined according to ASTM D3359-23. Specifically, a glass substrate with a thickness of 50 μm was used. After the adhesive composition of the sample was applied, a test was performed on the top of the specimen at a wavelength of 365 nm and a strength of 2 W / cm². 2 LED light radiation (UVEC-100*100WII manufactured by Heraeus) was applied for 2 seconds to cure the sample. Then, 12 cut lines (6 vertical and 6 parallel) were made at 1 mm intervals using a scalpel to form a grid. Adhesive tape was applied to the cut surface, ensuring it adhered firmly to the cut features, and smoothed with an eraser. After 90 seconds, the tape was peeled off at a 180° angle. Finally, the peeled film from the grid area on the glass substrate was examined under a magnifying glass, and the adhesion level was evaluated according to the following criteria:

[0103] In this invention, compositions with a volume assistance of 5 Ω are considered to have satisfactory antistatic properties. The results are recorded in Table 2.

[0104] Bending test Through a wavelength of 365 nm and an intensity of 2 W / cm 2 An adhesive with a thickness of 200 μm was prepared by curing for 2 seconds under LED light radiation (UVEC-100*100WII manufactured by Heraeus). Bending tests were measured under the following test conditions for Comparative Examples 1, 6 and 7 and all Invention Examples.

[0105] (Test conditions) Bending radius: 3 mm; Bending angle: 180°; Bending speed: 1 second / bend Visually inspect the bonded material after the bending test to confirm the presence of cracks. A bonded material without cracks is rated as О. A bonded material with cracks is rated as X. The results are recorded in Table 2.

[0106] Examples of the invention 1 to 4 (EX1 to EX4) and Comparative Examples 1 to 7 (CE1 to CE7) The compositions of the comparative examples and the inventive examples were prepared by the following steps: (i) Mix all components except the antistatic agent (silver filler / graphene / carbon nanotubes) in a mixer IKA EUROSTAR 60 at the weights specified in Table 1, and (ii) Add the antistatic agent (if any) weighed in the amounts specified in Table 1 at 2000 rpm for 60 minutes until a homogeneous composition is formed.

[0107] The properties were tested using the methods described above, and the evaluation results are shown in Tables 1 and 2.

[0108] Table 1

[0109] N / A means that the cured film is not too thin to be measured.

[0110] In Table 1, descriptions such as "1.00E+10" indicate 1.00 × 10⁻⁶. 10 wait.

[0111] Table 2

[0112] As can be seen from Tables 1 and 2, Comparative Examples 1 to 5 (CE1), which do not contain any antistatic agent, did not exhibit any antistatic properties. Comparative Examples CE2 to CE5, which contain silver or graphene, neither achieved the desired volume resistivity nor cured properly. Comparative Examples 6 and 7 show that adhesive compositions using different types of oligomers (rather than component (A)) cannot simultaneously achieve the desired volume resistivity and good adhesive mechanical properties. In contrast, the antistatic photocurable adhesive compositions of the present invention exhibit excellent adhesive strength and satisfactory electrical properties after curing.

[0113] Although some preferred embodiments have been described, many modifications and variations can be made to them based on the above teachings. Therefore, it should be understood that the invention can be practiced in ways different from those specifically described without departing from the scope of the appended claims.

Claims

1. An antistatic photocurable adhesive composition, said antistatic photocurable adhesive composition comprising: (A) At least one repeating unit – (C4H8O) in the main chain n – acrylic oligomers, where n is a number greater than 2. (B) At least one monofunctional (meth)acrylate monomer, (C) At least one photoinitiator, and (D) At least one carbon nanotube.

2. The antistatic photocurable adhesive composition according to claim 1, wherein component (A) is a polytetramethylene glycol di(meth)acrylate oligomer.

3. The antistatic photocurable adhesive composition according to claim 1 or 2, wherein component (B) is a monofunctional (meth)acrylate monomer containing one or more aliphatic groups, aromatic groups, alicyclic groups, aryl aliphatic groups, heterocyclic groups, and combinations thereof, preferably a monofunctional (meth)acrylate monomer containing alicyclic groups and / or heterocyclic groups, more preferably acryloylmorpholine, isobornyl acrylate (IBOA), dicyclopentyl acrylate, cyclohexyl (meth)acrylate (CHMA), tetrahydrofurfuryl acrylate (THFA), dicyclopentenyloxyethyl acrylate, 4-tert-butylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, and combinations thereof.

4. The antistatic photocurable adhesive composition according to any one of the claims, wherein component (D) is a single-walled carbon nanotube.

5. The antistatic photocurable adhesive composition according to claim 4, wherein the aspect ratio of component (D) is 1,000 to 50,000, more preferably 1,000 to 10,000.

6. The antistatic photocurable adhesive composition according to any one of claims, wherein, Based on the total weight of the composition, the amount of component (A) is from 8% to 86% by weight, preferably from 13% to 75% by weight.

7. The antistatic photocurable adhesive composition according to any one of claims, wherein, Based on the total weight of the composition, the amount of component (B) is from 10% to 80% by weight, preferably from 20% to 70% by weight.

8. The antistatic photocurable adhesive composition according to any one of claims, wherein, Based on the total weight of the composition, the amount of component (C) is 0.1% to 10% by weight, preferably 0.3% to 5% by weight, and more preferably 0.5% to 4.5% by weight.

9. The antistatic photocurable adhesive composition according to any one of claims, wherein, Based on the total weight of the composition, the amount of component (D) is 0.01% to 2% by weight, preferably 0.01% to 1% by weight, and more preferably 0.01% to 0.8% by weight.

10. The antistatic photocurable adhesive composition according to any one of claims, wherein the composition further comprises an additive (E) selected from silane coupling agents, adhesion promoters, thixotropic agents, surfactants, preservatives, plasticizers, lubricants, light stabilizers, defoamers, and combinations thereof.

11. The antistatic photocurable adhesive composition according to any one of the claims, wherein the composition does not contain any epoxy resin.

12. The antistatic photocurable adhesive composition according to any one of claims, wherein the adhesive composition exhibits a curing efficiency of less than 1 × 10⁻⁶. 4 Volume resistivity in Ω·cm.

13. A method for curing an antistatic photocurable adhesive composition, the method comprising: (1) Applying at least one of the antistatic photocurable adhesive compositions according to any one of claims 1-12 to a substrate, and (2) Expose to photochemical radiation until the adhesive composition is cured, wherein the photochemical radiation is selected from ultraviolet light, visible light, electron beam radiation, or a combination thereof.

14. An article comprising a substrate and a cured adhesive on the surface of the substrate, wherein the cured adhesive is formed by curing an antistatic photocurable adhesive composition according to any one of claims 1-12, and the substrate is selected from glass, polymer film, metal, and combinations thereof.

15. An electronic device comprising the article of claim 14 or prepared using the antistatic photocurable adhesive composition according to any one of claims 1-12.

16. Use of the antistatic photocurable adhesive composition according to any one of claims 1-12 or the article according to claim 14 in the manufacture of electronic devices.

Images