Method for sealing a battery having a nickel-based surface

Abstract

The present invention relates to a method for sealing articles having nickel-based surfaces, specifically electrical components having nickel-based surfaces, using a thermosetting polymer material as a sealing material. The present invention also relates to a kit of materials for sealing articles having nickel-based surfaces, and articles obtained from the sealing. The method of the present invention relates to the application of a first coating based on an acrylic-based polymer material between the article having a nickel-based surface and the sealing material.

Description

Technical Field

[0001] The present invention is directed to a novel method for encapsulating articles having a nickel-based surface, specifically electrical components having a nickel-based surface, using a thermosetting polymer as an encapsulating material. The method of the present invention is based on the application of a first coating based on an acrylic-based polymer material between an article having a nickel-based surface and the encapsulating material. The present invention also relates to a kit of materials for encapsulating articles having a nickel-based surface, and to the articles obtained from the encapsulation.

Background Art

[0002] Nickel and nickel-based alloys play an important role in our economy, from power generation to electronics and automotive manufacturing. They impart specific properties and are widely used in the assembly of various products, including battery components, electrical leads, mobile phones, and others. Such components can be provided with a nickel layer to protect against corrosion and wear and to improve contact resistance.

[0003] Generally, for the above applications, potting and / or encapsulation techniques are commonly used to protect the components and optimize their performance. Potting is the process of partially or completely filling or embedding components or sub-assemblies within a housing using a resin. Encapsulation is a similar process to potting, but differs in that the component is generally immersed in a mold using a resin, although not necessarily filling the entire cavity.

[0004] Resin systems to be used for encapsulating electrical components need to meet various properties (such as good adhesion, heat resistance, and insulating properties). The most common types of resins used as encapsulants are polyurethane, acrylic, epoxy resins, and silicone.

[0005] By sealing electrical components using these special polymer materials, thermal runaway and heat transfer can be prevented, mechanical shocks and vibrations under normal operating conditions can be reduced, and a seal against moisture, solvents, and corrosive substances can be created. These enhancements ensure improved safety, increased mechanical stability, and enhanced long-term performance.

[0006] However, a potential problem is the difficulty in achieving good adhesion of polymer materials to nickel and nickel-based alloys that make up the surfaces of electrical components, particularly battery surfaces. Nickel is an inherently inert material and tends to be smooth, resulting in a small effective surface area. Therefore, bonding components with nickel-based surfaces together using adhesive bonding is extremely difficult.

[0007] Surface pretreatment has been proposed to improve the bonding properties of adhesive layers on nickel surfaces to be bonded. Patent Document 1 describes a method for improving the adhesion of polymer materials to nickel surfaces by treating the substrate with H2O2 at temperatures exceeding 40°C. The disadvantages of this method are that it is a wet process, time-consuming, and involves the application of high temperatures that can degrade electrical components in certain cases.

[0008] Patent Document 2 describes a method for improving the adhesion of a polymer material to a nickel surface by treating the substrate with plasma or heat treatment. However, plasma treatment is not effective under all conditions because it negatively affects other components connected to the substrate of the bonding target. Also, while plasma treatment can improve adhesion values ​​in certain cases, it does not necessarily result in a cohesive failure pattern.

[0009] These prior art methods are not practical for encapsulating batteries with nickel-based surfaces in thermally conductive resins.

[0010] Given these technical issues, the applicant recognizes the need to improve the adhesion of sealing materials to nickel-based surfaces.

[0011] Therefore, an object of the present invention is to provide materials and methods for electronic component encapsulation, specifically battery encapsulation, that enable good adhesion properties and high bonding strength to nickel-based surfaces. The improved adhesion in this respect mainly means that an aggregate failure pattern is obtained when the bond between the encapsulant and the nickel-based surface of the electronic component is forcibly broken.

[0012] The applicant has surprisingly found that by combining at least two encapsulating materials, both of which would individually fail with interfacial failure patterns, it is possible to obtain a cohesive failure pattern between the encapsulating material and the nickel-based surface.

[0013] The method of the present invention essentially consists of applying a first layer of polymer material (P) and a second upper layer of encapsulating material (A) onto an article having a nickel-based surface. The polymer material (P) adheres better to the nickel-based surface than material (A), but fails to meet many of the requirements for encapsulating electronic components. Material (A) adheres well to the polymer material (P), which leads to cohesive failure in the layer of material (A). [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] U.S. Patent No. 5,532,024 [Patent Document 2] German Patent Application Publication No. 102017202851 [Overview of the Initiative]

[0015] The present invention relates to a method for sealing an article having a nickel-based surface (S) using a thermosetting polymer material (A), wherein the method is: i) A step of coating at least a portion of the surface (S) of an article with a first curable resin composition, ii) The step of at least partially curing the first curable resin composition to obtain a nickel-based article coated with a first layer of polymer material (P), iii) The step of applying at least a precursor composition of a thermosetting polymer material (A) onto a first layer of polymer material (P), iv) The step of curing the precursor composition to obtain a top layer of thermosetting polymer material (A), It includes at least, The first curable resin composition is selected from acrylate resins and methacrylate resins. Thermosetting polymer material (A) includes a polymer whose Tg is -10°C or lower, whose cured tensile strength is in the range of 0.5 MPa to 20 MPa, and whose cured elongation at break is in the range of 5% to 250%, with the tensile strength and elongation at break being measured according to ISO 527.

[0016] Advantageously, the nickel-based surface (S) of the article may be a solid nickel surface, a plated nickel surface, or a galvanized nickel surface.

[0017] Advantageously, the first curable resin composition is a) an acrylic acid ester or methacrylic acid a) a polymerizable monomer composition containing an ester or a derivative thereof, and b) at least one initiator, is a two-component composition comprising at least one component.

[0018] Preferably, the polymerizable monomer composition further comprises a) at least one acid (preferably selected from acrylic acid, methacrylic acid, vinyl acetic acid, and acrylooxypropionic acid, maleic acid, and crotonic acid) and / or at least one acid ester (preferably a phosphate ester).

[0019] According to the first embodiment, the thermosetting polymer material (A) is a polyurethane, and the precursor composition of the thermosetting polymer material (A) is a two-component composition containing at least a) a polyol component and b) an isocyanate component.

[0020] According to the second embodiment, the thermosetting polymer material (A) is an epoxy resin, and the precursor composition of the thermosetting polymer material (A) is a two-component composition containing at least a) an epoxy compound and b) a curing agent.

[0021] Advantageously, the precursor composition of the thermosetting polymer material (A) according to the first or second embodiment further contains a filler, preferably further contains at least 30% by weight of a filler.

[0022] Advantageously, the precursor composition of the thermosetting polymer material (A) according to the first or second embodiment further contains one or more additives selected from dyes, pigments, flame retardants, softeners, thermal degradation stabilizers, and thixotropy modifiers or rheology modifiers.

[0023] Advantageously, in steps i) and iii), the first curable resin composition and the precursor composition of the thermosetting polymer material (A) are each applied to the nickel-based article surface (S) in an amount that gives a dry film thickness of 0.1 to 3 mm.

[0024] Advantageously, in steps ii) and iv), the first curable resin composition and the second curable resin composition are each cured at ambient temperature.

[0025] According to another aspect, the present invention relates to a kit for sealing an article having a nickel-based surface (S), the kit comprising i) a first curable resin composition selected from acrylate resins and methacrylate resins, and ii) A precursor composition of a thermosetting polymer material (A), wherein the thermosetting polymer material contains a polymer having a Tg of -10°C or lower, a tensile strength in the range of 0.5 MPa to 20 MPa after curing, and an elongation at break in the range of 5% to 250% after curing, the tensile strength is measured by the ISO 527 method, and the elongation at break is measured by the ISO 527 method, and the precursor composition, Includes.

[0026] In another embodiment, the present invention relates to a device essentially composed of a sealed article, the device being obtained by carrying out a method according to the present invention. Preferably, the article is selected from a battery having a nickel-based surface.

[0027] In another aspect, the present invention relates to a method for manufacturing an electrical insulation device and an electronic insulation device, the method comprising at least one step which essentially consists of carrying out a method for sealing articles as described above and described in detail thereafter.

[0028] In another aspect, the present invention relates to the use of a combination of polymer material (P) and thermosetting polymer material (A) for sealing one or more electrical components, specifically batteries having a nickel-based surface, in a manner defined above and described hereafter, to improve the resistance of a sealing component to thermal cycling, prevent thermal runaway and heat propagation, and / or reduce mechanical shock and vibration. [Modes for carrying out the invention]

[0029] The term “essentially derived from” when one or more features follow means that, in addition to the explicitly stated components or steps, components or steps that do not substantially affect the properties and features of the present invention may be included in the process or materials of the present invention.

[0030] The expression "included in X~Y" includes the boundary unless otherwise explicitly stated. This expression means that the target range includes the X and Y values, as well as all values ​​within the X~Y range.

[0031] For the purposes of this invention, the terms “potting” and “sealing” or “sealing” are used interchangeably to describe a process of protecting electronic components, particularly batteries, from potential environmental threats by coating them with a resin according to methods well known in the art.

[0032] For the purposes of this invention, "thermosetting polymer material" refers to a polymer that is cured or transformed into a rigid shape using a curing method such as heat or radiation. The curing process is irreversible because it introduces a polymer network that is crosslinked by covalent chemical bonds.

[0033] A "curable composition" is intended to be a composition comprising one or two component compositions or prepolymers in which a chemical reaction occurs during curing that creates extensive crosslinking between polymer chains, resulting in an insoluble and non-meltable solid polymer network. Curing can be initiated by heat, radiation, or chemical additives.

[0034] As used herein, the term “ambient temperature” refers to the temperature of the surrounding working environment (e.g., the temperature of the place, building, or room where the curable system is used or produced), excluding any temperature changes induced by the chemical reaction. Ambient temperature is typically between approximately 10°C and approximately 30°C, more specifically, approximately 25°C. The term “ambient temperature” is used interchangeably with “room temperature” herein.

[0035] For the purposes of this invention, the term "Tg" refers to the glass transition temperature. This is the temperature below which an amorphous material behaves as a glassy solid, and above which the same material behaves as if it were a liquid or a rubbery solid. Various methods can be used to measure Tg, including differential scanning calorimetry (DSC), dynamic viscoelasticity measurement (DMA), and thermomechanical analysis (TMA).

[0036] For the purposes of this invention, interfacial fracture is defined as follows: when an article is subjected to loading, breaking, or delamination, fracture occurs when the sealant is pulled away from the nickel-based surface but does not rupture or split; that is, fracture occurs at the interface between the sealant and the nickel-based surface of the article.

[0037] For the purposes of this invention, cohesive failure is defined as follows: when an article is subjected to loading, breaking, or delamination, the failure occurs in the bulk layer of the sealant, thereby leaving some of the sealant on the sealant and some on the nickel-based surface of the article.

[0038] Method for sealing articles having a nickel-based surface According to a first aspect, the present invention relates to a method for sealing an article having a nickel-based surface (S) using a thermosetting polymer material (A), wherein the method is: i) A step of coating at least a portion of the surface (S) of an article with a first curable resin composition, ii) The step of at least partially curing the first curable resin composition to obtain a nickel-based article coated with a first layer of polymer material (P), iii) The step of applying at least a precursor composition of a thermosetting polymer material (A) onto a first layer of polymer material (P), iv) The step of curing the precursor composition to obtain a top layer of thermosetting polymer material (A), It includes at least, The first curable resin composition is selected from acrylate resins and methacrylate resins, and the thermosetting polymer material includes a polymer having a Tg of -10°C or lower, a tensile strength after curing in the range of 0.5 MPa to 20 MPa, preferably in the range of 1 to 10 MPa, and an elongation at break after curing in the range of 5% to 250%, preferably in the range of 5% to 100%, with the tensile strength measured by the ISO 527 method and the elongation at break measured by the ISO 527 method.

[0039] The applicant has found that the bonding between the thermosetting polymer material (A) and the nickel surface of the article can be improved by applying a coating layer of polymer material (P), which is an acrylate-type resin, before applying the thermosetting polymer material (A).

[0040] Acrylate resins are known to adhere well to nickel-based surfaces, but not completely. On the other hand, such polymer materials fail to meet many of the requirements for encapsulating materials for electrical components and are prone to fracture with interfacial failure patterns.

[0041] Specifically, the applicant has found that, surprisingly, by combining two materials (A) and (P), which individually would both fail with an interfacial failure pattern, it is possible to make the failure pattern of the junction of the thermosetting polymer material (A) to the surface of a nickel-based article cohesive failure in the thermosetting polymer material (A).

[0042] Nickel-based article surface (S) In the context of this invention, "nickel-based surface" refers to the surface of an article that primarily contains nickel. Advantageously, the surface contains at least 50% by weight, preferably at least 70% by weight, more preferably at least 90% by weight, and most preferably 100% by weight of nickel.

[0043] The surface of the article used in the method according to the present invention may generally be any form of nickel, including pure nickel and nickel-based alloys.

[0044] Nickel-based alloys may include, for example, nickel-phosphorus alloys, nickel-iron alloys, nickel-copper alloys, nickel-molybdenum alloys, nickel-chromium alloys, nickel-chromium-iron alloys, nickel-chromium-molybdenum alloys, and nickel-titanium alloys.

[0045] The nickel-based surface of the article used in the method according to the present invention may be a solid nickel surface, a plated nickel surface, or a hot-dip plated nickel surface. Nickel can be plated or hot-dip plated onto any suitable metal base, including, for example, copper, aluminum, aluminum alloys, iron, or steel.

[0046] According to a preferred embodiment of the present invention, the nickel-based surface of the article is a plated nickel surface or a hot-dip plated nickel surface.

[0047] "Plated nickel surface" refers to a metal surface treated with a thin layer of nickel for protection against oxidation. Plating can be achieved via electroplating requiring electric current or via electroless plating, which is a self-catalytic chemical process, and includes any conventional method, such as those using nickel(II) hypophosphite or nickel borate. "Hot-dip plated nickel surface" refers to a metal surface treated with a thin layer of nickel for protection against oxidation by using hot-dip plating methods well known in the art.

[0048] Preferably, the nickel surface is steel that has been hot-dip plated with nickel. An example of this type of surface is commercially available under the name Hilumin®.

[0049] Advantageously, the article used in the method according to the present invention is a battery, specifically a battery having a surface made of nickel, and preferably a battery having a surface made of nickel-plated steel.

[0050] Alternatively, articles used in the method according to the present invention may be selected from rotors or stators of electromechanical devices (such as motors or generators), (power)-electronic components, batteries, switch rings for electric motors, switchgear, printed circuit boards, bushings, transformers, dry transformers, instrument transformers, and metal inserts embedded in the structural materials of insulators.

[0051] First curable resin composition and polymer material (P) The present invention involves applying a layer of polymer material (P) to an article having a nickel-based surface (S) before applying a thermosetting polymer (A) as a sealing material.

[0052] A layer of polymer material (P) is obtained by applying a first curable resin composition to the surface of an article and then curing it at least partially to form a solid layer.

[0053] The first curable resin composition is advantageously liquid before curing and does not harden over the time required for its application to the surface of an article.

[0054] The first curable resin composition preferably comprises a two-component composition comprising a polymerizable monomer composition comprising an acrylic acid ester or a methacrylic acid ester or a derivative thereof, and an initiator comprising a free radical generating substance for causing crosslinking when the two parts are mixed.

[0055] A "two-component composition" is intended to be a composition containing two components as a two-pack system (or kit) designed for immediate mixing of the two components immediately before curing. When the two components are mixed / blended together and cured, they can form a cured solid coating or layer by forming chemical bonds called crosslinks between the two components.

[0056] Preferably, the polymerizable monomer composition is an acrylic acid ester or methacrylic acid ester selected from methyl methacrylate, methyl acrylate, butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, ethyl acrylate, isobornyl methacrylate, isobornyl acrylate 2-hydroxyethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, acrylamide, n-methylacrylamide, and mixtures thereof. This includes sterols. Further examples include acrylates or methacrylates containing monofunctional or polyfunctional monomers other than hydroxyl groups, including amide substituents, cyano substituents, chloro substituents, and silane substituents.

[0057] Derivatives of acrylic acid esters or methacrylic acid esters may be advantageously selected from a) esters of acrylic acid and / or methacrylic acid with monools, diols, and polyols; b) esters of acrylic acid and / or methacrylic acid with hydroxyl-functionalized polyethers; c) esters of acrylic acid and / or methacrylic acid with hydroxyl-functionalized polyesters; and d) esters of acrylic acid and / or methacrylic acid with hydroxyl-functionalized alicyclic compounds and hydroxyl-functionalized aromatic compounds. These derivatives may contain further polymerizable functional groups.

[0058] According to a preferred embodiment of the present invention, the acrylic acid ester or methacrylic acid ester is selected from ethyl acrylate, methyl acrylate, methyl methacrylate, and butyl methacrylate, and is preferably methyl methacrylate.

[0059] Preferably, the polymerizable monomer composition further comprises at least one acid and / or at least one acid ester.

[0060] Suitable acids may include ethylenically unsaturated monocarboxylic acids or ethylenically unsaturated polycarboxylic acids (such as acrylic acid, methacrylic acid, vinyl acetic acid, and acrylooxypropionic acid). Acids may also include maleic acid and crotonic acid. Compounds having at least one strongly acid-active hydrogen group or at least one phosphonic acid-active hydrogen group (such as hydroxyethyl diphosphonic acid, phosphonic acid, and their derivatives), or oligomeric or polymeric structures having phosphonic acid functionality or similar acid strength functionality.

[0061] Preferably, the acid is acrylic acid, methacrylic acid, or a mixture thereof.

[0062] Suitable acid esters include phosphate esters, sulfonic acid esters, and mixtures thereof.

[0063] Suitable examples of phosphate esters are 2-hydroxyethyl methacrylate phosphate (HEMA phosphate) and bis[2-(acryloyloxy)ethyl]hydrogen phosphate.

[0064] According to a preferred embodiment of the present invention, the polymerizable monomer composition comprises 2-hydroxyethyl methacrylate phosphate (HEMA phosphate) and / or methacrylic acid and / or acrylic acid.

[0065] Advantageously, the polymerizable monomer composition contains 0.1 to 20% by weight, preferably 0.2 to 10% by weight, and more preferably 0.5 to 5% by weight of the above-mentioned acid and / or acid ester.

[0066] Preferably, the polymerizable monomer composition contains 0.5 to 20% by weight, preferably 1 to 15% by weight, of the above-mentioned acid, preferably methacrylic acid and / or acrylic acid.

[0067] Preferably, the polymerizable monomer composition contains the above-mentioned phosphate ester, preferably 2-hydroxyethyl methacrylate phosphate (HEMA phosphate) and / or bis[2-(acryloyloxy)ethyl] hydrogen phosphate in an amount of 0.1 to 10% by weight. Or, it contains 0.1 to 5% by weight.

[0068] Initiators to be used in accordance with the present invention are known in the art. Examples of initiators to be used in accordance with the present invention include peroxides, hydroperoxides, peresters, peracids, and azo compounds. Representative examples of peroxide compounds and hydroperoxide compounds include, but are not limited to, benzoyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, tert-butyl peroxide acetate, tert-butyl perbenzoate, and combinations thereof.

[0069] Advantageously, the initiator is selected from the group consisting of peroxides, hydroperoxides, and mixtures thereof.

[0070] Advantageously, the polymerizable monomer composition portion and the initiator portion are present in a weight ratio in the range of approximately 20:1 to approximately 1:1.

[0071] Advantageously, the first curable composition further comprises other additives that may be included in the polymerizable monomer composition portion and / or initiator portion (such as epoxy resins, reinforcing agents (core-shell, rubber), plasticizers, colorants, viscosity modifiers, etc.).

[0072] According to a preferred embodiment of the present invention, the first curable composition is selected from ARALDITE® 2051 and ARALDITE® 2050, which are commercially available from Huntsman.

[0073] Advantageously, in step i) of the method according to the present invention, the first curable resin composition is applied at least partially to the surface of the article with a thickness of 0.05 mm to 1 mm, preferably 0.1 mm to 0.2 mm.

[0074] Preferably, the layer of the first curable resin composition has a uniform thickness over all surfaces of the article to which it is applied. Preferably, the layer of the first curable resin composition is applied to the entire surface of the article to be sealed.

[0075] The first curable resin composition layer may be applied by any method known to those skilled in the art, such as spraying, dipping, brush coating, or spin coating.

[0076] In a preferred embodiment, the nickel-based surface (S) of the article is purified and preferably dried before application of the first curable resin composition. Preferably, the surface of the nickel-based surface (S) is purified with isopropanol.

[0077] Advantageously, in step ii) of the method according to the present invention, the first curable resin composition is at least partially cured at ambient temperature, specifically at a temperature in the range of 10 to 30°C, preferably 23°C, to form a solid layer of polymer material (P).

[0078] Preferably, the first curable resin composition is at least partially cured over a period of time ranging from 15 minutes to 96 hours, preferably from 30 minutes to 72 hours, and more preferably from 60 minutes to 48 hours, to form a solid layer of polymer material (P).

[0079] According to one embodiment, in step ii) of the method according to the present invention, the first curable resin composition is fully cured before the application of the precursor composition for the thermosetting polymer material (A) in step iii).

[0080] Advantageously, the polymer material (P) layer obtained after curing has a glass transition temperature (Tg) in the range of 60°C to 170°C, preferably 90°C to 150°C, and more preferably 110°C to 140°C.

[0081] Advantageously, the polymer material (P) layer obtained after curing has a fracture elongation in the range of 5-20%, preferably 5-15%, according to ISO 527 for a sample with a thickness of 1 mm.

[0082] Advantageously, the polymer material (P) layer obtained after curing has a tensile strength in the range of 10 to 70 MPa, preferably 15 to 60 MPa, and more preferably 20 to 50 MPa, according to ISO 527. The tensile strength is measured by the ISO 527 method. Specifically, the polymer material (P) according to the present invention has a higher tensile strength than that of the thermosetting polymer material (A).

[0083] Precursor composition for thermosetting polymer material (A) and thermosetting polymer material (A): In step iii) of the method according to the present invention, the coated, at least partially cured surface of the article obtained from step ii) is sealed in a known manner using a precursor composition for a thermosetting polymer material (A).

[0084] According to the present invention, a precursor composition for a thermosetting polymer material (A) comprises a polymer having a glass transition temperature Tg of -10°C or less, preferably in the range of -50°C to -10°C, more preferably in the range of -50°C to -40°C, an elongation at break measured according to ISO 527 in the range of 5% to 250%, preferably in the range of 5% to 100%, and a tensile strength measured according to ISO 527 in the range of 0.5 to 20 MPa, preferably in the range of 1 to 10 MPa.

[0085] Preferably, the precursor composition for the thermosetting polymer material (A) comprises a polymer having a tensile modulus in the range of 10 MPa to 100 MPa, as measured according to ISO 527.

[0086] Advantageously, the precursor composition for the thermosetting polymer material (A) has a thermal conductivity of 0.1-2 W / m * Includes polymers in the K range.

[0087] Advantageously, the thermosetting polymer material (A) used in the method according to the present invention is selected from polyurethane, epoxy resin, and mixtures thereof. According to a preferred embodiment of the present invention, the thermosetting polymer material (A) is polyurethane.

[0088] According to the first embodiment, the precursor composition for the thermosetting polymer material (A) is a curable two-component resin system, and the curable two-component resin system is (a) A first portion comprising at least one polyol compound, (b) A second portion comprising at least one isocyanate compound, Includes.

[0089] Optionally, according to this embodiment, the precursor composition for the thermosetting polymer material (A) comprises one or more fillers, which are included as components of the first or second part.

[0090] The precursor composition of the thermosetting polymer material (A) according to the first embodiment may further contain one or more additives selected from dyes, pigments, flame retardants, softeners, thermal degradation stabilizers, and thixotropy modifiers or rheology modifiers in either the first or second part.

[0091] Polyol compounds Suitable polyols to be used in the present invention include, but are not limited to, polyether polyols, polyester polyols, polycaprolactone polyols, polycarbonate polyols, polyurethane polyols, polyvinyl alcohols, polymers containing hydroxy-functional acrylates, polymers containing hydroxy-functional methacrylates, polymers containing allyl alcohols, and mixtures thereof.

[0092] According to a preferred embodiment, the polyol compound is selected from polyether polyols and polyester polyols.

[0093] Examples of polyester polyols include those obtained by reacting a polyhydric alcohol with a polybasic acid. The polyhydric alcohol can be selected from, for example, ethylene glycol, polyethylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and 2-methyl-1,8-octanediol. The polybasic acid can be selected from, for example, phthalic acid, dimer acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, sebacic acid, and similar acids.

[0094] Polyether polyols can be selected from ethylene oxide-based polyether polyols, propylene oxide-based polyether polyols, corresponding ethylene oxide / propylene oxide copolymers which may be random copolymers or block copolymers, and mixtures of these polyether polyols. The ratio of ethylene oxide to propylene oxide in ethylene oxide / propylene oxide copolymers can vary within a wide range, as is known to those skilled in the art.

[0095] According to a preferred embodiment, the polyol compound is selected from polyether polyols.

[0096] Isocyanate compounds The isocyanate components useful in the present invention are well known in the art and are organic compounds containing two or more isocyanate groups per molecule. The isocyanate components may be aromatic, cycloaliphatic, or aliphatic, and may be monomeric or oligomeric compounds.

[0097] Advantageously, the isocyanate component has an NCO functional value of 2 or more, preferably in the range of 2 to 3.

[0098] "Isocyanate functional value" is the number of reactive NCO groups per molecule in an isocyanate molecule or polymer isocyanate. For example, most polyisocyanates, specifically MDI-type polyisocyanate compounds, contain blends of monomeric MDI and polymeric MDI, and the isocyanate functional value is the average functional value across different molecular and polymer species.

[0099] Suitable isocyanate compounds for use in the precursor composition of the thermosetting polymer material (A) according to the present invention include dodecane-1,12-diisocyanate, 2-ethyltetramethylene-1,4-diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate (HMDI), cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), hexahydrotoluene-2,4-diisocyanate, hexahydrotoluene-2,5-diisocyanate, and dicyclo The following can be selected: hexylmethane-2,2'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, toluene-2,4-diisocyanate (2,4-TDI), toluene-2,6-diisocyanate (2,6-TDI), diphenylmethane-2,2'-diisocyanate (2,2'-MDI), diphenylmethane-4,4'-diisocyanate (4,4'-MDI), diphenylmethane-2,4'-diisocyanate (2,4'-MDI) polyphenylpolymethylene polyisocyanate (crude MDI), and mixtures thereof.

[0100] As used herein, “MDI” refers to methylenediphenyl diisocyanate (also known as diphenylmethane diisocyanate) and its isomers. MDI exists as one of three isomers (4,4'MDI, 2,4'MDI, and 2,2'MDI) or as a mixture of two or more of these isomers. Unless otherwise specifically stated, “MDI” also refers to and may encompass polymeric MDI. Polymeric MDI is a compound having a chain of three or more benzene rings linked together by methylene crosslinks, with an isocyanate group attached to each benzene ring.

[0101] Advantageously, the mass ratio of the polyol compound to the isocyanate component in the precursor composition of the thermosetting polymer material (A) is in the range of 20:1 to 1:1, preferably in the range of 20:1 to 5:1.

[0102] filler Advantageously, the filler that may be included in the precursor composition for the thermosetting polymer material (A) is selected from mineral fillers or metal powders.

[0103] Preferably, the filler is an inorganic filler selected from the group consisting of quartz sand, quartz powder, silica, amorphous silica, quartz glass, aluminum oxide, titanium oxide, zirconium oxide, Mg(OH)2, Al(OH)3, dolomite [CaMg(CO3)2], AIO(OH), silicon nitride, boron nitride, aluminum nitride, silicon carbide, boron carbide, chalk, calcium carbonate, barite, gypsum, magnesium hydroxide, zeolite, talc, mica, kaolin and wollastonite, aluminum silicate, almosilicate, crushed glass, and glass beads. Optionally, the filler may be treated with silane. Preferably, the filler is Al(OH)3.

[0104] Advantageously, the precursor composition for the thermosetting polymer material (A) contains at least 30% by weight, preferably 40% by weight, and more preferably 50% by weight, of a filler, preferably an inorganic filler, relative to the total weight of the composition.

[0105] According to the second embodiment, the precursor composition for the thermosetting polymer material (A) is a curable two-component resin system, and the curable two-component resin system is (a) A first part comprising at least one epoxy resin, (b) A second part comprising at least one curing agent, Includes.

[0106] Optionally, according to this second embodiment, the precursor composition for the thermosetting polymer material (A) comprises one or more fillers, which are included as components of the first or second part.

[0107] The precursor composition of the thermosetting polymer material (A) according to the second embodiment may further contain one or more additives selected from dyes, pigments, flame retardants, softeners, thermal degradation stabilizers, and thixotropy modifiers or rheology modifiers in either the first or second part.

[0108] epoxy compounds The epoxy compound for use in the method according to the present invention is a compound containing at least one vicinal epoxy group. The epoxy compound may be saturated or unsaturated aliphatic, cycloaliphatic, aromatic, or heterocyclic, and may be substituted. The epoxy compound may also be a monomer or a polymer.

[0109] Advantageously, the epoxy component is prepared by methods well known in the art, specifically by reacting epichlorohydrin with a compound containing at least one phenol compound under basic conditions (such as in an alkaline reaction medium or in the presence of a suitable base).

[0110] Suitable epoxy resins include, but are not limited to, but but but but: butanediol diglycidyl ether, hexanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, hexahydrophthalate diglycidyl ester, trimethylolpropane triglycidyl ether, pentaerythritol polyglycidyl ether, neopentyl glycol diglycidyl ether, or mixtures thereof.

[0111] In preferred embodiments, the epoxy compound is selected from diglycidyl ethers of bisphenol A and polyglycidyl ethers of phenol-formaldehyde novolac. Examples of such epoxy components include, but are not limited to, EPON® 826 and EPON® DPL-862 available from Shell, and DEN439 and DEN438 available from Dow Chemical Co.

[0112] Optionally, the epoxy component may also include an aqueous organic solvent or diluent present in an amount effective in reducing the viscosity of the system to improve processability. Examples of diluents include ketones, alcohols, and glycol ethers.

[0113] hardening agent Suitable curing agents for use in epoxy resin compositions include, but are not limited to, amines, amides, anhydrides, phenols, and thiols.

[0114] Advantageously, the curing agent is liquid at ambient temperature and can be mixed with the epoxy compound without heating.

[0115] Preferably, the curing agent is an amine-based curing compound selected from aliphatic amines (such as ethylenediamine, diethylenetriamine, triethylenetetramine, and isophoronediamine) and aromatic amines (such as diaminodiphenylmethane (DDM)).

[0116] The amount of curing agent used must be sufficient to obtain complete curing. The amount of curing agent used in the second curable composition is such that the ratio of amine hydrogen equivalent to epoxy equivalent is in the range of 0.9 to 1.5, preferably in the range of 0.9 to 1.1, and more preferably 1.

[0117] A precursor composition for the thermosetting polymer material (A) can be prepared in a conventional manner, specifically by mixing and / or blending the above two-component resin system according to the first or second embodiment with one or more fillers of choice, and then applying it to the surface of an article already coated with a layer of polymer material (P). Application to the article may be by, for example, immersion, drop-in impregnation, vacuum pressure impregnation, and / or casting. It can be implemented.

[0118] The precursor composition for the thermosetting polymer material (A) is advantageously liquid before curing and does not cure over the time required for its application to the layer of polymer material (P).

[0119] Advantageously, the precursor composition for the thermosetting polymer material (A) has a sufficiently low viscosity. Preferably, the precursor composition for the thermosetting polymer material (A) has a pre-curing viscosity in the range of 0.5 to 10 poise, preferably 0.5 to 6 poise.

[0120] Advantageously, in step iii) of the method according to the present invention, the precursor composition for the thermosetting polymer material (A) is applied on top of the layer of polymer material (P) to a thickness of 0.05 mm to 1 mm, preferably 0.1 mm to 0.2 mm.

[0121] Advantageously, the first layer of polymer material (P) and the upper layer of thermosetting polymer material (A) are applied to the nickel-based article surface (S) in an amount that gives a total dry film thickness of 0.1 to 2 mm, preferably 0.2 to 0.4 mm.

[0122] The thermosetting polymer material (A) is prepared by curing a precursor composition for the thermosetting polymer material (A).

[0123] Advantageously, the precursor composition for the thermosetting polymer material (A) is cured at a temperature in the range of 10 to 35°C, preferably in the range of 15 to 30°C, advantageously at a temperature of about 23°C.

[0124] Preferably, the precursor composition for the thermosetting polymer material (A) is cured over a period of time ranging from 15 minutes to 96 hours, preferably from 30 minutes to 72 hours, and more preferably from 60 minutes to 48 hours, to form a solid layer of the thermosetting polymer material (A).

[0125] filler Advantageously, the filler that may be included in the precursor composition for the thermosetting polymer material (A) according to the second embodiment is selected from mineral fillers or metal powders.

[0126] Advantageously, the filler is an inorganic filler selected from the group consisting of quartz sand, quartz powder, silica, amorphous silica, quartz glass, aluminum oxide, titanium oxide, zirconium oxide, Mg(OH)2, Al(OH)3, dolomite [CaMg(CO3)2], AIO(OH), silicon nitride, boron nitride, aluminum nitride, silicon carbide, boron carbide, chalk, calcium carbonate, barite, gypsum, magnesium hydroxide, zeolite, talc, mica, kaolin and wollastonite, aluminum silicate, almosilicate, crushed glass, and glass beads. Optionally, the filler may be treated with silane. Preferably, the filler is Al(OH)3.

[0127] Advantageously, the precursor composition for the thermosetting polymer material (A) contains at least 30% by weight, preferably 40% by weight, and more preferably 50% by weight, of a filler, preferably an inorganic filler, relative to the total weight of the composition.

[0128] kit According to a second aspect, the present invention relates to a kit for sealing articles having a nickel-based surface (S), the kit comprising: i) A first curable resin composition selected from acrylate resins and methacrylate resins, ii) A precursor composition of a thermosetting polymer material (A), The thermosetting polymer material includes a polymer having a Tg of -10°C or lower, a tensile strength after curing of 0.5 MPa to 20 MPa, preferably in the range of 1 MPa to 10 MPa, and an elongation at break after curing of 5% to 250%, preferably in the range of 5% to 100%. The tensile strength is measured by the ISO 527 method, and the elongation at break is measured by the ISO 527 method.

[0129] Preferably, the thermosetting polymer material includes a polymer having a tensile modulus of elasticity in the range of 10 MPa to 100 MPa.

[0130] The features and preferences described above for the first curable resin composition and the precursor composition of the thermosetting polymer material (A) also apply to the kit.

[0131] device According to a third aspect, the present invention relates to a device essentially composed of a sealed article, the device being obtained by carrying out the above method.

[0132] Specifically, the method of the present disclosure results in an article having a polymer material (P) layer covering part or all of the surface, and a nickel-based surface (S) coated with a sealing resin layer of a thermosetting polymer material (A) on the polymer material (P) layer. Advantageously, there is no direct contact between the surface of the article and the thermosetting polymer material (A).

[0133] Advantageously, the device is a sealed battery.

[0134] Use of the method according to the present invention In another aspect, the present invention also relates to a method for manufacturing an electrical insulation device and an electronic insulation device, the method comprising at least one step essentially consisting of carrying out a method for sealing articles as detailed above.

[0135] In another aspect, the present invention relates to the use of a combination of polymer material (P) and thermosetting polymer material (A), as defined in detail above, as sealing material in one or more electrical components, specifically in battery cells, including a nickel-based surface, to improve the resistance of sealing components to thermal cycling, prevent thermal runaway and heat propagation, and / or reduce mechanical shock and vibration. [Examples]

[0136] In the following embodiments, unless otherwise specified, content and percentage are given by mass.

[0137] I-Raw materials - Base material (S): Hilumin®: This is a nickel-plated steel commercially available from Tata Steel.

[0138] - Precursor composition of thermosetting polymer material (A): Polyol component: ARATHANE® CW30664, Isocyanate component: ARATHANE® HY30665: This is a commercially available, two-component polyurethane system from Huntsman that cures at ambient temperature and contains 66% mineral fillers. It is based on a polyether polyol and an aromatic isocyanate. This material exhibits low temperature flexibility (Tg = -44°C) and high thermal conductivity (1 W / m²). * K), flame retardancy (UL94 V0 1mm), and elongation at break of 15% and tensile strength of 2 MPa (breakage). The elongation and tensile strength are characterized by the method measured according to ISO 527.

[0139] - First curable composition (P):Araldite® 2051: This is a commercially available, ambient temperature curing, two-component adhesive system from Huntsman. It is a methyl methacrylate-based polymer. It has a Tg of 127°C, a tensile strength of 40 MPa, and an elongation at break of approximately 10% (elongation at break and tensile strength were measured by ISO 527).

[0140] Preparation of II-Wrap Shear Test Specimens [Table 1]

[0141] Before applying the adhesive, the substrate samples were purified with isopropanol. After drying, plasma treatment was performed on the substrates of C2, C4, and C6: O2 plasma at 2 mbar 360 W for 3 minutes.

[0142] For C3 and C4, a mixture of Araldite® 2051 was applied in the amounts corresponding to the bonding thickness shown in Table 1, and the second substrate was placed in the jig to adjust the required bonding thickness of 1.5 mm. The test specimens were cured at 23°C for 24 hours.

[0143] For E1 and E2, a thin layer of Araldite® 2051 was applied to the substrate using a brush. It was then cured at 23°C for 15 minutes (the product should be non-stick).

[0144] Next, for C1, C2, E1, C5, C6, and E2, a mixture of ARATHANE® CW30664 and ARATHANE® HY30665 (100:7) was applied in an amount that resulted in the bonding thickness shown in Table 1, and these portions were cured at 23°C for 24 hours.

[0145] All data in Table 1 is from Hilumin® 100×25×1mm stock. The determination was made using standard test specimens created by overlapping and joining lip pieces. The joint area in each case was 12.5 × 25 mm. The thickness of the adhesive layer was adjusted to 1.5 mm or 0.3 mm (adjusted with glass beads).

[0146] Next, the average lap shear strength of the metal-to-metal joint was tested according to ISO 4587.

[0147] III-Results [Table 2]

[0148] The results summarized in Table 2 indicate that, for C1 and C5, the polyurethane-based material does not adhere sufficiently to Hilumin® and is destroyed with an interfacial failure pattern. This result is independent of the thickness of the adhesive layer.

[0149] C2 and C6 indicate that plasma treatment is completely ineffective in improving adhesion to Hilumin®.

[0150] C3 is a comparative trial demonstrating that even Araldite® 2051, a methyl methacrylate-based adhesive, does not adhere sufficiently to Hilumin®: however, this results in a much higher lap shear value and approximately 50% interfacial fracture.

[0151] C4 represents C3 combined with plasma: this pretreatment improves lap shear strength, but the fracture mode is still primarily interfacial fracture.

[0152] E1 and E2 are embodiments of the present invention, demonstrating that the application of a first layer in direct contact with Hilumin® and a subsequent polyurethane layer primarily results in an aggregate failure pattern in the polyurethane phase.

Claims

1. A method for sealing an article having a nickel-based surface (S) using a thermosetting polymer material (A), wherein the method is i) A step of coating at least a portion of the surface (S) of the article with a first curable resin composition, ii) The step of at least partially curing the first curable resin composition to obtain a nickel-based article coated with a first layer of polymer material (P), iii) The step of applying at least the precursor composition of the thermosetting polymer material (A) onto the first layer of the polymer material (P), iv) The step of curing the precursor composition to obtain an upper layer of thermosetting polymer material (A), It includes at least, The first curable resin composition is selected from acrylate resins and methacrylate resins. The method wherein the thermosetting polymer material (A) contains a polymer whose Tg is -10°C or lower, whose cured tensile strength is in the range of 0.5 MPa to 20 MPa, and whose cured elongation at break is in the range of 5% to 250, the tensile strength is measured by the ISO 527 method, and the elongation at break is measured by the ISO 527 method.

2. The method according to claim 1, wherein the nickel-based surface (S) of the article is a solid nickel surface, a plated nickel surface, or a hot-dip plated nickel surface.

3. The method according to claim 1 or claim 2, wherein the first curable resin composition is a two-component composition comprising at least a) a polymerizable monomer composition containing an acrylic acid ester or a methacrylic acid ester or a derivative thereof, and b) at least one initiator.

4. The method according to claim 3, wherein the polymerizable monomer composition further comprises at least one acid (preferably selected from acrylic acid, methacrylic acid, vinylacetic acid, and acrylooxypropionic acid, maleic acid, and crotonic acid) and / or at least one acid ester (preferably a phosphate ester).

5. The method according to any one of the prior claims, wherein the thermosetting polymer material (A) is polyurethane, and the precursor composition of the thermosetting polymer material (A) is a two-component composition comprising at least a) a polyol component and b) an isocyanate component.

6. The method according to any one of claims 1 to 4, wherein the thermosetting polymer material (A) is an epoxy resin, and the precursor composition of the thermosetting polymer material (A) is a two-component composition comprising at least a) an epoxy compound and b) a curing agent.

7. The method according to any one of the prior claims, wherein the precursor composition of the thermosetting polymer material (A) further comprises a filler, preferably at least 30% by weight of a filler.

8. The method according to any one of the prior claims, wherein the precursor composition of the thermosetting polymer material (A) further comprises one or more additives selected from dyes, pigments, flame retardants, softeners, thermal degradation stabilizers, and thixotropy modifiers or rheology modifiers.

9. In steps i) and iii), the first curable resin composition and the precursor composition of the thermosetting polymer material (A) each provide a dry film thickness of 0.1 to 2 mm. The method according to any one of the prior claims, applied in an amount to the surface (S) of the nickel-based article.

10. The method according to any one of the prior claims, wherein in steps ii) and iv), the first curable resin composition and the second curable resin composition are each cured at ambient temperature.

11. A kit for sealing articles having a nickel-based surface (S), wherein the kit comprises, i) A first curable resin composition selected from acrylate resins and methacrylate resins, ii) A precursor composition for a thermosetting polymer material (A), wherein the thermosetting polymer material contains a polymer having a Tg of -10°C or lower, a tensile strength in the range of 0.5 MPa to 20 MPa after curing, and an elongation at break in the range of 5% to 250% after curing, the tensile strength being measured by ISO 527, and the elongation at break being measured by ISO 527, and the precursor composition, The kit includes the above.

12. A device essentially composed of a sealed article, wherein the device is obtained by carrying out the method described in any one of claims 1 to 10.

13. The device according to claim 12, wherein the article is selected from batteries having a nickel-based surface.

14. A method for manufacturing an electrical insulation device and an electronic insulation device, the method comprising at least one step which essentially consists of carrying out a method for sealing an article as described in any one of claims 1 to 10.

15. The use of a combination of a polymer material (P) and a thermosetting polymer material (A) for sealing an article having a nickel-based surface (S) according to any one of claims 1 to 10, the use for improving the resistance of the sealing component to thermal cycling, preventing thermal runaway and heat propagation, and / or reducing mechanical shock and vibration.

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