Two-component curable composition

Abstract

The present invention relates to A first part (component A), at least 50% by weight, based on the total weight of the first portion, of one or more alkyl cyanoacrylate monomers, said alkyl cyanoacrylate monomers including only one cyanoacrylate functional group; The following formula (I): TIFF2024519605000012.tif40170, wherein R is an organic moiety and n is an integer equal to or greater than 2; and one poly(2-cyanoacrylate) monomer having the formula: a first portion including: a second part (component B) comprising a (meth)acrylate component having at least two (meth)acrylate functional groups; The present invention relates to a two-part curable composition comprising:

Description

[Technical field]

[0001] The present invention relates to the field of two-part curable compositions based on cyanoacrylates.

[0002] The present invention also relates to the use of the two-part curable composition. [Background technology]

[0003] Adhesive compositions based on cyanoacrylate (CA) esters are known, for example, as instant adhesives or so-called "super glues". They are popular in many application areas and are used by consumers, professional craftsmen and assemblers. They are typically solvent-free, 100% reactive materials and are recognized for their ability to rapidly form strong adhesive bonds on many different substrates.

[0004] In this field, there are 1K or 2K (two-part) CA adhesives. When describing the 2K approach, the separate components or parts of the adhesive and / or its container are generally referred to as, for example, "Part A" and "Part B". Thus, if Part A contains the CA composition in one compartment or reservoir, Part B may contain a composition selected to activate, react and / or modify the physical properties of the adhesive (plasticize, color, toughen, etc.) upon mixing of the two parts by any means.

[0005] Although the two-part approach typically offers some advantages over one-part (1K) adhesives, improvements are still needed. There are a variety of two-part CA adhesives on the market that have gap cure and short fix times on a variety of substrates.

[0006] Traditionally, efforts have been made to improve the heat resistance of cured cyanoacrylate compositions, especially when exposed to temperatures above 80°C. As temperatures increase, polycyanoacrylate adhesives begin to degrade and their physical properties decrease. As a result, commercial applications of cyanoacrylates likely to be exposed to high temperature conditions have proven difficult and are limited as a result.

[0007] However, conventional CA adhesives do not simultaneously possess "hot strength" (or high "use temperature") (i.e., the ability to retain high tensile strength, advantageously above about 5 MPa, while being exposed to high temperatures, typically at least above 100°C) and heat resistance (the ability not to degrade at high temperatures, e.g., above 100°C), and therefore generally find limited commercial use where exposure to high temperatures is likely. The "hot strength" or "use temperature" of an adhesive should not be confused with its "heat resistance". Heat resistance refers to the ability of an adhesive not to degrade even after continuous exposure to high temperatures for extended periods (e.g., 150°C for 3 days), unless it is subjected to mechanical loads at high temperatures. For example, when metal substrates are bonded with unmodified ethyl cyanoacrylate-based adhesives, a rapid decrease in bond strength is observed at temperatures above 100°C. Although the heat resistance of an adhesive is an important characteristic, it is not the only way to describe the performance of bonded parts used in high temperature environments.

[0008] This "hot strength" feature is important in many applications where the adhesive is loaded and exposed to high temperatures early in its life, such as in the electronics or automotive sector. In some applications, hot strength must be exhibited for a significant period of time, e.g., more than 3 days at 150°C. Examples may include adhesives used in high temperature process automotive part manufacturing, or adhesives used to join parts close to the automotive engine.

[0009] Therefore, there is a need for new CA adhesives that provide a good combination of fast bond time, good heat resistance and high hot strength of the cured assembled substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention relates to A first part (component A), at least 50% by weight, based on the total weight of the first portion, of one or more alkyl cyanoacrylate monomers, said alkyl cyanoacrylate monomers including only one cyanoacrylate functional group; The following formula (I): TIFF2024519605000002.tif40170, wherein R is an organic moiety and n is an integer equal to or greater than 2; and one poly(2-cyanoacrylate) monomer having the formula: a first portion including: a second part (component B) comprising a (meth)acrylate component having at least two (meth)acrylate functional groups; The present invention relates to a two-part curable composition comprising:

[0011] In the context of the present invention, the term "about" referring to a determined value is understood to indicate that a certain variation of + / - 5% of said value is generally allowed.

[0012] The term "work life" or "work time ("WT")" as used throughout this specification refers to the time between initially mixing a curing agent into a cyanoacrylate composition and then applying the thus activated composition to a part, i.e., the time that the activated product is present or resides in the static mixing element (used to hold the adhesive components together and used as a dispensing nozzle) itself, i.e., during the dispensing operation. The curing process begins once the curing agent is mixed and continues as the adhesive is dispensed from the static mixing element.

[0013] The term "open time" ("OT") refers to the time that an adhesive that has been activated and subsequently dispensed remains workable, i.e., remains substantially uncured to the extent that when applied as a drop, bead or glob on one substrate, it cannot form an effective adhesive bond when used to bond a second substrate. Thus, open time represents the time that the adhesive remains activated but substantially uncured and ready to usefully join components. An adhesive that has a long OT is one that does not prematurely set before the components are assembled, even after being present on a single component for a relatively long time.

[0014] The term "fix time" ("FT") as used herein is a measure of bonding or fixation speed and is defined as the time required for a bonded assembly to bond over 250 mm with a minimal amount of adhesive (a "small" drop) on two mated substrates when all evaluations are performed at room temperature (approximately 25°C) and humidity (50% HR). 2 This is defined as the time it takes for a joint assembly to have the ability to hang a 3 kg weight vertically for more than 10 seconds when one end of the joint assembly has a 3 kg weight hung vertically.

[0015] Ranges disclosed herein include both their lower and upper limits, for example, the phrase "in the range of x to y" or "between x and y" includes the limits x and y.

[0016] Component A - First Part Alkyl cyanoacrylate monomer Component A comprises at least 50% by weight, based on the total weight of Component A, of one or more alkyl cyanoacrylate monomers, which alkyl cyanoacrylate monomers contain only one cyanoacrylate functional group.

[0017] In a preferred embodiment, the alkyl cyanoacrylate monomer has the general formula (II): TIFF2024519605000003.tif20170In the formula, R is C1-C 18 Straight or branched alkyl groups, preferably C1-C 10A linear or branched alkyl group, even more preferably a C1-C8 linear or branched alkyl group; has.

[0018] The alkyl cyanoacrylate monomer may be selected from the group consisting of methyl cyanoacrylate, ethyl cyanoacrylate, n-propyl cyanoacrylate, isopropyl cyanoacrylate, n-butyl cyanoacrylate, sec-butyl cyanoacrylate, isobutyl cyanoacrylate, tert-butyl cyanoacrylate, n-pentyl cyanoacrylate, 1-methylbutyl cyanoacrylate, 1-ethylpropyl cyanoacrylate, neopentyl cyanoacrylate, n-hexyl cyanoacrylate, 1-methylpentyl cyanoacrylate, n-heptyl cyanoacrylate, n-octyl cyanoacrylate, 2-octyl cyanoacrylate, 2-ethylhexyl cyanoacrylate, n-nonyl cyanoacrylate, n-decyl cyanoacrylate, n-undecyl cyanoacrylate, and mixtures thereof.

[0019] Preferably, the alkyl cyanoacrylate monomer is selected from the group consisting of methyl cyanoacrylate, ethyl cyanoacrylate, and mixtures thereof, and more preferably, the alkyl cyanoacrylate monomer is ethyl cyanoacrylate.

[0020] Such monomers of formula (II) can be prepared by methods known to those skilled in the art, such as, for example, the methods described in US Pat. No. 2,467,927.

[0021] Some of them, such as ethyl cyanoacrylate (ECA) and methyl cyanoacrylate (MCA), are commercially available.

[0022] In the first part (component A) of the composition of the present invention, the total content of alkyl cyanoacrylate monomers may be at least 55% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, in particular at least 75% by weight, relative to the total weight of the first part.

[0023] In one embodiment, the total content of alkyl cyanoacrylate monomers in the first part of the composition of the present invention is in the range of 60 to 99% by weight, preferably 65 to 98% by weight, more preferably 70 to 95% by weight, based on the total weight of the first part.

[0024] Poly(2-cyanoacrylate) Monomer The first part (component A) has the following formula (I): TIFF2024519605000004.tif42170, wherein R is an organic moiety and n is an integer equal to or greater than 2; The poly(2-cyanoacrylate) monomer has the formula:

[0025] In the above formula (I), n may be equal to 2, 3 or 4, preferably n is 2.

[0026] In a preferred embodiment, the poly(2-cyanoacrylate) monomer has the following formula (I-1): TIFF2024519605000005.tif29170 where R is an organic moiety; has.

[0027] In one embodiment, in formulas (I) and (I-1), R can be an alkylene, alkenylene, cycloalkylene, arylene, alkoxyalkylene, aralkylene, or a divalent residue of a polymer, such as, for example, a polyolefin, a polysiloxane, a polyester, a polyether, a polyurethane, a polyethylene glycol, a polypropylene glycol, etc. Preferably, R represents an alkylene.

[0028] According to the present invention, the term "alkylene" includes both straight-chain and branched alkylenes, as well as "alkenylene" and "alkoxyalkylene".

[0029] The poly(2-cyanoacrylate) monomer is preferably a compound of formula (I-1), in which R represents alkylene and more preferably contains from 2 to 30 carbon atoms, even more preferably from 2 to 12 carbon atoms.

[0030] The poly(2-cyanoacrylate) monomer is even more preferably represented by formula (I-1), where R is -(CH2) m -, and m is 2, 3, 4, 5, 6, 8, 9, 10, or 12. Preferred examples of these monomers include 1,10-decanediol biscyanoacrylate, 1,8-octanediol biscyanoacrylate, and 1,6-hexanediol biscyanoacrylate.

[0031] Poly(2-cyanoacrylate) monomers may be prepared as disclosed in WO 94 / 15907, U.S. Patent Application Publication No. 2003194389, WO 2015 / 150882, or U.S. Patent No. 6,096,848.

[0032] In the first part of the composition of the present invention, the total content of poly(2-cyanoacrylate) monomers may be greater than 3% by weight, preferably ranging from 3 to 20% by weight, even more preferably from 5 to 15% by weight, relative to the total weight of the first part.

[0033] Additives The first part of the composition may further contain at least one additive selected from the group consisting of, for example, thixotropic agents, thickeners, toughening agents, accelerators, adhesion promoters, pigments, colorants, stabilizers, antioxidants, plasticizers, and mixtures thereof.

[0034] Suitable stabilizers may be selected from the group consisting of radical stabilizers, acid stabilizers, and mixtures thereof.

[0035] The radical stabilizer is typically a radical polymerization inhibitor, and is preferably selected from the group consisting of 4-methoxyphenol, hydroquinone, hydroquinone monomethyl ether, hydroxytoluene butyl ether, hydroxyanisole butyl ether, 4,4'-methylenebis(2,6-di-tert-butylphenol), and mixtures thereof.

[0036] The total content of the radical stabilizer in the first part of the composition may be in the range of 0.0001% to 0.2% by weight, preferably 0.001% to 0.1% by weight, more preferably 0.002% to 0.06% by weight, relative to the total weight of the first part.

[0037] The acid stabilizer is typically an inhibitor of anionic polymerization.The acid stabilizer can be selected from the group consisting of Bronsted acid, Lewis acid, and mixtures thereof.The acid stabilizer is preferably selected from the group consisting of methanesulfonic acid, p-toluenesulfonic acid, hydrofluoric acid, boron trifluoride, boron trifluoride etherate complex, fluoroboric acid, sulfur dioxide, and mixtures thereof.

[0038] In a preferred embodiment, the first part of the composition includes methanesulfonic acid, sulfur dioxide, boron trifluoride etherate complex, hydroquinone and hydroquinone monomethyl ether, and 4,4'-methylenebis(2,6-di-tert-butylphenol).

[0039] In the first part of the composition, the total content of the stabilizer is generally in the range of 0.0001% to 1% by weight, preferably 0.001 to 0.8% by weight, more preferably 0.0015 to 0.7% by weight, relative to the total weight of the first part.

[0040] Typically, the adhesion promoter may be selected from the group of aromatic carboxylic acids or anhydrides, preferably from the group consisting of trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, dianhydride of 3,3',4,4'-benzophenonetetracarboxylic acid, itaconic acid, itaconic anhydride, 3-butene-1,2,3-tricarboxylic acid, and mixtures thereof.

[0041] The total content of adhesion promoter in the first part of the composition may range from 0.02 to 0.1% by weight, more preferably from 0.03 to 0.08% by weight, based on the total weight of the first part.

[0042] Suitable accelerating agents (or accelerators) may be selected from calixarenes, crown ethers (e.g., 15-Crown-5, 18-Crown-6, Dibenzo 18-Crown-6, marketed by Alfa Aesar), cyclodextrins, and mixtures thereof.

[0043] Typically, the total content of accelerators in the first part of the composition may be in the range of 0.01 to 0.8 wt %, preferably 0.05 to 0.5 wt %, more preferably 0.1 to 0.3 wt %, relative to the total weight of the first part.

[0044] Suitable thixotropic agents may be selected from the group consisting of hydrogenated castor oil, optionally modified by reaction with amines, polyamides, silica and mixtures thereof.

[0045] Preferably, the thixotropic agent is silica, more preferably selected from the group consisting of fumed silica, hydrophobic fumed silica (e.g. Aerosil® R202 marketed by Evonik), hydrophilic fumed silica and precipitated silica.

[0046] Typically, the total content of thixotropic agents in the first part of the composition may range from 2 to 10% by weight, preferably from 3 to 8% by weight, more preferably from 4 to 7% by weight, relative to the total weight of the first part.

[0047] The thickener or thickening agent suitable for the first part of composition can be selected from those compatible with host monomer.Examples of such thickener include poly(meth)acrylate, acylated cellulose polymer, such as cellulose acetate, polyvinyl acetate, partially hydrolyzed polyvinyl acetate, polyvinylpyrrolidone, polyoxylate, polycaprolactone, polycyanoacrylate, such as vinyl acetate copolymer with vinyl chloride, (meth)acrylate copolymer with butadiene and styrene, copolymer with vinyl chloride and acrylonitrile, copolymer with ethylene and vinyl acetate, poly[butylene terephthalate-co-polyethylene glycol terephthalate, copolymer with lactic acid and caprolactone, and mixtures thereof.

[0048] These thickeners are known to those skilled in the art and described in the prior art. Preferably, in the adhesive of the present invention, the thickener is selected from the group consisting of poly(meth)acrylates, polymethyl(meth)acrylates, polyvinylpyrrolidones, polyvinyl acetates, partially hydrolyzed polyvinyl acetates, vinyl acetate copolymers, and acrylated cellulose polymers. Suitable thickeners for the first part of the composition can be, for example, polymethylmethacrylates (e.g. Degacryl® M 449, Evonik), copolymers of vinyl acetate and vinyl alcohol (e.g. Levamelt® 900, Lanxess), copolymers of vinyl chloride and vinyl acetate (e.g. Vinnol® H 40-60, Wacker), copolymers of ethylene, vinyl acetate and esters or partial esters of maleic acid (e.g. Vamac® G from DuPont), and mixtures thereof.

[0049] Typically, the total content of thickeners in the first part of the composition may range from 2 to 10% by weight, preferably from 3 to 8% by weight, more preferably from 4 to 7% by weight, relative to the total weight of the first part of the composition.

[0050] Suitable tougheners or toughening agents for the first part of the composition are block copolymers (e.g., polymethylmethacrylate-co-polybutylacrylate-co-polymethylmethacrylate), elastomeric rubbers, elastomeric polymers, liquid elastomers, polyesters, acrylic rubbers, butadiene / acrylonitrile rubbers, buna rubber, polyisobutylene, polyisoprene, natural rubber, synthetic rubbers such as styrene / butadiene rubber (SBR), polyurethane polymers, ethylene-vinyl acetate polymers, fluororubbers, isoprene-acrylonitrile polymers, chlorosulfonated polyethylene, homopolymers of polyvinyl acetate, block copolymers, core-shell rubber particles (e.g., commercially available from Arkema under the trade name Clearstrength® XT100), and mixtures thereof.

[0051] Preferably, the first part of the composition is per-compound-free, more preferably peroxide-free.

[0052] In a preferred embodiment, the first part of the composition comprises a thickening agent and a thixotropic agent, and preferably further comprises an adhesion promoter and at least one stabilizer.

[0053] Ingredient A In a preferred embodiment, component A does not include an alkoxyalkyl cyanoacrylate, such as methoxyethyl cyanoacrylate.

[0054] In a preferred embodiment, the first part of the composition comprises: 60% to 99% by weight of an alkyl cyanoacrylate monomer, the alkyl cyanoacrylate monomer containing only one cyanoacrylate functional group; 3% to 20% by weight of one poly(2-cyanoacrylate) monomer having formula (I-1) as defined above; 2% to 10% by weight of a thickener; 2% to 10% by weight of a thixotropic agent; Includes.

[0055] Component B Component B comprises a (meth)acrylate component having at least two (meth)acrylate functional groups.

[0056] The term "(meth)acrylate" refers to acrylates when their vinyl group is alpha-substituted with a -H atom, or methacrylates when their vinyl group is alpha-substituted with a -CH3 (methyl) group.

[0057] The (meth)acrylate component may have two (meth)acrylate functional groups (difunctional) or may have three or more (meth)acrylate functional groups (multifunctional, such as trifunctional or tetrafunctional).

[0058] The (meth)acrylate component may be selected from (meth)acrylate monomers, oligomers, polymers, and mixtures thereof.

[0059] Component B may comprise a total of more than 80 wt. %, preferably more than 90 wt. %, and even more preferably more than 95 wt. % (meth)acrylate components, based on the total weight of said component B.

[0060] The (meth)acrylate component having at least two (meth)acrylate functional groups is difunctional (meth)acrylate components, such as butanediol di(meth)acrylate, hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, triethylene oxide dimethacrylate, tricyclodecane dimethanol diacrylate, neopentyl glycol diacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, propoxylated bisphenol A diacrylate, (meth)acrylate functionalized oligomers and polymers, and mixtures thereof; polyfunctional (meth)acrylate components, such as tris-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated trimethylolpropane triacrylate (TMPETA), ethoxylated trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate (PETA), pentaerythritol tetramethacrylate (PETMA), dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, (meth)acrylate functionalized oligomers and polymers, and mixtures thereof; A mixture thereof, may be selected from the group consisting of:

[0061] The (meth)acrylate functionalized oligomer or polymer may be a di- or polyfunctional (meth)acrylate terminated urethane polymer or copolymer, such as products commercially available from SARTOMER under the trade names CN1993CG, CN2608, CN9210.

[0062] Examples of (meth)acrylate components are readily available from known suppliers such as, for example, Sartomer, Arkema, and BASF.

[0063] The multifunctional (meth)acrylate component can be an ester prepared from (meth)acrylic acid and a diol or polyol, such as butanediol, hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol, trimethylolpropane, neopentyl glycol, pentaerythritol, bisphenol A, or alkoxylated derivatives thereof, methods for their preparation being known to those skilled in the art.

[0064] In a preferred embodiment, the (meth)acrylate component having at least two (meth)acrylate functional groups is difunctional (meth)acrylate components, such as butanediol di(meth)acrylate, hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, triethylene oxide dimethacrylate, tricyclodecane dimethanol diacrylate, neopentyl glycol diacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, propoxylated bisphenol A diacrylate, and mixtures thereof; polyfunctional (meth)acrylate components, such as tris-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated trimethylolpropane triacrylate (TMPETA), ethoxylated trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate (PETA), pentaerythritol tetramethacrylate (PETMA), dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and mixtures thereof; A mixture thereof, is selected from the group consisting of:

[0065] Among the difunctional (meth)acrylate components, ethoxylated bisphenol A-diacrylate, ethoxylated bisphenol A-dimethacrylate, propoxylated bisphenol A-diacrylate, and mixtures thereof are preferred.

[0066] In one embodiment, the (meth)acrylate component is not a polyethylene glycol di(meth)acrylate.

[0067] Among the polyfunctional (meth)acrylate components, tris-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated trimethylolpropane triacrylate (TMPETA), ethoxylated trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate (PETA), pentaerythritol tetramethacrylate (PETMA), dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and mixtures thereof are preferred, with ethoxylated trimethylolpropane triacrylate (TMPETA) and ethoxylated trimethylolpropane trimethacrylate being more preferred.

[0068] In a preferred embodiment, component B comprises a mixture of a difunctional (meth)acrylate component and a multifunctional (meth)acrylate component. More preferably, the total content of the trifunctional (meth)acrylate components is greater than 50% by weight, more preferably greater than 70% by weight, based on the total weight content of the difunctional (meth)acrylate component and the multifunctional (meth)acrylate component combined.

[0069] In a preferred embodiment, the di- and multi-functional (meth)acrylate components are ethoxylated.

[0070] In a preferred embodiment, component B is 5 to 40% by weight, more preferably 5 to 20% by weight, of a difunctional (meth)acrylate component; 40 to 95% by weight, more preferably 65 to 85% by weight, of a multifunctional (meth)acrylate component; Includes.

[0071] Preferably, component B is Ethoxylated bisphenol A dimethacrylate, Ethoxylated trimethylolpropane triacrylate (TMPETA), Includes.

[0072] Initiator Component B of the composition may include a nucleophilic initiator for cyanoacrylate polymerization.

[0073] The nucleophilic initiator may be selected from the group consisting of organic bases, salts with hard anions, reactive inorganic fillers, metal salts with organic counter anions, and mixtures thereof. The initiator is preferably an organic base.

[0074] Suitable organic bases are, for example, caffeine, theobromine, 5-chloro-2-methylbenzothiazole, 2-(morpholinothio)benzothiazole and tetrahydroquinoline.

[0075] Suitable salts with hard anions are, for example, choline chloride and benzalkonium chloride.

[0076] A suitable reactive inorganic filler is, for example, hydrated calcium silicate known as Promaxon® D.

[0077] Suitable metal salts with organic counter anions are, for example, calcium stearate, calcium acrylate, calcium methacrylate, magnesium acrylate, magnesium methacrylate, zinc acrylate, zinc methacrylate.

[0078] The second part may contain an initiator at a concentration ranging from 0.05 to 1% by weight, more preferably from 0.1 to 0.5% by weight, relative to the total weight of the second part of the composition.

[0079] Additives Component B of the composition may further contain at least one additive selected from the group consisting of, for example, thixotropic agents, thickeners, toughening agents, accelerators, per-compounds, adhesion promoters, pigments, colorants, stabilizers, antioxidants, plasticizers, and mixtures thereof.

[0080] Suitable stabilizers may be selected from the group consisting of radical stabilizers, acid stabilizers, and mixtures thereof.

[0081] The radical stabilizer is typically a radical polymerization inhibitor, and is preferably selected from the group consisting of 4-methoxyphenol, hydroquinone, hydroquinone monomethyl ether, hydroxytoluene butyl ether, hydroxyanisole butyl ether, 4,4'-methylenebis(2,6-di-tert-butylphenol), and mixtures thereof.

[0082] The total content of the radical stabilizer in component B of the composition may be in the range of 0 to 0.5% by weight, preferably 0.001% to 0.3% by weight, and more preferably 0.01% to 0.1% by weight, relative to the total weight of component B.

[0083] The acid stabilizer is typically an inhibitor of anionic polymerization.The acid stabilizer can be selected from the group consisting of Bronsted acid, Lewis acid, and mixtures thereof.The acid stabilizer is preferably selected from the group consisting of methanesulfonic acid, p-toluenesulfonic acid, hydrofluoric acid, boron trifluoride, boron trifluoride etherate complex, fluoroboric acid, sulfur dioxide, and mixtures thereof.

[0084] In the second part of the composition, the total content of stabilizers may generally be in the range of 0% to 1% by weight, preferably 0.001 to 0.8% by weight, more preferably 0.0015 to 0.7% by weight, relative to the total weight of the second part.

[0085] Typically, the adhesion promoter may be selected from the group of aromatic carboxylic acids or anhydrides, preferably from the group consisting of trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, dianhydride of 3,3',4,4'-benzophenonetetracarboxylic acid, itaconic acid, itaconic anhydride, 3-butene-1,2,3-tricarboxylic acid, and mixtures thereof.

[0086] In the second part of the composition, the total content of adhesion promoters may range from 0 to 0.1% by weight, based on the total weight of the second part.

[0087] Suitable accelerating agents (or accelerators) may be selected from calixarenes, crown ethers (e.g., 15-Crown-5, 18-Crown-6, Dibenzo 18-Crown-6, marketed by Alfa Aesar), cyclodextrins, and mixtures thereof.

[0088] Typically, the content of the accelerator in the second part of the composition may range from 0 to 0.8% by weight, based on the total weight of the second part.

[0089] Suitable thixotropic agents may be selected from the group consisting of hydrogenated castor oil, optionally modified by reaction with amines, polyamides, silica and mixtures thereof.

[0090] Preferably, the thixotropic agent is silica, more preferably selected from the group consisting of fumed silica, hydrophobic fumed silica (e.g. Aerosil® R202 marketed by Evonik), hydrophilic fumed silica and precipitated silica.

[0091] Typically, the content of the thixotropic agent in the second part of the composition may range from 2 to 10% by weight, preferably from 3 to 8% by weight, more preferably from 4 to 7% by weight, relative to the total weight of the second part.

[0092] The thickener or thickening agent suitable for the second part of the composition can be selected from those compatible with the monomer that contains it.Among them, mention may be made of poly(meth)acrylate, acylated cellulose polymer, such as cellulose acetate, polyvinyl acetate, partially hydrolyzed polyvinyl acetate, polyvinylpyrrolidone, polyoxylate, polycaprolactone, polycyanoacrylate, such as vinyl acetate copolymer with vinyl chloride, copolymer of (meth)acrylate with butadiene and styrene, copolymer of vinyl chloride with acrylonitrile, copolymer of ethylene with vinyl acetate, poly[butylene terephthalate-co-polyethylene glycol terephthalate, copolymer of lactic acid with caprolactone, and mixtures thereof.

[0093] These thickening agents are known to those skilled in the art and described in the prior art. Preferably, in the compositions of the present invention, the thickening agent is selected from the group consisting of poly(meth)acrylates, polyvinylpyrrolidones, polyvinyl acetates, partially hydrolyzed polyvinyl acetates, vinyl acetate copolymers, and acylated cellulose polymers. Suitable thickening agents for the first part of the composition can be, for example, polymethyl methacrylates (e.g., Degacryl® M 449, Evonik), copolymers of vinyl acetate and vinyl alcohol (e.g., Levamelt® 900, Lanxess), copolymers of vinyl chloride and vinyl acetate (e.g., Vinnol® H 40-60, Wacker), copolymers of ethylene, vinyl acetate, and esters or partial esters of maleic acid (e.g., Vamac® G from DuPont), and mixtures thereof. Polycyanoacrylates themselves may be added to the cyanoacrylate composition to impart some degree of thickening properties. Additionally, the viscosity functionalized resin may also act as a thickener in place of any additional polymeric additives.

[0094] Percompounds are compounds which contain an OO group in their structure, such as peresters, perborates, persulfates, peracetals or peroxides.

[0095] Suitable per-compounds are, for example, tert-butyl perbenzoate (TBPB) or tert-butyl peroxide (TBP).

[0096] If present, the total content of percompounds is preferably comprised between 0.1 and 1% by weight, preferably between 0.1 and 0.5% by weight, relative to the total weight of the second part of the composition.

[0097] In a preferred embodiment, component B does not include a cyanoacrylate compound.

[0098] composition The two-part composition may be dispensed from a container (such as a two-part syringe) or a reservoir pot. The former is generally convenient for manual application, and the volume ratio of the first part to the second part may range from 1:1 to 10:1, more preferably 2:1 or 4:1. The two-part composition may also be dispensed using an automated device, and the mixing ratio may be continuously adjustable between 1:1 and 10:1.

[0099] In a two-part composition, the volume ratio of the first part to the second part may range from 1:1 to 10:1, preferably from 2:1 to 5:1, and even more preferably is 4:1.

[0100] A preferred two-component curable composition is A first part (component A), 60% to 99% by weight of an alkyl cyanoacrylate monomer, the alkyl cyanoacrylate monomer containing only one cyanoacrylate functional group; 3% to 20% by weight of one poly(2-cyanoacrylate) monomer having the above formula (I-1); 2% to 10% by weight of a thickener; 2% by weight to 10% by weight of a thixotropic agent; a first portion including: A second part (component B), 5 to 40% by weight, more preferably 5 to 20% by weight, of a difunctional (meth)acrylate component; 40 to 95% by weight, more preferably 65 to 85% by weight, of a multifunctional (meth)acrylate component; (The di- and multifunctional (meth)acrylate components are preferably ethoxylated.) 0.01 to 1% by weight of a nucleophilic initiator; 0-5% thixotropic agent, a second portion including Includes.

[0101] Syringe or Cartridge or Dispensing Head The present invention also relates to a syringe or a cartridge or a dispensing head comprising a two-part curable composition as defined above.

[0102] Preferably, the syringe (or cartridge) is a syringe (respectively a cartridge) having two chambers of different volumes, one for a first part of the composition as defined above and the other for a second part of the composition.

[0103] A first portion of the composition is preferably disposed in the chamber having a larger volume.

[0104] The preparation of the adhesive is carried out by mixing the two parts of the composition, preferably by manual pressure on the plunger of a syringe or cartridge, or assisted by a gun, which forces the contents of the chamber into a static mixer, at the outlet of which the adhesive of the invention is obtained, in which the two components are advantageously intimately mixed.

[0105] Automated dispensing preparation of the adhesive is preferably accomplished by forcing two portions of the composition together through valves and mixing elements that make up the dispensing head, allowing a specific amount of the desired mixture of composition to be dispensed onto the part.

[0106] Use of the composition The present invention also relates to the use of a two-part curable composition as defined above for bonding substrates.

[0107] The present invention also provides a method for bonding substrates, comprising the steps of: mixing together the two components of the two-part curable composition defined above; applying the mixture obtained above to at least one substrate; mating the substrates together for a time sufficient to form an adhesive bond between the mated substrates; The present invention relates to a method comprising the steps of:

[0108] The two-part adhesive composition of the present invention advantageously exhibits a good compromise between the following properties: Fast fix time, preferably less than 1 minute; -High bonding strength with no gap or even with a 2mm gap, -High heat aging resistance, High resistance to immersion in hot water (e.g. as measured by immersion in neutral water at 60°C and bond strength on clean ABS substrate after 3 days of continuous exposure), Resistance to organic solvents (e.g., as shown by high insolubility in acetone at room temperature for 24 hours), -Hot strength (usage temperature), Excellent shelf life stability.

[0109] More specifically, the two-part curable compositions according to the present invention advantageously exhibit both "hot strength" and heat resistance. EXAMPLES

[0110] All of the following ingredients were used: Ethyl cyanoacrylate (ECA): Cartell Chemical Co Ltd Methoxyethyl cyanoacrylate (MECA): Cartell Chemical Co. Ltd. SO2: Carburos Metalicos SA Sartomer SR 454: Ethoxylated trimethylolpropane triacrylate commercially available from Arkema Sartomer SR349: An ethoxylated bisphenol A dimethacrylate commercially available from Arkema Degacryl 449: A polymethyl methacrylate commercially available from Evonik Biscyanoacrylate (1,6-hexanediol biscyanoacrylate) of formula (I-1), where R=-(CH2)6-, synthesized according to U.S. Pat. No. 9,670,145. Aerosil® R202: A hydrophobic fumed silica commercially available from Evonik

[0111] The following products were obtained from Sigma Aldrich Merck: methanesulfonic acid, TBPB (tert-butyl peroxybenzoate), hydroquinone, 4-methoxyphenol, itaconic acid, 2,2'-methylenebis(6-tert-butyl-4-methylphenol).

[0112] The following materials were used in the examples: Grit Blasted Mild Steel (GBMS) Lap Shear (for all mechanical testing) Mild steel (MS) lap shear (for fixing time evaluation)

[0113] The performance of the compositions was evaluated using the following methods. Tensile shear strength test data measured in accordance with ASTM D1002, contact area 250 mm 2 The bond strength reflects the bond strength measured in MPa after assembling overlapping lapshears (standard specimens of grit blasted mild steel (GBMS)). After assembly prior to testing, the joined lapshears were first clamped and allowed to "rest" for 24 hours at room temperature (23°C ± 2°C). Testing was performed using an Instron tensile testing machine operating at a crosshead speed of 1.3 mm / min.

[0114] Cure through volume (CTV) or gap testing was performed using small horseshoe shaped spacers 2mm thick coated with gel adhesive.

[0115] Hot water resistance testing was performed on assembled GBMS lapshear specimens, which were completely immersed in hot water (60°C) for 3 days, then left at room temperature for 24 hours and subjected to destructive testing.

[0116] Heat resistance testing was carried out on a GBMS lapshear, where the samples were exposed to 150° C. for three consecutive days, then cooled to room temperature, allowed to stand for 24 hours, and then subjected to a destructive test.

[0117] Hot strength ("service temperature") tests were performed on GBMS lapshears that were heated to specific individual temperatures of 100°C or 125°C or 150°C. The heated specimens were insulated with a fabric thermal wrap that also had thermocouples placed next to the substrate surface so that the actual temperature during destructive testing could be tracked. The specimens were subjected to a tensile load while maintained at the elevated temperature during the actual destructive testing process.

[0118] Solvent resistance and insolubility tests are measured on the bulk cured polymer (0.3 g) after immersion of the sample in acetone (20 mL) for 24 hours. The insoluble portion is filtered, dried at 60°C to a constant weight and compared to the original weight or cured material.

[0119] Fixation time (FT) is the time at which an adhesive joint (250 mm2) is capable of supporting a load of 3 kg for 10 seconds at room temperature (23 ± 2°C) and 50% relative humidity (RH). FT was measured on mild steel (MS).

[0120] Example 1: Two-part adhesive composition Several types of Part A and two types of Part B were prepared according to the compositions shown in Table 1 below. For the formulation of Part A, first, the powder PMMA thickener was dissolved in the stabilizing monofunctional CA monomer at a temperature of 65° C. or less. When the clear mixture was cooled to room temperature, the solid bis-cyanoacrylate was dissolved at room temperature, followed by thickening the mixture with fumed silica. More stabilizers were added to Part A. If necessary, sufficient adhesion promoter was added to reach 100% by weight of Part A.

[0121] The Part B formulation was prepared without any special precautions and without heating. TIFF2024519605000006.tif244170TIFF2024519605000007.tif43170

[0122] Part 1 and Part 2 of Table 1 were mixed in a 4:1 volume ratio and dispensed. The two parts were placed in a 4:1 syringe with a 4:1 static mixer. Part 1 was the largest part by volume.

[0123] The performance of the adhesive compositions is summarized in Table 2 below. The columns in Table 2 are: · Tensile shear strength of GBMS joint lap shear (both 0 and 2mm gap between substrates) after 24 hours at room temperature (23℃±2℃). · Tensile shear strength of GBMS joint lap shear (0 gap between substrates) exposed to 150°C for 3 days and then measured at room temperature (23°C ± 2°C). · Tensile shear strength (hot strength) of GBMS joint lap shear (0 gap between substrates) measured when tested at 100℃. · Tensile shear strength (hot strength) of GBMS joint lap shear (0 gap between substrates) measured when tested at 125℃. · Tensile shear strength (hot strength) of GMBS joint lap shear (0 gap between substrates) measured when tested at 150°C. · Tensile shear strength of GMBS joint lap shear (0 gap between substrates) measured when exposed to 150°C for 3 days and then tested at 125°C (hot strength) (In a first step, the parts were exposed to 150°C for 3 days without load, then returned to room temperature and in a second step the parts were tested at 125°C (hot strength). · Tensile shear strength of GMBS joint lap shear (0 gap between substrates) measured when exposed to 150°C for 3 days and then tested at 150°C (hot strength) (In a first step, the parts were exposed to 150°C for 3 days without load, then returned to room temperature and in a second step the parts were tested at 150°C (hot strength). TIFF2024519605000008.tif255170

[0124] The composition C1 according to the invention advantageously comprises Fast bond time (45 seconds), -High bonding strength (16MPa) without gap setting, -High bonding strength (9MPa) with a gap of 2mm High heat resistance (18MPa after 3 days at 150℃) High tensile shear strength at high temperatures, as shown by hot strength values ​​(8 MPa at 100°C, 6 MPa at 125°C, 2 MPa at 150°C) and also after prolonged exposure to heat (5 MPa at 125°C, 2 MPa at 150°C after 3 days at 150°C), -High tensile shear strength (13MPa) after 3 days in water at 60°C, indicating good water resistance over time; Both are shown.

[0125] The comparative compositions C2, C3 and C4 exhibit low (even zero) hot strengths at 100° C. (C2: 4 MPa, C3: 2.5 MPa) and 125° C. (C2: 2 MPa, C3: 0 MPa, C4: 0.5 MPa) compared to the compositions according to the invention (8 MPa at 100° C. and 6 MPa at 125° C., respectively).

[0126] Composition C1 according to the invention also exhibits a higher heat resistance (18 MPa) than comparative compositions C2, C3 and C4 (15 MPa, 11 MPa and 4 MPa).

[0127] Composition C1 according to the invention also exhibits higher hot strength at 125°C (5 MPa) and 150°C (2 MPa) after prolonged thermal exposure (150°C, 3 days) than comparative compositions C2, C3 and C4 (0 MPa at 125°C for C3 and C4, 0 MPa at 150°C for C2, C3 and C4).

Claims

1. A two-component curable composition comprising: A first part (component A), at least 50% by weight, based on the total weight of the first portion, of one or more alkyl cyanoacrylate monomers, said alkyl cyanoacrylate monomers including only one cyanoacrylate functional group; The following formula (I): wherein R is an organic moiety and n is an integer equal to or greater than 2; and one poly(2-cyanoacrylate) monomer having the formula: A first portion comprising: a second part (component B) comprising a (meth)acrylate component having at least two (meth)acrylate functional groups; and A two-part curable composition comprising:

2. The alkyl cyanoacrylate monomer has the general formula (II): In the formula, R is C １ -C １８ A linear or branched alkyl group, preferably C １ -C １０ Linear or branched alkyl groups, even more preferably C １ -C ８ is a linear or branched alkyl group; The two-part curable composition according to claim 1 , having

3. 2. The two-part curable composition of claim 1, wherein the alkyl cyanoacrylate monomer is selected from the group consisting of methyl cyanoacrylate, ethyl cyanoacrylate, n-propyl cyanoacrylate, isopropyl cyanoacrylate, n-butyl cyanoacrylate, sec-butyl cyanoacrylate, isobutyl cyanoacrylate, tert-butyl cyanoacrylate, n-pentyl cyanoacrylate, 1-methylbutyl cyanoacrylate, 1-ethylpropyl cyanoacrylate, neopentyl cyanoacrylate, n-hexyl cyanoacrylate, 1-methylpentyl cyanoacrylate, n-heptyl cyanoacrylate, n-octyl cyanoacrylate, 2-octyl cyanoacrylate, 2-ethylhexyl cyanoacrylate, n-nonyl cyanoacrylate, n-decyl cyanoacrylate, n-undecyl cyanoacrylate, and mixtures thereof.

4. 2. The two-part curable composition according to claim 1, wherein the total content of alkyl cyanoacrylate monomers in the first part is at least 55 wt-%, preferably at least 60 wt-%, more preferably at least 70 wt-%, in particular at least 75 wt-%, based on the total weight of said first part.

5. The poly(2-cyanoacrylate) monomer has the following formula (I-1): where R is an organic moiety. The two-part curable composition of claim 1 having the formula:

6. The two-part curable composition according to claim 1, wherein in formulas (I) and (I-1), R is an alkylene, alkenylene, cycloalkylene, arylene, alkoxyalkylene, aralkylene, or a divalent residue of a polymer such as, for example, a polyolefin, a polysiloxane, a polyester, a polyether, a polyurethane, a polyethylene glycol, or a polypropylene glycol, and R preferably represents an alkylene.

7. In formula (I-1), R is -(CH ２ ) ｍ -, and m is 2, 3, 4, 5, 6, 8, 9, 10 or 12.

8. 2. The two-part curable composition according to claim 1, wherein the total content of poly(2-cyanoacrylate) monomers in the first part is greater than 3 wt.-%, preferably in the range of 3 to 20 wt.-%, even more preferably in the range of 5 to 15 wt.-%, based on the total weight of the first part.

9. 2. The two-part curable composition of claim 1, wherein the first part of the composition further comprises at least one additive selected from the group consisting of thixotropic agents, thickeners, toughening agents, accelerators, adhesion promoters, pigments, colorants, stabilizers, antioxidants, plasticizers, and mixtures thereof.

10. 2. The two-part curable composition according to claim 1, wherein component B comprises a total of more than 80 wt.%, preferably more than 90 wt.%, and even more preferably more than 95 wt.% of (meth)acrylate components, based on the total weight of component B.

11. a (meth)acrylate component having at least two (meth)acrylate functional groups, difunctional (meth)acrylate components, such as butanediol di(meth)acrylate, hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, triethylene oxide dimethacrylate, tricyclodecane dimethanol diacrylate, neopentyl glycol diacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, propoxylated bisphenol A diacrylate, (meth)acrylate functionalized oligomers and polymers, and mixtures thereof; multifunctional (meth)acrylate components such as tris-(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate (TMPTA), ethoxylated trimethylolpropane triacrylate (TMPETA), ethoxylated trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate (PETA), pentaerythritol tetramethacrylate (PETMA), dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, (meth)acrylate functionalized oligomers and polymers, and mixtures thereof; A mixture thereof, The two-part curable composition according to claim 1 , selected from the group consisting of:

12. Component B comprises a mixture of a difunctional (meth)acrylate component and a multifunctional (meth)acrylate component, and Component B preferably comprises 5 to 40 wt. %, more preferably 5 to 20 wt. %, of a difunctional (meth)acrylate component; 40 to 95 weight percent, more preferably 65 to 85 weight percent, of a multifunctional (meth)acrylate component; The two-part curable composition of claim 1 , comprising:

13. The two-part curable composition of claim 1 , wherein the di- and multi-functional (meth)acrylate components are ethoxylated.

14. 2. The two-part curable composition of claim 1, wherein component B comprises a nucleophilic initiator for cyanoacrylate polymerization, said nucleophilic initiator preferably being selected from the group consisting of organic bases, salts with hard anions, reactive inorganic fillers, metal salts with organic counter anions, and mixtures thereof.

15. 2. The two-part curable composition of claim 1, wherein component B further comprises at least one additive selected from the group consisting of thixotropic agents, thickeners, toughening agents, accelerators, percompounds, adhesion promoters, pigments, colorants, stabilizers, antioxidants, plasticizers, and mixtures thereof.

16. 2. The two-part curable composition according to claim 1, wherein the volume ratio of the first part to the second part ranges from 1:1 to 10:1, preferably from 2:1 to 5:1, and even more preferably is 4:

1.

17. The two-component curable composition according to claim 1, A first part (component A), 60% to 99% by weight of an alkyl cyanoacrylate monomer, said alkyl cyanoacrylate monomer containing only one cyanoacrylate functional group; 3% to 20% by weight of one poly(2-cyanoacrylate) monomer having formula (I-1) according to any one of claims 5 to 7, 2% to 10% by weight of a thickener; 2% to 10% by weight of a thixotropic agent; A first portion comprising: A second part (component B), 5 to 40 wt. %, more preferably 5 to 20 wt. %, of a difunctional (meth)acrylate component; 40 to 95 weight percent, more preferably 65 to 85 weight percent, of a multifunctional (meth)acrylate component; (The di- and multifunctional (meth)acrylate components are preferably ethoxylated.) 0.01 to 1% by weight of a nucleophilic initiator; 0-5% thixotropic agent; a second portion including A two-part curable composition comprising:

18. 2. The two-part curable composition according to claim 1, characterized in that component A does not comprise an alkoxyalkyl cyanoacrylate, e.g., methoxyethyl cyanoacrylate.

19. A syringe or cartridge or dispensing head comprising the two-part curable composition of claim 1.

20. 1. A method for bonding substrates, comprising: mixing together the two components of the two-part curable composition of claim 1; applying the mixture obtained above to at least one substrate; mating the substrates together for a time sufficient to form an adhesive bond between the mated substrates; The method includes:

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