Composition including monoalkyl (METH)acrylate of diacid and method of making a bonded article

Abstract

A composition includes at least one of an alkyl acrylate or an alkyl methacrylate; at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid; an acrylic monomer having at least one of a phosphate or phosphonate group; and at least one toughening agent. A method of making a bonded article using the composition is also described. Use of monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid as a corrosion inhibitor in an acrylic adhesive is also described.

Description

[0001] PA103159W002

[0002] COMPOSITION INCLUDING MONOALKYL (METH)ACRYLATE OF DIACID AND METHOD OF MAKING A BONDED ARTICLE

[0003] CROSS-REFERENCE TO RELATED APPLICATION

[0004] This application claims priority to U.S. Provisional Application No. 63 / 725315, filed November 26, 2024, the disclosure of which is incorporated by reference in its entirety herein.

[0005] BACKGROUND

[0006] Adhesives are known to be useful for bonding one substrate to another, e.g., a metal to a metal, a metal to a plastic, a plastic to a plastic, a glass to a glass. Structural adhesives are attractive alternatives to mechanical joining methods, such as riveting or spot welding, because structural adhesives distribute load stresses over larger areas rather than concentrating such stresses at a few points. Structural adhesives may also produce cleaner and quieter products because they can dampen vibration and reduce noise. Additionally, structural adhesives can be used to bond a variety of materials, sometimes without extensive surface preparation.

[0007] Certain acrylic adhesive compositions useful for bonding galvanized steel are disclosed in U.S. Pat. Nos. 7,060,327 (Xia et al.) and 9,771,501 (Chitnavis et al.). Further examples of structural acrylic adhesive compositions are disclosed in U.S. Pat. Appl. Pub. No. 2024 / 0279516 (Gasa et al.), 2024 / 0059940 (Rotto et al.), 2024 / 0084060 (Rotto et al.), 2024 / 0343951 (Rotto), 2023 / 0303898 (Ostlund et al.), and 2022 / 0325022 (Mahoney et al.), and U.S. Pat. Nos. 9,416,299 (Kropp et al.) and 11,739,172 (Rotto). U.S. Pat. No. 5,312,868 (Abe et al.) and Japanese Pat. Appl. Pub. No. 2019085479 (published June 6, 2019) disclose compositions including acrylic resins and isocyanate crosslinkers, and U.S. Pat. No. 8,399,569 (Murofushi et al.) discloses a curable composition including an ethylenically-unsaturated- group containing reactive urethane compound.

[0008] SUMMARY

[0009] The present disclosure provides a composition useful, for example, as a sealant or adhesive, for example, a component of a structural adhesive. Typically and advantageously, the composition of the present disclosure can provide acrylic adhesives with excellent adhesion to metals, corrosion resistance, and heat resistance.

[0010] In one aspect, the present disclosure provides a composition that includes at least one of an alkyl acrylate or an alkyl methacrylate; at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid; an acrylic monomer comprising at least one of a phosphate or phosphonate group; and at least one toughening agent. In some embodiments, the monoalkyl acrylate or monoalkyl methacrylate is a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate. In another aspect, the present disclosure provides a method of making a bonded article. The method includes combining the composition with a free-radical initiator to provide an adhesive composition, applying the adhesive composition on at least one of the first substrate or the second substrate, adhering the first substrate and the second substrate using the adhesive composition, and allowing the adhesive composition to at least partially cure to make the bonded article.

[0011] In another aspect, the present disclosure provides an article bonded with the composition disclosed herein and / or made by the method disclosed herein.

[0012] In another aspect, the present disclosure provides the use of at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid as a corrosion inhibitor in an acrylic adhesive. In some embodiments, the monoalkyl acrylate or monoalkyl methacrylate is a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate.

[0013] As used herein:

[0014] "alkyl group" and the prefix "alk-" have only C-C bonds and C-H bonds and are inclusive of both straight chain and branched chain groups and of cyclic groups. In some embodiments, alkyl groups have up to 30 carbons (in some embodiments, up to 20, 15, 12, 10, 8, 7, 6, or 5 carbons) unless otherwise specified. Cyclic groups can be monocyclic or polycyclic and, in some embodiments, have from 3 to 10 ring carbon atoms and other alkyl substituents;

[0015] "Aryl" and “aromatic” as used herein include carbocyclic aromatic rings or ring systems, for example, having 1, 2, or 3 rings and optionally containing at least one heteroatom (e.g., O, S, or N) in the ring optionally substituted by up to five substituents including one or more alkyl groups having up to 4 carbon atoms (e.g., methyl or ethyl), alkoxy having up to 4 carbon atoms, halo (i.e., fluoro, chloro, bromo or iodo), hydroxy, or nitro groups, examples of which include phenyl, naphthyl, biphenyl, fluorenyl as well as furyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, indolyl, isoindolyl, triazolyl, pyrrolyl, tetrazolyl, imidazolyl, pyrazolyl, oxazolyl, and thiazolyl; the term “acrylic” refers to both acrylic and methacrylic polymers, oligomers, and monomers;

[0016] “cure” refers to making polymer chains from one or more monomers; and the term "(meth)acryl" refers to acryl (also referred to in the art as acryloyl and acrylyl) and / or methacryl (also referred to in the art as methacryloyl and methacrylyl).

[0017] Terms such as "a", "an" and "the" are not intended to refer to only a singular entity but include the general class of which a specific example may be used for illustration. The terms "a", "an", and "the" are used interchangeably with the term "at least one".

[0018] The phrase "comprises at least one of followed by a list including the conjunction “or” refers to comprising any one of the items in the list and any combination of two or more items in the list. The phrase "at least one of followed by a list including the conjunction “or” refers to any one of the items in the list or any combination of two or more items in the list.

[0019] The term "polymer" refers to a molecule having a structure which includes the multiple repetition of units derived, actually or conceptually, from one or more monomers. The term “monomer” refers to a molecule of low relative molecular mass that can combine with others to form a polymer. The term “polymer” includes homopolymers and copolymers, as well as homopolymers or copolymers that may be formed in a miscible blend, e.g., by coextrusion or by reaction. The term ''polymer' ’ includes random, block, graft, and star polymers. The term “polymer” encompasses oligomers.

[0020] The term "crosslinking” refers to joining polymer chains together by covalent chemical bonds, usually via crosslinking molecules or groups, to form a network polymer. A crosslinked polymer is generally characterized by insolubility but may be swellable in the presence of an appropriate solvent. The term “crosslinked” includes partially crosslinked.

[0021] All numerical ranges are inclusive of their endpoints and non-integral values between the endpoints unless otherwise stated (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0022] Features and advantages of the present disclosure will be further understood upon consideration of the detailed description as well as the appended claims.

[0023] DETAILED DESCRIPTION

[0024] The composition of the present disclosure includes at least one of an alkyl acrylate or methacrylate. The alkyl group of the alkyl acrylate or methacrylate may be straight-chain, branched, or cyclic (including polycyclic) and may have 1 to 14, 1 to 12, or 1 to 10 carbon atoms. Examples include isodecyl (methjacrylate, isooctyl (methjacrylate, octadecyl (methjacrylate (stearyl (methjacrylate), cyclohexyl (methjacrylate, tridecyl (methjacrylate, methyl (methjacrylate, ethyl (methjacrylate, n-propyl (methjacrylate, n-butyl (methjacrylate, isobutyl (methjacrylate, n-hexyl (methjacrylate, 2-ethylhexyl (methjacrylate, n-octyl (methjacrylate, n-decyl (methjacrylate, n-dodecyl (methjacrylate, lauryl (methjacrylate and isobomyl (methjacrylate. In some embodiments, the at least one of an alkyl acrylate or an alkyl methacrylate comprises methyl methacrylate. Such monomers are available from a variety of commercial sources, for example, isobomyl acrylate available from Sartomer under the trade designation “SR506”, or from Evonik Performance Materials GmbH under the trade designation “VISIOMER IBOA”, isobomyl methacrylate available from Sartomer under the trade designation “SR423A” or from Evonik Performance Materials GmbH under the trade designation “VISIOMER IBOMA”, and lauryl methacrylate available from BASF, Florham Park, NJ, under the trade designation “LMA 1214 F”. Methyl methacrylate is commercially available from a variety of suppliers, including from Evonik Performance Materials GmbH under the trade designation “VISIOMER MMA”.

[0025] In some embodiments, the composition includes 30 weight percent (wt.%) to 80 wt.%, 40 wt.% to 80 wt.%, or 45 wt.% to 75 wt.% of the at least one of an alkyl acrylate or an alkyl methacrylate, based on the total weight of the composition. In some embodiments, the composition includes 30 wt.% to 80 wt.%, 40 wt.% to 80 wt.%, or 45 wt.% to 75 wt.% methyl methacrylate, based on the total weight of the composition. The composition may also be free of alkyl acrylate and methacrylate that are straight-chain, branched, or cyclic (including polycyclic) and have 2 to 14, 2 to 12, or 2 to 10 carbon atoms. The composition of the present disclosure further includes an acrylic monomer comprising at least one of a phosphate or phosphonate group. Useful acrylic monomers comprising a phosphate or phosphonate group include ethylene glycol methacrylate phosphate (available, for example, from Miwon

[0026] North America, Exton, Pennsylvania, under the trade designations “MIRAMER SC1400” and “MIRAMER SC1400A” and from Allnex, Alpharetta, GA, under the trade designation “EBACRYL 168”) and phosphate esters of polypropylene glycol) monomethacrylate (available, for example, under the trade designation “SIPOMER PAM” from Solvay Novecare, Cranbury, NJ). Vinyl phosphonic acid may also be useful. In some embodiments, the composition of the present disclosure further comprises an acrylic monomer comprising a phosphate group. Further examples of useful acrylic monomers comprising a phosphate group include glycerol mono methacrylate phosphates; glycerol dimethacrylate phosphates; hydroxy(C2-6 alkyl) methacrylate phosphates, such as hydroxylethylmethacrylate phosphates; bis-(methacryloxyethyl) phosphate; methacryloxypropyl phosphate; bis-(methacryloxypropyl) phosphate; bis-(meth acryloxy)propyloxyphosphate; methacryloxyhexylphosphate; bis-(methacryloxyhexyl) phosphate; methacryloxy octyl phosphate; bis-(methacryloxy octyl) phosphate; methacryloxy decyl phosphate; bis-(methacryloxydecyl) phosphate; caprolactone methacrylate phosphate; polymethacrylated polycarboxyl polyphosphonic acid; poly methacrylated polychlorophosphoric acid; and combinations thereof. The phosphonate- or phosphate-functionalized acrylic monomer can be present in composition, for example, in an amount up to 5 wt.%, 4 wt.%, or 3 wt.%, based on the total weight of the composition. In some embodiments, the phosphonate- or phosphate-functionalized acrylic monomer is present in an amount of at least 0.5 wt.%, 1 wt.%, 1.5 wt.%, or 1.9 wt.%, based on the total weight of the composition. Such monomers can be useful, for example, for enhancing the adhesion to metal substrates.

[0027] The composition of the present disclosure further includes at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid. The monoalkyl acrylate or methacrylate is represented by formula which bond A-B is a carbon-carbon single bond, a carbon-carbon double bond, or a bond in a phenyl ring, n is an integer from 1 to 18, and R is hydrogen or methyl. In some embodiments, n is an integer from 2 to 16, 2 to 12, 2 to 8, 2 to 6, or 2 to 4. In some embodiments, n is 2. In some embodiments, R is hydrogen. In some embodiments, R is methyl.

[0028] In some embodiments, A-B is a bond in a phenyl ring, providing a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate. In some embodiments, the phthalic acid monoalkyl acrylate or the phthalic acid monoalkyl methacrylate is beta-methacryloxy ethyl hydrogen phthalate. Useful phthalic acid monoalkyl acrylate or methacrylates include those available, for example, under product number X-821-2000 from ESSTECH, Inc., Essington, PA, USA,” and under the trade designation “NK Ester CB-1” from Kowa American Corporation, New York, NY, USA. The at least one of a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate can be present in composition, for example, in an amount less than 10 wt.%, or up to 9 wt.%, 8 wt.%, 7 wt.%, 6 wt.%, 5 wt.%, 4 wt.%, or 3 wt.%, based on the total weight of the composition. In some embodiments, the at least one of a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate is present in an amount of at least 0.5 wt.%, 1 wt.%, 1.5 wt.%, or 1.9 wt.%, based on the total weight of the composition. In some embodiments, a monoalkyl acrylate or a monoalkyl methacrylate of succinic acid or maleic acid is -acryloyloxy ethyl hydrogen succinate, / ? -methacryloyloxy ethyl hydrogen succinate, and 2- (methacroyloxy)ethyl maleate. In some embodiments, a monoalkyl acrylate or a monoalkyl methacrylate of succinic acid or maleic acid can be present in composition, for example, in an amount less than 10 wt.%, or up to 9 wt.%, 8 wt.%, 7 wt.%, 6 wt.%, 5 wt.%, 4 wt.%, or 3 wt.%, and / or at least 0.5 wt.%, 1 wt.%, 1.5 wt.%, or 1.9 wt.%, based on the total weight of the composition.

[0029] As shown in the Examples, below, the at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid has been shown to provide unexpected corrosion resistance in acrylic adhesives. Combinations of these compounds can also be useful.

[0030] In some embodiments, the composition of the present disclosure includes a second acrylic monomer comprising a carboxylic acid group. Examples of suitable acrylic monomers comprising a carboxylic acid group useful in combination with at least one of a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate include methacrylic acid, acrylic acid, / ?-acryloyloxy ethyl hydrogen succinate, / ?-methacryloyloxy ethyl hydrogen succinate, and 2-(methacroyloxy)ethyl maleate. In some embodiments, the second acrylic monomer comprising the carboxylic acid group is at least one of methacrylic acid or beta-acryloyloxyethyl hydrogen succinate. Many acrylic monomers comprising a carboxylic acid group are available from commercial sources, for example, methacrylic acid available from Evonik Performance Materials GmbH under the trade designation “ VISIOMER GMAA” and ?- methacryloyl oxyethyl hydrogen succinate available from Shin-Nakamura Co. Ltd., Arimoto, Japan, under the trade designation “NK ESTER SA”. In some embodiments, the second acrylic monomer comprising a carboxylic acid group is at least one of acrylic acid or methacrylic acid. In some embodiments, the second acrylic monomer comprising a carboxylic acid group is methacrylic acid. In some embodiments, the second acrylic monomer comprising a carboxylic acid group is present in the composition in an amount in an amount up to 5 wt.%, 4 wt.%, or 3 wt.%, at amount of at least 0.5 wt.%, 1 wt.%, 1.5 wt.%, or 1.9 wt.%, or any combination thereof, based on the total weight of the composition.

[0031] In some embodiments, the composition includes an acrylic monomer comprising a hydroxyl group. In some embodiments, the acrylic monomer including the hydroxyl group is present in an amount of at least 1 wt.%, 2 wt.%, or 5 wt.% and up to 25 wt.%, 20 wt.%, 15 wt.%, or 10 wt.%, based on the total weight of the composition. Examples of suitable additional acrylic monomers including a hydroxyl group include 2 -hydroxy ethyl acrylate, 2 -hydroxy ethyl methacrylate, 2- and 3 -hydroxypropyl acrylate, 2- and 3- hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, caprolactone mono(meth)acrylate, available under the trade designation “SR-495B” from Sartomer and other poly(e- caprolactone) mono[2-(meth)acryloxy ethyl] esters, poly(e-caprolactone) mono[2-acryloxy ethyl] esters, 2-hydroxy-3-alkyloxy methacrylate, 2 -hydroxy-3 -alkyloxy acrylate, and polyethylene glycol mono acrylates and methacrylates. Many acrylic monomers comprising a hydroxyl group are available from commercial sources, for example, 2 -hydroxy ethyl methacrylate (available from Evonik Performance Materials GmbH under the trade designations “VISIOMER HEMA 97” and “VISIOMER HEMA 98”), hydroxypropyl methacrylate (available from Evonik Performance Materials GmbH under the trade designations “VISIOMER HPMA 97” and “VISIOMER HPMA 98”), ultra-high purity 2-hydroxyethyl methacrylate (available from Evonik Performance Materials GmbH under the trade designation “VISIOMER UHP HEMA”), polypropylene glycol monomethacrylate (available from Miwon North America, Exton, Pennsylvania, under the trade designation “MIRAMER M1051”), and CH2=CHC(O)O(CH2CH2O)7-9H available, for example, from Nippon Oil & Fats Company, Tokyo, Japan under the trade designation "BLEMMER". The composition may also be free of monomers comprising a hydroxyl group, including any of those described above.

[0032] In some embodiments, the composition of the present disclosure includes a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof. Suitable crosslinkers having two or more acrylate groups, methacrylate groups, or a combination thereof include diacrylate esters of diols, such as ethylene glycol diacrylate, diethylene glycol diacrylate, propanediol diacrylate, butanediol diacrylate, butane- 1,3 -diyl diacrylate, pentanediol diacrylate, hexanediol diacrylate (including 1,6- hexanediol diacrylate), heptanediol diacrylate, octanediol diacrylate, nonanediol diacrylate, decanediol diacrylate, dimethacrylates of any of the foregoing diacrylates, and combinations thereof. Further suitable crosslinkers include polyacrylate esters of polyols, such as glycerol triacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, neopentyl glycol diacrylate, dipentaerythritol pentaacrylate, methacrylates of the foregoing acrylates, and combinations thereof. Further suitable crosslinkers include polyfunctional acrylate oligomers comprising two or more acrylate groups. The polyfunctional acrylate oligomer may be a urethane acrylate oligomer, an epoxy acrylate oligomer, a polyester acrylate, a polyether acrylate, a polyacrylic acrylate, a methacrylate of any of the foregoing acrylates, or a combination thereof. In some embodiments, the crosslinker is a non-cyclic crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof. Non-cyclic means that the crosslinker does not contain any aromatic or non-aromatic rings. For example, non-cyclic crosslinkers do not include aromatic rings, non-aromatic carbocyclic rings, or heterocyclic rings (that is, rings including N, O, or S as a member of the ring) of any size. The amount of the crosslinker present in the composition may be up to 5 wt.%, 4 wt.%, or 3 wt.%, based on the total weight of the composition. In some embodiments, the crosslinker is present in an amount of at least 0.5 wt.%, 1 wt.%, 1.5 wt.%, or 1.9 wt.%, based on the total weight of the composition. In some embodiments, the composition is free of a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof or comprises less than 0.5 weight percent of a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof, based on the total weight of the composition. In some embodiments, the composition is free of a polymer having at least two acrylate or methacrylate functional groups or contains less than 2, 1.5, 1, or 0.5 percent by weight of a polymer having at least two acrylate or methacrylate functional groups, based on the total weight of the composition.

[0033] In some embodiments, the composition of the present disclosure is free of a compound having at least two acrylate or methacrylate functional groups and a -CH2-CH2-CH2-CH2-O- segment, or contains less than 2, 1.5, 1, or 0.5 percent by weight of a compound having at least two acrylate or methacrylate functional groups and a -CH2-CH2-CH2-CH2-O- segment, based on the total weight of the composition. Such compounds include those described in U.S. Pat. Appl. Pub. No. 2022-0325022, which can be made, for example, by the reaction of a polyether polyprimary polyamine obtained from 3M Company (St. Paul, MN) under the trade designation “DYNAMAR HC-1101” with 2-isocyanatoethyl methacrylate.

[0034] In some embodiments, the composition of the present disclosure can include other acrylic monomers. Further examples of suitable additional acrylic monomers include 2-phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, alkoxylated lauryl (meth)acrylate, alkoxylated phenol (meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, caprolactone (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, ethylene glycol methyl ether (meth)acrylate, ethoxylated nonyl phenol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, allyl (meth)acrylate, 2 -methoxy ethyl (meth)acrylate, 2 -ethoxy ethyl (meth)acrylate, 2- or 3 -ethoxypropyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, glycidyl (meth)acrylate, N-(2-(2-oxo-l- imidazolidinyl)ethyl)methacrylamide, and methacrylamidoethyl ethylene urea ("MAEEU") available from Solvay Specialty Polymers USA, LLC under the trade designation “SIPOMER WAM II”), and combinations thereof. The composition may also be free of any of these monomers.

[0035] The composition of the present disclosure includes at least one toughening agent. A variety of elastomers may be suitable as toughening agents as long as the elastomer is a polymeric material having rubber elasticity at room temperature. Examples of elastomers suitable for the toughening agent include various synthetic rubbers such as a methyl methacrylate-butadiene-styrene copolymer (MBS), an acrylonitrile-styrene-butadiene copolymer, a linear polyurethane, acrylonitrile-butadiene rubber, a styrene-butadiene rubber, a styrene-butadiene-styrene rubber, an acrylic block copolymer, a polystyrene / EPDM (an ethylene / propylene / conjugated diene copolymer), a chloroprene rubber, a butadiene rubber, natural mbber, and combinations thereof. The elastomer useful in the second part may be a core-shell graft copolymers having a “rubbery” core and a “hard” shell. Examples of useful coreshell graft copolymers are those where "hard" monomers, such as styrene, acrylonitrile, or methyl methacrylate, are grafted onto a rubbery core made from polymers of “soft” or “elastomeric” monomers, such as butadiene or ethyl acrylate. The toughening agent may be a block copolymer containing hard segments and soft segments. The soft segments and uncrystallized hard segments form an amorphous phase, and a portion of the hard segment crystallizes to form crystalline microdomains, which can function as physical crosslinking domains. Such block copolymers are typically known as thermoplastic elastomers. The block copolymer can be an acrylic copolymer, in some embodiments, including poly(methyl methacrylate) (PMMA) hard segments. The soft segments of the block copolymer can be formed from monomers of an acrylate or methacrylate having a C4-C9 alkyl sidechain or mixtures thereof, for example. In some embodiments, the block copolymer is a triblock copolymer of methyl methacrylate / C4-C9 alkyl acrylate or methacrylate / methyl methacrylate. In some embodiments, the block copolymer is made from PMMA and poly(butyl acrylate) or poly(butyl methacrylate) and is a poly(methyl methacrylate)-poly(n-butyl (meth)acrylate)-poly(methyl methacrylate) triblock copolymer. In some embodiments, the amount of the at least one toughening agent may be 5 wt.% to 40 wt.%, 5 wt.% to 35 wt.%, 10 wt.% to 35 wt.%, or 15 wt.% to 30 wt.%, based on the total weight of the composition.

[0036] In some embodiments, the composition of the present disclosure includes a free-radical inhibitor. Examples of suitable free-radical inhibitors include benzoquinones, naphthoquinone, butylated hydroxytoluene (BHT), hydroquinone, p-methoxy hydroquinone (MEHQ), and combinations thereof. In some embodiments, the free-radical inhibitor is present in an amount from 0.05 wt.% to 2.0 wt.%, 0.25 wt.% to 2.0 wt.%, 0.5 wt.% to 1.5 wt.%, 0.05 wt.% to 1.0 wt.%, 0.1 wt.% to 0.5 wt.%, or 0.05 wt.% to 0.25 wt.%, based on the total weight of the composition.

[0037] In some embodiments, the composition of the present disclosure may include other components useful, for example, in sealant and adhesive compositions. For example, the composition can include at least one of plasticizers (e.g., aliphatic and aromatic hydrocarbons, alkyl esters, alkyl ethers, aryl esters, and aryl ethers), tackifiers, corrosion inhibitors, UV stabilizers, antioxidants, flame retardants, thixotropic agents such as fumed silica, dyes, pigments (e.g., ferric oxide, brick dust, carbon black, and titanium oxide), reinforcing agents (e.g., silica, magnesium sulfate, calcium sulfate, and beryllium aluminum silicate), clays such as bentonite, other suitable filler (e.g., glass beads, talc, and calcium metasilicate), dispersing agents, wetting agents, waxes, adhesion promoters (e.g., silane coupling agents), antistatic agents, thermally and / or electrically conductive particles, foaming agents, and hollow polymeric or ceramic microspheres (e.g., glass bubbles). In some embodiments, the composition of the present disclosure includes a filler. Examples of fillers useful for some embodiments of the two-part composition of the present disclosure include at least one of a micro-fibrillated polyethylene, a fumed silica, a talc, a wollastonite, an aluminosilicate clay (e.g., halloysite), phlogopite mica, calcium carbonate, kaolin clay, metal oxides (e.g., barium oxide, calcium oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide), nanoparticle fillers (e.g., nanosilica, nanozirconia). In some embodiments, the composition of the present disclosure includes fumed silica.

[0038] In some embodiments, the composition of the present disclosure includes filler. In some embodiments, the filler is present in the composition in an amount of 1 wt.% to 10 wt.%, 1 wt.% to 7 wt.%, or 2 wt.% to 4 wt.%, based on the total weight of the composition. In some embodiments, the composition includes a pigment, which may be any of those described above. In some embodiments, the composition includes carbon black. Any suitable amount of pigment (in some embodiments, carbon black) may be useful. Useful levels of pigment or carbon black include up to 2 wt.%, 1.5 wt.%, 1 wt.%, or 0.5 wt.%, at least 0.05 wt.% or 0.1 wt.%, or any combination thereof, based on the total weight of the composition. In some embodiments, the composition includes glass beads. Any suitable amount of glass beads may be useful, including up to 5 wt.%, 3 wt.%, 2 wt.%, or 1 wt.%, at least 0.05 wt.% or 0.1 wt.%, or any combination thereof, based on the total weight of the composition.

[0039] In some embodiments, the composition of the present disclosure further includes a wax. A wax can be useful, for example, for helping the surface curing of an acrylate adhesive composition when in contact with air, and for reducing the evaporation of methyl methacrylate. The wax may be any common wax known in the art. Examples of suitable waxes include paraffin waxes, microcrystalline waxes, polyethylene waxes, polypropylene waxes, Fischer-Tropsch waxes, oxidized Fischer-Tropsch waxes, functionalized waxes, fatty amide waxes, and any combination of these. Examples of commercially available waxes include those obtained under the trade designations “SASAOLWAX Hl” from Sasol Wax, “AC-400” and “AC-575P” from Honeywell, “MC-400” from Marcus Oil Company, “EPOLENE C- 18” from Eastman Chemical, “Wax 58” from Sinopharm, and “BYK-S 782”, from BYK USA Inc. The wax can be present in the composition, for example, in an amount of at least 0.5 wt.%, 1 wt.%, 1.5 wt.%, or 1.9 wt.% and up to 5 wt.%, 4 wt.%, or 3 wt.%, based on the total weight of the composition.

[0040] In some embodiments, the composition of the present disclosure comprises 30 weight percent to 80 weight percent of the alkyl acrylate or alkyl methacrylate, one weight percent to five weight percent of a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate, one weight percent to five weight percent of an acrylic monomer comprising a phosphate or phosphonate group, and from five weight percent to 40 weight percent of the toughening agent, based on the total weight of the composition.

[0041] Compositions of the present disclosure can also include at least one free-radical initiator (i.e., an initiator of free-radical polymerization) or a free-radical polymerization accelerator. The free-radical initiator and accelerator combination can be referred to as a free-radical initiator system.

[0042] In some embodiments, the free-radical initiator is included in a redox initiator system, as one- electron transfer redox reactions may be an effective method of generating free radicals under mild conditions. Redox initiator systems have been described, for example, in Progress in Polymer Science (1999), 24, pp. 1149-1204.

[0043] In some embodiments, the redox initiator system is a blend of a peroxide with an amine, where the polymerization is initiated by the decomposition of the organic peroxide (i.e., the free-radical initiator) activated by the redox reaction with amine reducing agent (i.e, the free-radical polymerization accelerator). Typically, the peroxide is benzoyl peroxide, and the amine is a tertiary amine. Further examples of peroxides (including hydroperoxides) include cumene hydroperoxide, paramenthane hydroperoxide, tert-butyl hydroperoxide, tert-amyl hydroperoxide, diisopropylbenzene dihydroperoxide, methyl ethyl ketone peroxide, benzoyl peroxide, t-butyl peroxyacetate, and tert-butyl peroxybenzoate. Aromatic tertiary amines, for example, are suitable for generating the primary radicals, with N,N- dimethyl-4-toluidine ("DMT") being the most common amine reducing agent.

[0044] Redox initiator systems can include other reducing agents as accelerators. Examples include acid chlorides (e.g, p-toluene sulfonyl chloride, p-methoxy benzene sulfonyl chloride, 4,4’-oxybis(benzene sulfonyl chloride), and diacid chlorides), thioureas (e.g., pyridyl thiourea), amines (e.g., primary amines, secondary amines, tertiary amines, pyridines such as 3, 5-diethyl-l,2-dihydro-l-phenyl-2 -propylpyridine, hydroxyethyl toluidine, imidazoles, and quinolines), aldehyde-amine condensates, and metal salt reducing agents (e.g., cobalt acetylacetonate, copper acetylacetonate, copper phthalocyanine, zinc acetylacetonate, iron acetylacetonate, titanium acetylacetonate, vanadium (III) acetylacetonate, vanadium (III) pentanedionate, vanadium (III) naphthenate, vanadium (IV) naphthenate, vanadyl acetylacetonate (i.e., vanadium (IV) oxide bis (2,4-pentanedionate and VO(acac)2), copper naphthenate, and copper salicylate).

[0045] In some embodiments, the redox cure initiator system comprises a barbituric acid derivative and a metal salt. In some embodiments, the barbituric acid / metal salt cure initiator system may further comprise an organic peroxide, an ammonium chloride salt (e.g., benzyltributylammonium chloride), or a mixture thereof.

[0046] Examples of free-radical initiators based on barbituric acid include redox initiator systems having (i) a barbituric acid derivative and / or a malonyl sulfamide, and (ii) an organic peroxide, selected from the group consisting of the mono- or multifunctional carboxylic acid peroxide esters. Examples of useful barbituric acid derivatives include 1,3, 5 -trimethylbarbituric acid, 1,3,5-triethylbarbituric acid, 1,3- dimethy 1-5 -ethylbarbituric acid, 1,5 -dimethylbarbituric acid, 1-methy 1-5 -ethylbarbituric acid, l-methyl-5- propylbarbituric acid, 5-ethylbarbituric acid, 5 -propylbarbituric acid, 5-butylbarbituric acid, l-benzyl-5- phenylbarbituric acid, 1-cyclohexy 1-5 -ethylbarbituric acid, and the thiobarbituric acids mentioned in published German patent application DE 42 19 700 Al (Imai et al.).

[0047] The barbituric acids and barbituric acid derivatives described in U. S. Patents 3,347,954 (Bredereck et al.) and 9,957,408 (Thompson), as well as the malonyl sulfamides disclosed in the European Pat. No. EP 0 059 451 Bl (Schmitt et al.), may also be useful in embodiments of the present disclosure. Examples of malonyl sulfamides include 2,6-dimethyl-4-isobutylmalonyl sulfamide, 2,6- diisobutyl-4-propylmalonyl sulfamide, 2,6-dibutyl-4-propylmalonyl sulfamide, 2,6-dimethyl-4- ethylmalonyl sulfamide or 2,6-dioctyl-4-isobutylmalonyl sulfamide.

[0048] Barbituric acid-based free-radical initiators typically contain mono- or multifunctional carboxylic acid peroxyesters as organic peroxides. Carbonic peroxyesters are also included among the multifunctional carboxylic acid peroxyesters within the meaning of the present disclosure. Suitable examples include carbonic-diisopropyl-peroxydiester, neodecanoic acid-tertiary-butyl-peroxyester, neodecanoic acid-tertiary-amyl-peroxyester, maleic acid-tertiary -butyl-monoperoxyester, benzoic acid- tertiary-butyl-peroxyester, 2-ethylhexanoic acid-tertiary-butyl-peroxyester, 2 -ethylhexanoic acid-tertiary- amyl-peroxyester, carbonic-monoisopropylester-monotertiary-butyl-peroxyester, carbonic -dicyclohexyl- peroxyester, carbonic dimyristyl-peroxyester, carbonic dicetyl peroxyester, carbonic-di(2-ethylhexyl)- peroxyester, carbonic-tertiary-butyl-peroxy-(2-ethylhexyl)ester or 3,5,5-trimethylhexanoic acid-tertiary- butyl-peroxyester, benzoic acid-tertiary -amyl-peroxyester, acetic acid-tertiary -butyl-peroxyester, carbonic -di(4-tertiary-butyl-cyclohexyl)-peroxyester, neodecanoic acid-cumene-peroxyester, pivalic acid- tertiary -amyl-peroxyester and pivalic acid tertiary -butyl-peroxyester.

[0049] In particular, carbonic-tertiary -butyl-peroxy-(2-ethylhexyl)ester (commercially available from Arkema, Inc. (King of Prussia, Pennsylvania) as LUPEROX TBEC) or 3,5,5-trimethyl-hexanoic acid- tertiary -butyl-peroxyester (commercially available from Arkema, Inc. as LUPEROX 270) can be used as organic peroxides in some embodiments of the present disclosure.

[0050] Metal salts that may be used as accelerators with the barbituric acid derivative can include transition metal complexes, especially salts of cobalt, manganese, copper, and iron. When the metal salt is a copper compound, the salt may possess the general formula CuXn, where X is an organic and / or inorganic anion and n = 1 or 2. Examples of suitable copper salts include copper chloride, copper acetate, copper acetylacetonate, copper naphthenate, copper salicylate or complexes of copper with thiourea or ethylenediaminetetraacetic acid, and mixtures thereof. In some embodiments, the copper salt is copper naphthenate.

[0051] Another redox initiator system suitable for use in embodiments of the present disclosure comprises an inorganic peroxide, an amine-based reducing agent, and an accelerator, where the amine may be an aromatic and / or aliphatic amine, and the polymerization accelerator is at least one selected from the group consisting of sodium benzenesulfinate, sodium p-toluenesulfinate, sodium 2,4,6- trisopropyl benzenesulfinate, sodium sulfite, potassium sulfite, calcium sulfite, ammonium sulfite, sodium bisulfate, and potassium bisulfate. An example of an inorganic peroxide useful in this system is peroxodisulfate as described inU. S. Patent 8,545,225 (Takei, et al.).

[0052] In some embodiments, the composition of the present disclosure includes a component of a free- radical initiator system comprising a metal salt (e.g., copper naphthenate) and an ammonium salt (e.g., benzyltributylammonium chloride) as an accelerator. In some embodiments, composition includes a cure initiator system comprising a barbituric acid derivative and a metal salt and optionally comprising at least one of an organic peroxide and an ammonium chloride salt.

[0053] The composition may include, alone or in combination with other free-radical initiator(s), at least one photoinitiator that is activated by light, generally using an ultraviolet (UV) lamp, although other light sources such as LED lamps, Xe flashlamps, and lasers can also be used with the appropriate choice of photoinitiator.

[0054] Useful photoinitiators include those known as useful for photocuring free -radically polyfunctional (meth)acrylates. Examples of suitable photoinitiators include benzoin and its derivatives such as alphamethylbenzoin; alpha-phenylbenzoin; alpha-allylbenzoin; alpha benzylbenzoin; benzoin ethers such as benzil dimethyl ketal (e.g., available as OMNIRAD BDK from IGM Resins USA Inc., St. Charles, Illinois), benzoin methyl ether, benzoin ethyl ether, benzoin n-butyl ether; acetophenone and its derivatives such as 2 -hydroxy -2 -methyl- 1 -phenyl- 1 -propanone (e.g., available as OMNIRAD 1173 from IGM Resins USA Inc. and 1 -hydroxy cyclohexyl phenyl ketone (e.g., available as OMNIRAD 184 from IGM Resins USA Inc.); 2-methyl-l-[4-(methylthio)phenyl]-2-(4-morpholinyl)-l-propanone (e.g., available as OMNIRAD 907 from IGM Resins USA Inc.); 2-benzyl-2-(dimethylamino)-l-[4-(4- morpholinyl)phenyl]-l-butanone (e.g., available as OMNIRAD 369 from IGM Resins USA Inc.), and triaryl phosphines and phosphine oxide derivatives such as ethyl-2,4,6-trimethylbenzoylphenyl phosphinate (e.g., available as TPO-L from IGM Resins USA Inc.), and bis-(2,4,6- trimethylbenzoyl)phenylphosphine oxide (e.g., available under the trade designation OMNIRAD 819 from IGM Resins USA Inc.).

[0055] Other examples of useful photoinitiators include pivaloin ethyl ether, anisoin ethyl ether, anthraquinones (e.g., anthraquinone, 2-ethylanthraquinone, 1 -chloroanthraquinone, 1,4- dimethylanthraquinone, 1-methoxyanthraquinone, or benzanthraquinone), halomethyltriazines, benzophenone and its derivatives, iodonium salts and sulfonium salts, titanium complexes such as bis(eta5-2,4-cyclopentadien- 1 -yl)-bis[2,6-difluoro-3 -( IH-py rrol- 1 -yl) phenyl]titanium (e.g. , available under the trade designation CGI 784DC from BASF, Florham Park, New Jersey); halomethylnitrobenzenes (e.g., 4-bromomethylnitrobenzene), and combinations of photoinitiators where one component is a mono- or bis-acylphosphine oxide (e.g., available under the trade designations IRGACURE 1700, IRGACURE 1800, and IRGACURE 1850 from BASF, Florham Park, New Jersey, and as OMNIRAD 4265 from IGM Resins USA Inc.).

[0056] The free-radical initiator can also be a thermally activated free-radical initiator such as an azo initiator (e.g., azobisisobutyronitrile) or a peroxide (e.g., benzoyl peroxide).

[0057] The free-radical initiator can be used in the composition in an amount sufficient to permit an adequate free-radical reaction rate of curing of the curable composition upon initiation of polymerization, amounts which may be readily determined by one of ordinary skill in the relevant arts. In some embodiments of the present disclosure, the free-radical initiator and / or accelerator is present in the curable composition at a level of 0.1 to 10 percent by weight, or 0.5 to 5 percent by weight of the free- radically polymerizable components in the composition; however, this is not a requirement.

[0058] The composition of the present disclosure may be provided as a one-part or two-part composition; for example, depending on the free-radical initiator chosen. When a free-radical initiator system including a combination of components is used, some of the components can be included in a first part and some components can be included in the second part of a two-part composition. In some embodiments, if the composition of the present disclosure is the first part of a two-part composition, the first part may include at least one of a metal salt or an ammonium chloride salt as described above in any of their embodiments, and the second part may include at least one of a barbituric acid derivative and an organic peroxide. The second part may be in the form of a paste, for example, that includes a plasticizer or other diluent and optionally at least one of tougheners, dyes, pigments, tackifiers, or fillers as described above. Some peroxide pastes, for example, are commercially available. An example of a useful second part is an acrylic adhesive accelerator obtained under the trade designation “3M SCOTCH-WELD Nylon Bonder Structural Adhesive DP8910NS”, from 3M Company, St. Paul, Minn.

[0059] In some embodiments, if the composition of the present disclosure is the first part of a two-part composition, the first part and the second part can be combined at any suitable volume ratio. For example, the first part and the second part can be combined at a volume ratio in a range of from about 5 : 100 to about 100: 1, about 10: 100 to about 50: 1, or about 1: 1 to 20:1.

[0060] The first part and the second part can be located in any suitable system or kit for containing, mixing, and dispensing the first part and the second part. The system can be suited for large-scale industrial applications or small-scale applications. Either system can include first and second chambers for holding the respective first part and second part. The chambers can be sized for any application and formed from plastic, metal, or any other suitable material. A dispenser can be adapted to receive the first part and the second part and dispense a mixture of the first part and the second part on a substrate. The dispenser can function to facilitate mixing of the first part and the second part, or a mixing chamber can be disposed upstream of the dispenser and in fluid communication with the first chamber and the second chamber. The mixing chamber can be adapted to rotate in order to facilitate mixing, or the mixing chamber can include a number of baffles to induce rotation of the first part and the second part.

[0061] To facilitate movement of the first part and the second part, the system can include elements such as one or more plunger or one or more pumps. The one or more plungers can be useful for systems that are handheld. In these embodiments, a user can push one or two plungers, between at least a first and a second position, to force the first part and the second part through the system. If there is one plunger, then the first part and the second part can be dispensed at equal volumes or at a predetermined volume ratio.

[0062] Pumps can be useful in industrial applications where large volumes or a continuous supply of the first part and the second part are dispensed. These systems can include one or more pumps that are in fluid communication with the first and second chambers. The one or more pumps can be located downstream of the first and second chambers but upstream of the mixing chamber. In embodiments of the system in which there are two pumps in fluid communication with respective first and second chambers, the pumps can be adapted or controlled to pump an equal volume of the first part and the second part or to pump different quantities of each part according to a predetermined volume ratio.

[0063] The composition of the present disclosure may be at least partially cured by exposure to actinic electromagnetic radiation (e.g., ultraviolet and / or visible light), thermal energy (e.g., in an oven, infrared radiation, or thermal conduction), by exposure to oxygen, by combining two parts of a two-part composition, or any combination of the foregoing.

[0064] After at least partial curing, a crosslinked composition is generally obtained, and if it is sufficiently cured, it may be suitable for use as a structural adhesive to bond two adherends. In such use, the composition is typically sandwiched between the adherends and at least partially cured; for example, sufficient to achieve at least a desired level of bond strength. Compositions of the present disclosure may be used, for example, to bond a first substrate to a second substrate to provide a bonded article. Thus, the present disclosure provides a method of making a bonded article. The method includes combining the composition disclosed herein with a free-radical initiator to provide an adhesive composition, applying the adhesive composition on at least one of the first substrate or the second substrate, adhering the first substrate and the second substrate using the adhesive composition, and allowing the adhesive composition to at least partially cure to make the bonded article. Many types of substrates may be bonded with compositions of the present disclosure such as metal (e.g., galvanized steel, stainless steel, or aluminum), glass (e.g., which may be coated with indium tin oxide), a polymer (e.g., a plastic, rubber, thermoplastic elastomer, or thermoset), or a composite. A composite material may be made from any two or more constituent materials with different physical or chemical properties. When the constituents are combined to make a composite, a material having characteristics different from the individual components is typically achieved. Some examples of useful composites include fiber-reinforced polymers (e.g., carbon fiber reinforced epoxies and glass-reinforced plastic), metal matrix compositions, and ceramic matrix composites. Useful polymeric substrates that can be bonded include polymers such as acrylonitrile butadiene styrene (ABS), polycarbonate (PC), PC / ABS blends, polyvinyl chloride (PVC), polyester, polyurethane (PUR), thermoplastic elastomers (TPE), polystyrene, poly(methyl) methacrylate (PMMA), polyvinyl chloride (PVC), and combinations thereof. The substrate may also include a metal coating on such polymers. In some embodiments, at least one of the first substrate or the second substrate comprises a metal, in some embodiments, galvanized steel. The composition of the present disclosure can be useful, for example, for bonding electronic articles and automotive and aerospace components.

[0065] After at least partial curing, a crosslinked composition is generally obtained, and if sufficiently cured, it may be suitable for use as a structural adhesive to bond two adherends. In such use, the composition is typically sandwiched between the adherends and at least partially cured; for example, sufficient to achieve at least a desired level of bond strength.

[0066] While it is not practical to enumerate a particular curing temperature suitable for all situations, generally suitable temperatures are in a range from about 23 °C to about 200 °C. In some embodiments, advantageously, the composition can be cured at room temperature (e.g., 23 °C to 30 °C), for at least 60 minutes, 90 minutes, 120 minutes, 6 hours, 12 hours, 24 hours, 48 hours, or 72 hours for example, to at least partially cure the composition.

[0067] As shown in Table 2 in the Examples below, when a variety of known corrosion inhibitors were added to an acrylic adhesive composition including an alkyl methacrylate, an acrylic monomer comprising a phosphate group, and a toughening agent, the resulting adhesives retained less than 60% of their overlap shear strength on steel panels after exposure to corrosion promoting conditions of 150 °F (65.6 °C) and 80% relative humidity for three weeks, and most of the resulting adhesives retained less than 45% or less than 40% of their overlap shear strength. Surprisingly, monoalkyl methacrylates of phthalic acid and succinic acid were more effective for retaining overlap shear strength under these corrosion promoting conditions than most conventional corrosion inhibitors when used at comparable levels as shown in Tables 3 and 4. Compositions of the present disclosure provided adhesives retaining at least 40% of their overlap shear strength when exposed to the Corrosion Test described in the Examples, below. Accordingly, the present disclosure provides the use of at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid as a corrosion inhibitor in an acrylic adhesive.

[0068] In some embodiments, a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid is surprisingly effective for retaining overlap shear strength under corrosion promoting conditions at a lower concentration, for example, from one weight percent to 9, 8, 7, 6, 5, or 4 weight percent, based on the total weight of the composition, in comparison to methacrylic acid or 2-methacryloyloxyethyl succinate. At such concentrations, compositions of the present disclosure including a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid provide adhesives that have excellent adhesion to metals, corrosion resistance, and heat resistance as determined by the Test Methods in the Examples, below. For example, the resulting adhesives retained more than 60% of their overlap shear strength on steel panels after exposure to corrosion promoting conditions of 150 °F (65.6 °C) and 80% relative humidity for three weeks. Furthermore, the data in Table 4 illustrate that a combination of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid with a second acid such as methacrylic acid or 2- methacryloyloxyethyl succinate provide adhesives that have excellent adhesion to metals, corrosion resistance, and heat resistance. Such properties can be achieved even in the absence of a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof as shown in Table 6.

[0069] In a first embodiment, the present disclosure provides a composition comprising: at least one of an alkyl acrylate or an alkyl methacrylate; at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid; an acrylic monomer comprising at least one of a phosphate or phosphonate group; and at least one toughening agent. In a second embodiment, the present disclosure provides the composition of the first embodiment, wherein the at least one of the monoalkyl acrylate or monoalkyl methacrylate is present in an amount from one weight percent to less than ten weight percent, or from one weight percent to 9, 8, 7, 6, 5, or 4 weight percent, based on the total weight of the composition. In a third embodiment, the present disclosure provides the composition of the first or second embodiment, wherein the at least one of the monoalkyl acrylate or monoalkyl methacrylate is a phthalic acid monoalkyl acrylate or monoalkyl methacrylate.

[0070] In a fourth embodiment, the present disclosure provides the composition of any one of the first to third embodiments, wherein the at least one of an alkyl acrylate or an alkyl methacrylate comprises methyl methacrylate. In a fifth embodiment, the present disclosure provides the composition of any one of the first to fourth embodiments, further comprising an acrylic monomer comprising a hydroxyl group. In a sixth embodiment, the present disclosure provides the composition of the fifth embodiment, wherein the acrylic monomer comprising the hydroxyl group is present in an amount from one weight percent to ten weight percent, based on the total weight of the composition. In a seventh embodiment, the present disclosure provides the composition of any one of the first to sixth embodiments, further comprising a second acrylic monomer comprising a carboxylic acid group, wherein the second acrylic monomer comprising the carboxylic acid group comprises at least one of methacrylic acid, acrylic acid, a monoalkyl acrylate of succinic acid, or a monoalkyl methacrylate of succinic acid. In an eighth embodiment, the present disclosure provides the composition of the seventh embodiment, wherein the second acrylic monomer comprising the carboxylic acid group is present in an amount from one weight percent to five weight percent, based on the total weight of the composition.

[0071] In a ninth embodiment, the present disclosure provides the composition of any one of the first to eighth embodiments, wherein the at least one of an alkyl acrylate or an alkyl methacrylate is present in an amount from 30 weight percent to 80 weight percent, at least one of a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate is present in an amount from one weight percent to five weight percent, the acrylic monomer comprising at least one of the phosphate or phosphorate group is present in an amount from one weight percent to five weight percent, and the at least one toughening agent is present in an amount from five weight percent to 40 weight percent, based on the total weight of the composition.

[0072] In a tenth embodiment, the present disclosure provides the composition of any one of the first to ninth embodiments, further comprising a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof. In an eleventh embodiment, the present disclosure provides the composition of the tenth embodiment, wherein the crosslinker is present in an amount from 0.5 weight percent to five weight percent, based on the total weight of the composition. In a twelfth embodiment, the present disclosure provides the composition of any one of the first to ninth embodiments, wherein the composition is free of a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof or comprises less than 0.5 weight percent of a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof, based on the total weight of the composition. In a thirteenth embodiment, the present disclosure provides the composition of any one of the first to twelfth embodiments, wherein the composition is free of a polymer having at least two acrylate or methacrylate functional groups or contains less than two percent by weight of a polymer having at least two acrylate or methacrylate functional groups, based on the total weight of the composition. In a fourteenth embodiment, the present disclosure provides the composition of any one of the first to thirteenth embodiments, wherein the composition is free of a compound having at least two acrylate or methacrylate functional groups and a -CH2-CH2-CH2-CH2-O- segment, or contains less than two percent by weight of a compound having at least two acrylate or methacrylate functional groups and a -CH2- CH2-CH2-CH2-O- segment, based on the total weight of the composition.

[0073] In a fifteenth embodiment, the present disclosure provides the composition of any one of the first to fourteenth embodiments, wherein the toughening agent comprises at least one of a core-shell rubber toughening agent, a linear polyurethane, acrylonitrile-butadiene rubber, a styrene-butadiene rubber, a styrene-butadiene-styrene rubber, an acrylic block copolymer, a polystyrene / EPDM (an ethylene / propylene / conjugated diene copolymer), a chloroprene rubber, a butadiene rubber, or natural rubber. In a sixteenth embodiment, the present disclosure provides the composition of any one of the first to fifteenth embodiments, wherein the toughening agent comprises at least one of a core-shell rubber toughening agent or an acrylonitrile-butadiene rubber toughening agent. In a seventeenth embodiment, the present disclosure provides the composition of any one of the first to sixteenth embodiments, further comprising filler in an amount up to ten percent by weight, based on the total weight of the composition.

[0074] In an eighteenth embodiment, the present disclosure provides the composition of any one of the first to seventeenth embodiments, further comprising a free-radical polymerization accelerator. In a nineteenth embodiment, the present disclosure provides the composition of any one of the first to eighteenth embodiments, further comprising a free-radical initiator. In a twentieth embodiment, the present disclosure provides the composition of any one of the first to eighteenth embodiments, packaged as a first part of a two-part adhesive composition, wherein the second part comprises a free-radical initiator.

[0075] In a twenty -first embodiment, the present disclosure provides a method of making a bonded article comprising a first substrate and a second substrate, the method comprising: combining the composition of any one of the first to eighteenth embodiments with a free-radical initiator to provide an adhesive composition; applying the adhesive composition on at least one of the first substrate or the second substrate; adhering the first substrate and the second substrate using the adhesive composition; and allowing the adhesive composition to at least partially cure to make the bonded article. In a twenty- second embodiment, the present disclosure provides the method of the twenty -first embodiment, wherein at least one of the first substrate or the second substrate comprises a metal. In a twenty -third embodiment, the present disclosure provides the method of the twenty -first or twenty-second embodiment, wherein at least one of the first substrate or the second substrate comprises galvanized steel.

[0076] In a twenty -fourth embodiment, the present disclosure provides use of at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid as a corrosion inhibitor in an acrylic adhesive. In a twenty -fifth embodiment, the present disclosure provides the use of the twenty -fourth embodiment, wherein the monoalkyl acrylate or monoalkyl methacrylate is a phthalic acid monoalkyl acrylate or monoalkyl methacrylate. In a twenty-sixth embodiment, the present disclosure provides the use of the twenty -fifth embodiment, wherein the phthalic acid monoalkyl acrylate or the phthalic acid monoalkyl methacrylate is present in an amount from one weight percent to less than ten weight percent, or from one weight percent to 9, 8, 7, 6, 5, or 4 weight percent, based on the total weight of the composition. In a twenty-seventh embodiment, the present disclosure provides the use of the twenty -fifth or twenty-sixth embodiment, wherein the phthalic acid monoalkyl acrylate or the phthalic acid monoalkyl methacrylate is combined with methacrylic acid or beta-methacryloyloxy ethyl hydrogen succinate to inhibit corrosion. In a twenty -eighth embodiment, the present disclosure provides the use of any one of the twenty -fourth to twenty-seventh embodiments, wherein the acrylic adhesive comprises the composition of any one of the first to twentieth embodiments. In a twenty -ninth embodiment, the present disclosure provides the composition, method, or use of any one of the first to twenty-eighth embodiments, wherein the phthalic acid monoalkyl acrylate or the phthalic acid monoalkyl methacrylate is betamethacryloxy ethyl hydrogen phthalate.

[0077] Objects and advantages of this disclosure are further illustrated by the following non-limiting examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.

[0078] EXAMPLES

[0079] Unless otherwise noted, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight. The following abbreviations are used in this section: wt.% = weight percent, in = inches, g = grams, kg = kilogram, lb = pound, kN = kilo Newtons, N = Newtons, Ibf = pound force, min = minutes, s = seconds, °C = degrees Celsius, °F = degrees Fahrenheit, RH = relative humidity, Hz = hertz, J = Joules, ° = degree angle, cm = centimeters, mm = millimeters, psi = pounds per square inch, and rpm = revolutions per minute.

[0080] Table 1 : Materials List

[0081] Test Methods

[0082] Overlap Shear (OLS) Test

[0083] All bonds were prepared by dispensing the Example or Illustrative Example composition through a static mixing tip onto galvanized metal and aluminum (Al) substrates to prepare overlap shear test samples. Aluminum coupon samples (part number 900000002 obtained from Joseph t. Ryerson and Son, Inc., Coon Rapids, MN) were 2.54 cm x 10.16 cm x 0.16 cm (1 in x 4 in x 1 / 16 in) and were prepared by manually abrading with a pad with the trade designation “SCOTCH BRITE” (3M Company, St. Paul, MN) followed by wiping with MEK solvent before bonding. Galvanized metal coupons (part number 160005999, obtained from Joseph t. Ryerson and Son, Inc.) were 2.54 cm x 10.16 cm x 0.0812 cm (1 in x

[0084] 4 in x 0.032 in) and were prepared by cleaning with MEK solvent prior to bonding. A 1.27 cm (1 / 2 in) overlap was used when preparing the overlap shear samples. The bond line was clamped with binder clips during cure, and the clips were removed after 24 hours at 25 °C. Testing for overlap shear was run on a Material Testing Systems Insight 30 EL instrument (obtained from MTS Systems Corporation, Eden Prairie, MN) with a 5,620 lb (25 kN) load cell at 2.54 mm (0.1 in) / min. The peak stress values (psi) were reported, and each value was an average of three or five specimens.

[0085] Side Impact Test

[0086] All bonds were prepared by dispensing the Example or Illustrative Example composition through a static mixing tip onto manually abraded and MEK cleaned aluminum coupons prepared as described above for the Overlap Shear Test. The aluminum coupon samples were the same type of aluminum coupons used for the Overlap Shear Test. The Side Impact samples were bonded with a 1.27 cm (0.5 in) overlap. The bond line was clamped with binder clips during cure, and the clips were removed after 24 hours at 25 °C (77 °F). The side to be impacted was polished using a grinder to make a sample in which the adhesive and aluminum substrates were flush. The samples were tested on an CP9050 Impact Pendulum (obtained from Instron, Norwood, MA) with the samples held in a clamp and impacted on the edge of the bonded area. The test parameters were ISO 179-1, using a 21.6 J hammer dropped from a 150.0° angle.

[0087] Paint Bake Test

[0088] All bonds were prepared by dispensing the Example or Illustrative Example composition through a static mixing tip onto R-13 Q-panels (obtained from Q-Lab Corporation, Westlake, Ohio, USA) to prepare overlap shear test samples. The R-13 Q-panels were bonded without any further cleaning or preparation. The Q panels were 2.54 cm x 7.62 cm x 0.081 cm (1 in x 3 in x 0.032 in). A 1.27 cm (1 / 2 in) overlap was used when preparing the overlap shear samples. The bond line was clamped with binder clips during cure, and the clips were removed after 24 hours at 25 °C. For each Paint Bake Test, eight overlap shear samples were prepared; three overlap shear samples were controls (no heat exposure), and five overlap shear samples were placed in an oven (VWR Oven Gr Con 3.7 CF, VWR Cat # 89511-406, Manufactured in Radnor, PA, USA) set at 200 °C (+ / - approx. 1 °C) for 30 minutes. The oven temperature was further monitored with separate thermometer (Fluke 52 II Thermometer, Fluke Corporation, Everett, WA, USA) equipped with a type K thermocouple to insure an accurate oven temperature of 200 °C. After the 30-minute, 200 °C exposure, the samples were removed and let stand at room temperature overnight. Both the control samples and the bake samples were tested using the Overlap Shear Test described above. The average peak stress value (psi) of the control samples was compared to the average peak stress (psi) value of the baked samples (( i.e., bake samples average psi / control samples average psi) * 100%), and a percent psi strength retention was reported.

[0089] Corrosion Test

[0090] All bonds were prepared by dispensing the Example or Illustrative Example composition through a static mixing tip to prepare overlap shear test samples as described above for the Paint Bake Test using the same R-13 Q-Panels. Five overlap shear samples were used as controls (no heat / humidity exposure) and five overlap shear samples were placed in an environmental chamber set at 150 °F and 80% RH for three weeks. After three weeks in the 150 °F / 80% RH chamber, the overlap shear samples were removed and let equilibrate to ambient conditions over a 30 to 60 min time period. Both the control overlap shear samples and the heat / humidity exposed samples were tested using the Overlap Shear Test described above. The average peak stress value (psi) of the control samples was compared to the average peak stress (psi) value of the 150 °F / 80% RH exposed samples (( i.e. 150 °F / 80% RH samples average psi / control samples average psi) * 100%), and a percent psi strength retention was reported.

[0091] Illustrative Examples A to K

[0092] Illustrative Examples A to K were prepared by combining the following components and the components and amounts indicated in Table 2 in a polypropylene MAX 60 or 100 DAC cup (FlackTek, Inc., Landrum, SC, USA). First, N+Cl- (0.1 wt.%), BHT (0.1 wt.%), CuNaph (0.2 wt.%), MMA (amount shown in Table 2), HEMA (5.6 wt.%), XL (3.0 wt.%), and phosphate (1.0 wt.%) were combined, and mixed in a dual asymmetric centrifugal mixer obtained under the trade designation “SPEEDMIXER DAC 400.2 VAC” (FlackTek, Inc.) for 4 minutes at 1500 rpm. NBR (14.6 wt.%) was then added next, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm. This mixing was repeated two or three more times until the NBR dissolved. The CSP 1(10.7 wt.%) and the corrosion inhibitor indicated in Table 2 were then added to the polypropylene cup, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm followed by cooling in a freezer for 5 minutes. This was repeated three more times. Next, the Wax (1.8 wt.%), CB (0.15 wt.%), and GS 2 (0.3 wt.%) were added, and the mixture was mixed in the same mixer at 1500 rpm for 4 min followed by cooling in a freezer for 5 minutes. The final adhesive resin mixture was then degassed by capping the mixing cup with a polypropylene lid that contained a vent hole, and high shear mixed under reduced pressure 0.68 psi (~35 Torr) for 2 minutes. The resulting composition was loaded into the “10” side of a 1:10 dual syringe cartridge dispenser. Part A was separately loaded into the “1” side of a 1: 10 dual syringe cartridge dispenser.

[0093] The materials were static mixed through a mixing tip, and the resulting adhesive was tested according to the test methods described above. The results are shown in Table 2, below.

[0094] Table 2. Illustrative Examples (IE) A to K Compositions and Results aHEMA was included at 5.8 wt.% for IE A.bAmount chosen based on vendor recommendation.

[0095] Illustrative Examples (IE) L to N and Examples 1 to 6

[0096] Illustrative Examples L to N and Examples 1 to 6 were prepared by combining the following components and the components and amounts indicated in Table 3 in a polypropylene MAX 60 or 100 DAC cup (FlackTek, Inc.). First, N+Cl- (0.1 wt.%), BHT (0.1 wt.%), CuNaph (0.1 wt.%), MMA (amount shown in Table 3), XL (1.0 wt.%), and phosphate (1.0 wt.%) were combined along with the carboxylic acids shown in Table 3, and mixed in a dual asymmetric centrifugal mixer obtained under the trade designation “SPEEDMIXER DAC 400.2 VAC” (FlackTek, Inc.) for 4 minutes at 1500 rpm. NBR (14.6 wt.%) was then added next, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm. This mixing was repeated two or three more times until the NBR dissolved. The CSP 1(10.9 wt.%) was then added to the polypropylene cup, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm followed by cooling in a freezer for 5 minutes. This was repeated three more times. Next, the Wax (1.8 wt.%), CB (0.15 wt.%), and GS 2 (0.3 wt.%) were added, and the mixture was mixed in the same mixer at 1500 rpm for 4 min followed by cooling in a freezer for 5 minutes. The final adhesive resin mixture was then degassed by capping the mixing cup with a polypropylene lid that contained a vent hole, and high shear mixed under reduced pressure 0.68 psi (~35 Torr) for 2 minutes. The resulting composition was loaded into the “10” side of a 1:10 dual syringe cartridge dispenser. Part A was separately loaded into the “1” side of a 1:10 dual syringe cartridge dispenser.

[0097] The materials were static mixed through a mixing tip, and the resulting adhesive was tested according to the test methods described above. The results are shown in Table 3, below. Table 3. Illustrative Examples (IE) L to N and Examples (EX) 1 to 6 Compositions and Results

[0098] !lnm = not measured.

[0099] Examples 7 to 20 Examples 7 to 20 were carried out using the method of Illustrative Examples L to N and Examples

[0100] 1 to 6 with the following modifications. First, N+Cl- (0.1 wt.%), BHT (0.1 wt.%), CuNaph (0.1 wt.%), HEMA (5.0 wt.%), MMA (amount shown in Table 4), XL (3.0 wt.%), and phosphate (1.0 wt.%) were combined along with the carboxylic acids shown in Table 4 and mixed in the dual asymmetric centrifugal mixer obtained under the trade designation “SPEEDMIXER DAC 400.2 VAC” (FlackTek, Inc.) for 4 minutes at 1500 rpm. NBR (14.6 wt.%) was then added next, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm. This mixing was repeated two or three more times until the NBR dissolved. The CSP 1(8.0 wt.%) was then added to the polypropylene cup, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm followed by cooling in a freezer for 5 minutes. This was repeated three more times. Next, the Wax (1.8 wt.%), CB (0.15 wt.%), Silica (1.0 wt.%) and GS 2 (0.3 wt.%) were added, and the mixture was mixed in the same mixer at 1500 rpm for 4 min followed by cooling in a freezer for 5 minutes.

[0101] Table 4. Examples (EX) 7 to 20 Composition and Test Results

[0102] !lnm = not measured.

[0103] Examples 21 to 30 Examples 21 to 30 were carried out using the method of Illustrative Examples L to N and Examples

[0104] 1 to 6 with the following modifications. First, N+Cl- (0.1 wt.%), BHT (0.1 wt.%), CuNaph (0.1 wt.%), HEMA (5.0 wt.%), MMA (amount shown in Table 5), XL (amount shown in Table 5), phosphate (2.0 wt.%), MA (1.3 wt.%), and APA (2.5 wt.%) were combined and mixed in a dual asymmetric centrifugal mixer obtained under the trade designation “SPEEDMIXER DAC 400.2 VAC” (FlackTek, Inc.) for 4 minutes at 1500 rpm. NBR (14.6 wt.%) was then added next, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm. This mixing was repeated two or three more times until the NBR dissolved. The particle shown in Table 5 in the amount shown in Table 5 was then added to the polypropylene cup, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm followed by cooling in a freezer for 5 minutes. This was repeated three more times. Next, the Wax (1.8 wt.%) and GS 1 (0.3 wt.%) were added, and the mixture was mixed in the same mixer at 1500 rpm for 4 min followed by cooling in a freezer for 5 minutes. Example 21 included no MA, included Silica (2 wt.%), and used 0.09 wt.% BHT. Table 5. Examples (EX) 21 to 30 Composition and Results aChemically etched aluminum coupons were used.

[0105] Examples 31 to 33 Examples 31 to 33 were carried out using the method of Illustrative Examples L to N and Examples

[0106] 1 to 6 with the following modifications. First, N+Cl- (0.1 wt.%), BHT (0.1 wt.%), CuNaph (0.1 wt.%), HEMA (5.0 wt.%), MMA (amount shown in Table 6), and phosphate (2.0 wt.%) were combined along with the carboxylic acids shown in Table 6, and mixed in a dual asymmetric centrifugal mixer obtained under the trade designation “SPEEDMIXER DAC 400.2 VAC” (FlackTek, Inc.) for 4 minutes at 1500 rpm. NBR (14.6 wt.%) was then added next, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm.

[0107] This mixing was repeated two or three more times until the NBR dissolved. The CSP 1(8.0 wt.%) was then added to the polypropylene cup, and the mixture was mixed in the same mixer for 4 minutes at 2250 rpm followed by cooling in a freezer for 5 minutes. This was repeated three more times. Next, the Wax (1.8 wt.%), CB (0.15 wt.% for Example 29 only), Silica (2.0 wt.%) and GS 2 (0.3 wt.%) were added, and the mixture was mixed in the same mixer at 1500 rpm for 4 min followed by cooling in a freezer for 5 minutes.

[0108] Example 31 used 0.09 wt.% BHT and used GS1 instead of GS 2. Table 6. Examples (EX) 31 to 33 Compositions and Results

[0109] The preceding description, given in order to enable one of ordinary skill in the art to practice the claimed disclosure, is not to be construed as limiting the scope of the disclosure, which is defined by the claims and all equivalents thereto.

Claims

What is claimed is:

1. A composition comprising: at least one of an alkyl acrylate or an alkyl methacrylate; at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid; an acrylic monomer comprising at least one of a phosphate or phosphonate group; and at least one toughening agent.

2. The composition of claim 1, wherein the at least one of the monoalkyl acrylate or monoalkyl methacrylate is a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate, and wherein the phthalic acid monoalkyl acrylate or phthalic acid monoalkyl methacrylate is present in an amount from one weight percent to less than ten weight percent, based on the total weight of the composition.

3. The composition of claim 2, further comprising a second acrylic monomer comprising a carboxylic acid group, wherein the second acrylic monomer comprising the carboxylic acid group comprises at least one of methacrylic acid, acrylic acid, a monoalkyl acrylate of succinic acid, or a monoalkyl methacrylate of succinic acid.

4. The composition of claim 3, wherein the second acrylic monomer comprising the carboxylic acid group is present in an amount from one weight percent to five weight percent, based on the total weight of the composition.

5. The composition of any one of claims 2 to 4, wherein the at least one of an alkyl acrylate or an alkyl methacrylate is present in an amount from 30 weight percent to 80 weight percent, at least one of a phthalic acid monoalkyl acrylate or a phthalic acid monoalkyl methacrylate is present in an amount from one weight percent to five weight percent, the acrylic monomer comprising at least one of the phosphate or phosphonate group is present in an amount from one weight percent to five weight percent, and the at least one toughening agent is present in an amount from five weight percent to 40 weight percent, based on the total weight of the composition.

6. The composition of any one of claims 1 to 5, wherein the at least one of an alkyl acrylate or an alkyl methacrylate comprises methyl methacrylate.

7. The composition of any one of claims 1 to 6, further comprising an acrylic monomer comprising a hydroxyl group.

8. The composition of claim 7, wherein the acrylic monomer comprising the hydroxyl group is present in an amount from one weight percent to ten weight percent, based on the total weight of the composition.

9. The composition of any one of claims 1 to 8, further comprising a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof.

10. The composition of any one of claims 1 to 9, wherein the composition is free of a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof or comprises less than 0.5 weight percent of a crosslinker having two or more acrylate groups, methacrylate groups, or a combination thereof, based on the total weight of the composition.

11. The composition of any one of claims 1 to 10, wherein the toughening agent comprises at least one of a core-shell rubber toughening agent, a linear polyurethane, acrylonitrile-butadiene rubber, a styrene-butadiene rubber, a styrene-butadiene-styrene rubber, an acrylic block copolymer, a polystyrene / EPDM (an ethylene / propylene / conjugated diene copolymer), a chloroprene rubber, a butadiene rubber, or natural rubber.

12. The composition of any one of claims 1 to 11, further comprising a free-radical polymerization accelerator.

13. The composition of any one of claims 1 to 12, packaged as a first part of a two-part adhesive composition, wherein a second part of the two-part adhesive composition comprises a free-radical initiator.

14. A method of making a bonded article comprising a first substrate and a second substrate, the method comprising: combining the composition of any one of claims 1 to 12 with a free-radical initiator to provide an adhesive composition; applying the adhesive composition on at least one of the first substrate or the second substrate; adhering the first substrate and the second substrate using the adhesive composition; and allowing the adhesive composition to at least partially cure to make the bonded article.

15. Use of at least one of a monoalkyl acrylate or a monoalkyl methacrylate of phthalic acid, succinic acid, or maleic acid as a corrosion inhibitor in an acrylic adhesive.

Images