EP4702065A1

EP4702065A1 - Polyurethane adhesives for aluminum bonding as well other substrates

Info

Publication number: EP4702065A1
Application number: EP24726865.9A
Authority: EP
Inventors: Jianxia Chen
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2023-04-27
Filing date: 2024-04-24
Publication date: 2026-03-04
Also published as: CN121443657A; WO2024226606A1; MX2025012745A

Abstract

The invention relates to a two component polyurethane adhesive composition applicable to bonding a substrate susceptible to corrosion, such as but not limited to aluminum, The adhesive includes a prepolymer component and a curative. The prepolymer includes silanes and the curative includes amines as silane activators.

Description

POLYURETHANE ADHESIVES FOR ALUMINUM BONDING AS WELL OTHER SUBSTRATES

TECHNICAL FIELD

The present invention relates to polymerizable adhesive compositions comprising a two-part urethane adhesive composition, and methods of making and using the adhesive obtained from polymerizing of the polymerizable adhesive composition. In particular embodiments, the polymerizable adhesive compositions may comprise a silane and/or silane terminated polymer and may comprise activating catalysts.

TECHNICAL BACKGROUND

Traditional epoxy and acrylate adhesives, while known for their good adhesion properties on metal, have limitations in their applications due to their high modulus and low elongation. This limits their ability to bond dissimilar materials effectively. On the other hand, polyurethane adhesives possess the capability of having a wide range of modulus and high elongation. However, their use in aluminum bonding has been limited due to their poor corrosion resistance and inadequate adhesion after exposure to water soak and/or salt spray. Silane is commonly used to improve adhesion on metal. However, adding silanes to polyurethane adhesives have been explored for years without success.

It has now been found that these aims can be achieved by the compositions described below.

BRIEF DESCRIPTION

The invention relates to adhesive compositions that may be used to bond to metals that exhibit a tendency to corrode. Preferably the adhesive compositions are polyurethane based adhesives.

A first such adhesive composition is a two-component polyurethane adhesive composition comprising: (a) an NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol, preferably a %NCO in the prepolymer comprises up to about 30%, and a silane component comprising up to 15 wt% of the adhesive. The silane component comprises at least an epoxy functional silane, preferably up to about 10 wt% of the adhesive, and an isocyanurato functional silane preferably up to about 5 wt% of the adhesive; and (b) a curative comprising a polyol, at least one of a tertiary amine, a blocked tertiary amine and combinations thereof, and optionally a diamine, preferably up to about 15 wt% and the diamine having a number average molecular weight of up to about 6000 Daltons.

A second adhesive composition disclosed herein is also a two-component adhesive. Preferably a polyurethane adhesive. The composition may include an NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol, preferably a %NCO in the prepolymer comprises up to about 30%. Preferably the prepolymer also includes an epoxy functional silane adhesion promoter having a number average molecular weight of at least about 1000 Daltons. A preferred concentration of the epoxy function silane adhesion promoter comprises up to about 10 wt% of the adhesive. The second adhesive may also include a curative comprising a polyol and at least one of a tertiary amine, a blocked tertiary amine and combinations thereof. A concentration of the tertiary amine or the blocked tertiary amine may comprise up to about 5 wt% of the adhesive. The curative may also include an optional polyether diamine. A preferred concentration of the optional polyether diamine may comprise up to about 15 wt% of the adhesive.

A third adhesive composition of the present disclosure is another two- component polyurethane adhesive. The third adhesive composition includes an NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol. Preferably a %NCO in the prepolymer comprises up to about 30%. The prepolymer may comprise a silyl modified polymer comprising at least one of the following: silyl terminated polyether, silyl terminated isocyanate, silyl terminated acrylate and combinations thereof. Preferably a concentration of the silyl modified polymer comprises up to about 25 wt%, of the adhesive. The prepolymer may also include an optional epoxy functional silane. A concentration of the epoxy functional silane may comprise up to about 10 wt% of the adhesive composition.

The third adhesive composition may further include a curative. The curative may include a polyol and an optional tin catalyst. An exemplary concentration of the tin catalyst may include at least about 0.02 wt% and up to about 10 wt% of the adhesive.

The disclosure further includes laminates made from 1 ^st and 2^nd substrates and one of the above adhesives. Preferably the adhesive is sandwiched between the 1^st and 2^nd substrates. Preferably at least one of the substrates is a metal susceptible to corrosion, such as but not limited to aluminum, aluminum alloys, coated aluminum or coated aluminum alloys. More preferably both of the 1^st substrate and the 2^nd substrates may comprise a metal susceptible to corrosion, such as but not limited to aluminum, aluminum alloys, coated aluminum or coated aluminum alloys.

The invention further includes methods of making the aforementioned laminates. The method may include applying one of the above adhesives to one of the 1^st and 2^nd substrates. Further the 1^st and 2^nd substrates are pressed together wherein the adhesive is disposed between the 1^st and 2^nd substrates.

The present invention makes it possible to address the needs mentioned above. In particular, the compositions according to the invention surprisingly: have exhibited improved adhesion to metal, such as but not limited to aluminum, aluminum, stainless steel, carbon steel, alloys of the aforementioned metals and coated versions of the aforementioned metals and their alloys.

The adhesives have also exhibited excellent water and corrosion resistance.

Preferably the aforementioned adhesives exhibit a young’s modulus of at least 1 MPa, preferably at least about 5 MPa. Exemplary young’s modulus may comprise at least about 7 MPa or at least about 10 MPa.

Embodiments of the adhesives disclosed herein have successfully addressed the limitations of prior polyurethane adhesives used for bonding a metal susceptible for corrosion. Laminates formed with the above adhesives have exhibited excellent lap shear strength and failure mode, even after 7-month’s exposure to salt spray.

The above adhesives have performed well in the automotive industry 8 weeks of salt spray testing, passing the standard. The above compositions can open new opportunities for the use of polyurethane adhesives in industries where corrosion resistance and durability in harsh environments are critical requirements.

DESCRIPTION OF THE INVENTION

Before explaining at least one embodiment of the present disclosure in detail, it is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of the components or steps, or methodologies set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

Unless otherwise defined herein, technical terms used in connection with the present disclosure shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

All patents, published patent applications, and non-patent publications mentioned in the specification are indicative of the level of skill of those skilled in the art to which the present disclosure pertains. All patents, published patent applications, and non-patent publications referenced in any portion of this application are herein expressly incorporated by reference in their entirety to the same extent as if each individual patent or publication were specifically and individually indicated to be incorporated by reference.

All the articles and/or methods disclosed herein can be made and executed without undue experimentation in light of the present disclosure. While the articles and methods of the present disclosure have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations can be applied to the articles and/or methods and in the steps or in the sequence of steps of the method(s) described herein without departing from the concept, spirit and scope of the present disclosure. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the present disclosure.

As utilized in accordance with the present disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings.

The use of the word “a” or “an” when used in conjunction with the term “comprising” can mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The use of the term “or” is used to mean “and/or” unless explicitly indicated to refer to alternatives only if the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the quantifying device, the method(s) being employed to determine the value, or the variation that exists among the study subjects.

References herein to "one embodiment," or "one aspect" or "one version" or “one objective” or "another embodiment," or “another aspect" or "another version" or “another objective” of the invention can include one or more of such embodiment, aspect, version or objectives, unless the context clearly dictates otherwise.

The term “at least one” refers to one as well as any quantity more than one, including but not limited to, 1 , 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100, etc. The term “at least one” can extend up to 100 or 1000 or more depending on the term to which it is attached.

All percentages, parts, proportions, and ratios as used herein are by weight of the total composition, unless otherwise specified. All such weights as they pertain to listed ingredients are based on the active level and therefore do not include solvents or by-products that can be included in commercially available materials, unless otherwise specified.

All references to singular characteristics or limitations of the present invention shall include the corresponding plural characteristics or limitations, and vice-versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made.

Numerical ranges as used herein are intended to include every number and subset of numbers contained within that range, whether specifically disclosed or not. Further, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range.

As used herein, the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. The terms “or combinations thereof’ and “and/or combinations thereof’ as used herein refer to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof’ is intended to include at least one of: A, B, C, AB, AC, BC, or ABC and, if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more items or terms, such as BB, AAA, AAB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context.

For purposes of the following detailed description, other than in any operating examples, or where otherwise indicated, numbers that express, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term “about”. The numerical parameters set forth in the specification and attached claims are approximations that can vary depending upon the desired properties to be obtained in carrying out the invention.

The term “or combinations thereof’, “and combinations thereof’, and “combinations thereof’ as used herein refers to all permutations and combinations of the listed items preceding the term.

The term "about" refers to a range of values + 10% of a specified value. For example, the phrase "about 200" includes ± 10% of 200, or from 180 to 220.

The term "polymerization" or “polymerizing” refers to methods for chemically reacting monomer compounds to form polymer chains. The polymer chain can be alternating, blocked, or random. The type of polymerization method can be selected from a wide variety of methods and include the following non-limiting examples: poly condensation, step growth polymerization, and free radical polymerization.

The term “polymer” refers to any large molecule, which includes macromolecules. The term “polymer” refers to a large molecule comprising one or more types of monomer residues (repeating units) connected by covalent chemical bonds. Non-limiting examples of polymers include homopolymers, and non- homopolymers such as copolymers, terpolymers, tetrapolymers and the higher analogues.

The term “monomer” refers to a small molecule that chemically bonds during polymerization to one or more monomers of the same or different kind to form a polymer.

The term “copolymer” herein refers to a polymer prepared from more than one monomer. The invention relates to adhesives that may used to bond metals that are susceptible to corrosion. Particular embodiments may be two-component adhesives, preferably polyurethane adhesives.

In certain embodiments, the polyurethane adhesive compositions may include combinations of silanes and catalysts. The certain embodiments have exhibited surprising bonding performance on aluminum.

The various embodiments disclosed herein relate to adhesive compositions, more particularly to polyurethane adhesive compositions. Further in particular to 2 component adhesive compositions. In typical embodiments, the 2-component adhesive composition will include a prepolymer, preferably an NCO prepolymer and a curative.

In a first embodiment, the 2-component polyurethane adhesive composition includes an NCO prepolymer (hereafter “the prepolymer”) comprising a reaction product of an isocyanate compound and a polyol. A %NCO in the prepolymer may comprises up to about 30 wt%. Exemplary embodiments of the %NCO in the prepolymer may include 1 to 20%, less than about 20%, at least about 10% and from 1 to 10%.

The NCO prepolymer may include a silane component. A concentration of the silane component may be up to about 15 wt%. The silane component may comprise at least an epoxy functional silane, preferably in amount up to about 10 wt%, and an isocyanurato functional silane preferably in an amount up to about 5 wt%.

Examples of suitable epoxy functional silanes include 2-glycidoxyethyl- dimethylmethoxysilane; 6- glycidoxyhexyl-tributoxysilane; 3-glycidoxy-propyl- trimethoxysilane; 3- glycidoxypropyl-triethoxysilane; 3-glycidoxypropyl- methyldiethoxysilane; 5- glycidoxypentyl-trimethoxysilane; 5-glycidoxypentyl- triethoxysilane, 3- glycidoxypropyl-triisopropoxysilane and combinations thereof, preferably the epoxy functional silane may comprise 3-glycidoxy- propyltrimethoxysilane.

Examples of suitable amounts of the epoxy silane compound may include up to about 10 wt%, up to about 8 wt%, up to about 5 wt%, up to about 4 wt%, at least about 0.1 wt%, at least about 0.4 wt% and at least about 0.6 wt%.

A non-limiting example of the isocyanurato silane includes but is not limited to 1 ,3,5-tris[3-(trimethoxysilyl)propyl]-1 ,3,5-triazine-2,4,6(1 H,3H,5H)-trione). Other examples include (isocyanatomethyl)methyldimethoxysilane, 3- Isocyanatopropyltrimethoxysilane, 3-lsocyanatopropyltriethoxysilane, 3- lsocyanatopropylmethyldimethoxysilane,3- lsocyanatopropylmethyldiethoxysilane,Tris[3-(trimethoxysilyl)propyl] isocyanurate, Tris[3-(triethoxysilyl)propyl] isocyanurate, Isocyanatomethyltrimethoxysilane, Isocyanatomethyltriethoxysilane. The aforementioned isocyanurato compounds may be used in any combination thereof.

Examples of suitable amounts of the isocyanurato functional silane compound may include up to about 5 wt%, up to 4 wt%, no more than 1 .5 wt%, at least about 0.4 wt% and at least about 0.6 wt%.

The first embodiment may also include a curative. The curative may include a polyol and at least one of a tertiary amine, a blocked tertiary amine and combinations thereof. Optionally the curative may include a diamine, preferably in an amount of up to about 15 wt%. A preferred diamine is a polyether diamine. The diamine may have a number average molecular weight of up to about 6000 Daltons. Optionally, the number average molecular weight may be up to about 4000 Daltons, at least about 200 Daltons and at least about 300 Daltons.

Regarding the NCO prepolymer, examples of compounds which may be used as the isocyanate compound include but are not limited to isocyanate compounds which contain two or more isocyanate groups. They can be used in the present disclosure as the stoichiometric isocyanates, the excess isocyanates and the free isocyanates. The isocyanates can be monomeric or polymeric isocyanate including aromatic, aliphatic and cycloaliphatic polyisocyanates.

The polyisocyanates can be diisocyanates that include aliphatic, cycloaliphatic, aromatic and aliphatic-aromatic diisocyanates. Specific examples of the aliphatic and cycloaliphatic diisocyanates can include, but are not limited to, ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, trimethylene diisocyanate, cyclopentylene-1 ,3-diisocyanate, cyclo-hexylene-1 ,4-diisocyanate, cyclohexylene-1 ,2-diisocyanate, dichlorohexa-methylene diisocyanate, furfurylidene diisocyanate, 1 ,4-tetramethylene diisocyanate, 1 ,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1 ,6-hexamethylene diisocyanate, 1 ,12-dodecamethylene diisocyanate, 1-isocyanato-2-isocyanatomethyl cyclopentane, 1 -isocyanato-3- isocyanato-methyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate or lPDI), bis- (4-isocyanatocyclohexyl)-methane, 2,4'-dicyclohexylmethane diisocyanate, 1 ,3- or 1 ,4-bis-(isocyanatomethyl)-cyclohexane, bis-(4-isocyanato-3-methylcyclohexyl)- methane, a',a',a',a'-tetramethyl-1 ,3- and/or -1 ,4-xylylene diisocyanate, 1 -isocyanato- 1-methyl-4(3)-isocyanatomethyl cyclohexane, 2,4- or 2,6-hexahydrotoluylene diisocyanate, and the like.

Specific examples of the aromatic and aliphatic-aromatic diisocyanates can include, but are not limited to, 2,4- or 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2-diphenylpropane-4,4'-diisocyanate, xylylene diisocyanate, 1 ,4- naphthylene diisocyanate, 1 ,5-naphthylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, diphenyl-4,4'-diisocyanate, azobenzene-4,4'-diisocyanate, diphenylsulphone-4,4'-diisocyanate, 2,4-tolylene diisocyanate, 1-chlorobenzene-2,4- diisocyanate, 4,4',4''-triisocyanatotriphenylmethane, 1 ,3,5-triisocyanato-benzene, 2,4,6-triisocyanato-toluene, 4,4'-dimethyldiphenyl-methane-2,2',5,5- tetratetraisocyanate, and modified aromatic diisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret.

The modified aromatic diisocyanate can be uretonimine modified isocyanate, which can be derived from 2,4- or 2,6-tolylene diisocyanate; or derived from 4,4'- or 2,4'-diphenylmethane diisocyanate such as uretonimine modified 4,4'- diphenylmethane diisocyanate. Suitable uretonimine modified isocyanates can include Rubinate® 1680, commercially available from Huntsman Corporation; and ISONATE™ 143L Modified MDI, commercially available from The Dow Chemicals Company.

In one non-limiting embodiment, the isocyanates can be hexamethylene diisocyanate, toluene diisocyanate (TDI), isophoronediisocyanate (IPDI), methyenebisphenyldiisocyanate (MDI), hydrogenated MDI (HMDI) or poly-MDI (with functionality greater than 2).

The polyol of the NCO prepolymer can be any polyols that are suitable for making polyurethanes. They can be polyols based on polyalkylene oxides, polyester or combinations thereof, which can include bulky side chains and/or long hydrophobic chains. The polyols based on polyalkylene oxides are often referred to as polyether polyols. The polyols can also include polyamide polyols, polycaprolactone polyols such as poly-s-caprolactone polyol, polycarbonate polyols, hydroxyl terminated polybutadienes such as fully hydrogenated hydroxy-terminated polybutadiene and/or partially hydrogenated hydroxy-terminated polybutadiene, polyisobutylene diols, as well as mixtures thereof.

Polyether polyols can include a linear and/or branched polyether having hydroxyl groups. Examples of the polyether polyols may include substituted and/or unsubstituted polyoxyalkylene polyols such as polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene ether glycol (PTMEG) and the like. Further, a homopolymer and a copolymer of the polyoxyalkylene polyols may also be employed. Particularly, the copolymers of the polyoxyalkylene polyols may include an adduct having at least one compound selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2- ethylhexanediol-1 ,3-glycerin, 1 ,2,6-hexane triol, trimethylol propane, trimethylol ethane, tris(hydroxyphenyl)propane, triethanolamine, triisopropanolamine, ethylenediamine and ethanolamine; with at least one compound selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide.

The polyether polyols can include polymers of propylene oxides and/or copolymers of ethylene and propylene oxides, wherein the oxides contain. In one nonlimiting embodiment, the polyether polyol is ethylene oxide capped polypropylene oxide.

The number average molecular weight of the polyether polyol is typically at least about 350 Daltons, preferable at least about 400 Daltons. If desired the polyether polyol may have a number average molecular weight which can be varied from about 2,000 Daltons to about 20,000 Daltons or in a range of about 3,500 Daltons to about 15,000 Daltons, or in the range of from about 2,000 Daltons to about 14,000 Daltons. For example, Acclaim® 4220N polyol (commercially available from Covestro) is based on propylene oxide and terminated by ethylene oxide, having number average molecular weight of 4000 Daltons.

The polyether polyols used in the present disclosure may include one or more 2-functionality polyether polyols, one or more 3-functionality polyether polyols, one or more 4-functionality polyether polyols, or their combinations thereof. The number average molecular weight of the 2-functionality polyether polyols can be varied from about 2,000 to about 20,000 Daltons, or in a range of about 2,000-12,000 Daltons. For example, Pluracol® P2010 is a polyether polyol having a number average molecular weight of 2000 Daltons, which is commercially available from BASF. PPG 2000 available from PPG is another example of a suitable polyol.

Further, the number average molecular weight of the 3-functionality polyether polyols can be varied from about 80 to about 20,000 Daltons or in a range of about 100-12,000 Daltons, including Pluracol® TP-440 polyol commercially available from BASF. The molecular weight of the 4-functionality polyether polyols can be varied from about 100 to about 20,000 Daltons or in a range of about 400-12,000 Daltons. For example, Pluracol® 355 is a polyether polyol having a number average molecular weight of 600 Daltons, which is commercially available from BASF. In some embodiments the polyether polyol will have a molecular weight of at least 4,000 Daltons. In an alternative example, the polyether polyol will have a molecular weight of no more than about 4,000 Daltons, preferably less than about 3,000 Daltons.

The polyols based on polyesters (also called polyester polyols) can include amorphous and liquid polyester polyols, fatty acid polyester polyols such as castor oil and vegetable oils having different molecular weights and functionalities.

The polyester polyols can be formed as reaction products of one or more carboxylic acids with one or more polyols such as diols and/or triols. Among the carboxylic acids useful in forming the polyester polyols can include, but are not limited to, adipic, glutaric, succinic, malonic, oxalic and mixtures thereof. Among the diols useful in forming the polyester polyols can include, but are not limited to, ethylene glycol, propanediol, butanediol, neopentyldiol, pentanediol and hexanediol and mixtures thereof. Among the triols which are considered useful in forming the polyester polyol can include trimethylol propane.

Examples of the fatty acid polyester polyols may include castor oil, the products of hydroxylation of unsaturated or polyunsaturated natural oils, the products of hydrogenations of unsaturated or polyunsaturated polyhydroxyl natural oils, polyhydroxyl esters of alkyl hydroxyl fatty acids, polymerized natural oils, soybean polyol, alkylhydroxylated amides of fatty acids, and cashew nutshell liquid.

In one non-limiting embodiment, the polyester polyol can be obtained from a reaction of a triol with azelaic acid. The triol can be glycerol. One example of such polyester polyol is Emerox® 14001 , which is derived from natural oils and commercially available from Emery Oleochemicals Company. The number average molecular weight of the polyester polyol is typically varied from about 1 ,000 to about 20,000 Daltons, or in a range of about 1 ,300-10,000 Daltons. Admex™ 525 polyol (commercially available from Eastman Chemical Company) is a 1 ,400-molecular-weight polyester polyol and may be used.

The prepolymer optionally may include one or more fillers. Examples of the fillers may include fumed silica, molecular sieves, pigments, talc, oxides, nano-clays, rubber particles, conductive particles and any combination thereof. The amount of optional fillers may range from about 1 to 45 wt% of the adhesive composition.

The above description regarding the polyol is equally applicable to the polyol of the curative. In one embodiment, the free polyol of the curative comprises a polyol having a number average molecular weight of at least about 300 Daltons, more preferably at least about 2,000 Daltons, further preferred at least about 4,000 Daltons, even more preferred at least about 15,000 Daltons.

Examples of the tertiary amine or blocked tertiary amine may include amidine compounds such as diazabicyclo compounds. Non-limiting examples of diazabicyclo compounds include but are not limited to 1 ,4-diazabicyclo[2.2.2]octane), also known as triethylenediamine, 1 ,8-Diazabicyclo[5.4.0]undec-7-ene, 1 ,5-diaza-bicyclo (5.4.0) undec-5-ene and combinations thereof.

Examples of suitable amounts tertiary amine may include up to about 3 wt%, up to about 2 wt%, up to about 1 wt%, up to about 0.5 wt%, at least about 0.02 wt% and at least about 0.03 wt%.

Examples of suitable amounts of the diamine may comprise up to about 10 wt%, up to about 7 wt% and at least about 0.5 wt%.

Optionally, the curative may include one or more alcohols, preferably a diol and/or a triol. Preferably, the diol or triol has an average number average molecular weight of no more than about 1000 Daltons, more preferably less than about 500 Daltons, even more preferably less than about 250 Daltons. Examples of suitable diols and triols include polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene ether glycol (PTMEG) and combinations thereof. Particular commercially available diols may include: PTMEG -650 (MW 650) from Korea PTG Co., Ltd. or Pluracol TP-440 from BASF.

The curative optionally may include one or more fillers. Examples of the fillers may include fumed silica, molecular sieves, pigments, talc, oxides, nano-clays, rubber particles, conductive particles and any combination thereof. The amount of optional fillers in the curative may range from about 1 to 45 wt% of the adhesive composition.

The curative may also include one or more catalyst. Examples of suitable catalyst may include organometallic and amine catalysts either separate or in combination.

Organometallic catalysts including organotin, bismuth, zirconium, zinc, and combinations thereof. In addition to organotin catalyst, the general class of tin catalyst may also be appropriate. The amount of catalyst may range from about 0.05 to about 10 wt%.

Other optional components of the curative may include diols, (such as but not limited to propylene-1 ,3-diol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1 ,10- decanediol and combinations thereof) and/or diethylene amines (such as diethylene diamines e.g., piperazine and diethylene triamines).

The composition may further include a mono ether, preferably a polypropylene glycol) mono ether, more preferably a polypropylene glycol) mono butyl ether. It is further preferred the mono ether comprises a component of the curative. The mono ether may comprise up to about 10 wt% of the adhesive composition.

A second embodiment of the adhesive composition is the same as the first embodiment except for the silane component. In the second embodiment, the silane component is an epoxy functional silane adhesion promoter having a number average molecular weight molecular weight of at least about 1000 Daltons. Non-limiting examples of the number average molecular weight may comprise at least about 1200 Daltons and at least about 1400 Daltons. A preferred concentration of the epoxy function silane adhesion promoter comprises up to about 10 wt% of the adhesive. The second embodiment of the adhesive may be devoid of the isocyanurato functional silane compound, preferably it may also be devoid of an additional epoxy functional silane component.

Exemplary amounts of the epoxy functional silane adhesion promoter having a number average molecular weight molecular weight of at least about 1000 Daltons is up to about 10 wt%, up to about 8 wt%, up to about 4 wt%, at least about 0.5 wt% and at least about 1 wt%. As stated, the second embodiment of the adhesive includes the above constituents of the prepolymer and the curative of the first embodiment and they are incorporated herein by reference in their entirety.

In a particular embodiment of either the first adhesive or the second adhesive, the curative may include a second polyol. The second polyol may comprise a polyoxyalkylene polyol having a hydroxyl number of at least about 15 mg KOH/g, preferably at least about 17 mg KOH/g, more preferably no more than about 30 mg KOH/g, and even more preferably no more than about 25 mg KOH/g. A number average molecular weight of the second polyol of the curative may comprise at least about 15,000 Daltons, more preferably at least about 25,000 Daltons, further preferred at least about 50,000 Daltons, even more preferred at least about 70,000 Daltons.

The composition may further include a mono ether, preferably a polypropylene glycol) mono ether, more preferably a polypropylene glycol) mono butyl ether. It is further preferred the mono ether comprises a component of the curative.

A third adhesive composition of the present disclosure is another two- component polyurethane adhesive. The third adhesive composition differs from the first and second adhesive compositions in terms of the silane component of the prepolymer. The prepolymer of the third adhesive composition may comprise a silyl modified polymer comprising at least one of the following: silyl terminated polyether, silyl terminated isocyanate, silyl terminated acrylate and combinations thereof.

Examples of the silyl modified polymer may include at least one of: dimethoxysily terminated polyether, tri methoxy si ly terminated polyether and combinations thereof. Another embodiment of the silyl modified polymer is:

An-D-SiXYZ wherein:

(a) A is a divalent linking group comprising at least one hetero atom, preferably at least one of S,N,0,P, and Si, more preferably O;

(b) D is a divalent hydrocarbon residue with 1-12 C-atoms, preferably 2-8 carbons, more preferably 3-6 carbon atoms;

(c) X, Y, Z are each independently substituents on the Si atom, independently selected from Ci-Cs alkyl, Ci-Cs alkoxy, Ci- Cs acyloxy, preferably C2-C5 alkyl, C2-C5 alkoxy, and C2-C5 acyloxy, at least one of the substituents X, Y, Z is a C1-C8 alkoxy or Ci-Cs acyloxy; and

(d) n is 0 or 1.

Other exemplary silyl modified polymers may include S203H, S303H,S227, S327, SAX 220, SAX 260, SAX350, SAX400, SAT010, SAX015, SAX115, SAT145, AX602, MAX923, MAX951 , SAX750, SAX510, SAX520, SAX 530, SAX540, SAX580, SAX590, MAX 451 , MAX 480, MAX850 Desmoseal®, for example S XP 2458, S XP 2636, S XP 2749, S XP 2774, S XP 2821 ; Gen- iosil® for example STP-E10, STP- E15, STP-E30 , STP-E35, Evonik Polymer for example ST47, ST 48, ST 77, ST 61 , ST 61 LV, ST 81 , ST 80 and TEGOPAC®, for example Seal 100, Bond 150, and Bond 250.

Preferably a concentration of the silyl modified polymer comprises up to about 25 wt%, of the adhesive. Examples of suitable amounts of the silyl modified polymer comprise up to about 20 wt%, up to about 15 wt%, at least about 1 wt%, at least about 2 wt%, and at least about 5 wt%.

The prepolymer may also include an optional epoxy functional silane. A concentration of the epoxy functional silane may comprise up to about 10 wt% of the adhesive composition. Exemplary amounts of the epoxy functional silane may be up to about 8 wt%, up to about 5 wt%, up to about 4 wt%, at least about 0.1 wt%, at least about 0.4 wt% and at least about 0.6 wt%.

In preferred embodiments, a number average molecular weight of the epoxy functional silane may comprise more than about 200 Daltons up to about 2000 Daltons.

The third adhesive composition may be devoid of an isocyanurato functional silane.

It is also preferred in the curative of the third adhesive embodiment that the curative includes the above tin catalyst. The amount of the tin catalyst may comprise up to 10 wt% of the adhesive. Suitable amounts of the tin catalyst may comprise up to about 8 wt%, up to about 5 wt%, up to about 2 wt% and at least about 0.5 wt%.

As stated, the third embodiment of the adhesive includes the above constituents of the prepolymer and the curative of the first embodiment and they are incorporated herein by reference in their entirety. Applicable to any of the above embodiments, a volume ratio of the prepolymer to curative may comprise from about 1 :10 to about 10:1 . Examples of preferable ratios include about 1 :1 , about 1.5:1 , about 1.75:1 , about 2: 1 , about 2.5:1 and about 3:1. The volume ratios are applicable to all the embodiments first, second and third and their various alternate, particular or specific embodiments and otherwise.

Any and all of the above embodiments of any adhesive may be used to form a laminate. Preferably the laminate will comprise a 1^st substrate and a 2^nd substrate. The adhesive is sandwiched between the 1^st and 2^nd substrates.

In one embodiment, at least one of the 1^st and 2^nd substrates comprises a metal susceptible to corrosion. In a further embodiment, both the 1^st and 2^nd substrates are metals susceptible to corrosion. In the further embodiment, the metals may be the same or different metals. Examples of suitable metals include aluminum, steel, iron, coated embodiments of the aforementioned metals as well as alloys of the metals. The substrates of may be formed of any combination of the aforementioned metals, their alloys and coated versions thereof.

In another embodiment, a coefficient of thermal expansion of the 1^st substrate differs from a coefficient of thermal expansion of the 2^nd substrate by no more than about 10%, preferably no more than about 5%, more preferably no more than about 2%, measured at a temperature in a range of about -30°C up to about 82°C.

In an alternative embodiment, a coefficient of thermal expansion of the 1^st substrate differs from a coefficient of thermal expansion of the 2^nd substrate by more than about 5%, preferably more than about 10%, more preferably more than about 15%, measured at a temperature in a range of about -30°C up to about 82°C.

In a further embodiment applicable to all embodiments of a laminate, the laminate may be devoid of a sufficient amount of primer to assist in the adhesive adhering to either of the 1^st and 2^nd substrates.

Alternatively, the laminate may include a primer on the 1^st, the 2^nd or both of the substrates.

In an additional embodiment, the laminate comprises 1 ^st and 2^nd substrates and an adhesive sandwiched between the 1^st and 2^nd substrates. A coefficient of thermal expansion of the 1^st substrate differs from a coefficient of thermal expansion of the second substrate by no more than about 10%, preferably no more than about 5%, more preferably no more than about 2%, measured at a temperature in a range of about -30°C up to about 82°C. The adhesive comprises a two-component adhesive composition including an NCO prepolymer comprising the reaction product of an isocyanate compound and a polyol. Preferably a %NCO in the prepolymer comprises up to at least about 30%, more preferably from about 1 to 20% or from about 1 to 10%. The adhesive further includes a polyol second component, preferably having a number average molecular weight of at least about 2000 Daltons, more preferably at least about 4000 Daltons, even more preferably at least about 8000 Daltons and most preferably no more than 15000 Daltons. The adhesive composition may also include an isocyanurato silane adhesion promoter, at a concentration of about 0.1 to 10 wt% of the adhesive. The adhesive may include a fourth component comprising an epoxy functional silane adhesion promoter, wherein a concentration of the fourth component comprises no more than about 20 wt%, preferably at least 0.5 wt% of the adhesive. A fifth component may comprise at least one of a tertiary amine, blocked tertiary amine and combinations thereof. An optional sixth component may be a polyether diamine.

In an alternate embodiment, the laminate comprises 1^st and 2^nd substrates and an adhesive sandwiched between the 1^st and 2^nd substrates. A coefficient of thermal expansion of the 1 ^st substrate differs from a coefficient of thermal expansion of the 2^nd substrate by more than about 15%, preferably more than about 10%, more preferably more than about 15%, measured at a temperature in a range of about -30°C up to about 82°C. The adhesive comprises a two-component adhesive composition including an NCO prepolymer comprising the reaction product of an isocyanate compound and a polyol. Preferably a %NCO in the prepolymer comprises up to at least about 30%, more preferably from about 1 to 20% or from about 1 to 10%. The adhesive further includes a second polyol component, preferably having a number average molecular weight of at least about 2000 Daltons, more preferably at least about 4000 Daltons, even more preferably at least about 8000 Daltons and most preferably no more than 15000 Daltons. The adhesive composition may also include an isocyanurato silane adhesion promoter, at a concentration of about 0.1 to 10 wt% of the adhesive. The adhesive may include a fourth component comprising an epoxy functional silane adhesion promoter, wherein a concentration of the fourth component comprises no more than about 20 wt%, preferably at least 0.5 wt% of the adhesive. A fifth component may comprise at least one of a tertiary amine, blocked tertiary amine and combinations thereof. An optional sixth component may be a polyether diamine. Number average molecular weight may be determined by, but not only by, Gel Permeation Chromatography (GPC), Vapor Phase Osmometry, Membrane Osmometry and Lowering of Vapor Pressure.

%NCO: One technique to determine the %NCO is ASTM D5155. Determining the %NCO is not necessarily limited to the aforementioned technique.

The NCO Index is the equivalence ratios of the isocyanates to polyols containing a hydroxyl group.

Viscosity: A TA Instruments Discovery HR-1 rheometer with a cone- plate may be used to measure viscosity. For measuring the viscosity in examples 1 and 2 the cone plate had a diameter of 40 mm. Unless otherwise stated, the temperature was 23°C and the shear rate was 0.79 1/s.

Tensile Strength of the Adhesive: The tensile strength may be determined in accordance with ASTM D-638. The embodiments disclosed herein are no limited to determining tensile strength by the aforementioned ASTM standard.

CTE: One test method that may be used to determine coefficient of thermal expansion (“CTE”) is ASTM Test Method E831. The embodiments disclosed herein are no limited to determining CTE by the aforementioned ASTM standard.

Hydroxyl number: The OH number may be determined by ASTM D4274 Standard Test Methods for Testing Polyurethane Raw Materials: Determination of Hydroxyl Numbers of Polyols. How to determine the OH number is not limited to the aforementioned ASTM standard. Types of titration methods may also be suitable.

Young’s modulus: While any suitable method or equipment may be used to determine the young’s modulus discussed herein one example equipment that may be used to measure the modulus is a LMEC-1 Young’s Modulus Apparatus.

Wt% stated above are based on the total adhesive composition unless otherwise noted.

All the embodiments described above can be combined with each other. In particular, the various aforementioned ingredients in the composition, and in particular the preferred embodiments, can be combined with each other.

The following examples illustrate the invention without limiting it. EXAMPLES

Table 1 and Table 2 show the formulations for Samples 1-9 (Controls 1-3 and Examples 4-9). General procedures for making the prepolymers and curatives are shown in Table 3 and Table 4.

In Samples 1-9 (Control 1-3 and Examples 4-9) as shown in Table 5, the prepolymers and curatives prepared in Table 1 and Table 2 were loaded separately into side-by-side cartridges and pump through a static mix tube to achieve complete mixing as shown in Table 5. Then the mixed polymerizable adhesive compositions were applied directly from the static mix tube onto one side of the testing substrate. A lap shear test was conducted to measure the lap shear strength and failure mode of adhesive bonds.

The lap shear test sample was prepared by overlapping the last 2.5 cm of a pair of 10 by 2.5 cm coupons to get a 17.8 cm long sample with the adhesive and 0.76 mm glass spacer beads between the overlap. The sample was placed between a two-sided fixture held at a curing temperature until solidified. Then the sample was removed from the fixture and held at about 20 to 25 °C for about 24 to 72 hours for the test. The lap shear test was conducted according to ASTM D5868 with a crosshead speed of 2 inches per minute. ASTM D5868 is incorporated herein by reference in its entirety. All adhesives were prepared at an isocyanate index in a range of from about 95 to about 110 unless otherwise noted. Salt spray was conducted according GMW14124 specification in a Q-FOG Cyclic Corrosion test chamber. Since lack of corrosion resistance and poor adhesion after water soak and/or salt spray are major issues with polyurethane adhesives, water soak and salt spray tests were used to evaluate the adhesives.

The adhesives prepared from Controls 1-3 and Examples 4-7 were used to bond Glass filled polypropylene (GFPP) to bare Aluminum (AI-6061). Before bonding, surface of GFPP was IPA wiped followed by flame treatment and surface of the AI-6061 was sanded. The lap shear test for the cured adhesives was conducted at room temperature (RT), after 1 week or 90 days water soak and/or after 8 weeks or 7 months salt spray. Both strength and failure pattern (% passing) were evaluated. A minimum of 90% passing failure pattern is required in the industry.

Brief explanation of the results shown in Table 6. Control 1 is the (reference/ control 1 ), which is a high-performance low modulus PU adhesive formulation based on best available knowledge but has no silanes. It showed poor strength and did not pass the required 90% cohesive-failure- mode when tested at RT and after 1 -week water soak

Control 2 (control 2) has only one silane in the prepolymer, which is the A-187 silane (epoxy functional). The silane activator, Jeffamine is in the curative. It showed good lap shear strength, but lap shear tested at RT did not pass the required 90% cohesive failure mode. However, it showed significant improvement on the results after the 1-week water soak. It achieved 95% cohesive-failure-mode.

Control 3 (control 3) has one silane in the prepolymer, which is the VPS 7163 (isocyanurato silane). Jeffamine (polyether amine) is in the curative. Both failure modes at RT and after water soak did not pass the required 90% cohesive failure mode.

Example 4 had both A-187 silane and VPS 7163 in the prepolymer, and Jeffamine in the curative. It showed excellent lap shear strength and failure mode when tested at RT and after 1 week water soak

Example 5 has both A-187 silane and VPS 7163 in the prepolymer, and Jeffamine plus DBU (tertiary amine) in the curative. It showed excellent lap shear strength and failure mode when tested at RT and after 1 week water soak

Example 6 has both A-187 silane and VPS 7163 in the prepolymer, and no Jeffamine, but DABCO 33LV in the curative. It showed excellent lap shear strength and failure mode when tested at RT and after 1 week water soak

Example 7 has both A-187 silane and VPS 7163 in the prepolymer, and Jeffamine in the curative. It showed excellent lap shear strength and failure mode after 90 days water soak and 8 weeks salt spray.

The adhesives prepared from Examples 5, 7 and 8 were also used to bond Al- 6061 to AI-6061 (bare Aluminum) and Alodined Al to Alodined Al (A-5200). Before bonding, the surface of the AI-6061 was sanded and surface of A-5200 was wiped with I PA. The lap shear test for the cured adhesives was conducted at room temperature (RT), after 1 -week’s water soak and/or after 8-week’s or 7-month’s salt spray.

Brief explanation of the results shown in Table 6. Example 5 has both A-187 silane and VPS 7163 in the prepolymer, and Jeffamine plus DBU (tertiary amine catalyst) in the curative. It showed excellent lap shear strength and failure mode for both Alodined aluminum and bare aluminum when tested after exposed to salt spray for 7 months, which is extremely hard to pass. Automotive OEMs normally only require passing 8 weeks salt spray

Example 7 had both A-187 silane and VPS 7163 in the prepolymer, and Jeffamine in the curative. It showed excellent lap shear strength and failure mode for both Alodined aluminum and bare aluminum when tested after exposed to salt spray for 8 weeks. For this adhesive, we only tested 8 weeks salt spray and did run longer exposure.

Controls 1-3 and Examples 4-7 were all low modulus adhesives. The modulus of each sample was lower than 10 MPa. Example 8 was a high modulus adhesive, having a modulus of at least 10 MPa. The modulus referred herein is the young’s modulus.

Example 8 is a high modulus adhesive, with modulus being about 500MPa. Example 8 has both A-187 silane and VPS 7163 in the prepolymer, and Jeffamine plus DBU in the curative. It showed excellent lap shear strength and failure mode for Alodine aluminum when tested after 1 week’s water soak. Did not run salt spray test. This indicated that this concept developed based on low modulus is also applicable for traditional high modulus PU adhesives.

The above data showed that the combination of A-187 and VPS, with the use of tertiary amine catalyst and/or Jeffamine achieved the surprisingly good water soak and salt spray results.

Example 9. The adhesive prepared from Example 9 was used to bond glass filled polypropylene (GFPP) to bare aluminum (AI-6061 ). Before bonding, the surface of GFPP was wiped with I PA followed by flame treatment and the surface of the AI-6061 was sanded. The lap shear test for the cured adhesives was conducted at room temperature (RT) and after 1 week’s water soak. Example 9 has a special silane in the prepolymer, VPS 4721 , which is a high molecular weight epoxy functional silane. It has the Jeffamine in the curative. It showed excellent lap shear strength and failure mode when tested at RT and after 1 -week’s water soak.

The SMP (silane modified polymer) included in the prepolymer was evaluated to for an improvement in adhesion to aluminum. Table 9 and Table 10 show the formulations for Examples 10 and 11. General procedures for making prepolymers and curatives are shown in Table 3 and Table 4.

In Examples 10-11 as shown in Table 11 , the prepolymers and curatives prepared in Table 9 and Table 10 were loaded separately into side-by-side cartridges and pump through a static mix tube to achieve complete mixing as shown in Table 11 . The adhesives prepared from Examples 10 and 11 were used to bond AI-6061 to AI-6061 (bare Aluminum) and Alodined Al to Alodined Al (A-5200). The lap shear test for the cured adhesives was conducted at room temperature (RT) and after 2 weeks water soak.

Brief explanation of the results shown in Table 12.

Example 10 has both A-187 silane and SAX 220 SMP in the prepolymer and DABCO 33LV in the curative. It showed excellent lap shear strength and failure mode for both Alodine aluminum and bare aluminum when tested at RT and after 2 weeks water soak. Therefore, the combination of A-187 and SMP is a good candidate for to improve the aluminum bonding performance of Pll adhesives.

Example 11 has only SAX 220 SMP in the prepolymer and Tib kat 417 (a tin catalyst) in the curative. It showed excellent lap shear strength and failure mode for both Alodine aluminum and bare aluminum when tested at RT. It is another good candidate for aluminum bonding.

In the below examples the term CH is used to indicate a cohesive failure and AD for an adhesive failure. In one case, preferable embodiments have a CH of at least about 90%, more preferably at least about 95%, most preferably about 100%.

Table 1. Prepolymer formulations

Table 2. Curative formulations

Table 3. General procedures for preparing the prepolymer Table 4. General procedures for preparing the curative

Table 5. Prepolymer and Curative Combinations Table 6. Lap shear tested on GFPP (ADX 1335x)/AI -6061 (bare Aluminum) * CH: Cohesive failure

AD: Adhesive failure

Table 7. Lap shear tested on AI-6061/AI -6061 (bare Aluminum) and Alodined Al/Alodined Al

(A-5200) Table 8. Lap shear results from Example on GFPP/AI-6061

Table 9. Formulations for prepolymer

Table 10. Formulations for curatives Table 11. Prepolymer and Curative Combinations

Table 12. Lap shear tested on AI-6061/AI -6061 (bare Aluminum) and Alodined Al/Alodined Al (A-5200)

Table 13 Prepolymer and Curative (Wt%) Table 14 Lap shear adhesion (psi) Substrate used: Alodine Al/Alodine Al

* CH: Cohesive failure

* AD: Adhesive failure

In table 13, the control-4 is devoid of the mono-ether, high molecular weight polyol (number average molecular weight of more than 10,000 Daltons) and silanes. The substrates used for both 1^st and 2^nd substrates to form the laminate were Alodine Al.

The lap shear adhesion was tested at room temperature and after 1 week of water soak. The control exhibited sufficient lap shear adhesion when tested at room temperature and appropriate types of failure and the Results showed:

(1) After 1 week water soak, the control-4 showed low strength and bad adhesion (adhesive failure) and

(2) Both Examples 21 and 22 showed good strength and good failure mode when tested at RT and 1 week water soak.

While this invention has been described in detail with reference to certain preferred embodiments, it should be appreciated that the present disclosure is not limited to those precise embodiments. Rather, in view of the present disclosure, many modifications and variations would present themselves to those skilled in the art without departing from the scope and spirit of this invention.

ASPECTS

In addition to the subject matter in the Brief Description, Detailed Description and Claims, the disclosure includes the Aspects recited herein.

A first aspect is a two-component polyurethane adhesive composition. The composition comprises an NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol. Preferably a %NCO in the prepolymer comprises up to about 30%, more preferably from about 1 to 20%, even more preferably less than 20% to at least 10% or from about 1 to 10%. The prepolymer may also include a silane component wherein the silane component comprises at least an epoxy functional silane, preferably up to about 10 wt%, more preferably up to about 8 wt% and even more preferably up to about 5 wt%, and further preferably up to about 4 wt%, also preferably at least about 0.1 wt%, more preferably at least about 0.4 wt% and further preferably at least about 0.6 wt%. The silane component may also include an isocyanurato functional silane preferably up to about 5 wt%, more preferably up to about 4 wt%, further preferably no more than about 1.5 wt%, even more preferably at least about 0.4 wt% and further even more preferably at least about 0.6 wt%.

The adhesive of the first aspect may also include a curative comprising a polyol, at least one of tertiary amine, a blocked tertiary amine and combinations thereof. A preferred concentration of the tertiary amine may comprise up to about 3 wt% more preferably up to about 2 wt%, further preferably no more than about 1 wt%, even more preferably no more than 0.5 wt% and further even more preferably at least about 0.02 wt% and most preferably at least about 0.03 wt% of the adhesive. Optionally the curative may include a diamine, preferably up to about 15 wt%, more preferably up to about 10 wt%, further preferably up to about 7 wt% and even more preferably at least about 0.5 wt% of the adhesive. Preferably a number average molecular weight of the diamine may comprise up to about 6000 Daltons, more preferably up to about 4000 Daltons and further preferably at least about 200 Daltons and even more preferably at least about 300 Daltons.

A second aspect includes a two-component polyurethane adhesive composition. The composition includes an NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol. Preferably a %NCO in the prepolymer comprises up to about 30%, more preferably from about 1 to 20%, even more preferably less than 20% to at least 10% or from about 1 to 10%. The prepolymer may include an epoxy functional silane adhesion promoter having a number average molecular weight of at least about 1000 Daltons , preferably at least about 1200, more preferably at least about 1400, preferably a concentration of the epoxy function silane adhesion promoter comprises up to about 10 wt%, more preferably up to about 8 wt%, even more preferably up to about 4 wt%, further preferably at least about 0.5 wt%, most preferably at least about 1 wt% of the adhesive.

The adhesive of the second aspect may also include a curative comprising a polyol and at least one of a tertiary amine, blocked tertiary amine and combinations thereof. A concentration of the tertiary amine may comprise up to about 5 wt%, more preferably up to about 4 wt%, even more preferably up to about 2 wt%, further preferably up to about 1 wt% and most preferred at least about 0.02 wt% of the adhesive. The curative may also optionally include a diamine, preferably a polyether diamine. A preferable concentration of the diamine, e.g., the polyether diamine, may comprise up to about 15 wt%, more preferably up to about 11 wt%, even more preferably up to 7 wt%, and further preferably at least about 0.5 wt% of the adhesive.

In a third aspect, the adhesive of the second aspect may be devoid of a second silane containing compound in the prepolymer, preferably in the composition.

A fourth aspect is applicable to either of the second or third aspects wherein the curative further comprising a second polyol. Preferably the second polyol comprises a polyoxyalkylene polyol having a hydroxyl number of at least about 15 mg KOH/g, preferably at least about 17 mg KOH/g, more preferably no more than about 30 mg KOH/g, and even more preferably no more than about 25 mg KOH/g and further preferred a number average molecular weight of the second polyol comprises at least about 15,000 Daltons, more preferably at least about 25,000 Daltons, further preferred at least about 50,000 Daltons, even more preferred at least about 70,000 Daltons.

In a fifth aspect, the two-component polyurethane adhesive composition of either aspects 2 or 3 the curative includes a second polyol and a number average molecular weight of the second polyol in the curative comprises at least about 300 Daltons, more preferably at least about 2,000 Daltons, further preferred at least about 4,000 Daltons, even more preferred at least about 15,000 Daltons.

A sixth aspect is applicable to any one of aspects 2 to 5 wherein the adhesive composition further comprises a mono ether, preferably a polypropylene glycol) mono ether, more preferably a polypropylene glycol) mono butyl ether, further preferred the mono ether comprises a component of the curative.

A seventh aspect is applicable to anyone of the preceding aspects wherein the adhesive composition further comprises at least one of a diol, a triol and combinations thereof, preferably the diol comprises a primary diol, also preferably the diol or triol has a number average molecular weight of no more than about 1000 Daltons, more preferably less than about 500 Daltons, even more preferred less than about 250 Daltons. In a preferred embodiment, the diol or triol is a component of the curative.

In an eighth aspect, the two-component polyurethane adhesive composition of any one of the preceding aspects further comprising a high molecular weight polyol in the curative, wherein a number average molecular weight of the high molecular weight polyol comprises at least 1000 Daltons, preferably at least about 4000 Daltons.

A ninth aspect includes a two-component polyurethane adhesive composition. The composition includes an NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol. Preferably a %NCO in the prepolymer comprises up to about 30%, more preferably from about 1 to 20%, even more preferably less than 20% to at least 10% or from about 1 to 10%. The prepolymer may also include a silyl modified polymer comprising at least one of the following: silyl terminated polyether, silyl terminated isocyanate, silyl terminated acrylate and combinations thereof. A preferably concentration of the silyl modified polymer comprises up to about 25 wt%, more preferably up to about 20 wt%, even more preferably up to about 15 wt%, further preferably at least about 1 wt%, event further preferred at least about 2 wt%, and most preferable at least about 5 wt% of the adhesive and optionally an epoxy functional silane, preferably up to about 10 wt%, more preferably up to about 8 wt% and even more preferably up to about 5 wt%, and further preferably up to about 4 wt%, also preferably at least about 0.1 wt%, more preferably at least about 0.4 wt% and further preferably at least about 0.6 wt% of the adhesives.

The adhesive composition of the ninth aspect may also include a curative comprising a polyol and an optional tin catalyst. A preferred concentration of the tin catalyst may comprise up to about 10 wt%, more preferably up to about 5 wt%, even more preferred up to about 2 wt% and further preferred at least about 0.5 wt% of the adhesive composition.

In a tenth aspect, the NCO prepolymer of the ninth aspect may further comprises an epoxy functional silane adhesion promoter having a number average molecular weight molecular weight of more than about 200 Daltons, preferably up to about 2000 Daltons.

In an eleventh aspect, the two-component polyurethane adhesive composition of either one of aspects 9 or 10 wherein the epoxy functional silane adhesion promoter comprises at least one of the following: 2-glycidoxyethyl- dimethylmethoxysilane; 6- glycidoxyhexyl-tributoxysilane; 3-glycidoxypropyl- trimethoxysilane; 3- glycidoxypropyl-triethoxysilane; 3-glycidoxypropyl- methyldiethoxysilane; 5- glycidoxypentyl-trimethoxysilane; 5-glycidoxypentyl- triethoxysilane, 3- glycidoxypropyl-triisopropoxysilane and combinations thereof, preferably the epoxy functional silane adhesion promoter comprises 3-glycidoxy- propyl-trimethoxysilane.

In a twelfth aspect, the two-component polyurethane adhesive composition of any one of aspects 9-11 wherein the silyl modified polymer comprises at least one of the following: dimethoxysily terminated polyether, trimethoxysily terminated polyether and combinations thereof.

In a thirteenth aspect, the two-component polyurethane adhesive composition of any one of aspects 9-11 wherein the silyl modified polymer comprises: An-D- SiXYZ end groups, wherein a. A is a divalent linking group comprising at least one hetero atom, preferably at least one of S,N,0,P, and Si, more preferably O; b. D is a divalent hydrocarbon residue with 1-12 C-atoms, preferably 2-8 carbons, more preferably 3-6 carbon atoms; c. X, Y, Z are each independently substituents on the Si atom, independently selected from C1-C8 alkyl, C1-C8 alkoxy, C1- C8 acyloxy, preferably C2-C5 alkyl, C2-C5 alkoxy, and C2-C5 acyloxy, at least one of the substituents X, Y, Z is a C1-C8 alkoxy or C1-C8 acyloxy; and d. n is 0 or 1 .

In a fourteenth aspect, the two-component adhesive of any one of the preceding aspects 9 to 13 wherein a volume ratio of the prepolymer to the curative comprise at least about 1 :1 and up to about 10:1 , preferably at least about 1.5:1.

Aspect 15 comprises a laminate having 1^st and 2^nd substrates and the adhesive of anyone of the preceding aspects, wherein the adhesive is disposed between the 1^st and 2^nd substrates.

In aspect sixteen, at least one of the 1^st or 2^nd substrates of the laminate of aspect 15 at least one of the substrates comprises a metal susceptible to corrosion, preferably the substrate susceptible to corrosion comprises one of aluminum, aluminum alloys, coated aluminum or coated aluminum alloys.

Aspect 17 applies to either of aspects 15 or 16 wherein a coefficient of thermal expansion of the 1^st substrate differs from a coefficient of thermal expansion of the 2^nd substrate by no more than about 10%, preferably no more than about 5%, more preferably no more than about 2%, measured at a temperature in a range of about -30°C up to about 82°C.

Aspect 18 applies to any one of aspects 15 to 17 wherein the laminate devoid of a sufficient amount of primer to assist in the adhesive adhering to either of the 1 ^st and 2^nd substrates.

One particular aspect includes a laminate comprising 1^st and 2^nd substrates and an adhesive sandwiched between the 1^st and 2^nd substrates. A coefficient of thermal expansion of the 1^st substrate differs from a coefficient of thermal expansion of the second substrate by more than about 5%, preferably by more than about 10%, more preferably by more than about 15%, measured at a temperature in a range of about -30°C up to about 82°C. The adhesive comprises a two-component adhesive composition including an NCO prepolymer comprising the reaction product of an isocyanate compound and a polyol. Preferably a %NCO in the prepolymer comprises up to at least about 30%, more preferably from about 1 to 20% or from about 1 to 10%. The adhesive further includes a polyol second component, preferably having a number average molecular weight of at least about 2000 Daltons, more preferably at least about 4000 Daltons, even more preferably at least about 8000 Daltons and most preferably no more than 15000 Daltons. The adhesive composition may also include an isocyanurato silane adhesion promoter, at a concentration of about 0.1 to 10 wt% of the adhesive. The adhesive may include a fourth component comprising an epoxy functional silane adhesion promoter, wherein a concentration of the fourth component comprises no more than about 20 wt%, preferably at least 0.5 wt% of the adhesive. A fifth component may comprise at least one of a tertiary amine, blocked tertiary amine and combinations thereof. An optional sixth component may be a polyether diamine.

Claims

1 . A two-component polyurethane adhesive composition comprising: a. A NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol, preferably a %NCO in the prepolymer comprises up to about 30%, more preferably from about 1 to 20%, even more preferably less than 20% to at least 10% or from about 1 to 10%, and a silane component, wherein the silane component comprises at least an epoxy functional silane, preferably up to about 10 wt%, more preferably up to about 8 wt% and even more preferably up to about 5 wt%, and further preferably up to about 4 wt%, also preferably at least about 0.1 wt%, more preferably at least about 0.4 wt% and further preferably at least about 0.6 wt%, and an isocyanurato functional silane preferably up to about 5 wt%, more preferably up to about 4 wt%, further preferably no more than about

1 .5 wt%, even more preferably at least about 0.4 wt% and further even more preferably at least about 0.6 wt%; and b. A curative comprising a polyol, at least one of tertiary amine, a blocked tertiary amine and combinations thereof, preferably up to about 3 wt% of the tertiary amine, more preferably up to about 2 wt%, further preferably no more than about 1 wt%, even more preferably no more than 0.5 wt% and further even more preferably at least about 0.02 wt% and most preferably at least about 0.03 wt% and optionally a diamine, preferably up to about 15 wt%, more preferably up to about 10 wt%, further preferably up to about 7 wt% and even more preferably at least about 0.5 wt%, preferably a number average molecular weight of the diamine may comprise up to about 6000 Daltons, more preferably up to about 4000 Daltons and further preferably at least about 200 Daltons and even more preferably at least about 300 Daltons.

2. A two-component polyurethane adhesive composition comprising: a. A NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol, preferably a %NCO in the prepolymer comprises up to about 30%, more preferably from about 1 to 20%, even more preferably less than 20% to at least 10% or from about 1 to 10%, and an epoxy functional silane adhesion promoter having a number average molecular weight of at least about 1000 Daltons, preferably at least about 1200, more preferably at least about 1400, preferably a concentration of the epoxy function silane adhesion promoter comprises up to about 10 wt%, more preferably up to about 8 wt%, even more preferably up to about 4 wt%, further preferably at least about 0.5 wt%, most preferably at least about 1 wt% of the adhesive; and b. A curative comprising a polyol, at least one of a tertiary amine, blocked tertiary amine and combinations thereof preferably comprising a concentration of up to about 5 wt%, more preferably up to about 4 wt%, even more preferably up to about 2 wt%, further preferably up to about 1 wt% (specific embodiment up to 0.5 wt%), most preferred at least about 0.02 wt% and an optional polyether diamine, preferably having a concentration of up to about 15 wt%, more preferably up to about 11 wt%, even more preferably up to 7 wt%, and further preferably at least about 0.5 wt%.

3. The two-component polyurethane adhesive composition of claim 2 wherein the prepolymer devoid of a second silane containing compound.

4. The two-component polyurethane adhesive composition of either of claims 2 or 3, the curative further comprising a second polyol, preferably the second polyol comprises a polyoxyalkylene polyol having a hydroxyl number of at least about 15 mg KOH/g, preferably at least about 17 mg KOH/g, more preferably no more than about 30 mg KOH/g, and even more preferably no more than about 25 mg KOH/g and further preferred a number average molecular weight of the second polyol comprises at least about 15,000 Daltons, more preferably at least about 25,000 Daltons, further preferred at least about 50,000 Daltons, even more preferred at least about 70,000 Daltons

5. The two-component polyurethane adhesive composition of either of claims 2 or 3 wherein a number average molecular weight of a second polyol in the curative comprises at least about 300 Daltons, more preferably at least about 2,000 Daltons, further preferred at least about 4,000 Daltons, even more preferred at least about 10,000 Daltons.

6. The two-component polyurethane adhesive composition of any one of the preceding claims 2-5 further comprising a mono ether, preferably a polypropylene glycol) mono ether, more preferably a polypropylene glycol) mono butyl ether, further preferred the mono ether comprises a component of the curative.

7. The two-component polyurethane adhesive composition of any one of the preceding claims 2-6 further comprising at least one of a diol, a triol and combinations thereof, preferably the diol comprises a primary diol, also preferred the diol or triol has a number average molecular weight of no more than about 1000 Daltons, more preferably less than about 500 Daltons, even more preferred less than about 250 Daltons.

8. The two-component polyurethane adhesive composition of any one of claims 4-7 further comprising a third polyol in the curative, wherein a number average molecular weight of the third polyol comprises at least 1000 Daltons.

9. The two-component polyurethane adhesive composition of any one of the preceding claims 4-8 wherein the number average molecular weight of the second polyol comprises at least 50,000 Daltons.

10. A two-component polyurethane adhesive composition comprising a. A NCO prepolymer comprising a reaction product of an isocyanate compound and a polyol, preferably a %NCO in the prepolymer comprises up to about 30%, more preferably from about 1 to 20%, even more preferably less than 20% to at least 10% or from about 1 to 10%, a silyl modified polymer comprising at least one of the following: silyl terminated polyether, silyl terminated isocyanate, silyl terminated acrylate and combinations thereof, preferably a concentration of the silyl modified polymer comprises up to about 25 wt%, more preferably up to about 20 wt%, even more preferably up to about 15 wt%, further preferably at least about 1 wt%, even further preferred at least about 2 wt%, and most preferable at least about 5 wt% of the adhesive and optionally an epoxy functional silane, preferably up to about 10 wt%, more preferably up to about 8 wt% and even more preferably up to about 5 wt%, and further preferably up to about 4 wt%, also preferably at least about 0.1 wt%, more preferably at least about 0.4 wt% and further preferably at least about 0.6 wt%; b. A curative comprising a polyol and an optional tin catalyst in a concentration of up to about 10 wt%, more preferably up to about 5 wt%, even more preferred up to about 2 wt% of the adhesive and further preferred at least about 0.02 wt%.

11. The adhesive composition of claim 10 wherein the NCO prepolymer further comprises the epoxy functional silane adhesion promoter having a number average molecular weight molecular weight of more than about 200 Daltons, preferably up to about 2000 Daltons.

12. The two-component polyurethane adhesive composition of either one of claims 10 or 11 wherein the epoxy functional silane adhesion promoter comprises at least one of the following: 2-glycidoxyethyl-dimethylmethoxysilane; 6- glycidoxyhexyl-tributoxysilane; 3-glycidoxypropyl-trimethoxysilane; 3- glycidoxypropyl-triethoxysilane; 3-glycidoxypropyl-methyldiethoxysilane; 5- glycidoxypentyl-trimethoxysilane; 5-glycidoxypentyl-triethoxysilane, 3- glycidoxypropyl-triisopropoxysilane and combinations thereof, preferably the epoxy functional silane adhesion promoter comprises 3-glycidoxy- propyltrimethoxysilane.

13. The two-component polyurethane adhesive composition of any one of claims 10 to 12 wherein the silyl modified polymer comprises at least one of the following: dimethoxysily terminated polyether, trimethoxysily terminated polyether and combinations thereof.

14. The two-component polyurethane adhesive composition of any one of claims 10 to 12 wherein the silyl modified polymer comprises: An-D-SiXYZ end groups, wherein a. A is a divalent linking group comprising at least one hetero atom, preferably at least one of S,N,0,P, and Si, more preferably O; b. D is a divalent hydrocarbon residue with 1-12 C-atoms, preferably 2-8 carbons, more preferably 3-6 carbon atoms; c. X, Y, Z are each independently substituents on the Si atom, independently selected from Ci-Cs alkyl, C1-Cs alkoxy, Ci- Cs acyloxy, preferably C2-

Cs alkyl, C2-C5 alkoxy, and C2-C5 acyloxy, at least one of the substituents X, Y, Z is a Ci-Cs alkoxy or Ci-Cs acyloxy; and d. n is 0 or 1 .

15. The two-component adhesive of any one of the preceding claims 10 to 14 wherein a volume ratio of the prepolymer to the curative comprise at least about 1 : 1 and up to about 10: 1 , preferably at least about 1.5:1.

16. A laminate comprising 1^st and 2^nd substrates wherein one of the 1^st and 2^nd substrates or both comprises aluminum and an adhesive of any one of the preceding claims sandwiched between the 1^st and 2^nd substrates.

17. A laminate comprising 1^st and 2^nd substrates and the adhesive of any one of the preceding claims 1 -15 sandwiched between the 1^st and 2^nd substrates, wherein a coefficient of thermal expansion of the 1^st substrate differs from a coefficient of thermal expansion of the 2^nd substrate by more than about 5%, preferably more than about 10%, more preferably more than about 15%, measured at a temperature in a range of about -30°C up to about 82°C. The laminate of either claims 16 or 17 wherein the laminate devoid of a sufficient amount of primer to assist in the adhesive adhering to either of the 1^st and 2^nd substrates.

18. The laminate of either claims 17 or 18 wherein at least one of the 1 ^st substrate and the 2^nd substrate comprises a metal known to oxidize, preferably a metal or an alloy of the metal, more preferably aluminum and/or aluminum alloy.

19. A laminate comprising 1^st and 2^nd substrates and an adhesive sandwiched between the 1^st and 2^nd substrates, wherein a coefficient of thermal expansion of the 1^st substrate differs from a coefficient of thermal expansion of the 2^nd substrate by more than about 5%, preferably more than about 10%, more preferably more than about 15%, measured at a temperature in a range of about -30°C up to about 82°C, wherein the adhesive comprises a two-component adhesive composition including: i. An NCO prepolymer comprising the reaction product of an isocyanate compound and a polyol, preferably a %NCO in the prepolymer comprises up to at least about 30%, more preferably from about 1 to 20% or from about 1 to 10%, ii. A polyol second component, preferably having a number average molecular weight of at least about 1000 Daltons, more preferably at least about 4000 Daltons, even more preferably at least about 8000 Daltons and most preferably no more than 15000 Daltons, iii. an isocyanurato silane adhesion promoter, at a concentration of about 0.1 to 10 wt% of the adhesive, iv. a fourth component comprising an epoxy functional silane adhesion promoter, wherein a concentration of the fourth component comprises no more than about 10 wt%, preferably at least 0.5 wt% of the adhesive, v. a fifth component comprising at least one of a tertiary amine, blocked tertiary amine and combinations thereof, and optionally a sixth component of a polyether diamine.