2k-low modulus polyurethane adhesive for bonding composites

Abstract

The invention relates to polyurethane adhesive compositions and laminates which include one of the adhesive compositions and methods of making such laminates. The adhesive may be a 2-component adhesive. The adhesive may be a structural adhesive. A 2-component polyurethane adhesive composition includes a. a prepolymer component and a curative component, wherein the prepolymer comprises (i) at least about 30 wt% of a polyol component, preferably up to no more than about 70 wt%, further preferably at least about 40 wt%, more preferably at least about 45 wt%, even more preferably at least about 50 wt%, and b. the adhesive composition comprises at least 0.05 wt% of a non-amine / non-tin containing catalyst and preferably less than 0.7 wt% of a tin containing catalyst.

Description

[0001] 2K-L0W MODULUS POLYURETHANE ADHESIVE FOR BONDING COMPOSITES

[0002] TECHNICAL FIELD

[0003] The present invention relates to adhesive compositions that may be used as a structural adhesive. In particular it may be used to bond dissimilar materials or similar materials, e.g., polycarbonate materials to other polycarbonate materials or to non-polycarbonate materials; as well as laminates formed by bonding such materials and methods of making such laminates.

[0004] TECHNICAL BACKGROUND

[0005] In 2012, the Environmental Protection Agency established a mandate requiring the average fuel efficiency of the United States' auto fleet to reach 54.5 miles per gallon by 2025. To meet this demanding standard, the automotive industry has turned to materials that can reduce vehicle weight. This can include bonding dissimilar materials to each other. Polycarbonate is an example of a material which may be desirable for such use.

[0006] Generally, industrial adhesives for bonding dissimilar materials must have an appropriate modulus and high elongation in addition to excellent adhesion. To meet these requirements, large quantities of plasticizers and toughening agents are added into polymerizable adhesive compositions. In addition, primers are used on some materials for good adhesion.

[0007] Bonding of dissimilar materials poses difficult challenges for industrial adhesives. Different substrate materials have different coefficients of thermal expansion. When materials warm up, they expand at different rates and stresses are created. An example of one such laminate is a laminate of aluminum bonded to glass. The differing in the expansion and contraction rates of the materials can shatter the glass.

[0008] In conventional practices, the blend of amine and tin catalysts finds frequent application in formulating polyurethane adhesives, delivering favorable mechanical adhesive performance. Traditionally, tertiary amines have served as the catalysts of choice for catalyzing polyurethane reactions. Nevertheless, the use of tertiary amines introduces complications stemming from their significant volatility. Volatility of the amine is noted as the source of unpleasant odor, which can be noticeable during the manufacturing process. Additionally, tertiary amines can provoke the onset of polycarbonate crazing when exposed to stress and specific conditions, posing a substantial challenge. Parallelly, tin catalysts exhibit a marked selectivity in catalyzing the isocyanate-hydroxyl reaction within the adhesive system. Yet, their widespread adoption is impeded due to the perceived health concerns associated with the use of tin compounds, such as those disclosed in the ATSDR August 2005 Public Health Statement.

[0009] BRIEF DESCRIPTION

[0010] The below and other embodiments will become apparent in light of the following disclosure.

[0011] The invention relates to a polyurethane two-component adhesive composition. The polyurethane two-component adhesive composition comprises a prepolymer component and a curative component. Preferably the prepolymer comprises a reaction product of at least one isocyanate compound and at least one polyol component, more preferably the prepolymer comprises an isocyanate terminated prepolymer. The prepolymer comprises (I) at least about 30 wt% of the polyol component, preferably up to no more than about 70 wt%, further preferably at least about 40 wt%, more preferably at least about 45 wt%, even more preferably at least about 50 wt%, and the composition also includes at least 0.05 wt% of a non-amine / non-tin containing catalyst (or “non-amine / non-tin catalyst”).

[0012] Another embodiment herein is a laminate comprising 1stand 2ndsubstrates adhered together wherein at least one of the 1stand 2ndsubstrates comprises a polycarbonate. The adhesive comprises the cured composition a polyurethane two-component adhesive composition. Preferably the polyurethane two-component adhesive includes a prepolymer comprising (i) at least about 30 wt% of a polyol component, preferably up to no more than about 70 wt%, further preferably at least about 40 wt%, more preferably at least about 45 wt%, even more preferably at least about 50 wt%, and the composition will have at least 0.05 wt% of a non-amine / non-tin containing catalyst. Preferably the prepolymer comprises a reaction product of at least one isocyanate compound and at least one polyol component, more preferably the prepolymer comprises an isocyanate terminated prepolymer.

[0013] A further embodiment includes a method of making the laminate. The method includes applying the polyurethane two-component adhesive composition to at least one of the 1stsubstrate, the 2ndsubstrate and combinations thereof. The polyurethane two-component adhesive composition comprises a prepolymer component and a curative component. Preferably the prepolymer comprises a reaction product of at least one isocyanate compound and at least one polyol component, more preferably the prepolymer comprises an isocyanate terminated prepolymer. The prepolymer comprises (i) at least about 30 wt% of the polyol component, preferably up to no more than about 70 wt%, further preferably at least about 40 wt%, more preferably at least about 45 wt%, even more preferably at least about 50 wt%, and the composition comprises at least 0.05 wt% of a non-amine / non-tin containing catalyst. At least one of the 1stsubstrate, the 2ndsubstrate and combinations thereof comprises polycarbonate.

[0014] Regarding particular embodiments, for a low modulus embodiment, the adhesive may have a Young’s modulus of no more than about 10 MPa, preferably no more than about 8 MPa, more preferably no more than about 7 MPa, more preferably no more than about 6 MPa, and further preferably at least about 3 MPa.

[0015] In further embodiments of the laminate and methods of making the laminate a coefficient of thermal expansion of the 1stsubstrate may differ from a coefficient of thermal expansion of the 2ndsubstrate by at least about 5%, preferably at least about 10%, more preferably at least about 15%, measured at a temperature in a range of about -30°C up to about 82°C.

[0016] In one or more embodiments disclosed herein the non-amine / non-tin containing catalyst may comprises a zirconium compound (also known as “zirconium complex catalyst” or “zirconium complex”). In a particular embodiment the zirconium compound comprises a zirconium tetra-dionato compound (AKA “zirconium tetra-dionato complex catalyst”), known as K-KAT 6212, incorporated within a reactive diluent. Either alternatively or in combination with the zirconium compound, the catalyst package may include a bismuth carboxylate such as commercially available 75% solution of bismuth tris(2- ethylhexanoate) dissolved in 2-ethylhexanoic acid. Another viable option is the synergistic amalgamation of a zinc catalyst with the bismuth catalyst, forming an alternative catalyst combination to facilitate the isocyanate and hydroxyl reaction.

[0017] Particular embodiments of the non-amine / non-tin containing catalyst may include the zirconium compound alone, combined with bismuth, or the zirconium compound paired with a bismuth / zinc. These catalyst packages have excelled in orchestrating the isocyanate-hydroxyl reactions at room temperature, generating green strength and achieving exceptional polycarbonate bonding efficacy.

[0018] A preferred NCO:OH index of the composition falls within the range of about 85-140, preferably about 90-140, more preferably about 90-130, more preferably about 90-120, more preferably about 100-120, further preferably about 105-less than about 120, preferably the NCO:OH index is for a volume ratio of about 1 :1 of the prepolymer to the curative. When the index resided within these bounds, it was observed the adhesive exhibited a balanced adhesive formulation. It is believed a lower index may lead to an elevated pre-polymer viscosity. Moreover, this might yield an adhesive with excessive softness, resulting in diminished lap shear strength, often measuring below 500 psi at room temperature. Conversely, an excessively high NCO:OH index jeopardizes adhesive performance by undermining adhesion quality. This can manifest as undesirable failure modes primarily characterized by suboptimal adhesion. In such scenarios, the adhesive's behavior deviates from the desired attributes, rendering it unsuitable for the intended application.

[0019] Benefits of the polyurethane two-component adhesive composition disclosed herein include expanding polycarbonate thermoplastic bonding market with the use of minimal or none of the amine and tin catalysts. Also the polyurethane two-component adhesive composition may be used with gravity feed equipment which may result in or more of reduced waste, less down time, and reduced equipment cost / maintenance. Embodiments disclosed herein may demonstrate at least one of the benefits of excellent flexibility and cure at below 100°C, preferably below 75°C, more preferably below 50°C, even more preferably below 40°C, further preferably below 30°C, even further preferably no more than about room temperature. Other benefits may include an open time of at least about 5 minutes, or more than about 5 minutes. Additionally, embodiments disclosed herein can be formulated for exceptional performance in polycarbonate bonding. Also, the bonding may occur at room temperature. The conventional two-component polyurethane adhesive, fortified by tin and tertiary amine catalysts, fell short of delivering the desired bonding performance for polycarbonate under room temperature curing conditions.

[0020] The present invention makes it possible to address the needs mentioned above. In particular, the compositions according to the invention surprisingly achieve excellent adhesion with high elongation and the appropriate Young’s modulus.

[0021] DESCRIPTION OF THE FIGURES

[0022] Figure 1 is a guide to explain the modes of failure in the Examples.

[0023] DETAILED DESCRIPTION

[0024] Before explaining at least one embodiment of the inventive concept(s) in detail by way of exemplary drawings, experimentation, results, and laboratory procedures, it is to be understood that the inventive concept(s) is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings, experimentation and / or results. The inventive concept(s) is / are capable of other embodiments or of being practiced or carried out in various ways. As such, the language used herein is intended to be given the broadest possible scope and meaning; and the embodiments are meant to be exemplary - not exhaustive. 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.

[0025] Unless otherwise defined herein, scientific, and 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. Generally, nomenclatures utilized in connection with, and techniques of chemistry described herein are those well-known and commonly used in the art. Reactions and purification techniques are performed according to manufacturer's specifications or as commonly accomplished in the art or as described herein.

[0026] 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 this 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 was specifically and individually indicated to be incorporated by reference.

[0027] All the compositions and / or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and / or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. 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 inventive concept(s) as defined by the appended claims.

[0028] 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” in the claims and / or the specification may 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” in the claims is used to mean “and / or” unless explicitly indicated to refer to alternatives only or 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 device, the method being employed to determine the value, and / or the variation that exists among the study subjects. The use of the term “at least one” will be understood to include one as well as any quantity more than one, including but not limited to, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100, etc. The term “at least one” may extend up to 100 or 1000 or more, depending on the term to which it is attached; in addition, the quantities of 100 / 1000 are not to be considered limiting, as higher limits may also produce satisfactory results. In addition, the use of the term “at least one of X, Y and Z” will be understood to include X alone, Y alone, and Z alone, as well as any combination of X, Y and Z.

[0029] As used in this specification and claim(s), 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.

[0030] The term “or combinations thereof” as used herein refers 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 item or term, such as BB, AAA, MB, 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.

[0031] 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.

[0032] The term “polymer” refers to a large molecule comprising one or more types of monomer residues (repeating units) connected by covalent chemical bonds. By this definition, polymer encompasses compounds wherein the number of monomer units may range from very few to very many.

[0033] In the field of adhesives, open time is the amount of time you have to bond materials together with an adhesive before the adhesive starts to cure.

[0034] Reference herein to the wt% of the composition, the adhesive composition, etc. is meant to be inclusive of both the prepolymer and the curative unless otherwise stated.

[0035] Unless otherwise stated, standards mentioned throughout the present application are those in effect on the date the application is filed. Samples of methods that may be used to determine properties are listed below. However, the methods may be equally applicable and the claims are not limited to the method below unless stated in the claim.

[0036] (1 ) Methods that may be used to determine number average molecular weight include but are not limited to Gel Permeation Chromatography (GPC), Vapor Phase Osmometry, Membrane Osmometry and Lowering of Vapor Pressure.

[0037] (2) NCO% (AKA %NCO) : One technique to determine the NCO% is ASTM D5155. Determining the NCO% is not necessarily limited to the aforementioned technique.

[0038] (3) NCO Index (AKA NCO:OH index or NCO to OH index) is the equivalence ratios of the isocyanates to polyols containing a hydroxyl group (calculate the ratio of the number of isocyanate (NCO) groups to the number of hydroxyl (OH) groups present in the reaction mixture, essentially dividing the equivalents of NCO by the equivalents of OH). The NCO index may be measured at a volume ratio of prepolymer to curative, typically, about 1 :1.

[0039] (4) Viscosity: A TA Instruments Discovery HR-1 rheometer with a cone-plate may be used to measure viscosity. Unless stated otherwise the cone plate had a diameter of 40 mm. Unless otherwise stated, the temperature was 23°C and the shear rate was 0.79 s’1.

[0040] (5) Tensile Strength of the Adhesive: The tensile strength may be determined in accordance with ASTM D-638. The embodiments disclosed herein are not limited to determining tensile strength by the aforementioned ASTM standard.

[0041] (6) 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 not limited to determining CTE by the aforementioned ASTM standard.

[0042] (7) 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.

[0043] (8) Young’s modulus: While any suitable method or equipment may be used to determine the Young’s modulus discussed herein one example of the equipment that may be used to measure the modulus is a LMEC-1 Young’s Modulus Apparatus.

[0044] (9) Lap shear adhesion: One test method that may be used to determine the lap shear adhesion is ASTM D5868. Other methods may also be used.

[0045] (10) % Elongation: The % elongation may also be determined in accordance with ASTM D-638. The embodiments disclosed herein are not limited to determining tensile strength by the aforementioned ASTM standard.

[0046] By “about X”, it is intended more or less 10% the value of X. In the context of the invention, the ranges of values are understood to be inclusive. For example, the range “between 0% and 25%” includes, in particular, the values 0% and 25%.

[0047] A first embodiment disclosed herein includes a two-component (“2K” or “2-component”) adhesive composition. Preferably the adhesive is a polyurethane adhesive. An application of the adhesive is as a structural adhesive. The adhesive may include a prepolymer (or “prepolymer component”), preferably comprising a polyol component and more preferably have an NCO content. The prepolymer may comprise the reaction product of an isocyanate compound and a polyol component. More preferably the prepolymer comprises an isocyanate terminated prepolymer. The prepolymer may be referred to as the first component or Part A of the 2K adhesive. The second component or Part B may be referred to as the curative component (or “curative”).

[0048] Isocyanates, which contains two or more isocyanate groups, 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 and cycloaliphatic polyisocyanates, more preferred are the aromatic monomeric isocyanates or the aromatic polymeric isocyanates.

[0049] The polyisocyanates can be diisocyanates that include cycloaliphatic, aromatic and aliphatic-aromatic diisocyanates. Specific examples of the cycloaliphatic diisocyanates can include, but are not limited to, cyclopentylene-1 ,3-diisocyanate, cyclo-hexylene-1 ,4- diisocyanate, cyclohexylene-1 ,2-diisocyanate, 1-isocyanato-2-isocyanatomethyl cyclopentane, 1-isocyanato-3-isocyanato-methyl-3,5,5-trimethylcyclohexane

[0050] (isophorone diisocyanate or IPDI), 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.

[0051] 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.

[0052] Another example of the modified MDI (modified diphenylmethane diisocyanate) may be a diphenylmethane diisocyanate in which at least about 2% of isocyanate groups have been modified to carbodiimide, or allophanate, or biuret, or polymeric structure.

[0053] In a further example, modified MDI may include a mixture of isomers of MDI, some of which have been modified to carbodiimide, or allophanate, or biuret, or polymeric structure, and some of which have not been modified, therefore, remain as monomers e.g., 4,4'-MDI, 2,4'-MDI, 2,2'-MDI, or combinations thereof.

[0054] 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). If so desired, optionally, the polyurethane composition may be free of an aromatic isocyanate compound. For example, the polyurethane composition may be free of an aromatic isocyanate compound selected from the group consisting of diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate, diisocyanato benzene, triisocyanato benzene, triisocyanato methylbenzene, bis(isocyanato methyl)benzene, and combinations thereof.

[0055] Preferred functionalities of the polymeric and / or monomeric isocyanates is least about 2 up to no more than 3, preferably less than 2.8. Particular of preferred examples of functionality may comprise at least about 2.1 , up to about 2.7, at least about 2.15, at least about 2.2, at least about 2.25, at least about 2.3 and at least about 2.35. Alternatively, the functionality may be about 2.0 to about 2.1 , about 2.1 to about 2.2, about 2.2 to about 2.3, about 2.3 to about 2.4, about 2.4 to about 2.5, about 2.5 to about 2.6, about 2.6 to about 2.7, about 2.7 to about 2.8, about 2.8 to about 2.9, about 2.9 to about 3.0 and combinations thereof.

[0056] The polyol component of the 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-8-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.

[0057] Non-limiting examples of suitable polyols include polyether polyols and polyester polyols. Exemplary 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 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.

[0058] The polyether polyols can include polymers of propylene oxides and / or copolymers of ethylene and propylene oxides, wherein the oxides contain. In one non-limiting embodiment, the polyether polyol is ethylene oxide capped polypropylene oxide.

[0059] The number average molecular weight of the polyether polyol can typically be varied from about 2,000 Daltons to about 20,000 Daltons or in a range of about 3,500 Daltons to about 12,000 Daltons, or in the range of from about 2,000 Daltons to about 12,000 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. Other suitable Acclaim® polyols include Acclaim® 6320N and Acclaim® 8200. Another example is PPG 4000. Examples of polyols with a number average molecular weight of more than 12,000 Daltons include Acclaim® 12200 and Hyperlite® E-855. Alternatively the number average molecular weight may range from about 2,000 to about 4,000, about 4,000 to about 6,000, about 6,000 to about 8,000, about 8,000 to about 10,000, about 10,000 to about 12,000, about 12,000 to about 14,000, about 14,000 to about 16,000, about 16,000 to about 18,000, to about 18,000 to about 20,000 and combinations thereof.

[0060] 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. The molecular weight of the 3-functionality polyether polyols can be varied from about 84 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.

[0061] Exemplary 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] In an embodiment, the viscosity of the prepolymer may be no more than about 400,000 cP, preferably no more than about 200,000 cP, more preferably no more than about 100,000 cP, further preferably no more than about 50,000 cP measured at 23°C and at a shear rate of about 0.79 s’1. Alternatively the viscosity of the prepolymer may comprise no more than about 400,000 cP to about 300,000 cP, about 300,000 cP to about 200,000 cP, about 200,000 cP to about 100,00 cP, about 100,000 cP to about 50,000 cP, about 50,000 cP to about 10,000 cP, or combinations thereof measured at 23°C and at a shear rate of about 0.79 s-1.

[0066] Preferably an NCO% in the prepolymer comprises up to about 30%, more preferably from about 1 to 25% such as from about 1 to 20%, even more preferably less than about 20%, further preferably at least about 3% or up to about 20%. In specific examples, one preferred range of NCO% is about 4-10%, another preferred embodiment is more than about 4% to less than 19% and in another embodiment a preferred range is about 4-20%. Alternatively, the NCO% may range from more than about 1 % to about 5%, about 5% to about 10%, about 10% to about 15%, about 15% to about 20%, about 20% to about 25%, about 25% to about 30% and combinations thereof.

[0067] A second component (“curative”) of the adhesive composition may include a second polyol component (or “second polyol”), or two or more second polyols (a plurality of the second polyols). Preferably the second polyol has a number average molecular weight of at least about 2,000 Daltons, more preferably at least about 4,000 Daltons, further preferably at least about 6,000 Daltons, even more preferably at least about 8,000 Daltons even further preferably at least about 12,000 Daltons, and most preferably more than about 100,000 Daltons. Exemplary polyols include the aforementioned PPG 4000, Acclaim®6320 N, Acclaim®8200, Acclaim® 12200 Pluracol TP-440, and Hyperlite® E-855.

[0068] In one particular embodiment, the number average molecular weight of the second polyol of the second component is no more than about 18,000 Daltons. Specific embodiments of the number average of the molecular weight of the second polyol may be up to about 15,000 Daltons, up to about 13,000 Daltons or up to about 12,000 Daltons. Alternatively, the number average molecular weight may be about 18,000 to about 16,000, about 16,000 to about 14,000, about 14,000 to about 12,000 to about 12,000 to about 10,000, about 10,000 to about 8,000, about 8,000 to about 6,000, about 6,000 to about 4,000, about 4,000 to about 2,000 and combinations thereof.

[0069] In another specific embodiment, the second polyol of the second component may have a number average molecular weight of at least about 5,000 Daltons, preferably at least about 10,000 Daltons, more preferably at least about 15,000 Daltons, even more preferably at least about 20,000 Daltons, further preferably at least about 50,000 Daltons and most preferably more than about 80,000 Daltons.

[0070] Examples of suitable components of the polyol second component may include a polymer modified polyol, preferably a modified polyether polyol. In a preferred embodiment a concentration of the polymer modified polyol comprises up to about 70 wt% of the second component.

[0071] In a specific embodiment, the second polyol comprises at least one polymer or prepolymer containing one or more polyether polyols having dispersed therein or grafted to the backbone one or more organic based polymer particles dispersed therein. The one or more organic based polymer particles may be based on monovinylidene aromatic monomers and copolymers of monovinylidene aromatic monomers with conjugated dienes, acrylates, methacrylates, unsaturated nitrites or mixtures thereof. The copolymers may be block or random copolymers. In one non-limiting embodiment of the present disclosure, the one or more organic based polymer particles comprise copolymers of unsaturated nitrites, conjugated dienes and a monovinylidene aromatic monomer, a copolymer of an unsaturated nitrile and a monovinylidene aromatic monomer or a polyurea. In another non-limiting embodiment of the present disclosure, the particles comprise polystyrene-acrylonitrile copolymers being most preferred. Preferably, the organic based polymer particles are included in the pre-polymer by inclusion of a polyol containing them, preferably a triol, having dispersed therein particles of an organic based polymer, for example one or more of thermoplastic polymers, rubber-modified thermoplastic polymers or polyureas dispersed in one or more triols. Preferable polyols having organic polymer particles dispersed therein or grafted thereto are disclosed in Zhou, U.S. Pat. No. 6,709,539 at column 4, line 13 to column 6, line 18, incorporated herein by reference. Preferably, the polyols used to disperse the organic particles is one or more polyether triols as described herein. Preferably pre-polymers containing one or more organic based polymers particles are present in compositions of the invention in a sufficient amount to enhance the elastomeric nature and the modulus of the compositions. In this specific embodiment, it also preferred that the second polyol has a number average molecular weight of at about 15,000 Daltons, further preferably at least about 20,000 Daltons, even more preferably at least about 50,000 Daltons and most preferably more than about 80,000 Daltons.

[0072] Preferably, the second polyol component is a multifunctional polyol such as a diol or a triol.

[0073] A wt% of the second polyol, or the plurality of the second polyols, in the second component may comprise at least about 10 wt% up to about 75 wt%, preferably in amount of less than about 70 wt%, more preferably less than about 65%, further more preferably more than about 15 wt%, further preferably at least about 20 wt%, even further preferably at least about 25 wt%, most preferably at least about 30 wt% or in the alternative an amount of the second polyol, or the plurality of the second polyols, in the second component comprises at least one of about 10 wt% to about 20 wt%, about 20 wt% to about 30 wt%, about 30 wt% to about 40 wt%, about 40 wt% to about 50 wt%, about 50 wt% to about 60 wt%, about 60 wt% to about 70 wt%, about 70 wt% to about 75 wt% or combinations thereof.

[0074] The second component may also include a monofunctional alcohol. The monofunctional alcohol preferably comprises a terminal hydroxyl group and a hydrocarbon chain. The hydrocarbon chain may include one or more polyether groups. In a particular embodiment, the monofunctional alcohol includes a terminal hydrocarbon having less than 9 carbon atoms, preferably less than 8 carbon atoms, and a hydroxyl terminal end. It is further preferred the back bone of monofunctional alcohol includes more than 1 alkoxylate unit, preferably at least 2 such units. Examples of suitable alkoxylation may range from at least 3 up to about 30 and all numbers in between. Nonlimiting examples of suitable alkoxylates include ethylene oxide (EO), propylene oxide (PO) and butylene oxide (BO) and combinations thereof.

[0075] A wt% of the monofunctional alcohol in the second component may comprise up to about 20 wt%, preferably less than about 15 wt%, more preferably no more than about 10 wt%, even more preferably no more than about 5 wt%, further preferably at least about 1 wt%, even further preferably at least about 3 wt% or in the alternative an amount of the monofunctional alcohol in the second component comprises at least one of about 1 wt% to about 5 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 20 wt% or combinations thereof.

[0076] Alternatively, the second component may also include one or more additional polyols. The additional polyols may be the same or different as those described earlier regarding the prepolymer. The additional polyol may be a polyether polyol. In one non-limiting embodiment, the polyether polyol is a polymer of propylene oxide or a copolymer of ethylene and propylene oxide. In another non-limiting embodiment, the free polyol may be a cardanol based polyester polyol or poly-8-caprolactone polyol.

[0077] Optionally, the second polyol may include an aspartic resin or diamines incorporated into its backbone. The adhesive composition may also include a silane adhesion promoter selected from the group comprising an isocyanurato silane adhesion promoter, an isocyanato silane adhesion promoter, epoxy functional silane adhesion promoters and combinations thereof. A concentration of the silane adhesion promoter may comprise from about 0.1 to 10 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- Isocyanatopropylmethyldimethoxysilane, 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.

[0078] Non-limiting examples of suitable epoxy functional silane adhesion promoters include: 3- Glycidoxypropyltriethoxysilane, 3-Glycidoxypropyltrimethoxysilane, 3-(2,3- Epoxypropoxypropyl)methyldiethoxysilane ,2-(3,4-

[0079] Epoxycyclohexyl)ethyltrimethoxysilane and combinations thereof.

[0080] The composition may also include at least 0.05 wt% of a non-amine / non-tin containing catalyst, preferably the non-amine / non-tin containing catalyst is present in at least one of the prepolymer, the curative and combinations thereof, more preferably non-amine / non-tin containing catalyst present in at least the prepolymer. In specific embodiments the wt% of the non-amine / non-tin containing catalyst, may comprise at least about 0.075 wt%, preferably at least about 0.1 wt%, more preferably at least about 0.25 wt%, further preferably at least about 0.3 wt%. Alternatively, the wt% of the non-amine / non-tin containing catalyst may comprise at least about 0.05 wt% to about 0.1 wt%, about 0.1 wt% to about 0.15 wt%, about 0.15 wt% to about 0.2 wt%, about 0.2 wt% to about 0.25 wt%, to about 0.25 wt% to about 0.3 wt%, about 0.3 wt% to about 0.35 wt%, about 0.35 wt% to about 0.4 wt% or combinations thereof. One example of the non-amine / non-tin containing catalyst may comprises a zirconium compound e.g., zirconium chelate catalyst. In other embodiments the non-amine / nontin containing catalyst comprises at least one of the following: zirconium chelate catalyst, bismuth catalyst, zinc catalyst and combinations thereof. Specific examples of the non- amine / non-tin containing catalyst comprises at least one of the following: zinc neodecanoate, zinc octoate, zinc acetylacetonate, zinc oxalate, zinc acetate, bismuth carboxylate, bismuth oxide, bismuth tris(2-ethylhexanoate), bismuth trisoctoate (e.g., Bi- OC, metal content 20%), bismuthic neodecanoate, bismuth octoate, bismuth acetylacetonate, bismuth oxalate, and bismuth acetate and combinations thereof.

[0081] In one embodiment the non-amine / non-tin containing catalyst of the two-component polyurethane composition comprises at least one of a zirconium compound, a zinc compound, a bismuth compound (also known as “bismuth complex”) and combinations thereof. Preferably, if present, the zirconium compound is present in no more than about 1.2 wt%, preferably no more than about 0.9 wt%, further preferably no more than about 0.7 wt%, further preferably no more than about 0.6 wt%, even more preferably at least about 0.1 wt%, and most preferably more than about 0.15 wt%. Also preferably, if present, the zinc compound present in no more than about 0.3 wt%, more preferably no more than about 0.1 wt%, further preferably no more than about 0.07 wt%, even further preferably no more than about 0.05 wt%, even more preferably at least about 0.01 wt%, and most preferably more than about 0.015 wt%. Further, if present, the bismuth compound is preferably present in no more than about 0.3 wt%, more preferably no more than about 0.1 %, further preferably no more than about 0.05 wt%, even further preferably no more than about 0.03 wt%, even furthermore preferably at least about 0.01 wt%, and most preferably more than about 0.015 wt%.

[0082] Optional components of the adhesive composition may include one or more catalyst, preferably a tin catalyst (or “tin containing catalyst”) in an amount of less than about 0.7 wt%, e.g., no more than about 0.6 wt%, no more than about 0.5 wt%, no more than about 0.4 wt%, less than about 0.3 wt%, or less than about 0.2 wt%, preferably no more than about 0.1 wt% of the tin catalyst, further preferably no more than about 0.05 wt%, event further preferably no more than about 0.01 wt%, more preferably no more than trace amounts of the tin-catalyst, even more preferably less than trace amounts of the tin catalyst , most preferably devoid of the tin-catalyst. Alternatively the wt% of the tin catalyst may be less than about 0.7 wt% to about 0.6 wt%, about 0.6 wt% to about 0.5 wt%, about 0.5 wt% to about 0.4 wt%, about 0.4 wt% to about 0.3 wt%, about 0.3 wt% to less than about 0.2 wt%, less than about 0.2 wt% to about 0.15 wt%, about 0.15 wt% to about 0.10 wt%, about 0.1 wt% to about 0.05 wt%, about 0.5 wt% to less than 0.1 wt% or combinations thereof. Examples of the optional tin catalyst may include dibutyl tin compounds, mercapto tin compounds and combinations thereof. In terms of the amount of tin, in a preferred embodiment, the adhesive composition contains no more than about 0.31 wt% of tin, preferably no more than about 0.25 wt%, more preferably no more than about 0.2 wt%, further preferably no more than about 0.1 wt%.

[0083] Further regarding the 2K polyurethane adhesive composition, optionally, the composition comprises no more than about 0.1 wt% or less than about 0.1 wt%, preferably no more than about 0.09 wt% of a tertiary amine catalyst, preferably no more than about 0.05 wt% or less than 0.05 wt%, further preferably no more than about 0.01 wt%, more preferably no more than trace amounts of the tertiary amine-catalyst, even more preferably less than trace amounts of the tertiary amine-catalyst, most preferably devoid of the tertiary amine- catalyst. Examples of the tertiary amine include a blocked tertiary amine, preferably the tertiary amine comprises at least one of: 1 ,4-Diazabicyclo[2.2.2]octane solution, DBll (diazabicycloundecene), 1 ,4-diazabicyclooctane and combinations thereof.

[0084] Another optional aspect is that the adhesive composition may comprise less than about 1 wt% of a solvent and / or water, preferably no more than a nominal amount of either the solvent and the water.

[0085] The adhesive composition may further include a further component selected from the group of at least one of: a polyether diamine, a mono ether and combinations thereof. A concentration of the further component may comprise no more than about 20 wt%, preferably at least about 0.5 wt%. Non-limiting examples of the polyether amine include diamine or triamines based on polyoxyalkylenepolyamine such as Jeffamines or Baxxodur polyether amines.

[0086] Non-limiting examples of the mono ether include: poly(ethylene glycol-ran-propylene glycol) monobutyl ether, polypropylene glycol) monobutyl ether, poly(ethylene-co-1 ,2- butylene)mono-ol, polyester ether mono-ol, C12 to C18 alcohol and combinations thereof.

[0087] The adhesive compositions disclosed herein may include less than about 10 wt% of a plasticizer, preferably less than about 5 wt%, more preferably less than about 4 wt%, even more preferably less than about 2 wt% and most preferably less than about 1 wt%. Specific embodiments may have less than about 0.5 wt%, less than about 0.1 wt% or below detection limits of the plasticizer. Alternatively the wt% of the plasticizer may be less than about 10 wt% to about 8 wt%, about 8 wt% to about 6 wt%, about 6 wt% to about 4 wt%, about 4 wt% to about 2 wt%, about 2 wt% to about less than about 0.5 wt% or combinations thereof.

[0088] Another component of the adhesive composition may include a chain extender comprising a polyol having a functionality of at least 2 or aromatic diamines. Suitable chain extenders include diols and triols. In one embodiment, the chain extender may be a low molecular weight chain extending compound and can either be hydroxyl terminated or amine terminated. In one non-limiting embodiment of the present disclosure, the chain extending compound can be a hydroxyl terminated one including a low molecular weight polyol that has a molecular weight ranged from about 25 to about 1 ,000 Daltons, or from about 32 to about 600 Daltons. The non-urethane modified low molecular weight chain extending compound may be selected from the group consisting of ethylene glycol, diethylene glycol, 1 ,5-pentandiol, 1 ,3-pentandiol, 1 ,3-butanediol, 1 ,4-butanediol, 1 ,2- propylene glycol, 1 ,3-propylene glycol, 1 ,6-hexylene glycol, dipropylene glycol, neopentyl glycol, 3-methyl pentane diol, 1 ,4-cyclohexane-dimethanol, and the combinations thereof. In one non-limiting embodiment, the non-urethane modified low molecular weight chain extending compounds can include 1 ,4-butylene glycol, ethylene glycol, 1 ,2-propylene glycol, dipropylene glycol and the combinations thereof. Examples of suitable aromatic diamine compounds may include diethyl toluene diamine, tetra-propoxylated ethylene diamine, methylene bis (ortho-ethylaniline) and combinations thereof.

[0089] The adhesive composition may also include various types of fillers, rheology modifiers, colorants and additives as desirable. A couple of examples of typical fillers for polyurethane adhesives includes talc, precipitated calcium carbonate and combinations thereof. Some embodiments of the adhesive composition may include less than about 1 wt% of the precipitated calcium carbonate, preferably less than about 0.5 wt%, more preferably less than about 0.1 wt%, even more preferably devoid of the precipitated calcium carbonate.

[0090] In one embodiment, the 2-component polyurethane composition may include fumed silica in the prepolymer. An amount of fumed silica in the prepolymer may comprise less than about 50 wt%, preferably less than about 30 wt%, further preferably less than about 15 wt%, more preferably less than about 10 wt %, most preferably less than about 5 wt%. If so desired, the prepolymer may include less than about 1 wt% of fumed silica. Optionally the prepolymer may have at least about 0.1 wt% of fumed silica.

[0091] Regarding the 2K polyurethane adhesive disclosed herein the second polyol component may comprise part of a curative (“Part B”). A volume ratio of the curative to prepolymer may comprise from about 1 :10 to about 10:1 , preferable volume ratios may comprise about 1 :1 , at least about 1 :1 .5, at least about 1 :4 and at least about 1 :2.

[0092] Typical components of the Part A prepolymer may include one or more of the aforementioned polyols, one or more isocyanate compounds, one or more non-amine / non-tin containing catalyst, one or more of the aforementioned fillers and other optional components. Typical components of Part B curative may include one or more of the aforementioned polyols, an optional chain extender, one or more optional fillers, a mono or diamine, optionally one or more non-amine / non-tin containing catalysts.

[0093] Preferably a tensile strength of the adhesive comprises at least about 3 MPa (about 435 psi), further preferable up to at least about 5 MPa (about 725 psi), more preferably at least about 6 MPa (about 870 psi), even more preferably no more than about 7 MPa (about at least 1000 psi) and an NCO to OH index of the composition of about 85 to 140, preferably at least about 90 (such as about 90 to 140) , further preferably at least about 100, more preferably at least about 110, further preferably not more than about 125 and even further preferably no more than about 120. Preferably the NCO:OH index is measured at a volume ratio of about 1 :1 of the prepolymer to the curative.

[0094] Preferably, the adhesive composition has Young’s modulus for a low modulus embodiment, the adhesive may have a Young’s modulus of up to no more than about 10 MPa, preferably no more than about 8 MPa, more preferably no more than about 7 MPa, further preferably at least about 1 MPa and even more preferably at least about 3 MPa.

[0095] Further the cured polyurethane adhesive composition may have a % elongation of at least about 100%, preferably at least about 200%, more preferably at least about 300%. In particular embodiments having one of the above % elongation the cured composition may have a tensile strength of at least about 3 MPa, preferably at least about 7 MPa, even more preferably up to about 8 MPa.

[0096] The adhesives disclosed may be part of a laminate. Preferably the laminate includes 1stand 2ndsubstrates. Preferably the any one of the adhesives disclosed herein is sandwiched between the 1stand 2ndsubstrates. In an embodiment the coefficient of thermal expansion (“CTE”) of the 1stsubstrate differs from a coefficient of thermal expansion of the 2ndsubstrate by at least about 5%, preferably at least about 10%, more preferably at least about 15%, measured at a temperature in a range of about -30°C up to about 82°C.

[0097] In one embodiment, the laminate is formed without the use of a sufficient amount of primer to assist with the adhesive adhering to one or both of the substrates. More preferably without the use of any primer. In another embodiment a primer may be used. In such an embodiment, the primer may be applied to one or both of the substrates. Typically, the primer is applied at a location of the substrate that will be adjacent the adhesive composition.

[0098] The laminates disclosed herein are not limited to any particular substrate. In one particular embodiment the 2 substrates have different CTEs as described above. Preferably one of the substrates comprises a polycarbonate material. Non-limiting examples of the substrate include glass, fiberglass composites, rubber, textiles, metal, coated metal, thermoplastic, a composite, preferably the composite may comprise carbon fibers or a sheeting molding compound, preferably the metal may comprise at least one of aluminum, copper steel, stainless steel, galvanized steel, carbon steel and alloys thereof. Preferably a coating for the coated metal may comprise nickel. Examples of the thermoplastic may comprise at least one of polyamide, polyolefins, and combinations thereof. Examples of polyolefins and other suitable materials for the substrate may include polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polypropylene (“PP”), polyethylene (“PE”), high density polyethylene (“HDPE”), polystyrene, polyvinyl chloride (“PVC”), acrylonitrile butadiene styrene (“ABS”) and combinations thereof. The various substrates listed herein may be used in any combination. Further one or more of the substrates may be powder coated or e-coated.

[0099] The disclosure also includes methods of making the laminates described herein. The method includes applying anyone the adhesives disclosed herein to either one of the 1stsubstrate and the 2ndsubstrate. The method also includes adhering the 1stsubstrate to the 2ndsubstrate. The aforementioned disclosure regarding CTEs applies to the method of making the laminate also.

[0100] Optionally, the method may not include applying the primer to either one of the 1stor 2ndsubstrates, preferably both the 1stand 2ndsubstrates. Additionally, the method may not include the step of mechanically pretreating either one of the 1stor the 2ndsubstrates prior to applying the adhesive, preferably not mechanically pretreating both the 1stand 2ndsubstrates. Also disclosed herein is a method of making a laminate. The method includes applying any one of the aforementioned adhesive compositions to the 1stsubstrate, the 2ndsubstrate or both. The adhesive composition is sandwiched between the 1stand 2ndsubstrates. The adhesive is cured at a temperature of no more than about 50°C, preferably no more than about 40°C, further preferably no more than about 35°C, more preferably no more than about 30°C, even more preferably no more than about 25°C, most preferably at least about 15°C.

[0101] The method of making the laminate may also optionally include applying a primer to one of the 1stsubstrate or the 2ndsubstrate, preferably the primer is not applied to the one of the 1stsubstrate or the 2ndsubstrate which the adhesive composition is applied. Preferably the primer is disposed at a location upon the sandwiching the adhesive the location contacts the adhesive composition applied to the other substrate.

[0102] Stated in the alternative, the primer is applied to one of the substrates (either the 1stsubstrate or the 2ndsubstrate) at a location which is aligned with contacting the adhesive which was or will be applied to the other substrate. The order of applying the adhesive or the primer first or second does not matter.

[0103] In a further alternative embodiment of the method, the primer is applied to a predetermined location on one of the 1stsubstrate and the 2ndsubstrate. The adhesive is subsequently applied to the predetermined location and then substrates are adhered together. In an additional alternate embodiment, the primer is applied to both the 1stand 2ndsubstrates at locations designed to contact the adhesive. The adhesive is applied to at least one of the 1stin 2ndsubstrates at the desired location that the primer was applied. Subsequently, the laminate was formed in which the substrate having the adhesive was brought into contact with the substrate including the primer without the adhesive. Preferably the section of the substrate having the primer previously disposed on thereon in brought into contact with the adhesive. The adhesive may have a Young’s modulus of at least about 1 MPa up to no more than about 10 MPa. Regarding particular embodiments of the adhesive composition, for a low modulus embodiment, the adhesive may have a Young’s modulus of at least about 1 MPa up to no more than about 7 MPa, preferably no more than about 6 MPa.

[0104] The aforementioned disclosure regarding laminates and methods of making the laminate are also applicable to the alternate adhesive composition.

[0105] Preferred is the following set of clauses 1 to 31 :

[0106] 1. A 2-component polyurethane adhesive composition comprising a prepolymer component and a curative component, preferably the prepolymer comprises a reaction product of at least one isocyanate compound and at least one polyol component, more preferably the prepolymer comprises an isocyanate terminated prepolymer, wherein the prepolymer comprises a. at least about 30 wt% of the polyol component, preferably up to no more than about 70 wt%, further preferably at least about 40 wt%, more preferably at least about 45 wt%, even more preferably at least about 50 wt% or alternatively the amount of the polyol component comprises at least about 30 wt% to about 40 wt%, about 40 wt% to about 50 wt%, about 50 wt% to about 60 wt%, about 60 wt% to about 70 wt%, or combinations thereof; and b. the composition comprises at least 0.05 wt% of a non-amine / non-tin containing catalyst, preferably at least about 0.075 wt, more preferably at least about 0.1 wt%, further preferably at least about 0.25 wt%, and at least about 0.3 wt% or alternatively the composition can comprise the non-amine / non-tin catalyst in an amount of at least about 0.05 wt% to about 0.1 wt%, about 0.1 wt% to about 0.15 wt%, about 0.15 wt% to about 0.2 wt%, about 0.2 wt% to about 0.25 wt%, about 0.25 wt% to about 0.3 wt%, more than about 0.3 wt%, or combinations thereof, preferably the non-amine / non-tin containing catalyst present in at least one of the prepolymer, the curative and combinations thereof, more preferably non-amine / non-tin containing catalyst present in at least the prepolymer wherein preferably the adhesive composition comprises less than about 1 wt% of precipitated calcium carbonate, preferably less than about 0.5 wt%, more preferably less than about 0.1 wt%, even more preferably devoid of the precipitated calcium carbonate.

[0107] 2. The 2-component polyurethane adhesive composition of clause 1 wherein the composition comprises less than 0.7 wt% of a tin catalyst, preferably no more than about 0.6 wt% of the tin catalyst, more preferably no more than about 0.5 wt% of the tin catalyst, further preferably no more than about 0.3 wt% or less than 0.3 wt%, of the tin catalyst, even further preferably no more than about 0.1 wt% of the tin-catalyst, even more preferably less than trace amounts of the tin catalyst, most preferably devoid of the tin- catalyst or alternatively the composition comprises the tin catalyst in an amount of less than 0.7 wt% to about 0.6 wt%, about 0.6 wt% to about 0.5 wt%, about 0.5 wt% to about 0.4 wt%, about 0.4 wt% to about 0.3 wt%, about 0.3 wt% to about 0.2 wt%, about 0.2 wt% to about 0.1 wt%, about 0.1 wt% to about 0.05 wt%, to less than about 0.05 wt% to devoid of the tin catalyst, or combinations thereof. Stated in terms of the amount of tin in the 2- component polyurethane adhesive composition, in a preferred embodiment, the adhesive composition contains no more than about 0.31 wt% of tin, preferably no more than about 0.25 wt%, more preferably no more than about 0.2 wt%, further preferably no more than about 0.1 wt%.

[0108] 3. The 2-component polyurethane adhesive composition of either clauses 1 or claim 2 wherein the composition comprises no more than about 0.1 wt% of a tertiary amine catalyst, e.g., no more than about 0.09 wt%, preferably no more than about 0.05 wt%, preferably less than 0.05 wt%, further preferably no more than about 0.01 wt%, more preferably no more than trace amounts of the tertiary amine-catalyst, even more preferably less than trace amounts of the tertiary amine- catalyst , most preferably devoid of the tertiary amine-catalyst, or alternatively the composition comprises the tertiary amine-catalyst in an amount of less than about 0.1 wt% to no more than about 0.09 wt%, 0.09 wt% to about 0.05 wt%, about 0.05 wt% to about 0.01 wt%, to about 0.01 wt% to devoid of the tertiary amine-catalyst.

[0109] 4. The 2-component polyurethane adhesive composition of anyone of clauses 1-3 wherein the polyol component of the prepolymer comprises at least one polyol having a number average molecular weight of at least about 4,000 Daltons, preferably the number average molecular weight comprises at least about 6,000 Daltons, more preferably the number average molecular weight comprises at least about 8,000 Daltons, further preferably the number average molecular weight comprises at least about 10,000 Daltons, even more preferably the number average molecular weight comprises at least about 12,000 Daltons.

[0110] 5. The 2-component polyurethane adhesive composition of anyone of clauses 1-4 wherein the composition having an NCO to OH index of at least about 85, preferably at least about 90, more preferably at least about 95, more preferably at least about 85 up to about 140, more preferably at least about 90 up to about 140, further preferably at least about 90 up to about 130, even more preferably at least about 90 up to about 125, even more preferably at least about 95 up to about 125, even further preferably at least about 100 to about 120, even more further preferably at least about 105 to less than about 120, alternatively the NCO to OH index may be in the amount of about 85 to about 90, about 90 to about 100, about 100 to about 105, about 105 to about 110, about 110 to about 115, about 115 to about 120, about 120 to about 130, about 130 to about 140 and combinations thereof, preferably the NCO to OH index is measured at a volume ratio of about 1 :1 of the prepolymer to the curative.

[0111] 6. The 2-component polyurethane adhesive composition of anyone of clauses 1-5 wherein at least one of the prepolymer, a curative and a combination thereof having a viscosity of no more than about 50,000 cP at @ 23C and .79 s'1shear rate, preferably no more than about 30,000 cP, further preferably no more than about 25,000 cP, more preferably about 15,000 cP, even more preferably more than about 10,000 cP or alternatively the viscosity may comprise no more than about 50,000 cP to about 40,000 cP, about 40,000 cP to about 30,000 cP, about 30,000 cP to about 20,000 cP, about 20,000 cP to about 10,000 cP or combinations thereof.

[0112] 7. The 2-component polyurethane adhesive composition of anyone of clauses 1-6 the prepolymer having an amount of fumed silica of less than about 50 wt%, preferably less than about 30 wt%, further preferably less than about 15 wt%, more preferably less than about 10 wt %, most preferably less than about 5 wt% or alternatively the composition can comprises fumed silica in an amount of less than about 50 wt% to about 40 wt%, about 40 wt% to about 30 wt%, about 30 wt% to about 20 wt%, about 20 wt% to about 10 wt%, about 10 wt% to less than about 5 wt% or combinations thereof .

[0113] 8. The 2-component polyurethane adhesive composition of anyone of clauses 1-7 wherein the amount of the non-amine / non-tin containing catalyst comprises no more than about 1 wt% of at least one of the prepolymer, the curative or both.

[0114] 9. The 2-component polyurethane adhesive composition of any one of clauses 1-8 wherein the non-amine / non-tin containing catalyst comprises at least one of a zirconium compound, a zinc compound, a bismuth compound and combinations thereof, a. preferably, if present, the zirconium compound presence in no more than about

[0115] 1 .2 wt%, more preferably no more than about 0.9 wt%, further preferably no more than about 0.7 wt%, even further preferably no more than about 0.6 wt%, even more preferably at least about 0.1 wt%, and most preferably more than about 0.15 wt% or alternatively the composition can comprise the zirconium compound in an amount of no more than about 1 .2 wt% to about 0.9 wt%, about 0.9 wt% to about 0.6 wt%, about 0.6 wt% to about 0.3 wt%, about 0.3 wt% to about 0.1 wt% or combinations thereof, b. preferably, if present, the zinc compound presence in no more than about 0.3% wt%, more preferably no more than about 0.1 wt%, further preferably no more than about 0.07 wt%, even further preferably no more than about 0.05 wt%, even more preferably at least about 0.01 wt%, and most preferably more than about 0.015 wt% or alternatively the composition can comprise the zinc compound in an amount of no more than about 0.3 wt% to about 0.1 wt%, about 0.1 wt% to about 0.05 wt%, about 0.05 wt% to about 0.01 wt% or combinations thereof, and / or c. preferably, if present, the bismuth compound presence in no more than about 0.3 wt%, more preferably no more than about 0.1 wt%, further preferably no more than about 0.05 wt%, even further preferably no more than about 0.03 wt%, even more further preferably at least about 0.01 wt%, and most preferably more than about 0.015 wt% or alternatively the composition can comprise bismuth compound in an amount of no more than about 0.3 wt% to about 0.1 wt%, about 0.1 wt% to about 0.05 wt%, about 0.05 wt% to about 0.01 wt% or combinations thereof.

[0116] 10. The 2-component polyurethane adhesive composition of any one of clauses 1-9 wherein the prepolymer further comprises a non-tertiary amine, preferably at least one of a primary amine, a secondary amine and combinations thereof, further preferably wherein the prepolymer having no more than traces amounts of free amine, more preferably less than trace amounts of free amine.

[0117] 11. The 2-component polyurethane adhesive composition of any one of clauses 1-10 wherein the composition when cured having a Young’s modulus of less than about 8 MPa, preferably less than about 7 MPa, further preferably less than about 6 MPa (for example less than 5 MPa), more preferably at least about 3 MPa.

[0118] 12. The 2-component polyurethane adhesive composition of any one of clauses 1-11 wherein the composition when cured exhibits at least one of an elongation of at least about 100%, preferably at least about 200%, more preferably at least about 300% and / or a tensile strength of at least about 3 MPa, more preferably up to about 8 MPa, further preferably up to about 7 MPa.

[0119] 13. The 2-component polyurethane adhesive composition of any one of clauses 1-12 further comprising a curative component, wherein the curative component comprises at least one a non-amine / non-tin containing catalyst, preferably the non-amine / non-tin containing catalyst comprises at least one from a zinc containing compound, a bismuth containing compound and combinations thereof, more preferably the non-amine / non-tin containing catalyst comprises at least about 0.025 wt% of the curative, further preferably the wt% comprises at least about 0.05%, more preferably the non-amine / non-tin containing catalyst comprises a zinc compound at least about 0.05 wt% of the curative, even more preferably the non-amine / non-tin containing catalyst comprises both the zinc compound and the bismuth compound and the wt% comprises more than about 0.05 wt% of the curative.

[0120] 14. The 2-component polyurethane adhesive composition of any one of clauses 1-13 wherein the prepolymer further comprises a polymeric MDI having a functionality of at least about 2.0, preferably a functionality of at least about 2.25, more preferably at least about 2.5 and further preferably at least about 2.7.

[0121] 15. The 2-component polyurethane adhesive composition of any one of clauses 1-14 wherein the prepolymer comprises a second polyol, the second polyol having a number average molecular weight comprising at least about 6,000 Daltons, preferably the number average molecular weight comprises at least about 8,000 Daltons, further preferably the number average molecular weight comprises at least about 10,000 Daltons, more preferably the number average molecular weight comprises at least about 12,000 Daltons.

[0122] 16. The 2-component polyurethane adhesive composition of any one of clauses 1-15 wherein the composition comprises a structural adhesive.

[0123] 17. The 2-component polyurethane adhesive composition of any one of clauses 1-16 wherein the non-amine / non-tin containing catalyst comprises a zirconium compound.

[0124] 18. The 2-component polyurethane adhesive composition of any one of clauses 1 -16 non- amine / non-tin containing catalyst comprises at least one of the following: zinc neodecanoate, zinc octoate, zinc acetylacetonate, zinc oxalate, zinc acetate, bismuth carboxylate, bismuth oxide, bismuth tris(2-ethylhexanoate), bismuth trisoctoate (Bi-OC, metal content 20%), bismuthic neodecanoate, bismuth octoate, bismuth acetylacetonate, bismuth oxalate, and bismuth acetate and combinations thereof.

[0125] 19. The 2-component polyurethane adhesive composition of any one of clauses 1-16 non-amine / non-tin containing catalyst comprises at least one of the following: zirconium chelate catalyst, bismuth catalyst, zinc catalyst and combinations thereof.

[0126] 20. The 2-component polyurethane adhesive composition of any one of clauses 1-19 wherein an NCO% of the prepolymer comprises up to about 30%, preferably less than about 30%, more preferably less than about 20%, more preferably at least about 1 %, further preferably at least about 3%, even further preferably at least about 4% up to about less than 20%.

[0127] 21. The 2-component polyurethane adhesive composition of any one of clauses 1-20 wherein the curative comprises a monofunctional alcohol, preferably the mono functional alcohol comprises a terminal hydroxyl group and a hydrocarbon chain, more preferably the hydrocarbon chain includes one or more polyether groups, even more preferably the monofunctional alcohol includes a terminal hydrocarbon having less than 9 carbon atoms, preferably less than 8 carbon atoms, and a hydroxyl terminal end, further preferably a back bone of monofunctional alcohol includes more than 1 alkoxylate unit, preferably at least 2 alkoxylate units, even further preferably the alkoxylate units includes at least one of ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO) and combinations thereof.

[0128] 22. The 2-component polyurethane adhesive composition of 21 wherein a wt% of the monofunctional alcohol in the second component (the curative) comprises up to about 20 wt%, preferably less than about 15 wt%, more preferably no more than about 10 wt%, even more preferably no more than about 5 wt%, further preferably at least about 1 wt%, even further preferably at least about 3 wt% or in the alternative an amount of the monofunctional alcohol in the second component comprises at least one of about 1 wt% to about 5 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 20 wt% or combinations thereof.

[0129] 23. The 2-component polyurethane adhesive composition of any one of clauses 1-22 wherein the curative comprises at least 1 multifunctional polyol having a number average molecular weight of at least about 4,000 Daltons, preferably the multifunctional polyol having a hydroxyl functionality of at least about 2, more preferably the hydroxyl functionality of at least about 3, preferably the number average molecular weight comprises at least about 5,000 Daltons, more preferably at least about 8,000 Daltons, further preferably at least about 10,000 Daltons, even further preferably at least about 15,000 Daltons.

[0130] 24. The 2-component polyurethane adhesive composition of clause 23 wherein a wt% of the at least one multifunctional polyol of the curative comprises at least about 10 wt% up to about 75 wt% of the curative, preferably in amount of less than about 70 wt%, more preferably less than about 65%, further more preferably more than about 15 wt%, further preferably at least about 20 wt%, even further preferably at least about 25 wt%, most preferably at least about 30 wt% or in the alternative the at least one multifunctional polyol of the curative is present in an amount of at least one of about 10 wt% to about 20 wt%, about 20 wt% to about 30 wt%, about 30 wt% to about 40 wt%, about 40 wt% to about 50 wt%, about 50 wt% to about 60 wt%, about 60 wt% to about 70 wt%, about 70 wt% to about 75 wt% or combinations thereof.

[0131] 25. A laminate comprising 1stand 2ndsubstrates adhered together and an adhesive wherein the adhesive comprises the adhesive composition of any one of clauses 1-24 in a cured form and at least one of the 1stand 2ndsubstrates comprises polycarbonate.

[0132] 26. The laminate of clause 25 wherein one of the 1stor 2ndsubstrates comprises polypropylene, preferably the substrate comprising the polypropylene is devoid of polycarbonate. 27. The laminate of either one of clauses 25 or 26 wherein the laminate exhibits good durability, preferably a tensile strength of at least about 3.0 MPa up to about 7.5 MPa.

[0133] 28. A method of making a laminate comprising: a. applying the adhesive composition any one of clauses 1-24 to one of a 1st substrate, a 2nd substrate or both; b. sandwiching the adhesive composition between the 1st and 2nd substrates; and c. curing the adhesive at a temperature of no more than about 50°C, preferably no more than about 40°C, further preferably no more than about 35°C, more preferably no more than about 30°C, even more preferably no more than about 25°C, most preferably at least about 15°C.

[0134] 29. The method of clauses 28 further comprising applying a primer to one of the 1stsubstrate or the 2ndsubstrate, preferably the primer not applied to the one of the 1stsubstrate or the 2ndsubstrate which the composition of any one of clauses 1-18 was applied, further preferably the primer is disposed at a location upon the sandwiching the location contacts the composition of any one of claims 1-19 applied.

[0135] 30. The method of either one of clauses 28 or 29 wherein at least one of the 1stsubstrate, the 2ndsubstrate or both comprises polycarbonate, preferably polycarbonate is used herein to include blends of including polycarbonate.

[0136] 31 . The 2-component polyurethane adhesive composition of any one of clauses 1 -13 or 15-24 wherein the prepolymer further comprises an isocyanate compound, wherein the isocyanate compound comprises at least one of an aromatic monomeric isocyanate, an aromatic polymeric isocyanate and combinations thereof, preferably the isocyanate compound having a functionality of at least about 2.0, more preferably no more than about 3.0, further preferably no more than about 2.7, even more preferably at least about 2.1 , even further preferably at least about 2.15, optionally it the isocyanate compound comprises MDI.

[0137] 32. A 2-component polyurethane adhesive composition comprising a prepolymer component and a curative component, preferably the prepolymer comprises a reaction product of at least one isocyanate compound and at least one polyol component, more preferably the prepolymer comprises an isocyanate terminated prepolymer, wherein the prepolymer comprises a. at least about 30 wt% of the polyol component, preferably up to no more than about 70 wt%, further preferably at least about 40 wt%, more preferably at least about 45 wt%, even more preferably at least about 50 wt% or alternatively the amount of the polyol component comprises at least about 30 wt% to about 40 wt%, about 40 wt% to about 50 wt%, about 50 wt% to about 60 wt%, about 60 wt% to about 70 wt%, or combinations thereof; b. the composition comprises at least 0.05 wt% of a non-amine / non-tin containing catalyst, preferably at least about 0.075 wt, more preferably at least about 0.1 wt%, further preferably at least about 0.25 wt%, and at least about 0.3 wt% or alternatively the composition can comprise the non-amine / non-tin catalyst in an amount of at least about 0.05 wt% to about 0.1 wt%, about 0.1 wt% to about 0.15 wt%, about 0.15 wt% to about 0.2 wt%, about 0.2 wt% to about 0.25 wt%, about 0.25 wt% to about 0.3 wt%, more than about 0.3 wt%, or combinations thereof, preferably the non-amine / non-tin containing catalyst present in at least one of the prepolymer, the curative and combinations thereof, more preferably non-amine / non-tin containing catalyst present in at least the prepolymer; and c. the curative comprises a monofunctional alcohol, preferably the mono functional alcohol comprises a terminal hydroxyl group and a hydrocarbon chain, more preferably the hydrocarbon chain includes one or more polyether groups, even more preferably the monofunctional alcohol includes a terminal hydrocarbon having less than 9 carbon atoms, preferably less than 8 carbon atoms, and a hydroxyl terminal end, further preferably a back bone of monofunctional alcohol includes more than 1 alkoxylate unit, preferably at least 2 alkoxylate units, even further preferably the alkoxylate units includes at least one of ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO) and combinations thereof.

[0138] 33. The 2-component polyurethane adhesive composition of 32 wherein a wt% of the monofuntional alcohol in the second component (the curative) comprises up to about 20 wt%, preferably less than about 15 wt%, more preferably no more than about 10 wt%, even more preferably no more than about 5 wt%, further preferably at least about 1 wt%, even further preferably at least about 3 wt% or in the alternative an amount of the monofunctional alcohol in the second component comprises at least one of about 1 wt% to about 5 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 20 wt% or combinations thereof.

[0139] 34. The 2-component polyurethane adhesive composition of any one of clauses 32 or 33 wherein the curative comprises at least 1 multifunctional polyol having a number average molecular weight of at least about 4,000 Daltons, preferably the multifunctional polyol having a hydroxyl functionality of at least about 2, more preferably the hydroxyl functionality of at least about 3, preferably the number average molecular weight comprises at least about 5,000 Daltons, more preferably at least about 8,000 Daltons, further preferably at least about 10,000 Daltons, even further preferably at least about 15,000 Daltons.

[0140] 35. The 2-component polyurethane adhesive composition of clause 34 wherein a wt% of the at least one multifunctional polyol of the curative comprises at least about 10 wt% up to about 75 wt% of the curative, preferably in amount of less than about 70 wt%, more preferably less than about 65%, further more preferably more than about 15 wt%, further preferably at least about 20 wt%, even further preferably at least about 25 wt%, most preferably at least about 30 wt% or in the alternative the at least one multifunctional polyol of the curative is present in an amount of at least one of about 10 wt% to about 20 wt%, about 20 wt% to about 30 wt%, about 30 wt% to about 40 wt%, about 40 wt% to about 50 wt%, about 50 wt% to about 60 wt%, about 60 wt% to about 70 wt%, about 70 wt% to about 75 wt% or combinations thereof.

[0141] The aforementioned description regarding the properties of adhesive and the alternate adhesive are equally applicable to the second alternate embodiment and are incorporated herein by reference as if fully rewritten.

[0142] 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.

[0143] The compositions and their applications according to the present disclosure may be prepared and used according to the examples set out below. These examples are presented herein for purposes of illustration of the present disclosure and are not intended to be limiting, for example, the preparations of the compositions and their applications.

[0144] EXAMPLES

[0145] In the examples, the adhesive failure modes are provided for the lap shear testing.

[0146] CH: Cohesion Failure- both sides coated with adhesive.

[0147] AD: Adhesive Failure- no or residual amount of adhesive on the substrate.

[0148] TF: Thin Film Failure- thin adhesive layer on the surface of substrate, thick adhesive layer on opposite substrate.

[0149] In Figure 1 , the adhesive is the dark color, and the substrate is a clear article. In each example, 2 laminates have been separated to illustrate the failure modes. Image (A) illustrates the AD, image (B) illustrates CH and image (C) illustrates TF.

[0150] Example A

[0151] In Example A, the below materials were used to make samples 1-4, also the procedure that was used is put forth below also. The procedure used to make Samples 1-4.

[0152] The polyols were charged into a reactor. The reactor was heated to 90°C. When the temperature in the reactor reached 80°C, the talc was charged into the reactor and a low shear agitation was applied, e.g., a rate of less than about 800 rpm. During agitation the silica was slowly added and agitation continued until the silica appeared as evenly dispersed in the reactor. The composition was further mixed under vacuum of greater than 27 mm Hg for 60 minutes at a temperature of 93°C. The composition was sampled for moisture until a percent moisture of less than 400 ppm was achieved. The reactor was cooled to 83°C. Next the isocyanate Rubinate 9720 and molecular sieves were charged into the reactor. Vacuum was re-applied and the composition was agitated for 2 hours at 83°C. Then the reactor was cooled to 70°C. The K-KAT 6212 catalyst was added to the reactor and the composition was agitated for 30 minutes under vacuum. The solid content, NCO% and viscosity at 23°C and 0.79 s-1shear rate was checked. NCO% was measured via titration using Metrohm 800 Dasino and viscosity was measured using Discovery HR-1 cone-plate rheometer.

[0153] Table 1 Samples 1-4 prepolymers In Example B, curative samples 5-8 were synthesized using the below procedure and materials.

[0154] The polyols were charged into a reactor. Vacuum was applied and the reactor was heated to 94°C. Talc and fumed silica was charged into the reactor at 94°C and a low shear agitation was applied until the talc and fumed silica wetted out. Next the stabilizer and the BDO was added to the reactor. The piperazine was added to the reactor and the composition was mixed at 65-70°C for 30 minutes. The molecular sieves and catalysts were added to the reactor and the composition was agitated for 60 minutes at 65-70°C. The composition was degassed for 30 minutes at 65-70°C. The composition was filtered and the viscosity of each sample was checked and adjusted as needed. The viscosity was checked at 23°C at 0.79 s-1shear rate.

[0155] Table 2 Samples 5-8 curatives Samples 9-14 as shown in Table 3, the prepolymers and curatives prepared in Tables 1 and 2 were loaded separately into side-by-side cartridges and pumped through a static mix tube (a static mixer with 24 element mixer tube having an 8.7 mm width) to achieve complete mixing as shown in Table 3. Then the mixed polymerizable adhesive compositions were applied directly from the static mix tube onto one side of the testing substrate.

[0156] Table 3 Prepolymer and curative combinations

[0157] 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 4X6 inches polycarbonate 3mm substrates with the adhesive and 0.76 mm glass spacer beads between the overlap. The polycarbonate substrates have films on both sides. The films were peeled off and adhesive was directly dispersed on the substrates. The test specimen was placed under 2-steel bars at room temperature for at least 4 days. The lap shear test was conducted according to ASTM D5868 at a crosshead speed of 2 inches per minute. ASTM D5868 is incorporated herein by reference in its entirety. All adhesives were prepared at an NCO to OH index in a range of from about 95 to about 105 unless otherwise noted.

[0158] Table 4 Lap shear results at different conditions

[0159] Environment: 72°C, 42% rh

[0160] Substrate: Polycarbonate, 3mm thickness having a protective film which was removed from both sides.

[0161] The prepolymer and curative were loaded separately into side-by-side cartridges and pumped through a static mix tube (having an 18 element mixer tube having an 8.7 mm width ) to achieve complete mixing. Then the mixed polymerizable adhesive compositions were applied directly from the static mix tube onto one side of the testing substrate.

[0162] The test samples were formed with 1" of overlap and an adhesive thickness of 30 mil.

[0163] The lap shear test was conducted according to ASTM D5868 at a crosshead speed of 0.5” per minute.

[0164] Cure Conditions: stored at room temperature for at least 4 days and then tested. Failure Mode Nomenclature: AD - Adhesive, FT - Fiber Tear, CH-Cohesive, TFC Thin Film Cohesive, SB - Stock Break. 30%CH / 70%AD = 30% cohesive, 70% adhesive.

[0165] The Table 4 results indicated that Sample 9 had the highest lap shear strength and cohesive failure mode is typically preferred in such applications. Sample 9 had prepolymer Sample 1 which was prepared with the high molecular weight polyols with the zirconium chelate catalyst. The zirconium chelate catalyst was used as a non-tin catalyst for two component plural gun or in-line mixing applications. Sample 9 exhibited rapid cure response and very good low temperature cure response, and high selectivity for - NCO / OH reaction over - NCO / water reaction. The zirconium chelate catalyst may be sensitive to moisture. Thus, this product is designed to be premixed with the polyisocyanate component.

[0166] Sample 2 did not contain zirconium catalyst with the same prepolymer composition and sample 6 contained the tin catalysts. Sample 10 (prepolymer sample 2 / curative sample 6) had good room temperature and 82°C lap shear strength and failure mode. However, the water soak had lower lap shear strength and exhibited adhesion failure mode. Sample 11 did not have zirconium catalyst in the prepolymer Sample 2 which had a much lower lap shear strength at all conditions.

[0167] Sample 12 contained tin catalysts instead of bismuth and zinc catalysts and exhibited lower lap shear strength at all conditions.

[0168] Sample 13 had the different composition in prepolymer sample 3 as compared to samples 1 and 2 and tin and amine catalysts in curative which exhibited lower lap shear strength at all conditions and exhibited poor failure mode for water soak.

[0169] Sample 14 is a commercially available Pliogrip® low modulus adhesive which had lower lap shear strength and exhibited adhesion failure mode.

[0170] Table 6 Prepolymer and curative combinations

[0171] Table 7 Lap shear results at different conditions

[0172] Samples 19-22 were made with the prepolymer samples 15-18 which had different isocyanates compounds. Sample 19 with prepolymer sample 15 Rubinate® M contains polymeric MDI with 2.7 functionality. Sample 20 with prepolymer sample 16 Mondur® MA2300 is an allophanate modified 4,4 '-diphenylmethane diisocyanate (MDI). Sample 21 with prepolymer sample 17 Mondur® MRS 4 is a low to medium functionality polymeric diphenylmethane-diisocyanate (pMDI) with a moderately high 2,4'-MDI isomer content. Sample 22 with prepolymer sample 18 Mondur MLQ monomeric diphenylmethane diisocyanate (MDI) contains a high percentage of 2,4-isomer. Sample 23 (below) Rubinate 9720 is industry standard for carbodiimide modified pure MDI which has higher reactivity, good adhesion, and flexibility. Prepolymers with the different isocyanate compounds exhibited different mechanical properties. Sample 23

[0173] Table 8 Prepolymer composition of sample 23

[0174] Samples 24 and 25

[0175] Sample 24 included only the bismuth catalyst and sample 25 included only the zinc catalyst in the curatives.

[0176] Table 9 Curative compositions

[0177] Table 10 Samples 27, 28 and 29

[0178] Table 11 Lap shear results at different conditions

[0179] Sample 27 had both bismuth and zinc catalysts in the curative and exhibited the best lap shear performance, regarding samples 27-29. Sample 28 having the bismuth catalyst in the curative exhibited good lap shear strength and good failure mode which were close to sample 27. The green strength buildup of sample 28 was slightly slower than sample 27. Sample 29 had only zinc catalyst in the catalyst, exhibited a lower lap shear strength at room temperature than both samples 27 and 28 and exhibited much slower green strength buildup than sample 27. The combination of bismuth and zinc catalysts in the curative exhibited the most balanced performance.

[0180] Adhesive compositions having prepolymers which included a second polyol having a number average molecular of at least about 12,000 Daltons exhibited a percent elongation of about 300%, which represented a 50% increase in elongation as compared to adhesive compositions having a second polyol having a number average molecular of up to about 8,000 Daltons. Table 14 Sample 27 test results 1 mm thickness 30% glass filler polycarbonate bonding

[0181] Table 15 The general properties of sample 27 prepolymer sample 23 / sample 24 curative

[0182] Sample 23 Sample 24

[0183] Prepolymer Curative

[0184] Color Light Tan Black

[0185] Viscosity, cP 20,000 - 43,000 20,000 - 50,000

[0186] Density, Ibs / gal (g / cm3) 10.7 (1 .25) 10.3 (1 .24)

[0187] Ratio by Volume 1.00 1.00

[0188] Odor Low Low

[0189] Table 16 The mechanical properties of sample 27 prepolymer sample 23 / sample 24 curative

[0190] Value Test Method*

[0191] Mixed Density, Ibs / gal (g / cm3) 10.5 (1.26) Calculated

[0192] Tensile strength, MPa @ 23°C 4 ASTM D-638

[0193] (73°F)

[0194] Young’s Modulus, MPa @ 23°C 5.4 ASTM D-638

[0195] (73°F)

[0196] Elongation, % 280 ASTM D-638

[0197] Glass Transition Temperatures, °C -42.8; 144.2 ASTM E-1640 (Tan

[0198] Delta Peak Example 30

[0199] Adhesive Composition Low Index NCO:OH 87

[0200] Table 17 Prepolymer compositions

[0201] Table 18 Curative compositions Table 19 Adhesive formulations

[0202] Table 20 Lap shear adhesives

[0203] 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.

Claims

CLAIMSWhat is Claimed is:1 . A 2-component polyurethane adhesive composition comprising a. a prepolymer component and a curative component, wherein the prepolymer comprises i. at least about 30 wt% of a polyol component, preferably up to no more than about 70 wt%, further preferably at least about 40 wt%, more preferably at least about 45 wt%, even more preferably at least about 50 wt%, and b. the composition comprises at least 0.05 wt% of a non-amine / non-tin containing catalyst, preferably at least about 0.075 wt%, more preferably at least about 0.1 wt%, further preferably at least about 0.25 wt%, preferably the non-amine / non-tin containing catalyst present in at least one of the prepolymer, the curative and combinations thereof, more preferably non-amine / non-tin containing catalyst present in at least the prepolymer wherein the adhesive composition comprises less than about 1 wt% of precipitated calcium carbonate, preferably less than about 0.5 wt%, more preferably less than about 0.1 wt%, even more preferably devoid of the precipitated calcium carbonate.

2. The 2-component polyurethane adhesive composition of claim 1 wherein the composition comprises less than 0.7 wt% of a tin containing catalyst, preferably no more than about 0.6 wt% of the tin catalyst, more preferably no more than about 0.5 wt% of the tin catalyst, further preferably no more than about 0.3 wt% of the tin catalyst, even further preferably less than 0.3 wt%, even further preferably no more than about 0.1 wt% of the tin catalyst, even more preferably no more than trace amounts of the tin-catalyst.

3. The 2-component polyurethane adhesive composition of either claim 1 or claim 2 wherein the composition comprises less than about 0.1 wt% of a tertiary amine catalyst, preferably no more than about 0.05 wt%, more preferably no more than about 0.01 wt%, even further preferably no more than trace amounts of the tertiary amine-catalyst, even more preferably less than trace amounts of the tertiary amine- catalyst.

4. The 2-component polyurethane adhesive composition of any one of claims 1-3 wherein the polyol component of the prepolymer comprises at least one polyol having a number average molecular weight of at least about 4000 Daltons, preferably the number average molecular weight comprises at least about 6000 Daltons, more preferably the number average molecular weight comprises at least about 8000 Daltons, further preferably the number average molecular weight comprises at least about 10000 Daltons, even more preferably the number average molecular weight comprises at least about 12000 Daltons.

5. The 2-component polyurethane adhesive composition of any one of claims 1-4 wherein the composition having an NCO to OH index of at least about 85, preferably at least about 90, more preferably at least about 90 up to about 140, further preferably at least about 95 up to about 130, even more preferably at least about 100 up to about 125, most preferably at least about 105 up to about 115, preferably the NCO to OH index measured at a volume ratio of about 1 :1 of the prepolymer to the curative.

6. The 2-component polyurethane adhesive composition of any one of claims 1-5 wherein at least one of the prepolymer, a curative and a combination thereof having a viscosity of no more than about 50,000 cP at @ 23C and .79 s-1shear rate, preferably no more than about 30,000 cP, further preferably no more than about 25,000 cP, more preferably no more than about 15,000 cP, even more preferably more than about 10,000 cP.

7. The 2-component polyurethane adhesive composition of any one of claims 1 -6 the prepolymer having an amount of fumed silica of less than about 50 wt%, preferably lessthan about 30 wt%, further preferably less than about 15 wt%, more preferably less than about 10 wt %, most preferably less than about 5 wt%.

8. The 2-component polyurethane adhesive composition of any one of claims 1-7 wherein the amount of the non-amine / non-tin containing catalyst comprises no more than about 1 wt% of the prepolymer, the curative or both.

9. The 2-component polyurethane adhesive composition of any one of claims 1-8 wherein the non-amine / non-tin containing catalyst comprises at least one of a zirconium compound, a zinc compound, a bismuth compound and combinations thereof, a. preferably, if present, the zirconium compound present in no more than about 1 .2 wt%, more preferably no more than about 0.9 wt%, further preferably no more than about 0.7 wt%, even further preferably no more than about 0.6 wt%, even more preferably at least about 0.1 wt%, and most preferably more than about 0.15 wt%, b. preferably, if present, the zinc compound present in no more than about 0.3 wt%, more preferably no more than about 0.1 wt%, further preferably no more than about 0.07 wt%, even further preferably no more than about 0.05 wt%, even more preferably at least about 0.01 wt%, and most preferably more than about 0.015 wt%, and / or c. preferably, if present, the bismuth compound present in no more than about 0.3 wt%, more preferably no more than about 0.1 wt%, further preferably no more than about 0.05 wt%, even further preferably no more than about 0.03 wt%, even more preferably at least about 0.01 wt%, and most preferably more than about 0.015 wt%.

10. The 2-component polyurethane adhesive composition of any one of claims 1-9 wherein the prepolymer further comprises a non-tertiary amine, preferably at least one of a primary amine, a secondary amine and combinations thereof, further preferably whereinthe prepolymer having no more than traces amounts of free amine, more preferably less than trace amounts of free amine.11 . The 2-component polyurethane adhesive composition of any one of claims 1-10 wherein the composition when cured having a Young’s modulus of less than about 8 MPa, preferably less than about 7 MPa, further preferably less than about 6 MPa, more preferably at least about 3 MPa.

12. The 2-component polyurethane adhesive composition of any one of claims 1-11 wherein the composition comprises a structural adhesive.

13. The 2-component polyurethane adhesive composition of any one of claims 1-12 further comprising a curative component, wherein the curative component comprises at least one a non-amine / non-tin containing catalyst, preferably the non-amine / non-tin containing catalyst comprises at least one from a zinc containing compound, a bismuth containing compound and combinations thereof, more preferably the non-amine / non-tin containing catalyst comprises at least about 0.025 wt% of the curative, further preferably the wt% comprises at least about 0.05%, more preferably the non-amine / non-tin containing catalyst comprises a zinc compound at least about 0.05 wt% of the curative, even more preferably the non-amine / non-tin containing catalyst comprises both the zinc compound and the bismuth compound and the wt% comprises more than about 0.05 wt% of the curative.

14. The 2-component polyurethane adhesive composition of any one of claims 1-13 wherein the prepolymer further comprises a polymeric MDI having a functionality of at least about 2.0, preferably a functionality of at least about 2.25, more preferably at least about 2.5 and further preferably at least about 2.7.

15. The 2-component polyurethane adhesive composition of any one of claims 1-14 wherein the prepolymer comprises a second polyol, the second polyol having a number average molecular weight comprising at least about 6,000 Daltons, preferably the number average molecular weight comprises at least about 8,000 Daltons, further preferably thenumber average molecular weight comprises at least about 10,000 Daltons, more preferably the number average molecular weight comprises at least about 12,000 Daltons.

16. The 2-component polyurethane adhesive composition of any one of claims 1-15 wherein the curative comprises a monofunctional alcohol, preferably the monofunctional alcohol comprises a terminal hydroxyl group and a hydrocarbon chain, more preferably the hydrocarbon chain includes one or more polyether groups, even more preferably the monofunctional alcohol includes a terminal hydrocarbon having less than 9 carbon atoms, preferably less than 8 carbon atoms, further preferably a back bone of the monofunctional alcohol includes more than 1 alkoxylate unit, preferably at least about 2 alkoxylate units, even further preferably the alkoxylate units include at least one of ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO) and combinations thereof.

17. The 2-component polyurethane adhesive composition of any one of claims 1-16 wherein the curative comprises a second polyol component comprising at least 1 multifunctional polyol having a number average molecular weight of at least about 4,000 Daltons, preferably the multifunctional polyol having a hydroxyl functionality of at least about 2, more preferably the hydroxyl functionality of at least about 3, preferably the number average molecular weight comprises at least about 5,000 Daltons, more preferably at least about 8,000 Daltons, further preferably at least about 10,000 Daltons, even further preferably at least about 15,000 Daltons.

18. The 2-component polyurethane adhesive composition of any one of claims 1 -17 wherein an NCO% of the prepolymer comprises less than about 30%, preferably less than about 20%, more preferably at least about 1 %, further preferably at least about 3%, even further preferably at least about 4% up to about less than 20%.

19. The 2-component polyurethane adhesive composition of any one of claims 1 -18 wherein the prepolymer comprises a reaction product of at least one isocyanate compound and at least one polyol, preferably the prepolymer comprises an isocyanate terminated prepolymer.

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