WO2001029143A1 - Ensemble comprenant un panneau ou une structure interieure de vehicule, et article adhesif - Google Patents

Ensemble comprenant un panneau ou une structure interieure de vehicule, et article adhesif Download PDF

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Publication number
WO2001029143A1
WO2001029143A1 PCT/US2000/025590 US0025590W WO0129143A1 WO 2001029143 A1 WO2001029143 A1 WO 2001029143A1 US 0025590 W US0025590 W US 0025590W WO 0129143 A1 WO0129143 A1 WO 0129143A1
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WO
WIPO (PCT)
Prior art keywords
pressure sensitive
sensitive adhesive
adhesive article
layer
adhesive
Prior art date
Application number
PCT/US2000/025590
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English (en)
Inventor
Wilson S. Bigham
Alain H. Lamon
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3M Innovative Properties Company
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Publication date
Application filed by 3M Innovative Properties Company filed Critical 3M Innovative Properties Company
Publication of WO2001029143A1 publication Critical patent/WO2001029143A1/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J5/00—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
    • C09J5/06—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers involving heating of the applied adhesive
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/10—Adhesives in the form of films or foils without carriers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
    • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
    • C09J2301/124—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present on both sides of the carrier, e.g. double-sided adhesive tape
    • C09J2301/1242—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present on both sides of the carrier, e.g. double-sided adhesive tape the opposite adhesive layers being different
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/20—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself
    • C09J2301/208—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself the adhesive layer being constituted by at least two or more adjacent or superposed adhesive layers, e.g. multilayer adhesive
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/302—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/304—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier the adhesive being heat-activatable, i.e. not tacky at temperatures inferior to 30°C
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2461/00—Presence of condensation polymers of aldehydes or ketones
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2463/00—Presence of epoxy resin
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2475/00—Presence of polyurethane

Definitions

  • the invention relates to an assembly comprising an adhesive article and a vehicle panel or vehicle frame as well as a method for attaching a vehicle panels or vehicle frame using an adhesive article, where the adhesive article comprises a pressure sensitive adhesive layer and a bondable layer.
  • the invention also relates to a method of applying an adhesive article having a pressure sensitive adhesive layer and a bondable layer to a vehicle panel to act, for example, as a seam sealer.
  • MIG Inert Gas
  • resistance spot welding resistance spot welding
  • adhesive bonding Vehicle body panels include door skins, quarter panels, and roof skins.
  • MIG welding and resistance spot welding have been long-used and are common (re)attachment methods, but they suffer from many disadvantages. These include the risk of fire, warpage of adjacent sheet metal, and the propensity to create so-called "corrosion hot spots”.
  • U.S. Patent No. 5,593,759 discloses a pressure sensitive structural adhesive material comprising a core layer of a thermally curable structural adhesive providing opposed surfaces having on at least one surface thereof a separate continuous or discontinuous layer of a tacky pressure sensitive adhesive, the pressure sensitive adhesive being absorbed into the core layer upon curing.
  • Japanese Kokai Patent No. 3-14888 discloses a heat curable tacky adhesive sheet with a heat curing area and pressure sensitive adhesive area on the same face of the sheet, in which both the heat curing area and the pressure sensitive area are continuous through the thickness of the film or are both coated, side-by-side, on a supporting film.
  • U.S. Patent No. 4,908,273 discloses a multilayer, heat curable adhesive film having a tacky external heat curable layer and a dry external heat curable layer, containing adducts which contain epoxide groups.
  • EP 942054 discloses an assembly comprising two substrates bonded together by an adhesive system comprising at least one pressure sensitive adhesive layer and at least one cured structural hybrid adhesive layer wherein at least one of the pressure sensitive adhesive layers is essentially continuous and extends essentially over the full width of the bonded area.
  • U.S. Patent No. 5,086,088 discloses a pressure-sensitive thermosetting adhesive comprising a blend of an acrylic ester and an epoxy resin.
  • the vehicle attachment industry continues to seek adhesive articles having a combination of benefits of different types of adhesives, for example, the properties of both a pressure-sensitive adhesive before cure and a strong bond after cure.
  • the present invention relates to an assembly comprising an adhesive article and outer vehicle body panel or vehicle inner structure, wherein the adhesive article comprises a bondable layer having on at least one major surface a discontinuous layer of pressure sensitive adhesive, wherein the bondable layer comprises a thermosetting material or a hybrid material, the pressure sensitive adhesive layer substantially retains pressure sensitive adhesive characteristics after storage at room temperature for at least about three months prior to heating the adhesive article, and the adhesive article has a overlap shear measured at room temperature according to ASTM D-1002-94 of at least about 6.9 MPa after bonding, and wherein the adhesive article is attached to the outer vehicle body panel or vehicle inner structure.
  • the adhesive article comprises a bondable layer having on at least one major surface a discontinuous layer of pressure sensitive adhesive
  • the bondable layer comprises a thermosetting material or a hybrid material
  • the pressure sensitive adhesive layer substantially retains pressure sensitive adhesive characteristics after storage at room temperature for at least about three months prior to heating the adhesive article
  • the adhesive article has a overlap shear measured at room temperature according to ASTM D-1002-94 of at
  • the present invention also relates to an assembly comprising an adhesive article and outer vehicle body panel or vehicle inner structure, wherein the adhesive article comprises a bondable layer having on at least one major surface a discontinuous layer of pressure sensitive adhesive, wherein the bondable layer comprises a thermosetting material selected from the group consisting of urethanes, cyanate esters, phenolics, and bismaleimides, and any combinations thereof, and wherein the adhesive article is attached to the outer vehicle body panel or vehicle inner structure.
  • the present invention relates to an assembly comprising an adhesive article and outer vehicle body panel or vehicle inner structure, wherein the adhesive article comprises a bondable layer having on at least one major surface a discontinuous layer of pressure sensitive adhesive, wherein the bondable layer comprises a fusible epoxide prepolymer which is a solid at room temperature, and wherein the adhesive article is attached to the outer vehicle body panel or vehicle inner structure.
  • the present invention relates to a method comprising the steps of (a) providing an adhesive article, wherein the adhesive article comprises a bondable layer having on at least one major surface a discontinuous layer of pressure sensitive adhesive, wherein the bondable layer comprises a thermosetting material or a hybrid material, the pressure sensitive adhesive layer substantially retains pressure sensitive adhesive characteristics after storage at room temperature for at least about three months prior to heating the adhesive article, and the adhesive article has a overlap shear measured at room temperature according to ASTM D-1002-94 of at least about 6.9 MPa after bonding, (b) attaching a major surface of the adhesive article to an outer vehicle body panel, (c) attaching another major surface of the adhesive article to a second outer vehicle body panel or a vehicle inner structure, and (d) bonding the adhesive article.
  • the present invention relates to a method comprising the steps of (a) providing an adhesive article, wherein the adhesive article comprises a bondable layer having on at least one major surface a discontinuous layer of pressure sensitive adhesive, wherein the bondable layer comprises a thermosetting material or a hybrid material, the pressure sensitive adhesive layer substantially retains pressure sensitive adhesive characteristics after storage at room temperature for at least about three months prior to heating the adhesive article, and the adhesive article has a overlap shear measured at room temperature according to ASTM D-1002-94 of at least about 6.9 MPa after bonding, (b) attaching a major surface of the adhesive article to vehicle inner structure, (c) attaching another major surface of the adhesive article to an outer vehicle body panel, and (d) bonding the adhesive article.
  • the present invention also relates to a method comprising the steps of (a) providing an adhesive article, wherein the adhesive article comprises a bondable layer having on at least one major surface a discontinuous layer of pressure sensitive adhesive, wherein the bondable layer comprises a thermosetting material or a hybrid material, the pressure sensitive adhesive layer substantially retains pressure sensitive adhesive characteristics after storage at room temperature for at least about three months prior to heating the adhesive article, and the adhesive article has a overlap shear measured at room temperature according to ASTM D-1002-94 of at least about 6.9 MPa after bonding, (b) attaching the pressure sensitive adhesive layer of the adhesive article to a union of two outer vehicle body panels or a union of an outer vehicle body panel and a vehicle inner structure, and (c) bonding the adhesive article to provide a seal.
  • the adhesive article of the present invention may have one or more features as described herein.
  • a pressure sensitive layer may be discontinuous over at least one major surface of the bondable layer.
  • a pressure sensitive adhesive layer preferably retains its pressure sensitive adhesive characteristics, as described herein.
  • a bondable layer may be a thermosetting material or a hybrid material as defined below.
  • a thermosetting or hybrid bondable layer when tested alone after bonding, may an overlap shear strength as tested in accordance with ASTM D-1002-94, at room temperature (approximately 23°C + 3°C) of at least about 6.9 MegaPascals ("MPa”), and preferably at a temperature from room temperature up to and including about 80°C of at least about 6.9 MPa.
  • An adhesive article of the present invention having a thermosetting or hybrid bondable layer, which has been bonded may also have an overlap shear strength as tested in accordance with ASTM D-1002-94, at room temperature (approximately 23°C ⁇ 3°C) of at least about 6.9 MPa, and preferably at a temperature from room temperature up to and including about 80°C of at least about 6.9 MPa.
  • the present invention relates to an assembly comprising an adhesive article and an outer vehicle body panel or vehicle inner structure.
  • the adhesive article comprises a bondable layer and a pressure sensitive adhesive (also referred to throughout as "psa”) layer on at least one major surface of the bondable layer as well as an assembly comprising at least one substrate and the adhesive article and may be as described in co-filed U.S. Serial No. 09/422,610.
  • a pressure sensitive adhesive also referred to throughout as "psa”
  • a bondable layer Before being bonded, a bondable layer may provide insufficient, if any, adhesion. Therefore, a pressure sensitive adhesive in accordance with the present invention provides adherence between at least one substrate and the bondable layer so that the adhesive article is held in place on the at least one substrate prior to bonding. Then, a second substrate may be applied to the other side of the bondable layer. In an adhesive article where the pressure sensitive adhesive layer is discontinuous, another discontinuous layer of pressure sensitive adhesive may be provided on the other side of the bondable layer.
  • the term “on” or “thereon” generally refers to the placement of one layer in contact with, attached to, or adhered to another layer.
  • a layer or material inte ⁇ osed between the two layers being described to enhance the features of the adhesive article or adherence between the layers, as understood by one skilled in the art.
  • a primer layer or a scrim layer may be present between a bondable layer and a pressure sensitive adhesive layer or within the bondable layer.
  • the pressure sensitive adhesive layer retains pressure sensitive adhesive characteristics, for example, tack, before bonding, more preferably retains these characteristics during the useful life of the bondable layer, so that the adhesive article will serve its dual purpose, i.e., forming a pressure sensitive adhesive bond, for example, by maintaining the position of the adhesive article, before bonding, by a pressure sensitive adhesive layer, and forming a sufficiently strong bond for its intended pu ⁇ ose, after bonding, by use of a bondable layer which becomes a bonded layer. If the pressure sensitive adhesive does not retain pressure sensitive adhesive characteristics sufficient to adhere the adhesive article to a substrate, the adhesive article may be basically reduced to the properties of the bondable layer alone, and the benefits of the combination with a pressure sensitive adhesive may not be realized.
  • pressure sensitive adhesive characteristics for example, tack
  • the bondable layer and the pressure sensitive adhesive layer are preferably selected so that the pressure sensitive adhesive layer retains pressure sensitive adhesive characteristics for as long as the bondable layer remains useable.
  • retention with respect to retention of pressure sensitive adhesive characteristics as used herein refers to a pressure sensitive adhesive layer that retains pressure sensitive adhesive characteristics after storage while in contact with a bondable layer.
  • the pressure sensitive adhesive characteristics are not necessarily the same after storage as before storage (i.e., when the adhesive article is first made) but the pressure sensitive adhesive characteristics are sufficiently retained such that they satisfy the requirements of a pressure sensitive adhesive described herein with reference to retaining pressure sensitive adhesive characteristics.
  • the pressure sensitive adhesive characteristics are substantially the same before and after storage.
  • the concept of retaining pressure sensitive adhesive characteristics after storage refers to a pressure sensitive adhesive that, after storage, remains aggressively and permanently tacky at room temperature and firmly adheres to a variety of dissimilar surfaces upon mere contact without the need of more than finger or hand pressure and that requires no activation by water, solvent, or heat and has a sufficiently cohesive and elastic nature so that, despite its aggressive tackiness, it can be handled with the fingers and removed from smooth surfaces without leaving a substantial residue.
  • the pressure sensitive adhesive characteristics of the pressure sensitive adhesive layer may be retained after bonding the bondable layer.
  • the bondable layer and the pressure sensitive adhesive layer are selected so that the characteristics of the bondable or the bonded layer, for example, the adhesion and/or the integrity of the bondable or bonded layer, are not affected by the presence of the pressure sensitive adhesive layer.
  • the pressure sensitive adhesive layer of an adhesive article of the present invention retains pressure sensitive adhesive characteristics for the duration of the usable life of the bondable layer.
  • the pressure sensitive adhesive layer of the present invention typically retains pressure sensitive adhesive characteristics after storage at room temperature (approximately 23 + 3°C) for at least 3 months, preferably at least six months, and more preferably at least 12 months.
  • the pressure sensitive adhesive layer retains pressure sensitive adhesive characteristics after storage at 38 to 42°C for at least about 20 days.
  • pressure sensitive adhesive characteristics are retained by using a pressure sensitive adhesive layer that is substantially incompatible with the bondable layer.
  • substantially incompatible refers to a bondable layer and a pressure sensitive adhesive layer whose components do not intermingle.
  • the pressure sensitive adhesive layer has either a substantial resistance to, or lack of any substantial interaction with, any migratory components of the bondable layer such that its pressure sensitive adhesive characteristics are retained. In other words, any migratory components of the bondable layer do not substantially affect the pressure sensitive characteristics of the pressure sensitive adhesive layer.
  • One way of achieving "substantial incompatibility" between a pressure sensitive adhesive layer and a bondable layer is to employ a pressure sensitive adhesive layer having a solubility parameter that differs substantially from the solubility parameter of any migratory components of the bondable layer.
  • the term "differs substantially” as used herein with reference to solubility parameters generally refers to a solubility parameter difference of at least about 1 (cal/cm 3 ) 0 5 , typically, at least 1.1 (cal/cm 3 ) 05 , preferably at least 1.2 (cal/cm 3 ) 05 , and more preferably at least 1.3 (cal/cm 3 ) 0 5 . Solubility parameters are described in E.A. Grulke in Polymer Handbook: 3 rd
  • the solubility parameter may be calculated as described in Fedors, Polym. Eng. and Sci., H (1974), 147 and WO 98/21287 (PCT US 96/18841).
  • the pressure sensitive adhesive layer and the migratory component(s) of the bondable layer may not have a solubility parameter difference as described above, but the pressure sensitive adhesive may be selected or formulated so that it can tolerate the presence of some amount of migratory components from the bondable layer without losing its ability to function as a pressure sensitive adhesive layer.
  • the pressure sensitive adhesive has a glass transition temperature, Tg, with or without migratory component(s) in the range of about -30°C to about 10°C (as described on pp.
  • Tg is to measure the maximum in the tan delta peak of a dynamic mechanical scan made by changing the sample temperature while holding the measurement frequency fixed at approximately 0.17 radians/sec (1 Hz).
  • 1/Tg (w ⁇ /Tg ⁇ + w 2 /Tg 2 ), where Wi and w 2 refer to the weight fraction of the two components and Tgi and Tg refer to the glass transition temperature of the two components, as described for example in L.H. Sperling, "Introduction to Physical Polymer Science", 2 nd Edition, John Wiley & Sons, New York, p. 357 (1992) and T.G. Fox, Bull. Am. Phys.
  • the Tg of the migratory component(s), and an estimate of a weight fraction of migratory component(s) in the pressure sensitive adhesive one may calculate the Tg of a pressure sensitive adhesive which can tolerate the presence of the migratory component(s) in the amount estimated and still retain the desired pressure sensitive adhesive characteristics.
  • the Fox equation expanded and used for a system with more than two components.
  • a suitable pressure sensitive adhesive is then selected or can be formulated to have the calculated Tg, as well understood by one skilled in the art.
  • the estimated amount of migratory component(s) can be pre-loaded into the selected pressure sensitive adhesive to preempt migration. This removes the concentration gradient which acts as a driving force for migration.
  • An example of a pressure sensitive adhesive that would not be considered tolerant of migratory components from the bondable layer is one in which curable components and curatives migrating into the pressure sensitive adhesive layer undergo a curing reaction prior to bonding that causes the pressure sensitive adhesive layer to no longer effectively function as a pressure sensitive adhesive as defined above even though the degree of cure (i.e., chemical curing) of the bondable layer is low enough that the bondable layer may still be usable.
  • each of the layers of an adhesive article of the present invention are selected depending on the intended use of the adhesive article, preferably to maximize the overlap shear strength of an adhesive article with a bonded layer.
  • a ratio of the thickness of the bondable layer to the thickness of the pressure sensitive layer may be chosen to achieve an adhesive article having the desired result.
  • the thickness of the bondable layer can be selected to maximize the performance of the bondable layer alone; then the thickness of the pressure sensitive adhesive layer may be chosen to maximize the performance of the bonded adhesive article.
  • Particular performance characteristics include overlap shear strength and peel strength.
  • the ratio of bondable layer thickness to pressure sensitive adhesive layer thickness is at least 4: 1.
  • a discontinuous pressure sensitive adhesive layer As the thickness of a discontinuous pressure sensitive adhesive layer increases, the ability of the bondable layer to wet out the substrate during bonding, for example, heating, may decrease. In addition, as the thickness of a pressure sensitive adhesive layer increases, the overlap shear strength of the adhesive article having a bonded layer may decrease in the regions where pressure sensitive adhesive is present. Furthermore, in embodiments where substrate surfaces of a uniform height are desired, it is preferable to minimize the thickness of a discontinuous layer of pressure sensitive adhesive in order to avoid the possibility of undesirable telegraphing of the discontinuous pattern to the exposed surface of a substrate such that the substrate surface becomes irregular.
  • a pressure sensitive adhesive layer generally has a thickness of from about 2 to 1000 micrometers, typically 5 to 250 micrometers, preferably 5 to 100 micrometers, more preferably 10 to 50 micrometers.
  • a bondable layer generally has a thickness of from about
  • micrometers typically 10 to 2000 micrometers, preferably 20 to 1000 micrometers, more preferably from 200 to 1000 micrometers.
  • a bondable layer of the present invention may comprise a thermosetting material or a hybrid material.
  • material refers to monomers, oligomers, prepolymers, and/or polymers.
  • the bondable layer may include optional additives, and in the case of a bondable material comprising a thermosetting material, may also include a curative or curatives.
  • bondable means that a bond between two substrates can be achieved by the application of heat; actinic radiation such as UV, visible, or infrared; microwave or X-ray energy; or combinations thereof; the term “bondable” may also refer to a curable material.
  • the bondable layer of the present invention is preferably a heat bondable layer which, upon application of heat, undergoes an initial decrease in viscosity which promotes wetting of the substrate and enhances adhesion and, in the case of, for example, a thermosetting material, causes a curing reaction.
  • a bondable layer After application of application of heat; actinic radiation such as UV, visible, or infrared; microwave or X-ray energy; or combinations thereof sufficient to accomplish a bond between substrates, a bondable layer is referred to herein as bonded or cured. Actinic radiation may be used to activate or complete bonding.
  • the type of bonding application is chosen depending on whether one or two substrates are present, the type of substrate, and the choice of bondable layer; for example, when two metal substrates are used, it is preferably to bond using heat.
  • bondable and bonded as used herein are not intended to encompass the act of attaching or applying the adhesive article to a substrate before the application of heat, actinic radiation such as UV, visible, or infrared, or microwave or X-ray energy.
  • actinic radiation such as UV, visible, or infrared, or microwave or X-ray energy.
  • bonding refers to forming a permanent bond.
  • thermosetting refers to a material, which undergoes a curing reaction that results in a chemical change upon bonding and an increase in the hardness of the material.
  • thermoset refers to a thermosetting material, which has been cured.
  • a thermosetting material may generally be bonded by application of heat, actinic radiation such as UV, visible, or infrared, or microwave or X- ray energy.
  • hybrid material refers to a material which is a combination of at least two components, wherein the at least two components are compatible in the melt phase (the melt phase is where the combination of the at least two components is a liquid), the at least two components form a inte ⁇ enetrating polymer network or semi-inte ⁇ enetrating polymer network, and at least one component becomes infusible (i.e., the component cannot be dissolved or melted) after application of heat or by other means of curing such as application of light.
  • a hybrid material will be described in more detail below.
  • a hybrid material may generally be bonded by application of heat, actinic radiation such as UV, visible, or infrared, or microwave or X-ray energy.
  • thermosetting materials and any optional additives will be considered non-hybrid materials if they do not meet the definition of hybrid material as defined herein.
  • the bondable material is preferably selected for an adhesive article of the present invention so that, upon contact with a pressure sensitive adhesive layer, pressure sensitive adhesive characteristics of the pressure sensitive adhesive layer are retained as described above.
  • the bondable layer is preferably storage stable at room temperature.
  • Suitable thermosetting materials are those that can be used to prepare a bondable layer in film form having latency.
  • latency it is meant that the bonding process can be substantially prevented until the adhesive article can be prepared and placed between substrates to be bonded. In some cases, achieving this latency may require dark and/or cold storage.
  • a bondable layer comprising a thermosetting material preferably, after bonding, has overlap shear strength according to ASTM D-1002-94, at room temperature
  • the bondable layer comprises a thermosetting material, which after bonding, has an overlap shear strength of at least about 6.9 MegaPascals
  • the resulting adhesive article with a thermosetting bondable layer upon bonding, has an overlap shear strength of at least about 6.9 MPa, in accordance with ASTM D-1002-94, at room temperature (approximately 23°C + 3°C).
  • An adhesive having an overlap shear strength of at least about 6.9 MPa, in accordance with ASTM D-1002-94, at room temperature (approximately 23°C + 3°C) is considered to be a structural adhesive, as described in A. V. Pocius, "Adhesion and Adhesives Technology” Hanser/Gardner 1997, p.183.
  • thermosetting materials include epoxides, urethanes, cyanate esters, bismaleimides, phenolics, including nitrile phenolics, and any combinations thereof.
  • Suitable epoxides include those containing at least two 1,2-cyclic ethers. Such compounds can be saturated or unsaturated, aliphatic, aromatic or heterocyclic, or can comprise combinations thereof. Suitable epoxides may be solid or liquid at room temperature.
  • polyepoxides Compounds containing at least two epoxide groups (i.e., polyepoxides) are preferred.
  • a combination of epoxide compounds may be employed, and an epoxide having a functionality of less than two may be used in a combination so long as the overall epoxide functionality of the mixture is at least two.
  • the polymeric epoxides include linear polymers having terminal epoxy groups (e.g., a diglycidyl ether of a polyoxyalkylene glycol), polymers having skeletal oxirane units (e.g., polybutadiene polyepoxide), and polymers having pendent epoxy groups (e.g., a glycidyl methacrylate polymer or copolymer). It is also within the scope of this invention to use a material with functionality in addition to epoxide functionality but which is essentially unreactive with the epoxide functionality, for example, a material containing both epoxid
  • Aromatic polyepoxides i.e., compounds containing at least one aromatic ring structure, e.g., a benzene ring, and at least two epoxide groups
  • Aromatic polyepoxides include the polyglycidyl ethers of polyhydric phenols, such as Bisphenol A- or Bisphenol-F type resins and their derivatives, aromatic polyglycidyl amines (e.g., polyglycidyl amines of benzenamines, benzene diamines, naphthylenamines, or naphthylene diamines), polyglycidyl ethers of phenol formaldehyde resole or novolak resins; resorcinol diglycidyl ether; polyglycidyl derivatives of fluorene- type resins; and g
  • Preferred aromatic polyepoxides are the polyglycidyl ethers of polyhydric phenols, such as the series of diglycidyl ethers of Bisphenol-A commercially available from Shell Chemical Inc., Houston, TX, for example, under the trade designations "EPON 828” and “EPON 1001F” and the series of diglycidyl ethers of Bisphenol-A and Bisphenol F and their blends commercially available from Shell Chemical Inc., for example, under the trade designations "Epikote 232" and "Epikote
  • aromatic epoxides include the "DER” series of Bisphenol epoxides, and "DEN” series of epoxy novolak resins available from Dow Chemical, Midland, Michigan, diglycidyl ether of fluorene Bisphenol, available from Shell Chemical Inc., Houston, Texas, under the trade designation "EPON HPT Resin 1079", a triglycidyl derivative of p-aminophenol commercially available from Ciba Performance Polymers, Brewster, New York under the trade designation "MY 0500”, a tetraglycidyl derivative of methylene dianiline commercially available from Ciba Performance Polymers, Brewster, New York under the trade designation "MY 720".
  • Flame retardant epoxides may also be used, for example, the flame retardant brominated Bisphenol-A diglycidyl ether commercially available from Dow Chemical, Midland, Michigan, under the trade designation "DER 580".
  • derivative as used herein with reference to thermosetting materials refers to a base molecule with additional substituents that do not interfere with the thermosetting bonding of the base molecule.
  • Representative aliphatic cyclic polyepoxides i.e., cyclic compounds containing one or more saturated carbocyclic rings and at least two epoxide groups, also known as alicyclic compounds
  • useful in the present invention include the series of alicyclic epoxides commercially available from Union Carbide Co ⁇ ., Danbury, CT, under the trade designation "ERL", such as vinyl cyclohexene dioxide (“ERL-4206”), 3,4- epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate (“ERL-4221”), 3,4-epoxy-6- methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexane carboxylate (“ERL-4201”), bis(3,4-epoxy-6-methylcycylohexylmethyl)adipate (“ERL-4289”), and dipentenedioxide (“ERL-4269”).
  • ERP vinyl cyclohex
  • Representative aliphatic polyepoxides include l,4-bis(2,3-epoxypropoxy)butane, polyglycidyl ethers of aliphatic polyols such as glycerol, polypropylene glycol, 1,4- butanediol, and the like, the diglycidyl ester of linoleic acid dimer, epoxidized polybutadiene (for example, those available under the trade designation "OXIRON 2001" from FMC Co ⁇ ., Philadelphia, Pennsylvania or "Poly bd” from Elf Atochem, Philadelphia, Pennsylvania), epoxidized aliphatic polyurethanes, and epoxy silicones, e.g., dimethylsiloxanes having cycloaliphatic epoxide or glycidyl ether groups.
  • polyglycidyl ethers of aliphatic polyols such as glycerol, polypropylene glycol, 1,4- butanedi
  • Suitable epoxide-based bondable layers that are commercially available in film form include those available from Minnesota Mining and Manufacturing Company ("3M"), St. Paul, MN under the trade designation “3M Scotch-Weld Structural Adhesive Film” including those having the following "AF” designations: "AF 42”, “AF 111”, “AF 126-2”, “AF 163-2”, “AF 3109-2”, “AF 191”, “AF 2635”, “AF 3002", "AF”
  • a preferred thermosetting bondable layer comprises a fusible epoxide prepolymer (which can melt and flow unlike a B stage resin) which is a solid at room temperature and, more preferably, further comprises a second epoxide component which may be solid or liquid at room temperature.
  • Suitable solid fusible epoxide prepolymers include those described above which are a solid at room temperature.
  • An exemplary bondable layer may comprise a solid fusible epoxide prepolymer comprising a diglycidyl ether of Bisphenol A alone or in combination with a diglycidyl ether of Bisphenol A or Bisphenol F or a blend thereof.
  • the bondable layer is a solid at room temperature after the addition of any optional components, more preferably the epoxide material (comprising single or multiple epoxides) is a solid at room temperature.
  • a preferable optional additive, as described below, is a core-shell toughener, which is present in an amount ranging from 10 to 30 parts by weight (pbw), based on 100 parts by weight of epoxide component(s).
  • active-hydrogen containing groups include primary alcohols, secondary alcohols, phenols and water; and primary and secondary amines (which react with the isocyanate to form a urea linkage).
  • active-hydrogen containing groups include primary alcohols, secondary alcohols, phenols and water; and primary and secondary amines (which react with the isocyanate to form a urea linkage).
  • isocyanate-terminated materials and appropriate co-reactants are well known, and many are commercially available (see for example, Gunter Oertel, "Polyurethane Handbook", Hanser Publishers, Kunststoff (1985)).
  • blocked refers to a compound that has been reacted with a second compound (i.e. "blocking group") such that its reactive functionality is not available until such time as the blocking group is removed, for example by heating, or by further reaction, such as with water.
  • blocked isocyanates include those that have been co-reacted with phenol, methyl ethyl ketoxime, and epsilon-caprolactam.
  • blocked active-hydrogen containing compounds examples include aldehyde or ketone blocked amines (known as ketimines); aldehyde blocked aminoalcohol (known as oxazolidines); and amines that have been complexed with a salt such as sodium chloride.
  • suitable co-reactants include polyether polyols such as poly(oxypropylene) glycols, ethylene oxide capped poly(oxypropylene) glycols, and poly(oxytetramethylene) glycols; diamino poly(oxypropylene) glycols; aromatic amine terminated poly(propylene ether) glycols; styrene-acrylonitrile graft polyols; poly(oxyethylene) polyols; polyester polyols such as polyglycol adipates, polyethylene terephthalate polyols, and polycaprolactone polyols; polybutadiene polyols, hydrogenated polybutadiene polyols, polythioether polyols, silicone carbinol polyols, polybutylene oxide polyols, acrylic polyols, carboxy-functional polypropylene oxide polyols, carboxy functional polyester polyols; and aromatic amine- terminated poly
  • Suitable urethane resins include blocked urethanes such as that available under the trade designation "Adeka Resin QR-9276” from Asahi Denka Kogyo K.K. Tokyo, Japan, and urethane modified epoxides such as that available under the trade designation "Rutapox VE 2306” from Rutgers Bakelite GmbH, Duisburg, Germany.
  • Suitable cyanate ester materials are those having two or more -O-C ⁇ N functional groups, including those described in U.S. Patent No. 5,143,785.
  • suitable cyanate ester compounds include the following: 1,3- and 1,4- dicyanatobenzene; 2-tert-butyl- 1 ,4-dicyanatobenzene; 2,4-dimethyl- 1 ,3-dicyanatobenzene; 2,5-di-tert-butyl- 1 ,4-dicyanatobenzene; tetramethyl- 1 ,4-dicyanatobenzene, 4-chloro- 1,3- dicyanatobenzene; 1,3,5-tricyanatobenzene; 2,2,- or 4,4,-dicyanatobiphenyl; 3,3',5,5',- tetramethyl-4,4',-dicyanatobiphenyl; 1,3-, 1,4-, 1,5-, 1,6-, 1,8-,
  • Suitable materials include cyanic acid esters derived from phenolic resins as described in U.S Pat. No. 3,962,184, cyanated novolac resins derived from novolac resins as described in U.S. Pat. No. 4,022,755, cyanated bisphenol-type polycarbonate oligomers derived from bisphenol-type polycarbonate oligomers as described in U.S. Pat. No. 4,026,913, cyanato-terminated polyarylene ethers as described in U.S. Pat. No. 3,595,900, dicyanate esters free of ortho hydrogen atoms as described in U.S. Pat. No. 4,740,584, mixtures of di-and tricyanates as described in U.S. Pat. No.
  • Suitable phenolic resins are generally described in Encyclopedia of Polymer Science and Engineering, Volume 11, John Wiley & Sons, Inc. (New York, 1988), pp. 45-
  • Phenolic-based resins are generally described in Alphonsus V. Pocius, Adhesion and Adhesives Technology: An Introduction, Hanser Publishers (New York, 1997), pp.185-188.
  • Preferred phenolic resins that can be used to impregnate a sheet which is suitable to prepare hot press laminated products from wood veneers are discussed in U.S.
  • Patent No. 1,960,176 is a patent No. 1,960,176.
  • Suitable phenolic materials are those made as the reaction product of phenols and formaldehydes, including resole phenolics and novolac phenolics.
  • phenols include phenol, resorcinol, para-substituted phenol, cresol, and the reaction product of bisphenol A and the monoglycidyl ether of bisphenol A.
  • Exemplary phenolic-based bondable layers include tissue paper impregnated with a thermosetting phenolic resin at a ratio of approximately two parts resin to one part tissue paper commercially available under the trade designation "Phenolic Glue Film" from Dyno Overlays Inc., High Point, NC.
  • Resole phenolic resins are characterized by being alkaline catalyzed and having a molar ratio of formaldehyde to phenol of greater than or equal to 1: 1. Typically, the ratio of formaldehyde to phenol is within a range of about 1: 1 to about 3: 1.
  • suitable alkaline catalysts for preparing resole phenolic resins include sodium hydroxide, potassium hydroxide, organic amines, or sodium carbonate.
  • Novolac phenolic resins are characterized by being acid catalyzed and having a molar ratio of formaldehyde to phenol of less than 1: 1. Typically, the ratio of formaldehyde to phenol is within a range of about 0.4: 1 to about 0.9: 1.
  • novolac phenolic resins examples include sulfuric, hydrochloric, phosphoric, oxalic, or p-toluenesulfonic acids.
  • novolac phenolic resins are typically considered to be thermoplastic resins rather than thermosetting resins, they can react with other chemicals (e.g., hexamethylenetetraamine) to form a thermoset resin.
  • Suitable nitrile phenolic materials include those made by including butadiene- nitrile elastomers in novolac phenolic resin-based materials.
  • suitable nitrile phenolic based bondable layers that are commercially available in film form include those available from Minnesota Mining and Manufacturing Company (“3M”), St. Paul, MN under the trade designation “3M Scotch- Weld Structural Adhesive Film” and having the following "AF” designations: "AF 10", “AF 30", “AF 31” and "AF 32".
  • suitable bismaleimide materials also known as N,N'-bismaleimide monomers and prepolymers, include the N,N'-bismaleimides of 1 ,2-ethanediamine, 1 ,6- hexanediamine, trimethyl-l,6-hexanediamine, 1 ,4-benzenediamine, 4,4'-methylene- bis(benzenamine), 2-methyl-l,4-benzenediamine, 3,3'-methylene-bis(benzenamine), 3,3'- sulfonyl-bis(benzenamine), 4,4'-sulfonyl-bis(benzenamine), 3,3'-oxy-bis(benzenamine), 4,4'-oxy-bis(benzenamine), 4,4'-methylene-bis(cyclohexanamine), 1 ,3- benzenedimethanamine, 1 ,4-benzenedimethanamine, and 4,4'-cyclohexane- bis(benzenamine) and mixtures thereof.
  • Other N,N'-bis-maleimides
  • bismaleimide materials include the series of materials available from Shell Chemical, Houston, TX under the trade designation "COMPIMIDE” such as 4,4'-bismaleimidodiphenyl methane (“COMPIMIDE Resin MDAB”), and 2,4'-bismaleimidotoluene (“COMPIMIDE Resin TDAB”), and from Dexter/Quantum, San Diego, CA under the trade designation "Q-Bond”.
  • COMPIMIDE 4,4'-bismaleimidodiphenyl methane
  • TDAB 2,4'-bismaleimidotoluene
  • thermosetting bondable layer preferably comprises a thermosetting material and a curative or curatives.
  • the term "curative” is used broadly to include not only those materials that are conventionally regarded as curatives but also those materials that catalyze or accelerate the reaction of the curable material as well as those materials that may act as both curative and catalyst or accelerator. It is also possible to use two or more curatives in combination.
  • Preferred heat activated curatives for use in the present invention exhibit latent thermal reactivity; that is, they react primarily at higher temperatures (preferably at a temperature of at least 80°C), or react at lower temperatures only after an activation step such as exposure to actinic radiation. This allows the adhesive composition to be readily mixed and coated at room temperature (about 23 + 3°C) or with gentle warming without activating the curative (i.e., at a temperature that is less than the reaction temperature for the curative).
  • room temperature about 23 + 3°C
  • curatives are appropriate for each class of thermosetting materials.
  • Suitable curatives for epoxide polymerization include polybasic acids and their anhydrides; nitrogen-containing curatives; chloro-, bromo-, and fluoro-containing Lewis acids of aluminum, boron, antimony, and titanium; photochemically activated generators of protic or Lewis acids; and phenolic materials as described above.
  • Exemplary polybasic acids and their anhydrides include di-, tri-, and higher carboxylic acids such as oxalic acid, phthalic acid, terephthalic acid, succinic acid, alkyl substituted succinic acids, tartaric acid, phthalic anhydride, succinic anhydride, malic anhydride, nadic anhydride, pyromellitic anhydride; and polymerized acids, for example, those containing at least 10 carbon atoms, such as dodecendioic acid, 10,12- eicosadiendioic acid, and the like.
  • carboxylic acids such as oxalic acid, phthalic acid, terephthalic acid, succinic acid, alkyl substituted succinic acids, tartaric acid, phthalic anhydride, succinic anhydride, malic anhydride, nadic anhydride, pyromellitic anhydride
  • polymerized acids for example, those containing at least 10 carbon
  • Nitrogen-containing curatives include, for example, dicyandi amide, imidazoles (e.g. hexakis(imidazole) nickel phthalate), imidazolates, dihydrazides (e.g. adipic dihydrazide and isophthalic dihydrazide), ureas, and melamines, as well as encapsulated aliphatic amines (e.g., diethylenetriamine, triethylenetetraamine, cyclohexylamine, triethanolamine, piperidine, tetramethylpiperamine, N,N-dibutyl-l,3-propane diamine, N,N-diethyl-l,3-propane diamine, 1 ,2-diamino-2-mefhyl-propane, 2,3-diamino-2-methyl- butane, 2,3-diamino-2-methyl-pentane, 2,4-diamino-2,6-
  • encapsulated means that the amine is surrounded by a material that prevents it from acting as a curative until the application of heat.
  • Polymer bound amines or imidazoles may also be used.
  • Pyridine, benzylamine, benzyldimethyl amine, and diethylaniline are also useful as heat activated curatives.
  • nitrogen-containing curatives examples include those commercially available from Air Products, Allentown, PA, under the trade designations, "Amicure CG-1200",
  • Exemplary chloro-, bromo-, and fluoro-containing Lewis acids of aluminum, boron, antimony, and titanium include aluminum trichloride, aluminum tribromide, boron trifluoride, antimony pentafluoride, titanium tetrafluoride, and the like.
  • these Lewis acids may be blocked to increase the latency of the thermosetting material.
  • Representative blocked Lewis acids include BF 3 -monoethylamine, and the adducts of
  • HSbF 5 X in which X is halogen, -OH, or -OR 1 in which R 1 is the residue of an aliphatic or aromatic alcohol, aniline, or a derivative thereof, as described in U.S. Patent No. 4,503,211.
  • Suitable photochemically activated curatives for epoxide polymerization include cationic photocatalysts that generate an acid to catalyze polymerization. It should be understood that the term “acid” can include either protic or Lewis acids. These cationic photocatalysts can include a metallocene salt having an onium cation and a halogen containing complex anion of a metal or metalloid. Other useful cationic photocatalysts include a metallocene salt having an organometallic complex cation and a halogen- containing complex anion of a metal or metalloid which are further described in US Patent 4,751,138 (e.g., column 6, line 65 to column 9, line 45).
  • useful photocatalysts include organometallic salts and onium salts, for example, those described in U.S. Pat. No. 4,985,340 (e.g., col. 4, line 65 to col. 14, line 50) and in European Patent Applications 306,161 and 306,162.
  • Still other cationic photocatalysts include an ionic salt of an organometallic complex in which the metal is selected from the elements of Periodic Group rVB , V 13 , VIB , V 1113 and VmB which is described in European Patent
  • a suitable photochemically activated curative is a curative commercially available from Ciba-Geigy, Hawthorne, New York under the trade designation "Irgacure 261".
  • Suitable curatives for urethane materials include the nitrogen-containing curatives as described for use with epoxides (which can react with a blocked isocyanate isocyanate group after the deblocking reaction to give a urea) as well as, for example, materials containing hydroxyl (e.g., phenols) or thiol functionality that can react with the deblocked isocyanate. Photochemically activated generators of protic or Lewis acids can be used to enhance these reactions.
  • Suitable curatives for cyanate ester materials include the nitrogen-containing curatives as described for use with epoxides as well as curatives that may be thermally or photochemically activated.
  • curatives include organometallic compounds containing a cyclopentadienyl group (C 5 H 5 ) and derivatives of a cyclopentadienyl group.
  • Suitable curatives include cyclopentadienyl iron dicarbonyl dimer ([C 5 H 5 Fe(CO) 2 ] ), pentamethylcyclopentadienyl iron dicarbonyl dimer
  • curatives include the hexafluorophosphate salt of the cyclopentadienyl iron mesitylene cation (C 5 H 5 (mesitylene)Fe + PF 6 ), and the trifluoromethanesulfonate salt of the cyclopentadienyl iron mesitylene cation (C 5 H 5 (mesitylene)Fe + (CF 3 SO 3 )), both of which may be prepared by methods described in U.S. Pat. 4,868,288.
  • Suitable curatives for phenolic materials and for nitrile phenolic materials include hexamethylene tetraamine (a latent source of formaldehyde) as well as combinations of organic acids (e.g. phosphoric acid, para toluene sulfonic acid, and salicylic acid) and metallic oxides (e.g. zinc oxide and magnesium oxide).
  • organic acids e.g. phosphoric acid, para toluene sulfonic acid, and salicylic acid
  • metallic oxides e.g. zinc oxide and magnesium oxide
  • Suitable curatives for bismaleimide materials include the nitrogen containing curatives as described for use with epoxides as well as latent sources of allyl phenol.
  • a hybrid material is a combination of at least two components wherein the at least two components are compatible in the melt phase (the melt phase is where the combination of the at least two components is a liquid), the at least two components form a inte ⁇ enetrating polymer network or semi-inte ⁇ enetrating polymer network, and at least one component becomes infusible (i.e., the component cannot be dissolved or melted) after application of heat or by other means of curing such as application of light.
  • a first component is a crosslinkable material and a second component is (a) a thermoplastic material, (b) monomers, oligomers, or polymers (and any required curative) which can form a thermoplastic material, (c) a thermosetting material, i.e., monomers, oligomers, or prepolymers (and any required curative) which can form a thermosetting material.
  • the second component is chosen so that it is not reactive with the first component. It may be desirable, however, to add a third component which may be reactive with either or both of the crosslinkable material and second component for the pu ⁇ ose of, for example, increasing the cohesive strength of the bonded hybrid material.
  • Suitable first components include thermosetting materials, for example, the thermosetting materials described above, as well as crosslinkable elastomers such as acrylics and urethanes as described above.
  • thermoplastic second components include, for example, polyesters, ethylene vinyl acetate (EVA), polyurethanes, polyamides, polyolefins, and derivatives thereof.
  • EVA ethylene vinyl acetate
  • derivatives refers to a base molecule with additional substituents that are not reactive towards a crosslinking or polymerization reaction.
  • thermoplastics which can be formed in situ, i.e., with monomers, oligomers, or polymers (and any required curative) which can form a thermoplastic material without undergoing any significant crosslinking reaction would be readily apparent to one skilled in the art.
  • Exemplary hybrid materials inco ⁇ orating a second component (a) are described, for example, in PCT/EP98/06323; U.S. Patent No.
  • thermosetting second components include those thermosetting materials described above.
  • Exemplary hybrid materials inco ⁇ orating a second component (c) are described, for example, in U.S. Patent No. 5,494,981.
  • a bondable layer comprising a hybrid material upon bonding preferably has overlap shear strength according to ASTM D-1002-94, at room temperature
  • the bondable layer may also include additives, such as film-forming materials, intended to improve handling characteristics before bonding or additives intended to improve the final performance of the bonded layer.
  • additives such as film-forming materials, intended to improve handling characteristics before bonding or additives intended to improve the final performance of the bonded layer.
  • additives include thixotropic agents such as fumed silica; pigments such as ferric oxide, brick dust, carbon black, and titanium oxide; fillers such as silica, magnesium sulfate, calcium sulfate, and beryllium aluminum silicate; clays such as betonite; glass beads; bubbles made from glass or phenolic resin; expandable microspheres, for example, microspheres commercially available from Expancel Inc./Akzo Nobel, Duluth, Georgia, under the trade designation "Expancel DU"; anti-oxidants; UV- stabilizers; corrosion inhibitors, for example, those commercially available from W.R.
  • thixotropic agents such as fumed silica
  • pigments such as ferric oxide, brick dust, carbon black, and titanium oxide
  • fillers such as silica, magnesium sulfate, calcium sulfate, and beryllium aluminum silicate
  • clays such as betonite
  • glass beads bubbles made from glass or phenolic resin
  • suitable additives include those that provide thermal or electrical conductivity such as electrically or thermally conductive particles, electrically or thermally conductive woven or non-woven webs, or electrically or thermally conductive fibers. It may also be desirable to provide additives that function as energy absorbers for such curing methods as microwave curing.
  • An additional exemplary additive is a rubbery heterophase that may be introduced into the thermosetting material. The rubbery heterophase can be introduced as a latex of dispersed natural or synthetic rubber as described in U.S. Pat. No.
  • the rubbery heterophase may also be introduced into the thermosetting material by dissolving reactive elastomer into the thermosetting material such that the elastomer reacts with and phase separates from the thermosetting material during curing as described in U.S. Pat. Nos. 4,107,116 and 3,894,112. It is also possible to use a thermosetting material that already includes a rubbery heterophase, such as that available from Shell Chemical, Houston, Texas, under the trade designation "EPON 58006".
  • a pressure sensitive adhesive layer in accordance with the present invention comprises a pressure sensitive adhesive material.
  • One well known means of identifying pressure sensitive adhesives is the Dahlquist criterion. This criterion defines a pressure sensitive adhesive as an adhesive having a 1 second creep compliance of greater than 1 x 10 "6 cm 2 /dyne as described in "Handbook of Pressure Sensitive Adhesive Technology", Donatas Satas (Ed.), 2 nd Edition, p. 172, Van Nostrand Reinhold, New York, NY, 1989.
  • pressure sensitive adhesives may be defined as adhesives having a Young's modulus of less than 1 x 10 6 dynes/cm 2 .
  • Another well known means of identifying a pressure sensitive adhesive is that it is aggressively and permanently tacky at room temperature and firmly adheres to a variety of dissimilar surfaces upon mere contact without the need of more than finger or hand pressure as described in "Glossary of Terms Used in the Pressure Sensitive Tape Industry” provided by the Pressure Sensitive Tape Council, August, 1985. Any of these methods of identifying a pressure sensitive adhesive may be used to identify suitable pressure sensitive adhesives of the present invention.
  • a suitable pressure sensitive adhesive preferably has a room temperature storage modulus within the area defined by the following points as plotted on a graph of modulus versus frequency at 25 °C: a range of moduli from approximately 2 x 10 5 to 4 x 10 5 dynes/cm 2 at a frequency of approximately 0.1 radians/sec (0.017 Hz) , and a range of moduli from approximately 2 x 10 6 to 8 x 10 6 dynes/cm at a frequency of approximately 100 radians/sec (17 Hz) (for example see Figure 8-16 on p. 173 of Donatas Satas, "Handbook of Pressure Sensitive Adhesive
  • the pressure sensitive adhesive layer of the present invention in one embodiment is a discontinuous layer.
  • discontinuous refers to the fact that the bondable layer is not completely covered by the pressure sensitive adhesive layer and, therefore, the bondable layer can make contact with and bond directly to a suitable substrate, although other layers may be inte ⁇ osed such as, for example, a primer layer.
  • the layer may take the form of such shapes as dots (preferably having a diameter of about 1 to about 3 mm), stripes, crescents, and logos.
  • a discontinuous pressure sensitive adhesive layer can be provided as microstructured adhesives or melt-blown non- woven microfibers.
  • dots for example, are more preferable than stripes.
  • the percent coverage of pressure sensitive adhesive in a discontinuous layer also is selected depending on the intended use of the adhesive article, preferably to maximize the overlap shear of an adhesive article with a bonded layer while also providing sufficient initial pressure sensitive adhesive characteristics to hold the adhesive article in place prior to bonding, for example, by heating.
  • the surface coverage of the discontinuous pressure sensitive adhesive layer is from about 1 to about 50 %, more preferably from 2 to
  • Suitable pressure sensitive adhesive materials may comprise acrylics, vinyl ethers, natural or synthetic rubber-based materials, poly(alpha-olefins), and silicones.
  • a pressure sensitive adhesive material is preferably selected for an adhesive article of the present invention so that, upon contact with a bondable layer, pressure sensitive adhesive characteristics of the pressure sensitive adhesive layer are retained as described above.
  • Useful acrylic pressure sensitive adhesive materials include those comprising at least one copolymerized monofunctional (meth)acrylic acid ester of a nontertiary alcohol in which the alkyl group contains about 4 to 14 carbon atoms (on average) whose homopolymer has a Tg (glass transition temperature) of no greater than about 0°C and at least one copolymerized monofunctional ethylenically unsaturated reinforcing monomer whose homopolymer has a Tg of at least about 10°C.
  • Tg glass transition temperature
  • the term "monofunctional” in the context of a "monofunctional (meth)acrylic acid ester” refers to a mono-(meth)acrylic monomer or a monomer containing one (meth)acrylic functionality, although other functionality can be present.
  • the term “monofunctional” in the context of a “monofunctional ethylenically unsaturated reinforcing monomer” refers to a monoethylenically unsaturated monomer or a monomer containing one ethylenically unsaturated functionality, although other functionality can be present.
  • reinforcing monomer means monomers that increase the modulus of the adhesive and thereby its strength.
  • the alkyl group of the nontertiary alcohol can optionally contain oxygen atoms in the chain, thereby forming ethers for example.
  • Suitable monofunctional (meth)acrylic acid esters include, but are not limited to, 2-methylbutyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, lauryl acrylate, n-decyl acrylate, 4-methyl-2-pentyl acrylate, isoamyl acrylate, sec-butyl acrylate, and isononyl acrylate.
  • Preferred (meth)acrylic acid esters that can be used include, but are not limited to, 2-ethylhexyl acrylate, isooctyl acrylate, lauryl acrylate, and 2-methylbutyl acrylate.
  • Monofunctional reinforcing monomers include, but are not limited to,
  • (meth)acrylic acid a (meth)acrylamide, a (meth)acrylate, an alpha-olefin, a vinyl ether, an allyl ether, a styrenic monomer, or a maleate.
  • Suitable monofunctional reinforcing monomers include, but are not limited to, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, 2-hydroxyethyl acrylate or methacrylate, cyclohexyl acrylate, t-butyl acrylate, phenyl acrylate, isobornyl acrylate, 2-phenoxyethyl acrylate, N-vinyl pyrrolidone, N-vinyl caprolactam, acrylamide, methacrylamide, N- substituted and N,N-disubstituted acrylamides such as N-ethyl acrylamide, N-hydroxyethyl acrylamide, N-octyl acrylamide, N-t-butyl acrylamide, N,N-dimethyl acrylamide, N,N- diethyl acrylamide, and N-ethyl-N-dihydroxyethyl acrylamide.
  • Preferred monofunctional reinforcing monomers include, but are not limited to, acrylic acid, t-butyl acrylate, N,N- dimethyl acrylamide, N-octyl acrylamide, isobornyl acrylate, and 2-phenoxyethyl acrylate. Various combinations of reinforcing monomers can also be employed.
  • the acrylic adhesives may optionally contain various types of crosslinking agents such as, for example, ethylenically unsaturated compounds which in the excited state are capable of abstracting hydrogen, and copolymerizable polyfunctional ethylenically unsaturated monomers.
  • crosslinking agents such as, for example, ethylenically unsaturated compounds which in the excited state are capable of abstracting hydrogen, and copolymerizable polyfunctional ethylenically unsaturated monomers.
  • An example of a suitable, optional crosslinking agent is a copolymerizable ethylenically unsaturated compound which in the excited state is capable of abstracting a hydrogen such as, for example, p-acryloxy-benzophenone.
  • Suitable copolymerizable polyfunctional ethylenically unsaturated monomers include, for example, 1 ,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, 1,2- ethylene glycol diacrylate and the diacrylate of ethylene oxide modified bisphenol A.
  • crosslinking agents can also be employed.
  • acrylic pressure sensitive adhesives include a water-based acrylic adhesive commercially available from KTWO Inc., Seabrook, Texas, under the trade designation "Kiwoprint D 146/3".
  • Other suitable acrylic pressure sensitive adhesives include those prepared from a copolymer of isooctyl acryl ate/acrylic acid/2 - poly(styrylethyl methacrylate) macromer as described in US 4,693,776.
  • An exemplary macromer is commercially available from Sartomer Company, Exton, Pennsylvania under the trade designation "CHEMLHNK 4500” (13,000 molecular weight).
  • Pressure sensitive adhesives may be made by polymerizing vinyl ether monomers or comonomers or by copolymerizing vinyl ether monomers with acrylic monomers. It is within the scope of this invention to use a blend of more than one vinyl ether resin.
  • the general guidelines for formulating acrylic pressure sensitive adhesives also apply to pressure sensitive adhesives based on vinyl ethers.
  • Cationic curing chemistry is the preferred method of polymerizing vinyl ether monomers. Free radical chemistry may be used to copolymerize vinyl ether monomers with acrylic monomers.
  • antioxidants are added to reduce degradation of the adhesives upon exposure to oxygen, heat, and/or light.
  • Useful vinyl ether pressure sensitive adhesive materials include those described in "Handbook of Pressure Sensitive Adhesive Technology, 2 nd Edition, D. Satas, Ed. Van Nostrand Reinhold, New York, 1989, Chapter 17, pages 494-507.
  • Examples of commercial available vinyl ethers include triethylene glycol divinyl ether (available from GAF, Wayne, N.J. under the trade designation "Rapicure DVE-3"),
  • VEctomer 1 ,4-cyclohexanedimethanol divinyl ether (available from GAF under the trade designation "Rapicure CHVE"), and resins from Allied Signal, under the trade designation "VEctomer” such as “VEctomer 2010", “VEctomer 2020”, “VEctomer 4010”, and “VEctomer 4020.”
  • Suitable vinyl ether include ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, butanediol divinyl ether, hydroxybutyl vinyl ether, cyclohexanedimethanol monovinyl ether, diethyleneglycol divinyl ether, and triethyleneglycol divinyl ether, which are available from BASF Aktiengesellschaft, Ludwigshafen, Germany.
  • Rubber-Based Materials Useful rubber-based pressure sensitive adhesives include an elastomeric component and a tackifying resin and, optionally, a crosslinking agent and/or an accelerator.
  • Suitable elastomeric components include, e.g., natural rubbers, synthetic rubbers such as styrene-butadiene rubber, styrene block copolymers such as styrene-isoprene- styrene, styrene-butadiene-styrene, styrene-ethylene/butylene-styrene, styrene- ethylene/propylene-styrene, and various combinations of such rubbers.
  • Suitable tackifying resins include resins derived from polymerization of C 5 to C 9 unsaturated hydrocarbon monomers, te ⁇ ene resins, and rosin ester resins.
  • tackifying resins based on a C 5 olefin fraction of this type include those commercially available under the trade designations "WINGTACK 95" and "WINGTACK 115" from
  • hydrocarbon based tackifying resins include those commercially available under the trade designations "REGALREZ 1078” and “REGALREZ 1126” from Hercules Chemical Company, Wilmington, DE; Arkon resins, which include those commercially available under the trade designation "ARKON PI 15” from Arakawa Forest Chemical Industries, Chicago, IL; and resins commercially available under the trade designation "ESCOREZ” from Exxon Chemical Company, Houston, TX.
  • Suitable te ⁇ ene resins include te ⁇ ene polymers, such as polymeric resinous materials obtained by polymerization and/or copolymerization of te ⁇ ene hydrocarbons such as the alicyclic, monocyclic, and bicyclic monote ⁇ enes and their mixtures.
  • Suitable te ⁇ ene resins include those commercially available under the trade designation "ZONAREZ B-Series” and “ZONAREZ 7000 Series” from Arizona Chemical Company, Wayne, NJ.
  • Suitable rosin ester tackifying resins include those commercially available under the trade designation "FORAL” and “STAYBELITE” from Hercules Chemical Company, Wilmington, DE.
  • the tackifying resin can contain ethylenic unsaturation; however, saturated tackifying resins are preferred for those applications where resistance to oxidation is important.
  • the amount of tackifying resin typically ranges from about 20 parts to about 70 parts by weight per 100 parts of elastomeric component.
  • Suitable accelerators may be added to the rubber-based adhesive composition to accelerate crosslinking. Examples of suitable accelerators include zinc salts (e.g., zinc rosinate), tin chloride, and acid accelerators (e.g., stearic acid).
  • the amount of accelerator typically ranges from about 0 to 15 parts by weight per 100 parts of elastomeric component.
  • Poly(alpha-olefins) Poly(alpha-olefin) adhesives suitable for use in the present invention comprise one or more monomer units derived from an alpha-olefin monomer that is a liquid at standard temperature and pressure.
  • the monomer preferably is a C 5 -C o alpha-olefin, more preferably a C 6 -C 20 alpha-olefin, most preferably a C 6 -C )2 alpha-olefin.
  • Such monomers optionally can be substituted with conventional substituents that do not interfere with the polymerization of these monomers or with the desired properties of the polymer produced therefrom.
  • the olefin may be linear or branched (i.e., comprising one or more side chains).
  • alpha-olefin monomers are 1-hexene and 1- octene.
  • Suitable alpha-olefin polymers are those described in U.S. Patent No. 5,112,882.
  • the alpha-olefin polymer can be a homopolymer, a random copolymer, te ⁇ olymer, or tetrapolymer. It can also comprise blocks of homopoly(alpha-olefins) interspersed with monomer units derived from various other copolymerizable monomers. Examples of potentially useful copolymerizable monomers include polyenes such as, for example, the
  • the above-described monomers can be polymerized, either in bulk or in one or more inert solvents, in the presence of a catalyst system over a wide range of temperatures, e.g., 0° to 140°C, preferably 30° to 90°C.
  • the amount of catalyst used is preferably in the range of 0.1 to 5 g per kg of monomer.
  • Useful catalyst systems include standard Zn catalysts systems, Zn catalyst systems where the transition metal compound is supported (e.g., on a MgCl powder), and Kaminsky-Ewen catalyst systems. All three catalyst systems are well known by those familiar with alpha-olefin polymerizations.
  • the alpha-olefin polymer has a glass transition temperature in the range of -70° to 0°C, more preferably in the range of -60° to -20°C; an inherent viscosity in the range of 0.4 to 9.0 dlJg, more preferably 0.5 to 6.0 dL/g; and a number average molecular weight in the range of 5,000 to 50,000,000, preferably 50,000 to 5,000,000.
  • Addition of one or more tackifying resins to the poly(alpha-olefin) can improve tack, lower viscosity, improve coatability, impart heat stability, improve peel adhesion, and enhance shear adhesion (with no concomitant loss of peel adhesion).
  • a tackifying resin it can be present in an amount from more than 0 to 150 parts by weight of polymer.
  • Potentially useful tackifying resins which may be used are those described above for use in rubber-based adhesives.
  • the alpha-olefin polymer composition also includes a photocrosslinking agent that is activated by actinic radiation, typically after the polymer is coated.
  • Suitable photocrosslinking agents include, but are not limited to, (a) aldehydes, such as benzaldehyde, chromophore-substituted acetaldehyde, and derivatives thereof; (b) ketones, such as acetophenone, benzophenone, and derivatives thereof, which include those commercially available under the trade designation "SANDORAY 1000" from Sandoz Chemicals, Inc., Charlotte, NC; (c) quinones, such as the benzoquinones, anthraquinone, and derivatives thereof; (d) thioxanthones, such as 2-isopropylthioxanthone and 2- dodecylthioxanthone; and (e) chromophore-substituted vinyl halomethyl-sym-triazines,
  • the photoactive crosslinking agent can be present in a range from about 0.005 to about 2% by weight, preferably from about 0.01 to about 0.5% by weight, more preferably from about 0.05 to 0.15% by weight of the polymer.
  • silicone pressure sensitive adhesive materials include those described in "Handbook of Pressure Sensitive Adhesive Technology, 2 nd Edition, D. Satas, Ed. Van Nostrand Reinhold, New York, 1989, Chapter 18, pages 508-517. Silicone pressure sensitive adhesives are well known in the art.
  • Silicone adhesives are, in general terms, blends of (i) polydiorganosiloxanes (also referred to as “silicone gums” typically having a number average molecular weight of about 5000 to about 10,000,000 preferably about 50,000 to about 1,000,000) with (ii) copolymeric silicone resins (also referred to as "MQ resins” typically having a number average molecular weight of about 100 to about 1,000,000, preferably about 500 to about 50,000 number average molecular weight) comprising triorganosiloxy units and SiO 4/2 units.
  • silicone adhesives comprise from about 20 to about 60 parts by weight silicone gum and, correspondingly, from about 40 to about 80 parts by weight of an MQ resin.
  • Silicone adhesives based on condensation chemistry can be prepared by admixing silanol functional copolymeric resins comprising triorganosiloxy units and SiO 4/ units with silanol-endblocked polydiorganosiloxanes as described in U.S. Pat. Nos. 2,736,721;
  • Such blends which are usually a solvent solution of copolymeric silicone resin and polydiorganosiloxane, as used in the art, are generally applied to a backing, heated to remove solvent, and crosslinked, if necessary, to improve the physical properties of the adhesive.
  • a silicone adhesive comprising the intercondensation product of a silanol functional polydiorganosiloxane and a silanol functional copolymeric silicone resin, as discussed above, can optionally include a free radical polymerization catalyst, such as a diaryl peroxide crosslinker, to crosslink the adhesive composition, thereby improving the high temperature shear properties of the adhesive with only a slight loss in peel adhesion as taught in The Handbook of Pressure-Sensitive Adhesive Technology, (Satas, 1982), p. 348.
  • a free radical polymerization catalyst such as a diaryl peroxide crosslinker
  • the adhesive When a peroxide crosslinker is present in a solution of silicone adhesive, the adhesive is generally applied to a backing, heated moderately to volatilize the solvent, and the dried adhesive is heated further to temperatures in the range of 150°C to about 250°C to activate the crosslinker as described in U.S. Pat. No. 4,039,707. In applications where adhesive performance at elevated temperature is not required, the crosslinking agent may be omitted.
  • the polydiorganosiloxanes used in the preparation of the silicone adhesive component of the instant invention can include any of the common structures and accompanying functionalities known in the art, including polydimethylsiloxane polymers and poly(dimethylsiloxane/diphenylsiloxane) copolymers.
  • copolymeric silicone resins useful in the preparation of the silicone adhesive component of the present invention include any of the common structures recited in the above references which include copolymeric silicone-resins having one or more of the following functionalities: silicon-bonded hydrogen, silicon-bonded alkenyl, and silanol.
  • Other useful silicone resins include three component te ⁇ olymers comprising R 3 SiO ⁇ /2 ,
  • SiO 4/2 , and R 2 SiO /2 structural units (also referred to as "MQD resins") wherein R is selected from the group consisting of alkyl radicals comprising 1 to 3 carbon atoms and phenyl radical, and wherein the ratio of R 3 SiO ⁇ /2 units to SiO /2 is between about 0.6 and about 0.9 inclusive as described in U.S. Pat. No. 2,736,721, and which comprise R SiO
  • Silicone adhesives prepared by addition-cure chemistry generally comprise polydiorganosiloxanes having alkenyl groups, copolymeric silicone resins comprising SiO 2 and R3 SiO ⁇ 2 structural units wherein R is as defined previously having one or more of the following functionalities: silicone-bonded hydrogen, silicone bonded alkenyl groups such as those selected from the group consisting of vinyl, allyl, and propenyl; or silanol, optionally a crosslinking or chain extending agent, and platinum or other noble metal hydrosilation catalyst to effect the curing of the silicone adhesive. Examples of such compositions are described in U.S. Pat. Nos. 3,527,842; 3,983,298; and 4,774,297; and European Patent Publication Nos.
  • Blends of silicone pressure sensitive adhesives are also useful. Examples include blends of two different dimethylsiloxane-based pressure sensitive adhesives, as described in The Handbook of Pressure-Sensitive Adhesive Technology (Satas, 1982), p. 346, or blends of dimethylsiloxane-based pressure sensitive adhesives with dimethylsiloxane/diphenylsiloxane-based pressure sensitive adhesives as descibed in U.S. Pat. No. 4,925,671.
  • silicone pressure sensitive adhesives examples include but are not limited to those available from Dow Corning, Midland, Michigan, under the trade designations "280A”, “282”, “Q2-7406”, and “Q2-7566”; those available from General Electric, Schenectady, New York, under the trade designations "PSA 590”, “PSA 600", “PSA 595", “PSA 610", “PSA 518", “PSA 6574", and “PSA 529”; those available from Shin-Etsu, Akron, Ohio, under the trade designations "KR-100P", "KR-100", and
  • the pressure sensitive adhesive materials may also include minor amounts of additives.
  • additives may include pigments, dyes, plasticizers, fillers, stabilizers, UV radiation absorbers, antioxidants, processing oils, and the like.
  • the amount of additive(s) used can vary from 0.1 to 50 weight percent of the pressure sensitive adhesive material, depending on the end use desired. Any additive(s) used preferably do not significantly absorb radiation near the wavelength of maximum abso ⁇ tion of any photocrosslinker included in the polymer composition.
  • a backing may be used on one side of the adhesive article, attached directly to the bondable layer or attached to a pressure sensitive adhesive layer.
  • Suitable backings that continue to function as backings after the heat bonding cycle are generally used.
  • suitable backings include metallic foils such as foils of aluminum, brass, or copper; and polymer films such as those made from polyester, polyimide, or polyolefin.
  • a release material may be coated onto at least one layer of the adhesive article, for example, a bondable layer, to form a low adhesion backsize (LAB).
  • a release liner having differential release characteristics may be employed on one or both sides of the adhesive article.
  • Suitable release materials for use as LAB and release liners are well known to those skilled in the art and include silicones and fluoropolymeric materials.
  • a release liner such as, for example, a silicone-treated paper release liner having a thickness of, for example, 76.2 micrometers (0.003 inches).
  • the thickness of the release material may be varied within a very wide range and depends on the end application.
  • the release (i.e., adhesion) value of an adhesive to the release material may vary to some degree depending on the thickness of the release material.
  • Vehicles such as ai ⁇ lanes, trains, automobiles, sport utility vehicles, vans, trucks, and boats, comprise outer vehicle body panels and inner structures.
  • the assembly of the present invention comprises an adhesive article as defined above in contact with an outer vehicle body panel or vehicle inner structure.
  • Outer vehicle body panels include all vehicle panels that attached to a vehicle inner structure.
  • Exemplary outer vehicle body panels with reference to an automobile, truck, van, or sport utility vehicle include roof skins, door skins, sport utility vehicle quarter panels, passenger car quarter panels, trunk lids, hoods, front fenders, truck box sides, van sides, and rear body panels attached to the trunk floor.
  • An inner structure comprises a frame or a unibody support member.
  • a unibody support member refers to the primary skeletal structure of the vehicle which may include but is not limited to such components as floor pans, frame rails, core supports, posts and pillars and the like.
  • a frame member of a vehicle is a full perimeter structure upon which the vehicle body is attached by mechanical means (i.e. bolts).
  • a method of making an adhesive article of the present invention includes selecting a bondable material to form the bondable layer.
  • a pressure-sensitive adhesive material may be selected such that upon interaction with the bondable layer, the pressure sensitive adhesive will retain pressure sensitive adhesive characteristics after storage.
  • the pressure sensitive adhesive layer of an adhesive article of the present invention retains pressure sensitive adhesive characteristics for the duration of the usable life of the bondable layer.
  • the pressure sensitive adhesive layer of the present invention typically retains pressure sensitive adhesive characteristics after storage at room temperature for at least 3 months, preferably at least six months, and more preferably at least 12 months.
  • the pressure sensitive adhesive layer retains pressure sensitive adhesive characteristics after storage at 38 to 42°C for at least about 20 days.
  • the pressure sensitive adhesive is then provided on a major surface of the bondable layer to form a pressure sensitive adhesive layer. If it is necessary to make the bondable layer, rather than using a commercially available product which can be used as a bondable layer, the bondable layer may made by mixing the desired components using a mixing method that does not compromise the latency of any curative used.
  • any coating method for forming the layer as a film may be chosen such that it does not interfere with the latency of any curative used.
  • thermosetting layer can be made by melt-mixing the thermosetting material, curative, and any other desired additives, at a temperature below the temperature at which the curative will be activated.
  • the warm mixture can then be made into film form by casting onto a suitable release liner using a hot knife-over-bed type coater.
  • a pressure sensitive adhesive layer is then selected.
  • the pressure sensitive adhesive may directly coated onto the bondable layer or coated onto a temporary liner so that it can then be transfer laminated to the bondable layer.
  • a pressure sensitive adhesive composition can be prepared in many forms that facilitate its application as a discontinuous layer to the bondable layer.
  • the pressure sensitive adhesive composition can be made suitable for printing, for example, screen printing.
  • the pressure sensitive material can be coated onto a structured liner as described in WO 98/29516A.
  • the pressure sensitive adhesive material may be made into a non- woven web of melt-blown microfibers by any suitable process, which may be a spunbond process or a melt-blown process, well known in the art, for example, as described in
  • a preferred method for the preparation of fibers, particularly microfibers, and nonwoven webs thereof, is a melt-blown process.
  • nonwoven webs of multilayer microfibers and melt-blown processes for producing them are described in U.S. Pat. Nos. 5,176,952; 5,232,770; 5,238,733; 5,258,220; and 5,248,455.
  • the pressure sensitive adhesive layer and the bondable layer are preferably selected so that the pressure sensitive adhesive layer retains pressure sensitive adhesive characteristics as defined above.
  • nonwoven fibers also known as scrims
  • the scrim can be placed inside the bondable layer during its production to provide greater dimensional stability to the adhesive article before bonding.
  • the bondable layer is made with pressure sensitive adhesive on only one side, the scrim can be laminated to the side of the bondable layer opposite the side with the pressure sensitive adhesive layer.
  • an adhesive article with a pressure sensitive adhesive layer on at least one side can be placed over the seam or area to be protected, with the pressure sensitive adhesive layer in contact with the substrate.
  • the bondable layer becomes a bonded layer as described above.
  • a release liner or release material as described above may be employed on the adhesive article to allow usability as a tape.
  • a tape can also be formed by employing a backing with an adhesive article in accordance with the present invention.
  • the adhesive article have, after bonding, an overlap shear strength of at least about 6.9 MPa, in accordance with ASTM D-1002-94, at room temperature (approximately 23°C + 3°C) and the bondable layer may be selected to give the adhesive article this property.
  • An adhesive article of the present invention can be used to form an assembly by bonding an adhesive article of the present invention to any of a variety of substrates such as metals including aluminum and aluminum alloys, stainless steel, cold-rolled steel, steel, galvanized steel, coated steel, titanium, brass; plastics and plastic composite materials that can survive a heat bonding cycle such as those based on epoxides, polyesters, polyamides, polyimides, cyanate esters, phenolics, and other engineering thermoplastics such as polycarbonate, poly(ether-ether) ketone, and poly(ether sulfone); ceramics; glass; wood; wood veneers; and corestock (also referred to throughout as "coreboard”), which is a generic term for the central core of a veneer panel.
  • substrates such as metals including aluminum and aluminum alloys, stainless steel, cold-rolled steel, steel, galvanized steel, coated steel, titanium, brass; plastics and plastic composite materials that can survive a heat bonding cycle such as those based on epoxides
  • the adhesive article may be applied or attached to a substrate and then another substrate can be applied thereto.
  • the pressure sensitive adhesive layer of the adhesive article may be applied to a substrate.
  • Another substrate can then be applied to the side of the bondable layer opposite the pressure sensitive adhesive layer.
  • the bondable layer may have another layer of pressure sensitive adhesive on the side opposite the first layer of pressure sensitive adhesive.
  • the second substrate may be adhered to the second layer of pressure sensitive adhesive layer.
  • the second substrate may itself comprise an adhesive article having a scrim to form a second assembly (which may be identical to the first assembly); in which case the first and second assemblies are bonded scrim to scrim.
  • the external scrim can be used to prevent any slight tack of the bondable layer from making it difficult to slide a second substrate into position for bonding.
  • the bondable layer may then be bonded in any manner described above as understood by one skilled in the art. Bonding is described, for example, with reference to application of heat.
  • the heating cycle required will depend upon the choice of bondable layer.
  • the adhesive article with at least one substrate may require the use of clamping during heating depending upon the bondable layer chosen.
  • the choice of heating cycle also depends on the bondable layer chosen and is selected to maintain the adhesive article at a suitable temperature for sufficient time to provide acceptable bond strength. If a thermosetting bondable layer is used, the temperature and time must be sufficient to provide substantial bonding or cure of the thermosetting material.
  • heating methods examples include convection oven, direct contact-heaters such as a heated press or hot-bar bonder, induction, infra-red, and microwave.
  • Exemplary induction can be accomplished by any conventional method. The power of the induction heating system is selected based upon the specific application.
  • Those skilled in the art of providing induction heating systems are capable of providing a system for specific substrates to bond the bondable layer.
  • a suitable induction apparatus may comprise a flexible, reshapeable cable assembly operably positionable adjacent a substrate wherein the a flexible, reshapeable cable assembly is capable of being manually shaped and re-shaped in accordance with the adhesive article and substrate(s) to be bonded, as described in co-filed application having
  • Another suitable induction apparatus may comprise a portable induction heating apparatus, having a hand holdable induction heating member that can be held, operated and controlled with one hand and operated remotely from the control unit, can be used, as described in co-filed application having U.S. Serial No. 09/422,607.
  • the adhesive article may be used to prepare assemblies such as a protection for a pipe weld; to form a panel bond, for example, attaching or reattaching a substrate such as an outer vehicle body panel to another outer vehicle body panel, or attaching or reattaching a vehicle inner structure to an outer vehicle body panel, by means of an adhesive article; or to seal a seam, for example, sealing a seam created at the union of two outer vehicle body panels or a union of an outer vehicle body panel and the vehicle inner structure.
  • the present invention provides a method of (re)attaching a substrate such as an outer vehicle body panels to the vehicle inner structure or to parts of other outer vehicle body panels by means of an adhesive article.
  • the method of (re)attaching an outer vehicle body panel to either another vehicle body panel or to a vehicle inner structure includes the steps of providing an adhesive article.
  • a major surface of the adhesive article may be attached to an outer vehicle body panel or to a vehicle inner structure (either of which is also referred to as a first substrate).
  • the adhesive article may be continuous or discontinuous on the surface to which it is attached.
  • the pressure sensitive adhesive layer of an adhesive article is attached to an outer vehicle body panel.
  • the assembly comprising an outer vehicle panel or a vehicle inner structure and the adhesive article, is then attached to a second substrate by placing a major surface of the adhesive article opposite the major surface already attached to the first outer vehicle panel or the vehicle inner structure in contact with a second substrate.
  • the first substrate is an outer vehicle body panel
  • the second substrate may be a second outer vehicle body panel or a vehicle inner structure.
  • the first substrate is a vehicle inner structure
  • the second substrate may be an outer vehicle body panel.
  • Fixturing clamps may be used to hold the adhesive article and all substrates together while the adhesive article is bonded.
  • the adhesive article is preferably bonded by any suitable heating method including induction as described above.
  • the present invention also provides a method of sealing a seam created at the union of two outer vehicle body panels or a union of an outer vehicle body panel and the vehicle inner structure.
  • the method includes the steps of first providing an adhesive article.
  • the adhesive article may be attached to a seam created by the union of two outer vehicle body panels or one outer vehicle body panel and the vehicle inner structure which have been previously joined, for example, by welding, mechanical fixturing, attaching, or any other method of contacting.
  • the adhesive article is placed on at least a part of the seam and then bonded so as to create a seal which prevents the migration of dirt, water, or other contaminants from the environment into seam.
  • the adhesive article is bonded by any suitable bonding method described above, preferably by application of heat, including induction as described above.
  • Example 7 A different heat bonding cycle was used in Example 7, that is, light contact pressure for 60 minutes at 175-185°C with heat-up rate of 5°C/min, and a different heat bonding cycle was used in Examples 19 and 20, that is, 50 kPa pressure for 5 minutes at 180°C.
  • Example 7 (March, 1980), using 2024-T3 clad aluminum substrates. During the test, a substrate of 0.5 mm thickness was peeled from a substrate of 1.6 mm thickness, both substrates having a width of 25.4 mm. A grip separation rate of 150 mm/min was used. Testing occurred at RT and 80°C. Unless otherwise noted, a sample was heat bonded in a heated press under light contact pressure (10 kPa) for 60 minutes at 125°C, with a heat-up rate from room temperature of 3.5°C/minute and then cooled prior to removal from the press. An alternate heat bonding cycle was used in Example 7 as follows: light contact pressure for 60 minutes at 175-185°C with heat-up rate of 5°C/min.
  • This method was used to test adhesive articles prior to performing the heat bonding step. Testing was done according to the Pressure Sensitive Tape Council's method "Peel Adhesion for Single Coated Pressure Sensitive Tapes at a 90 Degree Angle", using a specimen width of 2.54 cm, a peeled length of at least 10 cm, and a grip separation rate of
  • the top block had dimensions of 25 mm by 25 mm by 8 mm.
  • the hammer size was 50 joules and had an impact speed of 3.85 m sec. Samples were tested room temperature and -40°C.
  • a sample was first heat bonded in a heated press under light contact pressure (10 kPa) for 60 minutes at 125°C, with a heat-up rate from room temperature of 3.5°C/minute and then cooled prior to removal from the press.
  • the reaction exotherm of an aged unbonded samples was determined according to ASTM E537-86.
  • the reaction exotherm of the aged sample was compared to the reaction exotherm of a non-aged unbonded sample. Aging at 38-42°C was done by packing the samples into a watertight metallic container and immersing the container into a water bath with a temperature controlled to 40 +/- 2°C. This was done to provide better temperature control than could be obtained in a typical oven. The result was subtracted from 1 and multiplied by 100 to give the "percent conversion" of the aged sample.
  • the test results can be evaluated as follows: If the percent conversion of the sample was approximately 0%, the heat bonded performance of the aged sample may be assumed to be equivalent to that of a non-aged sample.
  • percent conversion was more than 0%, it may be necessary to couple this test with measurements of heat bonded performance to determine if the adhesive article is still suitable for use. Typically, percent conversions of up to 10% or more are acceptable. The acceptable percent conversion will depend upon the specific adhesive article tested and on the specific properties of the adhesive article that are required for it to be suitable for its intended use.
  • the adhesive article was placed between two sheets of release-coated polyester liner. Unless otherwise noted, a sample was first heat bonded in a heated press under light contact pressure (10 kPa) for 60 minutes at 125°C, with a heat-up rate from room temperature of 3.5°C/minute and then cooled prior to removal from the press. After the heat bonding cycle was complete, the release liner was removed and an ungloved finger was pressed with moderate pressure onto the adhesive article. The qualitative level of tack
  • the films were first bonded between two sheets of release coated polyester using a vented oven with a ramped heating rate of 2°C/min from approximately 50°C to a temperature of 150°C, followed by a 30 minute hold at 150°C.
  • the bonded films were allowed to cool completely prior to testing.
  • the pressure sensitive adhesive layer was discontinuous and the size of the areas of pressure sensitive adhesive were large compared to the size of the pencil tip, the test was done in the area covered by the pressure sensitive adhesive. The results were not affected by the test having been done on a sample with a discontinuous layer of pressure sensitive adhesive.
  • FTIR Fastier Transform Infrared Spectroscopy
  • IR spectra of the surface were obtained by attenuated total reflectance (ATR) using a vertical, variable angle (set to 45 degree) Ge crystal (3 inches long by -0.25 inches wide) on a Nicolet Magna 750 FTIR spectrometer (commercially available from Nicolet Instrument Co ⁇ oration, Madison, Wisconsin). The sample was applied to both sides of the Ge crystal for a contact length of ⁇ 6 inches. The spectra were acquired at 4 cm "1 resolution and 128 scans were co-added. The penetration depth at 1660 cm "1 with a Ge crystal was -0.4 microns, assuming the refractive index of the sample was 1.5.
  • IR spectra of the surface of discontinuous pressure sensitive adhesive layers were obtained by ATR using a ZnSe objective on a Nic-Plan microscope attached to a Nicolet
  • Magna 750 FT-IR spectrometer The spot size of the ZnSe crystal was -50 microns. The penetration depth at 1660 cm “1 with a ZnSe crystal was -1.21 micron, assuming the refractive index of the sample was 1.5. The spectra were acquired at 4 cm "1 resolution and 128 scans were co-added. The results obtained for a discontinuous layer of pressure sensitive adhesive were the same as would have been obtained for a continuous layer of pressure sensitive adhesive provided that the size of the pressure sensitive adhesive area was large compared to the spot size of the ZnSe crystal.
  • the samples tested comprised an acrylic pressure sensitive adhesive layer on an epoxide-based bondable layer.
  • the pressure sensitive adhesive layer individually and the epoxide bondable layer individually were tested to show that there was no detectable peak at 1510 cm " in the pressure sensitive adhesive layer by itself and no detectable peak at 1732 cm "1 in the bondable layer by itself.
  • Samples were tested according to ASTM D-1002-94 using cold roll steel substrates having dimensions of 25.4 mm x 101.6 mm x 0.76 mm. The overlap area was 12.7 mm by 25.4 mm.
  • the substrates Prior to application of any of the example adhesive articles, the substrates were cleaned with 3M General Pu ⁇ ose Adhesive Cleaner. The substrates bonded with adhesive articles that were comparative examples were clamped to hold the test specimen in place for one week. The substrates bonded with an adhesive article representative of the present invention were clamped in a similar manner and then cured at 149°C for 1 hour. The initial grip separation rate was 12.7 mm min and the secondary separation rate was 50.8 mm/min.
  • bondline thickness refers to the thickness of the adhesive article between the two substrates. The results were reported as an average of the five sample results.
  • a second cleaned and ground coupon was overlapped fully with the first such that the ground side contacted the adhesive article.
  • the coupons were clamped to hold the test specimen in place and the joined samples were cured at 149°C for 1 hour. All testing was done on a Sintech tester at a crosshead speed of 127 mm/ minute. Five samples were tested at 23 +/- 3°C (abbreviated herein as room temperature or as "RT"), and the resulting bondline thicknesses (i.e., the thickness of the adhesive article between the two substrates) were nominally 0.25 mm to 0.38 mm in all cases. The results were reported as an average of the five sample results.
  • aqueous acrylate dispersion at 60.5 weight percent solids available from KTWO Inco ⁇ orated, Seabrook, TX under the trade designation "Kiwoprint D 146/3" was printed through a silk screen onto a silicone-treated paper liner to give a uniform pattern of discontinuous dots.
  • pressure sensitive adhesive dots having a diameter of approximately 3.0 to 3.2 millimeters and a thickness of 25 to 30 micrometers were obtained in a repeating, uniform grid-like pattern having columns (y-direction) and rows (x-direction).
  • the dots had a center-to-center distance of 7.5 mm in the y-direction and a center-to-center distance of 15 mm in the x-direction between every other column. Adjacent columns of dots were offset by 3.7 mm in the y-direction from each other and, in the x-direction, were spaced equidistant from the closest columns on either side.
  • thermosetting, modified epoxy structural adhesive in film form having a weight of approximately 147 g/m 2 , available from 3M, St. Paul, MN under the trade designation "Scotch-Weld Structural Adhesive Film AF 163-2L". Transfer lamination was carried out by the use of nip rollers.
  • thermosetting, modified epoxy adhesive film having a weight of approximately 220 g/m 2 , available from 3M under the trade designation "Scotch-Weld
  • Structural Adhesive Film AF 3109-2K was employed as the bondable layer.
  • thermosetting, supported, non-volatile, modified epoxy adhesive having a weight of approximately 293 g/m 2 , available from 3M under the trade designation "Scotch-Weld Structural Adhesive Film AF 126-2" was employed as the bondable layer.
  • thermosetting, supported, modified epoxy film adhesive having a weight of approximately 391 g/m 2 , available from 3M under the trade designation "Scotch- Weld
  • Structural Adhesive Film AF 111 was employed as the bondable layer.
  • a sample was prepared in accordance with Example 1 with the following modification.
  • a core/shell toughened, thermosetting epoxy film was employed as the bondable layer.
  • This layer was prepared in the following manner. 30 parts by weight (pbw) of a blend of diglycidyl ether of bisphenol F and diglycidyl ether of bisphenol A in a weight ratio of 55:45 having an equivalent weight of 176, available from Shell Chemical Co., Pernis, The Netherlands, under the trade designation "Epikote 232" and 70 pbw of a solid epoxy resin having an equivalent weight of 475, available from Shell Chemical Co., Pernis, The Netherlands, under the trade designation "Epikote 1001" were melt mixed together in a high speed shear mixer at a temperature of approximately 80-85°C.
  • This material was then coated between two silicone- treated polyester release liners using a heated knife-over-bed coating station. Both the knife and bed were heated to approximately 60-65°C. The gap between knife and bed was set to provide a final bondable layer thickness of 508 micrometers (not including any liners).
  • Pressure sensitive adhesive dots were prepared as described in Example 1 and applied to one surface of the bondable layer.
  • Example 7 A sample was prepared in accordance with Example 1 with the following modification.
  • Example 7 A toughened, low density, expandable epoxy resin having a weight of approximately 1600 g/m 2 , available from 3M, under the trade designation "Scotch- Weld AF 3030 FST Grade 50 Foaming Structural Adhesive Film", was employed as the bondable layer.
  • Example 7 A toughened, low density, expandable epoxy resin having a weight of approximately 1600 g/m 2 , available from 3M, under the trade designation "Scotch- Weld AF 3030 FST Grade 50 Foaming Structural Adhesive Film", was employed as the bondable layer.
  • Adhesive Film was employed as the bondable layer.
  • a sample was prepared in accordance with Example 1 with the following modification.
  • a sample was prepared in accordance with Example 1 with the following modification.
  • a structural adhesive film comprising a phenolic-cured epoxy resin as the bondable layer was prepared and employed in the following manner.
  • Ni(imidazole)-6-phthalate can be made by combining 0.2 equivalents of the sodium or potassium salt of phthalic acid in 100 ml of water with 0.1 mole of (Ni(OAc) » 4H2O) and 0.6 moles of imidazole in 250 ml water at 50°C.) After cooling to 5°C, the Ni(imidazole) 6-phthalate salt precipitates.
  • the material is filtered, washed well with water to remove any remaining imidazole, and then dried.) The mixture was then degassed and flushed with nitrogen prior to casting between two polyester-treated release liners and UV-cured for approximately 1.8 minutes at an intensity of 1.3 mW/cm 2 ) to give a final film thickness (not including liner) of 500 micrometers.
  • Pressure sensitive adhesive dots were prepared as described in Example 1 and applied to one surface of the bondable layer.
  • a sample was prepared in accordance with Example 5, with the following modification.
  • a pressure sensitive adhesive in the form of a blown microfiber, was prepared having a composition of isooctyl acrylate:acrylic acid:2-(polystyryl)ethyl methacrylate macromer (having a molecular weight of 13,000), available from Sartomer Company, Exton, Pennsylvania under the trade designation "CHEMLINK 4500” in a ratio of 92:4:4 (weight weight).
  • the pressure sensitive adhesive composition was prepared in a blown microfiber (BMF) form as described in US 4,693,776.
  • the BMF pressure sensitive adhesive was coated onto silicone-treated paper liner at a coating weight of 5 g/m 2 , using a die tip having 0.38 millimeter diameter holes at a spacing of 10 holes per inch (10 holes per 2.54 centimeter). Heated air, at a temperature of 270°C, attenuated the fibers out of the die tip at a rate of 125 SCFM (standard cubic feet per minute).
  • the air knife configuration consisted of a 0.25 mm positive set back and a 0.76 millimeter air gap.
  • the polymer output rate and the die-to-collector distance were held constant at 0.45 kilograms pounds per hour and 18.4 cm, respectively.
  • a moderate vacuum was pulled through a medium mesh collector screen at the point of web formation.
  • the collector speed was set at 27.4 meters/minute (90 feet/minute) in order to collect a 5 g/m weight sample.
  • the temperature profile along the extruder was constant at 200°C, with the neck tube set to 185°C, and the die set to 220°C. After applying the BMF pressure sensitive adhesive to the release liner, it was transfer laminated to the bondable layer of Example 5, using the method described in Example 1.
  • Example 11 A sample was prepared in accordance with Example 5 with the following modification.
  • a water-based pressure sensitive acrylic adhesive available from 3M under the trade designation "Scotch-Grip 4224-NF" was applied directly to the bondable layer using a micropipet to give the grid-like pattern described in Example 1.
  • the pressure sensitive adhesive was dried at 23°C overnight followed by 3 hours at 70°C in a forced air oven.
  • the resulting dots of pressure sensitive adhesive had a diameter of approximately 2 millimeters and a thickness of 12 to 25 micrometers.
  • Example 5 A sample was prepared in accordance with Example 5 with the following modification.
  • An adhesive transfer tape available from 3M under the trade designation "Laminating Adhesive 671LE” was laminated onto a silicone-treated paper liner, cut into small square pieces measuring 2.5 mm x 2.5 mm, and applied by hand to the bondable layer to give the grid-like pattern described in Example 1.
  • the second liner was removed to expose the pressure sensitive adhesive surface.
  • the resulting dots of pressure sensitive adhesive had a thickness of approximately 60 micrometers.
  • a sample was prepared in accordance with Example 5 with the following modification.
  • a high tack, synthetic rubber resin, available from 3M under the trade designation "475XL Double Coated Film Tape” was laminated onto a silicone-treated paper liner, cut into small square pieces measuring 2.5 mm x 2.5 mm, and applied by hand
  • Example 2 to the bondable layer to give the grid-like pattern described in Example 1.
  • the second liner was removed to expose the pressure sensitive adhesive surface.
  • the resulting dots of pressure sensitive adhesive had a thickness of approximately 150 micrometers.
  • a sample was prepared in accordance with Example 5 with the following modification.
  • a soft rubber resin pressure sensitive adhesive available from 3M under the trade designation "464XL Extended Liner Tape” was laminated onto a silicone-treated paper liner, cut into small square pieces measuring 2.5 mm x 2.5 mm, and applied by hand to the bondable layer to give the grid-like pattern described in Example 1.
  • the second liner was removed to expose the pressure sensitive adhesive surface.
  • the resulting dots of pressure sensitive adhesive had a thickness of approximately 80 micrometers.
  • Example 15 A sample was prepared in accordance with Example 5 with the following modification. 6 parts by weight of a corrosion inhibitor available from W.R. Grace GmbH, Worms, Germany under the trade designation "Shieldex AC5" was added to the material for preparing the bondable layer during the mixing step prior to coating. Prior to the lamination of the dots onto the bondable layer, a scrim (12 g/m polyester tissue available from Technical Fibre Products , Slate Hill, New York) was laminated into the bondable layer by feeding the scrim into the rolling bank of bondable material prior to the first nip roller.
  • a corrosion inhibitor available from W.R. Grace GmbH, Worms, Germany under the trade designation "Shieldex AC5"
  • a scrim (12 g/m polyester tissue available from Technical Fibre Products , Slate Hill, New York
  • Example 16 A sample was prepared in accordance with Example 5 with the following modification.
  • the pressure sensitive adhesive printing method described in Example 1 was used to provide pressure sensitive adhesive dots approximately 1 millimeter in diameter in a repeating, uniform grid-like pattern having columns (y-direction) and rows (x-direction).
  • the dots had a center-to-center distance of 5 mm in the y-direction and a center-to-center distance of 10 mm in the x-direction between every other column.
  • Adjacent columns of dots were offset by 2.5 mm in the y-direction from each other and, in the x-direction, were spaced equidistant from the closest columns on either side.
  • Example 17 A sample was prepared in accordance with Example 5, with the following modification. 15 pbw of core/shell toughener was used.
  • Example 19 A sample was prepared in accordance with Example 15, with the following modification. No scrim was laminated onto the bondable layer. Example 19
  • a doorskin from a late 1980's model Oldsmobile Cutlass was replaced by an adhesive article prepared in accordance with Example 5.
  • the replacement panel was "dry-fit" to the vehicle structure, partially clamped in place and checked for fit and alignment. The replacement panel was then removed from the vehicle. The areas to be bonded were cleaned with soap and water.
  • 3M General Pu ⁇ ose Adhesive Cleaner was used to remove any grease, wax, and/or tar from the bonding surface.
  • a continuous strip of the adhesive article was placed on the inner door frame in all areas that would be contacted by the doorskin and the doorskin was then mounted into place and hemmed over the frame to complete the installation.
  • the adhesive article was bonded by inductively heating the replacement panel using the apparatus described in Application Number (FN 55179USA2A) to give bondline temperatures from 121°C to 149°C for 1 hour.
  • bondline temperature refers to the temperature of the adhesive article between the two substrates.
  • a 0.29 inch by 33 foot litz wire was utilized for the flexible, reshapeable cable assembly.
  • the cable assembly was coupled to a 1500 watt, 120 VAC, 25-50 kilohertz variable power supply.
  • the cable assembly was positioned in a non-dipole manner on the substantially continuous bondline, i.e., the width of the substrate which is attached to the adhesive article, along its length and the power supply was activated.
  • the power supply included a rheostat which was set to 85% to control the current to the cable assembly, thereby controlling the heating of the bond line.
  • the extent of cure of the adhesive article was determined using Differential Scanning Calorimetery (DSC) by comparing the reaction exotherm for the bonded article to that of the bondable article. The results confirmed that essentially 100% cure of the adhesive article was reached.
  • DSC Differential Scanning Calorimetery
  • An adhesive article having a bondable layer of Cytec FM 73M (having a weight of 300 g/m 2 ) and a continuous pressure sensitive adhesive film on both major surfaces of the bondable layer was prepared.
  • the pressure sensitive adhesive composition was 2-ethyl hexyl acrylate:methyl acrylate:glycidyl methacrylate:N-vinyl-2-pyrrolidone:acrylic acid / 67:23:0.5:2:7 and was prepared in the following manner.
  • a monomer mixture was made by mixing 423 g of 2-ethyl hexyl acrylate, 145 g of methyl acrylate, 3.15 g of glycidyl methacrylate, 12.6 g of N-vinyl-2-pyrrolidone and 44.1 g of acrylic acid. 157 g of this mixture was introduced to a 2 liter reactor equipped with a half-moon shaped agitator made of commercially available material under the trade designation "Teflon", a reflux condensor and a thermistor. 73.5 g of ethyl acetate and 78.8 g of hexane were added. The contents of the reactor were heated to reflux and 0.238 g of 2,2'-azobis-2-methylpropanenitrile, available from DuPont Company, Chemicals & Pigments Department, Wilmington, Delaware under the trade designation "Vazo 64" in
  • the pressure sensitive adhesive solution was coated onto a silicone-treated polyester release liner using a knife-over-bed coating station having a gap setting sufficient to provide an adhesive thickness of 12.7 micrometers (not including the release liner) after drying at 70°C for 30 minutes.
  • the dried sheet of continuous pressure sensitive adhesive film thus obtained was transfer laminated, at room temperature using two nip rollers, to a bondable layer of Cytec FM-73 having a nominal thickness of 500 micrometers.
  • a sample was prepared in accordance with Comparative Example 1 with the following modification.
  • a monomer mixture was made by mixing 453.6 g of isooctyl acrylate, 100.8 g of methyl acrylate, 6.3 g of glycidyl methacrylate, 25.2 g of N-vinyl caprolactam, 44.1 g of acrylic acid and 0.94 g of Vazo 64.
  • the pressure sensitive adhesive solution was coated onto a silicone-treated polyester release liner using a knife-over-bed coating station having a gap setting sufficient to provide an adhesive thickness of 12.7 micrometers (not including the release liner) after drying at 70°C for 30 minutes.
  • the dried sheet of continuous pressure sensitive adhesive film thus obtained was transfer laminated, at room temperature using two nip rollers, to a bondable layer of Cytec FM 73M having a nominal thickness of 500 micrometers.
  • a pressure sensitive adhesive layer was prepared as described in Comparative Example 1.
  • a bondable layer was prepared as described in Example 5. Lamination of the pressure sensitive adhesive layer and the bondable layer was performed as described in Comparative Example 1.
  • a sample was prepared in accordance with Comparative Example 2 with the following modification.
  • the pressure sensitive adhesive layer was coated to give a dry thickness of 75 micrometers.
  • a two part epoxy paste adhesive, which is sold for reattachment of automotive body panels, having the trade designation "3M Panel Bonding Adhesive 8115" was obtained from 3M, St. Paul, MN.
  • a two-part polyurethane paste adhesive which is sold for reattachment of automotive body panels, having the trade designation "Duramix 4179" was obtained from Polymer Engineering Co ⁇ oration, Oxnard California.
  • a two-part epoxy paste adhesive which is sold for reattachment of automotive body panels, having the trade designation "SEM 39537” was obtained from SEM Products Inc, Charlotte, NC.
  • a two-part acrylic paste adhesive which is sold for reattachment of automotive body panels, under the trade designation "Fusor 108B" was obtained from Lord Co ⁇ oration, Erie, PA.
  • a pressure sensitive adhesive layer was prepared from the composition described in Example 1. Rather than being screen printed as dots, the pressure sensitive adhesive composition was coated using the method described in Comparative Example 1 , to yield as dry film with a thickness of approximately 12.7 micrometers. The film was not laminated to a bondable layer. Control B
  • a pressure sensitive adhesive layer was made as described Control A, but prior to coating the film, 10 weight percent of epoxide commercially available from Shell Chemical, Houston, Texas under the trade designation "EPON 828", calculated as a fraction of the solids portion of the pressure sensitive adhesive composition, was blended into the pressure sensitive adhesive layer.
  • the mixed composition was cast by hand onto silicone-treated release liner to yield a dry film thickness of approximately 50 micrometers. The film was not laminated to a bondable layer.
  • a pressure sensitive adhesive layer was made as in Comparative Example 1 , but prior to coating the film, 10 weight percent EPON 828, calculated as a fraction of the solids portion of the pressure sensitive adhesive composition, was blended into the pressure sensitive adhesive layer in order to generally represent what occurs when the pressure sensitive adhesive layer.
  • the mixed composition was cast by hand onto silicone- treated release liner to yield a dry film thickness of approximately 50 micrometers. The film was not laminated to a bondable layer.
  • a pressure sensitive adhesive layer was made in accordance with Comparative Example 1 with the following exceptions.
  • the film was coated and dried to provide an adhesive thickness of approximately 75 micrometers.
  • the film was not laminated to a bondable layer.
  • a pressure sensitive adhesive layer was made in accordance with Comparative Example 2 with the following exceptions.
  • the adhesive solution was coated and dried to provide a dry film thickness of approximately 75 micrometers.
  • the film was not laminated to a bondable layer.
  • a pressure sensitive adhesive layer was made in accordance with Example 10B and was not laminated to a bondable layer.
  • a bondable layer was prepared as described in Example 5.
  • a pressure sensitive adhesive layer was not laminated to the bondable layer.
  • Control H A bondable layer was prepared as described in Example 8. A pressure sensitive adhesive layer was not laminated to the bondable layer.
  • Example 5 was also tested after more than three months of storage in accordance with the 90 Degree Peel Test Method (1 minute dwell) and provided a 10 result of 18 N/25mm.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Adhesive Tapes (AREA)

Abstract

L'invention concerne un ensemble comprenant un article adhésif, et un panneau extérieur de corps de véhicule ou une structure intérieure de véhicule. L'article adhésif comprend une couche pouvant être liée à au moins une surface principale d'une couche discontinue d'adhésif autocollant. La couche d'adhésif autocollant conserve sensiblement les caractéristiques des adhésifs autocollants après un stockage à température ambiante pendant au moins environ trois mois avant le chauffage de l'article adhésif. Ledit article adhésif possède un cisaillement de recouvrement, mesuré à température ambiant selon la norme ASTM D-1002-94, d'au moins environ 6,9 MPa après liaison. Il est fixé au panneau extérieur du corps de véhicule ou à la structure intérieure de véhicule. L'invention concerne également un procédé de fixation et un procédé d'étanchéité réalisé à l'aide dudit article adhésif.
PCT/US2000/025590 1999-10-21 2000-09-18 Ensemble comprenant un panneau ou une structure interieure de vehicule, et article adhesif WO2001029143A1 (fr)

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US09/422,482 1999-10-21

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100430423C (zh) * 2006-10-24 2008-11-05 河北工业大学 压敏胶粘剂用聚丙烯酸酯复合乳液的制备方法
EP2014459A2 (fr) 2007-06-08 2009-01-14 GM Global Technology Operations, Inc. Inhibiteurs de corrosion pour la liaison adhésive de structures de carrosseries de véhicule
WO2012078826A3 (fr) * 2010-12-08 2012-08-16 3M Innovative Properties Company Article adhésif pour applications tridimensionnelles
EP2529856A1 (fr) * 2011-05-31 2012-12-05 3M Innovative Properties Company Ensemble de composants métalliques et son procédé de fabrication
EP2700683B1 (fr) 2012-08-23 2016-06-08 3M Innovative Properties Company Film adhésif structurel
US9884663B2 (en) 2014-05-16 2018-02-06 Divergent Technologies, Inc. Modular formed nodes for vehicle chassis and their methods of use
US9975179B2 (en) 2014-07-02 2018-05-22 Divergent Technologies, Inc. Systems and methods for fabricating joint members
WO2018130719A1 (fr) * 2017-01-16 2018-07-19 Lohmann Gmbh & Co. Kg Dispositif support de véhicule automobile utilitaire
CN109536078A (zh) * 2018-12-06 2019-03-29 广东莱尔新材料科技股份有限公司 一种车用ffc线材的热熔胶膜制备方法及其热熔胶膜
CN111760534A (zh) * 2020-05-27 2020-10-13 北京化工大学 一种微波固化反应系统及其微波固化和定量评价微波固化反应非热效应的方法
US10960929B2 (en) 2014-07-02 2021-03-30 Divergent Technologies, Inc. Systems and methods for vehicle subassembly and fabrication

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US5593759A (en) * 1992-10-20 1997-01-14 Avery Dennison Corporation Pressure-sensitive structural adhesive
WO1999029793A1 (fr) * 1997-12-09 1999-06-17 Minnesota Mining And Manufacturing Company Article en caoutchouc pouvant se coller a un adhesif autocollant et procede de fabrication
EP0942054A1 (fr) * 1998-03-11 1999-09-15 Minnesota Mining And Manufacturing Company Structure adhésive multicouche

Patent Citations (3)

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Publication number Priority date Publication date Assignee Title
US5593759A (en) * 1992-10-20 1997-01-14 Avery Dennison Corporation Pressure-sensitive structural adhesive
WO1999029793A1 (fr) * 1997-12-09 1999-06-17 Minnesota Mining And Manufacturing Company Article en caoutchouc pouvant se coller a un adhesif autocollant et procede de fabrication
EP0942054A1 (fr) * 1998-03-11 1999-09-15 Minnesota Mining And Manufacturing Company Structure adhésive multicouche

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100430423C (zh) * 2006-10-24 2008-11-05 河北工业大学 压敏胶粘剂用聚丙烯酸酯复合乳液的制备方法
EP2014459A2 (fr) 2007-06-08 2009-01-14 GM Global Technology Operations, Inc. Inhibiteurs de corrosion pour la liaison adhésive de structures de carrosseries de véhicule
EP2014459A3 (fr) * 2007-06-08 2009-06-10 GM Global Technology Operations, Inc. Inhibiteurs de corrosion pour la liaison adhésive de structures de carrosseries de véhicule
WO2012078826A3 (fr) * 2010-12-08 2012-08-16 3M Innovative Properties Company Article adhésif pour applications tridimensionnelles
US9452462B2 (en) 2011-05-31 2016-09-27 3M Innovative Properties Company Metal panel assembly and method for making same
KR101953933B1 (ko) * 2011-05-31 2019-03-04 쓰리엠 이노베이티브 프로퍼티즈 컴파니 금속 패널 조립체 및 이의 제조 방법
KR20140033458A (ko) * 2011-05-31 2014-03-18 쓰리엠 이노베이티브 프로퍼티즈 컴파니 금속 패널 조립체 및 이의 제조 방법
CN103702782A (zh) * 2011-05-31 2014-04-02 3M创新有限公司 金属面板组件及其制备方法
US20140193603A1 (en) * 2011-05-31 2014-07-10 3M Innovative Properties Company Metal panel assembly and method for making same
JP2014523930A (ja) * 2011-05-31 2014-09-18 スリーエム イノベイティブ プロパティズ カンパニー 金属パネルアセンブリ、及びこの製造方法
RU2586369C2 (ru) * 2011-05-31 2016-06-10 Зм Инновейтив Пропертиз Компани Металлическая панель в сборе и способ ее изготовления
EP2529856A1 (fr) * 2011-05-31 2012-12-05 3M Innovative Properties Company Ensemble de composants métalliques et son procédé de fabrication
CN103702782B (zh) * 2011-05-31 2016-12-07 3M创新有限公司 金属面板组件及其制备方法
JP2017171922A (ja) * 2011-05-31 2017-09-28 スリーエム イノベイティブ プロパティズ カンパニー 金属パネルアセンブリ、及びこの製造方法
WO2012166257A1 (fr) * 2011-05-31 2012-12-06 3M Innovative Properties Company Ensemble panneau métallique et son procédé de fabrication
EP2700683B1 (fr) 2012-08-23 2016-06-08 3M Innovative Properties Company Film adhésif structurel
US9884663B2 (en) 2014-05-16 2018-02-06 Divergent Technologies, Inc. Modular formed nodes for vehicle chassis and their methods of use
US10668965B2 (en) 2014-05-16 2020-06-02 Divergent Technologies, Inc. Nodes with integrated adhesive ports and channels for construction of complex structures
US9975179B2 (en) 2014-07-02 2018-05-22 Divergent Technologies, Inc. Systems and methods for fabricating joint members
US10960929B2 (en) 2014-07-02 2021-03-30 Divergent Technologies, Inc. Systems and methods for vehicle subassembly and fabrication
US10960468B2 (en) 2014-07-02 2021-03-30 Divergent Technologies, Inc. Stress-based method for optimization of joint members within a complex structure
WO2018130719A1 (fr) * 2017-01-16 2018-07-19 Lohmann Gmbh & Co. Kg Dispositif support de véhicule automobile utilitaire
CN109536078A (zh) * 2018-12-06 2019-03-29 广东莱尔新材料科技股份有限公司 一种车用ffc线材的热熔胶膜制备方法及其热熔胶膜
CN109536078B (zh) * 2018-12-06 2021-07-06 广东莱尔新材料科技股份有限公司 一种车用ffc线材的热熔胶膜制备方法及其热熔胶膜
CN111760534A (zh) * 2020-05-27 2020-10-13 北京化工大学 一种微波固化反应系统及其微波固化和定量评价微波固化反应非热效应的方法

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