Method of separating combined articles

Abstract

The present disclosure relates to a method for debonding a bonded article, said method comprising the following steps: a) A step of providing a combined article, wherein the combined article comprises at least one layer of a first adhesive interposed between two substrate surfaces, and the combined article further comprises at least one layer of a second adhesive interposed between the two substrate surfaces, wherein: A fibrous web is at least partially included in the layer or each layer of the first adhesive; A step in which a layer of the first adhesive or each layer has a dry film thickness of 10 to 500 μm; b) A step of treating a combined article at a temperature of 20°C to 90°C with a solution in a polar solvent of at least one compound selected from the group consisting of C10-C26 fatty acids; salts of C10-C26 fatty acids; and C1-C4 alkyl esters of C10-C26 fatty acids, wherein the pH of the solution is 3 to 14; and c) A step of separating at least one layer of the first adhesive from its interposition between the two substrate surfaces.

Description

Technology Field

[0001] The present disclosure relates to the debonding of articles bonded with an adhesive. More particularly, the present disclosure relates to the use of a solution of a long-chain fatty acid or its salt or ester in a polar solvent in the debonding of articles bonded with an adhesive. Background Technology

[0002] Adhesive bonding and polymer coatings are commonly used for the assembly and finishing of manufactured products. Used in place of mechanical fasteners such as screws, bolts, and rivets, they provide bonds with reduced processing costs and greater adaptability in the production process. Adhesive bonding distributes stress evenly, reduces the risk of fatigue, and seals connections against corrosive substances.

[0003] Therefore, while adhesive bonding offers many advantages over mechanical fasteners, disassembling adhesive-bonded objects required in practical applications tends to be difficult. Removal of adhesives through mechanical processes, such as sandblasting or wire brushing, is often ruled out because the adhesive is partially embedded between the substrates, making it inaccessible, or because it is difficult to polish without damaging the substrate surface. Disassembly via the application of aggressive chemicals and / or high temperatures, as disclosed in U.S. Patent No. 4,171,240 (Wong) and U.S. Patent No. 4,729,797 (Linde et al.), can be effective but can be time-consuming and complex to perform. Furthermore, the required aggressive chemicals and / or harsh conditions can damage the separated substrates, rendering them unsuitable for subsequent applications. This can be particularly detrimental when the substrates themselves have high economic value, such as bonded electrical components and metal materials.

[0004] WO 01 / 30932 A2 (Henkel KGaA) describes the reversible separation of adhesive-bonded composites by applying an electromagnetic alternating field. The adhesive-bonded composite comprises at least one primer coating containing nanoscale particles having ferromagnetic, ferrimagnetic, superparamagnetic, or piezoelectric properties. By applying an electromagnetic alternating field, a large amount of local heat is generated in the primer coating of the adhesive-bonded composite. When the primer layer is interposed between the substrate and the thermoplastic adhesive layer, the thermoplastic resin softens due to local heat generation. Conversely, when the primer layer is interposed between the substrate and the thermosetting adhesive layer, local heat generation can split the cross-linking structure of the binder matrix. In both cases, strong local heating of the boundary layer enables the separation of the quasi-adhesive substrate at low force input.

[0005] EP 4 011 996 A1 (Henkel AG & Co. KGaA) relates to a method for separating two substrates bonded by an adhesive. The method comprises the following steps: i) treating two substrates bonded by an adhesive using a debonding agent comprising acetone and / or oleic acid at a temperature of 20°C to 90°C; and ii) removing the substrates from the adhesive.

[0006] WO2021 / 249749 A1 (BASF SE) discloses a method for debonding a bonded article, wherein the article comprises at least two components bonded together using a polyurethane adhesive selected from an aqueous polyurethane dispersion adhesive and a polyurethane hot melt adhesive. At least one of the components is a thermoplastic polyurethane. The components are debonded by treatment using an aqueous surfactant composition at elevated temperature.

[0007] It is considered that there remains a need in the art to provide an effective method for debonding bonded articles, which can be performed in a simple and efficient manner without requiring the simultaneous application of strong chemicals, elevated temperatures, mechanical abrasion, or significant force. Furthermore, it would be advantageous for the separated substrates to retain their utility and be reused or recycled.

[0008] Description of the Invention

[0009] According to a first aspect of the present disclosure, a bonded article is provided comprising at least one layer of a first adhesive interposed between two substrate surfaces, said bonded article further provided with at least one layer of a second adhesive interposed between the two substrate surfaces, wherein:

[0010] The fibrous web is at least partially included in the layer of the first adhesive or in each layer;

[0011] The first layer of adhesive or each layer has a dry film thickness of 10 to 500 μm, for example, 30 to 300 μm.

[0012] Generally, the combined article will comprise a first substrate having an inner surface; and a second substrate having an inner surface, wherein the layers of the first and second adhesives are interposed between the inner surfaces of the first substrate and the second substrate. In a key embodiment, at least one of the first substrate and the second substrate is metallic. Independently of or additionally to the above conditions, it is preferable that at least one layer of the first adhesive is in direct contact with the surface of the substrate.

[0013] In a specific embodiment, the fibrous web is substantially contained within the layer or each layer of the first adhesive. It is desirable that the fibrous web is completely contained within the layer or each layer of the first adhesive so that the fibers of the web do not protrude beyond the layer of the first adhesive, and thus the fibrous web is completely contained within the dry film thickness of the layer.

[0014] The fibrous web may be a woven web or a non-woven web in certain embodiments. Independently of or additionally to these features, the fibrous web may comprise natural fibers; one or more synthetic fibers; or a blend of natural fibers and one or more synthetic fibers. Exemplary synthetic fibers may be selected from the group consisting of polyester fibers; rayon; viscose; polyamide fibers; polyether sulfone (PES) fibers; polyphenylene sulfone (PPS) fibers; polyacrylic fibers; aramid-based fibers; melamine resin-based fibers; polybenzimidazole (PBI) fibers; polyolefin fibers; and mixtures thereof. Exemplary natural fibers may be selected from the group consisting of wool; lyocell; cellulose fibers; polysaccharide fibers; and mixtures thereof.

[0015] Good results were obtained when the fibers of the web are characterized by at least one of the following parameters determined by a laser diffraction / scattering method: an aspect ratio of 5 to 2000, preferably 20 to 2000; an average length of 1 to 20 mm, preferably 1 to 15 mm; and an average diameter of 1 to 50 μm, preferably 5 to 25 μm.

[0016] In an important embodiment, the first and second adhesives are distinct from each other. The second adhesive should preferably have a higher interlayer cohesion strength than the first adhesive, as determined by a comparative test of the adhesives under tensile stress applied to the corresponding layer. The term "as used herein" Interlayer cohesion robbery" represents the amount of force required to separate the adhesive layers by cohesion failure as measured according to ASTM F88-94, in a direction perpendicular to the plane of the layer. In a key embodiment, the second adhesive may have an interlayer cohesion strength at least 10% greater than the interlayer cohesion strength of the first adhesive. In an alternative expression, intended not to be mutually exclusive with the given, the interlayer cohesion strength of the first adhesive may be 2 to 8 MPa, and the interlayer cohesion strength of the second adhesive may be at least 10 MPa, e.g., 10 to 100 MPa.

[0017] The first adhesive is preferably a polyurethane adhesive selected from aqueous polyurethane dispersion adhesives and polyurethane hot melt adhesives. The aqueous polyurethane dispersion adhesive may be of the 1-part (1K) or 2-part (2K) type. It is preferable that the polyurethane dispersion adhesive be of the 2-part (2K) type. More particularly, in an important embodiment, the first adhesive is obtained by curing a 2-part (2K) aqueous composition comprising the following:

[0018] p) Part 1 including the following:

[0019] (pi) At least one anionic polyurethane polymer having a pendant hydroxyl group; and

[0020] q) a second part comprising at least one polyisocyanate compound having a pendant -NCO group,

[0021] Here, the 2-part (2K) aqueous composition is characterized by a molar ratio of active hydrogen atoms to -NCO groups in the composition of 5:1 to 1:5.

[0022] In a specific embodiment, part p) of the 2-part (2K) aqueous composition comprises at least one anionic polyurethane polymer characterized by: a hydroxyl functionality of 2 to 4; a hydroxyl value of 0.5 to 10 mg KOH / g, preferably 0.5 to 4 mg KOH / g; and a weight average molecular weight (Mw) of 50 to 200 kDa, preferably 50 to 150 kDa, more preferably 50 to 125 kDa. Independently of or additionally with the selection of this polyurethane polymer, it is preferable that part q) of the 2-part (2K) aqueous composition comprises a linear aliphatic polyisocyanate.

[0023] The provision of the first adhesive layer(s)—particularly as a layer disposed directly on the surface of the substrate—represents an important site for attack by a debonding solution, particularly the debonding solution described herein. At least partial removal of the first adhesive layer(s) through treatment with the debonding solution allows for easy separation of the bonded substrate.

[0024] Without being bound by theory, providing a fibrous web within the layer(s) of the first adhesive is considered to provide a diffusion pathway through that layer for the debonding solution. The arrangement of fibers within the adhesive layer can additionally provide nucleation sites for cavitation bubbles: the effect of cavitation can generate stress within the adhesive layer, thereby promoting erosion of that layer.

[0025] According to a second aspect of the present invention, C 10 ~C 26 Fatty acid; C 10 ~C 26 Salts of fatty acids; and C 10 ~C 26Use is provided for debonding articles bonded with an adhesive as defined in the present specification and appended claims, wherein a solution of at least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids in a polar solvent, said debonding solution has a pH of 3 to 14. The debonding composition may have a pH of, for example, 3 to 7, or 3 to 6.

[0026] The debonding solution comprises 5 to 30 weight%, preferably 5 to 25 weight%, of C based on the weight of the solution. 10 ~C 26 Fatty acid; C 10 ~C 26 Salts of fatty acids; and C 10 ~C 26 It is preferable to include at least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids.

[0027] The above at least one compound of the debonding solution is C 16 -C 18 Monounsaturated fatty acid; C 16 -C 18 Salts of monounsaturated fatty acids; and C 16 -C 18 Good results were obtained when selected from the group consisting of C1-C4 alkyl esters of monounsaturated fatty acids. And in a particularly effective embodiment, the at least one compound of the debonding solution is selected from the group consisting of oleic acid; salts of oleic acid; and C1-C2 alkyl esters of oleic acid.

[0028] The polar solvent of the debonding solution preferably comprises or consists of at least one compound selected from the group consisting of water; polyalkylene glycol dialkyl ethers; and dibasic esters. Independently of or additionally to this preference description, the debonding solution further comprises at least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants, in an amount of 0.5 to 50 weight%, preferably 0.5 to 40 weight%, based on the weight of the solution.

[0029] The present disclosure further provides a method for debonding a bonded article, said method comprising the following steps:

[0030] a) a step of providing a combined article as defined in the above specification and the appended claims, wherein the combined article comprises at least one layer of a first adhesive interposed between two substrate surfaces, and the combined article further comprises at least one layer of a second adhesive interposed between the two substrate surfaces, wherein:

[0031] The fibrous web is at least partially included in the layer of the first adhesive or in each layer;

[0032] A step in which the layer of the first adhesive or each layer has a dry film thickness of 10 to 500 μm, for example, 30 to 300 μm; and

[0033] b) An article combined at a temperature of 20°C to 90°C, for example, 30°C to 75°C, C 10 ~C 26 Fatty acid; C 10 ~C 26 Salts of fatty acids; and C 10 ~C 26 A step of treating with a solution in a polar solvent of at least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids, wherein the pH of the solution is 3 to 14; and

[0034] c) A step of separating at least one layer of the first adhesive from its interposition between the two substrate surfaces.

[0035] In an effective embodiment, the treatment step of this method comprises immersing an article bound to the solution. Except for this, the treatment step may be characterized by a contact time of 0.1 to 24 hours, preferably 0.5 to 20 hours.

[0036] Where the aspects of the disclosure are described above as having specific embodiments, any one or more of these embodiments may be implemented as or combined with any of the additional embodiments, even if the combination thereof is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitutions thereof remain within the scope of the present disclosure.

[0037] definition

[0038] The singular forms “indefinite article” and “definite article” used in this specification include plural objects unless the context clearly indicates otherwise.

[0039] Terms used in this specification " including ", " Includes " and " ~ro Consisting of " silver " Starting ", " to originate ", " Containing " or " Contains It is synonymous with " and is inclusive or open, and does not exclude additional, non-cited members, elements, or method steps.

[0040] Terms used in this specification "~" as It takes place " excludes any unspecified elements, components, members, or method steps. For completeness, the term " include doing " silver " Composed of Includes "

[0041] word " desirable ", " Preferably ", " Preferably " and " especially " is frequently used in this specification to refer to embodiments of the disclosure that may provide specific advantages under specific circumstances. However, the reference to one or more desirable, preferred, favored, or specific embodiments does not imply that other embodiments are not useful and is not intended to exclude such other embodiments from the scope of the disclosure.

[0042] word " Exemplary " is used to mean functioning as an example, illustration, or model in this specification. Exemplary Any embodiment or design described herein as such should not be interpreted as necessarily being more desirable or advantageous than other embodiments or designs. Instead, the use of the word 'exemplary' is intended to present concepts in a specific manner.

[0043] Words used throughout this application " ~days there is " is used in a permissive sense rather than an obligatory sense—that is, a sense of possibility.

[0044] Spatially relative terms, for example, " interior ", " external ", " top ", " back side ", " stomach ", " under ", " Left ", " RightTerms such as "etc." may be applied in this specification to describe the relationship between a component and another component(s) as described in the drawings. By definition, all such spatial relative terms are merely based on the directions shown in the drawings for the convenience of explanation and are not necessarily limited thereto, given that the assembly may take on directions and configurations different from those shown in the drawings when in use.

[0045] Terms used in this specification " plural " is defined as two or more.

[0046] Where quantity, concentration, dimensions, and other parameters are expressed in the form of a range, a desirable range, an upper limit, a lower limit, or desirable upper and lower limits, it should be understood that any range obtainable by combining any upper limit or desirable value and any lower limit or desirable value is also specifically disclosed, regardless of whether the obtained range is explicitly mentioned in the context.

[0047] In addition, according to the standard understanding, " 0 to x The weight range indicated as " specifically includes 0 weight%: the component defined by the range may be absent from the material or may be present in the material in an amount of up to x weight%.

[0048] The molecular weights mentioned in this specification may be measured by gel permeation chromatography (GPC) using a polystyrene calibration standard, such as that performed according to ASTM 3536.

[0049] Term " Sanga " indicates the mass (mg) of potassium hydroxide (KOH) required to neutralize 1 g of a compound. The acid value can be determined by potentiometry according to DIN EN ISO 2114.

[0050] Terms used in this specification " hydroxyl group" is defined as the mass (mg) of potassium hydroxide required to neutralize the acetic acid absorbed upon acetylation of 1 g of a chemical containing a free hydroxyl group. The hydroxyl value can be determined according to DIN 53240.

[0051] Terms used in this specification " flash point " refers to the minimum temperature at which a liquid within a test vessel releases vapor at a concentration sufficient to form an ignitable mixture with air near the liquid's surface. This can be determined using appropriate active standard test methods, among which ASTM D-56 Standard Method of Test for Flashpoint by Tag Closed Tester ; and ASTM D93 Standard Method of Test for Flashpoint by Pensky -Martens Closed Tester It can be mentioned.

[0052] Unless otherwise specified, the viscosity of the compositions described herein is measured using a Brookfield viscometer, Model RVT, under standard conditions of 20°C and 50% relative humidity (RH). The viscometer is calibrated using silicone oil of known viscosity, variable from 5,000 cps to 50,000 cps. An RV spindle set attached to the viscometer is used for calibration. Measurement of the coating composition is performed using the No. 6 spindle at a speed of 20 revolutions per minute for 1 minute until the viscometer is equilibrated. Then, the viscosity corresponding to the equilibrium reading is calculated using calibration.

[0053] The room temperature used in this specification is 23℃ + / - 2℃.

[0054] "as used in this specification" circumference condition " refers to the temperature and pressure of the surroundings where the adhesive composition, debonding solution, or bonded article is located.

[0055] "of the water-based (primer) composition used in this specification hardening " implies that a coating is formed on the substrate, while: curing will involve crosslinking reaction(s), which further include: water, and, if present, the evaporation (drying) of the co-solvent from the composition; and the aggregation of the particulate or dispersed phase of the composition. Such curing may be performed under ambient conditions or by exposure to intentional heat and / or radiation. The degree of curing may be partial or complete: the degree of crosslinking (%) may be determined by dynamic mechanical thermal analysis (DMTA) using a Polymer Laboratories MK III DMTA analyzer, particularly under an inert gas atmosphere.

[0056] Unless otherwise specified, the term " particle size " represents the largest axis of the particle. In the case of a spherical particle, the largest axis is the diameter.

[0057] "as used in this specification" d 50 particle size " means that the particle size distribution is such that at least 50 volume percent of the particles have a particle size diameter less than a specific value. Unless otherwise specified, particle size is determined by dynamic light scattering (DLS).

[0058] "as used in this specification" solids Content " represents the weight percent of the non-volatile component in the composition. The solid content can be determined as the reciprocal of the volatile content obtained according to ASTM D2369 Standard Test Method for Volatile Content of Coatings.

[0059] "as used in this specification" standard weight " refers to the weight of the dry fibrous web per unit area, generally in grams per square meter (GSM, gm -2It is expressed as ). The reference weight is measured according to ASTM D3776-96. For woven and non-woven sheets, the reference weight depends on the density of the fibers constituting the sheet and the relative number of fibers per unit area.

[0060] In the context of the present invention, " 2-part (2K) composition It is understood that the first part (A) and the second part (B) are a composition in which they must be stored in separate containers due to their (high) reactivity. The two parts are mixed only immediately before application and then react to form bonds, typically without additional activation, thereby forming a polymeric network. In this specification, higher temperatures may be applied to accelerate the cross-linking reaction.

[0061] Terms used in this specification " water system primer composition " refers to the composition that actually comes into contact with the substrate to be primed. The term " water system " means that the solvent or carrier fluid for the composition mainly or primarily contains water, and that water constitutes at least 50 weight%, for example, at least 60 weight% or at least 70 weight% of the continuous liquid phase of the composition.

[0062] "as used in this specification" metallic " means any type of metal, metal alloy, or mixture thereof. The term " as used herein alloy "It typically refers to a material composed of two or more types of metals or a metal and a non-metal that are closely bonded by fusing together and dissolving into each other when melted.

[0063] "as used in this specification" Active hydrogen compound" is a compound containing at least one hydrogen atom that can easily dissociate in an aqueous environment. Preferably, the hydrogen atom is bonded to a nitrogen atom, an oxygen atom, a phosphorus atom, or a sulfur atom.

[0064] "as used in this specification" ionic polyurethane It contains a hydrophilic ionizable group.

[0065] Terms used in this specification " blocked " is the second compound - " circuit breaker It refers to a compound having - that reacts with, and whose reactive functional group becomes unusable until the blocking group is removed. The blocking group may be selectively removed at an appropriate point in the synthesis sequence: the triggering event may be, among others, moisture, heat, or radiation. Examples of blocked isocyanates include those co-reacted with phenol, methyl ethyl ketoxime, or -caprolactam.

[0066] Terms used in this specification " debonding composition " refers to a composition that actually comes into contact with the combined article. This contact is formed, sized, and arranged so as to allow at least a portion of the substrate to be immersed, the so-called " Bath This can occur in the bath. Furthermore, the bath must be sized to allow the movement of the composition around and throughout the loaded substrate, and this movement can be further enhanced by recirculation and / or ultrasound. The pH of the composition in the bath, the temperature of the bath, and the contact time of the substrate are resulting effective variables that must be monitored manually or automatically if possible.

[0067] "as used in this specification" Inorganic acid " refers to an acid derived from one or more inorganic compounds. Inorganic acids are not organic, and all inorganic acids release hydrogen ions when dissolved in water.

[0068] "as used in this specification" Phosphoric acid " refers to an ortho-phosphoric acid having the formula H3PO4, which is typically available as an aqueous solution having a concentration of up to 75 wt% H3PO4. As used herein, " Phosphonic acid " refers to a phosphorus oxo acid having the formula H3PO3, which consists of a single pentavalent phosphorus covalently bonded to oxygen through a double bond and to a single hydrogen and two hydroxyl groups through a single bond.

[0069] Terms used in this specification " α- hydroxycarboxylic acid " refers to a carboxylic acid having at least one hydroxyl functional group occupying the α-position (carbon adjacent to the carboxylic acid functional group) of the above acid. The presence of a hydroxyl group occupying a position within the molecule other than the α-position of the above acid is not excluded. If present, the α-hydroxycarboxylic acid is included in the composition in the form of a free acid.

[0070] In this specification, " Basic " refers to the quality of being a base rather than an acid. More specifically, according to the Lewis theory of acids and bases, a base is an electron-pair donor. This definition includes, but is not limited to, Brønsted-Lowry bases, in which compounds act as proton acceptors.

[0071] In this specification, water for use as a (coal)solvent or diluent is intended to mean water with a low solids content as understood by those skilled in the art. For example, water may be distilled water, demineralized water, deionized water, reverse osmotic water, boiler condensate, or ultrafiltered water. In certain situations, tap water may be accepted.

[0072] "as used in this specification" menstruum " is a substance capable of dissolving another substance to form a homogeneous solution; during dissolution, neither the solvent nor the dissolved substance undergoes a chemical change. The solvent can be polar or nonpolar. The term " alcohol menstruum " includes any water-soluble mono-alcohol, diol, or polyol that is liquid at atmospheric pressure at 25°C.

[0073] Terms used in this specification " aprotic menstruum " refers to a solvent that neither produces nor accepts protons. Conversely, " Protons menstruum " is a solvent capable of producing or accepting protons. As used herein " polarity menstruum " means a solvent having a permittivity (ε) greater than 5 when measured at 25°C: this term includes both aprotic and protic solvents. The determination of permittivity (ε) is well known in the art and is within the knowledge of those skilled in the art: in such determination, the use of voltage measured across parallel plate capacitors may be mentioned.

[0074] Terms used in this specification " number- Non-marriage liquid " refers to a liquid that forms a two-phase system with water. In this regard, a liquid that is slightly soluble, very slightly soluble, or virtually insoluble in water may be particularly desirable, characterized in that ≥ 100 ml of water is required to dissolve 1 g of the named compound at room temperature ( https: / / www.sigmaaldrich.com / united-kingdom / technical-services / solubility.html ).

[0075] "as used in this specification" polyol " means any compound containing two or more hydroxyl groups: therefore, this term is intended to include diols, triols and compounds containing four or more -OH groups.

[0076] "as used in this specification" C 1 - C n alkyl " A group refers to a monovalent group containing 1 to n carbon atoms, being an alkane radical, and including straight-chain and branched organic groups. As such, " C 1 -C 4 alkyl The term "group" refers to a monovalent group containing 1 to 4 carbon atoms, is an alkane radical, and includes straight-chain and branched organic groups. Examples of alkyl groups include, but are not limited to, methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; sec-butyl; and tert-butyl. In the present disclosure, such alkyl groups may be unsubstituted or substituted with one or more halogens. Where applicable to a given moiety (R), the acceptance of one or more non-halogen substituents within the alkyl group will be described in the specification.

[0077] Term " alkylene energy " represents a group that is a radical of a linear, branched, or cyclic alkane, which may be substituted or unsubstituted and optionally interposed by at least one heteroatom.

[0078] Terms used in this specification " C 1 - C n hydroxyalkyl " represents an HO-(alkyl) group having 1 to n carbon atoms, wherein the attachment point of the substituent is through the oxygen atom and the alkyl group is as defined above.

[0079] " Alkoxy energy " represents a monovalent group denoted by -OA, where A is an alkyl group: non-limiting examples thereof are methoxy groups, ethoxy groups, and iso-propyloxy groups. The term " as used herein Alkoxyl " means containing at least one alkoxy group.

[0080] "as used in this specification" C 2 -C 6 Alkenil The term "group" refers to an aliphatic carbon group containing 2 to 6 carbon atoms and at least one double bond positioned at any location. The alkenyl group may be straight-chain, branched, or cyclic, and may optionally be substituted with one or more halogens. Where applicable to a given moiety (R), permission for one or more non-halogen substituents within the alkenyl group will be indicated in the specification. The term " Alkenil " also includes radicals having "cis" and "trans" configurations as understood by those skilled in the art, or alternatively, "E" and "Z" configurations. However, it should be noted that generally, unsubstituted alkenyl groups containing 2 to 6 (C2-C6) or 2 to 4 (C2-C4) carbon atoms are preferred. And examples of C2-C6 alkenyl groups include, but are not limited to, ethenyl; 1-propenyl; 2-propenyl; 1-methyl-ethenyl; 1-butenyl; 2-butenyl; 4-methylbutenyl; 1-pentenyl; 2-pentenyl; 3-pentenyl; 4-pentenyl; 4-methyl-3-pentenyl; 1-hexenyl; 3-hexenyl; and 5-hexenyl.

[0081] Terms used in this specification " C 3 -C 6 cycloalkyl" represents an optionally substituted, saturated cyclic hydrocarbon having 3 to 6 carbon atoms. In the present disclosure, such cycloalkyl groups may be unsubstituted or substituted with one or more halogens. Where applicable to a given moiety (R), the acceptance of one or more non-halogen substituents within the cycloalkyl group will be described in the specification. Exemplary cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl groups.

[0082] "as used in this specification" C 3 -C 6 cycloalkylene " refers to a divalent radical formed by the removal of two hydrogen atoms from one or more rings of a cycloalkyl group having three to six carbon atoms.

[0083] "as used in this specification" C 2 -C 18 Alkenil " refers to a hydrocarbyl group having 2 to 18 carbon atoms and at least one ethylene unsaturated unit. The alkenyl group may be straight-chain, branched, or cyclic and may optionally be substituted with one or more halogens. Where applicable to a given moiety (R), permission for one or more non-halogen substituents within the alkenyl group will be stated in the specification. The term " Alkenil " is also, as recognized by those skilled in the art, " Sis " and " Trans " Arrangement, or alternatively, " E " and " Z It includes radicals having a configuration. The above C2-C 20Examples of alkenyl groups include -CH=CH2; -CH=CHCH3; -CH2CH=CH2; -C(=CH2)(CH3); -CH=CHCH2CH3; -CH2CH=CHCH3; -CH2CH2CH=CH2; -CH=C(CH3)2; -CH2C(=CH2)(CH3); -C(=CH2)CH2CH3; -C(CH3)=CHCH3; -C(CH3)CH=CH2; -CH=CHCH2CH2CH3; -CH2CH=CHCH2CH 3; -CH2CH2CH=CHCH3; -CH2CH2CH2CH=CH2; -C(=CH2)CH2CH2CH3; -C(CH3)=CHCH2CH3; -CH(CH3)CH=CHCH; -CH(CH3)CH2CH=CH2; -CH2CH=C(CH3)2; 1-cyclopent-1-enyl; 1-cyclopent-2-enyl; 1-cyclopent-3-enyl; 1-cyclohex-1-enyl; 1-cyclohex-2-enyl; and 1-cyclohexyl-3-enyl are included, but not limited thereto.

[0084] As used in this specification, alone or a larger moiety - " Aralkyl energy Same as in - used as part of " C 6 -C 18 Aril"The group refers to a monocyclic, bicyclic, and tricyclic ring system in which the monocyclic ring system is aromatic or at least one ring in the bicyclic or tricyclic ring system is aromatic. Bicyclic and tricyclic ring systems comprise a benzo-fused 2-3-membered carbocyclic ring. In the present disclosure, such aryl groups may be unsubstituted or substituted with one or more halogens. Where applicable to a given moiety (R), the acceptance of one or more non-halogen substituents within the aryl group will be described in the specification. Exemplary aryl groups include phenyl; (C1-C4)alkylphenyls, such as tolyl and ethylphenyl; indenyl; naphthalenyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl; and anthracenyl.

[0085] "as used in this specification" alkylaryl " represents an alkyl-substituted aryl group, and " substituted alkylaryl " refers to an alkylaryl group having one or more additional substituents as indicated above. Additionally, as used herein, " Aralkyl " means an alkyl group substituted with an aryl radical as defined above.

[0086] Terms used in this specification " hetero " refers to a group or moiety containing one or more heteroatoms, such as N, O, Si, and S. Therefore, for example, " Heterocyclic " refers to a cyclic group having N, O, Si, or S as part of a ring structure, for example. heteroalkyl ", " Heterocycloalkyl " and " Heteroaryl The moiety is an alkyl, cycloalkyl, and aryl group as defined in the present specification, each containing N, O, Si, or S as part of their structure.

[0087] Term " Heterocyclil" represents a monovalent chain of carbon and heteroatoms, where the heteroatoms are selected from N, O, Si, or S, and some of which include at least one heteroatom form a ring.

[0088] Term " substituted " implies substitution with at least one suitable substituent. For completeness: a substituent may be attached to the specified group or moiety at one or more positions; unless otherwise specified, multiple degrees of substitution are permitted. Also, the term " substitution " or " ~ro substituted "It includes an implied clue that such substitutions depend on the allowed valence of the substituted atoms and substituents, and that the substitutions result in stable compounds that are not spontaneously modified by, for example, rearrangement, cyclization, or removal.

[0089] Term " In reality no " is intended to mean that constituents, components, compounds, moiety, functional groups, elements, ions, etc. are not intentionally added to the subject material and are present only in trace amounts that, at most, do not have a (negative) effect on the desired properties of the material. With respect to the composition, exemplary trace amounts are less than 1,000 ppm by weight of the composition. The term " In reality no " includes embodiments in which the specified compound, moiety, functional group, element, ion, or other similar component is completely absent from the target material or is present in any amount measurable by techniques commonly used in the art.

[0090] Terms used in this specification " myriad " is a term " In reality, the water no It is equivalent to ". Water is not intentionally added to the given composition and is present only in trace amounts that do not have a (negative) effect on the desired properties of the composition. Brief explanation of the drawing

[0091] The present disclosure will be described below together with the accompanying drawings, wherein the same reference numerals denote the same elements and are as follows: FIG. 1 illustrates a combined article according to a first embodiment of the present disclosure; FIG. 2 illustrates a combined article according to a second embodiment of the present disclosure; FIG. 3 illustrates a combined article according to a third embodiment of the present disclosure. Specific details for implementing the invention

[0092] Detailed description of the invention

[0093] a) Combined article

[0094] An article to be treated with the debonding solution described above comprises at least one constituent substrate joined by a first and second adhesive. Thus, it comprises an article comprising a single substrate that folds itself so that one part of the substrate can be bonded to another part thereof. However, generally, the joined article will comprise at least two substrates, which are joined together by the first and second adhesives.

[0095] The constituent substrate(s) are metallic materials; semiconductor materials; polymers, e.g., polyester, polyamide, and rubber; glass; ceramics; lignocellulose materials, e.g., cotton, rayon ( Viscose It may be selected from the group consisting of ) and cellophane; cellulose ester; and mixtures or complexes thereof. If the bonded article comprises at least two substrates, the substrates may be the same or different from each other. And as mentioned above, the present disclosure is particularly applicable to the debonding of articles comprising a metallic material as at least one constituent substrate.

[0096] FIG. 1 shows a combined article (10) according to a first embodiment of the present disclosure. The combined article (10) comprises a first substrate (11) and a second substrate (12), each having an inner surface (11a, 12a). A first adhesive layer (20) is provided directly on the inner surface (11a) of the first substrate (11) and has a dry film thickness (d 20 ) is 30 to 500 μm. Fibrous web ( Not displayed A first adhesive layer (20) comprising ) is obtained in an important embodiment by curing a polyurethane-based 2-part (2K) aqueous composition in the presence of the web, wherein the aqueous composition comprises a first part comprising at least one anionic polyurethane polymer having p) (pi) pendant hydroxyl groups; and a second part comprising at least one polyisocyanate compound having q) pendant -NCO groups, wherein the composition is characterized in that the molar ratio of active hydrogen atoms to -NCO groups in the composition is 5:1 to 1:5.

[0097] For completeness, the first adhesive layer (20) comprises at least partially the fibrous web. More specifically, the adhesive layer (20) comprises substantially all or even all of the fibrous web: in the latter case, the fibers of the web do not protrude beyond the layer of the first adhesive, and thus the fibrous web is completely contained within the dry film thickness of the layer (20).

[0098] Interposed between the first adhesive layer (20) and the inner surface (12a) of the second substrate (12) is a second adhesive layer (22), and this layer generally has a dry film thickness (d 22 ) must be 30 to 1000 μm, for example, 30 to 500 μm.

[0099] There is no particular intention to limit the constituent adhesive of the second adhesive layer (22), but it must be compatible with the first adhesive layer (20). However, as mentioned above, the second adhesive must preferably be distinguishable from the first adhesive and have a higher interlayer cohesive strength than the first adhesive, as determined by comparative testing of the adhesive under tensile stress applied to the layer. Cohesive strength is closely related to the bulk physical properties of the adhesive: in this disclosure, the increased interlayer cohesive strength of the second adhesive may be the result of an increased cross-linking density of the second adhesive compared to the first adhesive. Alternatively or additionally, the second adhesive may have a higher loading of particulate filler compared to the first adhesive, which may contribute to the cohesive bond strength.

[0100] In an important embodiment, the second adhesive may have an interlayer cohesion strength that is at least 10% greater than the interlayer cohesion strength of the first adhesive. Preferably, the second adhesive may have an interlayer cohesion strength that is at least 15% or at least 20% greater than the interlayer cohesion strength of the first adhesive.

[0101] In an alternative expression, the interlayer cohesion strength of the first adhesive, intended not to be mutually exclusive with that given immediately above, may be 2 to 8 MPa, and the interlayer cohesion strength of the second adhesive may be at least 10 MPa, for example, 10 to 100 MPa.

[0102] Exemplary adhesives for which the second adhesive layer (22) may be formed include, but are not limited to, epoxide, acrylate, and polyurethane adhesives. As the second adhesive, a combined article (10) comprising a polyurethane adhesive, and more particularly a polyurethane adhesive selected from water-based polyurethane adhesives, solvent-based polyurethane adhesives, and polyurethane hot melt adhesives may be preferred.

[0103] In an alternative embodiment shown in FIG. 2, the combined article (10) each has a fibrous web ( Not displayed Two layers (20, 21) of a first adhesive comprising at least partially ) are provided, each in direct contact with the inner surfaces (11a, 12a) of the first (11) and second (12) substrates, respectively. The specific composition of the two layers (20, 21) may be identical or different, but both adhesives, in a key embodiment, are obtained by curing a 2-part (2K) aqueous composition as defined herein in the presence of the fibrous web. Additionally, the dry film thickness (d) of the two layers 20 , d 21 ) may be the same or different, but each must be within the range of 30 to 500 μm. These adhesive layers (20, 21) can be considered as debondable primer layers of the substrate (11, 12). Generally, the dry film thickness (d) 22 A second adhesive layer (22) with a thickness of 30 to 1000 μm is interposed between the layers (20, 21) of the first adhesive.

[0104] In an additional embodiment illustrated in FIG. 3, the combined article (10) is provided with two layers (22, 23) of a second adhesive that are in direct contact with the inner surfaces (11a, 12a) of the first (11) and second (12) substrates, respectively. The specific configuration of the two layers (22, 23) may be the same or different. Furthermore, the dry film thickness (d) of the two layers 22 , d 23 ) may be the same or different, but each must be within the range of 30 to 1000 μm. Dry film thickness (d 22 A layer (20) of a first adhesive having a thickness of 30 to 500 μm is interposed between layers (22, 23) of a second adhesive: this layer (20) is at least partially a fibrous web ( Not displayed Includes ).

[0105] In each of these embodiments, the layer (20, 21) of the first adhesive is intended to provide a location where debonding of the article (10) may occur when the article is treated with the debonding solution described herein. Although the configuration of the bonded article (10) in FIG. 3 is operable, debonding of the article may leave a significant amount of residual second adhesive on the substrate (10, 11) after the debonding operation, and this residue may need to be removed to enable the reuse or recycling of the substrate. For this reason, providing a layer (20, 21) of the first adhesive in direct contact with one or more substrates (11, 12) is considered desirable.

[0106] For ease of explanation, the provision of two substrates (11, 12) is illustrated in the drawings. It will be recognized that the configurations shown in FIGS. 1–3 can actually be achieved using a single substrate: for example, a single substrate can be processed by bending, bending inward, folding, creasing, twisting, or other variations to position the inner surfaces of different parts of the substrate facing each other.

[0107] Additionally, the article (10) of FIGS. 1 to 3 is simplified. The combined article (10) to be processed may be provided in various forms including combined film, sheet, plate, fibrous non-woven sheet, fibrous woven sheet, rectangular prism, sphere, annular body, solid cylinder, tube, and wire: the provision of more complex, molded forms of the combined article obtained by conventional techniques such as bending, blanking, casting, forging, rolling, welding, and weaving is, of course, not excluded.

[0108] As described above, the combined article of the present disclosure comprises at least one layer (20, 21) of a first adhesive comprising at least a fibrous web. Without intending to limit the present disclosure, the first adhesive is preferably a polyurethane adhesive selected from water-based polyurethane dispersion adhesives and polyurethane hot melt adhesives.

[0109] A suitable polyurethane hot melt useful for providing a first layer of adhesive is a non-reactive thermoplastic resin comprising a) a polyisocyanate component; b) a polyol component; and c) optionally a chain extender component reaction product. The hot melt polyurethane adhesive must be substantially solvent-free: any solvent used in the reactive manufacturing process can be removed by conventional methods.

[0110] The polyurethane hot melt adhesive is solid at room temperature but can melt above room temperature. The polyurethane is applied as a melt to the surface of a substrate to be coated in the presence of a fibrous web and is allowed to recrystallize thereon to provide a layer(s) of the first adhesive. In a specific embodiment of the first adhesive, the polyurethane hot melt adhesive must feature one or both of the following: a melting point determined by dynamic mechanical analysis (DMA) of 60 to 180°C, e.g., 80 to 160°C; and a recrystallization time measured by differential scanning calorimetry (DSC) of less than 10 minutes, e.g., less than 5 minutes. The term " Recrystallization time " represents the amount of time between the melting peak and the recrystallization peak of the polyurethane hot melt adhesive.

[0111] Aqueous polyurethane dispersion adhesives may be of the 1-part (1K) or 2-part (2K) type. When the first adhesive is obtained by curing a 1-part (1K) aqueous composition based on polyurethane, it is preferable that the 1-part (1K) composition comprises an anionic polyurethane polymer having pendant hydroxyl groups; and a blocked polyisocyanate. Before application, such 1-part (1K) compositions must be prepared and stored under conditions that inhibit or prevent the activation of the blocked polyisocyanate. The anionic polyurethane constituent of this type of 1-part (1K) composition may be prepared in the manner described herein below for the 2-part (2K) aqueous composition.

[0112] 2-part aqueous composition

[0113] In an important embodiment, the bonded article contains at least one layer (20, 21) of a first adhesive obtained by curing a 2-part aqueous composition based on polyurethane. More particularly, the 2-part (2K) aqueous composition comprises:

[0114] p) Part 1 including the following:

[0115] (pi) At least one anionic polyurethane polymer having a pendant hydroxyl group; and

[0116] q) a second part comprising at least one polyisocyanate compound having a pendant -NCO group,

[0117] Herein, the composition is characterized by a molar ratio of active hydrogen atoms to -NCO groups in the composition of 5:1 to 1:5. The anionic polyurethane polymer of the composition or each anionic polyurethane polymer of the composition should preferably be dilutable in water.

[0118] As mentioned above, it is preferable to use a 2-part aqueous composition as an aqueous primer composition, and accordingly, a debondingable layer (20, 21) that comes into direct contact with the substrate surface (11a, 12a) upon curing is formed.

[0119] Part pi)

[0120] The preparation of polyurethane dispersions is known as exemplified in U.S. Patent No. 4,237,264; U.S. Patent No. 4,408,008; U.S. Patent No. 5,569,706; U.S. Patent Publication No. 2004 / 204559; U.S. Patent Publication No. 2005 / 004367; UK Patent Publication No. 2386898; and WO Publication No. 2005 / 023947.

[0121] Alternatively, and as is known in the art, a suitable polyurethane may be obtained from the reaction of i) at least one polyol; ii) optionally an additional active hydrogen compound; and iii) at least one polyisocyanate compound. To ensure that the polyurethane does not have pendant isocyanate (NCO) groups, the equivalent ratio of active hydrogen atoms to NCO groups of the reactants must be selected so that free NCO groups are not present in the polyurethane: thus, the molar ratio of active hydrogen atoms to isocyanate functional groups must be at least 1:1, e.g., 1.1:1 to 3:1 or 1.1:1 to 2:1.

[0122] "as used in this specification" polyol" means any compound containing two or more hydroxyl groups; thus, this term is intended to include diols, triols, and compounds containing four or more -OH groups. Additionally, in this specification, at least one reactant polyol must be selected from the group consisting of polyester polyols; polyether polyols; and polycarbonate polyols. The polyol must preferably have a number average molecular weight (Mn) of 1,000 to 50,000 g / mol, e.g., 1,000 to 25,000 g / mol. Alternatively or additionally to these molecular weight characteristics, the hydroxyl value of the reactant polyol must preferably be 20 to 850 mg KOH / g, e.g., 25 to 500 mg KOH / g.

[0123] Polycarbonate diols can be obtained by reacting a carbonate derivative with a diol. Exemplary carbonate derivatives are diyl carbonates, including but not limited to diphenyl carbonate, di(C1-C6)alkyl carbonate, and phosgene. Exemplary diols include but not limited to ethylene glycol; 1,2-propanediol; 1,3-propanediol; 1,3-butanediol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; cyclohexanedimethanol; diethylene glycol; dipropylene glycol; neopentyl glycol; and mixtures thereof.

[0124] Polyester diols can be obtained by reacting the diol with an aliphatic, aromatic, or alicyclic dicarboxylic acid, or in some cases, the corresponding anhydride thereof: the reaction may optionally take place in the presence of an esterification catalyst. Examples of suitable dicarboxylic acids include, but are not limited to, adipic acid; glutaric acid; pimelic acid; souveric acid; nonandicarboxylic acid; decandicarboxylic acid; succinic acid; maleic acid; sebacic acid; azelaic acid; terephthalic acid; isophthalic acid; o-phthalic acid; tetrahydrophthalic acid; hexahydrophthalic acid; trimellitic acid; and 1,4-cyclohexanedicarboxylic acid. Examples of suitable anhydrides include succinic acid, o-phthalic acid, and trimellitic anhydrides. It should be noted that various commercially available dimeric fatty acids in saturated (hydrogenated) or unsaturated forms may also be used as dicarboxylic acids. And examples of suitable diols for producing polyester diols are ethanediol; di-, tri- or tetraethylene glycol; 1,2-propanediol; di-, tri-, tetrapropylene glycol; 1,3-propanediol; 1,4-butanediol; 1,3-butanediol; 2,3-butanediol; 1,6-hexanediol; 1,5-pentanediol; 2,2-dimethyl-1,3-propanediol (neopentyl glycol); 1,4-dihydroxycyclohexane; 1,4-dimethylcyclohexane; 1,8-octanediol; 1,10-decanediol; 1,12-decanediol; 2,2,4- and / or 2,4,4-trimethyl-1,3-pentanediol; and mixtures thereof.

[0125] Other useful polyester diols are those that can be obtained from the diol-initiated polymerization of hydroxycarboxylic acids or their lactones containing 2 to 12 carbon atoms. The hydroxycarboxylic acids may be saturated or unsaturated, linear or branched, and examples thereof include glycolic acid; lactic acid; 5-hydroxyvaleric acid; 6-hydroxycaproic acid; ricinoleic acid; 12-hydroxystearic acid; 12-hydroxydodecanic acid; 5-hydroxydodecanic acid; 5-hydroxydecanoic acid; and 4-hydroxydecanoic acid. Examples of suitable lactones are β-propiolactone, δ-valerolactone, (C1-C6)alkyl-valerolactone, ε-caprolactone, and (C1-C6)alkyl-ε-caprolactone.

[0126] Apart from the foregoing, in a specific embodiment, the polyol from which the polyurethane is derived is a polyether polyol, in particular a polyether polyol having a polydispersity (PD) of less than 2, preferably less than 1.5, more preferably less than 1.3. For completeness, " polyether For the purposes of this disclosure, "is understood as a polymer whose repeating unit contains an ether functional group C-O-C in the main chain. Accordingly, polymers having side ether groups, such as polyacetals as well as cellulose ethers, starch ethers, and vinyl ethers, are not covered by this definition. Preferably, the polyether polyol is a polyoxyalkylene, in particular a polyoxy(C2-C3)alkylene.

[0127] In particular, as described in U.S. Patent No. 3,905,929 and U.S. Patent No. 3,920,598, the presence of polyoxy(C2-C3)alkylene chains in the reactant polyols can serve to internally stabilize the polyurethane in a dispersed state. This can minimize or eliminate the need to include an emulsifier within the dispersion to provide external stability to the polyurethane.

[0128] It should be noted that at least one monool may be used in the synthesis of polyurethane as an additional active hydrogen reactant in some embodiments. For example, a monofunctional hydrophilic polyoxyalkylene—e.g., polyoxyethylene or polyoxypropylene—may be included in the polyurethane as a means to modify the properties of the latex and improve the ease of emulsion formation. If present, the monool is present in an amount of 0.1 to 5 weight percent based on the weight of reactants i) to iii).

[0129] To make the resulting polyurethane anionic and, where applicable, water-dispersible, the polymer is generally functionalized with at least one functional group selected from: carboxylic acid groups; anhydride groups; sulfonic acid groups; or phosphate groups. These functional groups may be incorporated into the polyurethane by the post-functionalization of urethane bonds obtained from the reaction of polyol(s) and polyisocyanate(s). More generally, these functional groups are introduced using functionalized reactant polyols, wherein the functional groups are (sterically) inhibited from reacting with -NCO groups during the process of producing the polyurethane. Exemplary reactant diols are dimethylolpropionic acid (DMPA); 2,2-di(hydroxymethyl)acetic acid; 2,2,2-tri(hydroxymethyl)acetic acid; 2,2-di(hydroxymethyl)propionic acid; 2,2-di(hydroxymethyl)butyric acid; 2,2-di(hydroxymethylpentanoic acid); 2,4-dihydroxybenzoic acid; trimellitic anhydride (TMA); and sodium 4,4-dihydroxy-1-butanesulfonate, but not limited thereto.

[0130] "as used in this specification" polyisocyanate " means a compound containing at least two -N=C=O functional groups. Polyisocyanates suitable for inducing hydroxyl-functional polyurethanes are those also described in this specification below for part q) of an aqueous 2-part composition.

[0131] To facilitate the inclusion of these in the compositions of the present disclosure, at least one polyurethane may initially be provided as a dispersion, and the particles of the dispersion are preferably d measured by dynamic light scattering 50 It can be characterized by a mono-modal particle size distribution in which the particle size is less than 1 micron, for example, 50 to 400 nm.

[0132] The formation of a polyurethane dispersion in water can be achieved by: i) the first formation of a prepolymer having free NCO groups from the aforementioned reactants under anhydrous conditions or in the presence of an organic solvent; and ii) dispersion of the prepolymer in an aqueous phase into a continuous process, exemplified by a high internal phase ratio (HIPR) process, or a batch process, exemplified by an inverse phase. Reaction i) can be carried out under catalysis, for example, at a temperature of 25 to 100°C. The resulting prepolymer preferably features at least one of the following: i) an NCO content of 5 to 30 wt%, preferably 10 to 25 wt%, based on the weight of the prepolymer; and ii) an NCO function of 2.2 to 3.0, preferably 2.2 or 2.4 to 2.9. iii) viscosity of 300 to 35,000 mPa·s at 20°C, preferably 1,000 to 10,000 mPa·s; and iv) number average molecular weight (Mn) of 500 to 30,000, e.g., 500 to 15,000 or 500 to 10,000 g / mol. For completeness, these features i) to iv) are not intended to be mutually exclusive: in practice, the prepolymer may satisfy one, two, three, or four of these specified features.

[0133] Standard polyurethane catalysts known in the art include: tin salts of carboxylic acids, e.g., tin octoate, tin oleate, tin acetate, and tin laurate; dialkyltin dicarboxylates, e.g., dibutyltin dilaurate and dibutyltin diacetate; tertiary amines; alkanolamine compounds; 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine; tetraalkylammonium hydroxide; alkali metal hydroxide; alkali metal alcoholate; tin alkoxides, e.g., dibutyltin dimethoxide, dibutyltin diphenoxide, and dibutyltin diisopropoxide; tin oxides, e.g., dibutyltin oxide and dioctyltin oxide; reaction products of dibutyltin oxide and phthalic acid esters; tin mercaptides; alkyl titanates; Organoaluminum compounds, e.g., aluminum trisacetylacetonate, aluminum trisethylacetoacetate and diisopropoxyaluminum ethylacetoacetate; chelate compounds, e.g., zirconium tetraacetylacetonate and titanium tetraacetylacetonate; organosilicon titanium compounds; bismuth tris-2-ethylhexanoate; acid compounds, e.g., phosphoric acid and p-toluenesulfonic acid; triphenylborane; triphenylphosphine; 1,8-diazabicycloundec-7-ene (DBU); 1,5-diazabicyclo[4.3.0]non-5-ene; 1,4-diazabicyclo[2.2.2]octane; 4-dimethylaminopyridine; 1,5,7-triazabicyclo[4.4.0]dec-5-ene; It includes 7-methyl-1,5,7-triazabicyclo[4.4.0]dek-5-ene; 1,8-bis(tetramethylguanidino)naphthalene; and 2-tert-butyl-1,1,3,3-tetramethylguanidine. Depending on the properties of the isocyanate, the amount of catalyst used is generally in the range of 0.005 to 10 weight percent of the catalyzed mixture.

[0134] As previously mentioned, the prepolymer may optionally be prepared in the presence of a solvent, and the solvent may be removed at least partially, preferably entirely, before or after the formation of the aqueous dispersion. If a solvent is used, examples of solvents that do not react with the isocyanate include ketones such as acetone and butanone; ethers such as tetrahydrofuran, dioxane, and dimethoxyethane; ether esters such as methoxypropyl acetate; (cyclic) amides and ureas such as dimethylformamide and dimethylacetamide; N,N'-dimethyl-2,5-dizapentanone; N-methylpyrrolidone; and capped glycol ethers. These solvents may be added at any stage of the preparation of the prepolymer.

[0135] It is desirable that the aforementioned prepolymer be extended with a chain extender. As is known to those skilled in the art, common chain extenders have a weight-average molecular weight (Mw) of 18 to 500 g / mol and have at least two active hydrogen-containing groups. In particular, polyamines and / or water may be used as chain extenders, and a mixture of water and polyamine is particularly preferred. Exemplary polyamines that may be used alone or in combination include: aminated polypropylene glycol, such as Jeffamine D-400 from Huntsman Chemical Company; hydrazine; piperazine; aminoethylpiperazine; 2-methylpiperazine; 1,5-diamino-3-methylpentane; isophorone diamine; ethylenediamine; diaminobutane; hexanediamine; hexamethylenediamine; tetramethylenetetraamine; aminoethylpropyltrimethoxysilane; diethylenetriamine; triethylenetetramine; triethylenepentamine; ethanolamine; and lysine.

[0136] When a chain extender other than water—as a dispersion medium—is used to produce the anionic polyurethane polymer of the present disclosure, the equivalent ratio of active hydrogen provided by the chain extender to the NCO groups of the prepolymer must be selected so as to ensure that no free NCO groups are present in the final polyurethane (pi) described above.

[0137] Anionic polyurethanes (pi) may be partially neutralized, fully neutralized, or even over-neutralized with inorganic or organic bases. Exemplary bases include amine bases as identified herein; alkali metal hydroxides; ammonia; and phosphine. The degree of neutralization of the anionic functional groups of the polyurethane may be 0 to 150%, e.g., 25 to 125% or 50 to 100%. A degree of neutralization exceeding 100% indicates that the basic functional groups are present in a stoichiometric excess relative to the anionic groups.

[0138] Polyurethanes suitable for use in this specification are commercially available, examples of which include Dispercoll U56 from Covestro AG.

[0139] Part q) Curative containing polyisocyanate

[0140] The second part of a desirable 2-part (2K) aqueous composition is pendant -N=C=O ( Below -NCOIt comprises at least one polyisocyanate compound having a ) group, which acts as a crosslinking agent through a reaction with the pendant hydroxyl group provided by the first part of the composition. It is not excluded that the composition may comprise a blocked isocyanate as an auxiliary crosslinking agent for the polyisocyanate compound(s) having a pendant -NCO group. However, the use of such a blocked polyisocyanate co-crosslinking agent is undesirable, and therefore, in certain embodiments, the composition may be characterized as being substantially free of said blocked isocyanate.

[0141] A 2-part (2K) aqueous composition may contain a polyisocyanate in an amount characterized in that the molar ratio of active hydrogen atoms to -NCO groups in the composition is 5:1 to 1:5, e.g. 3:1 to 1:3 or 2:1 to 1:2. Certainly, the term " - NCO energy " contains a blocked -NCO group, which is therefore included in the molar ratio term.

[0142] The polyisocyanate will comprise at least two -NCO functional groups, for example, two to five or two to four -NCO functional groups. Suitable polyisocyanates include aliphatic, alicyclic, aromatic, and heterocyclic isocyanates, their dimers and trimers, and mixtures thereof.

[0143] Aliphatic and alicyclic polyisocyanates comprise 6 to 100 carbon atoms linked in a linear or cyclic manner and may have at least two isocyanate reactive groups. Examples of suitable aliphatic isocyanates include, but are not limited to, linear isocyanates such as ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, bis(isocyanatoethyl)-carbonate, and bis(isocyanatoethyl) ether. An exemplary alicyclic polyisocyanate is dicyclohexylmethane 4,4'-diisocyanate (H 12 MDI), 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethyl-cyclohexane (isophorone diisocyanate, IPDI), cyclohexane 1,4-diisocyanate, hydrogenated xylene diisocyanate (H6XDI), 1-methyl-2,4-diisocyanato-cyclohexane, m- or p-tetramethylxylene diisocyanate (m-TMXDI, p-TMXDI), and dimeric fatty acid diisocyanates, including but not limited to these.

[0144] Term " aromatic polyisocyanate" is used to describe organic isocyanates in which an isocyanate group is directly attached to the ring(s) of a mononuclear or polynuclear aromatic hydrocarbon group. Ultimately, the mononuclear or polynuclear aromatic hydrocarbon group essentially refers to a planar cyclic hydrocarbon moiety of conjugated double bonds, which may be a single ring or contain multiple condensed (fused) or covalently bonded rings. The term aromatic also includes alkylaryls. Generally, the hydrocarbon (major) chain contains 5, 6, 7, or 8 major chain atoms in a single ring. Examples of such planar cyclic hydrocarbon moiety are cyclopentadienyl, phenyl, naphthalenyl-,

[10] anulenyl-(1,3,5,7,9-cyclodecapentaenyl-),

[12] anulenyl-, [8]anulenyl-, phenalene (perinaphthene), 1,9-dihydropyrene, and chrysene. (1,2-benzophenanthrene) is included but not limited thereto. Examples of alkylaryl moiety are benzyl, phenethyl, 1-phenylpropyl, 2-phenylpropyl, 3-phenylpropyl, 1-naphthylpropyl, 2-naphthylpropyl, 3-naphthylpropyl, and 3-naphthylbutyl.

[0145] Exemplary aromatic polyisocyanates include, but are not limited to, all isomers of toluene diisocyanate (TDI) (in isomerically pure form or as a mixture of several isomers); naphthalene 1,5-diisocyanate; diphenylmethane 4,4'-diisocyanate (MDI); diphenylmethane 2,4'-diisocyanate and a mixture of diphenylmethane 4,4'-diisocyanate and its 2,4' isomer or a mixture of these with oligomers having higher functional groups (so-called crude MDI); xylylene diisocyanate (XDI); diphenyl-dimethylmethane 4,4'-diisocyanate; di- and tetraalkyl-diphenylmethane diisocyanate; dibenzyl 4,4'-diisocyanate; phenylene 1,3-diisocyanate; and phenylene 1,4-diisocyanate.

[0146] Polyisocyanates may be biuretized, allophanated, and / or isocyanurated by generally known methods as described in British Patent No. 889,050, if necessary. In use, such derivatives may be substantially free of the parent diisocyanate: the derivatives may be separated from any excess parent diisocyanate by conventional methods including, but not limited to, distillation.

[0147] Term " polyisocyanate It is noted that the above-mentioned aliphatic, alicyclic, aromatic, and heterocyclic isocyanates are intended to provide an isocyanate-functional oligomer comprising a prepolymer formed by partial reaction of a polyol—e.g., a polyether polyol or a polyester polyol—with a polyol, and the oligomer may be used alone or in combination with free isocyanate(s). However, in this specification, it is preferable that portion q) comprises less than 5 weight percent of the prepolymer based on the weight of said portion. For example, portion q) may comprise less than 1 weight percent of the prepolymer based on the weight of said portion, or may be substantially absent.

[0148] Additives and auxiliary agents of the composition of the first adhesive

[0149] A composition providing the first adhesive of the present disclosure—exemplified as a 2-part (2K) aqueous composition—will generally further comprise an adjuvant and an additive capable of imparting improved properties to such composition. For example, the adjuvant and the additive may provide one or more of improved adhesion to a substrate; reduced corrosiveness to a substrate surface; improved elastic properties; improved elastic recovery; longer processing time; faster curing time; lower residual tackiness; and improved planarization. Such adjuvants and additives include: adhesion promoters; corrosion inhibitors; catalysts; curing retardants; surfactants, for which nonionic surfactants may be preferred; wetting agents; plasticizers; stabilizers; reinforcing agents; rheology control agents; biocides; flame retardants; pigments; organic co-solvents; and non-reactive diluents.

[0150] These adjuvants and additives may be used in combinations and proportions as desired, provided that they do not adversely affect the properties and intrinsic characteristics of the composition. Although exceptions may exist in some cases, these adjuvants and additives, including all of them, should not exceed 50 weight percent of the total composition, and preferably should not exceed 20 weight percent of the composition.

[0151] For completeness, it should be noted that auxiliary materials and additives containing reactive groups are generally incorporated into the appropriate portion of the 2-part (2K) composition to ensure its storage stability. Non-reactive materials may be formulated in one or both of the 2 parts.

[0152] Aqueous polyurethane dispersion adhesives—exemplified by the 2-part (2K) compositions herein—may comprise one or more catalysts for the reaction of -NCO groups with active hydrogen compounds. Standard catalysts known in the art include: tin salts of carboxylic acids, e.g., tin octoate, tin oleate, tin acetate, and tin laurate; dialkyltin dicarboxylates, e.g., dibutyltin dilaurate and dibutyltin diacetate; tertiary amines; alkanolamine compounds; 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine; tetraalkylammonium hydroxide; alkali metal hydroxide; alkali metal alcoholates; tin alkoxides, e.g., dibutyltin dimethoxide, dibutyltin diphenoxide, and dibutyltin diisopropoxide; tin oxides, e.g., dibutyltin oxide and dioctyltin oxide; Reaction products of dibutyltin oxide and phthalic acid esters; tin mercaptide; alkyl titanates; organoaluminum compounds, e.g., aluminum trisacetylacetonate, aluminum trisethylacetoacetate, and diisopropoxyaluminum ethylacetoacetate; chelate compounds, e.g., zirconium tetraacetylacetonate and titanium tetraacetylacetonate; organosilicon titanium compounds; bismuth tris-2-ethylhexanoate; acid compounds, e.g., phosphoric acid and p-toluenesulfonic acid; triphenylborane; triphenylphosphine; 1,8-diazabicycloundec-7-ene (DBU); 1,5-diazabicyclo[4.3.0]non-5-ene; 1,4-diazabicyclo[2.2.2]octane; 4-dimethylaminopyridine; It comprises 1,5,7-triazabicyclo[4.4.0]dek-5-en; 7-methyl-1,5,7-triazabicyclo[4.4.0]dek-5-en; 1,8-bis(tetramethylguanidino)naphthalene; and 2-tert-butyl-1,1,3,3-tetramethylguanidine. Depending on the properties of the polyisocyanate, the amount of catalyst used in the 2-part (2K) composition is generally in the range of 0.005 to 2 weight percent of the composition.

[0153] The addition of specific additives can promote the adhesion of the first adhesive composition to a specific substrate. For example, in one embodiment, the 2-part (2K) aqueous composition may contain 0 to 5 weight%, e.g. 0.5 to 5 weight%, of an adhesion promoter based on the weight of the composition. Exemplary adhesion promoters include morin (2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-coumarone-4-ketone); 3,7-dihydroxy-2-naphthoic acid (3,7-dihydroxynaphthalene-2-carboxylic acid); pyrogallol carboxylic acid (2,3,4-trihydroxybenzoic acid); 3,4-dihydroxy-benzeneguanidine-acetic acid; gallic acid (3,4,5-trihydroxybenzoic acid); Para-aminosalicylic acid (4-amino-2-hydroxybenzoic acid, PAS); flutteric acid (4,4'-methylene-bis(3-hydroxy-2-naphthoic acid)); and citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid) are included, but not limited thereto. Among these compounds, it may be noted that the use of citric acid, gallic acid, and in particular para-aminosalicylic acid (PAS)—either alone or in combination—is preferred.

[0154] A corrosion inhibitor may be included in the first adhesive in an amount of up to 5 weight percent based on the weight of the adhesive. For example, in one embodiment, the 2-part (2K) aqueous composition may contain 0.1 to 2 weight percent, e.g. 0.1 to 1 weight percent, of a corrosion inhibitor based on the weight of the composition. Exemplary corrosion inhibitors that may be present in the composition alone or in combination include salts of alkali metals, alkaline earth metals, and transition metals, such as titanium, chromium, and zinc. Magnesium oxide, magnesium hydroxide; magnesium carbonate; magnesium phosphate; magnesium silicate; zinc oxide; zinc hydroxide; zinc carbonate; zinc phosphate; and zinc silicate may be mentioned.

[0155] Exemplary reinforcing agents may be selected from epoxy-elastomer adducts; and reinforcing rubber in the form of dispersed core-shell particles that do not have pendant reactive groups. In a specific embodiment, the reinforcing agent may be included in a 2-part (2K) aqueous composition in an amount of up to 10 weight percent based on the weight of the composition.

[0156] It will be understood that the polyurethane polymer can provide all film-forming polymers of the aforementioned aqueous polyurethane dispersion, as exemplified by the 2-part (2K) aqueous composition. However, the presence of additional film-forming resins is not excluded. For example, in certain embodiments, the 2-part (2K) aqueous composition may comprise one or more auxiliary film-forming resins, including up to 25 weight percent in total, based on the solid content of the composition. Any such auxiliary film-forming resin included in the first adhesive may be thermosetting or thermoplastic, but must be dispersible, emulsifiable, or soluble in water.

[0157] Rheology modifiers that may be optionally useful in the first adhesive may include fillers, thickeners, and combinations thereof. The total amount of rheology modifiers in the first adhesive generally should not exceed 10 weight percent based on the weight of the adhesive. For example, a 2-part (2K) aqueous composition may contain 0 to 5 weight percent, 0 to 2 weight percent, or even 0 to 1 weight percent of rheology modifier based on the weight of the composition.

[0158] Exemplary thickeners include, but are not limited to, clay-based thickeners, e.g., organic clay; polysaccharides, e.g., guar and xanthan; polyacrylates; and associative thickeners. In particular, the use of cellulose or cellulose derivatives as polysaccharide thickeners, such as carboxymethylcellulose; methylcellulose; hydroxyethylcellulose; hydroxyethylmethylcellulose; hydroxypropylmethylcellulose; cellulose nanofibers; and cellulose nanocrystals, may be mentioned.

[0159] Generally, there is no specific intention to restrict the shape of the particles used as fillers: needle-shaped, spherical, elliptical, cylindrical, bead-shaped, cubic, or plate-shaped particles may be used alone or in combination. Furthermore, it is expected that aggregates of more than one particle type may be used. Likewise, there is no specific intention to restrict the size of the particles used as fillers. However, such fillers are typically d as measured by dynamic light scattering 50 The particle size will be 0.1 to 1500 μm, for example, 1 to 1250 μm.

[0160] Exemplary fillers include, but are not limited to, calcium carbonate, calcium oxide, calcium hydroxide (lime powder), precipitated and / or pyrogenic silica, zeolite, bentonite, wollastonite, magnesium carbonate, diatomite, barium sulfate, aluminum oxide, aluminum silicate, clay, talc, titanium oxide, iron oxide, zinc oxide, sand, quartz, flint, mica, glass beads, glass powder, and other ground mineral materials. Organic fillers, in particular wood fibers, wood flour, sawdust, cellulose, cotton, pulp, cotton, wood chips, chopped straw, chaff, crushed walnut shells, and other chopped fibers may also be used. Short fibers, such as glass fibers, glass filaments, polyacrylonitrile, carbon fibers, Kevlar fibers, or polyethylene fibers, may also be added.

[0161] If present, exothermic and / or precipitated silica is preferably 10 to 90 m 2 They must have a BET surface area of ​​ / g. When used, they do not cause any additional increase in the viscosity of the composition according to the present disclosure, but contribute to strengthening the cured composition.

[0162] As a filler, a higher BET surface area, advantageously 100 to 250 m² 2 It is also conceivable to use exothermic and / or precipitated silica having / g: due to the larger BET surface area, the reinforcing effect of the hardened composition is achieved with a smaller proportion of silica by weight.

[0163] In addition, hollow spheres having a mineral shell or a plastic shell are suitable as fillers. These may be, for example, hollow glass spheres commercially available under the trade name Glass Bubbles®. Plastic hollow spheres such as Expancel® or Dualite® may be used and are described in EP 0 520 426 B1: these are made of inorganic or organic material and each has a diameter of 1 mm or less, preferably 500 μm or less.

[0164] Fillers that impart thixotropy to a composition may be desirable for many applications: such fillers are also described as rheological adjuvants, e.g., hydrogenated castor oil, fatty acid amides, or swelling plastics, e.g., PVC.

[0165] For the purposes of this disclosure plasticizer " is a substance that reduces the viscosity of the composition to facilitate its processability. In this specification, the plasticizer may constitute up to 10 weight percent or up to 5 weight percent based on the weight of the adhesive. For example, a 2-part (2K) aqueous composition may contain 0 to 5 weight percent or 0 to 2 weight percent of a plasticizer based on the weight of the composition. Suitable plasticizers are preferably diurethanes; monofunctional, linear, or branched C4-C 16Ethers of alcohols, e.g., Cetiol OE (available from Cognis Deutschland GmbH, Dusseldorf); esters of abietic acid, butyric acid, thiobutyric acid, acetic acid, propionic acid, and citric acid; esters based on nitrocellulose and polyvinyl acetate; fatty acid esters; dicarboxylic acid esters; esters of fatty acids carrying OH groups or epoxidized; glycolic acid esters; benzoic acid esters; phosphate esters; sulfonic acid esters; trimellitic acid esters; polyether plasticizers, e.g., terminal-capped polyethylene or polypropylene glycol; polystyrene; hydrocarbon plasticizers; chlorinated paraffins; and mixtures thereof are selected from the group consisting of. In principle, phthalic acid esters may be used as plasticizers, but it should be noted that they are undesirable due to their toxicological potential.

[0166] For the purposes of this disclosure stabilizator " should be understood as an antioxidant, UV stabilizer, heat stabilizer, or hydrolysis stabilizer. In this specification, the stabilizers may constitute up to 10 weight percent or up to 5 weight percent based on the total weight of the first adhesive. For example, a 2-part (2K) aqueous composition may contain 0 to 5 weight percent or 0 to 2 weight percent of the stabilizer based on the weight of the composition. Standard commercial examples of stabilizers suitable for use in this specification include sterically hindered phenols; thioethers; benzotriazoles; benzophenones; benzoates; cyanoacrylates; acrylates; amines of the hindering amine light stabilizer (HALS) type; phosphorus; sulfur; and mixtures thereof.

[0167] Terms used in this specification " pigment" refers to any substance that imparts one or more of color, opacity, or visual effects to a composition. Visual effects that may be imparted to a composition by a pigment include, in addition to or independently of color, reflectance; pearly luster; gloss; texture; phosphorescence; fluorescence; photochromic; photosensitive; thermochromic; and goniochromism. The term " pigment " is intended to include organic pigments; inorganic pigments; dyes; and color tones. One or more pigments may be included in the composition, and each added pigment is considered to be added independently in any suitable form, among which individual particles, dispersions, and solutions may be referred to.

[0168] As mentioned above, polyurethane dispersion adhesives—of which 2-part (2K) aqueous compositions are important examples—are aqueous and thus contain water primarily as the solvent or continuous phase of the dispersion. However, in certain embodiments, the first adhesive is obtained from a 1-part (1K) or 2-part (2K) aqueous composition based on polyurethane, which may further include an organic co-solvent and / or a non-reactive diluent, which can usefully control the viscosity of the composition. Exemplary co-solvents and non-reactive diluents are aromatic solvents, e.g., xylene, toluene, and cumene; ether solvents, e.g., ethylene glycol dimethyl ether; ethylene glycol diethyl ether; ethylene glycol dibutyl ether; ethylene glycol diphenyl ether; diethylene glycol; diethylene glycol monomethyl ether; diethylene glycol monoethyl ether; diethylene glycol mono-n-butyl ether; diethylene glycol dimethyl ether; Diethylene glycol diethyl ether; diethylene glycol di-n-butyl ether; propylene glycol butyl ether; propylene glycol phenyl ether; dipropylene glycol monomethyl ether; dipropylene glycol dimethyl ether; dipropylene glycol di-n-butyl ether; petroleum fractions such as naphtha and Solvesso® products (available from Exxon); acetates including glycol ether acetate; propionates, such as ethyl 3-ethoxypropionate; adipates; sebacates; phthalates; benzoates; organic phosphoric acid or sulfonic acid esters; and sulfonamides, but not limited thereto.

[0169] In addition to the above, it is preferable that the above-described non-reactive diluent and co-solvent together constitute less than 5% by weight, particularly less than 2% by weight, based on the total weight of the above-described 2-part (2K) aqueous composition based on polyurethane.

[0170] Formation of a 2-part (2K) aqueous composition

[0171] An exemplary 2-part (2K) aqueous composition is formulated by simply mixing various components as well as any auxiliary components. Although the order of mixing the components is not intended to be limited, it may be prudent to first form an aqueous dispersion of polyurethane before mixing additional components. In this scenario, the aqueous dispersion of polyurethane may be prepared with a solid content of, for example, 20 to 60 weight% or 30 to 60 weight%, respectively.

[0172] If necessary, a 2-part (2K) aqueous composition may be prepared well prior to its application. However, in an interesting alternative embodiment, the concentrated composition may first be obtained by mixing only a portion of the water present in the aqueous composition to be applied with the said component; and then the concentrated composition may be diluted with the remaining water immediately before application. Such concentrated compositions are considered to be prepared and stored as a single-package concentrate—which can be converted by dilution with water alone—or as a multi-part concentrate—two or more of which must be combined and diluted to form a complete working composition according to the present disclosure. Any dilution may be simply performed by adding water, in particular deionized and / or demineralized water, under mixing. The composition may be prepared equivalently in a rinse stream, thereby injecting one or more streams of concentrate(s) into a continuous stream of water.

[0173] Without any specific intention to limit the amount of water contained in the composition, the aqueous composition preferably contains 5 to 50 weight%, preferably 5 to 40 weight%, of water based on the weight of the composition. In an alternative but non-mutually exclusive characterization, the composition may be defined by a viscosity of 0.1 to 10 Pa.s, e.g., 0.5 to 5 Pa.s, as measured using a Brookfield viscometer at 25°C.

[0174] fibrous web(s) included

[0175] According to one aspect of the present disclosure, a fibrous web is disposed at least partially within a layer of the first adhesive. The web must be able to be at least partially impregnated with the first adhesive composition, for example, as an aqueous dispersion before curing or when provided in a molten state. With respect to providing the adhesive composition as an aqueous polyurethane dispersion, the fibrous web must provide an absorbent or adsorbent material that is: insoluble in the aqueous dispersion; not damaged by the dispersion; and capable of retaining the dispersion. In a specific embodiment, the fibrous web may be characterized by a maximum absorption of 1 to 8 parts by weight of the adhesive composition per unit weight of the web. An exemplary fibrous web may have a maximum absorption of 2 to 8 parts by weight or 2 to 5 parts by weight of the adhesive composition per unit weight of the web.

[0176] Independently of or in addition to absorbent properties, the preference for using a woven fibrous web or a non-woven fibrous web may be mentioned herein, particularly one having a reference weight of 5 to 200 g / m² 2 , for example, 5 to 100 g / m² 2 , 20 to 80 g / m² 2 or 30 to 70 g / m² 2 The use of woven or non-woven fibrous webs may be desirable.

[0177] Terms used in this specification " weaving Web " generally refers to a web comprising at least two sets of fibers, referred to as warp and weft, wherein one set of fibers is interwoven with another set of fibers to form an angle between the sets of fibers or threads. The term is intended to include a woven fibrous web comprising one or more warp threads, one or more weft threads, and any interwoven angle formed between a given warp thread and a given weft thread.

[0178] Terms used in this specification " Non-woven Web " refers to a web having a structure in which individual fibers are overlapped in a mat-like form in a random, ordered, and / or unidirectional manner. The term " Non-woven Web " specifically comprises a web formed of individual fibers or filaments, which are overlapping but not identifiable repeating patterns. The nonwoven web may be manufactured by various processes including, but not limited to, air-laid processes, wet-laid processes, hydroentanglement, staple fiber carding and bonding, and solution spinning. Exemplary nonwoven webs include, but are not limited to, needle-punched webs, spun-laced webs, melt-blown webs, air-laid webs, wet-laid webs, and combinations thereof.

[0179] The fibrous webs of the present disclosure, particularly woven and non-woven fibrous webs, generally contain natural fibers; one or more synthetic fibers; or a blend of natural fibers and said one or more synthetic fibers. Non-limiting examples of suitable synthetic fibers include polyester fibers, such as polyethylene terephthalate fibers; rayon; viscose; polyamides, such as nylon; polyether sulfone (PES) fibers; polyphenylene sulfone (PPS) fibers; polyacrylic fibers; aramid-based fibers; melamine resin-based fibers; polybenzimidazole (PBI) fibers; and polyolefin fibers, such as polyethylene and polypropylene fibers. Exemplary natural fibers include wool; lyocell; cellulose fibers, including cotton, hemp, hardwood fibers and softwood fibers; and polysaccharide fibers, such as starch and dextrin. A binder may or may not be present in the woven or non-woven sheet.

[0180] According to an important embodiment of the present disclosure, the fibers of the web are further characterized by at least one of the following parameters determined by a laser diffraction / scattering method: an aspect ratio of 5 to 2000, preferably 20 to 2000; an average length of 1 to 20 mm, preferably 1 to 15 mm; and an average diameter of 1 to 50 μm, preferably 5 to 25 μm. These characteristics are not intended to be mutually exclusive: the constituent fibers of the web may satisfy one, two, or all of these.

[0181] Method of forming a combined article

[0182] Most broadly, the bonded article is formed by applying the aforementioned layers of the first and second adhesives to two separate surfaces of a substrate or substrates; and by bringing the applied adhesive layer placed between them into contact with the surfaces under pressure to form a bond.

[0183] An adhesive composition for providing a first adhesive layer (20, 21)—e.g., the 2-part (2K) water-based composition described above—is cured or solidified in situ after being applied to a substrate surface(s). Before applying the composition, it is often desirable to pre-treat the relevant surface. Any such pre-treatment may include: cleaning the surface(s); polishing the surface(s); and at least one of the application of an anti-corrosion coating or a conversion coating or conversion treatment.

[0184] Cleaning serves to remove foreign substances from the surface. Cleaning treatments are known in the art and may be performed in a single or multi-stage manner, for example, by using one or more of the following: etching treatment with an acid suitable for the substrate and optionally an oxidizing agent; ultrasonic treatment; plasma treatment including chemical plasma treatment, corona treatment, atmospheric plasma treatment, and flame plasma treatment; immersion in an aqueous alkaline degreasing bath; treatment with an aqueous cleaning emulsion; treatment with a cleaning solvent such as carbon tetrachloride or trichloroethylene; and preferably rinsing with deionized or deionized water. If an aqueous alkaline degreasing bath is used, any degreasing agent remaining on the surface should preferably be removed by rinsing the substrate surface with deionized or deionized water.

[0185] Term " conversion coating " and " conversion treatment " refers to a treatment of a substrate surface that causes the surface material to be chemically converted into a different material. Generally, metal or alloy surfaces exhibiting defect regions are chemically converted to provide an adhesion coating, which consists entirely or partially of a stabilized form of the substrate metal—e.g., an oxidized form. Such chemical conversion coatings can not only demonstrate high corrosion resistance but also provide strong bonding affinity for subsequent coating layers.

[0186] Preferably, the subsequent application of the adhesive composition to the pre-treated surface of the substrate occurs in the presence of a fibrous web. In one embodiment, the fibrous web may be laid across the substrate and the composition is then applied by conventional application methods such as dipping; immersion; brushing; roll coating; doctor-blade application; printing methods; and spray methods including, but not limited to, air spray, air-assisted spray, airless spray, and high-volume low-pressure spray. In this embodiment, the fibrous web may initially be provided individually sealed with a heat-sealable or adhesive thermoplastic overlap. Likewise, the web may initially be packaged into several individual sheets for economical dispensing, which are then brought into contact with the adhesive composition on the substrate: these individual sheets may be nested or interlocked within the package such that removing one individual sheet leads to the next sheet. Additionally, the fibrous web may be formed as a continuous web during the manufacturing process and loaded into a suitable dispenser equipped with a stopper, preferably a resealable stopper. Such a divider may be provided with means for determining the desired length of fabric from a continuous web, such as a blade or a sawtooth edge. In an alternative embodiment, the continuous fabric web may be cut, perforated, folded, split, or partially cut into uniform or non-uniform sizes or lengths.

[0187] In an alternative embodiment, the fibrous web may be provided in a form pre-impregnated, for example, as part of a first adhesive composition or a 2-part (2K) composition. Means for providing the pre-impregnated web must include means for isolating the web from the external environment.

[0188] There is no specific intention to limit the size and shape of the web in contact with the adhesive composition. The web must have dimensions suitable for use in bonded articles. Alternatively or additionally, the fibrous web must be small enough to facilitate storage and transport, but large enough to provide adequate coverage of the relevant substrate surface.

[0189] The amount of adhesive composition applied to the fibrous web may vary to provide a desired loading of its components, and such variation may be achieved by metering the composition during the spraying operation or by passing the substrate through the application source at a controlled speed. If necessary, excess composition may be removed from the fibrous web after application by shaking, rolling, drip drying, etc. In this way, the web may be saturated with various degrees of adhesive composition, such as 10 to 100 weight percent or 10 to 90 weight percent of the maximum absorption rate.

[0190] Adhesive compositions—exemplified by 2-part (2K) water-based compositions—are recommended to be applied to surfaces with a wet film thickness of 10 to 1000 μm, e.g., 10 to 750 μm. Within this range, the application of thinner layers is more economical and provides a reduced possibility of harmful thick cured areas. However, when applying thinner coatings or layers to prevent the formation of discontinuous cured films, many controls must be exercised.

[0191] Curing of the water-based compositions applied in this disclosure typically occurs at temperatures ranging from 20°C to 120°C, preferably from 20°C to 120°C, particularly from 20°C to 80°C. Suitable temperatures depend on the specific compounds present and the desired drying and curing rates, and can be determined on a case-by-case basis by a person skilled in the art using simple preliminary tests if necessary. Of course, drying and curing at lower temperatures within the aforementioned ranges is advantageous as it eliminates the requirement to substantially heat or cool the mixture from the typically prevailing ambient temperature. However, where applicable, the temperature of the mixture formed from each element of the composition may be raised above the mixing temperature and / or application temperature using conventional means including microwave induction, ovens, and drying booths. The raised temperature may be maintained for up to 180 minutes to ensure complete curing.

[0192] The method of application of the present disclosure may further include a step of reducing the oxygen content in the environment of the curing material: this may be accomplished by introducing nitrogen (N2) gas into the curing environment. However, this step is not required to form a hard coating.

[0193] The cured or solidified adhesive composition must fill defect areas and any additional microdefects on the substrate surface, thereby providing a smooth surface for the application of subsequent adhesive layer(s). It is not excluded that the composition of the present application be applied in multiple coats that cure independently to achieve a desired layer thickness and cover surface defects.

[0194] For completeness, the present disclosure also relates to a method for placing multiple layers of adhesive between substrate(s) to be bonded. In a key embodiment, the method comprises, as one of the constituent steps, applying a 2-part (2K) water-based polyurethane composition as defined herein as a primer to at least one substrate surface in the presence of a fibrous web. More particularly, a method for preparing a multilayer adhesive may preferably comprise: i) providing a metal substrate; ii) applying a 2-part (2K) water-based polyurethane composition as defined herein in the presence of the fibrous web to the metal substrate; iii) curing at least partially a first layer; iv) applying a second layer of a second curable adhesive composition over the first layer that has been cured at least partially; and v) curing at least partially a second layer. In an iterative process, steps ii) through v) may be performed and repeated to place a third, fourth, and additional layers on the metal substrate. There are no specific restrictions on the type of adhesive composition that can be applied in step iv), and both water-based and solvent-based adhesive compositions are considered.

[0195] Terms used in this specification " At least partially hardened "This means that the curing of a curable composition has been initiated, for example, that crosslinking of a component of the composition has begun. This term includes any amount of curing when curing conditions are applied, ranging from the formation of a single crosslink to a state of full crosslinking. Clearly, the rate and mechanism of curing of a composition depend on various factors including its components, functional groups of the components, and parameters of the curing conditions.

[0196] At least partial solidification of a given adhesive layer generally indicates curing or drying. However, both drying and curing may be indicated in other ways, such as changes in the viscosity of the adhesive layer, increases in the temperature of the adhesive layer, and / or changes in the opacity of the adhesive layer.

[0197] It may be preferable that step iv) of the application process described above, or each step iv) be initiated only when the prior layer, which is at least partially cured or partially dried, can substantially maintain its shape when exposed to ambient conditions. his The shape substantially Maintaining " means that at least 50 volume%, more typically at least 80 volume% or 90 volume% of at least partially cured or dried layer maintains its shape and does not flow or deform when exposed to ambient conditions for a period of 5 minutes. In this situation, gravity should not substantially affect the shape of at least partially cured or partially dried layer when exposed to ambient conditions.

[0198] For completeness, the shape of the layer that is at least partially dried or at least partially cured will affect whether the layer substantially maintains its shape. For example, when the layer is rectangular or has other simple shapes, the layer that is at least partially cured or dried may be more resistant to deformation than a layer with a more complex shape, even if the degree of curing or drying is lower.

[0199] In a specific embodiment, application of a subsequent adhesive layer ( Step IV )) is when, before the at least partially cured layer reaches the final cured state, the nominal layer is still " green It occurs during ". In this embodiment, the application of the layer is such that adjacent layers can be at least physically bonded and also chemically bonded to each other " Wet -on- Wet (wet-on-wet) It can be considered as follows. For example, the components of each first layer and subsequent layer can be chemically cross-linked / cured across the application line, and this effect can be beneficial to the lifespan, durability, and appearance of the finished product. Importantly, the difference between the partially cured and the final cured state is whether the partially cured layer can undergo further curing or cross-linking. While the presence of functional groups in the final cured state is not actually excluded, these groups may remain unreacted due to steric hindrance or other factors.

[0200] In the aforementioned iterative process, the thickness, width, shape, and continuity of each layer can be selected independently, so that the preceding and subsequent layers, or each preceding and subsequent layer, may be identical or different from one or more of these. For example, a given subsequent layer may come into contact only with a portion of the exposed surface of at least partially cured or dried preceding layer: and depending on the desired shape of the adhesive layer, the subsequent layer may be optionally stacked on top of this layer.

[0201] B) debonding solution

[0202] The pH value of the debonding solution of the present disclosure is 3 to 14 and comprises the following:

[0203] i) C 10 ~ C 26 Fatty acid; C 10 ~ C 26 fatty acid salts; and C 10 ~ C 26 At least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids; and

[0204] ii) Polar solvent.

[0205] i) Fatty acids and their esters

[0206] As mentioned above, the solution must be i) C 10 ~ C 26 Fatty acid; C 10 ~ C 26 fatty acid salts; and C 10 ~ C 26 It comprises at least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids. The solution preferably comprises 5 to 30 weight% of i) the at least one compound based on the weight of the solution. An exemplary solution may comprise 5 to 25 weight% or 10 to 25 weight% of i) the at least one compound.

[0207] The fatty acids or, where applicable, esters or the fatty acids from which each ester is derived as components of the solution may be saturated, monounsaturated, or polyunsaturated linear aliphatic acids, examples of which are decanoic acid ( Capric acid ); Dodecanoic acid ( Mount Laur ), tetradecanic acid ( Mount Myrist ); Pentadecanoic acid; Hexadecanic acid ( palmitic acid ); heptadecanic acid ( Mount Margar ); Octadecanic acid (stearic acid or isostearic acid); Octadecenic acid ( oleic acid , linoleic acid or linolenic acid ); Hydroxyoctadecenoic acid ( Ricinoleic acid ); Eikosansan ( Mount Arachid ); and Dokosansan ( hemp cloth Hensan Includes ).

[0208] C 14 -C 20 It may be noted that there is a preference for the use of monounsaturated fatty acids and / or their C1-C4 alkyl esters in solution. Independently or additionally to the preferred choice of these fatty acids, it may also be noted that there is a preference for the use of C1-C2 alkyl esters and, more particularly, methyl esters.

[0209] In an important embodiment, part i) of the solution is C 16 -C 18 Monounsaturated fatty acids and C 16 -C 18 It comprises or consists of at least one compound selected from the group consisting of C1-C4 alkyl esters of monounsaturated fatty acids. Good results have been obtained when part i) of the composition comprises or consists of at least one compound selected from the group consisting of oleic acid and C1-C4 alkyl esters of oleic acid. For example, the composition may comprise or consist of at least one compound selected from the group consisting of oleic acid and C1-C2 alkyl esters. It may be particularly beneficial to use oleic acid and / or methyl oleate as part i) of the solution or in part i).

[0210] It will be recognized that fatty acids are generally obtained by the hydrolysis of naturally occurring triglycerides such as coconut oil, rapeseed oil, palm oil, tallow, lard, and fish oil. Hydrolysis yields a mixture of fatty acids, which can be useful in itself in this debonding solution. However, if specific individual fatty acids are required as components of the solution—for example, oleic acid—such acids can be obtained from the technical mixture by appropriate separation steps, such as distillation, nanofiltration, membrane separation, and separation through ion exchange resins.

[0211] ii) polar solvent

[0212] The debonding solution comprises a polar solvent. Exemplary compounds that may constitute the polar solvent independently or in combination include, but are not limited to: water; C1-C8 alkanols, e.g., ethanol; benzyl alcohol; acetonitrile; N,N-di(C1-C4)alkylacylamides, e.g., N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAc); hexamethylphosphoramide; N-methylpyrrolidone; pyridine; mono-C of a diol having 2 to 12 carbon atoms 1-4 - Alkyl ethers, e.g., ethylene glycol mono-(C1-C4)-alkyl ether, propylene glycol mono-(C1-C4)alkyl ether, in particular ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether; di(C2-C3)alkylene glycol mono-(C1-C4)alkyl ethers, e.g., diethylene glycol monomethyl ether, diethylene monobutyl ether, dipropylene glycol n-propyl ether, dipropylene glycol monopropyl ether and dipropylene glycol monobutyl ether; polyalkylene glycol dialkyl ether; Monoesters, e.g., (C1-C8)alkyl acetate, ethoxydiglycol acetate, ethyl lactate, benzyl benzoate, butyloctyl benzoate, and ethylhexyl benzoate; dibasic esters, e.g., dimethyl succinate, dimethyl glutarate, dimethyl maleate, dimethyl adipate, dipropyl oxalate; ketones, e.g., acetone, ethyl ketone, methyl ethyl ketone ( 2- Butanon ) and methyl isobutyl ketone; ethers, e.g., tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF) and 1,2-dimethoxyethane; 1,3-dioxolane; dimethyl sulfoxide (DMSO); and dichloromethane (DCM).

[0213] Polar solvents are water; polyalkylene glycol dialkyl ethers, particularly diethylene glycol dimethyl ether ( DiglaimGood results were obtained when comprising or consisting of at least one compound selected from the group consisting of ) or dipropylene glycol dimethyl ether (DPGDME); and dibasic esters. For completeness, an exemplary commercially available dibasic ester solvent is Imsol R, a mixture of dimethyl succinate, dimethyl glutarate, and dimethyl adipate (available from Invista).

[0214] iii) pH adjuster

[0215] As mentioned above, the debonding solution must have a pH of 3 to 14, preferably 3 to 7 or 3 to 6. A pH adjuster represents an optional component of the debonding solution, and the pH of the debonding solution determines the amount of any added pH adjuster. Broadly, pH adjusters are selected from acidic and basic substances. Certainly, the added pH adjuster is distinguished from component i) of the solution.

[0216] Exemplary acidic substances that may be added alone or in combination include, but are not limited to: inorganic acids; Formula R m Monocarboxylic acid of CO2H (where R m is a C1-C6 alkyl or C3-C6 cycloalkyl group); Formula R p (CO2H) n Polycarboxylic acid of (where n is 2 or 3, and R p is a C1-C6 alkylene or C3-C6 alkylene); and α-hydroxycarboxylic acid(s).

[0217] Regarding inorganic acids, the use of nitric acid is not excluded but is not desirable; on the contrary, the addition of at least one of phosphoric acid, phosphonic acid, sulfurous acid, sulfuric acid, hydrochloric acid and hydrobromide is considered suitable.

[0218] Non-limiting examples of monocarboxylic acids include: formic acid; acetic acid; propionic acid; butyric acid; valeric acid; hexanoic acid; cyclohexanecarboxylic acid; cyclopentanecarboxylic acid; and cyclobutanecarboxylic acid. Formic acid, acetic acid, and propionic acid are considered particularly suitable for use in this specification.

[0219] Exemplary α-hydroxycarboxylic acids are those represented by general formula (III):

[0220] R h CH(OH)COOH (III)

[0221] Among the formulas: R h is a hydrogen atom, a C1-C4 alkyl group, a C2-C6 alkenyl group, a C1-C6 alkoxy group, a C3-C6 cycloalkyl group, or a C6-C 10 It represents an aryl group.

[0222] Suitable α-hydroxycarboxylic acids are glycolic acid; lactic acid ( 2- Hydroxypropanoic acid ); 2-Hydroxybutanoic acid; 2-Hydroxypentanoic acid; 2-Hydroxyhexanoic acid; Glucuronic acid; Citric acid; Mandelic acid; Galacturonic acid; Ribonic acid ( 2,3,4,5- Tetrahydroxyphenic acid ); gluconic acid ( 2S,3S,4R,5S)-2,3,4,5,6-pentahydroxyhexanoic acid ); tartronic acid; tartaric acid; and malic acid are included but not limited thereto.

[0223] Exemplary basic compounds that may be added to the debonding solution, either alone or in combination, are: amine bases; alkali metals; alkaline earth metals; alkali metals (C1-C4) Alkaline earth metal (C1-C4) alkoxides; alkali metal carbonates; alkaline earth metal carbonates; alkali metal hydroxides; alkaline earth metal hydroxides; alkali metal hydrides; and alkaline earth metal hydrides are included but not limited thereto.

[0224] Terms used in this specification " amine base " includes, by reference: ammonia (NH3); primary amine (NH2R a ); secondary amine (NHR a R b ); and tertiary amine (NR a R b R c ), here R a , R b and R c Each is independently selected from alkyl, hydroxyalkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, alkalyl, aralkyl, and heteroaryl, or R a and R b They can form carbocyclic or heterocyclic rings together.

[0225] According to an embodiment of the present disclosure, a pH adjuster comprises at least one amine base selected from the group consisting of: ammonia; formula (NH2R a Primary amine of ); Formula NHR a R b The secondary amine of; and formula NR a R b R c tertiary amine of, where R a , R b and R c Each is independently a C1-C6 alkyl, C1-C6 hydroxyalkyl, C3-C6 cycloalkyl, or C6-C 18 Selected from Aryl, or R a and R b It forms a carbocyclic or heterocyclic ring having 4 to 8 constituent atoms together.

[0226] Exemplary amine bases useful in this specification include: methylamine; ethylamine; propylamine; n-butylamine; dimethylamine; diethylamine; triethylamine; cyclohexylamine; N,N-diethylethanolamine; diethanolamine; triethanolamine; aniline, p-chloroaniline; N,N-dimethylaniline; benzylamine; piperidine; piperazine, 1-methylpiperazine, 1,4-dimethylpiperazine and imidazole.

[0227] Aqueous debonding solutions may contain water-soluble buffers that serve to maintain the solution within a desired pH range under specific circumstances, the range of which will be determined by the operating pH of the debonding process. For example, the following water-soluble buffers may be useful herein: an acetate buffer for maintaining a pH of 4 to 5.5; a phosphate buffer for maintaining a pH of 6 to 8; and a glycine-sodium hydroxide buffer for maintaining a pH of 9. With respect to an operating pH of 6 to 8, suitable phosphate buffers include, but are not limited to: sodium phosphate; potassium phosphate; orthophosphate (H3PO4); ammonium phosphate (NH4H2PO4); and dibasic ammonium phosphate ((NH4)2HPO4).

[0228] The amount of water-soluble buffer added to the aqueous debonding solution should be effective in maintaining the pH within the desired pH range. For example, the water-soluble buffer may be added to the slurry in an amount of 1 to 1000 ppm by weight or 1 to 500 ppm by weight based on the total weight of the aqueous slurry.

[0229] iv) surfactants

[0230] The debonding solution may optionally comprise at least one surfactant selected from: anionic surfactants; cationic surfactants; zwitterionic surfactants; nonionic surfactants; and mixtures thereof. The composition may comprise, for example, 0.5 to 50 weight% or 0.5 to 40 weight% of surfactants based on the total weight of the composition, including all of them. Certainly, the at least one surfactant is distinguished from component i) of the composition.

[0231] In one embodiment, the surfactant(s) included in the solution include, are essentially composed of, or are composed of a nonionic surfactant. In one embodiment, the surfactant or each surfactant included in the composition may be nonionic. The nonionic surfactant used in the composition may be characterized by a number average molecular weight (Mn) of 2,000 to 20,000 daltons, e.g., 2,000 to 10,000 daltons, or 2,000 to 8,000 daltons. Exemplary nonionic surfactants include: polyethylene oxide, e.g., PEG 300 or PEG 400; fatty alcohols; primary alcohols (C2-C4)alkoxylates; secondary alcohols (C2-C4)alkoxylates; alkylphenols (C2-C4)alkoxylates; alkylaminos (C2-C4)alkoxylates; It includes amine polyglycol condensates, such as Triton® CF-32 available from Union Carbide; polyoxy(C2-C3)alkylene fatty acid esters; polysorbates; sodium lauryl sulfate; sorbitan monolaurate; sorbitan monooleate; sorbitan monopalmitate; sorbitan trioleate; and silicone surfactants, such as silicone polyether copolymers. However, the use of nonionic silicone surfactants is not desirable.

[0232] Commercial examples of suitable nonionic surfactants are: Lutensol ON 70, ethoxylated (7EO) isodecyl alcohol (available from BASF); and Lutensol TO 5C, ethoxylated (5EO) saturated iso-C 13 Contains alcohol (available from BASF).

[0233] In one embodiment, the surfactant(s) included in the debonding solution include, are essentially composed of, or are composed of an anionic surfactant. In one embodiment, the surfactant or each surfactant included in the solution may be anionic. The anionic surfactant used in the solution may be characterized by a number average molecular weight (Mn) of 200 to 5000 daltons, e.g., 200 to 2000 daltons. Furthermore, the anionic surfactant may be linear, partially branched, branched, or a mixture thereof.

[0234] Anionic surfactants may exist in an acidic form, or alternatively, the acidic form may be partially or completely neutralized to form a surfactant salt. Typical agents for neutralization include: metal counterionic bases, e.g., alkali metal hydroxides; ammonia; amines; or alkanolamines, non-limiting examples of which include monoethanolamine, diethanolamine, triethanolamine, 2-amino-1-propanol, 1-aminopropanol, monoisopropanolamine, and 1-amino-3-propanol. It is noted that neutralization by amines or alkanolamines may be complete or partial. For example, a portion of the anionic surfactant may be neutralized by a metal counterionic base, and a portion of the anionic surfactant may be neutralized by an amine or alkanolamine.

[0235] Non-limiting examples of suitable anionic surfactants are: alkoxylated alkyl sulfates, in particular (C2-C3)alkoxylated (C 12 -C 30)alkyl sulfate surfactants and more particularly water-soluble salts thereof; non-alkoxylated alkyl sulfates, e.g., sulfated C8-C 20 Fatty alcohols and 2-alkyl branched primary alkyl sulfates; alkyl benzene sulfonates, particularly (C8-C 18 )alkyl benzene sulfonates and more particularly linear (C8-C 18 It includes alkyl benzene sulfonates; methyl ester sulfonates; paraffin sulfonates; α-olefin sulfonates; internal olefin sulfonates; and alkali metal sulfosuccinate esters.

[0236] An exemplary alkali metal sulfosuccinate ester useful in the present disclosure includes a sodium sulfosuccinate ester of the following formula:

[0237] NaO3SCH(CO2R')CH2CO2R

[0238] In the formula: R is H, C6-C 18 Alkyl or (C2-C3)alkoxylated (C6-C 18 )alkyl and;

[0239] R' is C6-C 10 Alkyl or (C2-C3)alkoxylated (C6-C 18 It is an alkyl.

[0240] The compound according to this formula may be a mono- or a diester, and the use of the latter is preferred.

[0241] A commercial example of a suitable nonionic surfactant is: Triton GR 5M available from Dow Chemical ( 1,4- Bis (2- Ethylhexyl ) Sodium Sulfosuccinate Includes LIAL® and ISALCHEM® available from Sasol.

[0242] Additive and auxiliary components

[0243] The solution may additionally contain additives common in the field. In particular, the solution may include, alone or in combination: corrosion inhibitors, e.g., dialkylthiourea, copper(II) sulfate, and copper sulfate; oxygen scavengers; stabilizers, e.g., UV stabilizers; wetting agents; defoaming agents; sequestering agents; lubricants; and rheological adjuvants for controlling the viscosity or thixotropic properties of the solution, examples of which include thickeners, fillers, and diluents.

[0244] Any such additive is inevitably a non-major component of the solution and should be used only in an amount that is not detrimental to the performance of the solution. Additionally, regarding any additive or auxiliary material, it is desirable that said material have a flash point of at least 90°C, for example, at least 100°C.

[0245] The following commercial materials may be mentioned as additional exemplary corrosion inhibitors: the Rodine® series available from JMN Specialties, Inc. and Henkel Corporation; the Dodicor® series available from Clariant AG; and the Armohib® series available from Akzo Nobel Surfactants LLC.

[0246] The thickener represents an optional component of the solution and may constitute 0 to 5 weight percent or 0 to 2 weight percent based on the total weight of the emulsion. Exemplary thickeners include, but are not limited to, cellulose thickeners and derivatives thereof; natural gums, e.g., guar gum, karaya gum, locust bean gum, carrageenan, tragacanth gum, and xanthan gum; starch; stearates; fatty alcohols; hydrophobically modified alkali-soluble emulsion polymers (HASE); hydrophobically modified urethane-ethoxylate resins (HEUR); and acrylic acid polymers and crosspolymers. The use of cellulose thickeners and derivatives thereof may be specifically mentioned, examples of which are: carboxymethyl hydroxyethylcellulose; cellulose; hydroxybutyl methylcellulose; hydroxyethylcellulose; hydroxypropylcellulose; hydroxypropyl methylcellulose; methylcellulose; microcrystalline cellulose; It includes sodium cellulose sulfate.

[0247] The presence of nonpolar co-solvents and nonpolar diluents in the solution of the present disclosure is not excluded, provided that this allows the viscosity to be usefully adjusted. Where the required polar solvent comprises or consists of water, any added nonpolar co-solvent(s) or diluent must be a water-immiscible compound. Such compounds may be selected from the group consisting of alkanes (R-H); cyclic alkanes; branched alkanes; aromatic compounds (Ar-H); alkyl halides (R-X); and mixtures thereof. Exemplary but non-limiting nonpolar, water-immiscible solvents that may be used alone or in combination include n-pentane, n-hexane, cyclohexane, n-heptane, isooctane, trimethylpentane, toluene, xylene, and benzene.

[0248] Preparation of debonding solution

[0249] Debonding solutions are generally formulated by simply mixing various components under stirring at room temperature. If necessary, the solution may be prepared sufficiently prior to application. However, in an interesting alternative embodiment, a concentrated debonding solution may first be obtained by mixing only some of the solvent and components that may be present in the debonding solution to be applied; then, the concentrated debonding solution may be diluted with the remaining solvent immediately before being introduced into the debonding bath. Such concentrated debonding solutions are considered to be prepared and stored as a single-package concentrate—which can be converted by diluting only with solvent—or as a multi-part concentrate—of which two or more must be combined and diluted to form a complete working solution according to the present disclosure. Any dilution may be simply performed by adding a solvent—e.g., deionized water and / or demineralized water—under mixing. The debonding solution may be prepared equivalently within a rinse stream, thereby injecting one or more streams of concentrate(s) into a continuous stream of solvent.

[0250] Without any specific intention to limit the amount of solvent contained in the debonding solution, it is preferable that the solution contains 15 to 75 weight%, preferably 20 to 70 weight%, and more preferably 20 to 60 weight% of solvent based on the weight of the composition. In an alternative but non-mutually exclusive characterization, the debonding solution may be defined by a viscosity of 0.005 to 1 Pa.s (50 cps to 1000 cps), as measured using a Brookfield viscometer at 25°C.

[0251] Debonding Method and Application

[0252] The present disclosure also provides a method for debonding a combined article as described in the above specification, the method comprising the following steps:

[0253] a) A step of providing a combined article as defined in the present specification above, wherein the combined article comprises at least one layer of a first adhesive interposed between two substrate surfaces, and the combined article further comprises at least one layer of a second adhesive interposed between the two substrate surfaces;

[0254] b) A step of treating an article bonded with a debonding solution as defined in the present specification at a temperature of 20 to 90°C; and

[0255] c) A step of separating at least one layer of the first adhesive from its interposed position between the two substrate surfaces.

[0256] According to the process mode of the present disclosure, prior to step b) of the method, it is often desirable to clean the relevant surface to remove foreign substances—e.g., oil, dirt, and metal powder—from the provided bonded article. Such treatment is known in the art and may be performed in a single or multi-step manner, for example, by using one or more of an aqueous cleaning emulsion; a cleaning solvent, such as carbon tetrachloride or trichloroethylene; and a water rinse, preferably a deionized or deionized water rinse. After the cleaning, degreasing, and / or pretreatment steps, a debonding composition is applied to the substrate ( step b) The debonding composition may be applied at ambient temperature, or the temperature of the composition may be raised to a temperature in the range of, for example, 30°C to 90°C, or for example, 30°C to 75°C before application.

[0257] The provided bonded article may be further pretreated to mechanically remove a small portion of the first adhesive layer under certain circumstances. If small holes, gaps, or cavities are created on the exposed surface of the first adhesive layer, nucleation sites for subsequent contact between this layer and the debonding solution may be created.

[0258] An operating bath as described below is manufactured, and it is customary to apply the debonding composition to the bonded article, without limitation, by immersion, flooding, air spray, air-assisted spray, airless spray, high-volume low-pressure spray, and air-assisted airless spray. The minimum contact time with the article bonded to the composition is generally sufficient to weaken the adhesive bond so that the components can be separated by a reasonable or operable force. The contact time may be as short as 0.1 hours or as long as 48 hours when the debonding treatment is performed at a lower temperature; however, depending on the pH and concentration of the applied solution and the temperature of application, a contact time of 0.1 to 24 hours or 0.5 to 20 hours will be more typical.

[0259] The present disclosure does not exclude applying a supplementary debonding composition to a bonded article before applying the disclosed solution or after treating the bonded article with the disclosed solution. Accordingly, the present disclosure anticipates a repetitive process in which treating the bonded article with the described debonding solution constitutes at least one step. Any supplementary debonding composition may be applied by any suitable means known in the art, such as immersion, dipping, spraying, roll coating, electro-coating; painting; brushing; wiping; air spraying; air-assisted spraying; airless spraying; high-volume low-pressure spraying; and air-assisted airless spraying.

[0260] Removing the substrate from the adhesive is ( Step c)The use of external force may or may not be required. For example, if, after the application of the debonding composition(s), the adhesive has been completely separated from the substrate or even dissolved in the debonding composition(s), external force may not be required. However, if at least a portion of the adhesive is still in contact with the substrate(s), external force may be used to completely peel or remove the adhesive. External force—applied, for example, by liquid washing or mechanical force—is used to compensate for the residual bond strength between the adhesive(s) and the substrate(s).

[0261] In one embodiment, the tensile shear strength of the bonded substrate after step b) is up to 20 MPa, e.g., up to 15 MPa, up to 10 MPa, or even up to 5 MPa when determined according to ASTM-D1002.

[0262] After step c), it is not excluded that the removed substrate or each removed substrate undergo at least one cleaning step. Cleaning may be performed in a conventional manner, including but not limited to the use of an aqueous cleaning emulsion; a cleaning solvent such as carbon tetrachloride or trichloroethylene; a water rinse, preferably a deionized or deionized water rinse; a rinse of a diluted basic aqueous solution; and a rinse of a diluted silicate solution. Additionally, at the end of step c) or any subsequent cleaning step, the removed substrate may be dried using, for example, ambient air drying, circulating hot air, forced air drying, or infrared heating. The surface temperature of the substrate(s) must be controlled during drying to prevent any unwanted physical, morphological, or chemical changes to the substrate.

[0263] Various characteristics and embodiments of the present disclosure are described in the following examples, which are representative and intended to be non-limiting.

[0264] Examples

[0265] The following commercial product is used in the examples below:

[0266] Dipropylene Glycol DME: Stabilized dipropylene glycol dimethyl available from Dow Chemical.

[0267] Methocell 311: Hydroxypropyl methylcellulose available from Dow Chemical

[0268] Imsol R: A mixture of dimethyl succinate, dimethyl glutarate, and dimethyl adipate available from Invista

[0269] Triton GR 5M: 1,4-bis(2-ethylhexyl) sodium sulfosuccinate available from Dow Chemical

[0270] Mergital MES 2: Methyl oleate available from BASF

[0271] Lutensol ON 70: Ethoxylated (7EO) isodecyl alcohol available from BASF

[0272] Lutensol TO 5C: Ethoxylated (5EO) saturated iso-C available from BASF 13 alcohol

[0273] Dispercoll U8755: Anionic high molecular weight polyurethane dispersion available from Covestro AG

[0274] All remaining compounds listed in the examples can be obtained from Sigma Aldrich.

[0275] Lab shear strength test The lap shear test substrate was aluminum (Alu3003), and its surface was cleaned with an ethyl acetate wipe. The substrate was provided with a thickness of 0.1 inches and cut into six 2.5 cm x 10 cm (1" x 4") samples for the tensile test. The Tensile Lap Shear (TLS) test was performed according to ASTM D3163-01 Standard Test Method for Determining Strength of Adhesively Bonded Rigid Plastic Lap-Shear Joints in Shear by Tension Loading It was performed at room temperature based on [the following]. The bond overlap area for each mentioned substrate was 2.5 cm x 2.5 cm (1" x 1") and the bond thickness was 0.1 cm (40 mil).

[0276] Where applicable, the primer composition was applied to one substrate in the overlapping area and dried at 100°C for 15 or 30 minutes to yield a layer having a dry film thickness as specified in Table 3 below. Additional adhesive composition ( Teroson 5065 ) was applied, and cured to a dry film thickness of 1 mm in the overlapping area by applying a temperature of 60°C for 2 hours or a temperature of 40°C for 12 hours. The combined structure having the configuration shown in Fig. 1 was then stored at 25°C and 20% relative humidity for 24 hours before the initial tensile test.

[0277] For each bonded article, tensile lap shear strength was investigated initially and after full immersion in a debonding solution for 1, 5, and 18 hours, which was maintained at a temperature of 60°C. Where possible, three samples were tested for each contact-time data point, and both the average tensile lap shear strength and its standard deviation were determined: the standard deviation is recorded in parentheses in the table below.

[0278] 디본딩 용액 1

[0279] The first debonding solution (DB1) was prepared according to Table 1 in this specification below. The given components were mixed in a speed mixer (1200 rpm; 1 min) to ensure the formation of a homogeneous mixture. The first debonding solution (DB1) had a pH of 3.7.

[0280] Table 1

[0281]

[0282] 디본딩 용액 2

[0283] The second debonding solution (DB2) was prepared according to Table 2 in this specification below. The given components were mixed in a speed mixer (1200 rpm; 1 min) to ensure the formation of a homogeneous mixture. The second debonding solution (DB2) had a pH of 8.0.

[0284] Table 2

[0285]

[0286] Example 1

[0287] In this embodiment, the lap shear strength of the bonded article was investigated after the bonded area of ​​the substrate was completely immersed in the first debonding solution (DB1). The results are provided in Table 3 of this specification below.

[0288] Table 3

[0289]

[0290]

[0291] Considering the detailed description and embodiments described above, it will be apparent to those skilled in the art that equivalent variations thereof can be made without departing from the scope of the claims.

Claims

Claim 1 A bonded article comprising at least one layer of a first adhesive interposed between two substrate surfaces, wherein the bonded article is further provided with at least one layer of a second adhesive interposed between the two substrate surfaces, wherein: a fibrous web is at least partially included in the layer of the first adhesive or each layer thereof; and the layer of the first adhesive or each layer thereof has a dry film thickness of 10 to 500 μm. Claim 2 A combined article according to claim 1, comprising: a first substrate having an inner surface; and a second substrate having an inner surface, wherein the layers of the first and second adhesives are interposed between the inner surfaces of the first substrate and the second substrate. Claim 3 A combined article according to claim 1 or 2, wherein at least one of the first substrate and the second substrate is metallic. Claim 4 A combined article according to any one of claims 1 to 3, wherein the fibrous web is a woven web or a non-woven web. Claim 5 A combined article according to any one of claims 1 to 4, wherein the fibrous web comprises synthetic fibers selected from the group consisting of polyester fibers; rayon; viscose; polyamide fibers; polyether sulfone (PES) fibers; polyphenylene sulfone (PPS) fibers; polyacrylic fibers; aramid-based fibers; melamine resin-based fibers; polybenzimidazole (PBI) fibers; polyolefin fibers; and mixtures thereof. Claim 6 A combined article according to any one of claims 1 to 5, wherein the fibrous web comprises natural fibers selected from the group consisting of wool; lyocell; cellulose fibers; polysaccharide fibers; and mixtures thereof. Claim 7 A combined article according to any one of claims 1 to 6, wherein the fibers of the web are characterized by at least one of the following parameters determined by a laser diffraction / scattering method: an aspect ratio of 5 to 2000, preferably 20 to 2000; an average length of 1 to 20 mm, preferably 1 to 15 mm; and an average diameter of 1 to 50 μm, preferably 5 to 25 μm. Claim 8 A combined article according to any one of claims 1 to 7, wherein the layer of the first adhesive or each layer has a dry film thickness of 30 to 300 μm. Claim 9 A bonded article according to any one of claims 1 to 8, wherein at least one layer of the first adhesive is in direct contact with the surface of the substrate. Claim 10 A combined article according to any one of claims 1 to 9, wherein the first adhesive is a polyurethane adhesive selected from water-based polyurethane dispersion adhesives and polyurethane hot melt adhesives. Claim 11 A bonded article according to any one of claims 1 to 10, wherein the first adhesive is distinguished from the second adhesive and the second adhesive is characterized by having a higher interlayer cohesive strength than the first adhesive as determined according to ASTM F88-94. Claim 12 A combined article according to any one of claims 1 to 11, wherein the first adhesive is obtained by curing a 2-part (2K) aqueous composition comprising: p) a first part comprising the following: (pi) at least one anionic polyurethane polymer having a pendant hydroxyl group; and q) a second part comprising at least one polyisocyanate compound having a pendant -NCO group, wherein the 2-part (2K) aqueous composition is characterized in that the molar ratio of active hydrogen atoms to -NCO groups in the composition is 5:1 to 1:

5. Claim 13 In claim 12, a combined article wherein part p) of a 2-part (2K) aqueous composition comprises at least one anionic polyurethane polymer characterized by: a hydroxyl functionality of 2 to 4; a hydroxyl value of 0.5 to 10 mg KOH / g, preferably 0.5 to 4 mg KOH / g; and a weight average molecular weight (Mw) of 50 to 200 kDa, preferably 50 to 150 kDa, more preferably 50 to 125 kDa. Claim 14 A combined article according to claim 12 or 13, wherein part q) of the 2-part (2K) aqueous composition comprises a linear aliphatic polyisocyanate. Claim 15 C 10 -C 26 Fatty acid; C 10 -C 26 Salts of fatty acids; and C 10 -C 26 A use in debonding articles bonded with an adhesive as defined in any one of claims 1 to 14, wherein the pH of the debonding solution is 3 to 14, of a solution in a polar solvent of at least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids. Claim 16 In claim 15, the use comprising the debonding solution based on the weight of the solution: 5 to 30 weight%, preferably 5 to 25 weight%, of C 10 -C 26 Fatty acid; C 10 -C 26 Salts of fatty acids; and C 10 -C 26 The at least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids. Claim 17 In claim 15 or 16, the at least one compound of the debonding solution is C 16 -C 18 Monounsaturated fatty acid; C 16 -C 18 Salts of monounsaturated fatty acids; and C 16 -C 18 Uses selected from the group consisting of C1-C4 alkyl esters of monounsaturated fatty acids. Claim 18 The use according to claim 15 or 16, wherein at least one compound of the debonding solution is selected from the group consisting of oleic acid; a salt of oleic acid; and a C1-C2 alkyl ester of oleic acid. Claim 19 A use according to any one of claims 15 to 18, wherein the polar solvent of the debonding solution comprises or consists of at least one compound selected from the group consisting of water; polyalkylene glycol dialkyl ether; and dibasic ester. Claim 20 In any one of claims 15 to 19, the debonding solution further comprises, based on the weight of the solution: at least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants, in an amount of 0.5 to 50 weight%, preferably 0.5 to 40 weight%. Claim 21 A method for debonding a combined article comprising the following steps: a) A step of providing a combined article as defined in any one of claims 1 to 14, wherein the combined article comprises at least one layer of a first adhesive interposed between two substrate surfaces, and the combined article further comprises at least one layer of a second adhesive interposed between the two substrate surfaces, wherein: A fibrous web is at least partially included in the layer or each layer of the first adhesive; a) a layer of the first adhesive or each layer having a dry film thickness of 10 to 500 μm; and b) Articles combined at a temperature of 20℃ to 90℃ C 10 -C 26 Fatty acid; C 10 -C 26 Salts of fatty acids; and C 10 -C 26 A step of treating with a solution in a polar solvent of at least one compound selected from the group consisting of C1-C4 alkyl esters of fatty acids, wherein the pH of the solution is 3 to 14; and c) A step of separating at least one layer of the first adhesive from its interposition between the two substrate surfaces. Claim 22 A method according to claim 21, wherein the processing step comprises immersing an article combined in the solution. Claim 23 A method according to claim 21 or 22, wherein the processing step is performed at a temperature of 30 to 75°C. Claim 24 A method according to any one of claims 21 to 23, wherein the processing step is characterized by a contact time of 0.1 to 24 hours, preferably 0.5 to 20 hours.

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