Bonding components into article and separating article for recycling

Abstract

The present invention relates to a method for bonding at least two parts to form an article comprising the two parts using a composition comprising a thermoplastic polymer, wherein the thermoplastic polymer composition preferably has a flow initiation temperature (Tfb) 5 in the range of 50 DEG C to 160 DEG C measured according to method embodiment 1. The invention also relates to an article derived from the method according to the invention and to a method for separating the corresponding article into its parts by using heat.

Description

[0001] The present invention relates to bonding components with a hot melt adhesive (HMA), preferably a hot melt adhesive (HMA) comprising thermoplastic polyurethane (TPU), to form an article and separating these components by using heat.

[0002] Producing articles from different components by gluing these components is a method well known in the industry. Now, due to the increased environmental awareness in the past few years, the decomposition of articles is becoming increasingly important.

[0003] Consumer goods manufacturers increasingly need to improve the concept of sustainability by increasing the recycling rate of used bonded articles. For example, high-performance sports shoes are usually based on thermoplastic or thermosetting polymers, such as thermoplastic or thermosetting polyurethanes, bonded to other materials, such as non-polyurethane materials, such as ethylene-vinyl acetate, polyester textiles or synthetic leather. The non-polyurethane materials must be removed by a debonding mechanism on demand after the life cycle of the article, and then the thermoplastic polymer, especially thermoplastic polyurethane, is recycled and reused. The separation of crosslinked polyurethane and the subsequent recycling of the separated crosslinked polyurethane foam can also be carried out by glycolysis.

[0004] Similar needs exist in other technical fields to release the bonded components of different materials, so that different materials can be recycled separately, such as automotive seats or dashboards, instrument panels, meat or cheese food packaging, etc. For example, WO2019 / 175151 A1 describes a method for manufacturing thermoplastic polyurethane from recycled polyurethane materials. This method requires debonding non-polyurethane materials from polyurethane materials. WO 2018 / 156689 describes a debondable adhesive and its use for the manufacture and debonding of footwear articles. Debonding is achieved by using carboxylic acids and their salts and by using microwave radiation.

[0005] Especially in the footwear industry, there is still a need for improved methods to facilitate the recycling of shoe components. The problem underlying the present invention is to provide a method for preparing a bonded article made of different components, such as a shoe, to recycle different components (such as the upper material and the sole) under mild conditions, with relatively low energy consumption in a short cycle time. Under normal storage, use and cleaning conditions, the bonded article should exhibit high resistance to premature debonding. Providing materials with high bonding strength during the normal use of the article, while being able to be easily debonded according to need in a short time under the stimulation of appropriate conditions for recycling purposes, is a challenge.

[0006] An object of the present invention is to provide materials suitable as adhesives or for bonding two or more components and allowing the debonding of the corresponding articles obtained. This also allows the reuse of the components without completely decomposing the corresponding components.

[0007] According to the present invention, this problem is solved by a method for bonding at least two components using a composition comprising a thermoplastic polymer to form an article comprising those two components.

[0008] It has been found that bonded articles can be prepared according to the present invention, and these bonded articles can be debonded using mild conditions. This allows the separation of the components and the reuse or recycling of the separated components.

[0009] According to the present invention, at least two parts are joined. The components can include different materials and can also vary in shape and size. According to the present invention, the at least two components can also include the same material. The at least two components are joined to form an article. According to the present invention, the article can also include other parts or components.

[0010] According to the present invention, a composition comprising a thermoplastic polymer is used for bonding. The composition can include other components, such as other thermoplastic polymers, solvents, or additives. According to the present invention, the composition generally has a softening point above about 50 °C and below 160 °C. The melting point of the composition comprising a thermoplastic polymer must generally be adapted to allow the bonding of the components without affecting the surface or properties of the components forming the article according to the present invention. The composition comprising a thermoplastic polymer is used as an adhesive according to the present invention. According to the present invention, the bonding is preferably achieved by physically softening at a high temperature and re-solidifying upon cooling.

[0011] In the context of the present invention, a composition comprising a thermoplastic polymer can also be referred to as a hot melt adhesive.

[0012] Hot melt adhesives are generally solids at room temperature, solvent-free, and meltable above room temperature. Hot melt adhesives are generally non-reactive thermoplastics. A hot melt adhesive (HMA) is an adhesive system that is solid at room temperature, becomes tacky / sticky when heated, and melts into a liquid or fluid state. They generally cure rapidly upon cooling at ambient temperature to develop internal strength and cohesion. Hot melt adhesives are single-component solvent-free thermoplastic adhesives characterized by low to medium viscosity when applied at the desired dispensing temperature. Once applied, the hot melt adhesive cools and cures to form a strong bond between the articles. The bond formed with a thermoplastic hot melt adhesive is reversible. Under sufficiently high thermal stress, the thermoplastic hot melt adhesive will liquefy and lose its cohesive strength.

[0013] The melting point of a composition comprising a thermoplastic polymer, particularly a thermoplastic polyurethane, measured by differential scanning calorimetry (DSC) is preferably from about 50 °C to about 160 °C or from about 50 °C to about 130 °C. The test method refers to ASTM D 3418-12 by using Hitachi High-Tech Co., DSC7000Xε1 。

[0014] Surprisingly, it has been found that the flow onset temperature (Tfb) of a composition containing a thermoplastic polymer affects the bonding and debonding properties of the composition. Adjusting the flow onset temperature within a suitable range can be used to affect the temperature performance of the adhesion strength to obtain good bonding properties under the conditions of use of the article, and also allows easy debonding under relatively mild conditions.

[0015] It has surprisingly been found that a favorable combination of good bonding and debonding using mild conditions can be achieved by using a composition containing a thermoplastic polymer and by using a Shimadzu Flowtester capillary rheometer CFT-500D, the composition having a flow onset temperature (Tfb) of at least 50 °C, preferably at least 60 °C, more preferably at least 70 °C, measured according to Method Example 1 of JIS K7311-1995 and K7210-1999. It has been found that delamination of the article at high temperatures, which may occur during transportation in a container for example, can be avoided.

[0016] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the thermoplastic polymer composition has a flow onset temperature (Tfb) of between 50 °C and 160 °C, preferably 60 °C to 160 °C, more preferably 80 °C to 160 °C, more preferably 90 °C to 150 °C, most preferably between 100 °C and 150 °C, measured according to Method Example 1.

[0017] Preferably, the composition containing a thermoplastic polymer used according to the present invention has a relatively low softening temperature and a low flow onset temperature, which enables them to be used as adhesives without damaging the different components to be bonded during application.

[0018] The composition containing a thermoplastic polymer may include a variety of polymers commonly used in adhesives. For example, the composition may include at least one polymer selected from polyurethanes, polychloroprenes, latexes, polystyrenes, polyamides, polyolefins, polyacrylates, polyesters, polyethers, copolymers thereof, and any combination thereof. In some aspects, the polystyrene is or includes a polystyrene block copolymer. Suitable polystyrenes may include poly(styrene-isoprene-styrene), poly(styrene-butadiene-styrene), poly(styrene-ethylene-butene-styrene), and poly(styrene-ethylene-propylene).

[0019] In some aspects, a composition comprising a thermoplastic polymer comprises at least one thermoplastic polymer selected from thermoplastic polyurethanes, thermoplastic polyamides, thermoplastic polyolefins, thermoplastic polyesters, thermoplastic polyethers, their thermoplastic copolymers, and any combination thereof. In some aspects, the composition comprises a polyolefin, such as polyethylene, polypropylene, their copolymers, or any combination thereof. The polyolefin can be an ethylene copolymer. In some aspects, the composition comprises a thermoplastic polyolefin. In some aspects, the thermoplastic polyolefin comprises thermoplastic polyethylene, thermoplastic polypropylene, their thermoplastic copolymers, or any combination thereof. The thermoplastic polyolefin can comprise a thermoplastic ethylene copolymer. In some aspects, the thermoplastic ethylene copolymer is ethylene vinyl acetate (EVA).

[0020] In some aspects, the composition comprises at least one thermoplastic polymer that is a polymer or copolymer comprising a plurality of functional groups in its chemical structure, wherein the plurality of functional groups are selected from hydroxyl groups, carboxyl groups, amines, amides, urethane groups, and combinations thereof.

[0021] According to another embodiment, the invention also relates to a method as disclosed above, wherein the thermoplastic polymer composition comprises at least one polymer selected from thermoplastic polyurethanes, polychloroprene, latex, polystyrene, polyamides, polyolefins, polyacrylates, or mixtures thereof.

[0022] According to the invention, a composition comprising a thermoplastic polymer is applied in an amount and manner that allows bonded components to form an article. The composition is typically applied at an elevated temperature to produce an adhesive coating. The composition can be applied, for example, as a melt at a temperature preferably between 80°C and 220°C to the material to be coated, and the coated surface is at least partially coated with the composition comprising the thermoplastic polymer.

[0023] The application amount of the composition comprising the thermoplastic polymer is preferably between 10 g / m 2 and 700 g / m 2 , preferably between 20 g / m 2 and 600 g / m 2 , more preferably between 50 g / m 2 and 500 g / m 2 , particularly preferably between 100 g / m 2 and 400 g / m 2 range.

[0024] The application can be carried out by using a doctor blade technique, spraying, gravure, dot or pattern application of the melt, or by applying the coating at a higher temperature. According to the invention, the composition comprising the thermoplastic polymer can also be applied as a film.

[0025] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the thermoplastic polymer composition is a film.

[0026] According to the present invention, a film consisting essentially of a composition comprising a thermoplastic polymer can be applied, or a film comprising: a layer consisting essentially of a composition comprising a thermoplastic polymer and another layer comprising another adhesive layer, such as a layer (carrier layer) comprising a thermoplastic polymer or a crosslinked adhesive such as a one-component polyurethane adhesive or a two-component polyurethane adhesive. According to the present invention, the carrier layer can be coated with a composition comprising a thermoplastic polymer, or the composition comprising a thermoplastic polymer can be applied in a suitable pattern that does not completely cover the carrier layer.

[0027] Preferably, the composition comprises a thermoplastic polyurethane. According to another embodiment, the present invention also relates to a method as disclosed above, wherein the thermoplastic polymer is a thermoplastic polyurethane.

[0028] Suitable thermoplastic polyurethanes generally comprise the reaction product of a) a polyisocyanate component, b) a polyol component, and c) optionally a chain extender component. The reaction can or cannot be carried out in the presence of a catalyst. According to another embodiment, the present invention also relates to a method as disclosed above, wherein the thermoplastic polyurethane of the film is the reaction product of a building component polyol, isocyanate, and finally a chain extender.

[0029] The starting materials are preferably selected to adjust the flow onset temperature of the thermoplastic polyurethane. The flow onset temperature can be adjusted, for example, by reducing the hard segment content of the thermoplastic polyurethane.

[0030] According to the present invention, a mixture of polyols or a mixture of chain extenders can also be used to adjust the flow onset temperature. The structure of the polyol can also be adjusted by selecting a suitable monomer or monomer mixture to affect the flow onset temperature. In addition, the molecular weight and / or chain length of the chain extender used can be adjusted to affect the flow onset temperature.

[0031] Adjusting the molecular weight of the thermoplastic polyurethane by selecting a suitable NCO / OH group molar ratio also affects the flow onset temperature. According to the present invention, two or more of these adjustments can also be used to achieve an ideal combination of hardness, flow onset temperature, and other properties.

[0032] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the isocyanate is an aromatic isocyanate, an aliphatic isocyanate, an alicyclic isocyanate, and combinations thereof.

[0033] The isocyanate component can include one or more polyisocyanates. In some useful embodiments, the polyisocyanate component includes one or more diisocyanates. Suitable polyisocyanates include aromatic diisocyanates, aliphatic diisocyanates, cycloaliphatic diisocyanates, or combinations thereof. In some embodiments, the polyisocyanate component includes one or more aromatic diisocyanates. In some embodiments, the polyisocyanate component is substantially free or even completely free of aliphatic diisocyanates. In other embodiments, the polyisocyanate component includes one or more aliphatic diisocyanates and / or cycloaliphatic diisocyanates. In some embodiments, the polyisocyanate component is substantially free or even completely free of aromatic diisocyanates. In some embodiments, a mixture of aliphatic and aromatic diisocyanates can be useful. Examples of useful polyisocyanates include aromatic diisocyanates such as 4,4'-methylenebis(phenyl isocyanate) (4,4'-MDI), 2,4-diphenylmethane diisocyanate (2,4-MDI), 2,2'-diphenylmethane diisocyanate (2,2'-MDI), m-xylene diisocyanate (XDI), phenylene-1,4-diisocyanate (1,4-PDI), naphthalene-1,5-diisocyanate (NDI), 4,4'-diisocyanato-1,2-diphenylethane, 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI), and toluene diisocyanate (TDI); and aliphatic diisocyanates such as ethylene diisocyanate (EDI), 1,4-butane diisocyanate (BDI), 1,6-hexamethylene diisocyanate (HDI), decane-1,10-diisocyanate, 1,12-dodecane diisocyanate (DDI), lysine diisocyanate (LDI); and cycloaliphatic diisocyanates such as isophorone diisocyanate (IPDI), 1,4-cyclohexyl diisocyanate (CHDI), and dicyclohexylmethane-4,4'-diisocyanate (H12MDI). Isomers of these diisocyanates can also be useful. Mixtures of two or more polyisocyanates can be used. In some embodiments, the polyisocyanate is MDI and / or H12MDI. In some embodiments, the polyisocyanate consists essentially of MDI. In some embodiments, the polyisocyanate consists essentially of H12MDI.

[0034] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the aromatic isocyanate is more preferably selected from the group consisting of: 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, urethane-modified liquid 4,4'-diphenylmethane diisocyanate and / or 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanato-1,2-diphenylethane, 1,5-naphthalene diisocyanate, and combinations thereof.

[0035] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the aromatic isocyanate is most preferably 4,4'-diphenylmethane diisocyanate (4,4'-MDI).

[0036] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the aliphatic isocyanate is more preferably selected from the group consisting of: 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, and combinations thereof.

[0037] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the aliphatic isocyanate is most preferably 1,6-hexamethylene diisocyanate (HDI).

[0038] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the cycloaliphatic isocyanate is more preferably selected from the group consisting of: isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate and the corresponding isomer mixtures, 4,4'-dicyclohexylmethane diisocyanate, 2,4-dicyclohexylmethane diisocyanate, and 2,2'-dicyclohexylmethane diisocyanate and their corresponding isomer mixtures, and combinations thereof.

[0039] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the cycloaliphatic isocyanate is most preferably 4,4'-dicyclohexylmethane diisocyanate (H 12 MDI).

[0040] Thermoplastic polyurethanes are also made using b) a polyol component. Polyols that can be used in the present invention (which can also be described as hydroxy-terminated intermediates) include polyester polyols, polyether polyols, polycarbonate polyols, and combinations thereof. The polyester polyols are preferably linear polyesters. The hydroxy-terminated polymer intermediates have a number average molecular weight (Mn) of preferably from about 300 daltons to about 10,000 daltons, such as from about 400 daltons to about 8,000 daltons, and further such as from about 500 daltons to about 6,000 daltons. The molecular weight is determined by end group analysis and is related to the number average molecular weight. Unless otherwise stated, in the context of the present invention, the molecular weight can be determined via end group quantification or can be calculated from the OH value according to EN ISO 4629-1:2016.

[0041] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the polyol is a polyol having a number average molecular weight between 0.4×10 3 g / mol and 6×10 3 g / mol as measured by end group quantification.

[0042] Suitable polyester intermediates can be produced by (1) the esterification reaction of one or more diols with one or more dicarboxylic acids or acid anhydrides, or (2) by transesterification, i.e., the reaction of one or more diols with esters of dicarboxylic acids, or (3) ring-opening polymerization of, for example, polycaprolactone diol (PCL-diol), polylactide diol (PLA-diol), etc. A molar ratio of diol to acid generally in excess of one mole is preferred in order to obtain a straight chain with a predominance of terminal hydroxy groups. The desired dicarboxylic acids of the polyester can be aliphatic, cycloaliphatic, aromatic, or combinations thereof. Suitable dicarboxylic acids that can be used alone or in mixtures generally have a total of 4 to 44 carbon atoms and include: succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, dimer fatty acid, etc. Acid anhydrides of the above dicarboxylic acids, such as phthalic anhydride, tetrahydrophthalic anhydride, etc., can also be used. The diols that react to form the desired polyester intermediate can be aliphatic, aromatic, or combinations thereof, and have a total of 2 to 44 or 2 to 36 carbon atoms. Suitable examples include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, dodecamethylene glycol, dimer fatty diol, and mixtures thereof.

[0043] Suitable hydroxyl-terminated polyether intermediates include polyether polyols derived from diols or polyols having a total of 2 to 15 carbon atoms. In some embodiments, the hydroxyl-terminated polyether is an alkyl diol that has reacted with an ether containing an alkylene oxide having 2 to 6 carbon atoms (usually ethylene oxide or propylene oxide or a mixture thereof). For example, a hydroxyl-functional polyether can be produced by first reacting propylene glycol with propylene oxide and then subsequently reacting with ethylene oxide.

[0044] Primary hydroxyl groups produced from ethylene oxide are more reactive than secondary hydroxyl groups and are thus preferred. Useful commercial polyether polyols include: poly(ethylene glycol) including ethylene oxide reacted with ethylene glycol, poly(propylene glycol) including propylene oxide reacted with propylene glycol, poly(tetramethylene glycol) including water reacted with tetrahydrofuran (which can be described as polymerized tetrahydrofuran and which is commonly referred to as PTMEG).

[0045] Suitable polyurethanes described herein are made using optionally c) a chain extender component. Suitable chain extenders include low molecular weight diols (molecular weight less than 500), diamines, and combinations thereof. Suitable chain extenders include relatively small polyhydroxy compounds such as lower aliphatic or short-chain diols having 2 to 20, or 2 to 12, or 2 to 10 carbon atoms. Suitable examples include ethylene glycol (EDO), diethylene glycol (DEG), propylene glycol (PDO), dipropylene glycol (DPG), 1,4-butanediol (BDO), 2-methyl-1,3-propanediol (MPO), 1,6-hexanediol (HDO), 1,3-butanediol (1,3-BDO), 1,5-pentanediol (1,5-PDO), neopentyl glycol (NPG), 1,4-cyclohexanedimethanol (CHDM), 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane (HEPP), hexamethylene glycol (HDO), heptanediol, nonanediol (NDO), dodecanediol (DDO), 3-methyl-1,5-pentanediol (MPD), hydroquinone bis(2-hydroxyethyl) ether (HQEE), ethylenediamine (EDA), butanediamine (BDA), hexamethylenediamine (HDA), and hydroxyethylresorcinol (HER) etc. and mixtures thereof. In some embodiments, the chain extender includes BDO, HDO, 3-methyl-1,5-pentanediol, or combinations thereof. In some embodiments, the chain extender includes BDO. Other diols such as aromatic diols can be used. In some embodiments, the composition is formed using less than 40 wt%, such as only less than 30 wt%, preferably less than 25 wt%, such as less than 15 wt%, further such as less than 12 wt%, particularly less than 8 wt% of the chain extender based on the total reactants. In some embodiments, the thermoplastic polyurethane is substantially free or even completely free of chain extender.

[0046] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the chain extender is selected from ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, or a mixture thereof. More preferably, the chain extender is butylene glycol, hexylene glycol, cyclohexanedimethanol (CHDM), hydroquinone bis(2-hydroxyethyl) ether (HQEE), or a mixture thereof.

[0047] The thermoplastic polyurethanes used according to the present invention generally have a hard segment content of less than 50 wt%, preferably less than 40 wt%. Optionally, one or more polymerization catalysts may be present during the polymerization reaction. Generally, any conventional catalyst can be utilized to react the diisocyanate with the polyol intermediate or the chain extender. Examples of suitable catalysts that particularly accelerate the reaction between the NCO groups of the diisocyanate and the hydroxyl groups of the polyol and the chain extender are conventional tertiary amines known in the prior art, such as triethylamine, dimethylcyclohexylamine, N-methylmorpholine, Ν,Ν'-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo[2.2.2]octane, etc., and particularly organometallic compounds, such as titanates, iron compounds (e.g., iron acetylacetonate), tin compounds (e.g., stannous diacetate, stannous octoate, stannous dilaurate), bismuth compounds (e.g., bismuth trisneodecanoate) or dialkyltin salts of aliphatic carboxylic acids (e.g., dibutyltin diacetate, dibutyltin dilaurate), etc. The usual amount of the catalyst is 0.001 parts by weight / 100 parts by weight to 0.1 parts by weight / 100 parts by weight of the polyol component. In some embodiments, the reaction for forming the thermoplastic PU used according to the present invention is substantially free or completely free of a catalyst.

[0048] Various types of optional components may be present during the polymerization reaction and / or incorporated into the composition containing the thermoplastic polymer described above to improve processing and other properties. These additives include, but are not limited to, antioxidants (such as phenols), rheology modifiers (such as hydrophobic or hydrophilic pyrogenic silica), and adhesion promoters (such as malonic acid, fumaric acid, chlorinated rubber, vinyl chloride / vinyl acetate copolymer, vinyl chloride / vinyl acetate / maleic acid terpolymer). Other additives that can help increase the tackiness of the hot melt adhesive and slow down the recrystallization time, such as other resins, including but not limited to benzofuran-indene or terpene-phenol, can be used to enhance the performance of the composition or the blend product. All of the additives described above can be used in effective amounts commonly used for these substances. These additional additives can be incorporated into the components of the thermoplastic polymer, or into the reaction mixture for preparing the thermoplastic polymer, followed by melting, or they can be directly incorporated into the melt of the thermoplastic polymer.

[0049] Thermoplastic polyurethanes can be manufactured by any means known to those of ordinary skill in the art, such as batch methods, REX line processes, or Belt line processes. For example, the components: (a) a diisocyanate component, (b) a polyol component, and (c) an optional chain extender component react together to form a thermoplastic PU useful in the present invention. Any known method of reacting the reactants can be used to prepare the thermoplastic PU. In one embodiment, the method is a so-called "one-step" method, in which all the reactants are added, mixed, and reacted together. The equivalent weight of the diisocyanate: the total equivalent weight of the hydroxyl-containing components, i.e., the polyol intermediate and the chain extender diol (if included), can be from about 0.5 to about 1.30, or from about 0.6 to about 1.20, or from about 0.7 to about 1.10. The reaction temperature using a urethane catalyst in the reaction zone of a twin-screw reactive extruder (REX line) process can be from about 175 °C to about 245 °C, preferably 180 °C to 220 °C; or in the reaction zone of a Belt line process from about 80 °C to about 160 °C, preferably 90 °C to 150 °C.

[0050] As another example, thermoplastic PUs can also be prepared using the prepolymer method. In the prepolymer route, the polyol component is reacted with a generally equivalent excess of one or more diisocyanates in the presence of a suitable urethane catalyst to form a prepolymer solution having free or unreacted diisocyanate therein. Subsequently, a chain extender as indicated above is added in an amount generally equal to the equivalent of the isocyanate end groups and any free or unreacted diisocyanate compounds. Thus, the total equivalent ratio of the total diisocyanate to the total equivalents of the polyol intermediate and the chain extender can be from about 0.5 to about 1.30, or from about 0.6 to about 1.20, or from about 0.7 to about 1.10. Generally, the prepolymer route can be carried out in any conventional equipment.

[0051] The methods described for preparing thermoplastic PUs include both "prepolymer" methods and "one-step" methods carried out in batch or continuous fashion. That is, in some embodiments, thermoplastic PUs can be manufactured by reacting the components together in a "one-step" polymerization method, in which all the components (including reactants) are added to a mixer simultaneously or substantially simultaneously and reacted to form the thermoplastic PU. While in other embodiments, thermoplastic PUs can be manufactured by: first reacting the polyisocyanate component with a portion of the polyol component to form a prepolymer, and then completing the reaction by reacting the prepolymer with the remaining reactants, thereby producing the thermoplastic PU. After exiting the extruder, the composition can be pelletized and stored and ultimately sold in pellet form; or can be directly extruded through a die from the reaction extruder into a final product profile.

[0052] The application of the TPU hot melt adhesive preferably occurs by: hot melt coating, including but not limited to T-die extrusion, coating, spraying, gravure printing, dot coating, pattern printing, and injection molding, etc., to form including but not limited to films, webs, meshes, dots, patterns, and articles, etc., for further thermocompression lamination; or by directly hot melt coating on a laminate substrate including but not limited to T-die extrusion, coating, spraying, gravure printing, dot coating, and pattern printing, etc., followed by pressing with or without heating, and a cooling step. Automated or machine-assisted methods can be used, for example, using an automatic sprayer to apply the adhesive. The adhesive is applied on one or preferably two substrates. The amount of the TPU hot melt adhesive is preferably 10 g / m 2 to 700 g / m 2 (solid), more preferably 50 g / m 2 to 500 g / m 2 、specially preferably 100 g / m 2 to 400 g / m 2 。The hot melt polyurethane adhesive is preferably applied in a molten state or as a preformed film on the substrates, i.e., between the components to be bonded.

[0053] The bonded article includes at least two components or assemblies bonded to each other. The components of the bonded article are, for example, extruded components, injection molded components, pressed components, foamed components, cable sheaths, hoses, shaped elements, conveyor belts, fibrous materials, non-woven fabrics, films, molded components, shoe soles, sports goods, footwear components, plugs, housings, or damping elements for the electrical industry, for the automotive industry, for machine construction, for 3D printing, for medicine, or for consumer goods. Preferred bonded articles are footwear articles, components of footwear articles, automotive seats, instrument panels, meat or cheese food packaging, etc. More preferably, they are footwear articles or components of footwear articles.

[0054] The footwear article is preferably selected from the group consisting of shoes, boots, and sandals. Suitable shoes are, for example, sports shoes, tennis shoes, cross-training shoes, soccer shoes, children's shoes, dress shoes, and casual shoes.

[0055] The bond strength is preferably higher than 5 N / 50 mm, more preferably higher than 10 N / 50 mm, and most preferably higher than 20 N / 50 mm. The bond strength is preferably about 5 N / 50 mm to material fracture, more preferably about 10 N / 50 mm to about 1000 N / 50 mm, and most preferably about 20 N / 50 mm to about 300 N / 50 mm. The bond strength is measured by a peel test according to ISO 20344:2011, 5.2.

[0056] The first part or component of the bonded article can be made of a thermoplastic polymer. The thermoplastic polymer is preferably a thermoplastic elastomer, more preferably an expanded thermoplastic elastomer. A thermoplastic polymer is a plastic polymer material that becomes flexible or moldable at a certain elevated temperature and solidifies upon cooling. Examples of thermoplastic polymers are thermoplastic polyethylene, thermoplastic polypropylene, thermoplastic polyvinyl chloride, thermoplastic polystyrene, thermoplastic polyamide, thermoplastic polyester, and thermoplastic polyurethane. Thermoplastic elastomers preferably consist of phase-separated block copolymers and combine the performance benefits of rubber such as flexibility and elasticity with the processability of thermoplastic polymers.

[0057] Suitable materials for the first component are, for example, thermoplastic elastomers selected from the group consisting of: thermoplastic polyurethane (TPU), thermoplastic copolyamide (such as thermoplastic copolyether polyamide), thermoplastic copolyester elastomer (such as copolyether ester or copolyester ester), styrene block copolymer (such as styrene-butadiene block copolymer), thermoplastic ethylene vinyl acetate, and mixtures or blends thereof.

[0058] When using thermoplastic polyurethane, the thermoplastic polyurethane can be any desired thermoplastic polyurethane known to those skilled in the art. Thermoplastic polyurethanes and their preparation methods have been widely described, for example, in Gerhard W. Becker and Dietrich Braun, Kunststoffhandbuch, Volume 7, Polyurethane, Carl Hanser Verlag, Munich, Vienna, 1993. Thermoplastic polyurethane is preferably prepared by reacting a mixture of an isocyanate with an isocyanate-reactive compound (preferably having a molecular weight of 0.5 kg / mol to 10 kg / mol) and optionally a chain extender (preferably having a molecular weight of 0.05 kg / mol to 0.5 kg / mol). Thermoplastic polyurethane is preferably prepared by further adding at least one chain transfer agent, a catalyst, and optionally at least one filler, auxiliary, or additive to the mixture.

[0059] Expanded polymers (also known as foamed materials) or foams and in particular expanded polymer particles (also known as bead foams) are known and have been widely described in the literature, for example, in Ullmann's "Enzyklopadie der technischen Chemie", 4th Edition, Volume 20, pages 416 ff. The most preferred material for the first component is expanded thermoplastic polyurethane (E-TPU). Suitable E-TPU and its preparation methods are described, for example, in WO 2007 / 082838, W02013 / 153190, or WO2015 / 052265.

[0060] The polyurethane of the expandable thermoplastic polyurethane can be prepared by reacting a mixture of an isocyanate and an isocyanate-reactive compound. Preferred are aliphatic, cycloaliphatic and / or aromatic isocyanates as the organic isocyanate. It is particularly preferred to use aromatic, aliphatic and / or cycloaliphatic diisocyanates. Examples of preferred diisocyanates are trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, 2-methyl-1,5-pentamethylene diisocyanate, 2-ethyl-1,4-butylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,4-butylene diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-cyclohexane diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane diisocyanate, 3,3'-dimethylbiphenyl diisocyanate, 1,2-diphenylethane diisocyanate and phenylene diisocyanate.

[0061] The isocyanate-reactive compound includes at least one compound having at least two isocyanate-reactive hydrogen groups. The isocyanate-reactive hydrogen group is preferably a hydroxyl group. The compound having at least two isocyanate-reactive hydrogen groups is particularly preferably selected from polyether alcohols, polyester alcohols and polycarbonate diols. In this context, polyester alcohols, polyether alcohols and / or polycarbonate diols are also generally included under the term "polyol". The thermoplastic polyurethane is preferably prepared from at least one polyether alcohol. It is particularly preferred to use polyether diols. Polytetrahydrofuran is a particularly preferred polyether diol. Preferably, polyether alcohols and polytetrahydrofuran having a molecular weight between 0.4 kg / mol and 6 kg / mol are used. The polyether alcohol is used alone or as a mixture of various polyether alcohols.

[0062] Suitable materials for the second part or component of the bonded article are those common in the footwear industry, for example, and may be selected, for example, from the group of materials mentioned for the first component, or from the group consisting of: crepe rubber, natural leather, synthetic leather, polyurethane (such as polyurethane foam and / or thermoplastic polyurethane TPU), thermoplastic rubber, styrene-butadiene rubber, polyvinyl acetate, polyamide (PA), polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof. Preferably, the upper is made of PET, TPU, or PA. Most preferably, the upper is made of PET.

[0063] According to another embodiment, the invention also relates to a method as disclosed above, wherein at least one part of the article is selected from the group consisting of: crepe rubber, natural leather, synthetic leather, polyurethane such as polyurethane foam and / or thermoplastic polyurethane, thermoplastic rubber, styrene-butadiene rubber, polyvinyl acetate, polyamide (PA), polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof.

[0064] In particular, one part of the article may be polyurethane, preferably thermoplastic polyurethane.

[0065] A preferred bonded article is one in which the first component is expanded thermoplastic polyurethane and the second component is a material selected from the group consisting of: crepe rubber, natural leather, synthetic leather, polyurethane, thermoplastic polyurethane, thermoplastic rubber, styrene-butadiene rubber, vinyl acetate, polyamide, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, textiles, fabrics, and combinations thereof.

[0066] According to another embodiment, the invention also relates to a method as disclosed above, wherein one part comprises a material selected from the group consisting of: rubber, natural leather, synthetic leather, polyurethane, thermoplastic polyurethane, styrene-butadiene rubber, vinyl acetate, polyamide, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, or combinations thereof.

[0067] One aspect of the invention is a recyclable footwear article or a part thereof, the recyclable footwear article or a part thereof comprising a first component, a second component, and a polyurethane adhesive that adhesively bonds the first component to the second component, wherein at least one of the components is made of thermoplastic polyurethane, preferably expanded thermoplastic polyurethane.

[0068] The first component or assembly, the second component or assembly, or both can be any component common in footwear products and preferably include components selected from the group consisting of an upper, an insole, an outsole, a midsole, a strobel, a toe box, a toe tip, a vamp patch, a tongue, an eyelet, and combinations thereof. For example, polyurethane adhesives can bond the upper and the outsole, the upper and the insole, the midsole and the outsole, or any other combination of components common in the footwear industry.

[0069] Preferably, the first assembly is a sole made of rubber, natural leather, synthetic leather, polyurethane, thermoplastic polyurethane, styrene-butadiene rubber, vinyl acetate, polyamide, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, or combinations thereof, particularly thermoplastic polyurethane; and the second assembly is an upper preferably made of polyethylene terephthalate. The first component sole preferably contains a midsole made of expanded thermoplastic polyurethane. The adhesive preferably bonds the upper to the sole and / or the midsole.

[0070] According to another embodiment, the invention also relates to a method as disclosed above, wherein one component is a midsole, more preferably a midsole comprising polyurethane, polyurethane foam, thermoplastic polyurethane, expanded polyurethane, expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads, or mixtures thereof.

[0071] In some aspects, the adhesive bonds two sole components, such as the outsole and the midsole. In some aspects, the adhesive bonds the sole or sole components to the upper (or components of the upper). In some aspects, the upper component is a toe cap or a backstay. For example, the polyurethane adhesives described herein can be used to bond the upper surface of the outsole to the lower surface of the midsole. This will allow for easier debonding of the outsole and the midsole. The adhesives described herein can be used to bond the upper surface of the midsole to the lower surface of the upper. This will allow for easier debonding of the sole from the upper.

[0072] For example, a shoe can be formed from a sole and an upper, and the sole includes an outsole and a midsole. Each of these components can be bonded using the debondable adhesives described herein. Using the debondable adhesives described herein allows for easy debonding, for example, the materials of the upper, the outsole, and / or the midsole can be recycled separately.

[0073] According to another embodiment, the invention also relates to a method as disclosed above, wherein the article is a shoe.

[0074] According to a specific embodiment, the present invention thus also relates to a method comprising suitable steps for preparing a shoe. The method may for example comprise one or more of the following steps:

[0075] (a) Surface treatment of the bottom of the upper

[0076] (b) Application of a composition comprising a thermoplastic polymer, preferably in the form of a film;

[0077] (c) Preparation of the midsole and bonding it to the upper;

[0078] (d) The midsole can be bonded to the upper and the outsole.

[0079] The surface treatment according to step (a) may include surface treatments such as physical treatment, chemical treatment, solvent treatment or any combination thereof. Physical treatment may include treating the surface with an abrasive to increase surface roughness. Chemical treatment may include etching the surface with an acid. Solvent treatment may include contacting the surface with a solvent to remove contaminants from the surface. Preferably, the treatment step does not include primer treatment (i.e., coating with a primer solution before applying an adhesive).

[0080] According to step (b), the composition can be applied using a combination of heat treatment and pressure treatment. The heat treatment can be carried out at a temperature between, for example, 100°C - 170°C to soften the surface of the film. The pressure treatment is carried out for a period of time. The pressure can be, for example, about 2000 kPa to about 5500 kPa, and the period of time can be about 1 minute to about 30 minutes. The film can also be applied to the top surface of the outsole using the same method.

[0081] The midsole can be prepared separately and bonded to the upper using the same heat treatment and pressure treatment procedure according to step (c) with a composition comprising a thermoplastic polymer. Specifically, the bottom surface of the HMA-bonded upper is treated at a temperature between, for example, 100°C - 170°C to soften the surface of the film. Then, the midsole is placed on the bottom of the HMA-bonded upper, and a pressure treatment is applied for a period of time to bond them together with HMA between the midsole and the upper. The same method can also be applied to bond the outsole to the midsole.

[0082] According to step (d), the midsole can be directly bonded to the upper and the outsole, for example, by a direct injection method. The bottom of the upper should be bonded to the TPU hot melt film. The outsole can be bonded on the top surface with or without a TPU HMA film.

[0083] In the case of using a molding method, the method may include the following steps:

[0084] (d*1) Clean the bottom mold and the shoe last, and place the bottom mold, the top mold and the shoe last correspondingly so that the shoe last, the top mold and the bottom mold are arranged in sequence from top to bottom;

[0085] (d*2) Place the upper surface bonded with TPU HMA on the shoe last so that the inner side of the upper surface can be closely attached to the shoe last;

[0086] (d*3) Place the TPU HMA-bonded outsole on the bottom mold in an assembled manner;

[0087] (d*4) Lower the shoe last to correspondingly press the components between the bottom of the upper surface and the top of the bottom mold, and closely attach the shoe last, the upper surface and the bottom mold;

[0088] (d*5) Lower simultaneously to closely attach the top mold and the shoe last to the bottom mold.

[0089] (d*6) Inject the PU midsole foaming raw material between the TPU HMA-bonded upper surface and the TPU HMA-bonded outsole through the feeding hole on the left side of the bottom mold, foam and form, melt the TPU HMA surface at both the bottom of the upper surface and the top of the outsole, and further bond the upper surface and the outsole to the PU midsole through the heat and pressure generated during foaming.

[0090] (d*7) Cool, demold, and remove the extra TPU HMA film from the final shoe product.

[0091] According to another embodiment, the present invention also relates to the use of a composition comprising a thermoplastic polymer as an adhesive for the preparation of consumer goods, industrial goods, building products, sports equipment, automotive interiors or floors, the composition having a flow onset temperature (Tfb) measured according to Method Example 1 in the range of 50°C to 160°C, preferably 60°C to 160°C, more preferably 80°C to 160°C, more preferably 90°C to 150°C, most preferably 100°C to 150°C.

[0092] Therefore, according to another aspect, the present invention also relates to a method for preparing an article comprising at least a first component (C1) and a second component (C2), the method comprising the following steps:

[0093] (x) Provide the first component (C1) and the second component (C2),

[0094] (y) Provide a composition comprising a thermoplastic polymer, the composition having a flow onset temperature (Tfb) measured according to Method Example 1 in the range of 50°C to 160°C, preferably 60°C to 160°C, more preferably 80°C to 160°C, more preferably 90°C to 150°C, most preferably 100°C to 150°C,

[0095] (z) Bond the first component and the second component by means of the composition comprising thermoplastic polyurethane provided in step (y).

[0096] According to step (x), provide a first part and a second part. In the context of the present invention, the part may also be referred to as a component. Three or more parts or components according to the present invention may also be combined. These components may be made of the same material or different materials and may have the same or different dimensions.

[0097] According to another embodiment, the present invention also relates to the method as disclosed above, wherein the first component (C1) comprises a thermoplastic polymer.

[0098] According to another embodiment, the present invention also relates to the method as disclosed above, wherein the first component (C1) comprises a foamed thermoplastic polymer.

[0099] According to another embodiment, the present invention also relates to the method as disclosed above, wherein the second component (C2) comprises a thermoplastic polymer.

[0100] According to the present invention, for example, a composition comprising a thermoplastic polymer can be used as an adhesive in one step to combine a woven component and one or more other components (such as foamed beads).

[0101] According to the present invention, for example, one component consisting essentially of polymer foam can be combined with a second component that is essentially a woven structure.

[0102] The method of bonding the first component to the second component may include various surface treatments of the first component, the second component, or both, typically applied using an adhesive. The bonding method may include treating one or both of the surface of the first component and the surface of the second component before applying the polyurethane adhesive.

[0103] The method of bonding the first component to the second component may include applying pressure to ensure an appropriate bonding level between the components. For example, the bonding method may include applying pressure to the first component and the second component for a period of time to bond the first component and the second component. The pressure may be, for example, from about 2000 kPa to about 5500 kPa, and the period of time may be from about 5 seconds to 30 minutes, preferably from 1 minute to 25 minutes, particularly from 10 minutes to about 20 minutes, but is not limited thereto. The bonding method may also include applying heat to bond the first component and the second component. A suitable range is, for example, 50 °C to 170 °C.

[0104] A composition comprising a thermoplastic polymer can be applied, for example, in the form of a film onto a first component, such as onto the bottom of a shoe upper, and a combination of heat treatment and pressure treatment is carried out. The heat treatment can be carried out at a temperature between, for example, 50 °C and 170 °C to soften the surface of the film. The pressure treatment is carried out for a period of time. The pressure can be, for example, from about 2000 kPa to about 5500 kPa, and the period of time can be from about 5 seconds to about 30 minutes. The composition, such as the film, can also be applied to a second component, such as the top surface of an outsole, in the same manner.

[0105] According to the present invention, one or more of the components in the component can also be prepared by injection molding as described above. A composition comprising a thermoplastic polymer can be preferably placed in a suitable mold in the form of a film, for example, and the component can be prepared in situ according to this embodiment.

[0106] According to another aspect, the present invention also relates to an article derived from the bonding method disclosed above. According to another aspect, the present invention also relates to an article obtained or obtainable by the method disclosed above.

[0107] The articles according to the present invention can be used in a variety of applications, such as shoes, furniture, seats, automotive interiors, automotive exteriors, medical devices, industrial applications, consumer goods such as consumer electronics, wearable devices, headphones, speakers, packaging, protective devices, as cushion pads, toys, animal toys, saddles, balls and sports equipment, such as exercise mats, sports gloves, or as floor coverings and wall panels.

[0108] The article can also be footwear or a part of footwear, preferably selected from the group consisting of shoes, boots and sandals. Suitable shoes are, for example, sports shoes, tennis shoes, cross-training shoes, football shoes, children's shoes, dress shoes and casual shoes.

[0109] It has been found that the articles according to the present invention can be disassembled using suitable mild conditions, which makes them easier to recycle. According to the present invention, the article can be disassembled to obtain separate components, thereby allowing the separation of these components and their recycling. In this way, mixing of different components can be reduced or avoided. In addition, the separate components obtained can also be reused.

[0110] According to another embodiment, the present invention therefore also relates to the article disclosed above, wherein the article can be disassembled into components C1 and / or C2.

[0111] According to another embodiment, the present invention also relates to the article disclosed above, wherein the article is recyclable. If the components can be recovered during the recycling process, then the components can be reused as such. In addition, the components can also be recycled in a process including a further extrusion step of a thermoplastic elastomer.

[0112] According to the present invention, for example, an article can be prepared by bonding separate components (at least components C1 and C2) to obtain the article. Then the article can be disassembled and components C1 and / or C2 can be recovered. Subsequently, after a suitable separation step, components C1 and / or C2 can be reused to prepare the article as described above.

[0113] According to another embodiment, the present invention also relates to an article as disclosed above, wherein recycling of the article yields components (C1) and / or (C2).

[0114] The article according to the present invention is applicable to different applications, such as consumer goods. According to another embodiment, the present invention also relates to an article as disclosed above, wherein the article is a consumer good or part of a consumer good.

[0115] It has been found that the article can be debonded using mild conditions. Debonding can be carried out by treating the article at an elevated temperature, for example in an oven or with a solution and depending on the flow onset temperature of the given material, in the range from 75°C below the flow onset temperature of the composition comprising the thermoplastic polymer to 50°C above the flow onset temperature of the composition comprising the thermoplastic polymer, preferably in the range from 65°C below the flow onset temperature of the composition comprising the thermoplastic polymer to 40°C above the flow onset temperature of the composition comprising the thermoplastic polymer, preferably in the range from 50°C below the flow onset temperature of the composition comprising the thermoplastic polymer to 30°C above the flow onset temperature of the composition comprising the thermoplastic polymer, preferably in the range from 40°C below the flow onset temperature of the composition comprising the thermoplastic polymer to 20°C above the flow onset temperature of the composition comprising the thermoplastic polymer. Debonding can be carried out by treating the article at an elevated temperature for a period of 1 second to 15 minutes, preferably 15 seconds to 10 minutes, or also by treating the article at a temperature in the range from 20°C below the flow onset temperature of the composition comprising the thermoplastic polymer to 35°C above the flow onset temperature of the composition comprising the thermoplastic polymer for a period of 1 second to 15 minutes, preferably 15 seconds to 10 minutes.

[0116] Generally, debonding can be carried out at a temperature in the range from 50°C to 160°C, preferably in the range from 60°C to 140°C, more preferably in the range from 70°C to 120°C. Generally, debonding is carried out in air, in an aqueous environment, a steam environment or a dry environment. According to the present invention, debonding can be carried out at a temperature in the range from 50°C to 160°C, in air, in an aqueous environment, a steam environment or a dry environment.

[0117] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the article is separated into its components by using heat. The heat can be supplied by heating in an oven, treating with heated air, with heated water, with a heated aqueous solution comprising other additives such as surfactants, or with steam, or radiation such as microwave radiation according to the present invention can be used to generate it. According to the present invention, combinations of these methods can also be used.

[0118] At least two components of the bonded article can be debonded by treatment at an elevated temperature. If desired, the bonded article is cut into smaller pieces before debonding. Debonding is preferably carried out at a temperature below the flow onset temperature (Tfb) of the composition comprising the thermoplastic polymer by 75 °C, preferably below the flow onset temperature of the composition comprising the thermoplastic polymer by 60 °C, particularly below the flow onset temperature of the composition comprising the thermoplastic polymer by more than 50 °C, more preferably in the range between 50 °C below the flow onset temperature of the composition comprising the thermoplastic polymer and 50 °C above the flow onset temperature of the composition comprising the thermoplastic polymer, particularly more preferably in the range between 40 °C below the flow onset temperature of the composition comprising the thermoplastic polymer and 50 °C above the flow onset temperature of the composition comprising the thermoplastic polymer, and the bonded article (or its pieces) is treated for preferably 5 seconds to 120 minutes, more preferably 30 seconds to 90 minutes, particularly 2 minutes to 60 minutes.

[0119] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the heat used to separate the article is at least the flow onset temperature (Tfb) of the thermoplastic polymer composition.

[0120] According to another aspect, the present invention also relates to a method for disassembling an article obtained or obtainable by the method according to the present invention, the method comprising steps (A) and (B):

[0121] (A) Treating the article at a temperature in the range between 50 °C below the flow onset temperature of the composition comprising the thermoplastic polymer and 50 °C above the flow onset temperature of the composition comprising the thermoplastic polymer;

[0122] (B) Recycling component (C1) and / or (C2).

[0123] Preferably, there is no residual adhesive on the surface of the debonded components. This has the advantage that the residual adhesive does not interfere with the recycling of the debonded components. According to the present invention, a layer of residual adhesive can also be retained on the debonded components, which can be used in further processes without a recycling step.

[0124] According to another embodiment, the present invention also relates to a method as disclosed above, wherein the heat for separating the article is not more than 50 °C above the flow onset temperature (Tfb) of the thermoplastic polymer composition, preferably not more than 30 °C above, more preferably not more than 20 °C above, more preferably not more than 10 °C above, and most preferably not more than 5 °C above.

[0125] Another object of the present invention is a method for debonding an adhesive article and recycling it, wherein the adhesive article is debonded according to the method described above, and recycling is achieved by physically pulverizing the debonded thermoplastic polyurethane and chemically treating the pulverized material to produce a new thermoplastic polyurethane, for example as described in WO 2019 / 175151. The pulverized thermoplastic polyurethane is used, for example, in the form of fragments, in the form of granules, as an agglomerate or as a powder.

[0126] Further embodiments of the present invention can be found in the claims and the examples. It should be understood that the features of the subject matter / method / use according to the present invention described above and elaborated below can be used not only in the combinations specified in each case, but also in other combinations without departing from the scope of the present invention. For example, combinations of preferred features with particularly preferred features or combinations of features not further characterized with particularly preferred features, etc. are thus implicitly covered, even if the combination is not explicitly mentioned.

[0127] Exemplary embodiments of the present invention are listed below, but these do not limit the present invention. In particular, the present invention also covers those embodiments resulting from the combinations specified by the dependent references and thus below.

[0128] 1. A method for bonding at least two components using a composition comprising a thermoplastic polymer to form an article comprising those two components.

[0129] forming an article including those two components.

[0130] 2. The method according to embodiment 1, wherein the thermoplastic polymer composition comprises at least one polymer selected from thermoplastic polyurethane, polychloroprene, latex, polystyrene, polyamide, polyolefin, polyacrylate, or a mixture thereof.

[0131] 3. The method according to any one of embodiments 1 or 3, wherein the thermoplastic polymer composition is a film.

[0132] 4. The method according to any one of embodiments 1 to 3, wherein the thermoplastic polymer is thermoplastic polyurethane.

[0133] 5. The method according to any one of embodiments 1 to 4, wherein at least

[0134] A component is selected from the group consisting of crepe rubber, natural leather, synthetic leather, polyurethanes such as polyurethane foam and / or thermoplastic polyurethane, thermoplastic rubber, butadiene rubber, polyvinyl acetate, polyamide (PA), polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof.

[0135] styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof.

[0136] acrylonitrile butadiene styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof.

[0137] acrylonitrile butadiene styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof.

[0138] 6. The method according to any one of embodiments 1 to 5, wherein the thermoplastic polymer composition has a flow onset temperature Tfb in the range of 50 °C to 160 °C, preferably 60 °C to 160 °C, more preferably 80 °C to 160 °C, more preferably 90 °C to 150 °C, and most preferably 100 °C to 150 °C, measured according to Method Example 1.

[0139] to 160 °C, more preferably 80 °C to 160 °C, more preferably 90 °C to 150 °C, and most preferably 100 °C to 150 °C, measured according to Method Example 1.

[0140] to 160 °C, more preferably 80 °C to 160 °C, more preferably 90 °C to 150 °C, and most preferably 100 °C to 150 °C, measured according to Method Example 1.

[0141] 7. The method according to any one of embodiments 1 to 6, wherein the thermoplastic polyurethane of the film is a reaction product of a building component polyol, an isocyanate, and finally a chain extender.

[0142] 8. The method according to embodiment 7, wherein the polyol is a polyol having a number average molecular weight in the range of 0.4×10 3 g / mol to 6×10 3 g / mol.

[0143] 9. The method according to any one of embodiments 7 or 8, wherein the isocyanate is an aromatic isocyanate, an aliphatic isocyanate, an alicyclic isocyanate, and combinations thereof.

[0144] 10. The method according to any one of embodiments 7 to 9, wherein the aromatic isocyanate is more preferably selected from the group consisting of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, urethane-modified liquid 4,4'-diphenylmethane diisocyanate and / or 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanato-1,2-diphenylethane, 1,5-naphthalene diisocyanate, and combinations thereof.

[0145] 11. The method according to any one of embodiments 7 to 10, wherein the aromatic isocyanate is most preferably 4,4'-diphenylmethane diisocyanate (4,4'-MDI).

[0146] 12. The method according to any one of embodiments 7 to 11, wherein the aliphatic isocyanate is more preferably selected from the group consisting of 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, and combinations thereof.

[0147] 13. The method according to any one of embodiments 7 to 12, wherein the aliphatic isocyanate is most preferably 1,6-hexamethylene diisocyanate (HDI).

[0148] 14. The method according to any one of embodiments 7 to 13, wherein the cycloaliphatic isocyanate is selected from the group consisting of isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate and its corresponding isomer mixture, 4,4'-dicyclohexylmethane diisocyanate, 2,4-dicyclohexylmethane diisocyanate, and 2,2'-dicyclohexylmethane diisocyanate and their corresponding isomer mixtures, and combinations thereof.

[0149] 15. The method according to any one of embodiments 7 to 14, wherein the cycloaliphatic isocyanate is 4,4'-dicyclohexylmethane diisocyanate (H 12 MDI).

[0150] 16. The method according to any one of embodiments 7 to 15, wherein the chain extender is selected from ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, or mixtures thereof; more preferably, the chain extender is butylene glycol, hexylene glycol, cyclohexanedimethanol (CHDM), hydroquinone bis(2-hydroxyethyl) ether (HQEE), or mixtures thereof.

[0151] 17. The method according to any one of embodiments 1 to 16, wherein the article is a shoe.

[0152] 18. The method according to any one of embodiments 1 to 17, wherein one component is a midsole; more preferably, a midsole comprising polyurethane, thermoplastic polyurethane, polyurethane foam, expanded polyurethane, expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads, or mixtures thereof.

[0153] 19. The method according to any one of embodiments 1 to 18, wherein a component comprises a material selected from the group consisting of: rubber, natural leather, synthetic leather, polyurethane, thermoplastic polyurethane, styrene-butadiene rubber, vinyl acetate, polyamide, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, or combinations thereof.

[0154] 20. An article derived from the method according to any one of embodiments 1 to 19.

[0155] 21. The method according to any one of embodiments 1 to 19, wherein the article is separated into its components by using heat.

[0156] 22. The method according to embodiment 21, wherein the heat used to separate the article is at least the flow onset temperature (Tfb) of the thermoplastic polymer composition.

[0157] 23. The method according to any one of embodiments 21 or 22, wherein the heat used to separate the article is not more than 50 °C above, preferably not more than 30 °C above, more preferably not more than 20 °C above, more preferably not more than 10 °C above, and most preferably not more than 5 °C above the flow onset temperature (Tfb) of the thermoplastic polymer composition.

[0158] 24. A method for bonding at least two components (C1) and (C2) using a composition comprising a thermoplastic polymer to form an article comprising those two components.

[0159] 25. The method according to embodiment 24, wherein the thermoplastic polymer composition comprises at least one polymer selected from thermoplastic polyurethane, polychloroprene, latex, polystyrene, polyamide, polyolefin, polyacrylate, or mixtures thereof.

[0160] 26. The method according to any one of embodiments 24 or 25, wherein the thermoplastic polymer composition is a film.

[0161] 27. The method according to any one of embodiments 24 to 26, wherein the thermoplastic polymer is thermoplastic polyurethane.

[0162] 28. A method for bonding at least two components (C1) and (C2) using a composition comprising thermoplastic polyurethane to form an article comprising those two components.

[0163] 29. The method according to any one of embodiments 24 to 28, wherein at least one of the components (C1) or (C2) of the article is selected from the group consisting of crepe rubber, natural leather, synthetic leather, polyurethanes such as polyurethane foam and / or thermoplastic polyurethane, thermoplastic rubber, styrene-butadiene rubber, polyvinyl acetate, polyamide (PA), polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof.

[0164] 30. The method according to any one of embodiments 24 to 29, wherein the thermoplastic polymer composition has a flow onset temperature (Tfb) measured according to Method Example 1 in the range of 50°C to 160°C, preferably 60°C to 160°C, more preferably 80°C to 160°C, more preferably 90°C to 150°C, and most preferably 100°C to 150°C.

[0165] 31. A method for bonding at least two components (C1) and (C2) using a composition comprising a thermoplastic polymer to form an article comprising those two components, wherein the thermoplastic polymer composition has a flow onset temperature (Tfb) measured according to Method Example 1 in the range of 50°C to 160°C, preferably 60°C to 160°C, more preferably 80°C to 160°C, more preferably 90°C to 150°C, and most preferably 100°C to 150°C.

[0166] 32. The method according to any one of embodiments 24 to 31, wherein the thermoplastic polyurethane of the film is a reaction product of a building component polyol, an isocyanate, and finally a chain extender.

[0167] 33. The method according to embodiment 32, wherein the polyol is a polyol having a number average molecular weight in the range of 0.4×10 3 g / mol to 6×10 3 g / mol.

[0168] 34. The method according to any one of embodiments 32 or 33, wherein the isocyanate is an aromatic isocyanate, an aliphatic isocyanate, an alicyclic isocyanate, and combinations thereof.

[0169] 35. The method according to any one of embodiments 32 to 34, wherein the aromatic isocyanate is more preferably selected from the group consisting of: 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, urethane-modified liquid 4,4'-diphenylmethane diisocyanate and / or 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanato-1,2-diphenylethane, 1,5-naphthalene diisocyanate, and combinations thereof.

[0170] 36. The method according to any one of embodiments 32 to 35, wherein the aromatic isocyanate is most preferably 4,4'-diphenylmethane diisocyanate (4,4'-MDI).

[0171] 37. The method according to any one of embodiments 32 to 36, wherein the aliphatic isocyanate is more preferably selected from the group consisting of: 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, and combinations thereof.

[0172] 38. The method according to any one of embodiments 32 to 37, wherein the aliphatic isocyanate is most preferably 1,6-hexamethylene diisocyanate (HDI).

[0173] 39. The method according to any one of embodiments 32 to 38, wherein the cycloaliphatic isocyanate is selected from the group consisting of: isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate and its corresponding isomer mixture, 4,4'-dicyclohexylmethane diisocyanate,

[0174] 2,4-dicyclohexylmethane diisocyanate and 2,2'-dicyclohexylmethane diisocyanate and their corresponding isomer mixtures, and combinations thereof.

[0175] 40. The method according to any one of embodiments 32 to 39, wherein the cycloaliphatic isocyanate is 4,4'-dicyclohexylmethane diisocyanate (H 12 MDI).

[0176] 41. The method according to any one of embodiments 32 to 40, wherein the chain extender is selected from ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, or a mixture thereof. More preferably, the chain extender is butylene glycol, hexylene glycol, cyclohexanedimethanol (CHDM), hydroquinone bis(2-hydroxyethyl) ether (HQEE), or a mixture thereof.

[0177] 42. A method according to any one of embodiments 24 to 41, wherein the article is a shoe.

[0178] 43. A method according to any one of embodiments 24 to 42, wherein one component is a midsole, more preferably a midsole comprising polyurethane, thermoplastic polyurethane, polyurethane foam, expanded polyurethane, expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads, or a mixture thereof.

[0179] 44. A method according to any one of embodiments 24 to 43, wherein one component comprises a material selected from the group consisting of rubber, natural leather, synthetic leather, polyurethane, thermoplastic polyurethane, styrene-butadiene rubber, vinyl acetate, polyamide, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, or combinations thereof.

[0180] 45. An article obtained or obtainable by a method according to any one of embodiments 24 to 44.

[0181] 46. A method according to any one of embodiments 24 to 44, wherein the article is separated into its components by using heat.

[0182] 47. A method for debonding an article obtained or obtainable by a method according to any one of embodiments 1 to 19 or 24 to 44, wherein the article is separated into its components by using heat.

[0183] 48. A method according to embodiment 46 or 47, wherein the heat is supplied via heating in an oven, treatment with heated air, treatment with heated water, a heated aqueous solution comprising other additives such as surfactants, or steam treatment, or is generated using radiation such as microwave radiation.

[0184] 49. A method according to any one of embodiments 46 to 48, wherein the heat used to separate the article is at least the flow onset temperature (Tfb) of the thermoplastic polymer composition.

[0185] 50. A method according to any one of embodiments 46 to 49, wherein the heat used to separate the article is not more than 50 °C above, preferably not more than 30 °C above, more preferably not more than 20 °C above, more preferably not more than 10 °C above, and most preferably not more than 5 °C above the flow onset temperature (Tfb) of the thermoplastic polymer composition.

[0186] 51. A method for preparing an article comprising at least a first component (C1) and a second component (C2), the method comprising the steps of:

[0187] (x) providing the first component (C1) and the second component (C2),

[0188] (y) providing a composition comprising a thermoplastic polymer, the composition having a flow onset temperature (Tfb) measured according to Method Example 1 in the range of 50 °C to 160 °C, preferably 60 °C to 160 °C, more preferably 80 °C to 160 °C, more preferably 90 °C to 150 °C, most preferably 100 °C to 150 °C,

[0189] (z) bonding the first component and the second component by means of the composition comprising the thermoplastic polyurethane provided in step (y).

[0190] 52. An article obtainable or obtained according to the method of any one of embodiments 24 to 51.

[0191] 53. The article according to embodiment 52, wherein the article is capable of being disassembled into components (C1) and / or (C2).

[0192] 54. The article according to embodiment 52 or 53, wherein the article is recyclable.

[0193] 55. The article according to any one of embodiments 52 to 54, wherein recycling of the article yields components (C1) and / or (C2).

[0194] 56. A method for disassembling an article obtainable or obtained according to the method of any one of embodiments 1 to 55, the method comprising steps (A) and (B):

[0195] (A) treating the article at a temperature in the range of between 70 °C below the flow onset temperature of the composition comprising the thermoplastic polymer and 50 °C above the flow onset temperature of the composition comprising the thermoplastic polymer;

[0196] (B) recovering components (C1) and / or (C2).

[0197] 57. A method for disassembling an article obtainable or obtained according to the method of any one of embodiments 1 to 55, the method comprising steps (A) and (B):

[0198] (A) Treat the article at a temperature within a range from 50 °C below the flow onset temperature of the composition comprising the thermoplastic polymer to 40 °C above the flow onset temperature of the composition comprising the thermoplastic polymer;

[0199] (B) Recover component (C1) and / or (C2). Description of the Drawings

[0200] Figure 1 The structural diagram of Shimadzu Flowtester CFT - 500EX is shown.

[0201] (1) Die Plug

[0202] (2) Cylinder Barrel

[0203] (3) Heater

[0204] (4) Die

[0205] (5) Press

[0206] (6) Piston

[0207] (7) Pressure Connector

[0208] (8) Load Shaft

[0209] (9) Temperature Detector

[0210] (10) Potentiometer (for stroke detection)

[0211] (11) Load Rod

[0212] (12) Cylinder for weight lifting

[0213] (13) Solenoid Valve

[0214] (14) Balance Weight

[0215] (15) Wheel Pair

[0216] (16) Control Unit (CPU)

[0217] (17) Weight

[0218] (18) Moving Fulcrum

[0219] It consists of a main unit and a control unit. The main unit heats and pressurizes the sample inserted into the cylinder barrel and extrudes the molten sample through the die for testing. The control unit calculates the shear rate and viscosity based on the measurement data regarding the cylinder barrel temperature and the piston moving distance.

[0220] The sample is loaded into the cylinder and heated by a heater outside the cylinder. The force generated by the heavy weight is amplified by the load rod, applied to the piston through the load shaft, and the sample is extruded through the die hole. The piston stroke is detected by a potentiometer.

[0221] The potentiometer value is read by the instrument control unit. Then, the current rate is calculated based on the relationship between the extrusion time and the piston stroke to obtain the shear rate and viscosity.

[0222] By combining a wheel pair with a lever ratio of 1:2 and a load rod with a lever ratio of 1:5, the loading mechanism generates a load force that is 10 times that of the heavy weight. The wheel pair and the load rod operate together via a connecting steel belt. Since the upper and lower parts of the load shaft are fixed with guide bearings, the load shaft moves vertically, but its horizontal movement is restricted. When the heavy weight lifting cylinder rises or falls, the heavy weight does not generate a load force. However, when the cylinder descends, a load force is generated in the load shaft, thereby extruding the sample. When the load shaft rises and falls, the moving fulcrum of the counterweight rod moves horizontally on the flat fulcrum bearing to prevent any force other than the horizontal force from being applied to the load shaft.

[0223] Figure 2 A schematic diagram of the cylinder unit is shown. The cylinder (c) includes a die holder (dh) and a heater (h). The sample (s) is placed between the die (d) and the piston (p).

[0224] Figure 3 A schematic diagram of the die is shown. The die (d) has a die length (dl), a die hole diameter (ddi), and a die width (do).

[0225] Figure 4 A schematic flow test curve using the constant heating rate method is shown. The piston stroke (PS, y-axis) is plotted against the temperature (T, x-axis). Points A and B mark the preheating period. B and C determine the softening region. Between points C and D, there is a non-flow region. Starting at D and continuing at point E, the flow region is shown. The softening temperature (Ts) and the flow onset temperature (Tfb) are also marked.

[0226] The present invention is further described by way of examples. The examples relate to practical and in some cases preferred embodiments of the present invention, which do not limit the scope of the present invention. Examples

[0227] 1. Formulation and Characteristics of TPU HMA (Usage Grade)

[0228] 1.1 Melt 1

[0229] Diisocyanate: 4,4'-MDI

[0230] Polyol: PBA1000 (monomers: adipic acid, 1,4-butanediol, OHv: 112.2 mg KOH / g, Mn: 1,000 g / mol)

[0231] Chain extender: 1,6-HDO (≈5 wt% in TPU HMA)

[0232] Hard segment content: ≈15 wt%

[0233] DSC-Tm: Not detected

[0234] Tfb: 105 °C

[0235] 1.2 Melt 2

[0236] Diisocyanate: 4,4'-MDI

[0237] Polyol: PBA1000 (monomers: adipic acid, 1,4-butanediol, OHv: 112.2 mg KOH / g, Mn: 1,000 g / mol)

[0238] Polyol: PTHF1000 (monomers: THF, OHv: 112.2 mg KOH / g, Mn: 1,000 g / mol)

[0239] Chain extender: 1,4-BDO (≈3 wt% in TPU HMA)

[0240] Hard segment content: ≈12 wt%

[0241] DSC-Tm: 118 °C

[0242] Tfb: 125 °C

[0243] 1.3 Melt 3

[0244] PBA-1000 / HDO / MDI, HS ≈23.0 wt%

[0245] Diisocyanate: 4,4'-MDI

[0246] Polyol: PBA1000 (monomers: adipic acid, 1,4-butanediol, OHv: 112.2 mg KOH / g, Mn: 1,000 g / mol)

[0247] Chain extender: 1,6-HDO (≈7 wt% in TPU HMA)

[0248] Hard segment content: ≈23 wt%

[0249] DSC-Tm: 105 °C

[0250] Tfb: 118 °C

[0251] 1.4 Melt 4

[0252] Diisocyanate: HDI

[0253] Polyol: PBA-4000 (monomers: adipic acid, 1,4-butanediol, OHv: 28.0 mg KOH / g, Mn: 4,000 g / mol)

[0254] Chain extender: None

[0255] Hard segment content: 0.0 wt%

[0256] DSC-Tm: 60 °C

[0257] Tfb: 60 °C

[0258] 1.5 Determination of Hard Segment Content

[0259] The hard segment content is calculated according to the following formula:

[0260]

[0261] HS: Hard segment

[0262] m CE : Mass of the chain extender

[0263] m iso : Mass of the isocyanate

[0264] m 多元醇 : Mass of the polyol

[0265] 1.6 Preparation of Melts

[0266] The mixture of each component is heated to 80 °C while stirring at a speed of 500 - 1,000 revolutions per minute (rpm) for 1 - 3 minutes using a paddle mixer (SHIN KWANG GR-150R). Then, the TPU HMA is discharged. The TPU HMA is post-treated at 100 °C for 1 - 5 hours and then pelletized.

[0267] 2. Method 1: Measurement of Flow Initiation Temperature (Tfb)

[0268] 2.1 Principle :

[0269] The flow onset temperature (Tfb) of the sample is measured by placing the sample (s) in a hollow cylinder having a die head including a channel through which the molten sample flows, placing the sample under a piston in the hollow cylinder having a load, heating the sample until it melts and leaks through the channel, and determining the temperature at which the sample starts to flow (= flow onset temperature (Tfb)).

[0270] 2.2 Equipment :

[0271] The experimental apparatus is described in the JIS K 7311 and JIS K 7210 standards. The general setup of the apparatus used is shown in Figure 1 . As Figure 2 presented, a heatable concentric hollow cylinder has a piston in this hole. The hole of the cylinder is closed at the bottom with a die head that includes a channel, as Figure 3 described in detail. This cylinder is placed in the apparatus for measuring Tfb. The apparatus is constructed to allow the channel of the die head to be closed by screwing a press machine at the bottom of the cylinder and pressing the die head that fits tightly to the bottom of the cylinder. Closing the channel of the die head is important for removing air from the sample before the experiment starts. Removing air is done by compressing the sample in the hole of the cylinder, where the piston presses against the die head with a specific load without raising the temperature of the cylinder. After removing air, a piston with a specific load is set on the sample, and the sample is heated by heating the cylinder while increasing the temperature at a constant rate and simultaneously plotting the temperature around the sample. Once the sample reaches the flow onset temperature (Tfb), the melt starts to leak through the channel of the die head under the pressure of the piston with a specific load. The temperature at which the piston starts to move is detected by a suitable movement detection member. The temperature at which the piston starts to move is the flow onset temperature (Tfb).

[0272] 2.3 Detailed Description of the Measurement :

[0273] All the apparatus used in the experiments is the Shimadzu CFT - 500D from Shimadzu Corporation, Tokyo, Japan.

[0274] The sample is collected and cut into pieces with a maximum diameter not greater than the diameter of the cylinder, preferably not greater than 5 mm, and most preferably not greater than 2 mm.

[0275] Before measurement, the temperature of the cylinder with the piston is adjusted to 30 °C + / - 2 °C.

[0276] 1.9 g of the sample slices are filled into the hole of a preheated cylinder closed with a die head having a 1 mm channel (for details, see Figure 1 ). The sample is brought to the bottom of the hole using a plunger rod. Then, the hole with the sample is closed with a piston.

[0277] The die used in this measurement has D i = 1 mm, D l = 10 mm, as Figure 3 shown.

[0278] Then, the die's channel is closed with a member for closing the channel, and air is removed from the sample by repeatedly pressing the piston 3 times towards the sample with a load of 100 kg. Thereafter, the member for closing the channel is removed to open the channel again.

[0279] Then, the sample under the piston with a load of 100 kg is held at a temperature of 30 °C for 240 seconds. Thereafter, under a continuous load of 100 kg, the sample is heated at a heating rate of 3 °C / min, and the temperature close to the sample is continuously plotted.

[0280] The flow onset temperature (Tfb) is the temperature at which the piston starts to move under the load when the molten sample begins to pass through the die's channel. A typical graph for determining the flow onset temperature (Tfb) can be obtained from Figure 4 obtained.

[0281] Measurement of the flow onset temperature (Tfb) does not necessarily require the use of a Shimadzu CFT-500D from Shimadzu Corporation, Tokyo, Japan.

[0282] Within the scope of the present invention, other devices with a similar cylinder geometry will yield the same flow onset temperature (Tfb) results.

[0283] 3. Experimental Section

[0284] 3.1 Materials Used

[0285] Polyol 1: A polyester based on adipic acid and monoethylene, having an OH value of 52 mg KOH / g and a functionality of 2.00

[0286] Polyol 2: A polyester polyol based on adipic acid, glycerol, monoethylene glycol and diethylene glycol, where functionality: 2.3 and Mw: 2300 g / mol

[0287] CE: 1,4-butanediol

[0288] HS: Elastostab from BASF Polyurethanes GmbH

[0289] Isocyanate 1: 4,4'-diphenylmethane diisocyanate (MDI)

[0290] Select from the TPU melt the hot melts 1, 2, 3, and 4 as defined above from BASF Elastollan hotbonds.

[0291] 3.2 Use the thermoplastic hot melt as a film of different thicknesses and apply it to the surface of a pre-formed shoe upper by means of a hot air gun (so as to model the TPU film on the 3D upper surface). Select the same procedure to fix the hot bond film to a pre-formed TPU outsole (polyester-based TPU (Elastollan 565, available from BASF SE)).

[0292] Produce the TPU shoe outsole according to WO 15124476 and WO14095438. Use the following formulation:

[0293]

[0294]

[0295] The hot melts used are characterized by Tfb (flow onset temperature) of 105 °C, 125 °C, and 118 °C respectively (measured according to Method 1 described above). Table 1 reports the hot melts used.

[0296] Sample 1 is used to "coat" the TPU outsole, while sample 2 is used to coat the shoe upper.

[0297] Samples 3 and 4 are used to coat both the TPU sole and the shoe upper before injecting the shoe foam.

[0298] Table 1

[0299] Thickness, in mm Tfb °C Sample 1 Melt 1 0.12 105 Sample 2 Melt 1 0.25 105 Sample 3 Melt 2 0.11 125 Sample 4 Melt 3 0.22 118

[0300] Use a machine from Maingroup Technologies Srl to inject the shoe foam system 1. Inject (model: Pragma 1 ST) and the polyurethane foam system 1 as described below between the shoe upper and the outsole to allow the final component to be achieved.

[0301] 3.3 Use hot melt 4, sample 5 with a Tfb of 60 °C for another experiment.

[0302] Melt the hot bond particles (temperature 160 °C) and apply them to a PET fabric (42×20 cm 2 , a standard cotton soft towel with a thickness of 0.45 mm, type 10A from Fa.Rocholl) by using a coating equipment (Coatmaster510, at a temperature of 140 °C, with a hot melt thickness in the range of 250 - 450 μm).

[0303] The coated PET fabric back is foamed using the shoe foam system 1.

[0304] For the shoe foam system 1, the following component A and component B are used at a mixing weight ratio of 100 / 115 (polyol to diisocyanate).

[0305] Component A :

[0306]

[0307]

[0308] Component B :

[0309] A polyester-based prepolymer, based on 4,4 MDI / 2,4 MDI (obtained from BASF SE as Lupranat MRS), a carbodiimide of 4,4 MDI / MDI (obtained from BASF SE as Lupranat MM103), polyesters based on adipic acid, monoethylene glycol and 1,4-butanediol and polyesters based on adipic acid, monoethylene glycol, diethylene glycol and glycerol, propylene carbonate stabilized with diglycol-bischloroformate, NCO content: 18.2%.

[0310] The NCO content in weight-% is determined by back-titrating the corresponding sample with 1 M di-n-butylamine in excess in chlorobenzene with 1 mole of hydrochloric acid.

[0311] 3.4 The initial adhesion of the different components of the shoe is carried out at 23 °C according to ISO 20344:2011, 5.2.

[0312] The adhesion between the PET fabric and the foam is measured at 23 °C according to ISO 20344:2011, 5.2.

[0313] 4. Bonding Results

[0314] 4.1 Bonding of Outsole / Midsole

[0315] Sample 1 1.32 N / mm Sample 3 2.39 N / mm Sample 4 1.19 N / mm

[0316] 4.2 Bonding of Upper / Midsole

[0317] Sample 2 0.68 N / mm Sample 3 0.97 N / mm Sample 4 0.51 N / mm

[0318] 4.3 Bonding between PET Fabric and Shoe Foam 1

[0319] Material breakage (foam surface) was observed.

[0320]

[0321] 5. Disassembly Experiment

[0322] 5.1 In the Oven

[0323] Place the bonded shoe prepared according to Example 3 in an oven for 30 minutes. Start the experiment at an oven temperature of 60 °C. After 30 minutes, raise the temperature to 100 °C and maintain it for another 30 minutes. Repeat the experiment until the oven temperature reaches 130 °C. At temperatures > 80 °C, the different components of the shoe can be more easily debonded by hand pulling.

[0324] 5.2 Treatment with Hot Water

[0325] Contact 100 mL of water with a shoe piece of 2 × 3 cm 2 .

[0326] Stir the water bath (200 rpm) for 15 minutes with the aid of a magnetic stir bar.

[0327] For hot adhesives 1, 2, and 3, raise the water bath temperature from room temperature to 90 °C.

[0328] At a temperature of 70 °C, the different components of the shoe are more easily separated from each other.

[0329] For the PET fabric bonded to the shoe foam using hot adhesive 4, maintain the water bath at a temperature of 60 °C: delamination of the textile from the foam is achieved.

Claims

1. A method for bonding at least two components using a composition comprising a thermoplastic polymer to form an article comprising those two components.

2. The method according to claim 1, wherein the thermoplastic polymer composition comprises at least one polymer selected from the group consisting of thermoplastic polyurethane, polychloroprene, latex, polystyrene, polyamide, polyolefin, polyacrylate, or mixtures thereof.

3. The method according to any one of claims 1 or 2, wherein the thermoplastic polymer composition is a film.

4. The method according to any one of claims 1 to 3, wherein the thermoplastic polymer is thermoplastic polyurethane.

5. The method according to any one of claims 1 to 4, wherein at least one component of the article is selected from the group consisting of crepe rubber, natural leather, synthetic leather, polyurethanes such as polyurethane foam and / or thermoplastic polyurethane, thermoplastic rubber, styrene-butadiene rubber, polyvinyl acetate, polyamide (PA), polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, polyethylene terephthalate (PET), polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, and combinations thereof.

6. The method according to any one of claims 1 to 5, wherein the thermoplastic polymer composition has a flow onset temperature (Tfb) in the range of 50 °C to 160 °C, preferably 60 °C to 160 °C, more preferably 80 °C to 160 °C, more preferably 90 °C to 150 °C, and most preferably 100 °C to 150 °C, measured according to Method Example 1.

7. The method according to any one of claims 1 to 6, wherein the thermoplastic polyurethane of the film is a reaction product of a building component polyol, an isocyanate, and finally a chain extender.

8. The method according to claim 7, wherein the polyol is a polyol having a number average molecular weight in the range of 0.4×10 3 g / mol to 6×10 3 g / mol.

9. The method according to any one of claims 7 or 8, wherein the isocyanate is an aromatic isocyanate, an aliphatic isocyanate, an alicyclic isocyanate, and combinations thereof.

10. The method according to any one of claims 7 to 9, wherein the aromatic isocyanate is more preferably selected from the group consisting of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, urethane-modified liquid 4,4'-diphenylmethane diisocyanate and / or 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanato-1,2-diphenylethane, 1,5-naphthalene diisocyanate, and combinations thereof.

11. The method according to any one of claims 7 to 10, wherein the aromatic isocyanate is most preferably 4,4'-diphenylmethane diisocyanate (4,4'-MDI).

12. The method according to any one of claims 7 to 11, wherein the aliphatic isocyanate is more preferably selected from the group consisting of 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, and combinations thereof.

13. The method according to any one of claims 7 to 12, wherein the aliphatic isocyanate is most preferably 1,6 - hexamethylene diisocyanate (HDI).

14. The method according to any one of claims 7 to 13, wherein the cycloaliphatic isocyanate is selected from the group consisting of isophorone diisocyanate, 1,4 - cyclohexane diisocyanate, 1 - methyl - 2,4 - cyclohexane diisocyanate, 1 - methyl - 2,6 - cyclohexane diisocyanate and their corresponding isomer mixtures, 4,4'-dicyclohexylmethane diisocyanate, 2,4 - dicyclohexylmethane diisocyanate and 2,2'-dicyclohexylmethane diisocyanate and their corresponding isomer mixtures, and combinations thereof.

15. The method according to any one of claims 7 to 14, wherein the alicyclic isocyanate is 4,4'-dicyclohexylmethane diisocyanate (H 12 MDI).

16. The method according to any one of claims 7 to 15, wherein the chain extender is selected from ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, or mixtures thereof; more preferably, the chain extender is butylene glycol, hexylene glycol, cyclohexanedimethanol (CHDM), hydroquinone bis(2 - hydroxyethyl) ether (HQEE), or mixtures thereof.

17. The method according to any one of claims 1 to 16, wherein the article is a shoe.

18. The method according to any one of claims 1 to 17, wherein one component is a midsole, more preferably a midsole comprising polyurethane, thermoplastic polyurethane, polyurethane foam, expanded polyurethane, expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads, or mixtures thereof.

19. The method according to any one of claims 1 to 18, wherein one component comprises a material selected from the group consisting of rubber, natural leather, synthetic leather, polyurethane, thermoplastic polyurethane, styrene - butadiene rubber, vinyl acetate, polyamide, polyvinyl chloride, polystyrene, acrylonitrile - butadiene - styrene, polyethylene terephthalate, polybutylene terephthalate, textiles, fabrics, thermoplastic polyurethane knitted fibers, or combinations thereof.

20. An article derived from the method according to any one of claims 1 to 19.

21. The method according to any one of claims 1 to 19, wherein the article is separated into its components by using heat.

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