Composition and thermosettable adhesive film obtained thereof

Abstract

The invention relates to a composition and a heat-curable adhesive film obtained from the same. The heat-curable adhesive film can be activated at a low temperature (less than 100 DEG C, preferably 60 to 80 DEG C), is capable of self-supporting, and exhibits excellent adhesive strength after curing.

Description

Technical Field

[0001] This invention relates to a composition and a thermosetting adhesive film obtained therefrom. Specifically, the thermosetting adhesive film can be activated at low temperatures (below 100°C, preferably 60°C to 80°C), is self-supporting, and exhibits excellent adhesive strength after curing. Background Technology

[0002] Thermosetting adhesive films are widely used in the manufacture of films for substrate assembly. The term "thermosetting" (or "thermally activated") refers to a composition with latent adhesive properties, which are activated only after being heated to a specific temperature. Such thermosetting compositions offer several advantages over solvent-based adhesives, such as ease and speed of use, which require solvent evaporation. In the manufacturing process, the thermosetting adhesive film is placed between the surfaces of the substrates to be assembled, maintaining contact with the substrates, while the assembly is heated to activate the adhesive composition. The heating time can vary depending on the substrate thickness but should not be excessive to avoid thermal deformation of the substrate. After cooling, an adhesive layer with a certain bond strength is obtained for substrate assembly.

[0003] Currently, all publicly available or commercially available thermosetting adhesive films are based on polyols and NCO-terminated isocyanates. It has been observed that the activation temperature of these adhesives is very high (above 160°C). To fully utilize their adhesive properties, they must be heated to such a high temperature. Otherwise, their adhesive properties will be insufficient to provide effective adhesion to the substrate. However, some substrates, such as polyolefins and polypropylene, will degrade if heated above 160°C. Sometimes, the cured adhesive film exhibits insufficient adhesive strength.

[0004] In view of the above, there is a need for a thermosetting adhesive film that can be activated at low temperatures (below 100°C, preferably 60°C to 80°C), is self-supporting, and exhibits exceptional adhesive strength after curing. Summary of the Invention

[0005] According to a first aspect of the present invention, a composition comprising:

[0006] (A) At least one thermoplastic polymer having a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimum activation temperature of not more than 100 °C.

[0007] (B) At least one polyester polyol with a weight-average molecular weight (Mw) of less than 10,000 g / mol.

[0008] (C) At least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule, and

[0009] (D) At least one organic solvent, wherein the organic solvent is present in an amount greater than 36% to 95% based on the total weight of the composition.

[0010] According to a second aspect of the invention, a method for preparing a thermosetting adhesive film obtained from the composition of the invention is provided herein.

[0011] According to a third aspect of the invention, a thermosetting adhesive film obtained from the composition of the invention is provided herein.

[0012] According to a fourth aspect of the present invention, an article is provided comprising a first substrate, a second substrate, and a thermosetting adhesive film according to the present invention disposed between the first substrate and the second substrate.

[0013] According to a fifth aspect of the invention, this document provides the use of compositions according to the invention or thermosetting adhesive films or thermosetting adhesive film articles according to the invention in the manufacture of automotive parts, truck body covers, textile laminates, assembled goods and electronic devices.

[0014] The following section will elaborate on other features and aspects of this topic in more detail. Invention Details

[0016] Those skilled in the art will understand that this invention is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the invention. Unless otherwise expressly stated, each aspect described may be combined with any other one or more aspects. Specifically, any feature indicated as preferred or advantageous may be combined with any other feature indicated as preferred or advantageous.

[0017] Unless otherwise stated, the terminology used in the context of this invention shall be interpreted according to the following definitions.

[0018] Unless otherwise stated, the terms “a,” “an,” and “the” as used herein include both singular and plural references.

[0019] The term “comprising” as used herein is synonymous with “including” or “containing” and is inclusive or open-ended, and does not exclude additional, unlisted members, elements or process steps.

[0020] The terms “at least one” or “one or more” used in this document to define components refer to the type of component, not the absolute number of molecules. For example, “one or more polyols” refers to a single polyol or a mixture of several different polyols.

[0021] The term "thermally curable" (or "thermally activated") refers to an adhesive film having latent adhesive properties that are only activated when the film is heated to a specific temperature ("activation temperature"). It is during the thermal activation phase that the film exhibits its adhesive properties.

[0022] The term "adhesive film" refers to an adhesive in the form of a film.

[0023] The term "polyurethane" refers to polyurethane and polyurethanes containing urea groups in their main chain.

[0024] As used herein, the term "room temperature" refers to a temperature of about 20°C to about 25°C, preferably about 25°C.

[0025] Unless otherwise stated, the representation of numerical endpoints includes all numbers and fractions contained in the corresponding range, as well as the endpoints represented.

[0026] All references cited in this specification are incorporated herein by reference in their entirety.

[0027] Unless otherwise specified, all molecular weights are number average molecular weights (Mn). All molecular weight data were determined by gel permeation chromatography (GPC) unless otherwise specified, for example, according to DIN 55672.

[0028] The softening point mentioned in this article was determined using the ring and ball method according to DIN ISO 4625.

[0029] Unless otherwise defined, all terms used in this invention, including technical and scientific terms, shall have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] In one aspect, this disclosure generally relates to a composition comprising:

[0031] (A) At least one thermoplastic polymer having a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimum activation temperature of not more than 100 °C.

[0032] (B) At least one polyester polyol with a weight-average molecular weight (Mw) of less than 10,000 g / mol.

[0033] (C) At least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule, and

[0034] (D) At least one organic solvent, wherein the organic solvent is present in an amount greater than 36% to 95% based on the total weight of the composition.

[0035] (A) Thermoplastic polymers

[0036] According to the present invention, the composition comprises (A) at least one thermoplastic polymer having a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100°C.

[0037] The thermoplastic polymer (A) provides a framework for the thermosetting adhesive film obtained from the composition. Without the thermoplastic polymer (A), the thermosetting adhesive film obtained from the composition cannot achieve self-supporting adhesive film.

[0038] Thermoplastic polymers differ from thermosetting polymers. Thermosetting polymers harden by crosslinking or curing when heated and / or by a suitable curing agent, while thermoplastic polymers are flexible at elevated temperatures and harden upon cooling.

[0039] The term "optimal activation temperature" as used herein refers to the temperature range (or point) at which physical coalescence occurs within a thermoplastic polymer, at which the polymer exhibits satisfactory strength and the proportion of non-coalescing is less than 10%. The optimal activation temperature of the thermoplastic polymers described herein can be determined according to EN 12961:2001.

[0040] In a preferred embodiment, the optimal activation temperature of component (A) is below 85°C, preferably 30°C to below 80°C, more preferably 30°C to below 70°C, and even more preferably 30°C to below 60°C. Within this preferred range, the thermosetting adhesive film obtained from this composition is self-supporting and exhibits a certain adhesive strength after curing.

[0041] Typically, the thermoplastic polymers described herein are not chemically reactive, but they coalesce upon heating, thereby forming a flexible state with a certain degree of adhesion. In some embodiments, the thermoplastic polymer may contain hydroxyl groups that can react with component (C).

[0042] This invention can use a variety of known thermoplastic polymers, provided that their molecular weight and optimal activation temperature meet the requirements. The thermoplastic polymers applicable in this invention can be selected from thermoplastic polyurethane polymers, polyester polymers, acrylic polymers, ethylene-vinyl acetate copolymers, styrene block copolymers, polyvinyl acetone alcohols, styrene-acrylonitrile, polyolefins, polyacrylonitrile, ethylene-vinyl acetate terpolymers, functionalized ethylene-vinyl acetate, ethylene-acrylate copolymers, ethylene-acrylate terpolymers, ethylene-butadiene copolymers, and / or block copolymers, preferably selected from thermoplastic polyurethane polymers, polyester polymers, acrylic polymers, styrene block copolymers, and combinations thereof.

[0043] The thermoplastic polyurethane polymer used as component (A) has a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100 °C. It can be obtained by ring-opening polymerization of lactones (e.g., ε-caprolactone) or by reaction of polyester polyols and / or polyether polyols with diisocyanates. It can also be optionally obtained by further reaction of these components with chain extenders (e.g., low molecular weight polyols, preferably diols) or by further reaction with diamines to form urea bonds.

[0044] Examples of polyester polyols used in the preparation of thermoplastic polyurethane polymers include polyester polyols derived from linear dicarboxylic acids, dicarboxylic acid derivatives (e.g., acid anhydrides, esters, and acyl chlorides), aliphatic polyols, alicyclic polyols, linear polyols, branched polyols, and combinations thereof. Examples of dicarboxylic acids that can be used in the preparation of polyester polyols include adipic acid, succinic acid, sebacic acid, dodecanoic acid, phthalic acid, isophthalic acid, terephthalic acid, phthalic anhydride, and combinations thereof. Examples of aliphatic diols that can be used in the preparation of polyester polyols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentanediol, and combinations thereof.

[0045] Examples of useful polyether polyols for preparing thermoplastic polyurethane polymers can be obtained by polymerization of cyclic oxides (e.g., ethylene oxide, propylene oxide, butane oxide, and tetrahydrofuran) or by addition of one or more such oxides to a multifunctional initiator having at least two active hydrogens, such as water, polyols (e.g., ethylene glycol, propylene glycol, diethylene glycol, cyclohexanediol, glycerol, trimethylolpropane, pentaerythritol, and bisphenol A), ethylenediamine, propylenediamine, triethanolamine, and 1,2-propanedithiol.

[0046] Available thermoplastic polyurethane polymers (A) typically consist of soft segments (e.g., polyether or polyester polyols) and hard segments (typically obtained by reacting low molecular weight diols with diisocyanates). Commercially available thermoplastic polyurethane polymers used as component (A) include, but are not limited to, the Pearlstick series, such as 5707, 5703, 5701, 5714, 5713, 5715, 45-40 / 05TPU, 45-40 / 11STPU, 45-40 / 27TPU and 45-60 / 08 from Lubrizol, HF-4003LH, 3003EH series, HF-3H, 6H series from Huafeng Chemicals, and WHT-61, 63, 64, 65, 67 series from Wanhua Chemicals.

[0047] The polyester polymer used as component (A) has a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100 °C. It can be obtained by polycondensation of at least one polyester glycol and at least one dicarboxylic acid or its ester or anhydride derivative, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol (1,4-butanediol; 1,2-butanediol; 1,3-butanediol), neopentyl glycol, 2-methyl-1,3-propanediol, or hexamethylene glycol. Propylene glycol (propane-1,2-diol, propane-1,3-diol, or propylene glycol), trimethylolpropane, cyclohexanediol, or combinations thereof; one of the at least one dicarboxylic acid or its ester or anhydride derivative, such as terephthalic acid, dimethyl terephthalate, isophthalic acid, adipic acid, azelaic acid, sebacic acid, cyclohexanedicarboxylic acid, dodecanoic acid (1,10-decanedicarboxylic acid), succinic acid, phthalic anhydride, maleic anhydride, and hydroxycarboxylic acids, such as diesters obtained from polycaprolactone or ε-caprolactone and diethylene glycol, or combinations thereof. Commercially available polyester polymers used as component (A) include, but are not limited to, BX1001 manufactured by TOYOBO, CAPA from Perstorp. TM 6800, 6500, 6400, Daicel's PLACEL H series and Hunan Juren Chemical's PCL65000 and PCL68000.

[0048] Acrylic polymers used as component (A) with a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100°C can be obtained by polymerization of ester monomers of acrylic acid and methacrylic acid. Exemplary monomers available for use in the synthesis of component (A) include soft monomers such as ethyl acrylate, 2-ethylhexyl acrylate, and n-butyl acrylate, and hard monomers such as methyl methacrylate and isobutyl acrylate. Exemplary acrylic polymers used as component (A) include polymethyl methacrylate, n-butyl acrylate-based block copolymers, n-butyl acrylate / 2-ethylhexyl acrylate-based block copolymers, and combinations thereof. Acrylic block polymers obtained from soft monomers and hard monomers are preferred. Commercially available acrylic polymers used as component (A) include, but are not limited to, those manufactured by SANYO under the trade name Kuraray. TM LA2140, such as n-butyl acrylate-methyl methacrylate copolymer.

[0049] Styrene block copolymers used as component (A) with a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100 °C include aromatic vinyl polymer blocks and saturated mesoblocks, preferably hydrogenated conjugated diene polymer blocks, or unsaturated mesoblocks. The blocks can be arranged in various configurations, such as linear, branched, radial, star-shaped, and combinations thereof. The aromatic vinyl polymer blocks can be derived from a variety of aromatic vinyl compounds, including, for example, styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, tert-butylstyrene-2,4,6-trimethylstyrene, monofluorostyrene, difluorostyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, 1,3-vinylnaphthalene, vinylanthracene, indene, acenaphthene, and combinations thereof. Hydrogenated diene polymer blocks can be derived from a variety of diene-containing compounds, including, for example, isoprene, butadiene, hexadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and combinations thereof. Styrene block copolymers containing saturated mezzanine blocks that can be used as component (A) include, for example, triblock, multi-arm, and star copolymers, including, for example, styrene-ethylene / butene-styrene (SEBS), styrene-ethylene / propylene-styrene (SEPS), styrene-ethylene-ethylene / propylene-styrene (SEEPS), styrene / isobutylene / styrene (SIBS), and combinations thereof. Styrene block copolymers containing unsaturated mezzanine blocks that can be used as component (A) include styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), styrene-butadiene-isobutylene-styrene (SBBS), styrene-isoprene-butadiene-styrene (SIBS), and combinations thereof. Commercially available styrene block copolymers used as component (A) include, but are not limited to, HYBRAR from Kuraray. TM 5125 and 7311.

[0050] The ethylene-vinyl acetate copolymer used as component (A) having a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100°C is a copolymer derived from at least one ethylene monomer and at least one vinyl acetate monomer. From the perspective of the strength and flexibility of the adhesive film obtained from this composition, the vinyl acetate content of the ethylene-vinyl acetate copolymer used as component (A) is preferably 65% ​​by mass or higher. Commercially available ethylene-vinyl acetate copolymers used as component (A) include, but are not limited to, Levamelt from ARLANXEO. TM 686 (68wt% vinyl acetate), KBE-68A and KBE-68B produced by Kuraray Co., Ltd., etc.

[0051] Other useful thermoplastic polymers with a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100 °C include, but are not limited to, polyvinyl acetols, styrene-acrylonitrile, polyolefins, polyacrylonitrile, ethylene-vinyl acetate terpolymers, functionalized ethylene-vinyl acetate, ethylene-acrylate copolymers, ethylene-acrylate terpolymers, ethylene-butadiene copolymers and / or block copolymers, and combinations thereof.

[0052] The above-mentioned thermoplastic polymers may be used alone or in combination of two or more. If at least two thermoplastic polymers are used as component (A), the molecular weight and optimal activation temperature of each thermoplastic polymer should fall within the required range.

[0053] In a preferred embodiment, the number average molecular weight of the thermoplastic polymer is 10,000 to 200,000 g / mol, preferably 8,000 to 150,000 g / mol, and more preferably 20,000 to 100,000 g / mol.

[0054] Particularly preferably, based on the total weight of the composition, the content of component (A) can be from 1% by weight to 95% by weight, preferably from 10% by weight to 40% by weight.

[0055] (B) Polyester polyols

[0056] According to the present invention, the composition comprises at least one polyester polyol with a weight-average molecular weight (Mw) of less than 10,000 g / mol, which can react with the following component (C) under heating to form an effective adhesive.

[0057] The useful component (B) in this invention includes those that have at least two hydroxyl groups in a molecule, such as three or four hydroxyl groups, and have one or more aromatic groups in the molecule, preferably having a hydroxyl value of not less than 10 mg KOH / g, preferably greater than or equal to 15 mg KOH / g, more preferably in the range of 20 to 90 mg KOH / g, and even more preferably in the range of 30 to 60 mg KOH / g.

[0058] The component (B) used in this invention is preferably a solid at room temperature (20°C). In some embodiments, from the perspective of solubility in organic solvents, component (B) may be selected from amorphous polyester polyols, semi-crystalline polyester polyols, crystalline polyester polyols, and combinations thereof, preferably amorphous polyester polyols, semi-crystalline polyester polyols, and combinations thereof.

[0059] As used herein, the term "amorphous polyester polyol" refers to a polyester polyol that exhibits no melt transition when measured using differential scanning calorimetry (DSC) and does not possess a crystalline form. Its crystallinity (by weight percentage) is preferably less than 10%, more preferably less than 5%, advantageously less than 2%, and even more advantageously less than 1%.

[0060] The term "semi-crystalline polyester polyol" refers to a polyester polyol whose structure includes crystalline and amorphous regions. Its crystallinity (by weight percentage) is preferably at least 20% to less than 80%, preferably at least 30% to less than 80%, and most preferably at least 40% to less than 80%.

[0061] As used herein, the term "crystalline polyester polyol" refers to a polyester polyol exhibiting a melt transition when measured using differential scanning calorimetry (DSC) and having a crystalline form. Its crystallinity (by weight percentage) is preferably at least 80%, more preferably at least 90%.

[0062] Crystallinity represents the proportion of a substance in a crystalline state and can be determined by X-ray diffraction analysis at different incident angles, calorimetry (e.g., DSC (differential scanning calorimetry)), or any other technique that can estimate the proportion of crystalline phases in a semi-crystalline polyester polyol.

[0063] The amorphous polyester polyol used as component (B) in this invention comprises the reaction product of a polyacid component (e.g., polyacid, polyacid anhydride, polyacid ester, and polyacrylamide halide) and a stoichiometric excess of polyol. At least one of the polyacid component and the polyol contains an aromatic group. Suitable polyacids include, for example, diacids (e.g., dicarboxylic acids), tricarboxylic acids (e.g., tricarboxylic acids), and higher acids, examples of which include aromatic dicarboxylic acids, their anhydrides, and their esters (e.g., terephthalic acid, isophthalic acid, dimethyl terephthalate, diethyl terephthalate, phthalic acid, phthalic anhydride, methyl hexahydrophthalic acid, methyl hexahydrophthalic anhydride, methyl tetrahydrophthalic acid, methyl tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic acid, hexahydrophthalic acid, hexahydrophthalic anhydride). Acid anhydrides and tetrahydrophthalic acid), aliphatic dicarboxylic acids and their anhydrides (e.g., maleic acid, maleic anhydride, succinic acid, succinic anhydride, glutaric acid, glutaric anhydride, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, chlorobacteric acid, 1,2,4-butanediic acid, decanoic acid, octadecanoic acid, dimer acid, dimer fatty acid, trimer fatty acid, fumaric acid), alicyclic dicarboxylic acids (e.g., 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid), and mixtures thereof. Examples of suitable polyols include aliphatic polyols such as ethylene glycol, propylene glycol (e.g., 1,2-propanediol and 1,3-propanediol), butanediol (e.g., 1,3-butanediol, 1,4-butanediol and 1,2-butanediol), 1,3-butenediol, 1,4-butynediol, pentanediol (e.g., 1,5-pentanediol), pentenediol, pentynediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, neopentanediol, and dioxanediol. Glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol (e.g., dipropylene glycol and tripropylene glycol), 1,4-cyclohexanediol, 1,4-cyclohexanediol, dimerized glycol, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, glycerol, tetramethylene glycol, polytetramethylene glycol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, trimethylolpropane, pentaerythritol, sorbitol, glucose, and combinations thereof.

[0064] Specific examples of available amorphous polyester polyols include poly(hexanediol phthalate) polyol, poly(neopentyl glycol adipate) polyol, poly(neopentyl glycol phthalate) polyol, poly(neopentyl glycol hexanediol phthalate) polyol, poly(diethylene glycol phthalate) polyol, poly(ethylene glycol adipate terephthalate) polyol, polyethylene terephthalate polyol, ethylene glycol, hexanediol, neopentyl glycol, adipic acid and terephthalic acid random copolymer diols, and combinations thereof.

[0065] When using solid amorphous polyester polyols, from the viewpoint of obtaining good adhesive strength upon complete curing and easy dissolution in the composition, the softening point is preferably not greater than 130°C, more preferably not greater than 120°C, and even more preferably not greater than 105°C, for example 60°C, 80°C, or 100°C.

[0066] The crystalline polyester polyols suitable for use as component (B) in this invention can be obtained by ring-opening polymerization of lactones (e.g., ε-caprolactone) and / or derived from diols and diacids. Examples of diols used to prepare preferred polyester polyols include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and combinations thereof. Examples of diacids used to prepare preferred polyester polyols include succinic acid, glutaric acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, 1,12-dodecanoic acid, dimer acids, and combinations thereof. Within the scope of applicable diacids, various diacid derivatives are included, such as carboxylic acid esters (especially methyl and ethyl esters), acyl halides (e.g., acyl chlorides), and acid anhydrides, and combinations thereof.

[0067] Specific examples of suitable crystalline polyester polyols include poly(hexanediol adipate) polyol, poly(butanediol adipate) polyol, poly(ε-caprolactone) polyol, poly(hexanediol dodecanoate) polyol, poly(hexanediol terephthalate adipate) polyol, and combinations thereof.

[0068] The aforementioned polyester polyols may be used alone or in combination of two or more. If at least two polyester polyols are used in the composition, the weight-average molecular weight of each polyester polyol should fall within the required range.

[0069] Suitable commercially available polyester polyols (B) include FZPE-A03130 from Guangzhou FTRT Chemical Co., Ltd., DYNACOLL 7110, 7130, 7140 and 7150 from Evonik Industries AG, and FLP PA-1000N from Xuchuan Chemical (Suzhou) Co., Ltd.

[0070] Particularly preferably, the amount of component (B) may be from 0.01% to 80%, preferably from 5% to 40%, based on the total weight of the composition.

[0071] (C) Polyisocyanates

[0072] According to the present invention, the composition comprises (C) at least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule.

[0073] The useful polyisocyanate (C) usable according to the present invention corresponds to the following formula (I):

[0074]

[0075] in:

[0076] -R is a divalent group containing 6 to 13 carbon atoms, and

[0077] -n is an integer between 0 and 10.

[0078] Preferably, R is a divalent aromatic or polyaromatic group, more preferably generated from an aromatic diisocyanate such as toluene diisocyanate (TDI) or diphenylmethane diisocyanate (MDI).

[0079] Examples of polyisocyanates (C) that can be used according to the present invention correspond to one of the following formulas (I-1) or (I-2):

[0080]

[0081] Preferably, the polyisocyanate (C) usable according to the present invention has an NCO content of 15% to 40% by weight, more preferably 20% to 35% by weight, relative to the weight of the polyisocyanate (expressed as %NCO).

[0082] Preferably, the NCO / OH molar ratio in the composition is from 0.1 to 8. The isocyanate groups are provided by component (C) in the composition of the present invention, and the hydroxyl groups are provided by a small amount of hydroxyl groups (if present) in component (A) and component (B). Under the condition that the above molar ratio is satisfied, the weight percentages of the polyester polyol (B) and the polyisocyanate (C) are not particularly limited.

[0083] The suitable commercially available polyisocyanate (C) is Grilbond, sold by EMS-Griltech. TM A2bond (MDI diuretic), Addolink sold by Rhein Chemie TM TT (TDI ureadione).

[0084] Particularly preferably, the amount of component (C) is from 0.05% to 20% by weight, preferably from 0.5% to 5% by weight, based on the total weight of the composition.

[0085] (D) Organic solvents

[0086] According to the present invention, the composition comprises (D) at least one organic solvent, wherein the content of the organic solvent is greater than 36% to 95% by weight, preferably 50% to 85% by weight, based on the total weight of the composition.

[0087] The organic solvent (D) that can be used according to the invention preferably makes components (A) and (B), as well as other optional components or additives, soluble in the organic solvent (D) to form a mixture, and component (C) is uniformly dispersed in the mixture.

[0088] Preferably, the organic solvent (D) has a content of 6.9 to 10.0 (cal / cm³). 3 ) 1 / 2 The solubility parameter delta (δ) (also known as the Hildebrand solubility parameter, HSP) and the hydrogen bonding index (HBI) from 5.0 to 7.7, gamma (γ). These parameters are defined in the literature in a well-known manner, for example in sections 38 and 39 of patent application US 2004 / 0204524: - The solubility parameter delta is defined as follows: Lexikon Lacke and Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, “Solubility parameters”, pp. 361-365; - The hydrogen bonding index describes the ability of solvent molecules to form hydrogen bonds. Donor solvents have negative hydrogen bonding indices, while acceptor solvents have positive hydrogen bonding indices. The hydrogen bonding index is determined based on the deviation from the infrared band for the RO-H stretching band (RCNelson, RWHemwall and G.D. Edwards, Journal of Paint Technology, “Treatment of hydrogen bonding inpredicting miscibility”, Vol. 42, No. 550, 1970, pp. 636-643).

[0089] Preferably, the organic solvent (D) is selected from ketones, more preferably aliphatic ketones, and more preferably from acetone, methyl ethyl ketone (MEK), 2-pentanone, 3-pentane, methyl isobutyl ketone, ethyl acetate, and combinations thereof.

[0090] Preferably, the boiling point of the organic solvent (D) is lower than the optimal activation temperature of the thermoplastic polymer (A) to ensure that the organic solvent can be evaporated without activating the thermoplastic polymer (A) to form a heat-curable adhesive film, for example, less than 100°C, more preferably less than 80°C.

[0091] The above component (D) can be used alone or in combination of two or more.

[0092] Composition

[0093] Furthermore, the compositions according to the invention may contain or not contain at least one optional component selected from polyols such as polyether polyols, silanes, pigments such as carbon black, defoamers, leveling agents, stabilizers (antioxidants, UV stabilizers, heat stabilizers), catalysts, dyes, and mixtures thereof, other than component (B), as long as the advantageous properties of the compositions of the invention are not altered.

[0094] The compositions according to the invention may also contain 1% to 10% by weight of at least one optional additive as defined above.

[0095] In a particularly preferred embodiment, the composition comprises:

[0096] (A) 1% to 95% by weight, preferably 10% to 40% by weight, of at least one thermoplastic polymer having a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100°C, preferably below 85°C, more preferably 30°C to below 80°C, more preferably 30°C to below 70°C, and even more preferably 30°C to below 60°C.

[0097] (B) 0.01% to 80% by weight, preferably 5% to 40% by weight, of at least one polyester polyol with a weight-average molecular weight (Mw) of less than 10,000 g / mol.

[0098] (C) 0.05% to 20% by weight, preferably 0.5% to 5% by weight, of at least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule, and

[0099] (D) More than 36% to 95% by weight, preferably 50% to 85% by weight, of at least one organic solvent;

[0100] Based on the total weight of the composition.

[0101] Thermocurable adhesive film and its preparation method

[0102] According to a second aspect of the present invention, the present invention relates to a method for preparing a thermosetting adhesive film obtained from the above composition, comprising the following steps:

[0103] 1) The composition of the present invention is prepared by dispersing component (C) in a mixture comprising at least one component (A), at least one component (B), at least one component (D) and optionally present components or additives, each component as defined above;

[0104] Optionally 1a) the composition obtained in step 1) is applied to the separable liner; and

[0105] 2) Remove component (D) from the composition obtained in step 1) or 1a).

[0106] In step 1), component (A), component (B) and optionally present components or additives are dissolved in an organic solvent (D), preferably under heating conditions, for example at a temperature less than or equal to 75°C, preferably less than or equal to 65°C, and then component (C) is added, stirred rapidly, and then component (C) is added at room temperature to obtain a homogeneous mixture or homogeneous dispersion.

[0107] In some embodiments, the separable liner used in step 1a) has a non-stick surface on which the composition can be coated. Specifically, the composition is applied in a uniform layer to the non-stick surface of the separable liner, such as a silicone-treated surface. The application can be performed using a coating machine or a bar coater. After completing steps 1), 1a), and 2), a single-layer thermosetting adhesive film is advantageously obtained.

[0108] There are no particular limitations on the equipment used for mixing, stirring, and dispersing in this process. Automatic mortars equipped with stirrers and heaters, Henschel mixers, three-roll mills, ball mills, planetary mixers, bead mills, etc., can be used. Appropriate combinations of these devices can also be used. There are no particular limitations on the method of preparing this composition, as long as the above components can be mixed uniformly.

[0109] According to a third aspect, the present invention relates to a thermosetting adhesive film obtained by the method of the present invention.

[0110] According to the present invention, the thermosetting adhesive film comprises:

[0111] (A) 1% to 95% by weight, preferably 30% to 90% by weight, of at least one thermoplastic polymer having a molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature not higher than 100°C, preferably below 85°C, more preferably 30°C to below 80°C, more preferably 30°C to below 70°C, and even more preferably 30°C to below 60°C.

[0112] (B) 0.01% to 80% by weight, preferably 10% to 50% by weight, of at least one polyester polyol with a molecular weight (Mw) of less than 10,000 g / mol.

[0113] (C) 0.1% to 20% by weight, preferably 1% to 10% by weight, of at least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule, and

[0114] (D) less than 2.0% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight of at least one organic solvent;

[0115] All of the above are based on the total weight of the thermosetting adhesive film.

[0116] The thermosetting adhesive film according to the invention may also contain at least one optional component as defined above.

[0117] The thermosetting adhesive film according to the present invention has self-supporting properties. The term "self-supporting adhesive film" refers to an adhesive film that maintains its integrity even without any substrate. In the context of this invention, "pads" or "separable pads" are not considered substrates.

[0118] The thermosetting adhesive film according to the present invention preferably has a total thickness of 3 μm to 500 μm.

[0119] The thermosetting adhesive film according to the invention preferably exhibits an ejection strength of at least 3 MPa, more preferably at least 3.5 MPa.

[0120] The thermosetting adhesive film of this invention is ready to use and can be rapidly crosslinked on or between substrates, unlike solvent-based adhesive compositions, which must be dried before crosslinking. It has been observed that for a 100 μm thick thermosetting adhesive film of this invention, the crosslinking time is approximately 10 minutes at 80°C.

[0121] Products

[0122] According to the fourth aspect, this article provides an article of manufacture comprising:

[0123] First substrate,

[0124] Second substrate, and

[0125] The thermocurable adhesive film of the present invention is disposed between the first substrate and the second substrate.

[0126] In another embodiment, the article includes a first substrate, a second substrate, and a thermosetting adhesive film of the present invention disposed between the two substrates and in direct contact with the two substrates.

[0127] The first substrate and / or the second substrate may be a single material and a single layer, or may include multiple layers of the same or different materials. These layers may be continuous or discontinuous.

[0128] The substrate of the article described herein may have a variety of properties, including rigidity (e.g., a rigid substrate, i.e., a substrate that cannot be bent by a person's hands, or a substrate that will break if one attempts to bend it by hands), flexibility (e.g., a flexible substrate, i.e., a substrate that can be bent with a force no greater than that of two hands), porosity, conductivity, non-conductivity, and combinations thereof.

[0129] The substrate of the article can take many forms, including, for example, fibers, threads, yarns, woven fabrics, nonwoven fabrics, films (e.g., polymer films, metallized polymer films, continuous films, discontinuous films, and combinations thereof), foils (e.g., metal foils), sheets (e.g., metal sheets, polymer sheets, continuous sheets, discontinuous sheets, and combinations thereof), and combinations thereof.

[0130] In a preferred embodiment, at least one of the substrates may be selected from metals, such as metal sintering slurries, anode aluminum, tin, molybdenum, and silver; conductive metal oxides, such as indium tin oxide (ITO), fluorine-doped tin oxide, and aluminum-doped zinc oxide; glass, such as ink-coated glass and bare glass; and resins, such as polycarbonate, polybutylene terephthalate, and polyamide. Other suitable metals include copper, gold, palladium, platinum, aluminum, indium, silver-plated copper, silver-plated aluminum, tin, and tin-plated copper. Preferably, both substrates are selected from one of the above materials.

[0131] According to an alternative form of this preferred embodiment, the article may be a multilayer article obtained by laminating multiple substrates using a thermosetting adhesive film according to the invention.

[0132] For single-layer products, the film thickness is preferably 3 μm to 500 μm. For multi-layer products, the film thickness is preferably 10 μm to 1000 μm.

[0133] In one embodiment, an article having a first substrate and a second substrate is prepared by the following steps: contacting the first substrate with a first primary surface of one of the thermosetting adhesive films, contacting the second substrate with a second primary surface of the film such that the second primary surface of the film is in direct contact with the second substrate to form an article, and applying heat and optional pressure below 100°C (preferably 60°C to 80°C) to the article to cure the adhesive film such that the two substrates are bonded together.

[0134] In another embodiment, an article having a first substrate and a second substrate is prepared by the following steps: contacting the first substrate with a first primary surface of one of the thermosetting adhesive films, and applying heat of 40°C to 60°C to the adhesive film before or after applying the adhesive film to the first substrate to form a pre-laminated sheet, which can be stored and transported to other locations. During the pre-lamination process, partial agglomeration may occur in the thermoplastic polymer (A) before the composition has begun to cure or crosslink. After preparation, the pre-laminated sheet is used to manufacture the final article by contacting the second substrate with a second primary surface of the adhesive film, so that the second primary surface of the adhesive film is in direct contact with the second substrate to form the article, and then applying heat below 100°C (preferably 60°C to 80°C) and optionally applying pressure to the article (e.g., membrane pressure or airbag pressure, heated platen) to cure the adhesive film, such that the two substrates are bonded together by the adhesive film.

[0135] The composition can be applied to the substrate using any suitable application method, including, for example, automatic fine-line dispensing, jet dispensing, slot die coating, roller coating, gravure coating, transfer coating, pattern coating, screen printing, spraying, filament coating, by extrusion, air knife, drag blade, brush coating, dip coating, doctor blade, offset gravure coating, rotary gravure coating, and combinations thereof. The composition can be applied in the form of continuous or discontinuous coatings, single or multiple layers, and combinations thereof.

[0136] Understandably, the time and temperature curing profiles of each thermosetting adhesive film will differ, and different compositions can be designed to provide curing profiles suitable for specific industrial manufacturing processes.

[0137] use

[0138] According to a fifth aspect of the invention, this document provides the use of compositions according to the invention, thermosetting adhesive films according to the invention, or articles according to the invention in the manufacture of automotive parts, truck body covers, textile laminates, assembled goods, and electronic devices.

[0139] Thermosetting adhesive films can be used in a variety of applications, including, for example: temporary bonding of at least one substrate, permanent bonding of at least one or two substrates, protection of substrates, inhibition or prevention of movement of a first substrate relative to a second substrate, and combinations thereof. Thermosetting adhesive films can also be used in a variety of processes, including, for example: manufacturing processes (e.g., bonding two parts of an article together and maintaining a fixed relationship between the two parts during manufacturing), transportation processes, stacking processes, and combinations thereof.

[0140] Thermosetting adhesive films can be used to manufacture a variety of products, including, for example, automotive parts, truck bed covers, textile laminates, various assembled goods, and electronic devices.

[0141] Suitable electronic devices include, but are not limited to, wearable electronic devices (e.g., watches and glasses), handheld electronic devices (e.g., telephones (e.g., cellular phones and cellular smartphones), cameras, tablets, e-readers, monitors (e.g., monitors for use in hospitals and by healthcare workers, athletes, and individuals), watches, calculators, mice, touchpads, and joysticks), computers (e.g., desktop computers and laptops), computer monitors, televisions, media players, or other electronic components. Example

[0142] The following examples are intended to help those skilled in the art better understand and practice the present invention. The scope of the invention is not limited by the examples, but is defined by the appended claims. Unless otherwise stated, all parts and percentages are based on weight.

[0143] raw material:

[0144] Vitel TM 3300 is a thermoplastic polyester polymer with a weight-average molecular weight (Mw) of 63,000 g / mol and an optimal activation temperature of 125 °C. It is available from Bostik.

[0145] KURARITY TM LA4285 is a thermoplastic acrylic block copolymer with a weight-average molecular weight (Mw) of 40,000 g / mol and an optimal activation temperature of 140°C to 160°C. It is available from Kuraray.

[0146] HF4003LH-5 is a thermoplastic polyurethane polymer with a molecular weight (Mw) of 80,000 g / mol and an optimal activation temperature of 110°C to 130°C. It is available from Huafeng Chemical.

[0147] VYLON BX1001 is a thermoplastic polyester polymer with a weight-average molecular weight (Mw) of 28,000 g / mol and an optimal activation temperature of 82°C. It is available from TOYOBO.

[0148] Pearlstick TM 45-60 / 08 is a thermoplastic polyurethane polymer with a molecular weight (Mw) of 60,000 g / mol and an optimal activation temperature of 40 to 70 °C, which is derived from Lubrizol.

[0149] WH6190A is a thermoplastic polyurethane polymer with a weight-average molecular weight (Mw) of 50,000 g / mol and an optimal activation temperature of 55°C. It is available from Wanhua Chemical.

[0150] P60 / 64 is a thermoplastic polyurethane polymer with a weight-average molecular weight (Mw) of 60,000 g / mol and an optimal activation temperature of 50 °C. It is available from GUANGZHOU FTRT CHEMICAL CO.,LTD.

[0151] CAPA TM 6800 is a thermoplastic polyester polymer derived from polycaprolactone monomers. It has a weight-average molecular weight (Mw) of 80,000 g / mol and an optimal activation temperature of 60°C. It is available from Perstorp.

[0152] KURARITY TM LA2140 is a thermoplastic acrylic block copolymer with a weight-average molecular weight (Mw) of 40,000 g / mol and an optimal activation temperature of 40°C. It is available from Kuraray.

[0153] HYBRAR TM 5125 is a styrene block copolymer with a weight-average molecular weight (Mw) greater than 10,000 g / mol and an optimal activation temperature of 80 °C. It is available from Kuraray.

[0154] FZPE-A03130 is an amorphous polyester polyol with a weight-average molecular weight (Mw) of 3000 g / mol, which is available from GUANGZHOU FTRT CHEMICAL CO.,LTD.

[0155] Addolink TM TT stands for TDI (urea diketone), which is available from Rhein Chemie.

[0156] MEK is a methyl ethyl ketone organic solvent with a boiling point of 70°C to 80°C, which is available from Sinopharm.

[0157] Silquest A-189 is a silane available from Momentive.

[0158] Carbon black is a pigment that can be obtained from Cabot.

[0159] BYK-141 is a defoamer available from BYK.

[0160] BYK-3550 is a leveling agent available from BYK.

[0161] Preparation of compositions according to the present invention and thermosetting adhesive films obtained from the compositions (Examples 1 to 2) Example 7)

[0162] The compositions of Examples 1 to 7 of the present invention were prepared from the components described in Table 1 below. The contents shown in Table 1 are expressed in grams (g).

[0163] The corresponding thermocurable adhesive film obtained from the composition of the present invention is prepared according to the following steps:

[0164] (1) Add thermoplastic polymer (A), polyester polyol (B) and additives to organic solvent (D) and stir slowly at a temperature below 65°C for about 10 hours until the polymer is dissolved.

[0165] (2) After dissolution, cool the solution to room temperature. Then add the polyisocyanate (C) and transfer the mixture to a suitable container. Stir rapidly twice with a high-speed stirrer at 2000 rpm (rev / min), for 1 minute each time; and

[0166] (3) Apply the dispersion obtained in step (2) onto silicone-treated paper using a 500 μm coating applicator. Blow the adhesive film at room temperature for 1 hour to evaporate the organic solvent (D).

[0167] The preparation of comparative compositions (CEx. 1 to CEx. 5) and their thermosetting adhesive films (CEx. 1 to CEx. 4) Preparation

[0168] Compositions of Comparative Examples 1 to 5 were prepared according to the components described in Table 1 below, where the contents shown in Table 1 are expressed in grams (g).

[0169] The thermosetting adhesive films obtained from Cex.1 to Cex.4 were prepared according to the same method as in Examples 1 to 7 of the present invention, following the steps described above. Component (A) was replaced with the thermoplastic polymer Vitel. TM 3300, KURARITY TM LA4285 and HF4003LH-5 (CEx.2 to 4) or without (CEx.1).

[0170] CEx.5 corresponds to the composition of Example 2 of the present invention, wherein the organic solvent (D) accounts for 35% of the total weight of the composition. It was observed that it formed a gel rather than a homogeneous mixture, and therefore could not be tested further.

[0171] Test method:

[0172] Self-supporting performance:

[0173] After the organic solvent (D) evaporated, the adhesive films prepared from the compositions of Examples 1 to 7 and Comparative Examples 1 to 4 were peeled off by hand from silicone-treated paper to test their self-supporting properties. The observations are recorded in Table 2 according to the following criteria:

[0174] It can form a uniform film and be peeled off by hand –О

[0175] Unable to form a uniform film, such as scattered dots and a uniform surface - ×

[0176] Launch intensity:

[0177] Adhesive film preparation:

[0178] The compositions obtained in the above-described embodiments and comparative examples are applied to a surface of a separable liner and then left at room temperature for 1 hour to allow the organic solvent to evaporate and form an adhesive film. Preferably, the mixture is heated to 40°C to 70°C to accelerate evaporation.

[0179] Sample pre-lamination:

[0180] The adhesive films of the embodiments and comparative examples of the present invention were cut into 25×25mm pieces, and then pre-laminated with test samples on a heated platform. The test samples consisted of an ink-coated glass block and a window-shaped component made of anodized aluminum. At 50°C, the adhesive film was uniformly applied to the surface of the ink-coated glass block on the platform, and a 500g weight was applied to press the adhesive film for 30 seconds. Then, the backing on the adhesive film was removed. The ink-coated glass block and the window-shaped component were pressed together, with an adhesive area of ​​225mm². 2 The material is then heated at 60°C and 2 kg pressure for 30 seconds. This pre-lamination step helps activate the coalescence of the thermoplastic polymer, forming an initial bond.

[0181] Final lamination / thermosetting process:

[0182] The specimens obtained above are placed in a hot press and subjected to a final lamination / thermocurable process at 80°C. The hot press has flat metal heating blocks on the upper and lower sides (both metal blocks are pre-set to 80°C). The final lamination is performed at a pressure of approximately 2 bar and heated at 80°C for 10 minutes (typically 3 to 6 specimens are hot-pressed at a time), during which the adhesive film crosslinks and cures. The specimens are then transferred from the hot press to room temperature, and then pressurized again for 6 minutes with a weight of 2 kg.

[0183] Sample testing

[0184] The push-out strength test was conducted using a universal testing machine with a punch in an environment with a temperature of 23±2℃ and a relative humidity of 50%±5%. The punch applied pressure to the metal block of the specimen at a push-out speed of 2 mm / min until the component could no longer support the load. The maximum load was recorded in Table 2, and the push-out strength was calculated by dividing the maximum load by the bonded area.

[0185] An adhesive film with an extension strength of at least 3 MPa is considered acceptable, and preferably at least 3.5 MPa.

[0186]

[0187] Table 2

[0188]

[0189] N / A indicates that the composition cannot form a uniform adhesive film for further testing.

[0190] As can be seen from Table 2, the adhesive films made from the compositions of Examples 1 to 7 are self-supporting once peeled off and have sufficient flexibility to be rolled up. Of particular note is that the compositions of Examples 1 to 7 exhibit better mixing quality and better film-forming properties, thus making it possible to obtain thinner and more uniform films.

[0191] The composition of CEx.1 corresponds to Examples 1 to 7 of the present invention, wherein the thermoplastic polymer (A) was not added, and it was observed that it could not form a uniform self-supporting film. Compared with the adhesive films obtained in CEx.2 to CEx.4, the adhesive films obtained in Examples 1 to 7 exhibited excellent push-out strength after curing.

[0192] While some preferred embodiments have been described, various modifications and variations are possible based on the foregoing teachings. Therefore, it should be understood that the invention can be practiced in ways different from those specifically described without departing from the scope of the appended claims.

Claims

1. A composition comprising: (A) At least one thermoplastic polymer having a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100 °C. (B) At least one polyester polyol with a weight-average molecular weight (Mw) of less than 10,000 g / mol. (C) At least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule, and (D) At least one organic solvent, wherein the organic solvent is present in an amount greater than 36% to 95% based on the total weight of the composition.

2. The composition according to claim 1, wherein the optimal activation temperature of component (A) is below 85°C, preferably 30°C to below 80°C, more preferably 30°C to below 70°C, and even more preferably 30°C to below 60°C.

3. The composition according to claim 1 or 2, wherein component (A) is selected from thermoplastic polyurethane polymers, polyester polymers, acrylic polymers, ethylene-vinyl acetate copolymers, styrene block copolymers, polyvinylacetone alcohol, styrene-acrylonitrile, polyolefins, polyacrylonitrile, ethylene-vinyl acetate terpolymers, functionalized ethylene-vinyl acetate, ethylene-acrylate copolymers, ethylene-acrylate terpolymers, ethylene-butadiene copolymers and / or block copolymers, preferably selected from thermoplastic polyurethane polymers, polyester polymers, acrylic polymers, styrene block copolymers and combinations thereof.

4. The composition according to any one of the preceding claims, wherein component (B) is selected from amorphous polyester polyols, semi-crystalline polyester polyols, crystalline polyester polyols and combinations thereof, preferably amorphous polyester polyols, semi-crystalline polyester polyols and combinations thereof.

5. The composition according to any one of the preceding claims, wherein, The NCO / OH molar ratio of the composition is in the range of 0.1 to 8.

6. The composition according to any one of the preceding claims, wherein component (D) is selected from ketones, preferably aliphatic ketones, more preferably from the group consisting of acetone, methyl ethyl ketone (MEK), 2-pentanone, 3-pentane, methyl isobutyl ketone, ethyl acetate, and combinations thereof.

7. The composition according to any one of the preceding claims, wherein the composition further comprises at least one component selected from the group consisting of polyols, silanes, pigments, defoamers, leveling agents, stabilizers, dyes, and mixtures thereof, other than component (B).

8. The composition according to any one of the preceding claims, comprising: (A) 1% to 95% by weight, preferably 10% to 40% by weight, of at least one thermoplastic polymer having a weight-average molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature of not more than 100°C, preferably below 85°C, more preferably 30°C to below 80°C, more preferably 30°C to below 70°C, and even more preferably 30°C to below 60°C. (B) 0.01% to 80% by weight, preferably 5% to 40% by weight, of at least one polyester polyol with a weight-average molecular weight (Mw) of less than 10,000 g / mol. (C) 0.05% to 20% by weight, preferably 0.5% to 5% by weight, of at least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule, and (D) More than 36% to 95% by weight, preferably 50% to 85% by weight, of at least one organic solvent; Based on the total weight of the composition.

9. A method for preparing a thermosetting adhesive film, comprising the following steps: 1) The composition according to any one of claims 1 to 8 is prepared by dispersing component (C) in a mixture comprising at least one component (A), at least one component (B), at least one component (D) and optionally present components or additives; Optionally 1a) the composition obtained in step 1) is applied to the separable liner; and 2) Remove component (D) from the composition obtained in step 1) or 1a).

10. The method for preparing a thermosetting adhesive film according to claim 9, wherein the separable liner in step 1a) has a non-stick surface, and the composition is applied to the non-stick surface.

11. A thermosetting adhesive film obtained by the method of claim 9 or 10.

12. A thermosetting adhesive film, comprising: (A) 1% to 95% by weight, preferably 30% to 90% by weight, of at least one thermoplastic polymer having a molecular weight (Mw) of not less than 10,000 g / mol and an optimal activation temperature not higher than 100°C, preferably below 85°C, more preferably 30°C to below 80°C, more preferably 30°C to below 70°C, and even more preferably 30°C to below 60°C. (B) 0.01% to 80% by weight, preferably 10% to 50% by weight, of at least one polyester polyol with a molecular weight (Mw) of less than 10,000 g / mol. (C) 0.1% to 20% by weight, preferably 1% to 10% by weight, of at least one polyisocyanate having at least two isocyanate groups and at least one ureidone group in one molecule, and (D) less than 2.0% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight of at least one organic solvent; All of the above are based on the total weight of the thermosetting adhesive film.

13. The thermosetting adhesive film according to claim 11 or 12, wherein the total thickness is from 3 μm to 500 μm.

14. The thermosetting adhesive film according to claim 11 or 12, wherein the ejection strength is at least 3 MPa, preferably at least 3.5 MPa.

15. An article comprising: First substrate, Second substrate, and A thermosetting adhesive film according to any one of claims 11 to 14 disposed between the first substrate and the second substrate.

16. Use of the composition according to any one of claims 1 to 8, or the thermosetting adhesive film according to any one of claims 11 to 14, or the article according to claim 15 in the manufacture of automotive parts, truck bed covers, textile laminates, assembled goods, and electronic equipment.

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