USE OF COMPOUNDS WITH N 2-OXO-1,3-DIOXOLAN-4-CARBONIC ACID UNITS IN TWO-COMPONENT ADHESIVES

Description

[0001] This paper describes the use of compounds with 2-oxo-1,3-dioxolane-4-carboxylamide units as reactive components in two-component adhesives, preferably for the production of hydroxypolyurethanes or hydroxypolycarbonates for adhesive applications. Corresponding two-component adhesives and bonding processes are also described. A multifunctional hardener compound is preferably used as the second component of the two-component adhesive.

[0002] Two-component polyurethane systems based on polyisocyanates are frequently used as adhesives. In these systems, isocyanate components react with polyol components to form a high-molecular-weight polyurethane polymer. These systems are applied either as solvent-free and anhydrous reactive 100% systems or as an adhesive dissolved in an organic solvent. The coating materials are applied to a first substrate using a suitable application system and then cured, if necessary, after the solvent has evaporated. The resulting high bond strengths in combinations of a wide variety of film materials are advantageous.

[0003] The reactive, monomeric, low-molecular-weight (poly)isocyanate compounds contained in conventional two-component adhesives pose a toxicological risk, especially if they are highly volatile or migrating. This concerns, firstly, the handling of these adhesives during application, because the isocyanates generally exhibit high toxicity and a high allergenic potential. Secondly, there is a risk that incompletely reacted aromatic isocyanate can migrate through flexible substrates and be hydrolyzed by water to form carcinogenic aromatic amines. Therefore, isocyanate-free two-component systems for curable adhesive compositions with the best possible bond strength and good curing properties, ideally at room temperature, are desirable.

[0004] Polyurethane systems can also be obtained from cyclic carbonate compounds, which are toxicologically harmless. For example, glycerol carbonate (4-(hydroxymethyl)-2-oxo-1,3-dioxolane) is used in cosmetics.

[0005] Cyclic carbonate compounds react with amines via ring opening to form, among other things, hydroxyurethanes (see the formula scheme).

[0006] Disadvantages of glycerol carbonate-based systems include the low regioselectivity, which leads to reaction pathways A, B and C, the comparatively low reactivity of the systems at room temperature, and the fact that catalysts which accelerate ring opening also apparently promote the reverse reaction, which can lead to partial decomposition of the products already formed.

[0007] In WO 2011 / 157551, these problems are partially solved by using an ester group instead of an ether group in R. This electron-withdrawing group led to a considerable increase in the reaction rate and favored reaction pathway A. No reverse reaction was observed in the secondary hydroxyurethanes [I] formed. However, the production of adhesives containing two or more 2-oxo-1,3-dioxolane-4-carboxyl groups in the molecule is difficult, as this involves transesterification, which can also attack the cyclocarbonate ring. Furthermore, the aforementioned ester group can be partially attacked during the reaction with the amines (R'-NH₂) used for curing.

[0008] WO 2013 / 092011 describes certain cyclocarbonatamides and their production.

[0009] The objective of the present invention was to substantially avoid at least some of the disadvantages of the prior art described above. In general, an alternative 2-oxo-1,3-dioxolane system with an electron-withdrawing group was to be provided for adhesive applications. In particular, a 2-oxo-1,3-dioxolane system was to be provided that is safe, readily accessible, highly reactive with amines, can preferably cure at room temperature, and is also suitable as an adhesive (with a bond to the polymer chain that is not easily attacked by amines) exhibiting good adhesive properties.

[0010] This problem was solved using the features of the independent claims. The dependent claims relate to preferred embodiments.

[0011] An object of the present invention is the use of compounds with n 2-oxo-1,3-dioxolane-4-carboxylamide units as a reactive component in two-component adhesives, preferably for the production of hydroxypolyurethanes or hydroxypolycarbonates for adhesive applications, wherein n is a number greater than or equal to 2. Preferably, n = 2 to 5, in particular 2 to 3.

[0012] Suitable compounds with two or more 2-oxo-1,3-dioxolane-4-carboxylamide units are, for example, those of formula (I) where R1 and R3 are independently selected from H and an organic residue; and R2 is an n-valent organic residue substituted with n-1 further 2-oxo-1,3-dioxolane-4-carboxylic acid amide groups, and n is a number greater than or equal to 2.

[0013] R 1 is preferably selected from H, straight-chain, branched or cyclic C 1-12 alkyl groups, C 6-10 aryl groups, C 6-12 arylalkyl groups and C 6-12 alkylaryl groups.

[0014] R2 is preferably an alkyl group with 2 to 22 carbon atoms or a polymer chain; and is preferably selected from the group consisting of linear or branched C2 to C22 alkylene groups; polyether groups of the general formula -(AO) m -, where A means C2 to C5 alkylene and m is a number from 1 to 100; polycarbonate groups, polyester groups and poly(meth)acrylate groups.

[0015] R 2 is particularly preferably selected from n-alkyl units with 2-12 C atoms and polymer chains containing ethylene oxide and / or propylene oxide units.

[0016] R 3 is preferably selected from H, aryl groups and straight-chain, branched or cyclic C 1-12 alkyl groups, which may also contain O or N atoms; H is particularly preferred.

[0017] The carbon atom to which R3 is bonded can also carry another C1-12 alkyl group. The carbon atom in position 4 can also carry an additional C1-12 alkyl group. Both can occur simultaneously.

[0018] In the 2-oxo-1,3-dioxolane-4-carboxylic acid amides, groups R 1 and R 3 are each preferably H.

[0019] The compounds have a functionality with respect to the 2-oxo-1,3-dioxolane group of n greater than or equal to 2. R 2 is an n-valent residue substituted with n-1 further 2-oxo-1,3-dioxolane-4-carboxylic acid amide groups, preferably with those of general formula (II), wherein R 3 has the meaning mentioned above.

[0020] Preferably n = 2 to 5, in particular 2 to 3 .

[0021] The preparation of 2-oxo-1,3-dioxolane-4-carboxylic acid amides is described in WO 2013 / 092011 and in WO2016 / 062424 (Pt-catalyzed oxidation with oxygen). Key products in the preparation of 2-oxo-1,3-dioxolane-4-carboxylic acid amides are the 2-oxo-1,3-dioxolane-4-carboxylic acids of formula (VIII). where R 3 has the meaning given above. The preparation of the 2-oxo-1,3-dioxolane-4-carboxylic acid of formula (VIII) is described in WO 2013 / 092011.

[0022] The 2-oxo-1,3-dioxolane-4-carboxylic acid of formula (VIII) can be reacted with a polyisocyanate having n NCO groups to give the corresponding amides, where n has the meaning given above, and n-functionalized 2-oxo-1,3-dioxolane-4-carboxylic acid amides are formed. The polyisocyanate is preferably an aliphatic isocyanate, an aromatic isocyanate, or a combined aliphatic / aromatic isocyanate with an NCO functionality (number of NCO groups in the molecule) of n = 2 to 5, preferably n = 2 to 3.

[0023] Suitable polyisocyanates include tetramethylene 1,4-diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, hexamethylene 1,6-diisocyanate (HDI), 2,2,4- and 2,4,4-trimethylhexamethylene 1,6-diisocyanate (TMDI), dodecamethylene 1,12-diisocyanate, lysine diisocyanate, lysine ester diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4-diisocyanato-2,2,6-trimethylcyclohexane (TMCDI), 2,2'-, 2,4'- and 4,4'-dicyclohexylmethane diisocyanate (H12MDI), cyclohexane 1,3-diisocyanate, and cyclohexane 1,4-diisocyanate (CHDI). 1,3-Bis-(isocyanatomethyl)cyclohexane, 1,4-Bis-(isocyanatomethyl)cyclohexane, 4,4'-Diisocyanatodicyclohexyl-2,2-propane, m- and p-phenylene diisocyanate, 2,3,5,6-Tetramethyl-1,4-diisocyanatobenzene, 3,3'-Dimethyl-4,4'-diisocyanatodiphenyl (TODI), 2,4- and 2,6-Toluene diisocyanate (TDI), 2,2'-, 2,4'- and 4,4'-Diphenylmethane diisocyanate (MDI), Naphthalene-1,2-diisocyanate and Naphthalene-1,5-diisocyanate (NDI), m- and p-Xylylene diisocyanate (XDI),Tetramethylxylylene diisocyanate (TMXDI), and any mixtures of the aforementioned isocyanates.

[0024] For the purposes of the present invention, the polyisocyanates according to the invention also include dimers (uretdiones) and trimers (isocyanurates). The HDI trimer is of particular importance in this context. Furthermore, oligomers are also included, such as "polymeric MDI" with n preferably equal to 1 to 8.

[0025] Furthermore, prepolymers of polyisocyanates with polyols can also be used, provided there is a stoichiometric excess of NCO groups. Suitable polyols include polyoxyalkylene polyols (also called "polyether polyols"), which may contain, among others, ethylene oxide, propylene oxide, and butylene oxide units; aliphatic diols; aliphatic polyols; polyester polyols; polycarbonate polyols; castor oil; hydroxylated epoxidized soybean oil; and mixtures of the aforementioned polyols.

[0026] The following formula scheme provides an exemplary, non-exhaustive overview of reaction products of 2-oxo-1,3-dioxolane-4-carboxylic acid with polyisocyanates: where n is a number from 0 to 8, preferably from 1 to 8.

[0027] Preferred compounds with n 2-oxo-1,3-dioxolane-4-carboxylamide units are selected from the group consisting of Compounds of formula (III) where n is a number from 1 to 12; combinations of formula (IV) where y is a number from 1 to 12; combinations of formula (V) and compounds of formula (VI) where n is a number greater than or equal to 0, preferably 1 to 8.

[0028] The invention also relates to multifunctional 2-oxo-1,3-dioxolane-4-carboxamides with a flexible spacer group between the cyclocarbonate units of formula (I), which are particularly suitable for adhesive applications. where R1 and R3 are independently selected from H and an organic residue; and R2 is an n-valent organic residue substituted with n-1 further 2-oxo-1,3-dioxolane-4-carbamide groups, n being a number greater than or equal to 2, and wherein at least one linear or branched spacer group is included between the 2-oxo-1,3-dioxolane-4-carbamide groups, and the spacer group has a molecular weight of at least 200 g / mol and is preferably selected from alkylene groups, polyether groups, polycarbonate groups, polyester groups and poly(meth)acrylate groups.

[0029] R 2 in formula (I) is preferably selected from the group consisting of linear or branched C2 to C22 alkylene groups; polyether groups of the general formula -(AO) m -, where A means C2 to C5 alkylene and m is a number from 1 to 100; polycarbonate groups; polyester groups; and poly(meth)acrylate groups.

[0030] Particularly preferred 2-oxo-1,3-dioxolane-4-carboxamides are selected from compounds of formula (IV) where y is a number from 1 to 12; and combinations of formula (VII) where an alkoxylated glycerol residue, preferably with 2 to 5, in particular 2 and / or 3 carbon atoms in the alkoxy group, especially preferably ethoxylated / propoxylated glycerol.

[0031] In the application according to the invention, the 2-oxo-1,3-dioxolane-4-carboxylic acid amides react with amine hardeners to form hydroxypolyurethanes. This process predominantly yields hydroxypolyurethanes with secondary hydroxyl groups, since the negative charge on the oxygen atom closer to the CONR1R2 group is better stabilized during attack by the nucleophilic nitrogen atom. Hydroxyurethanes with secondary hydroxyl groups have the advantage that no reverse reaction occurs. Theoretically, an attack of the amine on the amide group would also be conceivable. However, it has been shown that the amine only attacks the 2-oxo-1,3-dioxolane group.

[0032] Suitable amines include primary and secondary amines with alkyl, aryl, aralkyl, and alkaryl groups as residues. Primary amines react faster than secondary amines; aliphatic amines react faster than aromatic amines. Higher molecular weight polyamines, such as Jeffamine® from Huntsman Corp. and polyetheramines from BASF SE, are particularly suitable.

[0033] In the case of primary amines with the formula R'-NH2, the reaction can be represented as follows, showing only the preferred reaction to hydroxyurethane with a secondary hydroxyl group:

[0034] In the use according to the invention, the 2-oxo-1,3-dioxolane-4-carboxylic acid amides react with hydroxy hardeners to form hydroxy polycarbonates. The following formula scheme shows only the preferred reaction to the hydroxy carbonate with a secondary hydroxyl group. Suitable alcohols of the formula R'-OH include, for example, the polyols mentioned above.

[0035] Mixtures of the compounds with two or more 2-oxo-1,3-dioxolane-4-carboxylamide units and a suitable multifunctional hardener compound can be used as a two-component adhesive, with the 2-oxo-1,3-dioxolane-4-carboxylamide compound in a first component and the multifunctional hardener compound in a second component. The multifunctional hardener component has at least two functional groups selected from the group consisting of primary amino groups, secondary amino groups, and hydroxyl groups. Preferably, the two-component adhesive contains at least one catalyst for catalyzing the reaction of the cyclocarbonate groups with the functional groups of the hardener.

[0036] It is also possible to use mixtures of different hardener compounds, e.g. a small amount of a "fast" hardener that builds up immediate strength without reducing the pot life of the adhesive too much, plus a slow hardener for final curing.

[0037] The two-component adhesive can be applied as a solution in an organic solvent or as a solvent- and water-free 100% system.

[0038] Preferably, the functional groups of the hardener are selected from aliphatic hydroxyl groups, aliphatic primary amino groups and aliphatic secondary amino groups.

[0039] A two-component adhesive is understood to be an adhesive containing at least two polyfunctional adhesive components that react with each other to form bonds and a polymeric network. Accordingly, two-component adhesive compositions contain, in addition to at least one multifunctional cyclocarbonatamide compound, at least one compound having at least two functional groups F, e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10 functional groups F, which are preferably selected from aliphatic hydroxyl groups or aliphatic primary or secondary amino groups. These compounds are hereinafter also referred to as hardeners. Preferably, the amount of hardener is selected such that the molar ratio of functional 2-oxo-1,3-dioxolane groups to the functional groups F in the hardener is in the range of 1:10 to 10:1, particularly in the range of 5:1 to 1:5, and especially in the range of 1:2 to 2:1.

[0040] The hardener can be a low molecular weight substance, i.e., its molecular weight is below 500 g / mol, or an oligomeric or polymeric substance that has a number-average molecular weight above 500 g / mol.

[0041] For particularly good adhesive properties, it is preferred that either the compound with two or more 2-oxo-1,3-dioxolane-4-carboxylamide units, or the hardener compound, or both, contain at least one flexible spacer group. A flexible spacer group is a linear or branched compound group having a molecular weight of at least 200 g / mol. The spacer group can form group R2 or part of group R2 in formula (I) and / or the spacer group can be located between two functional groups of the hardener. The spacer group is preferably selected from alkylene groups, polyether groups, polycarbonate groups, polyester groups, and poly(meth)acrylate groups.

[0042] Spacer groups include, for example, linear or branched alkylene groups with at least 15 carbon atoms; polyether groups of the general formula -(AO)m-, where A denotes C2- to C5-alkylene and m is a number chosen such that the molecular weight of -(AO)m- is at least 200 g / mol; polycarbonate groups; polyester groups; and poly(meth)acrylate groups. A preferred spacer group is alkoxylated glycerol, e.g., ethoxylated glycerol, propoxylated glycerol, and ethoxylated / propoxylated glycerol.

[0043] Amine hardeners, hereinafter also referred to as amine hardeners, include, for example, aliphatic and cycloaliphatic polyamines, aromatic and araliphatic polyamines, and polymeric amines, such as aminoplasts and polyamidoamines. Amine hardeners crosslink polymers with 1,3-dioxolan-2-one groups, hereinafter also called carbonate polymers, by reacting the primary or secondary amino groups of the polyamines with the 1,3-dioxolan-2-one groups of the carbonate polymers to form urethane groups. Preferred polyamine hardeners have, on average, at least two primary or secondary amino groups per molecule, e.g., two, three, or four primary or secondary amino groups per molecule. They may also additionally contain one or more tertiary amino groups. Suitable polyamines are, for example, Aliphatic polyamines such as ethylenediamine, 1,2- and 1,3-propanediamine, neopentanediamine, hexamethylenediamine, octamethylenediamine, 1,10-diaminodecane, 1,12-diaminododecane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 2,2-dimethylpropylenediamine, trimethylhexamethylenediamine, 1-(3-aminopropyl)-3-aminopropane, 1,3-bis-(3-aminopropyl)propane, 4-ethyl-4-methylamino-1-octylamine and the like; cycloaliphatic diamines such as 1,2-diaminocyclohexane, 1,2-, 1,3-, 1,4-bis(aminomethyl)cyclohexane, 1-methyl-2,4-diaminocyclohexane, N-cyclohexylpropylene-1,3-diamine, 4-(2-aminopropan-2-yl)-1-methylcyclohexane-1-amine, Isophoronediamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodicyclohexylmethane, 4,8-diamino-tricyclo[5.2.1.[0]-decane, norbornanediamine, menthanediamine, menthenediamine and the like; aromatic diamines such as toluenediamine, xylylenediamine, in particular meta-xylylenediamine (MXDA), bis(4-aminophenyl)methane (MDA or methylenedianiline), bis(4-aminophenyl)sulfone (also known as DADS, DDS or dapsone) and the like; cyclic polyamines such as piperazine, N-aminoethylpiperazine and the like; polyetheramines, in particular difunctional and trifunctional primary polyetheramines based on polypropylene glycol, polyethylene glycol, polybutylene oxide, poly(1,4-butanediol), polytetrahydrofuran (poly-THF) or polypentylene oxide, e.g. B. 4,7,10-Trioxatridecan-1,3-diamine, 4,7,10-Trioxatridecan-1,13-diamine, 1,8-Diamino-3,6-dioxaoctane (XTJ-504, Huntsman), 1,10-Diamino-4,7-dioxa-decane (XTJ-590, Huntsman), 1,12-Diamino-4,9-dioxadodecane (BASF SE), 1,3-Diamino-4,7,10-trioxatridecane (BASF SE), primary polyetheramines based on polypropylene glycol with an average molecular weight of 230, such as...Polyetheramine D 230 (BASF SE) or Jeffamine® < D 230 (Huntsman), difunctional primary polyetheramines based on polypropylene glycol with an average molecular weight of 400, e.g., Polyetheramine D 400 (BASF SE) or Jeffamine® < XTJ 582 (Huntsman), difunctional primary polyetheramines based on polypropylene glycol with an average molecular weight of 2000, such as Polyetheramine D2000 (BASF SE), Jeffamine® < D2000 or Jeffamine® < XTJ 578 (all Huntsman), difunctional primary polyetheramines based on propylene oxide with an average molecular weight of 4000, such as... B. Polyetheramine D 4000 (BASF SE), trifunctional, primary polyetheramines produced by reaction of propylene oxide with trimethylolpropane, followed by amination of the terminal OH groups with an average molar mass of 403, such as polyetheramine T 403 (BASF SE) or Jeffamine® < T 403 (BASF SE).Huntsman), trifunctional primary polyetheramines produced by reacting propylene oxide with glycerol, followed by amination of the terminal OH groups, with an average molar mass of 5000, such as polyetheramine T 5000 (BASF SE) or Jeffamine® < T 5000 (Huntsman); aliphatic polyetheramines composed of propylene oxide-grafted polyethylene glycol with an average molar mass of 600, such as Jeffamine® < ED-600 or Jeffamine® < XTJ-501 (both Huntsman); aliphatic polyetheramines composed of propylene oxide-grafted polyethylene glycol with an average molar mass of 900, such as... B. Jeffamine® ED-900 (Huntsman), aliphatic polyetheramines composed of polyethylene glycol grafted with propylene oxide and having an average molar mass of 2000, such as Jeffamine® ED-2003 (Huntsman).Huntsman), difunctional primary polyetheramines produced by amination of a propylene oxide-grafted diethylene glycol with an average molar mass of 220, such as Jeffamine® < HK-511 (Huntsman); aliphatic polyetheramines based on a copolymer of poly(tetramethylene ether glycol) and polypropylene glycol with an average molar mass of 1000, such as Jeffamine® < XTJ-542 (Huntsman); aliphatic polyetheramines based on a copolymer of poly(tetramethylene ether glycol) and polypropylene glycol with an average molar mass of 1900, such as Jeffamine® < XTJ-548 (Huntsman); aliphatic polyetheramines based on a copolymer of poly(tetramethylene ether glycol) and polypropylene glycol with an average molar mass of 1400, such as... B. Jeffamine® XTJ-559 (Huntsman), polyethertriamines based on a butylene oxide-grafted at least trihydric alcohol with an average molar mass of 400, such as Jeffamine® XTJ-566 (Huntsman).Huntsman), aliphatic polyetheramines produced by amination of butylene oxide-grafted alcohols with an average molar mass of 219, such as Jeffamine® < XTJ-568 (Huntsman); polyetheramines based on pentaerythritol and propylene oxide with an average molar mass of 600, such as Jeffamine® < XTJ-616 (Huntsman); polyetheramines based on triethylene glycol with an average molar mass of 148, e.g., Jeffamine® < EDR-148 (Huntsman); difunctional primary polyetheramines produced by amination of propylene oxide-grafted ethylene glycol with an average molar mass of 176, such as... B. Jeffamine® < EDR-176 (Huntsman) and polyetheramines produced by amination of poly-tetrahydrofuran (poly-THF) with an average molar mass of 250, e.g., PolyTHF-Amine 350 (BASF SE) and mixtures of these amines; polyamidoamines (amidopolyamines) produced by the reaction of dimeric fatty acids (e.g.,dimeric linoleic acid) with low molecular weight polyamines such as diethylenetriamine, 1-(3-aminopropyl)-3-aminopropane or triethylenetetramine or other diamines such as the aforementioned aliphatic or cycloaliphatic diamines; adducts obtainable by reacting amines, in particular diamines, with a deficiency of epoxy resin or reactive diluent, wherein preferably such adducts are used in which about 5 to 20% of the epoxide groups have been reacted with amines, in particular diamines; phenalkamines, as known from epoxy chemistry; Mannich bases, which are obtained by reacting amines, in particular diamines, with di ... B. by condensation of polyamines, preferably diethylenetriamine, triethylenetetramine, isophoronediamine, 2,2,4- or 2,4,4-trimethylhexamethylenediamine, 1,3- and 1,4-bis(aminomethyl)cyclohexane with aldehydes, preferably formaldehyde and mono- or polyhydric phenols with at least one aldehyde-reactive nucleus, e.g. the various cresols and xylenols, p-tert.-Butylphenol, resorcinol, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl-2,2-propane, but preferably phenol, are produced; . as well as mixtures of the aforementioned amine hardeners, in particular mixtures of difunctional amines from the group of aliphatic, cycloaliphatic and aromatic amines with the aforementioned polyetheramines.

[0044] Preferred amine hardeners are aliphatic polyamines, in particular 2,2-dimethylpropylenediamine, aromatic diamines, in particular m-xylylenediamine (MXDA), and cycloaliphatic diamines, in particular isophorone diamine, N-cyclohexylpropylene-1,3-diamine, and 4,4'-diaminodicyclohexylmethane (dicycan). Difunctional or trifunctional primary polyetheramines based on polypropylene glycol, such as Jeffamine® < D 230 or Jeffamine® < T 403, are also preferred. Polyamines exhibiting high mobility and low steric hindrance around the amino group are particularly preferred, e.g., 4,9-dioxadodecane-1,12-diamine, 4,7,10-trioxatridecane-1,13-diamine, and PolyTHF Amin 350 (BASF SE).

[0045] Mixtures of the amines mentioned as preferred are also preferred, for example mixtures containing 2,2-dimethylpropylenamine and isophoronamine.

[0046] Alcoholic hardeners primarily include low-molecular-weight and high-molecular-weight aliphatic and cycloaliphatic alcohols. These hardeners crosslink to form carbonate polymers through the reaction of the primary or secondary alcohol functional groups with the 1,3-dioxolan-2-one groups, forming carbonic acid diesters. Preferred alcoholic hardeners typically have at least two primary or secondary hydroxyl groups per molecule, for example, two, three, or four. Suitable low-molecular-weight alcoholic hardeners include, for example, 1,4-butanediol, ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, glycerol, diglycerol, pentaerythritol, dipentaerythritol, and sugar alcohols such as sorbitol and mannitol.

[0047] Suitable alcoholic hardeners also include higher molecular weight polymeric polyols, such as polyester polyols, polycarbonate polyols, polyether polyols, polyacrylate polyols, and polyvinyl alcohols. Suitable polymeric polyol hardeners preferably have an average OH functionality of at least 1.5 mol, and specifically at least 1.8, e.g., in the range of 1.5 to 10, and particularly in the range of 1.8 to 4. Average OH functionality refers to the average number of OH groups per polymer chain. Typical polymeric polyol components preferably have a number-average molecular weight of about 250 to 50,000 g / mol, more preferably of about 500 to 10,000 g / mol. Preferably, at least 50 mol% of the hydroxyl groups contained in the polymeric polyol component are primary hydroxyl groups.

[0048] Preferably, polyester polyols are linear or branched polymeric compounds with ester groups in the polymer backbone, exhibiting free hydroxyl groups at the ends of the polymer chain. Preferably, these are polyesters obtained by polycondensation of dihydric alcohols with dihydric carboxylic acids, optionally in the presence of higher-hydric alcohols (e.g., 3, 4, 5, or 6-hydric alcohols) and / or higher-hydric polycarboxylic acids. Instead of the free di- or polycarboxylic acids, the corresponding di- or polycarboxylic anhydrides or corresponding di- or polycarboxylic esters of lower alcohols or mixtures thereof can also be used to produce the polyester polyols. The di- or polycarboxylic acids can be aliphatic, cycloaliphatic, araliphatic, aromatic, or heterocyclic, preferably have 2 to 50 and particularly 4 to 20 carbon atoms, and can optionally, e.g.,They may be substituted by halogen atoms and / or unsaturated. Examples include: corkic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, alkenyl succinic acid, fumaric acid, and dimeric fatty acids. For the production of polyester polyols, aliphatic and cycloaliphatic diols with preferably 2 to 40 and especially 2 to 20 carbon atoms are particularly suitable as diols, e.g.Ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butane-1,4-diol, butene-1,4-diol, butyne-1,4-diol, pentane-1,5-diol, neopentyl glycol, bis(hydroxymethyl)cyclohexanes such as 1,4-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1,3-diol, methylpentanediols, and also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, and polybutylene glycols. Alcohols of the general formula HO-(CH₂)x-OH are preferred, where x is a number from 2 to 20, preferably an even number from 2 to 12. Examples include ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol, and dodecane-1,12-diol. Neopentyl glycol and pentane-1,5-diol are also preferred.

[0049] Suitable alcoholic hardeners are also lactone-based polyester polyols, wherein these are homopolymers or copolymers of lactones, preferably terminal hydroxyl-group-bearing addition products of lactones to suitable difunctional starter molecules. Preferably, the lactones are those derived from compounds of the general formula HO-(CH₂)z-COOH, where z is a number from 1 to 20 and an H atom of a methylene unit may also be substituted by a C₁ to C₄ alkyl group. Examples are ε-caprolactone, β-propiolactone, γ-butyrolactone, and / or methyl ε-caprolactone, as well as mixtures thereof. Suitable starter molecules are, for example, the low-molecular-weight dihydric alcohols mentioned above as building blocks for the polyester polyols. The corresponding polymers of ε-caprolactone are particularly preferred.Lower polyester diols or polyether diols can also be used as starters for the preparation of lactone polymers. Instead of lactone polymers, the corresponding, chemically equivalent polycondensates of the hydroxycarboxylic acids corresponding to the lactones can also be used.

[0050] Examples of suitable polyester polyols are, for example, the polyester polyols known from Ullmann's Encyclopedia of Technical Chemistry, 4th edition, volume 19, pages 62 to 65.

[0051] Furthermore, polycarbonate polyols, such as those that can be obtained by reacting phosgene with an excess of the low molecular weight alcohols mentioned as building blocks for polyester polyols, are also a possibility.

[0052] Polyether polyols are in particular polyether polyols that can be produced by polymerization of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with themselves, e.g. in the presence of BF 3 or by addition of these compounds, optionally in a mixture or sequentially, to bi- or polyfunctional starting components with reactive hydrogen atoms, such as polyols or polyfunctional amines, e.g. water, ethylene glycol, propane-1,2-diol, propane-1,3-diol, 1,1-bis-(4-hydroxyphenyl)propane, trimethylolpropane, glycerol, sorbitol, ethanolamine or ethylenediamine. Sucrose polyethers (see DE 1176358 and DE 1064938) and polyethers started on formit or formose (see DE 2639083 and DE 2737951) are also suitable.

[0053] Polyhydroxyolefins are also suitable, preferably those with 2 terminal hydroxyl groups, e.g. α-ω-dihydroxypolybutadiene.

[0054] Polyhydroxypolyacrylates are also suitable, with the hydroxyl groups being arranged laterally or terminally. Examples include α,ω-dihydroxypoly(meth)acrylates, which can be obtained by homo- or copolymerization of alkyl esters of acrylic acid and / or methacrylic acid in the presence of OH-group-containing regulators such as mercaptoethanol or mercaptopropanol, followed by transesterification with a low-molecular-weight polyol, for example, an alkylene glycol such as butanediol. Such polymers are known, for example, from EP-A 622 378. Further examples include polymers obtained by copolymerization of alkyl esters of acrylic acid and / or methacrylic acid with hydroxyalkyl esters of ethylenically unsaturated carboxylic acids, such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, or hydroxybutyl methacrylate.

[0055] Polyvinyl alcohols are also suitable, which can preferably be obtained by complete or partial saponification of polyvinyl esters, especially polyvinyl acetate. If the polyvinyl esters, preferably polyvinyl acetate, are partially saponified, preferably at most 50 to 95% of the ester groups are present as hydroxyl groups. If the polyvinyl esters, preferably polyvinyl acetate, are completely saponified, generally more than 95% to 100% of the ester groups are present as hydroxyl groups.

[0056] Among the higher molecular weight, polymeric polyols, preferred alcoholic hardeners are in particular polyacrylate polyols, these are available, for example, under the brand name Joncryl ®< from BASF SE, e.g. Joncryl ®< 945.

[0057] Suitable hardeners also include amino acids, e.g. lysine, arginine, glutamine and asparagine and their stereoisomers and mixtures thereof.

[0058] Of course, mixtures of different hardeners can also be used, e.g. mixtures of one or more amine hardeners with one or more alcoholic hardeners, mixtures of one or more amine hardeners with one or more amino acids, or mixtures of one or more alcoholic hardeners with one or more amino acids.

[0059] In the adhesive compositions according to the invention, the total amount of hardeners is preferably 0.1 wt.% to 50 wt.%, frequently 0.5 wt.% and in particular 1 wt.% to 30 wt.%, based on the total amount of cyclocarbonate compounds plus hardeners used.

[0060] The adhesive composition can be thermally cured by heating the mixture of the polymer and hardener according to the invention to a temperature above the mixing temperature. Curing can also take place at lower temperatures. Typically, the adhesive compositions according to the invention are cured at temperatures in the range of -10°C to 150°C, preferably in the range of 0 to 100°C, and particularly in the range of 10 to 70°C. Curing at temperatures of 20-30°C is especially advantageous. The suitable temperature depends on the specific hardeners and the desired curing rate and can be determined in individual cases by a person skilled in the art, for example, by means of simple preliminary tests. In the lower temperature range (5 to approximately 35°C), which corresponds to the most common ambient temperature, it is of course sufficient to simply mix the polymer and hardener according to the invention.Alternatively, hardening is preferably microwave-induced.

[0061] The two-component adhesive compositions can also contain one or more suitable catalysts for curing, selected in a known manner according to the type of reactive functional groups F. The catalysts are used, if desired, in proportions of 0.01 wt.% to approximately 10 wt.%, based on the total weight of the polymers according to the invention with functional alkylidene-1,3-dioxolan-2-one groups of formula I and the hardener. In one embodiment, no catalysts are required, particularly with hardeners that have amino groups as functional groups; i.e., the catalyst content in the composition is then less than 0.01 wt.%. Catalysts are preferably used when the hardener has reactive groups F that are different from amino groups, particularly when the hardener has hydroxyl groups.

[0062] Preferred catalysts are basic catalysts, particularly organic amines and organic phosphines. Among the organic amines, amidine bases such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), mono-C1-C6-alkyl, di-C1-C6-alkyl, and tri-C1-C6-alkylamines, especially triethylamine and tert-butylamine, are preferred. Among the organic phosphines, trialkylphosphines and triarylphosphines are preferred, for example, tri-n-butylphosphine and triphenylphosphine. The catalysts can of course also be used as mixtures, possibly in combination with Tri-C 1 -C 6 -alkylammonium halides and copper salts, for example triphenylphosphine in combination with a Tri-C 1 -C 6 -alkylammonium halide and a copper salt, e.g. copper(I) chloride, copper(I) bromide, copper(II) chloride or copper(II) sulfate.

[0063] In addition to the aforementioned components, the adhesive composition may contain the additives commonly used for this purpose. The choice of suitable conventional additives for the composition according to the invention depends on the specific application and can be determined by a person skilled in the art in each individual case.

[0064] Suitable additives include, for example, antioxidants, UV absorbers / light stabilizers, metal deactivators, antistatic agents, reinforcing agents, fillers, antifogging agents, biocides, plasticizers, lubricants, emulsifiers, colorants, pigments, rheology agents, adhesion regulators, optical brighteners, flame retardants, anti-drip agents, nucleating agents, wetting agents, thickeners, protective colloids, defoamers, tackifiers, solvents and reactive diluents, as well as mixtures thereof.

[0065] The light stabilizers / UV absorbers, antioxidants, and metal deactivators used, if any, preferably exhibit high migration stability and temperature resistance. They are selected, for example, from groups a) to t). The compounds in groups a) to g) and i) represent light stabilizers / UV absorbers, while compounds j) to t) act as stabilizers. a) 4,4-Diarylbutadiene, b) Cinnamic acid esters, c) Benzotriazoles, d) Hydroxybenzophenones, e) Diphenyl cyanoacrylates, f) Oxamides, g) 2-Phenyl-1,3,5-triazines, h) Antioxidants, i) Nickel compounds, j) Sterically hindered amines, k) Metal deactivators, l) Phosphites and phosphonites, m) Hydroxylamines, n) Nitrones, o) Amine oxides, p) Benzofuranones and indolinones, q) Thiosynergists, r) Peroxide-destroying compounds, s) Polyamide stabilizers and t) Basic costabilizers.

[0066] The two-component adhesive is preferably free of isocyanates, i.e., it preferably contains no isocyanate compounds as a hardener. The two-component adhesive is preferably either in the form of a solution in an organic solvent or it is solvent-free. Solvent-free means that it contains less than 5% by weight, particularly preferably less than 2% by weight, or no organic solvent or water.

[0067] The two-component adhesive according to the invention is able to build up high bonding forces in a short time and especially with amine hardeners even at room temperature.

[0068] The invention also relates to a two-component adhesive comprising as a reactive first component the at least one compound with n 2-oxo-1,3-dioxolane-4-carboxylic acid amide units described above; and The second component (hardener) is the at least one compound selected from polyamines and polyols as described above; where n is a number greater than or equal to 2; the polyamines have two or more amine groups; and the polyols have two or more alcoholic hydroxyl groups.

[0069] The two-component adhesive, after mixing the components, has a Brookfield viscosity at temperatures of 70°C or below, preferably at temperatures of 40°C or below, particularly preferably at temperatures of 23°C or below, of preferably less than 10,000 mPa s (Brookfield LVT, measured at 12 rpm with spindle 3).

[0070] The two-component adhesive has an adhesive strength preferably greater than 1.5 N / 15 mm, measured as the peel strength of two polyester films bonded together with an adhesive layer of 3 µm and a contact pressure of 3 bar after 24 hours.

[0071] The invention also relates to an adhesive bonding method, wherein two substrates are bonded together and a 2-component adhesive is applied to the surface of at least one of the substrates, which contains at least one of the compounds described above with n 2-oxo-1,3-dioxolane-4-carboxylic acid amide units as a reactive component and n is a number greater than or equal to 2.

[0072] Preferred applications and adhesive bonding methods include laminated film lamination, glossy film lamination, and lamination of shaped bodies, as is used particularly in furniture lamination or in the lamination of automotive interior parts.

[0073] The invention also relates to a laminating process for the production of laminated objects, selected from glossy films, composite films and laminated molded bodies, wherein one a) provides a first substrate in the form of a first film, b) provides a second substrate selected from paper, a second film and shaped bodies, c) provides a two-component adhesive according to the invention as described above, and d) applies the two-component adhesive to the first substrate and / or to the second substrate, optionally allows it to dry, and laminates the first substrate onto the second substrate, wherein the lamination can be carried out under thermal activation.

[0074] The first film is preferably selected from plastic films and aluminum films, whereby the plastic films may also be metallized.

[0075] Lamination is preferably carried out under pressure and / or increased temperature, in particular by thermal activation.

[0076] At least one of the substrates can be printed or metallized on the side coated with adhesive.

[0077] The invention also relates to foil-laminated articles produced according to the lamination process according to the invention, wherein the foil material is preferably selected from the group consisting of polyvinyl chloride, which may also contain plasticizers, and thermoplastic polyolefin (TPO) and combinations thereof.

[0078] The films used are often decorative plastic films and may have a surface texture. This surface texture on the plastic film can be embossed, for example, before, during, or after application.

[0079] Surface treatment of the film substrates is not strictly necessary before coating with the two-component adhesive. However, better results can be achieved if the surface of the film substrates is modified prior to coating. Conventional surface treatments can be applied, such as corona treatment to enhance adhesion. Preferably, the polymer film has hydrophilic groups on the surface that comes into contact with the adhesive. Hydrophilic groups include, for example, oxygen-containing groups (OH groups) or acid groups. These hydrophilic groups are preferably generated by corona treatment to enhance adhesion. The corona treatment or other surface treatments are carried out to the extent necessary for sufficient wettability with the coating composition.A corona treatment of approximately 10 watts per square meter per minute is typically sufficient for this purpose. Alternatively or additionally, primers or intermediate layers can optionally be used between the film substrate and the adhesive coating and / or the molded body substrate.

[0080] Furthermore, the films can have additional functional layers, such as barrier layers, printing layers, color or varnish layers, or protective layers. These functional layers can be located on the outside, i.e., on the side of the film substrate facing away from the adhesive, or on the inside, between the film substrate and the adhesive layer.

[0081] Lamination of molded parts involves the production of composite components through the permanent bonding of large-area, flexible films to rigid (three-dimensionally shaped, dimensionally stable, non-flexible) molded parts as a substrate. The flexible films are typically selected from polymer films and metal foils. They are bonded to the rigid molded parts, such as those made of metal, painted metal, wood, wood-based materials, fiber materials, or plastic. These molded parts can be furniture or furniture components, i.e., parts of furniture or automotive interior components.

[0082] In one embodiment, the laminated molded parts are foil-coated furniture. The foil-coated furniture produced according to the invention consists of composite parts. These composite parts may have additional primer layers between the foil and the adhesive layer and / or between the substrate and the adhesive layer to improve adhesion. The foils and substrates to be bonded may be pretreated with adhesion promoters. However, due to the already good adhesive properties of the adhesives according to the invention, the use of primers is not strictly necessary. The furniture parts may also be molded parts made of synthetic or natural fibers or chips bonded together by a binder. The molded parts can have any shape. MDF boards (medium-density fiberboard) are particularly preferred.

[0083] In the production of film-laminated molded parts for the automotive industry, the lamination is applied to a molded part intended for installation in a vehicle. These molded parts can also be made of synthetic or natural fibers or chips bonded together with a binder; in particular, molded parts made of plastic, e.g., ABS, are also suitable. The molded parts can have any shape.

[0084] Polymer films are particularly preferred as a first substrate. Polymer films are understood to be, in particular, flexible, sheet-like plastics with a thickness of 0.05 mm to 5 mm, preferably 0.25 mm to 1 mm, which can be rolled up. Thus, in addition to "films" in the strict sense of thicknesses less than 1 mm, the term also includes sealing membranes, such as those typically used for sealing tunnels, roofs, or swimming pools, with a thickness of typically 1 to 3 mm, and in special cases even up to a maximum thickness of 5 mm. Such plastic films are usually produced by coating, casting, extrusion, or, most preferably, by calendering, and are typically commercially available in rolls or produced on-site. They can be single-layer or multi-layered. The plastic of the polymer films is preferably a thermoplastic, e.g.,Polyesters, such as polyethylene terephthalate (PET), thermoplastic polyolefins (TPO) such as polyethylene, oriented polypropylene (OPP), unstretched polypropylene (CPP), polyvinyl chloride, especially flexible PVC, polyacetates, ethylene / vinyl acetate copolymers (EVA), ASA (acrylonitrile / styrene / acrylic acid ester copolymers), PUR (polyurethane), PA (polyamide), poly(meth)acrylates, polycarbonates, or their polymer alloys, cellophane, metal-coated (vapor-deposited) polymer films (in short: metallized films), or metal films, e.g., made of aluminum. The aforementioned films may also be printed with printing inks. Rigid PVC and thermoplastic polyethylene terephthalate (PET) are particularly preferred.

[0085] The coating of the films and substrates with the adhesive can be carried out using conventional application methods, for example by spraying, brushing, squeegeeing, stamping, rolling or casting. Spraying is preferred.

[0086] The amount of adhesive applied is preferably 0.5 to 100 g / m², particularly preferably 2 to 80 g / m², and most preferably 10 to 70 g / m², based on the adhesive. Preferably, only the film or only the substrate is coated on one side. However, coating both components to be bonded, i.e., the film and the substrate, is also possible. After coating, drying is usually carried out, preferably at room temperature or at temperatures up to 80 °C, to remove water or other solvents.

[0087] The adhesive can be thermally activated. The temperature in the adhesive layer is preferably at least 30°C or at least 40°C, e.g., from 30 to 200°C, or from 40 to 180°C. A particular advantage of the invention lies in the good activation of the adhesive even at temperatures below the temperature range of 60-70°C used with conventional adhesives, e.g., at temperatures of less than 60°C, e.g., a maximum of 58°C, a maximum of 55°C, or a maximum of 50°C.

[0088] Bonding is preferably carried out under pressure. For this purpose, the parts to be bonded can be pressed together with a pressure of at least 0.005, 0.01, or 0.08 N / mm², or, for example, 0.005 to 5 N / mm² or 0.01 to 0.8 N / mm². The contact pressure can be generated, for example, by applying a vacuum between the film and the substrate and / or by using air pressure.

[0089] The inventive method is also of particular importance for the production of vehicle components. The use of the adhesive according to the invention is especially preferred for the production of interior trim parts for automobiles. Examples of such interior trim parts include door panels, dashboards, instrument panels, parcel shelves, headliners, sliding headliners, center consoles, glove compartments, sun visors, pillars, door and arm handles, floor, load floor and trunk assemblies, as well as sleeper cabs and rear walls of vans and trucks. For this purpose, a vacuum thermoforming process or press lamination using a sealing process is particularly suitable. In the vacuum thermoforming process, the adhesive is applied to the molded part. This is followed, if necessary, by evaporation, e.g., at room temperature or in a drying tunnel at preferably a maximum of 40°C. Typically, the film to be bonded, e.g.,A decorative film made of airtight material is clamped airtight in a frame. Beneath the film is a sub-mold onto which the molded part is placed. Both the sub-mold and the molded part are perforated, allowing air to pass through. The device is further sealed airtight at the bottom. When the air is extracted from this device, the film conforms precisely to the molded part under the atmospheric pressure acting on its surface. The film is heated before the vacuum is applied. Due to the vacuum being created, the film is airtight. In the press lamination process, the adhesive is also applied to the molded part and, if necessary, to the film to be bonded, but at least to the molded part. This is followed, if necessary, by a drying process, typically at room temperature or in a drying tunnel at a preferably maximum temperature of 40°C.The bonding of shaped parts to the film can be carried out after heat activation, involving joining and pressing. The films used here are often decorative plastic films and have a surface texture. This surface texture on the plastic film can be embossed, for example, before, during, or after bonding.

[0090] In the laminating process according to the invention for producing composite films, the two-component adhesive described above, or a correspondingly prepared formulation, is applied to the substrates to be bonded, preferably with a layer thickness of 0.1 to 20 g / m², particularly preferably 1 to 7 g / m², e.g., by doctor blade application, brushing, etc. Conventional coating processes can be used, e.g., roller coating, counter-rotating roller coating, engraved roller coating, counter-rotating engraved roller coating, brush coating, rod coating, spray coating, airbrush coating, meniscus coating, curtain coating, or dip coating. After an optional short evaporation period for volatile components (preferably after 1 to 60 seconds), the coated film substrate can then be laminated with a second film substrate, the temperature being, for example, 20 to 200 °C, preferably 20 to 100 °C, and the pressure, for example,The tensile strength can range from 100 to 3000 kN / m², preferably from 300 to 2000 kN / m². Suitable substrates for laminated film include, for example, polymer films, especially those made of polyethylene (PE), oriented polypropylene (OPP), unstretched polypropylene (CPP), polyamide (PA), polyethylene terephthalate (PET), polyacetate, cellophane, metal-coated (e.g., aluminum), metallized films, or metal foils, e.g., aluminum. These films can be bonded to each other or to a different type of film, e.g., polymer films to metal foils, different polymer films to each other, etc. The films can also be printed with inks, for example.

[0091] One embodiment of the invention is a composite film obtainable by the lamination process described above, i.e., produced using one of the two-component adhesives described above. The material of a first film is preferably selected from OPP, CPP, PE, PET, and PA, and the material of a second film is preferably selected from OPP, CPP, PE, PET, PA, and metal foil. In one embodiment of the invention, the first film and / or the second film is printed or metallized on the respective side that is coated with the adhesive. The thickness of the substrate films can be, for example, from 5 to 100 µm, preferably from 5 to 40 µm. In preferred composite films, the film material is selected from the group consisting of aluminum foil, printed polyester film, unprinted polyester film, printed polyamide film, unprinted polyamide film, polypropylene film, polyethylene film, and combinations thereof.

[0092] In glossy film lamination, a first substrate is laminated with a second substrate, wherein the first substrate is a polymer film, preferably a transparent polymer film, and the second substrate is paper, cardboard, or corrugated board, preferably printed, and wherein the lamination is preferably carried out under pressure and heat. The lamination process is analogous to the production of composite films. Preferably, the glossy film laminate is produced using the two-component adhesive described above, wherein the material of a transparent polymer film (first substrate) is selected from oriented polypropylene (OPP), unstretched polypropylene (CPP), polyethylene (PE), polyamide (PA), polyethylene terephthalate (PET), polyacetate, and cellophane, and wherein the material of the second substrate is selected from paper, cardboard, and corrugated board.Preferably, a corona-treated OPP film is used as the polymer film for the glossy film lamination. In one embodiment of the invention, the second substrate of the glossy film is colored or printed on the side that is coated with adhesive. The thickness of the polymer film can be, for example, from 5 to 100 µm, preferably from 5 to 40 µm.

[0093] The present invention will now be explained in more detail with reference to the following examples. Examples Example 1: Compound with three 2-oxo-1,3-dioxolane-4-carboxamide groups based on ethoxylated / propoxylated glycerol

[0094] = Glycerol plus EO / PO M eq = 1870 g / mol (molecular weight per cyclocarbonate group)

[0095] Under a nitrogen atmosphere, 13.94 g of toluene-2,4-diisocyanate (TDI) (0.0825 mol) and 10.56 g of 2-oxo-[1,3]-dioxolane-4-carboxylic acid (0.08 mol) are dissolved in 70 mL of dry THF or acetone. 0.12 g (1 mol%) of 1,8-diazabicyclo[5,4,0]-undec-7-ene (DBU) are added, and the reaction mixture is stirred for 12 h at room temperature. After evaporation of the solvent, the product is obtained as a white solid in quantitative yield.

[0096] The reaction can also take place in dry acetonitrile and with 4-DMAP as a catalyst.

[0097] In the presence of DBTL (dibutyltin dilaurate, 0.02 wt%), the product obtained can be reacted with Lupranol® < 2095 (trifunctional polyether polyol with primary hydroxyl end groups) to form a difunctional prepolymer. For this purpose, 5.0 g (0.0195 mol) of the product are dissolved in dry THF, and 31.2 g of Lupranol® < 2095 (6.52 mmol) and 1.2 mg of DBTL (0.002 mmol) are added. The reaction mixture is heated to 60 °C for 4 h. After evaporation of the solvent, the product is obtained as a viscous yellow oil. Example 2 Compound with three 2-oxo-1,3-dioxolane-4-carboxamide groups, produced from glycerol carbonate carboxylic acid (2-oxo-1,3-dioxolane-4-carboxylic acid) and isocyanurate-modified hexamethylene diisocyanate (Basonat ®< HI 100) Basonat HI 100:

[0098]

[0099] 31.79 g of cyclocarbonate carboxylic acid (0.12 mol) in 80 ml of THF were added, yielding a yellow solution. 0.3704 g of DMAP (4-(dimethylamino)pyridine, 0.0012 mol) in 60 ml of THF were added. Then, 46.09 g of Basonat®< HI100 (0.12 mol based on NCO; the NCO number of Basonat®< HI100 corresponds to 21.9%) in 80 ml of THF were added. This solution was stirred at room temperature for approximately 24 hours. The solution became cloudy overnight. After evaporation of the THF, 73.76 g of yellow, highly viscous liquid remained. No NCO peak was visible in the IR spectrum, and the NCO number corresponded to 1.1%. Example 3: Two-component adhesives

[0100] The 2-oxo-1,3-dioxolane-4-carboxamide of Example 1 and Example 2 were dissolved in THF at 23°C and mixed with different amine hardeners (see Table 1).

[0101] The resulting reactive two-component adhesive was applied to a printed 36 µm thick polyester film immediately after mixing, in a layer thickness of 3 µm. The solvent was evaporated using a hot air stream, and then a second 36 µm thick polyester film, which had previously undergone corona treatment, was laminated onto the adhesive layer in a calender under a pressure of 3 bar. The resulting laminate was cut into 15 mm wide strips, and the peel strength of these strips was determined after 24 h at room temperature (20 °C) [N / 15 mm]. A tearing machine was used, and the peel strength test was performed at a tear angle of 90° (T-test). The results are shown in Table 1. Amine hardeners:

[0102] DODDA: 4,9-Dioxadodecane-1,12-diamine H 2 NCH 2 CH 2 CH 2 OCH 2 CH 2 CH 2 CH 2 OCH 2 CH 2 CH 2 NH 2 DATOTD: 1,13-diamino-4,7,10-trioxatridecane H 2 NCH 2 CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 CH 2 NH 2 DAP: 1,3-diaminopropane, H 2 NCH 2 CH 2 CH 2 NH 2 Table 1: Adhesive compositions and results of peel strength measurements Example 2-Oxo-1,3-dioxolane-4-carboxamide Amine hardener Peel strength 24h [N / 15 mm] 3.1 1872 g Example 1 102 g DODDA 3,1 3.2 1872 g Example 1 110 g DATOTD 4,5 3.3 1872 g Example 1 37 g DAP 3,3 3.4 280 g Example 2 240 g Polyetheramine D 400 3,4 3.5 280 g Example 2 37 g DAP 0,3 3.6 Comparison 40 g Liofol ®< UR7732 60 g Liofol ®< UR 6084 3,6 Liofol® < UR7732 / Liofol® < UR 6084: Two-component polyurethane laminating adhesive consisting of isocyanate-based binder (Liofol® < UR7732) and polyol hardener (Liofol® < UR 6084)

[0103] A peel strength greater than 1.5 N after 24 h is particularly suitable for applications of the adhesive in flexible packaging and for laminated film applications, in order to be industrially usable.

Claims

1. The use of compounds having n 2-oxo-1,3-dioxolane-4-carboxamide units as reactive component in 2-component adhesives, where n is a number greater than or equal to 2, preferably for preparing hydroxypolyurethanes or hydroxypolycarbonates for adhesives applications.

2. The use according to claim 1, wherein the compounds having two or more 2-oxo-1,3-dioxolane-4-carboxamide units have the formula (I) where R1 and R3 independently of one another are selected from H and an organic radical; and R2 is an n-valent organic radical which is substituted by n-1 further 2-oxo-1,3-dioxolane-4-carboxamide groups, and n is a number greater than or equal to 2.

3. The use according to claim 2, wherein in formula (I) R1 is selected from H, straight-chain, branched or cyclic C1-12 alkyl groups, C6-10 aryl groups, C6-12 arylalkyl groups and C6-12 alkylaryl groups; and R3 is selected from H and straight-chain, branched or cyclic C1-12-alkyl groups, preferably H.

4. The use according to either of claims 2 and 3, wherein R1 is selected from H, straight-chain, branched or cyclic C1-12 alkyl groups, C6-10 aryl groups, C6-12 arylalkyl groups and C6-12 alkylaryl groups and R3 in formula (I) is selected from H, aryl groups and straight-chain, branched or cyclic C1-12 alkyl groups, which may also comprise O or N atoms, where R1 and R3 in formula (I) are preferably each H; and R2 is an n-valent radical which is substituted by n-1 further 2-oxo-1,3-dioxolane-4-carboxamide groups of the general formula (II) where R3 in formula (II) is selected from H, aryl groups and straight-chain, branched or cyclic C1-12 alkyl groups, which may also comprise O or N atoms, where R3 in formula (II) is preferably H; and n is a number greater than or equal to 2.

5. The use according to any of the preceding claims, wherein n = 2 to 5, preferably n = 2 to 3.

6. The use according to any of the preceding claims, wherein a polyfunctional curing agent compound is used as a second component of the two-component adhesive and is selected from polyamines which have two or more amine groups and polyols which have two or more alcoholic hydroxyl groups.

7. The use according to any of the preceding claims, wherein either the compound having n 2-oxo-1,3-dioxolane-4-carboxamide units and / or the curing agent compound comprises at least one linear or branched spacer group, where the flexible spacer group has a molecular weight of at least 200 g / mol and is preferably selected from alkylene groups, polyether groups, polycarbonate groups, polyester groups and poly(meth)acrylate groups.

8. The use according to any of the preceding claims, wherein R2 in formula (I) is selected from the group consisting of linear or branched C2 to C22 alkylene groups; polyether groups of the general formula -(A-O)m-, where A is C2 to C5 alkylene and m is a number from 1 to 100; polycarbonate groups; polyester groups; and poly(meth)acrylate groups.

9. The use according to any of the preceding claims, wherein the compound having n 2-oxo-1,3-dioxolane-4-carboxamide units is selected from the group consisting of : compounds of the formula (III) where n is a number from 1 to 12; compounds of the formula (IV) where y is a number from 1 to 12; compounds of the formula (V) compounds of the formula (VI) where n is a number greater than or equal to 0, preferably 0 to 5; and compounds of the formula (VII) where is an alkoxylated glycerol radical.

10. A two-component adhesive comprising as reactive first component, at least one compound having n 2-oxo-1,3-dioxolane-4-carboxamide units; and as second component, at least one curing agent compound selected from polyamines and polyols; where n is a number greater than or equal to 2; the polyamines have two or more amine groups; and the polyols have two or more alcoholic hydroxyl groups; where preferably either the compound having n 2-oxo-1,3-dioxolane-4-carboxamide units and / or the curing agent compound comprises at least one linear or branched spacer group, where the flexible spacer group has a molecular weight of at least 200 g / mol and is preferably selected from alkylene groups, polyether groups, polycarbonate groups, polyester groups and poly(meth)acrylate groups.

11. The two-component adhesive according to the preceding claim, which at temperatures of 70°C or below has a Brookfield viscosity of less than 10 000 mPa s, measured at 12 rpm with spindle 3.

12. The two-component adhesive according to either of claims 10 and 11, which comprises at least one catalyst for catalyzing the reaction of the cyclocarbonate groups with the functional groups of the curing agent.

13. An adhesive bonding method wherein two substrates are bonded to one another and, to the surface of at least one of the substrates, a 2-component adhesive is applied which comprises at least one compound having n 2-oxo-1,3-dioxolane-4-carboxamide units as a reactive component, and n is a number greater than or equal to 2.

14. The adhesive bonding method according to the preceding claim, being a laminating method for producing laminated articles selected from high-gloss films, composite films, and laminated moldings, where a) a first substrate in the form of a first film is provided, b) a second substrate is provided, selected from paper, a second film, which may be identical to or different from the first film, and moldings, c) a two-component adhesive according to any of claims 10 to 12 is provided, and d) the two-component adhesive is applied to the first substrate and / or to the second substrate, and is optionally allowed to dry, and the first substrate is laminated onto the second substrate, it being possible for the lamination to take place with thermal activation.

15. A film-laminated article produced by the method of the preceding claim.