Moisture and heat curable sealing composition

Abstract

The present invention relates to a sealing composition comprising at least one epoxy-terminated polyurethane prepolymer (A), a heat-activatable curing agent or accelerator (B) comprising an amidoamine with primary amino groups and a dicyanodiamide, an impact modifier (I) being the reaction product of at least one polymeric diol, at least one polyisocyanate, and cardanol, and at least one polyaldimine (PA). The sealing compound composition is suitable for use as a sealing compound in vehicle bodies.

Description

[Technical Field]

[0001] The present invention relates to the field of sealing compositions, in particular for car bodywork. [Background technology]

[0002] In bodywork processing, individual metal plates are joined together. To minimize corrosion, the metal plates used are oiled. Furthermore, the body typically passes through a CDC bath (CDC = cathode dip coating) at the end of the body's assembly, resulting in the body being coated with a so-called CDC paint, which is then baked in a CDC oven. A good CDC coating on the entire surface area significantly contributes to corrosion resistance and is therefore the basis for the long-term use of the vehicle.

[0003] Therefore, these oiled metal plates, e.g., steel substrates, are typically coated with a sealer that must adhere reliably to the oil-coated sheet metal and that does not need to be cured with heat or UV light before immersion in a paint bath, yet still rapidly builds up strength.

[0004] WO 2012 / 084806 provides a thermosetting sealing compound composition with a dual curing mechanism. On the one hand, a skin is rapidly formed by the reaction of the polyisocyanate with the polyaldimine in contact with air and / or atmospheric humidity, ensuring that the sealing compound can pass through a CDC bath without damage. In high-quality applications, paint can adhere to the sealing compound. In a separate step, the sealing compound is cured by heat, for example, the heat prevailing in a CDC oven.

[0005] However, with these sealers there are sometimes problems with bubble formation. Furthermore, adhesion on oiled metal plates still needs to be increased to meet more demanding requirements in manufacturing. Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to provide a single-component sealing composition that has improved adhesion to oil-coated sheet metal and less bubble formation (e.g., no bubbles in the applied bead after 1-2 days at room temperature or within 30 minutes at 180°C), while still maintaining good mechanical properties and storage stability and rapid strength buildup. [Means for solving the problem]

[0007] Surprisingly, it has been found that the moisture and heat curable sealing composition according to claim 1 achieves this object.

[0008] The sealing compound composition is therefore particularly suitable for use as a sealing compound in vehicle bodies.

[0009] Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention provides - at least one epoxy-terminated polyurethane prepolymer (A), - a heat-activatable curing agent or accelerator (B) comprising an amidoamine having a primary amino group and a dicyanodiamide; an impact modifier (I) which is a reaction product of at least one polymeric diol, at least one polyisocyanate and cardanol; - at least one polyaldimine (PA) The present invention relates to a moisture and heat curable sealing composition comprising:

[0011] The term "polymer" as used herein refers, on the one hand, to a group of macromolecules that are chemically uniform but differ in terms of degree of polymerization, molecular weight and chain length, and are synthesized by multiple reactions (polymerization, polyaddition, polycondensation). On the other hand, the term also includes derivatives of such a group of macromolecules from multiple reactions, i.e., compounds obtained by reactions, for example, addition or substitution of functional groups on a given molecule, which may be chemically uniform or chemically heterogeneous. The term also includes so-called prepolymers, i.e., reactive oligomeric precursors whose functional groups participate in the structure of the macromolecule.

[0012] The term "polyurethane polymer" includes all polymers synthesized by the so-called diisocyanate polyaddition process. This also includes polymers that are largely or completely free of urethane groups. Examples of polyurethane polymers include polyether polyurethanes, polyester polyurethanes, polyether polyureas, polyureas, polyester polyureas, polyisocyanurates, and polycarbodiimides (Houben Weyl "Methoden der organischen Chemie [Methods of Organic Chemistry]," Thieme Verlag, Stuttgart 1987, Vol. E20, page 1561).

[0013] Substance names beginning with "poly", such as polyisocyanates, polyaldimines, polyamines, polyols, polymercaptans, or polyglycidyl ethers, are used herein to refer to substances that officially contain two or more functional groups (which also appear in their names) per molecule.

[0014] All industry standards referenced herein relate to the version in effect on the date of first filing, unless otherwise specified.

[0015] The terms "mass" and "weight" are used synonymously herein. Thus, "weight percent" (wt%) is a mass percentage relative to the mass (weight) of the total composition or, as the case may be, of all molecules, unless otherwise stated.

[0016] The term "molecular weight" as used herein in reference to polymers refers to the average molecular weight M, typically measured by gel permeation chromatography (GPC) against polystyrene standards. n Refers to...

[0017] Room temperature in this specification is understood to be a temperature of 25°C.

[0018] The term "vehicle" is understood herein to refer to any means of sea, land and air transport, including in particular ships, wheeled vehicles such as automobiles, buses, cars, trucks and rail vehicles such as trams and rail cars.

[0019] The term "primary amino group," as used herein, refers to an amino group in the form of an NH group that is attached to an organic group. Thus, a "primary amine" is a molecule having a primary amino group.

[0020] The term "secondary amino group" refers to an amino group in which the nitrogen atom is attached to two organic groups, which together may be part of a ring. Thus, a "secondary amine" is a molecule having a secondary amino group.

[0021] The term "tertiary amino group" refers to an amino group in which the nitrogen atom is bonded to three organic groups, two of which may together be part of a ring (= the tertiary amine nitrogen). Thus, a "tertiary amine" is a molecule containing a tertiary amino group.

[0022] "Aliphatic" refers to an amine or amino group in which the nitrogen atoms are bonded exclusively to aliphatic, alicyclic, or araliphatic groups.

[0023] The term "epoxide group" or "epoxy group" refers to a structural element [ka] is understood to refer to

[0024] "Glycidyl ether" refers to an ether of 2,3-epoxy-1-propanol (glycidol).

[0025] The dashed lines in the formulae herein represent in each case the respective substituents and the bonds between the respective molecular groups.

[0026] The moisture and heat curable sealing composition is a single component composition.

[0027] "Single-component" compositions, as used herein, refer to hardenable compositions in which all components of the composition are mixed and stored together in the same container, are stable on storage at room temperature for extended periods of time, such that they undergo little or no significant change in their use or application properties on storage, and such compositions harden following application by the action of moisture and / or heat.

[0028] The at least one epoxy-terminated polyurethane prepolymer (A) used in the moisture- and heat-curable composition of the present invention refers to an isocyanate group-containing polyurethane prepolymer that is partially terminated with epoxide and has a specific content of free isocyanate groups, preferably 0.8 to 3.0 wt %, preferably 1.0 to 2.5 wt %, more preferably 1.5 to 2.0 wt %, based on the total weight of the polyurethane prepolymer (A). Therefore, the epoxy-terminated polyurethane polymer used herein is different from a simple mixture of an epoxy resin and an isocyanate group-containing polyurethane prepolymer.

[0029] In the moisture and heat curable composition of the present invention, the at least one epoxy-terminated polyurethane prepolymer (A) is advantageously used in an amount of 35 to 60% by weight, preferably 40 to 55% by weight.

[0030] In one embodiment, the epoxy-terminated polyurethane prepolymer (A) has the following formula (IVa): [ka] (In the formula, R1 is a linear or branched polyurethane prepolymer PU1 terminated by n+m isocyanate groups after removal of all terminal isocyanate groups, Each R 2 is, independently of the others, of formula (II) [ka] (wherein, in each case, R 4 is the portion of an aliphatic, cycloaliphatic, aromatic or araliphatic epoxide containing a primary or secondary hydroxy group after removal of the hydroxide and epoxide groups, p=1, 2 or 3) is the basis of Each of n and m is a value from 1 to 7, provided that 2≦(m+n)≦8. It can be represented by:

[0031] R 1 The polyurethane prepolymer PU1 based on at least one diisocyanate or triisocyanate or else a polymer Q having terminal amino, thiol or hydroxy groups PM and / or polyphenol Q with substitutions where appropriate PP can be generated from

[0032] Suitable diisocyanates are aliphatic, cycloaliphatic, aromatic or araliphatic diisocyanates, in particular commercially available products such as methylene-diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), tolidine diisocyanate (TODI), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (TMDI), 2,5- or 2,6-bis(isocyanatomethyl)bicyclo[2.2.1]heptane, naphthalene 1,5-diisocyanate (NDI), dicyclohexylmethyl diisocyanate (HDI), 12HDI, IPDI, MDI or TDI are preferred.

[0033] Suitable triisocyanates are trimers or biurets of aliphatic, cycloaliphatic, aromatic or araliphatic diisocyanates, especially the isocyanurates and biurets of the diisocyanates mentioned in the paragraph above.

[0034] Of course, it is also possible to use suitable mixtures of di- or triisocyanates.

[0035] Particularly suitable polymers Q having terminal amino, thiol or hydroxy groups PM is a polymer Q having two or three terminal amino, thiol or hydroxy groups PM is.

[0036] Polymer Q PM has an equivalent weight of NCO-reactive groups of advantageously 300 to 6000, in particular 600 to 4000, preferably 700 to 2200 g / eq.

[0037] Suitable Polymer Q PM is a polyol, such as the following commercially available polyols or any desired mixture thereof: - polyoxyalkylene polyols, also called polyether polyols, which are the polymerization products of ethylene oxide, propylene 1,2-oxide, butylene 1,2- or 2,3-oxide, tetrahydrofuran or mixtures thereof, polymerized, where appropriate, with an initiator molecule having two or three active H atoms (for example, water or a compound having two or three OH groups). The materials used can be, for example, polyoxyalkylene polyols with a low degree of unsaturation (expressed in milliequivalents of unsaturation per gram of polyol (mEq / g) measured according to ASTM D2849-69), produced with what are known as double metal cyanide complex catalysts (abbreviated as DMC catalysts), or other polyoxyalkylene polyols with a higher degree of unsaturation, produced, for example, with anionic catalysts, such as NaOH, KOH or alkali metal alcoholates. Particularly suitable materials are polyoxypropylene diols and triols, polyoxybutylene diols and triols, polyoxypropylene diols and triols having a degree of unsaturation of less than 0.02 mEq / g and molecular weights in the range of 1,000 to 30,000 daltons, polyoxypropylene diols and triols having a molecular weight of 400 to 8,000 daltons, and also materials referred to as "EO-endcapped" (ethylene oxide-endcapped) polyoxypropylene diols or triols. The latter are, for example, certain polyoxypropylene polyoxyethylene polyols obtained by alkoxylating pure polyoxypropylene polyols after completion of the polypropoxylation reaction using ethylene oxide, so that the product has primary hydroxy groups. hydroxy-terminated polybutadiene polyols, such as those produced via polymerization of 1,3-butadiene and allyl alcohol or via oxidation of polybutadiene, and also their hydrogenation products; styrene-acrylonitrile-graft polyether polyols, such as those supplied by Elastogran under the trademark Lupranol®; - polyhydroxy-terminated acrylonitrile / butadiene copolymers, such as those obtained from carboxy-terminated acrylonitrile / butadiene copolymers (commercially available as Hycar® CTBN from Nanoresins AG, Germany) and epoxides or amino alcohols; polyesterpolyols derived from dihydric to trihydric alcohols, such as 1,2-ethanediol, diethylene glycol, 1,2-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, glycerol, 1,1,1-trimethylolpropane or mixtures of the aforementioned alcohols, using, for example, organic dicarboxylic acids or their anhydrides or esters (e.g., succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid and hexahydrophthalic acid or mixtures of the aforementioned acids), and also lactones, such as ε-caprolactone, Polycarbonate polyols, such as those obtained by reacting the above-mentioned alcohols (used in the construction of the polyester polyols) with dialkyl carbonates, diaryl carbonates or phosgene.

[0038] Polymer Q PM is advantageously an at least dihydric polyol having an OH-equivalent weight of 300 to 6000 g / OH equivalent, in particular 600 to 4000 g / OH equivalent, preferably 700 to 2200 g / OH equivalent. Further advantageous polyols are those selected from the group consisting of polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol block copolymers, polybutylene glycol, hydroxy-terminated polybutadiene, hydroxy-terminated butadiene / acrylonitrile copolymers, hydroxy-terminated synthetic rubbers, hydrogenation products thereof and mixtures of the aforementioned polyols.

[0039] Other polymers Q that can be used similarly PMare at least difunctional amino-terminated polyethylene ethers, polypropylene ethers, such as those sold by Huntsman under the trademark Jeffamine®, polybutylene ethers, polybutadienes, butadiene / acrylonitrile copolymers, such as those sold by Nanoresins AG, Germany under the trademark Hycar® ATBN, and also other amino-terminated synthetic rubbers or mixtures of the components mentioned.

[0040] For certain applications, polymer Q is particularly suitable PM is a hydroxylated polybutadiene or polyisoprene or a partially or fully hydrogenated reaction product thereof.

[0041] Polymer Q PM It is further possible that the may be chain extended in a manner known to those skilled in the art via reaction with polyamines, polyols and polyisocyanates, especially diamines, diols and diisocyanates.

[0042] For the chain extension reaction, diols and / or diamines and diisocyanates are particularly preferred. Of course, those skilled in the art will recognize that it is also possible to use higher functionality polyols, such as trimethylolpropane or pentaerythritol, or higher functionality polyisocyanates, such as isocyanurates of diisocyanates, for the chain extension reaction.

[0043] In general, in the case of polyurethane prepolymers PU1 and in particular in the case of chain-extended polyurethane prepolymers, it is advantageous to ensure that the prepolymer does not have excessive viscosity, especially when higher functionality compounds are used for the chain extension reaction, as this can cause difficulties in those reactions to obtain polymers of formula (IVa) or in the application of the composition.

[0044] Preferred Polymer Q PMis a polyol having a molecular weight of 600 to 6000 daltons selected from the group consisting of polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol block polymer, polybutylene, glycol, hydroxy-terminated polybutadiene, hydroxy-terminated butadiene-acrylonitrile copolymer, and mixtures thereof.

[0045] Particularly preferred polymer Q PM are α,ω-dihydroxypolyalkylene glycols having C2-C6 alkylene groups or mixed C2-C6 alkylene groups and terminated with amino, thiol or, preferably, hydroxy groups. Polypropylene glycol or polybutylene glycol are particularly preferred. Polyoxybutylene terminated with hydroxy groups is even more particularly preferred.

[0046] Bis, tris and tetraphenols are polyphenols Q PP Phenols are particularly suitable as: (I) (II) (III). This not only means unsubstituted phenols, but also, where appropriate, substituted phenols. The nature of the substitution can vary widely. This particularly means direct substitution on the aromatic ring that is connected to the phenolic OH group. Phenols here also include not only monocyclic aromatic compounds, but also polycyclic or fused aromatic compounds or heterocyclic aromatic compounds that have the phenolic OH group directly on the aromatic or heteroaromatic system.

[0047] The nature and location of this type of substituent is one of the factors that influence the reaction with isocyanates that is necessary to form the polyurethane prepolymer PU1.

[0048] Bis- and trisphenols are particularly suitable. Examples of suitable bisphenols or trisphenols are 1,4-dihydroxybenzene, 1,3-dihydroxybenzene, 1,2-dihydroxybenzene, 1,3-dihydroxytoluene, 3,5-dihydroxybenzoate, 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), bis(4-hydroxyphenyl)methane (=bisphenol F), bis(4-hydroxyphenyl)sulfone (=bisphenol S), naphthresorcinol, dihydroxynaphthalene, dihydroxyanthraquinone, dihydroxybiphenyl, 3,3-bis(p-hydroxyphenyl)phthalide, 5,5-bis(4-hydroxyphenyl)hexahydro- These include 4,7-methanoindan, phenolphthalein, fluorescein, 4,4'-[bis(hydroxyphenyl)-1,3-phenylenebis(1-methylethylidene)] (= bisphenol M), 4,4'-[bis(hydroxyphenyl)-1,4-phenylenebis(1-methylethylidene)] (= bisphenol P), 2,2'-diallylbisphenol A, diphenols and dicresols produced by reacting phenol or cresol with diisopropylidenebenzene, phloroglucin, gallic acid esters, phenol novolac, cresol novolacs with OH functionalities of 2.0 to 3.5, and also all isomers of the aforementioned compounds.

[0049] In a first embodiment, the polyurethane prepolymer PU1 is a polymer Q having at least one diisocyanate or triisocyanate and also terminal amino, thiol or hydroxy groups. PM The polyurethane prepolymer PU1 is produced from the polymer Q PM These are produced in a manner known to those skilled in the art of polyurethanes by using a stoichiometric excess of diisocyanates or triisocyanates based on the amino, thiol or hydroxy groups of the polyurethane.

[0050] In a second embodiment, the polyurethane prepolymer PU1 is prepared by the addition of at least one diisocyanate or triisocyanate and, if appropriate, a substituted polyphenol Q.PP Polyurethane prepolymer PU1 is produced from polyphenol Q PP Polyurethanes are produced in a manner known to those skilled in the art by using a stoichiometric excess of diisocyanate or triisocyanate based on the phenolic groups of the polyurethane.

[0051] In a third embodiment, the polyurethane prepolymer PU1 is a polymer Q having at least one diisocyanate or triisocyanate and also terminal amino, thiol or hydroxy groups. PM and also polyphenol Q, where appropriate with substitutions PP A polymer Q having at least one diisocyanate or triisocyanate and also terminal amino, thiol or hydroxy groups is produced from PM and / or polyphenol Q with substitutions where appropriate PP Various possibilities are available for the production of the polyurethane prepolymer PU1 from

[0052] The partially epoxy-terminated polyurethane prepolymer of formula (IVa) has isocyanate groups and is represented by the formula (III): [ka] and an appropriate amount of a polyurethane prepolymer PU1 having the formula (V) [ka] with a monohydroxyepoxide compound.

[0053] The monohydroxyepoxide compound of formula (V) has 1, 2 or 3 epoxide groups. The hydroxy group of the monohydroxyepoxide compound (V) can be a primary or secondary hydroxy group.

[0054] These monohydroxyepoxide compounds can be produced, for example, by reacting polyols with epichlorohydrin. Depending on the reaction of polyhydric alcohols with epichlorohydrin, the corresponding monohydroxyepoxide compounds are also produced as by-products in various concentrations. These can be isolated by conventional separation procedures. However, it is generally possible to simply use product mixtures composed of polyols obtained in the glycidylation reaction of polyols, which have been completely or partially reacted to give glycidyl ethers. Examples of these hydroxyepoxides are butanediol monoglycidyl ether (present in butanediol diglycidyl ether), hexanediol monoglycidyl ether (present in hexanediol diglycidyl ether), cyclohexanedimethanol glycidyl ether, trimethylolpropane diglycidyl ether (in the form of a mixture present in trimethylolpropane triglycidyl ether), glycerol diglycidyl ether (in the form of a mixture present in glycerol triglycidyl ether), and pentaerythritol triglycidyl ether (in the form of a mixture present in pentaerythritol tetraglycidyl ether). It is preferred to use trimethylolpropane diglycidyl ether, a relatively high proportion of which occurs in conventionally produced trimethylolpropane triglycidyl ether.

[0055] However, it is also possible to use other similar hydroxylated epoxides, in particular glycidol, 3-glycidyloxybenzyl alcohol or hydroxymethylcyclohexene oxide.More preferred are the β-hydroxyethers of formula (IX) which are present to an extent of about 15% in commercially available liquid epoxy resins made from bisphenol A (R=CH3) and epichlorohydrin, and also the corresponding β-hydroxyethers of formula (IX) which are formed during the reaction of bisphenol F (R=H) or a mixture of bisphenol A and bisphenol F with epichlorohydrin. [ka]

[0056] Further preferred are distillation residues produced during the production of high-purity distilled liquid epoxy resins. These distillation residues have a concentration of hydroxylated epoxides that is 1 to 3 times higher than commercially available non-distilled liquid epoxy resins. Hereinafter, it is also possible to use a wide variety of epoxides containing β-hydroxyether groups, which are produced by the reaction of (poly)epoxides with substoichiometric amounts of monofunctional nucleophiles, such as carboxylic acids, phenols, thiols, or secondary amines.

[0057] The free primary or secondary OH functionality of the monohydroxyepoxide compound of formula (V) allows for efficient reaction with the terminal isocyanate groups of the prepolymer, without the need here to use a disproportionate excess of the epoxide component.

[0058] In the moisture and heat curable sealing compositions of the present invention, it is important to include a heat-activatable curing agent or accelerator (B) which comprises an amidoamine and a dicyanodiamide having a primary amino group.

[0059] The amidoamines containing primary amino groups are preferably those obtainable by reaction of phthalic anhydride and polyamines containing primary amino groups, in particular diethylenetriamine (DETA) or triethylenetetramine (TETA).

[0060] The dicyanodiamide can be present in finely divided form and have an average particle size of <12 μm, in particular 1 to 10 μm, preferably 5 to 9 μm. The particle size is determined here by means of a screen.

[0061] The inventors have found that the use of a specific combination of an amidoamine having a primary amino group and a dicyanodiamide as a heat-activatable curing agent or accelerator in the sealing composition of the present invention can bring about a considerable improvement in adhesion to oil-treated plates and mechanical properties after curing.

[0062] The heat-activatable curing agent or accelerator (B) advantageously contains 1.0 to 3.3 wt. %, preferably 1.5 to 3.0 wt. %, of amidoamine having a primary amino group and 0.05 to 0.8 wt. %, preferably 0.12 to 0.55 wt. %, of dicyanodiamide, each based on the total weight of the sealing composition. It has been found that less than 0.05 wt. % of dicyanodiamide in the composition may result in excessively low tensile strength, while more than 0.8 wt. % may excessively impair elongation at break. By using the required amount of dicyanodiamide in combination with the amidoamine having a primary amino group, the overall mechanical properties can be balanced.

[0063] The impact modifier (I) required in the curable composition of the present invention is the reaction product of at least one polymeric diol, at least one polyisocyanate, and cardanol.

[0064] In this reaction, a polymeric diol is preferably reacted in a first step with a polyisocyanate to produce an isocyanate-functional polyurethane prepolymer. The isocyanate groups of the polyurethane prepolymer are then preferably end-capped with cardanol to obtain the final impact modifier I. The impact modifier I preferably does not contain any measurable amount of further isocyanate groups. In particular, it is preferred that at least 75%, in particular at least 90%, and preferably at least 99% of all remaining isocyanate groups of the prepolymer are end-capped with cardanol after the reaction.

[0065] The isocyanate group-containing prepolymers for the impact modifier I are obtained in particular from the reaction of at least one monomeric polyisocyanate, in particular a diisocyanate, and at least one suitable diol. The reaction is preferably carried out with the exclusion of moisture at temperatures in the range from 20 to 160°C, in particular from 40 to 140°C, and, if appropriate, in the presence of a suitable catalyst.

[0066] The NCO / OH ratio is preferably in the range of from 1.1 / 1 to 10 / 1, preferably from 1.3 / 1 to 10 / 1. The monomeric polyisocyanates remaining in the reaction mixture after reaction of the OH groups can be removed in particular by means of distillation.

[0067] If excess monomeric polyisocyanate is removed by distillation, the NCO / OH ratio in the reaction is preferably in the range from 3 / 1 to 10 / 1, in particular from 4 / 1 to 7 / 1, and the isocyanate group-containing prepolymer thus obtained after distillation preferably contains at most 0.5% by weight, particularly preferably at most 0.3% by weight, of monomeric polyisocyanate.

[0068] If excess monomeric polyisocyanate is not removed from the prepolymer, the NCO / OH ratio in the reaction is preferably in the range of 1.3 / 1 to 2.5 / 1. Such prepolymers contain in particular at most 3% by weight, preferably at most 2% by weight, of monomeric polyisocyanate.

[0069] Preferred impact modifiers I are polymers of formula (IV): [ka]

[0070] In this formula, x and x' are each independently a value of 0 or 1, preferably 1, with the proviso that at least one, preferably both, of x and x' is not 0; R 5 is a linear polyurethane prepolymer containing at least x+x' terminal isocyanate groups after removal of the x+x' terminal isocyanate groups, R 6 and R 3 is the residue of cardanol after removal of the hydroxyl H atom and is attached via the oxygen atom.

[0071] Cardanol (CAS Registry Number: 37330-39-5) is a phenolic lipid derived from anacardic acid, a major component of cashew nut shell liquid (CNSL), a by-product of cashew nut processing. The name is derived from the contraction of the genus Anacardium, which includes the cashew tree, Anacardium occidentale. The structure is shown in formula (X). [ka]

[0072] The name cardanol is used for the decarboxylated derivative obtained by thermal decomposition of any of the naturally occurring anacardic acids. This includes multiple compounds, as the side chain configurations vary in their degree of unsaturation. The major component (41%), triunsaturated cardanol, is shown below in formula (VI). The remaining cardanol is 34% monounsaturated, 22% diunsaturated, and 2% saturated. [ka]

[0073] The phenolic OH groups of cardanol react readily with the isocyanate groups of the isocyanate-functional prepolymer to yield impact modifier I.

[0074] It is notable and surprising that cardanol is the only phenolic reagent that can be used in producing Impact Modifier I of the present invention. Other similar phenolic reagents, particularly nonylphenol, do not result in impact modifiers with the same advantageous properties as Impact Modifier I.

[0075] Furthermore, cardanol has the advantage of being based on natural renewable resources, which makes it inexpensive.

[0076] Cardanol is commercially available, for example, under the trade name Cardolite® NC-700 by Cardolite Corporation.

[0077] At least one polymeric diol is used in the process for preparing the cardanol endcapped prepolymer to produce Impact Modifier I. Suitable polymeric diols are those described above as particularly suitable for preparing polyurethane prepolymers.

[0078] Preferred diols are polyoxyalkylene diols, polyester diols, polycarbonate diols, polybutadiene diols, and poly(meth)acrylate diols. Among them, particularly preferred are polyether diols, in particular polypropylene glycol diol and polytetrahydrofuran diol.

[0079] Firstly, room temperature liquid polyoxypropylene diols and polyoxyethylene-polyoxypropylene co-diols are particularly preferred, in particular polyoxypropylene diols having an average molecular weight in the range of 300 to 15,000 g / mol, in particular 1,000 to 10,000 g / mol, preferably 2,000 to 5,500 g / mol. Particularly preferred are such diols having an average OH functionality in the range of 1.5 to 2.5, preferably 1.8 to 2.3.

[0080] Room temperature liquid or solid, amorphous or semi-crystalline or crystalline diols, especially polyester polyols and polycarbonate diols, are particularly preferred, especially polyester diols having average molecular weights in the range of 300 to 15,000 g / mol, in particular 1,000 to 10,000 g / mol, preferably 1,500 to 8,000 g / mol, in particular 2,000 to 5,500 g / mol. Particularly suitable are crystalline or semi-crystalline adipic acid / hexanediol polyesters and dodecanedicarboxylic acid / hexanediol polyesters.

[0081] Polybutadiene diols having an average OH functionality in the range from 1.5 to 2.5, preferably from 1.8 to 2.3, and an average molar mass in the range from 300 to 15,000 g / mol, in particular from 1,000 to 10,000 g / mol, preferably from 1,500 to 8000 g / mol, more preferably from 2000 to 4000 g / mol and in particular from 2500 to 3000 g / mol are further particularly preferred.

[0082] Such polybutadiene polyols are obtained in particular by polymerization of suitable proportions of 1,3-butadiene and allyl alcohol or by oxidation of suitable polybutadienes.

[0083] Suitable polybutadiene polyols are in particular polybutadiene diols containing structural elements of formula (VII) and optionally structural elements of formulae (VIII) and (IX). [ka]

[0084] Preferred polybutadiene diols are 40 to 80%, in particular 55 to 65%, of structural elements of formula (VII), 0 to 30%, in particular 15 to 25%, of structural elements of formula (VIII), 0 to 30%, in particular 15 to 25%, of structural elements of formula (IX) Contains:

[0085] Particularly suitable polybutadiene polyols are available, for example, from Cray Valley under the trade name range Poly bd®.

[0086] Of all diols, the most preferred for the synthesis of impact modifiers I are polyoxypropylene diols and polyoxyethylene-polyoxypropylene co-diols which are liquid at room temperature, in particular polyoxypropylene diols having an average molecular weight in the range of 300 to 15,000 g / mol, in particular 1,000 to 10,000 g / mol, preferably 2,000 to 5,500 g / mol, which allow particularly high impact peel strengths to be achieved.

[0087] Thus, in a most preferred embodiment, the diol is a polyoxypropylene diol or a polyoxyethylene-polyoxypropylene copolymer diol, in particular a polyoxypropylene diol having an average molecular weight in the range of 300 to 15,000 g / mol, in particular 1,000 to 10,000 g / mol, preferably 2,000 to 5,500 g / mol. Such diols having an average OH functionality in the range of 1.5 to 2.5, preferably 1.8 to 2.3, are particularly preferred.

[0088] In the process of preparing the prepolymer endcapped with cardanol to produce Impact Modifier I, at least one polyisocyanate, preferably a diisocyanate, is used.

[0089] Suitable polyisocyanates are in particular monomeric di- or triisocyanates and oligomers, polymers and derivatives of monomeric di- or triisocyanates, and any mixtures thereof. These polyisocyanates may be those mentioned above for preparing the polyurethane prepolymers.

[0090] Suitable diisocyanates are in particular commercially available aliphatic, cycloaliphatic, arylaliphatic and aromatic, preferably cycloaliphatic and aromatic, diisocyanates.

[0091] Preferred diisocyanates are hexamethylene 1,6-diisocyanate (HDI), 2,2,4- and 2,4,4-trimethylhexamethylene 1,6-diisocyanate (TMDI), cyclohexane 1,3- and 1,4-diisocyanate and any desired mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (=isophorone diisocyanate or IPDI), perhydrodiphenylmethane 2,4'- and 4,4'-diisocyanate (HMDI), m- and p-xylylene diisocyanate (m- and p-XDI), m- and p-tetramethylxylylene 1,3- and 1,4-diisocyanate (m- and p-TMXDI), tolylene 2,4- and 2,6-diisocyanate (TDI) and any desired mixtures of these isomers, and diphenylmethane 4,4'-, 2,4'- and 2,2'-diisocyanate and any desired mixtures of these isomers (MDI).

[0092] More preferably, the diisocyanate is selected from the group consisting of HDI, IPDI, MDI and TDI, which are particularly readily available.

[0093] Particularly preferred polyisocyanates, especially diisocyanates, are forms of MDI that are liquid at room temperature. These are in particular so-called polymeric MDI and MDI containing fractions of oligomers or their derivatives. The MDI (= 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate and any mixtures of these isomers) content of such liquid forms of MDI is particularly 50 to 95% by weight, in particular 60 to 90% by weight.

[0094] Particularly preferred as polyisocyanates are polymeric MDI and MDI types which are liquid at room temperature, preferably containing a fraction of MDI-carbodiimide or its adducts.

[0095] The most preferred polyisocyanates for the synthesis of impact modifier I are 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate and any mixtures of these isomers (MDI), mixtures of MDI and MDI homologues (polymeric MDI or PMDI), in particular MDI in forms that are liquid at room temperature and containing fractions of oligomers or derivatives thereof. The MDI content of such liquid forms of MDI (= 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate and any mixtures of these isomers) is preferably 50 to 95% by weight, in particular 60 to 90% by weight.

[0096] Thus, in the most preferred embodiment, the polyisocyanate is 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate and any mixture of these isomers (MDI). MDI-based impact modifiers I allow particularly high impact peel strength.

[0097] The impact modifier (I) preferably has a nominal epoxy equivalent weight of >500 g / eq, in particular >1000 g / eq, preferably >1500 g / eq, in particular >2000 g / eq.

[0098] It has been found to be advantageous if the impact modifier (I) is contained in an amount of 1 to 25% by weight, preferably 3 to 15% by weight, based on the total weight of the sealing composition. Less than 1% by weight of impact modifier (I) may weaken the elongation at break, while more than 25% by weight may impair the tensile strength.

[0099] Polyaldimines (PA) can be synthesized from polyamines (PAM) having two or more primary amino groups and aldehydes.

[0100] Particularly suitable polyamines (PAMs) having two or more primary amino groups include: aliphatic, cycloaliphatic or araliphatic diamines, such as ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 2-methyl-1,2-propanediamine, 2,2-dimethyl-1,3-propanediamine, 1,3-butanediamine, 1,4-butanediamine, 1,3-pentanediamine (DAMP), 1,5-pentanediamine, 1,5-diamino-2-methylpentane (MPMD), 1,6-hexanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine (TMD), 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, methyl-bis-(3-aminopropyl)amine, 1,2-, 1, 3- and 1,4-diaminocyclohexane, bis-(4-aminocyclohexyl)methane, bis-(4-amino-3-methylcyclohexyl)methane, bis-(4-amino-3-ethylcyclohexyl)methane, bis-(4-amino-3,5-dimethylcyclohexyl)methane, bis-(4-amino-3-ethyl-5-methylcyclohexyl)methane (M-MECA), 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (=isophoronediamine or IPDA), 2- and 4-methyl-1,3-diaminocyclohexane and mixtures thereof, 1,3- and 1,4-bis-(aminomethyl)cyclohexane, 2,5(2,6)-bis-(aminomethyl)bicyclo[2.2.1]heptane (NBDA), 3(4),8(9)-bis-(aminomethyl)tricyclo[5.2.1.0]heptane (NBDA), 2,6 ]decane, 1,4-diamino-2,2,6-trimethylcyclohexane (TMCDA), 3,9-bis-(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane and 1,3- and 1,4-xylylenediamine, aliphatic diamines containing ether groups, such as bis-(2-aminoethyl) ether, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, 4,7-dioxadecane-2,9-diamine, 4,9-dioxadodecane-1,12-diamine, 5,8-dioxadodecane-3,10-diamine and the higher oligomers of these diamines, bis-(3-aminopropyl)polytetrahydrofuran and other polytetrahydrofuran diamines, for example with molecular weights in the range from 350 to 5200, and also polyoxyalkylenediamines, the latter typically being products of the amination of polyoxyalkylenediols and available, for example, under the name Jeffamine® (from Huntsman Chemicals), the name Polyetheramines (from BASF) or the name PC Amine® (from Nitroil). Particularly suitable polyoxyalkylene diamines include Jeffamine® D-230, Jeffamine® D-400, Jeffamine® D-2000, Jeffamine® D-4000, Jeffamine® XTJ-511, Jeffamine® ED-600, Jeffamine® ED-900, Jeffamine® ED-2003, Jeffamine® XTJ-568, Jeffamine® XTJ-569, Jeffamine® XTJ-523, Jeffamine® XTJ-536, Jeffamine® XTJ-542, Jeffamine® XTJ-559, Polyetheramine D230, Polyetheramine D400 and Polyetheramine D2000, PC Amine® DA250, PC Amine® DA400, PC Amine® DA650 and PC Amine® DA2000. aliphatic triamines, such as 4-aminomethyl-1,8-octanediamine, 1,3,5-tris(aminomethyl)benzene, 1,3,5-tris-(aminomethyl)cyclohexane, primary polyoxyalkylene triamines, which are typically products of the amination of polyoxyalkylene triols and can be obtained, for example, under the brand name Jeffamine® (from Huntsman Chemicals), the name Polyetheramine (from BASF) or the name PC Amine® (from Nitroil), such as Jeffamine® T-403, Jeffamine® T-5000, Polyetheramine T403, Polyetheramine T5000 and PC Amine® TA403, PC Amine® TA5000.

[0101] Preferred polyamines (PAM) include 1,6-hexamethylenediamine, MPMD, DAMP, IPDA, TMD, 1,3-xylylenediamine, 1,3-bis-(aminomethyl)cyclohexane, bis-(4-aminocyclohexyl)methane, bis-(4-amino-3-methyl-cyclohexyl)methane, 3(4),8(9)-bis-(aminomethyl)tricyclo-[5.2.1.0] 2,6 ] decane, 1,2-, 1,3- and 1,4-diaminocyclohexane, 1,4-diamino-2,2,6-trimethylcyclohexane, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, 4-aminomethyl-1,8-octanediamine, and polyoxyalkylene polyamines having two or three amino groups, in particular the products D-230, D-400, D-2000, T-403 and T-5000 from Huntsman, available under the brand name Jeffamine®, and similar compounds from BASF or Nitroil, as well as polyamines selected from the group consisting of mixtures of the above polyamines. The above diamines are particularly preferred polyamines (PAM).

[0102] Essentially any aldehyde is suitable as the aldehyde. These aldehydes can be aliphatic, cycloaliphatic, araliphatic or aromatic aldehydes, and can be mono- or polyaldehydes.

[0103] It has been found to be advantageous if the polyaldimine (PA) does not have a hydrogen atom on the carbon atom alpha to the carbon of the aldimino group: such aldimines cannot form any tautomeric forms (enamines), in contrast to aldimines with a hydrogen atom alpha to the carbon (see formula diagram below). [ka]

[0104] It has been found that compositions which are particularly stable on storage can be obtained with such polyaldimines which do not have a hydrogen atom in the alpha position.

[0105] Such polyaldimines include polyamines (PAM) having two or more primary amino groups according to the formula (II') or (III') [ka] wherein R1' and R2' each independently represent a monovalent hydrocarbon radical having 1 to 12 carbon atoms, or R1' and R2' together represent a divalent hydrocarbon radical having 4 to 12 carbon atoms that is part of an optionally substituted carbocyclic ring having 5 to 8 carbon atoms, preferably 6 carbon atoms. It can be synthesized from the aldehyde

[0106] Furthermore, Z 1 represents a monovalent hydrocarbon group having 1 to 32 carbon atoms and optionally having at least one heteroatom, especially oxygen in the form of an ether, carbonyl or ester group, or nitrogen, especially in the form of a tertiary amino group.

[0107] Furthermore, Z 2 is a substituted or unsubstituted aryl or heteroaryl group having a ring size of 5 to 8 atoms, preferably 6 atoms, or [ka] wherein R8 represents a hydrogen atom or an alkoxy group, or a substituted or unsubstituted alkenyl or arylalkenyl group having at least 6 carbon atoms.

[0108] Examples of such aldehydes of formula (II') are aromatic aldehydes such as benzaldehyde, 2-, 3- and 4-tolualdehyde, 4-ethyl, 4-propyl, 4-isopropyl and 4-butylbenzaldehyde, 2,4-dimethylbenzaldehyde, 2,4,5-trimethylbenzaldehyde, 4-acetoxybenzaldehyde, 4-anisaldehyde, 4-ethoxybenzaldehyde, isomeric di- and trialkoxybenzaldehydes, 2-, 3- and 4-nitrobenzaldehyde. aldehyde, 2-, 3- and 4-formylpyridine, 2-furfuraldehyde, 2-thiophenecarbaldehyde, 1- and 2-naphthylaldehyde, 3- and 4-phenyloxybenzaldehyde, quinoline 2-carbaldehyde and its 3-, 4-, 5-, 6-, 7- and 8-positional isomers and anthracene 9-carbaldehyde and also glyoxal, glyoxalic acid esters such as glyoxalic acid methyl ester, cinnamaldehyde and substituted cinnamaldehydes.

[0109] Examples of aldehydes of formula (III') are, for example, pivalaldehyde (=2,2-dimethylpropanal), 2,2-dimethylbutanal, 2,2-diethylbutanal, 1-methylcyclopentanecarboxaldehyde, 1-methylcyclohexanecarboxaldehyde, 2,2-dimethyl-3-phenylpropanal and 2,2-dimethyl-3-p-tolylpropanal, 2-hydroxy-2-methylpropanal and alcohols such as ethers of propanol, isopropanol, butanol and 2-ethylhexanol, 2-formyl-2-methylpropanal, Esters of 2-hydroxy-2-methylpropionic acid or 3-formyl-3-methylbutyric acid and alcohols, such as propanol, isopropanol, butanol and 2-ethylhexanol, esters of 2-hydroxy-2-methylpropanal and carboxylic acids, such as butyric acid, isobutyric acid and 2-ethylhexanoic acid, and ethers and esters of 2,2-disubstituted 3-hydroxypropanal, butanal or similar higher aldehydes, in particular 2,2-dimethyl-3-hydroxypropanal, and aldehydes of formula (IV') described below as particularly suitable.

[0110] Formula (I') [ka] Polyaldimines of the formula have been found to be particularly suitable, where A' represents the radical of an amine after removal of n primary aliphatic amino groups, said radical containing no active hydrogen atoms. Furthermore, n represents 2, 3, 4, or 5, preferably 2 or 3. Furthermore, R1' and R2' each independently represent a monovalent hydrocarbon radical having 1 to 12 carbon atoms, or R1' and R2' together represent a divalent hydrocarbon radical having 4 to 12 carbon atoms that is part of an optionally substituted carbocyclic ring having 5 to 8 carbon atoms, preferably 6 carbon atoms.

[0111] R3' represents a hydrogen atom or an alkyl group, particularly having 1 to 12 carbon atoms, or an aralkyl group, or an alkoxycarbonyl group.

[0112] R4' and R5' each independently represent a monovalent aliphatic, alicyclic, or araliphatic radical having 1 to 20 carbon atoms and optionally containing a heteroatom in the form of an ether oxygen or a tertiary amine nitrogen, or R4' and R5' together represent a divalent aliphatic radical having 3 to 20 carbon atoms that is part of an optionally substituted heterocyclic ring having 5 to 8 ring atoms, preferably 6 ring atoms, which ring also contains, in addition to the nitrogen atom, another heteroatom in the form of an ether oxygen or a tertiary amine nitrogen.

[0113] Furthermore, to synthesize aldimines of formula (I'), a compound of formula (IV'): [ka] (wherein R1', R2', R3', R4' and R5' have the meanings already given above). At least one sterically hindered aliphatic aldehyde (ALD) of the formula:

[0114] R1' and R2' preferably each represent a methyl group, and R3' preferably represents a hydrogen atom.

[0115] R4' and R5' preferably each independently represent methyl, ethyl, propyl, isopropyl, butyl, 2-ethylhexyl, cyclohexyl or benzyl, or together with the nitrogen atom they form a ring, in particular a pyrrolidine, piperidine, morpholine or N-alkylpiperazine ring, which ring is optionally substituted.

[0116] The aldehydes (ALD) of formula (IV') can be obtained in particular as the product of an α-amino alkylation (which can therefore also be called Mannich bases) analogous to the Mannich reaction or Mannich reactions known from the technical literature, where an aldehyde (Y1) of formula (V'), an aldehyde (Y2) of formula (VI') and a secondary aliphatic amine (C) of formula (VII') [ka] (wherein R1', R2', R3', R4' and R5' have the meanings already given above). reacts to form an aldehyde (ALD) with the elimination of water.

[0117] This reaction can be carried out with the free reagents, i.e., aldehyde (Y1) of formula (V'), aldehyde (Y2) of formula (VI'), and amine (C), or the reagents can be used in a partially or fully derivatized form. Thus, aldehyde (Y1) can be used as an enolate, enol ether, in particular a silyl enol ether, or an enamine. Aldehyde (Y2) can be used, for example, in the form of an oligomer (especially in the case of formaldehyde as 1,3,5-trioxane or paraformaldehyde), or as a hydrate, hemiacetal, acetal, N,O-acetal, aminal, or hemiaminal. Finally, secondary aliphatic amine (C) can be used in the form of a salt, in particular as an amine hydrochloride or amine sulfate, or as a silylamine. It is possible to use some of the reagents in free form and some in derivatized form, or to use them only in derivatized form. When using a derivatized reagent, the aldehyde (ALD) can also be obtained in a derivatized form, for example as a salt, under certain circumstances. In this case, it can be converted into the free form according to formula (IV') by appropriate post-treatment. In such a conversion reaction, it may be appropriate to further use an additive, such as a Lewis acid or a catalyst, depending on the circumstances.

[0118] Furthermore, the reaction can be carried out as a one-pot reaction in which all three reagents can react with each other simultaneously, or a stepwise procedure can be selected by reacting the first two reagents with each other and then reacting the intermediate thus obtained with the third reagent, with or without isolation of the intermediate. Suitable such intermediates include, in particular, iminium salts obtained from the reaction of an aldehyde (Y2) in free or derivatized form with a salt of a secondary aliphatic amine (C) and capable of reacting with an aldehyde (Y1) in free or derivatized form to form the corresponding salt of an aldehyde (ALD) of formula (IV'). Such a stepwise procedure can be advantageous in that it allows for milder reaction conditions and thus higher product yields.

[0119] Additionally, the reaction can take place using a solvent, particularly a polar solvent such as water or an alcohol, or the reaction can be carried out without the use of a solvent.

[0120] In a preferred embodiment, the reaction is carried out as a one-pot reaction with all reagents in free form, and after the reaction is complete, the aldehyde (ALD) is purified by distillation. Preferably, no organic solvents are used.

[0121] For example, the following aldehydes are suitable as aldehyde (Y1) of formula (V'): isobutyraldehyde, 2-methylbutyraldehyde, 2-ethylbutyraldehyde, 2-methylvaleraldehyde, 2-ethylcaproaldehyde, cyclopentanecarboxaldehyde, cyclohexanecarboxaldehyde, 1,2,3,6-tetrahydrobenzaldehyde, 2-methyl-3-phenylpropionaldehyde, 2-phenylpropionaldehyde and diphenylacetaldehyde. Isobutyraldehyde is preferred.

[0122] Suitable examples of aldehydes (Y2) of formula (VI') include the following aldehydes: formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, phenylacetaldehyde, benzaldehyde and substituted benzaldehydes, and glyoxylic acid esters, in particular glyoxylic acid ethyl ester. Formaldehyde is preferred.

[0123] Examples of suitable amines (C) of formula (VII') include the following secondary aliphatic amines: dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, di-sec-butylamine, dihexylamine, di-(2-ethylhexyl)amine, dicyclohexylamine, N-methylbutylamine, N-ethylbutylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, di-2-methoxyethylamine, pyrrolidine, piperidine, N-methylbenzylamine, N-isopropylbenzylamine, N-tert-butylbenzylamine, dibenzylamine, morpholine, 2,6-dimethylmorpholine, bis-(3-dimethylaminopropyl)amine, N-methyl or N-ethylpiperazine.

[0124] Preferred examples of amines (C) include dimethylamine, diethylamine, diisopropylamine, dibutylamine, diisobutylamine, N-methylcyclohexylamine, N-methylbenzylamine, N-isopropylbenzylamine, N-tert-butylbenzylamine, dibenzylamine, pyrrolidine, piperidine, morpholine, 2,6-dimethylmorpholine, N-methyl- and N-ethylpiperazine.

[0125] The aldehyde (ALD) is preferably synthesized by the reaction of isobutyraldehyde as the aldehyde (Y1) of formula (V'), formaldehyde as the aldehyde (Y2) of formula (VI') and one of the amines selected from the group consisting of dimethylamine, diethylamine, diisopropylamine, dibutylamine, diisobutylamine, N-methylcyclohexylamine, N-methylbenzylamine, N-isopropylbenzylamine, N-tert-butylbenzylamine, dibenzylamine, pyrrolidine, piperidine, morpholine, 2,6-dimethylmorpholine, N-methyl- and N-ethylpiperazine as the amine (C) of formula (VII').

[0126] Preferred aldehydes (ALD) include 2,2-dimethyl-3-dimethylaminopropanal, 2,2-dimethyl-3-diethylaminopropanal, 2,2-dimethyl-3-dibutylaminopropanal, 2,2-dimethyl-3-(N-pyrrolidino)propanal, 2,2-dimethyl-3-(N-piperidino)propanal, 2,2-dimethyl-3-(N-morpholino)propanal, 2,2-dimethyl-3-(N-(2,6- Examples of suitable aldehydes include 2,2-dimethyl-3-(N-(4-methylpiperazino))propanal, 2,2-dimethyl-3-(N-(4-ethylpiperazino))propanal, 2,2-dimethyl-3-(N-benzylmethylamino)propanal, 2,2-dimethyl-3-(N-benzylisopropylamino)propanal, and 2,2-dimethyl-3-(N-cyclohexylmethylamino)propanal. Preferred aldehydes (ALDs) have relatively low basicity.

[0127] Aldimines of formula (I') can be synthesized directly from polyamines (PAM) having two or more primary amino groups and aldehydes (ALD) of formula (IV'), as already described above, by reacting the polyamines (PAM) with aldehydes (ALD) in a condensation reaction with elimination of water.

[0128] It has been found that improved storage stability of the heat-cured sealant composition can be achieved when using polyaldimines of formula (I').

[0129] In one preferred embodiment, the polyaldimine (PA) is represented by formula (XI): [ka] where R represents the radical of the aldehyde ALD after removal of the aldehyde group, A represents the radical of a diamine DA having two primary aliphatic amino groups after removal of the two primary aliphatic amino groups, Q represents the radical of the diisocyanate DI after removal of both isocyanate groups, z represents 0 or an integer from 1 to 15, A and R do not have groups that are reactive with isocyanate groups in the absence of water It may be a dialdimine of the formula:

[0130] For further details on the preparation and application of the diamine of formula (XI), reference may be made to Chinese Patent Application Publication No. 101616891A, which is incorporated herein in its entirety.

[0131] Polyaldimine (PA) is typically used in an amount of 0.3% to 10% by weight, especially 0.5% to 5% by weight, preferably 1% to 3% by weight, based on the weight of the heat-curable sealant composition.

[0132] Furthermore, the polyaldimine (PA) is preferably present in the sealant composition in an amount such that the ratio between the number of aldimino groups and the number of isocyanate groups has a value of 0.2 to 0.8, in particular 0.3 to 0.7.

[0133] The inventive sealing compositions described herein may optionally contain further components, including, in particular, fillers (F), reactive excipients, catalysts, stabilizers, especially heat and / or light stabilizers, thixotropic agents, plasticizers, solvents, foaming agents, dyes and pigments, corrosion inhibitors, surfactants, foam suppressants and adhesion promoters.

[0134] The filler (F) is preferably mica, talc, kaolin, wollastonite, feldspar, syenite, chlorite, bentonite, montmorillonite, calcium carbonate (chalk, precipitated or ground), dolomite, quartz, silicic acid (pyrogenic or precipitated), cristobalite, calcium oxide, aluminum hydroxide, magnesium oxide, ceramic hollow beads, glass hollow beads, organic hollow beads, glass beads, carbon black, graphite, metal powder, powdered electrically conductive polymer or colored pigment.

[0135] It is particularly preferred that the sealing composition contains carbon black or other electrically conductive additives as fillers, in particular graphite, metal powders or powdered electrically conductive polymers, which provide a certain conductivity of the sealing compound composition during coating with CDC paint, which has a beneficial effect on the coating result.

[0136] Suitable fillers (F) include both organic coated and uncoated forms that are commercially available and known to those skilled in the art.

[0137] The total amount of total fillers (F) is preferably 3 to 50% by weight, especially 5 to 35% by weight, especially 5 to 25% by weight, based on the weight of the total composition.

[0138] In one preferred embodiment, the sealing composition further contains a reactive excipient, which may be a reactive excipient (G) containing an epoxy group.

[0139] Reactive excipients (G) containing epoxy groups include in particular: monofunctional, saturated or unsaturated, branched or unbranched, cyclic or acyclic C4-C glycidyl ethers, in particular selected from the group consisting of butanol glycidyl ether, hexanol glycidyl ether, 2-ethylhexanol glycidyl ether, allyl glycidyl ether, tetrahydrofurfuryl and furfuryl glycidyl ether, trimethoxysilyl glycidyl ether;30 Glycidyl ethers of alcohols. - bifunctional saturated or unsaturated, branched or unbranched, cyclic or acyclic C2-C diglycidyl ethers, in particular selected from the group consisting of ethylene glycol, butanediol, hexanediol, octanediol glycidyl ether, cyclohexanedimethanol diglycidyl ether and neopentyl glycol diglycidyl ether; 30 Glycidyl ethers of alcohols. glycidyl ethers of trifunctional or polyfunctional, saturated or unsaturated, branched or unbranched, cyclic or acyclic alcohols, such as epoxidized castor oil, epoxidized trimethylolpropane, epoxidized pentaerythritol, or polyglycidyl ethers of aliphatic polyols, such as sorbitol, glycerol or trimethylolpropane. - glycidyl ethers of phenols and anilines, in particular selected from the group consisting of phenyl glycidyl ether, cresyl glycidyl ether, p-tert-butylphenyl glycidyl ether, nonylphenol glycidyl ether, 3-n-pentadecenyl glycidyl ether (from cashew nut shell oil), N,N-diglycidylaniline and triglycidyl of p-aminophenol. Epoxidized amines, such as N,N-diglycidylcyclohexylamine. epoxidized mono- or dicarboxylic acids, in particular selected from the group consisting of neodecanoic acid glycidyl ester, methacrylic acid glycidyl ester, benzoic acid glycidyl ester, phthalic, tetra- and hexahydrophthalic acid diglycidyl esters, diglycidyl esters of dimeric fatty acids and terephthalic and trimellitic acid glycidyl esters. Epoxidized di- or trifunctional low to high molecular weight polyether polyols, in particular polyethylene glycol diglycidyl ether or polypropylene glycol diglycidyl ether.

[0140] Particularly preferred are hexanediol diglycidyl ether, cresyl glycidyl ether, p-tert-butylphenyl glycidyl ether, polypropylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether.

[0141] The total amount of reactive excipients (G) containing epoxy groups is advantageously between 0.1 and 20% by weight, preferably between 1 and 8% by weight, based on the weight of the total composition.

[0142] In another particularly preferred embodiment, the sealing composition further contains at least one catalyst (KA) that promotes the hydrolysis of aldimino groups. Such catalysts (KA) include, in particular, acids, such as organic carboxylic acids, such as benzoic acid, salicylic acid, or 2-nitrobenzoic acid; organic carboxylic acid anhydrides, such as phthalic anhydride, hexahydrophthalic anhydride, and hexahydromethylphthalic anhydride; silyl esters of organic carboxylic acids; organic sulfonic acids, such as methanesulfonic acid, p-toluenesulfonic acid, or 4-dodecylbenzenesulfonic acid; sulfonic acid esters; other organic or inorganic acids; or mixtures of the aforementioned acids and acid esters. Salicylic acid or 2-nitrobenzoic acid is most preferably used as the catalyst (KA).

[0143] Furthermore, it is particularly advantageous if the sealing composition further contains at least one catalyst (KN) that promotes the reaction of isocyanate groups. Such catalysts (KN) that promote the reaction of isocyanate groups include, in particular, organotin compounds such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate and dioctyltin dilaurate, bismuth compounds such as bismuth trioctanoate and bismuth tris-neodecanoate, and compounds containing tertiary amino groups such as 2,2'-dimorpholinodiethyl ether and 1,4-diazabicyclo[2.2.2]octane.

[0144] Furthermore, it is particularly advantageous if the sealing composition further comprises at least one rheology modifier (R), such as in particular a thickener or thixotropic agent, such as a urea compound, a polyamide wax, bentonite or pyrogenic silica.

[0145] The sealing composition of the present invention preferably comprises, i.e. in particular more than 95% by weight, - at least one epoxy-terminated polyurethane prepolymer (A), - a heat-activatable curing agent or accelerator (B) comprising an amidoamine having a primary amino group and a dicyanodiamide; an impact modifier (I) which is a reaction product of at least one polymeric diol, at least one polyisocyanate and cardanol; at least one polyaldimine (PA), optionally a filler (F), a reactive excipient (G) containing an epoxy group, optionally a plasticizer; - optionally a catalyst (KA) that promotes the hydrolysis of the aldimino groups; - optionally a catalyst (KN) that accelerates the reaction of isocyanate groups; - Optionally, a rheology modifier (R) It essentially consists of:

[0146] In the polyurethane prepolymer (A), it is clear that the heat-activatable curing agent or accelerator (B), impact modifier (I), polyaldimine (PA), filler (F), epoxy group-containing reactive excipient (G), plasticizer, catalyst (KA), catalyst (KN) and rheology modifier (R) are different substances in the present invention.

[0147] Sealing composition is prepared and stored in the absence of moisture.It is stable in storage, that is, after the relevant degree of curing for its use, it can be stored in suitable packaging or structure, such as drum, bag or cartridge, in the absence of moisture for several months or up to a year or even longer without change in application properties or its properties.Storage stability is usually determined by measuring viscosity.

[0148] The sealing composition is characterized by very good storage stability. The change in viscosity of the sealing compound in an airtight aluminum cartridge after 5 days of storage at 60 ° C in an air-circulating oven can be used as a measure of long-term storage stability at room temperature. Experience has shown that a maximum doubling of the viscosity, i.e., an increase of up to 100%, is acceptable for reliable use of the composition as a sealing compound. The sealing composition has been found to meet this requirement admirably, achieving viscosity changes of less than 55%, and in some cases even less than 35%.

[0149] During the curing of the sealing composition according to the present invention, little or no blisters are formed. Blisters are usually formed during the air curing of polyisocyanates. Therefore, they have excellent mechanical properties and an optimal visual appearance. This is particularly important because the CDC paint is above the surface of the sealing compound, so that the sealing compound surface can be seen through the CDC paint and / or colored paint subsequently applied thereon.

[0150] Furthermore, the sealing composition, after being cured by heat, can be very elastic and have extremely good impact strength, which is particularly advantageous for seals that are exposed to impact or movement during use.

[0151] This combination of advantageous properties allows the sealing compositions to be used as sealing compounds in engine spaces or in car bodywork, especially in doors, trunk lids, tailgates or bonnets. In particular, they can also be used as sealing compounds in flange fold seals, such as those disclosed in WO 2008 / 077918 A1.

[0152] In another aspect of the invention, there is provided a method of sealing, comprising the steps of: i) applying a sealing composition, such as those described above, to a substrate (S) so that part of the surface of the sealing composition is in contact with air; ii) forming a skin on the surface of the sealing composition in contact with air; iii) heating the sealing composition to a temperature above 120°C, particularly 160°C to 220°C, to form a cured sealing composition. A method is disclosed that includes:

[0153] Suitable materials for the substrate (S) include in particular metals, in particular those metals used in particular in the construction of automobile bodies. These include in particular steel, in particular electroplated steel, hot-electroplated steel, oiled steel, Bonazin-coated steel and subsequently phosphated steel or aluminum, in particular the variants typically occurring in automotive engineering. These include in particular steel or aluminum plates.

[0154] The application, i.e., deposition, is preferably carried out automatically, especially in the form of beads. However, the sealing compound composition can also be sprayed. Other application methods are also conceivable, such as swirl application, flat stream spraying, mini flat stream spraying, and thin stream spraying at speeds of >200 mm / s. Furthermore, manual application or manual reworking of the applied sealing compound composition with a spatula or paint brush is also possible.

[0155] Thus, in another aspect, the present invention also relates to a coated substrate, obtainable, for example, by applying the sealing composition described in detail above to the surface of the substrate.

[0156] In a particularly preferred embodiment, the sealing compound composition is applied to oiled steel. An advantage of the composition is that it adheres well to such substrates and cures with little or no blasting.

[0157] Step IIA): iia) applying a paint, especially a CDC paint, to the sealing composition is preferably carried out between step ii) and step iii).

[0158] Those skilled in the art of automotive engineering are very familiar with the concept of CDC paint, which refers to paint that is applied to sheet metal in a CDC bath (CDC = cathodic dip coating).

[0159] Step iii) is preferably carried out in a CDC oven.

[0160] Heating the sealing composition causes further curing, so that the sealing composition attains its final strength.

[0161] The sealing composition is particularly suitable for sealing gaps.

[0162] Therefore, in step i), the sealing composition is preferably applied in or to a gap, said gap being adjacent to two surfaces of a substrate (S) and a second substrate (S2), the second substrate (S2) being made of the same or a different material from the substrate (S).

[0163] Thus, a sealed article is obtained by the above method. [Example]

[0164] The examples presented below are merely illustrative of the invention.

[0165] Table 1 lists the raw materials used.

[0166] [Table 1]

[0167] [Table 2]

[0168] Synthesis of prepolymer A 417.5 g of Poly bd® R-45HTLO and 154.2 g of DGEBA were stirred with 328.6 g of diisodecyl phthalate (DIDP) under vacuum at 80°C. 0.8 g of a catalyst solution (10 wt% dibutyltin dilaurate (DBTDL) in diisononyl phthalate) was added. Next, 98.9 g of IPDI was added with stirring, and the mixture was stirred at 80°C for 2 hours. The polyurethane polymer and epoxy resin premix thus formed had an NCO content of 1.6 wt% and an epoxy content of 0.82 molar equivalents / kg.

[0169] Synthesis of impact modifier I A 1:1 (by weight) mixture of PolyTHF® 2000 (BASF) and Poly bd® R-45HTLO was reacted with IPDI (2 equivalents relative to the OH functional groups of the polyol), followed by endblocking of the isocyanate groups of the resulting polymer with cardanol (Cardolite® NC-700 (Cardolite)). The reaction was stopped as soon as free isocyanate could no longer be detected by IR spectroscopy (wavenumbers 2275-2230 cm).

[0170] Synthesis of polyaldimine PA A round-bottom flask was charged with 14.55 g of IPDA under a nitrogen atmosphere. With vigorous stirring, 30.00 g of 2,2-dimethyl-3-(N-morpholino)propanal was added via a dropping funnel. Volatile components were then removed in vacuo (10 mbar, 80° C.). Yield: 40.9 g of a clear, colorless oil with an amine content of 8.29 mmol N / g.

[0171] Preparation of the sealing composition Various sealing compositions were prepared in the absence of moisture using the components listed in Table 2, in parts by weight. All components were placed in three batches in a vacuum mixer at room temperature with stirring at 200-300 rpm / min. The epoxy-terminated polyurethane and impact modifier were placed in the first batch, followed by the powdered materials in the second batch, and finally the curing agent and liquid were added. The temperature was maintained at 50°C and stirring was continued for 40-50 minutes, after which nitrogen was introduced and the vacuum was broken.

[0172] After these preparations, the compositions were left in place for 24 hours and then used directly for testing. The mixtures were cured at 180°C for 30 minutes.

[0173] Measurement method The following properties of the compositions were measured:

[0174] Breaking elongation and tensile strength Elongation at break and tensile strength were measured primarily in accordance with ISO 37 and ISO 527-2. Specimens were prepared by creating 2 mm (±0.5 mm) thick sheets free of sealant bubbles. They were cured and then stored at 23°C / 50% RH for 2 to 6 hours. At least five dumbbells according to ISO 37 Type 2 / ISO 527-2 Type 5A (Chapter 6) were then punched out of the sheets. Tests were performed on these, and the results were the average of at least five measurements.

[0175] viscosity For the measurement of the viscosity of the compositions, an Anton Paar rheometer MCR102 was used under a temperature increase from 20°C to 70°C at a rate of 10 K / min. The samples were measured at 23°C (or 50°C, respectively) with a gap size of 1 mm and a 10 s -1 The shear stress was measured.

[0176] Skin formation To determine the skin formation time ("SFT"), the composition was applied to cardboard at room temperature in a layer thickness of approximately 3 mm, and the time until no residue of the composition remained on a pipette made of LDPE when the pipette was lightly tapped on the surface of the composition was determined in standard atmosphere (STP, 23±1°C, 50±5% relative humidity).

[0177] Extrusion force For the determination of the extrusion force, the composition was dispensed into an internally coated aluminum cartridge (external diameter 46.9 mm, internal diameter 46.2 mm, length 215 mm, metric ISO thread M15 x 1.5 mm) and hermetically sealed with a polyethylene stopper (diameter 46.1 mm) from Novelis Deutschland GmbH. After conditioning for 24 hours at 23 °C, the cartridge was opened and the contents were extruded using an extrusion device. For this purpose, a nozzle with an internal diameter of 5 mm was screwed onto the cartridge thread. Using an extrusion device (Zwick / Roell Z005), the force required to extrude the composition at an extrusion rate of 60 mm / min was determined. The reported value is the average value of the force measured after extrusion distances of 22 mm, 24 mm, 26 mm, and 28 mm. Measurements were stopped after an extrusion distance of 30 mm.

[0178] Blistering (air bubbles in the beads) To prepare the samples, triangular beads of the composition were applied to metal tiles. After storing at room temperature for one day, they were then placed in a convection oven at an elevated temperature of 180°C for 30 minutes to fully cure. The samples were placed under an exhaust vent. The beads were then cut with a cutter along the direction of application, parallel to the substrate. Visual checks were performed to see if any bubbles were visible. "None" means no visible bubbles.

[0179] Lap shear strength The 2 mm lap shear strength was measured on oiled hot-dip galvanized steel plates according to ISO 4587. For the compositions of the present invention, 100% CF (cohesive failure) was achieved on the substrate.

[0180] Sag resistance A piece of cardboard was placed in a completely upright position. A 15 cm long triangular bead measuring 8 mm x 10 mm was carefully applied onto the cardboard and held in this position for at least 2-3 minutes. Its appearance was then rated according to the following scale:

[0181] [Table 3]

[0182] [Table 4]

Claims

1. at least one epoxy-terminated polyurethane prepolymer (A), - heat-activatable curing agents or accelerators (B) comprising amidoamines and dicyanodiamides with primary amino groups, an impact modifier (I) which is the reaction product of at least one polymeric diol, at least one polyisocyanate and cardanol; - at least one polyaldimine (PA) A sealing composition comprising:

2. 2. The sealing composition according to claim 1, wherein the epoxy-terminated polyurethane prepolymer (A) is an isocyanate group-containing polyurethane prepolymer that is partially terminated with epoxide and has a specific content of free isocyanate groups, preferably 0.8 to 3.0 wt %, preferably 1.0 to 2.5 wt %, more preferably 1.5 to 2.0 wt %, of free NCO groups, based on the total weight of the polyurethane prepolymer (A).

3. The epoxy-terminated polyurethane prepolymer (A) has the following formula (IVa): 【Chemistry 1】 (In the formula, R １ is a linear or branched polyurethane prepolymer PU1 terminated by n+m isocyanate groups after removal of all terminal isocyanate groups, Each R ２ is independently of the other, a compound of formula (II) 【Chemistry 2】 (wherein, in each case, R ４ is the portion of an aliphatic, cycloaliphatic, aromatic or araliphatic epoxide containing a primary or secondary hydroxy group after removal of the hydroxide and epoxide groups, p=1, 2 or 3) is the basis of Each of n and m is a value from 1 to 7, provided that 2≦(m+n)≦8.

3. The sealing composition according to claim 1, wherein the sealing composition is represented by the formula:

4. 4. Sealing composition according to claim 1, characterized in that the polyaldimine (PA) is present in the sealing compound composition in an amount such that the ratio of the number of aldimino groups to the number of isocyanate groups has a value of 0.2 to 0.8, in particular 0.3 to 0.

7.

5. 5. The sealing composition according to claim 1, wherein the heat-activatable curing agent or accelerator (B) comprises 1.0 to 3.3 wt. %, preferably 1.5 to 3.0 wt. %, of an amidoamine having a primary amino group and 0.05 to 0.8 wt. %, preferably 0.12 to 0.55 wt. %, of dicyanodiamide, each based on the total weight of the sealing composition.

6. 6. The sealing composition according to claim 1, wherein the amidoamine containing primary amino groups is obtained by reaction of phthalic anhydride and a polyamine containing primary amino groups, in particular diethylenetriamine (DETA) or triethylenetetramine (TETA).

7. 7. The sealing composition according to claim 1, wherein the impact modifier (I) is contained in an amount of 1 to 25% by weight, preferably 3 to 15% by weight, based on the total weight of the sealing composition.

8. The impact modifier I is represented by the formula (IV) 【Transformation 3】 wherein x and x′, independently of one another, each have a value of 0 or 1, preferably 1, with the proviso that at least one, preferably both, of n and n′ is not 0; R ５ is a linear polyurethane prepolymer containing at least x+x' terminal isocyanate groups after removal of x+x' terminal isocyanate groups, R ６ and R ３ is the residue of cardanol after removal of the hydroxyl H atom and is attached via the oxygen atom) 8. The sealing composition according to claim 1, wherein the polymer is a polymer of the formula:

9. 9. Sealing composition according to any one of claims 1 to 8, characterized in that it further contains carbon black or other electrically conductive additives as fillers, in particular graphite, metal powders or powdered electrically conductive polymers.

10. A coated substrate obtained by applying the sealing composition according to any one of claims 1 to 9 to the surface of a substrate.

11. 1. A method of sealing, comprising: i) applying the sealing composition according to any one of claims 1 to 9 to a substrate (S) so that a part of the surface of the sealing compound composition is in contact with air; ii) forming a skin on the surface of the sealing composition that is in contact with the air; iii) heating the sealing compound composition to a temperature above 120°C, particularly 160-220°C, to form a fully cured sealing composition. A method comprising:

12. Step iia): ii) applying a paint, in particular a CDC paint, to said sealing composition; 12. The method of claim 11, wherein a step of:

13. 13. The method according to claim 11 or 12, characterized in that step iii) is carried out in a CDC oven.

14. 14. The method according to any one of claims 11 to 13, characterized in that in step i) the sealing composition is applied to or in a gap, the gap being adjacent to two surfaces of the substrate (S) and a second substrate (S2), the second substrate (S2) being made of the same material as the substrate (S) or of a different material.

15. A sealed article obtainable by the method according to any one of claims 11 to 14.

Images