EP1940993A1

EP1940993A1 - Alpha-ethoxysilane-modified polymers, production and use thereof

Info

Publication number: EP1940993A1
Application number: EP06806391A
Authority: EP
Inventors: Thomas Bachon; Jennifer Schmidt; Thomas Tamcke; Patrick Gawlik
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2005-10-29
Filing date: 2006-10-19
Publication date: 2008-07-09
Also published as: JP2009513806A; DE102005051921A1; US8003745B2; BRPI0617946A2; US20080269406A1; CN101300319B; CA2627006A1; CN101300319A; WO2007048538A1

Abstract

The invention relates to a-ethoxysilane-modified polymers of average general formula (I), wherein R represents a monovalent to quadrivalent polymer radical, no more than one third of the radicals R1, R2, and R3 contained in the polymer of formula (I) independently represent alkyl radicals with 1 to 4 carbon atoms, at least one fourth of the radicals R1, R2, and R3 contained in the polymer of formula (I) independently represent ethoxy radicals, the optionally remaining radicals R1, R2, and R3 independently represent methoxy radicals, and n = 1 to 4. The invention also relates to a method for producing the polymers of formula (I) and the use thereof in adhesives, sealants, and coating agents.

Description

α-Ethoxysilane modified polymers, their preparation and use

The present invention relates to silane-modified polymers, in particular α-ethoxysilane-modified polymers, their preparation and their use in adhesives and sealants, and coating compositions.

Silane-crosslinking adhesives and sealants contain alkoxysilane-terminated polymers as binders. Polymer systems that have reactive alkoxysilyl groups have long been known. In the presence of atmospheric moisture, these alkoxysilane-terminated polymers are capable, even at room temperature, of condensing one another with elimination of the alkoxy groups. Depending on the content of alkoxysilane groups and their structure, mainly long-chain polymers (thermoplastics), relatively wide-meshed three-dimensional networks (elastomers) or highly crosslinked systems (thermosets) are formed.

The polymers typically have an organic backbone bearing alkoxysilane groups at the ends. The organic skeleton may be, for example, polyurethanes, polyesters, polyethers, etc.

From DE 197 27 029 A1 a one-component reactive system composition is known which contains an alkoxysilane-terminated polyurethane, a curing catalyst and optionally conventional additives.

WO 99/48942 A1 discloses alkoxysilane-terminated polyurethanes and corresponding polyurethane-containing preparations which, in addition to the alkoxysilated polyurethanes, may contain solvents, catalysts, plasticizers, reactive diluents, fillers and the like.

WO 02/068501 describes the preparation of mixed-alkoxysilylated polymers based on γ-silanes using tin catalysts.

The alkoxysilane end group-containing polymers used in the prior art generally contain methoxysilane end groups. These binders are often used as a replacement for NCO-terminated polyurethanes and have significant toxicological advantages for the processor due to the absence of isocyanates on. However, a disadvantage is the elimination of small amounts of methanol during curing.

The currently customary silane-terminated polymers generally contain dimethoxymethyl-γ-silyl or trimethoxy-γ-silyl end groups. Replacement of the methoxy groups with ethoxy groups reduces the reactivity of the polymers to such an extent that the curing rate of the adhesives is no longer acceptable. It is an object of the present invention to provide silane-crosslinking polymers, the curing of which liberates less methanol and, moreover, allows an acceptable curing rate of the adhesives and sealants which can be prepared therefrom.

Surprisingly, it has been found that the abovementioned objects can be achieved by the provision of silane-modified polymers of the general formula (Ia),

in which

R is a mono- to tetravalent polymer radical,

R ^1, R ^2, R ^{3 are} independently an alkyl or alkoxy group having 1 to 8 carbon atoms, and

A represents a carboxy, carbamate, amide, carbonate, ureido, urethane or sulfonate group or an oxygen atom, x = 1 to 8 and n = 1 to 4.

R ¹ , R ² , R ^{3 are} hereby independently of one another alkyl or alkoxy radicals having 1 to 5 C atoms, particularly preferably methyl, ethyl, propyl and / or butyl as alkyl radicals and methoxy, ethoxy and / or propoxy as alkoxy radicals. R ¹ , R ² , R ³ are particularly preferably a combination of methoxy, ethoxy and / or methyl, ethyl, propyl, isopropyl, n-butyl or isobutyl, more preferably methoxy or ethoxy and / or methyl or ethyl.

X is preferably 1 or 2, particularly preferably 1. n is preferably 2 or 3, more preferably 2.

In the context of the present invention, a "carbamate group" is understood to mean a structural element of the general formula (II)

wherein the binding of the carbamate group can take place via R both via the nitrogen and via the oxygen.

In the context of the present invention, an "amide group" is understood as meaning a structural element of the general formula (III)

C (O) - N (H) - (III)

wherein the binding of the amide group can take place via R both via the nitrogen and via the carbon.

In a preferred embodiment, at most one third of the polymer in the

Formula (Ia) radicals R ¹ , R ² and R ³ independently of one another alkyl radicals having 1 to

4 carbon atoms, at least one quarter of the radicals R ¹ , R ² and R ³ contained in the polymer of the formula (Ia) independently ethoxy radicals, and the optionally remaining radicals R ¹ , R ² and R ³ independently

Methoxy radicals.

Consequently, in the case of n> 1, in some of the n [CO-NH-CH ₂ -SiR ¹ R ² R ³ ] radicals within the polymer (Ia) according to the invention other ratios

Alkyl: ethoxy: methoxy of the radicals R ¹ , R ² and R ³ are present, as long as by the other [CO-

NH-CH ₂ -SiR ¹ R ² R ³ ] radicals the above conditions for the entire formula (Ia) are satisfied.

Furthermore, it has surprisingly been found that the abovementioned objects are achieved by the provision of α-ethoxysilane-modified polymers of the average general formula (Ib): in which

R is a mono- to tetravalent polymer radical, at most one third of the radicals R ¹ , R ² and R ³ contained in the polymer of the formula (Ib) independently of one another are alkyl radicals having 1 to 4 carbon atoms, at least one fourth of that in the polymer of the formula (Ib) radicals R ¹ , R ² and R ^{3 are} independently ethoxy radicals which are optionally remaining radicals R ¹ , R ² and R ^{3 are} independently methoxy radicals, and wherein n = 1 to 4.

Consequently, in the case of n> 1, in some of the n [CO-NH-CH ₂ -SiR ¹ R ² R ³ ] radicals within the polymer (Ib) according to the invention other ratios of alkyl: ethoxy: methoxy of the radicals R ¹ , R ² and R ³ , as long as the other [CO-NH-CH ₂ -SiR ¹ R ² R ³ ] radicals satisfy the above conditions for the overall average formula.

Thus, for example, in addition to Dimethoxyethoxy-, methoxydiethoxy or Methyldiethoxy residues also trimethoxy- and dimethylethoxy residues or similar SiR be contained ¹ R ² R ³ groups in the overall molecule, if the required number of ethoxy groups of at least one quarter with respect to the Total molecule is reached and not more than one-third of the radicals R ¹ , R ² and R ^{3 are} straight-chain or decapped alkyl radicals having 1 to 4 carbon atoms.

In contrast to the α-silyl-crosslinking polymers known from the prior art, the polymers according to the invention have lower methanol elimination in the condensation due to at least partial replacement of the methoxy groups by ethoxy groups. On the other hand, the reactivity due to the α-silyl groups is sufficiently high to achieve good cure rates.

Accordingly, an object of the present invention is α-ethoxysilane-modified polymers of the general formula (Ib): in which

In this case, in particular, for the case n> 1, in some of the n [CO-NH-CH ₂ -SiR ¹ R ² R ³ ] radicals within the polymer (Ib) according to the invention, other ratios of alkyl: ethoxy: methoxy of the radicals R ¹ , R ² and R ³ are present, as long as the other [CO-NH-CH ₂ -SiR ¹ R ² R ³ ] radicals, the above conditions for the entire formula (Ib) are satisfied.

The monovalent or tetravalent polymer radicals R are preferably hydrocarbon radicals which may contain heteroatoms and / or organosiloxane groups, or organosiloxane radicals themselves. Examples of such radicals are alkyd resins, oil-modified alkyd resins, unsaturated polyesters, natural oils such as linseed oil , Tungöl or soybean oil, as well as epoxies, polyamides, thermoplastic polyesters, such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, polyethylenes, polybutylenes, polystyrenes, polypropylenes, Ethylenpropylenco- and terpolymers, acrylates such as homo- and copolymers of acrylic acid, acrylates, methacrylic acid, methacrylates , Acrylamides, their salts and the like, phenolic resins, polyoxymethylene homo- and copolymers, polyurethanes, polysulfones, polysulfide rubbers, nitrocellulose, vinyl butyrates, vinyl polymers such as vinyl chloride and / or vinyl acetate-containing polymers, ethyl cellulose, Ce cellulose ethers and butyrates, rayon, shellac, waxes, ethylene copolymers such as ethylene-vinyl acetate copolymers,

Ethylene acrylic acid copolymers, ethylene acrylate copolymers, organic rubbers, silicone resins and the like. Other examples include polyethers such as polyethylene oxide, polypropylene oxide and polytetrahydrofuran. Of the above-mentioned polymeric radicals Polyethers, polyesters and polyurethanes are particularly preferred. Very particularly preferred polymers from which the radical R are derived are, for example, polyalkylene glycols, such as polypropylene glycol having terminal hydroxyl groups. Such polymers are available, for example, under the trade name Acclaim® polyols from Bayer MaterialScience. The polymer radicals preferably have one to four terminal isocyanate-reactive groups.

The number average molar mass M _{n of} the polymer radicals is preferably in the range from 8000 to 50,000, more preferably 10,000 to 30,000, and most preferably 12,000 to 20,000 daltons.

The radicals R are preferably divalent or trivalent radicals, the divalent radicals being particularly preferred.

In a preferred embodiment, at least one-third, more preferably at least two-thirds of the radicals R ¹ , R ² or R ³ contained in the compounds of general formula (Ia) or (Ib) are ethoxy radicals.

The compounds of the general formula (Ia) or (Ib) preferably contain less than 1 part by weight, more preferably less than 0.75 part by weight, most preferably less than 0.5 part by weight, for example less than 0.25 part by weight of methoxy radicals , based on 100 parts by weight of the compounds of formula (Ia) or (Ib).

Another object of the present invention are curable compositions containing the silane-modified polymers of the general formula (Ia) according to the invention.

Another object of the present invention are curable compositions containing the α-ethoxysilane-modified polymers of the average general formula (Ib) according to the invention.

In addition, these curable compositions of the invention preferably contain fillers and other conventional additives such as plasticizers, solvents, UV stabilizers, antioxidants, catalysts, dry agents, rheological aids, aging inhibitors, thickeners, reactive diluents and adhesion promoters. Suitable fillers are, for example, chalk or limestone, precipitated and / or fumed silica, zeolites, bentonites, ground minerals, calcium carbonate, fumed silica, precipitated silica, silicic anhydride, silicon hydrate or carbon black, magnesium carbonate, calcined clay, clay, talc, titanium oxide, iron oxide, zinc oxide, Pulp, wood flour, mica, chaff, graphite, fine aluminum powder or flint powder, glass beads, glass powder, glass fibers and glass fiber short cuts, as well as other familiar to the expert inorganic fillers. Furthermore, it is also possible to use organic fillers, in particular short fiber slices or hollow plastic spheres, and functional fillers which have a positive influence on the rheological properties, for example highly disperse silica, in particular with a low BET surface area of 20-150 m ² / g, preferably 30-100 m ² / g, more preferably about 50 m ² / g and the like. For some applications, fillers which give thixotropy to adhesives or sealants are preferred, for example swellable plastics such as polyvinyl chloride.

The curable compositions of the invention may contain up to about 80% by weight of fillers.

The preferred as adhesion promoters, desiccants and / or reactive diluents α-silanes are advantageously selected from the group consisting of α-amino, α-methacrylic, α-carbamatosilanes and α-alkoxysilanes. Suitable examples are N-cyclohexylaminomethylmethyldiethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-phenylaminomethyltriethoxysilane, (methacryloxymethyl) methyldiethoxysilane and methacryloxymethyltriethoxysilane, N- (triethoxysilylmethyl) -O-methyl-carbamate and N- (methyldiethoxysilylmethyl) -O-methyl-carbamate.

However, the reactive diluents are preferably polyurethanes having at least one alkoxysilane group as the reactive group.

The reactive diluents may have one or more functional groups, but preferably the number of functional groups is from 1 to about 6, in particular from about 2 to about 4, for example about 3.

The viscosity of the reactive diluents in a preferred embodiment is less than about 20,000 mPas, more preferably about 1,000 to about 10,000, for example about 3,000 to about 6,000 mPas (Brookfield RVT, 23 ° C, spindle 7, 2.5 U / min). The reactive diluents which can be used can have any desired molecular weight distribution (PD), and can accordingly be prepared by the customary methods of polymer chemistry.

The reactive diluents used are preferably polyurethanes which can be prepared from a polyol component and an isocyanate component and subsequent functionalization with one or more alkoxysilyl groups.

In the context of the present text, the term "polyol component" encompasses a single polyol or a mixture of two or more polyols which can be used to prepare polyurethanes. By a polyol is meant a polyfunctional alcohol, that is, a compound having more than one OH group in the molecule.

As the polyol component for the preparation of the reactive diluents, a plurality of polyols can be used. For example, these are aliphatic alcohols having 2 to 4 OH groups per molecule. The OH groups can be both primary and secondary. Suitable aliphatic alcohols include, for example, ethylene glycol, propylene glycol, and the like polyfunctional alcohols.

Also suitable for use as a polyol component are polyethers which have been modified by vinyl polymers. Such products are obtainable, for example, by polymerizing styrene and / or acrylonitrile in the presence of polyethers.

Also suitable as a polyol component for the preparation of the reactive diluent are polyester polyols having a molecular weight of about 200 to about 5,000. Thus, for example, polyester polyols can be used by the above-described reaction of low molecular weight alcohols, in particular ethylene glycol, diethylene glycol, neopentyl glycol, hexanediol , Butanediol, propylene glycol, glycerol or trimethylolpropane with caprolactone. Also suitable as polyfunctional alcohols for the preparation of polyester polyols, as already mentioned, 1, 4-hydroxymethylcyclohexane, 2-methyl-1, 3-propanediol, butanediol-1, 2,4, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene - Glycol and polybutylene glycol. Other suitable polyester polyols can be prepared by polycondensation. Thus, difunctional and / or trifunctional alcohols with a deficit of dicarboxylic acids and / or tricarboxylic acids, or their reactive derivatives, can be condensed to polyester polyols.

Polyols used in the context of the present invention as polyol component for the preparation of the reactive diluents are, for example, dipropylene glycol and / or polypropylene glycol having a molecular weight of about 400 to about 2500, and also polyester polyols, preferably polyester polyols obtainable by polycondensation of hexanediol, ethylene glycol, diethylene glycol or neopentyl glycol or mixtures of two or more thereof and isophthalic acid or adipic acid, or mixtures thereof.

Polyacetals are also suitable as the polyol component for the preparation of the reactive diluents. Polyacetals are understood as compounds obtainable from glycols, for example diethylene glycol or hexanediol with formaldehyde. Polyacetals which can be used in the context of the invention can likewise be obtained by the polymerization of cyclic acetals.

Also suitable as polyols for the preparation of the reactive diluents are polycarbonates. Polycarbonates can be obtained, for example, by the reaction of diols such as propylene glycol, 1,4-butanediol or 1,6-hexanediol, diethylene glycol, triethylene glycol or tetraethylene glycol or mixtures of two or more thereof with diaryl carbonates, for example diphenyl carbonate or phosgene.

Also suitable as a polyol component for the preparation of the reactive diluents are OH-group-carrying polyacrylates. These polyacrylates are obtainable, for example, by the polymerization of ethylenically unsaturated monomers which carry an OH group. Such monomers are obtainable, for example, by the esterification of ethylenically unsaturated carboxylic acids and difunctional alcohols, the alcohol generally being in a slight excess. Examples of suitable ethylenically unsaturated carboxylic acids are acrylic acid, methacrylic acid, crotonic acid or maleic acid. Corresponding OH-bearing esters are, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate or 3-hydroxypropyl methacrylate or mixtures of two or more thereof. To prepare the reactive diluents preferred according to the invention, the corresponding polyol component is reacted in each case with an isocyanate which is at least difunctional. In principle, any isocyanate having at least two isocyanate groups is suitable as the at least difunctional isocyanate, but in the context of the present invention, as a rule, compounds having two to four isocyanate groups, in particular two isocyanate groups, are preferred.

The compound present as reactive diluent in the context of the present invention preferably has at least one alkoxysilane group, of which the di- and trialkoxysilane groups are preferred among the alkoxysilane groups.

In order to reduce the viscosity of the compositions according to the invention, a plasticizer may be used in addition to or instead of a reactive diluent.

Suitable plasticizers are, for example, esters such as abietic acid esters, adipic acid esters, azelaic acid esters, benzoic acid esters, butyric acid esters, acetic acid esters, esters of higher fatty acids having about 8 to about 44 carbon atoms, such as dioctyl adipate, diisodecylsuccinate, dibutyl sebacate or butyl oleate, esters OH-bearing or epoxidized Fatty acids, fatty acid esters and fats, glycolic esters, phosphoric esters, phthalic esters, linear or branched alcohols containing from 1 to 12 carbon atoms, such as dioctyl phthalate, dibutyl phthalate or butylbenzyl phthalate, propionic acid esters, sebacic acid esters, sulfonic acid esters, thiobutyric esters, trimellitic esters, citric acid esters and esters on nitrocellulose and polyvinyl acetate base, as well as mixtures of two or more thereof. Particularly suitable are the asymmetric esters of difunctional, aliphatic dicarboxylic acids, for example, the esterification of Adipinsäuremonooctylester with 2-ethylhexanol (Edenol DOA, Fa.Cognis, Dusseldorf).

Also suitable as plasticizers are the pure or mixed ethers of monofunctional, linear or branched C 4-16 -alcohols or mixtures of two or more different ethers of such alcohols, for example dioctyl ether (available as Cetiol OE, Cognis, Dusseldorf).

In a further preferred embodiment, end group-capped polyethylene glycols are used as plasticizers. For example, polyethylene or polypropylene glycol di-CI-4-alkyl ethers, in particular the dimethyl or diethyl ethers of diethylene glycol or dipropylene glycol, and mixtures of two or more thereof.

Also suitable as plasticizers in the context of the present invention are diurethanes. Diurethanes can be prepared, for example, by reaction of diols having OH end groups with monofunctional isocyanates, by selecting the stoichiometry such that substantially all free OH groups react. Optionally, excess isocyanate can then be removed from the reaction mixture, for example, by distillation. A further method for the preparation of diurethanes is the reaction of monofunctional alcohols with diisocyanates, wherein as far as possible all the NCO groups react.

Diols having 2 to about 22 carbon atoms, for example ethylene glycol, propylene glycol, 1,2-propanediol, dibutanediol, hexanediol, octanediol or industrial mixtures of hydroxy fatty alcohols having about 14 carbon atoms, in particular, can be used to prepare the diurethanes based on diols hydroxystearyl. Preference is given to linear Diolmischungen, in particular those containing polypropylene glycol having an average molecular weight (Mn) of about 1000 to about 6000 in amounts above about 50 wt .-%, in particular about about 70 wt .-%. Very particular preference is given to diurethanes exclusively based on propylene glycol having the same or different average molecular weights of about 1,000 to about 4,000. The free OH groups of the diol mixtures are essentially all reacted off with aromatic or aliphatic monoisocyanates or mixtures thereof. Preferred monoisocyanates are phenyl isocyanate or toluene isocyanate or mixtures thereof.

To prepare the diurethanes based on diisocyanates, aromatic or aliphatic diisocyanates or mixtures thereof are used. Suitable aromatic or aliphatic diisocyanates are, for example, the isocyanates, as have been indicated above as suitable for the preparation of the polyurethane according to the invention, preferably tolylene diisocyanate (TDI). The free NCO groups of the diisocyanates are reacted substantially completely with monofunctional alcohols, preferably linear monofunctional alcohols or mixtures of two or more different monofunctional alcohols. Particularly suitable are mixtures of linear monofunctional alcohols. Suitable monoalcohols are, for example, monoalcohols having 1 to about 24 C atoms, for example methanol, ethanol, the positional isomers of propanol, butanol, pentanol, hexanol, heptanol, octanol, Decanol or dodecanol, in particular the respective 1-hydroxy compounds, and mixtures of two or more thereof. Also suitable are so-called "technical mixtures" of alcohols and end-capped polyalkylene glycol ethers. Particularly suitable are mixtures of alcohols containing polypropyleneglycol monoalkyl ethers having an average molecular weight (Mn) of from about 200 to about 2,000 in an amount greater than about 50% by weight, preferably greater than about 70% by weight, based on the alcohol mixture , Particular preference is given to diurethanes based on diisocyanates whose free NCO groups have been completely reacted by means of polypropyleneglycol monoalkyl ethers having an average molecular weight of about 500 to about 2,000.

In addition to reactive diluents and plasticizers, the curable compositions of the invention may contain other additives which usually serve to modify certain material properties of the composition before or after processing or to promote the stability of the composition before or after processing.

Often it makes sense to stabilize the compositions according to the invention against penetrating moisture in order to increase the shelf-life. Such an improvement in storability can be achieved, for example, by the use of stabilizers. Suitable stabilizers are all compounds which react with water to form an inert group with respect to the reactive groups present in the composition, and thereby undergo the smallest possible changes in their molecular weight.

As stabilizers are, for example, preferably isocyanates or silanes. Suitable silanes are, for example, (methoxycarbonylaminomethyl) trimethoxysilanes, vinylsilanes such as 3-vinylpropyltriethoxysilane, vinyltrimethoxysilane, oximesilanes such as methyl-O, O ', O "-butan-2-one-trioximosilane or 0.0', 0", 0 '"-butane -2-on-tetraoximosilane (CAS Nos. 022984-54-9 and 034206-40-1) or benzamidosilanes such as bis (N-methylbenzamido) methylethoxysilane (CAs No. 16230-35-6).

The curable compositions of the invention typically contain from about 0 to about 6 weight percent stabilizers. The curable compositions of the invention may further contain up to about 7% by weight, more preferably from about 3 to about 5% by weight of antioxidants.

The stabilizers or antioxidants which can be used as additives in the invention include hindered phenols of high molecular weight (M _w ), polyfunctional phenols and sulfur and phosphorus-containing phenols. In the context of the invention usable as additives phenols are, for example, 1, 3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene; Pentaerythritol tetrakis-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate; n-octa-decyl-3,5-di-tert-butyl-4-hydroxyphenyl) propionate; 4,4-methylenebis (2,6-di-tert-butylphenol); 4,4-thiobis (6-tert-butyl-o-cresol); 2,6-di-tert-butylphenol; 2,4-dimethyl-6-tert-butylphenol, 2,2'-methylenebis (4-methyl-6-tert-butylphenol; 4,4'-butylidene bis (3-methyl-6-tert-butylphenol) butylphenol); 4,4'-thiobis (3-methyl-6-tert-butylphenol); 2,6-di-tert-butyl-p-cresol; 6- (4-hydroxyphenoxy) -2,4-bis (n octyl-thio) -1,3,5-triazine; tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane; 1, 1, 3-tris (2methyl-4 -hydroxy-4-tert-butylphenyl) butane; di-n-octadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate; 2- (n-octylthio) ethyl-3,5-di-tert-butylphosphonate; 4-hydroxybenzoate; and sorbitol hexa [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate].

Suitable photostabilizers are, for example, those which are commercially available under the name Thinuvin® (manufacturer: Ciba Geigy).

Suitable catalysts for promoting crosslinking are, in particular, aliphatic monoamines, diamines, polyamines and heterocyclic amines and aromatic amines, for example butylamine, hexylamine, octylamine, decylamine or laurylamine, ethylenediamine, hexanediamine, dibutylamine, triethanolamine, triethylenediamine, trimethylaminoethylpiperazine, pentamethyldiethylenetriamine,

Tetramethyliminobisopropylamine and bis (dimethylaminopropyl) -N-isopropanolamine; and dimorpholinodiethyl ether, diethylenetriamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, guanidine, diphenylguanidine, triethylenetetramine or tetraethylenepentamine, piperidine or piperazine, methaphenylenediamine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine , N-methylmorpholine, 1, 3-diazabicyclo [5.4.6] undecene-7 (DBU). Further suitable catalysts are those based on organic or inorganic heavy metal compounds, such as, for example, cobalt naphthenate, dibutyltin dilaurate, tin mercaptides, tin dichloride, zirconium tetraoctoate, tin naphthenate, tin stearate, antimony octoate, lead octoate, metal acetoacetate, especially iron acetylacetonate. In particular, all known for the acceleration of the silanol condensation catalysts come into question. For example, these are Organotin organotitanium, organozirconium or organoaluminum compounds. Examples of such compounds are dibutyltin dilaurate, dibutyltin dimaleate, tin octoate, isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate,

Bis (dioctyl pyrophosphate) oxyacetate titanate, tetrabutyl zirconate,

Tetrakis (acetylacetonato) zirconium, tetraisobutylzirconate, butoxytris (acetylacetonato) zirconium, tris (ethylacetoacetato) aluminum. Dibutyltin alkyl esters as

Dibutyltin alkyl maleates or dibutyltin laurates are particularly suitable, especially dibutyltin bisethyl maleate, dibutyltin bisbutyl maleate, dibutyltin bisoctyl maleate, dibutyltin bisoleyl maleate, dibutyltin bisacetylacetate, dibutyltin diacetate,

Dibutyltin dioctoate, dibutyltin oxide, dibutyltin bis-triethoxysilicate and their catalytically active derivatives. The catalysts mentioned can be used alone or as a mixture of two or more of the catalysts mentioned.

Also suitable as catalysts are amino compounds which carry an alkoxysilyl group, for example 3-aminopropyltromethoxysilane.

The preparation according to the invention may contain up to 5% by weight of such catalysts in the total amount.

Other additives which serve to vary certain properties of the curable compositions may be included. These include, for example, dyes such as titanium dioxide. Optionally, minor amounts of thermoplastic polymers or copolymers may additionally be included in the curable compositions of the present invention, for example, ethylene vinyl acetate (EVA), ethylene acrylic acid, ethylene methacrylate, and ethylene-n-butyl acrylate copolymers, which may provide additional flexibility, toughness, and strength to the adhesive. It is also possible to add certain hydrophilic polymers, for example polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl methyl ether, polyethylene oxide, polyvinylpyrrolidone, polyethyloxazolines or starch or cellulose esters, for example the acetates with a degree of substitution of less than 2.5.

The curable compositions of the present invention may contain up to about 2%, preferably about 1%, by weight of UV stabilizers. Particularly suitable as UV stabilizers are the so-called hindered amine light stabilizers (HALS). It is preferred in the context of the present invention if a UV stabilizer is used which carries a silane group and is incorporated into the final product during crosslinking or curing. Particularly suitable for this purpose are the products Lowilite 75, Lowilite 77 (Great Lakes, USA).

The curable compositions of the invention may contain, for example, additives which permit modification of the adhesive properties. For this purpose, for example, the so-called tackifier resins are suitable, which can be subdivided into natural resins and synthetic resins (synthetic resins). Suitable tackifier resins are, for example, alkyd resins, epoxy resins, melamine resins, phenolic resins, urethane resins, hydrocarbon resins and natural resins such as rosin, wood turpentine oil and tall oil. As the synthetic hydrocarbon resins, for example, ketone resins, coumarone-indene resins, isocyanate resins and terpene-phenolic resins are suitable. In the context of the present invention, the use of synthetic resins is preferred.

Furthermore, the curable compositions of the invention may contain flame retardants, such as conventional phosphorus-containing compounds, in particular elemental phosphorus, phosphates or phosphonates in question, for example triethyl phosphate or trichloropropyl phosphate. Such compounds may simultaneously have softening and viscosity regulating properties. Further suitable flame retardants are, for example, diphenyl cresyl phosphates, triphenyl phosphate, dimethyl methane phosphonate and the like. In addition, chloroparaffins can also be used as flame retardants. Also suitable are halogenated polyester or polyether polyols, for example commercially available brominated polyether polyol.

The curable compositions according to the invention, for example adhesives or sealants, advantageously comprise from 5 to 90% by weight, preferably from 10 to 70% by weight and more preferably from 15 to 50% by weight, of the polymer of the general formula (Ia) or ( Ib) based on the total weight of the curable compositions.

The invention further relates to a process for the preparation of α-ethoxysilane-modified polymers of the average general formula (Ib): in which

R is a mono- to tetravalent polymer radical, at most one third of the radicals R ¹ , R ² and R ³ contained in the polymer of the formula (Ib) independently of one another are alkyl radicals having 1 to 4 carbon atoms, at least one fourth of that in the polymer of the formula (Ib) radicals R ¹ , R ² and R ^{3 are} independently ethoxy radicals which are optionally remaining radicals R ¹ , R ² and R ^{3 are} independently methoxy radicals, and wherein n = 1 to 4, wherein a A compound of the formula RX _m , wherein m = 1 to 4 and m = n and X is an isocyanate-reactive group, such as a hydroxyl or amino group, with at least one compound of the formula OCN-CH ₂ -SiR ⁴ R ⁵ R ⁶ and at least one compound of the formula SiR ⁷ R ⁸ R ⁹ R ^{10 is} reacted in the presence of one or more catalysts, and wherein at least one of R ⁴ , R ⁵ and R ^{6 is} a methoxy radical and the radicals which may still be present R ⁴ , R ⁵ and R ⁶ alkyl radicals with 1 to 4 carbon atoms and at least one of R ⁷ , R ⁸ , R ⁹ and R ^{10 is} an ethoxy radical and the optionally remaining radicals R ⁷ , R ⁸ , R ⁹ and R ^{10 are} alkyl radicals having 1 to 4 carbon atoms ,

The catalysts used here catalyze the exchange of the alkoxy groups between the different silanes OCN-CH ₂ -SiR ⁴ R ⁵ R ⁶ and SiR ⁷ R ⁸ R ⁹ R ¹⁰ , and also the reaction of the isocyanate-reactive group with the isocyanatosilane connection. Suitable catalysts are, for example, transition metal complexes such as, for example, titanium catalysts, in particular organo-titanium compounds, for example titanium tetraalkoxylates or, for example, tin compounds, in particular organotin compounds, for example dialkyltin dicarboxylates, or bases or acids.

Particularly preferred catalysts are titanium compounds such as titanium tetraisopropylate. Preferably, in the process of the invention, the compound RX _{m is} initially charged with the catalyst and the compound of the formula SiR ⁷ R ⁸ R ⁹ R ¹⁰ , followed by reaction with a compound of the formula OCN-CH ₂ -SiR ⁴ R ⁵ R ⁶ in one Temperature range of preferably 60 to 130 ⁰ C. The resulting monomeric compounds are then preferably removed by distillation.

Preferred groups X in the polymers of the general formula RX _m are hydroxyl groups, thiol groups and amino groups.

Preferred compounds of the general formula OCN-CH ₂ -SiR ⁴ R ⁵ R ⁶ are alkyldimethoxysilanes and trimethoxysilanes, such as, for example, (isocyanatomethyl) methyldimethoxysilane or (isocyanatomethyl) trimethoxysilane.

Preferred compounds of the general formula SiR ⁷ R ⁸ R ⁹ R ¹⁰ are alkyldiethoxysilanes, alkyltriethoxysilanes, such as, for example, methyltriethoxysilane, ethyltriethoxysilane or tetraethoxysilane.

The invention additionally relates to the use of the silane-modified polymers according to the invention for the production of adhesives, in particular reactive post-crosslinking pressure-sensitive adhesives and sealants, and coating compositions.

The invention additionally relates to the use of the polymers according to the invention and α-ethoxysilane-modified polymers prepared according to the invention for the production of adhesives, in particular reactive postcrosslinking pressure-sensitive adhesives and sealants, and coating agents.

The invention further relates to the use of the curable compositions according to the invention for bonding wood, plastics, metals, mirrors, glass, ceramics, mineral substrates, leather, textiles, paper, cardboard and rubber, wherein the materials are bonded to each other with themselves or with each other can.

Moreover, the invention relates to the use of the curable compositions of the invention as a sealant mass. Advantageously, the compositions of the invention can also be used as a surface coating agent, as a water vapor barrier, as a dowel, hole or trowel and for the production of moldings. In the following the invention will be explained in more detail by means of exemplary embodiments.

EXAMPLES

example 1

450 g (24 mmol) of polypropylene glycol 18000 (hydroxyl number = 6.1) are dried in a 1000 ml three-necked flask at 80 ^° C. in vacuo. Under a nitrogen atmosphere, 0.1 g of titanium tetraisopropylate is added at 80 ^° C., and after three minutes of stirring, 40 g of methyltriethoxysilane are subsequently added and the mixture is stirred for a further 20 minutes. It is added to 0.1 g of dibutyltin dilaurate and then treated with 9.1 g (54 mmol) Isocyanatomethyldimethoxymethylsilan (isocyanate content = 25 wt .-%). After one hour of stirring at 80 ° C, volatile components (low molecular weight silanes) are distilled off in vacuo and the resulting polymer is cooled. The product is stored moisture-tight under a nitrogen atmosphere in a glass jar.

¹³ C-NMR (CDCl 3 / TMS): δ = -6.2 (Si (CH ₃₎ (OCHA) _2); -5.7 (-Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ )); 27.2 (NH-CH ₂ -Si (CH ₃ ) (OCHs) ₂ ); 27.6 (NH-CH ₂ -Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ )); 50.4

(-Si (CH ₃ ) (OCHa) ₂ ); 50.6 (-Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ )); 58.6

(-Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ ))

There is a mixture of dimethoxysilyl and methoxyethoxysilyl end groups (ratio 1: 1)

Example 2

450 g (24 mmol) of polypropylene glycol 18000 (hydroxyl number = 6.1) are dried in a 1000 ml three-necked flask at 80 ^° C. in vacuo. Under a nitrogen atmosphere, 0.1 g of titanium tetraisopropylate is added at 80 ^° C., and after three minutes of stirring, 90 g of tetraethoxysilane are subsequently added and stirring is continued for a further 20 minutes. It is added to 0.1 g of dibutyltin dilaurate and then treated with 9.1 g (54 mmol) Isocyanatomethyldimethoxymethylsilan (isocyanate content = 25 wt .-%). After stirring for one hour at 80 ^° C., volatile constituents (low molecular weight silanes) are distilled off in vacuo and the resulting polymer is cooled. The product is stored moisture-tight under a nitrogen atmosphere in a glass jar. ¹³ C-NMR (CDCU / TMS): δ = -6.2 (-Si (CH ₃ ) (OCHa) ₂ ); -5.7 (-Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ )); -5.3 (-Si (CH ₃ ) (OCH ₂ CHs) ₂ ); 27.2 (NH-CH ₂ -Si (CH ₃ ) (OCH ₃ ) ₂ ); 27.6 (NH-CH ₂ -

Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ )); 27.8 (NH-CH ₂ -Si (CH ₃ ) (OCH ₂ CH ₃ ) ₂ );

50.4 (-Si (CH ₃ ) (OCH ₃ ) ₂ ); 50.6 (-Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ ));

58.6 (-Si (CH ₃ ) (OCH ₂ CH ₃ ) (OCH ₃ )); 58.7 (-Si (CH ₃ ) (OCH ₂ CHs) ₂ ))

There is a mixture of dimethoxysilyl; Methoxyethoxysilyl and diethoxysilyl end groups (ratio 1: 2: 0.5)

Example 3

450 g (24 mmol) of polypropylene glycol 18000 (hydroxyl number = 6.1) are dried in a 1000 ml three-necked flask at 80 ^° C. in vacuo. Under an atmosphere of nitrogen, 40 g of methyltriethoxysilane are added at 80 ^° C. and, after stirring for 20 minutes, 0.2 g of titanium tetraisopropoxide are subsequently added and the mixture is stirred for a further 3 minutes. It is added to 0.1 g of dibutyltin dilaurate and then treated with 9.1 g (54 mmol) Isocyanatomethyldimethoxymethylsilan (isocyanate content = 25 wt .-%). After two hours of stirring at 120 ⁰ C volatile components (low molecular weight silanes) are distilled off in vacuo and the resulting polymer was cooled. The product is stored moisture-tight under a nitrogen atmosphere in a glass jar.

¹³ C NMR (CDClA / TMS): δ = -5.3 (-Si (CH ₃ ) (OCH ₂ CH ₃ ) ₂ ); 27.8 (NH-CH ₂ -Si (CH ₃ ) (OCH ₂ CH ₃ ) ₂ ); 58.7 (-Si (CH ₃ ) (OCH ₂ CHs) ₂ ))

It is present in a high excess of diethoxysilyl end groups. Methoxy-containing end groups are only recognizable by NMR.

Comparative Example 1

450 g (24 mmol) of polypropylene glycol 18000 (hydroxyl number = 6.1) are dried in a 1000 ml three-necked flask at 80 ^° C. in vacuo. Under a nitrogen atmosphere, 0.1 g of dibutyltin laurate is added at 80 ^° C., followed by addition of 9.1 g (54 mmol) of isocyanatomethyldimethoxymethylsilane (isocyanate content = 25% by weight). After stirring for one hour at 80 ⁰ C, the resulting polymer is cooled. The product is stored moisture-tight under a nitrogen atmosphere in a glass jar.

¹³ C-NMR (CDCl ₃ / TMS): δ = -6.2 (-Si (CH ₃ ) (OCH ₃ ) ₂ ); 27.2 (NH-CH ₂ -Si (CH ₃ ) (OCH ₃ ) ₂ ); 50.4 (- Si (CH ₃ ) (OCH ₃ ) ₂ ) Comparative Example 2

450 g (24 mmol) of polypropylene glycol 18000 (hydroxyl number = 6.1) are dried in a 1000 ml three-necked flask at 80 ^° C. in vacuo. Under nitrogen atmosphere 40 g of methyltriethoxysilane is added at 80 ⁰ C and stirred for 20 min. It is added to 0.1 g of dibutyltin dilaurate and then treated with 9.1 g (54 mmol) Isocyanatomethyldimethoxymethylsilan (isocyanate content = 25 wt .-%). After stirring for one hour at 80 ^° C., volatile constituents (low molecular weight silanes) are distilled off in vacuo and the resulting polymer is cooled. The product is stored moisture-tight under a nitrogen atmosphere in a glass jar.

¹³ C-NMR (CDCl 3 / TMS): δ = -7.1 (Si (CH ₃₎ (OCH ₂ CHs) _3); -6.2 (-Si (CH ₃ ) (OCH ₃ ) ₂ ); 27.2 (NH-CH ₂ -Si (CH ₃ ) (OCHs) ₂ ); 50.4 (-Si (CH ₃ ) (OCH ₃ ) ₂ ); 58.2 (Si (CH ₃ ) (OCH ₂ CH ₃ ) ₃ )

There is a mixture of the dimethoxysilyl polymer and the educt triethyoxymethylsilane. The desired ethoxysilyl polymer did not form.

Formulation example 1 for an adhesive of polymer 1:

The adhesive formulation contains 20% by weight of the polymer from Example 3, 20% by weight of plasticizer (Jayflex DINP, Exxon Mobil), 56% by weight of fillers (CaCO ₃ ), 0.5% by weight of AMEO ( Aminopropyltriethoxysilane: Geniosil GF93, from Wacker Chemie), 0.8% by weight of isooctyltriethoxysilane (from Wacker Chemie), 2% by weight of α-methacryltriethoxysilane (Geniosil XL36, from Wacker), and 0, 1% by weight of Polycat DBU (1,8-diazabicyclo [5.4.0] undec-7-ene, Air Products).

The skin-over-time is 30 minutes, the tack-free time is less than 12 hours and the methanol elimination is less than 0.15 wt .-%.

Claims

claims

1. Silane-modified polymer of the general formula (Ia):

(Ia) in which

R is a mono- to tetravalent polymer radical,

R ¹ , R ² , R ³ independently of one another are an alkyl or alkoxy radical having 1 to 8 C atoms and

The silane-modified polymer according to claim 1, wherein R is a polymer residue selected from the group consisting of alkyd resins, oil-modified alkyd resins, unsaturated polyesters, natural oils, epoxies, polyamides, thermoplastic polyesters, polycarbonates, polyethylenes, polybutylenes, polystyrenes, polypropylenes, ethylene-propylene co and terpolymers, (meth) acrylates and (meth) acrylamides and their salts, phenolic resins, polyoxymethylene homopolymers and copolymers, polyurethanes, polysulfones, polysulfide rubbers, nitrocelluloses, vinyl butyrates, vinyl polymers containing vinyl chloride and / or vinyl acetate, ethylcelluloses, cellulose acetates and butyrates, rayon, shellac, waxes, ethylene copolymers, organic rubbers, silicone resins and polyethers.

3. A silane-modified polymer according to claim 1 or 2, wherein R is a polypropylene glycol radical.

4. A silane-modified polymer according to any one of claims 1 to 3, wherein the radical R is a bivalent radical.

5. silane modified polymer according to any one of claims 1 to 4 wherein at least a third of the radicals R ^1, R ² or R ³ are ethoxy radicals.

The silane-modified polymer according to any one of claims 1 to 5, wherein 100 parts by weight of the polymer of the general formula (Ia) is less than 1 part by weight, preferably less than 0.75 part by weight, more preferably less than 0.50 part by weight, and most preferably less contain as 0.25 parts by weight of methoxy radicals.

7. α-Ethoxysilane modified polymer of average general formula (Ib):

(Ib) in which

8. α-ethoxysilane-modified polymer according to claim 7, wherein R is a polymer radical selected from the group consisting of alkyd resins, oil-modified alkyd resins, unsaturated polyesters, natural oils, epoxides, polyamides, thermoplastic polyesters, polycarbonates, polyethylenes, polybutylenes, polystyrenes, polypropylenes, Ethylenpropylenco- and terpolymers, (meth) acrylates and (meth) acrylamides and their salts, phenolic resins, Polyoxymethylenhomo- and - copolymers, polyurethanes, polysulfones, Polysulfidkautschuken, nitrocelluloses, vinyl butyrates, vinyl polymers containing vinyl chloride and / or vinyl acetate, ethylcelluloses, cellulose acetates and butyrates, rayon, shellac, waxes, ethylene copolymers, organic rubbers, silicone resins and polyethers.

9. α-Ethoxysilane modified polymer according to claim 7 or 8, wherein R is a polypropylene glycol radical.

10. α-Ethoxysilane modified polymer according to any one of claims 7 to 9, wherein the radical R is a bivalent radical.

11. α-ethoxysilane-modified polymer according to any one of claims 7 to 10 wherein at least one third of the radicals R ¹ , R ² or R ^{3 are} ethoxy radicals.

12. α-Ethoxysilane modified polymer according to any one of claims 7 to 11, wherein 100 parts by weight of the polymer of the average general formula (Ib) less than 1 part by weight, preferably less than 0.75 parts by weight, more preferably less than 0.50 parts by weight and am most preferably less than 0.25 parts by weight of methoxy radicals.

13. A curable composition comprising:

(A) at least one silane-modified polymer of the general formula (Ia)

(Ia) in which

R is a mono- to tetravalent polymer radical,

A represents a carboxy, carbamate, amide, carbonate, ureido, urethane or sulfonate group or an oxygen atom, x = 1 to 8 and n = 1 to 4, and

(B) one or more compounds selected from the group consisting of fillers, plasticizers, solvents, UV stabilizers, antioxidants, catalysts, drying agents, reactive diluents and adhesion promoters.

14. A curable composition comprising:

(A) at least one α-ethoxysilane-modified polymer of the average general formula (Ib):

(Ib) in which

R is a mono- to tetravalent polymer radical, at most one third of the radicals R ¹ , R ² and R ³ contained in the polymer of the formula (Ib) independently of one another are alkyl radicals having 1 to 4 carbon atoms, at least one fourth of that in the polymer of the formula (Ib) radicals R ¹ , R ² and

R ^{3 are} independently ethoxy radicals, optionally remaining radicals R ¹ , R ² and R ³ independently

Methoxy radicals, and wherein n = 1 to 4, and

(B) one or more compounds selected from the group consisting of

Fillers, plasticizers, solvents, UV stabilizers, antioxidants,

Catalysts, desiccants, reactive diluents and adhesion promoters.

15. Process for the preparation of α-ethoxysilane-modified polymers of the average general formula (Ib):

(Ib) in which

R is a mono- to tetravalent polymer radical, at most one third of the radicals R ¹ , R ² and R ^{3 present} in the polymer of the formula (Ib) are, independently of one another, alkyl radicals having 1 to 4 carbon atoms, at least one quarter of the radicals R ¹ , R ² and R contained in the polymer of the formula (Ib)

Methoxy radicals, and wherein n = 1 to 4, wherein a compound of the formula wherein m = 1 to 4 and m = n and X is an isocyanate-reactive group, with at least one compound of the formula

OCN-CH ₂ -SiR ⁴ R ⁵ R ⁶ and at least one compound of the formula SiR ⁷ R ⁸ R ⁹ R ^{10 is} reacted in the presence of one or more catalysts, and wherein at least one of R ⁴ , R ⁵ and R ^{6 is} a methoxy Radicals and optionally remaining radicals R ⁴ , R ⁵ and R ^{6 are} alkyl radicals having 1 to 4 carbon atoms and at least one of R ⁷ , R ⁸ , R ⁹ and R ^{10 is} an ethoxy radical and optionally still present R ⁷ , R ⁸ , R ⁹ and R ^{10 are} alkyl radicals having 1 to 4 carbon atoms.

16. The method according to claim 15, wherein first the compound RX _n with the one or more catalysts and the compound of the formula SiR ⁷ R ⁸ R ⁹ R ^{10 is} submitted and then a reaction with a compound of the formula OCN-CH ₂ -SiR ⁴ R ⁵ R ^{6 is carried out} in a temperature range of 60 to 130 ⁰ C.

17. The method according to any one of claims 15 or 16, wherein the catalyst used is a titanium organic catalyst.

18. The method according to claim 17, wherein the catalyst used is a titanium tetraalkoxylate.

19. Use of the silane-modified polymers of one or more of claims 1 to 6 for the production of adhesives, sealants and coating compositions.

20. Use of the α-ethoxysilane-modified polymers from one or more of claims 7 to 12 or prepared according to any one of claims 15 to 18 for the preparation of adhesives, sealants and coating compositions.

21. Use of the curable compositions according to any one of claims 13 or 14 for the bonding of wood, plastics, metals, mirrors, glass, ceramics, mineral substrates, leather, textiles, paper, cardboard and rubber, wherein the materials each with itself or arbitrarily glued together.

22. Use of the curable compositions according to any one of claims 13 or 14 as a sealant composition, surface coating, as a water vapor barrier, as a dowel, hole or trowel and for the production of moldings.