DE19644932A1 - Base-catalysed reaction of 1,3-di:isocyanato alkyl cycloalkane - Google Patents

Abstract

Base-catalysed reaction products of 1,3-di-isocyanato-alkylcyclohexane R1(NCO)2 in presence of acyclic urethane groups or corresponding isomeric cyclic allophanate groups (and optionally higher homologues) of formula (I) and (II) respectively, are claimed. The products are obtained by reaction of 1,3-di-isocyanato-alkylcyclohexane with polyols of formula A(OH)x. (OH)y-A-(O-CO-NH-R1)x-y-NCOn-x+y (I) A = residue of x-hydric hydroxyl compound; R1 = residue of 1,3-di-isocyanato-alkylcyclohexane; n = number of NCO equivalents in the di-isocyanate components; x = number of OH equivalents in the hydroxy components; y = (x - n) which is number of optionally unreacted OH groups, i.e. 0-4; n - x + y = number of NCO groups in the urethane of not more than 4. The NCO/OH ratio is (0.5:1)-(200:1) and the content of urethane or allophanate groups is 0.05-48 wt% based on the reaction mass used. The process comprises urethane-formation and a simultaneous or subsequent poly-addition reaction with NCO groups in excess (NCO/OH = 1.05:1-200:1), in the presence of 0.00005-10 wt% basic catalyst (in monomeric form or ionically or preferably covalently bonded to a sparingly-soluble matrix) and optionally in presence of air, to give poly-allophanate-polyisocyanates of formula (III) and/or (IV) with an allophanate group content of 2-55 wt%. A--OCO-N(R1-NCO)-CO-N(R1-NCO)m-Hx (III) m = more than 1.05; and p = 0 or more. The mixtures obtained have an average NCO functionality of more than 2.1, and contain less than 10 wt% sparingly soluble heterocyclic polyamide-1,1-compounds with no isocyanate groups, less than 10 wt% isocyanurate structures based on 1,3-di-isocyanato-alkylcyclohexane and less than 2 wt% monomeric di-isocyanate starting material. Also claimed are processes for the production of poly-allophanate-polyisocyanates as above.

Description

The invention relates to new lightfast, allophanate having higher radio tional polyisocyanates, process for their preparation and their use for Coating of any substrates.

It is known, with the help of Gasphasenphosgeniertechnik u. a. (Cyclo) aliphatic Diisocyanates with the isocyanate groups in 1.3 position to each other in high purity unit and synthesize good yield (EP-A-0 676 392). by virtue of of the known high level of technical properties "light fast" (cyclo) aliphatic diisocyanates would also be mentioned above. Diisocyanato (cyclo) alkanes of high interest for coating applications.

High quality isocyanate based paints with excellent optical properties and weatherproof properties as well as an excellent solvent-resistant in most cases contain isocyanurate moieties, optionally in Combination with proportionate urethane and / or allophanate units. For synthesis trimeric isocyanates are known to be quite a few predominantly basic catalysts used, for. B.H.J. Laas et al, Journal prakt. Chemistry 336 (1994) and D. Dieterich, Houben-Weyl, Vol. E20 (1987) p. 1742 f. For the production for technically important isocyanurates, eg. B. based on Hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI) become catalysis based on quaternary ammonium hydroxides (EP-A-0 330 966) fluorides (EP-A-3 393 396), organosilicon compounds (EP-A-57 653, EP- A-89 297, EP-A-187 105, EP-A-197 864) and in particular at a higher temperature Tertiary amines (GB-A-2 222 161) or aminoalcohols (GB-A-2 221 465) used.

Trimerization and dimerization reactions of (cyclo) aliphatic polyisocyanate Te can also be chemically covalently bound to a polymer matrix basic catalysts are carried out (eg US-A 5 221 743, US-A 5,315,004).

The main advantage of such a procedure is a quick quan titative stopping of the catalyzed trimerization at the desired Um degree of settling by removal of the fixed bed catalyst z. B. by filtration, without  that chemical deactivators, which can lead to disadvantages, concomitantly used Need to become.

For crosslinking properties of a chemically modified lacquer isocyanate is the so-called mean functionality, d.i. the number of polyadditions reaction available NCO groups per average molecular weight essential. In particular by Trimesierungs- and biuretization reactions of Diisocyanates with subsequent homologation to oligomeric to höhermole For subsequent crosslinking purposes, secondary products can be sufficiently high in NCO Functionalities are achieved.

The further the homologous polyaddition of the polyisocyanate isocyanurates under Er Increasing the average functionality is completed, the more it increases Viscosity of the final products obtained while reducing their NCO content.

A number of other desirable properties of lacquer isocyanates can by targeted incorporation of a proportion of urethane and / or allophanate groups be achieved.

In addition, urethane groups can have a cocatalytic effect effect favorable reaction course. Allophanate groups have in particular With regard to a desired reduction of the solvent content of Paint binders ("high solid paints") have a favorable viscosity-reducing Influence, z. (EP-A-0 566 037, EP-A 496 208, EP-A 524 501, EP-A 535 483, EP-A A 0 649 866). Also, they favor a better compatibility of isocyanate lacquer resins with the frequently used nonpolar lacquer solvents, eg. B. on Gasoline base.

The proportion of allophanate units, z. B. in admixture with trimeric isocyanates has to be limited because its comparatively lower mean NCO Functionality the crosslinking property of the trimer / allophanate mixture with stei decreasing allophanate content, with important application properties such as B. drying behavior, film hardness and solvent resistance ver (eg EP-A 0 566 037, EP-A 0 649 866).

The achievable allophanate content in the trimerization (cyclo-) aliphatic Diisocyanates in the presence of basic catalysts in combination with alcohols  is also chemically limited, because the Isocyanuratbildung preferably proceeds. By a targeted temperature control - the allophanatization reaction from the urethane i.a. with increasing temperature faster - can the Allophanate content of (cyclo) aliphatic isocyanurates in a limited amount Increase circumference.

Predominantly allophanate-containing isocyanates can be made from urethane groups by thermal treatment or by acid catalysis with acids (eg. EP-A 0 000 194) - associated with possibly strongly discolored end products (eg GB-A 994 890) - or z. As known in polyurethane chemistry tin catalysts (eg EP-A 0 682 012).

The use of basic catalysts does not - as mentioned above - not to pure allophanate, but to product mixtures with z. Eg uretdione, Isocyanurate and biuretan parts (eg EP-A 0 682 012, page 2, line 46 f).

Only by using higher-functionality alcohols can the mean NCO Increase the functionality of the described allophanate resins to such an extent that crosslinkers properties (eg EP-A 0 000 194).

The preparation of lightfast predominantly allophanatgruppenhaltiger isocyanates can be achieved with the help of acidic or Sn-containing catalysts. To increase the for a crosslinking effect important average NCO functionality is the use higher functional alcohols necessary. When using basic catalysts must the formation of substantial shares in isocyanurate structures accepted who the. The thermal cleavage of allophanate groups usually leads to an undesirable increase in the content of monomeric isocyanate.

The experiment 1,3-Diisocyanatoalkylcycloalkane (mixture of cis- and trans-stereo isomeric) in the presence of catalysis known from polyurethane chemistry gates such as B. lead salts of carboxylic acids, tertiary amines and amino To convert alcohols, does not lead to the formation of trimeric isocyanates, but to heterocyclic polyamide-1,1-polymerizates ("α-nylon", EP-A 0 014 365). The polyamide formation takes place essentially from the configuration Iso mers of the alkyl-substituted 1,3-diisocyanato-cyclohexanes used, the carry two NCO groups in cis position to each other.  

The trans configuration isomers remain largely unchanged, so that this method by precipitating the sparingly soluble, almost NCO-free poly amide can be used to separate the isomer mixture. The pure one cis-1,3-diisocyanate can then by thermal cleavage of the polyamide at higher temperatures (about 230 ° C) to be regenerated.

It has now surprisingly been found that 1,3-diisocyanatoalkyl cycloalkanes with basic catalysts to high-quality chemically modified Polyisocyanates react without substantial amounts of interfering polyamide-1,1- Shares are formed when the reaction in the presence of Urethane groups performs.

The allophanatization reaction of the 1,3-diisocyanates described already leads with monofunctional alcohols to heat and storage stable polyisocyanates, the one for networking properties suitable average NCO functionality above have half two, without significant proportions of higher functional isocyanurate structures are formed.

It must therefore be regarded as surprising that the described alkyl-substituted cycloaliphatic diisocyanates, allophanate group pen and their isocyanate folic addition products ("polyallophanates") containing Polyisocyanates in the paint level the known Trimerisaten on the Base (cyclo) aliphatic diisocyanates are equal and beyond Vor Share in terms of low viscosity and better compatibility with have non-polar paint solvent.

The invention relates to the base-catalyzed reaction products of 1,3-Diisocyanatoalkylcyclohexanen R₁ (NCO) ₂ in the presence of acyclic bonded Urethane (I) or the corresponding isomeric cyclically bound allophanate groups (II) and optionally their higher molecular weight homologues of the formula

the Ver by the reaction of covalently bonded hydroxide carrying Ver compounds A (OH) _x with the diisocyanates R₁ (NCO) ₂ are obtained, wherein
A is a radical obtained by removal of the OH groups from a hydroxyl-valent organic compound,
R₁ is a radical as obtained by removal of the isocyanate groups from a diisocyanate R₁ (NCO) ₂,
n denotes the number of NCO equivalents of Diisocyanatkom used components
x denotes the number of OH equivalents of the hydroxyl components used,
y = xn denotes the proportion of optionally unreacted hydroxyl groups and O <y <4
n-x + y stands for the number of NCO groups of the urethanes and is max. 4,
and wherein an NCO / OH ratio of 0.5: 1 to 200: 1 can be selected and the content of urethane (59 g / mol) or the corresponding isomeric cyclic allophanate groups (101 g / mol) between 0.05 to 48 wt .-%, based on the reaction mass used, and wherein, following or simultaneously with the urethanization reaction in a stoichiometric excess of NCO / OH groups (based on the amount of hydroxyl compound used) of 1.05: 1 to 200 : 1 optionally in the presence of air by addition of 0.00005-10 wt .-% of a monomeric or sparingly soluble matrix ionically or preferably covalently bonded basic catalyst which optionally has covalently bonded hydroxyl groups, a more extensive polyaddition reaction takes place, the Polyallophanate polyisocyanates containing allo phanatgruppen 2-55 wt .-% of the formula

leads, where x has the meaning previously mentioned, and
wherein mixtures of structures (III) and (IV) may occur and m is a number <1.05 and p <0, characterized in that these polyallophanate polyisocyanate

• - Less than 10 wt .-% of largely isocyanate-free heavy having soluble heterocyclic polyamide-1.1 compounds,
• their mean NCO functionality is above 2.1,
• less than 10% by weight of isocyanurate structures based on cycloaliphatic Contain alkyl-1,3-diisocyanates,
• - and the content of monomeric starting diisocyanate less than 2 wt .-% is.

The polyisocyanate mixtures according to the invention - hereinafter referred to as "polyallophanate polyisocyanates "- have a content of NCO groups between 1 and 25 wt .-%, an average NCO functionality of 2.1-6.0 a content of Urethane groups (59 g / mol) from 0.05 to 15 wt .-% and a content of Allo Phanatgruppen (101 g / mol) of 2-55 wt .-%. By choosing the stoichiometric NCO / OH ratios and the process parameters (eg temperature control, Concentration of the basic catalyst) may erfin the composition of Polyisocyanate according to the invention within the limits specified be varied.

The data concerning the average NCO functionality are calculated from the NCO content determined by titrimetry or IR spectroscopy and the mean molecular weight M _n obtained with the aid of gel permeation chromatography.

In the preparation of urethane group-containing starting materials is also the Concomitant use of (cyclo) aliphatic monoisocyanates and / or di- and / or higher than difunctional polyisocyanates possible. Examples are cyclo hexyl isocyanate, hexamethylene diisocyanate, isophorone diisocyanate and their trimers (Isocyanurates), as well as nonane triisocyanate.

For the preparation of allophanate polyisocyanate mixtures according to the invention in Presence of urethane groups and with the help of basic catalysts there ver different process versions.

The invention relates to a process for the preparation of these polyisocyanates by reacting a 1,3-diisocyanato-alkylcydohexane R₁ (NCO) ₂ of Mole kulargewichtsbereichs of 180-292 with a covalently bound hydroxide-carrying compounds compound while maintaining an equivalent ratio of NCO- to OH- Groups of 0.5: 1 to 200: 1 to urethane group-containing compounds having a urethane content [59 g / mol] between 0.05 and 48 wt .-%, and further reaction of these urethane group-containing compounds in a stoichiometric excess of 1,3-NCO NCO Groups of at least 1.05: 1 to 200: 1 (based on the OH compound used) with the assistance of a basic catalyst which optionally carries covalently bonded hydroxyl groups, in amounts of 5 × 10 ^-5 to 10 wt .-% optionally diluted in inert or isocyanate-reactive H-containing solvents, if appropriate in the presence of air allophanate-group-containing polyisocyanate mixtures and their secondary products in the sense of the isocyanate polyaddition having a urethane content [59 g / mol] between 0.05 to 15 wt.% and containing allophanate units [101 g / mol] of 2-55 wt. wherein the addition of the optionally present in dissolved form prior basic catalyst is carried out simultaneously with or after addition of the hydroxide group-carrying compounds A (OH) _x and wherein in the case that the basic catalyst capable of covalently bound to urethanization of the 1,3-diisocyanate used Has hydroxide groups, can be dispensed with the use of the hydroxide A (OH) _x and optionally with proportional di- and / or higher functional (cyclo) aliphatic poly isocyanates, which do not carry the NCO groups in the 1,3-position to each other, with and where appropriate, the reaction at the ge desired degree of conversion by adding a chemical stopper and / or thermal deactivation ivierung is terminated, and subsequent to the basic kata lysed Polyallophanatisierungsreaktion still present volatile, unreacted starting polyisocyanate is removed by distillation or extractive methods from the reaction mixture, or optionally wherein in the course of the allophanatization beingigender viscosity gradually added an isocyanate inert solvent so that ultimately a ca. 30-95, preferably 50-90% solution of Allophanatpolyiso cyanate arises,
characterized in that the resulting Polyallophanatpolyisocyanat mixtures

• - Less than 10 wt .-% of largely isocyanate-free, schwerlös have heterocyclic polyamide-1,1-compounds,
• their mean NCO functionality is above 2.1,
• less than 10% by weight of isocyanurate structures based on cycloaliphatic Containing alkyl 1,3-diisocyanates.

The invention is also a further process for the preparation of Polyallophanatpolyisocyanatgemische with the participation of basic to a matrix chemically fixed catalysts.

The trimerization and dimerization reaction of (cyclo) aliphatic diiso cyanates such as. As hexamethylene diisocyanate (HDI) using chemically fixed on a polymeric support matrix bound basic catalyst known per se compounds is described (US-A 5 221 743, US-A 315 004).

Surprisingly, it has now been found that the preparation of the erfindungsge according to higher-functionality allophanate polyisocyanate mixtures which are present is bound by urethane groups, also with the help of the above-mentioned fixed bed catalysts is possible by ensuring that by reaction of the 1,3- cycloaliphatic diisocyanate with covalently bonded OH groups one for the basic catalyzed allophanatization reaction, sufficient amount of urethane groups.  

The invention thus provides a further process for preparing the higher-functionality allophanate-polyisocyanate mixtures according to the invention by reacting a cycloaliphatic alkyl-1,3-diisocyanate R₁ (NCO) ₂ of the molecular weight range 180-292 with covalently bonded hydroxide groups while maintaining an equivalent ratio of NCO to OH. Groups of 0.5: 1 to 200: 1 to urethane group-containing compounds having a urethane content (59 g / mol) between 0.5 and 48 wt .-% and further reaction of these urethane group penhaltigen compounds, optionally in the presence of air, in a stoichiometric excess to 1,3-NCO groups of at least 1.05: 1 to 200: 1 (based on the OH equivalents used) with the aid of a basic catalyst, the ionic or preferably covalently in amounts of 0.005-10 meq / g of polymeric substance is present bound in a solid organic or inorganic matrix, to Polyallophanatpolyisocyanatgemischen containing urethane groups between 0.05 to 15% by weight and an allophanate group content of between 2 and 55% by weight, the contact of the starting materials with the described fixed bed catalyst after or simultaneously with the urethanization reaction of the cycloaliphatic 1,3 Diisocyanates Herge can be provided, wherein the covalently bound OH groups may be part of the described surrounded hydroxide A (OH) _x , and in the event that the che mix fixed fixed-bed catalyst ver added via covalently bound hydroxyl groups, on the participation of the OH Components A (OH) _x can be dispensed with, with proportional di- and higher functional (cyclo) aliphatic polyisocyanates, which do not carry the NCO groups in the 1,3-position to each other, can be used, and the reaction at the desired degree of conversion by removal - z. B. filtration - the sparingly soluble solid catalyst, optionally with the concomitant use of a chemical stopper is terminated and optionally still present, easily volatile starting isocyanates by distillation or extractive methods are removed from the reaction mixture or, where appropriate Beistigender in the course of Polyallophanatisierungsprozesse viscosity gradually towards an isocyanate inert Solvent is added, so that a 30-95% solution of Polyallophanatpolyisocyanatgemische arises, characterized in that the polyallophanate according to the invention mixtures

• - Less than 10 wt .-% of largely isocyanate-free heavy solution have aliphatic heterocyclic polyamide-1.1 compounds,  
• their mean NCO functionality is above 2.1,
• and less than 10% by weight of isocyanurate structures based on cycloalipha table alkyl-1,3-diisocyanates.

Finally, the invention also relates to the use of the according to both process variants obtained (poly) allophanatpolyisocyanategemi if appropriate in combination with appropriate reaction partners and given if appropriate in blocked form as a binder for the coating of any desired Substrates.

Starting materials for the preparation of the polyisocyanates of the invention are according to the two methods described cycloaliphatic alkyl diisocyanates with 9-17 carbon atoms and the isocyanate groups in the 1,3-position to each other:

R₁ (NCO) ₂

Suitable cycloaliphatic alkyl diisocyanates include 2,4-diisocyanate nato-1-methylcyclohexane, 2,6-diisocyanato-1-methylcyclohexane, 2,4-diisocyanato 1-methyl-3,5-diethylcyclohexane, 2,6-diisocyanato-1-methyl-3,5-diethylcyclohexane, 2,4-diisocyanato-1,3,5-triisopropylcyclohexane, 2,6-diisocyanato-1,3,5-triisopropyl cyclohexane, 2,4-diisocyanato-1-isopropylcyclohexane, 2,6-diisocyanato-1-isopropyl pylcyclohexane, and the isomeric mixtures of alkylcyclohexane listed diisocyanate.

In principle, the admixture of known (cyclo) aliphatic is possible Diisocyanates, such as. Hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI) in the preparation of the polyisocyanates of the invention. Also higher functional monomer starting isocyanates - such. Nonantriisocyanate - can be used.

While the addition of monofunctional (cyclo) aliphatic isocyanates is possible, but not preferred, it may be advantageous, even trifunk functional (cyclo) aliphatic isocyanurates z. B. based on the latter Diiso to use cyanate.  

The second structural component for the preparation of the polyiso invention cyanates are aromatic or acyclic or cyclic aliphatic hydroxyl group-containing compounds of the formula (V)

A (OH) _x (V)

in which
A is a radical as obtained by removal of hydroxyl groups from an x-valent organic hydroxyl group-containing compound.

As polyhydroxyl compounds A (OH) _x both aromatic compounds, and acyclic or cyclic aliphatic, one or more OH groups tra ing, alcohols are used. It is also possible to use mixtures of aromatic / aliphatic alcohols.

Preferred hydroxyl compounds A (OH) _x which may optionally also contain unsaturated carbon atoms, ether or ester compounds include:

• 1. Low molecular weight, mono- or higher valent, optionally ether bridges having aromatic alcohols, such as. Phenol, α-naphthol, cresol, Resorcinol or trishydroxybenzenes.
• 2. Low molecular weight, optionally ether bridges having monohydric or higher (cyclo) aliphatic alcohols of molecular weight range 32-300, such as. B.
  • 2.1 Acyclic aliphatic alcohols such as methanol, ethanol, propanol, isopropanol, allyl alcohol, isomeric butanols, pentanols, hexanols or heptanols, octanols, 2-ethylhexanol, fatty alcohols having 10-20 carbon atoms, ethanediol-1,2 and 1,3-propanediol, 1,2-, 1,3- and 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6- and 2,5-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2 propyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, trimethyl-1 , 6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, 2-methyl-1,4-butanediol, 2-methyl-1,3-propanediol, glycerol, butanetriol, 2-hydroxymethyl-2-methyl-1 , 3-propanediol, 1,2,6-hexanetriol, trimethylolethane, trimethylolpropane, pentaerythritol, ethylene glycol nionoalkyl or aryl ether, propylene glycol monoalkyl ether, diethylene glycol, triethylene glycol, tetraethylene glycol;
  • 2.2 Cyclic, aliphatic alcohols, such as cyclopentanol, cyclohexanol, methylcyclohexanol, trimethylcyclohexanol, 1-tert-butylcyclohexanol, menthol, borneol and isoborneol, 2-hydroxydecalin, 1,2-, 1,3- and 1,4-cyclohexanediol, 2, 4-Dihydroxy-1,1,3,3-tetramethylcyclobutane, 1,4-bis (hydroxy-methyl) -hydroxane, bis (4-hydroxycyclohexyl) -methane, 2,2-bis (4-hydroxycyclohexyl) -propane , 2,4-bis (4-hydroxycyclohexyl) -2-methylpentane, furfuryl- and tetrahydrofur furyl alcohol, bis (hydroxymethyl) norbornane, bis (hydroxymethyl) tricyclodecane;
  • 2.3 Low molecular weight araliphatic alcohols such as benzyl alcohol, phenylethyl alcohol, 2-phenylpropanol or 4,4'-bis (2-hydroxyl ethyl) diphenylmethane.
• 3. High molecular weight one or more hydroxyl-containing poly (thio) ethers, polyesters, polylactones, polyacrylates, polyacetals or poly carbonates in polyurethane chemistry known per se of Mole kulargewichtsbereiches 250-5000.
  • 3.1 Poly (thio) ether polyols:
    The present invention in question one or more hydroxyl-containing polyethers are those of the known type and z. B. by polymerization of epoxides such as ethylene, propylene, butylene oxide, tetrahydrofuran or styrene oxide with itself, z. B. in the presence of BF3, or by addition of these epoxides, optionally in admixture or in succession, to starter components with reactive hydrogen atoms, such as. For example, water or the mentioned under 1. and 2. Alko hole.
    In the polythioethers in particular the condensation products of thiodiglycol with itself and / or other glycols, dicarboxylic acids or formaldehyde are executed. Depending on the co-components, these are polythiomic ether or polythioether polyacetoles;
  • 3.2 polyacetals:
    As polyacetals come z. As the glycolic, such as diethylene glycol, triethylene glycol, hexanediol and formaldehyde produced compounds in question. By polymerization of cyclic acetals can be prepared according to the invention suitable polyacetals;
  • 3.3 Polyesters / Polylactones:
    The eligible one or more free hydroxyl-bearing polyesters are known per se and are caused by order z. As the mentioned under 1. and 2. polyhydric alcohols with preferably two-optionally polybasic carboxylic acids such. As adipic acid, phthalic acid, isophthalic acid, maleic acid, hexahydrophthalic acid, the corresponding anhydrides and / or dimeric or trimeric oleic acids.
    The well-known in polyurethane chemistry OH-functional polylactones arise z. B. by addition of the mentioned under 1. and 2. polyhydric alcohols to ε-caprolactone. Also low molecular weight ring-opening products, as z. B. by reaction of ε-caprolactone with the mentioned under 1. and 2. Alcohols z. B. in the molar ratio 1: 1, are suitable.
  • 3.4 polycarbonates:
    The polycarbonates known per se for the use according to the invention are produced, for example, by reacting the polyhydric alcohols mentioned under 1. and 2. with diaryl carbonates or phosgene;
  • 3.5 polyacrylates:
    The polyacrylate polyols which are suitable for use in accordance with the invention are soluble copolymers of hydroxyl-containing monomers with other olefinically unsaturated monomers, such as, for example, in paint solvents. As butyl acrylate, methyl methacrylate, styrene, acrylic acid, acrylonitrile and / or methacrylonitrile. Suitable hydroxyl-containing monomers are, in particular, 2-hydroxyethyl (meth) acrylate and the hydroxypropyl (meth) acrylate isomer mixture obtainable by addition of propylene oxide onto acrylic acid or methacrylic acid. The hydroxyl group content of the suitable polyacrylate polyols is generally between 0.5 and 6 wt .-% (based on solid resin).
    Fluorine-containing polyols, as described in EP 0 566 037, p. 6, be written, can be used as reactants for the erfindungsge MAESSEN polyallophanate polyisocyanates.
    In the case of the presence of unsaturated carbon bonds in the finished OH-polyacrylate, these z. B. after carrying out the use according to the invention by free-radical, thermal or photochemical induced polymerization for further reaction can be used.

Of course, mixtures of the abovementioned hydroxyl compounds are used to z. B. targeted certain mean NCO Funktio properties of the (poly) allophanate polyisocyanate.

Essential to the invention is the concomitant use of basic catalysts to from the described by reaction of 1,3-cycloaliphatic diisocyanates R₁ (NCO) ₂ with hydroxide-carrying compounds A (OH) _x obtained acyclic urethanes (I) or the cyclic allophanates (II) higher functional allophanatgruppenhaltige Produce polyisocyanate.

These basic catalysts are used in amounts of 5 × 10 ^-5 to 10 wt .-%, based on the total weight of the reactants. Suitable Kata catalysts for the preparation of allophanate polyisocyanates according to the invention based on 1,3-cycloaliphatic diisocyanates are virtually all the prior art - predominantly basic - trimerization or Dimeri sierungskatalysatoren.

Examples of suitable catalysts are alkali phenolates (GB-A 1 391 066 or A 1 386 399), alkali metal alkoxides, aziridine derivatives in combination with tertiary  Amines (US Pat. No. 3,919,218), quaternary ammonium phenates (US Pat. No. 4,335,219), amino-substituted pyridines (DE-A 37 39 549), organic phosphines (US-A 3 248 372, EP-A 45 995, EP-A 377 177), combinations of alkylene oxide and 4,4'-diazabicyclooctane (DABCO) according to US-A 3 211 703 and DE-A 2 44 684, quaternary ammonium and alkali metal carboxylates (US Pat. No. 4,454,317, DE-A 32 19 608), basic alkali metal salts complexed with acyclic organic Compounds (US Pat. No. 4,379,905), basic alkali complexed with crown ethers metal salts (US Pat. No. 4,487,928) and in particular at higher temperatures tert. Amines (eg GB-A 222 161) and alcohols with tertiary amine groups, if appropriate with the participation of further nitrogen-free hydroxy compounds (GB-A 2 221 465).

Preferred catalysts are quaternary ammonium salts A) of the formula (VI)

in which
R¹ is an alkyl radical having 1-20, preferably 2-12 carbon atoms, an araliphatic hydrocarbon radical having 7-10 carbon atoms or a cycloaliphatic hydrocarbon radical having 4-10 C atoms, each containing hydroxy and / or hydroxyalkyl groups having 1-4 Carbon atoms can be substituted,
R², R³, R⁴ are identical or different radicals and optionally hydroxyl-substituted alkyl radicals having 1-20, preferably 1-4 carbon atoms, where two of said radicals, R², R³ or R⁴ also together with the nitrogen atom, optionally together with an oxygen or a further nitrogen heteroatom can form a heterocyclic ring having 3-5 carbon atoms, the radicals R², R³ and R⁴ in each case being ethylene radicals which, together with the quaternary nitrogen atom and another tertiary nitrogen atom, form a bicyclic triethylenediamine skeleton (DABCO) and wherein X is hydroxide-OH or fluoride F.

The used quaternary ammonium hydroxides (X = OH) are, for example in EP-A 10 589, EP-A 0 047 452, EP-A 0 330 966, DE-A 28 06 731 and DE-A 29 01 479.

Examples of suitable quaternary ammonium hydroxides are tetramethyl, Tetraethyl, trimethylstearyl and dimethylethylcyclohexylammonium hydroxide, N, N, N-methyl-N- (2-hydroxyethyl) ammonium hydroxide, N, N, N, -trimethyl-N- (2- hydroxypropyl) ammonium hydroxide, N, N, N-Tn.methyl- (2-hydroxybutyl) -ammo ammonium hydroxide, N, N-dimethyl-n-dodecyl-N- (2-hydroxyethyl) -ammonium hydroxide, N- (2-hydroxy-ethyl) -N, N-dimethyl-N- (2,2-dihydroxymethylbutyl) -ammoni-um hydroxide, N-methyl-2-hydroxyethyl morpholinium hydroxide, N-methyl-N- (2- hydroxypropyl) pyrrolidinium hydroxide, N-dodecyltris-N- (2-hydroxyethyl) ammo ammonium hydroxide, tetra (2-hydroxyethyl) ammonium hydroxide and N, N, N-trimethyl N-benzyl-ammonium hydroxide.

The quaternary ammonium fluoride catalysts (X =F) to be used are, for example in EP-A 0 339 396. Basically, everyone can do it before exemplified quaternary ammonium hydroxides in their F-form at used in the preparation of allophanate polyisocyanates according to the invention become.

Examples are:
N, N, N, -tetramethylammonium fluoride, N, N, N, -tetra-n-butylammonium fluoride, N, N, N, -trimethyl-N-benzylammonium fluoride, N, N, N, -Tnalkyl (C₈-C₁₀) -N -methyl benzylammonium fluoride and N, N, N-benzyldodecyl-dimethylammonium fluoride.

Any mixtures of the catalysts exemplified can themselves understandably also be used. The used Ammo listed nium salts (X = OH, F) are thermolabile, so that when a be exceeded agreed limit temperature independent deactivation of the reaction mixed done. This circumstance can z. B. then be exploited, the Reaction targeted to carry out to a desired degree of conversion and to end thermally. Furthermore, by the thermal deactivability This type of catalyst undesirable residual activities in intermediate and end products, as well as possible turbidity when using a chemical Ab stoppers are avoided.  

The quaternary ammonium catalysts are used in the preparation of the inventions to the invention (poly) allophanate polyisocyanates in amounts of 1 × 10 ^-5 to 3, preferably from 5 × 10 ^-5 to 1 wt .-%, based on the 1,3-diisocyanate, used.

The quaternary ammonium salts (X = OH, F) can in principle, in substance, but preferably used in dissolved form as catalysts. When For example, inert isocyanate-inert solvents are suitable Acetone, toluene, dimethylformamide, ethyl acetate or butyl ester or also Mixtures thereof, in quantities of max. 5 wt .-%, based on the Reaction mixture used. These solvents may be present in the final product remain or in processes with distillative separation of the excess monomeric diisocyanate together with this from the finished reaction be removed.

However, preferably used for dilution of the catalyst are solutions agent with isocyanate-reactive hydrogen atoms ("Reaktivver thinner "), which in reacted form as urethane or allophanate derivatives in the end product remain.

For diluting the catalysts, the above-listed, in liquid or dissolved form handlable bearing organic hydroxyl compounds A (OH) _x are suitable.

Preferably used are low molecular mono- and higher functional Alcohols such. As methanol, ethanol, the isomeric propanols, butanols, hexa nole, n-decanol, cyclohexanol and benzyl alcohol, glycols, the isomeric butane diols, pentane and hexane diols, C₄-C₆ triols and their known alkyl sub substituted derivatives.

Preferred examples are methanol, isopropanol, n-butanol, ethylhexanol, Cyclohexanedimethanol, diethylene glycol, 1,3-butanediol, trimethylpentanediol, Gly cerin, 2-ethylhexanediol-1,3, neopentyl glycol, trimethylolpropane.

Further preferred catalysts used to prepare the allophanate polyisocyanates according to the invention are tertiary amines B1) which are used in combination with the stated alcohols A (OH) _x . Carry these tertiary amines in addition to isocyanate-reactive hydroxyl functional groups (catalysts B2), then the concomitant use of other - under the general form A (OH) _x described alcohols - essential for the invention urethanization of the diisocyanate.

The OH groups present in the hydroxy-functional tertiary amine B2) must be sufficient to produce a higher functional allophanate on the Basis of cycloaliphatic 1,3-diisocyanates sufficient number Urethangrup to form the previously described general formulas (I) and (II).

Of course, it is also possible to use these OH-functional tertiary amines as described in combination with the described alcohol components A (OH) _x .

The tertiary amines or tert-amino alcohols can be described in substance to the urethane group-containing polyisocyanate mixture (I, II) or - as in the above Use of quaternary ammonium salt catalysts described in ver thin form, preferably in alcohols. When using the tert.- Amines in dilute alcoholic solution may be due to the prehannanization of Diisocyanate components are dispensed with.

Examples of organic tertiary amines B1) which are used in the present invention in combination with alcohols of the general form A (OH) _x are trimethylamine, triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N-methyl-N '-Dimethylaminoethyl-piperazine, N, N-dimethylbenzylamine, N, N-dimethylcyclohexylamine, N, N, N', N'-tetramethyl-1,3-butanediamine, N, N-dimethyl-β-phenylethyl-amine, 1,2 Dimethyl imidazole, 2-methylimidazole, 3-azabicyclo [3.2.2] nonane, 1,4-diazabicyclo [2.2.2] octane (DABCO), 1-azabicyclo [2.2.2] octane (chir nuclidine). 1,8-diazabicyclo [5,4,9] undec-7-ene (DBU and the corresponding C₁-C₄ alkyl-substituted homologs, such as 2-methyl-triethylenediamine (methyl-DABCO), 2,3 dimethyl-triethylenediamine.

The content of tert-catalyst amine used is between 0.00005- 10 wt .-%, based on the diisocyanate component presented. If the tert.- Catalyst amine in the form of an alcoholic solution to the Diisocyanatkom components, the concentration is max. 50% by weight.  

Examples of hydroxy-functional tertiary amines B2) which can be used for the preparation of the allophanate-polyisocyanate mixtures according to the invention, optionally in combination with nitrogen-free alcohols of the general formula A (OH) _x , are N, N-dimethylethanolamine, N, N-diethylethanolamine, N , N, N-trimethylaminoethyl ethanolamine, N, N'-dimethyl-N, N'-bis (hydroxyethyl) ethylenediamine, N-hydroxyethyl-N, N, N'-tetramethyldiethylenetriamine, N, N, N '-Tetramethylamino-2-propanol, triethanolamine, N-methyl-diethanolamine, 1- (2-hydroxyethyl) -pyrrolidine, 1-methyl-2-pyrrolidine-ethanol, N-piperidineethanol, 4- (2-hydroxyethyl) - morpholine, N-ethyldiethanolamine, N.Isopropyldiethanolamin, 1- [N, N-bis (2-hydroxy-hydroxy) -ethyl] -2-propanol, 1,4-piperazine-diethanol. Triisopropanolamine, 3- (β-hydroxyethyl) oxazolidine. Also suitable are the reaction products of these hydroxy-functional tertiary amines with alkylene oxides, such as. For example, ethylene and / or propylene oxide or tetrahydrofuran.

The preparation of the (poly) allophanate polyisocyanates according to the invention Catalysis with tertiary amines in the presence of urethane-forming hydroxyl groups can also be prepared according to the specifications in GB-A 2 222 161 (tertiary amines / alcohols) or in GB-A 2 221 465 (tertiary amino alcohols, optionally alcohols for the Trimerization of organic diisocyanates even at higher temperatures (100- 275 ° C) with correspondingly low reaction times.

Notwithstanding the production conditions listed there, it has been found that the inhibiting and color-deteriorating influence of air (oxygen) on the isocyanate polyaddition reaction or on the quality of the end products (cf. GB-A 2 221 465 p.5, line 29, GB-A 2 222 161, p. 5, line 10, 24) in the ent speaking implemented implementation of cycloaliphatic 1,3-diisocyanates does not play a significant role.

On the other hand, it has been used in the preparation of the allophanate polyiso according to the invention cyanates with amine catalysis in the presence of urethane groups observed that the influence of air a significant acceleration of the desired poly take place without a significant deterioration of the Color quality of the final products occurs. If you start z. B. the amine catalyzed Allo phanation of the optionally pre-urethanized cycloaliphatic 1,3-diiso cyanate in an air-saturated reaction vessel, the reaction jumps under Release of heat and weak coloring (Hazen color number <150, after DIN 53 409) and runs controlled to the desired degree of conversion.  

After the onset of the reaction, the reaction vessel may be under an inert gas stream (For example, N₂-atmosphere) are set, without causing significant Verlang The reaction comes. The reactants, however, in a carefully brought together from air reaction vessel, so the reaction only jumps extremely sluggish.

A possible variant of the method, with regard to the reaction and the Product features can offer advantages - such as. B. minimization of through tion required amount of catalyst, is a small Part of the reactants with the amine catalyst in advance in the presence of air and then the remainder of one or more reactants under inert gas atmosphere (eg N₂ stream) and to complete the reaction.

Another class of preferred catalysts used for the production of (Poly) allophanate polyisocyanates according to the invention in the presence of urethane groups are aminosilyl compounds C) (EP-A 57 653, EP-A 89 297, EP-A 187 105, EP-A 197 864).

According to the state of the art, these aminosilyl catalysts are tri merization of (cyclo) aliphatic diisocyanates suitable. Your behavior in counter Wart (cyclo) aliphatic 1,3-diisocyanates is not described.

Examples of the use of silylated amino compounds for the preparation of polyisocyanatallophanates according to the invention are listed in EP-A 0 057 653: mono- and diaminosilanes, silylated ureas and disilazanes: p. 8, line 35 - p. 9, line 25. The amounts to the listed silylierten Aminover compounds, which are needed for the production of Polyisocyanatallophanate invention, move between 1 × 10 ^-5 and 12 wt .-%, preferably 5 × 10 ^-5 and 10 wt .-%. The temperature of the reaction is in the range between 20 and 160 ° C, preferably between 30 and 130 ° C. To deactivate the reaction at a desired degree of conversion in addition to the already mentioned predominantly acidic components and water such. As described in EP-A 0 197 864 used.

In the event that the mentioned Aminosilylkatalysatoren addition to iso have cyanate reactive N-H bonds, it must be expected,  that in the inventive allophanatization of the 1,3-diisocyanates also Urea adducts, and their derivatives such. B. Polyuretes are formed.

The preparation of the Polyallophanatpolyisocyanatgemische invention can according to a 2nd method also with the help of chemically in a solid, poorly soluble Polymer matrix built catalysts (fixed bed catalysts D)). The polymeric carrier substance may be inorganic (eg zeolites, silica gels) also organic, and the catalytically active catalyst units by ionic, preferably fixed by covalent chemical bond.

The functional catalyst groups of inert to the reaction medium polymeric matrix must be readily accessible to the reactants to both the "Transport" for the chemical conversion, as well as the "return transport" of Allow reaction products from the matrix.

Polymer matrices with carbon-carbon bonds are generally suitable based on z. As ethylene, propylene, isoprene, styrene, divinylbenzene, acrylates and similar. Polymers of the components styrene, divinylbenzene and acrylates are due to their thermal and chemical stability, the light functiona lability and good swellability and thus good accessibility for Reactants to be reacted are particularly suitable. Particularly preferred for the inventions 2. Method according to the invention for the basic, heterogeneously catalyzed allophanati Alkylation of cycloaliphatic alkyl-1,3-diisocyanates are copolymers of Sty rol / divinylbenzene, vinylbenzyl chloride and acrylates, as z. For manufacturing be used by ion exchange resins.

These polymers can be in the form of small balls, granules and also fines be used powder. In general, the bead shape is because of the light Separability by filtration is preferred.

The accessibility of the reaction medium to the catalyst centers is under Another decisive factor is the "mesh size" of the space-network structure Polymer matrix influences which z. B. in the case of styrene / divinylbenzene copoly merisate given by the proportion of the crosslinker divinylbenzene in styrene becomes. Well swellable polymers are obtained with 1-10% DVB content. It is However, also possible, so-called "macroporous" space-network structures ver apply, which are characterized in that although a high degree of crosslinking before  is due to a special polymerization technique under temporary installation nevertheless generates more or less large cavities of inert solvents can be installed on the walls later on the catalyst centers.

The amount or number of catalytic centers incorporated in the polymer may vary within a wide range, but preferably 5 x 10 ^-4 to 10 milliequivalents per gram of polymer are preferred.

To achieve per se known cocatalytic effects on the isocyanate poly addition reaction, the polymeric matrix in addition to chemically incorporated active hydrogen atoms, preferably hydroxide groups based on low molecular weight (cyclo) aliphatic alcohols previously described under the general form A (OH) _x be written type - z. As methanol, iso-propanol, 1,3-butanediol in amounts of 0.005 to 100 mEq per g of polymeric substance.

In addition to the co-catalytic effect of the polymer-bound hydroxide groups is the basic-catalyzed polyallophanatization reaction of the 1,3-diisocyanates to expect that in principle small proportions of the fixed OH components get into the liquid phase and thus inevitably on the inventive Participate in the implementation.

To carry out the fixed-bed-catalyzed reaction of cycloaliphatic alkyl 1,3-diisocyanates to Polyallophanatpolyisocyanatgemischen in the presence of Urethane groups are all already mentioned catalyst types A) to C), which chemically bound to a solid matrix, suitable.

To carry out both inventive methods are generally the Reactants used in amounts such that the equivalent ratio of NCO groups to OH groups at 0.5: 1 to 200: 1, using a stoichio metric excess of diisocyanate from the beginning to 1.05: 1 to 200: 1 is set. The production of urethane-containing starting material materials for the preparation of the polyallophanate polyisocyanate according to the invention Mixtures are made according to known methods of polyurethane chemistry, d. H. in particular by heating the starting materials at 40 to 140 ° C, preferably at 50 to 90 ° C. The submitted 1,3-diisocyanates are z. B. at approx. 50 to 70 ° C, the OH-containing reaction components are added dropwise in liquid form, stirred and after the end of the exothermic temperature rise at the  adjusting temperature of about 55 to 80 ° C implemented. The course of the reaction This is done by controlling the NCO value by titration, pursuit of the Refractive index or by a quantitative IR determination. To Achieving the desired degree of urethanization, if not from is worked in advance with an equivalent NCO excess, more Diisocyanate added and in the first process according to the invention by Dosing a basic catalyst in liquid form, optionally in a concentration of 0.005 to 50% by weight in an alcoholic diluent dissolved, the allophanatization reaction in the temperature range between 20 and 140 ° C, preferably carried out between 35 and 120 ° C.

The equivalent amount of hydroxide groups, optionally with the alkoho lischer diluent for the catalyst in the NCO reaction introduced be sized, is that the above statement about the max. NCO / OH Ratio of 200: 1 is maintained.

In the case that it is ensured that one for the allophanatization reaction sufficiently large number of urethane groups is present

• a) Use of the low molecular weight basic catalyst in an alkoho reactive diluents,
• b) Use of a low molecular weight catalyst which is additionally covalent has bound hydroxide groups,

can the urethanization and allophanatization reaction of cycloaliphatic Alkyl-1,3-diisocyanates present at the beginning of the reaction NCO / OH ratio of 1.05: 1 to 200: 1 in a reaction step.

The reaction temperature is between 20 to 140 ° C, preferably between 30 and 120 ° C.

The components containing hydroxide groups, in addition to their main function, which to provide urethane intermediate stages necessary for the folate allophanate products, another co-catalytic effect known from polyurethane chemistry on the catalyzed isocyanate polyaddition reaction.  

Furthermore, all substances that have a cocatalytic effect on isocyanate have implementations - such. B. in DE-A 28 06 731 described - with be used.

During the polyaddition reaction of the NCO groups to Polyallophanatpolyiso Cyanatgemischen the NCO course of the reaction as described above ana pursued lytically, and the reaction at the desired degree of conversion, the zwi 10-95%, preferably between 15 and 90%, based on the used Amount of diisocyanate is, by

• a) distilling off the volatile catalyst
• b) thermal and / or chemical deactivation of the basic low mols gular catalyst

ended, as the catalyst poisons from the polyurethane chemistry itself be knew, mostly acid Absopper - such. HCl, benzoyl chloride, dibutyl phosphate, di- (2-ethylhexyl phosphate), formic acid, chloropropionic acid, p-toluene Sulfonic acid esters, sulfur, acidic ion exchangers and in the cases of Co-use of aminosilyl catalysts C) Water - in quantities between 0.2-50 times the equivalent amount of catalyst used be used.

When using a ("higher molecular weight") chemically fixed to a solid, sparingly soluble matrix basic catalyst as in the 2nd manufacturing method of the invention, the fixed bed catalyst in amounts of 5 × 10 ^-4 to 10 m equivalents of catalytic active groups per g of polymers Matrix, wherein the proportion by weight of the catalytically active polymer material be less the diisocyanate used is between 0.01 to 20 wt .-%, used. The fixed bed catalyst can be used in the form of small spheres, granules and also as a fine powder. Because of the easy separability, the bead form is preferred. The catalytically active fixed bed can be flowed through in a tank or tube from the reaction medium, or in a stirred reactor -. B. suspended in at least a portion of the liquid reaction components or in an inert solvent and then contacted with the reaction components. The generation of the urethane groups necessary for the preparation of the polyallophanate-polyisocyanate mixtures according to the invention can be carried out, as in the first process according to the invention, with the proportions of the NCO / OH equivalents and process parameters given there. Subsequently, contact is made with the fixed bed catalyst which may be as stated above.

The catalytically active unit of the polymer matrix additionally has over covalently bonded hydroxide groups, which react with the diisocyanates used Urethane formation, so can the urethanization and the catalyzed Allophanate sequencer reaction in one step at the beginning of the reaction present NCO / OH ratio of 200: 1 to 1.05: 1 are performed.

It is to be expected in principle that small proportions of a covalently bound dene OH groups catalyst having either the particular at quaternary ammonium salts of the aforementioned type A) known thermally Induced decomposition reaction or via equilibrium settings in the liquid Phase and participate in the Polyallophanatisierungsreaktion.

After reaching the desired degree of conversion of heterogeneously catalyzed Reaction in excess diisocyanate or in an inert solvent the reaction by interrupting the contact between the reaction medium and the fixed bed catalyst -. B. by filtration - finished.

The filtered reacted reaction mass is optionally additionally with a thermal and / or chemical aftertreatment, as in the first inventions described to the invention, stabilized. The further procedure and the properties of the products are for the homogeneously catalyzed (process 1) and the heterogeneously catalyzed (process 2) polyallophanatization of cyclo Aliphatic alkyl-1,3-diisocyanates and are described below ben.

The stopped Polyallophanatpolyisocyanatgemisch is, if not vice initial free starting diisocyanate is present, by means of a distillation over a Thin-film or short-path evaporator or an extractive work-up method - z. With n-hexane - from the monomer to a residual content <2, preferably <0.5% by weight, freed. The process products according to the invention are characterized by excellent stability during the thermal Strain on the thin film distillation. It does not occur in others  chemically modified polyisocyanates with z. B. uretdione or biuret structure observed side and / or equilibration reactions that cause annoyance baking or an undesirable increase in viscosity can lead.

Both methods of the invention are also suitable for a continuous reaction tion management.

In the first method with homogeneous catalysis, either several Reactors to a boiler cascade with continuous passage of the reaction switched, or it becomes a tubular reactor with a predominantly turbulent Flow profile used. In the first or several reactors of the Cascade distributed or in the inlet of the tubular reactor while the isocyanate and the hydroxy component together with the basic catalyst, optionally distributed, metered and mixed via one or more nozzles, and within a design and geometry of the equipment used as well as the process parameters (eg temperature profile, throughput speed) certain residence time to the desired degree implemented.

Because in any case for the presence of a sufficiently large number Urethane groups in the preparation of Polyallophanatpolyisocyanatgemische must be taken care of, the dosage of the basic catalyst only after an upstream urethanization step in one of the first subsequent Reactors of the cascade take place.

It is also possible, the urethanization reaction of 1,3-diisocyanate perform component with alcohols in an upstream batch reactor and the product continuously in a catalyst-charged reaction cascade to the allophanates.

In the second indicated method for producing the inventive Polyallophanate polyisocyanate mixtures with the help of a chemical to a solid, sparingly soluble matrix-bound catalyst are also continuous Reaction guides possible.

In one case, the solid catalyst in suspended form in the before described reaction vessel cascade be used. For the dosage  possible reactants (diisocyanate and alcohol component) applies mutatis mutandis, the procedure dealt with in the first method.

By filtering devices in the course of the cascade reactors is the "hetero "Separated catalyst from the homogeneous reaction solution and Passie ren of the last reactor, optionally after additional thermal and / or chemical deactivation of the filtered reaction product is optionally carried out described distillative or extractive separation of excess monomials rem starting diisocyanate.

Instead of cascade reactors in this process, several behind cascaded columns packed with fixed bed catalyst can be used; flow through the reaction mixture continuously.

In the case that the preparation of Polyallophanatpolyisocyanatgemische without phy sikalische separation of excess residual monomers are carried out should increase with the degree of conversion over time, the viscosity of the reaction mixed, so that gradually one more isocyanate-inert Solvent - such. B. methoxypropyl acetate, solvent naphtha or butyl acetate is added, so that the resulting solution of the reaction mixture stir well remains bar. Ultimately, a 20-95, preferably 50-95% Lö remains solution of the polyallophanate-polyisocyanate mixtures according to the invention on the basis of cycloaliphatic alkyl-1,3-diisocyanates. Furthermore, nonpolar Lö in the manner described in EP-A 0 566 037, p. 5, as Thinner of Polyallophanatpolyisocyanate invention used who the.

The polyallophanate polyisocyanates of the invention are in pure or in stable solubility and show even at elevated storage temperatures at approx. 60 ° C no tendency to change their characteristic properties, such as z. As NCO content, color number and viscosity. There will be no splitting too observed monomeric starting diisocyanate.

The Polyallophanatpolyisocyanatgemische invention or their solutions are characterized by a low color number, high light fastness and a ver comparatively low viscosity. The color of the polyallo invention phanatpolyisoeyanatgemische may, if necessary according to DE 39 00 053  made statements z. B. improved by the addition of peroxide compounds so that ultimately Hazenfarbzahlen (DIN 53 409) of less than 25 achieved can be. Notwithstanding the details of the aforementioned Auflellungsverfah An effective color number improvement of the mixtures according to the invention can be achieved already be achieved at room temperature.

If it is in the Polyallophanatpolyisocyanatgemischen invention are highly viscous to solid substances, they may be in blocked Find form as powder coating crosslinked application.

The Polyisoscyanatgemische invention provide valuable, high quality Starting materials for the production of one- or two-component coating tions with a high visual and technical level.

Preferred reactants for the inventive, optionally in Blocked form paint polyisocyanates present in the invention Use are in particular those from the polyurethane coating technology itself known polyhydroxy compounds such as polyhydroxy polyethers and in particular polyhydroxypolyesters and / or polyhydroxypolyacrylates if in admixture with low molecular weight, polyhydric alcohols.

Also polyamines, especially in blocked form (polyketimines or oxa zolidine) are conceivable reactants for the invention Lackpoly isocyanates in the use according to the invention. A particularly interesting class of conceivable reactants for the invention Lacquer polyisocyanates in the use according to the invention are the secondary ones Amino groups "polyaspartic acid ester" according to EP-A 0 403 921, often in combination with polyhydroxy polyesters and in particular Polyhydroxypolyacrylates known from paint technology known type Ver find a turn.

In all variants of the use according to the invention, the amounts ratios of the binder components generally chosen so that each blocked isocyanate group of the lacquer polyisocyanates 0.7 to 3.0 according to the invention, preferably 0.8 to 1.1 optionally blocked isocyanate-reactive groups omitted.  

To accelerate the curing can in the known manner in Iso cyanatchemie conventional catalysts are used, such as. B. tertiary amines such as Triethylamine, pyridine, methylpyridine, benzyldimethylamine, N, N-dimethylamino cyclohexane, N-methylpyridine, pentamethyldiethylenetriamine, 1,4-diazabicyclo- (2,2,2) octane and N, N'-dimethylpiperazine or metal salts such as iron (III) chloride, Zinc chloride, zinc 2-ethylcaproate, tin (II) ethyl caproate, tin (II) 2-ethylhexanoate, Dibutyltin dilaurate and molybdenum glycolate.

Suitable blocking agents for blocking if necessary Lacquer polyisocyanates are, for example, monophenols (phenol, cresol), tertiary Alcohols (t-butanol, dimethylphenylcarbinol), slightly enolating compounds (Ethyl acetoacetate, diethyl malonate), secondary amines (diisopropyl amine, N-methylaniline, N-phenylxylidine), imides (succinimide), lactams (ε-Capro lactam, δ-valerolactam), oximes (butanone oxime, cyclohexanone oxime), mercaptans (Methylmercaptan, ethylmercaptan), triazoles (1H-1,2,4-triazole), pyrazoles e.g. B. Dimethyl (pyrazole) or mixtures of such blocking agents.

The preparation of the ready-to-use coating agent is carried out in be of known kind, possibly with the concomitant use of paint technology union auxiliaries and additives such. As pigments, dyes and fillers, Light stabilizers, oxygen inhibitors, flow control agents and the like. The particularly preferred two-component polyurethane coatings according to the invention generally have a content of inert solvents from 5 to 90, preferably from 10 to 75% by weight. The paint polyisocyanates according to the invention however, if they are solids, they can also be used as powder coating crosslinkers Use, what they also with blocking agents of the example mentioned type in blocked form use. The invention Lacquer polyisocyanates are also suitable for the production of one-component processing, air-drying paints. This will be done in paint technology known per se polyhydroxyl compounds of the type exemplified and Excess amounts of the coating polyisocyanates NCO-prepoly according to the invention mers, preferably in dissolved form, under the influence of air represent moisture-curable one-component binders.

The coatings produced with the paint polyisocyanates according to the invention Depending on their consistency, agents can be made from solution, from the melt or in solid form according to the usual methods such. B. painting, rolling  Casting, spraying, the vortex sintering process or the electrostatic Powder spray applied to the object to be coated.

The coatings containing the lacquer polyisocyanates according to the invention result in films that adhere surprisingly well to metallic substrates, are particularly lightfast, heat stable and very resistant to abrasion and, if they are in air-drying paints are used, especially quickly, even at Tempe dry at 0 ° C. In addition, they are characterized by great hardness, Elasticity, very good chemical resistance, especially superbenzine resistance, high gloss, excellent weather resistance and pigmentability.

A paint application test of a solution of an exemplary poly allophanate-polyisocyanate mixture based on hexahydro-2,4,2,6- Diisocyanate toluene (mixture of isomers) compared to the corresponding Solution of an isocyanurate based on isophorone diisocyanate (IPDI) the same high level (see application example No. 1b).

Examples

The percentages are by weight unless otherwise stated.

A) Examples of homogeneously catalyzed poly-allophanatization reactions of 1,3-diisocyanato-alkylcyclohexanes example 1 Catalysis with Quaternary Ammonium Hydroxides (Catalysts A))

1,3-diisocyanate used:
The hexahydro-1,3-diisocyanatotoluene (H₆-TDI) used is a mixture of about 80% 1-methyl-2,4- and about 20% 1-methyl-2,6-diiso cyanatocyclohexan. The ratio of the cis / trans configuration isomers is about 60:40 (GC and13 C NMR analysis).

Example 1a Trimethylbenzylammonium hydroxide as a catalyst with distillative mono merenabtrennung

3 500 g of H₆-TDI are degassed several times under vacuum and be with nitrogen be ventilated. Under a gentle stream of nitrogen at 55 ° C then 128.46 g a 0.06% catalyst solution - consisting of one with 128.26 g of butanediol 1.3 diluted 40% methanolic solution of methylbenzylammo ammonium hydroxide (Triton B®) - added dropwise within 10 minutes and stirred. The NCO / OH equivalent ratio is 13.6: 1, the theoretical urethane content (59 g / mol) is 4.6%. As a result of a weakly exothermic reaction increases Temperature to 60 ° C and is held there until after about 4 hours titrimetrically determined NCO value of 38.4% could be measured.  

The clear, still excess diisocyanate containing allophanate solution is then with 0.14 g of dibutyl to stop the reaction at 60 ° C about 0.5 Stirred for hours.

Thereafter, an NCO content of 38.3% was measured.

Subsequently, the distillative separation of the excess monomer takes place H₆-TDI using one of a falling film and a downstream thin stratified evaporator existing distillation apparatus at a temperature of 150 ° C and a vacuum of about 0.05 mbar.

The resulting solid resin has an NCO content of 15.8% and a residual content at monomeric H₆-TDI of 0.21%.

After dissolution of these Polyallophanatpolyisocyanatgemische, in a 1: 1 Mixture of methoxypropyl acetate and xylene has the 70% resin solution the following characteristic data:

Viscosity (23 ° C): 1 050 mPa · s Color number (DIN 53 409): 65 Hazen NCO content (titration): 11.0% Content of monomeric H₆-TDI: 0.15%

Part of this 70% resin solution is mixed with 300 ppm of a 50% solution of butanone peroxide in plasticizer and for 1 hour at room temperature stirred. With otherwise unchanged characteristics, the now measured color number is 20 Hazen.

After four weeks of storage at room temperature and at 50 ° C, the listed characteristics of the 70% resin solution within the measuring tolerances constant.

Data from spectroscopic (IR, 1 H-NMR, 13 C-NMR) and gelchromato graphical (GPC) examination with the polyallophanate polyisocyanate resin (100%) from Example 1a.

IR spectra show no measurable levels of uretdione (1765 cm ^-1 ) and isocyanurate (1690 cm ^-1 ) structures in the polyallophanate polyisocyanate mixture.

Example 1b Application testing data

A paint application test of the 70% polyallophanate solution according to Example 1a compared to a 70% solution of Trimerisats of Isophorone diisocyanate in solvent naphtha (trade name: Desmodur Z 4370 SN®) in combination with the OH components Desmophen A 565 X® (Polyacrylatpolyol, 65% in xylene) and some in the clearcoat formulation usual aids the following values:

With the specified clearcoat formulations of the new polyallophanate polyisocyanate was compared to the polyisocyanate isocyanurate Desmodur Z 4370® a Weathering test according to DIN 53 231/1 ("Xeno-Test") performed and after 2000 h the following values were determined.

The result of the paint inspection - especially with regard to a Suitability for the auto prime (OEM) and auto refinishing - results for the Polyallophanate polyisocyanate based on H₆-TDI according to the invention clearly low viscosity compared to a trimer the base of isophorone diisocyanate (IPDI).

Example 1c Blocked H₆-TDI polyallophanate polyisocyanate

For the blocking reaction was a 70% prepared according to Example 1a Resin solution in solvent naphtha used with the following characteristics

NCO content: | 11.1% Viscosity [mPa.s at 23 ° C]: 1320 Monomeric H₆-TDI: 0.15% Color number: 60 Hazen

944 g (2.50 equivalents NCO) of the 70% resin solution were heated to 50 ° C and within one hour with 218.5 g (2.51 equivalents) of butanone oxime. The exothermic reaction causes a temperature rise to 60 ° C, and it becomes until the quantitative NCO conversion (NCO content <0.05%) for 1 h at 70 ° C. stirred. Subsequently, the solids content by addition of 190.0 g Solvent naphtha adjusted to 65%, and the solution by adding 300 ppm Butanone peroxide in plasticizer brightened at room temperature.

Characteristic data: Content of monomeric H₆-TDI | <0.03% Content of monomeric butanone oxime 0.03% Viscosity [mPa · s at 23 ° C] 12,550 color number 65 Hazen

Example 1e Reaction with OH-functional ester

3000 g (16.67 mol) of TDI are introduced at 65 ° C and several times with nitrogen degassed and ventilated.

Subsequently, 223.1 g (1.08 mol) of a reaction product of Butanediol-1,3 with ε-caprolactone (molar ratio 1: 1, OH = 542, viscosity (23 ° C): 180 mPa · s) at 65 ° C.

As a result of exotherm, the temperature rises to 71 ° C, and the reaction becomes carried out at 65 ° C to an NCO value of 41.6%.

Subsequently, the catalysis is carried out with 12.88 g of a 1% solution of Triton B, which consists of a 40% methanolic stock solution by dilution with Butanediol-1,3 has been produced.

After exothermic reaction up to 70 ° C, the reaction at 65 ° C up to an NCO value of 32.0% and with 1.61 g of dibutyl phosphate stopped off.

The excess H₆-TDI is distilled off as described. The resulting resin (41% yield) has an NCO content of 13.2% and an average NCO Functionality (GPC spectrum) of 2.81.

The 70% resin solution (methoxypropyl acetate / xylene 1: 1) has the following Characteristics:

NCO content: 9.2%, viscosity: 1,490 mPa.s (23 ° C.)
Monomer 0.40%, color number: 40 Apha
H₆ TDI.

Example 1f Reaction of H₆-TDI / HDI mixture (molar ratio 70:30)

A mixture of 200 g (1.19 mol) of hexamethylene diisocyanate (HDI) and 500 g (2.77 moles) H₆-TDI is degassed with nitrogen.

Subsequently, 23.2 g of 1,3-butanediol are added at 60 ° C. The NCO / OH Ratio is 15.8. The urethanization reaction is carried out at 65 ° C to a NCO value of 43.0%.

Subsequently, with 5.5 g of a 0.5% solution of Triton B (40% Stock solution in methanol, diluted with butanediol-1,3). At a NCO value of 37.0%, the reaction by addition of 0.18 g Dibutyl phosphate terminated.

After removal of the excess monomeric diisocyanates via a Short path evaporator, the following data were determined:

Resin: 32% yield 0.35% monomeric H₆-TDI 0.05% monomeric HDI NCO: 17.8% Avg. NCO functionality (GPC): 3.7 Composition of the distillate / GC: 26.4 mol% HDI 74.8 mole% H₆-TDI

The 70% solution of the mixed resin in Methoxylpropylacetat / xylene (1: 1) has the following characteristics:

NCO content: 12.40%, viscosity: 260 mPa · s (23 ° C <
Color number: 50 Apha

A dried at 80 ° C, clear film of the mixed resin of H₆-TDI / HDI has a smooth, crack-free surface.

Example 1d Blocked allophanate solid resin (powder coating)

528.6 g (2.94 mol) of H₆-TDI are degassed with nitrogen and 68.0 g (0.76 mol) of 1,3-butanediol at 65 ° C up to an NCO value of 31.9% (theory: 30.7%).

Subsequently, at 70 ° C in three equal portions a total of 7.16 g of a 0.5% Triton B solution (40% stock solution diluted in methanol with Butanediol-1,3) was added.

At an NCO value of 21.4% (corresponding to 3.08 equivalents of NCO groups) becomes the viscous reaction mass with 0.09 g of dibutyl phosphate stopped and heated to 80 ° C.

Then within 20 minutes in portions a total of 350 g (3.09 mol) of solid ε-caprolactam added, the temperature of the viscous Reaction mixture is gradually increased to 140 ° C.

After an NCO value of 0.40% could be measured, we measured the liquid Melt tipped to solidify on a sheet.

The pale yellow, clear solid resin has the following data:

free NCO groups: | 0.15% Melting point: 80 ° C Content of block. NCO groups (theoretical) 13.6%

Example 2 Triton B® as catalyst, reaction in solvent

3500 g of H₆-TDI are mixed with 50 ppm of ionol (light stabilizer) and under Vacuum degassed several times and aerated with nitrogen.

113.8 g of butanediol are then added at 55 ° C. under a gentle stream of nitrogen. 1.3 metered and stirred for 0.5 hours. The NCO / OH equivalent ratio is 15.4: 1 and the theoretical urethane content (59 g / mol) is 4.1%.

The refractive index of the urethanized solution in excess H₆-TDI is n _D (23 ° C) = 1.4775 (corresponding to 42.3% NCO).

A small part of the batch is thinned as described in Example 1a layers and the resulting solid, colorless urethane resin based on H₆-TDI has the following characteristics:

NCO content: | 12.9% Average molecular weight M _n (from GPC): 700 Medium functionality (from GPC) F: 2.15 Content of fr. H₆ TDI: 0.07% Color number: 25 Hazen

The remaining part of the above approach is at 60 ° C by portions Add a total of 733.1 g of a 0.5% Triton B solution, which is replaced by Ver thin of a 40% methanolic stock solution with 724 g of 1,3-butanediol continuously over a period of 27 hours set. The NCO / OH equivalent ratio of the catalyzed reaction is included 2.23: 1 and the theoretical total urethane content (59 g / mol) at 25.4%.

After addition of 87.0 g of the 0.5% catalyst solution becomes an NCO content of 29.3%, a viscosity (23 ° C) of 1,950 mPa · s, a content of free H₆-TDI measured from 31.8% and from the GPC spectrum a mean NCO Functionality of Allophanatfestharzanteils of 3.9 determined.  

Finally, with further catalyst addition, the reaction solution is more viscous, so that gradually by adding a solvent mixture of methoxy propyl acetate / xylene 1: 1 ensures good stirrability.

After complete addition of the specified amount of catalyst / alcohol and Ab Stopping with 6.9 g of dibutyl phosphate gives a 70% solution of a poly allophanate polyisocyanate mixture with the following characteristics:

NCO content: | 9.1% Content of monomeric H₆-TDI: 0.15% Color number: 140 Hazen Viscosity (23 ° C): 1 640 mPa · s Mean NCO functionality F: 4.4

Example 3 Trimethylbenzylammoniumfluorid as catalyst 13) with distillative mono merenabtrennung

3500 g (19.44 mol) of H₆TDI are at 50 ° C with 588.6 g (4.52 mol) of 2-ethyl hexanol-1 and vice versa under a gentle stream of nitrogen for 1 hour puts. The NCO / OH equivalent ratio is 8.6: 1, and the theoretical Urethane content is 6.5%.

The titrimetically determined NCO value after the pre-urethanization reaction is at 35.8% (theory: 35.30%).

Subsequently, within 10 minutes 0.53 g of a 5.70% solution of Trimethyibenzylammoniumfluorid in 2-ethylhexanol-1 metered. The After another reaction time of 7 hours at 50 ° C., the mixture reaches an NCO Value of 25.2% - corresponding to a total turnover of 45.9% based on the starting mixture.

Subsequently, the reaction by adding 0.02 g of bis (2-ethylhexyl) phos phoric acid stopped. The excess monomeric H₆-TDI will, as in Example 1a, distilled off at 140 ° C / 0.1 mbar.  

The clear, colorless polyallophanate polyisocyanate mixture has the following characteristic characteristics on:

NCO content: | 17.5% Monomeric H₆-TDI: 0.11% GPC data: @ Mean molecular weight M _n : 631 Mean NCO functionality F: 2.63

A 90% solution of the H₆-TDI-based resin in ethyl acetate has the following Characteristics:

NCO content: | 15.60% Monomeric H₆-TDI: 0.09% Color number: 35 APHA Viscosity (23 ° C): 850 mPa · s

Example 4 Dimethylethanolamine as a catalyst (type B2)) with distillative monomers separation

In a 100 ml laboratory flask 40 g (0.22 mol) of H₆-TDI (refractive index n _D (23 ° C): 1.4770) were initially charged and 0.80 g (0.009 mol) of N, N-dimethylethanolamine at 23 ° C added. The NCO / OH equivalent ratio is 49.3: 1, and the theoretical urethane content (59 g / mol) is 1.3%. The temperature increases due to exothermic reaction to 32 ° C.

At 40 ° C was then stirred for about 4 hours until a refractive index n _D (23 ° C) = 1.4923, corresponding to a 30% conversion could be measured. The reaction was then stopped by adding 12.5 g of benzoyl chloride.

The stopped solution of Polyallophanatpolyisocyanatgemisches was in a Microdestillus of excess monomer at 140 ° C and 0.1 mbar freed.

The resulting yellowish solid resin has the following characteristics:

NCO content: | 15.5% Monomeric H₆-TDI: 0.85% GPC data: @ Mean molecular weight M _n : 607 Mean NCO functionality F: 2.24 From the IR spectra: @ Content of polyamide-1,1: 1.9% Content of uretdione: 2.7% Content of isocyanurate: 2.5%

Example 5 Dimethylbenzylamine in combination with alcohols as catalysts (Typ 131)) with distillative monomer separation Example 5a Isopropanol as alcohol component

In a 100 ml laboratory flask 80 g (0.44 mol) of H₆-TDI are submitted. to Finally, 2.4 g (0.04 mol) of isopropanol are added and 1.5 hours at 40 ° C stirred until an NCO content of 42.7% is measured. The NCO / OH Equivalent ratio is 22 and the theoretical urethane content (59 g / mol) is 2.9%.

Then, the reaction vessel with an air flow, which is such that a slight excess of air through a bubble counter from the reaction vessel ent softened, charged and then 0.8 g (0.006 mol) of dimethylbenzyl added amine.

After a slight exotherm, the temperature briefly rises to 43 ° C, the air flow through the reaction vessel is replaced by a nitrogen and after another reaction of about 3 hours a refractive index n _D (23 ° C) = 1.5000 - corresponding to one Sales of 70% - reached.

By adding 4 g of strongly acidic ion exchanger (Lewatit SPC 118 dry) the amine catalyst is largely adsorbed and after filtration a clear, storage-stable Polyallophanatpolyisocyanatlösung. The excess, mono mere H₆-TDI was separated in a micro-still at 160 ° C and 0.5 mbar.

The remaining pale yellow solid resin has the following characteristics:

NCO content: | 15.8% Monomeric H₆-TDI: 0.78% GPC data: @ Mean molecular weight M _n : 652 Mean NCO functionality F: 2.45

From the IR spectra:

Content of polyamide-1,1: | 1,30% Content of uretdione: 3.30% Content of isocyanurate: 0.54% 1 H-NMR (d₆-acetone): @ 9 ppm polyallophanate NH 40 mol% 8.5 ppm allophanate NH 40 mol% 6 ppm urethane-NH 5 mol%

Example 5b Butanediol-1,3 as alcohol component

In a 5 l laboratory flask, 3000 g (16.7 mol) of H₆-TDI were initially charged, 67.5 g (0.75 mol) of 1,3-butanediol and stirred at 40 ° C for one hour. The NCO / OH equivalent ratio is 22.3 and the theoretical urethane content (59 g / mol) at 2.9%.

Then the reaction vessel is filled with air as described in Example 5a charged and 7.5 g (0.06 mol) of dimethylbenzylamine are added. The Temperature rises due to exothermic reaction to 46 ° C.

After about 20 minutes at 40 ° C, the air flow is replaced by a stream of nitrogen, and the reaction is completed for 6 hours until a refractive index n _D (23 ° C) of 1.4845 - corresponding to a degree of conversion of 26% - is reached ,

After stopping the reaction with 23.2 g (0.11 mol) of dibutyl phosphate is the excess monomeric H₆-TDI via a short-path evaporator at Distilled off 145 ° C / 0.2 mbar.

The resulting solid resin has the following characteristic characteristics:

NCO content: | 15.0% Melting point: 1 24 ° C Monomeric H₆-TDI: 0.12% GPC data: @ Mean molecular weight M _n : 882 Mean NCO functionality F: 3.15

The solid resin was added with a 1: 1 mixture of solvent naphtha / butyl acetate a 65% solution and additionally with 50 ppm dibutyl phosphate stabilized.

NCO content: | 9.0% Monomeric H₆-TDI: 0.08% Viscosity (23 ° C): 1 200 mPa · s Color number: 110 APHA

An analogous as in Example 1b carried out paint inspection of Polyallo phanatpolyisocyanatgemisches from Example 5b resulted in Trocknungsver solvent resistance, pendulum hardness and service life are the same Level.

Example 5c (Comparative Example to Example 5a) Reaction of hexamethylene diisocyanate (HDI) with isopropanol / dimethyl benzylamine

73.8 g (0.44 mol) of HDI were placed in a laboratory flask and 2.4 g (0.04 mol) of isopropanol. After 2 hours at 40 ° C, an NCO Content of 46.6% determined. The NCO / OH ratio is 22: 1, and the theoretical urethane content is 3.1%. After exposure to the reaction Vessels with a weak stream of air are 0.8 g (0.006 mol) of dimethyl added benzylamine.  

Even after several hours of stirring at 40 ° C and portionwise Nach catalyze with a further total of 0.8 g dimethylbenzylamine, and increase the reaction temperature to 50 ° C, no conversion was observed.

Catalysis with Aminosilyl Compounds (Catalyst Type C)) Example 6 Hexamethyldisilazane as catalyst with distillative monomer separation

In a 500 ml laboratory flask, 246 g (1.37 mol) of H₆-TDI are brought to 60 ° C. and with 5.6 g (0.062 M) of 1,3-butanediol at 90 ° C to a titrated NCO value of 43.5% implemented. The NCO / OH ratio is 22: 1 and the theore urethane content (59 g / mol) at 2.9%.

Subsequently, to the vorurethanisierte mixture under a stick stream 10 g (0.06 mol) of hexamethyldisilazane was added, the temperature increases up to 95 ° C due to an exothermic reaction.

At this temperature, the reaction becomes an NCO value after 3 hours of 39.4% by adding 0.5 g (0.03 mol) of water. The 30 minutes NCO value measured after stopping is 38.7% and remains constant.

The excess monomeric H₆-TDI is transferred via a laboratory short-path evaporator at 155 ° C / 0, 1 mbar removed from the crude solution.

The clear, almost colorless solid resin obtained has the following characteristic Characteristics:

NCO content: | 13.8% Monomeric H₆-TDI: 0.21% GPC data: @ Mean molecular weight M _n : 739 g / mol Mean NCO functionality F: 2.43   Polyamide-1,1-content: 1.6% (from IR spectrum) @ Color number: 25 APHA (80% solution in butyl acetate)

The color number of the 80% solid resin solution can be - as in Example 1a be - improve by addition of 100 ppm of butanone peroxide to 10 APHA.

B) Example of the heterogeneously catalyzed allophanatization reaction of cycloaliphatic alkyl-1,3-diisocyanates Example 7 Catalysis with chemically fixed N-hydroxyethyl-N-methyl-N-benzyl ammonium hydroxide (fixed bed catalysts D))

In a 1 liter laboratory flask, 400 g (2.22 mol) of H₆-TDI (refractive index at 23 ° C: 1.4770) and with 2.4 g (0.027 mol) of 1,3-butanediol at 40 ° C approximately. 1 hour implemented. The NCO / OH ratio is 83: 1 and the theoretical Urethane content (59 g / mol) at 0.8%.

Subsequently, 36 g of carefully dried beads of the ion exchanger Lewatit® MP 600 (4.5 meq functional catalyst groups / g polymer) added and suspended with stirring.

After about 7 hours of stirring, a refractive index of 1.4860 - was at a 29% conversion rate.

After filtration of the ion exchange beads, the crude solution was 300 ppm Stabilized dibutyl phosphate, and the excess H₆-TDI through a laboratory short-path evaporator distilled off at 145 ° C / 0.1 mbar.

The recovered yellow solid resin has the following data:

NCO content: | 15.1% Content of polyamide-1,1: <1.0% (from IR spectrum) @ GPC data: @ Mean molecular weight M _n : 598 g / mol Mean NCO functionality F: 2.15

Claims (5)

1. Base-catalyzed reaction products of 1,3-diisocyanatoalkylcyclo hexanes R₁ (NCO) ₂ in the presence of acyclically bonded urethane (I) or the corresponding isomeric cyclically bound allophanate groups (II) and optionally their higher molecular weight homologs of the formula the compounds A (OH) _x bearing the reaction of covalently bonded hydroxide groups are obtained with the diisocyanates R₁ (NCO) ₂, where
A is a radical obtained by removal of the OH groups from an x-valent organic hydroxyl compound,
R₁ is a radical as obtained by removal of the isocyanate groups from a diisocyanate R₁ (NCO) ₂,
n denotes the number of NCO equivalents of the diisocyanate cyanatkomponenten used
x denotes the number of OH equivalents of the hydroxyl components used,
y = xn denotes the proportion of optionally unreacted hydroxyl groups and is O y 4,
n-x + y stands for the number of NCO groups of the urethanes and is max. 4,
and wherein an NCO / OH ratio of 0.5: 1 to 200: 1 can be selected and the content of urethane (59 g / mol) or the corresponding isomeric cyclic allophanate groups (101 g / mol) between 0.05 to 48 wt .-%, based on the reaction mass used, and wherein, following or simultaneously with the urethanization reaction in a stoichiometric excess of NCO / OH groups (based on the amount of hydroxyl compound used) of 1.05: 1 to 200 : 1, optionally in the presence of air by addition of 0.00005-10 wt .-% of a monomeric or sparingly soluble matrix ionically or preferably covalently bound basic catalyst, where appropriate, has covalently bonded hydroxyl groups, a further polyaddition reaction takes place, to Polyallophanatpolyisocya data containing allophanate groups between 2-55 wt .-% of the formula leads, wherein mixtures of structures (III) and (IV) may occur and m is a number <1.05 and p 0, characterized in that these Polyallophanatpolyisocyanatgemische

• have less than 10% by weight of substantially isocyanate-group-free heavy-soluble heterocyclic polyamide-1,1-compounds,
• their mean NCO functionality is above 2.1,
• contain less than 10% by weight of isocyanurate structures based on cycloaliphatic alkyl-1,3-diisocyanates,
• - And the content of monomeric starting diisocyanate less than 2 wt .-% is.

2. A process for the preparation of the polyisocyanates according to claim 1, by reacting a cycloaliphatic alkyl-1,3-diisocyanate R₁ (NCO) ₂ the molecular weight range of 180-292 with a covalently bonded hydroxide-carrying compound while maintaining an equivalent ratio of NCO to OH Groups of 0.5: 1 to 200: 1 urethane group-containing compounds having a urethane content [59 g / mol] between 0.05 and 48 wt .-%, and further reaction of these urethane group-containing compounds in a stoichiometric excess of 1.3 -Content NCO groups of at least 1.05: 1 to 200: 1 (based on the OH compound used) with the participation of a basic cata- sators, which optionally carries covalently bonded hydroxide groups, in amounts of 5 × 10 ^-5 to 10 % By weight, which is diluted if necessary in inert or isocyanate-reactive H-containing solvents, if appropriate in the presence of air, to all ophanatgruppentragenden polyisocyanate mixtures and their consequence products in the sense of the isocyanate polyaddition with a content of allo phanateinheiten [101 g / mol] of 2-55 wt .-%, wherein the addition of the optionally present in dissolved basic catalyst simultaneously with or after addition of the hydroxidgruppentragenden Verbin compounds A (OH) _x takes place and wherein in case that the basic catalyst has covalently bonded to the urethanization of the used 1,3-diisocyanate capable of hydroxide groups on the use of the hydroxide A (OH) _x may be omitted and wherein gegebe if appropriate proportionally di- and / or higher functional (cyclo) aliphatic poly isocyanates, which do not carry the NCO groups to one another in the 1,3-position, and where appropriate, the reaction at the desired degree of conversion by adding a chemical stopper and / or thermal deactivation is terminated, and following the basic catalyzed P olyallophanatisierungsreaktion remaining volatile, unreacted starting polyisocyanate are removed by distillation or extractive methods from the reaction mixture, or optionally in the course of Allophanatisierungsreaktion with increasing viscosity gradually added to an isocyanate inert solvent, so that in the end about a 30 -95, preferably 50-90% solution of the allophanate polyisocyanate is formed,
characterized in that the resulting Polyallophanatpolyisocyanat mixtures

• have less than 10% by weight of substantially isocyanate-group-free, sparingly soluble heterocyclic polyamide-1,1-compounds,
• their mean NCO functionality is above 2.1,
• - Containing less than 10 wt .-% isocyanurate based on (cyclo) aliphatic alkyl-1,3-diisocyanates.

3. A process for the preparation of the polyisocyanates according to claim 1, by imple mentation of a cycloaliphatic alkyl-1,3-diisocyanate R₁ (NCO) ₂ the molecular weight range 180-292 with covalently bound hydroxide groups while maintaining an equivalent ratio of NCO to OH groups of 0.5: 1 to 200: 1 urethane group-containing compounds having a urethane content (59 g / mol) between 0.5 and 48 wt .-% and further reaction of these urethane group-containing compounds, optionally in the presence of air, in a stoichiometric excess of 1, 3- permanent NCO groups of at least 1.05: 1 to 200: 1 (based on the OH equivalents used) with the participation of a basic cata- capacitor, the ionic or preferably covalently in amounts of 0.005 to 10 meq / g of polymeric substance in a solid organic or inorganic matrix is present, to Polyallophanatpolyisocyanatgemischen containing allophanate groups between 2-55 wt .-%, wherein the contact d it can be prepared starting materials with the described fixed bed catalyst after or simultaneously with the urethanization reaction of the cycloaliphatic alkyl-1,3-diisocyanate, wherein the covalently bonded OH groups may be part of the described hydroxide components A (OH) _x , and in the case that the chemically fixed fixed-bed catalyst has covalently bonded hydroxide groups, can be dispensed with the participation of the OH components A (OH) _x , proportionally di- and higher functional (cyclo) aliphatic polyisocyanates, not the NCO groups in 1.3 Carrying one another can be used concomitantly, and the reaction at the desired degree of conversion by removing -. B. filtration - the sparingly soluble solid catalyst, optionally with the concomitant use of a chemical stopper is stopped and optionally still present, easily volatile starting isocyanates by distillation or extractive methods from the reaction mixture or optionally in the course of Polyallophanatisierungs beesteigender viscosity gradually an isocyanate inert solvent is added, so that 30-95% solution of Polyallophanatpolyiso cyanatgemisches arises, characterized in that the erfindungsge MAESSEN Polyallophanatgemische

• have less than 10% by weight of substantially isocyanate-group-free heavy-soluble heterocyclic polyamide-1,1-compounds,
• their mean NCO functionality is above 2.1,
• - And less than 10 wt .-% isocyanurate structures based on cycloaliphatic alkyl-1,3-diisocyanates.

4. Use of the polyisocyanates according to claim 1 as a binder for the Coating of any substrates. 5. Use of the polyisocyanates according to claim 4 in blocked form as Binders for the coating of any substrates.