Process for the production of compounds containing isocyanurate groups and olefinic double bonds, the compounds obtainable by this process and their use as binders or binder component in coating compositions

A process for the production of compounds which crosslink under the effect of high-energy radiation containing isocyanurate groups, olefinic double bonds, and, optionally, blocked or free isocyanate groups by reacting PA0 (i) isocyanurate-group-containing polyisocyanates which are based on aliphatic and/or cycloaliphatic diisocyanates with PA0 (ii) compounds containing at least one isocyanate-reactive group and at least one olefinic double bond, such as hydroxyl-containing esters of acrylic acid and methacrylic acid with at least dihydric aliphatic alcohols having a molecular weight of from 62 to about 300, to form urethanes, the quantitative ratios between the reactants being selected so that for every free isocyanate group in component (i), the reaction mixture contains from about 0.9 to 1.5 hydroxyl groups of component (ii). The present invention also relates to the compounds prepared by this process and to the use of these compounds as the binder or a binder component in coating compositions crosslinkable by high-energy radiation.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a new process for the production of compounds 
containing isocyanurate groups and olefinic double bonds by reacting 
polyisocyanates containing isocyanurate groups with compounds containing 
isocyanate-reactive hydrogen atoms and olefinic double bonds, to the 
reaction products obtainable by this process and to their use as binder or 
as binder component in coating compositions crosslinkable by high-energy 
radiation. 
2. Description of the Prior Art 
Compounds containing olefinically unsaturated groups have long been known 
as binder-containing coating compositions. They are hardened by 
high-energy radiation, such as UV-radiation or electron beams, and are 
used for example for coating heat-sensitive substrates, such as wood or 
for the production of coatings for graphic purposes, i.e. for example in 
the printing industry or in the production of printed wiring boards. 
A sub-group of radiation-crosslinked coating compositions of the type in 
question are urethane oligomers modified by compounds containing both 
ethylenically unsaturated groups and also isocyanate-reactive groups. 
Oligomers such as these are known, particularly for applications in the 
printing industry, and are described for example in DE-OS Nos. 21 15 373 
and 21 21 253 and in GB-PS No. 1,379,228. 
Radiation-crosslinking coating compositions which may be based on different 
types of oligourethanes have recently been described, again for 
applications in the printing industry (British Pat. No. 1,491,695). 
Among those oligourethanes, a polyisocyanate modified by ethylenically 
unsaturated groups is particularly remarkable because, in addition to the 
purpose states in the above-mentioned patent, it is also suitable for the 
production of high quality lacquers. This particular oligourethane is 
based on the biuret-group-containing aliphatic polyisocyanate which 
corresponds to the following idealized formula 
##STR1## 
Olefinically unsaturated oligourethanes based on this polyisocyanate, i.e. 
in particular its reaction products with hydroxyalkyl acrylate or 
methacrylate, may be reacted under the influence of high-energy radiation 
to form highly crosslinked, hard coatings or, alternatively, are suitable 
for use as additives to conventional radiation-crosslinking coating 
compositions to which they impart greater hardness or better abrasion 
resistance for example. However, their particular advantage lies in the 
fact that they may be used for producing coatings at room temperature, 
thereby enabling heat-sensitive substrates, such as wood, paper or 
leather, to be coated. 
However, the oligourethanes referred to are also attended by certain 
disadvantages. Thus, radiation crosslinking is accompanied by more or less 
serious discoloration which is particularly troublesome in the coating of 
white and light-colored substrates. In addition, their weather resistance 
is often inadequate. 
It has now surprisingly been found that these disadvantages may be overcome 
by using isocyanurate-group-containing polyisocyanates based on aliphatic 
and/or cycloaliphatic polyisocyanates for the production of olefinically 
unsaturated isocyanate addition products. 
This discovery is particularly surprising in view of the fact that 
two-component polyurethane lacquers based both on aliphatic 
polyisocyanates containing biuret groups and on aliphatic polyisocyanates 
containing isocyanurate groups may be used with equal effect for the 
production of light-stable and weather-resistant coatings, so that 
radiation-crosslinkable binders based on isocyanurate polyisocyanates 
could not be expected to differ with advantage in these properties from 
radiation-crosslinkable binders based on biuret polyisocyanates. 
SUMMARY OF THE INVENTION 
The present invention relates to a process for the production of compounds 
which crosslink under the effect of high-energy radiation containing 
isocyanurate groups, olefinic double bonds and, optionally, isocyanate 
groups which are optionally blocked by reacting 
(i) isocyanurate-group-containing polyisocyanates, wherein up to about 70% 
of the isocyanate groups may be blocked with blocking agents for 
isocyanate groups and which are optionally present in admixture with 
isocyanurate-group-free, aliphatic and/or cycloaliphatic polyisocyanates, 
up to about 70% of whose isocyanate groups may be blocked with blocking 
agents for isocyanate groups, these isocyanurate polyisocyanates being 
based on aliphatic and/or cycloaliphatic diisocyanates, with 
(ii) compounds containing at least one isocyanate-reactive group and at 
least one olefinic double bond, comprising a member selected from the 
group consisting of hydroxyl-containing esters of acrylic acid and/or 
methacrylic acid with at least dihydric aliphatic alcohols having a 
molecular weight in the range from 62 to about 300, 
to form urethanes, the quantitative ratios between the reactants being 
selected in such a way that, for every free isocyanate group in component 
(i), the reaction mixture contains from about 0.9 to 1.5 hydroxyl groups 
of component (ii). 
The present invention also relates to the isocyanurate-group-containing 
reaction products obtainable by this process, characterized by 
(a) a content of isocyanurate groups (molecular weight=126) of from about 5 
to 20% by weight, 
(b) a content of free isocyanate groups of from 0 to about 15% by weight, 
(c) a content of blocked isocyanate groups (expressed as NCO) of from 0 to 
about 10% by weight and, 
(d) a content of olefinic C.dbd.C double bonds (molecular weight=24) of 
from about 2 to 15% by weight, 
these percentages being based on the total weight of the reaction products, 
excluding the weight of the blocking agent for isocyanate groups 
optionally present. 
Finally, the present invention also relates to the use of the reaction 
products containing isocyanurate groups and olefinic double bonds 
obtainable by this process as the binder or a binder component in coating 
compositions crosslinkable by high-energy radiation. 
DETAILED DESCRIPTION OF THE INVENTION 
Isocyanurate-group-containing polyisocyanates based on aliphatic and/or 
cycloaliphatic diisocyanates are used as component (i) in the process 
according to the invention. The corresponding isocyanato-isocyanurates 
based on hexamethylene diisocyanate and/or 
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (isophorone 
diisocyanate=IPDI) are particularly preferred. The production of 
isocyanurate polyisocyanates such as these is described, for example, in 
DE-PS No. 2,616,416, in EP-OS No. 3765, in EP-OS No. 10 589, in EP-OS No. 
47 452, in U.S. Pat. No. 4,288,586 or in U.S. Pat. No. 4,324,879. The 
starting materials (i) suitable for use in accordance with the invention 
are of course not confined to the products of these prior publications 
which are mentioned purely by way of example. On the contrary, any 
isocyanurate polyisocyanates based on aliphatic and/or cycloaliphatic 
diisocyanates which have a total isocyanate content of from about 10 to 
30% by weight and preferably from about 15 to 25% by weight may be used in 
the process according to the invention. These compounds are simple 
tris-isocyanatoalkyl (or cycloalkyl) isocyanurates corresponding to the 
following formula 
##STR2## 
in which X.sub.1, X.sub.2 and X.sub.3 may be the same or different and 
represent the hydrocarbon radical on which the starting diisocyanate is 
based, or mixtures of these isocyanurates with their higher homologs 
containing more than one isocyanurate ring. 
Up to about 70% (and preferably up to about 50%) of the isocyanate groups 
in the isocyanurate polyisocyanates used as component (i) may be blocked 
by blocking agents known per se for isocyanate groups, such as for example 
.epsilon.-caprolactam, butanone oxime, malonic acid diethyl ester or 
acetoacetic acid ethyl ester. However, unblocked isocyanurate 
polyisocyanates based on only one starting diisocyanate (X.sub.1 =X.sub.2 
=X.sub.3) are preferably used in the process according to the invention. 
In the practical application of the process according to the invention, the 
isocyanurate polyisocyanates essential to the invention may also be used 
in admixture with up to about 60 and preferably with up to about 40 
NCO-equivalent percent, based on the total quantity of polyisocyanates, of 
isocyanurate-free polyisocyanates containing aliphatically and/or 
cycloaliphatically bound isocyanate groups. However, it is preferred to 
use the "technically pure" starting substances, i.e. starting substances 
of which at least 95 NCO-equivalent percent are isocyanurate 
polyisocyanates. 
The starting materials optionally used together with these preferred 
starting compounds are, for example, uretdione diisocyanates containing 
aliphatically and/or cycloaliphatically bound isocyanate groups 
corresponding to the following formula 
##STR3## 
which, in any event, are often formed in minor quantities (from about 0.1 
to 5 and, more particularly, from about 0.3 to 3 NCO-equivalent percent) 
in addition to the isocyanurate polyisocyanates in the trimerization of 
aliphatic and/or cycloaliphatic diisocyanates. 
Apart from these uretdione diisocyanates, the isocyanurate polyisocyanates 
according to the invention may also be used in admixture with simple 
aliphatic and/or cycloaliphatic diisocyanates, such as, for example 
hexamethylene diisocyanate and/or isophorone diisocyanate, and/or in 
admixture with the traditional "lacquer polyisocyanates" such as, for 
example, tris-(6-isocyanatohexyl)-biuret and its higher homologs, and the 
urethane-group-containing polyisocyanates obtained by reacting excess 
quantities of isophorone diisocyanate with polyhydric alcohols, such as 
trimethylol propane. Up to about 70% and preferably up to about 50% of the 
isocyanate groups of the polyisocyanates optionally used in addition to 
the isocyanurate polyisocyanates essential to the invention may also be 
blocked by blocking agents of the type mentioned by way of example. 
Component (ii) is a hydroxyl-containing ester of acrylic acid and/or 
methacrylic acid with at least dihydric aliphatic alcohols having a 
molecular weight in the range from 62 to about 300. Typical compounds of 
this type are, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl 
methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3- 
and 4-hydroxybutyl acrylate, 3- and 4-hydroxybutyl methacrylate, 
6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, 
3-hydroxy-2-ethylhexyl acrylate, 3-hydroxy-2-ethylhexyl methacrylate, the 
di(meth)acrylic acid esters of 1,1,1-trimethylol propane or of glycerol. 
Particularly preferred starting components (ii) are 2-hydroxyethyl and 
2-hydroxypropyl acrylate or methacrylate. Mixtures of these compounds may 
of course also be used. The reaction according to the invention is 
generally carried out by mixing the components at elevated temperatures in 
the range from about 40.degree. to 100.degree. C. and preferably in the 
range from about 50.degree. to 80.degree. C. In general, steps should be 
taken to ensure that undesirable, heat-induced polymerization reactions 
are suppressed. Because of this, it is often best to work at relatively 
low temperatures within the ranges indicated using known catalysts which 
accelerate the isocyanate addition reaction. Suitable catalysts are, for 
example, alkali metal alcoholates such as sodium ethylate; tertiary amines 
such as triethylamine, diethylene triamine or dimethyl benzylamine; or tin 
catalysts such as tin dioctoate or dibutyl tin dilaurate. 
The reaction may be carried out in the absence or presence of inert 
solvents such as, for example, ethylacetate, butylacetate, ethyl glycol 
acetate and/or methyl isobutyl ketone. 
In the reaction according to the invention, the quantitative ratios between 
the reactants are selected in such a way that, for every free isocyanate 
group in the polyisocyanate component (i), which is composed of the 
isocyanurate polyisocyanates and, optionally, isocyanurate-free 
polyisocyanates, the reaction mixture contains from about 0.9 to 1.5 and 
preferably from about 1.0 to 1.2 hydroxyl groups of component (ii). Where 
unblocked polyisocyanates are used and where the reaction according to the 
invention is carried out using stoichiometric quantities of the starting 
materials, isocyanate-free, olefinically unsaturated products are formed 
and may be used as radiation-crosslinkable binders or binder components 
for coating compositions. Where partly blocked polyisocyanates are used 
and/or where a substoichiometric quantity of component (ii) is used, the 
products formed contain free and/or blocked isocyanate groups in addition 
to olefinic double bonds. These reaction products according to the 
invention are suitable, for example, as binders or as binder components in 
combination with compounds containing isocyanate-reactive groups, such as 
for example the polyhydroxy polyesters and/or polyhydroxy polyacrylates 
known from the chemistry of polyurethane lacquers, with which they may be 
processed as the polyisocyanate component in two-component systems. After 
polyurethane formation which takes place either spontaneously (free 
isocyanate groups) or after thermal hardening (blocked isocyanate groups), 
systems such as these may be converted by high-energy radiation into their 
crosslinked state. 
The preferred reaction products according to the invention are 
characterized by the above-mentioned contents of isocyanurate groups, free 
isocyanate groups, blocked isocyanate groups and olefinic double bonds. 
The reaction products according to the invention crosslinkable by 
high-energy radiation are generally clear, medium viscosity to high 
viscosity, colorless liquids. If their viscosity is too high for the 
desired application, they may be diluted with solvents. Solvents suitable 
for this purpose are aromatic hydrocarbons such as toluene, xylenes and 
more highly substituted benzenes; esters such as ethylacetate, 
butylacetate, methoxy or ethoxy ethylacetate and butoxy ethylacetate; 
ketones such as acetone, methylethyl ketone, methyl isobutyl ketone and 
cyclohexanone; and also alcohols such as methanol, ethanol, propanol, 
i-propanol, butanol, i-butanol, etc. However, alcohols can only be used in 
cases where the binders according to the invention do not contain any free 
isocyanate groups. 
Solvents in the broader sense also include ethylenically unsaturated, low 
molecular weight compounds, such as for example esters of acrylic or 
methacrylic acid with aliphatic C.sub.1 -C.sub.8 -, cycloaliphatic C.sub.5 
-C.sub.6 -, araliphatic C.sub.7 -C.sub.8 -monoalcohols, for example 
methylacrylate, ethylacrylate, n-propylacrylate, n-butylacrylate, 
methylhexylacrylate, 2-ethylhexylacrylate and the corresponding 
methacrylic acid esters; cyclopentyl acrylate, cyclohexylacrylate or the 
corresponding methacrylic acid esters; benzylacrylate, 
.beta.-phenylethylacrylate and corresponding methacrylic acid esters; 
hydroxyalkyl esters of acrylic or methacrylic acid containing from 2 to 4 
carbon atoms in the alcohol component, such as 2-hydroxyethylacrylate, 
2-hydroxypropylacrylate, 3-hydroxypropylacrylate, 2-hydroxybutylacrylate, 
4-hydroxybutylacrylate or corresponding methacrylic acid esters; di- and 
polyacrylates and also di- and polymethacrylates of glycols containing 
from 2 to 6 carbon atoms and polyols containing from 3 to 4 hydroxyl 
groups and from 3 to 6 carbon atoms, such as ethylene glycol diacrylate, 
1,3-propane diol diacrylate, 1,4-butane diol diacrylate, 1,6-hexane diol 
diacrylate, trimethylol propane triacrylate, pentaerythritol tri- and 
tetra-acrylate and corresponding methacrylates; also di(meth)acrylates of 
polyether glycols of glycol, 1,3-propane diol, 1,4-butane diol, 
tetraethoxylated trimethylol propane tris-acrylate; aromatic vinyl and 
divinyl compounds, such as styrene, methyl styrene, divinylbenzene; 
N-methylol acrylamide or N-methylol methacrylamide and corresponding 
N-methylol alkyl ethers containing from 1 to 4 carbon atoms in the alkyl 
ether group and corresponding N-methylol allyl ethers, particularly 
N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide and 
N-allyloxymethyl(meth)acrylamide; vinyl alkyl ethers containing from 1 to 
4 carbon atoms in the alkyl group, such as vinyl methylethyl ether, vinyl 
ethyl ether, vinyl propyl ether, vinyl butyl ether; trimethylol propane 
diallyl ether mono(meth)acrylate, vinyl pyridine, N-vinyl carbazole, 
triallyl phosphate, triallyl isocyanurate and others. These olefinically 
unsaturated "solvents" listed by way of example are not in fact genuine 
solvents, but instead should be regarded as "reactive diluents" because, 
in the radiation crosslinking of the reaction products according to the 
invention, they react off with those products through copolymerization. In 
cases where the reaction products according to the invention do not have 
to be processed at elevated temperatures, i.e. at temperatures above the 
boiling point of the reactive diluents in question (absence of blocked 
isocyanate groups), reactive diluents such as these are preferably used 
instead of the usual solvents. 
Other compounds containing olefinic double bonds which may optionally be 
used in the application in accordance with the invention are, for example, 
olefinically unsaturated resins such as unsaturated polyester resins, 
unsaturated hydrocarbon resins or unsaturated polyurethane resins. 
However, when using the specific reaction products according to the 
invention (i.e. reaction products of isocyanurate polyisocyanates with the 
starting component (ii)) in combination with other olefinically 
unsaturated compounds (reaction products of isocyanurate-free 
polyisocyanates with component (ii), reactive diluents of the type 
mentioned by way of example and/or unsaturated resins of the type 
mentioned last), it is important to ensure that the percentage of the 
specific reaction products, based on the total quantity of olefinically 
unsaturated compounds, amounts to at least about 20 and preferably to at 
least about 40% by weight. 
The reaction products according to the invention and combinations thereof 
with compounds containing isocyanate-reactive groups (where 
isocyanate-group-containing reaction products according to the invention 
are used) and/or which other olefinically unsaturated compounds are 
valuable binders for coatings. They may be used as such or in combination 
with the auxiliaries and additives known from lacquer technology such as 
fillers, pigments, solvents, leveling aids and the like, and optionally 
after the addition of a photoinitiator, for the production of coatings on 
any substrates. These coating compositions may be applied in known manner 
by spray coating, knife coating, roll coating, spread coating, dip coating 
or casting. After the evaporation of any inert solvents used, crosslinking 
of the coatings may be initiated by exposure to high-energy radiation. The 
isocyanate polyaddition reaction which may also occur (use of the reaction 
products according to the invention containing free or blocked 
polyisocyanate groups in combination with polyhydroxyl compounds) may take 
place before or during this irradiation, optionally under the effect of 
heat. 
The high-energy radiation may entail, for example, bombardment with 
electrons under a voltage of about 150-500 KV and a current of about 
0.1-10 mA. The total dose depends upon the thickness of the film applied 
and the density of its pigmentation (when it has been pigmented). It may 
amount to between about 0.1 and 50 Mrad and preferably amounts to between 
about 1 and 20 Mrad. In this context, 1 rad represents a radiation dose 
corresponding to an absorption of 10.sup.5 joules per gram of substrate, 
i.e. in this case per gram of the coating. 
In general, the electron beam is generated in a linear electron accelerator 
in which the electrons emitted from a heated metal body are accelerated in 
a d.c. voltage field to a velocity corresponding to the d.c. voltage 
indicated above. By electrostatic or electromagnetic deflection, the beam 
can be fanned out to a considerable extent so that the entire width of a 
coated workpiece is irradiated when it is moved through beneath the 
radiation source. 
UV-light may also be used as the high-energy radiation for initiating 
crosslinking. Where UV-light is used, however, additives have to be 
introduced on the one hand to prevent the inhibition of radical 
cross-linking by atmospheric oxygen and, on the other hand, to initiate 
radiation crosslinking. 
Additives suitable for preventing inhibition include phenols and phenol 
derivatives, preferably sterically hindered phenols carrying alkyl 
substituents in both o-positions to the hydroxyl group; amines, preferably 
secondary acrylamines and derivatives thereof; copper-(I) salts or organic 
acids; and adducts of Cu-(I) halides with phosphites. 
Suitable photoinitiators are the compounds normally used, for example 
benzophenone, and--quite generally--aromatic keto compounds derived from 
benzophenone, such as alkyl benzophenones, halogen-methylated 
benzophenones according to DE-OS No. 19 49 010, Michler's ketone, anthrone 
and halogenated benzophenones. Other suitable photoinitiators are benzoin 
and its derivatives, for example according to DE-OS Nos. 17 69 168, 17 69 
853, 17 69 854, 18 07 297, 18 07 301, 19 16 678 or 24 30 081 and DE-AS No. 
16 94 149. Other effective photoinitiators are anthraquinone and many of 
its derivatives, for example .beta.-methyl anthraquinone, tert.-butyl 
anthraquinone and anthraquinone carboxylic acid esters, also oxime esters 
according to DE-OS No. 17 95 089. 
The above-mentioned photoinitiators, are used in quantities of from about 
0.1 to 20% by weight and preferably in quantities of from about 0.1 to 5% 
by weight, based on polymerizable components, depending on the purpose for 
which the reaction products according to the invention are to be used. The 
photoinitiators may be used either individually or, by virtue of frequent, 
favorable synergistic effects, in combination with one another. Suitable 
radiation sources for carrying out photopolymerization include artificial 
radiation sources emitting in the range from about 250 to 500 nm and 
preferably in the range from about 300 to 400 nm. It is of advantage to 
use mercury vapor, xenon and tungsten lamps, with high pressure mercury 
lamps being particularly advantageous. 
In general, layers of the reaction products according to the invention 
having a thickness of from about 1 .mu.m to 0.1 mm (1 .mu.m=10.sup.-3 mm) 
may be hardened to form a film in less than 1 second when exposed to the 
light of a high pressure mercury lamp, for example of the HTQ-7 type 
manufactured by Philips, arranged at a distance of approximately 8 cm. 
Where fillers are used in the application of the resin compositions 
according to the invention as UV-light-hardening coatings, their use is 
confined to those which do not suppress the polymerization reaction 
through their absorption behavior. For example, talcum, heavy spar, chalk, 
gypsum, silicas, asbestos powders and light spar, may be used as 
light-permeable fillers. 
Suitable substrates are paper, cardboard, leather, wood, plastics, bonded 
fabrics, textiles, ceramic materials, mineral materials, glass, metals, 
artificial leather, photographic materials, such as for example 
emulsion-coated paper, transfer films, preferably wood, plastics, ceramic 
materials, mineral materials and photographic materials. Since the coating 
compositions harden to form films having excellent mechanical properties 
in fractions of a second to a few seconds, it is possible for example to 
adapt the coating process to the processing speeds normally encountered in 
the printing field. 
In addition, the binders according to the invention may also be emulsified 
in water using external emulsifiers and, optionally, additives of the type 
normally used for emulsification and applied in the form of emulsions. 
Suitable emulsifiers are anionic, non-ionic, cationic, ampholytic or high 
molecular weight substances and mixtures thereof. Corresponding 
emulsifiers are described, for example, in Ullmanns Enzyklopadie der 
Technischen Chemie, Vol. 10, 4th Edition, Chapter on Emulsions, pages 449 
et seq. Suitable emulsifiers may readily be determined both qualitatively 
and quantitatively by simple small-scale tests. 
The emulsions may contain from about 10 to 70% by weight, preferably from 
about 30 to 70% by weight, and more particularly, from about 40 to 60% by 
weight of the binders according to the invention.

In the following Examples, all the figures quoted in percent and in parts 
represent percentages by weight and parts by weight, respectively. 
The isocyanurate polyisocyanates used in the following Examples are 
prepared as follows: 
1. Polyisocyanate of hexamethylene diisocyanate (HDI) 
1 ml of 2-dimethylaminomethyl nonylphenol was added at 23.degree. C. to 
1344 g of HDI in a three-necked flask. After stirring for 5 minutes, 40 ml 
of a 2% solution of 2-hydroxyethyl trimethylammonium hydroxide in dimethyl 
formamide/methanol (8:1) were added dropwise over a period of 15 minutes, 
again at 23.degree. C. In that time, the temperature rose to 35.degree. C. 
and, after another 45 minutes, to 40.degree. C. The trimerization reaction 
was maintained at that temperature. After 6 hours, the NCO-content had 
reached 40.5%. The reaction product was stabilized with 0.3 ml of 
nonafluorobutane sulfonic acid in 1 ml of dimethyl formamide and 
subsequently thin-layered in a high vacuum. 
Yield: 417 g (31%) 
Iodine color number (DIN 6162): 3 
NCO-content: 22.0% 
Viscosity (25.degree. C.): 3100 mPa.s 
Monomeric HDI: 0.18% 
2. Polyisocyanate of 3-isocyanatomethyl-3,5,5-trimethyl cyclohexyl 
isocyanate (IPDI) 
1332 g of IPDI were heated to 80.degree. C. in a three-necked flask. 15 ml 
of a 6% solution of 2-hydroxyethyl trimethyl ammonium hydroxide in 
dimethyl formamide/methanol (4:1) were slowly and uniformly added dropwise 
from a dropping funnel over a period of 45 minutes, the temperature rising 
to around 88.degree. C. (the temperature should not exceed 90.degree. C.; 
at too high a temperature, trimerization is unspecific and leads to 
relatively high viscosities of the end product). After the dropwise 
addition, the mixture was stirred for 30 minutes, the temperature falling 
to 80.degree. C. The NCO-content of the trimer solution then amounted to 
30.6%. The reaction product was thin-layered in a high vacuum and the 
resin subsequently dissolved to form a 75% solution in ethyl glycol 
acetate. 
Yield (resin): 580 g (44%) 
Viscosity (solution): 5107 mPa.s (25.degree. C.) 
NCO-content (solution): 12.5% 
Free IPDI (solution): 0.18% 
3. Polyisocyanate of a mixture of HDI and IPDI 
100 ml of a 5% solution of 
N-dodecyl-N,N-dimethyl-N-(2-hydroxyethyl)-ammonium hydroxide in 2-ethyl 
hexanol/ethanol (8:1) were added at 65.degree. C. to a mixture of 4704 g 
(28 moles) of HDI and 1554 g (7 moles) of IPDI. The reaction was 
immediately exothermic and was held at 80.degree. C. for 10 minutes by 
cooling. After removal of the cooling, the temperature rose to 96.degree. 
C. After another 15 minutes, the temperature fell and was kept at 
80.degree. C. by heating. After a total of 1 hour, the catalyst was 
deactivated. The NCO-content of the mixture was then constant and amounted 
to 39.9%. The product almost completely freed from monomeric diisocyanates 
by thin-layer distillation (residual HDI content: 0.25%, residual IPDI 
content: 0.37%) had a slight yellowish color, an NCO-content of 19.8% and 
a viscosity of 5320 mPa.s (23.degree. C.). 
EXAMPLE 1 
191 parts of polyisocyanate 1 were dissolved in 365 parts of anhydrous 
toluene, followed by the addition at room temperature of 174 parts of 
hydroxyethylacrylate. After the addition of 0.5 part of tin dioctoate, the 
temperature is slowly increased to 60.degree. C. and the mixture was 
stirred until the NCO-content had fallen to 0. After cooling to room 
temperature, 1.8 parts of 2,6-di-t-butylphenol were added and solvent was 
removed by vacuum distillation until the concentration amounted to 70%. 
The solution obtained was almost colorless with a slight yellow tinge and 
had a viscosity of approximately 5000 mPa.s (23.degree. C.). The content 
in the oligourethane of olefinic double bonds (MW=24) amounted to 7.8% and 
that of isocyanurate groups (MW=126) amounted to 13.6%. 
EXAMPLE 2 
191 parts of polyisocyanate 1 were dissolved in 90 parts of anhydrous 
xylene and the resulting solution was mixed at room temperature with 168 
parts of 2-hydroxypropyl methacrylate. After the addition of 0.5 part of 
tin dioctoate, the temperature was slowly increased to 60.degree. C. and 
the mixture was stirred until the NCO-content had fallen to 0. After 
cooling to room temperature, 1.8 parts of 2,6-di-t-butylphenol were added. 
The 80% solution was substantially colorless and had a viscosity of 
approximately 12,000 mPa.s (23.degree. C.). The content in the 
oligourethane of olefinic double bonds amounted to 7.1% and that of 
isocyanurate groups amounted to 12.5%. 
EXAMPLE 3 
336 parts of polyisocyanate solution 2 were diluted with 50 parts of ethyl 
glycol acetate, followed by the addition at room temperature of 152 parts 
of hydroxy ethyl methacrylate. After the addition of 1 part of tin 
dioctoate, the temperature was slowly increased to 70.degree. C. and the 
mixture was stirred until the NCO-content had fallen to 0. After cooling 
to room temperature, 2 parts of 2,6-di-t-butylphenol were added. The 75% 
solution was substantially colorless and had a viscosity of approximately 
10,000 mPa.s (23.degree. C.). The content in the oligourethanes of 
olefinic double bonds amounted to 6.2% and that of isocyanurate groups 
amounted to 10.9%. 
EXAMPLE 4 
212 parts of polyisocyanate 3 were dissolved in 104 parts of ethyl glycol 
acetate and 58 parts of butanone oxime were added to the resulting 
solution at room temperature. The mixture was heated to 80.degree. C. and 
stirred until the NCO-content had reached or just fallen below 3.7%. It 
was then cooled to 50.degree. C., followed by the addition of 42.5 parts 
of hydroxyethyl acrylate and 1 part of tin dioctoate. The temperature was 
then increased to around 70.degree. C. When the NCO-content had fallen to 
0, the mixture was cooled to room temperature and 1.5 parts of 
2,6-di-t-butylphenol were added. The 75% solution obtained was clear and 
almost colorless and had a viscosity of approximately 3500 mPa.s 
(23.degree. C.). The content in the oligourethane (not including the 
weight of the blocking agent) of olefinic double bonds amounted to 3.1%, 
that of isocyanurate groups amounted to 10.0% and that of blocked 
isocyanate groups (MW=42) amounted to 16.7%. 
EXAMPLE 5 
250 parts of the adduct of Example 3 were diluted with 125 parts of xylene. 
After the addition of 9.4 parts of benzophenone and 0.9 parts of Darocur 
1173 (a commercially available UV-initiator manufactured by the Merck 
Company, Darmstadt), the solution was applied by spray gun to a bonderized 
steel plate in a wet layer thickness of approximately 60 .mu.m. After the 
solvent had been evaporated off, the plate was moved below a Hanovia lamp 
(80 W/cm, distance 8 cm) at a speed of 20 meters per minute. The coating 
was immediately dry, clear and completely colorless and had a Konig 
pendulum hardness of 170 seconds (DIN 53157). 
EXAMPLE 6 
250 parts of the unsaturated resin according to Example 3 of EP-OS No. 53 
749 and U.S. Pat. No. 4,380,604 were dissolved in 675 parts of a mixture 
of equal parts of xylene and butyl acetate. 200 parts of the adduct of 
Example 1 were added to the resulting solution, followed by stirring until 
a homogeneous mixture was obtained. 22.5 parts of benzophenone and 2.3 
parts of Darocur 1173 were then added. The 40% solution had a viscosity of 
approximately 1000 mPa.s at 23.degree. C. In a casting machine, a printed 
carton was coated in such a way that a dry layer thickness of 15 .mu.m was 
obtained after evaporation of the solvents. The coated carton was moved 
below a Hanovia lamp at a speed of 20 m/minute in the same way as in 
Example 5. A dry, glossy, colorless and elastic coating having a pendulum 
hardness of 90 seconds was obtained. 
EXAMPLE 7 
229 parts of polyisocyanate 1 and 152 parts of a biuret polyisocyanate with 
an NCO-content of 22%, containing a mixture of 
N,N',N"-tris-(isocyanatohexyl)biuret with its higher homologs, were 
dissolved in 659 parts of anhydrous toluene, followed by the addition at 
room temperature of 278 parts of hydroxyethylacrylate. After the addition 
of 1.5 parts of tin dioctoate, the temperature was slowly increased to 
60.degree. C. and the mixture was stirred until the NCO-content had fallen 
to 0. After cooling to room temperature, 3.6 parts of 2,6-di-t-butylphenol 
were added and solvent was removed by vacuum distillation until the 
concentration amounted to 70%. The solution obtained was substantially 
colorless and had a viscosity of 7000 mPa.s (23.degree. C.). The content 
in the oligourethane of olefinic double bonds (MW=24) amounted to 7.8% and 
that of isocyanurate groups (MW=126) amounted to 8.1%. 
EXAMPLE 8 
190 parts of the biuret polyisocyanate of Example 7 were dissolved in 364 
parts of anhydrous toluene, followed by the addition at room temperature 
of 174 parts of hydroxyethylacrylate. After the addition of 0.5 part of 
tin dioctoate, the temperature was slowly increased to 60.degree. C. and 
the mixture was stirred until the NCO-content had fallen to 0. After 
cooling, 1.8 parts of 2,6-di-t-butylphenol were added and the solvent and 
excess hydroxyethylacrylate were removed by vacuum distillation. The 
residual oligourethane was colorless but slightly cloudy and had a 
viscosity of approximately 35,000 mPa.s. The content in the oligourethane 
of olefinic double bonds (MW=24) amounted to 7.8%. 
EXAMPLE 9 
9.4 parts of benzophenone and 0.9 part of Darocur 1173 (cf. Example 5) were 
added to quantities of 250 parts of the adducts of Examples 1, 7 and 8, 
followed by knife coating onto bonderized steel plates in such a way that 
all three oligomers form a 25 .mu.m thick dry layer after evaporation of 
the solvent. The plates were moved below a Hanovia lamp (80 W/cm, distance 
8 cm) at a speed of 20 meters per minute. Thereafter the coatings were 
hard and tack-free. 
The coatings according to Examples 1 and 7 were substantially colorless 
while the coating according to Example 8 had assumed a pale yellow-brown 
coloration. 
The three plates were subjected to a 1000-hour weathering test on a Q.U.V. 
Weatherometer (Q.-Panel Company, England). 
The Table shows the 20.degree. reflectometer values of the following gloss 
assessment according to DIN 67530 (Gardner Reflectometer): 
______________________________________ 
Example No. Initial Value 
After Weathering 
______________________________________ 
1 89 75 
7 87 68 
8 90 53 
______________________________________ 
EXAMPLE 10 
43.2 parts of 2-hydroxypropyl methacrylate were added at room temperature 
to 336 parts of polyisocyanate solution 2. After the addition of 1 part of 
tin dioctoate, the temperature was slowly increased to 60.degree. C. and 
the mixture was stirred for 2.5 hours. After cooling, 2 parts of 
2,6-di-t-butylphenol were added. The solution obtained had a solids 
content of 78% and an NCO-content of 6.9%. Its viscosity at 23.degree. C. 
amounted to approximately 6500 mPa.s. The oligomer contained 2.7% of 
olefinic double bonds (MW=24) and approximately 12.8% of isocyanurate 
groups (MW=126). 
EXAMPLE 11 
A mixture of 84 parts of a polyester diol of 1,6-hexane diol and adipic 
acid (OH number 134) and 4.5 parts of 1,4-butane diol dissolved in 84 
parts of DMF was mixed with 76.8 parts of the adduct of Example 10 and 
heated to 60.degree.-70.degree. C. after the addition of 0.8 part of 
2,6-di-t-butylphenol. The mixture increased in viscosity and was kept 
readily stirrable by dilution at intervals with a total of 130 parts of 
toluene. After the solvent had been added, the viscosity was increased by 
the addition of portions amounting to 1 part of the adduct according to 
Example 10 at relatively long intervals until it amounted to approximately 
10,000 mPa.s at 23.degree. C. 8 parts of 1,4-butane diol diacrylate, 7.7 
parts of benzophenone and 0.77 part of Darocur 1173 (cf. Example 5) were 
then added. 
The solution was then knife-coated onto an aluminum plate in such a way 
that a 30 .mu.m thick dry film was formed. Evaporation of the solvents 
left a strong elastic film which could be removed from the substrate with 
acetone. After the coated plate had been passed beneath a high-pressure 
mercury lamp in the same way as described in Example 5, the coating showed 
only a slight tendency to swell in acetone. 
Although the invention has been described in detail in the foregoing for 
the purpose of illustration, it is to be understood that such detail is 
solely for that purpose and that variations can be made therein by those 
skilled in the art without departing from the spirit and scope of the 
invention except as it may be limited by the claims.