Polymerizable compositions containing compounds based on N-acylamido-piperazines are provided. Such compounds have the formula: ##STR1## wherein: R.sup.1, R.sup.2, and R.sup.3 are each independently selected from the group consisting of hydrogen and lower alkyl, PA1 B is a linking group selected from the group consisting of carbonyl, sulfonyl, amide, and carboxyl; PA1 n is one or zero; PA1 R.sup.4 is a radical selected from the group consisting of a higher aliphatic group (i.e. at least four carbon atoms, preferably from about 6 to about 50 carbon atoms), a substituted higher aliphatic group, an alicyclic group, a heterocyclic group, a non-benzenoid aromatic group, and a substituted aromatic group. Compositions containing these compounds which are stable against gelation can be prepared. The compound is preferably present in said composition in a major amount on a mole percent basis of the polymerizable monomers. These polymerizable compositions are useful as coatings, particularly in formulations containing a photoinitiator susceptible to ultra-violet radiation. The coating is exposed to ultra-violet radiation sufficient to cause the compound to polymerize and thus cure the coating.

FIELD OF THE INVENTION 
The present invention relates to polymerizable compounds and to their use. 
More particularly, it relates to N,N'-substituted piperazine acrylamide 
compounds and to processes of polymerizing these compounds, e.g. for 
preparing coatings. 
BACKGROUND OF THE INVENTION 
The use of N,N'-substituted piperazine is disclosed in a number of 
documents. U.S. Pat. No. 5,192,766 purports to disclose 
N-acryloylpiperazine derivatives and their pharmaceutical use as platelet 
activating factor antagonists. While the title uses the term 
N-acryloylpiperazine, it is clear from the disclosure that the compounds 
disclosed have a phenyl substituent bonded to the alpha,beta-unsaturated 
acylamido group such that the compounds are, thus, apparently cinnamoyl 
derivatives or homologues thereof. 
M. Taningher et al., "Genotoxicity of N-acryloyl-N'-phenylpiperazine, a 
Redox Activator for Acrylic Resin Polymerization", Mutation Research, vol. 
282, pp. 99-105 (1992) discusses the use of N-acryloyl-N'-phenylpiperazine 
as a promoter of redox reactions in place of other tertiary aromatic 
amines, e.g. N,N-dimethylaniline. It is speculated that the acryloyl group 
will allow the compound to be copolymerized into the final material and 
thus avoid release thereof into the environment. 
U.S. Pat. No. 5,045,427 discloses the use of a variety of polymerizable 
compounds, including N,N'-bis-acrylamido-piperazine, in a photographic 
material. This photographic material is comprised of a support on which is 
provided a light-sensitive layer comprised of a photosensitive silver 
halide, a non-photo-sensitive silver salt, a reducing agent, a color 
image-forming material and a polymerizable compound. 
EP-0356960 discloses polyacrylamide gels which employ as crosslinking 
agents diacylyl compounds with tertiary amide groups, e.g. diacrylyl 
piperazine (a.k.a. N,N'-bis-acrylamido-piperazine). These gels contain a 
chaotropic agent which permits the use of the gels in the separation of 
proteins or nucleic acids. 
U.S. Pat. No. 3,510,247 discloses the modification of cellulosic materials 
with tertiary bis-acrylamides, e.g. diacryloyl piperazine (a.k.a. 
N,N'-bis-acrylamido-piperazine). The bis-acrylamide is applied to the 
cellulosic substrate and a crosslinking reaction is catalyzed by the use 
of an alkaline compound and elevated temperatures, generally 200 degrees F 
to 350 degrees F. U.S. Pat. No. 3,528,964 discloses a similar 
modification, but the amides are sulfonic acid amides, wherein the 
sulfonic acid groups contain ethylenic unsaturation. 
The technology for the production of coatings by curing monomeric 
compositions on the surface of various substrates is generally known. For 
example, J. Lowell, "Coatings", Encyclopedia of Polymer Science and 
Engineering, vol.3, pp. 615-675, discusses, at page 647, the production of 
coatings by free-radical polymerization of monomers, e.g. unsaturated 
polyesters in a solution of an unsaturated monomer such as styrene, 
acrylates, and methacrylates, and polyfunctional low volatility monomers 
such as trimethylolpropane triacrylate. When such systems are cured with 
ultra-violet radiation, a photoinitiator such as benzophenone is often 
used to increase the production of free-radicals and thereby promote 
curing of the coating. 
While N,N'-bis-acrylamido-piperazine is a useful monomer in many 
applications, it has been found its performance as the major component of 
a radiation curable composition has certain drawbacks. For example, it has 
been observed that cured films thereof are quite brittle. 
SUMMARY OF THE INVENTION 
This invention relates to a composition of matter comprising a compound of 
the formula I: 
##STR2## 
wherein: R.sup.1, R.sup.2, and R.sup.3 are each independently selected 
from the group consisting of hydrogen and lower alkyl (preferably R.sup.1 
and R.sup.2 are hydrogen and R.sup.3 is hydrogen or methyl), 
B is a linking group selected from the group consisting of carbonyl, 
sulfonyl, amide, and carboxyl; 
n is one or zero; 
R.sup.4 is a radical selected from the group consisting of a higher 
aliphatic group (i.e. at least three carbon atoms, preferably from about 4 
to about 50 carbon atoms and more preferably about 7 to about 50 carbon 
atoms), a substituted higher aliphatic group, an alicyclic group, a 
heterocyclic group, a non-benzenoid aromatic group, and a substituted 
aromatic group (said substituted aromatic group preferably having an 
aliphatic group or a substituted aliphatic group as substituents, e.g. an 
alkyl group, an alkaryl group, an aralkyl group, an alkoxy group, an 
alkaryloxy group, an aralkoxy group, an acyl group or a carboalkoxy group 
(e.g. --C--(O)--O-alkyl), preferably each having at least four carbon 
atoms), wherein said composition is stable against gelation, i.e. does not 
gel (e.g. set to a solid mass) after an extended period of time, e.g. at 
least about 150 hours, at an elevated temperature, e.g. about 60.degree. 
C. It has been found that compositions which contain compounds of the 
above formula may contain sufficient concentrations of residual free amine 
compounds to cause the composition to gel when maintained at elevated 
temperatures for extended periods of time. Compositions which have been 
produced in such a way as to avoid the presence of such concentrations 
have been found to exhibit improved high temperature stability. 
A preferred class of compositions contain compounds within the scope of 
this invention having the formula II: 
##STR3## 
wherein each R.sup.1, R.sup.2 and R.sup.3 is independently selected from 
the group consisting and lower alkyl, 
each B and B' linking group is independently selected from the group 
consisting of carbonyl, sulfonyl, amide, and carboxyl; 
n and m are independently one or zero; 
R.sup.8 is a divalent radical selected from the group consisting of an 
aliphatic group, an alicyclic group, an aromatic group, and a heterocyclic 
group (preferably a higher alkylene group (i.e. at least four carbon 
atoms, preferably from about 5 to about 50 carbon atoms), a substituted 
higher alkylene group, an aryl group (preferably a phenyl group), an 
aralkyl group, and an alkaryl group. 
Another special class of compounds within the scope of this invention have 
the following formula III: 
##STR4## 
wherein the variables have the same meaning as set forth above and 
R.sup.17 is a polyvalent radical selected from the group consisting of an 
aliphatic group, an alicyclic group, an aromatic group, and a heterocyclic 
group (preferably an alkylene group, a substituted alkylene group, an 
aralkyl group, a substituted aralkyl group, an alkyleneoxyalkyl group, a 
substituted alkyleneoxyalkyl group, an alkyleneoxyaralkyl group, a 
substituted alkyleneoxyaralkyl group). 
Particularly preferred compounds of this invention are those wherein n is 
one (and B is preferably a carbonyl group) and R.sup.4 is an 
alkylene-amido group having the structure --R.sup.8 
--C(O)--N(R.sup.9)--R.sup.10 or an alkylene-ester group having the 
structure --R.sup.8 --C(O)--O--R.sup.11, wherein R.sup.8 is a divalent 
group selected from the group consisting of a higher alkylene group, a 
substituted higher alkylene group, an aromatic group, and a substituted 
aromatic group, and R.sup.9, R.sup.10, and R.sup.11 are independently 
selected from the group consisting of an aliphatic group, an alicyclic 
group, an aromatic group, and a heterocyclic group (preferably an alkyl 
group, a substituted alkyl group, an alkenyl group, a substituted alkenyl 
group, an aromatic group, and a substituted aromatic group), provided that 
R.sup.9 and R.sup.10 may together form a divalent alicyclic or 
heterocyclic radical, e.g. wherein R.sup.4 has the formula IV: 
##STR5## 
wherein R.sup.12 , R.sup.13, and R.sup.14 are independently selected from 
the group consisting of hydrogen and lower alkyl. 
This invention also relates to a polymerizable composition comprising a 
composition comprising a compound of formula I, above, and to a method of 
coating a substrate comprising (i) contacting a surface of a substrate 
with a polymerizable composition comprising a compound of formula I, 
above, and (ii) exposing said surface to radiation sufficient to cause 
said compound to polymerize in contact with said surface. In preferred 
methods, said compound is present in said composition in a major amount on 
a mole percent basis of all of the monomers of said polymerizable 
composition. 
DETAILED DESCRIPTION OF THE INVENTION 
This invention relates to novel compositions of this invention, e.g. 
compositions containing compounds of formula I, and to methods of making 
these novel compositions. These compounds are piperazine derivatives in 
which one of the amine nitrogen atoms of the piperazine molecule has been 
reacted with an acylating agent to introduce the acrylamido group (or a 
homologue thereof) which contains the groups R.sup.1, R.sup.2, and 
R.sup.3, and in which the other piperazine nitrogen atom has been reacted 
with a compound to introduce the R.sup.4 group (and optionally a B linking 
group) into the molecule. Thus, one of the starting materials for 
preparing the novel compounds of this invention is piperazine, or a 
derivative thereof (e.g. an amide that is susceptible to trans-amidation). 
Because piperazine has secondary amine groups, there is a possibility that 
compositions prepared therefrom will contain residual free secondary 
amine, e.g. from unreacted piperazine or a piperazinyl-functional 
intermediate. It is believed that the presence of even small amounts of 
such impurities can lead to gelation of compositions which contain 
compounds of formula I. Such gelation is believed to be caused by reaction 
of the residual free secondary amine with the ethylenic unsaturation of 
the compounds of formula I. 
The composition of the invention should not gel when held at a temperature 
of 60.degree. C. for an extended period of time, preferably at least about 
150 hours, more preferably at least about 175 hours, and even more 
preferably at least about 200 hours. The compositions of this invention 
will typically not gel after at least 300 hours at 60.degree. C. and most 
preferably at least about 450 hours. 
A means of evaluating the stability of the compositions of this invention 
with respect to gelation is to subject the composition to heat aging and 
to measure the viscosity of the aged composition. For example, the 
viscosity of the composition is measured, e.g. at an ambient temperature 
of 25.degree. C. Then, the composition is aged by placing it in an oven at 
60.degree. C. After aging and cooling to an ambient temperature of 
25.degree. C., the viscosity of the composition is then measured again. If 
there is a significant increase in the viscosity of the composition after 
such aging, the composition thus shows a tendency to gel. Preferably, the 
composition will show an increase in viscosity of less than 100%, more 
preferably less than 50%, and even more preferably less than 20%, after a 
period at 60.degree. C. of at least about 3 hours, more preferably, at 
least about 24 hours and even more preferably at least about 150 hours. 
Ideally, the composition will show no increase in viscosity that is 
measurable within the limits of detection of the apparatus and procedure 
chosen after being held for more than 150 hours at 60.degree. C. An 
example of a useful viscometer is a cone and plate viscometer available as 
the Carri-Med CSL Rheometer, distributed by Mitech Corp., Twinsburg, Ohio, 
and manufactured by Carri-Med Ltd., Dorking, Surrey, UK. 
Because of the presence of free secondary amine groups which is thought to 
cause gelation of compositions containing compounds of this invention, it 
is believed that methods of making the compositions of this invention 
which minimize the presence of residual free secondary amine will be 
useful in preparing compositions of this invention. Such methods include 
the use of a catalyst, as discussed more fully below, for the reactions 
which consume the free secondary amine functionality of the piperazine 
starting material and/or piperazinyl intermediate. 
Also, techniques to reduce the reactivity of the mixture, such as the 
inclusion of polymerization inhibitors in the composition. A preferred 
polymerization inhibitor in this regard is phenothiazine. Quinones, e.g. 
methyl hydroquinone is also useful as an inhibitor, but the mechanism of 
inhibition of quinones such as methyl hydroquinone requires the presence 
of oxygen for effective inhibition and it may not be practical to maintain 
sufficient levels of oxygen in the compositions to allow the use of such 
inhibitors. 
The group R.sup.4 is an aliphatic, substituted aliphatic, non-benzenoid 
aromatic, or substituted aromatic radical having at least four carbon 
atoms, preferably from 4 to about 50 carbon atoms. Such aliphatic radicals 
include any (a) straight chain and branched alkyl radicals having from 4 
to about 50 carbon atoms; (b) cycloalkyl radicals having from 4 to about 
20 carbon atoms; (c) straight chain and branched alkenyl radicals having 
from 4 to about 40 carbon atoms; (d) cycloalkenyl radicals having from 5 
to about 20 carbon atoms; (e) straight chain and branched alkynyl radicals 
having from 4 to about 30 carbon atoms; cycloalkynyl radicals having from 
6 to about 20 carbon atoms. Aliphatic radicals also include those 
above-mentioned aliphatic radicals which contain one or more heteroatoms 
substituted for one or more hydrogen or carbon atoms. The heteroatoms 
include the halogens, nitrogen, sulfur, oxygen, and phosphorus or groups 
of heteroatoms such as nitro, sulfonic acid, C.sub.1-10 alkyl sulfonate 
ester, sulfoxide, sulfone, phosphoryl, trihalomethyl, and the like. 
An aromatic radical is any benzenoid or non-benzenoid aromatic radical 
having a valence of 2 to 8. A non-benzenoid aromatic radical excludes 
simple phenyl groups, but includes aromatic, polynuclear aromatic, other 
carbocyclic aromatic radicals (e.g. those having cycloaliphatic groups), 
and heterocyclic aromatic radicals. For purposes of this invention, a 
substituted aromatic radical is any benzenoid or non-benzenoid aromatic 
radical having a valence of from 2 to 6 wherein one or more hydrogen atoms 
is replaced by an atom or a group of atoms other than hydrogen including 
the alkyl, alkenyl, alkoxy, halogens, nitrogen, sulfur, oxygen, and 
phosphorus or groups of heteroatoms such as nitro, sulfonic acid, 
C.sub.1-10 alkyl sulfonate ester, sulfoxide, sulfone, phosphoryl, 
trihalomethyl, and the like. Such an aromatic radical also includes those 
radicals which contain other aliphatic moieties, aromatic groups, and/or 
hetero atoms. 
In preferred embodiments, R.sup.4 has at least seven carbons and, in more 
preferred embodiments, is ethylenically unsaturated. This ethylenic 
unsaturation should be copolymerizable with the acrylamido group defined 
by R.sup.1, R.sup.2, and R.sup.3, e.g. an acrylamido group. The size of 
the group will affect the physical properties of a polymer prepared 
therefrom such that a larger R.sup.4 group will impart different physical 
properties than a smaller group. For example, a higher alkyl group as (or 
part of) the R.sup.4 group will tend to impart greater flexibility to the 
polymer. 
The B linking group, if present, is introduced into the molecule by the 
derivatization of one of the piperazine nitrogen atoms. The B linking 
group is a carbonyl, sulfonyl, amide, or carboxyl group, i.e. a group 
having the respective formula: 
##STR6## 
In each respective case, the compound will then have at that piperazine 
nitrogen atom an amide functionality, a sulfonamide functionality, a 
substituted-urea functionality, or a urethane functionality. Because the 
piperazine nitrogen atom can be covalently bonded to the R.sup.4 group 
directly, a B linking group may not be present and, thus, n may be zero 
(in which case there will be a tertiary amine functionality at that 
piperazine nitrogen atom). 
To prepare the compounds of this invention, piperazine is reacted with two 
different derivatizing agents, the identity of each being determined by 
the desired structures of R.sup.1, R.sup.2, and R.sup.3, and R.sup.4 (and 
the B linking group, if present), and the leaving group (if any) in these 
derivatization reactions. Thus, one of the derivatizing agents will have 
the following formula VI: 
##STR7## 
wherein R.sup.1, R.sup.2, and R.sup.3 are as defined above and X is a 
leaving group (e.g. a halogen such as chlorine or another displacable 
anion-forming atom or group, e.g. a carboxylate group when the acylating 
agent is an acid anhydride). The other agent will have the formula VII: 
##STR8## 
wherein R.sup.4 is as defined above and X' is a leaving group (e.g. as set 
forth above). Of course, when the derivatizing agent is an isocyanate, 
i.e. that used to form a substituted-urea functionality, there is no 
"leaving group" as such in the strictest sense because the nitrogen atom 
of the isocyanate reactant, does not leave the molecule. 
The reactions of the piperazine compound and the derivatizing agents may be 
conducted sequentially or simultaneously, depending on whether the two 
acylating agents are compatible. In a simultaneous reaction, both agents 
will be mixed with the piperazine compound under conditions which will 
cause the reaction to proceed as follows in scheme 1: 
##STR9## 
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, X and X' are as defined above. 
If one of the derivatizing agents has a higher reactivity for piperazine 
than the other derivatizing agent and this higher reactivity cannot be 
practicably compensated for (e.g. by adjusting the ratio of derivatizing 
agents in the reaction mixture), or if the derivatizing agents will react 
with each other to any degree that will provide an unacceptable by-product 
(e.g. if R.sup.8 contains a hydroxyl or amine group susceptible to 
acylation), then the reactions will be performed sequentially. For 
example, if R.sup.4 contains a hydroxyl or amine function, then a reaction 
sequence according to scheme 2 may be employed: 
##STR10## 
wherein R.sup.15 and R.sup.16 are hydrogen or an organic group susceptible 
of displacement in the acylating reaction and the other groups are as 
defined above. 
The reaction to introduce the acrylamide functionality into the molecule is 
an acylation reaction. Acylation techniques for amide formation are 
generally described in Encyclopedia of Chemical Technology, vol. 2, pp. 
252-258 (Kirk-Othmer, eds., John Wiley & Sons, Inc., N.Y., N.Y., 1978), 
and in R. Larock, Comprehensive Organic Transformations: A Guide to 
Functional Group Preparations, pp. 978 and 979 (VCH Publishers, N.Y., 
N.Y., 1989) the disclosures of which are incorporated by reference. In the 
acylation of an amine, an acylating compound of the desired molecular 
formula with a leaving group is reacted with the amine compound. For 
example, a carboxylic acid, acid anhydride or acid halide (e.g., chloride, 
of acrylic or methacrylic acid) is reacted with the amine, or derivative 
thereof, optionally in the presence of a catalyst, e.g. 
N,N-dimethylaminopyridine (typically in an amount of from about 0.001% to 
about 5%, more typically from about 0.01% to about 2% by weight of the 
combined weight of the reactants). When the carboxylic acid form of the 
acylating agent (i.e. leaving group is a hydroxyl group) is used, a strong 
acid catalyst, e.g. p-toluenesulfonic acid, is typically employed. 
The reaction is typically accomplished in an inert solvent, but the 
catalyst or one of the reactants may also act as a solvent. Because 
piperazine is hydrophilic, but the reaction product tends to be less so, 
the choice of solvent and reaction conditions can affect the efficiency of 
the reaction. Generally, it has been found that an organic solvent having 
a greater polarity than an aromatic solvent (e.g. toluene) is preferred, 
for example, a mixture of acetonitrile and dichloromethane (e.g. 1:1 by 
volume) is a preferred solvent. 
Because piperazine is a secondary amine, an acylating agent with a more 
labile leaving group (e.g. an acid halide wherein the leaving group is a 
halogen anion such as chloride) is preferred. With such a leaving group, a 
hydrohalic acid (e.g. hydrochloric acid) is a by-product of the reaction, 
and thus, an alkaline material should be added to the reaction mixture to 
neutralize by-product acid. It has been found that inorganic alkaline 
materials, e.g. alkali metal carbonates, are less preferred due to 
problems associated with product isolation and that lower alkyl tertiary 
amine bases (having the formula NR.sup.1 R.sup.2 R.sup.3 wherein R.sup.1, 
R.sup.2, and R.sup.3 are independently C.sub.1 to C.sub.4 alkyl, e.g. 
triethylamine) are useful in neutralizing acid formed during an acylation 
reaction which employs an acyl halide as the acylating agent. 
It should also be noted that when an ester functional compound is prepared 
as a result of the use of an anhydride as an acylating agent (e.g. when 
phthalic anhydride is used as an acylating agent to introduce the R.sup.4 
group into the molecule), the leaving group will be a carboxyl anion that 
is covalently bonded to R.sup.8. Thus, the carboxyl group must, in this 
case, be esterified to introduce the R.sup.11 group into the molecule. 
Conventional esterification techniques which employ an alcohol having the 
formula R.sup.11 --OH, or an ester thereof that is susceptible to 
transesterification, will be useful to esterify the carboxyl anion that is 
created upon the opening of the anhydride linkage. Alternatively, the 
alcohol R.sup.11 --OH can be reacted with an anhydride to prepare an 
intermediate that has both ester and carboxyl functionality. The carboxyl 
functionality of this intermediate can then be used as an acylating agent 
in schemes 1 and 2. If the alcohol R.sup.11 --OH is a polyol, then the 
reaction of a molar amount of the anhydride equal to the polyol 
functionality can be used to prepare an intermediate that has sufficient 
carboxyl functionality to introduce a piperazine functionality into the 
molecule that is equal to the polyol functionality, followed by reaction 
of the n-functional piperazine intermediate with a derivatizing agent of 
formula VI to introduce one or more ethylenic unsaturations into the 
molecule, i.e. as set forth in the following scheme: 
##STR11## 
wherein R.sup.19 is the residue of an organic dicarboxylic acid anhydride. 
Examples of the anhydrides that can be used as an acylating agent (or 
half-esters thereof) include substituted succinic anhydrides which are 
preferred due to their low viscosity at room temperature. The low 
viscosity at room temperature leads to advantages in the final product 
(i.e. liquid final products) as well as in the synthetic procedure (i.e. a 
stirrable liquid that can serve as a reactant and thus provide a liquid 
reaction medium without the addition of a solvent). Preferred substituted 
succinic anhydrides are the alkyl- or alkenyl-substituted succinic 
anhydrides, e.g. n-octenyl succinic anhydride, n-nonenyl succinic 
anhydride, dodecenyl succinic anhydride, and iso-octadecenyl succinic 
anhydride. 
The choice of the reactant X--(B).sub.n --R.sup.4 will determine the nature 
of the B linking group that is introduced into the molecule. When there is 
no B linking group, the reactant will typically be an alkyl halide or an 
aryl alkaline earth metal halide (e.g. the Grignard reagent phenyl 
magnesium bromide). Alkylation of amines is discussed in Encyclopedia of 
Chemical Technology, vol. 2, pp. 67 and 68 (Kirk-Othmer, eds., John Wiley 
& Sons, Inc., N.Y., N.Y., 1978), the disclosure of which is incorporated 
by reference. When the B linking group is a carbonyl group, the reactant 
will typically be an acid halide and the product can be characterized as a 
acylamide. Acylation reactions are discussed in Encyclopedia of Chemical 
Technoloay, vol. 2, pp. 252-258 (Kirk-Othmer, eds., John Wiley & Sons, 
Inc., N.Y., N.Y., 1978), the disclosure of which is incorporated by 
reference. When the B linking group is a sulfonyl group, the reactant will 
typically be a sulfonyl halide and the product can be characterized as a 
sulfonamide. The reaction to form a sulfonamide is very similar to an 
acylation reaction. The synthesis of sulfonamides is discussed in 
Encyclopedia of Chemical Technology, vol. 2, pp. 795 and 803-806 
(Kirk-Othmer, eds., John Wiley & Sons, Inc., N.Y., N.Y., 1978), the 
disclosure of which is incorporated by reference. 
As discussed above, when the B linking group is an amide, the reactant will 
typically be an isocyanate. The synthesis of urea compounds by the 
reaction of an amine with an isocyanate is discussed in Encyclopedia of 
Chemical Technology, vol. 12, pp. 319-321 (Kirk-Othmer, eds., John Wiley & 
Sons, Inc., N.Y., N.Y., 1980), the disclosure of which is incorporated by 
reference. 
Further, when the B linking group is a carboxylate group such that the 
compound has a urethane functionality, a reaction sequence as shown in 
scheme 3, below will be useful: 
##STR12## 
wherein all of the variables are as set forth above and R.sup.18 is a 
group susceptible to transesterification, e.g. an alkoxy group or an 
aryloxy group, preferably lower alkoxy (e.g. a methoxy group). 
Transesterification reactions are generally known. They are typically 
catalyzed by a base (e.g. alkali) or an acid and are governed by 
principles of mass transfer so that the reaction can be driven to 
substantial completion by removal of the by-product alcohol R.sup.18 --OH 
(e.g. by distillation). Transesterification reactions are discussed in 
Encyclopedia of Chemical Technology, vol. 9, pp. 306-308 (Kirk-Othmer, 
eds., John Wiley & Sons, Inc., N.Y., N.Y., 1980), the disclosure of which 
is incorporated by reference. 
In the special case where R.sup.4 has the formula IV, i.e. there are two 
piperazine groups in the molecule, it is convenient to employ the 
following scheme 4 to prepare the compound: 
##STR13## 
wherein the groups are selected as set forth above. It should be noted 
that the R.sup.1, R.sup.2, and R.sup.3 groups on each end of the molecule 
need not be the same, i.e. if, for example, a mixture of acryloyl chloride 
and methacryloyl chloride are used to acylate the di-piperazine 
intermediate in scheme 4 above, the R.sup.1, R.sup.2, and R.sup.3 groups 
on one end of the molecule will differ from the R.sup.1, R.sup.2, and 
R.sup.3 groups on the other end of the molecule. The R.sup.8 group is 
derived from a di-carboxylic acid compound, preferably a di-carboxylic 
acid having a higher alkylene group between the acid groups, or a reactive 
derivataive thereof, e.g. an anhydride, an acid halide, or 
transesterifiable ester thereof. Examples of diacids include aliphatic 
diacids, e.g. succinic acid and substituted succinic acids (as described 
below, and aromatic diacids, e.g. phthalic acid. Preferred diacids having 
a higher alkylene chain are described in Encyclopedia of Polymer Science 
and Technology, vol. 11, pp. 476-489, (John Wiley & Sons, Inc. N.Y., N.Y., 
1988), the disclosure of which is incorporated herein by reference. Such 
preferred diacids include dimer acids (produced by the dimerization of 
fatty acids that results in an R.sup.8 group which is a divalent 
hydrocarbon, e.g. oleic acid that results in an R.sup.8 group which is a 
divalent hydrocarbon having 36 carbon atoms), tridecanedioc acid (produced 
by the ozonolysis of erucic acid), C.sub.19 diacid (produced by the 
hydroformylation of oleic acid with carbon monoxide) and C.sub.21 diacid 
(produced by the reaction of tall oil fatty acid with acrylic acid). The 
preferred diacids are dimer acids. Dimer acids are also described in 
detail in U.S. Pat. No. 5,138,027 (Van Beek), the disclosure of which is 
incorporated herein by reference. The compounds of formula II can be 
considered compounds of formula I wherein R.sup.4 is a substituted 
aliphatic group, e.g. when R.sup.8 is derived from a dimer acid such that 
R.sup.4 is a higher alkyl group substituted with an 
acrylamido-piperazinyl-carbonyl group. 
In the special case of compounds of formula III, i.e. there are two 
piperazine groups in the molecule and an R.sup.17 group, it is convenient 
to employ the following scheme 5 to prepare the 
N,N'-diacylamido-piperazine compound: 
##STR14## 
wherein the groups are selected as set forth above. It should be noted 
that the R.sup.1, R.sup.2, and R.sup.3 groups on each end of the molecule 
need not be the same; if, for example a mixture of acryloyl chloride and 
methacryloyl chloride are used to acylate the di-piperazine intermediate 
in scheme 5 above, the R.sup.1, R.sup.2, and R.sup.3 groups on one end of 
the molecule will differ from the R.sup.1, R.sup.2, and R.sup.3 groups on 
the other end of the molecule. The reactant HO--R.sup.17 --OH is a polyol 
reactant. Examples of polyols are polyalkyleneoxy compounds, e.g. those 
described in Encyclopedia of Polymer Science and Technology, vol. 6, pp. 
225-322 (John Wiley & Sons, Inc., N.Y., N.Y. 1986), the disclosure of 
which is incorporated herein by reference. Preferred polyols are 
alkyleneoxyalkyl or alkyleneoxyaralkyl compounds having at least two free 
hydroxyl groups. Examples of alkyleneoxyalkyl compounds are ethoxylated 
and/or propoxylated lower alkane polyols, e.g. propoxylated 
trimethylolpropane (e.g. Photonol PHO-7072), ethoxylated 
trimethylolpropane (e.g. Photonol PHO-7149, Photonol PHO-7155, and 
Photonol PHO-7158), propoxylated glycerol (e.g. Photonol PHO-7094), 
propoxylated neopentylglycol (e.g. Photonol PHO-7127), and ethoxylated 
neopentylglycol (e.g. Photonol PHO-7160). Examples of alkyleneoxyaralkyl 
compounds are ethoxylated and/or propoxylated alkylpolyphenols, e.g. 
propoxylated bisphenol A (e.g. Photonol PHO-7020) and ethoxylated 
bisphenol A (e.g. Photonol PHO-7025, and Photonol PHO-7028). All of these 
Photonol products are available commercially from Henkel Corporation, 
Ambler, Pa. 
The polymerizable components useful in this invention are any materials 
which are capable of addition copolymerization with the 
N,N'-diacylamido-piperazine compounds of formula I described above to form 
a useful polymer composition. The polymerization of acrylamide monomers is 
discussed in Encyclopedia of Polymer Science and Engineering, vol. 1, pp. 
169-211 (John Wiley & Sons, Inc., N.Y., N.Y., 1985), the disclosure of 
which is incorporated by reference. The polymerizable components include 
mono-ethylenically unsaturated monomers capable of homopolymerization, or 
copolymerization with other ethylenically unsaturated monomers, as well as 
copolymerization with the compound. Examples of suitable 
mono-ethylenically unsaturated compounds include alkyl acrylates, alkyl 
methacrylates, vinyl esters, vinyl amines and vinyl aromatic compounds. 
Specific examples include ethyl acrylate, t-butyl acrylate, 2-ethylhexyl 
acrylate, methyl methacrylate, lauryl methacrylate, vinyl acetate, N-vinyl 
pyrrolidinone, styrene, and vinyl toluene. 
Polymerizable compounds which may be used in the present invention are 
addition-polymerizable monomers and oligomers and polymers thereof. 
Addition-polymerizable monomers are compounds having one or more 
carbon-carbon unsaturated bonds. Examples of the compounds are acrylic 
acid and salts thereof, acrylates (e.g. lower alkyl acrylates), 
acrylamides (e.g. lower N-alkyl acrylamides), methacrylic acid and salts 
thereof, methacrylates, methacrylamides, maleic anhydride, maleates, 
itaconates, styrenes, vinyl ethers, vinyl esters, N-vinyl-heterocyclic 
compounds, allyl ethers, and allyl esters and derivatives thereof. 
In addition, a crosslinking compound having an activity of increasing the 
degree of hardening or the viscosity of the formed polymeric compounds, by 
crosslinking the polymeric coating, can be employed. Such crosslinking 
compounds are so-called poly-functional monomers having a plurality of 
ethylenic or vinyl groups or vinylidene groups in the molecule. This 
addition will be especially useful if the N,N'-substituted 
acylamido-piperazine compound chosen has only one ethylenic unsaturation, 
e.g. N-(o-alkyl-phthalamido), N'-acrylamido-piperazine. 
Examples of a number of the various polymerizable compounds which may be 
included in the polymerizable compositions of the present invention 
include acrylic acid, methacrylic acid, butyl acrylate, methoxyethyl 
acrylate, butyl methacrylate, acrylamide, N, N-dimethylacrylamide, N, 
N-diethylacrylamide, N-acrylamido-morpholine, N-acrylamido-piperidine, 
glycidyl acrylate, 2-ethylhexyl acrylate, acrylic acid anilide, 
methacrylic acid anilide, styrene, vinyltoluene, chlorostyrene, 
methoxystyrene, chloromethylstyrene, 1-vinyl-2-methylimidazole, 
1-vinyl-2-undecylimidazole, 1-vinyl-2-undecylimidazoline, 
N-vinylpyrrolidone, N-vinylcarbazole, vinylbenzyl ether, vinylphenyl 
ether, methylene-bis-acrylamide, trimethylene-bis-acrylamide, 
hexamethylene-bis-acrylamide, N, N'-diacrylamidopiperazine, 
m-phenylene-bis-acrylamide, p-phenylene-bis-acrylamide, ethylene glycol 
diacrylate, propylene glycol dimethacrylate, diethylene glycol diacrylate, 
polyethylene glycol diacrylate, bis(4-acryloxypolyethoxyphenyl)propane, 
1,5-pentanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol 
acrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate, 
trimethylolpropane triacrylate, pentaerythritol tetraacrylate, 
N-methylol-acrylamide, diacetone-acrylamide, triethylene glycol 
dimethacrylate, pentaerythritol tetra-allyl ether. 
Examples of useful reactive oligomers include low molecular weight polymers 
(e.g., about 1,000 to 25,000 g/mole) having polymerizable ethylenic 
unsaturation. Specific examples include maleic-fumaric unsaturated 
polyesters, acrylate-terminated polyesters (e.g. those described in U.S. 
Pat. No. Re 29,131 to Smith et al.) acrylic copolymers having pendant 
vinyl unsaturation (e.g. allyl acrylate/acrylic copolymers), epoxy 
acrylates, and polyurethane acrylates. 
Examples of useful reactive polymers include graft polymerizable 
polyolefins, e.g., polyethylene, polypropylene, and ethylene/propylene 
copolymers, and polymers having polymerizable ethylenic unsaturation along 
the backbone, for example diene homopolymers or copolymers (e.g., 
styrene-butadiene copolymers, cis-polybutadiene, and 
butadiene-acrylonitrile copolymers). 
The polymerizable component and N,N'-acylamido-piperazine compound can be 
mixed in any convenient manner which will place the component and compound 
in a sufficiently reactive association to form a polymer on subsequent 
curing thereof. Generally, simple mixing of the polymerizable component 
and N,N'-acylamido-piperazine compound will suffice. Other useful 
techniques include conventional wet chemistry techniques, e.g., 
dissolution in a common solvent system. 
The amount of the N,N'-acylamido-piperazine compound in the polymerizable 
composition will vary depending upon the contemplated application of the 
cured polymeric composition, but will generally be sufficient to 
detectably affect the properties of the polymer and/or crosslink the 
polymeric composition. The affect on the properties of the polymer and/or 
degree of crosslinking of the cured polymeric composition can be 
determined by conventional techniques, e.g., adhesion to substrates, 
resistance to solvents (e.g., swelling, extractibles, and/or 
spot-testing). In preferred compositions, the amount of a 
diacrylamido-piperazine compound will be sufficient to measurably increase 
the gel content of the cured polymeric composition, e.g., preferably by at 
least about 1% and more preferably at least about 5%. Typical levels of 
N,N'-acylamido-piperazine compound that have only one ethylenic 
unsaturation will range from about 5 mole % to about 90 mole %, preferably 
from about 10 mole % to about 50 mole %, of the polymerizable components 
of the polymerizable composition. 
The polymerizable composition of the present invention can be applied to a 
variety of substrates. These include, for example, porous stock such as 
paper and cardboard, wood and wood products, metals such as aluminum, 
copper, steel, and plastics such as P.V.C., polycarbonates, acrylic and 
the like. After addition of a suitable photoinitiator, e.g., PHOTOMER 
51.RTM. brand photoinitiator (benzyl dimethyl ketal), the compositions are 
applied by methods such as spraying, rollcoating, flexo and gravure 
processes onto a selected substrate. The resulting coated substrate, e.g., 
a paper, is typically cured under a UV or electron beam radiation. The 
compositions may optionally include other substances such as pigments, 
resins, monomers and additives such as anti-oxidants and rheological 
modifiers. For example, flow and levelling agents, e.g. BYK-307 and/or BYK 
310, available form BYK-Chemie USA, Wallingford, Conn., can be used to 
modify the coating characteristics of the polymerizable composition. 
Methods of coating and materials used in coatings are described in 
Encyclopedia of Polymer Science and Engineering, vol. 3, pp. 552-671 and 
supp. vol., pp. 53, 109 and 110 (John Wiley & Sons, Inc., N.Y., N.Y., 
1985), the disclosure of which is incorporated by reference. 
The coated surface is then exposed to sufficient energy, e.g. heat or 
electromagnetic radiation to cure the composition through the reactive pi 
bonds. Suitable sources of radiation include ultraviolet light, electron 
beam or radioactive sources such as are described in U.S. Pat. No. 
3,935,330 issued Jan. 27, 1976 to Smith et al. To enhance the rate of 
curing free radical initiators may be included in the composition such as 
benzoin, benzoin ethers, Michier's Ketone and chlorinated polyaromatic 
hydrocarbons. Other free radical initiators are ordinarily organic 
peroxides, hydroperoxides, peroxy acids, peroxy esters, azo compounds, 
ditertiary butyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, 
tertiary butyl hydroperoxide, 1,5-dimethyl-2,5-bis (hydroperoxy)-hexane, 
peroxyacetic acid, peroxybenzoic acid, tertiary butyl peroxypivalate, 
tertiary butyl peroxyacetic acid and azobisisobutyronitrile. The free 
radical initiator is typically present at from about 0.01 to about 20% by 
weight of the radiation curable components. To ensure that the composition 
does not prematurely polymerize, a free radical inhibitor may be added to 
the polymerizable composition. Examples of suitable inhibitors include 
hydroquinone and the methyl ether thereof or butylated hydroxy toluene at 
a level of from about 5 ppm to about 2000 ppm by weight of the 
polymerizable components. 
Particularly preferred sources of radiation emit electromagnetic radiation 
predominantly in the ultra-violet band. When such a source is used, the 
polymerizable composition preferably contains a photoinitiator susceptible 
to ultra-violet radiation, e.g. benzoin, benzoin ethers, alpha, 
alpha-dimethoxy-alpha-phenylacetophenone, diethoxyacetophenone, 
alpha-hydroxy-alpha,alpha-dimethylacetophenone, and 1-benzoylcyclohexanol. 
The amount of radiation necessary to cure the composition will of course 
depend on the angle of exposure to the radiation, the thickness of the 
coating to be applied, and the amount of polymerizable groups in the 
coating composition, as well as the presence or absence of a free radical 
initiating catalyst. For any given composition, experimentation to 
determine the amount of radiation sensitive pi bonds not cured following 
exposure to the radiation source is the best method of determining the 
amount and duration of the radiation required. Typically, an ultra-violet 
source with a wavelength between 200 and 300 nm (e.g. a filtered mercury 
arc lamp) is directed at coated surfaces carried on a conveyor system 
which provides a rate of passage past the ultra-violet source appropriate 
for the radiation absorption profile of the composition (which profile is 
influenced by the degree of cure desired, the thickness of the coating to 
be cured, and the rate of polymerization of the composition). 
The polymerizable compositions of this invention may also find use as a 
starting material for applications in addition to coatings. Particular 
examples include articles formed by the shaping (e.g. casting, molding, or 
extrusion) of polymeric materials, as well as binders (e.g. for pigments 
of printing inks, magnetic media, etc.), or by use of the composition as 
an adhesive or sealant. Further, steric polymerization techniques as 
described by E.J. Murphy et al., "Some Characteristics of Steric 
Polymerization", Proceedings of RadTech 1990--North America, vol. I, pp. 
217-226, the disclosure of which is incorporated herein by reference, may 
be useful. In such techniques, where a pool of polymerizable composition 
is subjected to a focused laser beam of ultra-violet radiation, an object 
is formed within the pool from discrete thin layers formed at the top of 
the pool where the laser beam is focused. In a sense, the composition 
polymerizes in contact with the surface of a layer of cured polymer. The 
particular procedures used and the choice of the other necessary or 
desirable starting materials, catalysts, and other functional additives, 
as well as the amount of N,N'-acylamido-piperazine compound, will be 
within the skill of the art within which the crosslinked polymeric 
composition is employed. 
U.S. Ser. No. 08/242,797, filed May 19, 1994, U.S. Pat. No. 5.565.567 which 
is a continuation-in-part of U.S. Ser. No. 08/073,014, filed Jun. 4, 1993, 
now abandoned, the disclosures of which are incorporated herein by 
reference, discloses acrylamido-piperazine compounds useful in radiation 
curable coatings.

The following examples will serve to further illustrate the invention, but 
should not be construed to limit the invention, unless expressly set forth 
in the appended claims. All parts, percentages, and ratios are by weight 
unless otherwise indicated in context. 
EXAMPLES 
Coating Procedures and Apparatus 
In the following examples, coatings were prepared by the following 
procedure. The substrates used, unless noted otherwise, were aluminum 
panels available commercially as Q-panels from Q-Panel Corporation, and 
are coated using RDS Coating Rods. The curing apparatus was a Fusions 
Systems Model F440 with a 300 watt/inch mercury bulb. The variables in the 
tests include the speed of the belt which transports the substrate under 
the bulb, the number of passes the substrate makes under the bulb, and the 
thickness of the coating on the substrate, and variations in the coating 
formulation, e.g. type and amount of additives and co-monomers, which will 
be noted below. 
Example 1 
The compound N-acrylamido-N'-(n-butyl phthalamido)-piperazine was prepared 
using the specific procedure set forth therebelow. The compound was then 
used to form a coating by the procedure set forth below. 
Procedure for the Synthesis of Phthalic Piperazine Amide Acid 
Into a 3 liter, four-necked round-bottom flask fitted with mechanical 
stirring, dry nitrogen and a reflux condenser were charged 129.2 grams 
piperazine, 750 ml dichloromethane, 750 ml acetonitrile, and 6.1 grams 
dimethylaminopyridine. To this mixture was added portion-wise 222.2 g 
phthalic anhydride. Following the addition, the mixture was refluxed for 3 
hours, at the end of which period no residual anhydride was present by 
infrared analysis. The solvent was decanted from the solid product 
precipitate. 
Procedure for the Synthesis of Phthalic Piperazine Amide Acid Butyl Ester 
To the precipitated product from the previous procedure were added 150 ml 
12N HCl, 200 ml n-butanol, and 7.1 g p-toluenesulfonic Acid. A Dean-Stark 
trap was attached to the reflux condenser, and the reaction mixture was 
heated to reflux. The mixture was refluxed for 15 hours, at which time 
infrared analysis showed extensive conversion to the butyl ester, and TLC 
showed a single product using 1:1 methanol-water as eluent. The ester 
product was separated from the residual n-butanol by pressure filtration. 
Procedure for the Synthesis of Phthalic Piperazine Acrylamide Butyl Ester 
Into a 3 liter, four-necked round-bottom flask fitted with a reflux 
condenser dry air, and mechanical stirring, were charged 324 g of the 
ester from the previous procedure, 500 ml acetonitrile, 250 ml 
dichloromethane, 253 g triethylamine, 3.0 g dimethylaminopyridine, and 
0.21 g hydroquinone monomethyl ether. The mixture was cooled in an ice 
bath, and 100 g acryloyl chloride was added dropwise over a period of two 
and one half hours, with the addition rate sufficient to maintain a 
reaction temperature of 0-10 degrees C. The mixture was then allowed to 
warm to ambient temperature and stirred for an additional 90 minutes. The 
reaction mixture was then filtered through a Buchner funnel to remove 
undissolved solids. The resultant solution was washed with 1N HCl to 
remove unreacted triethylamine, dried with anhydrous sodium sulfate, and 
stripped of solvent under reduced pressure. 
Procedure for Coating with Phthalic Piperazine Acrylamide Butyl Ester 
A coating formulation was prepared by mixing 93 parts by weight of the neat 
phthalic piperazine acrylamide butyl ester, and 7 parts by weight of a 
photoinitiator blend consisting of 4 parts by weight of Darocure 1173, a 
photoinitiator available from Ciba-Geigy, Hawthorne, N.Y., 2 parts by 
weight of Photomer 81, a liquid form of benzophenone available from Henkel 
Corporation, Ambler, Pa., and 1 part by weight of triethanolamine. This 
composition was coated at 6.86 micrometers thickness and cured in one pass 
at 100 ft./min. The resulting coating exhibited a pencil hardness of 2H 
and dissolved with two methyl ethyl ketone (MEK) rubs. The resistance to 
MEK could be improved by the inclusion of a di-ethylenically unsaturated 
monomer, e.g. N,N'-bis-acrylamido piperazine. 
Example 2 
The compound bis-(N'-acrylamido-piperazinyl) dimer acid amide was prepared 
using the specific procedures set forth therebelow. The compound was then 
used to form a coating by the procedure set forth below. 
Procedure for the Synthesis of EMPOL 1008 Acid Chloride 
Into a 1 liter, four-necked round-bottom flask fitted with a magnetic 
stirrer, reflux condenser, thermometer, and dry nitrogen were charged 
250.0 grams of EMPOL 1008, 250 ml hexane, and 2 ml dimethylformamide. To 
the stirred mixture was added 115.7 g thionyl chloride dropwise through an 
addition funnel over a period of 30 minutes. No exotherm was noted, 
however significant bubbling was noted. Infrared spectroscopic analysis of 
the reaction mixture showed approximately 50% conversion to the acid 
chloride after 1 hour, with complete conversion after stirring the mixture 
overnight. 
Procedure for the Synthesis of EMPOL 1008 Piperazine Amide 
Into a 2 liter, four-necked round-bottom flask fitted with a Dean-Stark 
trap, reflux condenser, and mechanical stirrer were charged 1000 ml 
toluene, 152.3 grams piperazine, and 134.4 grams potassium carbonate. The 
mixture was refluxed for 30 minutes to dry the reactants. The reaction 
mixture was then cooled to 10 degrees C. in an ice bath, and 250 ml 
dichloromethane was added to aid stirring. The Empol 1008 acid chloride 
was added dropwise through an addition funnel at a rate sufficient to 
maintain a reactant temperature of 10-15 degrees C. Following the 
addition, the mixture was allowed to warm to ambient temperature and 
stirred overnight. This material was then immediately converted to the 
acrylamide. 
Procedure for the Synthesis of EMPOL 1008 Piperazine Acrylamide 
To the stirred reaction flask of the previous procedure was added 201.5 
grams potassium carbonate. The reaction mixture was cooled in an ice bath 
to 12 degrees C., and 132.0 grams acryloyl chloride was added dropwise 
over a period of 1 hour, maintaining a reactant temperature of 8-10 
degrees C. The reaction mixture was pressure filtered through Celite to 
remove insoluble salts. 
Procedure for Coating with EMPOL 1008 Piperazine Acrylamide 
A coating formulation was prepared by mixing 93 parts by weight of the neat 
Empol 1008 piperazine acrylamide, and 7 parts by weight of a 
photoinitiator blend consisting of 4 parts by weight of Darocure 1173, a 
photoinitiator available from Ciba-Geigy, Hawthorne, N.Y., 2 parts by 
weight of Photomer 81, a liquid form of benzophenone available from Henkel 
Corporation, Ambler, Pa., and 1 part by weight of triethanolamine. This 
composition was coated at 6.86 micrometers thickness and cured in one pass 
at 100 ft./min. The resulting coating exhibited a pencil hardness of 2H 
dissolved with four methyl ethyl ketone (MEK) rubs, zero adhesion by a 
rudimentary test (in simple peel test with adhesive tape all of the 
coating in contact with the tape lifted from the substrate) and exhibited 
a Mandrel of less than 0.27. The resistance to MEK could be improved by 
the inclusion of a di-ethylenically unsaturated monomer, e.g. 
N,N'-bis-acrylamido piperazine. A second coating at 76.2 micrometers 
thickness was cured in one pass at 100 ft./min. The resulting coating 
exhibited a pencil hardness of 2H dissolved with forty-five methyl ethyl 
ketone (MEK) rubs, and zero adhesion. 
Example 3 
A compound was prepared by the same (or substantially similar) procedure of 
Example 2, with the exception that dodecanedioic acid was employed to 
prepare a compound in accordance with scheme 3 wherein R.sup.8 is the 
divalent alkylene radical having the formula --(CH.sub.2).sub.10 --. A 
coating formulation was prepared by mixing 93 parts by weight of the 
dodecanedioic acid piperazine acrylamide, and 7 parts by weight of a 
photoinitiator blend consisting of 4 parts by weight of Darocure 1173, a 
photoinitiator available from Ciba-Geigy, Hawthorne, N.Y., 2 parts by 
weight of Photomer 81, a liquid form of benzophenone available from Henkel 
Corporation, Ambler, Pa, and 1 part by weight of triethanolamine. This 
composition was coated at 6.86 micrometers thickness and cured in one pass 
at 100 ft./min. The resulting coating exhibited a pencil hardness of 2H, 
dissolved after thirty-four methyl ethyl ketone (MEK) rubs, zero adhesion 
by a rudimentary test (in simple peel test with adhesive tape all of the 
coating in contact with the tape lifted from the substrate). A second 
coating at 76.2 micrometers thickness was cured in one pass at 100 
ft./min. The resulting coating exhibited a pencil hardness of 2H dissolved 
only after greater than 100 methyl ethyl ketone (MEK) rubs, and zero 
adhesion. A third coating was prepared at 6.86 micrometers thickness, but 
at 800 ft./min. The cured coating had a pencil hardness of 5H and 
dissolved after six MEK rubs. 
Example 4 
A compound was prepared by the same (or substantially similar) procedure of 
Example 2, with the exception that adipic acid was employed to prepare a 
compound in accordance with scheme 3 wherein R.sup.8 is the divalent 
alkylene radical having the formula --(CH.sub.2).sub.4 --. A coating 
formulation was prepared by mixing 93 parts by weight of the adipic acid 
piperazine acrylamide, and 7 parts by weight of a photoinitiator blend 
consisting of 4 parts by weight of Darocure 1173, a photoinitiator 
available from Ciba-Geigy, Hawthorne, N.Y., 2 parts by weight of Photomer 
81, a liquid form of benzophenone available from Henkel Corporation, 
Ambler, Pa, and 1 part by weight of triethanolamine. This composition was 
coated at 6.86 micrometers thickness and cured in one pass at 100 ft./min. 
The resulting coating exhibited a pencil hardness of 2H and zero adhesion 
by a rudimentary test (in simple peel test with adhesive tape, all of the 
coating in contact with the tape lifted from the substrate) and exhibited 
a Mandrel of less than 0.27. A second coating at 76.2 micrometers 
thickness was cured in one pass at 100 ft./min and exhibited a pencil 
hardness of 2H with 50% adhesion. A third coating was prepared at 6.86 
micrometers thickness, but at 800 ft./min. The cured coating had a pencil 
hardness of 2H. 
Example 5 
Coatings were prepared using N,N'-bis-acrylamido-piperazine as the only 
polymerizable monomer. A coating formulation was prepared by mixing 93 
parts by weight of the piperazine bis-acrylamide, and 7 parts by weight of 
a photoinitiator blend consisting of 4 parts by weight of Darocure 1173, a 
photoinitiator available from Ciba-Geigy, Hawthorne, N.Y., 2 parts by 
weight of Photomer 81, a liquid form of benzophenone available from Henkel 
Corporation, Ambler, Pa, and 1 part by weight of triethanolamine. This 
composition was coated at 6.86 micrometers thickness and cured in one pass 
at 100 ft./min. The resulting coating exhibited a pencil hardness of 2H 
and zero adhesion by a rudimentary test (in simple peel test with adhesive 
tape, all of the coating in contact with the tape lifted from the 
substrate) and exhibited a Mandrel of zero. A second coating at 76.2 
micrometers thickness was cured in one pass at 100 ft./min and exhibited a 
pencil hardness of 2H with zero adhesion. 
Example 6 
Alternate Procedure for the Synthesis of EMPOL 1008 Piperazine Amide 
Into a flask fitted with a distillation head and mechanical stirrer were 
charged 459.8 grams of Empol 1008 dimer acid, 12 ml of water and 4 drops 
of an inert anti-foam (from Dow Chemical). To this mixture was added 140.2 
grams piperazine (a molar ratio of piperazine to dimer acid of about 2:1). 
The resulting mixture was heated to 126.degree. C. over about 25 minutes 
and then to about 160.degree. C. over about 65 minutes and held at about 
160.degree. C. for about 15 minutes. Then 4 drops of 85% phosphoric acid 
was added and the mixture was held at about 160.degree. C. for one hour. 
After one hour, 36 ml of water had distilled over. Infra-red analysis of 
the mixture showed a residual carboxylate peak. The mixture was heated to 
175.degree. C. and held over about 70 minutes after which the infra-red 
analysis still showed a very small carboxylate peak. The mixture was 
heated to 200.degree. C. and held over about 130 minutes after which the 
infra-red analysis showed no remaining carboxylate. 
Example 7 
Synthesis of a Diester of Polybutyleneoxy glycol with 
N'-Acryloyl-N-(n-octenylsuccinoyl)-piperazine 
A compound having the following formula was prepared: 
##STR15## 
wherein R.sup.11 is the residue of an alpha,omega-butyleneoxy glycol, 
R.sup.19 is the residue of n-octenylsuccinic anhydride, n is 2 and 
R.sup.1, R.sup.2, and R.sup.3 are all hydrogen. 
Into a 1 liter resin kettle fitted with mechanical stirrer and dry nitrogen 
gas were charged 250.0 grams of a polybutyleneoxy glycol (available from 
Dow Chemical, Midland, Mich., as B100-1000 and having a molecular weight 
of about 1000 g/mole) 105.2 grams of n-octenylsuccinic anhydride, and 3.5 
grams dimethylaminopyridine. The reaction mixture was heated to 
100.degree. C. until the anhydride was completely reacted as determined by 
infra-red analysis. The resulting diacid compound was then reacted with 
piperazine as set forth in the alternate procedure for the synthesis of 
EMPOL 1008 piperazine amide and the product was then converted to a 
diacrylamide compound by reaction with acryloyl chloride. 
Example 8 
The compound bis-(N'-acrylamido-piperazinyl) dimer acid amide was prepared 
by the following reactions. The compound was then used to form a coating 
by the procedure set forth below. 
Procedure for the Synthesis of EMPOL 1008 Piperazine Amide 
Into a flask with a nitrogen atmosphere fitted with a distillation head and 
mechanical stirrer were charged 69.5 parts by weight of Empol 1008 dimer 
acid, 21.1 parts by weight of piperazine (a molar ratio of piperazine to 
dimer acid of about 2:1), 2 parts by weight of water and 0.13 parts by 
weight of an inert anti-foam (from Dow Chemical). To this mixture was 
added 0.15 parts by weight of 85% phosphoric acid. The resulting mixture 
was heated to 160.degree. C. and held at about 160.degree. C. for about 2 
hours. Then 0.15 parts of additional 85% phosphoric acid was added and the 
mixture was heated to 180.degree. C. and held at about 180.degree. C. for 
two hours. The mixture was then heated to 200.degree. C. and held at about 
200.degree. C. for about 2 hours. The reaction is complete when the amine 
value of the mixture is between 125-130 and the acid value is between 
0-10. 
Procedure for the Synthesis of EMPOL 1008 Piperazine Acrylamide 
To the cooled product of the preceding reaction was added 151 parts by 
weight of a mixture of ethyl acetate and cyclohexane (in a weight ratio of 
1: 1), 0.4 parts by weight of the methyl ether of hydroquinone, and 25 
parts by weight of triethylamine all under a dry nitrogen atmosphere. This 
mixture was cooled to 5.degree. C. and 22.3 parts by weight of acryloyl 
chloride (the distillate of a reaction product of 29.5 parts by weight of 
acrylic acid and 48.8 parts by weight of thionyl chloride in equal parts 
by weight of additional ethyl acetate/cyclohexane solvent to make a 1:1 
solution of acryloyl chloride in solvent) was added at a rate that 
maintains the reaction temperature of 5-15.degree. C. After addition is 
complete, the reaction mixture was allowed to warm to room temperature. 
The reaction is allowed to continue until the product shows no absorption 
at 1800 cm.sup.-1 by infra-red spectroscopy. The reaction mixture was then 
mixed with 62 parts by weight of water to dissolve suspended solids and 
the resulting lower aqueous layer was separated by gravity. The organic 
layer was then heated to 55-60.degree. C. at reduced pressure to distill 
solvent to less than 0.2% by weight of the product. 
Procedure for Coating with EMPOL 1008 Piperazine Acrylamide 
A coating formulation was prepared by mixing 93 parts by weight of the neat 
Empol 1008 piperazine acrylamide, and 7 parts by weight of a 
photoinitiator blend consisting of 4 parts by weight of Darocure 1173, a 
photoinitiator available from Ciba-Geigy, Hawthorne, N.Y., 2 parts by 
weight of Photomer 81, a liquid form of benzophenone available from Henkel 
Corporation, Ambler, Pa, and 1 part by weight of triethanolamine. This 
composition was coated at 6.86 micrometers thickness and cured in one pass 
at 100 ft./min. 
Example 9 
The procedure of Example 8 can be repeated with the addition of 0.02 parts 
by weight of N,N-dimethylaminopyridine to the 151 parts by weight of a 
mixture of ethyl acetate and cyclohexane. 
Example 10 
The procedure of Example 8 can be repeated with the addition of 0.2 parts 
by weight of N,N-dimethylaminopyridine to the 151 parts by weight of a 
mixture of ethyl acetate and cyclohexane. 
Example 11 
The procedure of Example 8 can be repeated with the addition of 2.0 parts 
by weight of N,N-dimethylaminopyridine to the 151 parts by weight of a 
mixture of ethyl acetate and cyclohexane.