Aldehyde or imine oxygen scavengers for vinyl polymerizations

Oxygen scavengers, especially for vinyl polymerizations, comprising an aldehyde or imine of the formula EQU R.sub.3 Q.sub.n wherein n is 1-4; R.sub.3 is an organic radical having a valence of 1-4 or hydrogen; Q is of the formula ##STR1## wherein A is 0 or NR.sub.4 ; R.sub.2, R.sub.2, and R.sub.4 are independently selected C.sub.1-6 alkyl or aryl radicals or mixtures thereof are disclosed. A preferred composition is a mixture of aldehydes which are the reaction product of (a) ethylene urea, (b) formaldehyde, (c) isobutyraldehyde, and (d) 2-ethylhexanal in a molar ratio of (a):(b) of 1:2 and of (a) to the sum of (c) and (d) of 1:2.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to oxygen scavengers useful in the polymerization of 
vinyl unsaturated monomers, oligomers, and polymers in the presence of 
oxygen. 
2. Description of the Prior Art 
Eickoff et al, U.S. Pat. No. 4,395,361, assigned to Proctor and Gamble 
Company, teach a class of oxygen-activated free radical polymerization 
catalysts comprising cobalt (II) compounds and certain autoxidizable 
cyclic hydrocarbons and benzaldehyde. 
Eickoff et al also describe a method of catalyzing an oxygen-initiated free 
radical polymerization reaction using these catalysts. No other aldehydes 
than benzaldehyde are disclosed. 
Gruber U.S. Pat. No. 4,017,652, assigned to PPG Industries, Inc., teaches 
oxygen inhibition of the photopolymerization of acrylic resins being 
reduced by employing a photocatalyst system containing an aromatic ketone 
and/or aromatic aldehyde photosensitizer of a certain type which promote 
polymerization through bimolecular photochemical reactions, and an 
aromatic ketone photoinitiator. 
Petersen, U.S. Pat. No. 3,551,423, assigned to BASF, teaches production of 
certain amides by reaction of amides with formaldehyde and an appropriate 
CH-acid aldehyde and the use of the new amide products as textile finishes 
and as valuable intermediates for the production of amino aldehydes and 
aminocarboxylic acids, pharmaceuticals and aminoplasts. Peterson does not 
disclose utility of the aldehydes as oxygen scavengers, nor does he 
disclose the corresponding imines. 
Collins et al, Reactions of UV curable Resin Formulations and Neat 
Multifunctional Acrylates II Photoinitiated Polymerization of Neat 
1,6-hexanedioldiacrylate, Journal of Coatings Technology, Vol. 51, No. 
648, January 1979, teach benzoin isobutyl ether photoinitiated 
polymerization of 1,6-hexanedioldiacrylate, and eliminating the inhibition 
by dissolved oxygen by the addition of N,N-dimethylaminobenzaldehyde and 
eosin-Y. 
Imoto et al, Vinyl Polymerization. 364. Polymerization of Methyl 
Methacrylate Initiated with Benzaldehyde, J. Poly. Science: Polymer 
Chemistry Edition, 17:385-92 (1979) show an anaerobic initiation of the 
radical polymerization of methyl methacrylate with benzaldehyde. Oxygen 
scavenger activity is not needed in anaerobic reactions, and so Imoto et 
al is not pertinent to oxygen scavenging. 
In recent years, certain vinyl monomer, oligomer, and polymer systems have 
been developed which have sufficiently high molecular weight and 
sufficiently low odor, volatility, and toxicity so as to be useful as 
non-volatile reactive components of high or 100% solids resin formulations 
which can be cured rapidly by free radical polymerization in the absence 
of oxygen, i.e. anaerobically, for example in radiation cure applications 
or in engineering adhesives where polymerization occurs between two 
substrates to be bonded. However, when cure of these vinyl unsaturated 
systems is attempted in the presence of air, i.e. aerobically, serious 
inhibition of free radical polymerization by oxygen at the air interface 
occurs. It is this problem to which the present invention is addressed. 
It is an object of the present invention to provide a new class of highly 
efficient oxygen scavengers for use in compositions comprising at least 
one vinyl unsaturated monomer, oligomer or polymer. It is a further object 
of the invention to provide compositions comprising at least one vinyl 
unsaturated monomer, oligomer or polymer which have improved curing 
characteristics in the presence of oxygen. 
SUMMARY OF THE INVENTION 
These objects, and others as will become apparent from the following 
disclosure, are achieved by the present invention which comprises in one 
aspect the use as an oxygen scavenger system of compositions comprising an 
aldehyde or imine of the formula 
EQU R.sub.3 Q.sub.n 
wherein n is 1-4; R.sub.3 is an organic radical having a valence of 1-4 or 
hydrogen; Q is of the formula 
##STR2## 
wherein A is 0 or NR.sub.4 ; R.sub.1, R.sub.2, and R.sub.4 are 
independently selected C.sub.1-6 alkyl or aryl radicals or mixtures 
thereof. 
In another aspect, the invention comprises the aforementioned aldehyde or 
imine and a transition metal ion selected from Co++, Cu++, and Mn++. In 
another aspect the invention comprises the aldehyde or imine and a vinyl 
unsaturated monomer and/or polymer. 
DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTS 
Various compositions which comprise at least one vinyl unsaturated monomer, 
oligomer, and polymer and which are designed for cure in the presence of 
oxygen are available in the field of paints and other coating 
compositions, gel coats, tank linings, polymer concrete, high solids 
baking finished and the like. A particular field in which oxygen 
inhibition occurs is in thin films which contain vinyl monomers where it 
is usually an object to obtain tack-free finishes rapidly. In some cases, 
the desired finish is hard, whereas in other cases, such as with roof 
mastics, the desired finish is flexible. Particularly important systems in 
which the oxygen scavengers described below are useful include unsaturated 
polyester, acrylic/melamine, reactive coalescent, vinyl ester, UV cure, 
concrete sealant, polymer concrete, engineering adhesive, and the like. 
As mentioned before, the oxygen scavengers of the invention are selected 
from the group consisting of compounds of the formula 
EQU R.sub.3 Q.sub.n 
wherein n is 1-4; R.sub.3 is an organic radical having a valence of 1-4 or 
hydrogen; Q is of the formula 
##STR3## 
wherein A is 0 or NR.sub.4 ; R.sub.1, R.sub.2, and R.sub.4 are 
independently selected C.sub.1-6 alkyl or aryl radicals or mixtures 
thereof. 
R.sub.3 is preferably of the formula 
EQU R.sub.5 Y CH.sub.2 -- 
wherein R.sub.5 is hydrogen or an organical radical of 1-4 valence and 
selected from C.sub.1 --.sub.36 alkyl, cycloalkyl, aryl, arylalkyl, 
alkylaryl, and acyl; Y is 0 or NR.sub.6 ; and R.sub.6 is hydrogen or a 
C.sub.1-6 alkyl or aryl group. 
Some of the suitable aldehydes are 
##STR4## 
wherein R.sub.1 and R.sub.2 are selected from methyl, ethyl, butyl, and 
mixtures thereof, and m is 4 or 7; 
##STR5## 
wherein R.sub.9 is methyl, ethyl, or butyl; 
##STR6## 
wherein R is methyl, a 1/1 mixture of ethyl and butyl, or a 0.82/0.09/0.09 
mixture of methyl, ethyl, and butyl; 
##STR7## 
wherein R is methyl or ethyl; 
##STR8## 
Some of the suitable imines are 
##STR9## 
wherein m is 4 and R is methyl, ethyl, and butyl. R.sub.3 can also be 
selected from: 
##STR10## 
or a radical of the formula 
##STR11## 
wherein R.sub.8 is a C.sub.1-6 alkyl or aryl, and Z is NR.sub.8 R.sub.8. 
In the imines, A can be of the formula 
##STR12## 
wherein R.sub.7 is C.sub.1-6 alkyl or aryl. 
A problem with some of the aldehydes of the invention, even the preferred 
ones, is poor pot stability of the aldehyde/vinyl unsaturated system 
mixtures, apparently due to premature oxidation of the aldehyde. This 
problem can be solved by using the corresponding imine of the invention 
which is in a sense a chemically blocked form of the aldehyde. However, 
ambient moisture is needed to hydrolyse the imine to the active aldehyde. 
An alternative to the imine approach is to use oxime or thiuram stabilizers 
to preserve the pot life of aldehyde/vinyl unsaturated system mixtures. 
One suitable thiuram is tetramethyl thiuram disulfide (TMTDS), which is 
most preferred. One suitable oxime is methyl ethyl ketone oxime. 
The oxygen scavengers of the invention are most useful in vinyl unsaturated 
systems which would not readily polymerize under aerobic conditions, and 
in such widely diverse applications as aqueous or solvent based coatings, 
impregnates, plastics, reinforced plastics, tank linings, gel coatings, 
and polymer concrete. The vinyl unsaturated systems are monomers, 
oligomers, and/or polymers which undergo free radical polymerization and 
are polymerized from such monomers as: 
i. Mono, di- and trifunctional acrylates and methacrylates 
ii. fumarates 
iii. maleates 
iv. vinyl esters 
v. styrenes 
vi. acrylamides 
vii. acrylonitrile 
viii. itaconate esters 
ix. alpha-methylene glutarate esters 
x. acryloxyproprionic acid and esters 
xi. methacrylic acid or acrylic acid. 
Such polymers as: 
i. maleate containing polyesters 
ii. fumarate containing polyesters 
iii. itaconate containing polyesters 
iv. alpha-methylene glutarate containing polyesters 
v. vinyl resins 
vi. urethane multi ((meth)acrylates) 
vii. polyester multi ((meth)acrylates) 
can comprise the vinyl unsaturated system. 
The vinyl unsaturated system can also include additive(s) selected from 
pigments, colorants, sand, glass fibers, surfactants, dispersants, and 
defoamers. 
The usual ratio of aldehyde or imine to vinyl unsaturated system is about 1 
to 20 parts by weight aldehyde or imine and about 99 to 80 parts by weight 
vinyl unsaturated system. 
Mixtures of aldehydes and imines can be used. 
In the aldehyde or imine formula, R.sub.1 cannot be connected to R.sub.2 so 
that benzaldehyde is excluded from the scope of the formula. 
A preferred mixture of aldehydes is the reaction production of (a) ethylene 
urea, (b) formaldehyde, (c) isobutyraldehyde, and (d) 2-ethyl hexyl 
aldehyde in a molar ratio of (a):(b) of 1:2 and of (a) to the sum of (c) 
and (d) of 1:2. A particularly preferred group of imines is the reaction 
product of the just-mentioned aldehyde mixture with t-butyl amine.

The following examples are presented to illustrate a few embodiments of the 
invention but are not intended to be limiting thereto. In these examples 
all parts and percentages are by weight unless otherwise indicated. 
The following abbreviations are utilized in the examples which follow. 
IDMA=isodecyl methacrylate 
IBOMA=isobornyl methacrylate 
IBOA=isobornyl acrylate 
HPMA=hydroxypropyl methacrylate 
TEGMA=tetraethylene glycol dimethacrylate 
DCPOMA=dicyclopentenyloxyethyl methacrylate 
C.sub.8 AM=N-nonyl acrylamide 
TMPTA=trimethylol propane triacrylate 
LMA=lauryl methacrylate 
CEMA=cetyl iscosyl methacrylate 
IDMA=isodecyl methacrylate 
EXAMPLES 
Example 1 
Preparation of 2-Oxoimidazolidine-1,3-bis (2,2-dimethylpropanal) 
A 500 ml., three-necked flask equipped with a thermometer, condenser, and 
mechanical stirrer was charged, under nitrogen blanket, with 86.1 g of 
2-imidazolidone (ethyleneurea, 1.0 mole), 151 g. of isobutyraldehyde (2.1 
moles), and 162 g. of 37% aqueous formaldehyde solution (2.0 moles). A 
mild exotherm resulted (22.degree.-45.degree. C.). On addition of 21.5 g 
of 50% aqueous sulfuric acid solution (w/w), the temperature of the 
reaction mixture rose to 58.degree. C. with the onset of reflux. To 
maintain reflux, the temperature of the reaction mixture was gradually 
increased, reaching 95.degree. C. after 2.75 hours. The product was cooled 
and neutralized with 50% aqueous sodium hydroxide solution. After standing 
for several hours, two layers formed. 
The organic layer was decanted from the aqueous (bottom) layer, then mixed 
with methylene chloride (500 l.) and extracted with two, 100 ml. portions 
of water. Methylene chloride and tracese of water were stripped from the 
product using a rotary evaporator, affording 254 g. of product/(100% 
yield) as a yellow oil which crystallized slowly on cooling. Further 
purification of the product by recrystallization from methylene chloride 
and ethyl ether gave 175 g. of colorless crystals, mp 
83.degree.-84.degree. C. NMR (CDCL.sub.3); 9.63 (s, 2H, --CHO), 3.35 (s. 
4H, --CH.sub.2 --), 3.30 (s, 4H, --CH.sub.2 --), and 1.10 (s, 12H, 
--CH.sub.3). The product is slightly soluble in water (5 wt. %) and 
readily soluble in common polar organic solvents. 
Example 2 
Preparation of 2-Oxiomidazoline-1,3-bis (dialkylpropanal) 
A 1000 ml. four-necked flask equipped with a thermometer, condenser, 
mechanical stirrer, and nitrogen ebullator was charged with 215.3 g. 
ethyleneurea (2.5 moles), 150.0 g. paraformaldehyde (5.0 moles), and 100 
g. water. Aqueous sulfuric acid (50%, 8.0 g., 0.04 mole) was then added 
slowly to the slurry, with stirring, over a period of 15 minutes. A 
moderate exotherm resulted (25.degree.-60 .degree. C.). When the exotherm 
ceased, 72.1 g. isobutyraldehyde (1.0 mole) was added over 15 minutes 
while concurrently heating the reaction mixture to 80.degree. C. After a 
15 minute hold at temperature, at which point essentially all of the 
isobutyraldehyde had been consumed, the mixture was heated to 100.degree. 
C. and 192.3 g. 2-ethylhexanal (1.5 moles) was added over 15 minutes. The 
temperature was maintained between 95.degree. C. and 100.degree. C. for 
2.5 hours. The reactor was cooled to 80.degree. C. and 185.0 g. 
isobutyraldehyde (2.56 moles) was then added over 30 minutes. A 1.5 hour 
hold at reflux completed the condensation. The mixture was cooled to 
70.degree. C. and treated with 5.0 g. of sodium hydroxide pellets (0.125 
mole) to effect catalyst neutralization. After 15 minutes of agitation, 
the stirrer was stopped to allow phase separation (rapid) and removal of 
the aqueous (bottom) layer. Unreacted isobutyraldehyde and water were then 
distilled in vacuo (80.degree. C., 20 mm). Filtration of the residue 
through a Celite pad afforded 684 g. of product (95% yield) as a light 
yellow oil with a Brookfield viscosity of 6,000 cps at 25.degree. C. 
Example 3 
Preparation of 2,2-Dimethyl-3-oxopropyl Laurate 
To a hot (80.degree. C.) solution of lauric acid (70 g., 0.35 mole), and 
hydroxypivaldehyde (30.6 g., 0.3 mole) in 120 g. of toluene was added 1.75 
g. of p-toluenesulfonic acid monohydrate (0.009 mole). The mixture was 
then heated at total reflux for 1.5 hrs. and water generated in the 
reaction mixture was removed by azeotropic distillation. The reaction 
mixture was cooled, washed with saturated aqueous sodium bicarbonate and 
brine, then dried over magnesium sulfate, filtered, and evaporated in 
vacuo. GLC analysis of the product showed that it contained 90% of the 
desired laurate ester. Fractional distillation of the crude sample gave a 
product cut, b.p. 180.degree. C./4.0 mm, of 95% purity (GLC, area %). NMR 
(CDCL.sub.3): 9.73 (s, 1H,--CHO), 4.2 (s, 2H, --CO.sub.2 CH.sub.2 --), 2.3 
(t, 2H, --CH.sub.2 CO.sub.2 --), 0.9-1.9 (m, 23H, CH.sub.2 
(CH.sub.2).sub.10 CH.sub.2 CO.sub. 2 --), and 1.17 (s, 6H, 
--C(CH.sub.2).sub.2. 
Example 4 
Preparation of Bis(2,2-dimethyl-3-oxopropyl) Fumarate 
Crude bis (2,2-dimethyl-3-oxopropyl) maleate was treated with a catalytic 
amount of morpholine (10 wt. %) in refluxing toluene for 4 hrs. The 
resulting solution was cooled to room temperature, washed with diluted 
hydrochloric acid and brine, then dried over magnesium sulfate. 
Evaporation of volatiles in vacuo gave crud bis (2,2-dimethyl-3-oxopropyl) 
fumarate in essentially quantitative yield. NMR* (CDCL.sub.3): 9.7 (s, 
1H,--CHO), 6.93 (s, 2H, trans --CH=CH--), 4.33 (s, 2H, --CO.sub.2 CH.sub.2 
--), and 1.2 (s, 6H, --C(CH.sub.3).sub.2 --). 
FNT *Obtained with a distilled sample of bis (2,2-dimethyl-3-oxopropyl) 
fumarate, m.p. 55.degree. C. 
Example 5 
Preparation of Bis(2,2-dimethyl-3-oxopropyl) Azelate 
A 3 liter, four-necked flask equipped with a mechanical stirrer, nitrogen 
sparage, steam-jacketed additional funnel, Dean-Stark trap and condenser 
was charged with 380 g. of azelaic acid )2moles), 500 g. of toluene and 
13.3 g. of p-toluenesulfonic acid monohydrate (0.07 mole). The mixture was 
heated at reflux, yielding an homogeneous solution within 20 minutes. To 
the reaction mixture was then dropwise added a preheated solution of 450 
g. of hydroxypivaldehyde (4.4 moles) in 500 g. of toluene. Water was 
removed azeotropically via the Dean-Stark trap. When the reaction was 
complete, the mixture was cooled to room temperature and washed with 
saturated aqueous sodium bicarbonate and brine, then dried over magnesium 
sulfate and evaporated in vacuo giving 720 g. of the crude dialdehyde 
azelate. GLC analysis (area %) indicated that the product contained 75% of 
bisaldehyde azelate. NMR (CDCL.sub.3): 9.7 (s, 2H, --CHO), 4.26 (s, 4H, 
--CO.sub.2 CH.sub.2 --), 2.3 (t, 4H, --CH.sub.2 CO.sub.2 --), 0.9-1.8 (m, 
10H, --O.sub.2 CH.sub.2 --(CH.sub.2).sub.5 --CH.sub.2 CO.sub.2 --), and 
1.2 (s, 12H, --C(CH.sub.3).sub.2 --). 
Example 6 
Preparation of Bis (t-Butyl Imine) of Example 1 
A 500 ml. three-necked flask equipped with a thermometer, mechanical 
stirrer, Dean-Stark trap, and condenser was charged, under a nitrogen 
blanket, with 50.8 g. 2-oxoimidazolidine-1,3-bis (2,2-dimethyl propanal) 
(0.2 mole), 50 g. t-butylamine (0.65 mole) and 200 g. methylene chloride. 
The reaction mixture was heated to reflux (46.degree. C.) and water was 
removed azeotropically. After a total of 20 hours at reflux, the 
theoretical amount of water was isolated (7 ml.). The reaction was cooled 
and the crude product was stripped on a rotary evaporator. Upon cooling, 
the residue solidified to give the bisimine as a colorless waxy solid, mp 
46.degree.-47.degree. C. 
Example 7 
Use of Aldehydes/Imines as Oxygen Scavengers in Thin Film Polymerizations 
A filter paper matrix was used to approximate thin film conditions. The 
sample to be tested is weighed onto an approximately equal weight of 
filter paper (Whatman No. 1). Weight changes are followed with time. At 
selected intervals the test sample is extracted with chloroform (or 
CDCL.sub.3) and the weight % extractables determined. The extractables may 
be subjected to a variety of tests as warranted (i.e. nmr/ir spectrum, 
titration, elemental analysis). If the sample to be tested is a solid or a 
high viscosity liquid the material is diluted with chloroform prior to 
absorption onto the filter paper. 
______________________________________ 
Monomers 
Monomer Cures in a Filter Paper Matrix 
0.1% Co++; rt 
Cure.sup.1 
Monomer(s) Ratio Time Sol. F.sup.2 
______________________________________ 
TEGMA 100 &gt;&gt;3 days -- 
TEGMA/EX. 1 98/2 &gt;&gt;2 days -- 
95/5 &gt;2 days -- 
90/10 1 day 0.29 
80/20 4-5 hours 0.16 
70/30 4-5 hours 0.30 
IBOMA/EX. 1 95/5 2 days -- 
90/10 2 days 1.00 
80/20 1 day 0.99 
TMPT/EX. 1 90/10 1 day 0.22 
______________________________________ 
.sup.1 Cure = no methacrylate in nmr spectrum of soluble fraction. 
.sup.2 Fraction of material which can be extracted from the filter paper 
by chloroform post cure. 
Example 8 
Thin Film Oxidative Polymerizations with Aldehyde of Example 2--Filter 
Paper Matrix/1 day/rt/0.1% CO++ 
Using the aldehyde of Example2 in a system, the following data was 
observed: 
______________________________________ 
% 
% Mono- % Nature of 
Sample Ratio Evap. mer Polymer 
Polymer 
______________________________________ 
IDMA/EX. 2 
90/10 10.5 89.5 0 
80/20 6.0 54 40 soluble 
IBOMA/EX. 2 
90/10 20 40 40 soluble 
80/20 7 23 70 soluble 
IBOA/EX. 2 
90/10 35 20 45 soluble 
80/20 5.5 10 85 soluble 
HPMA/EX. 2 
90/10 52 0 48 soluble 
80/20 13 0 87 loose gel 
TEGMA/EX. 2 
90/10 +4 0 104 gel 
80/20 +2 0 102 gel 
DCPM/EX. 2 
90/10 +2 0 102 gel 
80/20 +2 0 102 gel 
C.sub.8 Am/EX. 2 
90/10 6 20 74 soluble 
80/20 5 0 95 soluble 
______________________________________ 
Example 9 
Cure of Unsaturated Polyester Resin with Aldehyde Oxygen Scavenger 
An aldehyde which was of the formula 
##STR13## 
wherein R is a 1/1 mixture of Et and Bu was used in a 1 mil film; 0.1% 
CO.sup.++ ; 2 days; room temperature experiment using a fumaric 
acid/neopentyl glycol (1/1) unsaturated polyester, and the following data 
resulted: 
______________________________________ 
Equiv Soluble Fraction 
System CHO/db in CHCl.sub.3 
______________________________________ 
Unsaturated Polyester (UPE) 
-- 1.01 
Aldehyde -- 1.00 
UPE/aldehyde 
= 9/1 0.15 0.44 
= 8/2 0.34 0.23 
= 7/3 0.59 0.23 
______________________________________ 
Example 10 
Monomer Evaluation in Unfilled Castings 
The following unfilled castings were prepared at room temperature to 
determine the effect of the oxygen scavenger aldehyde in Example 2. 
______________________________________ 
Cure 
Time 24 Hr. 
HPMA + Catalysts.sup.1 (min) Surface 
______________________________________ 
IDMA CHP/Co NC* Liquid 
DPMA CHP/Co 360 Liquid 
LMA CHP/Co NC Liquid 
CEMA CHP/Co 300 Liquid 
IDMA CHP/Co/Example 2 124 Hard 
DPMA CHP/Co/Example 2 100 Hard 
LMA CHP/Co/Example 2 95 Hard 
CEMA CHP/Co/Example 2 70 Hard 
______________________________________ 
*NC = No Cure 
.sup.1 2% Cumene Hydroperoxide; 0.13% Co.sup.++ +; 3% Aldehyde 
Example 11 
Comparison of Aldehyde of Example 9 with Imine of Example 6 
This example demonstrates the advantage to the imines as to pot stability: 
______________________________________ 
Approx. Cure Times (rt) 
Sample (+0.1% Co.sup.++) 
Solution Thin Film 
______________________________________ 
Tetraethyleneglycol dimethacrylate 
5-9 days 9 days 
Tetraethyleneglycol dimethacrylate/ 
&lt;&lt;1 day &lt;1 day 
Example 9 (9/1) 
Tetraethyleneglycol dimethacrylate/ 
12-14 days 
&lt;1 day 
Example 6 (9/1) 
Dicyclopentenyloxyethyl 
&lt;1 day 2-5 days 
methacrylate 
Dicyclopentenyloxyethyl 
&lt;&lt;1 day &lt;1 day 
methacrylate/Example 9 (9/1) 
Dicyclopentenyloxyethyl 
&lt;1 day &lt;1 day 
methacrylate/Example 6 (9/1) 
Unsaturated Polyester Resin.sup.1 
&gt;10 days &gt;10 days 
Unsaturated Polyester Resin/ 
&lt;1 day 1 day 
Example 9 (8/2) 
Unsaturated Polyester Resin/ 
&gt;10 days &gt;10 days.sup.2 
Example 6 (8/2) 
______________________________________ 
.sup.1 Unsaturated polyester resin prepared from fumaric acid and 
neopentyl glycol. 
.sup.2 After 3 days at rt, thin film cured well at 3 hours/60.degree. C. 
Example 12 
Effect of Cobalt Ions and Thiuram on Pot Stability 
This example shows the effect tetramethyl thiurom disulfide (TMTDS) as a 
stabilizer for aldehyde promoted oxidative polymerizations. Twenty parts 
of the aldehyde of Example 2 was mixed with 80 parts trifunctional 
acrylate monomer and to this mixture was in turn added selected amounts of 
Co++ and TMTDS with the following results: 
______________________________________ 
0.2% Cure Time 
Co.sup.++ 
1000 ppm TMTDS Pot Stability 
(thin film) 
______________________________________ 
- - 4-20 hours no cure 
+ - &lt;2 hours 4-20 hours 
- + 1 month no cure 
+ + 6-9 weeks 20-24 hours 
______________________________________ 
Example 13 
Use of Oxime Stabilizer 
This example demonstrates the use of methyl ethyl ketone oxime (Exkin No. 
2) in a TEGMA/Cymel 303/Tetraethylene glycol Dimethacrylate/Cobalt 
(56.2/18.8/20/5/0.06/0.5 Cycat 600) binder formulation. 
______________________________________ 
Exkin No. 2 Viscosity (Brookfield, cps/ICI, poise) 
(Percent on Binder) 
Initial 3 Days 5 Days 10 Days 
______________________________________ 
-- 105/1.28 Gelled 
0.15 105/1.25 160/1.42 145/1.50 
170/1.68 
0.30 110/1.22 160/1.35 140/1.42 
165/1.58 
0.60 105/1.22 150/1.32 135/1.40 
155/1.50 
-- 130/1.42 Gelled 
______________________________________ 
Example 14 
UV Cure of Diacrylate of Bisphenol A Diepoxide Using Aldehyde Oxygen 
Scavenger 
Forty parts diacrylate of Bisphenol A diepoxide (Shell DRH-370 brand), 60 
parts DCPOMA, and 2 parts diethoxyacetophenone were exposed to equal 
levels of UV radiation with the following results: 
______________________________________ 
Oxygen Scavenger 
Film Thickness (Mils) 
Result 
______________________________________ 
-- 1-1.5 Hard, slight tack 
10% EX. 9 1-1.5 Hard, tack free 
-- &lt;0.5 Moderate tack 
10% EX. 9 &lt;0.5 Tack free 
______________________________________ 
Example 15 
Aldehyde Oxygen Scavenger Effect on Surface Cure of Unsaturated Polyester 
Castings 
When 2% of the aldehyde of Example 2, when added to an unsaturated 
polyester/unsaturated monomer casting resin formulation containing 1% 
benzoyl peroxide, 0.6% Co++, 0.2% dimethyl aniline at polyester/monomer 
ratios of between 38/62 and 65/35, and using as monomers either 
dicyclopentenyloxyethyl methacrylate, dicyclopentenyloxyethyl acrylate, or 
styrene, a hard, tack-free surface was obtained versus either a liquid or 
very tacky surface when the aldehyde was deleted. 
Example 16 
Use of Oxygen Scavengers in Polymer Concrete 
The oxygen scavenger aldehydes of Example 9 and Example 1 were used as 
levels up to 20% based on polymer concrete formulations containing sand, 
silica flour, Fe.sub.3 O.sub.4, TiO.sub.2, benzoyl peroxide, catalyst, 
acrylic resin, and acrylic monomer, with excellent results as to improving 
cure and adhesion characteristics. 
______________________________________ 
Pot Cure Surface 
Life Speed Cure Quality 
Aldehyde (Ex.) 
Level (hrs.) (hrs.) 
(16 hrs.) 
Adhesion 
______________________________________ 
0 0 31/2 None None None 
9 2 3 None None None 
1 2 3 None None None 
9 5 31/2 4 Excellent 
Excellent 
1 5 31/2 4 Excellent 
Excellent 
9 10 21/2 3 Excellent 
Excellent 
1 10 3 3 Excellent 
Excellent 
9 20 2 21/2 Excellent 
Excellent 
1 20 3 3 Excellent 
Excellent 
______________________________________ 
Although the invention has been described in great detail herein, various 
modifications, alternatives, and improvements thereto should become 
readily apparent to those skilled in the art without departing from the 
spirit and scope thereof.