Surfactant system of polyethoxylated compounds and glyceride compounds

In an inverse emulsion polymerization system for producing water-soluble polymers from a monomer system comprising an N-vinyl lactam and/or a vinyl-containing sulfonic acid or salt thereof utilizing a surfactant system having (1) a surfactant with a bulky lipophilic portion and a hydrophilic portion and (2) a generally straight-chain monionic surfactant having a lipophilic hydrocarbon group and an OH-terminated hydrophilic group, i.e. an alcohol. Such a system having both the right HLB and the right chemical combination results in a stable emulsion for the polymerization of these particular water-soluble monomers.

BACKGROUND OF THE INVENTION 
In one aspect, this invention relates to a surfactant system which includes 
a blend of different surfactant compositions. According to another aspect, 
the invention relates to inverse emulsion polymerization using such a 
surfactant system. 
Conventional emulsion polymerization generally has involved an oil phase 
finely dispersed in a continuous water phase. However with the production 
of water-soluble polymers a problem results in that the polymer as it is 
formed, being water-soluble, dissolves in the continuous water phase and 
increases the viscosity to an unacceptable extent. If dilute solutions are 
used, the cost of transportation is prohibitive. 
It might seem, then, that the proper approach would be to form the polymer 
and separate it as a dry solid so that only the polymer has to be 
transported. However these types of polymers are hard to redissolve in 
water because the water surrounds the individual particles and swells the 
outer surface thus forming an "insulation" which greatly slows down the 
rate at which the polymer goes into solution. 
It is known to use an inverse emulsion system wherein water-soluble 
polymers can be produced in a dispersed water phase within a continuous 
hydrocarbon phase. Here the polymer formed remains in the dispersed water 
droplets and does not significantly affect the viscosity of the emulsion. 
This not only offers an advantage over ordinary emulsions but offers an 
advantage over forming a dry product. This is because the inverse emulsion 
is of low viscosity for easy handling and can be quite concentrated for 
easy transportation. Then at the well site it is easily possible to dilute 
with a large quantity of water and break the emulsion. Since the polymer 
is formed in small droplets in the inverse emulsion and is already in 
solution it easily disperses in the water. 
The prior art broadly discloses parameters which can be used to achieve 
inverse emulsions. U.S. Pat. No. 4,147,681 for instance discloses the use 
of a relatively high concentration of surfactants having a 
hydrophilic/lipophilic balance (HLB) of at least 7 to give a stable 
emulsion which can be inverted by dilution. 
Recently, copolymer compositions based on certain monomers have been 
developed which are particularly suitable for high temperature utility. 
These polymers have high molecular weight and contain either N-vinyl 
lactam monomers such as N-vinylpyrrolidone or vinyl-containing sulfonate 
monomers such as 2-acrylamido-2-methylpropane sulfonic acid or a salt 
thereof. For these polymers, suitable inverse emulsion polymerization 
techniques have proven especially difficult. Thus while such monomers are 
broadly mentioned in the art dealing with inverse emulsions, satisfactory 
techniques for inverse emulsion polymerization of these monomers to high 
molecular weight polymers has not heretofore been available. 
SUMMARY OF THE INVENTION 
It is an object of this invention to provide a stable inverse emulsion 
polymerization system for at least one ethylenically unsaturated monomer 
to produce a water-in-oil latex comprising a water-soluble polymer of said 
at least one ethylenically unsaturated monomer. 
It is another object of this invention to provide a stable inverse emulsion 
polymerization system for monomer compositions comprising an N-vinyl 
lactam and/or a vinyl-containing sulfonate which monomers are used to make 
water-soluble polymers; and 
It is a further object of this invention to provide an improved surfactant 
composition for inverse emulsion polymerization to produce water-soluble 
polymers. 
The above objects are at least partially realized by a water-in-oil 
emulsion polymerization process for making water-soluble polymer from at 
least one ethylenically unsaturated monomer comprising: admixing an 
aqueous component, at least one organic liquid characterized as 
substantially immiscible with water, at least one ethylenically 
unsaturated monomer, at least one polymerization initiator and a 
surfactant system to form an admixture, wherein the surfactant system is 
characterized by an HLB number within the range of about 7 to about 9 and 
comprises (1) a first surfactant composition having at least one 
surfactant characterized by a lipophilic portion and a hydrophilic 
portion, the first composition having an HLB of about 7 to about 9; and 
(2) a second surfactant composition comprising at least one generally 
straight chain nonionic surfactant having a lipophilic hydrocarbon group 
and an OH terminated hydrophilic group, the second composition also having 
an HLB of about 7 to about 9; and subjecting the admixture to 
polymerization conditions sufficient to produce a water-in-oil latex 
comprising a water-soluble polymer. 
According to another aspect of the invention, a surfactant system is 
provided which comprises: a first surfactant composition having an HLB of 
about 7 to about 9 comprising a blend of a sorbitan fatty acid ester and 
an ethoxylated sorbitan fatty acid ester, as hereinbelow defined; and a 
second surfactant composition having an HLB of about 7 to about 9 
comprising an alkoxylated alcohol. 
According to a further aspect of the invention, a surfactant system is 
provided which comprises: a first surfactant composition having an HLB of 
about 7 to about 9 comprising a blend of a glyceride and an ethoxylated 
sorbitol fatty acid ester, as hereinbelow defined; and a second surfactant 
composition having an HLB of about 7 to about 9 comprising an alkoxylated 
alcohol. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A substantial feature of this invention is the discovery that the prior art 
teachings as to the proper HLB to achieve the desired result are not 
entirely correct. Actually it is the right chemical type of surfactant 
composition having the right HLB which must be utilized. Even more 
unexpectedly, it has been found that for the type of system of this 
invention there must be a surfactant system of the right HLB made up of 
two different components each of the right chemical type. 
As to the make-up of the surfactant system, the system comprises two 
different surfactant compositions hereinafter described. 
The first surfactant composition comprises at least one surfactant which is 
characterized by a lipophilic portion and a hydrophilic portion, and which 
is further characterized by an HLB of about 7 to about 9, most preferably 
8 for the most stable emulsion. Although it is within the scope of certain 
aspects of the invention to use only one surfactant for the first 
composition, it is usually necessary to use a blend of surfactants to 
achieve the proper HLB. 
One suitable first composition surfactant is a sorbitan fatty acid ester, 
which as used herein and in the appended claims is a fatty acid ester of 
sorbitan having the general formula 
EQU C.sub.6 H.sub.8 O(OH).sub.4-n (R.sup.1 COO).sub.n 
where R.sup.1 is a hydrocarbon group comprising a straight-chain of alkyl 
groups having 6 to 22 carbon atoms, and where n is an integer of 1 to 3. 
Such an ester results from the esterification of sorbitan (C.sub.6 H.sub.8 
O(OH).sub.4), also called sorbitol anhydride, with n molecules of a fatty 
acid (RCOOH) such as lauric acid, stearic acid, oleic acid, etc. R.sup.1 
can be considered the lipophilic portion and the remainder the hydrophilic 
portion. Several particularly suitable sorbitan fatty acid esters which 
are sold under the trademark "Span" by ICI Americans, Inc. are sorbitan 
monolaurate (Span 20) wherein R.sup.1 has 11 carbon atoms and n is 1, 
sorbitan monopalmitate (Span 40) wherein R.sup.1 has 15 carbon atoms and n 
is 1, sorbitan monostearate (Span 60) wherein R.sup.1 has 17 carbon atoms 
and n is 1, sorbitan tristearate (Span 65) wherein n is 3, sorbitan 
monooleate (Span 80) wherein R.sup.1 has 17 carbon atoms and n is 1, and 
sorbitan trioleate (Span 85) wherein n is 3. As is well known to those 
skilled in the art, the compound names are derived from the number and 
type of RCOO group(s) per molecule. For example, sorbitan monooleate 
includes one oleate group (oleic acid minus the terminal hydrogen), and 
thus has the formula C.sub.6 H.sub.8 O(OH).sub.3 (C.sub.17 H.sub.33 COO), 
or more accurately, C.sub.6 H.sub.8 O(OH).sub.3 (CH.sub.3 (CH.sub.2).sub.7 
CH:CH(CH.sub.2).sub.7 COO). 
Another particularly suitable first composition surfactant is a 
polyethoxylated sorbitan fatty acid ester which as used herein and in the 
appended claims is a polyethoxylated fatty acid ester of sorbitan having 
the general formula 
EQU C.sub.6 H.sub.8 O(OH).sub.4-n (OCH.sub.2 CH.sub.2).sub.m (R.sup.1 
COO).sub.n 
where n is an integer from 1 to 3 as above, R.sup.1 is defined as above, 
and m is an integer from 4 to 20 and denotes the number of oxyethylene 
groups (OCH.sub.2 CH.sub.2). R.sup.1 is generally the lipophilic portion 
and the remainder the hydrophilic portion. Several suitable compounds 
which are sold under the trademark "Tween" by ICI Americas, Inc. are the 
following where the value of m is in parenthesis after "polyoxyethylene": 
polyoxyethylene (20) sorbitan monolaurate (Tween 20), polyoxyethylene (20) 
sorbitan monopalmitate (Tween 40), polyoxyethylene (20) sorbitan 
monostearate (Tween 60), polyoxyethylene (4) sorbitan monostearate (Tween 
61), polyoxyethylene (20) sorbitan tristearate (Tween 65), polyoxyethylene 
(20) sorbitan monooleate (Tween 80), and polyoxyethylene (20) sorbitan 
trioleate (Tween 85). 
Another particularly suitable first composition surfactant is a 
polyethoxylated sorbitol fatty acid ester which as used herein and in the 
appended claims is a polyethoxylated fatty acid ester of sorbitol having 
the general formula 
EQU C.sub.6 H.sub.8 (OH).sub.6-b (OCH.sub.2 CH.sub.2).sub.m (R.sup.1 COO).sub.b 
where b is an integer from 1 to 6, R.sup.1 is defined as above, and m is an 
integer from 4 to 60 and denotes the number of oxyethylene groups 
(OCH.sub.2 CH.sub.2). R.sup.1 is generally the lipophilic portion and the 
remainder the hydrophilic portion. Some suitable compounds which are sold 
by ICI Americas, Inc. are the following where the value of m is in 
parenthesis after "polyoxyethylene": polyoxyethylene (50) sorbitol 
hexaoleate (G-1096) and polyoxyethylene (40) sorbitol hexaoleate (G-1086). 
A further particularly suitable first composition surfactant is a 
glyceride. Glycerides are known in the art as esters of glycerol and fatty 
acids in which one or more of the hydroxyl groups of the glycerol have 
been replaced by acid radicals. Preferred glycerides are the mono- and 
diglycerides or mixtures thereof. These preferred glycerides can be 
represented by the general formula: 
EQU C.sub.3 H.sub.5 (OH).sub.3-q (R.sup.1 COO).sub.q 
where R.sup.1 COO is the fatty acid moiety, R.sup.1 is as previously 
defined and q is an integer which is 1 or 2. Suitable glycerides can be 
obtained from natural products (fats and oils) or can be prepared 
synthetically. Many such products are available commercially. Atmos 300 is 
a suitable product characterized as a mixture of mono- and diglycerides of 
fat forming fatty acids available from ICI Americas, Inc. 
Sorbitan fatty acid esters and polyethoxylated sorbitan fatty acid esters 
are the preferred compounds for the first surfactant composition. However 
to achieve the proper HLB, it is usually necessary to blend such esters. 
This is because the sorbitan fatty acid esters have low HLB values, 
predominantly under 8, and polyethoxylated sorbitan fatty acid esters have 
high HLB values above 9. 
Other preferred blends of compounds for the first surfactant composition 
are combinations of glycerides and polyethoxylated sorbitol fatty acid 
esters which exhibit the proper HLB values. 
Other surfactants can be employed according to certain aspects of the 
invention for use as the first surfactant composition. One example is a 
class of compounds called polyethoxy substituted phenols commercially 
available under the trademark "Triton" from Rohm and Haas Co. Specific 
examples include polyethoxy octyl phenol (Triton X-15) and polyethoxy 
nonyl phenol (Triton N). Like the ester compounds discussed above, the 
polyethoxy substituted phenols are usually blended to achieve the proper 
HLB. 
The second surfactant composition comprises at least one generally 
straight-chain nonionic surfactant characterized by a lipophilic portion 
and an OH terminated hydrophilic portion and further being characterized 
by an HLB of about 7 to about 9, preferably about 8. 
Preferably, a straight-chain hydrocarbon group constitutes the lipophilic 
portion and a straight-chain alkoxy group terminated by an OH group 
constitutes the hydrophilic portion. Of the general class of such 
alkoxylated compounds, ethoxylated alcohols are presently preferred as 
giving the most stable emulsions. Ethoxylated alcohols can be represented 
by the general formula 
EQU R.sup.2 (OCH.sub.2 CH.sub.2).sub.x OH 
where R.sup.2 is a 10 to 30 carbon atom hydrocarbon group, preferably a 
straight-chain 16-18 atom hydrocarbon group, and x is an integer from 1 to 
50, preferably 4. Where R.sup.2 has 16-18 carbon atoms and x is 4, this 
constitutes a polyethoxylated alcohol having an HLB of about 8 available 
under the trademark "Siponic E-2" from Alcolac, Inc. This compound blended 
with the first composition has been found to give highly stable emulsions 
which yield polymers which give desirably high viscosity polymer solutions 
in brine, especially where a blend of the above described esters is used 
as the first composition (Span and Tween). Other suitable Siponic 
polyethoxylated alcohols include polyoxyethylene(2)cetyl alcohol (Siponic 
C-20) and polyoxyethylene cetyl/stearyl alcohol (Siponic E-10) both of 
which are usually blended to achieve the proper HLB. Yet other suitable 
compounds under the ethoxylated alcohol general formula include compounds 
sold under the trademark "Brij" by ICI Americas, Inc., such as Brij 72 
(R.sup.2 has 18 carbons, and x is 2) and Brij 78 (R.sup.2 has 18 carbons 
and x is 20) which also must normally be blended to achieve the proper 
HLB. 
Other alkoxylated compounds suitable for use for the second surfactant 
composition are ethoxylated fatty acids sold under the trademark 
"Pegosperse" by Glyco Chemicals, Inc. and ethoxylated amines. 
Suitable initiators for inverse polymerization include azo compounds such 
as 2,2'-azobisisobutyronitrile (commercially available as Vazo-64.RTM. 
from E. I. DuPont), 2-t-butylazo-2-cyanopropane, 
2,2'-azobis(2,4-dimethylvaleronitrile) (Vazo-52.RTM. from E. I. DuPont), 
2,2'-azobis(2-amidinopropane) hydrochloride (V-50 from Wako), 
2-t-butylazo-2-cyanopropane, 2-t-butylazo-2-cyanobutane, 
2-t-butylazo-1-cyanocyclohexane, 
2-t-butylazo-2-cyano-4-methoxy-4-methylpentane (commercially available as 
Luazo.RTM. 55 from Lucidol Div., Pennwalt Corp.), hyponitrites such as 
t-butyl hyponitrite and t-amyl hyponitrite 
2-t-butylazo-2-cyano-4-methylpentane (Luazo.RTM. 70, available from same 
source), 4,4'-azobis(4-cyanovaleric acid), 4-t-butylazo-4-cyanovaleric 
acid and the like. A particularly suitable lower temperature azo initiator 
is 2,2'-azobis(2,4-dimethyl-4-methoxy-valeronitrile) commercially 
available as Vazo 33 from E. I. DuPont. 
Other suitable initiators include organic peroxide compounds such as 
benzoyl peroxide, di-t-butyl peroxide, t-butyl peroxyacetate. A 
particularly suitable peroxide initiator because of its effectiveness at 
low temperatures is p-menthane hydroperoxide activated by 
FeSO.sub.4.7H.sub.2 O complexed with tetrasodium salt of ethylene diamine 
tetracetic acid and reduced with sodium formaldehyde sulfoxylate. 
Of the above initiators, the azo compounds are presently preferred for most 
applications, as some peroxides appear to have a tendency to adversely 
affect the polymer; however, some peroxides are effective at lower 
temperatures than those at which most azo compounds are useful. It should 
be understood that compounds, such as persulfates, other than azo and 
peroxide compounds can be used as initiators. 
A thiol compound can be added to the inverse emulsion polymerization system 
as a chain transfer agent, if so desired, to provide a means of reducing 
the molecular weight of the polymer produced therein. For certain 
applications, water-in-oil latexes comprising water-soluble polymers of 
reduced molecular weight are more suitable than the high molecular weight 
polymer latexes. A preferred group of thiol compounds for use in this 
manner is represented by the general formula HS-Y(Z)p, wherein Y is a 
hydrocarbyl radical having 2-5 carbon atoms and a valence of p+1; Z is 
selected from the group consisting of --OH, --CO.sub.2 H, and --CO.sub.2 
R.sup.8 wherein R.sup.8 is an alkyl radical of 1-3 carbon atoms; p is an 
integer of 1 or 2; and wherein the total number of carbon atoms per 
molecule of said thiol is 2-7. Examples of suitable preferred thiol 
compounds include 2-mercaptoethanol, mercaptoacetic acid, methyl 
3-mercaptopropionate, 3-mercaptopropionic acid, 3-mercapto-1-propanol, 
3-mercapto-1,2-propanediol, mercaptosuccinic acid, propyl mercaptoacetate, 
ethyl mercaptoacetate, methyl mercaptoacetate, and dimethyl 
2-mercaptomalonate. When utilized, the amount of thiol compound employed 
will be about 0.00007 to about 0.07, preferably about 0.00009 to about 
0.05, and more preferably about 0.00013 to about 0.03, parts by weight per 
100 parts by weight of the total polymerization mixture. 
Any suitable temperature can be used as for instance from -10.degree. to 
100.degree. C. and in fact even temperatures above 100.degree. C. can be 
used if pressure is utilized to prevent vaporization of the water. Thus 
broadly any temperature from the freezing point to the boiling point of 
water under the conditions used can be employed. Preferably, however, 
relatively low temperatures are preferred, i.e. from 1.degree. to 
10.degree.0 C. 
Polymerization times are the same as those conventionally used in the art, 
generally 2 to 18 hours and preferably 2 to 6 hours, although as little as 
one-half hour could be used. However, attempting more rapid polymerization 
over a shorter period of time creates problems with removing heat. In this 
regard it is greatly preferred that the polymerization medium be stirred 
well or otherwise agitated during the polymerization. 
The equipment utilized for the polymerization can simply be standard 
reactors such as are used for oil-in-water emulsion polymerizations. 
With regard to charge order, it is preferred that the water-soluble 
ingredients including the monomers be mixed together and that the 
surfactant compositions be mixed with the oil, and thereafter the two 
mixtures combined. If a thiol compound is employed, it is usually added 
after the two mixtures are combined. The water is generally either 
distilled or deionized water. 
The initiator is not generally added until after the other ingredients are 
all combined. 
The water is generally present in an amount within the range of 50 to 200 
parts by weight per 100 parts by weight of monomer(s) with about 80 to 120 
parts by weight being preferred. In the case of one particular monomer 
combination, N-vinylpyrrolidone/2-acrylamido-2-methylpropane sulfonate, 
sodium salt, the preferred concentration is about 100 to 120 parts by 
weight of water and most preferably about 110. 
Any suitable inert organic liquid which is substantially immiscible with 
water can be employed as the oil phase in preparing the water-in-oil 
emulsions and latexes according to this invention. It is preferred that 
this organic liquid, which is substantially immiscible with water, be a 
liquid hydrocarbon or a mixture of liquid hydrocarbons. More preferably, 
the oil phase will comprise liquid paraffinic or isoparaffinic 
hydrocarbons and mixtures of such hydrocarbons. An example of a more 
preferred oil phase is a hydrocarbon such as that sold under the trademark 
"Soltrol 145" hydrocarbon. This component is generally present in an 
amount within the range of 60 to 120 parts by weight per 100 parts by 
weight of monomer(s), most preferably about 80 to 100 parts. With the 
specific monomer combination of vinylpyrrolidone and 
2-acrylamido-2-methylpropane sulfonate, sodium salt, the preferred 
concentration is about 80 to 100 with about 90 parts by weight per 100 
parts by weight of monomer(s) being most preferred. 
In the case of the preferred surfactant components, Span 80 is present in 
an amount of about 9 parts by weight, Tween 85 in an amount of about 11 
parts by weight and Siponic E-2 in an amount of about 12 parts by weight 
based on 100 parts by weight of monomer(s), there being very little leeway 
in these matters since with regard to the Span 80 and Tween 85 they must 
be present in the right proportions to give the correct HLB. The second 
composition of the surfactant system such as the Siponic E-2 can be viewed 
as being present in an amount sufficient so as to give the best emulsion. 
In another example of preferred surfactant components, Atmos 300 is 
present in an amount of about 4 parts by weight, G1096 is present in an 
amount of about 6 parts by weight, and Siponic E-2 in an amount of about 6 
parts by weight based on 100 parts by weight of monomer(s). As before, the 
second composition of the surfactant system such as Siponic E-2 can be 
viewed as being present in an amount sufficient so as to give the best 
emulsion. 
When para-menthane hydroperoxide is used as the initiator it is generally 
present in an amount within the range of 0.0125 to 0.05, preferably about 
0.025, parts by weight per hundred parts by weight of monomer(s), with the 
iron compound being present in an amount within the range of about 
0.000005 to 0.001, preferably about 0.00002, parts by weight per hundred 
parts by weight of monomer(s). The ethylene diamine tetracetic acid sodium 
salt with 4 molecules of water of hydration is generally present in an 
amount of about 0.00006 parts by weight. The reductant sodium formaldehyde 
sulfoxylate is generally present in the amount of 0.01 to 0.04, preferably 
about 0.02 parts by weight per hundred parts by weight of monomer(s). 
Broadly, 0.01 to 1.0 weight per cent initiator based on monomers can be 
used. 
After the polymerization has run its desired course a shortstop may be 
added such as "Thiostop N" which is a 40 percent sodium dimethyl dithio 
carbamate solution. It can be added in an amount in the range of 0.2 to 
0.8, preferably about 0.4, parts by weight per 100 parts by weight of 
monomer(s). 
With respect to the monomers, the N-vinyl lactam monomers can be depicted 
by the formula: 
##STR1## 
where R.sup.3 and R.sup.4 are selected independently from the group 
consisting of hydrogen, methyl and ethyl and y is an integer of from 1 to 
3. These monomers are generally water-soluble or water-dispersible. A more 
preferred class of compounds are those of the formula 
##STR2## 
where R.sup.5 is hydrogen, methyl or ethyl. The N-vinyl lactam monomer 
presently most preferred is N-vinyl-2-pyrrolidone (VP). 
The vinyl-containing sulfonate monomer which is meant to encompass the acid 
also is represented by the following formula 
##STR3## 
where R.sup.6 is methyl, ethyl or H, preferably methyl or H, and provided 
further that at least one of the R.sup.6 groups on the terminal carbon of 
the vinyl group is H and the other is H or methyl. 
M is H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, Ca.sup.++ or Mg.sup.++, and z is 
an integer equal to the valence of M. 
X is 
##STR4## 
where n' is an integer of 1-5 preferably 1-3 and R.sup.7 is a 1-3 carbon 
atom alkyl group or H. 
Examples of suitable vinyl-containing sulfonate compounds are: 
##STR5## 
vinyl sulfonate, sodium salt; 
##STR6## 
sodium 2-acrylamido-2-methylpropane sulfonate (sodium AMPS); 
##STR7## 
styrene sulfonate, sodium salt; 
##STR8## 
sodium vinyl toluene sulfonate; 
##STR9## 
sodium p-vinylbenzyl sulfonate. 
These are known monomers and can be produced as is known in the art. 
Particularly with regard to the N-sulfohydrocarbon-substituted 
acrylamides, they are disclosed in U.S. Pat. No. 3,679,000 assigned to the 
Lubrizol Corporation, the disclosure of which patent is incorporated by 
reference. The 2-acrylamido-2-methylpropane sulfonic acid is available 
from Lubrizol under the designation AMPS. 
There can be used in place of, or in addition to, the vinyl containing 
sulfonate, an ester of the formula: 
##STR10## 
where R' is methyl, ethyl or H, preferably methyl or H, and further 
provided that at least one of the R' groups on the terminal carbon is H 
and the other is H or methyl, and where n" is 1 to 20, i.e. compounds such 
as (3-sulfo-n-propyl)methacrylic ester, potassium salt. 
The inverse emulsion polymerization system of this invention can be used to 
prepare copolymers of the N-vinyl lactam and the vinyl containing 
sulfonate or copolymers of either one with an unsaturated amide such as 
acrylamide (AM) or terpolymers, i.e. VP/AM/AMPS. 
The unsaturated amide monomers referred to hereinabove have the formula 
##STR11## 
where R" is an unsaturated radical selected from the group ethenyl 
(vinyl), propenyl, isopropenyl, 1-butenyl, isobutenyl 
(2-methyl-2-propenyl), 1-pentenyl, 1-isopentenyl (3-methyl-t-butenyl), and 
1-methyl-1-butenyl. These unsaturated amides are generally water-soluble 
or water dispersible. 
A more preferred class of unsaturated amide monomers are those of the 
formula 
##STR12## 
wherein each R'" is individually selected from H and methyl. Especially 
suitable in addition to acrylamide are N-methylacrylamide and 
N,N-dimethylacrylamide (DMAM). For both the vinyl lactam and unsaturated 
amide the scope can be viewed functionally as including the replacement of 
hydrogens with hydrocarbon groups so long as the monomer remains 
hydrophilic. By hydrophilic is meant if the monomer were homopolymerized, 
the polymer would be water soluble. 
Other suitable monomers useable with monomers discussed above are 
unsaturated organic acid monomers such as acrylic acid and methacrylic 
acid, and also water soluble esters of such unsaturated organic acids. 
The monomer weight ratios can vary widely. Generally the copolymers will 
have weight ratios of 10:90 to 90:10 with the vinyl lactam/unsaturated 
amide copolymers generally having ratios within the range of 25:75 to 
75:25, preferably 40:60 to 70:30 of lactam:amide. 
Similar weight ratios can be utilized for the lactam/vinyl containing 
sulfonate copolymers. However, with the particular system of VP/AMPS, 
ratios of about 10:90 are particularly desirable. 
Monomer ratios for vinyl containing sulfonate and unsaturated amide can be 
the same as those set out hereinabove for the N-vinyl lactam/unsaturated 
amide. 
Terpolymer compositions can vary widely in composition but generally will 
contain 20 to 40 weight percent N-vinyl lactam, 10 to 20 weight percent 
unsaturated amide and 40 to 65 weight percent of vinyl containing 
sulfonate, a 30:15:55 VP:AM:NaAMPS being particularly suitable.

EXAMPLE I 
Screening tests were conducted with the following recipe in order to 
determine a suitable HLB range for the surfactant system employed in 
preparing the water-in-oil (inverse) emulsion of a N-vinyl 
pyrrolidone/acrylamide (VP/AM) (50/50) copolymer. The tests were made by 
preparing the emulsions (1/4 recipe in grams) at room temperature and then 
simply making visual observations on the stability of the emulsions as 
judged by their tendency to form layers on separation of the phases. The 
monomers were not polymerized in these screening tests. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 50 
AM 50 
Water 100 
Hydrocarbon.sup.a 
100 
Surfactant.sup.b 
20 
______________________________________ 
.sup.a Three different hydrocarbon phases were employed: isopentane, 
isoparaffinic solvent (Soltrol 145 from Phillips Petroleum Co.) and a 
50/50 by wt blend of isopentane and Soltrol 145. 
.sup.b Surfactants were obtained from a test kit supplied by Atlas 
Chemical Industries (Atlab HLB Series). HLB values of 2, 4, 6, 8, 10, 12 
and 14 were used in the screening tests. 
The emulsions were prepared by dissolving the monomers in water, dissolving 
the surfactant in the hydrocarbon phase then vigorously mixing the two 
solutions in glass test tubes. 
The results showed that for each of the three hydrocarbon phases employed 
the most stable emulsions appeared to be formed when the HLB value of the 
surfactant was 8. 
EXAMPLE II 
Additional screening tests were conducted in a manner similar to that used 
in Example I. The inverse emulsion recipe used in these tests is shown 
below. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 50 
AM 50 
Water 100 
Hydrocarbon.sup.a 
300 
Surfactant 20 
______________________________________ 
.sup.a A 50/50 by wt blend of isopentane and Soltrol 145. 
A variety of commercially available surfactants and blends thereof were 
screened with HLB values near 8. 
A listing of the surfactants used and the corresponding HLB values are 
shown in the Table I below. 
TABLE I 
______________________________________ 
Run Surfactant 
No. Name Composition (Ratio) HLB 
______________________________________ 
1 Triton X35 Polyethoxy octyl phenol 
7.8 
2 Siponic TD-3 
Polyoxyethylene (3) tridecyl alcohol 
7.9 
3 Span 20 Sorbitan monolaurate 8.6 
4 Span 40 Sorbitan monopalmitate 
6.7 
5 Siponic C-20/ 
Polyoxyethylene (2) cetyl alcohol/ 
7 
Siponic E-10 
Polyoxyethylene (20) cetyl/stearyl 
alcohol (83/17) 
6 Span 85/ Sorbitan trioleate/ 7 
Tween 85 Polyoxyethylene (20) sorbitan 
trioleate (43/57) 
7 Span 65/ Sorbitan tristearate/ 7 
Tween 65 Polyoxyethylene (20) sorbitan 
tristearate (42/58) 
8 Span 80/ Sorbitan monooleate/ 7 
Tween 80 Polyoxyethylene (20) sorbitan 
monooleate (75/25) 
9 Brij 52/ Polyoxyethylene (2) cetyl ether/ 
7 
Brij 58 Polyoxyethylene (20) cetyl ether 
(84/15) 
10 Brij 72/ Polyoxyethylene (2) stearyl ether/ 
7 
Brij 78 Polyoxyethylene (20) stearyl ether 
(80/20) 
11 Span 60/ Sorbitan monostearate/ 
7 
Tween 60 Polyoxyethylene (20) sorbitan 
monostearate (77/23) 
12 Span 60/ Sorbitan monostearate/ 
7 
Tween 61 Polyoxyethylene (4) sorbitan 
monostearate (53/47) 
______________________________________ 
Suppliers are as noted previously: Triton from Rohm and Haas Co.; Siponic 
from Alcolac, Inc.; Span, Tween and Brij from ICI Americas, Inc. 
Observations on the emulsions indicated that Runs 5 and 12 were the most 
stable in this series of tests. 
EXAMPLE III 
Based on the screening test results of Example II, VP/AM (50/50) 
copolymerization runs were made with the surfactant blends of Runs 5 and 
12 but at three different ratios to obtain HLB values of 6, 7 and 8. The 
recipe employed in these runs is shown below. The polymerizations were 
conducted at 50.degree. C. with 1/4 recipe in grams per run. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 50 
AM 50 
Water 110 
Isopentane/Soltrol 145 (50/50) 
300 
Surfactant 20 
Initiator - K.sub.2 S.sub.2 O.sub.8.sup.a 
0.3 
______________________________________ 
.sup.a The K.sub.2 S.sub.2 O.sub.8 was added with 10 parts H.sub.2 O as a 
aqueous solution. 
Charge order: VP and AM were dissolved in water, surfactants were dissolved 
in the hydrocarbons and the two solutions mixed in beverage bottles which 
served as the polymerization reactors. Initiator solution was then charged 
to each bottle to start the polymerization. Table II presents further 
details for the runs and certain of the results obtained. 
TABLE II 
______________________________________ 
Run Surfactant.sup.a 
Time, 
No. HLB Wt Ratio hr. Observations 
______________________________________ 
1 6 93/7 1 Slight separation.sup.b 
2 7 83/17 1 " 
3 8 73/27 1 " 
4 6 73/27 17 Slight separation.sup.c 
5 7 53/47 17 " 
6 8 33/67 17 " 
______________________________________ 
.sup.a In Runs 1-3 the surfactant was a Siponic C20/Siponic E10 blend, 
while in Runs 4-6 it was a Span 60/Tween 61 blend. 
.sup.b The slight separation appeared towards the bottom of the reaction 
mixture. 
.sup.c The slight separation appeared towards the top of the reaction 
mixture. 
Solids measurements and Brookfield viscosities were obtained on diluted 
inverse emulsions produced in Runs 4-6. The results are shown in Table 
III. 
TABLE III 
______________________________________ 
Run Solids Conversion.sup.a 
Brookfield.sup.b 
No. % % Viscosity, cp 
______________________________________ 
4 22.7 100 1.6 
5 22.4 99 1.6 
6 21.5 95 1.5 
______________________________________ 
.sup.a Calculated, based on a theoretical solids of 22.6% for 100% 
conversion to polymer. 
.sup.b LVT model viscometer, @ 25.degree. C. 6 rpm, ultra low spindle, 
0.25 wt % polymer in deionized water. 
The results in Tables II and III show that adequate polymerizations were 
obtained but that improvement in emulsion stability and molecular weight 
are still needed to be achieved with the two-component surfactant blends 
tested. Note in particular in Table II that the emulsions were unstable 
even when the surfactant blends (Siponic C-20/Siponic E-10 and Span 
60/Tween 61) had an HLB of 8, which was found previously to be the optimum 
HLB with respect to emulsion stability. 
EXAMPLE IV 
Further runs were made to examine the effect of an added third surfactant 
to certain two component surfactant blends used in preparing inverse 
emulsions of the VP/AM (50/50) copolymer. The recipe used in these runs is 
shown below. The polymerizations were conducted at 50.degree. C. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 50 
AM (50% aq. solution) 
100 
Water 50 
Soltrol 145 100 
Surfactant variable 
Initiator, AIBN.sup.(a) 
0.05 
______________________________________ 
.sup.(a) AIBN is 2,2azo-bis-isobutyronitrile. It was charged as a solutio 
in VP, 5% by wt. 
Charge order (1/4 recipe in grams per run): AM, VP, H.sub.2 O, and Soltrol 
having surfactant dissolved therein were mixed. Each mixture was poured 
into a 10 oz bottle. The contents were purged 25-30 minutes with N.sub.2 
and the bottle capped with a perforated crown cap having a self-sealing 
rubber liner. The initiator was then charged to each bottle through the 
cap by means of a hypodermic syringe and needle. Each bottle was then 
placed in a 50.degree. C. polymerization bath. 
The effect of the surfactants on emulsion stability prior to initiation was 
observed by adding increasing amounts of Siponic E-2 to reaction mixtures 
already having a fixed (5 g) amount of a surfactant blend. The amount of 
Siponic E-2 needed to give a visibly stable emulsion was noted for each 
surfactant blend. In effect, a "titration" of the reaction mixture to a 
point of emulsion stability was performed. 
The surfactant blends used and the results obtained are shown below in 
Tables IV and V, respectively. 
TABLE IV 
______________________________________ 
Siponic 
Run E-2 Total 
No. Surfactant Blend, (g/g) 
g phm.sup.b 
Observations 
______________________________________ 
1 Triton X-15/Triton X-100.sup.a 
0 20 unstable 
(2.78/2.22) 
2 Triton X-15/Triton X-100.sup.a 
1 24 " 
(2.78/2.22) 
3 Triton X-15/Triton X-100.sup.a 
2 28 " 
(2.78/2.22) 
4 Triton X-15/Triton X-100.sup.a 
3 32 " 
(2.78/2.22) 
5 Triton X-15/Triton X-100.sup.a 
4 36 " 
(2.78/2.22) 
6 Triton X-15/Triton X-100.sup.a 
5 40 stable 
(2.78/2.22) 
7 Span 60/Tween 61 0 20 unstable 
(1.64/3.36) 
8 Span 60/Tween 61 1 24 " 
(1.64/3.36) 
9 Span 60/Tween 61 2 28 stable 
(1.64/3.36) 
10 Span 60/Tween 60 0 20 unstable 
(3.38/1.62) 
11 Span 60/Tween 60 1 24 " 
(3.38/1.62) 
12 Span 60/Tween 60 2 28 " 
(3.38/1.62) 
13 Span 60/Tween 60 3 32 stable 
(3.38/1.62) 
14 Span 60/Tween 65 0 20 unstable 
(2.16/2.84) 
15 Span 60/Tween 65 1 24 " 
(2.16/2.84) 
16 Span 60/Tween 65 2 28 " 
(2.16/2.84) 
17 Span 60/Tween 65 3 32 stable 
(2.16/2.84) 
______________________________________ 
.sup.a Triton X15 and Triton X100 are polyethoxy (1 and 10 resp.) octyl 
phenols from Rohm and Haas Co. 
.sup.b Parts by wt per 100 parts by wt of monomer(s). 
Each of the surfactant blends as well as Siponic E-2 have an HLB of about 
8. 
Conversion data and viscosity measurements were obtained for Runs 6, 9, 13 
and 17 and these results are shown in Table V. 
TABLE V 
______________________________________ 
Run Conversion, % @ Brookfield.sup.a 
Inherent.sup.b 
No. 6 hr 23 hr 71 hr Viscosity, cp 
Viscosity 
______________________________________ 
6 44 53 87 2.4 2.33 
9 64 74 118 2.9 3.92 
13 74 102 -- 4.6 4.29 
17 74 97 -- 3.0 3.67 
______________________________________ 
.sup.a LVT model viscometer, spindle UL, 6 rpm, @ 25.degree. C., using 
0.25 wt % polymer solutions in a brine, (Synthetic North Sea Water) SNSW 
made by diluting the emulsions with SNSW with thorough mixing. 
.sup.b Determined at 25.degree. C. with 0.25 wt % polymer solutions in 
SNSW made as described above. 
The results show that stable emulsions which give high viscosity polymer 
solutions in a brine can be obtained with a three component surfactant 
system of the Span/Tween/Siponic E-2 type. The results with the surfactant 
system of Run 6 using a Triton surfactant blend were not as satisfactory. 
EXAMPLE V 
Another series of runs were made using the same recipe and essentially the 
same procedures as in Example IV and the same surfactant components as in 
Example IV but the amounts were reduced about 50%. A further difference 
was the use of acetone as a solvent for the AIBN initiator rather than the 
monomer VP. Table VI below shows the amounts or surfactants used and the 
observations on emulsion stability prior to initiation. 
TABLE VI 
______________________________________ 
Siponic 
Run E-2 Total 
No. Surfactant Blend, (g/g) 
g phm Observations 
______________________________________ 
1 Triton X-15/Triton X-100 
0 9.9 unstable 
(1.39/1.11) 
2 Triton X-15/Triton X-100 
0.5 11.9 " 
(1.39/1.11) 
3 Triton X-15/Triton X-100 
1.0 13.9 " 
(1.39/1.11) 
4 Triton X-15/Triton X-100 
1.5 15.9 " 
(1.39/1.11) 
5 Triton X-15/Triton X-100 
2.0 17.9 stable 
(1.39/1.11) 
6 Span 60/Tween 61 0 10 unstable 
(0.82/1.68) 
7 Span 60/Tween 61 0.5 12 " 
(0.82/1.68) 
8 Span 60/Tween 61 1.0 14 " 
(0.82/1.68) 
9 Span 60/Tween 61 1.5 16 stable 
(0.82/1.68) 
10 Span 60/Tween 60 0 10 unstable 
(1.69/0.81) 
11 Span 60/Tween 60 0.5 12 " 
(1.69/0.81) 
12 Span 60/Tween 60 1.0 14 stable 
(1.69/0.81) 
13 Span 60/Tween 65 0 10 unstable 
(1.08/1.42) 
14 Span 60/Tween 65 0.5 12 " 
(1.08/1.42) 
15 Span 60/Tween 65 1.0 14 " 
(1.08/1.42) 
16 Span 60/Tween 65 1.5 16 stable 
(1.08/1.42) 
______________________________________ 
Runs 5, 9, 12 and 16 were charged with initiator for polymerization at 
50.degree. C. but each emulsion destabilized during polymerization so that 
no conversion data and viscosity measurements were obtained. The results 
of Examples IV and V indicate that at least about 25-28 phm of total 
surfactant is needed for stable inverse emulsion polymerization of VP/AM 
at 50.degree. C. with an azo initiator using a Span/Tween/Siponic E-2 
surfactant blend. 
EXAMPLE VI 
Further runs were conducted using the recipe of Example IV and essentially 
the same procedures as in Examples IV and V with the exception that the 
"titrating" surfactant component Siponic E-2 was replaced by a blend of 
two surfactants Brij 72/Brij 78 at a wt ratio of 70.2/29.8 (HLB 8) in the 
Brij blend. As in Example V the AIBN initiator was charged as a solution 
in acetone for polymerization at 50.degree. C. 
The surfactant blends employed and observations on inverse emulsion 
stability prior to initiation are presented in Table VII below. 
TABLE VII 
______________________________________ 
Run B72/B78.sup.a 
Total Observa- 
No. Surfactant Blend, (g/g) 
g phm tions 
______________________________________ 
1 Triton X-15/Triton X-100 
0 20 unstable 
(2/78/2.22) 
2 Triton X-15/Triton X-100 
1 24 " 
(2/78/2.22) 
3 Triton X-15/Triton X-100 
2 28 " 
(2/78/2.22) 
4 Triton X-15/Triton X-100 
3 32 " 
(2/78/2.22) 
5 Triton X-15/Triton X-100 
4 36 " 
(2/78/2.22) 
6 Triton X-15/Triton X-100 
.sup. 8.sup.b 
52 stable 
(2/78/2.22) 
7 Span 60/Tween 61 0 20 unstable 
(1.64/3.36) 
8 Span 60/Tween 61 1 24 " 
(1.64/3.36) 
9 Span 60/Tween 61 2 28 " 
(1.64/3.36) 
10 Span 60/Tween 61 3 32 stable 
(1.64/3.36) 
11 Span 60/Tween 60 0 20 unstable 
(3.38/1.62) 
12 Span 60/Tween 60 1 24 " 
(3.38/1.62) 
13 Span 60/Tween 60 2 28 " 
(3.38/1.62) 
14 Span 60/Tween 60 3 32 stable 
(3.38/1.62) 
15 Span 60/Tween 65 0 20 unstable 
(2.16/2.84) 
16 Span 60/Tween 65 1 24 " 
(2.16/2.84) 
17 Span 60/Tween 65 2 28 " 
(2.16/2.84) 
18 Span 60/Tween 65 3 32 stable 
(2.16/2.84) 
______________________________________ 
.sup.a B72/B78 is the 70.2/29.8 wt ratio blend of Brij 72/Brij 78. 
.sup.b This run required three successive 1 g additions beyond 5 g to 
reach stability. 
Runs 6, 10, 14 and 18 were polymerized as described. The conversion results 
and viscosity measurements obtained are presented in Table VIII. 
TABLE VIII 
______________________________________ 
Run Conversion, % @ Brookfield.sup.a 
Inherent.sup.b 
No. 17 hr 23 hr 71 hr Viscosity, cp 
Viscosity 
______________________________________ 
6 35 59 117 2.9 3.44 
10 93 102 -- 3.8 3.85 
14 16 17 105 3.1 3.79 
18 90 96 -- 4.0 3.85 
______________________________________ 
.sup.a See footnote a Table V. 
.sup.b See footnote b Table V. 
Runs 10 and 18 appeared to give adequate polymerization behavior and 
reasonably good viscosity values. However, the results in general were not 
as good as those of Example IV using Siponic E-2 as a surfactant 
component. Moreover, one less surfactant component is utilized in the runs 
of Example IV than the runs of this example thus reducing the complexity 
of the system. 
EXAMPLE VII 
In order to simplify inverse emulsion (of VP/AM copolymer) evaluation and 
provide a closer correlation of viscosity results with a possible end use 
application, it was desired to use a brine (Synthetic North Sea 
Water-SNSW) as a substantial portion of the aqueous phase in the 
preparation of the inverse emulsions of VP/AM (50/50) copolymer. Screening 
tests showed that a Span/Tween/Siponic E-2 surfactant blend (at about 24 
phm total) could provide visibly stable emulsions at room temperature 
using the recipe shown in Example IV wherein 50 parts of water was 
replaced by 50 parts of SNSW. 
Polymerization runs then were made using the recipe shown below at a 
temperature of 50.degree. C. using substantially the same procedures as in 
Examples IV-VI. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 50 
AM (50% aq. solution) 
100 
SNSW 50 
Soltrol 145 100 
Surfactant variable 
AIBN.sup.a 0.25 
______________________________________ 
.sup.a Charged as a solution in acetone, 0.5% by wt. 
The surfactant systems used in these runs are shown in Table IX with 
observations on emulsion stability. 
TABLE IX 
______________________________________ 
Add'l 
Run Surf., Total Observa- 
No. Surfactant Blend, (g/g) 
g phm.sup.b 
tions 
______________________________________ 
1 Triton X-15/Triton X-100 
5a 40 unstable 
(2.78/2.22) 
2 Triton X-15/Triton X-100 
5.sup.b 40 unstable 
(2.78/2.22) 
3 Span 60/Tween 61 1.sup.a 24 stable 
(1.64/3.36) 
4 Span 60/Tween 61 1.sup.b 24 stable 
(1.64/3.36) 
5 Span 60/Tween 60 1.sup.a 24 stable 
(3.38/1.62) 
6 Span 60/Tween 60 1.sup.b 24 stable 
(3.38/1.62) 
7 Span 60/Tween 65 1.sup.a 24 stable.sup.c 
(2.16/2.84) 
8 Span 60/Tween 65 1.sup.b 24 stable 
(2.16/2.84) 
______________________________________ 
.sup.a The added surfactant was Siponic E2. 
.sup.b The added surfactant was a blend of Brij 72/Brij 78 at a 70.2/29.8 
wt ratio. 
.sup.c In this run phase separation occurred during polymerization. 
Conversion data and viscosity results were not obtained for runs 1 and 2. 
The results obtained in runs 3-8 are shown in Table X. 
TABLE X 
______________________________________ 
Run Conversion, % Brookfield.sup.a 
Inherent.sup.b 
No. @ 20 hr Viscosity, cp 
Viscosity 
______________________________________ 
3 83 --.sup.c --.sup.c 
4 96 4.2 4.88 
5 80 --.sup.c --.sup.c 
6 103 3.5 4.45 
7 99 4.3 5.13 
8 94 4.4 5.12 
______________________________________ 
.sup.a See footnote a Table V. 
.sup.b See footnote b Table V. 
.sup.c Not determined. 
The results show that reasonably good conversions and viscosity values can 
be obtained in the presence of a brine, SNSW, during the polymerization of 
VP/AM in an inverse emulsion system. 
EXAMPLE VIII 
Other polymerization runs were conducted employing the recipe shown in 
Example IV at 50.degree. C. for about 18 hours. These runs utilized a 
different group of surfactants each at a total PHM of 20 as shown below in 
Table XI. 
TABLE XI 
______________________________________ 
Run 
No. Surfactant, (g) HLB 
______________________________________ 
1 Pegosperse 100-ML.sup.a /Pegosperse 400-DL.sup.b 
(2.5/2.5) 8.0 
2 Pegosperse 100-O.sup.c /Pegosperse 400-DL.sup.b 
(1.67/3.33) 
7.8 
3 Pegosperse 400-DO.sup.d 
(5) 7.2 
4 Pegosperse 400-DS.sup.e 
(5) 7.8 
5 Pegosperse 100-ML.sup.a 
(5) 6.0 
6 Pegosperse 400-DL.sup.b 
(5) 10.0 
______________________________________ 
Unfortunately, each run destabilized during polymerization so that no 
conversion data or viscosity results could be obtained. 
.sup.a Pegosperse 100ML is polyethyleneglycol (PEG) (100) monolaurate. 
.sup.b Pegosperse 400DL is PEG (400) dilaurate. 
.sup.c Pegosperse 100O is PEG (100) monoleate. 
.sup.d Pegosperse 400DO is PEG (400) dioleate. 
.sup.e Pegosperse 400DS is PEG (400) distearate. 
The Pegosperse surfactants are supplied by Glyco Chemicals, Inc. 
EXAMPLE IX 
Further runs were conducted at 50.degree. C. using the recipe of Example IV 
except that several different mineral oils were used instead of Soltrol 
145 and a variety of surfactant systems were employed. The particular 
combinations of mineral oil and surfactants used as shown in Table XII. 
TABLE XII 
______________________________________ 
Siponic 
Run Oil E-2 Total 
No. Name Surfactant Blend, (g/g) 
g phm 
______________________________________ 
1 Parol 100 
Triton X-15/Triton X-100 
5 40 
(2.78/2.22) 
2 Span 60/Tween 60 2 28 
(3.38/1.62) 
3 Span 60/Tween 61 2 28 
(1.64/3.36) 
4 Span 80/Tween 80 5 40 
(3.27/1.73) 
5 Parol 70 Triton X-15/Triton X-100 
5 40 
(2.78/2.22) 
6 Span 60/Tween 60 2 28 
(3.38/1.62) 
7 Span 60/Tween 61 4 
(1.64/3.36) 
8 Span 80/Tween 80 5 40 
9 Oil 2257 Triton X-15/Triton X-100 
5 40 
(2.78/2.22) 
10 Span 60/Tween 60 1 24 
(3.38/1.62) 
11 Span 60/Tween 61 1 24 
(1.64/3.36) 
12 Span 80/Tween 80 4 36 
(3.27/1.73) 
______________________________________ 
Conversion data was obtained for Runs 8, 10, 11 and 12 but all the other 
runs were too severely destabilized during polymerization. The conversion 
data was as follows: 
______________________________________ 
Run Conversion % @ hr. 
______________________________________ 
8 85 @ 72 hr 
10 81 @ about 18 hr. 
11 81 @ about 18 hr. 
12 84 @ about 18 hr. 
______________________________________ 
No viscosity measurements were made. 
These results suggest that Soltrol 145 is more effective than the mineral 
oils in providing a stable inverse emulsion. 
Parol 100, Parol 70 and oil 2257 are white mineral type oils obtained from 
Penreco of Butler, Pa. 
EXAMPLE X 
Polymerization runs were conducted using the recipe shown below at 
30.degree. C. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 60 
AM (50% aq. solution) 
80 
SNSW 60 
Soltrol 145 100 
Surfactant 40 
Vazo 33.sup.a 0.1 
______________________________________ 
.sup.a Charged as a solution (0.05 g/mL) in VP. 
Charge Order (1/4 recipe in grams): AM and VP were dissolved in SNSW. A 
separate solution of the surfactant components (Span and Tween) dissolved 
in Soltrol 145 was prepared. The solutions were mixed thoroughly and 
Siponic E-2 added ("titrated") to provide a visibly stable emulsion. 
The surfactants employed are shown in Table XIII below. 
TABLE XIII 
______________________________________ 
Siponic 
Run E-2 
No. Surfactants (g/g) g 
______________________________________ 
1 Span 80/Tween 80 
(3.27/1.73) 
5 
2 Span 80/Tween 85 
(2.24/2.76) 
5 
3 Span 85/Tween 80 
(2.65/2.35) 
5 
4 Span 85/Tween 85 
(1.67/3.37) 
5 
______________________________________ 
An additional 3 mL of SNSW was added to Run 1 which reduced the turbidity 
somewhat though it still was not as clear as Run 2. Runs 1 and 2 were 
initiated and polymerization continued for about 18 hours. The conversion 
data and viscosity results for these runs are shown in Table XIV. 
TABLE XIV 
______________________________________ 
Run Conversion, Brookfield.sup.a 
Inherent.sup.b 
No. % Viscosity, cp 
Viscosity 
______________________________________ 
1 101 5.6 4.20 
2 86 5.1 3.94 
______________________________________ 
.sup.a See footnote a Table V. 
.sup.b Determined at 25.degree. C. on a sample diluted to 0.1 wt % polyme 
in SNSW as described in footnote a Table V. 
The results show that a VP/AM (60/40) copolymer can be prepared in an 
inverse emulsion system in the presence of a brine (SNSW) to high 
viscosity products at a reasonably good conversion rate. 
EXAMPLE XI 
Other runs were made at 30.degree. C. using a recipe very similar to that 
of Example X except that the brine was prepared in situ by charging a 
commercially available solid salts mixture with water in the preparation 
of the emulsions. The salts mixture (available from Lake Products Co., 
Inc., of Ballwin, Mo., prepared according to ASTM D-1141-52) is made to 
approximate that found in ocean brine composition (Synthetic Ocean Water, 
"SOW", salt). The recipe used is shown below: 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 60 
AM (50% aq. solution) 
80 
Water 54.93 
SOW salt 5.07 
Soltrol 145 100 
Surfactant 40 
Vazo 33.sup.a 0.1 
______________________________________ 
.sup.a Charged as a solution (0.05 g/mL) in VP. 
Charge Order (1/4 recipe in grams): The SOW salt was added to the water 
followed by AM and VP. A separate solution of the surfactants (Span & 
Tween) dissolved in the Soltrol 145 was prepared. The solutions were 
thoroughly mixed and the Siponic E-2 added ("titrated") to provide visibly 
stable emulsions. 
The surfactants employed are shown in Table XV below. 
TABLE XV 
______________________________________ 
Siponic 
Run E-2 
No. Surfactants (g/g) g 
______________________________________ 
1 Span 80/Tween 80 
(3.27/1.73) 
5 
2 Span 80/Tween 85 
(2.24/2.76) 
5 
3 Span 85/Tween 80 
(2.65/2.35) 
5 
4 Span 85/Tween 85 
(1.67/3.37) 
5 
______________________________________ 
An additional 1 mL of SNSW was added to Run 1 to reduce turbidity. Runs 1 
and 2 were initiated and polymerization continued at 30.degree. C. for 
about 18 hours. Conversion data and viscosity results are shown in Table 
XVI. 
TABLE XVI 
______________________________________ 
Run Conversion, Brookfield.sup.a 
Inherent.sup.b 
No. % Viscosity, cp 
Viscosity 
______________________________________ 
1 97 4.9 4.19 
2 97 5.6 4.37 
______________________________________ 
.sup.a See footnote a Table V. 
.sup.b See footnote b Table XIV. 
Again, the results show that a VP/AM (60/40) copolymer can be prepared in a 
inverse emulsion system in the presence of an in situ produced brine to 
high viscosity products at a reasonably good conversion rate. 
EXAMPLE XII 
Another series of runs was made at 30.degree. C. for the preparation of 
VP/AM (60/40) copolymers in an inverse emulsion system. In this series the 
effect of added NaCl was examined in contrast to the more complex brines 
used in Examples VII-XI. The recipe employed is shown below. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 60 
AM (50% aq. solution) 
80 
Water 60 
NaCl variable 
Soltrol 145 100 
Surfactant 40 
Vazo 33.sup.a 0.1 
Thiostop-N.sup.b 0.8 
______________________________________ 
.sup.a Charged as a solution in VP (0.05 g/mL). 
.sup.b ThiostopN is sodium dimethyldithiocarbamate charged as received. 
Charge order (1/4 recipe in grams): NaCl was added to the water followed by 
AM and VP. A separate solution of the surfactants (except Siponic E-2) in 
the Soltrol 145 was prepared. The solutions were thoroughly mixed and 5 g 
Siponic E-2 added to provide visibly stable emulsions. 
The surfactant combinations used and NaCl amounts are shown in Table XVII. 
TABLE XVII 
______________________________________ 
Run NaCl 
No. Surfactants (g/g) g 
______________________________________ 
1 Span 80/Tween 80 
(3.27/1.73) 
2 " " 1.0 
3 " " 0.5 
4 " " 0 
5 Span 80/Tween 85 
(2.24/2.76) 
1.5 
6 " " 1.0 
7 " " 0.5 
8 " " 0 
9 Span 80/Span 85/ 
(1.25/1.25/ 
0.5 
Tween 80/Tween 85 
.sup. 1.25/1.25) 
10 Span 60/Span 65/ 
(1.25/1.25/ 
0.5 
Tween 80/Tween 85 
.sup. 1.25/1.25) 
______________________________________ 
Prior to initiation each bottle reactor was purged 15 minutes with 
nitrogen. Polymerization continued for 21 hours at 30.degree. C. then each 
mixture was charged with the shortstop. Conversion data and viscosity 
results are shown in Table XVIII. 
TABLE XVIII 
______________________________________ 
Run Conversion NaCl Brookfield.sup.a 
Inherent.sup.b 
No. % g Viscosity 
Viscosity 
______________________________________ 
1 -- 1.5 4.6 2.06 
2 109 1.0 5.2 0.93 
3 105 0.5 5.5 1.00 
4 85 0 4.5 1.04 
5 101 1.5 4.9 1.72 
6 100 1.0 5.0 2.06 
7 107 0.5 4.8 0.79 
8 98 0 5.0 0.96 
9 95 0.5 4.7 1.89 
10 103 0.5 4.9 1.68 
______________________________________ 
.sup.a See footnote a of Table V. 
.sup.b See footnote b of Table XIV. 
Conversion data showed reasonably good results with the exception of Run 4. 
However, viscosity values, especially inherent viscosities, seem to be 
unexpectedly low in view of results obtained in Examples X and XI. The 
reason for the apparent low values is not known. 
EXAMPLE XIII 
Additional runs were made using the recipe shown below with different 
surfactant combinations for polymerizations conducted at 30.degree. C. for 
about 16 hours. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 60 
AM 40 
Water 100 
Soltrol 145 100 
Surfactant variable 
Vazo 33.sup.a 0.1 
______________________________________ 
.sup.a Charged as a solution in VP (0.05 g/mL). 
Charge order (1/4 recipe in grams): A solution of AM and VP was prepared in 
the water component. A separate solution of surfactants (except Siponic 
component) in Soltrol 145 was prepared. The two solutions were thoroughly 
mixed and the Siponic component added to provide visibly stable emulsions. 
The mixtures were purged with N.sub.2 then charged with initiator and 
placed in the 30.degree. C. constant temperature bath. 
The surfactant combinations used are shown in Table XIX. 
TABLE XIX 
______________________________________ 
Run Siponic Total 
No. Surfactants (g/g) g phm HLB 
______________________________________ 
1 Span 60/Tween 65 
(2.2/2.8) 
3.sup.a 
32 8 
2 Span 80/Tween 80 
(3.7/1.3) 
1.sup.b 
24 7 
3 Span 80/Tween 80 
(3.3/1.7) 
3.sup.a 
32 8 
4 Span 80/Tween 85 
(2.2/2.8) 
3.sup.a 
32 8 
5 Span 80/Atlas G 1096.sup.c 
(2.4/2.6) 
2.sup.a 
28 8 
______________________________________ 
.sup.a Siponic E2. 
.sup.b Blend of Siponic C20/Siponic E2 at a 37/63 weight ratio. 
.sup.c Atlas G 1096 is polyoxyethylene (50) sorbitol hexaoleate. 
Percent solids data and viscosity measurements are presented in Table XX 
below. 
TABLE XX 
______________________________________ 
Run Solids, Brookfield.sup.a 
Inherent.sup.b 
No. wt % Viscosity Viscosity 
______________________________________ 
1 39.1 6.1 7.05 
2 41.9 3.8 5.14 
3 38.2 4.1 5.49 
4 37.0 4.7 5.92 
5 .sup. --.sup.c 
-- -- 
______________________________________ 
.sup.a Model LVT viscometer, UL spindle, 60 rpm, 25.degree. C., determine 
on sample diluted to 0.25 wt % polymer in SNSW. 
.sup.b See footnote b of Table XIV. 
.sup.c Run destabilized during polymerization so that data could not be 
obtained. 
The results showed that copolymers of VP/AM (60/40) with good viscosity 
values could be obtained using the Span/Tween/Siponic surfactant 
combination. 
EXAMPLE XIV 
Other runs were made using the recipe of Example XIII except that the Vazo 
33 initiator was replaced by a redox type initiator system. Polymerization 
was conducted at 5.degree. C. rather than 30.degree. C. used in Example 
XIII. 
The redox system employed p-menthane hydroperoxide (PMHP) (0.06 phm), 
ferrous sulfate heptahydrate (Fe) (0.0003 phm), sodium formaldehyde 
sulfoxylate (SFS) (0.05 phm) and ethylene diamine tetraacetic acid tetra 
sodium salt with 4 moles of water of hydration (Questex 4SW or QSW) (0.001 
phm). The PMHP "initiator" was charged as a solution in toluene (0.06 
g/mL). The activator was an aqueous solution of 0.003 g Fe, 0.01 g QSW and 
0.5 g SFS in 100 mL water. In these (1/4 recipe in grams) runs the 
initiator (PMHP) was charged to the N.sub.2 purged mixture of monomers, 
water, Soltrol and surfactants followed by the activator. The mixtures 
were then allowed to polymerize at 5.degree. C. for about 16 hours. The 
surfactants used in these runs are shown in Table XXI below. 
TABLE XXI 
______________________________________ 
Run Siponic Total 
No. Surfactants (g/g) g phm HLB 
______________________________________ 
1 Span 80/Tween 80 
(3.7/1.3) 
1.sup.a 
24 7 
2 Span 80/Tween 85 
(2.2/2.8) 
3.sup.b 
32 8 
3 Span 80/Atlas G 1096 
(2.4/2.6) 
2.sup.b 
28 8 
______________________________________ 
.sup.a See footnote a of Table XIX. 
.sup.b See footnote b of Table XIX. 
The solids data and viscosity results are shown in Table XXII. 
TABLE XXII 
______________________________________ 
Run Solids, Brookfield.sup.a 
Inherent.sup.b 
No. wt % Viscosity Viscosity 
______________________________________ 
1 34.0 3.7 5.02 
2 35.0 4.5 5.66 
3 36.0 4.2 5.42 
______________________________________ 
.sup.(a) See footnote (a) Table XX. 
.sup.(b) See footnote (b) Table XIV. 
Other runs were made with similar redox initiator recipes but at 50.degree. 
C. and with reduced total surfactant levels, e.g., about 1/2 and 1/4 the 
amounts used in Table XXI. However, each of these runs destabilized rather 
quickly and no data were obtained. 
EXAMPLE XV 
Other runs were made using a redox type initiator system for the inverse 
emulsion polymerization of VP/AM (60/40) at 5.degree. C. for 20 hours 
wherein the HLB of the surfactant system was 8. The recipe used is shown 
below. 
______________________________________ 
Recipe 
Parts, by wt 
______________________________________ 
VP 60 
AM 40 
Water 100 
Surfactants variable 
Soltrol 145 100 
p-Menthane hydroperoxide 
variable 
FeSO.sub.4.7H.sub.2 O 
variable 
Questex 4 SW variable 
Sodium formaldehyde sulfoxylate 
variable 
Thiostop N (shortstop) 
0.8 
______________________________________ 
Charge Order: The VP and AM were dissolved in water to form an aqueous 
solution 1. All of the surfactant components were dissolved in Soltrol 145 
to form solution 2. The solutions 1 and 2 were thoroughly mixed then 
purged with N.sub.2 for 15 minutes. An aqueous solution of Fe and QSW was 
then charged followed by an aqueous solution of SFS. The mixtures were 
cooled to 5.degree. C. and held at that temperature for 30 minutes then 
charged with PMHP and allowed to polymerize for 20 hours. Shortstop was 
charged as a 40% by wt aqueous solution. 
The surfactants employed in these runs are shown in Table XXIII. 
TABLE XXIII 
______________________________________ 
Run Total 
No. Surfactants (g/g/g) phm 
______________________________________ 
1 Span 80/Tween 80/Siponic E2 
(3.3/1.7/3) 32 
2 Span 80/Tween 85/Siponic E2 
(2.2/2.8/3) 32 
3 Span 80/G1096/Siponic E2 
(2.4/2.6/2) 28 
4 Span 80/Tween 80/Siponic E2 
(1.65/0.85/1.5) 
16 
5 Span 80/Tween 85/Siponic E2 
(1.1/1.4/1.5) 
16 
6 Span 80/G1096/Siponic E2 
(1.2/1.3/1) 14 
7 Span 80/Tween 80/Siponic E2 
(3.3/1.7/3) 32 
8 Span 80/Tween 85/Siponic E2 
(2.2/2.8/3) 32 
9 Span 80/G1096/Siponic E2 
(2.4/2.6/2) 28 
10 Span 80/Tween 80/Siponic E2 
(3.3/1.7/3) 32 
11 Span 80/Tween 85/Siponic E2 
(2.2/2.8/3) 32 
12 Span 80/G1096/Siponic E2 
(2.4/2.6/2) 28 
______________________________________ 
The amounts of redox initiator system components and the results obtained 
are shown in Table XXIV. 
TABLE XXIV 
______________________________________ 
Run PMHP Fe SFS Solids 
Brookfield.sup.a 
Inherent.sup.b 
No. phm phm phm Wt % Viscosity 
Viscosity 
______________________________________ 
1 0.06 0.003 0.05 34.4 3.8 5.13 
2 " " " 37.5 4.3 5.63 
3 " " " 21.2 ND.sup.d 
ND 
4 " " " --.sup.c 
" " 
5 " " " 39.1 " " 
6 " " " --.sup.c 
" " 
7 0.12 " 0.10 36.1 3.9 5.20 
8.sup.e 
" " " 7.7 1.1 0.03 
9.sup.e 
" " " 16.3 1.1 0.26 
10 " 0.001 " 39.4 5.3 6.59 
11.sup.e 
" " " 25.7 ND.sup. ND 
12.sup.e 
" " " 12.3 1.3 0.06 
______________________________________ 
.sup.(a) See footnote (a) Table XX. 
.sup.(b) See footnote (b) Table XIV. 
.sup.(c) Destabilized during run. 
.sup.(d) Not Determined 
.sup. (e) Boosted with 0.06 phm PMHP and 0.05 phm SFS at 20 hours and 
polymerized for an additional 24 hours. 
Although several runs had poor results in terms of solids content (low 
conversion) and low viscosities, other runs showed that high viscosity 
values and solids content could be achieved with a redox initiator system 
and a Span/Tween/Siponic surfactant blend at HLB 8. 
EXAMPLE XVI 
Several additional runs were made using a Span 80/Tween85/Siponic E-2 
surfactant system, a redox initiator system of the type used in Examples 
XIV and XV, and various combinations of monomers. The recipes are shown 
below. 
__________________________________________________________________________ 
Recipes 
Parts, by wt. 
1 2 3 4 5 6 
__________________________________________________________________________ 
VP 50 30 -- -- 30 10 
AM 50 15 -- 40 10 -- 
Sodium AMPS.sup.a 
-- 55 100 60 55 90 
Acrylic Acid -- -- -- -- 5 -- 
Water 120 120 120 110 110 110 
Soltrol 145 100 100 100 90 80 90 
Span 80 9 9 9 9 9 9 
Tween 85 11 11 11 11 11 11 
Siponic E-2 12 12 12 12 12 12 
p-Menthane Hydroperoxide 
0.054 0.054 0.054 0.054 0.054 0.054 
FeSO.sub.4.7H.sub.2 O 
0.00001 
0.00001 
0.00001 
0.00001 
0.00001 
0.00001 
Questex 4 SW 0.00003 
0.00003 
0.00003 
0.00003 
0.00003 
0.00003 
Sodium Formaldehyde sulfoxylate 
0.05 0.05 0.05 0.05 0.05 0.05 
__________________________________________________________________________ 
.sup.a Sodium AMPS is sodium 2acrylamido-2-methylpropane sulfonate 
Each recipe (full recipe, in grams) was mixed and inverse emulsion 
polymerization carried out in six corresponding runs 1-6 using essentially 
the same charge order and polymerization conditions described in Example 
XV. Viscosity and percent solids results for these runs are shown in Table 
XXV. 
TABLE XXV 
______________________________________ 
Run Solids Inherent.sup.a 
No. wt. % Viscosity 
______________________________________ 
1 28.4 7.7 
2 28.4 8.1 
3 28.4 &gt;10 
4 30.1 10.4 
5 32.1 7.3 
6 30.1 6.9 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
All of the runs achieved highly stable emulsions and, as can be seen from 
Table XXV, desirably high viscosities. 
While this invention has been described in detail for the purpose of 
illustration it is not to be construed as limited thereby but is intended 
to cover all changes and modifications within the spirit and scope 
thereof. 
EXAMPLE XVII 
Additional runs were conducted for the copolymerization of acrylamide (AM) 
and sodium 2-acrylamido-2-methylpropane sulfonate (NaAMPS) in an inverse 
emulsion polymerization system. The surfactant blends employed Atmos 300 
(mono-and diglycerides of fat forming fatty acids from ICI Americas, 
Inc.), G1096 (polyoxyethylene (5) sorbitol hexaoleate) and Siponic E-2 
(SE-2). The recipe employed in this series of runs is shown below. 
______________________________________ 
Recipe 
Parts, by Weight 
______________________________________ 
AM.sup.(a) 40 
NaAMPS.sup.(a) 60 
Water 101 
Soltrol 145 104 
Emulsifier: 
Atmos 300 Variable 
G1096 Variable 
Siponic E-2 Variable 
Initiator: 
PMHP 0.024 
FeSO.sub.4.7H.sub.2 O 
0.00002 
Questex 4SW 0.00006 
SFS 0.025 
Shortstop: 0.4 
Thiostop-N 
Temperature, .degree.C. 
5 
Time, hours 18 
______________________________________ 
.sup.(a) Charged as a 50% by weight aqueous solution. 
The charging procedure for this series of runs was substantially the same 
as that employed in Example XV. The results obtained in this series of 
runs are presented in Table XXVI below. 
Runs 1 and 7 are comparative (control) runs since no Siponic E-2 was 
employed in the surfactant. 
TABLE XXVI 
______________________________________ 
Run Surfactant, phm Solids 
Inherent 
No. Atmos 300 G1096 SE-2 HLB wt % Viscosity.sup.(a) 
______________________________________ 
1 10.2 9.8 0 7 36.6 ND.sup.(b) 
2 10.2 9.8 4 7.16 37.7 ND 
3 10.2 9.8 8 7.29 38.4 ND 
4 10.2 9.8 12 7.38 39.0 ND 
5 10.2 9.8 16 7.44 38.4 ND 
6 10.2 9.8 20 7.55 39.4 8.6 
7 8.0 12.0 0 8.0 37.8 ND 
8 8.0 12.0 4 8.0 37.9 ND 
9 8.0 12.0 8 8.0 38.8 9.4 
10 8.0 12.0 12 8.0 38.8 9.2 
11 8.0 12.0 16 8.0 39.6 9.4 
12 8.0 12.0 20 8.0 40.3 8.3 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
.sup.(b) Not determined. 
The latexes for Runs 1-5, 7 and 8 appeared to be somewhat unstable while 
the latexes for Runs 9-12 showed a tendency for phase separation on 
standing but were easily dispersed on mild agitation. The latex for Run 6 
was viscous but stable. The inherent viscosity (I.V.) values were quite 
high indicative of high molecular weight polymers suitable for use in 
applications where such high molecular weight water soluble polymers are 
desired. 
EXAMPLE XVIII 
Additional runs were conducted in essentially the same manner as the series 
shown in Example XVII except that kerosene was used instead of Soltrol 145 
as the hydrocarbon phase and a polymerization time of 20 hours rather than 
18 hours was employed. However, four parts by weight of Soltrol 145 was 
used in preparing the redox initiator system instead of kerosene. The 
results obtained in this series of runs is shown in Table XXVII below. 
Runs 1 and 7 are control runs since no Siponic E-2 was used in the 
surfactant. 
TABLE XXVII 
______________________________________ 
Run Surfactant, phm Solids 
Inherent 
No. Atmos 300 G1096 SE-2 HLB wt % Viscosity.sup.(a) 
______________________________________ 
1 10.2 9.8 0 7 D.sup.(b) 
.sup. ND.sup.(c) 
2 10.2 9.8 4 7.16 D ND 
3 10.2 9.8 8 7.29 D ND 
4 10.2 9.8 12 7.38 37.7 8.1 
5 10.2 9.8 16 7.44 37.9 9.0 
6 10.2 9.8 20 7.55 37.8 9.4 
7 8.0 12.0 0 8.0 D ND 
8 8.0 12.0 4 8.0 D ND 
9 8.0 12.0 8 8.0 36.3 9.0 
10 8.0 12.0 12 8.0 37.8 9.3 
11 8.0 12.0 16 8.0 37.4 9.3 
12 8.0 12.0 20 8.0 37.9 9.4 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
.sup.(b) D indicates latex destabilized. 
.sup.(c) Not determined. 
Latexes from Runs 11 and 12 were viscous and showed a slight tendency 
toward phase separation on standing. Latexes from Runs 4-6 and 10 showed a 
more pronounced tendency to phase separate but were easily dispersed on 
mild agitation. The latex from Run 9 also settled on standing but was 
difficult to disperse on agitation. The I.V. values were again quite high 
as in the runs of Example XVII. 
A comparison of the overall results in Examples XVII and XVIII indicates 
that Soltrol 145 was better than kerosene in terms latex stability 
behaviour. The addition of Siponic E-2 as part of the surfactant also 
significantly improved the latex stability characteristics with Soltrol 
145 or kerosene as the hydrocarbon phase, particularly at HLB values of 
7.55 and 8.0. 
EXAMPLE XIX 
Additional control runs were conducted in the manner of Example XVII but 
which employed mixtures of Atmos 300 and G1096 in different amounts as the 
surfactant and which used Soltrol 145 or kerosene as the hydrocarbon 
phase. These runs were conducted for 17 hours. The results obtained in 
these runs are presented in Table XXVIII. 
TABLE XXVIII 
______________________________________ 
Surfactant, phm 
Run Hydrocarbon 
Atmos Solids 
Inherent 
No. phase 300 G1096 HLB wt % Viscosity.sup.(b) 
______________________________________ 
1 S-145.sup.(a) 
4 6 8 37.8 10.8 
2 S-145 6 9 8 34.7 --.sup.(c) 
3 S-145 8 12 8 37.2 --.sup.(c) 
4 Kerosene 4 6 8 36.2 11.4 
5 Kerosene 6 9 8 39.0 10.7 
6 Kerosene 8 12 8 37.8 --.sup.(c) 
______________________________________ 
.sup.(a) Soltrol 145. 
.sup.(b) See footnote (b) of Table XIV. 
.sup.(c) These runs failed to polymerize for unknown reasons. 
Runs 1, 4 and 5 produced very high inherent viscosity polymers but each 
latex showed tendency toward phase separation on standing that could be 
dispersed easily on mild agitation. The erratic polymerization behaviour, 
e.g. Runs 2, 3 and 6, is not currently understood. 
EXAMPLE XX 
Further runs were made according to my invention in the manner of Example 
XVII but which employed different amounts of water and hydrocarbon 
(Soltrol 145 or kerosene). These runs employed 17 hours for the 
polymerization reaction. Each run also employed Atmos 300, G1096 and 
Siponic E-2 as the surfactant at levels of 8, 12, and 12 phm respectively. 
The HLB value was 8 for each run. The results obtained are shown in Table 
XXIX below. 
TABLE XXIX 
______________________________________ 
Run Hydrocarbon Water Solids Inherent 
No. Type phm phm wt % Viscosity.sup.(a) 
______________________________________ 
1 S-145 94 91 39.7 9.7 
2 S-145 94 101 38.9 9.9 
3 S-145 104 91 38.8 9.7 
4 S-145 104 101 37.4 9.8 
5 S-145 114 91 38.0 8.1 
6 S-145 114 101 36.0 10.0 
7 Kerosene 94 91 39.2 10.7 
8 Kerosene 94 101 39.0 10.7 
9 Kerosene 104 91 38.5 10.5 
10 Kerosene 104 101 35.8 10.9 
11 Kerosene 114 91 36.4 10.7 
12 Kerosene 114 101 34.9 10.6 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
The results of this series of runs show the production of high inherent 
viscosity water soluble AM/NaAMPS (40/60) copolymers. Although the 
inherent viscosity values for runs 1, 4 and 5 of Example XIX are higher 
than the values obtained in the runs of this example, the latex stability 
was clearly improved in the runs made according to my invention. The 
latexes for runs 2 and 11 showed no signs of phase separation and the 
latexes for all the other runs though showing signs of phase separation 
were easily dispersed on mild agitation. 
EXAMPLE XXI 
Additional runs were conducted for the copolymerization of AM/NaAMPS 
(40/60) in the manner of Example XVII but which utilized different amounts 
of Atmos 300, G1096 and Siponic E-2 in the surfactant. The hydrocarbon 
phase employed was Soltrol 145 (Runs 1-8) or kerosene (Runs 9-16) in an 
amount of 94 phm. The results obtained in this series of runs are shown in 
Table XXX below. 
TABLE XXX 
______________________________________ 
Run Surfactant, phm Solids 
Inherent 
No. Atmos 300 G1096 SE-2 HLB wt % Viscosity.sup.(a) 
______________________________________ 
1 8 12 0 8 36.7 10.4 
2 6 9 0 8 37.1 10.8 
3 4 6 0 8 34.7 10.9 
4 2 3 0 8 D.sup.(b) 
.sup. ND.sup.(c) 
5 8 12 12 8 37.8 9.7 
6 6 9 9 8 36.7 10.2 
7 4 6 6 8 38.2 10.9 
8 2 3 3 8 D ND 
9 8 12 0 8 37.9 11.8 
10 6 9 0 8 37.7 12.1 
11 4 6 0 8 D ND 
12 2 3 0 8 D ND 
13 8 12 12 8 38.1 10.8 
14 6 9 9 8 36.7 10.8 
15 4 6 6 8 36.3 12.1 
16 2 3 3 8 D ND 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
.sup.(b) D indicates latex destabilized. 
.sup.(c) Not determined. 
Runs 1-4 and 9-12 are control runs since Siponic E-2 was not utilized in 
the surfactant employed in these runs. Runs 4, 8, 11, 12 and 16 indicates 
that low levels of surfactant causes latex destabilization with or without 
the use of Siponic E-2. However, a visual comparison of latexes from Run 3 
with Run 7 and Run 11 with Run 15 clearly showed the latex stabilizing 
effect of the addition of Siponic E-2 to the surfactant. Inherent 
viscosity values were quite high indicating suitable high molecular weight 
water soluble AM/NaAMPS (40/60) copolymers had been obtained. 
EXAMPLE XXII 
Further runs were conducted according to my invention for the preparation 
of AM/NaAMPS (40/60) copolymers in the manner of Example XVII using as 
surfactant mixtures of Atmos 300, G1096, and Siponic E-2 at levels of 8, 
12, and 12 phm respectively (HLB 8). In this series the hydrocarbon phase 
was Soltrol 145 or kerosene and the polymerization temperature was 
5.degree. or 30.degree. C. for 20 hours. The results obtained in this 
series of runs are presented below in Table XXXI. 
TABLE XXXI 
______________________________________ 
Run Temperature Hydrocarbon 
Solids Inherent 
No. .degree.C. Type wt % Viscosity.sup.(a) 
______________________________________ 
1 5 S-145 38.5 9.9 
2 5 kerosene 39.9 10.9 
3 30 S-145 39.7 9.5 
4 30 kerosene 38.6 10.2 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
The results shown in Table XXXI indicate that suitable high inherent 
viscosity water soluble copolymers of acrylamide (AM) and sodium 
2-acrylamido-2-methylpropanesulfonic acid (NaAMPS) were obtained in 
inverse emulsion form on polymerization at 5.degree. C. or 30.degree. C. 
with a redox initiator system. 
EXAMPLE XXIII 
Additional runs were conducted according to my invention for the 
preparation of AM/NaAMPS (40/60) copolymer in the general manner of 
Example XVII except that 111 phm water and 94 phm Soltrol 145 were used. 
Different amounts of Atmos 300, G1096, and Siponic E-2 were employed in 
this series of runs. The results obtained in this series of runs are shown 
in Table XXXII below. 
TABLE XXXII 
______________________________________ 
Run Surfactant, phm Solids 
Inherent 
No. Atmos 300 G1096 SE-2 HLB wt % Viscosity.sup.(a) 
______________________________________ 
1 8 12 12 8 37.8 9.4 
2 6 9 9 8 37.7 8.9 
3 4 6 6 8 35.7 9.9 
4 2 3 3 8 D.sup.(b) 
ND.sup.(c) 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
.sup.(b) D indicates latex destabilized. 
.sup.(c) Not determined. 
The results in Table XXXII indicate that as the total surfactant level 
drops below about 15-16 phm the latex tends to destabilize during 
polymerization. 
EXAMPLE XXIV 
Runs were conducted for the copolymerization of N-vinyl-2-pyrrolidone (VP), 
acrylamide (AM), sodium 2-acrylamido-2-methylpropanesulfonic acid (NaAMPS) 
and acrylic acid (AA) in an inverse emulsion polymerization system. These 
runs utilized a surfactant according to my invention of Atmos 300, G1096, 
and Siponic E-2. The recipe employed in this series of runs is shown 
below. 
______________________________________ 
Recipe 
Parts, by weight 
______________________________________ 
VP 30 
AM.sup.(a) 10 
NaAMPS.sup.(a) 55 
AA 5 
Water Variable 
Soltrol 145 Variable 
Emulsifier: 
Atmos 300 8 or 6 
G1096 12 or 9 
Siponic E-2 12 or 9 
Initiator: 
PMHP 0.024 
FeSO.sub.4.7H.sub.2 O 
0.00002 
Questex 4SW 0.00006 
SFS 0.025 
Temperature, .degree.C. 
5 
Time, hours 24 
______________________________________ 
.sup.(a) Charged as 50% by weight aqueous solution. 
Each run was conducted substantially in the following manner. 
The monomers were mixed with substantially all of the water and the mixture 
sparged with nitrogen. A second mixture of the emulsifier components in 
substantially all of the Soltrol 145 was prepared and sparged with 
nitrogen. The second mixture was added to the first mixture in a glass 
bottle reaction vessel with agitation and the vessel pressured to 25 psig 
with nitrogen. The mixture was cooled to 5.degree. C. and charged with the 
initiator system. The bottle reactor was tumbled in a constant temperature 
water bath to provide agitation to the polymerization mixture. 
The results obtained in this series of runs are presented in Table XXXIII 
below. 
TABLE XXXIII 
______________________________________ 
Sol- 
Soltrol Surfactant, ohm ids 
Run H.sub.2 O 
145 Atmos wt 
No. ohm phm 300 G1096 SE-2 HLB % I.V..sup.(a) 
______________________________________ 
1 100 80 8 12 12 8 42.0 7.0 
2 112 90 8 12 12 8 38.6 7.2 
3 93 75 8 12 12 8 43.9 7.1 
4 100 80 6 9 9 8 40.9 7.5 
5 116 93 6 9 9 8 36.3 7.2 
6 98 78 6 9 9 8 39.9 7.2 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
All of the latexes showed some tendency toward phase separation but only 
the products of Runs 3 and 6 showed any sign of polymer settling from the 
latex. However, all latexes except the product from Run 6 were easily 
dispersed on mild agitation. The latex from Run 6 required more vigorous 
agitation to be dispersed after standing. 
EXAMPLE XXV 
Additional runs were conducted according to my invention for the inverse 
emulsion copolymerization of VP, AM, NaAMPS and AA in substantially the 
same manner as Example XXIV. Different amounts of water, Soltrol 145, and 
surfactant components were employed in this series of runs. The results 
obtained in this series of runs are presented below in Table XXXIV. 
TABLE XXXIV 
______________________________________ 
Sol- 
Soltrol Surfactant, ohm ids 
Run H.sub.2 O 
145 Atmos wt 
No. ohm phm 300 G1096 SE-2 HLB % I.V..sup.(a) 
______________________________________ 
1 110 90 8 12 12 8 40.1 7.3 
2 111 91 8 12 12 8 39.6 7.3 
3 92 76 8 12 12 8 44.7 7.4 
4 110 90 5 7.5 7.5 8 37.7 7.3 
5 117 96 5 7.5 7.5 8 36.8 7.3 
6 99 81 5 7.5 7.5 8 41.1 7.5 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
All of the latexes showed some tendency toward phase separation, but those 
of Runs 1-3 were easily dispersed on mild agitation while those of Runs 
4-6 were less stable and more difficult to disperse on agitation. 
EXAMPLE XXVI 
Two other runs (duplicates) were carried out according to my invention for 
the copolymerization of AM and NaAMPS (40/60) in substantially the same 
manner as described in Example XVII above. Both runs utilized 117 phm 
water and 96 phm Soltrol 145. The polymerization time was 21 hours in 
these runs. The results obtained in these runs are presented in Table XXXV 
below. 
TABLE XXXV 
______________________________________ 
Run Surfactants, phm Solids 
Inherent 
No. Atmos 300 G1096 SE-2 HLB wt % Viscosity.sup.(a) 
______________________________________ 
1 5 7.5 7.5 8 38.0 9.0 
2 5 7.5 7.5 8 38.0 9.1 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
The latexes from these runs tended to phase separate with some indication 
of polymer settling out on standing. The solids and inherent viscosity 
values indicate good reproducibility was achieved in these runs. 
EXAMPLE XXVII 
Additional runs were conducted according to my invention for the 
copolymerization of AM and NaAMPS (40/60) in substantially the same manner 
as described in Example XVII above. Different amounts of water, Soltrol 
145 and surfactant were employed in these runs. The results obtained in 
these runs are shown in Table XXXVI below. 
TABLE XXXVI 
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Sol- 
Soltrol Surfactant, ohm ids 
Run H.sub.2 O 
145 Atmos wt 
No. ohm phm 300 G1096 SE-2 HLB % I.V..sup.(a) 
______________________________________ 
1 110 90 8 12 12 8 40.2 9.5 
2 110 91 8 12 12 8 39.8 9.6 
3 110 90 6 9 9 8 39.1 10.2 
4 115 94 6 9 9 8 38.6 10.0 
5 110 90 5 7.5 7.5 8 38.4 10.2 
6 117 96 5 7.5 7.5 8 37.4 10.3 
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.sup.(a) See footnote (b) of Table XIV. 
All the latexes appeared to of good stability with very high inherent 
viscosity values indicative of high molecular weight water soluble 
polymers. 
EXAMPLE XXVIII 
Two further runs were conducted according to my invention for the 
copolymerization of AM and NaAMPS (40/60) in an inverse emulsion 
polymerization system. These runs used azo initiators at a polymerization 
temperature of 30.degree. C. for 18 hours. Run 1 employed 
2,2'-azobis(N,N'-dimethyleneisobutyramidine)dihydrochloride (VA-044 Wako 
Industries) while Run 2 used 2,2'-azobis 
(2,4-dimethyl-4-methoxyvaleronitrile) (Vazo 33-duPont). Both were employed 
at a level of 0.1 phm. The results obtained in these runs are shown in 
Table XXXVII below. 
TABLE XXXVII 
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Sol- 
Soltrol Surfactant, ohm ids 
Run H.sub.2 O 
145 Atmos wt 
No. ohm phm 300 G1096 SE-2 HLB % I.V..sup.(a) 
______________________________________ 
1 117 91 5 7.5 7.5 8 38.0 6.9 
2 112 96 5 7.5 7.5 8 38.5 8.8 
______________________________________ 
.sup.(a) See footnote (b) of Table XIV. 
The latex from Run 1 was clearly less stable than that from Run 2 which 
showed no tendency to phase separate. The inherent viscosity value for Run 
2 was also significantly higher than that obtained in Run 1.