вход по аккаунту


Патент USA US3058951

код для вставки
United States Patent O??ce
Patented Oct. 16, 11962
ing and stabilizing agent for the in situ emulsion polym
erization of the excess monomeric liquid, thereby forming
Aqueous MEDIUM
Richard W. Rees, Wilmington, Del, assignor to Shawini
gan Chemicals Limited, Montreal, Quebec, Canada, a
corporation of Canada
No Drawing. Filed May 22, 1959, Ser. No. 814,975
9 Claims. (Cl. Zed-29.6)
This invention relates to new products prepared by
polymerizing copolymerizable monomers with polyeth
ylene glycols in aqueous solution, and to the processes for
a stable aqueous resin emulsion of the polymer of the
monomeric liquid.
The invention further consists in a process as described
above, wherein the molar ratio of polymerizable liquid
to ethylene oxide units lies between 1.5 and 20, prefer
ably between 4 and 10; these ratios ensure that a copoly
mer of the polyethylene glycol and part of said liquid is
produced and that simultaneously a polymer of the re
mainder of said liquid is produced in the form of an aque
ous resin emulsion stabilized by said copolymer.
The proportion of water in which the process of the re
action is carried out does not appear to be critical. Ob
preparing said products.
viously if a concentrated aqueous solution of copolymer
It has previously been found that certain polymerizable 15 were wanted, it would advantageously be prepared by
monomers can be reacted with polyoxyethylene com
making the copolymer under anhydrous conditions, for
pounds to form copolymers which have useful proper
example by the process described in the copending ap
ties. Those copolymers which are Water soluble have
plication of Leo M. Germain, Ser. No. 706,901, filed Janu
been found to have surface active properties, i.e. to exert
ary 3, 1958, then dissolving the anhydrous product in the
surface tension depressing effects; such copolymers, for
minimum amount of water required to give the desired
example, can be used as emulsi?ers and stabilizers in the
concentration of solution. The present invention is ad
preparation of resin emulsions which form water-insensi
vantageous for the preparation of the copolymer in dilute
tive ?lms. Copolymers of polyoxyethylene compounds
aqueous solutions, such as for example the aqueous medi
and polymerizable monomers have hitherto been prepared
um which forms the aqueous phase of an aqueous resin
in the absence of appreciable amounts of water, and pre 25 emulsion. For these purposes, the proportion of water
vious attempts to prepare them in aqueous medium have
can be up to, for example, one hundred times the amount
been unsuccessful.
of copolymer by weight.
It has now been found that water-soluble copolymers
When a polyethylene glycol and a polymerizable mon
of polyethylene glycols and copolymerizable monomers 30 omeric liquid suitable for the processes of this invention
can be prepared directly in aqueous medium, in the pres
are stirred together in water in the absence of a polym
ence of suitable catalysts. Furthermore, by using excess
erization catalyst, the surface tension of the mixture re
monomer, it has now been found possible to prepare
mains substantially unchanged. However, when an effec
stable aqueous resin emulsions with the simultaneous for
tive water-soluble polymerization catalyst is added to the
mation of the emulsifying agent in situ. The polyethyl
mixture at a temperature suitable to bring about a polym
ene glycols, as hereinafter referred to, are polyoxyethylene 35 erization reaction, the surface tension of the resulting
compounds having at least four oxyethylene units in their
mixture is lowered to a marked extent, thereby indicating
The invention therefore consists in a process for the
that a surface active material has been formed as a result
of a polymerization or copolymerization reaction.
preparation of a copolymer of (A) a polyethylene glycol, 40 ple mixtures of the polyethylene glycol and separately
and (B) a monomeric liquid copolymerizable with the
prepared polymer of the monomer do not exhibit and sim
polyethylene glycol, said liquid being selected from the
ilar reduction in surface tension, showing that the lower
group consisting of (a) vinyl esters of alkanoic acids hav—
ing in surface tension is due to the combination of poly
ing four to ten carbon atoms in the ester, (12) alkyl esters
ethylene glycol with the polymerized liquid in a copolymer
of acrylic and methacrylic acids having one to eight car 45 arrangement.
bon atoms in the alkyl radical and (0) mixtures of the
When a polyethylene glycol and an excess of a polym
said vinyl and alkyl esters, which process comprises (1)
erizable monomer suitable for the processes of this inven
agitating at polymerization temperatures in the range be
tion are agitated together in water in the absence of an
tween 20° C. and re?ux temperature a system comprising
added surface-active material, emulsi?cation occurs only
(i) water, (ii) the polyethylene glycol, (iii) the copolym 50 after a water-soluble polymerization catalyst is added.
erizable liquid, and (iv) a water-soluble polymerization
This shows clearly the formation of the emulsi?cation
catalyst for the copolymerizable liquid, and (2) continu
ing the agitation at polymerization temperature until po
lymerization is substantially complete.
Optimum proportions of copolymerizable monomeric
liquid and polyethylene glycol for the formation of just
the water soluble surface active copolymer in aqueous
medium are in the range of one molecule of monomer to
agent in sitn. The copolymer of polyethylene glycol is
a distinct species which is separable by solution chroma
tography from the polymer derived solely from the mon
The proportion of polymerized monomer in these
55 omer.
copolymers of polyethylene glycol can be determined by
standard analytical procedures.
The formation in situ of a copolymer of polyethylene
glycol and polymerizable liquid as an emulsi?er simulta
glycol. With higher proportions of copolymerizable 60 neously with the formation of a resin emulsion is obvious
monomer than the foregoing, the homopolymer of the
ly economically advantageous, because the elimination of
monomeric liquid also tends to form. This range of op
the preparation of emulsi?er as a separate step results
timum proportions for formation of the copolymer alone
in a cost reduction. Additionally, the similarity of the
in aqueous medium corresponds to molar ratios of po
compositions of the emulsi?er and resin renders them
lymerizable monomer to ethylene oxide units of 0.05 to 65 exceptionally compatible, hence dried ?lms cast from
0.025. Effective surface active copolymer is obtained
the emulsions have exceptional clarity.
tExamples of suitable water-soluble catalysts for pro
however, with ratios as low as 0.005.
between about 20 and 40 ethylene oxide units of the
The invention further consists in the process as afore
moting the copolymerization of polyethylene glycols and
said wherein there is used an amount of monomeric liq
copolymerizable liquids in aqueous medium are the water
uid in excess of that utilized in the formation of surface 70 soluble free-radical catalysts such as potassium persul
active copolymer, whereby the copolymer of polyethylene
fate, sodium persulfate, and ammonium persulfate. ' Re
glycol and monomer is formed and acts as an emulsify
duetion-activated catalyst systems such as alkali metal
resistance. These resin emulsions are useful in paint and
persulfate and sodium formaldehyde sulfoxylate are also
effective in promoting the copolymerization reaction in
coating formulations, and as adhesives‘.
aqueous medium to form surface active materials.’
The ‘following examples illustrate the invention which
is de?ned by the claims. The polyethylene glycol used
vated catalyst systems are also eifective in promoting the
in the examples was “Carbowax,” the registered trade
mark, :for such glycols sold by Union Carbide ‘Chemicals
Water-soluble free-radical catalysts‘ and reduction-acti
simultaneous formation in aqueous medium of an emulsi-v
fying agent from a polyethylene glycol and a polymeriz
able liquid and of an emulsion of the polymerized liquid,
when said liquid is present in excess. The proportion of
polymerization catalyst is not critical; conveniently it is
Company. A number (e.g. 4000, and 20M,’ meaning
20,000) following the trademark indicates the approxi
mate average molecular weight of the particular poly:
ular weight from about 200 to 20,000 are preferable for
use in this invention. Such glycols have at least four
used in a proportion of less than 1% by weight of the
monomer to be polymerized, as in conventional emulsion
polymerizations, but much larger proportions, for ex
ample up_ to ten percent, can be vused.
In the preparation in aqueous media of water-soluble
ethylene glycol. ‘Polyethylene glycols ranging in molec
copolymers of polyethylene glycols and polymerizable
oxyethylene units in their structure.
In this example, approximately equal weights of vinyl
acetate and Carbowax 4000 were reacted in water in the
monomers, the total quantity of the polyethylene glycol
. presence of a reduction activated catalyst.
can, be dissolved in water in the reaction vessel before the
Potassium persulfate (0.5 gram) andv sodium formalde~
copolymerization reaction ‘begins, or optionally, only a 20 hyde
sulfoxylate (0.3 gram) were dissolved in water
portion may be included in the initial reaction charge and
(300 ml.) and stirred at room temperature while a solu
the remainder added gradually as an aqueous solution
of 'Carbowax 4000 (50 grams) in water (100 ml.) and
during‘the courseof the copolymerization. Similarly, the 7 vinyl acetate (50 ml.) were added separately at propor
monomer to be reacted with the polyethylene glycol can
tional rates over a period of 1.5 hours. The liquid turned
be added in toto before copolymerization is initiated, or 25 milky after one hour, and after stirring overnight a bluish
optionally, a portion may be added at the beginning and
emulsion was obtained. This was stripped of monomer
the remainder added gradually during the copolymeriza
by air blowing at 60° C. and water was added to restore
tion reaction. Likewise the catalyst solution can ‘be added .- ; the volume to the original level. The surface tension of
in a manner most conducive to the desired results; with
the emulsion product at 30° C. was 51.8 dynes per cm.
The emulsion was heated to drive off the water, leav
one or all of such components can similarly be added
ing a liquid phase and a colorless solid material at 110°
either'at the beginning or gradually during the polymeri~
after the water had evaporated. The liquid product was
zation reaction. '
separated and was found to be completely water soluble.
Likewise, in the preparation of stable resin emulsions
The surface tension of a 1% solution of the liquid at 30°
stabilized by these ‘water-soluble copolymers made in situ, 35 Was ‘found to ‘be 51 dynes/cm., compared to 65 dynes/
emulsion polymerization procedures well-known in the art
cm. for a 1% solution of Carbowax 4000 in water at 30°.
can be modi?ed and adapted. As before, the total quan
The vinyl acetate content of the liquid was 2.5% as deter
tity of the polyethylene glycol can be dissolved in water .J .1 mined by saponi?cation, and the liquid was thus identi?ed
in ‘the reaction vessel; before the, copolymerization re
as a copolymer of vinyl acetate and Carbowax. The
action begins, or optionally, only a portion may be in 40 solid material from the evaporated emulsion was ex
cluded in the initial reaction charge and the remainder
tracted with 100 ml. Water to remove occluded water~sol'
added ‘gradually as an aqueous solution during the course
uble liquids; the residual insoluble portion was shown
catalyst systems consisting of two or more components, 30
of the copolymerization. ‘Similarly,
the liquid to 'be po- ' ‘‘
lymerized can be added in to to before polymerization
is initiated, or optionally, a portion may be added at the
beginning and the remainder added’ at a rate to be deter
mined by some variable, such as the temperature of the
reaction or the rate of re?ux of unreacted monomer. ‘
Likewise the catalyst solution can be added in a manner
most conducive to the desired results; with catalyst sys
by analysis after drying to be polyvinyl‘ acetate (14
In this example, potassium persulfate was the sole
catalyst and approximately equal Weights of Carbowax
and vinyl acetate were reacted. The water-soluble por
tion of the emulsion product was subjected to chroma
tems consisting of two or more components, one or all of
tographic analysis.
such components can similarly be added either at the be
ginning or Igradually during the polymerization reaction. '
Carbowax 4000 (15 grams) was dissolved in water
(343 ml.) and heated to 60° C. with stirring. Potassium
It is sometimes advisable to utilize a minor amount of an
additional material in the form of a Wetting agent which
assists in the initial emulsi?cation of liquid monomer in
aqueous medium.
persulfate (0.8 gram) and‘ vinyl acetate (‘4 ml.) were
added and the temperature was raised slowly to 82° C.
Additional vinyl acetate ('11 ml.) was added while the
temperature was being raised from 70° to 82° C. The
temperature Wasmaintained at 82° C. for 10 minutes, and
The temperatures at which the polymerization and co
polymerization reactions are carried out arev preferably
was then increasedrto 90° C. before cooling. The product
between 20° C. and the re?uxing temperatures of the re 60 was an emulsion.
acting mixtures.
When the polymerization reaction is substantially com
plete, it is generally desirable to remove the small quan
tities’ or traces of unreacted, monomer which remain in
the reaction mixture, especially whenthe presence of such
monomer might have an adverse effect on the properties
of ?lms prepared from the emulsions of this invention.
Such unreacted monomer may be removed by any of
The emulsion was dried by evaporation of'the water
and the residue extracted with water ( at 60°.
The water-soluble extract when dried was a brownish
solid. Thesurface tension of a 1% solution of. the water
soluble extractwas 47.2 dynes/cm. while that of 1%
Carbowax 4000 solution was 65 dynes/cm, both at 30".
The combined vinyl acetate content of the water-soluble
extract was 8.8%, as determined by saponi?cation.
the conventional methods, such as by blowing with, air, 70 ' A sample of the water-soluble extract wasdissolvedin
benzene and adsorbed on a 5.5-inch column of alumina
distillation, or addition of, active catalyst systemsi
(25 grams). The column was eluted with two 50 ml.
Films‘ formed from resin emulsionscontaining the
portions of benzene, followed by six 50ml. portions of
benzene containing 2% methanol, and then by 100 ml.
copolymers as emulsifying agents formed in situare clear
and exhibit unexpectedly good water-resistance and scrub 75 methanol. Thewater-soluble extractwas foundto con
sist almost entirely of a surface active vinyl acetate
water-soluble polyethylene glycol-polymerizable liquid
Carbowax compound containing 4 to 7% vinyl acetate
by weight, or 1.6 to 3 moles vinyl acetate monomer to 1
thus obviously not due i0 simple mixtures of Carbowax
and polyvinyl acetate.
mole Carbowax 4000 (average molecular weight 3350).
All the fractions had a surface-tension depressant effect
In this example, an emulsifying agent was formed in
similar in magnitude to that noted above in this example.
This series of experiments (a) to (d) Was carried out
situ during emulsion polymerization of vinyl acetate. A
portion of the vinyl acetate evidently reacted with Carbo
to demonstrate that vinyl acetate and polyethylene glycol
(1) Water’ _________________________ __ 343.0 ml.
wax to form a surface active agent.
can combine in the presence of a suitable catalyst to give 10 (2) Santomerse S (30%) ____________ _. 7.0 ml.
a surfactant in aqueous media.
Potassium persulfate catalyst and Carbowax were dis
solved in water (quantities shown in Table I), heated to
(3) Carhowax 4000 ________________ __ 27.25 grams.
(4) Sodium bicarbonate ____________ __ 1.0 gram.
(5) Potassium persulfate (initial) ____ __ 0.8 gram.
4.0 ml.
421.0 ml.
(6) Vinyl acetate (initial) __________ __
60° C. and maintained at this temperature for one hour,
after which the vinyl acetate was added slowly. The pro 15 (7) Vinyl acetate (delayed) __________ __
(8) Potassium persulfate (delayed) __.__
portions were so chosen that the vinyl acetate was almost
(9) Potassium persulfate (terminal) ____
completely soluble in the water. The surface tensions of
the products are shown in Table I. The surface tension
of a 5% solution of Carbowax 4000 was 63.5 dynes/ cm.
Santornerse S is a'cornrnercial alkyl aryl
0.3 gram.
0.15 gram in
4 ml. H2O.
sodium sulfo
at 30° C. In another experiment identical with (0) below 20 nate wetting agent supplied by Monsanto Chemical Co.
except that no catalyst was used, the surface tension re
The ?rst six ingredients listed above were stirred to
gether at 240 rpm. and heated to 60° C. Addition of
that no surfactant was formed. In the four experiments
delayed vinyl acetate was then begun and heating was
in Table I, which employed the persulfate catalyst, the
continued to maintain the reaction temperature at 80—84°
surface tension of 5% solutions of the products at 30° C. 25 C. The rate of addition of vinyl acetate was controlled
was markedly lower than this value, indicating that a
so as to eliminate any re?ux. Delayed catalyst was added
surface active material was formed.
in small portions at intervals when the reaction showed a
tendency to diminish. Terminal catalyst was added after
Table 1
mained close to this value of 63.5 dynes/cm., indicating
completion of the delayed addition of vinyl acetate, while
Number Wate
CarboVinyl Potassi- Reaction Tension
wax 4000, Acetate, umPer- Temp, ofProd
° C.
uct at
30° 0.,
5. 1
0. 5
43. 4
the temperature was raised to 90° C. Total reaction time
was 6.75 hours.
The resulting stable emulsion had a solids content of
52% and residual monomer content of 0.8%. Particle
size was 0.2 to 0.8 micron. Films from the emulsion were
glass-clear and ?exible and had good water-spotting re
In similar experiments, the procedure was varied by
‘mixing together only items 1 to 4 and 6, while the catalyst
(item No. 5) was added subsequently. It was found
that emulsi?cation of the monomer did not occur until
the catalyst had been added and the reaction begun. This
In order to con?rm that the surface tension effects ob
indicated that the emulsi?er was being formed in situ.
tained in the previous examples could not be explained as
the effects of small amounts of low molecular weight poly
vinyl acetate dissolved in aqueous Carbowax solutions, the 45
Example 5 was repeated, using 15 grams of Carbowax
following two solubility experiments were carried out.
4000 instead of the 27.25 grams of Example 5, and 0.4
Gelva 2.5 (a commercial grade of polyvinyl acetate) was
gram delayed catalyst instead of the 0.3 gram of Example
the low molecular weight resin used. The “2.5” indicates
5. The other ingredients were the same as in Example 5.
‘the viscosity in centipoises of a solution of 86 grams of
resin made up to one liter with benzene and measured 50 The procedure was the same except that the total reaction
time was 9 hours instead of the 6.75 hours of Example 5.
at 20° C.
‘The solids content of the resulting emulsion was 51.2%,
(a) Carbowax 4000 (125 grams) was dissolved in
residual monomer 0.9%, and the particle size 0.2 to 0.5
distilled water (500 ml.) and the surface tension of the
micron. Films from the emulsion were glass-clear and
solution measured at 30° C. and found to be 54.0 dynes/
cm. Gelva 2.5 (2 grams) was added to the stirred solu 55 ?exible, and had excellent water-spotting resistance.
When the procedure of Example 6 was varied by em
'tion at 60°. The temperature was then raised to 90° C.
ploying a reduction~activated catalyst (potassium per
sulfate with sodium formaldehyde sulfoxylate), an emul
and maintained at that point for 3 hours. On cooling, a
slightly turbid solution was obtained, and the volume
was corrected to the original value. The surface tension
was found to be 55 dynes/cm. at 30°
sion of 46% solids and an average particle size of 0.1
'micron was obtained. Films of the dried emulsion were
clear and water-resistant.
acetate emulsion was prepared in
maintained at 70° C. The mixture was then evaporated
which the CarboWax-polyvinyl acetate compound as pre
to a volume of 250 ml. and the volume corrected to 500
65 pared in situ was the only surface active agent present,
ml. with distilled water. A turbid solution was thus ob
with the following ingredients:
tained. The polyvinyl acetate content of the solution was
(b) Carbowax 4000 (125 grams) and Gelva 2.5 (2.0
grams) were dissolved in methanol (350 ml.). The solu
tion was added, with vigorous stirring, to water (500 ml.)
found to be 0.02%, and the surface tension at 30° was
53.5 dynes/cm.
Aqueous solutions of Carbowax containing dissolved 70
polyvinyl acetate thus exhibit no signi?cant surface ten
sion depressing e?ects as a result of the dissolved poly
vinyl acetate. Furthermore, the solubility of polyvinyl
(1) Water ______________________ __ 343.0 ml.
(2) Carbowax 200 _______________ .._ 15.0 grams.
(3) Potassium persulfate __________ __ 1.5 grams.
(4) Vinyl acetate (initial) _________ __ 10.0 ml.
(5) Vinyl acetate (delayed) _______ __ 250.0 ml.
(6) Potassium persulfate (delayed) _.__ 0.5 gram in 20
acetate in aqueous Carbowax solutions is very low, under
ml. H20.
the most favorable conditions. The surface tension de 75 (7) Potassium persulfate (terminal) ___ 0.2 gram.
pressing effects of the products of Examples 1 to 3 are
The ?rst three ingredients were stirred together and
in a temperature rise to 80° C. The product was then
heated to 60° C. The initial vinyl acetate was added over
a period of 10 minutes, and when the temperature reached
70°, the addition of delayed vinyl acetate was begun.
The reaction temperature was increased to 80° C., and the
additionof delayed monomer and catalyst was completed
in about’ 5 hours. Terminal catalyst was then added, and
the temperature increased to 90° C. before cooling.
a solids content of 40.6%, and a particle size from 0.2
to 0.5 micron. Dried ?lms formed from the emulsion
were ?exible and glass-clear, and had good water-spotting
It will be readily understood by those skilled in the art
There was asmall quantity of resin adhering to the stirrer
at the end of the run.
The resulting stable emulsion contained 36% solids and
that numerous modi?cations may be made in the preced
had an average particle size between 0.6 and 0.7 micron.
It formed clear ?lms with good water-spotting resistance.
A stable polymethyl methacrylate emulsion was pre
pared in which the emulsifying agent was formed in situ,
using the following ingredients:
(1) Water.
7(2) Carbowax 4000 _________________ __grams__.
(A) a polyethylene glycol, and (B) a monomeric liquid
copolymerizable with the polyethylene glycol, said liquid
being selected from the group consisting of (a) vinyl
esters of alkanoic acids having four to ten carbon atoms
in the ester, ([1) alkyl esters of acrylic and methacrylic
acids having one to eight carbon atoms in the alkyl radi
temperature in the range between 20° C. and re?ux tem
(5) Potassium persulfate ______________ .._do_..__ 0.8
I claim:
1. A process for the preparation of a copolymer of
which process comprises ( 1) agitating at polymerization
(.4) Sodium formaldehyde sulfoxylate ____grams__ 0.3
ing examples without departing from the essence of the
invention as de?ned in the following claims.
30 20 cal, and (0) mixtures of the said vinyl and alkyl esters,
,(3) Methyl methacrylate (initial) ________ __ml__ '60
(6) Water _
The resulting stable polymethyl acrylate emulsion had
perature a system consisting essentially of: (i) water, (ii)
the polyethylene glycol, (iii) the copolymerizable liquid,
(7). Methyl methacrylate (delayed) _______ __ml__ 150 25 and (iv) a water-soluble polymerization catalyst for the
copolymerizable liquid of the group consisting of water
The inhibitor was removed from the monomer by wash
soluble free radical catalysts and water-soluble reduction
ing with an alkaline solution. The ?rst four ingredients
activated catalyst systems, and (2) continuing the agita
and 5* ml. of the persulfate solution (items 5 and 6) were
tion at polymerization temperature until polymerization is
stirred? at 40° C. in a one-litre kettle. Delayed addition
of items 5, 6 and 7 was started slowly. After 10 minutes, 30 ‘substantially complete.
the liquid became white, indicating that emulsi?cation of
2. A process as claimed in claim 1, wherein the poly
the monomer was taking place. The addition of delayed
ethylene glycol has an average molecular weight in the
range from 200 to 20,000.
methyl methacrylate was. completed in 85 minutes. The
temperature was. raised from 39° C; to 55° C. by heating.
3. A process as claimed in claim 2, wherein the molar
A total of 0.5 gram. persulfate and 0.3 gram sulfoxylate 35 ratio of polymerizable liquid to ethylene oxide units of
were added at intervals during the run. With addition of
the polyethylene glycol lies between 0.05 and 0.005.
the'remaining persulfate solution, the temperaturev rose
4. A process as claimed in claim 3, wherein the molar
from 67° C. to 85° C., after which the product was
ratio of polymerizable liquid to ethylene oxide units lies
between 0.05 and 0.025.
The product was a stable emulsion of polymethyl meth 40
5. A process as claimed in claim 4, wherein the polym
erizable liquid is vinyl acetate.
acrylate withv 43% solids and a particle size of 0.2-0.3
micron. The water-resistance of dried ?lms cast from the
6. \A process as claimed in claim 2, wherein the molar
ratio of polymerizable liquid toethylene oxide units lies
between 1.5 and 20, whereby a copolymer of the poly
ethylene glycol and the polymerizable liquid is produced
A_ stable polymethyl acrylate emulsion was prepared in
and simultaneously a polymer of the polymerizable liquid
the absence, of, any stabilizer other than that formed in
is produced as an emulsion stabilized by the copolymer.
emulsion was excellent.
situ, using the following ingredients:
('1), 'Water ________ _._ ____________ _._
7. A process as claimed in claim 6, wherein the polym
270 ml.
(2*) Carbowax 4000 ______________ __ 30 grams.
(3) Potassium persulfate __________ __ 0.8 gram in 30
ml. H20.
(4) Methyl; acrylate (initial) _______ __ 60.0 ml.
(5) Sodium formaldehyde sulfoxylate __ 0.3 gram.
‘(6) FeSO4 (catalyst activator) _____ __ 0.1 gram.
(7) Methyl acrylate (delayed) _____ __. 150.0 ml.
erizable liquid is vinyl acetate.
8. A process as claimed in claim 1, wherein the molar
ratio of polymerizable liquid to ethylene oxide units lies
between 1.5 and 20 whereby a copolymer of the poly
ethylene glycol and the polymerizable liquid is produced
simultaneously a polymer of the polymerizable liquid
is produced as an emulsion stabilized by the copolymer.
9. A process, as claimed in claim 2, in which the co
polymerizable liquid is methyl acrylate.
The Carbowax was dissolved in the water, the initial
monomer added, and 10 ml. of potassium persulfate solu
References Cited in the ?le of this patent
tion was added along with 0.2 gram sodium formaldehyde 60
sulfoxylate and stirred at 35° C. On addition of 0.1 gram
ferrous sulfate, the temperature rose to 52° C. The addi
Gibello ____________ __ Aug. 13, 1940
tion of delayed. monomer was carried out in 24 minutes,
Nozaki ______.___._____ Sept. 16, 1958
,at. the end of which time the ?nal temperature was 63 ° C.
Anderson et al.. ________ _._ Oct. 25, 1960
The remaining. 8 ml. of potassium persulfatesolution to 65
gether with 0.1 gram sulfoxylate were added, and resulted
Canada ______________ __ Jan. 26, 1954
Patent No. 3,058,940
October 16, 1962
Richard W‘, Rees
It is hereby certified that error appears in the above 'numbered pat
> ent requiring correction and that the said Letters Patent should read ‘as
corrected below.
Column 4,
line 21,
for "s0lu—" read —-—- solution —
Signed and‘ sealed this 23rd day of April 1963.,
Attesting Officer
Commissioner of Patents
Без категории
Размер файла
756 Кб
Пожаловаться на содержимое документа