Toner compositions

A toner comprised of color pigment and an addition polymer resin, and wherein said resin is generated by emulsion polymerization of from 70 to 85 weight percent of styrene, from about 5 to about 20 weight percent of isoprene, from about 1 to about 15 weight percent of acrylate, or from about 1 to about 15 weight percent of methacrylate, and from about 0.5 to about 5 weight percent of acrylic acid.

PENDING APPLICATIONS 
Illustrated in copending application U.S. Ser. No. 633,570 pending, filed 
concurrently herewith, the disclosure of which is totally incorporated 
herein by references, is a toner comprised of pigment and a 
styrene-isoprene-acrylic acid resin, and wherein said resin is obtained by 
the emulsion polymerization of from about 75 to about 90 weight percent of 
styrene, from about 5 to about 25 weight percent of isoprene, and from 
about 0.5 to about 5 percent of acrylic acid. 
BACKGROUND OF THE INVENTION 
The present invention is generally directed to toner compositions, 
developers thereof, and toner preparative processes, and more 
specifically, to a preparative process which involves aggregation of 
latex, colorant, and additive particles into toner sized aggregates, 
followed by coalescence or fusion of the latex particles within the 
aggregates to form integral toner particles to provide toner compositions. 
In embodiments, the present invention is directed to a chemical in situ 
preparative process for toners without the need to utilize conventional 
pulverization and classification methods, thus rendering the present 
process economical and wherein toner compositions with a particle size as 
herein defined by volume average diameter of from about 1 to about 20, and 
preferably from 2 to about 10 microns, and narrow particle size 
distribution as conventionally characterized by GSD (geometric standard 
deviation) of, for example, from about 1.10 to about 1.35, and more 
specifically, from about 1.15 to about 1.25 as measured on the Coulter 
Counter can be obtained. The resulting toners can be selected for known 
electrophotographic imaging and printing processes. In embodiments, the 
present invention is directed to toners based on addition polymer resins 
derived from emulsion polymerization of a mixture of styrene, isoprene, 
acrylate or methacrylate, and acrylic acid monomers, and a preparative 
process thereof comprised of blending by high shearing device a latex 
emulsion stabilized with an ionic surfactant, and an optional nonionic 
surfactant with an aqueous pigment dispersion containing an oppositely 
charged ionic surfactant and optional charge control additive, and other 
known toner additives. The volume average diameter of the latex particles 
suitable for the process of the present invention is from about 0.01 
micron to about 1.0 micron, and preferably from about 0.05 to about 0.5 
micron, while the amount of each ionic surfactant ranges from about 0.01 
percent to about 10 percent by weight of the total amount of the reaction 
mixture. The mixing of the two oppositely charged surfactants induces 
flocculation of latex, pigment, surfactants, and optional additive 
particles, which flocculent mixture, on heating with gentle mechanical 
stirring at a temperature range of from about 25.degree. C. below to about 
1 .degree. C. below the glass transition temperature (Tg) of the latex 
resin enables the formation of electrostatically bound toner sized 
aggregates comprised of latex, pigment, and optional additive particles. 
The size of the aggregates is primarily dependent on the temperature at 
which aggregation is carried out, and for a given latex composition, 
larger aggregates are obtained at higher temperatures, provided that the 
temperature is not above the Tg of the resin so as to cause fusion or 
coalescence of the latex particles. The particle size distribution of the 
aggregates does not appear to be dependent on the aggregation temperature, 
and is generally narrow as typified by a GSD of less than 1.35, and more 
specifically, of less than about 1.25. These aggregates, which have a 
volume average diameter of from about 1 to about 20 microns, are then 
subjected to further heating in the presence of additional anionic 
surfactant at a temperature above the Tg of the latex resin, and more 
specifically, at a temperature ranging from about 10.degree. C. to 
50.degree. C. above the Tg for a duration of 30 minutes to a few hours to 
effect fusion or coalescence of the latex particles within the aggregates 
to form integral toner particles. The degree of coalescence is dependent 
on the temperature and duration of the heating. Suitable temperatures for 
coalescence range, for example, from slightly above the Tg to over 
100.degree. C., depending on the nature of the latex resin, its 
composition, the pigment and optional additives. In general, the 
coalescence is conducted at a temperature of between about 65.degree. C. 
to about 110.degree. C., and preferably between about 75.degree. C. to 
about 105.degree. C. The resulting toner particles retain the size of the 
precursor aggregates, that is the volume average particle size of the 
aggregates is substantially preserved during coalescence wherein 
electrostatically bound aggregates are converted to integral toner 
particles as a result of the fusion of the latex particles within the 
aggregates. In another embodiment thereof, the present invention is 
directed to an economical chemical process comprised of first blending by 
high shear mixing an aqueous pigment dispersion containing a pigment, such 
as HELIOGEN BLUE.TM. or HOSTAPERM PINK.TM., and a cationic surfactant, 
such as benzalkonium chloride (SANIZOL B-50.TM.), with a latex emulsion 
comprised of suspended relatively low molecular weight latex resin 
particles derived from emulsion polymerization of styrene, isoprene, 
acrylate or methacrylate, and acrylic acid monomers. The latex emulsion is 
generally stabilized with an anionic surfactant, such as sodium 
dodecylbenzene sulfonate, for example NEOGEN R.TM. or NEOGEN SC.TM., and a 
nonionic surfactant, such as alkyl phenoxy poly(ethylenoxy)ethanol, for 
example IGE 897.TM. or ANTAROX 897.TM.. The latex size ranges from, for 
example, about 0.01 to about 1.0 micron in volume average diameter as 
measured by the Brookhaven Nanosizer. The mixing of the two dispersions 
with two oppositely charged surfactants induces flocculation of the latex, 
pigment, optional additive particles and surfactants, which flocculent 
mixture on heating at a temperature of from about 25.degree. C. to about 
1.degree. C. below the Tg of the latex resin results in the formation of 
electrostatically bound aggregates ranging in size from about 2 microns to 
about 10 microns in volume average diameter as measured by the Coulter 
Counter. On subsequent heating at about 10.degree. C. to about 50.degree. 
C. above the Tg of the resin in the presence of additional anionic 
surfactant, the aggregates are converted into integral toner particles. 
The aforementioned toners are especially useful for the development of 
colored images with excellent image resolution, color fidelity, and image 
projection efficiency. 
While not being desired to be limited by theory, it is believed that the 
aggregation is caused by the attraction between or neutralization of two 
oppositely charged surfactants, one absorbed on the pigment and optional 
additive particles, and the other on the latex particles. The aggregation 
process is temperature dependent, and is faster at higher temperatures. 
Subsequent heating of the aggregates at a temperature of, for example, 
10.degree. C. to 50.degree. C. above the latex resin Tg fuses or coalesces 
the latex particles within the aggregates, enabling the formation of 
integral toner particles comprised of polymer resin, pigment particles, 
and optionally charge control agents. Furthermore, in other embodiments 
the ionic surfactants on the pigment and latex particles can be 
interchanged, such that the pigment dispersion contains an anionic 
surfactant, while the latex emulsion contains a cationic surfactant. It is 
of importance in the processes of the present invention in embodiments 
that proper temperature control be exercised as the temperature affects 
both the aggregate size during aggregation, and the shape and surface 
morphology of the resulting toner particles during coalescence or fusion. 
Similarly, to obtain toners of the present invention with the required 
performance characteristics, critical selection of certain latex 
compositions derived from emulsion polymerization of styrene, isoprene, 
acrylate or methacrylate, and acrylic acid monomers is mandatory. 
In U.S. Pat. No. 5,366,841, the disclosure of which is totally incorporated 
herein by reference, there are illustrated emulsion/aggregation processes, 
and more specifically, a process for the preparation of toner compositions 
comprising: 
(i) preparing a pigment dispersion in water, which dispersion is comprised 
of a pigment, an ionic surfactant and optionally a charge control agent; 
(ii) shearing the pigment dispersion with a latex blend comprised of resin 
particles, an ionic surfactant of opposite charge polarity to that of said 
ionic surfactant in the pigment dispersion and a nonionic surfactant 
thereby causing a flocculation of resin, pigment, and charge control 
additive particles to form a uniform dispersion of solids in the water, 
and surfactant; 
(iii) heating the above sheared blend at a critical temperature region 
about equal to or above the glass transition temperature (Tg) of the 
resin, while continuously stirring to form electrostatically bounded toner 
size aggregates with a narrow particle size distribution, and wherein said 
critical temperature is from about 0.degree. C. to about 10.degree. C. 
above the resin Tg, and wherein the resin Tg is from about 30.degree. C. 
to about 65.degree. C. and preferably in the range of from about 
45.degree. C. to about 65.degree. C.; 
(iv) heating the statically bound aggregated particles from about 
10.degree. C. to about 45.degree. C. above the Tg of the resin particles 
to provide a toner composition comprised of polymeric resin, pigment and 
optionally a charge control agent; and 
(v) optionally separating and drying said toner. 
As examples of resins, in the U.S. Pat. No. 5,366,871 patent is indicated 
that there may be selected polymers selected from the group consisting of 
poly(styrene-butadiene), poly(para-methyl styrene-butadiene), 
poly(meta-methyl styrene-butadiene), poly(alpha-methyl styrene-butadiene), 
poly(methylmethacrylate-butadiene), poly(ethylmethacrylate-butadiene), 
poly(propylmethacrylate-butadiene), poly(butylmethacrylate-butadiene), 
poly(methylacrylate-butadiene), poly(ethylacrylate-butadiene), 
poly(propylacrylate-butadiene), poly(butylacrylate-butadiene), 
poly(styrene-isoprene), poly(para-methyl styrene-isoprene), 
poly(meta-methyl styrene-isoprene), poly(alpha-methylstyrene-isoprene), 
poly(methylmethacrylate-isoprene), poly(ethylmethacrylate-isoprene), 
poly(propylmethacrylate-isoprene), poly(butylmethacrylate-isoprene), 
poly(methylacrylate-isoprene), poly(ethylacrylate-isoprene), 
poly(propylacrylate-isoprene), and poly(butylacrylate-isoprene); 
terpolymers, such as poly(styrene-butadiene-acrylic acid), 
poly(styrene-butadiene-methacrylic acid), PLIOTONE.TM. available from 
Goodyear, polyethylene-terephthalate, polypropylene-terephthalate, 
polybutylene-terephthalate, polypentylene-terephthalate, 
polyhexalene-terephthalate, polyheptadene-terephthalate, 
polyoctalene-terephthalate, and the like. With the present invention, 
there are provided toners based on certain 
styrene-isoprene-acrylate-acrylic acid or 
styrene-isoprene-methacrylate-acrylic acid resin derived from 70 to 85 
weight percent of styrene, 5 to 20 weight percent of isoprene, 1 to 15 
weight percent of acrylate or methacrylate, and 0.5 to 5 weight percent of 
acrylic acid; the weight average molecular weight (M.sub.w) of the resin 
relative to the styrene standards is from about 20,000 to about 40,000 
while the number average molecular weight (M.sub.n) is from about 5,000 to 
about 10,000. Advantages achievable with the toners of the present 
invention include, for example, lower toner fusing temperatures of from 
about 135.degree. C. to about 170.degree. C., enhanced image resolution 
from narrow toner particle size distribution, low or no image background 
noise from narrow toner triboelectric charge distribution and lesser 
extent of out-of-specification fine particles, high image gloss and 
excellent image fix characteristics enabled by the relatively low 
molecular weight resin of specific compositions derived from emulsion 
polymerization of styrene, isoprene, acrylate or methacrylate, and acrylic 
acid monomers in embodiments of the present invention. All these 
attributes have contributed to the attainment of high image quality. 
There is illustrated in U.S. Pat. No. 4,996,127 a toner of associated 
particles of secondary particles comprising primary particles of a polymer 
having acidic or basic polar groups, and a coloring agent. The polymers 
selected for the toners of the '127 patent can be prepared by an emulsion 
polymerization method, see for example columns 4 and 5 of this patent. In 
column 7 of this '127 patent, it is indicated that the toner can be 
prepared by mixing the required amount of coloring agent and optional 
charge additive with an emulsion of the polymer having an acidic or basic 
polar group obtained by emulsion polymerization. Also, in column 9, lines 
50 to 55, it is indicated that a polar monomer, such as acrylic acid, in 
the emulsion resin is necessary, and toner preparation is not obtained 
without the use, for example, of acrylic acid polar group, see Comparative 
Example I. Additionally, the process of the '127 patent does not appear to 
utilize counterionic surfactant and flocculation process as does the 
present invention, and does not use a counterionic surfactant for 
dispersing the pigment. In U.S. Pat. No. 4,983,488, there is illustrated a 
process for the preparation of toners by the polymerization of a 
polymerizable monomer dispersed by emulsification in the presence of a 
colorant and/or a magnetic powder to prepare a principal resin component 
and then effecting coagulation of the resulting polymerization liquid in 
such a manner that the particles in the liquid after coagulation have 
diameters suitable for a toner. It is indicated in column 9 of this patent 
that coagulated particles of 1 to 100, and particularly 3 to 70 are 
obtained. This process is thus directed to the use of coagulants, such as 
inorganic magnesium sulfate, which results in the formation of particles 
with wide GSD. In U.S. Pat. No. 4,797,339, there is disclosed a process 
for the preparation of toners by resin emulsion polymerization, wherein 
similar to the '127 patent polar resins of opposite charges are selected, 
and wherein flocculation, as in the present invention, is not disclosed; 
and in U.S. Pat. No. 4,558,108, there is disclosed a process for the 
preparation of a copolymer of styrene and butadiene by specific suspension 
polymerization. Other prior art that may be of interest includes U.S. Pat. 
Nos. 3,674,736; 4,137,188 and 5,066,560. 
The process described in the present application has several advantages as 
indicated herein including the effective preparation of small toner 
particles with narrow particle size distribution without the need to 
utilize conventional classification processes; the process is very energy 
efficient as it is a wet process and does not involve energy intensive 
grinding or pulverization, and classification processes, high process and 
materials yields, short or reduced process times, and shorter or reduced 
change over time for preparing different color toners, therefore rendering 
it attractive and economical. The process of the present invention is 
particularly efficient for generating particle size below 10 microns, or 
more specifically, below 8 microns, which is in the regime where 
conventional pulverization methods become very cost ineffective. 
SUMMARY OF THE INVENTION 
Examples of objects of the present invention in embodiments thereof 
include: 
It is an object of the present invention to provide toner compositions and 
processes with many of the advantages illustrated herein. 
Another important object of the present invention resides in the provision 
of toners containing certain styrene-isoprene-acrylate-acrylic acid or 
styrene-isoprene-methacrylate-acrylic acid resins, and which toners 
provide high image gloss and excellent image fix at low fusing 
temperatures. 
In another object of the present invention there are provided simple and 
economical processes for the direct preparation of black and colored toner 
compositions with, for example, excellent pigment dispersion to enable 
high image color fidelity and excellent image projection efficiency. 
In another object of the present invention there are provided simple and 
economical chemical processes for black and colored toner compositions 
comprised of an aggregation step in which the latex, pigment and additive 
particles aggregate to form electrostatically bound toner sized 
aggregates, followed by a coalescence step in which the latex particles 
within the aggregates coalesce and fuse together to form integral toner 
particles of the present invention. 
In a further object of the present invention there is provided a process 
for the preparation of toner particles with a volume average diameter of 
from between about 2 to about 10 microns, and with a narrow GSD of from 
about 1.10 to about 1.35 without the need for size classification. 
In a further object of the present invention there is provided a chemical 
process for the preparation of toner compositions by aggregation and 
coalescence of latex, pigment and optional additive particles, with the 
resultant toner particle size being precisely achieved through proper 
control of the temperature at which aggregation is carried out, and which 
temperature is generally in the range of from about 25.degree. C. to about 
65.degree. C. 
In yet another object of the present invention there are provided toner 
compositions with lower fusing temperature characteristics of about 
5.degree. C. to about 30.degree. C. lower than those of conventional 
styrene-based toners. 
In another object of the present invention there are provided toner 
compositions which provide high image projection efficiency of, for 
example, from over 65 to about 95 percent as measured by the Match Scan II 
spectrophotometer available from Milton-Roy. 
In a further object of the present invention there are provided toner 
compositions which, when properly fused on paper substrate, afford minimal 
or no paper curl. 
These and other objects of the present invention are accomplished in 
embodiments by the provision of toners and processes thereof. In 
embodiments of the present invention, there are provided toners and 
processes for the economical preparation of toner compositions by 
aggregation of latex, pigment and additive particles, followed by 
coalescence or fusion of latex particles with the aggregates to give 
integral toner particles, and wherein the aggregation is conducted at a 
temperature of from about 25.degree. C. below to about 1.degree. C. below 
the Tg of the latex resin, while the coalescence is accomplished at a 
temperature that is about 10.degree. C. to about 55.degree. C. above the 
Tg temperature. 
The toners of the present invention preferably include as the resin an 
addition polymer derived from emulsion polymerization of about 70 to about 
85 weight percent of styrene, about 5 to about 20 weight percent of 
isoprene, about 1 to about 15 weight percent of acrylate or methacrylate, 
and about 0.5 to about 5 weight percent of acrylic acid monomers, and 
wherein the resin has an M.sub.w of from about 20,000 to about 35,000, and 
an M.sub.n of from about 5,000 to about 10,000. 
Embodiments of the present invention include a toner comprised of color 
pigment and an addition polymer resin, and wherein said resin is generated 
by emulsion polymerization of from about 70 to about 85 weight percent of 
styrene, from about 5 to about 20 weight percent of isoprene, from about 1 
to about 15 weight percent of acrylate, or from about 1 to about 15 weight 
percent of methacrylate, and from about 0.5 to about 5 weight percent of 
acrylic acid; a toner comprised of pigment and a 
styrene-isoprene-acrylate-acrylic acid resin or 
styrene-isoprene-methacrylate-acrylic acid resin, and wherein said resin 
is generated by the emulsion polymerization of from about 75 to about 85 
weight percent of styrene, about 5 to about 15 weight percent of isoprene, 
about 1 to about 15 weight percent of acrylate or about 1 to about 15 
weight percent of methacrylate, and about 0.5 to about 3 weight percent of 
acrylic acid, and wherein said resin possesses a weight average molecular 
weight (M.sub.w) of from about 20,000 to about 35,000 and a number average 
molecular weight (M.sub.n) of from about 6,000 to about 10,000 relative to 
the styrene standard; and a process for the preparation of toner 
compositions comprising: 
(i) preparing a pigment dispersion in water, which dispersion is comprised 
of a pigment, an ionic surfactant and optionally a charge control agent; 
(ii) shearing the pigment dispersion with a latex emulsion derived from a 
mixture of styrene, isoprene, acrylate or methacrylate, and acrylic acid, 
and wherein said resin is generated by the emulsion polymerization of from 
about 75 to about 85 weight percent of styrene, about 5 to about 15 weight 
percent of isoprene, about 1 to about 15 weight percent of acrylate or 
about 1 to about 15 weight percent of methacrylate, and about 0.5 to about 
3 weight percent of acrylic acid, and wherein said resin possesses a 
weight average molecular weight (M.sub.w) of from about 20,000 to about 
35,000 and a number average molecular weight (M.sub.n) of from about 6,000 
to about 10,000 relative to a styrene standard, and said resin is 
stabilized with an optional nonionic surfactant and an ionic surfactant 
having an opposite charge polarity to that of said ionic surfactant in the 
pigment dispersion, thereby causing a flocculation of the resin, pigment, 
surfactants, and optional charge control additive particles; 
(iii) heating the above flocculent mixture while stirring at a temperature 
of from about 25.degree. C. below to about 1.degree. C. below the glass 
transition temperature (Tg) of the resin to effect formation of 
electrostatically bounded toner sized aggregates with a narrow aggregate 
size distribution, and wherein the resin has a Tg of from about 45.degree. 
C. to about65.degree. C.; 
(iv) heating the aggregates from about 10.degree. C. to about 55.degree. C. 
above the Tg of the resin to form toner particles comprised of said 
polymeric resin, pigment and optionally a charge control agent; and 
(v) optionally separating and drying said toner. 
In embodiments, the present invention is directed to processes for the 
preparation of toner compositions, which comprises initially preparing an 
ionic pigment dispersion, for example by homogenizing an aqueous mixture 
of a pigment or pigments, such as carbon black like REGAL 330.RTM., 
phthalocyanine, quinacridone or RHODAMINE B.TM. type with a cationic 
surfactant, such as benzalkonium chloride, by means of a high shearing 
device, such as a Brinkman Polytron, thereafter blending this mixture 
using a high shear device, such as a polytron, a sonicator or 
microfluidizer, with a latex emulsion comprised of 
styrene-isoprene-acrylic acid resin particles stabilized with an anionic 
surfactant, such as sodium dodecylbenzene sulfonate and optional nonionic 
surfactants, and wherein the latex size ranges from about 0.01 to about 
1.0 micron, thereby giving rise to flocculation of latex particles with 
the pigment particles; heating the mixture at a temperature of preferably 
from 25.degree. C. below to 10.degree. C. above the Tg of the latex resin 
while being mechanically stirred at about 200 to about 500 rpm to effect 
formation of electrostatically bound aggregates with an average aggregate 
size ranging from about 1 to 20 microns, and preferably from about 3 to 10 
microns; followed by coalescing the resultant aggregates to integral toner 
particles at a temperature of preferably from about 10.degree. C. to about 
50.degree. C. above the Tg of the latex resin; and subsequently washing 
the toner with water; and drying by means of, for example, freeze dryer, 
fluidized bed dryer, or spray dryer to afford toner compositions comprised 
of styrene-isoprene-acrylic acid resin, pigment and optional additives 
with toner size of preferably from 3 to 10 microns in volume average 
diameter. 
Embodiments of the present invention include a process for the preparation 
of toner compositions comprised of pigment, optional additives, and 
certain critical resins derived from emulsion polymerization of a mixture 
of styrene, isoprene, acrylate or methacrylate, and acrylic acid monomers, 
comprising 
(i) preparing a pigment dispersion in water, which dispersion is comprised 
of a pigment, an ionic surfactant and optionally a charge control agent; 
(ii) blending by high shear mixing the pigment dispersion with a latex 
emulsion derived from a mixture of styrene, isoprene, acrylate or 
methacrylate, and acrylic acid monomers stabilized with an optional 
nonionic surfactant and an ionic surfactant that is of opposite polarity 
to that in the pigment dispersion; 
(iii) heating the resultant homogenized mixture at a temperature of 
preferably from 25.degree. C. below to 1.degree. C. below the Tg 
temperature of the latex resin, thereby inducing aggregation of latex, 
pigment and optional additive particles to form electrostatically bound 
toner sized aggregates; followed by 
(iv) coalescing the aggregates to form integral toner particles by heating 
at a temperature of about 10.degree. C. to about 55.degree. C. above the 
Tg temperature of the latex resin. 
Also, in embodiments the present invention is directed to processes for the 
preparation of toner compositions which comprises (i) preparing a pigment 
mixture by dispersing a pigment, such as carbon black like REGAL 330.RTM., 
HOSTAPERM PINK.TM., or PV FAST BLUE.TM. of from about 1 to about 20 
percent by weight of toner in an aqueous mixture containing a cationic 
surfactant, such as dialkylbenzene dialkylammonium chloride, for example 
SANIZOL B-50.TM. available from Kao, or MIRAPOL.TM. available from Alkaril 
Chemicals, utilizing a high shearing device, such as a Brinkman Polytron 
or IKA homogenizer for a duration of from about 1 minute to about 120 
minutes; (ii) adding the aforementioned cationic pigment dispersion to a 
latex emulsion derived from emulsion polymerization of styrene, isoprene, 
acrylate or methacrylate, and acrylic acid stabilized with an anionic 
surfactant like sodium dodecylsulfate, dodecylbenzene sulfonate or NEOGEN 
R.TM. and a nonionic surfactant, such as polyethylene glycol or 
polyoxyethylene glycol nonyl phenyl ether or IGE 897.TM. obtained from 
GAF Chemical Company, thereby causing a flocculation of latex, pigment, 
charge control additive particles; (iii) homogenizing the flocculent 
mixture using a high shearing device, such as a Brinkman Polytron or IKA 
homogenizer, at a speed of from about 3,000 revolutions per minute to 
about 10,000 revolutions per minute for a duration of from about 1 minute 
to about 120 minutes, and heating the resultant mixture at a temperature 
of from 25.degree. C. below to 1.degree. C. below the Tg of the latex 
resin while mechanically stirred at a speed of from about 250 to about 500 
rpm to effect formation of electrostatically bound aggregates of from 
about 2 microns to about 10 microns in volume average diameter; (iv) 
subsequently heating the aggregate mixture at 65.degree. C. to about 
110.degree. C. for a duration of about 30 minutes to a few hours in the 
presence of additional anionic surfactant in the amount of from about 0.01 
percent to about 5 percent by weight to form integral toner particles of 
from about 2 microns to about 10 microns in volume average diameter and a 
GSD of from about 1.15 to about 1.30 as measured by the Coulter Counter; 
and (v) isolating the toner particles by washing, filtering and drying 
thereby providing toner particles with a styrene-isoprene-acrylate-acrylic 
acid resin or styrene-isoprene-methacrylate-acrylic acid resin and 
pigment. Flow additives to improve flow properties and charge additives to 
improve charging characteristics may be optionally added by blending with 
the above mentioned toner, such additives include AEROSILS.RTM. or 
silicas, metal oxides like tin, titanium and the like, metal salts of 
fatty acids like zinc stearate, and which additives can be present in 
various effective amounts, such as from about 0.1 to about 10 percent by 
weight of toner. 
The aforementioned latex resins selected for the process of the present 
invention are present in various effective amounts, such as from about 70 
to about 98, and preferably from about 80 weight percent to about 98 
weight percent of the toner, and the latex particle size can be in 
embodiments of from about 0.01 micron to about 1 micron in volume average 
diameter as measured by the Brookhaven Nanosizer particle analyzer. 
Illustrative examples of the acrylate and methacrylate monomers utilized in 
the emulsion polymerization for the preparation of latex resin for the 
toner compositions of the present invention include methyl acrylate, ethyl 
acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl 
acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, 
butyl methacrylate, and the like, including other alkyl acrylates. 
Various known colorants or pigments present in the toner in an effective 
amount of, for example, from about 1 to about 20 percent by weight of the 
toner, and preferably in an amount of from about 3 to about 15 weight 
percent, that can be selected include carbon black, like REGAL 330.RTM., 
REGAL 660.RTM., REGAL 400.RTM., REGAL 400 R.RTM., and REGAL 330R.RTM., 
REGAL 660R.RTM. and other equivalent black pigments. As colored pigments, 
there can be selected known cyan, magenta, red, green, blue, brown, 
yellow, or mixtures thereof. Specific examples of pigments include 
phthalocyanine HELIOGEN BLUE L6900.TM., D6840.TM., D7080.TM., D7020.TM., 
PYLAM OIL BLUE.TM., PYLAM OIL YELLOW.TM., PIGMENT BLUE 1.TM. available 
from Paul Uhlich & Company, Inc., PIGMENT VIOLET 1.TM., PIGMENT RED 
48.TM., LEMON CHROME YELLOW DCC 1026.TM., E.D. TOLUIDINE RED.TM. and BON 
RED C.TM. available from Dominion Color Corporation, Ltd., Toronto, 
Ontario, NOVAperm YELLOW FGL.TM., HOSTAPERM PINK E.TM. from Hoechst, and 
CINQUASIA MAGENTA.TM. available from E.I. DuPont de Nemours & Company, and 
the like. Generally, colored pigments that can be selected are cyan, 
magenta, or yellow pigments. Examples of magenta materials that may be 
selected as pigments include, for example, 2,9-dimethyl-substituted 
quinacridone and anthraquinone dye identified in the Color Index as CI 
60710, CI Dispersed Red 15, diazo dye identified in the Color Index as CI 
26050, CI Solvent Red 19, and the like. Illustrative examples of cyan 
materials that may be used as pigments include copper tetra(octadecyl 
sulfonamido) phthalocyanine, x-copper phthalocyanine pigment listed in the 
Color Index as CI 74160, CI Pigment Blue, and Anthrathrene Blue, 
identified in the Color Index as CI 69810, Special Blue X-2137, and the 
like; while illustrative examples of yellow pigments that may be selected 
are diarylide yellow 3,3-dichlorobenzidene acetoacetanilides, a monoazo 
pigment identified in the Color Index as CI 12700, CI Solvent Yellow 16, a 
nitrophenyl amine sulfonamide identified in the Color Index as Foron 
Yellow SE/GLN, CI Dispersed Yellow 33 2,5-dimethoxy-4-sulfonanilide 
phenylazo-4'-chloro-2,5-dimethoxy acetoacetanilide, and Permanent Yellow 
FGL. 
The toner may also include known charge additives in effective amounts of, 
for example, from 0.1 to 5 weight percent, such as alkyl pyridinium 
halides, bisulfates, the charge control additives of U.S. Pat. Nos. 
3,944,493; 4,007,293; 4,079,014; 4,394,430 and 4,560,635, which 
illustrates a toner with a distearyl dimethyl ammonium methyl sulfate 
charge additive, the disclosures of which are totally incorporated herein 
by reference; nitrobenzene sulfonates; TRH, a known charge enhancing 
additive aluminum complex, BONTRON E-84.TM. and E-88.TM., available from 
Orient Chemicals of Japan, and other known charge enhancing additives, and 
the like. Mixtures of charge additives may also be selected. 
Examples of anionic surfactants employed in the emulsion polymerization for 
the preparation of latex resin for the toner compositions of the present 
invention include, for example, sodium dodecylsulfate, sodium 
dodecylbenzene sulfonate, sodium dodecylnaphthalene sulfate, dialkyl 
benzenealkyl, sulfates and sulfonates, abetic acid, available from 
Aldrich, NEOGEN R.TM., NEOGEN SC.TM. obtained from Kao and the like. An 
effective concentration of the anionic surfactant is, for example, from 
about 0.01 to about 10 percent by weight, and preferably from about 0.1 to 
about 5 percent by weight of the latex resin. 
Illustrative examples of nonionic surfactants in amounts of, for example, 
from about 0.01 to about 10 percent by weight, and preferably from about 
0.1 to about 5 percent by weight of latex resin in embodiments, include 
dialkylphenoxypoly(ethyleneoxy) ethanol available from Rhone-Poulenac as 
IGE CA-210.TM., IGE CA-520.TM., IGE CA-720.TM., IGE 
CO-890.TM., IGE CO-720.TM., IGE CO-290.TM., IGE CA-210.TM., 
ANTAROX 890.TM. and ANTAROX 897.TM.. 
Examples of cationic surfactants utilized in the pigment dispersion for the 
toners and processes of the present invention include, for example, 
dialkyl benzenealkyl ammonium chloride, lauryl trimethyl ammonium 
chloride, alkyl benzyl methyl ammonium chloride, alkyl benzyl dimethyl 
ammonium bromide, benzalkonium chloride, cetyl pyridinium bromide, 
C.sub.12, C.sub.15, C.sub.17 trimethyl ammonium bromides, halide salts of 
quaternized polyoxyethylalkylamines, dodecylbenzyl triethyl ammonium 
chloride, MIRAPOL.TM. and ALKAQUAT.TM. available from Alkaril Chemical 
Company, SANIZOL.TM. (benzalkonium chloride) available from Kao Chemicals, 
and the like, and mixtures thereof. This surfactant is utilized in various 
effective amounts, such as for example from about 0.01 to about 10 percent 
by weight of latex resin. Generally, the molar ratio of the cationic 
surfactant in the pigment dispersion to the anionic surfactant utilized in 
the latex preparation is in the range of from about 0.05 to about 4, and 
preferably from 0.05 to 2. 
Examples of the additional surfactants, which are added just before the 
coalescence step to prevent further growth in aggregate size with 
increasing temperature, include anionic surfactants such as sodium 
dodecylbenzene sulfonate, sodium dodecylnaphthalene sulfate, dialkyl 
benzenealkyl, sulfates and sulfonates, abitic acid, available from 
Aldrich, NEOGEN R.TM., NEOGEN SC.TM. obtained from Kao and the like, and 
nonionic surfactants such as polyvinyl alcohol, polyacrylic acid, 
methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy 
ethyl cellulose, carboxy methyl cellulose, polyoxyethylene cetyl ether, 
polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene 
octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan 
monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl 
ether, dialkylphenoxypoly(ethyleneoxy) ethanol available from 
Rhone-Poulenac as IGE CA-210.TM., IGE CA-520.TM., IGE CA-720.TM., 
IGE CO-890.TM., IGE CO-720.TM., IGE CO-290.TM., IGE 
CA-210.TM., ANTAROX 890.TM. and ANTAROX 897.TM.. An effective 
concentration of the surfactant that serves to stabilize the aggregate 
size during coalescence ranges, for example, from about 0.01 to about 10 
percent by weight, and preferably from about 0.05 to about 5 percent by 
weight of the total weight of reaction mixture. 
Surface additives that can be added to the toner compositions after washing 
and drying include, for example, those mentioned herein, such as metal 
salts, metal salts of fatty acids, colloidal silicas, mixtures thereof and 
the like, which additives are usually present in an amount of from about 
0.1 to about 2 weight percent, reference U.S. Pat. Nos. 3,590,000; 
3,720,617; 3,655,374 and 3,983,045, the disclosures of which are totally 
incorporated herein by reference. Preferred additives include zinc 
stearate and AEROSIL R972.RTM. available from Degussa in amounts of from 
0.1 to 2 percent, which can also be added during the aggregation or 
coalescence process, the washing step or the dry blending step wherein 
additives are mechanically coated onto the surface of the toner product. 
Developer compositions can be prepared by blending the toners obtained with 
the processes of the present invention with known carrier particles, 
including coated carriers, such as steel, iron, ferrites, and the like, 
reference U.S. Pat. Nos. 4,937,166 and 4,935,326, the disclosures of which 
are totally incorporated herein by reference, for example from about 2 
percent toner concentration to about 8 percent toner concentration.

The following Examples are being submitted to further define the various 
aspects of the present invention. These Examples are intended to be 
illustrative only and are not intended to limit the scope of the present 
invention. Comparative Examples are also provided. 
EXAMPLE I 
A mixture of 49.0 grams of styrene, 60.0 grams of isoprene, 48.0 grams of 
butyl acrylate, 12.0 grams of acrylic acid, and 18.0 grams of 
dodecanethiol was mechanically emulsified in 935.0 grams of aqueous 
solution of 13.5 grams of sodium dodecyl benzene sulfonate (SDBS) anionic 
surfactant (NEOGEN R.TM. which contains 60 percent of active SDBS and 40 
percent of water component), 12.9 grams of polyoxyethylene nonyl phenyl 
ether nonionic surfactant (ANTAROX 897.TM., 70 percent active, 
polyethoxylated alkylphenols), and 6.0 grams of ammonium persulfate 
initiator at room temperature for 25 minutes. The emulsion was then heated 
with mechanical stirring at 70.degree. C. for 6 hours to produce a latex 
emulsion containing 40 percent by weight of a latex polymer of styrene, 
isoprene, butyl acrylate, and acrylic acid monomers. The latex polymer 
evidenced a particle size of 120 nanometers, as measured on Brookhaven 
Nanosizer, and possessed a Tg of 54.5.degree. C. (mid-point), as measured 
on a DuPont DSC, an M.sub.w of 22,000, and an M.sub.n of 8,400 as 
determined on a Hewlett Packard GPC. 
260.0 Grams of the above latex emulsion and 230.0 grams of an aqueous 
mixture containing 7.5 grams of dispersed BHD 6000 Sunsperse Cyan Pigment 
(54.4 weight percent of pigment) obtained from Sun Chemicals, and 2.6 
grams of cationic surfactant, SANIZOL B.TM., were simultaneously added to 
400 grams of water with high shear stirring by means of a polytron. 
Subsequently, the mixture was transferred to a 2 liter reaction vessel and 
heated at 50.degree. C. for 95 minutes to effect formation of toner sized 
aggregates with a volume average aggregate size of 6.2 microns and a GSD 
of 1.18. After addition of 15.0 milliliters of 20 percent aqueous anionic 
surfactant (NEOGEN R.TM.) solution, the aggregate suspension was heated to 
a temperature of 95.degree. C. and held there for a period of 3 hours. The 
particle size of the resulting toner product was 6.6 microns with a GSD of 
1.20. 
Standard fusing properties of the toner compositions of the present 
invention were evaluated as follows: unfused images of toner on paper with 
a controlled toner mass per unit area of 1.2 milligrams/cm.sup.2 were 
produced by one of a number of methods. A suitable electrophotographic 
developer was produced by mixing from 2 to 10 percent by weight of the 
toner with a suitable electrophotographic carrier, such as, for example, a 
90 micron diameter ferrite core, spray coated with 0.5 weight percent of a 
terpolymer of poly(methyl methacrylate), styrene, and 
vinyltriethoxysilane, and roll milling the mixture for 10 to 30 minutes to 
produce a tribocharge of between -5 to -20 microcoulombs per gram of toner 
as measured by the Faraday Cage. The developer was introduced into a small 
electrophotographic copier, such as Mita DC-111, in which the fuser system 
had been disconnected. Between 20 and 50 unfused images of a test pattern 
consisting of a 65 millimeter by 65 millimeter square solid area were 
produced on 8 1/2 by 11 inch sheets of a typical electrophotographic paper 
such as Xerox Corporation Image LX.COPYRGT. paper. 
The unfused images were then fused by feeding them through a hot roll fuser 
consisting of a fuser roll and pressure roll with elastomer surfaces, both 
of which are heated to a controlled temperature. Fused images were 
produced over a range of hot roll fusing temperatures from about 
130.degree. C. to about 210.degree. C. The gloss of the fused images was 
measured according to TAPPI Standard T480 at a 75.degree. angle of 
incidence and reflection using a Novo-Gloss.COPYRGT. Statistical 
Glossmeter, Model GL-NG 1002S from Paul N. Gardner Company, Inc. The 
degree of permanence of the fused images was evaluated by the Crease Test 
(crease test data can be expressed as MFT). The fused image was folded 
under a specific weight with the toner image to the inside of the fold. 
The image was then unfolded and any loose toner wiped from the resulting 
Crease with a cotton swab. The average width of the paper substrate, which 
shows through the fused toner image in the vicinity of the Crease, was 
measured with a custom built image analysis system. 
The fusing performance of a toner is traditionally judged from the fusing 
temperatures required to achieve acceptable image gloss and fix. For high 
quality color applications, an image gloss greater than 50 gloss units is 
preferred. The minimum fuser temperature required to produce a gloss of 50 
is defined as T(G.sub.50) for a given toner. Similarly, the minimum fuser 
temperature required to produce a Crease value less than the maximum 
acceptable Crease is known as the Minimum Fix Temperature (MFT) for a 
given toner. In general, it is desirable to have both T(G.sub.50) and MFT 
as low as possible, such as for example below 190.degree. C., and 
preferably below 170.degree. C., in order to minimize the power 
requirements of the hot roll fuser. 
Fusing evaluation showed that the toner of this Example had a T(G.sub.50) 
of 136.degree. C. and an MFT of 144.degree. C. 
EXAMPLE II 
A latex emulsion was prepared in accordance with the procedure of Example I 
with the exception that 72.0 grams of isoprene and 36.0 grams of butyl 
acrylate were utilized in place of 60.0 grams of isoprene and 48.0 grams 
of butyl acrylate. The resulting latex emulsion showed a latex size of 125 
nanometers, a Tg of 56.5.degree. C. (mid-point), an M.sub.w of 30,500, and 
an M.sub.n of 8,900. 
A toner was prepared with the above latex emulsion in accordance with the 
procedure of Example I except that the aggregation reaction was conducted 
at 50.degree. C. for 50 minutes to produce 6.4 micron sized aggregates 
with a GSD of 1.17. The coalescence step was performed at 95.degree. C. 
for 5 hours to give a toner product with a particle size of 6.8 microns 
and a GSD of 1.21. Fusing evaluation indicated that the toner of this 
Example had a T(G.sub.50) of 135.degree. C. and an MFT of 142.degree. C. 
EXAMPLE III 
A latex emulsion was prepared in accordance with the procedure of Example I 
except that 504.0 grams of styrene, and 36.0 grams of butyl acrylate were 
utilized in place of 492.0 grams of styrene and 48.0 grams of butyl 
acrylate. The latex particle was measured to be 130 nanometers, and the 
latex polymer had a Tg of 58.5.degree. C. (mid-point), an M.sub.w of 
23,800, and an M.sub.n of 8,400. 
A toner was prepared with the above latex emulsion in accordance with the 
Example I except that the aggregation reaction was conducted at 53.degree. 
C. for 80 minutes to produce 6.1 micron aggregates with a GSD of 1.19. The 
subsequent coalescence step was performed at 95.degree. C. for a period of 
6 hours to give a toner product having a particle size of 6.6 microns and 
a GSD of 1.21. Fusing evaluation indicated that the toner of this Example 
had a T(G.sub.50) of 139.degree. C. and an MFT of 147.degree. C. 
EXAMPLE IV 
A latex emulsion was prepared in accordance with the procedure of Example I 
except that 84.0 grams of isoprene and 24 grams of butyl acrylate were 
used instead of 60.0 grams of isoprene and 48.0 grams of butyl acrylate. 
The latex emulsion showed a latex size of 120 nanometers, and the polymer 
possessed a Tg of 49.5.degree. C. (mid-point), an M.sub.w of 28,500, and 
an M.sub.n of 8,800. A toner was prepared from this latex emulsion as 
above except that the aggregation reaction was conducted at 48.degree. C. 
for 80 minutes to give an aggregate size of 8.1 microns and a GSD of 1.17. 
The subsequent coalescence was performed at 95.degree. C. for a period of 
5 hours. The toner size was measured to be 8.3 microns with a GSD of 1.20. 
Fusing evaluation indicated that the toner of this Example had a 
T(G.sub.50) of 134.degree. C. and an MFT of 140.degree. C. 
EXAMPLE V 
A latex emulsion was prepared as before with the exception that 36.0 grams 
of isoprene and 72.0 grams of butyl acrylate were used instead of 60.0 
grams of isoprene and 48.0 grams of butyl acrylate. The latex size was 
measured to be 125 nanometers, and the polymer had a Tg of 57.degree. C. 
(mid-point), an M.sub.w of 22,700, and an M.sub.n of 9,500. 
A toner was prepared from the above latex emulsion as before except that 
the aggregation reaction was conducted at 52.degree. C. for 2 hours to 
give an aggregate size of 6.8 microns and a GSD of 1.19. The subsequent 
coalescence was performed at 95.degree. C. for a period of 7 hours, 
affording a toner product with a particle size of 7.1 microns and a GSD of 
1.21. Fusing evaluation indicated that the toner of this Example had a 
T(G.sub.50) of 138.degree. C. and an MFT of 148.degree. C. 
Other embodiments and modifications of the present invention may occur to 
those skilled in the art subsequent to a review of the information 
presented herein; these embodiments and modifications, as well as 
equivalents thereof, are also included within the scope of the present 
invention.