Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
' 90 ~1~/02 22 30 ~OB 532 78f33 MAKINO ~ COMPANY 1~ o4/~47
2t~X2~
MASTER BATCH FOR PRODUCTIO~ OP TONERS
_ _ USE9 IN EL~CTROPHOTOGRAPHY _ _
BACKGROU~D o~ e INYENTION
Piald of tha Invention
Shis invention relates to a master bàtch for the
p~oduction of toner partlcle~ used in electroPhotograPhY,
and production of toner partlcles using such a master batch.
DescriPtion of the Prior Art
An electrophotographic process is well kno~n wherein
an electrostatic image i~ formed on a photoconductor, and
the electrostat3c i~ge is then developed with a devsloper
which contains toner particles, to providc a tonsr image.
and then the tonor i~ag~ is transferred and fixed on a
substrate,
Two methods are w~ll known for develoPing an electro-
s ta tic Ima~e on a photocond~ctor: a one-compOnsnt developing
method ~nd a two-component developin~ ~ethod. The two-
co~ponent dsveloper is composed o~ toner particl~s and
carrier particles, and now widely used in a magnetic brush
method, In a mul ~lcolor or ful I oolor electroPhotographic
~0 process which ha~ been very recently put to practical use,
a full color tonar ImA~e is produced by forming primary
color toner ima~es In laYers sequently on a substrate, and
accordingly th~ tho-co~Ponent devcloping ~ethod are mainly
eMployed ;n the proc~ss.
In general, triboelectricitY of toner partioles has a
' gO lfl/~2 22 31 ~(:)~ 532 7~3~3 MAI:INO & COMPANY 1~lo~5/~47
2~22Q~ ~
great influ8nce upon quality of fixed images either in the
one-co~ponent or in the two-co0ponent develol)ing ~ethod.
When tone~ particles used in ~he two-component developing
method have an insufficient specific oloctric charse (an
electric cha~ge per weighl of toners), Ihe toner particles
have an insufficlent electrostatic interaction ~ith the
carrier partlcles, so that ~he toner contaminales ths
surroundin~ of the develoPing device, or adheres to areas
having no images on a photoconductor, to produce fo~ on
the resultant fixed Image. On the olher hand. when ~oner
particles have an sxcesslvelY large specific electric
charge, an insufficlent arount of toner particler, adheres
to an electrostatic image, to produce a fixed image ~Ith
an in~ufflcient darkness. Thus, ~hen toner particle~
contain a dye or a pigment dispersed unevenly ~herein as
particles of varied sizes. there arise problems of
unstabllity of i~age darkDess, background contamination or
fog on the ima~e, but also of filming of toner psrticles
on photocondùctors,
In th~, one-component developing method, toner
particles ~re ussd whlch contain ma~netic particles
therein, and the ton~r particles are charged by mutual
friction or by frictlon with daveloping sleeves ~owever,
in the one-component developing method, toner particles
are apt to 'c,e charged morë unstably and insufficiently
than in the tWo-comPonent developing method. Thus, when
toner partlcle~ contaln s~ch parlicles as have insufficient
specific electric char8e, the resultant fixed images haue
a small or varied darkness as well as fog
In this way, when toner particles have a Yar i ed
specific electric charge, cither in the t~o-comPonent
developing ~ethod or the one-component developin method,
there arise a nu~ber of undeslrable problems,
Therefore it is very important that individual toner
particles have varlous additives, in particuldr. a dye or
' ~10 ()~02 22 32 5(:)ô 532 7~63 MAKINO & ~OMPANY 1~l~06/l347
2022~
a pigMent as a charge cont~ol agent, dispersed as finely
and evcnly as possible therein so that the individual toner
particle~ ars equally electrifi~d, thereby to produce hi~h
quality fixed images stablY and constantly
However, it is difficult to disperse a dye or a
pigment as a charge control agent or a coloring agent finely
and evenly in the individual toner p~rticles bY a known
conv~ntional method. Su~h a known conventional method of
producing toners comPrises admixing a binde~ resin with a
10 dye or a pigmant by an effective agitation t~ form a mixture,
melting and kneadin~ the mixture with, for exsmple, a twin
screw extruder, a heating kneadsr or a heatin8 roll, and
then cooling a~d crushing the mi~ture to a powder When
needed, the powde~ is classifled to a desirable particle
lS ~ize, and the Powder Is surface-treated with, for example,
colloidal silica, so that the powd~r has a high fluidity.
~l~ost all the dyes and pigments which have heretofor
been used in the productlon of toners contain at least In
part particles having a larger diameter than the desirable
diameter of tonqrs, Th~se particles can not be finely
dispsrsed in toner particle~ by a convention~l method, wi th
ths consequence that the toner particles eontain an
insufficient anount of dye or pigment thereln, or it
haPpens thst s0~8 of toner particles contain only a single
~5 pa r t I c Io of dye or p i g ~e n t therein.
Shus thqre is proposed an imProved method of the
production of toner partioles to obviate such a problem as
aboYe mentioned in Japanese Patent Appli ca tion Laid-oPen
No. 62-30~59. According to the method, at ~irst. a part
of a binder resin. and a full amount of a dye or a pigment
are Mixed, melted and kneaded to8ethen, and then cooled
and crushed to form a master batch Then the master batch
is mixed with the re~ainder of the binder neslnt melted,
kneaded. cooled and crushed to provide toner particles.
However, binder reslns generallY have a low polarity,
' 90 ~)~/l)2 22 33 ~lG 5~2 78f33 MAKINO 1~ COMPANY l~t~7/~47
20229~3.
whereas dy~s and pigments generally h~ve a high polarity,
so that it is essentially difficult from the chemical
standpoint to disPsrse such dyes or pigments finely and
ev~nly in the binder resins by melt-kn~ading.
A further method is disclo~ed in Jap~nese Patent
APPlication Laid-open No. 61-156054. In the ~ethode at
first, a part of a binder resin and a charge control agent
are dissolved in an organic solvent, and then the solvent
ic removed, to form a mastsr batch. The master batch is
then melted and kneaded togeth~r with the remainder of the
binder resin, and the mixture is cooled and crushsd to
tonor particles, However. this ~ethod needs a la~ge amount
of solvent and costs a great deal, since the ch~rge control
aent is in gene~sl rar~ly soluble in organic ~olvents.
1~
BRIEP SUMMARY QF THE INVENTION
It ls, ther~fore, an obJect of the i.nv~ntion to
provide a method of producing ton~r particles. elther
monochroMatic or colored. for use in electrophotograPhy
which individually have ~ dye or a pigmcnt evenlY
dlspersed therein as finely divided particles.
It is a further obJect of the invention to provide
a master batch suitablY used for the production of such
toner particles as above mentioned.
In accordance with t~e invcntion, there is provided
a method of prod~cing a ~aster batch for the production of
toners used in electrophotography, which eomprises:
(a) prePerin~ a resin solution;
tb) preParing a mixture which has a dye or e pig~ent
flnely dispersed in the resin solutioni ~nd
(c) re~ovin~ the solvent from the m~xture.
The resin solution is prepared either bY polymerizlng
monomera in an organic solvent or by dissolving a binder
resin in ~n organic solvent.
9(~ )2 22 34 ~(~6 532 7~63 MA~IN0 & COMPANY ~08/~47
2~22~
Thus, more specifically, in accordanoe with the
lnvention, there is provided a method of producing a mas~er
b~tch for the production of to~ers used in electrophoto-
graphy, which comprises:
(a) polym~rizing monomers in an or~anic solvent to
PrePare a resin solution; and
(b) prcparing a mixturc which has a dye or a pigment
}inely dlsPersed in the resin solution; and
(c) removing the solYent from the mixture.
~urther in accordanc~ with the invention. there is
provided a method of prod~cing a master batch for the
production of toners used in electrophotographY, which
compris es:
(a) di~solving a binder resin in an organic solvsnt
to PrApsre a resin solution;
tb) milllng and dispersing a dye or a pig~ent in ths
resin solution to prePare a mixturs; and
(c) removing the solvent from thfi mixture.
There is provided a further method of producing a
~aster batch for the productlon of toner partcl~ used in
electrophotography, which comprises:
(a) dissolving a binder r~sin in an organic solven~
to prepare a resin golution:
(b) milling and dispersing a dye or a pi~ment in an
or~anic solvent to prsPare a di~perslon; and
(c) ~ixing thc resin solution and the dispersion
to~ether to prepare a mixture, ~nd removing the solvent
fro~ the mixture.
In accordance with the invention, there is also
provided a method of producing toner particles for use in
electrophoto~r~phy, which, in adition to the stePS (a),
(b) and (c) as above s~S fo~th, furth~r comprises:
(d) adding a further amount of a second bindar resin
to~ether with an effective amount of an additi~e when
necessary, to form a second mixture, and kneading thc
so 08/02 22 3~ 532 7863 MAK I N0 & COMPANY (~ ~)09/~)97
2022nll
sec~nd mixture to a composition; dnd
(e) crushing the composition So toner particle~.
Other features and advantages of the invention will
be apparent fr~m the folloNing descr.iption taken in
connection wi th the drawines, In which:
~ig. 1 is a graph show;ng the relation between the
nu~be~ of copied ~heets prepared using a develoPer
according to the invention and the fixed ima8e darkness;
Pig 2 Is ~ grapl~ owln~ the rel~tion betwcon ths
number of copied sheets prepared using a develoPer of
comparative examples and the fixed i~age darknass;
P~g. 3 is a graph showing the relation bet~e~n the
number of copied sheets prepared using a devcloPer
according to the invention and a developer of comparative
lS exa~ples, respe~tively, and the fixed i~age dar~noss:
~i~. 4 is a ~raPh showlng a distribution of tribo-
electrioity of toner particle~ according to the lnvention;
Plg. S is a graph showing ~ distrib~tion of tribo-
el~etricity of toner psrticles of comparative examples:
Pig. 6 is a graph showing a dlstribution of tribo-
electricity of toner particles accordin~ to the invention
and toner particles of co~parative examples, resPectively;
Pig. 7 is a graph showin8 the r~lation betweqn the
number of coPied shects prePared u~ing a develoPer
according to the inventlon and the fixed i~a~e darkness:
~ig. 8 is a g~aPh showing the relation between the
number of copied sheets prepared usin~ a developer of
comParative exa~ples and the flxed image darkness;
Fig 9 is a graph showlng a distribution of tribo-
electricity of toner particles according to the invention;
Fig. 10 is d grsph shôwin2 a distribution of tribo-
electricity of toner particles of comparative examples;
Fig. Il ~s a g~aph shohing the ~elation between the
number of eopied sheets prepared using a developer
35 accordlng to the invention and th~ fixed ima~e darkness;
'~0 08~02 22 35 ~06 532 7~63 MA~INO ~ ~OMPANY ~ 010/~47
2022~1~
Pi~. 12 is a graph ~howing the relation between the
number of copied sheets prepared using a develoPer of
comparative examples and the toner image d~rkness:
Fig. 13 is a graPh showing a distribution of tribo-
èlectricity of toner particles accordin~ to ~he invention;and
Fi~, 14 is a g~aPh showing a distribution of tribo-
electricity of toner particles of comParative examples.
.
DETAI~ED DeSCRlPT10~ ~ THE lNVeNTlON
She bindcr resin used is not specifically limited.
but any resin may be used which i~ known in thc art of
toners for use in electroPhotography. There maY be
~entioned as such a binder resin, for instance. a homo-
polymers or copolymers of two or more of radical polymeri-
zable MOnOmers such as styr~ne, o-Methylsty~ene, m-~ethyl-
stYrene, p-methylstyrene, P-chloro~tyrene. vinYI acetate,
vinyl propionate, methYl acryl~te, e~hyl acrYlate, n-butyl
acrylate, isobutyl ecrYlate. n-octyl acrylate. dodecyl
acrylate, 2-ethylh~xyl acrYlate, stea~yl scrylate. ~-
chlorostearyl acrylate, phenyl acryalte, methYI ~-chloro-
acrylate, methyl ~ethacrYlate. ethyl methacryl~te. proPYI
methacrylate, n-butyl methacrYlate1 isobutyl ~ethacrylate,
n-octyl methacrylate, dodccyl me~hacrylate, 2-ethYlhexyl
~ethacryl~te, st~aryl methacrylate, phenyl methacrylate,
di~ethylaminoethyl methacrylate, diethylamino~thyl
methacrylate, acrylonitrile. m~thacrylonitrile,
acryloamide, glycidyl acrYlate, ~Iycidyl methacrylate,
acrylic acid, meth~crYIic acid, 2-vinylpyridine or
4-vinylpyridine.
Among the above. howeve~, polystyrene or a styrcne-
acrylate or methacrYlste such as butyl acrYIate or butyl
methacrylate is prsferrcd.
The organic solvent us~d in the preparation of resin
12 22 36 ~06 532 7~63 MA~IN0 & COMPANY 1~11/0~7
~Q22~
solution is such that the blnder resin used is soluble
therein. It is preferred that the dye or Piement used is
readily wetted with the solvent. Since any dye or pigment
is ~enerally of high polarity, the solvent used preferably
has a polar group therein. Th~refore, there may be
mentioned as such pol~r sol~ants, for exa~Ple, aliphatic
ketones such as methyl ethyl ketone or methyl 5sobutyl
hetone. alkyl esters of lower aliphatie carboxylic acids
such as m~thyl acetate. ethyl acetate, propyl acetate or
butyl acetate, lower aliphatic ~Icohols such as propanol
or butanol, or ethers such as tetrahydrofuran. However,
when a dYe or a pigment of a relativHly low polarity is
used, an aromatlc hydrocarbon 9uch ~s tolu~ne or xylene
may be used as the solvent. When needed, a mixture of the
~llphatic alcohol and tha aromatic hydrocarbon may be us~d
ac the sol~ent Ho~ver. the solvent ~sed in the invsntion
is not limlted to the abova 0xe~pl~fied.
in the prgParation of ths resin sol~tion, ~ res5n is
used in an amount of 1-40 parts by ~elght, preferably in An
amount of 5-20 paFts by wel8ht, In relation to 100 parts
by weight of the organ~c 8 0 I V ent.
The resin solution is prepsred by dissolvin~ a resin
in an organic solvQnt as hcreinbefore set fortb. but the
resin solution may b~ prepared by polymerizing a poly-
~erizable monomer in an organic solvent. In ~he l~tter
method, the resultant resin solution may contain unreacted
monomers.
Then a dye or a pigment is added to the resin
solution, and m~lled and disPersed therein bY use of a
cunv~nliun~l mill;ng ~ns DUC a~ a h~ll mill. th*r~by to
prePare a ~ixture of resin, dye or pigment. and solvent.
~hen desirable, a dispersing agent s~ch as ethylene-
~inyl acetate coPolymers may be used in the preparation of
l51~ mlxtule, ~hen 3u~h a disp~roine a~en~ io ussd. a
~elatively low polar org8nic ~olvent is prsferablY used as
22 37 2S~ 532 78~3 MAKINO ~ COMPANY ~012~047
2~22~
a medium for th~ mlxture. The dy~ or pigment functions as
a coloring a~ent ~Ind/or a ch~rge control a8ent in the
resul tant toner p~rticl~s.
The dy0 or pigment used ~n the ~nvenSion is not
specifically lim;t~d, and there may be m0ntioned. for
ex3mple~, a proton donatin~ dye stlch ag a ni~rosine dy
repr~sen ted by:
~ U $
wher~in X~ is ~n anlotl ~pocl~, and a pro~on ~cc~ptin~
d~e sllch a-~ ~ chrolliu-i Gontslning dye r~pressnt~d by:
~ 1~ x
~R I N~NO~
wh4tH;n X~ i~ a cation species, or Spi~on Bl~ck TRH~ (by
Hodogay~ N0gak~ Kogyo K. K., Japan) rePre~en tcd by:
' 9~8, . 19~2e~ ~6 532 7863 MAKINO & OMPANY ~ 2~002
2022nl~
0,N~O 1 ~CO~H~)
~IINOC~ T _~N 0
wherein ~1' is a c~tlon ~peci0~.
C~rbon bl~ck is pr~lfcrably use~ ~s a coloring agcnt
in the production o~ ~onochro~atic toaer particl~s whereas
a Y~riety of ~o dyes or phthalocyanino plgmsnts are
preferably used ~n the productlon of colorcd toner particles.
The dye or pi~nlont 1~ u~d in 3n emount o~ 1-40 parts
by weight, preferably in an amount of 2^50 parts by ~eight,
in rel~tion to 100 part~ by wl~ht of the orgsnic solvent
used for the production of re~ln solu~ion.
The or~anlc solvent ls then removed from the mixture
by any conventional means such a~ h~atin~ or d~Yin~ under
reduced Press~re or frozen drylne ther~by to provide a
~a3t~r b~tch of th~ invention. The ~aster batch moY be
cru~hed or 1~1 Ied, when needed.
The resultant m~ator batch h~s a dye or a pi8ment
diapersed therein as finely dlvided p~rtlcle~ of not more
thsn about 5 ~n, and ~bout 1 ~ ~ In prefHrred embodiments,
eve~ ~hen the dye or pig~ent co~tains pa~tlcles iarger in
dia~eter than the preferr0d toner part~cles.
~ ~a3ter batch 13 ~ener~llg defined as a colo~ed
materlal co0po~ad of a rs3in havin~ a colorant disPersed
therein in a hi eh con~ent. Such a ~agt~r bstch h~s hith~rto
~5 been pro~uc~d by m~lting an~ kneading to8ether a mixture
' ~0 08/t~2 22 38 ~)~ 532 7863 MAI:IN0 & COMPANY 014/047
2~22$~
of a resin ~nd a coloring agent in the absence of a solvent,
cooling ths resultant kneaded mass and then crushing ~r
granulating the mass, as hereinbefore set forth. However,
a resin is generally of ION polarity whereas many dyes or
pi~me11ts are Or h16~ lv.i~y~ t ~h~ ~o~ mc~t;onod
conventional methods fail to provide a master bateh in
which dyes or pi8ments are ev0nly dispersed t~erein a~
finely dividsd particles. tn contrast to this prior art,
a ~aster batch is produced according to the invention by
dissolvin8 a resin in an organic solvent to prepare a
resin solution, ~illing and dispersing a dye or a p;gment
in the resln solution to prcpare a mlxturs, and thcn th~
solvent is removed from th0 ~ixture. Thus, the ~ f
the inventi~n Provide~ a m~ster batch which n.nntains a dYe
or a pig~ent evenly disPersed thsrein as finely divided
particles.
In accordance ~ith the invention, there is providod
a further method of producin~ a master batch for the
production of toner partcles used in electrophoto~raphy,
which comprlses:
(a) d;~ olv;~ b;ndol . ~q;n; n An ore~n;c solvent
to prepare a resin solution;
~b) milling and dispersing a dYe or a pigment in an
organic solvent to prepare a di~persion; and
(c) mixin~ the reein ~ol~tioo and the dispersion
to~ether ~o ~r~pale a mlxture, ~nd r~movin~ the solv~nt
f rom the mix ture
The resin solution is pr~pared in the same manner as
he~einbcfore ~t forth. In thi.e sacond method of produoing
a master batch, ~ disPersion of a dYe or pigment in an
organic solvent is prePared. and then the dispers;on is
admixed with the resin solution to prepare a mixture.
~he solvent used in the preparation of the dispersion
of a dYe or a pi~ment is such that the dye or pigment used
is readily wetted therewith. lt is preferred tha~ lh~
2~2g~
8~ 22 ~0 ~P~6 532 7863 MAKINO & ~OMPANY 1~015~047
~olven~ i~ th<~ mc ~ tho ~olvont i r1 th~ r~;n ~ ior~.
However, the solvent uged for the prepar~tion of the
P~rs~ ay bc diff~rent from thc solvont in th~ r~sin
solution if the reSin Is soluble therein when the resin
soIution and the d iepersion ar e mlxed tog eth t' r to prepare
a mlxture.
~ dye or a pigmeat is milled with a eonventional
crushln~ ~eans ~uch as a bal I mi 11 and dispersed in ~
solvent to preP~rc a dispsrsion. In the preparation of
~ d;spel~loQ, ~ dr~ o- pl6mcnt i~ uood in ~n amount ~f
1-40 part~ by wal8ht, pr~f~rably in an ~mount of ~-50 parts
by wel~h~, in t~0lation to 100 parts by wiaht of the organic
solvent used. ~hen desitable~ a dispersing agent such 3s
ethyll~ne-vinyl acet~te copol~Hrs may be ussd in the
preparation of the di~Per~lon. Wh~n such a dispersing
agant is used, a relatively low Polar organic sol~ent i9
pt~eferably u3ed as a mediull for the disp~rslon.
~ the preparntlon of a m~xture ~f the resin solution
nnd the dispersion, the dlspersion ~s mixed wi th the resln
~olutlon so th~t the resultan~ mastsr batch contains the
dy~ or Plrmcne tn 1l r~qulr~a ~r prcdc~r~lnu~ IVU~
Then the ~olv~nt i!l reMoved from the mixture by any conven-
tlonal m~ans as h~r~lnbefor~ Ment~oned thereby to provide
a ~as t~r ba Lch of tho i nvon t i on . The ma~ tcr ba tch ~a~ be
cru9h~d or mi I led. ~h~n n0sded.
Sim{lsrly ~ith the master b3tch prepared by th~
firqt ~ethod, th0 resultant ma3t~r ba kh prepared by the
~econd ~thod al~o h~s a dYe or a pigment dispersed therein
as finely dlvid~d particles of not mor~ than about 5 ~ ~,
and ~bout 1 ~ ~ in pr~ferred e~bodimen ts, even wh~n the
dy- or P~e~ent cont~nq ~rticl~s larger in diareter than
Ihs Prc~orred tonor particlo~.
A~ a ~urths~r 31~p~Ct of th~ ;Rv~n~ n, th~re ig
provid~d a ~ethod of produclng toner partlclf~,s f<~r u~
c I ec tropho tography . The r~e thod, i n add I t i on t~ the s teps
' 9~ 0~()2 22 41 ~lf3 532 7S63 MAKIN0 & COMPANY [i~016/1347
~022~1~
o~ ~a), (b) and (~ r tho preparati~n of ~ m~ster b~tch.
further comprises:
(d) add{ng a further amount of a second binder resin
to the master batch togeSher hith an effectlve amount of
an additive when neCeSSarY, to form a sscond mixture. and
kneading the second mixture to a composition; and
(e) crushing the composition to toner particles.
The second binder ~esin may be either the same as or
different froM the first binder resin usod in the Production
of the master batch. But when the second binder resin is
different from the first, it is preferr~d that the sscond
bind~r resin is comPatible wl th the first binder resin.
The additives used in the production of tonsr
particles are ~ell known in the art of toner production,
lS and are added in an effective amount to the master batch
together with the second binder resin so that the
resultant toner particles have desirable or designed
proPerties. For instance, the additive ~ay be a magnetic
material to provide toner partlcles with magnetic properties
or a polyolefin wax such as polyethylene wax or poly-
propylene wax to provide toner particles wlth antioffset
prop~rties. A dye or a pigment such as hereinbefore
mentioned may also b~ incorporated into toner particles as
an additive in this sta~e. Magnetic oxides such as ferrite
or magne~ite, or other magne$1c metals are used as the
magnetic material~ The magnetic materi~l is used in an
amount of 30-300 parts by weight, preferablY of 30-1~0
parts by weight, in relation to 100 parts by Nei~ht of the
total amount of bindor resin used.
As a still further aspect of the invention. such a
mastcr batch may be produced according to the inventlon as
conSains a dye or a pigment or other additives in such an
amount that toner particlcs require. Such a mas ter bs tch
is crushcd and millsd as it is or after being mixed with
additives to provide toner particl~s. The master batch in
_ ~ g~l 0~03 2~):32 ~lB 532 7~ff3 MAKINO & COMPANY 1~ J1
2 ~
14
this sense does not contain a dye or a pi~en~ in A high
content, but it is referred to as a master batch in the
invention.
The above master batch may be produced by either
method set forth hereinbefore. ~ors specificallY. a dYc
or pigment is added to and ~ixed with a solution of resin,
the dYe or pigment is milled and dispersed in the
solution. and then the solvsnt is removed fro~ the mixture
to provide a magter batch. Alternatively, ~ dispe~sion of
~ye or PigmenS is added to and mixed with a solution of
resin to dlsperse the dye or pigment in the solution. and
then the solvent ls reMoved from the mixtu~e to provide a
master batch. In these methods, however, a dYe or pigment
is u6ed in an amount of 0.5-10 parts by weight. preferably
1-5 parts by weight in relation to IOO parts by weight of
rssin.
When the toner of the 1nv~ntion is used as a two-
component developing aeent, the toner is ~ixed with a
carrier material such as a powder of iron. ferrite or
~0 ~a8netite aj well known in the art of el~ctroPhotograPhy,
The two-component developing agent contains th~ toner in an
amount of 2-20 X by weight, preferably of 5-10X by weight.
~ he resultant toner particle~ have a uniform dis~ri-
bution of ~pecific electric charge snd coloring agen~ so
that they produces eithar ~onochromatic or full color Loner
images with a sufficient darkness constantlY free from fogs
or contamination thereon. Further, there arises no prblem
of fil0in~ of toners on a photoconducti~e body.
The invention will now be described more specifically
with reference to examples, howev~r, the lnYention is not
limited thereto.
xa~Qle
One part by weight of a nlgrosina dye ~Nigrosine
Base EX available fro~ Orient Kagaku Xo~yo X.~ s a charge
~o 08~l~3 20l~ ~l)6 532 7~3 MAKINo & c`Ol~PANY ~3/~J32
2022~
controlJing agent and 0.4 parts by wei~h~ of ethylene-vinyl
Acetste copolymer (Soablene CH dva;lable f~om Nippon Goaei
Kagaku Ko~yo K.K.) as a dlspersing ~gent were addad to 10
parts by ~eight of xylene. The mixture was milled in a
ball mill over a p~rlod of 50 hours lo provide a disp~rsion
of dyo.
An amount of 80 pa~ts by weight of stYrsne and 20
parts by w~ight of b~tyl methacrylate were copoly~eri2ed
in xYlene using azobisisobutYronitrile as a polYmsrization
initiator to prep~re a solution of low molecular weight
styrenlc copolym~r h~ving a wei~ht averaee molecular weight
of 2.0 x 10~1 a glass tran~itlon teMperature of 72 C and
an acid v~lue of 0.1.
An amount of 60 parts by weight of styrene ~nd 40
psrts by wslght of butyl methacrylate w~e bulk-
copolymeriæ~d and then solution-copolYmerized in xylene
to prepare a solution of high ~ol~cular weight styrenic
copolymer havln~ 8 weight avers~e molecular weight of 3.0
x 10~. a ~la~s transition temperature of 60-C and an acid
~0 valus of 0.1.
th~ solution of low molecular wei~ht st~renic copolyer
and the solution of high molecular weight slyrenic copolymer
wore mixed toRether ln ~n squdl weight ratio. Ths above
~entioned dlsperslon o~ charge controlling agsnt was addsd
to the resln solution dnd the mixture was stirred. The
mixturs was thsn heated undar reduced pressure to remove
the solvent therefrom and the resul~ant ~ass was cnushed
to provids a master batch.
An amount of 101 par~s bY weight of the master batch
(compos~d of 100 psrt~ by weight of binder rssin and one
part by weight of charRe controllin~ ~ent) was mixed with
thrse parts by we~ght of low molecular weight polypropylene
(ava;lable from SanYo Kas~i Kogyo K.K.) 1.5 parts by weight
of carbon black (MA-8 av~ilable from Mitsubishi Kasei
KogYo K K.) and 60 pa~ts by weight of magnetite powder
3 2~) 07 ~36 532 7~63 MAK I NO & COMPANY 1~ 004~032
20~2~
16
~EPT S0 available from Toda KoeyQ K.~.). melt-kneaded ~iSh
a twin screw extruder, and then milled with a ~e~ mill,
The resultant powder was classified to provide toner
particl~s of 5-20 microns,
The toner was aPPlied to a commercial copying machine
(Model NP-150 available from Canon K,U,) and lO000 sheets
of copi~s were made continuously to evaluate copied images.
The results are shown in the Table l, while the relation
between the number of sheets coPied and the i~age darknes~
i9 shown ln Fig, 1. All of the images were clear and had
no background contaMination. No fil0ing was observed on
the photoconductor,
The toner was mixed with a carrisr Material in a
concentratlon of 5 X by weight to prepare a developer and
tha distribution of triboeleotriclty of the toner was
measured by use of a charge distribution testing mschine
(available from Hosokawa Micron K,K.), As the results are
shown in Pig. 4, the toner was found to have a narrv~
distribution of triboelectricity.
~0
ExamPle 2
Three p~rts by weight of the nigrosine dye and 1.2
parts by wHight of ~hs ethylene-vinyl acatate copolymsr,
both th~ same as used in the Example 1, were added to 30
parts by weight of xYlene. The mixture was mil1ed in 8
ball mill over a Period of 50 houra ~o provide a dlspersion
of charge con~rolling agent,
The solution of low molecular wRight stYreniC
copoly~er and the solution of high molccular ~oight styrenic
copolymer, both the same as in the ExamPle 1. were mixed
to~ether in an eqùal weight ratio. The a~ove mentjoned
dispersion of char~e controlling agent was added to the
rosultant solution, and the mixture was stirr~d. The
mixture was then heated ~nder reduced pressure to remove
the solven~ therefrom, and the resultant ~ass was crushed
~ ~o l)8~3 20 07 ~ 532 7863 MAKINO ~ OMPANY 12 0~5/~332
2~22~11
to provide a master bstch.
An amoun~ of 103 parts by weight of the master batch
(comPosed of 1~ parts bY wei8ht of binder resin and three
parts by height of chargs controlling agent~ was mixed with
three parts by weight of the low molecular weight poly-
propylene, 1.5 parts by weight of carbon black lnd 60 parts
by weight of magnetite powder, all the same as in the
Exa~ple 1. melt-knead~d with a twin screw extruder. and
then milled with a jet mill. The resultant powder was
classified to provide toner particles of 5-20 microns.
In the same manner as in the Example 1, 10000 sheets
of copies were Made continuously to evaluaSe copied ima~es.
The results are shown in the Tabla 1, wbile Fig. 1 shows
the relation betws~n the number of copied sheeta and the
i~age darkness, All of the sheets were found to have
clear imags~ without background contamination. No filming
was observed on the photoconductor.
~ he tonar was mixed with 8 c~rrier material in a
concentration of 5 X by wsight to prepa~s a developer and
the distributlon of triboelectricity of the toner was
measured in thH sa~e manner as in the Exa~Ple 1. As the
rssults are shown In Flg. 4, the ton~r was found to have a
narrow distribution of tribo~lectricity,
Thrse parts by wei~ht of the nigrosin~ dye and 1.2
parSs by weight of the ethYIene-vinyl acetate copolYmer,
both the same as used in the Example 1, were added to 30
parts by weight of xylen~. The mixlure was milled in a
ball mill over a period of 50 hours to provide a disPersion
of charge controlllng a~ent.
The solution of low molecular we}sht stYrenic
copolymer and the solution of high molscular weight styrenic
coPolymer, both the same as in the Example 1, were mixed
together in an equal weight ratlo. The above mentioned
` ~0 ~8~3 2~1 08 ~l:)6 532 7~3 MAI~IN0 & COMPANY ~006/~)32
2Q22~1 1
dispersion of charge controlling 3gent was added to the
resultant solution in such an amount that the resultant
mixture contained one Part of charge controllin8 agent i n
relation to 10 parts by wei~ht of solid resin, and the
mixture was stirred. The mixture was then heat~d under
reduced pressure to remove the solvent therefrom. snd the
resultant ~ass was crushed to provide a master batch.
An amount of 11 parts by weight of the master batch
(composed of 10 p~rts by weight of binder resin and one
part by weight of charge controlling agent) was mixed with
90 parts b~ weight of styrene-butyl methacrylate copolymer
(a mixture of the aforesaid low molecular weight styrenic
copolymer and high molecular weight styrenic coPolYmer in
an equal weight ratio), 3 psrts by ~eight of the loh
molecular weight polypropylene, 1.5 psrts by welght of
carbon black and 60 parts by weight of magnetite powder,
all the sa~e as in the ~xample 1. melt-kneaded with a twin
screw extruder, and then milled with a 3~t m~ll. The
resultant powder was clsssified to provide toner particles
Of 5-20 microns,
In the same ~anner as in the Example 1, 10000 sheets
of copies were made continuo~sly to evaluate copied 3mages,
The results are shown in the ~able 1. while Fi~. 1 shows
the rulati~n betw~n th~ numh~r nf copied sheets and the
image darkness. All of the sheets uer~ found to have
cle~r ima~es w}thout background contamination. No filming
was observ~d on the photoconductor.
The toner w&s mixed with a carrler mat~rlal in a
concentration of 5 X by wei~ht to prepare a develoPer ~nd
the distribution of triboelectrlcity of ~he toner wa3
Measursd in the same ~anner a~ in the ExamPle 1~ As the
results are shown in Ple. 41 the toner was found to have a
narrow distribution of triboelectricity.
ExamPle 4
sO(8~03 20~1g ~l~6 532 7863 MA~INO & COMPANY ~)7/~32
21D22~
19
Three pa~ts by weight of monoazo chromium dye
Spiron Black ~RH from Hodo~aya Ka8aku Kogyo K K.) as a
char~e contro]ling a~ent and 1.2 parts by wei~ht of the same
athylene-vinyl acetats copolymer as in the Example 1 were
added to 30 parts by weight of xylene, The MiXtUre was
milled in a ball mill over a period of 50 hours to provide
a dispersion of char8e controlling agent~
The solution of low molecular ~eight styrenic
copolymer and the solution of high ~olecular wei8ht styrenic
copolYmer, both the sa~e as in the example 1, were mixed
together in an equ~l wsight ratio. ~he above ~entioned
dispersion of charge con~rolling agent was added to the
~sin solution, and the mixture was st~rred. The ~ixt~re
was then heated under reduced pressure to rem~ve the solvent
therefrom, and the r~sultant mass was cr~shed to provide a
maste~ batch.
An amount of 103 parts by weight of ~he maste~ batch
~co~pos~d of 100 parts by weight of binder resin and three
parts by weight of charge controlling agent) was mixed with
three Parts by ~eight of ths low molecular weight poly-
propylene and 10 p8rts by weight of carbon black, melt-
k~eaded with a twln screw extruder, and then milled ~ith
a jet mill. The resultant powder was classified to proYide
ton~r particles of S-20 ~icrons.
In the saMe ~anner as in the 8xamPIe 1. lQ000 sheets
of copies w8re made cont~nuously to evaludte coPied images.
The results are shown in the Table 1. while Fi~. 3 shows
the relation between the number of copied sheets and the
image darkness. All of the sh~ets wero found to have
clear images ~ithout background contaminatlon. No fil~ing
was obs~rved on the photoconductor.
The toncr wao mixsd with a carrier m~terial in d
concent~ation of 5 X by weight to Prepare a devsloper and
ths distributian o~ triboelectricity of the toner W3S
m~asured in the same ~anner a~ in the E~a~Ple 1. As the
` ~0 t~83 2() 1~) ~()6 532 7863 MAKIN0 & COMPANY 1~ o8~32
2~22~1
results are shown in Fig. 6. the toner was found to have a
narrow distribution of trlboelectricitY.
Comparative Exam~le
One part by weight of the same nigrosine dye as in
the Example 1. 100 parts by weight of the same styrene-
butyl methacrylate copolymer as prepared in ths Exam~le 3,
3 parts by weight of low molecular weight polypropYlene,
l.S part~ by weight of carbon black and 60 p~rts by wei8ht
of magnetite powder, all the sa~e as in the Example 1.
were mixed together, The ~ixture was th~n melt-kneaded
with a twin screw extrudar. and then ~illed with a jet
mill. The resultent powder was classif{ed to provide toner
particles of 5-20 mi~ronS.
In the sam8 manner as in tho ~xample 1. 10000 sheet
of copiz~ werc made continuously to evaluate eoPiHd i~ages.
~he results are sho~n in th~ Tabl0 1I while Fig. 2 showa
the relation betwe~n the nu~b~r of copied shests and the
image darkness. A~ound tbe 1sst stage of 10000 sheets
copying, the Ims~es were found to be remarkablY contaminated
and unclear,
The tonsr was mixed wlth ~ carrier Material in a
concentration of 5 X by wei~ht to prepare a develoPer and
the distribution of triboelectrici ty of the toner was
measured In th0 same manne~ as in tbe ~xample 1. ~s the
results ars shown in Fig. 5, the tonsr was found to have a
wide distribution of triboelactricity,
ComPa ra tive E~ample ~
Three parts by weieht of nigrosine dye were used.
but otherwise in the sams ~anner as in the Co~Parative
Example 1, toner particles were prepa~ed.
In the sa~e manner a~ in the ~xample 1, 10000 sheet
of copies were made continuously to evaluate eopied i~a~es.
~he resultq are shown in the Table 1, while Fig. ~ shows
~ 9~ 3 2~ 6 532 78~3 MAKINO & COMPANY 1~0~/~32
2~22~
the relation between the number of copied sheets and the
i~age darkness. Around the last stage of 10000 shee~
copyJn~, the ima~e~ got remarkably contaminated and
uncle~r. Filiming was observed on the Photocanductor.
The toner was mixed with a carrier material in a
concentration of 5 X ~Y ~eight to prepare a developer and
the distribution of ~riboelectricity of the toner ~as
measured in the same mann~r as in the Example 1. As the
results are shown in ~ig. 5, the toner was found to have a
wide distribution of triboelectricity.
Çomparativ QExamp~e 3
A developer wa~ pr~pa~ed bY ~ixing 100 parts bY
weight of toner particles prepared in the Co~Parative
Exa~ple ~ with one part bY weight of cerium oxide.
~n the SaM8 mdnner as in the ExamPle 1. 10000 sheet
of copies were made continuouslY to evaluate copied images.
Th~ results are shown in the Table 1, while ~ig. 2 shows
th~ relation betw~en the nu~ber of copied sh~ets and the
iMage darkne~s, The toner failed to prov~de copies having
a stable ~msge darknesses.
The toner was mix~d with a carrier ~atarisl in a
concentration of S X by weight to prepare a dsveloper and
the distribution of t~iboslectricity of th~ toner was
measursd In the sama manner as in the Example 1. As the
results are shown in Fig. 5, the toner was fo~nd to have a
wide distrlbution of triboelectricity.
ComP~rative Exa~Ple 4
3~ One part bY wei~ht of monoazo chro~iu~ dye (SPiron
Black TRH), 100 parts by weight of styrene-acrYlic acid
copolymsr ~Himer TB-1000 available from Sanyo Kasel Kogyo
K.K.), 3 parts by w~ght of low molecular weight poly-
propylene and 10 parts by weight of carbon hlack, ~o~h the
35 same as in the examPle 1. wera mixed together. ~he mixture
'9~) 08~)3 20 12 ~ 532 7863 MAKINO & (.OMPANY ~ J/~32
2 ~
was melt-kneaded ~ith a twin screw extrudèr, and then milled
with a jet mill. The resultant powder was classified to
provide toner particles of 5-20 mlcrons,
~n amount of 0.3 parts by weieht of silica powder
(Aerosil R-972 available from Nippon Aerosil K.K.) was
added to and ~ixed with 100 parts by weight of toner
particles. A developer was then prepared b~ Mixing the
toner particlas with iron powder (E~V-2S0 available from
Nippon T~ppun K,K,) in a concentration of 6 % by weight,
The developer was aPPlied to a commercial copying
machin~ (SF~-1102-Z available from SanYo Denki K.K.~ and
10000 sheets of copies ~ere made continuouslY to evaluate
copied images, The results are shown in the Table 1, while
Fig. 3 shows the relation bet~een the number of copied
sheeta and the imaBe darkness. Around ths l~st stage of
1~00~ sheet copying. there was observed remarksble fo~ on
the ima~es. Also no copies ~ere obtained with a stable
image darkness,
The toner was mixed ~ith a c~rrier material in a
conc~ntration of 5 X by welght to prepars & dsvoloP~r and
the distribution of triboelect~icity of the toner was
measur~d in the same manner a~ ~n the BxamPle 1. As the
results are shown in Fig. 6. the toner was found to have a
wide distribution of triboelectricity.
' 9O e~ .0 13 2S~16 532 7863 MAKINO ~ COMPANY ~1011~032
2Q22~
23
TABLE
... . . .
lmage Fog on ~ min~ Reproduc-
~rkn~ss Image on Photo- tivity of
~ ---- conductor Fine
lnltiAl Finsl~ Writin s
~XamPIe 1 1.22 1.~3 NO NO E%Ce1lent
2 1 . 25 1 . 27 NO ~IO EXCe I I en t
3 1.?3 _1.23 _NO IIO EXCellenl
CrfiPara t i Ve
10EXa~PIe ~ 6 1.02 YeS NO ~ad
2 1.22 1.~8 YeOE Yes Excellsnt
_ 3 1.23 I.17_ YeJ No Excellent
ExsmPle 4 1.4~ 1.38 No No Excellent
C o ~ e
15E~PI~ 4 1.33 _ 1.43 Y~S No Excellcnt
~) Around IOOOOth lheet of copy
Ex~m~lo 5
An amount of ~.5 P~rts by weight of monoa~o chromium
dy~ (Spiron Black TR~ avallable tro~ Nodogaya Ka~aku Kogyo
K.K.) a~ a char~e controlling ~gent and 0.2 parts by weight
o~ ethyl~ne-vinyl acetats coPolymer (Soablene CH available
from Nlppon Gos~i Kagaku Kogyo K.K.) a3 a di~Persing agent
were added to 5 parts by ~Bht of toluene. The mixSure
was millRd in a ~all ~11 over a poriod of 50 hours to
prepare a di~pergion of char3e controllin~ agent.
One p~rt by welght of styrene-acryllc acld ester
coPoly~er tHi~er TB~1~00 available fro~ SanYo Kasei ~o8Yo
K,K.) as ~ binder resin w~s dissolved in 10 parts by
weight of toluene to PrePare a rcsin solut;on.
The ~bov~ mentioned disper~ion was added to the resin
solution, and the ~ixture was stirred, ~he mixture was then
heated under reduccd pressure to re~ove the solvent thore-
from, and th6 re~ultant mass ~ crashed to provide a ~aster
3~ batch.
~ 90 O~ 3 2~)~13 ~6 532 7.~63 MAKINO & COMPANY 1~l0l2~03~
2~22~ 1
24
An a~ount of 1.7 parts by weight of the ~aster batch,
98.8 parts by weight of the same styrene-acrylic acid ester
copolym~r as above. three parts by weight of low molecular
wei~ht Polypropylene (Biscol 550-P avai lable from Sanyo
Kasel Kogyo K,K,) as an antioffset a~ent and 10 parLs by
wRight of carbon black (MA-8 avai lable from ~li tsubishi
Kasei Kogyo K.K,) wcrc mlxed and mel t-kncsded wi th a twin
screw extruder, and then mllled with a ;et mill. The
resul tant powder was classif ied to provide toner Particles
of 5-~0 raicrons,
~n amount of 0,3 parts by weight of si 1 ica powder
(Aerosil R-972 avallabla fro~ Nippon Aerosii K.~.) w~s
added to 100 parts by weight of toner particles. and then
tha ~i x tur0 wa~ f urthcr ;ni xed wi th a carr i er ma ter i a I
lS (iron powder EFY-250 availabla fro~ Nippon ~eppun K.K.) in
a concentlAtion of 6 % by weight, thereby to pr~Pare a
two-co~ponen t deve I oper.
The developer was applied to a com~ercial copYin~
machine (SFT-1102-Z available from Sanyo Denki K.K,) and
10000 sheets o~ cop~as were made continuously to evaluate
copied imagos. As the re~ul ts are shown in the Table 2.
images were cl~ar and had no background contamination at
the last stage of 10000 shee~ copying. Further. as the
ralstion between the number of sheets of coPies and their
2S image darkness Is shown in ~ig. 7, the d8rkness was
~ubstantially constant over continuous copying operation.
~o fil~ing was obse~ved on the photoconductor.
The toner was ~ixed ~ith a Garrier material in a
concentration of 5 X by weight to prepare a developer and
the distrlbution of triboelectricity of the toner was
~easured by use of chag~ distribu t i on tes t i ng machine
tavailabla from Hosoka~a Mlcron K.K.), As the results
arc shown in Pl~. 9, th~ ton~r was f~und to have a narrow
distributlon of triboelectricitY, and contain sub~t~ntially
no particlcs reYerslbly charged.
` g~) ~8~03 2(1 1~ ~6 532 78G3 MAKINO & OMPANY 1~013~32
2~22~11
ExamPle 6
One part bY weight of dye and 0.4 Parts by weight of
8thYlen~-vlnyl scetate copolymer, both the same a~ in the
Example 5, were added to 10 Par~s by weight of toluene.
Jhe mixture was mill8d In a bnll mill over a Period of 50
hours to prep~re a dispersion of charge controlling a~ent.
Two parta by welght of the same styrene-acrYlic acid
ester copolymer as i n the Example 5 were d;ssolved in 20
part.~ by weight o~ toluene to prepare a resin solution.
~ he above mentioned dispersion was added to the resin
solution, and the mixture was stirred. The ~ixture was then
h0ated under reduced pressure to remove the sol~ent there-
f~om, and the resultant ~ass was crushed to provide a msster
batch,
An amount of 3.~ parts bY weight of the master batch,
97.6 part9 bY weight of the same styrene-acrylic acid e~ter
copolymer as above, thr~e P~rts by weight of low moleculsr
welght polypropylene and 10 parts b~ ~esght of carbon black,
all the sa~e aa before, were mixed and melt-kneaded with a
twin scrëw extruder. and then milled with a jet mill. The
resultant powder WAS classified to provide toner particles
of 5-20 microns.
An amount of 0.3 parts by wei~ht of silica powder
~Aerosil R-972 available from ~ippon Aerosil K,K.) was
added to 100 parts by weight of tone~ particles. and then
the ~Ixture was further mlxed wlth a carrier material
~iron powder ~FV-250 available from ~iPpon Teppun K,K.) in
a con~entration of 6 % by wei~ht, thereby t~ prepare a
two-component develoPer.
In the same manner as in the Example 5. 100~0 sheet
of copieg were made continuouslY to evaluate copied images.
The results are shown in the Table 2, while Fig, 7 shows
the rela~ion between the number of copied sheets and the
ima8e dsrkness. Thcre were obtained clear ;ma~es without
.
18~03 2~15 ~O~ 632 78~3 MAKINO & ~:~OMPANY 1;~01~1~()32
2022!~1~
26
back~round con~amination at th~ last stage of 10000 sheet
copying. Nei~her filming on ~he photoconductor nor
conta~ination in.qide the copying machina with toner
particles werf observed.
The toner was mlxed with a carrier materlal in a
concentration of 5 % bY weight to prepare a develope~ ~nd
the distribution of triboelect~lcity of the toner was
measured in the same manner as in the ExarPIe 1. As the
results are shown in Fi8. 9. the toner was found to have a
narrow dlstribution of triboelectricity, and contain
Qubstantially no particles reversibly charged.
e xam D le _7
One pArt by wgi~ht of nigrosine dye (Nigrosine Base
EX available ~rom Drient Na~aku Kogyo K.K.) as a charge
controlllng a~ent and 0.4 parts by wsight of the same
ethylene-vinyl acetate copoly~er as in the ExaMple 5 were
added to 10 parts by wei8ht of toluene. The mixture was
milled in a ball ~ill over a period of 50 hours to prepare
a di9perslon of char~e controlling a~ent.
~wo parts by welght of the same stYrene-acrYlic acid
e~ter copoly~er ~a in the Example 5 were dissolved in 20
parts by weight of toluene to prepars a ~esin ~olution.
The above nlention~d dispersion was added to the r~sin
25 solution, and the ~Ixture w~s stirred The mixture was then
heatcd under r~duced pressure to rcmove the solvent there-
from, and the resultant mass was crushed to provide a master
batch,
An amount of 3 4 parts by weight of the master batch,
97.6 parts bY weight of the sam~ styren~-acrylic acid ester
copolymer a9 above, thr~s p~rts by height of low molecular
welght polypropylene and 60 parts by wei~ht of magnetite
powder (~PT-SOO available from Toda KogYo K.K.) were mixsd
and ~elt-kneaded with a twin screw extruder, and then millsd
with a iet ~ill . ~he resultant POwder was classiflad to
' 90 0~03 2l~ 18 ~013 532 '78~33 MA~INO & COMPANY 1~315~03~
2Q~2~ ~
27
provide toner particles of 5-20 microns.
In the same manner as in the Example 5. 10000 sheet
of copies were made continuouslY to evaluate copied images,
The results are shown in the Table 2, ~hile Fig. 11 shows
the relaSion between the number of copied sheets and the
image darkness. There wer0 obtained clear images without
background contamination at the last sSage of 10000 sheet
copying. Neither filming on the photoconductor nor
contamination inside the copying machine with tone~
particles were observed.
The toner was mixed with a carrier material in ~
concentration of 5 X by weight to prepare a devaloper and
the distribution of triboelectricity of th~ toner was
measured in the sam6 Manner as in thc Example 1. As the
results are shown in Pi8, 13, the toner was found to have
a narrow distribution of triboelectricity, and contain
substantially no particles reverslbly charged.
ExamPle ~
Three Parts by weight of the sa~e nigrosine dye as
in the Exampls 7 and 1.2 parts by weight of the ~ame
ethylene-vinyl acet~te copolymer as in the Example 5 ~ere
added to 30 parts bY welght of toluene. The mixture was
milled in a ball mill over ~ perlod o~ 50 hours to prepare
a dispersion of charge controllln8 agent.
Six parts by ~eight of the sa~e styrene-acrYlic acid
ester copolymer as in the ExamplH 5 were dissolved in ~0
parts by weight of toluene to prepare a resin solution~
The above mentioned dlspersion was add~d to the resin
solution, and the mixture was stirred. ~he mixtu~e was then
heatsd under ~educed pressure to remove the solvent there-
from, and the resultant mas~ w~s crushed to ~rovide a maste~
batch.
An amount of 10.2 parts by weight of the master batch.
92.8 parts bY weight of the same styrene-acryl~c acid ester
)3 ~ 17 ~ 532 7863 MAKINO & COMPANY Ç~016/~32
2~22Q~
~8
copolymer as above, three parts by weight of low molecular
weight polypropylen~, 1.5 parts by weight of carbon black
and 60 parts by weight of ~agnetlts powder, all the same
as before, were mixed and melt-kneaded with a twin screw
extrudor, Rnd then milled with a iet miil. The resultant
powder wa~ classi~isd to provid~ toner particles of 5-20
mlcrons,
In the same manner as in the Example S, 10000 sheet
of copies were madc contlnuously to evalu~te copied images
The r0sults are shown in the Table 2. while Fig. 11 shows
the relation bstween the number of copied sheets and the
image darknHss. There w~re obtalned clear images without
background contamination ht the last stage of 10000 sheet
copying. Nelther filming on the photocond~ctor nor
lS contamination Inslds the copying ~achine with tonsr
particles were obsHrved.
the toner was mix~d with a carrisr material in a
concentration ~f 5 X by weight to prePare a dev~loPsr and
the diatribution of triboelectricity of ths toner wa9
~easured in the ~s~e ~anner as in the Example 1. As the
results are shown in Pig. 13, the toner was found to h~ve
a narrow distribution of triboel8ctricity, and contaln
substantially no particles reveraiblY chsrged.
Co~Parative exa~ole 5
An a~ount of 0.5 parts by weight of ~onoazo chromium
dye, 100 p2rt~ by weight of ethylene-vinyl acetate copolymer,
3 parts by welght of low molecular weight polypropylene
and 10 parts by weight of c~rbon black were mixed and melt-
3~ kneaded w~th a twin screw extruder, and then milled withJet ~ill. The resultant p~wder was classified to provide
toner particles of S^20 micron~.
An a~ount of 0.3 parts by weight of silica powder
(Aerosil ~-972 available from Nippon Aerosil K.K.) wa~
added to 100 parts by w8ight of toner p~rticles. and then
~ g~ o~ 3 2tl 1~ 532 7~3 MAKIN0 & COMPANY [~17~032
2~%~Qll
29
the mixture WdS further ~ixed with a carrier mat~ri~l
~iron powder ~FV-250 available from Nippon Teppun K.~,) in
a concentration of 6 X by weight, thereby to prepare a
thO ' co~ponent developer.
In the s3~e manner as in the Exa~Ple 5. 1000~ sheets
of copies were made continuouslY to evaluate copied images.
~he results are shown in the ~able 2, while Fig. 8 shows
the relation between the number of copied sheets and the
image darkness, The developer Provided toner images having
varicd i~age darkness and fog.
The tonsr was mixed with ~ carrier material in a
concentration of 5 X by we1ght to prepare a develoPer and
the distribution of tribocle~tricity of the toner was
measured in the ~a~e ~s~er as i n the ExamPle 1. As the
results are shown in ~ig. 10. the toner was found to have
a wide distributlon of triboelectricity, and contain a
significant amount of rever~ibly charged particles.
One part by weight of ~onoazo chro~iu~ dye was used,
and otherwise in the sam~ ~anner as in the CoMparative
Exa~Ple S, a develoPcr was prepar~d.
In the sa~e ~anner as in the Example 5, 10000 sheets
of copies were Mad~ contlnuously to evaluate copied images.
The results are shown In the Table 2. while Fig, 8 shows
the relation b~tween the number of copled sheets and the
i~age darkness, The developer provided toner iMages having
varied image darkness and fog,
The toner was m~xed with a carrier material in a
concentration of 5 X by weight to prepars a develoPer and
the distribution of trlboelectriclty of the toner was
~easured in the sam~ ~anner ~s in the ExamPle 1. ~s the
results are shown in ~Ig. 10, th~ toner was found to have
a wide distributlon of trlboelectricity, and contain a
significant a~eunt of ~eversibly char~ed particles.
` 90 08~03 20 19 ~1~6 532 7~63 MAKIN0 & COMPANY 12101~/kl3~
2~22~ ~
Com~a,r~tive examole 7
T~o parts by weight of monoazo chromium dYe was used,
and otherwise ~n the same manner as in the Comparative
S Ex~mple S. a developer was prepared.
In the sa~e manner as in the Example 5. 10000 sheet~
of coples here made continuously to evaluate copied images.
The results sre shown in the Table 2. while Fig. 8 shows
the relation bet~cen ths number of copied shee~s and the
image darkness, The developer Provided toner images having
varied image darkness and fog.
The toncr was mixed with a carri~r msterial in a
concentration of S X by weight to prepare a developer and
the distribution of triboelectricity of the toner was
measured in the sams manner as in the Example 1. As the
result~ are shown in Fig. 10, the toner was found to have
a wide distribution of triboelectricity, and contain a
3ignificant smount of reversibly char~ed Particles.
~
One p~rt by weight of the ~ame nigrosine dY~ as in
the 8xaMple 7, 100 p2rts by weight of ethYlene-vinYl acetate
copolYm0r, 3 parts bY wei~ht of low molecular welght poly-
propylene, 1.5 p~rts by wei8ht of carbon black and 60 p~rts
by weighht of magnetite powd0r, all the same as before,
were mlxed and melt-kneaded with fl twin screw extruder,
and then mill0d with a jot mill, The resultant powder was
classified to provide toner partlcles of 5-20 microns.
In the sama ~nner as in the Exa~Ple S. 10000 sheets
of copies w~re made continuou31Y to.evaluatP, copied ~mages,
The results are shown in the Table 2, while Fig. 12 shows
thc relation between the number of copied shee~s and the
im~8e darkness, Iho develoPer provided toner ;ma~es havi~g
varied i~a~e darkness and fog,
The toner was mlxed wlth a carrier ma~erlal in a
' 90 ~18~3 2~) 19 t5`~1~ 532 78G3 MAKINO & COMPANY 1~lol~l/o32
2022
31
concentration of 5 X by wei~ht to prepare a developer and
the distribution of tribo~lectricity oF the toner was
mea3ured ln ths same manner a~ in the ExamPIe 1. As th~
results are shown in ~ig. 14. the toner was fo~nd to havs
a wide distribution of triboelectricity, and contain a
9ignificant amount of r~versibly chang~d particles~
ComDarative examPle ~
Throe parts by weight of ni~rosine dye w~s used and
otherwise in the s~mc manner as in the ComParative Example
8, a developer was pr~Pared.
In the sa~e ~anner as in the Example 5, 10000 sheets
of coPies were made continuously to evaluate copi~d images,
The results are shown in the ~able 2. while Fig. 12 shows
the relatlon between thH number of copied sheets and the
image darknes~, Thc developer provided toner images havin~
varied imags darknes-~ and fog.
The tonor was ~ixed with a carrier material in a
conce~tration of 5 X bY wei8ht to prepare a devoloper and
th¢ distribution of triboelectricity of the toner was
mea9ursd in the same manner as in the ExamPle 1. ~s the
results are shown ~n P~8~ 14. the toner was found to have
a wide distrlb~tion of trlboeleotricity, and contain a
signiflcant amount of reversibly charged particles.
go ~ 8~ll3 2t) 2l~~06 532 7863 MA~ I No & ( OMPANY ~1 ()20/~32
2~22~
32
TABI,E 2
_ _
Image Fog on Piliming Reproduc-
Darkne-cs Irnage on Photo- tivi ty of
conduc tor Pi ne
_ Inltial Final~ w~e~
Exa~p 1 e 11. 43 1. 39 No No Excs 1 1 en t
21. 37 1. 33 No No Exce I I en t
. _ .................... ... ..
Compara t i ve
Example 1 1.38 1.49 Yes No ~ad
2 1. 33 1. 43 Yes No Bad
Exar~ple 3 1.24 1.2~1 No No 2xc~ nt
Exa~pls 4 1.2~ 1.28 No No Excellent
.. ._ __ .. . ... _
15 Co~para t i V8
EXaMPIe 4 1. 16 1. 02 Yes No Bad
Example 5 1.22 1.18 Yes Yfls Bad
*) Around 10000th sheet of copY
