Process for developing latent electrostatic image using toner containing polyester resin

Toner for developing an electrostatic latent image comprising (a) a polyester resin of a non-linear copolymer having, as its side chain, an aliphatic hydrocarbon group containing therein 3 to 22 carbon atoms, said copolymer being obtained from polymerization of an etherified bisphenol monomer, a di-carboxilic acid monomer, and a polyhydric alcohol of tri-hydric or more and/or a monomer component containing a polycarboxylic acid monomer of tricarboxylic acid or more carboxylic or more, and at least one compound selected from the group consisting of (b) an alkylene-bis-aliphatic acid amide compound represented by the general formula; ##STR1## wherein R.sub.1 and R.sub.2 are independently selected from saturated or unsaturated aliphatic hydrocarbon groups having not less than 10 carbon atoms, R.sub.3 and R.sub.4 are independently selected from a hydrogen atom and a group represented by --OCR.sub.5 wherein R.sub.5 is a saturated or unsaturated hydrocarbon group and n is a positive integer and (c) a wax containing not less than 20% by weight of ester component, the needle penetration degree of wax being not more than 4.

FIELD OF THE INVENTION 
The present invention relates to a toner for developing an electrostatic 
latent image formed in electrophotography, electrostatic recording, 
electrostatic printing, etc. 
BACKGROUND OF THE INVENTION 
Image formation process in electrophotography generally comprises a step of 
forming an electrostatic latent image by uniformly charging and, 
thereafter, imagewise exposing a photoconductive photoreceptor, a step of 
developing thus formed electrostatic latent image with a toner, which is 
formed of a fine resin powder containing therein a colorlant, etc., a step 
of transferring thus formed toner image onto a transferee such as transfer 
paper, and a step of fixing the toner image by means of heating, 
pressurizing, etc., to obtain a visualized image. 
The image forming process making use of the electrostatic latent image 
should preferably be performed as quick as possible, and in this view, the 
heat roll fixing process, which has better heat efficiency and other 
advantages in comparison with other fixing processes of the art, has been 
widely applied in this field. 
Recently, however, further speed-up of the total image formation process is 
strongly demanded, and for the attainment of this purpose, it becomes 
essential for the fixing step to be speeded up. For the fixing of toner to 
be carried out at higher speed in the heat roll fixing method, the toner 
for the development is required to have a fixability at lower temperature, 
and for this purpose, the binder resin to be used should necessarily have 
a lower softening point. However, in general, when the softening point of 
the binder resin of a toner is lowered, a part of the toner image tends to 
be transferred to the surface of the heat roll and thus transferred toner 
is re-transferred to the surface of the subsequent transfer sheet, which 
is so-called an off-set phenomenon, to cause deterioration in the toner 
image. In addition, in the heat roll fixing method there is a tendency 
that a transfer sheet easily winds round the surface of the heat roll, 
which is so-called a winding penomenon. This winding phenomenon is likely 
to take place especially when the temperature of the heat roll is too low. 
For the purpose of preventing the off-set or the winding phenomenon from 
taking place, various measures have been proposed and some of them have 
been put into practice. As one of such measures, it has been proposed that 
fixing be carried out while providing to and coating the surface of heat 
roll with a mold releasing oil such as silicone oil. The another proposed 
measure is to confer the toner itself with mold releasing property and 
thus to give it the off-set prevention property. The latter measure has an 
advantage over the former that no oil providing system in the copying 
machine is necessary and, therefore, the structure of a fixing unit could 
be made simpler and that no maintenance, such as repleniching of silicone 
oil, is needed, etc. 
As for the means for conferring the toner itself with good off-set 
prevention property there has been proposed a method of (a) using as a 
binder resin for the toner a polymer having high molecular weight, or (b) 
incorporating a mold releasing compound into the toner. However, by means 
of method (a), although the off-set prevention property of the toner may 
be improved, due to the rise of the softening point of the resin, it 
becomes difficult to carry out fixing operation at low temperature. 
Recently as a binder resin having low softening point, polyester resin has 
been drawn attention. By the use of a polyester resin, as low molecular 
weight resin being readily obtainable, it is possible to obtain a toner 
having relatively low softening point. The toner using the polyester resin 
as a binder has, in comparison with the toner in which a vinyl-type 
polymer is used, such an advantage that it has better wetting property 
against a transfer sheet such as paper and, therefore, fixing at lower 
temperature becomes possible comparing with the case where a vinyl-type 
polymer having approximately the same softening point is used. 
On the other hand, as for method (b), wherein toner is incorporated with a 
mold releasing agent, it has been proposed, as disclosed in Japanese 
Patent Publication No. 3304/1977 or 3305/1977, to use as a mold releasing 
agent a polyolefin wax such as a polypropylene or polyethylene. It is 
generally effective to use such mold releasing agent, however, in order to 
make a toner having sufficient off-set prevention and winding prevention 
properties as well as wide practical fixing temperature range, the 
proportion of the mold releasing agent to be incorporated must be 
increased to a considerable extent. However, with the increace of the 
proportion of such mold releasing agent in the toner, fluidity of the 
toner powder comes to be lowered, and as the result, satisfactory 
development becomes difficult despite of the improvement in the fixing 
operation and it becomes difficult to obtain an toner image of good image 
quality. 
Further, with the use of a toner containing a polyolefin wax, there has 
been observed a disadvantage that, when such toner is used together with 
carrier particles in a so-called two-component developer, the carrier 
particles are liable to wear out easily and the effective life time of 
such carrier is shortened. This is considered due to so-called filming 
phenomenon by adhesion of the wax component in the toner to the surface of 
the carrier particles. Reason for the occurrence of the toner filming is 
considered to reside in the the fact that it is necessary to increase the 
content of such wax in the toner in order to attain sufficient off-set 
prevention effect, and in addition, since the dispersion capability of the 
resin of such wax is relatively low and the domain of the wax becomes too 
large, the wax is considered to be present in the toner resin in a 
separate phase. 
OBJECT OF THE INVENTION 
The present invention has been made under such background of the art and 
the object of the invention is to provide a toner for developing an 
electrostatic latent image which has a low minimum fixing temperature, 
sufficient offset prevention property and good fluidity with less 
aggregation, which is capable of stably producing visual toner images of 
good image quality for the long repetition of copying performance, and 
which is suitably used for the rapid fixing process. 
SUMMARY OF THE INVENTION 
The present invention specifically relates to toner for developing an 
electrostatic latent image which comprises (a) a polyester resin of a 
non-linear copolymer having, as its side chain, an aliphatic hydrocarbon 
group containing therein 3 to 22 carbon atoms, said copolymer being 
obtained from polymerization of an etherified bisphenol monomer, a 
di-carboxylic acid monomer, and a polyhydric alcohol of trihydric or more 
and/or a monomer component containing a polycarboxylic acid monomer of 
tricarboxylic acid or more carboxylic or more, and at least one compound 
selected from the group consisting of (b) an alkylene-bis-aliphatic acid 
amide compound represented by the general formula; 
##STR2## 
wherein R.sub.1 and R.sub.2 are independently selected from saturated or 
unsaturated aliphatic hydrocarbon groups having not less than 10 carbon 
atoms, R.sub.3 and R.sub.4 are independently selected from a hydrogen atom 
and a group represented by --OCR.sub.5 wherein R.sub.5 is a saturated or 
unsaturated hydrocarbon group and n is a positive integer and (c) a wax 
containing not less than 20% by weight of ester component, the needle 
penetration degree of wax being not more than 4. 
DETAILED DESCRIPTION OF THE INVENTION 
The monomer components used for the synthesis of the non-linear polyester 
resin which constitutes the binder resin of toner of the present invention 
are as follows: (i) a diol monomer containing as the main constituent 
thereof an etherified bisphenol and dicarboxylic acid monomer, which 
monomers constitute the main structure of the copolymer; (ii) a polyhydric 
alcohol monomer of trihydric or more and/or a polycarboxylic acid monomer 
of tri-carboxylic or more, which monomers function for the 
non-linearization of the copolymer, i.e., forming of a branched or a 
network structure; and (iii) a polyhydric alcohol monomer of diol or more 
containing a saturated or unsaturated hydrocarbon group having 3 to 22 
carbon atoms and/or a polycarboxylic acid monomer of dicarboxylic acid or 
more containing a saturated or unsaturated hydrcarbon group having 3 to 22 
carbon atoms, either of which monomers is capable of forming a side chain 
containing a hydrocarbon group having 3 to 22 carbon atoms. 
If necessary, other monomers than those mentioned hrerinbefore may also be 
used in the present invention within the range which does not jeopardize 
the advantages of the present invention. 
As for the etherified phenols, as defined in (i) above, for example, 
polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane, 
polyoxyethylene(2)-2,2-bis(4-hydroxyphenyl)propane, 
polyoxypropylene(6)-2,2-bis(4-hydroxyphenyl)propane, 
polyoxyproptrene(1.3)-2,2-bis(4-hydroxyphenyl)propane may be mentioned. 
As for other diols, for example, ethylene glycol, diethylene glycol, 
triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 
1,4-butanediol, neopentyl glycol, 1,4-butenediol; 
1,4-bis(hydroxymethyl)cyclohexane; and other bisphenols such as bisphenol 
A and hydrgenated bisphenol A may be mentioned. 
As for xamples of dicarboxylic acid monomers, maleic acid, fumaric acid, 
metaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic 
acid, iso-phthalic acid, terephthalic acid, cyclohexane-di-carboxylic 
acid, succinic acid, adipic acid, sebacic acid, malonic acid and anhydride 
thereof, and other dibasc acid monomers may be mentioned. The proportion 
of these acid monmers to be used is, preferably, within the range from 10 
to 90 molar % and, more preferably, within the range from 20 to 60 molar % 
with respect to the total acid component. 
Further as for the polyhydric alcohol monomer defined in (ii) above, for 
example, sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 
di-pentaerythritol, tripentaerythritol, saccharose, 1,2,4-butanetriol, 
1,2,5-pentanetiol, glycerol, 2-methylpropanetriol, 
2-methyl-1,2,4-butanetriol, trimethylol ethane, trimethylol propane and 
1,3,5-trihydroxymethyl benzene and the like may be mentioned. The amount 
of the polyhydric alcohol to be used is, preferably, within the range from 
5 to 50 molar % and, more preferably, 10 to 40 molar % with respect to the 
total alcohol component. In the case the proportion exceeds 50 molar %, 
there will be a tendency that the fixability of the toner becomes 
insufficient, and at the proportion less than 5%, the non-linearization 
being insufficient, and the off-set prevention property of the toner will 
be reduced. 
As for the polycarboxylic acid monomer of tricarboxylic or more, for 
example, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzene tricarboxylic 
acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetri-carboxylic 
acid, 1,2,4-naphthalenetricaboxylic acid, 1,2,4-butanetricaboxylic acid, 
1,2,5-haxanetricaboxylic acid, 
1,3-dicarboxyl-2-methyl-2-methylenecarboxylic-propane, 
tetra(methylenecalboxylic)methane, 1,2,7,8-octane-tetracarboxylic acid, 
empol trimer acid, and acid anhydride of heretofore-mentioned organic 
acids can be mentioned. 
It is preferable in the present invention that the proportion of the 
polyhydric alcohol to be used is within the range from 5 to 50 molar % 
and, more preferably within the range from 10 to 40 molar % with respect 
to the total acid component. In the case the proportion exceeds 50 molar 
%, there will be a tendency that the fixability of the toner becomes 
insufficient, and at the proportion less than 5%, the non-linearization 
being insufficient, and the off-set prevention property of the toner will 
be reduced. 
As for examples of the polyhydric alcohol as defined in (iii) above, those 
compounds as listed in (i) or (ii) above may be used. Especially, 
n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic 
acid, isododecyl succinic acid, iso-octyl succinic acid, n-octyl succinic 
acid, n-butyl succinic acid and the like may be mentioned as the 
preferable compounds. The total proportion of these polyhydric alcohol 
monomer and polycalboxylic acid monomer containing the hydrcarbon group is 
within the range from 1 to 50 molar % and, more preferably, 1 to 30 molar 
% with respect to the total monomer components. In the case the proportion 
exceeds 50 molar %, there will be a tendency that the aggregation 
preventive property of the toner becomes insufficient, and at the 
proportion less than 5%, fixability of the toner at low temperatue becomes 
insufficient. 
The representative examples of the alkykene-bis-aliphatic acid amide 
represented by the general formula, which is used in the present invention 
are given below: 
##STR3## 
As for alkylene bis-aliphatic acidamide compounds available in the market, 
the followings may be mentioned. 
"BISAMIDE" (Nitto Chemical Ind., Co., Ltd.), 
"PLASTFLOW" (Nitto Chemical Ind., Co., Ltd), 
"DIADD 200BIS" (Nippon Hygrogen Co., Ltd.), 
"LUBRON E" (Nippon Hydrogen Co., Ltd.), 
"ALFLOW H50S" (Nippon Oil and Fats Co., Ltd.), 
"ALFLOW V-60" (Nippon Oil and Fats Co., Ltd.), 
"AMIDE 6-L" (Kawaken Fine Chemical Co.), 
"AMIDE 7-S" (Kawaken Fine Chemicak Co.), 
"ARMOWAX-EBS" (Lion-Armer Co.,), 
"Hoechst Wax C" (Hoechst), 
"Nobuko Wax-22DS" (Nobuko Chemical Co.,), 
"Adva Wax-280" (Advance Co.,), 
"Kao Wax-EB" (Kao Soap Co., Ltd.), 
"Parycin-285" (Baker-Caster Oil Co.,) 
The alkylene bis-aliphatic acidamide compound of the formula generally has 
an increased softening point with the increase of the number of carbon 
atoms in the hydrocarbon group or of the length of the alkylene chain 
contained in the molecule. In view of the heating temperature to be 
applied during the manufacture of the toner and intended lowering of the 
fixing temperature thereof, those having the softening point of 
100.degree. to 180.degree. C., and more preferably, those having the 
softening temperature of 130.degree. to 160.degree. C. are advantageously 
used in the present invention. For this reason, it is preferred that n in 
the general formula be not more than 5. 
The preferable proportion of the amount of the compound as the mold 
releasing agent to be contained in the toner conposition is within the 
range of 1 to 20% by weight relative to the binder resin and, more 
preferably, within the range of 1 to 10% by weight. When the proportion to 
be contained is less than 1%, there will atendency that the effect of 
compound as the mold releasing agent is hardly exerted and, accordingly, 
off-set prevention effect may be weakened and the effect of lowering the 
minimum fixing temperature may not be obtained. When, on the other hand, 
the proportion exceeds 20% by weight, the fluidity of the toner is likely 
to degrade, causing degrading of good developability and transferability 
of the toner, thus to make the good image formation difficult. Further, 
excess addition of the mold releasing tends to cause adhesion of the mold 
releasing agent to the sleeve in the developing unit or to the 
electrostatic latent image-bearing support (i.e., photoreceptor, etc.), 
and thus to hinder the exertion of the normal function of the toner. 
The compound (c) used in the present invention contains as a component 
thereof an ester at a proportion of more than 20% by weight, together with 
other component such as higher fatty acids, higher alcohols or 
hydrocarbons, which may optionally be contained therein, and the needle 
penetration degree of which is not more than 4. 
It is preferable in the present invention that such compound is selected 
from waxes having a melting point of between 60.degree. and 110.degree. C. 
In the present invention the needle penetration degree is a value obtained 
in accordance with the measuring method described in JIS K2235-1980. That 
is to say, a sample wax which is heated and melted is taken in a sample 
container and, after the sample is left and cooled down, the sample is 
kept constant in its temperature at 25.degree. C. in a water bath. A 
needle the total mass of which is fixed to be 100 g is then penetrated 
vertically into the sample wax for 5 minutes, and the depth of the needle 
thus penetrated is measured to the precision of 0.1 mm. The value of the 
needle penetration degree of the invention is defined as the value 
obtained by multiplying the depth by 10. 
The melting point of the resin can be obtained by Differential Scanning 
Calorimetory (DSC), i.e., the peak fusion value of the sample, when a few 
mg of sample was heated at a constant temperature rising rate of 
10.degree. C./min, is taken as the melting point. 
Some representative examples of the wax of this class are given below: 
______________________________________ 
Ester Component Needle Melt- 
Content Pene- ing 
Mold Releasing (% tration 
Point 
Agent Kind by weight) Degree 
(.degree.C.) 
______________________________________ 
Carnauba Wax 
Ester of 80-85 below 84 
No.1 Fatty Acid 1 
(Noda Wax Co.) 
Candelilla Wax 
Ester of 24-30 1 66 
(Special) Fatty Acid 
(Noda Wax Co.) 
Candelilla Wax 
Ester of 24-30 2 64 
No.1 Fatty Acid 
(Noda Wax Co.) 
Candelilla Wax 
Ester of 24-30 2 64 
No.2 Fatty Acid 
(Noda Wax Co.) 
Hoechst Wax E 
Ethylene above 1 78 
(Hoechst Glycol Ester 
50 
Japan Co.) of Montanic 
Acid 
Hoechst Wax 
Partially above 1 79 
OP(Hoechst Saponified 50 
Japan Co.) Butylene 
Glycol 
Ester of 
Montanic 
Acid 
Kao Wax 85P 
Glycerol- above 2 83 
(Kao Soap Co.) 
tril2- 80 
hydroxy 
Stearate 
Hohoba Solid 
Ester of 97 2 68-78 
Wax Unsaturated 
(Noda Wax Co.) 
Alcohol and 
Unsaturated 
Acid 
______________________________________ 
The preferable proportion of the the wax to be contained in the present 
invention is within the range of 1 to 20% by weight relative to the binder 
resin and, more preferably, within the range of 1 to 10% by weight. If the 
proportion to be contained is less than 1%, the effect as the mold 
releasing agent is hardly exerted and, accordingly, off-set prevention 
effect and good fixability at low temperature of the toner may not be very 
effective. If, on the other other, the proportion exceeds 20% by weight 
the fluidity of the toner is likely to degrade, causing degrading of goog 
developability and transferability of the toner, thus to make the good 
image formation difficult. Further, excess addition of the mold releasing 
tends to cause adhesion of it to the sleeve in the developing unit or to 
the electrostatic latent image-bearing support (i.e., photoreceptor, 
etc.), and thus to hinder the exertion of the normal function thereof. 
When the alkylene bis-aliphatic acidamide compound and the wax are used in 
combination the ratio of the alkylene bis-aliphatic acidamide compound 
against the wax is, in terms of the weight by part, preferably within the 
range from 0.5:1 to 10:1, and more preferably, from 0.5:1 to 5:1. 
The toner of the present invention is in a fine powder form prepared by 
incorporating into and dispersing in the above-mentioned binder resin and 
the mold releasing agent and, if necessary, other additives for the 
improvement of the properties of the toner, such as colorant, magnetic 
material and the like. The average particle size of the toner is generally 
5 to 30 microns. 
As for the colorant usable in the present invention, any conventionally 
known colorants and such colorant includes carbon black, Nigrosine(C.I. 
No. 50415B), Aniline Blue(C.I. No. 50405), Ultranarine Blue(C.I. No. 
77103), Chrome Yellow(C.I. No. 14090), Quiniline Yellow(C.I. No. 47005), 
Rose Bengal(C.I. No. 45435), Du Pont Oil Red(C.I. No. 26105), 
Phthalocyanine Blue(C.I. No. 74160), Lamp Black(C.I. No. 77266), etc. and 
a mixture thereof may be used. The amount of the colorant to be 
incorporated into the toner of the present invention may not be limited 
but, in general, 1 to 20 parts by weight relative to 100 parts of the 
binder resin may be preferable. 
In the case where toner of the present invention is applied to a so-called 
one-component toner, a magnetic material may be incorporated into the 
toner composition instead of, or together with the colorants. The magnetic 
material that may be used includes a compound or an alloy containing 
therein a ferromagnetic element such as iron, cobalt and nickel; ferrite, 
magnetite; such an alloy as so-called Heusler's alloy which contains 
manganese and copper in the alloy, like Mn-Co-Al or Mn-Co-Sn, and whhich 
does not contain magnetic element but turns to show a ferromagnetic nature 
under suitable treatment by heat; or cromium dioxide, etc. may be 
mentioned. 
These magnetic materials are usually incorporated into and uniformely 
dispersed in the the toner composition in the form of a fine powder of the 
average particle size of 0.1 to 1 micron. The amount of the magnetic 
material to be incorporated is generally 20 to 70 parts by weight relative 
to 100 parts by weight of toner and, preferably, at a proportion of 40 to 
70 parts by weight relative to the same. 
As for the other additives for improving other properties of the toner, for 
example, charge controlling agent, fluidity improving lubricants such as 
fine powdery silica and the like may be mentioned. 
In addition to the polyester resin of the present invention, certain type 
of resin may be used for the purpose of improving various properties of 
the toner, for example, for preventing the occurrence of toner filming or 
for the purpose of improving pulverization property or chargeability of 
the toner. The resins to be preferably used for this purpose include, for 
example, polymers not having undergone cross-linking treatment and not 
containing chloroform-insoluble component. As for such resins, for 
example, homopolymers, copolymers or a mixture thereof obtained by 
polymerizing at least one of the following monomer may be mentioned: 
Styrenes such as styrene or para-chlorostyrene; vinyl naphtharene; vinyl 
esters such as vinyl chloride, vinyl bromide, vinyl fluoride, vinyl 
acetate, vinyl propionate, vinyl benzoate and vinyl butyrate; methylene 
aliphatic carboxylic acid esters such as methyl acrylate, ethyl acrylate, 
n-butyl acrylate, iso-butyl acrylate, dodecyl acrylate, n-octyl acrylate, 
2-chloroethyl acrylate, phenyl acrylate, alpfa-chloromethehtyl acrylate 
methyl methacrylate, ethyl methacrylate, butyl methacrylte; acrylonitrile, 
methacrylonitrile; acrylamide; vinyl ethers such as vinyl methyl ether, 
vinyl iso-butyl ether or vinyl ethyl ether; vinyl ketones such as vinyl 
methyl ketone or vinyl hexyl ketone; N-vinyl compound such as N-vinyl 
pyrrole, N-vinyl carbazole, N-vinyl indole or N-vinyl pyrrolidone and the 
like compounds. Further non-vinyl thermo plastic resins such as a 
rhosin-modified a phenol-formalin resin, an oil-modified epoxy resin, a 
polyurethane resin, a cellulose resin or a polyether resin, or a mixture 
of these nonvinyl resin and a heretofore mentioned vinyl resin may also be 
used. The amount of these resins to be incorporated into the toner 
composition in not limited unless such incorporation jeopartize the effect 
of the present invention, however, 30% by weight with respect to the total 
binder resin may be preferable. 
EFFECTS OF THE PRESENT INVENTION 
With the use of the toner of the present invention following technical 
advantages can be expected. 
(i) Minimum fixing temperature can be lowered and practical fixing 
temperature range may be widened. 
(ii) Improved off-set and winding prevention effects can be obtained. 
(iii) Toner having improved fluidity and and copying durability can be 
obtained. 
(iv) Even in the recycling system, toner image with a stable image quality 
can be obtained. 
(v) Contamination due to the adhesion of the toner to carrier, 
photo-receptor or sleeve will be reduced. 
(vi) Because of good fluidity of the toner the use of fluidity-improving 
agent such as powdery silica may be decreased or omitted and, therefore, 
disadvantages with the use of the silica such as the damage of the 
photoreceptor can be reduced or eliminated. 
And thus according to the present invention toner images with sufficient 
high density will be obtainable at relatively low temperature, without 
causing off-set phenomenon, at high speed and stably when the copying is 
repeated for a long time. 
The present invention is further explained with reference to Examples, 
however, the scope of the invention is not limited by them.

In the Examples the binder resins and the mold releasing agents used are as 
follows: 
PREATION OF A BINDER RESIN 
(1) Binder Resin A 
______________________________________ 
Polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 
700 g 
Fumaric acid 150 g 
n-Dodecenyl succinic acid anhydride 
55.4 g 
Hydroquinone 0.1 g 
______________________________________ 
A round bottomed flask equipped with a thermometer, a stainless steel 
stirrer, a glass tube through which to introduce nitrogen and a condenser 
was charged with the above-mentioned composition. The flask was set in a 
mantle heater and heated to 250.degree. C. while nitrogen gas was 
introduced into the flask to keek its interior under an inert atomosphere. 
Then, the reaction was carried out while stirring the composition. At the 
time when water, which is formed by the the reaction, stopped flowing out 
the acid value was measured to be 1.5. 
65.4 g of 1,2,4-benzene tricarboxylic acid anhydride was added to the 
reaction product and further reaction was carried out for 8 hours and the 
reaction was finished when the acid value was 20. The softening point of 
the thus obtained polyester resin in accordance with the Ball and Ring 
Method(by JIS K2531-1960) was 120.degree. C. 
This polyester resin is designated as Binder Resin A. 
(2) Binder Resin B 
______________________________________ 
Polyoxyethylene(2)-2,2-bis(4-hydroxyphenyl)propane 
650 g 
Fumaric acid 120 g 
iso-Decenyl succinic acid anhydride 
55.4 g 
______________________________________ 
The above composition was reacted at 200.degree. C. using the same 
apparatus as in the case of Resin A. The reaction was terminated when the 
softening point of the reaction product was 120.degree. C. 
This polyester resin was designated as Binder Resin B. 
(3) Binder Resin C(For Comparison) 
______________________________________ 
Polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl) 
211 g 
propane 
Terephthalic acid 299 g 
Pentaerythritol 82 g 
______________________________________ 
The above composition was heated using the same apparatus as in the case of 
Resin A, and thereto 0.05 g of dibutyl tin oxide was added and the 
reaction was carried out at 200.degree. C. The reaction was terminated 
when the softening point by the Ball and Ring Method was 131.degree. C. 
Thus obtained polyester resin was designated as Binder Resin C. 
______________________________________ 
Mold Releasing Agent a1 
"HOECHST WAX C" (HOECHST JAPAN Co.) 
Mold Releasing Agent a2 
Alkylene bis-aliphaticacidamide 
"BISAMIDE" (Nitto Chemical Ind., Co., Ltd.) 
Mold Releasing Agent a3 
Alkylene bis-aliphaticacidamide 
"ARMOWAX-EBS" (Lion-Armer Co., ) 
Mold Releasing Agent a4 
Alkylene bis-aliphaticacidamide 
"HOECHST WAX C" (HOECHST JAPAN Co.) 
Mold Releasing Agent b1 
"Carnauba Wax No. 1" (Noda Wax Co.) 
Mold Releasing Agent b2 
"Candelilla Wax" (Noda Wax Co.) 
Mold Releasing Agent c1 
Low molecular polypropylene 
"Viscol 660P" (Sanyo Chemical Co.) 
Polyolefin Wax, Needle Penetration Degree(N.P.D.) = 1.5; 
Melting Point(m.p.) = 142.degree. C. 
Mold Releasing Agent c2 
"Hi-Wax 400P" (Mitsui Petrochemical Co.) 
Low molecular polyethylene Wax 
Mold Releasing Agent c3 
Synthesized Wax(Aliphatic acid ester content of 10% by 
weight, N.P.D. = 1 and m.p. = 64.degree. C.) 
Mold Releasing Agent c4 
"HOECHST WAX GL-3" (HOECHST JAPAN Co., a parafin wax, 
N.P.D = 1, m.p. = 74.degree. C.) 
Mold Releasing Agent c5 
"Rice Wax F-1" (Noda Wax Co., aliphatic acidester containing 
wax, ester content; 93-96% by weight, N.P.D. = 6, m.p. = 79.degree. 
______________________________________ 
C.) 
In the following Examples, the toner components shown in TABLE 1 were mixed 
and neaded in a extruder, the temperature of the inside thereof having 
been fixed to the one which is below the softening point of the resin used 
by 10.degree. C. Then the mixture was cooled down by water, pulverized and 
classified to obtain a toner having the average particle size of 11 
microns. Finally 0.8% by weight of hydrophobic silica was added to the 
thus prepared tone, to prepare the toner of the Examples. In TABLE 1 the 
numerals in the brackets are given in terms of parts by weight. 
TABLE 1 
______________________________________ 
Mold Releasing Other 
Example Compound of the 
Wax Carbon 
No. Binder Invention Used Black 
______________________________________ 
Present 
Invention 
1 A a1 -- -- MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
2 A a1 -- -- MOGAL L 
(100) (6) (Cabbot Co.) 
(10) 
3 A a2 -- -- MOGAL L 
(100) (3) 
(10) 
4 A a3 -- -- MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
5 B a1 -- -- MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
6* A a1 -- -- MOGAL L 
(48) (3) (Cabbot Co.) 
(10) 
7 A -- b1 -- MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
8 A b1 -- MOGAL L 
(100) (6) (Cabbot Co.) 
(10) 
9 A -- b2 -- MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
10 B -- b1 -- MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
11* A -- b1 -- MOGAL L 
(48) (3) (Cabbot Co.) 
(10) 
12 A a4 b1 -- MOGAL L 
(100) (2) (2) (Cabbot Co.) 
(10) 
13 A a4 b1 -- MOGAL L 
(100) (6) (2) (Cabbot Co.) 
(10) 
14 A a3 b1 -- MOGAL L 
(100) (2) (2) -- (Cabbot Co.) 
(10) 
15 A a4 b2 -- MOGAL L 
(100) (2) (2) (Cabbot Co.) 
(10) 
16 A a3 b2 -- MOGAL L 
(100) (2) (2) (Cabbot Co.) 
(10) 
17 B a4 b1 -- MOGAL L 
(100) (2) (2) (Cabbot Co.) 
(10) 
18* A a4 b1 -- MOGAL L 
(48) (2) (2) (Cabbot Co.) 
(10) 
Compari- 
son 
1 A -- -- c1 MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
2 A -- -- c2 MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
3 C -- -- c1 MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
4 A -- -- -- MOGAL L 
(100) (Cabbot Co.) 
(10) 
5 A -- -- c3 MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
6 A -- -- c4 MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
7 A -- -- c5 MOGAL L 
(100) (3) (Cabbot Co.) 
(10) 
8 C -- b1 -- MOGAL L 
(100) (2) (Cabbot Co.) 
(10) 
9 C -- b1 a4 MOGAL L 
(100) (2) (2) (Cabbot Co.) 
(10) 
______________________________________ 
In TABLE I, toners of Examples 6, 11 and 18 are so-called one-component 
developer and the respective toners contain, in addition to the component 
listed in the table, 52 parts by weight of fine powder of magnetic 
material "BL-100" (Titane Industry Co.) and 1 part by weight of a 
nigrosine dye as the charge controlling agent, "Nigrosine Base EX" (Orient 
Chemical Co.). 
Thus obtained toners according to the present invention (Toners 1 to 18) 
and the toners for comparison (Comparative Toners 1 to 9) were subjected 
to various tests explained below: 
First, making use of the nature of the powder that the higher the fluidity 
of a powder is, the smaller is the condensation rate of the powder, the 
bulk density of the respective toners were measured in order to determine 
the fluidity of the toners. The respective toners were poured down into a 
container having a diameter of 28 mm and the total volume of 100 ml to its 
full through a sieve of 100 mesh and the weight was measured. 
The respective toners, except toners in Examples 6,11 and 18, were mixed 
with a resin coated carrier to prepare as many developers, of which toner 
content was 2% by weight respectively. 
Thus prepared developer was subjected to an image formation test using a 
electrophotographic copying machine "U-Bix 4500" (product of Konishiroku 
Photo Industry Co., Ltd.), in which so-called toner recycling system is 
employed, and 60000 times of repeated copying tests were carried out to 
determine developability of the electrstatic latent image, transferability 
of the developed toner image to the transfer sheet and fixability with the 
use of heat roll fixing unit of the toner, and the toner density of the 
copied image of the first and after 60000th copies were measured. 
After 60000 times of copying test, the bulk density of the toner, extent of 
contamination on the surface of the carrier particles, photosensitive drum 
and developing sleave in the development unit were also observed. 
Further the minimum fixing temperature, the minimum off-set occurring 
temperature and winding occurring temperature were measured. 
As to the minimum fixing temperature, fixing test by the use of a heat roll 
fixing unit consisting of a heat roll, the surface of which is formed of 
TEFLON (polytetrafluoroethylene produced by du Pont), and a pressure roll, 
the surface of which is formed of a silicone rubber "KE-1300 RTV" (product 
of Shinetsu Chemical Industry Co., Ltd.), was carried out by passing 
through the fixing unit a sample transfer sheet, onto which 64 g/m.sup.2 
of toner has been adhered, at a line feeding speed of 200 mm/sec, and this 
procedure was repeated while increasing stepwise the temperature of the 
heat roll by 5.degree. C. from 100.degree. C. The fixed toner image thus 
obtained was subjected to rubbing test with KIM wiper and the minimum 
fixing temperature was determined as the lowest temperature at which the 
fixed toner image has a sufficient durability against rubbing. 
Incidentally, the fixing unit used does not have a silicone oil providing 
device. 
The lowest temperature at which off-set phenomenon is first observed was 
determined in the similar manner as in the determination of the minimum 
fixing temperature, that is, the temperature at which the off-set 
phenomenon is first observed was measured by, first, developing an 
electrostatic image formed in an ordinary electrophotographic method with 
a developer and, transferring the toner image onto a plain paper sheet and 
fixing the transferred image in the abovementioned fixing unit, and, 
thereafter, by passing a white paper through the fixing unit under the 
same conditions, to observe if any contamination is seen on the surface of 
the white paper due to the toner attached to the roll in the fixing unit. 
By repeating above-mentioned operation at various temperatures, the 
temperature, at which off-set phenomenon is first seen was obtained. 
Still further, winding occurrence temperature was measured by the use of a 
uniformly black original, whereby toner was attached to the whole surface 
of the transfer sheet by development and transfer processes, and by 
carrying out fixing test while lowering stepwise the temperature of the 
heat roll of the fixing unit. 
Results of the tests are shown in TABLES 2 and 3 below. 
TABLE 2 
______________________________________ 
Minimum Minimum Winding 
Fixing Off-set Occurrence 
Temperature 
Ocurring Temperature 
Sample. No. 
(.degree.C.) 
Temperature (.degree.C.) 
(.degree.C.) 
______________________________________ 
Toner of 
the 
Invention 
1 150 240 170 
2 140 above 240 160 
3 150 240 170 
4 150 240 170 
5 150 240 170 
6 160 above 240 170 
7 140 240 150 
8 130 240 140 
9 140 240 150 
10 140 240 150 
11 150 240 160 
12 140 240 150 
13 130 above 240 140 
14 140 240 150 
15 140 240 150 
16 140 240 150 
17 140 240 150 
18 150 above 240 150 
Comparative 
Toner 
1 160 240 180 
2 160 240 180 
3 160 above 240 180 
4 280 200 210 
5 140 240 170 
6 140 240 170 
7 140 240 170 
8 160 240 170 
9 160 240 150 
______________________________________ 
TABLE 3 
______________________________________ 
Bulk Density 
(g/cc) Image Density 
After After Degree 
60000 60000 of 
Sample No. 
Initial copies Initial 
copies 
Contamination 
______________________________________ 
Toner of 
the 
Invention 
1 0.46 0.44 1.34 1.33 Without 
2 0.45 0.42 1.33 1.30 Without 
3 0.45 0.44 1.34 1.32 Without 
4 0.45 0.43 1.34 1.31 Without 
5 0.46 0.44 1.34 1.31 Without 
6 0.78 -- -- -- -- 
7 0.44 0.42 1.34 1.32 Without 
8 0.43 0.40 1.32 1.30 Without 
9 0.44 0.42 1.34 1.33 Without 
10 0.44 0.42 1.33 1.32 Without 
11 0.77 -- -- -- -- 
12 0.44 0.42 1.34 1.32 Without 
13 0.43 0.41 1.33 1.30 Without 
14 0.44 0.42 1.34 1.31 Without 
15 0.44 0.42 1.34 1.32 Without 
16 0.44 0.42 1.34 1.31 Without 
17 0.44 0.42 1.34 1.31 Without 
18 0.77 -- -- -- -- 
Comparative 
Toner 
1 0.40 0.37 1.18 0.97 Observed 
2 0.40 0.37 1.16 0.97 Observed 
3 0.46 0.44 1.33 1.31 Without 
4 0.46 0.45 1.34 1.33 Without 
5 0.40 0.37 1.18 0.97 Observed 
6 0.39 0.37 1.16 0.95 " Extensively 
Observed 
7 0.44 0.32 1.32 0.90 Extensively 
Observed 
8 0.44 0.42 1.33 1.31 Without 
9 0.44 0.42 1.33 1.31 Without 
______________________________________ 
As apparent from TABLES 2 and 3, the toner of the present invention has 
higher off-set and winding prevention ability, fixability at reduced 
temperature, excellent developability with sufficient density and 
excellent stability in image formation after long time repetition of 
copying in comparison with the toner of the prior art. Further no serious 
contamination in the sleeve of the developing unit or in the surface of 
the photoreceptor was observed even after 60000 times of copying. 
Further, by the use of toner of the present invention, having the lower 
minimum fixing temperature, the transfer sheet need not be exposed to high 
temperature. Thus the the ccurrence of creases can effectively be be 
prevented, which is especially advantageous when both surfaces of the 
transfer paper sheet are to be used for copying. 
In contrast thereto the comparative toner shows lower off-set coccurring 
temperature, inferior image quality and inferior stability in the image 
formation. 
Further it is apparent from the TABLES that overall exellent copying 
performance can be obtained when the mold releasing agent of the present 
invention is used in combination with the case where the second or third 
molod releasing agent is used singly together with the resin of the 
present invention.