Toner for development of electrostatic images and image forming method by use thereof

This invention relates to a toner for development of electrostatic images to be used for development of electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, etc., and an image forming method by use thereof. The toner of the present invention uses a resin constituted mainly of a copolymer comprising a crystalline polymer block and an amorphous polymer block chemically bound together, the cyrstalline polymer block has a specific melting point, the amorphous polymer block has a specific glass transition point, the moduli of the toner has a value with a specific range, and therefore according to the present invention, a toner excellent in durability can be provided, which is capable of fixing sufficiently even at a low temperature and yet also good in off-set resistance within such a temperature range, further having excellent anti-blocking characteristic, flowability, charging characteristic, anti-filming characteristic, cleaning property, thus being capable of forming good visible images stably.

TECHNICAL FIELD 
This invention relates to a toner for development of an electrostatic image 
to be used in development of electrostatic images formed in 
electrophotography, electrostatic printing, electrostatic recording, etc., 
and an image forming method by use thereof. 
BACKGROUND ART 
For example, in electrophotography, an electrostatic image bearing member 
comprising a photoconductive photosensitive member is charged and exposed 
to light to form an electrostatic latent image thereon, then the 
electrostatic latent image is developed with a toner formed in fine 
particles by having colorants, etc. contained in a binder comprising a 
resin, and the toner image obtained is transferred onto a support such as 
a transfer paper, followed by fixing, to form a visible image. 
Thus, in order to obtain a visible image, it is necessary to fix a toner 
image, and hot roller fixing system, which is high in thermal efficiency 
and capable of high speed fixing, has been widely employed in the prior 
art. 
Whereas, in these days, for such demands as (a) suppresion of overheating 
of copying machine, (b) prevention of thermal deterioration of 
photosensitive member, (c) shortening of warm-up time required to 
elevation of temperature of hot roller to a temperature capable of fixing 
from the beginning of actuation of fixer, (d) feasibility of continuous 
copying for a large number of times by making lowering in temperature of 
hot roller due to absorption of the heat to transfer paper smaller, (e) 
enhanced thermal stability, etc., it has been strongly required to enable 
fixing treatment under the state where the temperature of the hot roller 
is made lower by lowering the consumed power of the heater for fixing. 
Accordingly, the toner is also required to be fixable well at a lower 
temperature. 
Besides, a toner is required to be capable of existing stably as powder 
without agglomeration under the conditions during use or under the storage 
environment, namely excellent in anti-blocking property. Further, in the 
hot roller fixing system, which is preferred as the fixing method, since 
the off-set phenomenon, namely the phenomenon wherein a part of the toner 
constituting the image during fixing is transferred onto the hot roller 
and retransferred onto the next transfer paper delivered to stain the 
image, is liable to occur, it is required to impart to the toner a 
performance which can prevent generation of off-set phenomenon, namely 
off-set resistance. 
For such reasons, in the prior art, there have been proposed a technique in 
which a polymer comprising at least one crystallizable polymer portion 
with a melting point of 45.degree. to 150.degree. C. and an amorphous 
polymer portion with a glass transition point of 0.degree. C. or lower 
chemically linked together as is used as the binder resin constituting the 
toner, as disclosed in Japanese Unexamined Patent Publication No. 
87032/1975, or a technique in which a thermoplastic polymer containing in 
its molecule a crystalline block with melting point of 50.degree. to 
70.degree. C. and an amorphous block having a glass transition point 
higher by at least 10.degree. C. than the melting point of the crystalline 
block, with the content of the crystalline block being 70 to 95 wt.%, is 
used as the binder resin constituting the toner, as disclosed in Japanese 
Unexamined Patent Publication No. 3446/1984. 
Also, Japanese Unexamined Patent Publication No. 8549/1982 discloses a 
toner containing a graft copolymer comprising a crystalline trank polymer 
portion comprising at least one monomer selected from ethylene, propylene 
and vinyl acetate; an unsatureted polyester trank polymer portion; and a 
vinyl type branch polymer portion. 
However, in the technique disclosed in the above Japanese Unexamined Patent 
Publication No. 87032/1975, the toner, which is constituted of a copolymer 
having a crystalline polymer portion which is soft at normal temperature 
and an amorphous polymer portion which is sticky and soft due to the glass 
transition point of 0.degree. C. or lower chemically linked together, has 
the disadvantage that it may cause blocking phenomenon in a developing 
instrument, etc., even at normal temperature. Also, developing 
characteristic is bad due to poor triboelectric chargeability and 
flowability to give unclear images much in fog. Also, after a large number 
of copying, a soft toner will generate the filming phenomenon that the 
toner is attached on the carrier particles or the surface of the 
photosensitive member. Further, the toner becomes fused onto a cleaning 
member such as cleaning blade, etc., whereby the images become unclear 
with much fog and low density. Also, due to its softness, the toner is 
liable to be formed into a mass in a pulverizing machine during 
pulverization at normal temperature, thus having the disadvantages such 
that pulverization can be done with difficulty to give no toner with 
desired particle size to make the cost higher with poor production 
efficiency. Further, due to high stickiness, off-set phenomenon is liable 
to be generated on a hot roller fixer which is not coated with a large 
amount of oil. 
On the other hand, in the technique disclosed in Japanese Unexamined Patent 
Publication No. 3446/1984, since an amorphous block having a high glass 
transition point of 100.degree. C. or higher is used, a large amount as 70 
to 95 wt.% of a crystalline block must be used as a method to satisfy 
meltability at a low temperature, whereby the properties of the soft 
crystalline block having plastic deformability at normal temperature are 
reflected on the toner. That is, due to its softness, triboelectric 
chargeability and flowability are bad to make developing characteristic 
bad, whereby unclear images with much fog are obtained. Also, after a 
large number of copies are made, the toner will generate the filming 
phenomenon that the toner is attached on the carrier particles or the 
surface of the photosensitive member, and also triboelectric chargeability 
becomes bad and the toner is further fused onto a cleaning member such as 
cleaning blade, etc., whereby the images become unclear with much fog and 
low density. Further, in a fixing method by heating within a short time 
with the use of a hot roller fixer not coated with a large amount of oil, 
the fixable temperature becomes higher due to the high glass transition 
point of the above amorphous block of 100.degree. C., and also off-set 
phenomenon is liable to be generated due to much crystalline block which 
is 70 to 95 wt.%. 
Further, the toner disclosed in Japanese Unexamined Patent Publication No. 
8549/1982 is also bad in flowability, whereby no developer having toner 
uniformly dispersed in carrier can be formed and no sufficient 
triboelectric chargeability can be obtained to make developing 
characteristic poorer and generate image drop-off, thus giving unclear 
images. Further, in copying over a large number of times, due to bad 
flowability of the toner, the toner cannot be dispersed uniformly into the 
developer even when the toner may be supplemented, whereby the images 
become unclear. 
The prior art has failed to provide a practical toner which avoids the 
disadvantages described above. 
DISCLOSURE OF THE INVENTION 
The present invention has been accomplished based on the situation as 
described above, and its first object is to provide a toner for 
development of electrostatic images which is low in fixing temperature, 
good in off-set resistance and broad in the range of fixable temperature. 
A second object of the present invention is to provide a toner which does 
not generate off-set phenomenon even in a hot roller fixing system without 
coating of an oil. 
A third object of the present invention is to provide a toner having good 
antiblocking property. 
A fourth object of the present invention is to provide a toner which is 
good in flowability, stability of triboelectric charging and developing 
characteristic to give sharp images without fog. 
A fifth object of the present invention is to provide a toner which does 
not generate filming on carrier particles, the surface of photosensitive 
member or cleaning member and is good in cleaning characteristic to give 
sharp images without fog. 
A sixth object of the present invention is to provide a toner which is good 
in dispersibility of colorants to give images with high image density. 
A seventh object of the present invention is to provide a toner which is 
good in filming resistance, cleaning characteristic, uniform 
dispersibility of the toner into a developer and developing characteristic 
even in a large number of uses, thereby giving sharp images of high image 
density without fog. 
An eighth object of the present invention is to provide an image forming 
method by use of the above toner for development of electrostatic images. 
The present inventors have studied intensively, and consequently found that 
the above objects can be accomplished by a toner for development of 
electrostatic images, which is constituted of at least a resin and a 
colorant, characterized in that the above resin is constituted mainly of a 
copolymer comprising a crystalline polymer block and an amorphous polymer 
block chemically bound together, the above crystalline polymer block has a 
melting point of 50.degree. to 120.degree. C., the above amorphous polymer 
block has a glass transition point of 50.degree. to 100.degree. C., and at 
least one point of the dynamic moduli at 70.degree. to 140.degree. C. of 
the above toner has a value of not smaller than 2.times.10.sup.3 
dyn/cm.sup.2 and not greater than 1.times.10.sup.5 dyn/cm.sup.2. 
In the toner for development electrostatic images of the present invention, 
the objects of the present invention can be accomplished only when the 
three conditions shown below are satisfied at the same time, namely: 
(1) a copolymer comprising a crystalline polymer block and an amorphous 
polymer block chemically bound together is used; 
(2) the crystalline polymer block has a specific melting point and the 
amorphous polymer block has a specific glass transition point; 
(3) the modulus of the toner has a value within a specific range. 
Here, "crystalline polymer block" means the polymer portion having a 
melting point, and "amorphous polymer block" means an amorphous polymer 
portion having no melting point. 
Also, "melting point of crystalline polymer block" or "glass transition 
point of amorphous polymer block" means respectively the melting point or 
the glass transition point of the crystalline polymer block or the 
amorphous polymer block under the state which are not coupled with each 
other. 
The present invention is described in detail below. 
The resin constituting the toner of the present invention is constituted 
mainly of (1) a copolymer comprising a crystalline polymer block and 
amorphous polymer block chemically bound together, (2) the melting point 
Tm of the above crystalline polymer block being 50.degree. to 120.degree. 
C., preferably 50.degree. to 100.degree. C., and the glass transition 
point Tg of the above amorphous polymer being 50.degree. to 100.degree. 
C., preferably 50.degree. to 85.degree. C., (3) at least one point of the 
dynamic moduli G' at 70.degree. to 140.degree. C. of the toner containing 
the above copolymer having a value of not smaller than 2.times.10.sup.3 
dyn/cm.sup.2 and not greater than 1.times.10.sup.5 dyn/cm.sup.2. 
A toner not satisfying the above three conditions will be worsened in 
anti-blocking property, off-set resistance, flowability, low temperature 
fixability, and also fixable range will be narrowed. 
To describe in more detail, if the melting point of the above crystalline 
polymer block is lower than 50.degree. C., anti-blocking property of the 
toner obtained becomes poor, while with a melting point exceeding 
120.degree. C., the melt flowability at low temperature will be lowered to 
make fixability bad. If the glass transition point of the above amorphous 
polymer block is lower than 50.degree. C., flowability, off-set 
resistance, pulverizability, anti-blocking property, filming resistance 
and durability of the toner obtained will become poor, while its low 
temperature fixing characteristic becomes bad with a glass transition 
point over 100.degree. C. 
Also, the molecular weight of the above crystalline polymer block should 
preferably be 1,000 to 20,000 in terms of number average molecular weight 
and 2,000 to 100,000 in terms of weight average molecular weight. When the 
molecular weight is within this range, off-set resistance and 
pulverization efficiency of the toner can be further improved. The 
molecular weight of the above amorphous polymer block should preferably be 
1,000 to 50,000 in terms of number average molecular weight and 5,000 to 
150,000 in terms of weight average molecular weight. When the molecular 
weight is within this range, anti-blocking property, pulverization 
efficiency, low temperature fixing characteristic of the toner can be 
further improved. 
The above crystalline polymer block and the amorphous polymer block may be 
either compatible or non-compatible with each other, but preferably 
non-compatible from the view point of pulverizability, anti-blocking 
property, etc., of the toner. Here, "non-compatible" refers to absence of 
the property of sufficient dispersion of the both polymers through the 
same or similar chemical structures of both or the action of functional 
groups, exhibiting a difference in solubility parameter of, for example, 
0.5 or greater in terms of the S.P. value according to the method of 
Fedors (R.F. Fedors, Polym. Eng. Sci., 14, (2) 147 (1974)). 
The copolymer to be used in the present invention is a copolymer having 
block portions having different physical properties as described above, 
and comprises at least one crystalline polymer block and at least one 
amorphous polymer block chemically linked to each other. Such a copolymer 
may be a block copolymer or a graft copolymer having block portions 
grafted at the side chain other than the main chain, or alternatively it 
may be a straight chain or may have branches. Among them, a block 
copolymer is particularly preferred. 
The molecular weight of the above copolymer may differ depending on the 
composition/proportion of the crystalline polymer block and amorphous 
polymer block and other factors and cannot be specified indiscriminately, 
but approximately its number average molecular weight Mn may be 1,000 or 
more and its weight average molecular weight Mw 5,000 or more, 
particularly preferably Mn being 1,000 to 30,000 and Mw 5,000 to 300,000 
from the viewpoint of off-set resistance, durability, pulverization 
efficiency. 
The softening point Tsp of the above copolymer may be different depending 
on the kind of the polymer employed and is not particular limited, but it 
is within the range of from 70.degree. to 150.degree. C., more preferably 
from 90.degree. to 140.degree. C. When the softening point is within this 
range, the toner obtained becomes further better in off-set resistance, 
anti-filming property and low temperature fixability. 
Also, the glass transition point of the above copolymer is correlated with 
the glass transition point of the amorphous polymer block, and the glass 
transition point of the copolymer is substantially equal to that of the 
amorphous polymer block when the crystalline polymer block and the 
amorphous polymer block are non-compatible with each other. 
The toner of the present invention contains a specific copolymer as 
described above as the resin, and contains at least 50 wt.% of the above 
copolymer. 
As for the dynamic moduli G' of the toner obtained, at least one point 
thereof in the temperature range from 70.degree. to 140.degree. C. takes a 
value not smaller than 2.times.10.sup.3 dyn/cm.sup.2 and not greater than 
1.times.10.sup.5 dyn/cm.sup.2 as mentioned above, and its dynamic 
viscosity .eta.' is not particularly limited, but at least one point in 
the temperature range from 70.degree. to 140.degree. C. should preferably 
be 1.times.10.sup.6 poise or less, above all 1.times.10.sup.5 poise or 
less from the viewpoint of fixable temperature range. 
The proportion of the crystalline polymer block constituting the above 
copolymer should preferably be 1 to 60 wt.%, more preferably 5 to 50 wt.%, 
most preferably 5 to 40 wt.% based on the copolymer. With a proportion 
less than 1 wt.%, the effect on the low temperature fixing characteristic 
is small, while flowability, development characteristic, anti-filming 
property, off-set resistance and durability of the toner tend to be 
impaired if it exceeds 60 wt.%. 
As the crystalline polymer block which can be used in the present 
invention, any crystalline polymer may be available and its structure is 
not particularly limited, but there may be employed polyesters, 
polyolefins, polyvinyl esters, polyethers, etc. Specific example are 
enumerated below. 
Polyesters: 
polyethylene sebacate, polyethylene adipate, polyethylene suberate, 
polyethylene succinate, polyethylene-p-(carbophenoxy)undecaate, 
polyhexamethylene oxalate, polyhexamethylene sebacate, polyhexamethylene 
decanedioate, polyoctamethylene dodecanedioate, polynonamethylene azelate, 
polydecamethylene adipate, polydecamethylene azelate, polydecamethylene 
oxalate, polydecamethylene sebacate, polydecamethylene succinate, 
polydecamethylene dodecadioate, polydecamethylene octadecanedioate, 
polytetramethylene sebacate, polytrimethylene dodecanedioate, 
polytrimethylene octadecanedioate, polytrimethylene oxalate, 
polyhexamethylene-decamethylene-sebacate, 
polyoxydecamethylene-2-methyl-l,3-propane-dodecanedioate and others. 
Polyolefins: 
poly-1-butene, poly-3-methylbutene, poly-1-hexadecene, poly-1-octadecene, 
poly-1-pentene, poly-4-methylpentene and others. 
Polyvinyl esters: 
polyallyl acrylate, polyisobutyl acrylate, polydecyl acrylate, 
polyoctadecyl acrylate, polydodecyl acrylate and others. 
Polyethers: 
polybutyl vinyl ether, polyisobutyl vinyl ether, polyisopropyl vinyl ether, 
polyethyl vinyl ether, poly-2-methoxyethyl vinyl ether and others. 
Among them, polyesters are particularly preferred, and polyalkylene 
polyesters are further preferred. These polyesters, above all polyalkylene 
polyesters can be used to give the effect in low temperature fixing 
characteristic of the toner and improve flowability, probably for the 
reason as mentioned below. That is, in condensation system resins such as 
polyester resin, a low molecular weight resin can be obtained with ease, 
and further the "flow" onto a supporting member such as transfer paper, 
etc., is better when melted as compared with a vinyl type resin such as 
styrene, etc., whereby sufficient fixing can be effected at lower 
temperature than the toner containing a vinyl type resin having a 
substantially equal softening point. 
The amorphous polymer block to be used in the present invention is not 
particularly limited, provided that it is an amorphous polymer having no 
specific crystalline structure, but it can be selected from vinyl 
polymers, polyester polymers and others. Among them, polyester polymers 
are particularly preferred, more preferably aromatic polyester polymers. 
By use of an aromatic polyester polymer, triboelectric chargeability is 
good, exhibiting stable chargeability even in a large number of uses, and 
also because it is rigid, flowability and durability of the toner are 
good, thus giving sharp images. This is because of the same reason for 
using preferably a polyester in the crystalline polymer portion. As such 
an aromatic polyester, at least one of the polyvalent carboxylic acid or 
polyvalent alcohol may be an aromatic monomer. As the monomer for such an 
amorphous polymer, examples of the alcohol to be used may include diols 
such as ethylene glycol, diethylene glycol, triethylene glycol, 
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl 
glycol, 1,4-butenediol and the like; 1,4-bis(hydroxymethyl)cyclohexane, 
and bisphenol A, hydrogenated bisphenol A, etherated bisphenol A such as 
polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A, etc., and 
other divalent alcohol monomers. 
Examples of the carboxylic acid may include maleic acid, fumaric acid, 
mesaconic, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, 
isophthalic acid, terephthalic acid, cyclohexane dicarboxylic acid, 
succinic acid, adipic acid, sebacic acid, malonic acid, anhydrides of 
these acids, dimers of lower alkyl esters and linolenic acid, and other 
divalent organic acid monomers. 
As the polyester polymer to be used as the amorphous polymer block in the 
present invention, not only the polymers of only bifunctional monomers as 
mentioned above, but also polymers containing a component by use of a 
trifunctional or more polyfunctional monomer may be also included as 
preferable ones. Examples of trivalent or higher polyhydric alcohol 
monomers which are such polyfunctional monomers may include sorbitol, 
1,2,3,6-hexanetetrol, 1,4-sorbitane, pentaerythritol, dipentaerythritol, 
tripentaerythritol, sucrose, 1,2,4-butane triol, 1,2,5-pentane triol, 
glycerol, 2-methyl propane triol, 2-methyl-l,2,4-butne triol, trimethylol 
ethane, trimethylol propane, 1,3,5-trihydroxymethyl benzene and others. 
Also, trivalent or higher polyvalent carboxylic acid monomers may be 
exemplified by 1,2,4-benzene tricarboxylic acid, 1,2,5-benzene 
tricarboxylic acid, 1,2,4-cyclohexane tricarboxylic acid, 
2,5,7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic 
acid, 1,2,4-butane tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, 
1,3-dicarboxy-2-methylcarboxypropene, 
1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, 
tetra(methylenecarboxy)methane, 1,2,7,8-octane tetracarboxylic acid, 
enpole trimer acid, acid anhydrides of these and others. 
Specific examples to be used as the amorphous polymer portion may include 
the following. 
##STR1## 
In the present invention, the melting point Tm of the crystalline polymer 
block, the glass transition point Tg of the amorphous polymer block, the 
dynamic moduli G' and the dynamic viscosity .eta.' of the toner of the 
present invention can be measured as follows. 
Measurement of melting point Tm of crystalline polymer block: 
Following differential scanning calorimetry (DSC), it can be measured by 
use of, for example, "DSC-20" (manufactured by Seiko Denshi Kogyo Co.), 
and the melting peak value obtained under the measuring condition of 
heating 10 mg of a sample at a constant temperature elevation rate 
(10.degree. C./min) is defined as the melting point Tm. 
Measurement of glass transition point Tg of amorphous polymer block: 
Following differential scanning calorimetry (DSC), it can be measured by 
use of, for example, "DSC-20" (manufactured by Seiko Denshi Kogyo Co.) 
specifically by heating 10 mg of a sample at a constant temperature 
elevation rate (10.degree. C./min), and the glass transition point Tg is 
obtained from the crossing point between the base line and the slanted 
line of heat absorption peak. 
Measurement of dynamic moduli G' and dynamic viscosity .eta.' of toner: 
For example, they can be measured by "Shimazu Rheometer RM-1" (manufactured 
by Shimazu Seisakusho Co.), specifically by melting a sample at a constant 
temperature and applying a sign wave vibration on the sample under molten 
state, and the dynamic moduli G' and the dynamic viscosity .eta.' are 
obtained from the amplitude ratio and the phase difference of torsion. 
Measurement of softening point of copolymer: 
The softening point Tsp in the present invention is measured by use of a 
high-level type flow tester (manufactured by Shimazu Seisakusho Co.) under 
the measuring conditions of a load of 20 kg/cm.sup.2, a nozzle diameter of 
1 mm, a nozzle length of 1 mm, preheating at 50.degree. C. for 10 minutes, 
a temperature elevation rate of 6.degree. C./min and a sample amount of 1 
cm.sup.3 (weight represented by genuine specific gravity.times.1 cm.sup.3) 
in the recorded chart, when the height of the S curve in the curve of 
plunger drop of flow tester-temperature (softening flow curve) is defined 
as h, the temperature at h/2 is measured. 
Measurement of weight average molecular weight and number average molecular 
weight: 
The values of the weight average molecular weight Mw and number average 
molecular weight Mn in the present invention can be determined according 
to various methods and may differ slightly depending on the measuring 
method, but they are determined according to the following measuring 
method in the present invention. 
That is, according gel permeation chromatography (GPC), weight average 
molecular weight Mw and number average molecular weight Mn are measured 
under the conditions as specified below. At a temperature of 40.degree. 
C., a solvent (tetrahydrofuran) is flowed at a rate of 1.2 ml per minute 
and 3 mg as the sample weight of a tetrahydrofuran sample solution at a 
concentration of 0.2 g/20 ml is injected to carry out measurement. In 
measuring the molecular weight of a sample, the measuring conditions are 
selected so that the molecular weight possessed by said sample is included 
within the range where the logarithmic of the molecular weights of the 
calibration curve prepared from several kinds of monodispersed polystyrene 
standard samples and the count number form a straight line. 
In this connection, reliability of the measurement result can be confirmed 
that the NBS706 polystyrene standard sample as measured under the 
conditions as described above has the following molecular weights 
weight average molecular weight Mw=28.8.times.10.sup.4 
number average molecular weight Mn=13.7.times.10.sup.4. 
As the column of GPC to be used, any column may be employed which satisfies 
the above conditions. More specifically, for example, TSK-GEL, GMH 
(produced by Toyo Soda Co.), etc., can be used. 
The solvent and the measurement temperature are not limited to the 
conditions as described above but they can be altered to appropriate 
conditions. 
For obtaining a copolymer comprising the above crystalline polymer block 
and the amorphous polymer block chemically linked together, for example, 
they can be directly bonded in a head-tail fashion through the coupling 
reaction between the terminal functional groups existing in the respective 
polymers. Alternatively, the terminal functional groups of the respective 
polymers can be bonded with a bifunctional coupling agent. For example, 
they can be bonded with a urethane bond formed by the reaction of the 
polymers having hydroxyl groups as the terminal groups with diisocyanate 
or the ester bond formed by the reaction of the polymers having hydroxyl 
groups as the terminal groups and a dicarboxylic acid or the reaction of 
the polymers having carboxyl groups as the terminal groups and a glycol or 
other bonds formed by the reaction of polymers having hydroxy groups as 
the terminal groups and phosgen, dichlorodimethyl silane. 
Specific examples of the above coupling agent may include bifunctional 
isocyanates such as hexamethylene diisocyanate, diphenylmethane 
diisocyanate, tolylene diisocyanate, tolidine diisocyanate, naphthylene 
diisocyanate, isophorone diisocyanate, xylylene diisocyanate and the like; 
bifunctional amines such as ethylenediamine, hexametylenediamine, 
phenylenediamine and the like; bifunctional carboxylic acids such as 
oxalic acid, succinic acid, adipic acid, sebacic acid, terephthalic acid, 
isophthalic acid and the like; bifunctional alcohols such as 
ethyleneglycol, propyleneglycol, butanediol, pentanediol, hexanediol, 
cyclohexanedimethanol, p-xylyleneglycol and the like; bifunctional acid 
chlorides such as terephthalic acid chloride, isophthalic acid chloride, 
adipic acid chloride, sebacic acid chloride and the like; other 
bifunctional coupling agents such as diisothiocyanate, bisketene, 
biscarbodiimide and others. 
The amount of the coupling agent used may be at a proportion of 1 to 10 
wt.%, preferably 2 to 7 wt.% based on the total weight of the above 
crystalline polymer and the amorphous polymer. If it exceeds 10 wt.%, the 
copolymer has too high a molecular weight, whereby the softening point 
becomes too high and fixing characteristic is impaired. In the case of an 
amount less than 1 wt.%, the molecular weight is so small that off-set 
resistance, anti-filming property and durability tend to be impaired. 
The copolymer of the present invention can be also obtained according to 
the following method. That is, first a crystalline polymer is synthesized 
according to a conventional method and then a monomer required for 
formation of an amorphous polymer is added and the amorphous polymer is 
elongated from the terminal end of the crystalline polymer to synthesize 
the above copolymer. On the contrary, it is also possible to synthesize 
the above copolymer by elongating a crystalline polymer from the terminal 
end of an amorphous polymer. 
The toner for development of electrostatic images of the present invention 
comprises a colorant contained in the resin comprising the specific 
copolymer as described above, and it may further contain a magnetic 
material, characteristic improving agents in the resin, if necessary. 
Examples of the colorant may include carbon black, Nigrosine dye (C.I.No. 
50415B), Aniline Blue (C.I.No. 50405), Carcooil Blue (C.I.No. Azoec Blue 
3), Chrome Yellow (C.I.No. 14090), Ultramarine Blue (C.I.No. 77103), Du 
Pont Oil Red (C.I.No. 26105), Quinoline Yellow (C.I.No. 47005), Methylene 
Blue chloride (C.I.No. 52015), Phthalocyanine Blue (C.I.No. 74160), 
Marachite Green oxalate (C.I.No. 42000), Lamp Black (C.I.No. 77266), Rose 
Bengal (C.I.No. 45435), these mixtures and others. These colorants are 
required to be contained at a proportion enough to form a visible image 
with a sufficient density, ordinarily in amounts of about 1 to 20 parts by 
weight per 100 parts by weight of the resin. 
As the above magnetic material, there may be included metals or alloys 
exhibiting ferromagnetic property such as iron, cobalt, nickel, etc., 
typically ferrite, magnetite or compounds containing these elements, or 
alloys containing no ferromagnetic element but which will exhibit 
ferromagnetic property by application with appropriate heat treatment such 
as alloys of the kind called Whisler alloy containing manganese and copper 
such as manganese-copper-aluminum, manganese-copper-tin, or chromium 
dioxide and others. These magnetic materials are dispersed uniformly into 
the resin in the form of fine powder with an average particle size of 0.1 
to 1 .mu.. And its content is 20 to 70 parts by weight, preferably 40 to 
70 parts by weight per 100 parts by weight of the toner. 
The above mentioned characteristic improvers may include fixability 
enhancers, charge controllers and others. 
As the fixability enhancer, for example, polyolefins, fatty acid metal 
salts, fatty acid esters and fatty acid ester type waxes, partially 
saponified fatty acid esters, higher fatty acids, higher alcohols, fluid 
or solid paraffin waxes, polyamide type waxes polyhydric alcohol esters, 
silicon varnish, aliphatic fluorocarbons, etc., can be used. In 
particular, waxes having softening points (ring and ball method JIS K2531) 
of 60.degree. to 150.degree. C. are preferred. 
As the charge controller, those which have been known in the prior art can 
be used, for example, nigrosine type dyes, metal containing dyes, etc. 
Further, the toner of the present invention should be preferably used with 
inorganic fine particles of a flowabilty enhancer, etc., mixed therein. 
The above inorganic fine particles to be used in the present invention are 
particles having a primary particle size of 5 m.mu. to 2 .mu., preferably 
5 m.mu. to 500 m.mu.. Also, the specific surface area according to the BET 
method should preferably be 20 to 500 m.sup.2 /g. The proportion to be 
mixed into the toner is 0.01 to 5 wt.%, preferably 0.01 to 2.0 wt.%. 
Examples of such inorganic fine powder may include silica fine powder, 
alumina, titanium oxide, barium titanate, magnesium titanate, calcium 
titanate, strontium titanate, zinc oxide, silicious sand, clay, mica, 
wollastonite, diatomaceous earth, chromium oxide, cerium oxide, lead iron 
oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium 
salfate, barium carbonate, calcium carbonate, silicon carbide, silicon 
nitride, etc., particularly preferably silica fine powder. 
The silica fine powder as herein mentioned refers to fine powder having 
Si-O-Si bonds, including either one produced according to the dry process 
and the wet process. Also, other than anhydrous silicon oxide, either one 
of aluminum silicate, sodium silicate, pottasium silicate, magnesium 
silicate, zinc silicate, etc., containing 85 wt.% or more of SiO.sub.2 is 
preferred. 
Specific examples of these silica fine powders include various commercially 
available silicas, but those having hydrophilic groups on the surface are 
preferred, as exemplified by AEROSIL R-972, R-974, R-805, R-812 (all 
manufactured by Aerosil Co.), Taranox 500 (manufactured by Tarco Co.), 
etc. Otherwise, silica fine powders treated with silane coupling agent, 
titanium coupling agent, silicon oil, silicon oil having amines in the 
side chain, etc., can be used. 
Referring now to a preferable example of the process for preparation of the 
toner of the present invention, first a material resin or a mixture 
containing toner components such as colorant added thereto if necessary is 
melted and kneaded through, for example, an extruder and after cooling 
finely pulverized by means of a jet mill, etc., followed by classification 
to obtain a toner with desired particle size. Alternatively, the melted 
and kneaded product through an extruder can be atomized or dispersed into 
a liquid under the molten state by a spray drier, etc., to obtain a toner 
with desired particle size. 
As the image forming method of the present invention, a developer is 
prepared by use of the specific toner as described above, formation and 
development of electrostatic images are performed by means of a 
conventinal electrophotographic copying machine by use thereof, the toner 
image obtained is electrostatically transferred onto a transfer paper, 
followed by fixing by means of a hot roller fixer in which the hot roller 
temperature is set at a constant temperature to form a copied image. 
The image forming method of the present invention may be used particularly 
preferably in carrying out fixing in which the contact time between the 
toner on transfer paper and the hot roller is within 1 second, 
particularly within 0.5 second.

BEST MODE FOR PRACTICING THE INVENTION 
Example 1 
By coupling 30 parts by weight of a crystalline polymer A shown below in 
Table 1 and 70 parts by weight of an amorphous polymer a shown below in 
Table 2 with 4.0% by weight of hexamethylene diisocyanate, a copolymer 1 
shown below in Table 3 was obtained. 
A mixture of 100 parts by weight of the copolymer 1, 10 parts by weight of 
a carbon black "Mogal-L" (produced by Cabot Co.), 3 parts by weight of a 
polypropylen "Biscol 660P" (produced by Sanyo Kasei Kogyo Co.), 2 parts by 
weight of "Wax-E" (produced by Hoechst Co.) and 2 parts by weight of a 
charge controller "Bontron-E-81" (produced by Orient Kagaku Co.) was 
kneaded on hot rolls. After cooling, the mixture was coarsely pulverized 
and further finely pulverized by a ultra-sonic jet mill, followed by 
classification by a wind force classifing machine to obtain colored fine 
particles. 
By mixing 100 parts by weight of the colored fine particles with 0.8 parts 
by weight of hydrophobic silica fine powder "AEROSIL R-972" (produced by 
Aerosil Co.) by a V-type mixer to obtain toner 1 of the present invention 
with a volume average particle size of 11.0 .mu.m. 
The crystalline polymers and the amorphous polymers used for preparation of 
the copolymers and their weight part ratios, the number average molecular 
weights Mn and weight average molecular weight Mw of the copolymers 
obtained are shown in Table 3. In the Table, the crystalline polymers 
shown by A-F, their melting points Tm, weight average molecular weights 
Mw, number average molecular weights Mn and solubility parameters (S.P. 
value) are as shown in Table 1, and the amorphous polymers shown by a-f, 
their glass transition points, weight average molecular weights Mw, number 
average molecular weights Mn and solubility parameters (S.P. value) are as 
shown in Table 2. 
Also, the dynamic moduli G', the dynamic viscosity .eta.', etc., of the 
toners obtained are as shown in Table 4. 
TABLE 1 
__________________________________________________________________________ 
Weight 
Number 
average 
average 
Solubility 
m.p. 
molecular 
molecular 
parameter 
Tm weight 
weight 
(S.P. value) 
Crystalline polymer 
.degree.C. 
Mw Mn (cal/cm.sup.3) 1/2 
__________________________________________________________________________ 
A Polyhexamethylene sebacate 
65 14000 4600 10.2 
B Polydecamethylene adipate 
78 12000 3800 10.2 
C Polyethylene succinate 
95 8900 3100 12.5 
D Polyethylene sebacate 
72 10400 3300 10.7 
E Polyethylene adipate 
47 7600 2900 10.8 
F Polypentamethylene 
134 
9100 3200 11.2 
terephthalate 
__________________________________________________________________________ 
TABLE 2 
__________________________________________________________________________ 
Glass 
Weight 
Number 
transi- 
average 
average 
Solubility 
tion 
molecular 
molecular 
parameter 
point 
weight 
weight 
(S.P. value) 
Amorphous polymer 
Tg .degree.C. 
Mw Mn (cal/cm.sup.3) 1/2 
__________________________________________________________________________ 
a Polypropylene isophthalate 
54.5 
13400 4500 11.2 
b Poly-(2,2'-dimethyl)-1,3- 
57.0 
10800 3600 11.1 
propylene-isphthalate 
c Polyoxypropylene bisphen- 
67 13300 4600 9.8 
ol A-fumarate .multidot. terephthal- 
ate (molar ratio of 2:1:1) 
d Polyoxypropylene bisphen- 
0 4900 1800 10.4 
ol A-sebacate 
e Polyester obtained from 
62.5 
10000 3800 12.5 
equimolar mixture of iso- 
phthalic acid, propylene 
glycol and cyclohexane 
dimethanol 
F Polyester obtained from 
65.0 
18400 6200 10.8 
terephthalic acid and 
polyoxypropylene-,2)- 
2,2-bis(4-hydroxyphenyl)- 
propane 
__________________________________________________________________________ 
TABLE 3 
__________________________________________________________________________ 
Amorphous Weight 
Number 
Crystalline 
polymer average 
average 
polymer and 
and its molecular 
molecular 
its weight 
weight weight 
weight 
Copolymer 
part ratio 
part ratio 
Mw Mn 
__________________________________________________________________________ 
Example 1 
Copolymer-1 
A 30 wt. parts 
a 70 wt. parts 
29200 5800 
Example 2 
Copolymer-2 
B 20 wt. parts 
b 80 wt. parts 
30800 6300 
Example 3 
Copolymer-3 
C 30 wt. parts 
c 70 wt. parts 
43500 7200 
Example 4 
Copolymer-4 
D 10 wt. parts 
a 90 wt. parts 
36000 6900 
Example 5 
Copolymer-5 
B 40 wt. parts 
a 60 wt. parts 
35000 7500 
Example 6 
Copolymer-6 
C 50 wt. parts 
a 50 wt. parts 
42000 8200 
Example 7 
Copolymer-7 
A 30 wt. parts 
c 70 wt. parts 
29900 6500 
Example 8 
Copolymer-8 
C 40 wt. parts 
e 60 wt. parts 
29600 6200 
Example 9 
Copolymer-9 
D 30 wt. parts 
f 70 wt. parts 
36500 7000 
Example 10 
Copolymer-10 
D 40 wt. parts 
a 60 wt. parts 
35000 6900 
Comparative 
Copolymer-11 
E 30 wt. parts 
a 70 wt. parts 
32300 6300 
Example 1 
Comparative 
Copolymer-12 
A 30 wt. parts 
d 70 wt. parts 
29100 5900 
Example 2 
Comparative 
Copolymer-13 
F 30 wt. parts 
a 70 wt. parts 
39800 8300 
Example 3 
Comparative 
Copolymer-14 
C 0.5 wt. parts 
a 99.5 wt. parts 
42700 8400 
Example 4 
Comparative 
Copolymer-15 
A 70 wt. parts 
a 30 wt. parts 
36600 7300 
Example 5 
__________________________________________________________________________ 
Next, 3 parts of the toner 1 and 97 parts of a carrier coated with a 
styrene-methyl methacrylate copolymer resin having an average particle 
size of 100 .mu.m were mixed to prepare a developer. By use of this 
developer, real copying test was conducted, wherein formation of an 
electrostatic image and development thereof were carried out by means of 
an electrophotographic copying machine "U-Bix 1600" (produced by 
Konishiroku Photo Industry Co.), the toner image obtained was transferred 
onto a transfer paper and the transferred image was fixed by a heated 
roller fixer to form a copied image. The lowest fixing temperature (the 
lowest temperature of the heating roller at which fixing is possible), the 
off-set generation temperature (the lowest temperature at which off-set 
phenomenon occurs) were measured, and also the fixable range was 
determined. 
The lowest fixing temperature: 
After formation of an unfixed image by the above copying machine, by means 
of a fixer comprising a hot roller of 30 .phi. having a surface layer 
formed of Teflon (polytetrafluoroethylene produced by Du Pont Co.) and 
pressure roller having a surface layer formed of a silicone rubber 
"KE-1300RTV" (produced by Shinetsu Kagaku Kogyo Co.), the operation of 
fixing the toner image with a sample toner transferred onto a transfer 
paper of 64 g/m.sup.2 at a line speed of 70 mm/sec, a line pressure of 0.8 
kg/cm and a nip width of 4.9 mm was repeated at the respective 
temperatures of the hot roller elevated stepwise by 5.degree. C. within 
the set temperature range of from 80.degree. to 240.degree. C., and 
Kimwipe scraping was applied on the fixed image formed. The lowest set 
temperature capable of giving a fixed image exhibiting sufficient scraping 
resistance is defined as the lowest fixing temperature. The fixer used 
here has no silicone oil feeding mechanism. 
Off-set generation temperature: 
Measurement of off-set generation temperature is similar to measurement of 
the lowest fixing temperature. After formation of an unfixed image by the 
above copying machine, the operation of transferring the toner image and 
carrying out fixing treatment by the fixer as described above, and 
subsequently delivering a white transfer paper to the fixer under the same 
conditions for observation with eyes whether toner staining occurs thereon 
or not is repeated under the state where the set temperature of the hot 
roller of the above fixer is successively elevated. The lowest set 
temperature at which staining with the toner occurred is defined as the 
off-set generation temperature. 
Fixable range: 
The difference between the off-set generation temperature and the lowest 
fixing temperature is defined as the fixable range. 
The results are shown in Table 4. 
Further, blocking characteristic, pulverization efficiency, filming 
characteristic, cleaning characteristic and charged quantity (Q/M) of the 
toner 1 and flowability of the developer prepared by use of the above 
toner were measured as follows. 
Anti-blocking property: 
Anti-blocking property test was examined by whether an agglomerated mass 
was formed or not when the toner was left to stand under the environmental 
conditions of 45.degree. C. and 43% RH for 2 hours. 
Pulverization efficiency: 
Judged by the feed quantity when finely pulverized by a ultra-sonic jet 
mill under the condition of a pressure of 5.4 kg/cm.sup.2. 
Filming characteristic: 
Filming characteristic was judged by presence or absence of attached matter 
when the carrier and the surface of the photosensitive member were 
observed. 
Cleaning characteristics: 
Cleaning characteristic was judged by presence or absence of attached 
matter when the surface of the photosensitive member after cleaned with a 
cleaning member was observed. 
Flowability of developer: 
Flowability of developer was judged by visual observation of the developer 
in a developing instrument, and one at a practical level was rated as 
good. 
Charged quantity (Q/M): 
The charged quantity is the value of triboelectric charges per 1 g of toner 
measured according to the known blow off method. 
The results are shown also in Table 4. 
Further, for the images obtained by use of the toner 1, fog, the maximum 
image density (D.sub.max), and sharpness were measured and evaluated as 
follows. 
Fog: 
Fog is shown by the relative density to the developed image at the white 
ground portion with manuscript density of 0.0 (white ground reflective 
density is defined as 0.0). 
O less than 0.01 
.DELTA. 0.01 - less than 0.03 
x 0.03 or higher 
Maximum image density (D.sub.max): 
This is shown by the relative density of the developed image when the image 
density of the original picture is made 1.3. Measurement was performed by 
Sakura densitometer (produced by Konishiroku Photo Industry Co.). 
Sharpness: 
With the line picture chart of the manuscript as original, its 
reproducibility is enlarged and judged visually. 
The results obtained are shown also in Table 4. 
Further, durability test was conducted by use of the toner 1. That is, 
after the developing process was repeated for 30,000 times, charged 
quantity Q/M, the change in charged quantity .DELTA. Q/M of the toner, 
flowability, filming characteristic and cleaning characteristic of the 
developer, and fog, the maximum image density (D.sub.max), sharpness of 
the image obtained were measured and evaluated similarly as described 
above. The results are shown in Table 5. 
TABLE 4 
__________________________________________________________________________ 
A B C D E F G H I J K L M N 
__________________________________________________________________________ 
Example 
Toner 
110 
240 
130 
.circle. 
Very 
-21.4 
Very 
.circle. 
1.33 
Good 
1.2 .times. 10.sup.4 
2.2 .times. 10.sup.4 
110 
1 1 good good 
Example 
Toner 
110 
240 
130 
.circle. 
Very 
-21.2 
Very 
.circle. 
1.35 
Good 
1.3 .times. 10.sup.4 
2.5 .times. 10.sup.4 
140 
2 2 good good 
Example 
Toner 
115 
240 
125 
.circle. 
Very 
-20.8 
Very 
.circle. 
1.34 
Good 
1.4 .times. 10.sup.4 
4.1 .times. 10.sup.4 
130 
3 3 good good 
Example 
Toner 
110 
240 
130 
.circle. 
Very 
+12.1 
Very 
.circle. 
1.35 
Good 
1.5 .times. 10.sup.4 
2.6 .times. 10.sup.4 
140 
4 4 good good 
Example 
Toner 
110 
210 
100 
.circle. 
Very 
-20.5 
Very 
.circle. 
1.31 
Good 
1.1 .times. 10.sup.4 
2.2 .times. 10.sup.4 
100 
5 5 good good 
Example 
Toner 
105 
200 
95 .circle. 
Very 
19.8 
Very 
.circle. 
1.30 
Good 
8.0 .times. 10.sup.3 
1.6 .times. 10.sup.4 
100 
6 6 good good 
Example 
Toner 
110 
190 
80 .DELTA. 
Slight- 
-18.2 
Slight- 
.DELTA. 
1.30 
Slight- 
9.5 .times. 10.sup.3 
3.4 .times. 10.sup.4 
110 
7 7 ly bad ly bad ly bad 
Example 
Toner 
115 
190 
75 .DELTA. 
Slight- 
-18.3 
Slight- 
.DELTA. 
1.29 
Slight- 
1.4 .times. 10.sup.4 
4.2 .times. 10.sup.4 
110 
8 8 ly bad ly bad ly bad 
Example 
Toner 
110 
200 
90 .DELTA. 
Slight- 
-17.9 
Slight- 
.DELTA. 
1.30 
Slight- 
3.4 .times. 10.sup.4 
3.4 .times. 10.sup.4 
110 
9 9 ly bad ly bad ly bad 
Example 
Toner 
110 
185 
75 .DELTA. 
Slight- 
-18.4 
Slight- 
.DELTA. 
1.31 
Slight- 
3.3 .times. 10.sup.4 
3.3 .times. 10.sup.4 
110 
10 10 ly bad ly bad ly bad 
Com. Ex. 
Com. 
110 
140 
30 X Bad 11.8 
Slight- 
X 0.71 
Bad 1.0 .times. 10.sup.3 
2.3 .times. 10.sup.3 
100 
1 toner 1 ly bad 
Com. Ex. 
Com. 
110 
120 
10 X Bad 11.5 
Bad X 0.77 
Bad 8.6 .times. 10.sup.2 
9.8 .times. 10.sup.2 
70 
2 toner 2 
Com. Ex. 
Com. 
210 
240 
30 .circle. 
Very 
-19.8 
Slight- 
.circle. 
1.33 
Good 
2.1 .times. 10.sup.6 
5.4 .times. 10.sup.6 
140 
3 toner 3 good ly bad 
Com. Ex. 
Com. 
200 
240 
40 .circle. 
Very 
20.6 
Very 
.circle. 
1.31 
Good 
1.5 .times. 10.sup.6 
3.7 .times. 10.sup.6 
140 
4 toner 4 good good 
Com. Ex. 
Com. 
120 
120 
0 .DELTA. 
Bad 11.0 
Bad X 0.62 
Slight- 
2.3 .times. 10.sup.2 
8.8 .times. 10.sup.2 
70 
5 toner 5 ly bad 
__________________________________________________________________________ 
Note for Table 4 
A: Toner 
B: Minimum fixing temperature .degree.C. 
C: Offset generation temperature .degree.C. 
D: Fixable range .degree.C. 
E: Antiblocking property 
F: Flowability of developer 
G: Charged quantity Q/M .mu.c/g 
H: Pulverization efficiency 
I: Fog 
J: Maximum image density D.sub.max 
K: Sharpness 
L: Dynamic modulus G dyn/cm.sup.2 
M: Dynamic viscosity .eta. poise 
N: Measurement temperature for G', .eta. 
TABLE 5 
__________________________________________________________________________ 
Charged 
Change in Flow- 
quantity 
charged 
Filming 
Cleaning 
ability Maximum 
Q/M quantity 
charac- 
charac- 
of image 
Toner .mu.c/g 
.mu.c/g 
teristic 
teristic 
developer 
Fog 
density 
Sharpness 
__________________________________________________________________________ 
Ex. 1 
Toner 1 
-20.5 
0.9 None Very good 
Very good 
.circle. 
1.28 Good 
Ex. 2 
Toner 2 
-20.3 
0.9 None Very good 
Very good 
.circle. 
1.30 Good 
Ex. 3 
Toner 3 
-20.1 
0.7 None Very good 
Very good 
.circle. 
1.30 Good 
Ex. 4 
Toner 4 
+11.6 
0.5 None Very good 
Very good 
.circle. 
1.31 Good 
Ex. 5 
Toner 5 
-19.1 
1.4 None Very good 
Very good 
.circle. 
1.27 Good 
Ex. 6 
Toner 6 
-18.6 
1.2 None Very good 
Very good 
.circle. 
1.25 Good 
Ex. 7 
Toner 7 
-14.5 
3.7 Slightly 
Slightly 
Slightly 
.DELTA. 
1.07 Slightly 
" bad bad bad 
Ex. 8 
Toner 8 
-14.7 
3.6 Slightly 
Slightly 
Slightly 
.DELTA. 
1.10 Slightly 
" bad bad bad 
Ex. 9 
Toner 9 
-14.2 
3.7 Slightly 
Slightly 
Slightly 
.DELTA. 
1.05 Slightly 
" bad bad bad 
Ex. 
Toner 10 
-15.0 
3.4 Slightly 
Slightly 
Slightly 
.DELTA. 
1.08 Slightly 
10 "bad bad bad 
Com. 
Compara- 
-2.6 9.2 Much Bad Bad X 0.42 Unclear 
ex. 1 
tive 
toner 1 
Com. 
Compara- 
-2.3 9.2 Much Bad Bad X 0.41 Unclear 
ex. 2 
tive 
toner 2 
Com. 
Compara- 
-25.3 
5.5 None Very good 
Very good 
.DELTA. 
0.78 Slightly 
ex. 3 
tive unclear 
toner 3 
Com. 
Compara- 
-23.8 
3.2 None Very good 
Very good 
.circle. 
0.97 Slightly 
ex. 4 
tive unclear 
toner 4 
Com. 
Compara- 
-1.3 9.9 Much Slightly 
Slightly 
X 0.40 Unclear 
ex. 5 
tive bad bad 
toner 5 
__________________________________________________________________________ 
Examples 2-3 
Copolymers 2 and 3 were prepared respectively in the same manner as in 
Example 1 except for using the crystalline polymer and the amorphous 
polymers at prescribed weight part ratios shown in Table 3, and further 
toners 2 and 3 were obtained. The respective physical property values and 
performances of the toners 2 and 3 obtained were measured similarly as in 
Example 1. 
Real copying test was conducted similarly as in Example 1 by use of the 
toners 2 and 3 to measure and evaluate the respective performances. 
Example 4 
A copolymer 4 was obtained in the same manner as in Example 1 except for 
using the crystalline polymer and the amorphous polymer at a prescribed 
weight part ratio shown in Table 3. 
In the same manner as in Example 1 except for using 100 parts by weight of 
the copolymer 4, 60 parts by weight of a magnetic material "BL-500" 
(produced by Titan Kogyo Co.), 3 parts by weight of a polypropylene 
"Piscol-660P" (produced by Sanyo Kasei Kogyo Co.) and 1.5 parts by weight 
of a charge controller "Nigrosine S.O." (produced by Orient Kagaku Co.), a 
toner 4 which is one-component magnetic toner was obtained. The respective 
physical property values and performances of the toner 4 obtained were 
measured similarly as in Example 1. 
Real copying test was conducted by means of an electrophotographic copying 
machine "U-Bix 1200" (produced by Konishiroku Photo Industry Co.) by use 
of the toner 4, and the respective performances were measured and 
evaluated similarly as in Example 1. 
Examples 5-10 
Copolymers 5-10 were respectively prepared in the same manner as in Example 
1 except that the crystalline polymer and the amorphous polymers at 
prescribed weight ratios shown in Table 3 were employed, and further 
toners 5-10 were obtained. The respective physical property values and 
performances of the toners obtained were measured similarly as in Example 
1. By use of toners 5-10, real copying test was conducted similarly as in 
Example 1 to measure and evaluate the respective performances. 
Comparative example 1 
A copolymer 11 was obtained in the same manner as in Example 1 except for 
using 30 parts by weight of the crystalline polymer E and 70 parts by 
weight of the amorphous polymer a. 
A comparative toner 1 was obtained in the same manner as in Example 1 
except for using 100 parts by weight of the copolymer 11, 10 parts by 
weight of a carbon black "Mogal-L" and 3 parts by weight of the charge 
controller. The physical property values and performances of the 
comparative toner 1 obtained were measured similarly as in Example 1. 
By use of the comparative toner 1, real copying test was conducted 
similarly as in Example 1 to measure and evaluate the respective 
performances. 
Comparative examples 2-5 
Copolymers 12-15 were obtained in the same manner as in Comparative example 
1 except for using the crystalline polymers and the amorphous polymers at 
prescribed weight part ratios shown in Table 3, and further comparative 
toners 2-5 were obtained. The physical property values and performances of 
the comparative toners 2-5 obtained were measured similarly as in Example 
1. 
By use of the comparative toners 2-5, real copying test was conducted 
similarly as in Comparative example 1 to measure and evaluate the 
respective performances. 
The measurement results obtained Example 2-10 and Comparative example 1-5 
are shown respectively in Table 4 and Table 5. 
As is apparent from Table 4 and Table 5, all of the toners according to the 
present invention exhibit good results for respective performances. In 
contrast, in comparative toners 1, 2, 5, dynamic moduli are too low and 
therefore bad in off-set resistance with the fixable range being narrow, 
and also bad in anti-blocking characteristic, generating filming in 
durability test and causing cleaning characteristic badness. 
Also, flowability and charging characteristic of the developer prepared by 
use of this toner were bad, and there could be obtained only images by use 
thereof which are much in fog, low in developed density and unclear. In 
the durability test, the charged quantity was greatly lowered to give only 
unclear images with much fog and low image density. Thus, the toner was 
inferior in durability. Further, in Comparative examples 3, 4, the dynamic 
viscosity .eta.' was too great and therefore fixing characteristic was 
bad, and also elevation of charged quantity and generation of fog were 
recognized in durability test to give unclear images. 
Utilizability in industry 
The toner of the present invention uses a resin constituted mainly of a 
copolymer comprising a crystalline polymer block and an amorphous polymer 
block chemically bound together, the crystalline polymer block has a 
specific melting point, the amorphous polymer block has a specific glass 
transition point and the dynamic moduli of the toner have a value within a 
specific range. Therefore, according to the toner of the present 
invention, it is possible to provide a toner excellent in durability, 
which is capable of sufficiently fixing even at a low temperature and yet 
good in off-set resistance within such a temperature range, having further 
excellent anti-blocking characteristic, flowability, charging 
characteristic, anti-filming characteristic, cleaning characteristic, 
thereby enabling formation of good, stable visible images.