DE3149575A1 - TONER FOR DEVELOPING LATEN ELECTROSTATIC IMAGES - Google Patents

Description

T 53 089 I ₁ 3: '»JOTS

Applicant; Konishiroku Phto Industry Co., Ltd., No. 26-2 Nishishinjuku 1-chorae, Shinjuku-ku, Tokyo / Japan

Toner for developing latent electrostatic

pictures

The invention relates to a toner for latent development Electrostatic Images - it relates particularly to a toner for developing latent electrostatic images in the context of an electrophotographic process, * an electrostatic recording process, one electrostatic copying method and the like;

The method for developing latent electrostatic images can be roughly divided into two groups - of which are referred to as liquid development a group - in which a developer is used prepared f by finely dispersing various pigments or dyes in an insulating solvent and the other group is called the so-called dry development process, such as the cascade development process, ¹ the brush development process, the magnetic brush development process, the imprint development process and the powder cloud development process, in which powdery developers, called dry toner, are used which can be prepared by dispersing colorants, such as carbon black and the like, in natural or synthetic resins. The present invention is

draws itself on a toner that is in a process of
latter type, i.e.; in a dry development process / is used.

A dry toner has hitherto generally been produced in such a way that a pigment, such as ZiB. Carbon black - is mixed in a molten state with a thermoplastic resin to produce a uniformly dispersed product, ¹ which is then pulverized by means of a suitable pulverizing device to a powder with a particle size - as required for a toner / pulverized. The toner produced in this way can offer various excellent advantages, but at the same time it also has various disadvantages; for example, there are restrictions on the use of the materials for
Production of the toner / these limitations being such that the production of the toner requires conditions / under which the material is fluidized at a suitable temperature so that the pigment can be mixed in uniformly, because the implementation of a
Melting and pulverization process is required and the desired particle size must be obtained at a substantial rate with equipment such as that used in pulverization of the mixing system
However, if it is an easily pulverizable material
is used, the material tends to be further pulverized while inside the electrophotographic copying machine, causing fog to appear on the copied image, while when only an easily fusible material is used, it is Toner caking and discoloration

(Staining) on the surface of the photoconductive Layer (toner deformation) occurs;

If a pigment which has been embedded in the resin gel on the surface at the time of pulverization, locally uneven triboelectric properties may sometimes occur and there may also be problems with moisture resistance depending on the kind of pigment used. Even more serious disadvantages are that the toner produced by pulverization has an indeterminate shape, - which leads to the formation of aggregation of the toner particles, which properties are sometimes determined as an undesirable factor, - such as; the stabilization of the toner during storage, the fluidity of the toner during supply, the toner transfer efficiency, the sharpness of the developed toner image and the possibility of cleaning the toner with repeated use, with the practical disadvantages being great undesirable influence on the quality of the toner image obtained, in particular the resolution, ¹ the sharpness, ¹ the fog and the like; have the same;

In contrast to the toner ^{1 produced} using the above-described pulverization, for example, Japanese Patent Publications 10 231/1961, 51 830/1972, 14 895/1976, 17 735/1978, 17 736 / 1978 and 17 737/1978 described processes for the production of toners by the so-called polymerization processes, which are based on the so-called suspension polymer

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ation processes are based, which provides toner in such a way that a mixture of a monomer, a polymerization initiator, ¹ a colorant and the like, is suspended in water and polymerized to thereby produce toner; Although they do not have the above-enumerated defect of toners produced by pulverization, these toners produced by polymerization have another disadvantage which is that they become worse with the change of the amount of charge in successive \ copying operations, - d; h; the rate of consumption of the toner is much higher for larger particle sizes thereof than for the toner in the indefinite form, so that the change in the amount of charge of the toner at the time of successive copying operations is greater, with undesirable results with respect to the image leads to ongoing operations. In particular, when the toner is recycled, deterioration (deterioration) occurs in image density and fog.

The aim of the present invention is therefore ^{to find 1} a toner for developing latent electrostatic images which does not have the disadvantages of the known toners described above; Another object of the invention is to find a toner for developing electrostatic latent images which is excellent in fluidity; Another object of the invention is to find a toner for developing electrostatic latent images, by means of which toner images with excellent resolution, sharpness and

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little or no haze can be produced; Another object of the invention is to provide a To find toners for developing electrostatic latent images which have satisfactory image transfer efficiency Another object of the invention is to find a toner for developing electrostatic latent images in which the amount of charge. at the time of the successive Copying processes changes only a little; The aim of the invention is finally to 'a toner for developing latent to find electrostatic images that have good recovery properties (recovery properties).

It has now been found that the above objects according to the invention can be achieved with a toner for developing electrostatic latent images (hereinafter referred to as "inventive toner") with im essentially spherical toner particles, - their ratio of longer diameter (a) to shorter diameter (b) is within the range of 1.00 ^ a / b ^ .1.05, the size of which is within the range from 1 to 30 μm, with at least 70% by weight of the toner particles having one size within the main particle size range £ 3 µm;

When the ratio of the longer diameter (a) to the shorter diameter (b) in the toner particle of the present invention exceeds 1.05, the toner behaves substantially like one with an indefinite one Form with the formation of undesirable effects in terms of flowability, transferability, - the

Resolution and sharpness / compared with the toner according to the invention, the particles of which are within the above-mentioned diameter ratio of Ι, ΌΟ ^. a / b £ 1.05.

If the toner contains particles smaller than 1 µm in diameter, "severe fogging occurs, ¹ while if it contains particles larger than 30 µm" there are undesirable results in terms of a coarse grain image and poor resolution brings with it.

When the toner of less than 70 percent; ~%, ⁿ in particular less than 65 stripwound% of particles of a size within the range of the primary particle size + contains pm 3, 'the change of the charge amount becomes large at the time of successive copying operations, causing undesirable results with regard to the current copy properties as well as with regard to the toner recovery or; Bringing recreational properties.

The weight percent of the toner within the range of the main particle size by + 3, 'as applied here, then, ¹ if the average particle diameter of the toner X .mu.m, - the percentage of the total amount of the toner which is occupied by the toner particles , -whose size is within the range of X-3 to X + 3 µmi

The toner according to the invention normally contains a resin (preferably a thermoplastic resin), ¹ a coloring agent

tel and also, - if necessary, - a charge control agent, - ■ a release agent, ¹ a magnetic material and the like

The process for producing the toner according to the invention comprises the spray drying process and the suspension polymerisation process. ¹ consisting of a polymerizable monomer, a colorant, a charge control agent, a polymerization initiator and the like, is dispersed in water and the dispersed mixture is then dispersed in the presence of a dispersion stabilizer with stirring at a speed of 3,000 to 10,000 rpm using a dispersing device, - which can provide a high shear rate, - is suspended, - and when the required particle size distribution is reached, - which is determined by viewing through a microscope, The temperature is increased from 40 to 85 ° G to thereby accelerate the polymerization, ¹ and then it is washed, filtered and dried, ¹ whereby the toner of the present invention is obtained.

To polymerizable en monomers - which can be used according to the invention, ¹ include, for example, styrenes such as styrene, - o-Methy 1 styrene, ¹ m-Methy 1 styrene, · p-methylstyrene, p-ethylstyrene, 2, ^ {- Dimethylstyrene, pn-butylstyrene, - ptert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, - pn-nonyl styrene, pn-decyl styrene, - pn-dodecyl styrene, p-methoxystyrene, p-phenyl styrene, ¹ p- Chlorostyrene, ¹ 3,4-dichloro

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styrene and the like; Vinyl naphthalenes} monoolefins such as ethylene, ¹ propylene, ¹ butylene, isobutylene and the like; Vinyl halides such as vinyl chloride, vinyl bromide, vinyl fluoride and the like; Vinylester, ¹ such as vinyl acetate, - vinyl propionate, vinyl butyrate and the like Vinylbenzoaty ;; a-methylene aliphatic Monocarbonsäureester, 'such as methyl acrylate, ethyl acrylate ^1, n-butyl acrylate, isobutyl acrylate, - propyl, - n-octyl acrylate, -Dodecylacrylat, 2-ethylhexyl acrylate, stearyl acrylate, 2-Chloräthylacrylat, -Phenylacrylat, methyl-ccchloracrylat, ¹ Methyl methacrylate, ¹ ethyl methacrylate _} propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n ~ octyl methacrylate, · dodecyl methacrylate, - 2-ethylhexyl methacrylate / stearyl methacrylate, - phenyl methacrylate, - diethylaminoethyl methacrylate or , ■ methacrylonitrile, -. j acrylamide and the like Viny lather as Viny 3me thy lather, ¹ Vinyläthy lather, vinyl isobutyläth he and dgli j vinyl ketones, ¹ Viny lme thy Ike tone, such as - Vinylhexylketony methyl isopropenyl ketone and the like ;; and N-Viny! compounds such as N-vinylpyrrole, -N-vinylcarbazole, N-vinylindole, -N-vinylpyrrolides and the like

As colorants - which can be used according to the invention, - suitable pigments or dyes can be used in any way, - such as ZiB, carbon black (including the prepolymerized or graft polymerized carbon black), - nigrosine dye, aniline blue, ¹ Chalco Oil Blue, - chrome yellow, ¹ Ultramar in blue, DuPont Oil Red, quinoline yellow, methylene blue chlorine id y phthalocyanine blue y malachite green oxalate, lamp black, yellow rose and mixtures thereof ^ The toner must contain sufficient quantities of these coloring agents.

keep 'that visible images in the development process can arise

In addition, a charge control agent such as; hydrophobic silica, ¹ can be used, and besides, other known ¹ toner properties improving agents can be used if necessary;

According to the invention, one for a 1-component developing toner can also be used useful magnetic material can be used; In a 1-component developing toner the magnetic material can be used as a coloring agent;

This magnetic material is ^one which is strongly magnetized depending on the applied magnetic field in the direction thereof and which should preferably be black and which should be well dispersed in a resin to chemically stabilize it, and it should be in finely divided form with a particle size of less than 1 µm; In order to meet these requirements, magnetite (triiron tetraoxide) is most suitably used; Magnetic or magnetizable materials can be classified in metals, · such as cobalt, - iron, - Nickel j alloys and mixtures of such metals as aluminum, 'cobalt / steel, ¹ lead, - magnesium, · nickel, tin, zinc, antimony, BeryHium , Bismuth, cadmium, ¹ calcium, · manganese / selenium, titanium, · tungsten, vanadium; Metal compounds - such as; Metal oxides, such as

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Aluminum oxide, iron oxide, copper oxide, nickel oxide, zinc oxide, Titanium oxide and magnesium oxide j refractory (difficult to melt) nitrides, such as vanadium nitride, chromium nitride; Carbides, such as tungsten carbide and silicon carbide; and ferrite and mixtures of these materials. Those to be worked into the toner Amounts of these ferromagnetic materials expediently about 50 to about 300 parts by weight, in particular 70 to 200 parts by weight, per 100 parts by weight of the used Resin component

The particle size and the particle size distribution of the toner are determined by the degree of shear, the shear duration, the type of dispersing device used, the amount and type of dispersion stabilizer used, the proportions of the monomer and the water used, the viscosity of the polymerization mixture and the like. It is also known that the larger the resulting particle size, the smaller the larger the greater the amount of the dispersion stabilizer used, the greater the shear rate the smaller the proportion of the polymerization mixture and the water and the lower the viscosity of the polymerization mixture. -

However, these factors are interrelated and all of these factors are difficult to control (to control) so that a shear is applied while viewing through a microscope in order to to find the point at which the desired particle size and the desired particle size distribution is achieved,

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and the stirring speed is reduced to the normal stirring speed to continue the polymerization, this is the most convenient way to manufacture the toner of the present invention.

In the electrophotographic process, after Development of an electrostatic latent image using a toner is fixed, the fixation is made however, generally carried out either by directly fusing the generated toner image by developing on a photosensitive body or on a dielectric material or by melting the Toner image on a sheet (a film), such as a sheet of paper, - this toner image from a light-sensitive. chen body or a dielectric material on this Sheet (this slide) is transferred. The melting of the The toner image at this time is effected either by contacting the image with a solvent vapor brings or heats the image, the heating being generally called non-contact heating in an electric oven or as heating under pressure by heating rollers.

Heating under pressure by means of a heating roller, general referred to as a heat roller fixing method, is used to fix the toner image so that the image · that on a Sheet is to be fixed, is passed through and brought into pressure contact with a heating roller that is on its entire surface is coated with a material that allows separation from the toner. This procedure he ~

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gives such a good thermal efficiency at the time the fusing of the toner image onto the sheet, so that rapid fixing can take place, since the surface of the The heat roller and the toner image to be fixed on a sheet - are brought into pressure contact with one another, -so that the process is well suited for an electrophotographic Image transfer type copying apparatus such as they are particularly useful for high-speed image reproductions is used. Since the surface of the fixing roller and the toner image are melted in one by heating State can be brought into pressure contact with each other with this method, however, sometimes the so-called offset phenomenon occurs, in which a part of the toner image,

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sticks to the surface of the fusing roller and the! part of the picture adhering to it then onto the next Sheet is transferred. In order to avoid this phenomenon, the surface of the roller must undergo subsequent treatment which is essential to the heat roller fixing process;

In order to prevent the toner from sticking to the surface of the fixing roller, a treatment has already been used in which, for example, a material which is excellently separated from such a toner, which contains or consists of a fluorocarbon resin, is applied to the surface of the roller , to which an offset preventing agent such as silicone oil is also applied, ¹ whereby the surface of the roller is covered with a liquid membrane ₀ Although this method is suitable for preventing the offset phenomenon, it has

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the disadvantage that it complicates the structure of a copying machine because it is necessary to use the apparatus with a device for removing the odor resulting from the heating of the offset preventive agent as well as to be provided with a device for supplying the liquid, and because the copier too becomes expensive in order to meet the requirements for achieving constant, satisfactory reproduction results suffice. However, if the offset preventing agent does not is added, the toner adheres to the surface of the fixing roller to produce an offset phenomenon, so that it is so today - that the feeding of the offset prevention means is inevitable despite these drawbacks;

On the other hand, it has already been proposed · various additives to prevent the offset phenomenon, such as in Japanese Patent Publications 11 492/1976 and 47 622/1976 described ^ These proposals led to effects in the kneading process (mixing process), at the same time, however, they impose restrictions on the use of additives, because in the process for producing toners by suspension polymerization, the reaction under the conditions expires that all the various necessary additives including the colorant to the polymerizable Monomers are added so that compounds · which do not have Influence on the polymerization reaction must be selected · or compounds that are in the monomers only poorly solve, - cannot be used.

Another object of the invention is to provide a toner

for the development of latent electrostatic images / with the help of which it is possible to develop a highly effective to carry out a satisfactory heat roller fixing process without causing an offset phenomenon of the toner itself occurs when using a fixing roller whose surface is not provided with an offset preventing agent is"

This further object of the invention can be achieved with a toner of this invention, - the particles have a substantially spherical shape, · as the ratio between the longer diameter (a) and the shorter Duarchmesser (b) Ι, ΌΟ £ a / b £ 1, 05 is ₉ - and its particles have a size within the range of 1 to 30 µm, with 70 wt Contains polymers of an α, β-unsaturated ethylenic monomer, - the weight average molecular weight of which is not less than 80,000;

In studying the process of making the By using the suspension polymerization method of toner, the toner resins prepared under various polymerization conditions were investigated to find It has been found that the use of resins having a molecular weight within a certain range is effective is to prevent the offset phenomenon Sj, - and on the present invention is based! d, h », it was found that, if the molecular weight of the resin formed is small, an offset phenomenon at the time of fixing

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you can see that the paper is wrapping itself around the roller, the toner sometimes aggregates and its fluidity decreases, making the toner unsuitable for development will;

The toner is generally composed of a resin component, a resin component Colorant component, such as B; Pigments or dyes, · and an additional component, - from or with a plasticizer, a charge control agent and the like. to control (control) the physical and development properties of the toner, the resin component comprising various natural resins and synthetic resins, the individually or can be used in the form of a suitable mixture;

The toner of the present invention contains α, β-unsaturated ethylenic as a unit of its main resin component Monomers having a weight average molecular weight of 80,000 or more, i.e. that of the present invention Resin is preferably used in a proportion of about 60% by weight of at least 75% by weight, based on the total resin component content of the toner, in the toner incorporated, - whereby the above objects of the invention can be achieved; in particular, this can Offset phenomenon of the toner on the heat fixing roller to be effective Way to be prevented;

There is one characteristic of the present invention in that the toner contains as its main component an α, β-unsaturated ethylenic monomer, the resin can either have a single poly-

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meres, - which has been produced by polymerizing only a monomer, or a copolymer which has been produced by polymerizing obtained from two or more kinds of monomers, or it may also be one Act as a mixture of such a single polymer (horn copolymer) and such a copolymer;

Another characteristic of the present invention is that the toner of the present invention has a weight average Has a molecular weight (Mw) of 80 or more; This value is then $ if <fer according to the invention Toner is one of a single polymer (homopolymer) or a copolymer, the value which is due to the polymers, while then, -when the toner according to the invention is a mixture of these Polymers, this is the value of the total mixed polymers, i.e. in the case of such Mixing the polymers, the respective polymers do not necessarily need a molecular weight of 80,000 or more, - as long as the value of the total mixture is within the above range.

The value of Mw can be determined by various methods, but the results vary somewhat depending on the procedure used; The value of Mw given in the present invention was obtained using the following Procedure determined;

All values are those that are used in the Gel permeation chromatography (GPC) under such conditions

- where a solvent (tetrahydrofuran) allowed to flow at a flow rate of 1.2 ml / mini at a temperature of 40 ° C and then 300 ml of a tetrahydrofuran sample solution, which contained the resin sample at a concentration of 0/2 g / 20 ml, was poured into the column thereby perform the measurement; When determining the molecular weight of the sample, the measuring conditions be chosen so that the molecular weight distribution of the sample falls within the range, ii <fem the calibration curve, which indicates the relationships between the logarithm and the numerical values of the weight, - those using several individually dispersed polystyrene reference samples have been prepared / become linear;

It can also ensure the reliability of the measurement that it is confirmed that the Mw / Mn of a reference NBS 706 polystyrene sample (Mw = 28/8 χ 10 / Mn (number average molecular weight) = 13.7 χ 10 / Mw / Mn = 2/11) - those used under the above measurement conditions was 2.11 + 0.10

Columns which can be used as columns for the GPC ¹ meet the above-mentioned conditions, such as ZiBi TSK-GeI, GMH6 (manufactured by Toyo Soda Mfgi Co./ Ltd);

These resins, which as the main component are a-methylene-aliphatic Monocarboxylic acid esters or aromatic vinyl compounds and cc-methylene ~ aliphatic monocarboxylic acid esters

contain, ¹ can be used successfully according to the invention, and such a resin, - which contains these monomers together and also at least about 30 mol; »% styrenes, is particularly suitable for the present invention, - because it is not only able to - to prevent the occurrence of the offset phenomenon but also has excellent manufacturing properties in terms of the triboelectric effect and the uniform dispersibility of the additives required for the toner;

In the production of the toner according to the present invention, in order to obtain a toner having an Mw of 80,000 or more, although the conditions for obtaining the Mw cannot be determined uniformly due to the fact that various conditions such as the types and the combination of the polymerizable monomers used, - the kinds and the addition amounts of the colorant, such as carbon black ^, ^1, the addition amounts of other additives, including the Polymerisätionsinitiatorsj- the temperature and the duration of the polymerization reaction, and the like; are interwoven in a complicated manner, the conditions are determined taking into account the fact that, in general, with a large amount of the polymerization initiator and a high polymerization temperature, the weight-average molecular weight becomes smaller, for example in such a way that, while the amounts of monomers are kept constant ^ Colorants and other additives ¹ that are required for the toner, the amount of polymerization initiator and the polymerization temperature are varied, ¹ more attempts

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to be carried out to determine the conditions under which the desired weight-average molecular weight can be achieved;

On the other hand, the particle size and the particle size distribution of the toner are determined by the degree of shear, the shear duration, - the type of dispersing device used, the amount and type of dispersion stabilizer used, - the proportion between the monomers used and the water, the viscosity of the polymerization mixture and dgli It is also known ¹ that the resultant particle size is smaller, the higher the shear rate, the greater the amount of the dispersion stabilizer used, 'the smaller the ratio between the polymerization and water and the lower the viscosity of the polymerization mixture is.

However, these factors are interrelated and it is difficult to - control all factors . (to control) so that a shear is applied looking through a microscope, - to find out the point, ' on which the desired particle size and the desired particle size distribution is achieved, - and for Continuing the polymerization, the stirring speed is reduced to the normal stirring speed, what is the most convenient way of making the toner of the present invention;

Also the above-mentioned aim of preventing the offset phenomenon of the invention can be achieved with a

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Toner for developing latent electrostatic images _{f of} the particles, the ratio of the longer diameter (a) to the shorter diameter (b) of which is 1.00 ^ a / b ^ 1.05 and the particle size of which is within the range of 1 to 30 µm - where 70% by weight of the toner has a particle size within the range of the main particle size + 3 μm, - where in the case of the main resin the ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer is 3.5 or is more;

According to a preferred embodiment of the invention contains the toner of the present invention as the main resin is a polymer having a high molecular weight component (a resin) and a component with a low mole-! kular weight (a resin) contains, 'wherein the content of the component having a high molecular weight having an Mw from 150,000 or more is 5 to 50% by weight of the amount of the polymer;

The use of the toner of the present invention to develop an electrostatic latent image enables it to be carried out a very effective and satisfactory heat roller fixation without an offset phenomenon or wrapping of paper sheets around the fixing roller occurs even when there is no offset preventing agent on the Surface of the fixing roller is applied, - so that not only the mechanism of the fixing device is simplified, but also the accuracy, the stability and the

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reliability of a high-speed copying device ¹ in which such a fixing device is built-in can be improved and, in addition, the cost of manufacturing such a device can be reduced; The toner of the present invention therefore has the advantage that it facilitates the construction of a high-speed copier;

The toner generally contains or consists of a resin component, a colorant component, ¹ such as; Pigments or dyes, - and an additive component, - consisting of a plasticizer, 'a Ladungskontrollraittel and the like;, - for controlling (control) the physical and developing properties of the toner ¹ wherein the resin component different natural resins and polymer resins containing' individually or in form a suitable mixture may be used - and the invention also comprises dieFälle, ¹ in which the toner contains as the resin component a polymer · which is itself colored by coupling with a dye;

According to a preferred embodiment of the invention, the toner according to the invention contains as a component unit an α, β-unsaturated ethylenic monomer and it contains a resin in which the molecular weight distribution of the main resin consists of a component having a low molecular weight and a component having a high molecular weight Molecular weight, ¹ Mw / Mn is 3.5 or more, and particularly it contains the resin of the present invention as an Ilaupthars component; that is, the toner of the present invention contains

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the resin according to the invention in an amount of at least 60% by weight, preferably of at least 75% by weight on the total amount of the resin component of the toner, - thereby eliminating the offset phenomenon of the toner on the heat fixing roller as well the wrapping of paper sheets around the fixing roller is avoided;

The above-described resin of the preferred embodiment composed of a low molecular weight component and a high molecular weight component is one having a molecular weight distribution Mw / Mn of 3 _} 5 or more (Homopolymers) or a copolymer, - this value is the value of the respective polymers, ¹ while if the resin according to the invention consists of mixed polymers, this value stands for the value of the total mixed polymers ^ hi ^ in the case of mixed polymers, the value of Mw / Mn of each of the mixed polymers need not necessarily be 3, '5 or more as long as the value of the total mixture is within the above !! Range is »The molecular weight of the low molecular weight component of the invention according to the resin is, - in terms of the weight average molecular weight, ¹ less than 150,000, - preferably it is within the range of 10,000 to 150,000, while the molecular weight of the High molecular weight component in terms of number average molecular weight more than 150,000 _? preferably 200,000 to

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500,000, - is ^ and the proportion of the two components is such that the component with the high molecular weight in an amount within the range of 5
, preferably%, from 10 to 40 wt, - -, is present% _5, and the component with low molecular weight to 50 percent by
an amount within the range from 95 to 50% by weight, ·
preferably from 90 to 60% by weight 'is present;

In the preferred embodiment of the invention, a
Resin uses · which has a low molecular weight component and a high molecular weight component | contains lar weight; The low molecular weight component plays an effective role in lowering the softening point of the toner of the present invention, specifically it is possible to adjust the temperature of the fuser roller discontinue, 'so that energy can be saved with the copier used f; The reduction of the molecular X kulargewicht it also means' that the resin WEI itself leads I likely will, leading to an improvement in the conditions when | Fixing with pressure by the fixing roller caused On the other {hand, the component passes the high molecular weight {an effective role in respect to the prevention of off-J set phenomenon as well as in respect to the prevention of the \ around Wick one of sheets of paper around the fixing roller; ie; ', | the resin with the high molecular weight is the component ¹ that is difficult to melt with heat and therefore has good release properties with respect to the fuser roller; However, when the high molecular weight resin is used in an amount of more than 50% by weight, | it is difficult to melt the resin through the heating roller *

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gen, 'resulting in poor fixation;

The resin of the present invention has an Mw / Mn of at least 3.5, those having a weight average molecular weight However, Mw from about 10,000 to about 200,000 are desirable. In addition, the values of Mw / Mn and Mw / Mn can be determined in several ways and they vary slightly depending on the one used Measuring method; The values given here according to the invention for Mw, Mn and Mw / Mn were described in accordance with the above certain measuring methods

The above object of the invention of preventing the offset phenomenon can be achieved with a toner for developing electrostatic latent images having substantially spherical particles in which the ratio between their longer diameter (a) and their shorter diameter (b) is within the range of 1.00 · £ = a / b <= 1.05, where d5.e size of the particles is within the range from 1 to 30 pn and 70% by weight of the toner has a particle size within the range of the main particle size + 3 µm, where the main resin of the toner is a uniform mixture of a component having a low molecular weight and a component having a high molecular weight; _s the ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn.) Of the toner Is 3, -5 or more and the glass transition point of the high molecular weight component is within the range of 30 to 70 ° C lies.

According to a preferred embodiment of the invention, in the toner according to the invention, the weight-average molecular weight of the component with the high molecular weight is 150,000 or more and the polymer is in the toner in an amount of 5 to 50% by weight, based on the main resin, ¹ contain;

When the GIasumwandlungspunkt of the toner is less than 45 ° G / on the other hand the risk 'that a Blökkierung occurs as a result of the Kaltfließphänomeiis that hatj an undesirable influence on the mounting of the toner dih ;, ^1, substantially spherical toner used in the invention has a low softening point of as little as 150 ° C or less and a high glass transition point of 45 ° C or more; These physical properties can be achieved with a toner which contains the main resin component, which consists of a copolyra of, for example, 65 to 95% by weight of styrene, 5 to 35 % by weight of methacrylic acid ester and / or acrylic acid ester; When the styrene content is less than 65% by weight, it becomes difficult to set the glass transition point to 45 ° C. or higher, while when it is more than 95% by weight, it becomes difficult to set the softening point 150 G or lower so that the toner of the present invention cannot be obtained in either case;

The content of the main resin component of the toner according to the invention is expediently at least about 60% by weight or more ¹ , preferably 75% ^{by weight or more, 1} based on the total amount of the resin component of the toner;

A selenium photosensitive body can be used to form an image using, for example, the electrophotographic process and using the toner according to the invention; or a photosensitive body can be used which has been produced by coating an electrically conductive support with a photosensitive layer, produced by dispersing an inorganic photoconductive material such as zinc oxide, cadmium sulfide, cadmium selenide, cadmium sulfide selenide, lead oxide Mercury sulfide and the like in a binder? or a photosensitive body made by coating an electroconductive support with a photosensitive layer made by incorporating an organic photoconductive material such as anthracene, polyvinyl carbazole and the like into a binder resin photosensitive body is charged by means of a corona generator using a corotron or scorotron charger, and then imagewise light or the like; exposed to thereby form an electrostatic latent image thereon; The latent electrostatic image is then developed - for example with a developer ¹ which consists of a mixture of the toner according to the invention and glass beads or iron carriers, - for example using the I-cascade process or the magnetic brush process; The toner image, which is obtained, for example, using a corona discharge, is then brought into pressure ^{contact with a paper 1 onto which it is to be transferred;} The toner image created on the paper is then

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heated by means of a heating roller fixing device for fixing; As the fixing roller, there can generally be successfully used ^one which has a smooth surface obtained by using a fluororesin such as; Teflon (manufactured by DuPont) y EFP (manufactured by DuPont), - Fluon (manufactured by ICI), - KeI-F (manufactured by 3M), - Daiflon (manufactured by Daikin) and the like, or a relatively hard silicone rubber such as KE-1300RTV (manufactured by Shin-etsu Chemical Industries Co ;, ¹ Ltd;), or, if necessary, one having a metal surface may be used;

The invention is explained in more detail by the following examples, without, however, being restricted thereto; The one in it "Parts" given relate to "parts by weight" unless otherwise stated;

example 1

Styrene

Carbon black no; 30 (manufactured by Mitsubishi Chemical Industries Ltd;)

2, '2' -Azobis (2, -4-dimethylvaleronitrile)

Hydrophobic silicon dioxide Aerosil R-972. (Charge control agent, - manufactured by Degussa) 1 ^u .

The above materials are mixed together to form Preparation of a polymerization mixture; on the other hand

100 Parts 5 ti 3 t!

η ·; Λ Γ r; Γ

O i ·, -rj O / O

were three parts of tricalcium phosphate and 0/04 parts of sodium dodecylbenzenesulfonate placed in a 2 liter separable flask and the mixture became distilled water added. Then the above mixture was added and the mixture was made using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., - Ltd.) Stirred, Stirring was stopped at the time - when the particles · as determined by viewing through a microscope "had the desired particle size" was replaced with normal speed stirring. The mixture was then heated to 60 C and at this temperature over a period of 10 hours while stirring Subjected to a polymerization reaction at 100 rpm no change in particle size was observed at the end of the polymerization reaction.

After completion of the polymerization reaction, the solid product particles were treated with hydrochloric acid, filtered and washed to obtain two-component negative toner samples No. 1 to No. 6;

The toner thus obtained consisted of particles having a substantially spherical shape; The relationship between the longer particle diameter (a) and the shorter particle diameter (b) was within the range of 1, 'OO ^ a / b ^ l, 05i

The relationship between the number of revolutions of the TK-homomixer 'of the stirring time, ¹ of the particle size and particle size distribution are given in the following table I *

SZ

Table I.

irobe stirring medium particle wt% toner

No; shrinking duration Particle size (um) within the

dness (min) size (um) main particle

(Rpm) size + 3 um

1 3 000 120 15th 5 - 40 70 % 2 4th 000 60 13th 5-35 72 % 3 5 000 60 10 1-30 75% 4th 6th 000 30th 10 1 - 30 68 % 5 7th 000 20th 10 Ο, α - 35 65% 6th 8th 000 10 10 0.1 to 35 63 %

The above weight percent of toner within the primary particle + 3 to indicate what percentage of the total amount of the toner, the toner particles ¹ whose particle size is up 13 is located to within the range of 7, with the proviso that the average particle diameter of the toner 10 .mu.m .

Using a U-Bix V copier (manufactured by Konishiroku Photo Industry Co., Ltd Image tests were carried out on Samples No. 1 to No. 6 to determine the dissolution ^ of the veil and the Change in the amount of charge at the time of successive ~ the subsequent copy operations; The results are given in Table II below;

Table II

Sample resolution Fog Nri (lines / mm) Reflection density

Change in the amount of charge. for successive copy operations

(at the beginning *> after 10

Scroll)

1 4th 0.03 16 pc / g> - 22 jjc / g 2 5 0.03 18 pc / g 5- 22 pc / g 3 7th 0.02 20 pc / g s ^ 20 pc / g 4th 6th 0.02 20 pc / g> - 2G pc / g 5 5 0.06 20 pc / g * - 30 pc / g 6th 5 0.08 20 pc / g s- 32 pc / g

The sample no; 3 had excellent resolution and one slight fog and no impairment (deterioration) occurred even with successive copying operations the image density. Even after 10,000 copies, no change in the amount of charge was found »

Example 2

Polystyrene carbon black No. 30

Aerosil R-972 hydrophobic silica

100 pieces 5 "

Il

The above materials were melted, - by-

3Ή3575 '■■;

kneaded and pulverized and then classified by means of a classifying device ¹ so that the particle sizes were 1 to 30 µm and the toner contained 70 wt. Component Toner Sample No. 7 was obtained, ¹ which was then subjected to a spray-drying treatment 'to make it spherical,' using Sample Nos; shown in Table III below. 8 and no; 9 received;

Table III

Sample no; Relationship between the longer diameter (a) and the shorter diameter

(b) ■

5 line xi / ircn.

6 lines / mm

7 lines / ram

7th 2.0 and more 8th 1, ^ 5 and more 9 1.Ό5

These samples were subjected to image tests in the same manner as in Example 1, the results obtained showing that Sample No. 9 gave satisfactory results in terms of fluidity, ¹ sharpness and resolution, ¹ compared with Sample No. * 7 and no. 8.

Example 3

Styrene. 50 parts

Methyl methacrylate 30 parts

n-butyl methacrylate 20 parts

Carbon black No. 30 5 parts

3 HOο75

Aezobisisobutyronitrile 3 parts

Aerosil hydrophobic silicon dioxide

R-972 1 part

The above materials were mixed together to prepare a polymerization mixture, which was then treated in the same manner as in Example 1 to obtain a two-component toner having a negative polarity. The toner particles obtained thereby had a substantially spherical shape the ratio between the longer particle diameter (a) and the shorter particle diameter (b) were within the range of Ij ¹ OO ^. a / b ^ l, O5i The toner particle size was, as was determined by measurement by means of a Coulter counter, -within the range from 1 to 30 pm, ¹ and the amount of the toner, - in the range of the main particle size + _ 3 um fell, ¹ was 75 wt%;

The results obtained when the toner obtained was tested using the U-Bix V device showed that that the resolution was 7 lines / mm, that the fog was 0.02, and that the change in the amount of charge was only was low and increased from -20 µC / g in the initial stage -21 JiC / g changed after 10,000 copies and there was no impairment (Deterioration) in the image density

Example 4

Styrene

4-vinyl pyridine

Soot No. 2300

90 Parts 10 11 5 Il

1 "' ■' ° · ζ 7 5 - 33 -

Azobisisobutyronitrile '3 parts

Iron tetraoxide powder, - Mapicoblack

BL-500 (Titanium Industry Co., - Ltd.) 70 "

The above materials were mixed together to prepare a polymerization mixture ^1, which was then treated in the same manner as in Example 1 to obtain a 1-component toner having a positive polarity. The toner particles were substantially spherical in shape; the ratio between the longer particle diameter (a) and the shorter particle diameter (b) was within the range of 1 ^ 00 < a / b_ £ 1 ^ 05.

The particle size of the toner obtained was, as determined by measurement with a Coulter counter, within the range from 1 to 30 μm and the amount of the toner, whose particle size was within the range of the main particle size + 3 μm, ¹ was 75% by weight;

The results obtained when the toner was tested using a U-Bix T device (manufactured by Konishiroku Photo Industry Co., ¹ Ltd.) showed that the resolution was 6 lines / mm, the fog was 0.02 and the change in the amount of charge in successive copying was little and changed from 16 pC / g at the initial stage to 17 pC / g after 10,000 copies, ¹ and no deterioration (deterioration) in image density was found;

31 -9575

Example 5

The polymerization mixtures shown in Table IV below were prepared using styrene and butyl methacrylate as the monomers to be polymerized, using No. 30 carbon black as the colorant, and using 2.2 ^L azobis (2,4-dimethylvaleronitrile) as the polymerization initiator .

Polymerisation mixture and polymerisation conditions

sample

Table IV

Sty butyl dye ini-

rol meth- betia-

(Partial acry «with« tor

le) lat tel (TeI- (parts) (Part- Ie) Ie)

Polymerisationsbedin conditions Temp; duration

(° C) (hrs.)

, -
Toner (A) 100 - -__ »_ 5 3 65 8th Toner (B) 100 5 3 50 8th Toner (C) 100 5 2 50. 7th Toner (D) 100 20th 5 1 50 8th Toner (E) 80 20th 5 3 63 6.5 Toner (F) 80 20th 5 2 48 '" 7th Toner (G) 80 20th 5 1 50 7th Toner (H) 80 20th 5 2 50 8th Toner (I) 80 5 1.5 50 8th

On the other hand, there were 3 parts of tricalcium phosphate and 0/04 Parts of sodium dodecylbenzenesulfonate were placed in a 2 liter separable flask / the mixture was distilled Water and the above polymerization mixture were added, and the mixture thereby obtained was added using a TK homomixer (manufactured by Tokushu Kika Kogyo Co ;, Ltd ·) stirred / around the components dispersing the same, under observation through a microscope after the point at which the desired particle size was / was achieved by using a stirrer at normal speed on the homomixer replaced / to stir the mixture at a speed of 100 rpm, and then the dispersed mixture became under the conditions given in Table IV of the Subjected to polymerization reaction. No change in particle size was observed until the end of the reaction After the completion of the polymerization, the solid particles obtained were treated with hydrochloric acid / filtered and then washed, using a 2-component toner received.

Each particle of the toner thereby obtained had a substantially spherical shape; the ratio between the longer particle diameter (a) and the shorter particle diameter (b) was within the range of 1 pound. a / b ^ l, 05. The results of the mean particle size, the particle size distribution / amount of the toner having a particle size within the range of the major particle size + 3 µm and the weight average molecular weight of the toner obtained using a Coulter counter are in the following table

3: ^f > 9575

V indicated / in which the percentage by weight of the toner within the main particle size + 3 jam indicates the percentage of the total toner, - which the particles with a particle diameter within the range from 7 to 13 _µm occupy ί provided that the average particle diameter of the toner 10 µm was »

Results

Table V

Average particle GEWI% To- weight durchTeilchen- größenver- _ner within schnittligröße division half of ches MoIe-. , v main part-weight Y ^m) V ^m) particle size + of the resin

3 um "" (Mw)

toner (A) 11 3 - 25th 77 4.8 X 10 ⁴ toner (B) 13th 5 - 30 75 9.9 X 3 O ⁴ toner (C) 3 _m 25 80 15.3 X 10 ⁴ toner (D) 11 5 - 25th 79 23.4 X 10 ⁴ Toner- (E) 12th 3 - 23 76 6.5 X 10 ⁴ toner (F) 10 3 - 25th 81 14.2 X 10 ⁴ toner (G) 11 5 - 25th 83 25.1 X 10 ⁴ toner (H) 12th 5 . 40 57 13.8 X 10 ⁴ toner (D 12th 3 - 35 61 17.2 X 10 ⁴ 12th

Each of the toners given in Table V was "carrier particles with iron powder" with a resin coating, the partial

particle size was about 50 to about 80 µm, ¹ mixed to prepare a developer / which was then used to develop an electrostatic latent image formed by the usual electrophotographic method, after which image tests for resolution, fog, change in the amount of charge (at the beginning after 10,000 copies) during the subsequent copying operations using a copying machine having a toner recycler and with respect to the image density. The results obtained are given in Table VI below.

As can be seen from Table VI, the toners gave the Samples (B), - (C), - (D) / (F) and (G) because of the narrow areas particle size distributions have little fog / no change in the amount of charge and good images with a satisfactory image density / while the control toners (H) and (I) because of the broad ranges of particle size distribution resulted in a lot of fog and especially the toner (H) to deterioration (deterioration) the resolution as well as the image density due to the fluctuation in the amount of charge

3: -9575

Table VI

Results

Sample"

Resolution _, _Ί . Change of / ,. . / Schlei- _T j. (Lines / amount of charge mm). he ^

to order
starts 10,000
Copies

Image anti-density offset effect

Toner (Λ) 7th 0.02 20th 21st Toner (B) 7th 0.02 20th 19th Toner (C) 7th 0.02 21st 20th Toner (D) 7th 0.02 20th 20th Toner (E) 7th 0.02 19th 20th Toner (F) 7th 0.02 20th 21st Toner (G) 7th 0.02 20th 20th Toner (H) 5 0.05 18th 25th Toner (1) 7th 0.05 20th 27

Good Bad

Il

Il

Il

It

Il

Well

It

Il

bad good

It

less

Il

It

Regarding the offset preventing effect, after the electrostatic latent image was developed, the toner image was transferred onto a sheet of transfer paper, which was then brought into pressure contact with a fixing roller heated to a temperature of 165 to 175 ° C * the surface of which was made with a fluorocarbon resin (EFP) from DuPont) was coated _?

Toner image was fixed by fusing it. Then, in order to determine whether or not the fused toner image was transferred to the surface of the fixing roller to produce an offset phenomenon, after the respective fixing operations were completed, a blank transfer sheet with no toner image was applied with the fixing roller in the same manner as above brought into pressure contact to thereby determine the presence of discoloration (staining) on the sheet transfer paper caused by the offset phenomenon of the toner, - where _v as shown in Table VI, it was found that the toners (A) and ( E), which had a lower weight average molecular weight, colored stains on the paper transfer sheets caused by the offset phenomenon of the toners _{} were} observed, while the toners (B), (C), (D), (F) and (G) and the remaining toners (H) and (i) gave no offset phenomenon. The results did not change even when the fixing operations were repeated in the same way.

In addition, blocking tests were carried out on the samples in an incubation chamber kept at a temperature of 50 ° C., but none of the samples Blockage still resulted in caking.

Example 6

Styrene 80 parts

n-butyl methacrylate 20 "

Soot No. 30 5 "

31 V 9 5 7 5

2.2 ^l -Azobis (2,4-dimethylvalero-

nitrile) 3 parts

Hydrophobic silica

Aerosil R-972 1 "

The above materials were mixed together to prepare a polymerization mixture. on the other hand 3 parts of tricalcium phosphate and 0.04 part of sodium dodecylbenzenesulfonate were placed in a 2 liter separable flask and to the mixture were added distilled water and then the above polymerization mixture admitted. The resulting mixture was stirred using a TK homomixer and after, as by observation the required particle size and the required particle size distribution was determined under the microscope had been reached ^ became the Homoraixer by a Replaced normal stirrer, the mixture was heated to 60 G and kept at that temperature for a period of 10 hours at a normal resting speed of R.p.m. to the polymerization reaction, whereby the polymerization reaction was completed. During the No change in particle size was observed for the duration of the reaction.

After the completion of the polymerization, the solid particles were treated with hydrochloric acid, filtered and then washed to obtain a two-component toner having a negative polarity. The obtained toner consisted of substantially spherical toner particles, their Ratio between longer diameter (a) and shorter diameter (b) within the range of

1.00 ^ a / b ^ 1.05 lay. The particle sizes of the toner obtained, measured en by means of a Coulter counter, was 1 to 30 µm and the amount of the toner was within the range the main particle size £ 3 µm was 75% by weight. The softening point the toner was 135 C and the glass transition spunlct was 59 C.

The obtained toner was made using an electrophotographic Copier's U-Bix V subjected to image tests «The results of the tests showed that the resolution was 7 lines / mm was that the fog was 0.02 and the change in the amount of charge with successive copying runs was only slight and was within the range from 20 iic / g in the initial stage to 21 iic / g after 10,000 copies and the image density was not deteriorated · In the fixing test using the heat roller of the U-Bix V at 160 C and a speed of 122 mm / sec; was carried out, it was found that the toner had a satisfactory fixing power »The in one incubation chamber held at a temperature of 50 ° C The blocking test showed that there was no blocking of the toner particles.

Styrene carbon black No. 30

2.2 ^f -azobis (2,4-dimethylvaleronitrile)

Aerosil R-972 hydrophobic silica

The above materials were mixed together for

100 Parts 5 Il 3 ti 1 Il

31-; 95 7 5
- kt - IS

Preparation of a polymerization mixture, which was then polymerized in the same manner as in Example 6 to obtain a toner having the particle size and particle size distribution required in accordance with the invention. The softening point and the GIasumwandlungspunkt of the toner was 160 ⁰ C and 80 ° C.

The heating roller of the U-Bix V was at 160 ⁰ G with 122 mm / sec. used to carry out fixing tests, the results obtained showing that the toner was incompletely fixed.

Styrene 60 parts

n-butyl methacrylate 40 parts

Carbon black No. 30 5 parts

2,2-azobis (2,4-dimethylvalero-

nitrile) 3 parts

Hydrophobic Silicon Dioxide Aero-

sil R-972 1 part

The above materials were mixed together to produce a polymerization mixture, which was then applied was polymerized in the same manner as in Example 1, using a toner having the required particle size and the required particle size distribution. The softening point and the glass transition point of this The toner obtained was 110 ° C. and 43 ° C., respectively. That carried out in an incubation chamber kept at 50 ° C. The blocking test indicated that blocking occurred with the toner.

Example 7

100 ml of a 0.1 Mol / l aqueous trisodium phosphate solution by adding 600 ml of distilled water and diluted to the aqueous 18.7 ml of a 1.0 ml / l aqueous calcium chloride solution and then 0.1 g of a 10% strength sodium dodecylbenzenesulfonate solution were added with stirring added to the preparation of a dispersion medium [S]; To the mixture obtained a suspended polymerization mixture to be dispersed, consisting of 80 g of styrene and 20 g of n-butyl methacrylate and 0.3 g of benzoyl peroxide, added and after which the air inside the flask is replaced by nitrogen gas had been replaced, the suspension was heated to 80 C and at this temperature for a period of Subjected to a polymerization reaction for 20 hours. After the completion of the reaction, the polymerized product became cooled, dehydrated and washed repeatedly to obtain a high molecular weight resin (A)

On the other hand, another similar dispersion medium [S] was prepared; Then 80 parts of styrene, 20 parts of n-butyl methacrylate, 5 parts of No. 30 carbon black, 1 part of Aerosil R-972, 5 parts of 2,2'-azobis (valeronitrile), 6 parts of dodecyl mercaptan and 30 parts of the above resin were added high molecular weight [A] mixed with each other to sufficiently disperse the carbon black therein to prepare a polymerization ^{mixture, 1} which was then added to the above dispersion medium, and the mixture thus obtained was stirred with a TK homomixer at a speed of 3500 rpm 65 ° G heated and

3 1 Λ 9 5 7 5

stirring was continued at this temperature for 30 minutes. Thereafter, the stirring was stopped by stirring with normal speed using a normal stirrer at 100 rpm to carry out the polymerization over a period of 8 hours, maintaining the same temperature, until the end of the Polymerization. After the end of the polymerization, the product was cooled, the solid was filtered off and into a dilute 5% aqueous hydrochloric acid solution immersed to decompose the calcium phosphate in it, Then it was washed until the washing water became neutral, and then it was dried to dehydrate, whereby a toner [1] according to the present invention having an average particle diameter of 12 µm was obtained.

The resin of the toner [1] obtained thereby had Mw / Mn of 16.5, - an Mw of 90,000 and a softening point of 138 C (the value was measured in a flow tester determined).

Control example 1

A polymerization mixture consisting of 8 parts of styrene, 20 parts of n-butyl methacrylate ^ 5 parts of carbon black No. 30, 1 part Aerosil R-972, 3 parts 2, -2'-Azobis (valeronitrile) ^ was made using the above dispersion medium [S] for 15 hours at 60 ° C Subjected suspension polymerization, wherein one Control Toner 1 received. The resin of the control toner 1 obtained in this way had an Mw / Mn of 3 »2, - an Mn of

Ί - ■ /.ORT s
- 4r3r-

52,000 and a softening point of 141 C.

Example 8

A toner [2] was prepared in the same manner as in Example 7 except that this time 5 parts of that in Example 7 synthesized high molecular weight resin [A] - 80 parts of styrene, 20 parts of n-butyl methacrylate, 5 parts Carbon black No. 30, - 1 part Aerosil R-972, 5 parts 2, -2 * ~ Azobis (valeronitrile) and 6 parts of dodecyl mercaptan were used.

The resin of the toner of the present invention obtained thereby [2] had an Mw / Mn of 10/8, an Mw of 47,000 and a Softening point of 135 C.

Example 9

A toner [3] was prepared in the same manner as in Example 7, this time using the high molecular weight resin [A] prepared in Example 7 in an amount of 40 parts. The resin of the toner thus obtained [3] had an Mw / Mn of 18.6 _y a Mw of 120,000 and a softening point of 143 C.

In addition, each had in Examples 7 _f 8 and 9 and obtained in the Control Example 1 toner has a substantially spherical particle shape, wherein the ratio between the longer diameter (a) and the shorter diameter (b) within the range of 1.00 ^ a / b £ 1.05, the size of the toner particles was within the range from 1 to 30 µm, determined by measurement with the Coul-

149575

- AG -

ter counter and the proportion of the particles having a size within the range of the major particle size was + 3 µm 70 wt%.

Test 1

3 parts of each of toners [1], [2] and [3] and control toner 1 and 97 parts of iron powder carrier with an average Particle sizes from 50 to 80 μm were mixed with one another to produce a developer. Everyone of these three prepared developers were used to develop one using the usual electrophotographic Process generated latent electrostatic image and the toner image developed in the process was transferred to a transfer paper using a fixing roller, the surface of which was coated with FEP (tetrafluoroethylene / hexafluoropropylene copolymer, manufactured by DuPont), which was coated on a Temperature of 160 to 170 C had been brought to fix the toner image by melting «.

After that, was to determine whether after the respective fixing work s went the fused toner image was transferred onto the surface of the fixing roller to cause an offset phenomenon, a simple one Transfer paper with no toner image in pressure contact with the fixing roller under the same conditions as above and the occurrence of the "offset" phenomenon on the transfer paper was noted

It was found that when using the toner des

Control Example 1 shows staining (discoloration) on the transfer paper as a result of the offset phenomenon However, with toners [1] and [3] no staining (discoloration) whatsoever on the transfer paper was found as a result of the offset phenomenon »

When using the toner [2], "no or only a slight opening phenomenon was found on the transfer paper, which did not affect the reproduced image.

Further, tests were conducted on the wrapping of paper sheets around the fixing roller, and this wrapping phenomenon occurred in the control toner 1, ¹ while in the toners [I], - [2] and [3] no curling phenomenon occurred at all.

Image tests were carried out on toners [1] and [3] using an electrophotographic copier U-Bix-V and the results showed - that the resolution was 7 lines / mm, - that the haze was 0.02 (reflection density), ' that the change in the amount of charge in successive copying operations was so small that in the toner [1], the change of 20, -5 yuc / g in the initial stage went to 22.5 Äic / g after 10,000 copies, and that in the toner [3], the change from 21.0 / µc / g in the initial stage went to 23.0 Aic / g after 10,000 copies - so that the image densities were not impaired (worsened) »

51
Test 2

To determine the shelf life of the toner, each of the toners was kept at a temperature of 50 ° for 24 hours C and a relative humidity of 60% in an incubation chamber kept; The results of the test showed that the toners [I], "[2] and [3] did not cause any lump formation led.

Synthesis example 1

In a flask equipped with a conventional anchor-shaped stirrer piston 340 of an aqueous solution containing 1 wt .-% wt .-% of tricalcium phosphate and 0.01 NL-R (sodium dodecylbenzenesulfonate) were prepared ml, ¹ based on the monomers indicated below, contained. To the aqueous solution thus prepared, a monomer mixture consisting of 80 parts of styrene, 20 parts of n-butyl acrylate and 1.6 parts of lauryl peroxide was added with stirring at a speed of 200 rpm, and the mixture obtained was stirred at a temperature of 70.degree subjected to a polymerization reaction for a period of 7 hours until the completion of the reaction. The reaction product thereby obtained was then cooled, treated with a dilute hydrochloric acid solution to add and remove tricalcium phosphate, followed by repeated washing to obtain a resin having a Tg of 52 ° C. and an Mw of 250,000.

Example 10

95 parts of styrene, 5 parts of n-butyl methacrylate, 5 parts of carbon black

No. 30, · 5 parts of 2.2 ^l -azobis (2,4-dimethylvaleronitrile), -1 part of n-dodecyl mercaptan, 30 parts of the resin synthesized in Synthesis Example 1, 3.5 parts of polypropylene PP-660 (produced from Shin-etsu Chemical Industry Co., Ltdi) and 1 part of Aerosil R-972 were sufficiently mixed with each other and dispersed using a sand stirrer; Then 700 ml of an aqueous solution were prepared which contained tricalcium phosphate in an amount of 3% by weight, NL-R in an amount of 0.04% by weight, ammonium molybdate in an amount of 0.06% by weight and sodium nitrite in an amount of 0.1 wt .-%, ¹ based on the above-mentioned monomers, and containing the resin, - and to the solution TK homomixer was added with stirring using a speed of 5000 rpm, the dispersed mixture prepared above After the desired particle size had been achieved, as was observed by observation, the stirring was replaced by stirring at normal speed of 200 rpm by means of a normal stirrer to carry out the polymerization reaction for a period of 7 hours at 65 ° C, - to complete the reaction. The reaction product was cooled, treated with a dilute aqueous hydrochloric acid solution, - to decompose and remove the trichloro-calcium phosphate, - washed repeatedly and then dried to produce a toner according to the invention having an average particle diameter of 12 .mu.m. The toner thereby obtained was in a substantially spherical shape, and the ratio between the longer particle diameter (a) and the shorter particle diameter (b) was within the range of 1.00 £ a / b £ 1.05. _ "- .:

The size of the toner particles was within the range from 1 to 30 µm and the amount of those toner particles ¹ whose size was within the range of the main particle size + 3 µm was - determined by measurement by means of a Coulter counter, 74% by weight . The toner had a Tg of 60 C, an Mw / Mn of 20.0, an M ¹ SV of 80,000 and a softening point (Cm) of 135 C.

5 parts of the obtained toner and 95 parts of iron powder carrier were mixed together to prepare one Developer.

The developer obtained was used to develop an electrostatic latent image produced by a conventional electrophotographic method, and the toner image thus developed was transferred to a sheet of transfer paper, which was then fused ¹ by treating it at 160 to 170 ^° C. with a The fixing roller, the surface of which was coated with EFP, was brought into pressure contact, whereby satisfactory fixing was achieved.

To determine whether the fused toner image is fused onto the surface of the fusing roller was transferred causing an offset phenomenon, became a simple transfer paper without a toner image is brought into pressure contact with the fixing roller under the same conditions as above to print them Way the occurrence of an offset phenomenon of the toner on the sheet of transfer paper.

3H9575

It was found that no discoloration (staining) was found as a result of the offset phenomenon. Tests were also carried out on the wrapping of the Paper transfer sheets around the above fixing roller carried out, but it was found that when the toner of the present invention is used, there is no curling phenomenon around the fixing roller.

Further, image tests were carried out on the toner using an electrophotographic copier U-Bix V and the results showed that the resolution was 7 lines / mm, that the fogging was 0.02, that the change the amount of charge in successive copying operations was low and within the range of 20.5 yuc / g in the initial stage to. 21.0 yuc / g after 10,000 copies and no deterioration (deterioration) in image density was found.

Synthesis Example · 2

A resin with a Tg of 52.5 C and an Mw of 350 was prepared in exactly the same way as in Synthesis Example 1, but this time 1.0 part of lauryl peroxide were used and the polymerization reaction was carried out at a temperature of 65 ° G

Example 11

A toner was produced in the same manner as in Example 10, but this time using 20 parts of the

SS

gen Synthesis Example 2 the obtained resin in place of the resin of Synthesis Example 1 used in Example 10 were NND as a result had the toner thus obtained having a Tg of 61 ° C, - a Mw / Met "of 25.0, ¹ a Mw of 85 000, and a Tm of 137 ° C. The resulting toner was in a substantially spherical shape, the ratio between the longer particle diameter (a) and the shorter particle diameter (b) being within the range of 1.00 £: a / b - The size of the toner particles, determined by means of a Coulter counter, was within the range from 1 to 29 µm and the proportion of particles with a size within the main particle size of £ 3 pn was 77% by weight;

This toner was used to make a developer was used in the same manner as in Example 10, and the toner thereby obtained was subjected to tests for determination both the offset phenomenon and the curling phenomenon on the fixing roller, and it was found that none of these phenomena occurred.

In addition, image tests were carried out on the toner using the U-Bix V copier and the results showed that the resolution was 7 lines / mm, that the fog was 0.02, that the change in the amount of charge in successive copying was little and was within the range of 21 µc / g at the initial stage to 22 µc / g after 10,000 copies, and that the image density was not deteriorated. It a blocking test was also carried out with the toner in one at

3U9575 -:: ;; -;

incubation chamber kept at a temperature of 50 ° C but no caking phenomenon was observed.

Synthetic tea example 3

A resin with a Tg of 75 ^° C. and an Mw of 270,000 was produced in exactly the same way as in Synthesis Example 1, but this time 90 parts of styrene and 10 parts of butyl acrylate were used.

Control example 2

A toner was prepared in the same manner as in Ex.10 except that 40 parts of the resin of the above Synthesis Example was prepared. 3.80 parts of styrene and 20 parts of n-butyl methacrylate were used instead of the resin of Synthesis Example 1 in Example 10, then a toner having the Tg \ on 55 ° G, the Mw / Mn of 150, the Mw of 100,000 and the Tm of 155 ° C obtained; The obtained toner was evaluated in the same manner as in Example 10 to find that the toner had an offset phenomenon - a curling phenomenon around ^! the fixing roller and insufficient fixing occurred.

In addition, a blocking test was carried out with the toner in one carried out at a temperature of 50 ° C maintained incubation chamber, which was found - that caking in which toner occurred.

Claims (1)

T 53 089 ° ^: - ^ύ ' ^D Applicant; Konishiroku Photo Industry Co., Ltd., No. 26-2 Nishishinjuku 1-chome _r Shinjuku-ku, Tokyo / Japan * Claims Toner for developing an electrostatic latent image, characterized in that it ¹ contains a colorant and a resin and consists of substantially spherical toner particles having a ratio of their longer diameter to their shorter diameter within the range of 1.00 to 1.05 - the size of which is within the range from 1 to 30 μm, the size of at least 70% by weight of the toner particles being within the range of the main particle size + 3 μm, 2i toner according to claim 1, characterized in that the resin at least 60% by weight, based on the total weight of the resin, a polymer of an α, β-unsaturated ethylenic monomer, its weight average Molecular weight is 80,000 or more; 3; Toner according to Claim 2, ^1, characterized in that the polymer is selected from the group of the homopolymers of α-methylene-aliphatic monocarboxylic acid esters and the copolymers of an aromatic vinyl compound with α-methylene-aliphatic monocarboxylic acid esters. - 2 - ^: ""'3U9575 4i toner according to claim 3, characterized in that it the aromatic vinyl compound is a styrene. 5; Toner according to one of Claims 1 to 4, characterized in that the resin is a polymer having a ratio of weight average molecular weight to number average Contains molecular weight of 3.5 or more; 6; Toner according to Claim 5, characterized in that the Polymers both a high molecular weight component and a low molecular weight component contains ^ 7. Toner according to claim 6, 'characterized in - that the the weight average molecular weight of the high molecular weight component is 150,000 or more and that this component constitutes 5 to 50% by weight of the amount of the polymer. 8th; Toner according to claim 7, characterized in that the the weight average molecular weight of the high molecular weight component is 200,000 to 500,000. 9; Toner according to one of Claims 6 to 8, characterized / that the component with the low molecular weight is a component · whose weight average molecular weight is less than 150,000. 10i toner according to claim 9, - characterized in that the weight average molecular weight of the lower molecular weight component 10,000 to 150,000 amounts to; Hi toner according to one of claims 6 to 10, characterized in that the glass transition point of the high molecular weight component is 30 to 70 ° C. 12i toner according to one of claims 1 to 11, characterized in that that it has a softening point of 150 ° C or less and a glass transition point of 45 ° C or more having·