JPH0547825B2 - - Google Patents

Description

Claim 1 Manufactured by suspension polymerization and has an average particle size of 2 to 2.
25 μm internally colored thermoplastic base particles or main particles, on the surface of the base particles,
Manufactured by emulsion polymerization or microsuspension polymerization, with an average particle size of 0.05 to 0.05 of the average particle size of the above base particles.
33% of the particulate polymer, whereby 10 to 91% of the surface of the base particle is coated with the particulate polymer. A toner with a raised surface suitable for printing.

2. The toner according to claim 1, wherein 20 to 91% of the surface of the base particles is covered with the fine particulate polymer.

3. The toner according to claim 1 or 2, wherein the average particle diameter of the fine particulate polymer is 0.2 to 15% of the average particle diameter of the base particles.

4. The toner according to claim 1 or 2, wherein 30 to 80% of the surface of the base particles is coated with the fine particulate polymer.

5. The toner according to any one of claims 1 to 4, wherein the particulate polymer is also colored inside.

6 The melting point of the particulate polymer is lower than the melting point of the base particles.
The toner according to any one of claims 1 to 5, characterized in that the temperature is 10°C or more higher.

7. The toner according to any one of claims 1 to 6, wherein the particulate polymer is produced by microsuspension polymerization and contains a charge control agent.

8 Manufactured by suspension polymerization and has an average particle size of 2~
An aqueous dispersion of internally colored thermoplastic base particles of 25 μm is contacted with a finely divided polymer latex having an average particle size of 0.05 to 33% of the average particle size of the base particles, followed by increasing the temperature. A method for producing a toner having a raised surface suitable for electrophotographic copying or electrostatic printing, characterized in that the fine particulate polymer is adsorbed onto the surface of the base particles so as to cover the surface of the base particles by 10 to 91%.

9. The method according to claim 8, characterized in that the fine particulate polymer is adsorbed onto the surface of the base particles so as to cover 20 to 91% of the base particles.

10. A method according to claim 8 or 9, wherein the aqueous dispersion of colored base particles comprises a polymerized serum resulting from polymerization of the base particles, and this serum contains a protective colloid system.

11. Contacting an aqueous dispersion of colored base particles with a latex of a finely divided polymer, then forming a protective colloid system in the aqueous dispersion, and increasing the temperature, thereby bringing the finely divided polymer onto the surface of the base particles. The method according to claim 8 or 9, characterized in that the method is made to adsorb to.

12. Claim 10, characterized in that the protective colloid system is deactivated before the addition of the finely divided polymer latex, and that the protective colloid system is subsequently reformed and the temperature is raised. the method of.

13 adding a particulate polymeric latex having functional groups of opposite charge to the base particles, thereby attracting the latex particles to the base particles;
11. The method according to claim 10, characterized in that the colloid layer is permeated.

14. The method according to claim 10, characterized in that the protective colloid system is dissolved before the addition of the particulate polymer latex, and the latex particles have a melting point higher than that of the base particles. .

15 The protective colloid system is dissolved and removed from the base particles, the base particles are redispersed, and then finely particulate polymer latex is added, and the latex particles have a higher melting point than the base particles and a lower charge. 11. A method according to claim 10, characterized in that the opposite base particles are used.

16 Internally colored thermoplastic base particles with an average particle size of 2 to 25 μm are
It is produced by suspension polymerization of a monomer or monomer mixture in the presence of a finely divided polymer latex having an average particle size of 0.05 to 33%, and the particles of said latex are insoluble in said monomer and are produced by said suspension polymerization. 1. A method for producing a toner having a raised surface suitable for electrophotographic copying or electrostatic printing, characterized in that a polymeric substance of greater hydrophilicity than the polymeric material of the base particles formed is used.

17. The method according to claim 16, characterized in that the latex polymeric material is obtained from a monomer mixture containing anionic monomers under alkaline conditions for hydrophilicity adjustment.

18. The method according to claim 16, characterized in that the latex polymerized material is obtained from a monomer mixture containing cationic monomers under acidic conditions for hydrophilicity.

19. The method according to claim 18, wherein the latex polymeric material is obtained from a monomer mixture containing a monomer having an amino group for hydrophilicity.

20. Process according to claim 17, characterized in that the latex polymeric material is obtained from a monomer mixture containing monomers having hydroxyl groups for hydrophilicity.

21. Claims 16 to 20, characterized in that the latex particles are crosslinked.
The method described in any one of paragraphs.

22 Manufactured by suspension polymerization and has an average particle size of 2~
Dry internally colored thermoplastic base particles of 25 μm are prepared by emulsion polymerization or microsuspension polymerization and have an average particle size of that of the above base particles.
0.05 to 33% of the particulate polymer is mixed in a sufficient proportion so that 10 to 91%, preferably 20 to 91%, of the surface of the base particle is coated with the particulate polymer, and then the temperature is increased. electrophotographic copying or electrostatic electrophotography, characterized in that the fine particulate polymer is adsorbed onto the surface of the base particles by causing the fine particulate polymer to adhere to the surface of the base particles, and further characterized in that the fine particulate polymer has a melting point higher than that of the base particles. A method of producing a toner having a raised surface suitable for printing.

Description The present invention relates to toner particles used in electrophotographic reproduction or electrostatic printing. In particular, the present invention relates to toner particles having a pimply surface. Furthermore, the present invention also relates to a method for producing toner particles as described above.

In electrophotographic copying, a latent image formed on a photographic drum is developed with toner consisting of fine colored thermoplastic particles. The most common method for manufacturing this toner is to melt a certain thermoplastic material, mix it with pigments, charge adjusters, dissociators, etc., cool it, and crush it.
Crush and sieve in a stream of air to obtain particles with a particle size of 5 or more.
Consisting of obtaining 30 μm particles. This method results in particles having a wide variety of shapes and sizes. When particles have different shapes and sizes as described above, it is disadvantageous for copying. Therefore, efforts have been made to produce toners that are spherical in shape and have good dimensional uniformity.

For example, a method is known in which a spray dryer is used to finely divide molten wax or a low molecular weight thermoplastic. If this spray dryer can be used and conditions can be set to directly obtain particles of an appropriate particle size, the pulverization step can be omitted. However, a disadvantage of this spray drying is that the size distribution of the resulting powder is quite broad. Furthermore, it is not possible to satisfactorily spray dry the thermoplastic melts commonly used for so-called heating fixing by means of heated rolls or irradiation. The powder obtained by spray drying is more preferable as a toner for cold fixing by pressure. Further, the spray-dried powder has a spherical shape, which is advantageous in that it does not have a non-uniform shape as is the case with pulverized particles.

One method for manufacturing toner particles suitable for hot fixing, which is a fundamentally inexpensive method, is to first add a pigment, a charge control agent, a dissociating agent, a polymerization initiator, and a polymer with properties suitable for hot fixing. dispersed in the monomer given,
It consists of emulsifying this monomer in water using a suitable colloidal system, increasing the temperature and directly obtaining a spherical fine colored powder by polymerization. This powder can be washed and dried to make an excellent powder for copying. Since this method is extremely simple, several attempts have been made to make toner using this method. One such method is disclosed in British Patent Application No. 2091435. In practical tests, particles made by suspension polymerization were found to be advantageous in that they enable high-resolution copying. However, it has also been found that these particles exhibit a strong adhesion to the photographic drum and have the serious drawback that transfer to paper must be extremely incomplete. Furthermore, these particles tend to aggregate strongly with each other, resulting in extremely poor free-flowing properties as a toner.

The various drawbacks of the particles as described above are believed to be due to the smooth surface condition of the spherical particles produced by conventional suspension polymerization. When such spherical particles having a smooth surface are used, the adsorption to the photographic drum becomes extremely strong and cannot be completely removed even when cleaning the photographic drum after the transfer process. If toner remains on the photo drum in this way, the quality of copies will deteriorate rapidly. This strong adsorption of toner onto the photographic drum becomes particularly serious when the toner consists of extremely small particles, ie, 5 μm or less. This is because such fine particles are more difficult to remove from the photographic drum surface by mechanical cleaning systems.

According to the present invention, it has been found that spherical particles with a bumpy surface do not exhibit the above-mentioned disadvantage of strong adsorption to the surface of a photographic drum. In some instances, the particles have been found to be less adsorbent than toner particles obtained by conventional milling methods.

Accordingly, the present invention comprises internally pigmented base particles or main particles made by suspension polymerization and having an average particle size of 2 to 25 μm; The present invention relates to a toner whose surface is coated with a finely divided polymer having an average particle size of 0.05 to 33% of the average particle size of the particles. Preferably, 10% or more of the base particles or main particles are covered with the above-mentioned particulate polymer.

Herein "internally colored base particles"
means particles made by incorporating a pigment into a monomer before its polymerization, and thus:
The pigment is contained in a more or less uniformly dispersed state within the final polymerized base particles.

The method of applying the particulate polymer to the surface of the toner particles is technically very simple and the entire process from monomer to production of coated toner particles is therefore economically advantageous.

Accordingly, the present invention provides a method of producing high quality toner in a more economical manner.

The size of the particulate polymer forming protrusions on the surface of the base particles or main particles must be substantially smaller than that of the base particles or main particles. That is, the diameter of this particulate polymer should be at most 33%, preferably at most 15%, of the diameter of the base particles. This lower particle size limit is determined by the smallest size effective to reduce adhesion to the photographic drum.
For example, it has been found that even protrusions with dimensions of 0.005 μm can effectively reduce adsorption. Therefore, it is possible to use a finely divided polymer having a particle size of 0.0005 to 5 μm, preferably a particle size of 0.02 to 2 μm.

Another important requirement of the present invention is the degree of coverage, ie, how much of the base particle surface is coated with the particulate polymer. The most densely coated case corresponds to 91% of the base particle or main particle surface. However, such high coverage is not necessary to reduce adhesion to the photographic drum. It has been found that even at 50% coverage, this adsorption reduction effect is quite large. Furthermore, a clear effect of reducing adsorption was observed even at a coverage rate of about 10%. Therefore, this coverage is between 10 and 91%, preferably between 20 and 91%.
%, most preferably 30-80%. In principle, it is preferable that the fine particulate polymer has a thickness of only a single layer, but at least a portion thereof may have a thickness of several particle layers.

The toner particles of the present invention, which are formed by protruding particulate polymers on the surface of base particles or main particles, can be produced by various methods as shown below.

First, a method for adsorbing a particulate polymer onto the surface of base particles prepared in advance by suspension polymerization will be described. First, a monomer, a monomer-soluble polymerization initiator, a pigment, an optional charge control agent, and a dispersant for the pigment are mixed. This mixture is emulsified in water using a suitable colloid system. Next, after evacuation, the temperature is increased for polymerization to obtain spherical base particles. The average particle size of the base particles is 2 to 25 μm, preferably 3 to 15 μm.
The small polymer particles applied to the base particle surface can be produced by known emulsion polymerization or microsuspension polymerization. In this case, for example, a charge control agent and a pigment may be introduced during the micropolymerization step, if necessary.

Preferably, the fine particulate polymer is strongly fixed to the surface of the base particles. This can be accomplished by softening the base particles using small amounts of softeners or heat. As a result, the fine particulate polymer is dissolved and fixed onto the surface of the base particles. In this case, it is preferable to dissolve the particulate polymer into the base particles to a depth corresponding to about half the diameter of the particulate polymer. However, this depth is not limited to this, and the important point is to firmly fix the fine particulate polymer within the base particles and at the same time make them protrude from the surface of the base particles.

The polymer composition of the fine particulate polymer may be the same as that of the base particles, but it is preferable to select one having a higher melting point than the base particles. When the melting point is as high as this, it is possible to reduce the risk that the fine particulate polymers will not adsorb to the base particle surface and will coagulate with each other during the coating process. Furthermore, in order to prevent the particulate polymer from melting, especially at its surface, it may be crosslinked to a higher extent than the base particles.

Bottled particles can be produced by applying this particulate polymer to the surface of preformed base particles by a wet method, or by applying a monomer to the surface of droplets and polymerizing them together with latex particles by a special method as described below. can do.

The toner is produced by contacting an aqueous dispersion of colored base particles with a latex of a finely divided polymer, forming a protective colloid system in the aqueous dispersion, and increasing the temperature of the aqueous dispersion to form a protective colloid system on the surface of the base particles. It can be manufactured by a process of adsorbing.

In this production method, the protective colloid system used for the suspension polymerization of the base particles is first suitably deactivated. If stabilizers, for example consisting of certain inorganic powders, such as sparingly soluble phosphates, are used as protective colloids, these can be dissolved by acidifying the aqueous suspension of the base particles. The particulate polymer latex should be added gradually and conditions should be maintained such that the latex does not immediately precipitate out on contact with the suspension of base particles. This is because there is a risk that the small particles in the latex will agglomerate instead of adhering to the surface of the base particles.

By continuing stirring for a certain period of time, the particulate polymer will precipitate on the surface of the base particles.
This system is then made more alkaline, allowing the protective colloid system to form again. When the dispersion is warmed and the particulate polymer is dissolved on the surface of the base particles, there is no risk that the particulate polymer will coagulate with each other again.
Acidification and washing then take place.

However, if the latex particles are of a higher melting point than the base particles, there is no need to reform the protective colloid system. Even when the base particles are heated and softened to the extent that they can dissolve into the base particles, the latex particles still maintain their hardness and therefore do not aggregate with each other. If the protective colloid is not reformed, its preferred coverage should be at least 30%.

In some cases, the protective colloid system may be kept intact when adding the particulate polymeric latex. In this case, the latex particles and base particles are of opposite charge. This can be obtained by copolymerization with functional monomers having opposite charges. The charged latex particles are attracted to the oppositely charged base particles, thereby penetrating or penetrating the colloid layer.

Another method of production is to decompose the protective colloid system after production of the base particles, then wash and redisperse them and add a finely divided polymer latex. In order to deposit this finely divided polymer on the surface of the base particles in the absence of a protective colloid, it is necessary to supply the base particles and latex particles with opposite charges. This can be done by controlling the zeta potential of these particles. Therefore, the surface chemical composition of the base particles and latex particles must be chosen such that they have zeta potentials of opposite charge under the conditions of use. The required composition of these particle surfaces can be obtained by copolymerization using functional monomers in a known manner. Furthermore, in this method, the latex particles must have a higher melting point than the base particles. This is to prevent latex particles from coagulating with each other in the next heating step.

In order to impart the correct triboelectric charge to the toner, the particulate polymer must have a certain triboelectric charge on its surface, which is later achieved by depositing a charge control agent on the surface of the coated particles. . If the particulate polymer is made by microsuspension polymerization, the charge control agent may be mixed with the monomer prior to polymerization of the particulate polymer. Finally, the chemical composition of the particulate polymer can be chosen such that it does not require the addition of charge control agents. Examples of such particles that give a positive triboelectric charge are polyacrylonitrile or particulate polymers of amino group-containing monomers.
A negative triboelectric charge is obtained when a finely divided polymer made of polyvinyl chloride or a fluorine-based polymer is used.

Finely divided polymers can also be applied by dry methods. When applying particulate polymers by dry method, the base particles are first dried and then placed in a mixer. To maintain uniform mixing in the powder bed, it is desirable to incorporate large beads, for example glass beads of 5 mm size. Small polymer particles are then introduced into the powder bed to coat the base particle surface. The small particles may be introduced dispersed in a suitable liquid and the liquid evaporated from the powder bed, or they may be introduced as a pre-dried fine powder. The temperature of the powder bed is increased under stirring. This allows the small particles to adsorb onto the surface of the base particles and, at higher temperatures, at least partially dissolve into the surface of the base particles.

Another method of melting small polymer particles onto the surface of the base particles involves introducing the coated base particles into an air stream and raising its temperature over a short period of time to 150°C.
This is a method of heating between ℃ and 400℃. This heating temperature also depends on the residence time in the heating zone.

According to the above-mentioned method, base particles are first produced by suspension polymerization, and then these are coated by treatment with a particulate polymer latex by a wet method, so that the toner particles with a bumpy surface according to the invention are obtained. can get.

According to other methods of producing toner particles with a rough surface, special methods are employed. In this case, a latex, ie a particulate polymer, is first produced and the base particles are produced by suspension polymerization in the presence of this pre-formed latex.

Next, the manufacturing method that forms part of the present invention will be described in detail.

Spherical particles with a bumpy surface useful as toners in electrophotographic reproduction and electrostatic printing are produced in the following manner. That is, a latex, which is an aqueous dispersion of particulate polymer, is first made. This latex is made by emulsion polymerization using a water-soluble polymerization initiator and a suitable emulsifier, or by microsuspension polymerization. Here, the monomers are first finely divided in water using strong emulsification and surfactants and then polymerized using polymerization initiators that are usually soluble in the monomers. Optionally, water-soluble polymerization initiators can be used in microsuspension polymerizations.

The latex particles need to be insoluble in monomers and optionally other solvents, so they are preferably crosslinked. Furthermore, the surface of the latex particles must have a certain hydrophilicity/hydrophobicity.

When producing grained particles in this manner, the latex is mixed with a monomer or monomer mixture. Monomer-soluble polymerization initiator, pigment,
A charge control agent, a dissociating agent, etc. may be added to the monomer in advance. Mixing conditions such as pH must be selected so that the latex particles leave the aqueous phase and migrate to the monomer phase or monomer/aqueous phase interface. Water and a suitable colloidal system are then added to this. The monomers are suspended as droplets and the temperature is increased for polymerization. During this polymerization, a finely divided colored powder is obtained. When this was examined by scanning electron microscopy, it was found that latex particles with a suitable hydrophilic/hydrophobic balance migrated from the inside of the droplet to the surface of the polymer particles formed by suspension polymerization. This results in a bumpy surface of the base particles.

By changing the hydrophilic/hydrophobic balance, the migration of latex particles to the base particle surface can be controlled. If the latex particles are large and hydrophobic, for example made from pure styrene, divinylbenzene, and hydrogen peroxide is used as the polymerization initiator, these particles do not penetrate the surface of the formed polymer particles at all. Therefore, such latex particles cannot be found when the formed polymer particles are observed under a scanning microscope. On the other hand, if the latex particles are too hydrophilic, they will be completely expelled from the main particles during polymerization, and after polymerization,
Found in the aqueous phase.

The appropriate hydrophilicity for latex particles depends on the hydrophilicity of the main particles. Latex particles are required to have higher hydrophilicity than the polymer of the main particles. The upper limit of the hydrophilicity of the latex particles is determined by the level at which the latex particles begin to be expelled from the main particles into the aqueous phase during polymerization.

The degree of hydrophilicity can be controlled by adding anionic monomers such as methacrylic acid, itaconic acid, styrene sulfonic acid, etc. under alkaline conditions during the production of latex particles. Compounds that are cationic under acidic conditions, such as halogenated trimethylammonium methyl methacrylate, can be added to the latex polymer to make the latex particles more hydrophilic. However, it is not necessary to use ionized groups to achieve hydrophilicity. This hydrophilicity control is
This can be achieved with polar nonionized monomers such as methyl methacrylate, acrylonitrile, allyl alcohol, 2-dimethylaminoether methacrylate, and the like. The polar monomer preferably contains an amino group or a hydroxyl group.
Additionally, amphoteric latexes containing both acid groups and bases can be used to obtain appropriate hydrophilicity. The important requirements for the latex particles for roughening the particle surfaces by this method are that they are insoluble in the monomer forming the main particles and that the latex particle surface has greater hydrophilicity than the polymer forming the main particles. .

Naturally, if the polymer composition of the latex particles is insoluble in the monomer, even if it is not due to crosslinking,
Crosslinking is no longer necessary. This is the case, for example, when the latex particles consist of polyacrylonitrile, a copolymer with a high acrylonitrile content. Otherwise, the latex particles are crosslinked to render them insoluble.

The degree of crosslinking of the latex particles has a certain important meaning. If the degree of crosslinking is low, the latex particles will swell in the monomer and the size of the protrusions in the final product particles will be larger than the size of the particles in the latex. Therefore, a relatively small amount of latex is sufficient to cover most of the surface of the main particles. Swelling of the latex particles will reduce the hydrophilicity difference between the monomer and the latex particles. This is because the composition of the swollen latex particles becomes more similar to that of the monomer.

The size of the protrusions on the surface of the base particles is determined by the size of the particles in the latex in addition to the degree of swelling. The smaller the size of the latex particles, the smaller the minimum amount of latex required to cover a given proportion of the final base particles. The minimum size of this protrusion is determined by whether it can sufficiently reduce the force attracted to the photographic drum due to the Van der Waals force, and also by the technically possible size. The Juan der Waals attraction is significantly reduced when the base particles (principal particles) are separated from each other by 10 nm. Therefore, assuming that half of the protrusions come out from the surface of the base particle, a diameter of 20 nm for the particles in the latex is sufficient. The maximum dimension of this protrusion corresponds to about 33% of the diameter of the spherical main particle. Therefore, the average diameter of the particles in the latex is the average diameter of the main particles,
That is, it should be 0.05 to 33% of the range of 2 to 25 μm.

The chemical composition of the latex particles forming the protrusions can be arbitrarily selected as long as it is insoluble in the monomer or monomer mixture used to form the main particles. However, as mentioned above, it is also necessary to consider the hydrophilic/hydrophobic balance. Furthermore, the fact that this protrusion affects the triboelectric properties of the final particles must also be taken into account. This protrusion constitutes the outer shell of the toner particle. Therefore, the type and level of triboelectric charge when friction is applied is determined by the chemical composition of this protrusion. Furthermore, it should be taken into account that in the case of bump-like protrusions, the surface area of the powder particles increases, so that the triboelectric charge also increases.

The chemical composition of the latex particles forming the protrusions is preferably selected to be harder than the main particle polymer. This reduces deformation and reduces the contact surface when the toner particles are attracted to the photographic drum. Therefore, the Juan der Waals force also decreases. This hard surface is also advantageous when storing powders. This is because the risk of agglomeration may also be reduced. Finally, this harder surface can reduce the risk of sticking when in contact with a hot fuser roll.

Regarding the degree of coverage, which is an important requirement, the above-mentioned range is appropriate. Typical coverage in this production is 20 to 80% in a single particle layer, preferably
40 to 80%.

The properties of rough spherical particles that reduce adhesion to the surface of a photographic drum and adhesion between toner particles are advantageous in fields other than electrophotographic reproduction. That is, it has been found that when this is used for electrostatic printing by the "dry silk screen" method, adhesion to the screen is reduced. Therefore, the resulting print has a stronger degree of coloration than when using spherical particles with a smooth surface.

As mentioned above, the rough surface reduces the mutual attraction between particles. Such particles will therefore have better free-flowing properties. As a result of the reduced tendency to form agglomerates, the rough particles are also advantageous in powder coating operations, such as powder coating and firing of metal products.

The selection of materials will be discussed in more detail below, and unless otherwise stated, this is common regardless of the method of manufacturing the particulate polymer coated base particles or main particles.

Monomers (alone or in mixtures) for producing latex particles include, for example, styrene and its various derivatives, acrylic acid and methacrylic acid or their esters, acrylonitrile, vinyl chloride, vinyl fluoride, vinylidene fluoride, acetic acid. Vinyl etc. Polyfunctional monomers for crosslinking, such as divinylbenzene, ethylene glycol, diacrylate, ethylene glycol dimethacrylate, trimethylolpropane
Triacrylate and the like can be used. The amount of crosslinking agent can vary widely so long as the latex particles meet appropriate hydrophilicity and insolubility requirements.

The same monomers and crosslinking agents as described above may be used as materials for the manufacture of the base or main particles, but suitable mixtures are generally used to achieve a softening point lower than that of the latex particles.

Preferred primary monomers for the latex particles and base or main particles are styrene, acrylates and methacrylates.

As emulsifiers for the production of latex particles, conventional surfactants used for emulsion polymerization and microsuspension polymerization can be used. but,
Care must be taken that the emulsifier does not significantly impair the functionality of the colloidal system used to produce the base or main particles. Furthermore, it is preferred that the selected emulsifier is water-soluble and can be washed away from the surface of the rough toner particles produced.

When producing latex particles by emulsion polymerization, conventional water-soluble polymerization initiators such as persulfates, hydrogen peroxide, and hydroperoxides are used as polymerization initiators. For microsuspension polymerization latexes, conventional monomer-soluble polymerization initiators such as dialkyl peroxydicarbonate, tert-butyl peroxypivalate, octanoyl peroxide, lauroyl peroxide, tert-butyl peroxy(2-ethylhexanoate) are used. ), benzoyl peroxide, 2,2-azobisisobutyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, and other similar compounds may be used. In the production of the base or main particles, polymerization initiators similar to those used in the production of latexes by microsuspension polymerization can be used.

As a protective colloid in the colloid system for producing the base or main particles, water-soluble colloids such as cellulose derivatives and polyvinyl alcohol, or powdered stabilizers such as sparingly soluble phosphates, metal hydroxides, and silica can be used. This pulverulent stabilizer is preferably used in conjunction with a suitable co-stabilizer.

As the coloring agent mixed with the base or main particle monomer, inorganic or organic coloring agents, magnetite, and carbon black can be used. In some cases, it may be preferable to surface treat the pigment so that it remains finely dispersed within the monomer droplets. The toner particles according to the present invention are entirely colored, that is, they contain a colorant,
It is more or less uniformly dispersed in the base or main particles consisting of the polymer. As mentioned above, colorants and other additives may be present in latexes made by microsuspension polymerization techniques.

The toner particles of the present invention can be used in accordance with known methods with carriers conventionally used in developing compositions.

EXAMPLES Hereinafter, the present invention will be explained in more detail based on Examples, but this is not intended to limit the gist of the present invention. In addition, all parts and percentages in the examples are based on weight unless otherwise specified.

The following Examples 1 to 14 show various modifications of the first method, that is, the method of adsorbing a particulate polymer to the surface of base particles, and Examples 15 to 21 show the second method. That is, a method is shown in which a finely divided polymer is present during the production of base particles.

Example 1 Production of fine particulate polymer Styrene 40g, sodium dodecyl sulfate 1.8g
and water to make a total of 395g, and this
It was introduced into a 500 ml glass flask (equipped with cooling means, stirrer and valves for evacuation and introduction of nitrogen gas). The mixture was heated to 80°C under stirring. At a temperature of 80° C., 5 g of 3.5% hydrogen peroxide were added, and at the same time the mixture was placed under a nitrogen atmosphere.

The polymerization reaction was continued for 12 hours, resulting in a 10% seed latex of 0.11 μm.

120g of the above seed latex, 200g of 5g/Kg sodium dodecyl sulfate, 0.4g of divinylbenzene,
Approximately 27.6 g of 50% styrene and water (395 g total)
was introduced into the same apparatus as above, and the same treatment was performed. As a result, the particle size was 0.16 μm and the solid content was 10
% crosslinked polystyrene latex was obtained.

Example 2 Production of fine particulate polymer Styrene 250g, neozapon schwartz X51 (charge control agent; BASF
) 0.8g and 2,2′-azobis(2,4-
2.5 g of dimethylvaleronitrile) was charged into the same apparatus as in Example 1. The monomer mixture was heated and bulk polymerization was carried out for 2 hours at 85°C, resulting in an increase in viscosity from 10.5 to 13 seconds (24°C) (Ford-Cup, 4 mm nozzle).

189g of this bulk polymer, 2g of divinylbenzene,
7 g of approximately 50% 2,2'-azobis(2,4-dimethylvaleronitrile) was emulsified for several minutes in an Ultra Turrax with 828 g of 3 g/Kg sodium dodecyl sulfate.

This pre-emulsion was placed in a two-stage Manton Gaulin homogenizer, model 15M, which produced a narrow drop size distribution of 0.19 μm (Coulter nanosizer).
(determined by Nanosizer). Add this homogenized emulsion and 1 g of sodium dodecyl sulfate to
It was placed in a 1.5 mm glass autoclave and kept under nitrogen gas atmosphere. This emulsion is heated at 65℃.
Polymerization occurred in 12 hours. In this way, a 0.19 μm, 19% microsuspension containing the charge control agent introduced during the polymerization and crosslinked with 0.5% divinylbenzene was obtained.

Example 3 Production of base particles In 2Kg of 0.16M trisodium phosphate solution,
Add 520 g of 1.0M calcium chloride solution under stirring,
In addition, sodium dodecylbenzenesulfonate
150 g of 0.2% solution was added. Add this mixture to 0.2%
It was diluted with 2965 g of potassium dichromate solution to form a dispersion medium.

700g of styrene, 300g of butyl methacrylate,
Carbon black “Printex V”
V)'' (Degussa) and 3 g of Neozapon Schwartz x 51 (BASF) were dispersed in a ball mill to obtain a carbon-monomer dispersion.

10 g of 2,2-azobis(2,4-dimethylvaleronitrile) was added to the above carbon monomer dispersion.
The solution was dissolved in 990 g and charged into a reactor together with the above dispersion medium (2965 g). The mixture was placed under a nitrogen atmosphere, rapidly heated from room temperature to polymerize, and kept under gentle stirring at 85° C. for 1 hour. The mixture was cooled to room temperature, the pH was adjusted to about 3, and then 35 g of 2,2-azobis(2,4-dimethylvaleronitrile) was added. After stirring this for a few minutes, the pH was adjusted to about 9. This mixture is distributed in the dispersion unit “Ystrall” (Bergius
Trading AB) and emulsified into a suitable drop size for toner particles.

Place the reactor again under nitrogen atmosphere and heat the polymerization to 65℃.
Continued under gentle stirring for 18 hours. The suspension was then cooled to room temperature.

A portion of the polymer was transferred to a container, the pH was adjusted to 2 with HCl, and then calcium phosphate was added to act as a protective colloid. The suspension was filtered, washed first with acidified water and then with distilled water, and then dried at 35°C.

This resulted in a particle size of approximately 10 μm and a particle diameter of approximately 10 μm.
A toner with a charge of -12 μC/g relative to the carrier was obtained. When we conducted a copy test using this toner on a Mita DC 313Z, we found that
Initially good copies were obtained, but the reproducibility deteriorated rather rapidly due to the strong adhesion of the spherical smooth toner particles to the photographic drum.

Example 4 Coating base particles with particulate polymer 362 g of 10% polystyrene latex prepared in Example 1, 1.5 g/Kg of sodium dodecyl sulfate
390 g and 2 parts water were mixed to prepare a coating dispersion.

2 Kg of sodium dodecyl sulfate at a concentration of 1.5 g/Kg was charged into a reactor containing 4 Kg of the suspension obtained according to Example 3, and the pH was adjusted to 2 with HCl. The above coating dispersion was added over a further 20 minutes under stirring and allowed to mix for a total of 1 hour before increasing the temperature to 65°C. The PH was adjusted to 8.3 with _NH3 at 65°C and the temperature was further increased to 90°C. 5 at 90℃
The coated toner suspension was cooled to room temperature before the end of the minute.

Thereafter, the pH was adjusted to 2 with HCl, and calcium phosphate, which functions as a protective colloid, was dissolved therein. The suspension was filtered and washed first with acidified water and then with distilled water. Then 0.05 to the sample
Doped with % Neozaponswalz X51 (based on the amount of polymer). This was obtained by slurrying the filter cake in water after the above washing, mixing it with a 1% methanol solution of the above charge control agent, and filtering again. This technique is necessary because the latex particles on the surface of the base particles block the effect of the charge control agent in the base particles.

As a result of examination using a scanning electron microscope, it was confirmed that the polystyrene particles were adsorbed by the base particles, and that about half of their volume was dissolved into the base particles by heat treatment. Approximately 50% of base particles
The amount of polystyrene latex was adjusted such that the polystyrene latex was covered with particulate polymer. In this way, toner particles with a "bumpy" surface are obtained, which are resistant to the Höganäs carrier.
A charge of 14 μC/g was applied. Mita DC
Copy tests using the 313Z showed that it produced very good copies from the beginning, and that repeatability persisted even after making 30,000 copies. Particular attention was paid to the good background and clear copy. The photographic drum was coated with only a small amount of toner, which was also easily removed.

Example 5 Coating of base particles with particulate polymer Base particles were obtained in the same manner as in Example 3 and coated with 218 g of the 19% polystyrene latex obtained in Example 2 in the same manner as in Example 4.

As a result of examining electron micrographs, it was found that the particulate polymer was adsorbed to the base particles in a state in which about half of its volume was dissolved in the base particles.
Also, the surface coverage was on the order of 50%. A rough toner article was thus obtained whose "protrusions" contained a charge control agent giving a charge of -17 .mu.C/g. Like the toner of Example 4, this toner also exhibited excellent copying properties.

Example 6 The procedure of Example 4 was repeated except that the amount of latex in Example 4 was reduced to 228 g. When the obtained toner was examined under a microscope, the coverage rate was 30~30.
It was as low as 35%. Despite this, this toner particle had better copying properties than those of Example 3.

Example 7 Preparation of base particle suspension The same operation as Example 3 was repeated except that 35 g of 2,2-azobis(2,4-dimethylvaleronitrile) was added at pH 3 and 8 g of dimethylaminoethyl methacrylate was added. . In this way, a suspension of base particles was obtained whose zeta potential changed from positive to negative as the PH value changed to a higher value than the suspension of Example 3.

Example 8 Preparation of base particle suspension The procedure of Example 3 was repeated except that 11 g of trimethylaminoethyl bromide methacrylate was added after emulsification to a drop size suitable for toner particles. This created a suspension of base particles. The zeta potential of this product is Example 3 and 7.
The pH of the suspension changed from positive to negative at higher pH.

Example 9 Production of fine particulate polymer Styrene 100g, sodium dodecyl sulfate 2g,
397.5 g of water (NH ₃ +NH ₄ ) buffered to PH 9 and 0.5 g of 1 mM CuSO ₄ solution were charged into the reactor. The mixture was heated to 80° C. and 0.9 g of 50% methyl ethyl ketone peroxide was added at 80° C., while the mixture was placed under a nitrogen gas atmosphere. Polymerization was carried out for 12 hours, resulting in a 20% latex of 0.1 μm.

100 g of this obtained seed latex, 1.6 g of sodium dodecyl sulfate, 0.5 g of 1 mM CuSO ₄ solution and 317.5 g of water buffered to PH 9 and 80 g of styrene.
g was placed in an autoclave. 80% of this mixture
0.7 g of 50% methyl ethyl ketone peroxide was added at 80° C. and at the same time the mixture was placed under nitrogen atmosphere. Polymerization took place for 12 hours,
As a result, a 20% latex of 0.17 μm was obtained.

An autoclave was charged with 100 g of this latex, 1.6 g of sodium dodecyl sulfate, 0.5 g of 1 mM CuSO ₄ solution, 317.5 g of water buffered to pH 9, and 65 g of styrene. Heat this mixture to 80 °C and 80
Add 0.6 g of 50% methyl ethyl ketone peroxide at °C.
At the same time, the mixture was placed under a nitrogen atmosphere. The polymerization reaction took place for 12 hours, and as a result,
A coating latex (20% solids) with particles of 0.27 μm was obtained.

Example 10 Production of fine particulate polymer 1 g of 2-sulfoethyl methacrylate was dissolved in 309 ml of water.
Put it in an autoclave with g, and PH it with _NH3 .
Adjust to about 4 and add 0.4g of 1mM _CuSO4 solution.
and 80 g of styrene were added. This mixture was heated to 80℃
At 80° C., 3.5% H ₂ O ₂ g was added and at the same time the mixture was placed under a nitrogen atmosphere. polymerization reaction
After 12 hours, a 0.14 μm 20% latex containing no surfactant was obtained.

40.6g of this latex, 200g of water, 1mM
0.4 g of CuSO ₄ solution was charged into an autoclave (equipped with two drop funnels). Add 72g of styrene to one of these drop funnels and add water to the other drop funnel.
76g and 1g 2-sulfoethyl methacrylate
was added, and the pH was further adjusted to about 4 with _NH3 . Heat this autoclave to 80℃, 3.5% at 80℃
H ₂ O ₂ g was added and the whole was placed under a nitrogen atmosphere at the same time. The contents of both drop funnels were added over approximately 3 additional hours, and the polymerization reaction was then continued for 12 hours. This results in a surfactant-free
Coating latex containing 0.26μm particles (solids content
20%).

Example 11 Coating base particles with latex 150 g of the 20% coating latex obtained in Example 9,
5g/Kg sodium dodecyl sulfate 90g, water 1260
g to form a coating dispersion.

4 kg of suspension of base particles obtained in Example 3, 5
g/Kg sodium dodecyl sulfate 480g, water 3520
g, into an autoclave, and the PH of this mixture
was adjusted to 2, and then the above coating dispersion was added over 20 minutes with thorough stirring. After stirring the mixture for about 1 hour, the temperature was raised to 83°C,
Holding at 83°C and PH2 for less than 5 minutes, the coated toner suspension was cooled to room temperature.

This suspension was filtered, washed with water, and then 0.05% Neozapon Schwarz X51 (BASF) was added. That is, the filter cake was slurried with water, mixed with a 1% methanol solution of the charge adjustment medium, and filtered again. lastly,
This sample was dried at 35°C to obtain toner particles with a bumpy surface. This one is Höganäs (H
It has a charge of -16 .mu.C/g relative to the carrier, and when tested using Mita DC 313Z, good copying properties were obtained.

This example describes latex-coated base particles with dissolved calcium phosphate colloid (PH2). In other words, this shows that when the latex particles are harder than the base particles, the base particles and latex particles can be adsorbed to each other by raising the temperature without causing aggregation, even without lowering the pH and reforming the protective colloid. .

Example 12 Coating base particles with latex 150 g of the 20% coating latex obtained in Example 10,
5g/Kg sodium dodecyl sulfate 90g, water 1260
g were mixed to obtain a coating dispersion.

4 kg of suspension of base particles obtained in Example 7, 5
480 g of sodium sulfate (g/kg) and 3520 g of water were placed in an autoclave, and the coating dispersion was added thereto over 20 minutes with good stirring. At this time the PH
No preparation was made beforehand and therefore the protective colloid was not dissolved. After the mixture was stirred for 1 hour, the temperature was raised to 90° C., maintained at 90° C. for about 1 minute, and then the coated toner suspension was cooled to room temperature. After adjusting the pH of this suspension to 2, it was filtered and washed with water. As a result of doping this sample with a charge control agent in the same manner as in Example 11, a rough toner with good copying properties was obtained.

This example illustrates latex coated base particles in the presence of a protective colloid.
In other words, this shows that it is possible to cause latex particles and base particles to adsorb to each other by heating a mixture of latex particles and base particles despite the presence of a protective colloid consisting of precipitated calcium phosphate.

The same operation as above was repeated except that the base particles obtained in Example 8 were used. As a result, it was confirmed that similar results were obtained regardless of whether the base particles were those of Example 7 or 8.
Example 9 using both these tests as latex
When the temperature was raised, the latex agglomerated in the aqueous phase, and toner particles with particularly uneven surfaces could not be obtained. Similar results were obtained when the steto was repeated using the base particles of Example 3 and the latex of Example 9. Furthermore, the base particles of Example 3,
When the test was repeated using the latex of Example 10, no coating layer remained on the toner after drying. It has been confirmed that even in the presence of an active protective colloid, it is possible to coat the surface of the base particles with the latex particles by copolymerizing both the base particles and the latex particles with functional monomers of opposite charges. Ta.

Example 13 Coating of base particles with latex particles 4 kg of the suspension of base particles of Example 3 was acidified to a pH of 2, then filtered and washed with water. The obtained filter cake was suspended in 7 kg of water and the pH was adjusted to 1.
Adjusted to. Next, 125 g of the coating latex obtained in Example 10 was diluted to 1250 g and added thereto. The mixture was heated to slightly above 80°C and then cooled to room temperature. Filter this suspension and
Doping was carried out with a charge control agent in the same manner as in Example 11.
As a result, rough toner particles with good copying properties were obtained.

Example 14 Coating of the base particles with latex The method of Example 13 was repeated using 4 kg of the base particles obtained in Example 8. In this case, coating with latex could be achieved by increasing the pH above 1. Additionally, the pH could be selected up to about 5. However, this test was performed with PH2. As a result, rough toner particles with good copying properties were obtained.

Examples 13 and 14 illustrate a surfactant-free coating process using the latex of Example 10, in this case by controlling the zeta potential of the base particles. When the PH is higher, the zeta potential of the base particles becomes negative and no or very little sulfonated latex particles are adsorbed on the base particle surface. When the pH becomes low, the zeta potential of the base particles becomes positive, and the latex particles begin to migrate to the base particles. Adsorption between the base particles and the latex particles can therefore occur by heating the mixture.
Also, even if this sample is not heated,
A certain degree of adsorption between these particles is possible. This also applies to the particles of Example 14.

By copolymerizing with functional monomers such as dimethylaminoethyl methacrylate and trimethylaminoethyl bromide methacrylate, it is possible to influence the zeta potential of the base particles at any PH, which results in a higher In Example 14, it becomes possible to carry out the coating operation at a high pH.

Example 15 Production of anionic latex Styrene 110g, sodium dodecyl sulfate 0.33
A total of 1067 g of a mixture consisting of
1.5 into a glass reactor. The mixture was heated to 80°C under vigorous stirring. Furthermore, 33 g of 1% potassium persulfate solution was added at 80° C., and at the same time the mixture was placed under a nitrogen gas atmosphere. The polymerization reaction was continued for 12 hours, yielding an 8% seed latex of 0.28 μm.

300 g of the above seed latex, 0.30 g of sodium dodecyl sulfate and water, totaling 1060 g, were introduced into the same apparatus as above. In addition,
In this case, a drop funnel was connected. Various amounts of methacrylic acid, divinylbenzene (approximately 50%) and styrene were loaded depending on the desired composition of the final latex. In this example, methacrylic acid
1.8 g, approximately 50% divinylbenzene, 24 g, and 74.2 g styrene. This is estimated to yield a polystyrene latex crosslinked with 9.7% divinylbenzene (100%) and containing 1.5% methacrylic acid.

The mixture was heated to 80° C. in a glass reactor under gentle stirring. When the temperature reaches 80℃, 1
% potassium persulfate was added and at the same time the mixture in the reactor and funnel was placed under a nitrogen atmosphere. The monomer mixture was then added dropwise into the reactor over a period of approximately 3 hours. The polymerization reaction was carried out for 12 hours, resulting in a 0.48 μm, 9% latex.
This was presumed to consist of the above-mentioned composition.

Example 16 Production of rough toner particles In a solution of 2 kg of 0.16 M trisodium phosphate
520 g of 1.0M calcium chloride solution was added under stirring and finally 150 g of 0.2% sodium dodecylbenzene sulfate. The resulting mixture was diluted to 2965 g with 0.2% potassium dichromate solution to form a dispersion medium. Next, 700g of styrene,
Butyl methacrylate 300g, carbon black (Printex V: Degussa)
80g, charge control agent (Neozapon Schwarz)
X51: BASF) 3g, azobisisobutyronitrile 3.5g and polyethylene wax (dissociation agent)
50 g were dispersed in a ball mill at a given temperature. During this step, the temperature was gradually increased to 105°C. Next, 1 kg of this carbon/monomer dispersion in a fairly warm state was mixed with the 9% latex obtained in Example 15.
It was introduced into an autoclave containing 555 g and water (added for a total of 1 Kg). Further HCl was gradually added with stirring until the latex was absorbed by the monomer phase. This was confirmed using a simple microscope. Next, NH ₃ was added to this mixture to make it alkaline (PH about 9), and then 35 g of 2,2-azobis(2,4-dimethylvaleronitrile) was added. After a few minutes of stirring, the dispersion medium (2965 g from above) was added. The stirring in the reactor was increased and the mixture was recycled through a dispersion unit "Ystral" (Bergius Trading AB) and emulsified to the appropriate size as toner particles. Place the reactor under nitrogen atmosphere and run the polymerization reaction at a temperature of 65 °C under gentle stirring.
It lasted 18 hours. The suspension was then cooled to room temperature and the pH was adjusted to 2 with HCl to dissolve the calcium phosphate, which acts as a protective colloid. The suspension was then filtered, washed first with acidified water, then with distilled water and finally dried at 35°C. Scanning electron microscopy revealed that the polystyrene latex particles crosslinked with 1.5% methacrylic acid were oriented toward the phase interface of the toner particles, with approximately half of the latex particle's volume protruding from the surface of the base particles.

Copying tests carried out on a Mita DC 313Z using Hogana's carrier still gave good reproducibility even after 30,000 copies.

Example 17 This example demonstrates the extent to which the position of latex particles at the phase interface of the toner particles can be controlled in the production of rough toner particles.

Examples include four latexes with varying amounts of methacrylic acid (0.5%, 1%, 2% and 2.6%) and a constant amount of divinylbenzene 9.7%.
I made it according to 15.

Analogously to Example 16, 5% of the latex described above (calculated as dry latex) was added sequentially to 1 kg of the warm carbon monomer dispersion described above and then emulsified and polymerized according to the method of Example 16.
By this method, four types of toners with different surface roughness were obtained. When these were examined using a scanning electron microscope, the following results were obtained.

(1) Most of the toner particles adsorbed with a latex containing 0.5% methacrylic acid had a smooth surface.

(2) The toner treated with the 1% methacrylic acid latex had a non-smooth surface, but only a very small percentage of the diameter of the latex particles protruded above the phase interface of the toner particles.

(3) The toner particles treated with 2% methacrylic acid latex had an uneven surface, and the latex particles were clearly visible on the phase interface. In this case, slightly more than half the volume of the latex particles was estimated to protrude from the phase interface.

(4) It was found that the toner particles treated with 2.6% methacrylic acid latex had better visibility of latex particles on the surface, and the latex particles were more protruding than the previous one.

In all cases, the roughness was uniformly distributed throughout the surface of the toner particles. Mita DC 313Z by Hogan
a¨s) When copying tests were carried out using carriers, all toners treated with latex containing a high proportion of methacrylic acid showed good copying properties.

Example 18 This example shows how the size and coverage of protrusions on the surface of toner particles can be controlled.

Methacrylic acid 2.6% and divinylbenzene (100%
A latex containing 5% (calculated as ) was prepared according to Example 15. However, the amount of seed latex and the total amount of monomer added were adjusted to obtain a latex with particles of 0.3 μm. 2% and 3.2% latex (calculated on dry matter) were absorbed by the emulsified carbon monomer dispersion as in Example 16.
Polymerization was carried out according to. It has been found that the first degree of coverage (the ratio of the latex-coated surface to the total smooth toner surface to which no latex is adsorbed) increases in proportion to the amount of absorbed latex. The case with 3.2% latex absorption had better coverage than all of Examples 16 and 17. This is due to the absorption of latex with finer particle size (Examples 16 and 17).
0.5μm vs. 0.3μm) as well as those based on
This is believed to be due to the increased swelling of the latex particles in this example due to the low degree of crosslinking of the latex. Furthermore, the diameter of the protrusions in this example is approximately 0.4 μm, which means that the mass of the latex particles is increased by that amount. A third test in this context involves the absorption of 5% of a 0.5 μm particle size latex (calculated as dry matter) with 2.6% methacrylic acid and 5% divinylbenzene. In other words, the same particle size and amount as in Examples 16 and 17 were used, but with a smaller degree of crosslinking. As a result, many of the latex particles are oriented toward the toner particle surface, thereby deforming their original shape from spherical to somewhat buckled, thus providing an increased surface area for the oriented latex. Become. Copying tests with toners treated with 3.2% adsorbed latex as described above yielded good copying properties similar to the previous examples.

Example 19 Production of amphoteric latex In the same apparatus as in Example 15, 1.5 g of "Querton 16C129" (Keno Gard), 1 mM
1.5g of CuSO ₄ and water (total amount is 1032g)
introduced. Further connect the funnel with styrene 150
filled with g. This mixture in the glass reactor was heated to 80 °C with gentle stirring, and at 80 °C the mixture was heated to 3.5%
The mixture in the reactor and funnel was placed under a nitrogen gas atmosphere while adding 18 g of H ₂ O ₂ . The monomers were then added into the reactor over a period of approximately 30 minutes, and after an additional 2 hours, Quelton 16Cl29 was charged and the reactor was again placed under nitrogen gas atmosphere. Next, as a result of continuing the polymerization reaction for 10 hours,
A 11% seed latex of 0.13 μm was obtained.

15g of the above seed latex, Querton 16Cl29 3.3
g, 1.5 g of 1mM CuSO ₄ and water (total 1082 g
) was filled into the same apparatus as above. The funnel was charged with 103.5 g of monomer. Additionally, varying amounts of (2-dimethyl-aminoethyl)-methyl acrylate (DMAEMA), methacrylic acid, divinylbenzene (approximately 50%) and styrene were loaded depending on the desired composition of the final latex.

In this example, 4.71 g of DMAEMA, 0.51 g of methacrylic acid, 12 g of approximately 50% divinylbenzene, and 86.28 g of styrene were charged. Therefore, this crosslinked with 5% divinylbenzene (100%), 3.9% DMAEMA and 0.4% methacrylic acid.
It is estimated that a polystyrene latex containing %.

The PH of the mixture in the reactor was adjusted to 2 with HCl. It was then heated to 80° C. under gentle stirring and 15 g of 3.5% H ₂ O ₂ was added at 80° C., at the same time the mixture in the reactor and funnel was placed under a nitrogen atmosphere. The monomer mixture is then placed in the reactor for approximately 3
It was dripped over time. The polymerization reaction was continued for 12 hours, resulting in a 0.2 μm, 9% latex. The composition of this product is presumed to be as described above.

Example 20 Preparation of toner particles with a "bumpy" surface using an amphoteric latex In analogy to Example 16, 3.5% (calculated as dry matter) of the amphoteric latex obtained in Example 19 was added to a hot monomer/carbon dispersion. absorbed inside. however,
This absorption was carried out in an alkaline atmosphere with NH ₃ /NaOH. Next, after adjusting the pH of this absorption mixture to about 9, this mixture was emulsified and polymerized in the same manner as in Example 16.

As a result of examining the obtained product with a scanning electron microscope,
Latex particles with a diameter of 0.2 μm were oriented toward the toner particle surface, and the original shape of the toner particles also changed from a smooth spherical shape to a buckly spherical shape.

Similar to Example 19, two different types were prepared with the same dry matter content calculated in moles, but with the ratios of amino groups and carboxylic acid groups changed from 5:1 to 1:1 and 1:5, respectively. made latex. Two additional types of toner particles were created using these new latexes.

Microscopic examination of these products revealed that the latex with a particle size of 0.2 μm was oriented toward the toner surface, but the original shape of the toner particles remained smooth; It was observed that some parts protruded from the phase interface.

In this way, toner particles suitable for electrostatic printing were obtained.

Example 21 Orientation of a Cationic Latex A cationic crosslinked latex was prepared analogously to Example 19 based on 2-trimethylammonium bromide methacrylate (TMAEMA). however,
In this case, TMAEMA was charged to the reactor and only divinylbenzene and styrene were charged to the drop funnel. Similarly, two types of 0.2 μm polystyrene latexes were prepared, namely, 5% divinylbenzene (100
%) and TMAEMA containing 0.5% and 4.1
I created one containing %. Similar to Example 16, this cationic latex was absorbed at 3.5% (as dry matter) into a warm carbon/monomer dispersion, the pH was adjusted to about 9 using _NH3 /NaOH, and
These mixtures were emulsified and polymerized in the same manner as in Example 16 to obtain two types of toner particles. When these were examined using a scanning electron microscope, the latex particles were oriented toward the toner particle surface to varying degrees depending on the amount of TMAETA in the latex.

That is, no such orientation was observed in the case of 0.5% TMAETA. In the case of 4.1% TMAETA, most of the latex particles aggregated on the outside of the toner particles and therefore migrated to the aqueous phase. This shows that it is possible to control the orientation of latex particles even with latex containing TMAEMA after being absorbed into the carbon/monomer dispersion.

Examples 22-24 relate to the application of particulate polymers by dry process.

Example 22 Preparation of particulate polymer The method of Example 2 was repeated. However, in this case, divinylbenzene and sodium dodecyl sulfate were excluded. The organic phase was instead emulsified using 828 g of 3 g/Kg ammonium laurate. This resulted in a 0.2 μm microsuspension containing the charge control agent.

Example 23 Coating of base particles with finely divided polymer (obtained by dry process) 4 kg of the base particle suspension obtained according to example 3 was acidified, filtered and washed with water. The resulting filter cake was finally dried at 35°C. The microsuspension obtained in Example 22 was precipitated by addition of acid, spread thinly on a glass sheet and air-dried at 30°C. 40 g of dry finely divided polymer obtained from this dry suspension
and 1 kg of dry base particles were charged into a mixer together with polyethylene particles (about 4 mm in size) and mixed for 1 hour. The temperature of this powder bed was then increased to 55°C under stirring.
The temperature was raised to 100.degree. C. and held at this temperature for 30 minutes to adhere the finely divided polymer to the base particles. Finally, the temperature was raised to 70°C to allow some of the particulate polymer to dissolve into the base particles. The powder bed was then cooled to room temperature and the coated base particles were sieved from the polyethylene particles.

In some cases, toner particles may be mixed with Aerosil R.
972 to maintain good powder properties and triboelectric properties.

This resulted in toner particles with good copying properties.

Example 24 Coating of base particles with particulate polymer 4 kg of the suspension of base particles obtained in Example 3 was acidified, filtered and washed with water. The resulting filter cake was finally dried at 35°C. The dry base particles were loaded into a mixer along with polyethylene particles having a particle size of about 4 mm. The mixer was evacuated and the jacket temperature was adjusted to 30°C. The microsuspension from Example 22 was added in 10 ml portions.
Add at a rate of approximately 50ml/min, and when the volume reaches 200ml,
Addition of the suspension was discontinued. This 200 ml amount corresponds to 40 g of dry finely divided polymer. The mixer was operated until the mixture was dry and then the vacuum pump was also discontinued. During this continuous stirring the temperature is 55
The temperature was then increased to 70°C as in Example 23.

Then, toner particles were obtained in the same manner as in Example 23. Toner particles with good copying properties were thus obtained.