DE3303130A1 - TONER FOR DEVELOPING LATEN ELECTROSTATIC IMAGES AND DEVELOPER CONTAINING THEM - Google Patents

Description

Henkel, Pfenning, Feiler, Hänzel & Meinig

Patent attorneys LlO ^; -lüg- rvrv "g ^ f.- r

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KONISHIROKU PHOTO INDUSTRY CO., LTD. TOKYO Japan

PP-1298
January 31, 1983

Toners for developing electrostatic latent images and developers containing them

Toners for developing electrostatic latent images and developers containing them

The invention relates to a developer for developing of electrostatic latent images and any contained therein Toner.

There are already a number of methods for producing visible images by electrostatographic means. the in the meantime formed latent electrical

20 static images need to have the help of a developer

be made visible. To develop latent electrostatic There are already pictures from a wide variety of developers, e.g. one-component developers and in comparison two-component developers supplying these with sharper, visible image copies. The two-component developers consist of a toner and a carrier, the toner triboelectrically when rubbing with the Carrier receives a special polarity. When using such a two-component developer, the Toner with the help of an electrostatic attraction between its triboelectric charge and the das electrostatic charge forming a latent electrostatic image on the support of the latent electrostatic image adhere, with the desired development taking place.

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The toner of such a two-component developer is composed of resin binder particles with dispersed therein Colorants such as carbon black, etc. Usually, as the particle size of the toner decreases, the image sharpness becomes greater. Practically usable toners have an average particle diameter in particle size volume distribution of 10 - 15 μΐη and a fairly wide range of particle diameter distribution.

^{T he} toner particle diameter or its distribution can influence the quality of the visible image produced (cf. JP-OS 134636/1979 and 72054/1979).

However, the toners known from the cited references contain a fairly high proportion of fine Particles with a particle diameter of less than 5 μm. Hence, it prepares a smooth toner supply because of it poor flowability difficulties. In addition, the ratio of triboelectric charge to changes Mass (Q / M) in the toner, which leads to changes in density and a gray background in the visible image. In addition, the electrostatographic recording material can only be cleaned or cleaned inadequately. Furthermore, the toner is atomized, thereby contaminating the interior of a copier. The latter in turn leads to a loss of sharpness of the visible image. So if to increase the sharpness of the image If the toner particle diameter is reduced, no quality is obtained in practice for a variety of reasons

30 high quality image copies.

It was an object of the invention to provide a toner or developer for developing latent electrostatic images to create high quality visible images of great sharpness and excellent gradation.

The invention thus relates to a toner for developing a latent electrostatic image , which consists essentially of particles with an average particle diameter in the particle size volume distribution or an average diameter of 6-10 μm and a particle diameter of the largest number of particles in the particle size number distribution or an apex (value) diameter of 5 - 8 μm, the number of toner particles with a particle diameter of less than 5 μm not more than 15% of the total particle number and the number of toner particles with a particle diameter of over 16 μm not more than 2% of the total particle number.

The invention also relates to a developer for developing latent electrostatic images from toner particles and a carrier, the toner particles having an average particle diameter at Particle size volume distribution or a mean diameter in the range of 6-10 µm and a particle diameter the largest number of particles in the particle size number distribution or a vertex (value) diameter in the range of 5 to 8 µm and the number of particles with a particle diameter of less than 5 µm not more than 15% of the total number of particles and the number of particles having a particle diameter of over 16 by not more than 2% of the total number of particles turn off.

A developer according to the invention provides high quality visible images of superior sharpness and clarity Gradation. It has good flowability and does not tend to atomize in the copier. A developer according to the invention is also characterized by a larger proportion of soot in the toner, a higher toner blackness and

better triboelectric chargeability of the toner by friction with the carrier. The toner content of a developer according to the invention can vary widely be. Furthermore, a developer according to the invention is excellent in durability and storability and keeps the triboelectric charge state of its toner stable. The fixing properties, e.g. temperature range width for fixing, and anti-ghosting properties of a developer according to the invention are excellent. In addition, a developer according to the invention is also excellent Charging properties.

The particle size distribution of the toner or carrier is determined using a Coulter Counter Model TA II Coulter Electric Co., Ltd., USA. When measuring the particle size distribution of the toner, one uses Orifice tube with a diameter of 100 μm, when measured the particle size distribution of the carrier is a pipe having a diameter of 500 µm.

A developer according to the invention consists of a two-component system of a special toner and a carrier. A number of beneficial results can be obtained in its use. So you get at its use typically visible, high-definition images without a gray background. This is on an accurate development of even fine parts of the image and a marked improvement in the stability of the development and the like.

The toner and carrier are explained in more detail below.

toner

In the case of a toner according to the invention, the special

Ratios of fine particles to coarse particles for sufficient toner flowability with less tendency to atomize and acceptable cleaning capability of the electrostatographic recording material. Any "dust formation" does not occur here. When the average particle diameter is the particle size volume distribution is above 10 μm or If the diameter of the majority of the particles is more than 8 µm, on the other hand, great sharpness cannot be obtained the former diameter is less than 6 µm or the latter diameter is less than 5 µm (including the case where the proportion of fine particles is over 15%), the can be applied to a larger proportion known disadvantages attributable to fine particles

15 do not avoid.

According to one embodiment, the toner contains a resin binder having a styrene component as a main component and 10-30% by weight of acidic black dispersed therein.

In this embodiment, the resin binder is made

from a copolymer with A wt .-% styrene units. The resin forming the carrier coating consists of a copolymer with B% by weight of styrene units. The ratio A / B satisfies the equation: 0.7 < A / B <3.0.

Another resin binder that can be used in the present invention consists of a copolymer with at least three different monomer units, one of the three Monomer units consists of a styrene component and the other two monomer units are formed from alkyl acrylate and / or alkyl methacrylate components. Preferably one of the other components consists of an alkyl acrylate monomer component and the other of one Alkyl methacrylate monomer component.

Examples of styrene monomers that can be used as the styrene monomer component suitable or which provide styrene units are styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ct-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert.-butylstyrene, p-n-hexylstyrene oil, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene and 3,4-dichlorostyrene.

Examples of alkyl acrylate monomers that can be used as the alkyl acrylate monomer component suitable or provide the alkyl acrylate unit are methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethyl

15 hexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, Phenyl acrylate and methyl-OC-chloroacrylate.

Examples of alkyl methacrylate monomers that emerge as Alkyl methacrylate monomer components are suitable or the Supply alkyl methacrylate unit are methyl methacrylate, Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, Isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, Lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, Phenyl methacrylate, dimethylaminoethyl

25 methacrylate and diethylaminoethyl methacrylate.

As a result, the resin binder usable as the main binder component or the sole binder is obtained by interpolymerization of the styrene monomer and a monomer composed of or with two alkyl acrylate monomers Copolymerization of the styrene monomer and a monomer of or with two alkyl methacrylate monomers or through copolymerization of the styrene monomer and a monomer from or with the alkyl acrylate and methacrylate monomers. The latter copolymer is particularly preferred.

1 The proportion of the styrene monomer component in the

Copolymer is 50-90% by weight, the proportion of the acrylate monomer component is preferably 10-50% by weight. The two monomer components of the 5 acrylate monomer components are in a ratio

of at least 5% by weight. That as the main binder usable resin binders constitute at least 70% by weight of the total resin binder. Examples for resin binders which can be used together with the main binder are commonly used for this purpose Resin binders, e.g. polyolefins, styrene resins, Acrylic resins, polyester resins, phenolic resins, epoxy resins and the like.

Further resin binders which can be used according to the invention are Polyester. Polyester as such can easily be negatively charged and guarantee with relatively simple availability their low molecular weight products have uniform negative charge properties. When using such Polyester as a binder thus gives toners with uniform charging properties and lower softening points. Better wetting is preferably achieved here - when the polyester is in the melted state the substrate, e.g. the image receiving material, than with a vinyl polymer as a binder Toner. Finally, using a polyester as a resin binder can be compared to a vinyl polymer with approximately the same softening point at a lower temperature.

However, if only one polyester is used alone as the resin binder, on the one hand it already comes at lower temperature for ghosting to occur, on the other hand, the range is the fixing temperature tighter. It has now been shown that when using

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• VHF

Preparation of a polyester with a content of 5-25% by weight of chloroform-insoluble a toner is obtained, which only with higher temperature provides ghosting and still has its low softening point (and thus the broad Fusing temperature range). When a polyester of the type described is used as a resin binder Thus, one can obtain a toner having excellent fixing properties and practically no ghosting leads. When the chloroform-insoluble content is more than 25% by weight, the softening point of the increases Toner and the fusing temperature. When the chloroform-insoluble content is less than 5% by weight, it is in question Toner is not practical because of the occurrence of ghosting.

The proportion of "chloroform-insoluble" is determined as follows:

A 150 ml jar is filled with 5.00 g by grinding a resin and sieving it through a 0.417 mm (40 mesh) sieve was obtained Resin powder and 5.00 g of a commercially available filtration aid are charged. After adding 100 g of chloroform the vessel is closed and allowed to rotate on a ball mill rack for 5 hours to remove the vessel contents in the chloroform as completely as possible in solution.

Furthermore, 5.00 g of the filtration aid becomes uniform on a placed on a pressure filter and on this with the help of a small volume of chloroform to adhere applied filter paper No. 2 with a diameter of 7 cm. The contents of the vessel are then transferred to the Poured filtration device. The vessel is washed thoroughly with 100 ml of chloroform so that no back

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1 stood more remains on the vessel walls. The washing chloroform is also put into the filtration device Finally, the top lid of the filtration device is poured closed and un-

started at a pressure not exceeding 392.4 kPa. After no more chloroform drips out / the residue on the filter paper is washed with 100 ml of fresh chloroform, whereupon it is pressure-filtered again. After completion of the above operation, the filter paper, the residue thereon and the entire filtration aids are transferred onto an aluminum foil and then for 10 hours in a vacuum dryer at 80-100 ⁰ C and a pressure of 13300 Pa dried.

15 The total weight "a" (in grams) of the dried product is weighed, and the chloroform-insoluble "X" (in% by weight) is calculated from the following equation:

a- (weight of the filter paper) - (weight of the

Filtration aid)
20 X = ", _{χ 100}

Sample weight

As the polyester according to the invention preferably polyesters having a softening point from 125 to 145 ⁰ C, in particular 130-140 ° C. The softening point is half the height from an outflow start point to the outflow end point of a melted resin sample with a volume of 1 cm \ when flowing out in a flow tester with a tool hole diameter of 1 mm, a pressure of 1962 kPa and a temperature rise rate of 6 ° C / min. Preference is also given to using polyesters with a glass transition ^{temperature of not less than 55 °} C., in particular 60 ^° C. or above (determined with the aid of a differential scanning calorimeter)

35 brought.

A toner according to the present invention can be used in the resin binder a coloring agent and, if necessary, a property improving agent and a magnetic material contain.

Examples of colorants that can be used are carbon black (C.I.Nr. 77266), nigrosine dyes (C.I.Nr. 5O415B), aniline blue (C.I.Nr. 50405), Calcoil blue (C.I.Nr. Azo blue), chrome yellow (C.I.Nr. 14090), ultramarine blue (C.I.Nr. 77103), Du Pont Oil Red (C.I. No. 26105), Quinoline Yellow (C.I. No. 47005), methylene blue chloride (C.I. No. 52015), phthalocyanine blue (C.I.No. 74160), malachite green oxalate (C.I.No. 42000), lamp soot (C.I.No. 77266), Rose Bengal (C.I.Nr. 45435) and mixtures thereof. The dye should be present in such an amount that a visible image of sufficient concentration is formed. As a rule, the amount of colorant is about 1-20 part (s) by weight / 100 parts by weight of binder.

If carbon black is used as the colorant, the should be considered in view of the triboelectric charging properties of the Toners and the good dispersibility in the binder, preferably an acidic type of carbon black is used. Under an "acid soot" is a type of soot to understand that when boiling in water and leaving the protruding Imparts a pK value of not more than 5.0 to the liquid.

Examples of usable magnetic materials are ferromagnetic substances such as iron, cobalt and Nickel, alloys of the same or compounds with the elements mentioned, such as ferrite or magnetite, metal alloys without ferromagnetic element, but which have ferromagnetic properties e.g. manganese and so-called copper containing. Heusler's see alloys, such as Mn-Cu-Al and Mn-Sn-Cu, chromium dioxide and the like.

The magnetic material is usually uniform in the binder in a finely powdered form Particle diameter of 0.1-1 μm dispersed. Per 100 parts by weight of toner is the amount of magnetic Material 20-70, preferably 40-70 parts by weight.

Examples of property improving agents are charge control agents, the creation of ghost images preventive agents that prevent fluidity

10 improving lubricants and the like Toners inherently have good toner properties, need the property-improving agents, if at all, only to be added in a minor amount. Examples of the occurrence of

5 Anti-ghosting agents or release agents

are polyolefins with softening points of 80 - 180 ° C, determined by the ring and ball method, fatty acids, metal salts of the same and fatty acid amides. That the occurrence Anti-ghosting agents can be used in

in an amount of 1-10, preferably 1-5% by weight of the binder.

Further additives can be incorporated into a toner according to the invention. Examples of such additives are finely divided hydrophobic silicon dioxide powder or fluororesin powder (added amount: 0.1-1.2% by weight) for Improvement of the flowability and lubricants, e.g. fatty acids or fatty acid metal salts (additional amount; at most 2.0% by weight) to improve the cleaning

GO properties.

carrier

There are carriers which can be used for developers according to the invention for example from a core material provided with a resin coating.

Resins suitable for coating the core material are any copolymers or terpolymers with a styrene component derived from a styrene monomer, preferably copolymers or terpolymers of styrene with alkyl acrylates and / or ethacrylates. Preferably, these resins should have a glass transition temperature of at least 5O ° C and a softening point of 80 - 15O ⁰ C have. The styrene component should preferably be contained in the resin used for the coating in an amount of 30-90% by weight. As with the resin binder, if the styrene component is present in any larger amount, durability and moisture dependency can be improved. If the styrene component is more than 90% by weight, however, the application or coating properties deteriorate in such a way that the film-like coating, once applied to the core material, can be detached or detached.

Any substances, preferably magnetic materials, such as Iron, ferrite or magnetite are used. The particulate core material is preferably spherical Shape. The thickness of the film-shaped resin coating is preferably 0.5-5, more preferably 1.0-3.0 µm.

In this embodiment, the particle diameter should be the carrier has an average particle diameter in the particle size volume distribution of 50-120, preferably 60-100 µm.

Accordingly, the carrier of the developer of the present invention should be composed of particles having an average particle diameter with a particle size volume distribution of 50-120, preferably 60-100 µm.

With regard to its particle diameter distribution, it applies that preferably particles with a diameter of not more than 40 μπι in an amount of not more than 4% and those of a diameter of not less than 130 µm in an amount of not more than 30% (in the Particle size volume distribution) are present. Because of the mentioned average particle diameter becomes the ratio of the total surface area of a toner particle to the total surface area of a carrier particle designed in such a way that a preferred stable Q / M value is achieved in a toner and one with the developer Obtains high-quality, high-density, visible images with numerous copying operations. When the average particle diameter is below

15 50 µm, stable charging properties can be achieved achieve, but the carrier particles tend to stick to the photoconductive recording material. If the diameter is over 120 μm, no preferred triboelectric charge properties can be

Reach 20 shafts. At the same time only visible ones emerge Bad quality images. Finally, there is also a change in the toner concentration larger change in the Q / M value, so that stable development cannot be guaranteed.

In another embodiment, the carrier consists of particles of the specified average particle diameter in the particle size volume distribution with polyhedral particles. The polyhedral particles are

shown in Fig. 1. As a whole, they own about

spherical or egg-like shape, with its outer surface made from a series of flat surfaces or nearly flat, slightly curved surfaces. Such Particles are obtained, for example, by mechanical

35 action of spherical particles, amorphous particles or of

Particles with a porous surface made of metals or alloys by colliding with a flat surface in a ball mill, a vibrating mill or other suitable device. In this embodiment lets .the total surface of the carrier increase considerably, since the polyhedral particles compared to a carrier with spherical particles of approximately the same particle diameter are larger in area. In addition, can in the case of a carrier with the specified average particle diameter, the increase in the total surface area of a toner with a reduced toner particle diameter is the ratio of the total toner surface to the total carrier surface can be compensated to a preferred range so that the toner always has a favorable state of charge and a wide range of toner concentrations is available to the developer. Hence one obtains if the developer has a sufficient shelf life, visible images usually of constant image quality. Under use a developer with toner particles of the type described is therefore guaranteed that even with high quality image copies can still be obtained for many successive copying operations. the Carriers can consist of the named materials for the sake of easy formation of polyhedral particles however, by mechanical treatment in the manner described, metals or metal alloys are preferred. In fact, it is used as a starting material because of its ready availability, its easy workability and its low cost iron is preferred. Thus, for the production of this embodiment of a carrier polyhedral particles made by mechanical treatment of iron powder are preferred. Suitable as iron powder inexpensive amorphous or porous iron powder, since the iron powder particles as a whole by the mechanical Treatment a uniform shape and smooth surface

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obtain. Of course, however, a relatively expensive spherical iron powder can also be used as the iron powder starting material be used.

5 If the carrier is electrically conductive, the

Coming into contact with the latent electrostatic to be developed Image with the carrier in an undesirable manner to a charge drain (from the latent electrostatic Picture) come. In this case the poly-

10 edrischen particles of iron, other metals or Alloys of the type described are provided on their outside with a resin coating. Using Such an insulating carrier can be a film-like entrainment of carrier particles with adhering thereto

Toner particles on the recording material surface impede. In addition, the triboelectric charging properties of the carrier to the toner remain stable, so that the durability of the developer is improved. Examples of how to coat the polyhedral particles suitable resins are homopolymers from the polymerization of monomers, for example styrene derivatives, such as p-chlorostyrene, methylstyrene, vinyl halides, such as Vinyl chloride, vinyl bromide or vinyl fluoride, vinyl esters, such as vinyl acetate, vinyl propionate, vinyl benzoate or vinyl butyrate, aliphatic OC-methylene monocarboxylic acid esters, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 3-chloroethyl acrylate, phenyl acrylate, methyl-ft-chloroacrylate, Methyl methacrylate, ethyl methacrylate or butyl methacrylate, Acrylonitrile or methacrylonitrile, acrylamide, vinyl ethers, e.g. vinyl methyl ether, vinyl isobutyl ether or vinyl ethyl ether, vinyl ketones, e.g. methyl isopropeny! ketone, or epoxy resins, colophony-modified phenol / formaldehyde resins, cellulose derivatives,

35 polyether resins, polyvinyl butyral resins, polyester resins,

1 styrene / butadiene resins, polyurethane resins, vinyl molded

aldehyde resins, melamine resins, polycarbonate resins and / or Fluorocarbon resins. Styrene / acrylic resins are preferred, e.g. styrene / methyl methacrylate or styrene / butyl methacrylate copolymers, epoxy resins, styrene / butadiene resins, Butyral resins and in particular cellulose resins or derivatives.

According to the invention, the particles of a toner and a carrier meet certain requirements (of the type described), so that one cheap triboelectric Can ensure charge properties. However, there is no need to add a charge control agent to the toner. Neither are there any restrictions on reducing the amount of toner. In any case, you get razor-sharp visible images with graduated tone value high resolution and no gray background. With developers according to the invention, latent Excellent development of electrostatic images into visible images without any deterioration.

The following examples and comparative examples are intended to illustrate the invention in more detail. 25th

Example 1_

100 parts by weight of a styrene / methyl methacrylate-butyl acrylate copolymer a freezing temperature of

30 86 ⁰ C and a softening point of 132 ⁰ C

80% by weight styrene component, 5% by weight methyl methacrylate component and 15% by weight of n-butyl acrylate component, 15 parts by weight of commercially available acidic carbon black with a pH of 3.0 and 5 parts by weight of a commercially available poly-

35 propylene are used for 15 minutes using a Henschel

Mixer premixed, then melted by means of an extruder and mixed, after cooling roughly grind and finally finely ground using a jet mill. The powder obtained is by means of a Classification device for a toner powder with an average particle size of 9.0 μπι in the Particle size volume distribution classified. A further 0.8% by weight of a finely divided toner is used to produce a toner hydrophobic silica powder added.

Furthermore, an average particle size of 98 μm is applied to a carrier core material made of an iron powder a styrene / methyl methacrylate copolymer composed of 65 parts by weight of styrene component and 35% by weight of methyl

15 methacrylate component applied in a thickness of about 2 μπι, whereby a carrier is obtained.

20 g of the obtained toner are mixed with 1000 g of the obtained Carrier mixed to a developer according to the invention 1 20.

The developer 1 is a commercially available one in the development part electrophotographic copier charged. After stirring for 1 minute, according to the blow-off method-25 de is the ratio of triboelectric charge to mass

(Q / M), with an initial Q / M value of 24.3 \ iC (Coulomb) / g being reached. Then it is copied, whereby

high quality image copies with high image density (D = 1.45)

Max

and sharp resolution (8 lines / mm) without 30 gray background can be obtained. After 20,000 copies have been made, the Q / M will decrease of the developer according to the invention, based on the initial Q / M value, only 1.25%.

1 Comparative example 1

The procedures of Example 1 are repeated, but using acidic carbon black in an amount of 5.0 parts by weight is used. As a result, a toner having an average particle size of 9.2 µm was obtained.

To produce the carrier, the measures described in Example 1 are also carried out with a styrene / methyl methacrylate copolymer with 60 parts by weight of styrene component and 40 parts by weight of methyl methacrylate component repeated.

Using the toner and carrier, a comparative developer 1 is prepared according to Example 1,

This shows in the corresponding test as in example 1 an initial Q / M value of 25.8 µC / jf The maximum Image density (D) in the image copies is 1.24, das

ΙΠ el X

Resolving power of only 5 lines / mm and the reduction in Q / M value after production of 20,000 image copies 10.1%.

The results show that although comparative developer 1 gives copies of relatively high image density, however, that their sharpness deteriorates and the resolution decreases. In fact show up the image copies broken lines in a letter part.

Example 2

According to Example 1, 100 parts by weight of a styrene / n-butyl acrylate copolymer a glass transition temperature of 63 ⁰ C and a softening point of 129.5 ° C with 75 wt .-% of styrene component and 25 wt .-% n-Butylacrylatkomponente, 25 Parts by weight more commercially available

/ Ti

■ 1 acidic carbon black having a pH of 2.5 and 3.5 parts by weight of a commercially available polypropylene for the production of a toner powder with an average particle size of 10 μm with 0.4% by weight of a commercially available fine hydrophobic silica powder.

The toner prepared in the manner described and the carrier prepared in Example 1 becomes a
According to the invention, developer 2 was produced with a toner concentration 10 of 2.0%.

Tests similar to those in Example 1 show that an initial Q / M value of 26.8 iiC / g

Image copies with a D of 1.40 and a resolution of max

Property of 8 lines / mm. The reduction of the The Q / M value after 20,000 image copies are made is 4.3%. All the values achieved are excellent.

Comparative example 2

The procedures of Example 2 are repeated, but the acidic carbon black in one toner production Amount of 34 parts by weight is used.

In the production of the carrier, the measures outlined in Example 1 are also carried out with a styrene / methyl methacrylate copolymer with 70% by weight styrene component and 30% by weight methyl methacrylate component

repeated.

Using the toner and carrier obtained, a comparative developer 2 having a toner concentration of 2% is prepared.
35

Similar tests as in Example 1 show that with the Comparative demolisher 2 with, an initial Q / M value of 22.8 uC / g after the production of 20,000 image copies, the Q / M value was reduced by 37.1%. Thus become with an increasing number of copies, the copies get worse and worse.

Examples 3 to 5

As the resin binder is a terpolymer of a glass transition temperature of 66 ⁰ C and a softening point of 136 ⁰ C of 70 wt .-% of styrene component, 10 wt .-%. Methyl methacrylate component and 20 wt .-% n-butyl acrylate component used.

100 parts by weight of the terpolymer are mixed with 15 parts by weight one of the three commercially available types of carbon black specified in Table I for 15 minutes using a Henschel mixer, whereupon the whole thing by means of an extruder is melted and mixed. After cooling, it is finely ground. The received Powder is finally classified, with three types of toner having an average particle size of about 9.0 μπι can be obtained.

3 TABLE I. 1 PH value , 0 4th Acid soot 2 3 , 5 example 5 soot 3 2 , 0 example soot 2 example soot

From the toners of Examples 3 to 5 and the carrier of the

Example 1 Three different developer 3 according to the invention are prepared to 5 each having a toner concentration of 2 io.

The developers 3 to 5 are in a commercially available Copier to its initial Q / M value that is achievable D and the achievable resolution of the image copies tested. In addition, each one small amount of the toner of Examples 3 to 5 melted on a glass lens carrier and to form a Toner layer covered with a cover slip. Thereafter, the dispersion state of the carbon black is determined by observing determined by a transmission microscope. The results are summarized in the following Table II.

15 posed.

TABLE II

pH value initial D dissolving disperdes Soot Q / M- ¥ em-

_n in μθ / g capacity of the

^ΛΌ in soot

Lines / mm

toner 3 3 , 0 24, 2 1 , 42 8th Well toner 4th 2 , 5 25, 8th 1 , 45 8th Well toner 5 2 , 0 25, 6th 1 , 38 8th Well

Comparative Examples 3 to 5

According to Examples 3 to 5 toners are produced, the types of carbon black identified in more detail in Table III below are used.

Comparison soot 3 3 - 5 - 4th 4th O TABLE III 5 PH value O 7, Comparative example 8th, Comparative example 9, Comparative example

Furthermore, a carrier is produced according to Example 1, but with a styrene / methyl methacrylate copolymer for coating with 30 wt .-% styrene component and 70% by weight methyl methacrylate component is used.

From the toners and the carrier produced in the manner described, Examples 3 to 3 are obtained 5 comparative developers 3 to 5 were prepared.

Tests similar to those in Examples 3 to 5 are carried out with these. The results are in Table IV compiled.

TABLE IV

pH value initial D dissolving Q / M value ^max

Soot in μθ / g

Dispersing

The ability to dissolve in the number of lines / mm of soot

Comparison
toner 3 7, 5 22 1 1 , 27 6th not
particularly
Well Comparison
toner 4 8th, 0 20, 7th 1 , 18 4th Il Il Comparison
toner 5 9, 0 21 0 1 »11 4th bad

A comparison of the results in Tables II and IV shows that the developers according to the invention excellent triboelectric charging properties can ensure high image density and high resolution using the same copies receives.

Examples 6 and 7

According to example 1, two types of toner are produced » however, a styrene / methyl methacrylate mixed polymer in a weight ratio is used as the resin binder Styrene component / methyl methacrylate component of 85/15 (Resin A) and the other time one

15 copolymer with a weight ratio of 50/50 (resin B) is used.

Using the two types of toner and the carrier from Comparative Examples 3 to 5, two developers 6 and 7 according to the invention, each having a toner concentration of 1.7 tf>, are produced.

Comparative example 6

A toner is produced according to Examples 6 and 7, however, a styrene / methyl methacrylate copolymer is used as the resin binder a styrene component / methyl methacrylate component weight ratio of 30/70 (resin C) is used. Under use

A comparative developer 6 is prepared from this toner.

In developers 6 and 7 and Ιπι comparative developer 6, the initial Q / M values at a temperature of 20 ⁰ C and a relative humidity of 50 % (loading

Condition I) or at a temperature of 33 ⁰ C and a relative humidity of 80 $> (Condition II) ■ determined. The results are shown in Table V. It should be expressly noted that the developer used for the toner with the resin binder with a low proportion of the styrene component (resin C) exhibits markedly deteriorated triboelectric charging properties at higher temperature and humidity (condition II).

Developer 6 Developer 7

Comparison developer 6

TABLE V

Resin binder of the toner

Resin A Resin B

Resin C

Start B-Q / M value in μΡ / g Condition I Condition II

31.3
28.6

24.6

26.9 20.4

11.8

In a commercially available electrophotographic copier, conditions I and II are used with the developers 6 and 7 and the comparative developer 6 copy tests carried out and the resulting copies evaluated. The results are shown in Table VI. When the comparative developer 6 is used, only copies of images with a low resolution are obtained Preserved on gray background. In each column of Table VI, the top value corresponds to Results for Condition I the lower value of the results for Condition II.

TABLE VI

Max gray picture
background Dissolution
fortune in
Lines / mm Developer 6 1.28 0.00 8th 1.24 0.00 6th Developer 7 1.25 0.00 6th 1.09 0.01 5 Comparative
winder 6 1.26
0.98 0.01
0.02 4th
4th

example

100 parts by weight of a terpolymer of a glass transition temperature of 62 ⁰ C and a softening point of 130.5 ⁰ C from a styrene component, a methyl methacrylate component and a n-Butylacrylatkomponente in the ratio 75: 5: 20, 15 parts by weight of commercially available carbon black and 3 Parts by weight of a commercially available polypropylene are premixed in a Henschel mixer for 15 minutes, melted with the aid of an extruder and mixed, after cooling, coarsely ground »then finely ground and finally classified, giving a total of four types of toner particles with the distribution given in Table VII will. The measures of fine grinding and elassification are varied here. 0.8% by weight of hydrophobic finely divided silica powder is added to each toner. Ultimately, two toners 1 and 2 (which meet the requirements according to the invention) and two comparison toners 1 and 2 (which do not meet the requirements according to the invention) are obtained.

TABEL VII 0 N * · ■ **
2 -SO MRI * (Mm) N ₁ ** 2 (Weight (Weight 8th 0 2 5.5 16, ⁵ 0, 2 Toner 1 6.7 9 » 1t 1 Toner 2 8.8 6, 3 » Comparison
toner 2 11.3

* MRT: Average particle size of the toner in the volume distribution

** N ₁ : ratio of fine particles having a particle size of less than 5 µm to the total amount of toner particles

*** Np: ratio of the particles of one particle size of not less than 16 µm to the total amount of the toner particles.

On the other hand, a carrier core material is made of iron powder with a styrene / methyl methacrylate copolymer coated from a styrene component and a methyl methacrylate component in a ratio of 50:50 »whereby a Carrier of an average particle diameter

(MRC) of 98 points obtained in volume distribution

will. With 100 parts by weight of the carrier obtained, 2 parts by weight of toner 1 or 2 or Comparison toner 1 or 2 mixed, whereby developers 8 and 9 or comparison developers 7 and 8 are obtained

the.

The various developers are seen in the development station of a commercially available electrophotograph Copier charged. After stirring for 1 minute, the initial charge volume of the developer and

same developer determined. After that, be using the developer according to the invention and the comparative developer in the context of long-term copy tests 20,000 image copies produced as opposed to the degree of toner atomization and a change in the charge volume of the developer the initial Q / M value. The results are summarized in Table VIII:

TABLE VIII Develop
ler 8 Develop
ler 9. Ver
equal
developed
ler 8 Ver
equal
un-
winder 7 28.6 25.6 20.3 Initial-O / M-
Value ΤμΟ / g) 38.2 8th 8th 4th Resolutionver
like in
Lines / mm 8th 1.23 1.31 1.36 Max 1.14 - - weak gray background
reason strong - - - - Tonerzer
dusting strong strong Change in
Q / M value strong

It can be seen from Table VIII that excellent results have been obtained with the developers of the present invention.

Example 9

In accordance with Example 8, carrier core materials of different particle diameters are used for the production of four carriers with MRC values of 48 μΐη, 66 μπι, 98 μΐπ and

135 μΐη used.

According to Example 8, developers are then produced from these carriers and the toner 2. These are examined for their initial Q / M value. Furthermore, those made with these developers Image copies examined for their resolving power and their D. Finally there is also liability of the support on the photoconductive drum surface determined after making 20,000 image copies. The results are shown in Table IX.

TABLE IX Develop
ler 10 Develop
11th 5 Yer-
equal
develop-
ler 10 Ver
equal
developed
ler 9 66 98 135 MRC (\ m) 48 24.3 26, 30th 32.0 Initial-O / M-
value (uC / g) 20.8 8th 8th 4th Dissolution
fortune in
Lines / mm 8th 1.30 1, 1.14 Max 1.32 _ - - Liability of
Carrier strong

It can be seen from Table IX that only the developers of the present invention give favorable results.

Example 10

According to Example 8, 100 parts by weight of a styrene / 2-Ethylhe7:-yl acrylate copolymer having a styrene component and a 2-te Ethylhexylacrylatkomponen- ⁵ in the ratio 80:20 -and 9 parts by hand el sübli more carbon black to the toner particles of a average particle diameter of 9 »2 pm" at the volume distribution, a percentage of fine particles N ^ (below 5 μπι) of 4 »4 wt .- ^ and a proportion of particles of a large ¹⁰ diameter (more μια than 16) of 0, 8 wt.

Furthermore, carrier core materials are made from iron powders different particle diameters with a styrene / methyl methacrylate copolymer with a styrene component and a methyl methacrylate component im Ratio 40:60 coated, with two different types of carrier with MRC values of 66 μm and 135 μm the volume distribution can be obtained.

Using these carriers and toners, developers of various toner concentrations are prepared and examined according to Example 8 for their initial charge values. The results are compiled in table X

MHC value
in around . ' * ■; ",: :.; ·:.;. 3303130 TABLE X developer 66 Toner concentration
in wt .-? t> Initial Q / M
Value in μθ / g A. 1.0 24.3 2.0 22.6 C. 3.0 20.7 D. 135 4.0 20.1 E. 1.0 39.8 Έ
G 2.0
3.0 33.8
26.5 H 4.0 • 21.2 -

From Table X it can be seen that when the toner concentration is changed strong changes in the initial Q / M value can be determined if the wearer's MRC value is above 120 | in lies. Thus, only those developers who meet the requirements of the invention deliver stable ones Ratios of triboelectric charge to mass, if in repeated development processes with higher Toner concentrations must be expected (like this

25 is the Pail for two-component developers).

Example 11

By mixing 5 parts by weight of Toner 1 of Bei-30 game 8 with 100 parts by weight of a commercially available

Iron oxide powder carrier of an average particle diameter a developer according to the invention is produced from 65 μm in the volume distribution.

A measurement of the initial Q / M of this developer

corresponding to Example 8 gives a value of 24.8 μθ / g. Visible images are obtained when 20,000 image copies are made in a long-term copy test high sharpness without a gray background. The reduction of the Q / M value after producing 20,000 image copies only goes up to 20.5 μθ / g.

Examples 12. to 14

10 Made of styrene / methyl methacrylate and n-butyl methacrylate three terpolymers with the values given in table ΣΙ specified proportions of styrene component, methyl methacrylate component and n-butyl methacrylate component produced. Table XI also contains information on

the softening point (St) and the glass transition temperature (Tg) of the terpolymers.

TABLE XI

20 Terpolymerssat Ratio of the monomers SP in Tg in

components in bulk parts ⁰ C ⁰ C

St * MMA ** n-BMA *** 132 61 1 50 20th 30th 128 65 2 75 10 15th 127 63 3 80 5 15th

* Stvri & omponeji t e

3Q ** methyl methacrylate component
*** n-butyl methacrylate component

In each case 100 parts by weight of terpolymers 1 to 3 (resin binder), 10 parts by weight of commercially available carbon black

and 3 parts by weight of a commercially available one, a low one Polypropylene having a softening point are premixed for 15 minutes in a Henschel mixer, with Melted and mixed with the help of an extruder, after cooling down coarsely ground »then finely ground and finally to three different types of toner with an average particle diameter of about 9 »7 µm classified (toner 3 to 5). Each of Toners 3 to 5 becomes 0.8% by weight of a commercially available hydrophobic one finely divided silicon dioxide powder added, whereupon 2 parts by weight of the mixture obtained with 100 parts by weight of a carrier coated with a resin average particle diameter of about 100 μΐη be mixed. You get three different ones

15 developers.

Comparative Examples 7 to 10

Through interpolymerization of styrene with n-butyl

methacrylate in the ratios given in Table XII are four copolymers with only a styrene component and an n-butyl methacrylate component manufactured. Its properties are also given in Table XII.

TABLE XII

Mixed polymer 1 Ratio of mono
mer en components in
Parts by weight n-BMA ** SP in ^Ü C Tg in
⁰ C IV) St * 25th Comparison
copolymer 3 75 30th 139 57 t! 4th 70 40 HO 55 It 60 45 131 49 ti 55 121 46

* Styrene component ** n-butyl methacrylate component

In a manner corresponding to that in Examples 12 to 14, using the comparative copolymers 1 to 4 as resin binders, comparative toner 5 to .6 and made from these comparative developers. 5

With the developers according to the invention of Examples 12 to 14 and the comparative developers of the comparative examples 7 to 10 are made using a commercially available electrophotographic copier unfused toner images produced. The fixing the toner images are created with the aid of a fixing tester from the fixing part of another commercially available one electrophotographic copier. This test is used to determine the lowest possible fixation

15 temperature T ₁ and the lowest temperature T ₂ 1 at which ghosting occurs. The Q / M values and the durability of the developers are also determined. The shelf life results from the observation of possible clumping or aggregation at 7 days

20 leave the toner in a thermostat

a temperature of 55 ⁰ C and a relative humidity of 55 #. The results are shown in Table XIII.

M- ^T 1 • <- . ■ _r - - · =. . 3303130 TABEL in ⁰ C Q / M value 160 XIII in μθ / g 160 τ Clumping toner 23.4 155 in ⁰ C 25.5 160 235 no Toner 3 25.9 180 220 no Toner 4 23.2 160 215 no Toner 5 22.8 150 200 slightly Comparison
toner 3 20.7 200 slightly "4 20.5 175 Yes VJl HO Yes "6

The results in Table XIII show that
that the developers according to the invention have a high
Have a Q / M value and good fixability, only allow ghost images to form at high temperatures and a wide range for the fixation temperature

20 at the preferred temperature and have excellent durability.

With the help of the developers containing toners 3 to 5 are in a commercially available copier. Copy test for the production of 10,000 image copies

carried out. Until the end of the copy tests to get high quality image copies.

The comparison developers, whose toners are used as resin binders, have copolymers with only two

Contain monomer components, the temperature at which ghosting occurs will be lower. About that In addition, these developers have no or only a narrow fixing temperature range and poor durability and a low Q / M value.

Also with those containing comparison toners 3 to 6 Comparison developers are described in the Way, copy test carried out. These tests show that although good quality image copies can be produced. however, that the rollers in the fixing part are contaminated and the transfer paper is substantially wound on the rollers. So you can these toners cannot be used in practice.

Example 15

By copolymerizing styrene, methyl methacrylate and n-butyl acrylate, a terpolymer with a Styrene component, a methyl methacrylate component

15 and a n-butyl acrylate component in the table XIV specified ratio and produced with the properties also specified in Table XIV.

TABLE XIV

Terpolymer weight ratio SP in ⁰ C Tg in ⁰ C

of the monomer components

St * MIiA ** n-BA ***

". 4 75 10 15 132 64

* Styrene component
** Methyl methacrylate component
*** n-butyl acrylate component

According to Examples 12 to 14 using the terpolymer 4 as a resin binder which meets the requirements according to the invention sufficient toner 6 of a 35 average particle diameter of 8.8 \ in the manufacturing

and processed to a developer.

Comparative Examples 11 and 12

Through copolymerization of styrene and n-butyl acrylate are two copolymers with a styrene component and an n-butyl acrylate component in that in Table XV and with the also in

Properties given in Table XV. 10

TABLE XV SP ■
in ⁰ C Tg '
in ⁰ C Mixed polymer Weight ratio
the monomer
components St * n-BA ** 153
133 61
49 Comparative mix
polymer 5
"6 85 15
80 20

* Styrene component ** n-butyl acrylate component

According to Examples 12 to 14, using the comparative copolymers 5 and 6 as resin binders Comparative toners 7 and 8 each having an average particle diameter of 8.8 μm were prepared and processed to comparison developers.

From the inventive developer of Example 15 and comparative developers 11 and 12 determine the durability by determining the lowest fixing temperature T., and the lowest temperature Ϊ £ »at the Geißterbilder occur, determined. The results

35 can be found in the following Table XVI.

to the TABEL XVl T ₂ in ^Q C Lump Developer with 7th
8th T ₁ in ⁰ C 250
200
160 Toner 6
Comparison toner
Comparison toner 160
190
150

B is ρ ie 1

16

Through copolymerization of styrene and methyl methacrylate and 2-ethylhexyl acrylate becomes a terpolymer seed with high molecular weight fraction and low molecular weight fraction as well as a styrene component and a methyl methacrylate component and a 2-ethylhexyl acrylate component according to the information in the following table XVII, which also has the properties given in Table XVII »manufactured.

TABLE XVII SP
in ⁰ C Day
in ⁰ C Terpolymeri sat Weight ratio of
Monomeric components St * MMA * - * 2-EHA *** 1 30th 60 5 75 10 15

* Styrene component e ** methyl methacrylate component *** 2-ethylhexyl acrylate component

According to Examples 12 to 14, using the terpolymer 5 as a resin binder, a according to the invention Requirements satisfactory toner 7 one

average particle diameter of 9 »2 pm. manufactured and processed into a developer.

5 Comparative example 13

By. Copolymerization of styrene with 2-ethylhexyl acrylate becomes a copolymer with a styrene component and a 2-ethylhe: x: ylacrylate component accordingly the ratio given in Table XVIII and a softening point (SP) which is approximately the softening point of the terpolymer 5 from Example 16 corresponds, manufactured. The properties of the copolymer obtained can be found in Table ZVIII.

¹⁵ TABLE XVIII .

Comparative mixing weight ratio SP Tg polymer of the monomers in ⁰ C in

components

St * 2-EHA **

_20th

85 15 129 45

* Styrene component
** 2-ethylhexyl acrylate component

In accordance with Examples 12 to 14, using the comparative copolymer 7 as resin binder, a comparative toner 9 with an average particle diameter of 9 »2 μm is prepared and processed into a comparative developer.

Of the inventive developer of Example 16 and the comparative developer of the comparative example is the shelf life by determining the lowest

Fixing _{temperature T 1} and the lowest temperature Tp at which ghost images arise. The results are compiled in Table ZIX.

TABLE XIZ

Developer with the T ₁ in ⁰ C Tg in ⁰ C clumping

Toner 7 160 215

Comparison toner 9 160 180 yes

Examples 17 and 18
and Comparative Examples 14 and 15

"—--——— ■

100 parts by ^{weight of a terpolymer with a glass transition temperature of 64 0} C and a softening point of 132 ⁰ O with a high molecular weight fraction of a styrene component, a methyl methacrylate component and an n-butyl acrylate component in a ratio of 75: 5: 20 and a low molecular weight fraction of the three components in Ratio 70:20:10, 10 parts by weight of commercially available carbon black and 5 parts by weight of a polypropylene having a low softening point

25 are premixed for 15 minutes in a Henschel mixer, then melted and mixed in an extruder, coarsely ground after cooling, then finely ground and finally classified. By different Finely ground and classify

₃₀ ultimately four different types of toner particles with a distribution according to Table XX were obtained. To produce two toners 8 and 9 that meet the requirements of the invention or two comparison toners 10 and 11, the respective toner particle powder is 0.8

% By weight of a finely divided, hydrophobic silicon dioxide

1 powder added.

1 0 TABLE XX ^N 1 N ₂ 2 toner MET (pm) in weight? 1 18.0 5 Comparison toner 1 1 5.1 8.8 i in wt .- # Toner 8 7.2 6.0 0 Toner 9 9.2 2.8 0, Comparison toner 11.5 1, 3,

The indications "MRT", "N ₁ " and "already given definition.

correspond to the

Furthermore, an iron powder core material for a Carrier with a styrene / methyl methacrylate copolymer composed of a styrene component and a methyl methacrylate component coated in a ratio of 50:50, with a carrier with an MRC value of 98 μΐη is obtained in the particle size volume distribution. 2% by weight of toners 8 and 9 and comparative toners 10 and 11 are mixed with 100 parts by weight of the carrier, According to the invention, developers 12 and comparative developers 11 and 12, respectively, are obtained.

The developers and comparative developers obtained are tested according to Example 8, the in the results summarized in Table XXI below would be obtained.

• - 3303130 - ■ rr-H- TABLE XXI Develop-
same 12
develop
11th Develop
ler 13 Ver
equal
developed
ler 12 39.4 27.3 23.8 19.6 Initial-O / M-
Value ΧμΟ / g) 8 8 8th 4th Dissolution
fortune in
lines / mm 1.06 1.25 1.32 1.35 Max strong - weak gray background
reason strong _ _ Tonerzer
dusting strong weak weak strong Change in
Q / M value

The results in table ΣΧΙ show that one can with Use of developers according to the invention which meet the specified requirements, in particular with regard to the Sufficient particle diameter, achieved a large Q / M value, and many times high quality image copies high sharpness and high resolution.

example

By reacting 270 g of 1,4-butanediol, 150 g of terephthalic acid and 231 g of benzene-1,2,4-tricarboxylic acid, at 200 ⁰ C, a polyester with 12 wt .- # to Chloroformunlöslichem and a softening point of 130 ⁰ C is established.

330313Q

1 100 parts by weight of the polyester (resin binder),

13 parts by weight of commercially available carbon black, 3 parts by weight of commercially available Polypropylene and 1 wt .- # of a commercially available Fatty acid amides are mixed in a Henschel mixer premixed, then melted in an extruder and mixed, cooled, coarsely ground and finally finely ground, being a toner powder is obtained.

10 The toner powder obtained is with the aid of a

Zigzag IQ. Classification device, whereby, on the one hand, two toners satisfying the requirements according to the invention with regard to particle diameter 10 and 11 and further three comparison toners 12, 13 and 14 which do not satisfy these conditions can be obtained.

The particle diameter distributions of the toners obtained are shown in Table XXII. 20th

TABLE XXII ^N 1 in weight D (μΐη) toner MET I.
in wt .- $ 0.2 (around) 11.0 1.6 5.04-6.35 Toner 10 7.5 3.6 0 6.35-8.00 Toner 11 9.6 24.8 3.2 4.00-5.04 Comparison
toner 12 6.2 2.4 6.5 6.35-8.00 »13 10.2 1.1 8.00-10.08 η Η 11.3

In the table, the abbreviations "MET", "N-." and

1 "N ₂ " has the meaning already given. "D" stands for the particle diameter range including the highest or largest number of particles according to the Coulter Counter "Model TA II".

2 parts by weight of the respective toner or comparison toner are with 100 parts by weight of a resin-coated carrier of an average Particle diameter of 100 μαη mixed, with two inventive developers 14 and 15 and three comparative developers 13, 14 and 15 can be obtained.

The developers or comparative developers are used in a commercially available electrophotographic copier subjected to a permanent copy test to produce 10 copies of images. After making 10 Image copies received next image copy is then sent to its D__. their resolving power and the degree "Cleaning stains" on the developed image were examined. Perner is examined to what extent a good or poor cleaning is possible, whether there is a gray image background, whether there is toner atomization comes and what flowability of the developer or comparative developer at the beginning of the long-term copy test

25 owns.

"Cleaning stains" or "brush stains" on the developed image are shown in an evaluation of the white areas in a "solid" part of the image. The developer fluidity is derived from the bulk density value determined with the aid of a suitable measuring device determined. The results can be found in Table XXIII.

TABLE XXIII

developer

D dissolving "cleaning gray cleaning toner cleaner flowing

^a ability in spots "on image dusting capable lines / mm of the development back- ground

th picture in% reason

Developer H 1.12 Developer 15 1.21

Comparison developer 1? 1.08

Comparison developer 14 1.24

Comparative developer 15 1.15

8th 1.7 8th 2.5 8th 1.4 6th 4.3 4th 5.2

Well
Well

weak 0.38
0.42

strong bad strong
Well
Well

0.31
0.43
0.45

Approx

CO OJ CD GO

330313Q

The results show that the developers of the present invention have good imaging properties and remain stable when performing numerous copying operations. In contrast, the comparative developer conditionally 13 with a large proportion of particles with a small particle diameter, problems with cleaning, in terms of gray image background and toner atomization, and in terms of its flowability. Comparative developers 14 and 15, on the other hand, do not have good imaging properties.

Example 20

A polyester having 8 wt .- ^ to Chloroformunlöslichem is prepared by reacting 299 g of terephthalic acid, 211 g PoIyoxypropylen- (2,2) -2,2-bis (4-hydroxyphenyl) propane and 82 g of pentaerythritol at 200 ⁰ C .

100 parts by weight of the polyester obtained (Harzbinde-20 medium), 10 parts by weight of commercially available acidic carbon black,

2 parts by weight of a commercially available polypropylene and 2 parts by weight of a commercially available fatty acid amide are premixed in a Henschel mixer, then Melted in an extruder and mixed, cooled, coarsely ground, finely ground and finally classified, with a toner 12 meeting the requirements of the invention being an average Particle diameter of 9 »2 pm is obtained.

2 parts by weight of the toner 12 with 0.8 wt .- ^ of a finely divided hydrophobic silica powder and 0.2 wt .- ^ zinc tearate with 100 parts by weight of a with a resin-coated carrier with an average particle diameter of 100 μm

35 sets, a developer 12 according to the invention being obtained.

Example 21

A polyester resin with 18% by weight of chloroform-insolubles is prepared according to Example 20, where ~ however, the reaction time is changed. This gives one of the requirements according to the invention sufficient toner 13 with an average particle diameter of 8.8 (im.

¹⁰ Comparative Examples 16 and 17

According to Example 20, two polyesters with 2% by weight and 29% by weight of chloroform-insoluble matter are produced. In the production of the polyesters, the reaction time is changed compared to Example 20.

Finally, two comparison toners with an average particle diameter of 9.2 μm and 9.0 pm (comparative toners 15 and 16) were obtained. From these Comparative toners are made from comparative developers.

The inventive developers of Examples 20 and 21 and the comparative developers of Comparative Examples 16 and 17 become Comparative Examples, respectively 7 to 10 tested, with those in the following

Results compiled in Table XXIV were obtained will.

TABLE XXIV

developer

T ₁ T ₂ Tg SP Q / M value clumping evaluation in ⁰ C in ° c in ⁰ C ( ⁰ C)

inventive developer 12

inventive developer 13 165

Comparison developer 15

Comparison developer 16

160> 23O 61 127 26.6

> 23O 68 136 28.1

155 195 54 121 27.2

180> 230 72 151 27.0

no

no

no

Well

Well

bad
bad

.

* S

CO CO O CO

330313Q

1 The results show that the invention Developers distinguish themselves through favorable fixing properties » to a large extent the creation of ghost images prevent »a wide fusing temperature range

have and are extremely durable.

Using the developers 12 and 13 according to the invention, a commercially available electrophotographic Copier continuous copy tests for

10 Production of over 10,000 image copies carried out. High quality image copies can be made by the end of the test. In similar continuous copy tests, the comparative developer 15 fails to a high degree Ghost images arise and is the comparative development

ler 16 only insufficiently fixable. So you can the comparison developers are not used in practice will.

Example 22

In accordance with Example 21, a toner 14 according to the invention is produced. Furthermore, according to Example 21 a comparison toner produced »but with the polypropylene and the fatty acid amide wax as release agents

can be omitted. From the toner satisfying the requirements according to the invention and the comparison toner a developer 16 according to the invention and a comparative developer 17 are prepared according to Example 21.

Fixing tests according to Example 20 provide the results compiled in Table XXV.

■ »". * developer • a - ^T 2
in ⁰ C 49- $
TABEL according to the invention
Developer 16
Comparison developer 17 XXV > 230
180 in ⁰ C 1
1 65
65

From Table 2JV it can be seen that the addition of release agents when fixing by means of heated
WaIi / en can prevent the occurrence of ghosting to a high degree.

Example 2?

By reacting 299 g of terephthalic acid, 211 g of polyoxypropylene- (2,2) -2,2-bis- (4-hydroxyphenyl) propane
and 82 g of pentaerythritol becomes a polyester A with
17% by weight of chloroform insolubles.

In a conventional manner for toner production (mixing, melting, grinding and classification), 100 parts by weight of polyester A, 10 parts by weight of commercially available carbon black and 2 parts by weight are used
a commercially available polypropylene and 2 parts by weight of a fatty acid amide wax a toner 15 that meets the requirements of the invention and has an average

³ ^ borrowed particle diameter with the volume distribution of 9.1 fom, a particle diameter of the largest number of particles in the number distribution of 7 »1 µm, a ratio N ^ of the number of particles with a particle diameter of less than 5 μm to the total number of particles of 4» 2 ia and a ratio Np of the number of particles

330313Q

. SC-

with a particle diameter of more than 16 μm for the total particle number of 0.1 $> .

Furthermore, by polymerizing styrene with Methyl methacrylate in a weight ratio of 70:30 a Prepared mixed polymer solution. This is on a fluidized bed made of an iron powder carrier material of polyhedral particles of an average Particle diameter of 98 .mu.m in the volume distribution sprayed on, with on the carrier material a resin coating with a thickness of about 2 pm is formed. Using 1176 g of the obtained Carrier A with 24 g of the previously prepared Toner 15, a inventive developer 18 prepared.

In a continuous copy test to produce more than 20,000 image copies with the help of a commercially available using an electrophotographic copier of the developer 17 according to the invention, sharp copies of images with a high resolution are obtained. the The quality of the copies at the end of the continuous copy test corresponds to the quality of the image copies at the beginning of the test. Measurements of the Q / M values at the beginning and at the end of the test show values of -26.8 pC / g and -24.8 μθ / g, respectively.

This means that the triboelectric chargeability is very stable

Comparative example 18

A carrier B is produced according to Example 23, but spherical iron powder is used as the carrier material an average particle diameter of 103 is used in the volume distribution. Under use of carrier B is then according to Example 23

35, a comparative developer 17 was prepared.

330313Q

Obtained in the continuous copying test described in Example 23 using the comparative developer 17 At the beginning of the test you get high quality images, but the image quality will decrease after the production of 10,000 image copies, particularly in terms of sharpness » Resolving power and practical usability worse and worse. The one at the beginning of the copy « tests measured Q / M value of -28.9 μθ / g reduced with a large change in volume at the end of the test to -23.4 μθ / g. During the copy test moreover, as the number of copies increases, the image density deteriorates considerably. This is based presumably due to a direct influence of the change in the toner concentration in the developer, the image

15 density.

These results also show that spherical carriers are not even with practically the same particle diameter lead to equally good results as polyhedral carrier particles.

Example 24

By reacting 150 g of terephthalic acid and 270 g of 1,4-butanediol and 231 g of benzene-1,2,4-tricarboxylic acid becomes a polyester B with 12% by weight of chloroform-insoluble manufactured.

As in Example 23, using 100 parts by weight of polyester B, 13 parts by weight becomes more commercially available Carbon black and 4 parts by weight of a commercially available polypropylene produced a toner powder. This is classified with one of the requirements according to the invention with regard to toner particle diameter sufficient toner 16 and two of these requirements

330313Q

gen insufficient comparative toners 18 and 19 can be obtained. Me particle size volume distribution of the various Toner is shown in Table XXVI below.

MRI TABLE XXVI in O Weight - ° j ί 6, D (\ in the) 00 toner (pm) N ₁ O , 9 5, 35 8.8 in% by weight 4th 8th, 35 - 8th, , 08 Toner 16 6.1 2.4 " ,1 04 - 6, Comparison
toner 17 11.6 18.2 OO - 10 Comparison
toner 18 0.1

In the table, the abbreviations ¹¹ MRT "," N ₁ "," K ₂ "and" D "have the meaning already given.

By mixing the three toners with the carrier A of Example 23, a developer according to the invention and two comparison developers with a toner concentration of 2 wt .- ^ each prepared. The different Developers become those described in Example 23

Subjected to 25 tests, the ones listed in Table XXVII Results are obtained.

TABLE XXVII

developer invention
according to Ent
winder 18 Comparative
develop
over 18 Comparative
develop
ler 19 toner Toner 16 Comparison
toner 17 Comparison
toner 18 Q / M value in μθ / g -27.3 -35.4 -20.8 Fluidity Well bad Well Max 1.18 0.85 1.21 Resolutionver
like in
Lines / mm 8th 8th 6th gray background
reason - there there Cleaning stains
on development
th image in $ 1.2 0.9 4.6

According to Example 23, a permanent copying test is now carried out carried out to produce more than 20,000 copies of images. An evaluation of the developers and those with the Copies of images produced by different developers result in the following table XXVIII summarized

25 presented results.

330313Q

TABLE XXVIII

developer invention
according to Ent
winder 19 Comparative
develop
over 18 Comparative
develop
ler 19 Percentage
Change of the
Q / M value * 10.2 26.8 16.8 Max
Resolutionver
like in
Lines / mm 1.16
8th 1.11
8th 1.19
4th gray picture
background - - Purge
spots on the
developed
Image in % 1.4 1.1 4.2

* Percentage change in the Q / M value after 20,000 copying processes, "based on the Q / M value at the beginning of the copy test (see Table XXVII).

The results show that the developers of the invention provide relatively high quality copies of images, over and above ensure a stable state of charge of the toner for a long time and are very durable.

example

25th

A developer is prepared according to Example 23, However, the iron powder carrier material used without a resin coating is used. A developer 20 according to the invention is thereby obtained.

330313Q

With the developer 20 according to the invention, the Endurance copying test of Example 23 was carried out. Tested too The developer 18 of example 23 is shown again. The following result. Table 29 summarizes the results relating to the percentage change in the Q / M value and a picture score.

TABEL developer XXIX - 1.2 developer
20th Percentage change in
Q / M value developer
18th 24.3 Max 7.5 ' 1.02 Resolving power in
Lines / mm 1.18 5 Gray image background 8th weak Cleaning stains on the
developed image in % 2.8

The results in Table XXIX show that

The use of resin-coated supports gives more favorable results.

example

26th

Corresponding to the measures carried out for the production of the polyester A in Example 22 are carried out with alternating Reaction times polyester B and C produced. Their properties are along with the properties of polyester A given in Table XXX.

A.
B.
C. TABLE XXX - Chloroform insol
Liches in wt .-% 17th
22nd
4th SP in ⁰ C polyester 133
138
129 polyester
polyester
polyester

3303Ί

Using polyester C and D according to Example 22, two toners 20 and 21 are now produced. Using the developers 18, 21 and 22 according to the invention, fixing tests are carried out, the results of which are summarized in Table XXXI

TABEL XXXI T ₁ in ⁰ C T ₂ in ⁰ C developer Resin binder
Toners of 170
180
155 > 230
> 200 18th
21
22nd Polyester A
Polyester C
Polyester D

From Table XXXI it can be seen that developers containing the toner binder contain an adequate amount of chloroform insolubles contains quite a low fixing temperature and a high temperature at which ghosting arise, have and are consequently characterized by a wide fixing temperature range.

Claims (32)

PATENT CLAIMS 1. toner for developing latent electrostatic images; consisting essentially of particles of a ¹ ^ average particle diameter at the Particle size volume distribution or a mean diameter in the range of 6-10 µm and one Particle diameter of the largest number of particles in the particle size number distribution or one * ° vertex (value) diameter in the range of 5-8 µm, the number of particles having a particle diameter of less than 5 µm being not more than 15% by weight of the total particle number and the number of particles having a particle diameter of more than 16 µm being not more than ^{w make up} 2% by weight of the total number of particles. 2. Toner according to claim 1, characterized in that its resin binder consists of a styrene-containing copolymer consists. 3. Toner according to claim 2, characterized in that its resin binder consists of a styrene / alkyl acrylate copolymer or styrene / alkyl methacrylate mixed polymer is made.
30th 4. Toner according to claim 2, characterized in that it additionally contains a colorant. 5. Toner according to claim 4, characterized in that the colorant consists of acid soot. 6. Toner according to claim 1, characterized in that its resin binder consists of a polyester. 7. Toner according to claim 6, characterized in that its resin binder made of a polyester with 5 - 5 contains 25% by weight of chloroform insolubles. 8. Toner according to claim 1, characterized in that it additionally contains a release agent. 9. The toner according to claim 8, characterized in that the release agent is the same from a polyolefin having a softening point of 80 ° to 180 ⁰ C, a fatty acid amide of a fatty acid or a metal salt. 10. Toner according to claim 9, characterized in that the polyolefin consists of polyethylene or polypropylene. 11. Toner according to claim 1, characterized in that its resin binder consists of a copolymer with consists of at least three different monomer units. 12. Toner according to claim 11, characterized in that the copolymer of at least one styrene monomer component and at least two alkyl acrylate and / or alkyl methacrylate monomer components. 13. Toner according to claim 11, characterized in that the copolymer of at least one styrene monomer component, at least one alkyl acrylate monomer component and at least one alkyl 35 methacrylate monomer component. 14. Developer for developing latent electrostatic images from toner particles and a carrier and optionally further constituents, characterized in that the toner particles have an average Particle diameter in the particle size volume distribution or a mean diameter in the range of 6-10 µm and a particle diameter, the largest number of particles in the particle size number distribution or a vertex (value) through 10 knives in the range of 5 - 8 µm and the Number of particles with a particle diameter of less than 5 µm not more than 15% of the total number of particles and the number of particles with a particle diameter of over 16 μπι not more than 2% of the 15 make up the total number of particles. 15. Developer according to claim 14, characterized in that the carrier consists essentially of particles an average particle size in the partial 20 chen size volume distribution or a mean diameter in the range of 50-120 µm. 16. Developer according to claim 15, characterized in that the particles are composed of polyhedral particles 25 exist. 17. Developer according to claim 15, characterized in that the carrier consists of a core material provided with a resin coating. 18. Developer according to claim 17, characterized in that the resin coating consists of a styrene-containing copolymer consists. 19. Developer according to claim 18, characterized in that that the coating consists of a styrene / alkyl acrylate copolymer or styrene / alkyl methacrylate copolymer. 20. Developer according to claim 14, characterized in that its Karzbinder consists of a styrene-containing
Copolymer consists. 21. Developer according to claim 20, characterized in that that its resin binder consists of a styrene / alkyl acrylate copolymer or a styrene / alkyl methacrylate copolymer consists. 22. Developer according to claim 20, characterized in that its copolymer containing toner additionally contains a colorant. 23. Developer according to claim 22, characterized in that the colorant consists of acidic carbon black. 24. Developer according to claim 14, characterized in that the resin binder of the toner consists of a copolymer with A wt .-% styrene units
and the copolymer B forming the resin coating of the carrier contains% by weight of styrene units, the ratio A / B of the equation: 0.7 <A / B <3.0 30 is sufficient. 25. Developer according to claim 14, characterized in that the resin binder of the toner consists of a polyester consists. 26. Developer according to claim 25, characterized in that the polyester 5 to 25 wt .-% of chloroform-insoluble contains. 27. Developer according to claim 20, characterized in that the toner additionally contains a release agent. 28. Developer according to claim 27, characterized in that the release agent consists of a polyolefin of a softening point from 80 - 180 ° C, a fatty acid amide, a fatty acid or a metal salt thereof. 29. Developer according to claim 28, characterized in that the polyolefin is made of polyethylene or polypropylene consists. 30. Developer according to claim 18, characterized in that the copolymer is at least three different Contains 20 monomer units. 31. Developer according to claim 30, characterized in that the copolymer consists of at least one styrene monomer component and at least two alkyl acrylate 25 and / or alkyl methacrylate monomer components. 32. Developer according to claim 31, characterized in that the copolymer of at least one styrene monomer component, at least one alkyl acrylate monomer component and at least one alkyl methacrylate monomer component consists.