JPS63113560A - Polymerized toner - Google Patents

Abstract

PURPOSE:To improve a fixing characteristic and image characteristic by incorporating a polymerizable monomer, specific carbon black and low softening point compd. having 40-130 deg.C softening point at specific ratios into a titled toner. CONSTITUTION:This polymerized toner is prepd. by suspension polymn. of the monomer compsn. contg. the polymerizable monomer, the carbon black and the low softening point compd. having 40-130 deg.C softening point. The number average grain size of the carbon black is 40-130mmu and the oil absorption by a DBP method is <=100(cc/100g). The monomer compsn. contains the low softening point compd. at 50-3,000pts.wt. per 100pts.wt. polymerizable monomer. The dispersion of the carbon black in the monomer compsn. is uniformized by using the carbon black limited by such number average grain size and oil absorption, by which the generation of the resin particles without contg. the carbon black is decreased. The low temp. fixability and/or low pressure fixability is improved and the satisfactory image density is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for developing electrostatic images, etc., and in particular, the number average particle diameter and the DBP method (A S TM-D2414-6
Carbon black defined by the oil absorption amount according to 5T) is used as a coloring agent, and a monomer composition consisting of this, a polymerizable monomer, and a low softening point compound with a softening point of 40 to 130"C is suspended. This invention relates to a polymerized toner formed by turbid polymerization.

1 Rin Ai 3 When obtaining a developing toner by a conventional general suspension polymerization method, a monomer composition containing at least a colorant and a polymerizable monomer is mixed into a toner in an aqueous medium or the like. The radicals generated when the pre-added polymerization initiator (or newly added polymerization initiator) is decomposed by heat are used to polymerize the ffU-merizable monomer. The particles coalesce to form a polymerized toner. That is, since this method does not include a pulverization step, the polymerized toner does not need to be brittle, and since its shape is spherical, the polymerized toner has excellent fluidity and has uniform triboelectric charging properties. It has characteristics.

In recent years, efforts have been made to improve the image quality of copied images, increase the speed of copying machines, and/or reduce energy consumption.
#There is a long-awaited toner that can form a good fixed image with lower temperature fixing and/or lower pressure fixing without reducing abrasion properties.

In order to obtain such a toner, attempts have been made to produce a polymerized toner in which a low softening point compound such as a solid paraffin wax that has shape retention properties at room temperature or a low molecular weight polyolefin is included in the monomer composition. ing.

However, it is not always easy to uniformly disperse carbon black in a polymerizable monomer and granulate it to a suitable particle size. When a polymer (lower than the polymerizable monomer) coexists, it tends to become even more difficult to perform the above-mentioned dispersion and granulation uniformly. As a result, the polymerizable monomer and
If a system consisting of carbon black is simply coexisted with a low softening point compound (for example, in an aqueous medium) and granulated,
Problems have arisen in which only toner is formed with uneven dispersion of carbon blur, and carbon black is released from the toner binder, and when trying to improve toner fixing characteristics, image quality such as image density and resolution has to be improved. A decline was inevitable.

The main object of the present invention is to provide a toner with improved fixing properties and image properties, that is, a low-temperature fixing and/or toner with good carbon black dispersibility and providing appropriate image density and high resolution. An object of the present invention is to provide a polymerized toner having low pressure fixing properties.

As a result of intensive research for the above purpose, the inventors discovered that when granulating a mixture system consisting of carbon black and a polymerizable monomer, a large amount of a low softening point compound is coexisted. discovered that the dispersion of the monomer composition as a whole containing all of these components and the dynamic properties (especially viscosity) during granulation are extremely important, and furthermore, in order to achieve these favorable dynamic properties, found that it is essential to use carbon black having specific physical properties and to contain a specific amount of a low softening point compound having a certain softening point.

The polymerized toner of the present invention is based on such knowledge, and more specifically, the polymerized toner of the present invention is a monomer containing at least a polymerizable monomer, carbon black, and a low softening point compound having a softening point of 40 to 130''C. The carbon black has a number average particle diameter of 40 to 300 mp, and an oil absorption amount of 100 (c) by DBP method.
c/l OOg) or less, and the monomer composition contains 50 to 3000 parts by weight of a low softening point compound per 1 oz part of the polymerizable monomer. It is something.

The reason why such an effect is obtained in the toner of the present invention is not necessarily clear, but it is presumed as follows.

That is, when producing toner using the conventional suspension polymerization method,
A mixed system consisting of a polymerizable monomer and carbon black is
Normally, it has a certain degree of viscosity, but if a large amount of a low softening point compound is simply added thereto, the viscosity of the monomer composition increases significantly. For this reason, it is difficult to uniformly disperse carbon black in such a monomer composition, and even if carbon black can be uniformly dispersed, it is difficult to granulate it to a particle size suitable for toner. becomes extremely difficult.

Therefore, when conventional manufacturing methods are used and a low softening point compound is simply allowed to coexist, carbon black particles that do not bind resin or resin particles that do not contain carbon black are generated, resulting in a decrease in the blackness of the toner as a whole and electrical It is presumed that due to non-uniform properties and variations in particle size and specific gravity, a toner with uniform and good fixing properties and image properties cannot be obtained.

On the other hand, when producing the toner of the present invention, carbon black having an average particle size and oil absorption amount according to the DBP method is in a specific range is mixed with a polymerizable monomer and a large amount of a low softening point compound. Even when dispersed in carbon black, the viscosity of the monomer composition made of these components is suppressed within a certain range, so that uniform dispersibility and suitable granulation properties of carbon black are ensured in this monomer composition. estimated to be obtained.

Therefore, according to the present invention, not only is it possible to obtain good low-temperature fixing and/or low-pressure fixing properties of the toner based on the inclusion of a large amount of low softening point compound, but also the carbon black is uniformly and favorably applied to the binder resin. It is presumed that a dispersed toner is obtained and the drawbacks of the conventional polymerized toner described above are eliminated.

According to the present invention, the encapsulation of such a low softening point compound and the high dispersibility of carbon black are the characteristics of a suspended IWJ polymerized toner (for example, deterioration of the binder resin is prevented, and the spherical shape is In addition to the above-mentioned characteristics, in combination with toner particles, it has high fluidity and good charging properties due to friction with carrier particles, etc.
In addition, during development, the toner image can be easily separated from the developer layer, selectively adsorbed to electrostatic images, etc., and the developed toner image can be easily transferred from the surface of the image carrier to a recording medium such as paper. It is possible to obtain a toner which has the following properties and also has excellent storage stability and long life.

The present invention will be explained in more detail below. In the following description, "%" and "part" expressing quantitative ratios are based on weight unless otherwise specified.

1. The polymerized toner of the present invention is a monomer containing a polymerizable monomer, carbon black having a specific particle size and oil absorption amount, and a specific amount of a low softening point compound having a softening point of 40 to 130°C. The composition is subjected to rg, turbid polymerization.

The polymerized toner of the present invention usually has a volume average particle size of about 0.1 to
It has a particle size of about 30 mm and has a softening point of 40 to 100 parts for 100 parts of the polymer produced from polymerizable monomers by suspension polymerization.
It contains 50 to 3000 parts of a compound with a low softening point of 130''C.

As described above, the polymerized toner of the present invention has excellent blocking resistance even though it contains a larger amount of a low softening point compound than conventional polymerized toners. This is because the low softening point compound is well encapsulated in the polymer obtained from the polymerizable monomer, and the low softening point compound is not exposed on the surface of the polymerized toner particles.

In the present invention, whether or not the low softening point compound is substantially encapsulated in the polymer is confirmed as follows. That is, the obtained polymerized toner is melt-kneaded, cooled to solidify, and then pulverized, classified to produce a pulverized powder having the same average particle size as the polymerized toner, and the resistance of this prepared pulverized powder is determined. By comparing the blocking property with the blocking resistance of the polymerized toner used as a raw material, the presence or absence of the above-mentioned encapsulation is confirmed.

This blocking resistance can be measured, for example, by putting 1 to 5 g of a sample into a 100 m container with a diameter of about 5 CI11 and placing it at a temperature of 50°C.
C1 It can be measured by the presence or absence of aggregates with a long particle size of about 1+am or more remaining on a 20 mesh sieve after being left in an environment with a relative humidity of about 60±5% for one day.

In the present invention, a plurality of low softening point compounds may be used in combination, and the softening point (40 to 130°C) and usage amount of the plurality of low softening point compounds to be used are determined (T1.
Wl), (T2, W2)...(T n -1,
W n −1), (Tn, Wn), it is preferable that the following conditions are satisfied.

In addition, use of low softening point compound 41. (W n ) is a value assuming that the added polymerizable monomer is almost Zoo% polymerized to form a polymer combination, and is 50≦W l + W 2 with respect to 100 parts of polymer. +------W
The condition n-1+Wn≦3000 is satisfied. In other words, 100 parts of the polymerizable monomer is 100 parts of the polymerizable monomer that is effectively used to produce the polymer that forms the polymerized toner.
means part. Therefore, taking into consideration the amount dissolved in the aqueous medium and the amount unreacted, 100 parts or more of the polymerizable monomer may be used to produce 100 parts of the polymer.

If the value deviates from the above conditions and becomes 0.05 or less, the amount of the low softening point compound used is too large, resulting in a tendency for the bronking resistance to decrease and the mechanical strength of the polymerized toner to be insufficient. It increases. On the contrary, if the value is 0.8 or more, the degree of improvement in low temperature fixing properties and/or low pressure fixing properties will be reduced.

In the present invention, the carbon black has a number average particle size of 40 to 300 mg (preferably 50 to 200 m
pL), and the DBP method (AS TM02414-6
5T) having an oil absorption of 100 (cc/100 g) or less, preferably 70 (cc/100 g) or less.

When the number average particle size of the carbon black is less than 40 mg, the surface area of the carbon black is large and aggregation tends to occur, so that good dispersibility of the carbon black with respect to the low softening point compound cannot be obtained.

On the other hand, carbon black with a particle size exceeding 300 m has good dispersibility, but the blackness of the carbon black itself is low, so it is not suitable for toner for electrostatic charge development.

As mentioned above, the particle size is somewhat large (40 to 300 m
g) By using carbon black, it is possible to uniformly disperse carbon black even in a mixture of a polymerizable monomer and a low softening point compound, and even in toner obtained by suspension polymerization, carbon black Good dispersibility can be obtained.

On the other hand, the oil absorption amount of carbon black by DBP method is l
When O0 (cc/100 g) is exceeded, the viscosity of the monomer composition mixed with the polymerizable monomer containing the low softening point compound becomes (
(more than when carbon black is not mixed), it becomes difficult to suspend and granulate the monomer composition in an aqueous medium or the like to a particle size comparable to that of a toner. Therefore, due to the relationship between the dispersibility of carbon black and the viscosity of the monomer composition,
The carbon black to be used in the suspension polymerization toner of the present invention is limited by its number average particle diameter and oil absorption amount.

In the present invention, by using carbon black whose number average particle size and oil absorption are limited,
The dispersion of carbon black in the monomer composition becomes uniform, and the generation of resin particles that do not contain carbon black is reduced. Therefore, in the present invention, in particular, the amount of resin particles that do not contain carbon black is generated in a large amount in the past. Even in the case of a toner having a number average particle diameter of 5 μm or less, it is possible to extremely reduce the generation of resin particles that do not contain carbon black.

Commercially available carbon blacks that can be used in the present invention include the following, but are not limited to the following as long as they have the number average particle diameter and oil absorption amount described above.

For example, REGAL S manufactured by Capot Co., Ltd.
RF-5, STERING SO, STERING V, STERING R, STERING NS, C3X-23
8; :I+:+7 Via carbon Nippon prosthetics -be7
(RAVEN) H20, Rahen MT-P, Raven 4
10, Raven 420, Raven 430, Raven 45
0, Chiben 500; Printex manufactured by West German Degussa (
Pr1ntex) 25, Special Black (Spec
ial Black) 100, Printex G: manufactured by Mitsubishi Chemical Industries, Ltd., CF9, #10B, #5B: and the like.

Further, these carbon blacks may be used alone or in combination of two or more in various compositions.

In addition, the amount of carbon black contained in the toner is
The amount is usually 3 to 30 parts (more preferably 5 to 20 parts) per 100 parts of toner binder resin consisting of a polymer of polymerizable monomers and a low softening point compound.

In the toner of the present invention, carbon black, which is a coloring agent, is present during or before the polymerization of the binder polymer, so there is no need to add a pigment to the polymer and melt-knead it afterwards. It is presumed that a toner having excellent properties can be obtained without deterioration due to molecular chain scission during polymer kneading.

Furthermore, since the toner of the present invention is a spherical toner that does not undergo a pulverization process, it has better fluidity than an amorphous toner that has undergone a pulverization process, and the dispersion of carbon black is uniform as described above. Frictional charging properties are also uniform and stable.

When producing the toner of the present invention, the viscosity of the monomer composition containing at least a polymerizable monomer, a low softening point compound having a softening point of 40 to 130'C, and carbon black does not become excessively high, so that it can be dispersed. By dispersing and suspending in a medium, the monomer composition can be easily suspended to a particle size that is equal to or smaller than that of conventional toner particles, and the particle size distribution can also be narrowed. becomes.

Even when the polymerized toner of the present invention has a number average particle diameter of 5 μm or less, electrophotographic images using such a toner have excellent resolution, and the dispersibility of carbon black in the toner is also good. Therefore, sufficient image density can be obtained, resulting in a high-quality image. When the number average particle diameter of the toner is larger than 5 pLm, there is a tendency that scattering occurs and the resolution decreases.

As the polymerizable monomer constituting the binder resin of the toner of the present invention, any polymerizable monomer can be used without particular limitation.

Examples of such polymerizable monomers include styrene, O
-Methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p
-ethylstyrene, 2,4-dimethylstyrene, p-
n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, etc. Styrene and its derivatives; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and imbutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; vinyl acetate, vinyl propionate, Vinyl esters such as vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobutyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, α-methylene aliphatic monocarboxylic acid esters such as phenyl methacrylate, diethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, acrylic 5in-
Butyl, butyl acrylate, propyl acrylate,
Acrylic acid esters such as n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and acrylic phenyl; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl imbutyl ether, etc. Class; vinyl methyl ketone, vinyl hexyl ketone.

Vinyl ketones such as methyl isopropenyl ketone; N
- N-vinyl compounds such as vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone; vinylnaphthalenes; acrylic acid or methacryl M derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

These monomers may be used alone or, if necessary, in combination of two types in various compositions.

On the other hand, the low softening point compound in the present invention refers to a compound having a softening point of 40 to 130" C1, preferably 50 to 1" as measured by the ring and ball method.
20"C. If the softening point is less than 40°C, the blocking resistance of the toner is insufficient;
If it exceeds , the effect of lowering the toner fixing temperature will be small.

Examples of the low softening point compound include paraffin, low molecular weight polyolefin, modified wax having an aromatic group, hydrocarbon compound having an alicyclic group, natural wax, long chain carboxylic acid having a long hydrocarbon chain having 12 or more carbon atoms, An example of this is ester extraction.

Specifically, the low softening point compounds include paraffin wax (Nippon Oil Bag Co., Ltd.), paraffin wax (Nippon Seiro Co., Ltd.), microwax (Nippon Seiro Co., Ltd.), microcrystalline wax (Nippon Seiro Co., Ltd.) PE-130. (Manufactured by Hoechst); Mitsui Hiwax tiop, Mitsui Hiwax 220P, Mitsui Heiwax 660F, Mitsui Hiwax 210F, Mitsui Hiwax 320F, Mitsui Hiwax 410F, Mitsui Hiwax 420P, /' I L/ -/ TT OOX, Highlets T-2O
OX, Highlets T-300X (Mitsui Petrochemical iM
); Vetrogin 80. Vetrogin 100, Vetrogin 1
20, Tuck Ace A-100, Tuck Ace F-10
0, Tac Ace B-60, modified wax JC-141
1. Modified wax JC-2130, modified wax JC-
4020, modified wax JC-1142, modified wax JC-5020 (manufactured by Mitsui Petrochemical); beeswax, carnauba wax, montan wax, and the like. The amount of these low softening point compounds added is 50 to 3000 parts, preferably 50 to 3000 parts, per 100 parts of the polymerizable monomer.
1000 copies.

If the amount of the low softening point compound added is less than 50 parts, the effect of lowering the fixing temperature of the toner will be small, and if it exceeds 3,000 parts, the blocking resistance of the toner will be insufficient.

A polymerizable monomer as described above, carbon black,
The toner of the present invention obtained by suspension polymerization of a monomer composition containing a low softening point compound was observed under a 400x optical microscope, and white toner particles (particles containing no carbon black) were observed. several watts and black toner particles (
When measuring the number of particles B (particles containing carbon black), the value of (hereinafter referred to as "carbon black dispersion rate") is 8.
It is preferably 0% by number or more, more preferably 85% by number or more.

In obtaining the toner of the present invention, as the polymerization initiator used to polymerize the above-mentioned monomer composition, any chemical used in ordinary polymerization reactions can be used without particular limitation.

The polymerization initiator used in the present invention is soluble in the polymerizable monomer, and is in the amount range normally used (monomer l.

It is preferable that the polymerization initiator (2 to 5 parts) has the property of being well dissolved in the polymerizable monomer.

As a polymerization initiator that can be used in the present invention, 2゜2'-azobis-(2,4-dimethylvaleronitrile), 2.2'
-7zobisisobutyronitrile, 1.1'-azobis(
cyclohexane-1-carbonitrile), 2.2'-7
Zobis-4-methoxy-2,4-dimethylvaleronitrile, other azobisinbutyronitriles (A I B
Azo or diazo polymerization initiators such as N); benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxy carbonate.

Examples include peroxide-based polymerization initiators such as cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide. Two or more of these polymerization initiators may be used in combination.

These initiators generally range from about 0.1 to 10% (more preferably 0.1 to 10%) of the total weight of monomers in the monomer composition.
~5%) is sufficient.

Alternatively, a toner containing a crosslinked polymer may be obtained by polymerizing the monomer composition in the presence of the following crosslinking agent.

Examples of such crosslinking agents include divinylbenzene, divinylnaphthalene, divinyl ether, divinyl sulfone, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate.

Diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexane gelicold dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2' −Bis(
4-methacryloxyjethoxyphenyl)propane, 2
．． 2'-bis(4-acryloxyjethoxyphenyl)
Common crosslinking agents such as propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, dibromneopentyl glycol dimethacrylate, diallyl phthalate, etc. can be used as appropriate.

If the amount of these crosslinking agents used is too large, the monopolymer becomes difficult to dissolve or melt, resulting in poor fixing properties. Also, if the amount of crosslinking agent used is too small, properties such as blocking resistance and durability necessary for toner will deteriorate, and during hot roll fixing, some of the toner will not completely adhere to the paper and will adhere to the roller surface. , it becomes difficult to prevent the offset phenomenon of transfer to the next paper.

Therefore, these crosslinking agents are preferably contained in an amount of 0.001 to 15 parts (more preferably 0.1 to 10 parts) in 100 parts of the monomer composition.

In the toner of the present invention, a charge control agent, various coloring agents, and fluidity modifiers may be added as necessary.The charge control agent and fluidity modifier are mixed with toner particles (external addition). Examples of charge control agents that may be used include metal-containing dyes and nigrosine, and examples of fluidity modifiers include colloidal silica and total fatty acid salts. In addition, fillers such as calcium carbonate and finely divided silica may be added to the toner in an amount of 0.5 to 20% by weight for the purpose of increasing the amount.Furthermore, it prevents toner particles from coagulating with each other and improves fluidity. For this purpose, a fluidity improver such as fine Teflon powder may be added.

In addition, when a low softening point compound is used such as a hydrocarbon compound or Karunahawa wax that improves the release property during hot roll fixing 1
For example, hydrocarbon compounds are hydrophobic and have a low molecular weight, so they cannot be mixed with polymers produced by polymerization.
Compared to polar polymers, it is less likely to appear on the surface and is forced into the interior of the polymerized toner. As a result, even if a large amount of a low softening point compound is contained, the toner has excellent durability and blocking resistance because it is encapsulated.

During fixing, this low softening point compound comes out from inside the toner and significantly improves fixing properties and offset properties. In this case, the hydrocarbon compound is thought to function as a plasticizer, a lubricant, and an oil.

In addition, if a polymer, copolymer, or cyclized rubber having a polar group is added as an additive during polymerization of the monomer, a preferable polymerized toner can be obtained. In this case, a monomer composition containing a polar group-containing polymer, copolymer, or cyclized rubber is suspended in an aqueous phase in which a dispersant having an opposite charge to the polar polymer is dispersed, and polymerization is carried out. It is preferable to let

That is, the cationic or anionic polymer, copolymer or cyclized rubber contained in the monomer composition is combined with the oppositely charged 7-ionic or cationic dispersant dispersed in the aqueous medium and the toner. The particles are electrostatically attracted to each other on the surface, and the dispersant covers the particle surface to prevent particles from coalescing.
In addition to stabilizing the toner, the added polar polymer and the like gather on the surface layer of the toner particles, forming a kind of shell-like form, and the resulting particles become pseudo-capsules.

In addition, when a relatively high molecular weight polar polymer, copolymer, or cyclized rubber is used, polymerized toner particles are provided with excellent properties such as blocking resistance, developability, and abrasion resistance. Possible polar polymers (including polar copolymers)
and counterloadable dispersants are illustrated below. The polar polymer has a weight average molecular weight of 5.000 to 50 as measured by GPC (gel permeation chromatography).
A value of 0.000 is preferably used.

(1) Examples of the cationic polymer include polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl acrylate, or copolymers of styrene, unsaturated carboxylic acid esters, etc., and the nitrogen-containing monomers. be.

(2) Examples of anionic polymers include nitrile monomers such as acrylonitrile, halogen-containing monomers such as vinyl chloride, unsaturated carboxylic acids such as acrylic acid, unsaturated dibasic acids, and unsaturated dibasic acids. There are anhydride polymers of

(3) As an anionic dispersant, Aerosil #200
, #300 (manufactured by Nippon Aerosil Co., Ltd.) and other colloidal silicas.

(4) As the cationic dispersant, aluminum oxide,
Examples include hydrophilic positively charged silica fine powder such as magnesium hydroxide and aminoalkyl-modified colloidal silica.

An anionic cyclized rubber may be used instead of the above polar polymer.

In addition, the monomer composition contains chain transfer agents such as lauryl mercaptan, various plasticizers, charge control agents, magnetic particles, modifying polymers, prepolymers, oligomers, conductive particles, organic and inorganic It may also contain pigments, dyes, etc.

In the present invention, the suspension polymerization reaction is usually carried out with a degree of polymerization of 50
The upper temperature limit is set in consideration of the decomposition rate of the polymerization initiator. If the set polymerization temperature is too high, the polymerization initiator 1 will be rapidly decomposed, which is not preferable.

Therefore, the softening point temperature of the low softening point compound used is high (
(usually 70°C or higher), granulation at a temperature suitable for one polymerization cannot be carried out because the viscosity of the monomer composition increases, so the temperature of the dispersion medium (e.g., aqueous dispersion medium) is adjusted to above this softening point. After first granulating the monomer composition without adding a polymerization initiator, the temperature of the dispersion system is lowered to a temperature range below the upper limit temperature suitable for polymerization, and then the polymerization system (e.g. Special techniques are required to add the polymerization initiator (in an aqueous medium).

Suspension and granulation of the monomeric MI product in a dispersion medium.

For example, it is preferable to perform as follows. That is,
A monomer composition is obtained by uniformly dissolving or dispersing a polymerizable monomer (additives, etc. as necessary) in a dispersion of a colorant (carbon black) and a low softening point compound. The monomer composition is mixed with a dispersion medium that is substantially incompatible with the monomers (for example, at a temperature lower than the polymerization temperature) containing 0.1 to 50% by weight of a suspension stabilizer (for example, a poorly soluble inorganic dispersant). The monomer droplets are dispersed in an aqueous medium heated to a temperature of 5° C. or above, preferably 10" size, - generally less than 30 p-m (
For example, the stirring speed, sowing temperature, and temperature of the aqueous medium are adjusted so that the volume average diameter is 0.1 to 20 grn. Thereafter, the temperature of the dispersion medium is lowered to the polymerization temperature while stirring is carried out to the extent that sedimentation of the particles is prevented so that this state is substantially maintained by the action of the dispersion stabilizer.

Polymerization temperature is 50°C or higher, preferably 55-80°C1
Particularly preferably, a substantially water-insoluble polymerization initiator is added to the polymerization system (for example, in an aqueous medium) at a temperature of 60 to 75° C. with stirring, and after the reaction is completed, the produced toner is The particles are recovered by a suitable method such as washing, filtration, decantation, centrifugation, etc. and dried to obtain a polymerized toner. In the suspension polymerization method, usually
It is preferable to use 200 to 3000 parts of water as the aqueous dispersion medium per 100 parts of the polymerizable monomer.

Also suitable stabilizers, such as polyvinyl alcohol,
Gelatin, methylcellulose, methylhydropropylcellulose, ethylcellulose, sodium salt of carboquine methylcellulose, polyacrylic sauce and their salts, starch, gum alginate, zein, casein,
Tricalcium phosphate, talc, clay, silicic acid, barium sulfate, calcium sulfate, barium carbonate, magnesium carbonate, bentonite, aluminum hydroxide, ferric hydroxide,
Titanium hydroxide, thorium hydroxide, metal oxides, etc. may be contained alone or in combination of two or more in an aqueous medium to an extent that does not adversely affect the method for producing the toner of the present invention. Also good.

Further, in order to uniformly disperse the inorganic dispersant, a surfactant may be used to the extent that it does not adversely affect the production method of the present invention, and this promotes the intended action of the dispersion stabilizer. It is for the purpose of

Specific examples include sodium dodecylbenzenesulfonate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate, sodium allyl-alkyl-polyethersulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate,
Potassium stearate, calcium oleate, 3.3
-Disulfone diphenyl urea-4,4-diazo-bis-
Sodium amino-8-naphthol-6-sulfonate,
Examples include ortho-carboxybenzene-azo-dimethylaniline, 2,2,5.5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-disulfone sodium, and others.

In addition, since 7-mer, which is easily soluble in water, undergoes emulsion polymerization simultaneously in water and contaminates the resulting suspension polymer with small emulsion polymer particles, water-soluble polymerization inhibitors, such as metal salts, are added to the water. It is also possible to prevent emulsion polymerization in the phase, and it is also possible to add glycerin, glycol, etc. to the water in order to increase the viscosity of the aqueous medium and prevent coalescence of particles during polymerization. or,
Na0 content due to decreased solubility of easily soluble monomers in water,
It is also possible to add salts such as KCJI, Na2 SO4, or Brønsted acids such as hydrochloric acid to the aqueous medium to increase the ionicity of the polar groups.

The polymerized toner of the present invention can be applied to known electrostatic image development methods. One-component development methods using magnetic toner such as , jumping development method: Powder cloud method and fur brush method; Toner is held on a toner carrier by electrostatic force and transported to the development section, where it is developed. Magnetic-component development method: Applicable to electric field curtain development method in which toner is transported to a developing section and developed by an electric field curtain method.

Color difference 1 As described above, according to the present invention, a monomer composition containing a polymerizable monomer, a specific carbon black, and a low softening point compound is provided! i Polymerization provides a polymerized toner that has improved low-temperature fixing properties and/or low-pressure fixing properties, has good carbon black dispersibility, and provides images with sufficient image density.

The toner of the present invention can provide images with even better resolution by granulating the monomer composition with a relatively low viscosity to produce a toner with a smaller number average particle diameter than conventional toners. .

Further, the present invention will be described in more detail below based on Examples.

A monomer composition was prepared by mixing for 4 hours. 254 parts by weight of the obtained monomer composition was mixed with 20 parts by weight of amine-modified silica (100 parts by weight of Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) treated with 5 parts by weight of aminopropyltriethoxysilane. , into an aqueous medium heated to 85°C containing 25 parts by weight of O, 1 Njll liquor and 1200 parts by weight of distilled water, while being stirred by a TK homomixer, and for 15 minutes after being added. The mixture was stirred at 0OOvp- to perform 1-dispersion granulation.

After granulation, lower the liquid temperature to 60°C and add 2.2% as a polymerization initiator.
'-azobis=(2,4-dimethylvaleronitrile)3
Parts by weight and 1 part of 2,2'-7zobisisobutyronitrile
．． 5 parts by weight were added to the aqueous medium and stirred for 30 minutes.

Furthermore, the stirring was changed to paddle blade stirring, and the mixture was stirred at 60° C. for 10 hours to complete the polymerization.

The obtained aqueous medium containing the polymerized toner is cooled and dehydrated,
After washing with a sodium hydroxide solution to dissolve and remove the amino-modified silica, it is further washed with water, dehydrated, and dried (classified as necessary to remove fine particulate unnecessary component particles), with a number average particle size of 5. A polymerized toner of #Lm (measured with a Coulter counter using 100 pm 7 percher) was obtained.

The resulting polymerized toner contained about 180 parts by weight of paraffin wax based on 100 parts by weight of polystyrene. Further, the obtained toner did not cause blocking even when left in an environment of 50° C. for one day. From this, it was found that paraffin wax was encapsulated inside the polymerized toner particles.

Further, the obtained toner was observed with an optical microscope to measure the dispersion rate of carbon black.

10 parts by weight of the polymerized toner obtained above, 0.1 parts by weight of zinc stearate powder, hydrophobic silica (Aerosil R
972, manufactured by Nippon Aerosil Co., Ltd.) and insulating carrier particles (triiron tetroxide 75) with an average particle size of 40 lm.
A developer was prepared by mixing 90 parts by weight of Form 1&) with 25 parts by weight of the epoxy resin, and development was carried out under the following conditions.

The developing device shown in the drawing was used. Image carrier l
had a selenium photoreceptor 12, the peripheral speed of the image carrier 1 was 100 am/sec, and the highest potential of the electrostatic image formed on the image carrier 1 was +750V. In addition, the outer diameter of the sleeve (developer carrier) 2 is 20 mm, its circumferential speed is lOO■IIl/sec, and the N and S of the magnetic roller 3 are
The magnetic flux density in the vertical direction on the surface of the pole sleeve is 1000 Gauss, the thickness of the developer layer is 200 μm, the gap between the sleeve 2 and the image bearing weight is 300 μm, and the bias voltage applied to the sleeve is a DC voltage component +200V and an AC voltage component 3. 0KH
z and 1400 Vpp.

The electrostatic charge latent image is well developed, and the developed toner image is electrostatically transferred to plain paper, and the toner image on the plain paper is transferred to l O
When the above-mentioned image was fixed by passing it through a heat-pressing roller fixing device consisting of a fixing roller having a silicone rubber surface layer under pressure of Kg/cTxl and a pressure roller, with a tongue width of 7 cm and a paper advancing speed of 150 cm/sec), Toner image is 100
Good fixing was achieved at a fixing temperature of 0 (fixing roller surface temperature).

In addition, in the developing device shown in the drawing, toner T having an external additive is used.
is quantitatively supplied to the lower chamber by the supply roller 8 and the elastic member 7, and is mixed with the carrier to form the developer 4. A DC bias is applied to the sleeve 2 containing the magnet roller 3 and the doctor blade 10 from a DC bias power supply 5, and an AC bias is applied from an AC bias power supply 6. As the sleeve 2 rotates in the direction A, the developer 4 is conveyed and used to develop an electrostatic latent image on an image carrier 1 consisting of an aluminum cylinder 11 and a selenium photoreceptor 12. The developer layer regulating member 9 serves as an outer wall of the developing device.

The optical reflection density ([) 1Ilax) and resolution of the image obtained by the above development and fixing are shown in Table 2 below.

Paraffin wax 140''F (softening point 6
0°C) 500 parts by weight, and paraffin 155@(
A polymerized toner with a number average particle size of 5 tiles was prepared in the same manner as in Example 1, except that part by weight of Zoooo (softening point: 69°C) was used, and the temperature of the aqueous medium during dispersion and granulation was set to 90'C. generated. The obtained polymerized toner was made of polyethylene 10Qf
It contained about 125ii parts of paraffin wax per i part of paraffin wax. A toner image on plain paper obtained in the same manner as in Example 1 was fixed at a fixing temperature of 130°C using the same fixing device as in Example 1.
A good fixed image was obtained when the image was fixed. The Dmax, resolution, and carbon dispersion rate of this toner are also shown in Table 2 below.

A monomer composition was prepared by mixing for 4 hours.

To 254 fii parts of the obtained monomer composition, 2°2'-7
A mixture of 6 parts by weight of zobis(2,4-dimethylvaleronitrile) and 3 parts by weight of 2,2'-azobisisobutyronitrile was added to amine-modified silica (ioo-Z-double part of Aerosil 200). treated with 5 parts by weight of aminopropyltriethoxysilane) 20 parts by weight and 0
．． The mixture was poured into an aqueous medium heated to 60°C containing 5 parts by weight of 1N salt distilled liquor and 1200 parts by weight of distilled water while being stirred by a TK homo mixer, and heated at 10,00 O for 15 minutes after the addition.
The mixture was dispersed and granulated by stirring at rpm.

Furthermore, stirring was changed to paddle blade stirring and stirring was carried out at 60°C for 10 hours to complete the polymerization.Next, post-treatment was carried out in the same manner as in Example 1, resulting in polymerization with a volume average particle size of 5.3 m. Got toner. The obtained polymerized toner was made of polystyrene 10. O
It contained about 20 parts by weight of paraffin wax based on the amount of fi.

10 parts by weight of the polymerized toner obtained above, 0.1 parts by weight of zinc stearate powder, hydrophobic silica (7Erosyl R
972, manufactured by Nippon Aerosil Co., Ltd.) and 90 parts by weight of carrier particles having an average particle size of 40 tom (same as in Example 1) were mixed to prepare a developer. rlJ
Using the prepared developer, development, transfer, and fixing were carried out in the same manner as in Example 1, and a practically usable fixed image was obtained at a fixing temperature of 190° C. or higher. Incidentally, when the fixing roller temperature was 100° C., 120° C., or 140° C., the toner was insufficiently fixed, and no fixed image that could be used for practical use was obtained.

Stop J mouth The monomer composition was prepared by mixing for 4 hours.

0.5 ff of 2゜2'-azobis-(2,4-dimethylvaleronitrile) was added to 254 parts by weight of the obtained monomer composition.
x parts, and 2,2'-azobisisobutyronitrile 0
．． Amino-modified silica (100 fi parts of Aerosil 200 treated with 5 parts by weight of aminopropyltriethoxysilane) 202
Parts of Tr, 25 parts by weight of 0,IN hydrochloric acid, and 120 parts of distilled water
0 parts by weight of an aqueous medium heated to 60°C, while stirring with a TK homomixer, and after 15 minutes 1
'1lJ10. One-dispersion granulation was performed by stirring at OOO rpm.

Furthermore, the stirring was changed to paddle blade stirring and stirred at 60°C for 10 hours to perform polymerization.Next, when post-processing was carried out in the same manner as in Example 1, there were many particles with a particle size of 100 μm or more, and they remained as they were. Therefore, it could not be put to practical use as a toner for developing electrostatic images. Therefore, although particles having a number average particle diameter of 5 μm were obtained by classification, the blocking resistance was insufficient.

In place of the carbon black C5X-238 used in Example 1, Columbia Carbon Nippon Hoso RAVEN 14 was used.
(Particle size: 59 mμ, oil absorption amount by DBP method: 111 (c
c/100g) ) 12 g was used, and a toner with a number average particle size of 8 Lulo was obtained. etc.), a toner having the same particle size as Example 1 could not be obtained because the particle size of the monomer composition was high. Using the toner obtained above, microscopic observation and image formation were performed in the same manner as in Example 1 (fixing temperature was 100°C).
, (see Table 1.2) "Blood Comparison 1" Instead of the carbon black C3X-238 used in Example 1, Pr1ntex 35 (particle size 3
Oil absorption amount by DBP method: 43 (cc/10
When the same process as in Example 1 was carried out except that 12 g (0 g) was used, a toner having an average number of 5 ILrB was obtained. Using this toner, microscopic observation and image formation were performed in the same manner as in Example 1. (Fixing temperature was 100''C) (See Tables 1 and 2) The results obtained are shown in Tables 1 and 2 below.

Table 2 1) Coulter counter (aperture diameter loo g
) Measured value 2) Measured value after being left in an oven for 24 hours at a temperature of 50° C. and a humidity of 50% The measurement of the above "fixing temperature" was carried out as follows. Method〉 1〉 Carry out at a paper speed of 15017 seconds and a paper temperature of 25±1°C.

2) Set the pressure of the fixing device to l　OKg/cm''.

3] Under the pressure of this fixing device, the fixing roller surface temperature is
The temperature is increased from 50°C to 55°C, 60°C, and 65°C in 5°C increments to fix the image.

4) Test the fixed image using the Kosuri test method.

That is, 5 sheets of Silpon crepe paper (20g/rd) manufactured by H-Guru Co., Ltd.) were stacked with the photosensitive surface facing down, and the photosensitive surface was pressed against the image surface to be tested with a pressure of 40g/crrl.
The tear of the crepe paper is rubbed in the grain direction (indicating the direction of the fibers) 5 times back and forth, and the ratio of the density after the test to the density before the test ((density after rubbing/density before rubbing) x 1oO) is determined as the fixability. shall be.

5) The lowest temperature at which the fixability is 80 or higher is defined as the fixing temperature.

Looking at the results shown in Tables 1 and 2 above, it is clear that the toner of the present invention has excellent blocking resistance and low-temperature fixing properties, and also has good image density and resolution due to the high dispersibility of carbon black. You can understand that it gives a nice image.

[Brief explanation of the drawing]

The drawing is a sectional view schematically showing a developing device used in Examples and Comparative Examples of the present invention. 1...Photosensitive drum 2...Sleeve 3...Magnetic roller 4...Developer 5.6...Development bias power supply 10...Doctor blade

Claims (1)

[Claims] 1. At least a polymerizable monomer, carbon black,
A polymerized toner obtained by suspension polymerizing a monomer composition containing a low softening point compound having a softening point of 40 to 130°C, wherein the carbon black has a number average particle size of 40 to 300 mμ.
, the oil absorption amount by DBP method is 100 (cc/100g) or less, and the monomer composition has a polymerizable monomer of 10
A polymerized toner characterized by containing 50 to 3000 parts by weight of a low softening point compound based on 0 parts by weight. 2. The polymerized toner according to claim 1, having a number average particle diameter of 5 μm or less.