JPS63208864A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To obtain a toner which is subjected to electric charge control to negative for a long period of time without losing the intrinsic color of a color material by forming a binder resin of a polyester resin and an electric charge control agent of a specific compd. CONSTITUTION:The binder resin of the toner for developing electrostatic latent images essentially consisting of a coloring agent, the binder resin and the charge control agent is the polyester resin and the charge control agent is the compd. expressed by general formula I. In formula, X denotes -NH2, -N=NCl, -NO2 or -NHNH2, R denotes hydrogen, alkyl group of 1-10C, alkenyl group or phenyl group. This toner exhibits a stable electrostatic charge quantity; in addition, the toner has a smaller environmental fluctuation and a good transfer characteristic. The toner is, therefore, effective in obtaining a large number of copies.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a toner for developing electrostatic images, and more specifically, a specific binder resin is used, and a specific compound is added to the toner as a charge control agent (
The present invention relates to a negatively charged toner for developing an electrostatic image, which contains the toner as a polarity control agent.

[Prior art]

There are two methods for developing an electrostatic latent image formed on an electrophotographic photoreceptor or electrostatic recording material: a method using a liquid developer (wet development method), and a method using a colorant dispersed in a binder resin. A method (dry development method) using a toner or a one-component type or two-component type dry developer in which this toner is mixed with a solid carrier is generally adopted. Although each of these methods has its own advantages and disadvantages, the dry developing method is currently widely used.

By the way, in the above-mentioned toner (developing powder), dyeing such as carbon black or the like is simply added to a binder resin such as polystyrene.
Particles obtained by finely pulverizing pigments into particles of about 1 to 30 μm are used, but since these toners do not have the desired chargeability, an appropriate amount of a charge control agent (polar control agent) is added to them. It is normal to have Typical examples of conventional charge control agents include (i) nigrosine dyes, which impart a positive charge to toner, and (...)
Examples of things that impart a negative charge to the toner include metal-containing dyes such as chromium-containing monoazo complexes, chromium-containing salicylic acid compound complexes, and chlorine-containing organic dyes (copper phthalocyanine green, chlorine-containing monoazo dyes). However, these conventional charge control agents are hexagonal colored substances, have poor compatibility or wettability with the binder resin, or are sublimable, so they do not have good charge control properties over a long period of time. Therefore, it is not suitable for electrophotographic toners, especially color toners.

In addition, although toners containing such conventional charge control agents initially exhibit good development characteristics, they have a short lifespan and are not able to provide stable chargeability (Q/M), such as reverse charging during continuous copying. In addition, they have drawbacks such as poor environmental stability (degree of stability against changes in temperature and humidity) and poor transferability for three or four colors. Regarding these conventional colorants and charge control agents, Japanese Patent Publication No. 48-259
No. 41, Special Publication No. 48-26784, Special Publication No. 49-20
No. 225, JP-A-50-140137, JP-A-50-
142037, JP 50-142038, JP 46-43440, JP 48-30899, JP 49-46423, JP 49-26909, JP 49-51949, JP It is disclosed in publications such as No. 49-134303.

However, in order to control the toner to be negatively charged, chlorinated paraffin, unsaturated polyester, etc. are used as binder resins, and specific polyester resins (non-linear, low melting point aromatic Although it is known to use a reaction product of a group resin and a salicylic acid chelate (Japanese Patent Application Laid-open No. 59-29259), it is difficult to obtain the desired molecular weight as a binder with these resins, and therefore The important thermal properties of a toner (melting properties on the heat roll during fixing) are not obtained, resulting in copies being wrapped around the heat roller, resulting in copy ejection errors, and offset phenomenon, in which the toner image on the paper transfers to the roller surface, making characters unclear. It was recognized that there were disadvantages such as the tendency to cause

〔the purpose〕

The first object of the present invention is to contain a substantially colorless polarity control agent and to use a polyester resin as a binder resin, so that a negative charge can be controlled for a long period of time without impairing the original color of the coloring material. The present invention provides a toner in a component type or two-component type dry developer. The second object of the present invention is to provide an electrostatic charge image that does not generate oppositely charged toner even during continuous copying, always provides clear images without background smear (fog), and has excellent durability and environmental stability. It provides toner for development. A third object of the present invention is to provide a dry color toner that does not cause an offset phenomenon and has excellent full-color multiple transfer properties.

〔composition〕

The present invention provides a toner for developing electrostatic images containing a colorant, a binder resin, and a charge control agent as main components, wherein the binder resin is a polyester resin, and the charge control agent has the following general formula (where X is -NH2, -N=NCfi, -NO,
or -N1 (NH, R represents hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkenyl group, or a phenyl group).

Incidentally, the inventors of the present invention have conducted various studies and studies on the development characteristics, transferability, etc. of dry toners, and have found that polyester resin is used as the binder resin, and a compound represented by the above general formula is used as the charge control agent. The present invention was made based on this knowledge.

In the present invention, polyester resin is used as the binder resin, as described above. Polyester resin has excellent fixing properties, transparency, and gloss, and in color toners, this transparency makes it an excellent resin from the viewpoint of color reproducibility of originals by multicolor overlapping. However, the charging properties are not without problems, and although desired polarity and charging amount can be obtained at constant temperature, the charging properties tend to change due to changes in temperature and humidity.

Because of this, the softening point or melting point is between 50℃ and 150℃.
'C range is preferable.

When a temperature below 50° C. is used, the toner and the toner have poor storage stability during development, harden after a while, and the spent carrier increases, resulting in a shortened developer life. On the other hand, if a temperature of 150° C. or higher is used, the above-mentioned drawbacks are eliminated, but the amount of heat required for fixing increases, the cost of the fixing device increases, and electric power is also required.

A particularly preferred polyester resin is a polyester resin synthesized from a bisphenol diol and a polyhydric carboxylic acid. When this particular resin is used as a binder.

The toner comes to exhibit good negative chargeability.

Specific examples of bisphenol diols here include the following 6(1) Polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane (2) Polyoxyethylene ( 2)-2,
2-bis(4-hydroxyphenyl)propane (3) polyoxystyrene (6)-2,2-bis(4-
hydroxyphenyl)propane (4) polyhydroxybutylene (2) -2,2-bis(4-hydroxyphenyl)propane (5) polyoxypropylene (3) -bis(4-hydroxyphenyl)
Thioether (6) Polyoxypropylene (2)-2,2-bis(4
-cyclohexanol)propane (7) polyoxyethylene (2) -,2,6-dichloro-4-hydroxyphenyl (8) polyoxyethylene (2+ 5) -Py P-bisphenol (9) polyoxybutylene (4) -Bis(4-hydroxyphenyl)ketone (10) Oxyethylene-2,2-bis(4-hydroxyphenyl)propane (11) Oxypropylene-2,2-bis(4-hydroxyphenyl)propane Also, polyhydric carbon Specific examples of acids include maleic acid,
Fumaric acid, glutaric acid, phthalic acid.

Maleic anhydride, fumaric anhydride, phthalic anhydride.

Isophthalic acid, terephthalic acid, trimellitic acid, 1.2
．． Examples include 4-benzenetricarboxylic acid.

Therefore, the polyester resin in the present invention is preferably synthesized from (1) the diol described in (1) above and fumaric acid (obtained by a condensation reaction) and has a softening point of about 100°C.
(2) A compound with a softening point of about 90°C synthesized from the diol of (2) above and terephthalic acid; (2) A compound with a softening point of about 110 synthesized from (5) above, a diol, and isophthalic acid.
'C's.

■Those with a softening point of about 130"C synthesized from the diol of (1) above and fumaric acid and trimellitic acid; ■Those with a softening point of about 130"C;
10), which is synthesized from diol and fumaric acid and has a softening point of about 100°C. The molecular weight of the synthesized polyester resin is suitably about 3,000 to 20,000. Note that this synthesis can be performed by known means.

Here, some production examples of the polyester resin synthesized from bisphenol type diol and polyhydric carboxylic acid are as follows.

(Production Example 1) 7 mol (1162 g) of terephthalic acid, 2 mol of trimellitic acid
Mol (420g), polyoxypropylene (2,2)-
2,2-bis(4-hydroxyphenyl)propane8.
A polyester resin was synthesized by condensing 84 mol (2457 g) of glycerin and 0.16 mol (i 4.7 g) of glycerin using a conventional method. During the synthesis, sufficient care was taken not to distill out or dissipate any of the hexamers, and if they distilled out or dissipated, that amount was added during the synthesis.

(Production Example 2) Using 9 moles of polyoxyethylene (2)-2,2-bis(4-hydroxyphenyl)propane and 9 moles of terephthalic acid as raw materials, they were condensed by a conventional method to synthesize a polyester resin.

(Production Example 3) A polyester resin was synthesized by condensing 9 moles of polyoxypropylene (3)-bis(4-hydroxyphenyl)thioether and 9 moles of isophthalic acid as raw materials by a conventional method.

(Production Example 4) Polyoxypropylene (2,2)-2,2-bis(4-
9 moles of hydroxyphenyl)propane, 7 moles of terephthalic acid
A polyester resin was synthesized by condensing mol and 2 mol of trimellitic acid as raw materials by a conventional method.

In the present invention, a polyester resin is used as a binder, but toners in which a colorant is simply dispersed may have poor chargeability during run (continuous copying) due to differences in the type and dispersibility of the colorant. The toner tends to become unstable and generate reversely charged toner, and as a result, there is a tendency for the image to have background smudges, or for the Q/M value to increase, resulting in only copies with low image density being obtained.

Therefore, the present inventors solved this problem by using the compound represented by the above general formula as a charge control agent. Specific examples of such polarity control agents include P
-toluenesulfonylhydrazide, 2,4-toluenedisulfonylhydrazide, p-toluenesulfonylacetohydracin, and the like.

The toner of the present invention is produced with these compounds as essential components, as well as a colorant and the above-mentioned binder resin (a polyester resin, preferably a polyester resin synthesized from a bisphenol diol and a polyhydric carboxylic acid).

Coloring agents used in the present invention include carbon black, conventional magenta and cyan.

All of the colorants that have been used as colorants for color toners such as yellow can be applied. Specifically, inorganic pigments such as ultramarine, navy blue, silica, alumina, and titanium; azo dyes and pigments, anthraquinone dyes and pigments, phthalocyanine dyes and pigments, quinacridin dyes and pigments, perylene dyes and pigments, indigo dyes and pigments, and bases. Examples include organic dyes and pigments such as synthetic dyes and their lake salts. Two or more of these colorants can also be used in combination. Among these colorants, it is particularly desirable to use carbon black, phthalocyanine dyes and pigments, and benzidine yellow pigments.

Typical examples of phthalocyanin and nin-based pigments are C and I.

Pigment Blue 15, C, 1, Pigment Blue 16
゜C,1, Pigment Blue 17, C,1, Pigment Green 7, C,1, Pigment Green 12, C,1
, Pigment Green 36. Examples of phthalocyanine dyes include C,1, Pigment Green 37, C,R, and Pigment Green 38.
Solvent Blue 25. C, 1, Solvent Blue 5
5, C0■, Solvent Blue 0. Examples include C,1, Direct Blue 25, C,1, Direct Blue 86, etc.

Modified versions of these phthalocyanine dyes and pigments can also be used effectively, and these phthalocyanine dyes and pigments can also be blended with other coloring agents exhibiting blue or green colors.

Representative examples of benzidine yellow pigments include Benzidine Yellow (C, 1, 21090) #2300 Dainichi Benzidine Yellow (C, 1, 21090) Benzidine Yellow GR (C, 1, 21090) Benzidine Yellow FOR (C, 1, 21100) Examples include Sanyo Light Fast Benzine Yellow R (C, 1, 21100) and Benzidine Yellow GE (C, 1, 21 100).

In addition to the above-mentioned components, the toner of the present invention contains various plasticizers (dibutyl phthalate, dioctyl phthalate, etc.), resistance adjusters ( It is also possible to add auxiliary agents such as tin oxide, lead oxide, antimony oxide, etc.).

In addition, it may be possible to substitute a part of the polyester resin that is the binder resin with another resin, or to blend and use the polyester resin with another resin, but in that case, the binder resin It is necessary that the specific polyester resin accounts for 20% by weight or more, preferably 50% by weight or more of the total weight.

Examples of binder resins other than polyester resins include monopolymers of styrene and its substituted products such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymers, and styrene-propylene copolymers. coalescence, styrene-vinyltoluene copolymer,
Styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer,
Styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinylethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene- Styrenic copolymers such as acrylonitrile-indene copolymers; polyvinyl chloride,
Polyvinyl acetate, polyethylene, polypropylene, silicone resin, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenolic resin, xylene resin, aliphatic or alicyclic hydrocarbon resin, aromatic resin petroleum resin,
Examples include chlorinated paraffin and paraffin wax.

The amount of the polarity control agent represented by the above general formula in the toner is about 0.1 to 20 parts by weight, preferably about 0.5 to 10 parts by weight, based on 100 parts by weight of the binder resin. Further, the amount of the colorant in the toner is about 0.1 to 30 parts by weight per 100 parts by weight of the binder resin.

Furthermore, in the present invention, after producing toner particles (5 to 20 um), fine powders such as Tie, Al, O, and 5iO2 are added to the toner particles and the surfaces of the toner particles are coated with the particles, thereby improving the fluidity of the toner. It is also effective to modify the photoreceptor or add zinc stearate, phthalic acid, etc. to prevent deterioration of the photoreceptor.

As described above, the toner of the present invention can be used as a one-component developer (non-magnetic toner) in the NSP process, or can be mixed with a carrier and used as a two-component developer.

As a carrier, iron powder with a particle size of about 50 to 300 μm,
Nickel powder, ferrite powder, glass peas, etc. are used as a core material, and the surface is coated with styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, acrylic ester polymer, methacrylic ester polymer. , silicone resin, polyamide resin, ionomer resin, polyphenylene sulfide resin, or a mixture of these resins is used. In particular, as in the toner of the present invention, a polyester resin is used as a binder resin, and the specific polarity control agent is added thereto, thereby providing a more stable negative charge as desired. When a resin is provided, it is also advantageous to use a silicone resin or a silicone resin in which conductive fine powder is dispersed.

Next, examples and comparative examples will be shown. All parts herein are parts by weight.

Example 1 100 parts of the above polyester resin (1) Part P (top)
Three parts of ensulfonyl hydrazide were melt-kneaded in a hot roll mill, cooled, coarsely ground using a hammer mill, and finely ground using an air jet type pulverizer. The obtained fine powder was classified to obtain toner particles having a particle size of 5 to 20 μm.

Five parts of this toner and 95 parts of carrier iron powder (EFV200/300 manufactured by Nippon Tetsuko Co., Ltd.) having a particle size of 50 to 100 μm were mixed to prepare a two-component dry developer.

Using this developer, 10℃15%RH120℃60%R
When development was carried out using a dry type electrophotographic copying machine (Copy F T4060 manufactured by Ricoh Co., Ltd.) under an environment of H, a clear blue toner image was obtained without fogging, transfer omission, blurring, etc. Furthermore, no deterioration in copy quality was observed even after 20,000 copies were made continuously. Furthermore, 30℃, 9
Although 10,000 sheets were continuously copied in an environment of 0% RH, the image quality remained good without any change.

In addition, when these developers were put into the cyan developing section of a dry full-color electrophotographic copying machine (Ricoh Co., Ltd.'s Rip Color 5ooo) and a full-color image was produced, there were no problems with transfer omissions, transfer unevenness, etc.
A high-quality full-color image without blur or the like was obtained.

Example 2 A developer was prepared in the same manner as in Example 1, except that the toner formulation was changed to 100 parts of polyester resin and 10 parts of carbon black, and the same tests were conducted. Good results were obtained.

Example 3 A developer was prepared in the same manner as in Example 1, except that the toner formulation was changed to 100 parts of the polyester resin (1) and 4 parts of p-toluenesulfonyl hydrazide, and the same test was conducted, and good results were obtained. .

Example 4 Toner formulation: 100 parts of polyester resin (2) 2.4-
A developer was prepared in the same manner as in Example 1, except that 5 parts of toluenesulfonyl hydrazide was used, and the same tests were conducted, and good results were obtained.

The specific charge amount (Q/M) of the toner in these four types of developers was measured using the blow-off method under the following environment.
A result similar to 1 was obtained.

Table 1 Comparative Example A comparative developer was prepared in the same manner as in Example 1, except that the type of polyester resin was changed and the toner material was changed to 100 parts of polyester resin and 10 parts of carbon black, without using a polarity control agent. When (Q/M) was measured, the results were as shown in Table 2.

Table 2 When copying was carried out under the same conditions as in Example 1 using these comparative developers, fogging occurred after 100 consecutive copies, and the image density decreased after 500 consecutive copies, and the fogging became increasingly severe. Become.

It was observed that the developing ability was lost after 1000 copies were made.

In addition, when this developer was put into the cyan developing section of a dry full-color electrophotographic copying machine (Color 5ooo manufactured by Ricoh Co., Ltd.) and a full-color image was produced, there was blurring and uneven transfer even in the early stages of copying. I got a poor quality copy.

〔effect〕

As is clear from the description of the examples, the developer of the present invention is effective in producing a large number of copies because the toner exhibits a stable charge amount, has little environmental fluctuation, and has good transferability. It is something.

Claims (1)

[Claims] 1. A toner containing a colorant, a binder resin, and a charge control agent as main components, wherein the binder resin is a polyester resin, and the charge control agent has the following general formula ▲ mathematical formula, chemical formula , tables, etc.▼ (However, X is -NH_2, -N=NCl, -NO_2 or -NHNH_2, R is hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkenyl group, or a phenyl group.) An electrostatic image developing toner characterized by being a compound.