JPH06186777A - Positively charged red developer for electrostatic charge development - Google Patents

Abstract

PURPOSE:To provide the developer which has sufficient offset resistance at the time of fixing, lowers the lower limit temp. difference for fixing and does not generate sticking around a fixing roll by incorporating a binder resin, release agent, charge control agent and coloring agents which are respectively specific into the developer. CONSTITUTION:This developer contains at least a polyester resin and a styrene acrylic resin having 60 to 75 Tg and 0% toluene insoluble-content as the toner binder resin and contains a free fatty acid carnauba wax, etc., having <=5 acid value as the release agent. Further, the developer contains a quaternary ammonium salt copolymer compd.. having the constitutional units expressed by formulas I, II and 65:35 to 97:3 ratio of the formula I and the formula II as the charge control agent. The developer contains C.I. Pigment Red 48; n(n=1 to 4), etc., as the coloring agents. In the formulas, I, II, R1, R2 denote a hydrogen atom or methyl group; R3 denotes an alkylene group; R4 to R6 denote an alkyl group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic two-component developer used in electrophotography, electrostatic printing and the like.
Particularly in the heat roll fixing method, fixing is sufficiently performed at a lower temperature,
Further, the present invention relates to a two-component red developer for electrophotography, which does not affect developer properties such as charging properties even when used for a long period in a developing device.

[0002]

2. Description of the Related Art In the case of an electrostatic image formed by electrophotography, electrostatic printing, electrostatic recording, etc. in the case of a dry method, it is generally developed with a dry toner containing a binder resin and a colorant as main components,
Transferred and fixed on copy paper. Although there are various methods for fixing a toner image, the heat roller fixing method is widely used because of its high thermal efficiency and high-speed fixing. When performing high-speed fixing by such a heat fixing method, the toner is required to have good low-temperature fixability (or often when the lower limit fixing temperature is low), and for this reason, a binder resin having a low softening point is used. It However, when a low softening point resin is contained in the toner, a part of the toner image adheres to the surface of the heat roller at the time of fixing, and this transfers to the copy paper to cause scumming, a so-called offset property and winding phenomenon (particularly It often occurs when the heat roller temperature is low). Therefore, as means for preventing these phenomena, JP-A-51-143333 and JP-A-57-148752.
No. 58-97056 and No. 60-247250, solid silicone varnish, higher fatty acid,
It has been proposed to add higher alcohols, various waxes, etc., but none of them is known to exhibit sufficient offset resistance and wrapping resistance while maintaining good low-temperature fixability. Specifically, conventional polyolefin waxes such as low molecular weight polypropylene have good offset resistance, but low temperature fixability is not sufficient. Moreover, since the conventional release agent has poor dispersibility in the binder resin, the release agent is often detached from the toner and adheres to the photoconductor or the developing sleeve during development, so-called filming. Contamination also occurred, and it was difficult to form a stable and high-quality image for a long period of time.

Further, since the colorant used has insufficient dispersibility in the binder resin, the same phenomenon is likely to occur, and at the same time, the colorant itself has a charging property, so that the toner has a stable and appropriate charge amount. Was difficult to obtain.

On the other hand, as a binder resin for toner, a styrene resin has been often used conventionally. However, although this toner is excellent in stability of charge amount in use over time and in the environment, it has many problems such as incapability of being fused to a vinyl chloride mat and fixing at low temperature.

Therefore, in recent years, polyester resin has been used instead of styrene resin. Since the SP values of the polyester resin and the plasticizer in the vinyl chloride mat are distant from each other, fusion to the vinyl chloride mat can be prevented, and good fixing can be achieved at a low temperature without causing an offset phenomenon.

However, the polyester resin is more expensive than the styrene-based resin, and the resin itself has a strong negative charging property, so that it is difficult to use the resin for the positive charging toner, and it is used for the negative charging toner. In this case, since it depends on the chargeability of the polyester resin itself, it is difficult to make the toner have a desired charge amount.

As a method of improving the latter drawback, there is a method of adding a charge control agent. Nigrosine dyes, quaternary ammonium salts, and the like are used as positive charge control agents in practical use. In particular, the nigrosine dye has been widely used from the past because it is inexpensive as a high-charge imparting member. These various charge control agents have made it possible to sufficiently increase the triboelectric charge amount. However, the problem that the charge amount of the developer greatly varies depending on the use environment and the like is still unsolved. Further, since the nigrosine dye itself is not colorless, it is not suitable for color toner, and there is a drawback that a clear color image cannot be obtained.

Generally used as a carrier material for a two-component developer is a metal oxide such as magnetite or ferrite, which has a smaller apparent density than an iron powder carrier and is lighter in weight as a developer. Since it is possible, when the developer is stirred in the developing device, there is an advantage that the stirring resistance becomes small. In addition, the residual magnetic flux density is lower than that of the iron powder carrier, the coercive force is small, and the area of the hysteresis loop is small as a result, and the initial characteristics are always maintained for magnetization reversal and magnetization history. It has characteristics. Also magnetite,
Since ferrite and the like are oxides, they are chemically stable and are unlikely to undergo chemical changes due to ozone, NO _x, etc. generated in the copying machine.

However, such oxide carriers such as ferrite and magnetite also collide between developer particles due to high-speed development or copying of a large number of sheets, or mechanical collision such as collision between developer particles and a developing machine, or these collisions. Due to the heat generated by the action, a toner film is formed on the surface of the carrier, so-called spent is formed, the charging characteristics of the carrier are deteriorated with use time, and toner scattering, background fog, etc. occur.

In order to prevent such spent formation,
Conventionally, a method of coating various resins on the surface of core particles has been proposed, but a satisfactory method has not been obtained yet. For example, a carrier coated with a resin such as a styrene-methacrylate copolymer or a styrene polymer has excellent charging characteristics, but has a relatively high critical surface tension on the surface, and therefore, after repeated copying, a spent state may occur. The life as a developer was not so long. Further, a carrier coated with a tetrafluoroethylene polymer is unlikely to cause spent of the toner, but since the tetrafluoroethylene polymer is located on the most negative side in the triboelectrification series, the toner is negatively charged. If it does, it cannot be used.

On the other hand, a method of coating the surface of the carrier with a material having a low surface energy such as silicone has been devised, but the carrier coated with such a resin also has the following two drawbacks. I was seen. The first drawback is that when used as a developer due to the high electric resistance of the carrier, the image quality is inferior due to the edge phenomenon and charge accumulation phenomenon. The second drawback is friction between the developer particles due to high-speed development and copying of many sheets,
Or, due to mechanical friction such as friction between the developer particles and the developing machine, the coat film of the carrier is abraded over time,
That is, the charging property is deteriorated.

The first drawback of this coated carrier can be remedied by dispersing a conductive substance in the coating layer. That is, when the carrier is given a certain degree of conductivity, the carrier acts as a developing electrode, and the development is carried out in a state where the developing electrode and the surface of the photoconductor to be developed are in close contact with each other. Even a large area of black area is faithfully reproduced as the original. Conventionally, carbon, tin oxide, etc. have been used as such a conductive material, but when such a conductive material is dispersed in the coating layer of the carrier, the following drawbacks occur.

Generally, the toner and the carrier are charged when they come into contact with each other. In this case, when the electric resistance of the carrier becomes small, the charge generated in the toner is attenuated through the carrier, and the charge amount cannot be maintained. Further, there is a problem that the conductive material is separated from the coating layer due to use over time and the charge amount changes. In order to solve this problem, in JP-A-62-182759, carbon is treated by treatment with aminosilane, amino-modified silicone oil or the like, but the problem is that the cost increases due to an increase in treatment steps. It was

[0014]

The object of the present invention is to have sufficient offset resistance at the time of fixing, to have a low fixing lower limit temperature, and to prevent winding around a fixing roll. There is no toner scattering, and even with continuous use, an image with high fidelity equivalent to the initial image is obtained,
An object of the present invention is to provide an inexpensive positively charged red developer suitable for high-speed fixing.

Still another object is that the image quality is not deteriorated due to the edge phenomenon and the charge accumulation phenomenon, and the carrier coating layer is not peeled off even when it is continuously used, and the conductive fine powder is not separated, so that the triboelectrification is stable and the initial stage is stable. It is an object of the present invention to provide a positively chargeable red developer capable of obtaining an image having high fidelity equivalent to that of the image.

[0016]

As a result of intensive investigations, the present inventors have found that a carrier coated with a silicone resin and a toner containing a binder resin, a release agent, a colorant, and a charge control agent as a main component. In the constituted electrophotographic developer, a polyester resin and a T resin are used as a binder resin of at least the toner.
g containing 60-75 and styrene-acrylic resin having a toluene insoluble content of 0%, and a free fatty acid type carnauba wax having an acid value of 5 or less and / or a montan ester wax and / or an acid value of 10 as a releasing agent. To 30 of oxidized rice wax, a compound of the following (a) as a charge control agent, and a colorant of
C. I. Pigment Red 48: n (n = 1 to 1
4) and C.I. I. Pigment Red 81: 1
It has been found that a red developer capable of improving the above-mentioned drawbacks can be obtained by additionally containing (according to the name described in the color index third edition).

(A) It has structural units represented by the following structural formulas (I) and (II), and the ratio of (I) to (II) is 65: 3.
A quaternary ammonium salt copolymer compound of 5 to 97: 3,

[0018]

[Chemical 3]

(In the above formula, R ¹ represents a hydrogen atom or a methyl group)

[0020]

[Chemical 4]

(In the above formula, R _{2 to} R ₆ each represent the following) R ₂ : hydrogen atom or methyl group R ₃ : alkylene group R ₄ , R ₅ , R ₆ : alkyl group) When only a polyester resin is used as a binder, the environmental stability is poor and the price is high. Therefore, by using a styrene-acrylic resin having a Tg of 60 to 75 and a toluene insoluble content of 0% as a subresin,
It has been found that it is possible to obtain a toner that does not impair the use when only a polyester resin is used. Tg
Is less than 60, the storage stability is deteriorated, and the Tg is 7
If it is larger than 5, there is a drawback that the fixability is deteriorated. It was also found that the content of toluene insoluble is 0%, and the pulverizability at the time of toner production is improved, which is economically advantageous.

Further, it has been found that particularly when the styrene / acrylic resin is a styrene-butyl acrylate copolymer or a mixture of polystyrene and butyl acrylate, the fusion property to a vinyl chloride mat can be improved. In addition, the present invention has found that the inclusion of a phthalic acid-based plasticizer (phthalic acid ester) in the toner can prevent the toner from being fused to the vinyl chloride mat.

Further, according to the present invention, by coating the surface of the core particles with the silicone resin containing the conductive fine powder and the silane coupling agent, the advantages of the conventional silicone resin coated carrier can be maintained as well. By imparting conductivity to the carrier, the phenomenon of charge accumulation in the carrier, peeling of the coating layer, and detachment of the conductive fine powder are effectively suppressed.

Further, in particular, since the silane coupling agent is an alkoxysilane coupling agent containing chlorine having a functional group showing a negative polarity in a charge series with the toner constituent component, the toner is easily charged to the positive polarity, It has been found that a long-life developer can be obtained because a stable positive charging property can be supplied to the toner.

Next, the materials used for the toner of the present invention will be described in detail. The polyester resin used as a binder in the present invention is obtained by polycondensation of alcohol and carboxylic acid, and the alcohol used is polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol. 1,4-butanediol, neopentyl glycol, 1,4-butenediol and other diols, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, poly Examples thereof include etherified bisphenols such as oxypropyleneated bisphenol A, divalent alcohol simple substances obtained by substituting them with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, and other divalent alcohol simple substances. It is possible.

Examples of the carboxylic acid used to obtain the polyester resin include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, Succinic acid, adipic acid, sebacic acid, malonic acid, divalent organic acid monomers obtained by substituting them with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, their acid anhydrides, and lower alkyl esters. Examples thereof include a dimer of linoleic acid and other divalent organic acid monomers.

In order to obtain the polyester resin used as the binder resin, not only the following polymers containing only bifunctional monomers but also polymers containing components containing trifunctional or higher polyfunctional monomers are used. Is also suitable. Examples of such a trifunctional or higher alcohol monomer which is a polyfunctional monomer include, for example, sorbitol, 1,2,3,6-hexanetetrol, 1,4-salbitan, pentaethritol, dipentaethene. Litol, tripentaethritol, sucrose, 1,2,4-butanetriol, 1,2,5
-Pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like. .

Examples of trivalent or higher polyvalent carboxylic acid monomers include 1,2,4-benzenetricarboxylic acid,
1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-
Hexanetricarboxylic acid, 1,3-dicarboxyl-2
-Methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, embol trimer acid, acid anhydrides thereof, and the like.

The phthalate compound used in the present invention includes dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate,
Examples thereof include diisononyl phthalate, octyldecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, and the like. The compounding amount of the present compound is preferably 0.2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

Further, the toner of the present invention may further contain a magnetic material to be used as a magnetic toner. The magnetic material contained in the magnetic toner of the present invention includes magnetite, hematite, iron oxide such as ferrite, iron, cobalt, metals such as nickel, or aluminum of these metals, cobalt, copper, lead, magnesium, tin, Examples thereof include alloys of metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof.

These ferromagnetic materials have an average particle size of 0.1 to 2
It is desirable that the amount is about 20 μm to 100 parts by weight of the resin component, particularly preferably 40 to 100 parts by weight of the resin component.
It is 150 parts by weight.

Further, the toner of the present invention may be mixed with additives as required. As the additive, for example, Teflon,
Lubricants such as zinc stearate or cerium oxide,
An abrasive such as silicon carbide, or a fluidity-imparting agent such as colloidal silica or aluminum oxide, an anti-caking agent, or a conductivity-imparting agent such as carbon black or tin oxide, or a fixing aid such as a low molecular weight polyolefin. is there. Further, as a colorant, C.I. I. P
igment Red 48: n (n = 1 to 3) and C.I. I. Pigment Red 81 (according to the name described in the Color Index 3rd edition), it is possible to impart an appropriate charge amount to the toner, which cannot be obtained with conventional red colorants, and to combine with CCA. Is economically advantageous.

C. I. Pigment Red 4
8: n (n = 1 to 4), C.I. I. Pigment Re
The structural formula of d 81: 1 is as follows.

[0034]

[Chemical 5]

(N = 1: X = Ba ² +, n = 2: X = Ca
² +, n = 3: X = Sr ² +, n = 4: X = Mn ² +)

[0036]

[Chemical 6]

In addition, C.I. I. Pigment Red
48: n (n = 1 to 3), C.I. I. Pigment R
The compounding ratio of ed 81 is 1: 9 to 9: 1, preferably 6: 4 to 3: 6. Further, the blending amount of both colorants is preferably 1 to 15 parts by weight with respect to 100 parts by weight of the binder resin.

The released free fatty acid type carnauba wax used as a release agent in the toner of the present invention is a free carbauba wax from which free fatty acids have been released, and therefore has an acid value of 5 % And less than that of conventional carnauba wax, and the dispersed particle size in the binder resin is 1 μm or less, so that the dispersibility is improved.

The montan ester wax is refined from minerals and becomes fine crystals like the carnauba wax, and the dispersed particle diameter in the binder resin is 1 μm or less, and the dispersibility is improved. In the case of montan ester wax, the acid value is particularly preferably 5-14.

The oxidized rice wax of the present invention is obtained by air-oxidizing rice bran wax. Acid value is 10
When it is less than 10, the lower limit fixing temperature rises and the low temperature fixability becomes insufficient, and when it is more than 30, the cold offset temperature rises and the low temperature fixability also becomes insufficient. The above waxes may be used alone or in combination, and if the wax is contained in an amount of 1 to 15 parts by weight based on the total weight of the toner, the above-described good results can be obtained.

Further, the compound represented by the above (a) imparts a positive charging property to the toner. The compounding amount of the present compound is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the binder resin.

The carrier core particles coated with the silicone resin in the present invention may be those conventionally known, for example, ferromagnetic metals such as iron, cobalt and nickel; alloys and compounds such as magnetite, hematite and ferrite; glass. Examples thereof include beads. The average particle size of these core particles is usually 10 to 1000 μm, preferably 30 to 5 μm.
It is 00 μm. The amount of the silicone resin used is usually 1 to 10% by weight based on the carrier core particles.

The silicone resin used in the present invention may be any conventionally known silicone resin, for example, commercially available KR261, KR271, KR272, KR27 manufactured by Shin-Etsu Silicone Co., Ltd.
5, KR280, KR282, KR285, KR25
1, KR155, KR220, KR201, KR20
4, KR205, KR206, SA-4, ES100
1, ES1001N, ES1002T, KR3093 and SR2100, SR2101, S made by Toray Silicone Co., Ltd.
R2107, SR2110, SR2108, SR210
9, SR2115, SR2400, SR2410, SR
2411, SH805, SH806A, SH840 and the like are used. As a method of forming the silicone resin layer, the silicone resin may be applied to the surface of the carrier core particles by a method such as a spraying method or a dipping method as in the conventional method. The coating composition is prepared by adding conductive fine powder and a silane coupling agent to a silicone resin solution and dispersing them with an appropriate mixer.

The conductive fine powder dispersed in the coating layer is
Particles having a particle size of about 0.01 to 5.0 μm are preferable, and 0.01 to 30 parts by weight is preferably added to 100 parts by weight of the silicone resin, and more preferably 0.1 to 20 parts by weight. As the conductive fine powder, conventionally known carbon black may be used, and examples thereof include contact black, furnace black and thermal black.

[0045] As the silane coupling agent, X-Si-R n ( n is an integer of 1 to 3) is a compound represented by comprising the formula, X is a functional group which reacts with organic, R represents alkoxy group 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, is added to 100 parts by weight of the silicone resin. Specific examples of the silane coupling agent used in the present invention include:
A compound having the following structure can be used.

[0046]

[0047]

[Chemical 7]

[0048]

[0049]

[Chemical 8]

The alkoxy group of the above compound may be a chlorine atom.

[0051]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. All parts are parts by weight.

Next, production examples of carriers having some silicone resins in the coating layer will be shown. These can be performed by known means.

Carrier Production Example 1 Composition of coating layer forming liquid Silicone resin solution (KR250 manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts Carbon black (# 44 manufactured by Mitsubishi Kasei Co., Ltd.) 4 parts Toluene 100 parts The above formulation was dispersed for 30 minutes with a homomixer. To prepare a coating layer forming liquid. This coating layer forming liquid has an average particle size of 100 μm.
Carrier A having a coating layer formed on the surface of 1000 parts of spherical ferrite of No. 3 using a fluidized bed coating apparatus was obtained.

Carrier Production Examples 2 to 4 Each component shown in Table 1 below was mixed with 100 parts of toluene,
A homomixer dispersed for 30 minutes to prepare a coating layer forming liquid.

[0055]

[Table 1]

The coating layer forming liquid was used to obtain carriers B, C and D in which a coating layer was formed on the surface of 1000 parts of spherical ferrite having an average particle size of 100 μm using a fluidized bed type coating apparatus.

Example 1 Polyester resin (weight average molecular weight 250,000) 70 parts Styrene-methyl methacrylate copolymer (Tg = 70, toluene insoluble content 0%) 30 parts Oxidized rice wax (acid value 15) 4 parts C.I. I. Pigment Red 48:25 5 parts C.I. I. Pigment Red 81: 1 (x = 12, y = 1) 2 parts Charge control agent (a) (R ₁ = H, R ₂ = CH ₃ , R ₃ = C ₂ H ₅ , R ₄ = R ₅ = CH ₃ , R ₆ = H) 0.5 part After thoroughly stirring and mixing the mixture having the above composition in a Henschel mixer, the mixture is mixed in a roll mill at a temperature of 130 to 140 ° C. for about 3 parts.
After heating and melting for 0 minutes and cooling to room temperature, the obtained kneaded product was pulverized and classified to obtain a toner having a particle diameter of 5 to 20 μm. 2.5 parts of this toner was mixed with 97.5 parts of Carrier A in a ball mill to obtain a developer.

Next, a plain paper copier equipped with a Teflon roller using the above developer as a fixing roller (manufactured by our company FT70
When it was set to 30) and developed at a heat roller temperature of 130 ° C., a clear high image quality was obtained without causing offset or winding phenomenon, and the image did not change after 100,000 images were printed.

Further, when the toner charge amount was measured by the blow-off method, the initial charge amount was +22.6 μc / g, and the toner charge amount after running 100,000 sheets was +.
There was almost no difference from the initial value of 21.5 μc / g.
Also, in a high humidity environment of 35 ° C. and 90% RH, +21.4
Under a low humidity environment of 10 μC / g and 10 ° C. and 15% RH, the charge amount was +22.7 μc / g, which was not so different from normal humidity, and an equivalent image was obtained.

Further, when the penetration of this toner was measured after it was stored at 50 ° C. for 24 hours, it showed a good value that the needle penetrated, and there was no problem with the storage stability. Further, when the copy image obtained by the image test was sandwiched between Plus PVC mat (W) manufactured by PLUS Co., Ltd. and stored at 50 ° C. for 24 hours, some fusion of the toner to the PVC mat was observed. The PVC storability was good, not at a problematic level.

Comparative Example 1 A developer was obtained and an image test was conducted in the same manner as in Example 1 except that the styrene-methylmethacrylate copolymer of Example 1 was removed and only the polyester resin was used as the binder resin. . A clear high quality image was obtained from the initial image without causing offset or wrapping phenomenon, and the image did not change after 100,000 images were printed, but under high humidity environment of 35 ° C. 90% RH +10.0 μc / g 10 ° C 15% RH
In the low-humidity environment, +22.8 μc / g, which was greatly changed depending on the environment.

Comparative Example 2 A developer was obtained and an image test was conducted in the same manner as in Example 1 except that 1 part of a conventionally known nigrosine dye was used except for the charge control agent (a) of Example 1. Although no offset or winding phenomenon occurred, the image became dull red and a clear red image could not be obtained. Further, when the charge amount was measured in the same manner as in Example 1, it was +5.8 μ in a high humidity environment of 35 ° C. and 95% RH.
c / g under low humidity environment of 10 ° C. and 15% RH +17.
It was 9 μc / g, which was greatly changed depending on the environment.

Comparative Example 3 A developer was obtained and an image test was conducted in the same manner as in Example 1 except that the carrier D in which the coating layer of the carrier was changed from the silicone resin to the styrene-acrylic resin was used. As the initial image, a clear image was obtained without causing an offset or a winding phenomenon, but from about 10,000 sheets, it became an unclear image with fog. When the charge amount was measured in the same manner as in Example 1, the initial charge amount was +21.3 μc.
/ G, but it decreased to +4.9 μc / g after 10,000 sheets.

Example 2 A developer was prepared in the same manner as in Example 1 except that 10 parts of isononyl phthalate was added to the formulation of Example 1, and an image test was conducted. A clear high quality image was obtained from the initial image without causing an offset or a winding phenomenon, and the image did not change even after 100,000 images were output.

When the toner charge amount was measured in the same manner as in Toner Example 1, the initial charge amount was +23.0 μc /
The toner charge amount after running 100,000 sheets was +22.5 μc / g, which was almost the same as the initial value. Also, in a high humidity environment of 35 ° C 90% RH, +2
Under a low humidity environment of 2.8 μc / g and 10 ° C. and 15% RH, the charge amount was +23.3 μc / g, which was not so different from normal humidity, and an equivalent image was obtained.

When the storability was tested in the same manner as in Example 1, the needle penetrated, showing a good value and no problem.

Regarding the PVC matt preservability, no fusion of the toner to the mat was observed and the PVC matte preservability was excellent.

Example 3 A developer was obtained and an image test was conducted in the same manner as in Example 1 except that the carrier A of Example 1 was replaced with the carrier B in which a silane coupling agent was added to the coating layer. A clear, high-quality image free from fog was obtained from the initial image without causing any offset or wrapping phenomenon, and the image did not change even after 200,000 images were printed.

When the toner charge amount was measured in the same manner as in Example 1, the initial charge amount was +23.8 μc / g, and the toner charge amount after running 200,000 sheets was +22.9 μc / g. There was almost no difference from the initial value.
Also, in a high humidity environment of 35 ° C. and 90% RH, +23.3
In a low humidity environment of 10 μC / g and 10 ° C. and 15% RH, the charge amount was +24.1 μc / g, which was not so different from normal humidity, and an equivalent image was obtained.

Example 4 A developer was prepared in the same manner as in Example 1 except that 8 parts of isononyl phthalate was added to the formulation of Example 1 and the carrier A was replaced with the carrier B having a silane coupling agent added to the coating layer. An image test was conducted. A clear high quality image was obtained from the initial image without causing an offset or a winding phenomenon, and the image did not change even after 200,000 images were output.

When the toner charge amount was measured in the same manner as in Example 1, the initial charge amount was +24.0 μc / g, and the toner charge amount after running 200,000 sheets was +23.1 μc / g. There was almost no difference from the initial value.
Also, in a high humidity environment of 35 ° C 90% RH, +23.5
In a low humidity environment of 10 μC / g and 10 ° C. and 15% RH, the charge amount was +24.4 μc / g, which was not so different from normal humidity, and an equivalent image was obtained.

When the storability was tested in the same manner as in Example 1, the needle penetrated, showing a good value, and there was no problem. Also, regarding PVC storability,
No fusion of the toner to the mat was observed, indicating good PVC mat storage stability.

Example 5 A developer was obtained and an image test was carried out in the same manner as in Example 1 except that the carrier A of Example 1 was replaced with the carrier C in which the alkoxysilane coupling agent containing chlorine was added to the coating layer. . A clear high quality image was obtained from the initial image without causing an offset or a winding phenomenon, and the image did not change even after outputting 250,000 images. Further, when the charge amount of the toner was measured in the same manner as in Example 1, the initial charge amount was +24.
The toner charge amount was 1 μc / g, and the toner charge amount after running 250,000 sheets was +23.0 μc / g, which was almost the same as the initial value. Also, in a high humidity environment of 35 ° C. 90% RH, +23.2 μc / g, and in a low humidity environment of 10 ° C. 15% RH, +24.7 μc / g, the charge amount is not so different from normal humidity, and the same image is obtained. was gotten.

Example 6 Polyester resin (weight average molecular weight 250,000) 75 parts Styrene-butyl acrylate copolymer (Tg = 67, toluene insoluble matter 0%) 25 parts Degreased fatty acid type carnauba wax (acid value 2) 4 parts C.I. I. Pigment Red 48: 1 6 parts C.I. I. Pigment Red 81 2 parts Charge control agent (a) (R ₁ = H, R ₂ = CH ₃ , R ₃ = C ₂ H ₅ , R ₄ = R ₅ = CH ₃ , R ₆ = H) 0.4 parts Above The mixture having the composition was thoroughly stirred and mixed in a Henschel mixer in the same manner as in Example 1, and then 130 to 1 by a roll mill.
After heating and melting at a temperature of 40 ° C. for about 30 minutes and cooling to room temperature, the obtained kneaded product was pulverized and classified to obtain a toner having a particle size of 5 to 20 μm. To 100 parts of this toner, 0.4 parts of hydrophobic colloidal silica was sufficiently stirred and mixed with a speed kneader to obtain a toner. For 2.5 parts of this toner,
A developer was prepared in the same manner as in Example 1 and the same image output test was conducted. As a result, a clear high image quality was obtained without causing an offset or winding phenomenon, and the image did not change even after 100,000 images were output. It was

When the toner charge amount was measured in the same manner as in Example 1, the initial charge amount was +21.8 μc / g, and the toner charge amount after running 100,000 sheets was +.
It was 20.3 μc / g, which was almost the same as the initial value.
Also, in a high humidity environment of 35 ° C and 90% RH, +20.6
In a low humidity environment of 10 μC / g and 10 ° C. and 15% RH, the charge amount was +22.4 μc / g, which was not so different from normal humidity, and an equivalent image was obtained.

Further, when the storability was tested in the same manner as in Example 1, the needle penetrated, showing a good value, and there was no problem. Regarding the storage stability of the vinyl mat, there was almost no fusion of the toner to the mat, and the storage stability of the vinyl mat was good.

Comparative Example 4 The C.I. I. Pigment Red 48:
1, C.I. I. Pigment Red 81 instead of C.I. I. Pigment Red 239 was used in the same manner as in Example 6 except that 8 parts of Pigment Red 239 was used, and an image test was performed. The initial image provided a clear high image quality without causing an offset or wrapping phenomenon, but as the number of copies increased, some toner fog occurred on the background portion of the image, and a good image could not be obtained.

Comparative Example 5 The styrene-butyl acrylate copolymer of Example 6 was used as T
A developer was obtained and an image test was conducted in the same manner as in Example 2 except that a compound having a Tg of 53 of g or less was used. A clear high image quality was obtained from the initial image without causing offset or wrapping phenomenon, and the image did not change even after 100,000 sheets of images were printed. However, in the penetration measurement after storing this toner at 50 ° C. for 24 hours, A value of 2 mm was shown, and a good result was not obtained regarding storage stability.

Comparative Example 6 The styrene-butyl acrylate copolymer of Example 6 was used as T
A developer was obtained in the same manner as in Example 6 except that a compound having Tg = 82 in which g was 75 or more was used, and an image test was conducted. As a result, a winding phenomenon occurred and a good image was not obtained.

Comparative Example 7 Instead of the released free fatty acid type carnauba wax of Example 6, low molecular weight polypropylene (660 manufactured by Sanyo Chemical Industry Co., Ltd.) was used.
A developer was obtained in the same manner as in Example 6 except that P) was used,
When an image test was conducted, a winding phenomenon occurred and a good image was not obtained.

Example 7 A developer was obtained and an image test was conducted in the same manner as in Example 4 except that 7 parts of isononyl phthalate was added to the formulation of Example 4. A clear high quality image was obtained from the initial image without causing an offset or a winding phenomenon, and the image did not change even after 100,000 images were output.

When the toner charge amount was measured in the same manner as in Example 1, the initial charge amount was +22.0 μc / g, and the toner charge amount after running 100,000 sheets was +.
There was almost no difference from the initial value of 20.9 μc / g.
Also, in a high humidity environment of 35 ° C and 90% RH, +21.3
Under a low humidity environment of 10 μC / g and 10 ° C. and 15% RH, the charge amount was +22.2 μc / g, which was not so different from normal humidity, and an equivalent image was obtained.

When the presence test was conducted in the same manner as in Example 1, the needle penetrated and showed a good value, and there was no problem. Regarding the storage stability of the vinyl mat, no fusion of the toner to the mat was observed, and the storage stability of the vinyl mat was excellent.

Example 8 Polyester resin (weight average molecular weight of 250,000) 75 parts Polystyrene-butyl acrylate mixture (Tg = 71, toluene insoluble matter 0%) 25 parts Free fatty acid type carnauba wax (acid value 2) 3 Part C. I. Pigment Red 48: 1 6 parts C.I. I. Pigment Red 81 2 parts Charge control agent (a) (R ₁ = H, R ₂ = CH ₃ , R ₃ = C ₂ H ₅ , R ₄ = R ₅ = CH ₃ , R ₆ = H) 0.6 part Above The mixture having the composition was thoroughly stirred and mixed in a Henschel mixer in the same manner as in Example 1, and then 130 to 1 by a roll mill.
After heating and melting at a temperature of 40 ° C. for about 30 minutes and cooling to room temperature, the obtained kneaded product was pulverized and classified to obtain a toner having a particle size of 5 to 20 μm. To 100 parts of this toner, 0.4 parts of hydrophobic colloidal silica was sufficiently stirred and mixed with a speed kneader to obtain a toner. For 2.5 parts of this toner,
A developer was prepared in the same manner as in Example 1 and the same image output test was conducted. As a result, a clear high image quality was obtained without causing an offset or winding phenomenon, and the image did not change even after 100,000 images were output. It was

When the toner charge amount was measured in the same manner as in Example 1, the initial charge amount was +20.5 μc / g, and the toner charge amount after running 100,000 sheets was +19.9 μc / g. There was almost no difference from the initial value.
Also, in a high humidity environment of 35 ° C. and 90% RH, it is +18.9.
In a low humidity environment of 10 μC / g and 10 ° C. and 15% RH, the charge amount was +20.4 μc / g, which was not so different from normal humidity, and an equivalent image was obtained.

When the storability was tested in the same manner as in Example 1, the needle penetrated and showed a good value, and there was no problem. Regarding the storage stability of the vinyl mat, there was almost no fusion of the toner to the mat, and the storage stability of the vinyl mat was good.

Example 9 A developer was obtained and an image test was carried out in the same manner as in Example 8 except that the carrier A of Example 8 was replaced with the carrier B in which a silane coupling agent was added to the coating layer. A clear, high-quality image free from fog was obtained from the initial image without causing any offset or wrapping phenomenon, and the image did not change even after 200,000 images were printed.

When the toner charge amount was measured in the same manner as in Example 1, the initial charge amount was +21.3 μC / g, and the toner charge amount after running 200,000 sheets was +.
There was almost no difference from the initial value of 20.5 μC / g. Again 3
+ 20.9μC in a high humidity environment of 5 ° C and 90% RH
/ G, and in a low humidity environment of 10 ° C and 15% RH +
The charge amount was 21.8 μC / g, which was not so different from that at room temperature, and an equivalent image was obtained.

Example 10 A developer was obtained and an image test was conducted in the same manner as in Example 8 except that the carrier A of Example 8 was replaced with the carrier C in which the alkoxysilane coupling agent containing chlorine was added to the coating layer. . A clear high quality image was obtained from the initial image without causing an offset or a winding phenomenon, and the image did not change even after outputting 250,000 images.

When the toner charge amount was measured in the same manner as in Example 8, the initial charge amount was +22.4 μC / g, and the toner charge amount after running 250,000 sheets was +.
There was almost no difference from the initial value of 21.6 μC / g. Again 3
+ 21.8μC in a high humidity environment of 5 ° C and 90% RH
/ G, and in a low humidity environment of 10 ° C and 15% RH +
The charge amount was 22.9 μC / g, which was almost the same as that at room temperature, and an equivalent image was obtained.

Example 11 The same as Example 8 except that 8 parts of phthalene isononyl was added to the formulation of Example 8 and the carrier A was replaced with the carrier C in which the alkoxysilane coupling agent containing chlorine was added to the coating layer. A developer was obtained and an image test was conducted. A clear high quality image was obtained from the initial image without causing an offset or a winding phenomenon, and the image did not change even after outputting 250,000 images.

When the toner charge amount was measured in the same manner as in Example 1, the initial charge amount was +22.8 μC / g, and the toner charge amount after running 250,000 sheets was +.
There was almost no difference from the initial value of 21.7 μC / g. Again 3
+ 21.5μC in a high humidity environment of 5 ° C and 90% RH
/ G, and in a low humidity environment of 10 ° C and 15% RH +
The charge amount was 23.3 μC / g, which was not so different from the room temperature, and an equivalent image was obtained.

When the storability was tested in the same manner as in Example 1, the needle penetrated, showing a good value and no problem. Regarding the storage stability of the vinyl mat, no fusion of the toner to the mat was observed, and the storage stability of the vinyl mat was excellent.

[0094]

As described above, by using the specific developer as in the present invention, it has sufficient offset resistance at the time of fixing, the lower limit temperature of fixing is low, and the winding around the fixing roll occurs. The image having the same quality as the initial image is obtained even after continuous copying, and stable triboelectric chargeability is obtained. Further, a red developer having excellent environmental stability was obtained, and a clear copy image was obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G03G 9/08 9/113 G03G 9/08 331 351 365 365 9/10 354 361 (72) Inventor Aoki Mitsuo 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (2)

[Claims] 1. An electrophotographic developer comprising a carrier coated with a silicone resin containing conductive fine powder and a toner containing a binder resin, a release agent, a colorant, and a charge control agent as main components. Containing at least a polyester resin as a binder resin for the toner and a styrene-acrylic resin having a Tg of 60 to 75 and a toluene insoluble content of 0%, and a release agent of free fatty acid type carnauba having an acid value of 5 or less. A wax and / or a montan ester wax and / or an oxidized rice wax having an acid value of 10 to 30 and a compound represented by the following (A) as a charge control agent, and a C.I. I. Pigment Re
d 48: n (n = 1 to 4) and C.I. I. Pigmen
t Red 81: 1 (according to the name described in Color Index 3rd Edition) is also contained, and a positively chargeable red developer for electrostatic charge development. (A) It has structural units represented by the following structural formulas (I) and (II), and the ratio of (I) to (II) is 65:35 to 97: 3.
Which is a quaternary ammonium salt copolymer compound. [Chemical 1] (In the above formula, R ₁ represents a hydrogen atom or a methyl group) (In the above formula, R _{2 to} R ₆ each represent the following) R ₂ : hydrogen atom or methyl group R ₃ : alkylene group R ₄ , R ₅ , R ₆ : alkyl group) 2. The positively chargeable red developer for developing an electrostatic charge image according to claim 1, wherein the toner contains a phthalate compound.