JP2002139868A - Positive charge type toner for full color development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for full color development effectively used in full color development adopting an oilless fixing system. SOLUTION: In the positive charge type toner for full color development containing a colorant, a releasing gent, a positive charge controlling agent and a positive charge supporting agent each dispersed in a polyester resin, the releasing agent is dispersed in an amount of 5-15 pts.wt. based on 100 pts.wt. polyester resin, the positive charge controlling gent is dispersed in an amount of 1-3 pts.wt. based on 100 pts.wt. polyester resin and the positive charge supporting agent is a copolymer comprising styrene units, acrylic units and 9-20 wt.% quaternary ammonium salt units and is dispersed in an amount of 1-5 pts.wt. based on 100 pts.wt. polyester resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positively chargeable full-color developing toner, and more particularly, to an oilless fixing system in which fixing is performed using a fixing roller to which no oil is applied. The present invention relates to a positively chargeable full-color developing toner to be applied.

[0002]

2. Description of the Related Art In an electrostatographic method employed in an image forming apparatus such as a copying machine, a facsimile, a printer, or the like, the surface of a photoreceptor is uniformly charged, and the surface of the photoreceptor is charged based on constant image information. An electrostatic latent image (charge image) is formed by performing light irradiation, and the electrostatic latent image is developed using a developer containing a toner charged to positive or negative polarity.
An image is formed by transferring the toner image onto a transfer sheet surface such as paper or an OHP film and thermally fixing the transferred toner image by a heat roller (fixing roller). Recently, full-color image forming apparatuses have become widespread. In full-color development, toner of each color (for example, black toner, cyan toner, magenta toner, and yellow toner) is used, and an image forming process is performed for each color. A full-color image is formed by superimposing toner images of each color on the transfer sheet. Therefore, each color toner used for full-color development is required to be particularly excellent in charge stability. That is, since a predetermined full-color image is formed by superimposing images of these toners on the transfer sheet, if the charging of the toner of any color is unstable, the color reproduction This is because it is impaired.

Various toners having excellent charge stability have been proposed. For example, Japanese Patent Application Laid-Open No. H11-242360 discloses
A positive charge control agent (CC) is contained in the fixing resin (binder resin).
There is disclosed a positively chargeable toner for developing an electrostatic latent image having A) and a positive charge reinforcing agent (CCR) having a function of increasing a positive charge amount.

[0004]

In the conventional image forming process, as described above, the toner image formed on the transfer sheet is heated and pressed by a fixing roller (heat roller). Is fixed on the surface of the transfer sheet. This is exactly the same when a full-color image is formed. In such a fixing system,
Oil such as silicone oil has been applied to the surface of the fixing roller in order to prevent the toner from adhering to the surface of the fixing roller (offset). However, providing a roller for applying the oil increases costs and changes the oil. Because of the problem that maintenance is required, a so-called oilless fixing system that does not apply oil to the surface of the fixing roller has come to be used. However, conventionally known toners disclosed in the above-mentioned prior art (Japanese Patent Application Laid-Open No. H11-242360) are not suitable for an oilless fixing system, and particularly when an oilless fixing system is used for full-color development. However, there has been a disadvantage that color reproducibility is impaired. That is, when an oilless fixing system is employed, a large amount of a release agent such as wax which is incompatible with the fixing resin is incorporated into the toner in order to prevent offset. As a result, the uniform dispersibility of the charge control agent and the charge reinforcing agent (these agents are also basically incompatible with the fixing resin) is significantly impaired, and the charge stability of the toner is impaired. It seems that the color reproducibility of the full-color image is unsatisfactory.

Accordingly, it is an object of the present invention to provide a full-color developing toner which is effectively used for full-color development using an oilless fixing system. Another object of the present invention is that when applied to full-color development using an oilless fixing system, not only offset resistance, but also excellent charging stability and excellent color reproducibility over a long period of time are obtained. An object of the present invention is to provide a toner for full color development that can be obtained.

[0006]

According to the present invention, there is provided a positively chargeable full-color developing toner in which a colorant, a release agent, a positive charge control agent and a positive charge control reinforcing agent are dispersed in a polyester resin. The release agent is a polyester resin 10
The positive charge control agent is dispersed in an amount of 1 to 3 parts by weight per 100 parts by weight of the polyester resin, and the positive charge control agent is dispersed in an amount of 5 to 15 parts by weight per 0 parts by weight. An acryl-based unit and a quaternary ammonium salt unit, wherein the quaternary ammonium salt unit is 9 to 20.
1% by weight of a copolymer resin, wherein the positive charge reinforcing agent is dispersed in an amount of 1 to 5 parts by weight per 100 parts by weight of the polyester resin. A toner is provided.

Since the toner of the present invention contains a relatively large amount of a release agent, it exhibits excellent offset resistance even when an oilless fixing system is applied. In particular, a polyester resin is used as a fixing resin. As a positive charge reinforcing agent (CCR), a styrene-acryl-quaternary ammonium salt copolymer resin containing a quaternary ammonium salt in a fixed ratio is used together with a positive charge control agent (CCA). An important feature is that they are used together. That is, despite the combination of such a fixing resin, a positive charge control agent and a positive charge reinforcing agent, a release agent having an amount sufficient to show good offset resistance in an oilless fixing system is compounded. At a high charging level, charging rises quickly and excellent charging stability is ensured. Although the reason why the toner of the present invention exhibits such charging characteristics is not clear, the fixing resin used is limited to polyester, and when another type of fixing resin (for example, a styrene-acrylic resin) is used, the charging is not performed. Loss of stability,
The content of the quaternary ammonium salt in the positive charge reinforcing agent (styrene-acryl-quaternary ammonium salt copolymer resin) used is limited to a certain range (9 to 20% by weight). Considering that the charge stability is impaired even if the amount is large or small, the positive charge control agent and the positive charge reinforcing agent having a specific structure are appropriately uniformly dispersed in the polyester resin, and as a result, It is thought that excellent charging characteristics (especially charging stability) are ensured despite the fact that a large amount of release agent is blended.

[0008]

(Fixing resin) In the present invention,
A polyester resin is used as a fixing resin. That is, when a material other than a polyester resin is used as a fixing resin, such as a styrene-acrylic resin, excellent charging characteristics, particularly, charging stability cannot be secured, and an oilless fixing system is employed. When full color development is performed, color reproducibility is impaired in a short period of time. In the present invention, as the polyester resin used as the fixing resin, those obtained by polycondensation of a polyhydric alcohol and a polycarboxylic acid known per se can be used.

Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butene Diol, 1,5-
Pentanediol, 1,6-hexanediol, 1,4
-Cyclohexanediol, dipropylene glycol,
Polyethylene glycol, polypropylene glycol,
Diols such as polytetramethylene glycol; bisphenols such as bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxypropylene bisphenol A; sorbitol, 1,2,3,6-hexane tetrol, 1 , 4-Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methylpropanetriol , 2-methyl-1,
Trihydric or higher alcohols such as 2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene can be exemplified, and these polyhydric alcohols may be used alone. But 2
More than one combination may be used.

[0010] Polycarboxylic acids include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid,
Phthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-butylsuccinic acid, n-butenylsuccinic acid, isobutylsuccinic acid, isobutenylsuccinic acid, n
Divalent carboxylic acids such as -octylsuccinic acid, n-octenylsuccinic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid and isododecenylsuccinic acid; 1,2,4-benzenetricarboxylic acid (tri- Melitic acid), 1,2,5-benzenetricarboxylic acid, 2,2
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, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,2
7,8-octanetetracarboxylic acid, pyromellitic acid,
Trivalent or higher carboxylic acids such as empole trimer can be raised. These polycarboxylic acids can be used alone or in combination of two or more.
It can also be used in the form of an acid anhydride or a partial ester.

The acid value of the fixing resin comprising the above-mentioned polyester resin is preferably 10 or less, and the glass transition temperature (Tg) is preferably in the range of 50 to 75 ° C. That is, when the acid value is higher than the above range, the positive charging characteristics of the toner of the present invention may be impaired. When the Tg is less than 50 ° C., the toners are liable to be fused to each other, and the toner is stored. Stability tends to be impaired, and when Tg is higher than 75 ° C., toner fixability tends to be poor.

The fixing resin used in the present invention is desirably made of only the polyester resin described above. However, the toner has positive charge characteristics (particularly, charge stability), fixability, and the like.
As long as properties such as offset resistance are not impaired, thermosetting resins such as other thermoplastic resins (for example, styrene resin, styrene-acrylic resin, etc.) and epoxy resins are contained in a small amount of 10% by weight or less. May be.

(Releasing Agent) In the toner of the present invention, 5 to 15 parts by weight per 100 parts by weight of the polyester resin described above.
It is necessary to be mixed and dispersed in an amount of part by weight, especially 7 to 10 parts by weight. That is, since the toner of the present invention is used particularly in an oil-less fixing system, if the amount of the release agent used is smaller than the above range, the offset resistance becomes unsatisfactory. When a large amount is used, the uniform dispersibility of other components incorporated in the fixing resin is significantly impaired, and as a result, charging characteristics such as charging stability of the toner are impaired. As the release agent, a conventionally known release agent can be used.
Aliphatic hydrocarbon waxes such as paraffin wax, petroleum wax, polyethylene wax, polypropylene wax, polyethylene oxide wax, montan wax, carnauba wax, beeswax, wood wax, or oleyl palmitoamide, stearyl erucamide, 2-stearo Fatty acid amides such as midoethyl stearate, ethylenebisfatty acid amide, and silicone oil can be mentioned. Generally, aliphatic hydrocarbon waxes are preferred, and most preferably, polyolefin waxes such as polyethylene wax and polypropylene wax can be used.

(Positive Charge Control Agent) In the toner of the present invention, a positive charge control agent (CCA) is blended in order to secure a constant positive charge amount. Since it is incompatible with the polyester resin, its blending amount must be strictly adjusted. Specifically, 1 to 3 parts by weight per 100 parts by weight of the polyester resin is used.
It is incorporated in an amount of 1 part by weight, especially 1 to 2 parts by weight. That is,
If the amount is smaller than this range, it is not possible to secure a charge amount (positive charge amount) sufficient to form an image having an appropriate density. Is difficult to disperse, and as a result,
Variations in the charge amount occur, and it is difficult to ensure the stability of the charge amount, and image fogging and the like easily occur.

[0015] Such a positive charge controlling agent is conventionally known, and examples thereof include the following. Pyridazine, pyrimidine, pyrazine, orthooxazine, methoxazine, paraoxazine, orthothiazine, metathiazine, parathiazine, 1,2,3-triazine,
1,2,4-triazine, 1,3,5-triazine,
1,2,4-oxadiazine, 1,3,4-oxadiazine, 1,2,6-oxadiazine, 1,3,4-thiadiazine, 1,3,5-thiadiazine, 1,2,3,4
-Tetrazine, 1,2,4,5-tetrazine, 1,2,2
3,5-tetrazine, 1,2,4,6-oxatriazine, 1,3,4,5-oxatriazine, phthalazine,
Azine compounds such as quinazoline and quinoxaline. Azin Fast Red FC, Azin Fast Red 12BK, Azin Violet BO, Azin Brown 3G, Azin Light Brown GR, Azin Dark Green BH / C, Azin Deep Black EW, Azin Deep Black 3
Azine direct dyes such as RL. Nigrosine compounds such as nigrosine, nigrosine salts and nigrosine derivatives, and nigrosine-based acid dyes such as nigrosine BK, nigrosine NB and nigrosine Z. Metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, alkylamides, and quaternary ammonium salts such as benzylmethylhexyldecylammonium and decyltrimethylammonium chloride. The above positive charge control agents (CCA) can be used alone or in combination of two or more. Nigrosine compounds or nigrosine-based direct dyes are preferred from the viewpoint of charge rising properties. When a colored one of the above-described positive charge control agents is used, the same color as a later-described colorant is used so as not to impair the tint of the toner.

(Positive Charge Reinforcing Agent) In the present invention, a positive charge reinforcing agent (CCA) is used together with the positive charge controlling agent (CCA).
R) is used, and as such a positive charge reinforcing agent, a styrene-based unit, an acrylic-based unit, and a quaternary ammonium salt unit, and the quaternary ammonium salt unit is 9 to 20% by weight, particularly 10% It is necessary to use a copolymer resin contained in an amount of from 15 to 15% by weight. That is, by using such a copolymer resin as a positive charge reinforcing agent, it is possible to stably secure charging characteristics for a long period of time. Although the reason why the use of such a copolymer resin stabilizes the charging characteristics of the toner has not been clearly elucidated, it is supposed that the copolymer resin containing a quaternary ammonium salt unit at a certain ratio is probably As well as having a positive charge control function by itself, it also has a surfactant-like function, and the polyester resin in which a large amount of a release agent is dispersed and blended, contains the above-described positive charge control agent ( It is presumed that CCA) is distributed uniformly. For example, when a copolymer resin having a quaternary ammonium salt unit content outside the above range is used, its surfactant function is not exhibited, and the positive charge control agent (CCA) is uniformly dispersed in the polyester resin. The toner does not disperse, and the triboelectric charging characteristics of the toner become unstable, and the use of the toner for a short period of time causes fluctuations in the triboelectric charge amount, which tends to cause a decrease in image density and fog, thereby impairing full-color image reproducibility. I will be.

In the above copolymer resin, the styrene-based monomer used for introducing the styrene-based unit includes the following formula (1): CH ₂ ＣC (R ¹ ) -Φ (1) , R ¹ is a hydrogen atom, a lower alkyl group having 4 or less carbon atoms or a halogen atom, Φ is a benzene ring,
The benzene ring may have a substituent such as a lower alkyl group having 4 or less carbon atoms or a halogen atom, for example, styrene, vinyltoluene, α-methylstyrene, α-chloroform. Examples thereof include styrene, o-, m-, p-chlorostyrene, and vinyl xylene, and these styrene monomers may be used alone or in combination of two or more.

On the other hand, the acrylic monomer used for introducing the acrylic unit includes the following formula (2): CH ₂ ＣC (R ² ) —COO—R ³ (2) ² is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms, and R ³ is a substituted or unsubstituted hydrocarbon group having 18 or less carbon atoms, such as methyl acrylate. , Ethyl acrylate, butyl acrylate,
2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-hydroxyacrylate, butyl δ-hydroxyacrylate , Β-hydroxyethyl methacrylate and the like. Further, in addition to those exemplified above, esterified products of other ethylenically unsaturated carboxylic acids, for example, alkyl esters such as maleic acid, fumaric acid, crotonic acid, and itaconic acid can be given. These acrylic monomers may be used alone or in combination of two or more.

The monomer for introducing the quaternary ammonium salt unit into the copolymer resin is represented by the following formula (3): (A ¹ ) ₃ N ⁺ (A ² ) · B ⁻ (3) Wherein A ¹ is an alkyl group, three A ^{1 s} may be different from each other, A ² is an organic group containing an ethylenically unsaturated double bond, and B ⁻ is an anion ,
And a quaternary ammonium salt compound represented by the following formula: for example, a tertiary ammonium salt compound such as dialkylaminoalkyl (meth) acrylate or dialkylaminoalkyl methacrylamide.
A compound obtained by quaternizing a quaternary amino group-containing compound with an alkyl halide such as alkyl iodide can be used. Examples of the tertiary amino group-containing compound subjected to such quaternization treatment include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, and dibutylamino. Di-lower alkylaminoethyl (meth) acrylates such as ethyl (meth) acrylate and dimethylaminopropyl methacrylamide are preferred. Further, the quaternary ammonium group is introduced by copolymerizing (random polymerization, block polymerization or graft polymerization) the above-mentioned quaternary ammonium compound with the above-mentioned styrene monomer or acrylic monomer. However, it can also be introduced by copolymerizing the above tertiary amino group-containing compound and then performing a quaternization treatment.

In the present invention, the positive charge reinforcing agent (CCR)
The copolymer resin used as described above, as described above,
The fourth is used in an amount of 9 to 20% by weight, especially 10 to 15% by weight.
Although it contains a quaternary ammonium group, a quaternary ammonium salt unit / styrene unit (weight ratio) of 0.1 to 0.
Preferably, it is set to be 5. In addition, the surfactant function of the copolymer resin is not impaired,
In addition, a small amount of other units may be contained as long as the positive chargeability of the toner is not impaired.

The positive charge reinforcing agent (CCR) comprising the above copolymer resin is used in an amount of 1 to 100 parts by weight of the polyester resin.
To 5 parts by weight, especially 2 to 4 parts by weight. When the amount is smaller than the above range, it is difficult to uniformly disperse the positive charge control agent (CCA), and the charge stability cannot be ensured. The effect is not obtained, and this is not only economically disadvantageous but also impairs the fixing property of the toner. In the present invention, the amount of the positive charge reinforcing agent (CCR) is preferably adjusted according to the amount of the positive charge control agent (CCA). For example, CCR / CCA
Most preferably, the weight ratio is adjusted to be in the range of 1 to 5.

(Colorant) In the toner of the present invention, pigments of each color can be blended as colorants in accordance with the color of the target toner, similarly to conventionally known toners.
Suitable examples include, but are not limited to: Colorant for black toner: carbon black, acetylene black, lamp black, aniline black and the like. Colorant for yellow toner: C.I. I. Pigment Yellow 1, C.I. I. Pigment Yellow 5, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 15,
C. I. Pigment Yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 74,
C. I. Pigment Yellow 4, C.I. I. Pigment Yellow 81, C.I. I. Pigment Yellow 97, C.I.
I. Azo pigments such as CI Pigment Yellow 93; inorganic pigments such as yellow iron oxide and loess; I. Nitro dyes such as Acid Yellow 1; I. Solvent Yellow 2,
C. I. Solvent Yellow 6, C.I. I. Solvent Yellow 14, C.I. I. Solvent Yellow 15, C.I.
I. Solvent Yellow 19, C.I. I. Oil-soluble dyes such as Solvent Yellow 21; Most preferred are C.I. I. And benzidine pigments such as CI Pigment Yellow 12. Colorant for magenta toner: C.I. I. Pigment Red 4
9, C.I. I. Pigment Red 57, C.I. I. Pigment Red 81, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 184, C.I. I. Pigment Red 238, C.I. I. Solvent Red 19, C.I. I. Solvent Red 49, C.I. I. Solvent Red 52,
C. I. Basic Red 10, C.I. I. Disperse Red 15 etc. Most preferred are C.I.
I. Quinacridone pigments such as CI Pigment Red 122; Colorant for cyan toner: C.I. I. Pigment Blue 1
5, C.I. I. Pigment Blue 16, C.I. I. Solvent Blue 55, C.I. I. Solvent Blue 70, C.I.
I. Direct Blue 25, C.I. I. Direct Blue 86 etc. Most preferred are C.I. I. Pigment Blue 15 and the like.

The above-mentioned colorant is used in an amount of 2 to 20 parts by weight, especially 5 to 15 parts by weight, per 100 parts by weight of the fixing resin.

(Toner) The toner of the present invention is obtained by melt-kneading the above-mentioned various components with a fixing resin (polyester resin) manufactured so as to have a predetermined molecular weight distribution, and obtaining a melt-kneaded product (resin for toner). The composition is obtained by pulverizing and classifying the composition, and is mixed with a magnetic carrier such as ferrite or iron powder to be used as a two-component magnetic developer, and in some cases as a one-component magnetic developer for full-color development. Is done. The particle size of such a toner is generally 5 to 20 μm.
m, especially in the range of 7 to 13 μm,
To improve the fluidity of the toner particles,
A fluidity improver composed of an inorganic oxide such as hydrophobic silica or TiO ₂ can also be externally added. Further, when used in a mixture with a magnetic carrier, toner: carrier = 2:
The ratio is preferably 98 to 10:90 (weight ratio).

[0025]

The present invention will be described with reference to the following examples and comparative examples. In the following examples, the following polyester resin was used as the fixing resin, and a quinacridone pigment (CI Pigment Red 122) was used as the colorant. A quaternary ammonium salt (P-51 manufactured by Orient Chemical Co., Ltd.) is used as the positive charge control agent (CCA), and carnauba wax (melting point 85 ° C.) is used as the release agent.
Was used. Polyester resin Tg: 60 ° C Tm: 120 ° C

Example 1 A styrene-acrylic copolymer resin containing 9% by weight of quaternary ammonium salt units (quaternary ammonium salt / styrene = 9/74) was used as a positive charge reinforcing agent (CCR). Then, according to the following formulation, each component is mixed with a mixer, and then melt-kneaded with a twin-screw extruder to prepare a resin composition for toner, which is finely pulverized with an air-flow type pulverizer and then pulverized with an air classifier. After classification, a magenta toner having an average particle size of 9 μm on a volume basis was obtained. Polyester resin 100 parts by weight Colorant 4 parts by weight Carnauba wax 5 parts by weight Positive charge control agent (CCA) 1 part by weight Positive charge reinforcing agent (CCR) 4 parts by weight

Example 2 A styrene-acrylic copolymer resin having a quaternary ammonium salt content of 15% by weight (quaternary ammonium salt / styrene = 15/74) was used as a positive charge reinforcing agent (CCR). A magenta toner was prepared in exactly the same manner as in Example 1 except that the amounts of the positive charge reinforcing agent (CCR) and the positive charge control agent (CCA) were changed as follows. Positive charge control agent (CCA) 2 parts by weight Positive charge reinforcing agent (CCR) 4 parts by weight

Example 3 A magenta toner was prepared in exactly the same manner as in Example 2 except that the amounts of the positive charge reinforcing agent (CCR) and the positive charge control agent (CCA) were changed as follows. Positive charge control agent (CCA) 5 parts by weight Positive charge control agent (CCR) 1 parts by weight

Example 4 Release Agent (Carnauba Wax)
A magenta toner was prepared in exactly the same manner as in Example 2 except that the amount of was changed as follows. 10 parts by weight of carnauba wax

Example 5 Release Agent (Carnauba Wax)
A magenta toner was prepared in exactly the same manner as in Example 2 except that the amount of was changed as follows. 15 parts by weight of carnauba wax

Example 6 A styrene-acrylic copolymer resin having a quaternary ammonium salt content of 20% by weight (quaternary ammonium salt / styrene = 20/74) was used as a positive charge reinforcing agent (CCR). A magenta toner was prepared in exactly the same manner as in Example 1 except that the amounts of the positive charge reinforcing agent (CCR) and the positive charge control agent (CCA) were changed as follows. Positive charge control agent (CCA) 3 parts by weight Positive charge control agent (CCR) 5 parts by weight

Comparative Example 1 A magenta toner was prepared in exactly the same manner as in Example 3 except that no positive charge control agent (CCA) was added.

Comparative Example 2 A styrene-acrylic copolymer resin having a quaternary ammonium salt content of 6% by weight (quaternary ammonium salt / styrene = 6/74) was used as a positive charge reinforcing agent (CCR). A magenta toner was prepared in exactly the same manner as in Example 1, except that the amount of the positive charge reinforcing agent (CCR) was changed as follows. Positive charge reinforcing agent (CCR) 3 parts by weight

(Comparative Example 3) The copolymer resin used in Comparative Example 2 was used as a positive charge reinforcing agent (CCR), and the compounding amounts of the positive charge reinforcing agent (CCR) and the positive charge controlling agent (CCA) were as follows. A magenta toner was prepared in exactly the same manner as in Example 1 except for the above changes. Positive charge control agent (CCA) 2 parts by weight Positive charge control agent (CCR) 10 parts by weight

Comparative Example 4 A styrene-methyl acrylate-quaternary ammonium salt copolymer resin having a quaternary ammonium salt content of 25% by weight (quaternary ammonium salt / styrene = 25/74) was positively charged. A magenta toner was prepared in exactly the same manner as in Example 2 except that the amount of the positive charge reinforcing agent (CCR) was changed as described below. Positive charge reinforcing agent (CCR) 2 parts by weight

Comparative Example 5 Release Agent (Carnauba Wax)
A magenta toner was prepared in exactly the same manner as in Example 5, except that the amount of was changed as follows. 17 parts by weight of carnauba wax

Comparative Example 6 A magenta toner was prepared in exactly the same manner as in Example 2, except that the amounts of the positive charge reinforcing agent (CCR) and the positive charge control agent (CCA) were changed as follows. Positive charge control agent (CCA) 4 parts by weight Positive charge control agent (CCR) 3 parts by weight

For the toners prepared in each of the above Examples and Comparative Examples, the quaternary ammonium salt content (N4 content) in the copolymer resin used as the positive charge reinforcing agent (CCR), C
Table 1 shows the amounts of CR, CCA and release agent (wax).
It was shown to.

(Experiment) Each of the toners obtained in the above Examples and Comparative Examples was mixed with a ferrite carrier coated with silicone (toner: carrier = 4: 96).
A developer was used. Using these developers, a digital copier (Creage7325 manufactured by Kyocera Mita) employing an oilless fixing system was used to print 10,000 sheets, and the change in charge amount, image density and fog density were measured. The results are shown in Tables 2, 3 and 4.

[0040]

Table 1 N4 content of CCR CCR compounding amount CCA compounding amount WAX compounding amount Example 1 9% by weight 2 parts by weight 1 part by weight 5 parts by weight Example 2 15% by weight 4 parts by weight 2 parts by weight 5 parts by weight Example 3 15 weight% 5 weight parts 1 weight part 5 weight parts Example 4 15 weight% 4 weight parts 2 weight parts 10 weight parts Example 5 15 weight% 4 weight parts 2 weight parts 15 weight parts Example 6 20 weight% 5 weight parts Parts 3 parts by weight 5 parts by weight Comparative Example 1 15 parts by weight 5 parts by weight -5 parts by weight Comparative Example 2 6 parts by weight 2 parts by weight 1 part by weight 5 parts by weight Comparative Example 3 6 parts by weight 10 parts by weight 2 parts by weight 5 parts by weight Comparative Example 4 25% by weight 2 parts by weight 2 parts by weight 5 parts by weight Comparative Example 5 15% by weight 4 parts by weight 2 parts by weight 17 parts by weight Comparative Example 6 15% by weight 3 parts by weight 4 parts by weight 5 parts by weight Note) Compounding amount: Amount per 100 parts by weight of polyester resin N4 content: Quaternary resin in copolymer resin Moniumu salt content

[0041]

(Table 2) (Charge amount per printing number μC / g) Printing number (K) 0 0.01 1 3 5 10 Example 1 12.4 17.5 20.2 22.1 23.5 23.8 Example 2 14.8 19.5 26.5 26.9 26.7 26.6 Example 3 14.5 19.2 26.4 27.4 27.1 27.7 Example 4 14.8 19.0 25.0 26.5 25.8 25.6 Example 5 14.2 18.9 24.2 27.9 28.9 29.2 Example 6 18.5 23.2 27.1 29.1 28.9 27.9 Comparative Example 1 15.3 18.8 25.4 29.7 37.8 38.0 Comparative Example 2 11.8 14.8 18.7 17.9 18.2 18.4 Comparative Example 3 16.2 19.4 28.5 33.8 40.1 43.6 Comparative Example 4 15.8 20.7 28.7 32.8 33.1 32.4 Comparative Example 5 14.7 19.3 26.8 28.9 32.5 38.8 Comparative Example 6 16.2 20.0 28.7 32.6 37.6 37.8

[0042]

(Table 3) (Image density per printing number) Printing number (K) 0 0.01 1 3 5 10 Example 1 1.9 1.8 1.6 1.6 1.6 1.6 Example 2 1.7 1.6 1.5 1.5 1.5 1.5 Example 3 1.7 1.6 1.4 1.5 1.4 1.4 Example 4 1.7 1.6 1.5 1.5 1.5 1.48 Example 5 1.7 1.6 1.4 1.5 1.4 1.3 Example 6 1.6 1.5 1.4 1.4 1.4 1.37 Comparative Example 1 1.7 1.6 1.5 1.4 1.0 1.0 Comparative Example 2 2.0 1.9 1.6 1.6 1.6 1.7 Comparative Example 3 1.6 1.5 1.4 1.2 0.9 0.9 Comparative Example 4 1.6 1.5 1.4 1.2 1.1 1.1 Comparative Example 5 1.7 1.5 1.4 1.4 1.2 1.1 Comparative Example 6 1.6 1.5 1.4 1.1 1.1 1.0

[0043]

(Table 4) (Fog density per printing number) Printing number (K) 0 0.01 1 3 5 10 Example 1 0.004 0.003 0.002 0.001 0.002 0.002 Example 2 0.001 0 0 0.001 0 0.001 Example 3 0.001 0 0 0 0 0 Example 4 0 0 0.001 0.001 0.001 0 Example 5 0.001 0 0 0 0 0.001 Example 6 0 0 0 0.001 0.001 0 Comparative example 1 0.001 0 0 0.001 0 0 Comparative example 2 0.008 0.00615 0.006 0.006 0.007 0.006 Comparative example 3 0 0.001 0 0 0 0 Comparative Example 4 0 0.001 0 0.001 0 0 Comparative Example 5 0.002 0.001 0 0 0 0 Comparative Example 6 0 0.001 0 0 0 0

As is clear from the experimental results in Tables 2 to 4,
In the toners of Examples 1 to 6, the charge amount is stable at 20 to 30 μC / g even when the number of printings exceeds 1,000,
The image density (ID) is 1.4 or more, and the fog density (FD) is 0.4.
005, and a good image could be formed stably despite the large amount of the release agent (wax). On the other hand, in the toners of Comparative Examples 1 and 3 to 6, the charge amount gradually increased and exceeded 30 μ / g, and the image density (ID) was less than 1.4. I can't get an image. Comparative Example 2
Is too low, the fog density (FD) is 0.005
As a result, the toner was scattered in the apparatus, and the results were not satisfactory.

[0045]

According to the present invention, a polyester resin is selected as a fixing resin, and a styrene-acryl-quaternary ammonium salt copolymer resin having a quaternary ammonium salt content of 9 to 20% by weight has positive charge reinforcement. When used in combination with a positive charge control agent and a release agent, an excellent charge can be obtained even when the release agent is mixed and dispersed in such an amount that no offset occurs when used in an oilless fixing system. Stability can be ensured, and a full-color image with good color reproducibility can be formed over a long period of time.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G03G 9/08 361 (72) Inventor Yoko Matsuoka 1-2-28 Tamazo, Chuo-ku, Osaka F-term in Kyocera Mita Corporation (Reference) 2H005 AA01 AA06 AA21 CA04 CA08 DA03 EA07 2H033 AA09 AA11 AA32 BA58

Claims (5)

[Claims] 1. A positively chargeable full-color developing toner in which a colorant, a release agent, a positive charge control agent and a positive charge control reinforcing agent are dispersed in a polyester resin, wherein the release agent is 100% by weight of the polyester resin. The positive charge controlling agent is dispersed in an amount of 1 to 3 parts by weight per 100 parts by weight of the polyester resin, and the positive charge reinforcing agent is a styrene-based unit and an acrylic-based And a quaternary ammonium salt unit, the copolymer resin containing the quaternary ammonium salt unit in an amount of 9 to 20% by weight.
A positively chargeable full-color developing toner which is dispersed in an amount of 1 to 5 parts by weight per 0 parts by weight. 2. The copolymer resin as a positive charge reinforcing agent is a fourth resin.
Quaternary ammonium salt units / styrene units = 0.1 to 0.5
2. The positively chargeable full-color developing toner according to claim 1, wherein the toner is contained in a weight ratio of: 3. The quaternary ammonium salt unit of the copolymer resin is represented by the following formula: (A ¹ ) ₃ N ⁺ (A ² ) · B ^{− wherein} A ¹ is an alkyl group, and A ² is , An organic group containing an ethylenically unsaturated double bond, and B ⁻ is a group derived from a quaternary ammonium salt compound represented by the formula: Chargeable full-color developing toner. 4. The positive charge controlling agent and the positive charge reinforcing agent,
4. The positively chargeable full-color developing toner according to claim 1, wherein the positive charge enhancer / positive charge control agent is dispersed in the polyester resin in a weight ratio of 1 to 5. 5. A full-color image formed on the surface of the transfer sheet by the positively chargeable full-color developing toner of claim 1 is fixed on the surface of the transfer sheet by using a fixing roller not coated with oil. Oilless fixing system.