JP3101782B2 - Full-color toner and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry developer for electrophotography, and more particularly to a full-color toner for a full-color copying machine using a non-magnetic toner and a magnetic toner at the same time, an image forming method using the toner, and a black-and-white method. The present invention relates to a full-color toner for a full-color developer composed of two components, a carrier and a toner, which is suitable for an image having different surface glossiness between a black image and a full-color image, and an image forming method using the toner. Things.

[0002]

2. Description of the Related Art In recent years, the development from black-and-white copying machines to full-color copying machines has been rapidly progressing, and the market for two-color copying machines and digitized full-color copying machines has been increasing.

In general, full-color image formation by electrophotography is performed in three primary colors, yellow, magenta, and cyan.
The color reproduction is performed by using color toners of four colors or four colors including black. As the method, first, an electrostatic latent image is formed on a photoconductive layer by passing light from a document through a color separation light transmitting filter having a complementary color relationship with the color of the toner. Next, the above-described steps are sequentially performed a plurality of times, and while the registration is being performed, the toner is overlaid on the same support, and the final full-color image is obtained by performing the fixing only once.

In general, many developing methods are known in such an electrophotographic method. In a full-color developing method, in particular, a magnetic brush method using a two-component developer mainly composed of a toner and a carrier, a cascade method, and the like. Has been widely put to practical use. Each of these methods is an excellent method that can obtain a good image relatively stably, but has the common drawbacks related to the two-component developer such as toner spent on the carrier surface and fluctuation of the mixing ratio of the toner and the carrier. .

In order to avoid such drawbacks, various developing methods using a one-component developer consisting of toner alone have been proposed. Among them, a method using a developer consisting of magnetic toner particles has excellent performance. There are many things.

However, among the materials used for the magnetic toner, especially the magnetic substance usually has a weight of 20% with respect to the whole toner.
-70% by weight, and is considered to be a factor that greatly affects the performance of the toner. For example, as can be seen in JP-A-58-189646, a magnetic toner containing a magnetic powder having an FeO content of 16 to 25% by weight can provide a high electrostatic image development efficiency and a good transfer efficiency. However, due to the restriction of magnetic powder in full-color toner, the frequency of use is low except for the case of using only black toner as a one-component toner. Is usually used for black and white copiers, but the resulting image is obtained because ordinary color toners pass through the fixing process in a form close to complete melting using a colorant such as a binder resin and dyes and pigments of very sharp melt. Has a high surface smoothness and a high-gloss copy image is obtained, whereas magnetic powder used in most black-and-white copiers contains about 20 to 70% by weight of magnetic powder. Even after fixing apparently uniform image surface is rough state, if a low image gloss is obtained is almost.

[0007] On the other hand, in recent years, with the widespread use of such full-color copiers, new user needs in the market have been demanding full-color copiers, printers, and the like to have functions of both monochrome and black-and-white machines. In other words, there is a demand for a copier capable of obtaining a clear, high-quality, full-color image while maintaining the color tone of black toner having the same speed and the same texture as a general-purpose black-and-white machine in an office environment. It is coming.

In other words, it is desired that the black toner in a full-color copying machine is made to have a low gloss like a black-and-white copying machine, so that a black image having the same texture can be obtained in all different copying machines. Like a general black and white machine,
Since the number of uses of the black toner alone increases and the toner consumption inevitably increases, the black toner in full-color copying machines required in the future is required to be improved particularly in terms of excellent image quality and durability stability. I have.

The effect of such a black toner means that the viscosity term is more important than the elastic term in the viscoelastic properties of the binder resin as the fixing property of the toner.

That is, at the time of heating, the toner behaves more viscously so that the heat melting property is increased and the gloss is obtained.

However, such a binder resin design emphasizing the viscosity term inevitably reduces intermolecular cohesion at the time of heat melting, and also increases the adhesion of the toner to the heat roller when passing through the fixing device. become. These cause the hot offset phenomenon.

In particular, when a silicone rubber roller is used as a fixing roller, a high-temperature offset is likely to occur due to a substantial reduction in the releasability of the surface of the silicone rubber roller which is repeatedly used regardless of whether a releasing oil is applied.
In the early stage of use of the silicone rubber roller, a certain degree of releasability can be maintained due to the smoothness and cleanliness of the roller surface. However, the image area is large like a color image, and the amount of toner held on a support such as plain paper is
If color copying, which is much more common than a black copy image, continues to be copied, the releasability of the roller gradually decreases. The speed at which the releasability deteriorates reaches several times that of black and white copying.

Further, since the toner itself has almost no elasticity as described above, it is ineffective for the anti-offset effect. As a result, after only several thousand to several tens of thousands of sheets, a toner film or a granular attachment is formed on the surface of the fixing roller, and the toner upper layer on the image surface is peeled off when passing through the heat roller. A so-called high-temperature offset occurs.

Various approaches have been tried with toners to solve or alleviate the above problems, but further improvements are desired. For example, JP-A-55-60960,
JP-A-57-208559, JP-A-58-119
No. 53, JP-A-58-14144, JP-A-58-14144
As described in JP-A No. 0-123852, a method of adding a low-molecular-weight polyethylene, polypropylene, wax, higher fatty acid, or the like, which is a releasing component, to a toner is also used in order to increase releasability. Although these methods are effective in preventing offset, they contain a large amount that is sufficiently effective in offset resistance, resulting in poor compatibility with the main binder resin and impairing the transparency of color toner OHP images. In addition, adverse effects such as unstable charging characteristics and reduced durability are also observed, and it is difficult to say that these are sufficient.

Further, Japanese Patent Application Laid-Open Nos. 47-12334, 57-37353, and 57-20855
In JP-A-9, a monomer containing an etherified bisphenol monomer, a dicarboxylic acid monomer, a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyhydric carboxylic acid monomer is disclosed. Although a toner containing a binder composed of a non-linear copolymer obtained as a component and a polyester as a binder has been proposed, such a technique includes a polyester composed of an etherified bisphenol monomer and a dicarboxylic acid monomer,
Offset to the toner by incorporating a polyester obtained by crosslinking with a large amount of a monomer component containing a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyhydric carboxylic acid monomer as a binder. It has a preventive performance. However, in such a toner, its softening point is slightly high, so that good low-temperature fixing is difficult.When a black toner using the polyester as a binder is used for full-color copying, the high-temperature offset resistance is poor. Although it is at a level that can be put to practical use, it has poor fixability and sharp meltability as described above, so that color mixing and color reproducibility cannot be expected. Also, JP-A-57-109825 and JP-A-62-78568.
JP-A-62-78569, JP-A-59-7960, JP-A-59-29256, and an etherified bisphenol monomer,
Contains a dicarboxylic acid monomer or other dicarboxylic acid monomer into which a long-chain aliphatic hydrocarbon has been introduced, and a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyhydric carboxylic acid monomer Disclosed is a toner containing, as a binder, a non-linear copolymer obtained from a monomer component, the polyester having a saturated or unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms in a side chain thereof. However, these polyester resins are mainly intended for toners for high-speed copying, and the viscoelastic properties of the resins are completely opposite to those of the above-mentioned viscosity-oriented polyesters. High temperature offset was significantly reduced. At the time of fixing, the pressure and heating of the heat roller are increased as much as possible, and the toner is pressed into the semi-molten state between the fibers of the transfer paper, and the pressure and heat are fixed to achieve the object. is there.

Therefore, it is almost impossible to obtain a smooth surface by fusing the toner layer necessary for full-color copying to form a continuous film, and the fixed toner is present in the form of particles on the transfer paper. The image is dull and lacks saturation. In the OHP image, light is scattered and diffused on the surface of the toner particles, hardly transmits light, and cannot be practically used.

Japanese Patent Application Laid-Open Nos. 2-73366 and 1-2224776 disclose novel polyester resins which are excellent in high-temperature offset resistance and can be applied to color copying. Indeed, although it is superior to the conventional resin for color toner, the effect of preventing the offset to the fixing roller is exhibited at most about 20,000 to 50,000 copies repeatedly, and the effect of preventing the offset of the black and white toner is 100,000 sheets. The above is sufficient, and it is preferable to further improve the performance in view of the fact that the printing durability and the offset resistance of hundreds of thousands of sheets are present at present. Further, the polyester has been studied with fixing property in color copying as a primary problem, and in terms of charge, the difference in charge amount between a low-temperature, low-humidity environment and a high-temperature, high-humidity environment is large. In a color image, the density tends to be slightly lower on the low humidity side, and on the high humidity side, toner scattering or fogging may occur.

Further, Japanese Patent Application Laid-Open No. Sho 62-195676,
JP-A-62-195678, JP-A-62-195
Japanese Patent No. 680 discloses a polyester resin in which the ratio between the hydroxyl value and the acid value is specified, and these polyester resins are also intended for high-speed fixing. And a full-color toner using the resin did not reach a point where sufficient color mixing was obtained.

As described above, when a magnetic toner and a non-magnetic toner are used together in a developing process in a full-color copying machine,
The problems caused by the differences as described above must be solved.

That is, in the magnetic toner, the dispersion state of the magnetic powder in the binder resin and the cleaning ability are regarded as problems. On the other hand, in the non-magnetic toner, the dispersion of the color dye and the pigment in the binder resin and the improvement of the light transmittance are improved. Is a problem. In addition, the fact that both toners finally have excellent fixability after solving such a problem can be cited as an indispensable factor in such a case.

Further, in a system in which a magnetic toner and a non-magnetic toner are mixed and multiplexed on the same image, there arises a problem that the fixed images of the magnetic toner and the non-magnetic toner have different surface smoothness. 20 to 70 magnetic powder in the magnetic toner
% By weight, and the apparently uniform image surface is in a rough state after fixing, whereas the non-magnetic toner containing dyes and pigments is completely melted.
Surface smoothness is superior to magnetic toner. Because of this, the angle of reflection of the light that shows the gloss that human eyes perceive differs, and nonmagnetic toners have high glossiness, whereas magnetic toners have poor glossiness. When an image is obtained, there arises a problem that the texture of the obtained image changes.

As described above, it is necessary to mainly improve the fixing characteristics of a full-color toner, particularly a black toner, to be used in a full-color copying machine to be used in the future.

That is, in order to satisfy the above-mentioned required properties, if a sharp-melt type binder resin of all colors is used, a very high level of image quality and fixing properties can be obtained in a pictorial image. However, during black-and-white copying, the gloss is higher than that obtained with other black-and-white copying machines due to its sharp melt property, and even with the same sample image, a strange image can be seen as a black image, and it is fixed in high-speed copying etc. There is a problem that an offset or the like to the roller occurs.

[0024]

SUMMARY OF THE INVENTION An object of the present invention is to provide a full-color toner and an image forming method which solve the above-mentioned problems.

That is, an object of the present invention is to provide a full-color toner having stable color reproduction, high image density, and high durability in a full-color toner using four color toners, and an image forming method using the toner. In full-color copying, (1) it shows good fixability and color mixing, (2) it has sufficient triboelectricity, and (3)
(4) Carrier spent is less likely to occur even after repeated copying and has excellent durability. (5) High-temperature offset is sufficiently prevented, and the fixing temperature range is wide. (6) An object of the present invention is to provide a color toner which maintains the offset resistance even after repeated fixing paper passing.

[0026]

The present invention attains the above objects and provides the following first to fourth inventions. That is, the first is a full-color toner that forms a color image by appropriately using at least one of a yellow toner, a magenta toner, and a cyan toner together with a black toner, and the yellow toner, the magenta toner, and the cyan toner. Is a non-magnetic toner in which an external additive is externally added to colored resin particles obtained by mixing and dispersing a colorant in a binder resin, wherein the binder resin is a diol component 45 selected from bisphenol derivatives or substituted products. And 55 to 45 mol% of a carboxylic acid component selected from dicarboxylic acids, acid anhydrides and lower alkyl esters thereof.
Having a hydroxyl value of 50 or less, a weight average molecular weight (Mw) of 6,000 to 100,000, and a number average molecular weight (Mn) of 1,500 to 50, 000, Mw / Mn is 4
Wherein the black toner is prepared by mixing and dispersing a magnetic iron oxide powder containing 25 to 30% by weight of FeO and a release agent in a binder resin, and externally adding an external additive to magnetic resin particles. A toner, wherein the binder resin comprises 25 to 35 mol% of an aromatic dicarboxylic acid component selected from isophthalic acid, terephthalic acid, and derivatives thereof; and an aromatic tricarboxylic acid component selected from trimellitic acid and derivatives thereof. 2-4mo
1%, 12 to 18 mo of a dicarboxylic acid component selected from dodecenylsuccinic acid, octylsuccinic acid, and anhydrides thereof
1%, and a polyester resin produced from a monomer composition comprising 45 to 60 mol% of a propoxylated and / or ethoxylated etherified diphenol component, wherein the hydroxyl value of the polyester resin is 10 to 20, Weight average molecular weight (Mw) is 13,000 to 20,000, number average molecular weight (Mn) is 5,000 to 8,000, Mw /
A full-color toner having Mn of 2 to 3.5.

The second type is a full-color toner for forming a color image by appropriately selecting at least one of yellow toner, magenta toner, cyan toner, and black toner. The binder resin used for the cyan toner is a diol component 4 selected from bisphenol derivatives or substituted products.
A polyester resin obtained by polycondensation of 55 to 55 mol% of a dicarboxylic acid, 55 to 45 mol% of a carboxylic acid component selected from an acid anhydride or a lower alkyl ester thereof, and a hydroxyl value of the polyester resin is 50
Hereinafter, the weight average molecular weight (Mw) is from 6,000 to 100,
000, number average molecular weight (Mn) is 1,500 to 50,000
00, Mw / Mn is 4 to 6, and the binder resin used for the black toner is an aromatic dicarboxylic acid component 25 selected from isophthalic acid, terephthalic acid, and derivatives thereof.
３５35 mol%, 2-4 mol% of an aromatic tricarboxylic acid component selected from trimellitic acid and derivatives thereof, 12-18 mol% of a dicarboxylic acid component selected from dodecenyl succinic acid, octyl succinic acid and anhydride thereof, and It contains a polyester resin produced from a monomer composition comprising 45 to 60 mol% of a propoxylated and / or ethoxylated etherified diphenol component, the polyester resin has a hydroxyl value of 10 to 20, and a weight average molecular weight (Mw). ) Is 13,000 to 20,000, the number average molecular weight (Mn) is 5,000 to 8,000, and Mw / Mn is 2 to
3.5 is a full-color toner.

Thirdly, the first full-color toner is used, and at least one of a yellow toner, a magenta toner, and a cyan toner is appropriately and selectively used together with a black toner to form an electrostatic charge on an electrostatic image carrier. An image forming method includes developing an image to form a toner image, and sequentially transferring the toner image onto a transfer material to form an image.

Fourth, using the second full-color toner, a yellow toner, a magenta toner, a cyan toner,
And developing the electrostatic image on the electrostatic image carrier to form a toner image by appropriately using at least one of black toner and forming a toner image, and sequentially transferring the toner image onto a transfer material to form an image. This is an image forming method characterized by performing the following.

The compositions of the polyester resins used in the yellow, magenta and cyan toners constituting the first and third full-color toners of the present invention are as follows.

As the polyester resin, 4% of all components
5 to 55 mol% is a diol component, and 55 to 45 m
ol% is the carboxylic acid component.

In this case, a bisphenol derivative represented by the following formula (I) or a substituted product thereof is used as the diol component.

[0033]

Embedded image (Wherein R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2
The carboxylic acid component is a dicarboxylic acid such as fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, or an acid anhydride thereof, or a lower alkyl ester. Is used.

The polyester resin obtained with the carboxylic acid and alcohol shown above has sharp melting properties,
It has good color mixing properties as a full-color toner and a heat roller fixing toner, and has excellent offset resistance.

The polyester resin obtained here has a glass transition temperature of 50 to 75 ° C., preferably 55 to 65 ° C.
C is desirable.

Further, the number average molecular weight Mn is from 1,500 to
50,000, preferably 2,000 to 20,000,
The weight average molecular weight Mw is from 6,000 to 100,000, preferably from 10,000 to 90,000, and Mw / M
n is 4-6.

The hydroxyl value is 50 or less, preferably 30 or less. This is because, as the number of terminal groups in the molecular chain increases, the charging characteristics of the toner become more environmentally dependent.

The polyester resin used in the black toner of the present invention can be said to have a so-called transient character, which has the characteristics of both a linear polyester resin and a non-linear crosslinked polyester resin. Thus, it is considered that when used as a full-color toner, good color mixing properties and color reproducibility were obtained, and the anti-offset to the fixing roller was obtained.

That is, the reason why preferable characteristics can be obtained by using a specific polyester resin for the black toner in the present invention is presumed as follows. (A) Trimellitic acid, which is a cross-linking monomer component, contains at most 20 to 30 units of a condensate of one molecule of a divalent acid component and one molecule of a dihydric alcohol component in a repeating linear condensate chain at most. Introduces one molecule to form weak crosslinks. And although it is a weak crosslink, the entire condensate in the polyester is constituted as one three-dimensional polymer. This provides much better offset resistance than a mixture of mere linear polyesters. However, the level of cross-linking of the present invention is also within a range that does not prevent easy mobility of the polyester resin by heat. (B) By extremely limiting the composition and amount of the divalent acid component having a soft segment, when obtaining a full-color image, good results of color mixing and color reproducibility are obtained, and the offset resistance is adversely affected. To prevent it from happening. In the weakly crosslinked condensate in the feature (a), the amount of the crosslinkable acid component and the amount of the acid component are determined so as to naturally maintain a balance. If the amount is too large, an abnormal sharp melt property is generated. In the color image, the gloss and the saturation are reduced.

In the present invention, while using a trivalent carboxylic acid as an essential component, the molecular weight distribution is narrower than that of an ordinary crosslinked binder resin (Mw / Mn = 2 to 3.5, preferably 2.0 to 3). .0), the above effect can be achieved. (C) The other divalent acid component is isophthalic acid or terephthalic acid, and a composition having elasticity without reducing the viscosity of the polymer is selected as much as possible. On the other hand, if the acid component is changed to an aliphatic acid component, the molecular chain becomes linear and long, so that the molecular chain is easily moved by heat, and the polymer exhibits more viscous behavior, and the fixing roller Offset to is easier. (D) The production conditions of the polyester resin of the present invention are changed from the conventional ones, and the molecular weight distribution of the resin is particularly adjusted to be as sharp and narrow as possible. It is important to make the distribution of the molecular chains of the condensate in the polyester uniform within a narrow range in order to achieve both the color mixing property and the offset resistance in the color toner. That is, a condensate with a short molecular chain having a small molecular weight is easily heated, and the main chain of the molecule moves. Conversely, a condensate with a long molecular chain having a high molecular weight hardly moves with its thermal energy. When the unbalance exists in the polyester resin, when a color toner using the resin passes through a low-temperature fixing roller,
A phenomenon occurs in which a low molecular condensate quickly melts, exhibits a behavior of fixing and mixing colors, and a high molecular condensate hardly dissolves.

On the other hand, if a high temperature at which the polymer is melted is applied to the fixing roller, the low molecule behaves as a viscous material having no elasticity at all, and causes a high temperature offset.

Therefore, in particular, in the case of a full-color toner, the ratio between the weight average molecular weight and the number average molecular weight is required to have a relatively sharp melt property and to increase the intermolecular aggregation of the polyester resin constituting the toner. Needs to be as small as possible. This is an important attribute beyond that discussed for black and white toner. (E) In the feature (d), it is stated that the change of the production conditions of the polyester resin is indispensable for the control of the molecular weight distribution. However, in order to keep the value of the hydroxyl value within a certain range, the production conditions are changed. Is necessary. The hydroxyl value is a measure of the hydratability of the resin and is an important factor influencing the chargeability of the color toner. If the value is too large or too small, favorable charging characteristics cannot be obtained.

The value of the hydroxyl value is determined only by the production conditions of the composition constituting the polyester resin according to the present invention. However, in order to achieve both the fixing property and the charging property satisfying the color mixing property, color reproducibility and offset resistance of the color toner, the conditions (a) to (d) must be satisfied.

Although the monomer composition and the like according to the present invention can be seen at first glance to be similar to the prior art, the true aim of the present invention and the attained technical achievement are the conventional polyester resin and color toner. It could not be reached.

Therefore, in the black toner of the present invention, it is extremely difficult to attain the object of the present invention unless the monomer component, composition ratio, and various physical properties are in ranges other than those disclosed in the present invention.

The preferred etherified diphenol in the present invention is an etherified bisphenol. Preferred etherified bisphenols are ethoxylated or propoxylated, with 2-3 moles of oxyethylene or oxypropylene per mole of bisphenol.

The coloring agents suitable for the purpose of the present invention include the following pigments or dyes. In the present invention, C.I. I. Disperse Y164; I. Solvent Y77 and C.I. I. Colorants such as Solvent Y93 are not recommended.

As the dye, for example, C.I. I. Direct red 1; I. Direct red 4; I. Acid Red 1; I. Basic Red 1; I.
Modant Red 30; I. Direct blue 1;
C. I. Direct blue 2; I. Acid Blue 9; I. Acid blue 15; I. Basic blue 3; I. Basic blue 5; I. Modant Blue 7 and the like.

As the pigment, naphthol yellow S, Hansa yellow G, permanent yellow NCG, permanent orange GTR, pyrazolone orange, benzidine orange G, permanent red 4R, watching red calcium salt, brilliant carmine 3B, fast violet B, methyl violet Lake, phthalocyanine blue, fast sky blue, indanthrene blue BC and the like.

Preferably, disazo yellow, insoluble azo pigment and copper phthalocyanine are suitable as pigments, and basic dyes and oil-soluble dyes are suitable as dyes and pigments.

Particularly preferably, C.I. I. Pigment Yellow 17; I. Pigment Yellow 15; I. Pigment Yellow 13; I. Pigment Yellow 1
4; I. Pigment Yellow 12; I. Pigment Red 5; I. Pigment Red 3; I.
Pigment Red 2; I. Pigment Red 6;
C. I. Pigment Red 7; I. Pigment Blue 15; I. Pigment Blue 16 or a copper phthalocyanine pigment having the following structural formula (II) in which two or three substituents are substituted on the phthalocyanine skeleton.

[0052]

Embedded image As the dye, C.I. I. Solvent Red 49;
I. Solvent Red 52; I. Solvent Red 109; I. Basic Red 12; I. Basic Red 1; I. Basic Red 3b and the like.

With respect to the content of the yellow toner which is sensitive to the transparency of the OHP film,
12 parts by weight or less based on 100 parts by weight of the binder resin,
Preferably, it is 0.5 to 7 parts by weight.

If the content is more than 12 parts by weight, the reproducibility of human skin color as a mixed color of green, red, and human images is inferior.

For other magenta and cyan color toners, the amount is preferably 15 parts by weight or less, more preferably 0.1 to 9 parts by weight, based on 100 parts by weight of the binder resin.

The magnetic iron oxide powder having an FeO content of 25 to 30% by weight used in the black toner according to the first full-color toner of the present invention has a high blackness as a black pigment,
It has the effect of stabilizing the amount of toner charge to maintain an appropriate electric resistance, thereby improving the image density, and has the function of improving the fog rank on the image in terms of developability.

Here, when a magnetic iron oxide having an FeO content of less than 25% by weight is used for the toner, it becomes difficult to appropriately control the charge amount of the toner in a low-temperature and low-humidity environment, especially when considering application to a high-speed machine. However, it is not possible to sufficiently cope with a decrease in image density due to an excessive increase in the toner charge amount and a stain on the background, and it is also difficult to control a color tone for obtaining a clear color tone as a black toner.

On the other hand, when a magnetic iron oxide having an FeO content of more than 30% by weight is used for the toner, the charge amount of the toner is reduced particularly in a high humidity environment, and the image density is reduced.

This magnetic material has an average particle of 0.1 to 2 μm,
Preferably about 0.1 to 0.5 μm,
The amount contained in the toner is about 20 to 200 parts by weight, preferably 10 parts by weight, per 100 parts by weight of the resin component.
40 to 150 parts by weight to 0 parts by weight is good.

The magnetic iron oxide used in the present invention is iron sulfate (F
eSO ₄ ) is neutralized with caustic soda (NaOH) and Fe (O
H) ₂ is obtained, the pH is adjusted to 12 to 13 by alkali adjustment, and then oxidized by steam and air to obtain a magnetite slurry. In the next drying step, the drying temperature and the drying time are controlled using a hot air drier, so that the FeO in the magnetic iron oxide is controlled.
Can be controlled. After drying is completed, the powder is crushed to obtain magnetite powder.

Here, the measurement of FeO in the magnetic iron oxide is performed according to the following procedure.

1.000 g of magnetic iron oxide is placed in a 500 ml beaker, 50 ml of deionized water is added, and 20 ml of special grade sulfuric acid is further added to completely dissolve the magnetic iron oxide.

Next, 100 ml of deionized water was added, and Mn was further added.
SO ₄ , H ₂ SO ₄ and H ₃ PO ₄ (mol ratio 0.3:
2.0: After the MnSO ₄ mixture 10ml added a total of 180ml, which consists of 2.0), were taken 10ml, 0.
Titrate with 1N KMnO ₄ solution.

Then, according to the following formula, 1.000 g of magnetic iron oxide is obtained.
The FeO (%) contained therein is determined.

[0065]

(Equation 1) Further, as a colorant for the black toner in the second full-color toner of the present invention, carbon black having an average primary particle size of 50 to 70 μm is used, and the carbon black has a surface area of 10 μm.
４０40 m ² / g, oil absorption 50-100 cc / 100 g-
It is preferable that the DBP has a pH value of 6.0 to 9.0.

Particularly preferred ranges are respectively 60 to 70 m.
μ, 30-40 m ² / g, 60-70 cc / 100 g-
DBP.

When the average particle diameter is smaller than 50 μm, the amount of triboelectric charge between the toner particles and the carrier particles decreases, causing toner scattering and fogging. When the surface area exceeds 40 m ² / g. The toner scatters at the edge of the obtained visible image, and the oil absorption exceeds 100 cc / 100 g-DBP, causing the aggregation of carbon black particles during image fixation, resulting in 50 cc / 1.
If it is less than 00 g-DBP, a sufficient image density cannot be obtained. On the other hand, when the pH value is less than 6.0, the dispersion of carbon black in the binder resin becomes non-uniform, resulting in unstable charging ability.

In the measurement of the physical properties of the carbon black, the particle diameter was measured by directly and selectively counting the particle diameter in a scanning electron micrograph. Next, surface area, oil absorption,
A method for measuring the pH value will be described. The measurement of surface area is
Performed in accordance with the BET method in ASTM method D3037-78.

A mixed gas of N ₂ and He is caused to flow through carbon black, N ₂ is adsorbed, the amount is detected by a thermal conductivity cell, and the specific surface area of the sample is obtained by calculation from the amount of N ₂ adsorbed. 1) After drying the sample at 105 ° C. for 1 hour, 0.1 to 1 g is precisely weighed, placed in the U-shaped tube 14 and attached to the channel. 2) The N ₂ / He mixture ratio is changed by the flow controllers 10 and 11 and set to a predetermined P / P ₀ . 3) Open the cock and introduce the adsorption gas into the sample layer, then immerse the U-shaped tube in liquid N ₂ 13 to adsorb N ₂ . 4) After reaching the adsorption equilibrium, the liquid N ₂ was removed and exposed to the air for about 30 seconds.
Detach ₂ 5) A desorption curve is drawn on a recorder and the area is measured. 6) Using a calibration curve prepared by introducing a known amount of N ₂ prior to these operations, the N ₂ adsorption amount at a predetermined P / P ₀ is determined from the area obtained for the above sample.

Hereinafter, the surface area is obtained by applying the following equation.

[0071]

(Equation 2) P ₀ : Saturated vapor pressure of adsorbate at measurement temperature P: Pressure at adsorption equilibrium ν: Adsorption amount at adsorption equilibrium C: Constant The relationship between P / P ₀ and P / ν (P ₀ −P) is a straight line,
Ν _m is obtained from the gradient and the intercept. If ν _m is determined, the specific surface area S is calculated by the following equation.

S = A × ν _m × N / W where S: specific surface area A: cross-sectional area of adsorbed molecule N: Avogadro number W: sample amount Oil absorption (DBP method) The oil absorption is measured by ASTM method D2414-79. Perform according to. Operate the cock of the absorber meter, fill DBP (dibutyl phthalate) completely so that no air bubbles remain in the automatic burette system, and make the specifications of the apparatus the following conditions.

(1) Spring tension
2.68 kg / cm (2) Rotor speed 125 rpm (3) Scale of torque limit switch 5 (4) Damper valve 0.150 (5) DBP dripping speed 4 ml / m
After adjusting the dropping speed of the in DBP by actual measurement, a fixed amount of the dried sample is put into the absorption meter mixing chamber, the buret counter is set to zero, and the switch is automatically turned on to start dropping. When the torque reaches the set point (5 in this case), the limit switch is activated and the dripping stops automatically,
The scale (V) of the bullet counter at that time is read, and the oil absorption is calculated by the following equation.

OA = (V / W) × 100 OA: Oil absorption (ml / 100 g) V: DB used up to the end point (limit switch operating point)
Amount of P used (ml) W: Weight of dried sample (g) pH value 1 to 10 g of carbon black is measured in a beaker, water is added at a ratio of 10 ml per 1 g of sample, covered with a watch glass, and boiled for 15 minutes. . To make the sample wet easily, a few drops of ethyl alcohol may be added. After boiling, cool to room temperature, remove the supernatant by decanting or centrifuging,
Leave mud. An electrode of a glass electrode pH meter is placed in the slurry, and the pH is measured according to JIS Z8802 (pH measurement method). In this case, the measured value may change depending on the insertion position of the electrode, so move the beaker to change the position of the electrode, and measure carefully so that the electrode surface and the muddy surface are in sufficient contact. Read the value where is constant.

In the present invention, carbon black is 2.0 to 10% by weight, preferably 3.10% by weight, based on the total weight of the toner.
It is preferable to use 0 to 7% by weight. If the added amount of carbon black is less than 2.0% by weight, the resulting visible image may be rough and the image density may be reduced.
If the content is more than 0% by weight, it scatters on an image and causes fogging.

The carrier used in the present invention includes, for example, metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium, rare earth and the like, and their alloys or oxides and magnetic ferrite, which are not oxidized or surface oxidized. Can be used. There is no particular restriction on the manufacturing method.

A system in which the surface of the carrier is immersed in a resin or the like is particularly preferable. As the method, any conventionally known method such as a method of dissolving or suspending a coating material such as a resin in a dissolving agent, coating and attaching to a carrier, or a method of simply mixing with a powder can be applied.

The substance fixed to the carrier surface varies depending on the toner material. For example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, Polyvinyl butyral, nigrosine, amino acrylate resin,
It is appropriate to use a basic dye and its lake, fine silica powder, fine alumina powder, a metal complex or metal salt of dialkylsalicylic acid alone or in combination.

The amount of the compound to be treated may be appropriately determined so that the carrier satisfies the above conditions, but is generally 0.1 to 30% by weight (preferably 0.5 to 30% by weight) based on the carrier of the present invention. 20% by weight).

The average particle size of these carriers is 20 to 100.
μm, preferably 25-70 μm, more preferably 25
It preferably has a thickness of up to 65 μm.

In a particularly preferred embodiment, Cu—Zn—
Fe ternary ferrite, the surface of which is a combination of a resin such as a fluorine resin and a styrene resin, for example, polyvinylidene fluoride and styrene-methyl methacrylate resin; polytetrafluoroethylene and styrene-methyl methacrylate resin; 90:10 to 20:80, preferably 70:30 to 3
0:70 mixture, 0.01 to 5% by weight, preferably 0.1 to 1% by weight.
The carrier may be a coated magnetic ferrite carrier having the above average particle diameter in which carrier particles of 50 mesh pass and 350 mesh on are 70% by weight or more. As the fluorine-based copolymer, a vinylidene fluoride-tetrafluoroethylene copolymer (10:90 to 90:10) is exemplified, and as the styrene-based copolymer, a styrene-2-ethylhexyl acrylate copolymer (20 : 80-80: 2
0), styrene-acrylic acid-ethylhexine-methyl methacrylate copolymer (20-60: 5-30: 30)
50) is exemplified.

The coated ferrite carrier has a sharp particle size distribution, provides favorable triboelectric charging properties to the toner of the present invention, and has the effect of improving electrophotographic properties.

When a two-component developer is prepared by mixing with the full-color toner of the present invention, the mixing ratio is 1% by weight to 15% by weight, preferably 2% by weight, as the toner concentration in the developer.
Good results are usually obtained at weight percents of up to 13 weight percent. If the toner concentration is less than 1% by weight, the image density will be low. If the toner concentration is more than 15% by weight, fog and scattering in the machine will increase, and the useful life of the developer tends to be shortened.

In the first full-color toner of the present invention, yellow toner, magenta toner and cyan toner are used.
In the second full-color toner, it is desirable that titanium oxide fine particles having a weight average particle diameter of 0.01 to 0.2 μm are externally added to the black toner. Although the initial cleaning property or the fluidity of the toner is improved by the hydrophobic silica generally known as a flow improver, the initial cleaning property or the environmental property cannot be maintained without stabilizing the charge of the toner. was difficult. However, by using the titanium oxide fine particles, the charge stability and the fluidity are improved, and the cleaning characteristics or the environmental characteristics can be improved.

In order to ensure the above performance and to have stable charging characteristics, it is preferable that the titanium oxide fine particles be contained in an amount of 0.5 to 1.0% by weight based on the toner.

Further, as titanium oxide fine particles particularly suitable for the present invention, it is preferable to use titanium oxide fine particles that have been surface-treated while hydrolyzing a coupling agent in an aqueous system.

If necessary, a fatty acid metal salt such as zinc stearate, aluminum stearate or the like, or a fine powder of a fluorine-containing polymer such as polytetrafluoroethylene, polyvinylidene fluoride or the like and tetrafluoroethylene A fine powder of vinylidene fluoride copolymer or a conductivity-imparting agent such as tin oxide or zinc oxide may be added.

The first full-color toner of the present invention preferably contains a flow improver as an external additive.

Any such fluidity improver can be used as long as it can be added to the colorant-containing resin particles to increase the fluidity before and after the addition.
For example, hydrophobic colloidal silica fine powder, colloidal silica fine powder, hydrophobic titanium oxide fine powder, titanium oxide fine powder, hydrophobic alumina fine powder, alumina fine powder, a mixed powder thereof, and the like, and the like. In this respect, those having a BET specific surface area of 50 m ² / g or more are preferred.

In particular, as the fluidity improver that can be contained in the black toner, a silica fine powder having a weight average diameter of 0.001 to 2 μm is preferable.

The silica fine powder includes wet-process silica,
There are dry-processed silica, silica treated with a silane coupling agent, titanium coupling agent, silicone oil, and the like on the silica, and a preferred silica fine powder is produced by vapor-phase oxidation of a silicon halide compound. This is a so-called dry process silica or fumed silica, which is manufactured by a conventionally known technique. For example, it utilizes the thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame, and the basic reaction formula is as follows.

SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl In this manufacturing process, another metal halide such as aluminum chloride or titanium chloride is used together with a silicon halide to produce a composite fine powder of silica and another metal oxide. It is also possible to obtain bodies, including them.

The particle size is 0.0% as the average primary particle size.
It is desirable to be within the range of 01 to 2 μm, and it is particularly preferable to use silica fine powder within the range of 0.002 to 0.2 μm.

The commercially available silica fine powder produced by the vapor phase oxidation of a silicon halide compound used in the present invention includes, for example, those commercially available under the following trade names.

Aerosil Nippon Aerosil Co., Ltd. 130 200 300 380 TT600 MOX170 MOX80 COK84 Ca-O-SiL Cabot Co., Ltd. (CABOT Co.) M-5 MS-7 MS-75 HS-5 EH-5 Wacker HDK N20 V15 Wacker Chemi N20E (WACKER-CHEMIE GMBH) T30 T40 DC fine silica (Fine Silica) Dow Corning Co. Furansol Co., Ltd. Fransil Co., Ltd. Further, it is more preferable to use a treated silica fine powder obtained by subjecting a silica fine powder produced by vapor-phase oxidation of the silicon halide compound to a hydrophobic treatment. It is particularly preferable that the treated silica fine powder is obtained by treating the silica fine powder such that the degree of hydrophobicity measured by a methanol titration test shows a value in the range of 30 to 80.

As a method for hydrophobizing, a reaction with silica fine powder
Alternatively, it is provided by a chemical treatment with an organic silicon compound that physically adsorbs.

As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halide is treated with an organosilicon compound.

Examples of such organosilicon compounds include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyl Dimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, ρ-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxy Silane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldi Examples include siloxane, 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having from 2 to 12 siloxane units per molecule and having a hydroxyl group bonded to Si, each of which is located at one terminal unit. . These are used alone or as a mixture of two or more.

The particle size of the treated silica fine powder is as follows.
It is preferable to use one having a range of 0.003 to 0.1 μm. Commercial products include Taranox-500 (Talco) and Aerosil R-972 (Nippon Aerosil).

The amount added to the magnetic resin particles is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the resin particles. When the amount is less than 0.01 part by weight, the fluidity is not improved, and when the amount is more than 10 parts by weight, fogging and bleeding of characters and scattering in the machine are promoted.

The magnetic black toner according to the first full-color toner of the present invention contains a release agent. The intention is that by specifying the molecular weight distribution of the binder resin in an appropriate range, the offset resistance is good, and the dispersion state of the magnetic powder in the binder resin is good, and a high-density visible image is obtained. However, if the magnetic and non-magnetic toners are present on the same latent image carrier as in the configuration according to the present invention, the fixability between the two toners is different, and after fixing, the layer surface is relatively Since the surface of the magnetic toner layer is rougher than the non-magnetic toner that can maintain a smooth state, when the transfer material such as paper and sheet is peeled off from the fixing heating roller, the releasability is improved. Must be further improved, and the addition of an auxiliary release agent leads to a further improvement in fixability.

As described above, the release agent used in the present invention has a melting start temperature of 40 ° C. or more, preferably 50 ° C. or more.
C. or higher and 50 to 250 ° C. as measured by DSC, preferably having at least two or more melting points between 70 to 200 ° C., or a mixture of two or more having different melting points. it can. This is because if the melting start temperature of the release agent is 40 ° C. or lower, blocking resistance is poor, and those having a plurality of melting points between 50 ° C. and 250 ° C. release over a wider range from low to high temperatures. This is because a mold effect can be exhibited. Further, more preferable use methods of the release agent for the binder resin used in the present invention include two types of release agents having different melting points and having no polar group and a release agent having a polar group. It is desirable to use a combination of the above. This is because, when the binder resin of the present invention is used, most of the non-polar release agent is present in the matrix resin, and conversely, most of the release agent having a polar group is present in the domain resin. By doing so, it has a releasing effect on both the matrix resin and the domain resin. Therefore, there is no problem even if one kind of release agent is used as long as it can be present in the matrix resin and the domain resin and has a plurality of melting points between 50 and 250 ° C.

The following are examples of the release agent having no polar group used in the present invention. Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or block copolymers thereof, and carnauba Examples of the wax include waxes mainly containing a fatty acid ester such as wax, sasol wax and montanic acid ester wax, and those obtained by partially or entirely deoxidizing fatty acid esters such as deoxidized carnauba wax. The following are examples of the releasing agent having a polar group used in the present invention. Saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid, unsaturated fatty acids such as brandinic acid, eleostearic acid, and vinaric acid, stearyl alcohol, alkyl alcohol, behenyl alcohol, carnaubyl alcohol, seryl alcohol, Saturated alcohols such as melisyl alcohol, polyhydric alcohols such as sorbitol, linoleic acid amide, oleic acid amide, fatty acid amides such as lauric amide, methylene bisstearic acid amide,
Saturated fatty acid bisamides such as ethylenebiscapric amide, ethylenebislauric amide, hexamethylenebisstearic acid amide, ethylenebisoleic amide, hexamethylenebisoleic amide, N, N '
Unsaturated fatty acid amides such as -dioleyl adipamide, N, N'-dioleyl sebacamide, m-
Aromatic bisamides such as xylene bisstearic acid amide and N, N'-distearyl isophthalic acid amide;
Using fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (commonly referred to as metal soaps), and aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid Examples of the grafted wax include a partially esterified product of a fatty acid such as behenic acid monoglyceride and a polyhydric alcohol, and a methyl ester compound having a hydroxyl group obtained by hydrogenation of a vegetable oil or the like.

The amount of the release agent used in the present invention is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the binder resin. If the amount of the release agent is at least 20 parts by weight, the blocking resistance and the high-temperature offset will be poor. If it is less than 1 part by weight, there is no releasing effect.

These release agents are usually contained in the binder resin by dissolving the resin in a solvent, increasing the temperature of the resin solution and adding and mixing while stirring, or by mixing at the time of kneading.

In a multicolor developing method of sequentially forming an image on a latent image carrier using these full-color toners, in the present invention, the black toner is developed on the latent image carrier in the first order, From the eyes onward, it is desirable to sequentially develop cyan toner, yellow toner, and magenta toner to form multiple images. In the case of a black-and-white copier as in the present invention, there are many chances of obtaining a monochromatic black color and a continuous copy image. If so-called coalescence between particles is performed, the fixing characteristic has two peaks. It is desirable to use a medium having a relatively high binder resin as a medium. However, when copying a pictorial image such as a full-color image, a clear color is required, and a binder resin that is relatively easy to melt is desired in order to make it easy to mix colors.

In the above case, in order to satisfy both, the influence of the surface gloss due to the difference of the binder resin as shown in FIGS. 1 and 3 is a factor largely influenced by the difference.

Therefore, when the magenta toner is developed in the first order and the multi-color development is performed in the conventional development order of sequentially developing the cyan toner, the yellow toner, and the black toner, the full-color toner of the present invention is used. In this case, the black toner comes to the uppermost layer, which impairs the glossiness of the three colors coming to the lower layer. In the case of a full-color image in which four colors are superimposed, different glossiness occurs particularly in the image portion. Result. For this reason, in the present invention, by obtaining a multi-color image in an appropriate development order, a low-gloss black toner is formed on the lowermost layer on the transfer paper to prevent irregular reflection of light, and to achieve uniform gloss. It is possible to obtain a full-color image having

The full-color toner of the present invention may contain a charge control agent for stabilizing the charge characteristics. At that time, a colorless or light-colored charge control agent that does not affect the color tone of the toner is preferable. In the present invention, when a negatively charged developer is used, the present invention is more effective. In this case, as the negatively charge controlling agent, for example, a metal complex of an alkyl-substituted salicylic acid (for example, chromium of di-tert-butylsalicylic acid) Complex or zinc complex).
When the negative charge control agent is blended in the toner, the binder resin 10
0.1 to 10 parts by weight, preferably 0.1 to 10 parts by weight, based on 0 parts by weight.
It is preferable to add 5 to 8 parts by weight.

The method for measuring each physical property value according to the present invention will be described below.

(1) Measurement of glass transition temperature Tg In the present invention, the measurement is carried out using a differential thermal analysis measuring device (DSC measuring device), DSC-7 (manufactured by PerkinElmer).

The measurement sample is 5 to 20 mg, preferably 10
Weigh the mg precisely.

This is put in an aluminum pan, and an empty aluminum pan is used as a reference. First, the following operation is performed for the purpose of deleting the previous history. Room temperature to 200 in N ₂ atmosphere
The temperature is raised to 10 ° C at 10 ° C / min and kept at 200 ° C for 10 minutes. Thereafter, the mixture is rapidly cooled, the temperature is lowered to 10 ° C., and the temperature is kept at 10 ° C. for 10 minutes. Then, at a heating rate of 10 ° C./min, 2
Raise the temperature to 00 ° C. In this heating process, the temperature is 40 to 10
An endothermic peak of the main peak in the range of 0 ° C. is obtained.

The intersection between the line of the midpoint of the baseline before and after the endothermic peak appears and the differential heat curve is defined as the glass transition temperature Tg in the present invention (see FIG. 2).

(2) GPC Measurement Method In the present invention, the molecular weight distribution of a chromatogram by GPC (gel permeation chromatography) using THF as a solvent is measured under the following conditions.

That is, the column is stabilized in a heat chamber at 40 ° C., THF (tetrahydrofuran) as a solvent is flown into the column at this temperature at a flow rate of 1 ml / min, and about 100 μl of a THF sample solution is injected to measure. .
In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number.
As a standard polystyrene sample for preparing a calibration curve, for example, Tosoh Corporation or Showa Denko Corporation has a molecular weight of 10 ²
Used of about 10 ^7, it is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns, and for example, Showdex GPC KF-801, 802, 80 manufactured by Showa Denko KK
3,804,805,806,807,800P or TSKgel G1000H manufactured by Tosoh Corporation
(H _XL ), G2000H (H _XL ), G3000H
(H _XL ), G4000H (H _XL ), G5000H
(H _XL ), G6000H (H _XL ), G7000H
(H _XL ), TSK guard column (guardcolumn)
n).

A sample is prepared as follows.

The sample is placed in THF, left for several hours, shaken sufficiently, mixed well with THF (until the sample is no longer united), and allowed to stand for 12 hours or more. At this time, TH
The time of leaving in F is set to 24 hours or more. Then, a sample processing filter (pore size 0.45 to
0.5 μm, for example, Myshoridisk H-25-6
A sample passed through Tosoh Corporation and an Exiclodisc 25CR (manufactured by Germanic Science Japan) can be used as a GPC sample. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml. (3) Measurement of hydroxyl value: It is measured by the following method according to the method shown in JIS K007.

6 g of a sample was placed in a 200 ml Erlenmeyer flask in 1 m.
The mixture was precisely weighed in units of g, and a mixed solution of acetic anhydride / pyridine = 1/4 was added with a 5 ml hole pipette.
Add 1 with a measuring cylinder. A condenser is attached to the conical flask, and the reaction is carried out in an oil bath at 100 ° C. for 90 minutes.

Add 3 ml of distilled water from the top of the cooler, shake well, and let stand for 10 minutes. With the condenser still attached, the conical flask is pulled up from the oil bath and allowed to cool. When the temperature reaches about 30 ° C., the condenser and the flask port are washed with a small amount of acetone (about 10 ml) from the upper port of the condenser. THF50
The mixture is added with a graduated cylinder, and a neutralization titration is performed using a 50 ml (0.1 ml scale) burette with an N / 2KOH-THF solution using an alcohol solution of phenolphthalein as an indicator. Immediately before neutralization end point, neutral alcohol 25ml
(Methanol / acetone = 1/1 volume ratio) and titration is performed until the solution shows a faint red color. At the same time, perform a blank test.

Next, the hydroxyl value is determined according to the following equation.

[0122]

(Equation 3) Here, A: number of ml of N / 2KOH-THF solution required for the main test B: number of ml of N / 2KOH-THF solution required for blank test f: titer of N / 2KOH-THF solution S: sampled amount (G) C: acid value or alkali value. However, the acid value is plus and the alkali value is minus.

The average value of the two measured values is adopted.

(4) Gloss (gloss) measuring method: VG-1
Using a 0-type gloss meter (manufactured by Nippon Denshoku), measurement is performed using each solid image used for chromaticity measurement as a sample.

[0125] As a measurement, first, a 6 V
Set to.

Next, the light projection angle and the light reception angle are each set to 60
Adjust to °.

Using the zero point adjustment and the standard plate, after setting the standard, place the sample image on the sample stage,
Perform overlay measurement on the sheet, and read the numerical value shown in the marked part in%.

At this time, the S, S / 10 switch SW is set to S, and the angle and sensitivity switch SW is set to 45-60.

A sample having an image density of 1.5 ± 0.1 is used.

[0130]

EXAMPLES Examples of the present invention will be described below, in which "parts" and "%" are all "parts by weight" and "% by weight".

Example 1 Polyester resin obtained by condensing 100 parts of propoxylated bisphenol and fumaric acid (Mn = 4000, Mw = 16000, Tg = 57 ° C., acid value = 6.7, OH value = 15) .6) C.I. I. Pigment Yellow 17 3.5 parts di-tert-butylsalicylic acid chromium complex 4 parts were sufficiently premixed with a Henschel mixer,
The mixture was melt-kneaded in a twin-screw extruder, cooled, and coarsely ground to a particle size of about 1 to 2 mm using a hammer mill. Next, it was pulverized by a pulverizer using an air jet method. Further, the obtained finely pulverized product was classified by a multi-segment classifier to obtain yellow resin particles having a weight average particle size of 8.0 μm.

With respect to 100 parts of the yellow resin particles, 0.7 parts of hydrophilic titanium oxide (BET 70 m ^{2 /} g) synthesized from titanium chloride and an average particle diameter of 0.4 μm
And 0.5 parts of the spherical methyl methacrylate resin particles were combined to obtain a yellow toner.

Next, C.I. I. A magenta toner was prepared in the same manner as the yellow toner using 4 parts of a rhodamine pigment instead of Pigment Yellow 17.

Next, C.I. I. Pigment Yellow 17 was replaced by 5 parts of a phthalocyanine pigment represented by the following structural formula, and a cyan toner was obtained in the same manner as the yellow toner.

[0135]

Embedded image The yellow, magenta, and cyan toners are mixed with Cu-Zn-Fe-based ferrite particles whose surfaces are coated with a methyl methacrylate-butyl acrylate (75:25) copolymer so as to have a toner concentration of 5%. Agent.

Next, C.I. I. Pigment Yellow 17, FeO content 26.1%, specific surface area 8.1 m ² /
g, 60 parts of magnetite having a bulk density of 0.44 g / cm ³ , the following resin (A) as a binder resin, and a low molecular weight polyethylene wax as a release agent (melting point 123 ° C., melting onset temperature 75 ° C.) 2.0 Parts and calcium laurate (1
Melting point peaks at 06,125,142,160 ° C,
0.5 part of silicate fine powder (BET 230 m ^{2 /} g) hydrophobized with hexamethyldisilazane and 0.5 part of strontium titanate are used as additives. Thus, a black magnetic toner was obtained.

(Polyester resin A) Terephthalic acid 2 m
ol, 1.09 mol of dodecenyl succinic anhydride, 3.4 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, and 0.01 g of dibutyltin oxide in a four-necked 21-neck glass flask. And a thermometer, a stir bar, a condenser, and a nitrogen inlet tube were attached and placed in a heating mantle. Next, after replacing the inside of the flask with nitrogen gas, the temperature was gradually increased while stirring,
The mixture was reacted at 170 ° C. for 5 hours, then heated to 190 ° C. and reacted for 4 hours. The hydroxyl value of the resin formed at this point was 59.8.

Thereafter, trimellitic anhydride 0.2 mol
l, and 0.08 g of dibutyltin oxide,
The mixture was further reacted at 300C for 3 hours, further heated to 200C, and reacted for 5 hours to complete the reaction, thereby obtaining a polyester resin (A).

At that time, the hydroxyl value was 16.8, the glass transition temperature was 64 ° C., the weight average molecular weight was 16,000, the number average molecular weight was 5,900, and the ratio was 2.7.

A commercially available color copier (CLC-500 manufactured by Canon) using the above three kinds of developers and black magnetic toner.
Was modified so that images could be output in the order of black, cyan, yellow, and magenta.
The image output was evaluated at a constant value of 50 V. However, even if the durability test was performed on 50,000 full-color images, the images had clear colors and the image quality was not significantly changed, and no ground fog was observed. The densities were as high as 1.4 to 1.5 for each color, and no cleaning failure after running was confirmed.

Further, an endurance test of 30,000 sheets was performed using only the black toner, and no toner fusion to the photosensitive member was observed.
No offset to the surface of the fixing roller was confirmed.

Example 2 In Example 1, the magnetite in the black toner had an FeO content of 28.1%, a specific surface area of 7.4 m ² / g and a bulk density of 0.46 g / cm ^3. When the same evaluation was performed except that the binder resin used was the resin shown in (B) below, a high image density was stably obtained, and the durability evaluation was 80,000 for a full-color image and 50,000 for a black image. However, no offset, poor cleaning or the like was observed.

(Polyester Resin B) Isophthalic Acid
8 mol, 1.06 mol of dodecenyl succinic anhydride, 3.5 mol of polyoxypropylene (2.0) -2,2-bis (4-hydroxyphenyl) propane
The reaction was carried out in a nitrogen atmosphere in the same manner as described above. Subsequently, 0.16 mol of trimellitic anhydride and 0.09 g of dibutyltin oxide were added, and the reaction was carried out at 180 ° C. for 5 hours to obtain a polyester resin (B) of the present invention. At that time, the hydroxyl value was 18.5, the glass transition temperature was 63 ° C, the weight average molecular weight was 17,000, the number average molecular weight was 5,800, and the ratio was about 2.9.

(Embodiment 3) In Embodiment 1, yellow,
The hydrophilic titanium oxide contained in each of the magenta and cyan toners uses 0.5 parts of hydrophilic titanium oxide (BET 120 m ² / g) synthesized from titanium isopropoxide, and is used as a binder resin for black toner. The same evaluation was performed except that the resin was the resin shown in (C) below. As a result, no offset and poor cleaning were observed, and stable image quality was obtained.

(Polyester resin C) Terephthalic acid 2 m
ol, 1.15 mol of octylsuccinic acid, and 3.6 mol of polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane were reacted in a nitrogen atmosphere in the same manner as the polyester resin A. Subsequently, 0.18 mol of trimellitic anhydride and 0.08 g of dibutyltin oxide were added, and the reaction was carried out at 180 ° C. for 5 hours to obtain a polyester resin (C) of the present invention.

This resin has a hydroxyl value of 16.5, a glass transition temperature of 64 ° C., a weight average molecular weight (Mw) of 17000, and a number average molecular weight (Mn) of 6300, and Mw / Mn is about 2.
It was 7.

(Polyester resin D) 2.0 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.
0) 2.1 mol of 2,2-bis (4-hydroxyphenyl) propane, 2 mol of terephthalic acid, 1.6 mol of dodecenylsuccinic acid, and 0.46 mol of trimellitic acid at 250 ° C. in the same apparatus as the polyester resin (A).
For 8 hours to obtain a polyester resin (D) of the present invention.

The resin had a hydroxyl value of 20.4, a weight average molecular weight (Mw) of 110,000, and a number average molecular weight (Mw) of 5
540, and Mw / Mn was about 19.9. The glass transition temperature was 61.5 ° C.

Example 4 Image formation was performed in the same manner as in Example 1, except that 0.5 parts of titanium oxide obtained by hydrophobizing hydrophilic titanium oxide with dimethyl silicone oil was used as an external additive used for the black toner. As a result, no fusion of the toner to the photoreceptor or the like occurred, and no significant change was observed in the image quality even when the durability test was performed on 50,000 sheets of black images.

(Comparative Example 1) The same evaluation was performed as in Example 1 except that the image was developed in the order of magenta, cyan, yellow, and black. No defective cleaning, no offset, etc. were found in the test, but in the case of a full-color image, the gloss of the gray image was insufficient, hindering the tint and leading to a reduction in the overall image quality.

(Comparative Example 2)
When the same evaluation was performed except that the binder resin used for each of the magenta and cyan toners was polyester resin D, the color was not sufficiently mixed and fixed in a full-color image because color was not sufficiently fixed at the time of fixing. And the offset occurred in the durability test of about 5,000 sheets.

(Comparative Example 3) Example 1 was repeated except that the toner was constituted in the same manner as in Example 2 except that the hydrophilic titanium oxide as a fluidity improver used for the color toner and the black toner was omitted.
The same evaluation as above was performed.
(0% RH), fog occurred on a white background.

Example 5 Polyester resin obtained by condensing 100 parts of propoxylated bisphenol and fumaric acid (Mn = 4000, Mw = 16000, Tg = 57 ° C., acid value = 6.7, OH value = 15 .6) C.I. I. Pigment Yellow 17 3.5 parts di-tert-butylsalicylic acid chromium complex 4 parts were sufficiently premixed with a Henschel mixer,
The mixture was melt-kneaded in a twin-screw extruder, cooled, and coarsely ground to a particle size of about 1 to 2 mm using a hammer mill. Next, it was pulverized by a pulverizer using an air jet method. Further, the obtained finely pulverized product was classified by a multi-segment classifier to obtain yellow resin particles having a weight average particle size of 8.0 μm.

Titanium oxide (BET 90 m ² / g) obtained by hydrophobizing hydrophilic titanium oxide synthesized from titanium chloride with respect to 100 parts of the yellow resin particles.
A yellow toner was obtained by combining the toner with 0 part.

Next, C.I. I. A magenta toner was prepared in the same manner as the yellow toner using 4 parts of a rhodamine pigment instead of Pigment Yellow 17.

Next, C.I. I. Pigment Yellow 17 was replaced by 5 parts of a phthalocyanine pigment represented by the following structural formula, and a cyan toner was obtained in the same manner as the yellow toner.

[0157]

Embedded image The yellow, magenta, and cyan toners are mixed with Cu-Zn-Fe-based ferrite particles whose surfaces are coated with a methyl methacrylate-butyl acrylate (75:25) copolymer so as to have a toner concentration of 5%. Agent.

Next, C.I. I. Pigment Yellow 17, average particle diameter 60 μm, surface area 30 m ² / g Oil absorption 6
A black toner was obtained by using 3.5 parts of carbon black having physical properties of 5 cc / 100 g and a pH value of 8.0 and using the polyester resin A as a binder resin.

A commercially available color copier (CLC-500) was prepared using the above-mentioned yellow, magenta, cyan and black developers.
Canon) in black, cyan, yellow,
Modification was performed so that images could be output in the magenta color order, and image output was evaluated with the development contrast kept constant at 350 V. However, even when a durability test was performed on 20,000 full-color images, a clear color tone was obtained. There was no significant change in image quality, no background fogging or the like was observed, and the image density was as high as 1.4 to 1.5 for each color, and no cleaning failure after running was confirmed at all.

Further, a durability test was conducted on 30,000 sheets using only the black toner, and no toner fusion to the photosensitive member was observed.
No offset to the surface of the fixing roller was confirmed, and the same texture as an image of a black-and-white copying machine was obtained.

(Example 6) Carbon black used as a colorant for a black toner in Example 5 had an average particle size of 6
8 mμ, surface area 20 m ² / g, oil absorption 76 cc / 100
g and pH value of 6.0, and the same evaluation was performed except that the binder resin used for the black toner was polyester resin B. As a result, a high image density was obtained stably, and 20,000 in a full-color image. The durability of 30,000 sheets was evaluated with respect to the sheets and the black image, but no offset, poor cleaning, etc. were found.

Example 7 The same evaluation was performed except that the binder resin used for the black toner was polyester resin C. No offset and poor cleaning were observed, and a glossy full-color image and black-and-white image were obtained. A black image having the same gloss as the copying machine was obtained.

(Comparative Example 4) The same evaluation was performed as in Example 5 except that the images were developed in the order of magenta, cyan, yellow, and black. No defective cleaning, no offset, etc. were observed in the test, but in the case of a full-color image, the color mixing was insufficient and the color was hindered.
The translucency of P and the like was also poor, resulting in a decrease in the overall image quality.

(Comparative Example 5)
When the same evaluation was performed except that the binder resin used for each of the magenta and cyan toners was polyester resin D, the color was not sufficiently mixed and fixed in a full-color image because color was not sufficiently fixed at the time of fixing. And the offset occurred in the durability test of about 5,000 sheets.

Comparative Example 6 The same evaluation as in Example 5 was carried out except that the toner was constituted in the same manner as in Example 6, except that titanium oxide as a fluidity improver used for the color toner and the black toner was used. Humid environment (30 ℃ / 80% R
H), fog occurred on the white background.

[0166]

The present invention has stable fixing characteristics in both black-and-white copying and color copying. Particularly in color copying,
This makes it possible to obtain an image having a higher glossiness without deteriorating the surface smoothness. In particular, in the first invention, it has become possible to improve image characteristics in a combined system of non-magnetic and magnetic toner.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating gloss of a black-and-white image and a full-color image.

FIG. 2 is a diagram illustrating a method of measuring a glass transition point.

FIG. 3 is a diagram illustrating gloss of a black-and-white image and a full-color image.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI G03G 9/087 G03G 9/08 101 15/01 331 (58) Investigated field (Int.Cl. ⁷ , DB name) G03G 9/08-9 / 09

Claims (9)

(57) [Claims] 1. A full-color toner for forming a color image by appropriately using at least one of yellow toner, magenta toner, and cyan toner together with a black toner, wherein the yellow toner, magenta toner, and cyan toner are used. Is a non-magnetic toner in which an external additive is externally added to colored resin particles obtained by mixing and dispersing a colorant in a binder resin, wherein the binder resin is a diol component 45 selected from bisphenol derivatives or substituted products. And 55 to 45 mol% of a carboxylic acid component selected from dicarboxylic acid, an acid anhydride thereof or a lower alkyl ester thereof, and a polyester resin having a hydroxyl value of 50 or less; Weight average molecular weight (Mw) of 6,000
~ 100,000, number average molecular weight (Mn) is 1,500
A magnetic resin obtained by mixing and dispersing a magnetic iron oxide powder containing 25 to 30% by weight of FeO and a release agent in a binder resin, wherein the black toner has a Mw / Mn of 4 to 6; A magnetic toner in which an external additive is externally added to particles, wherein the binder resin is an aromatic dicarboxylic acid component selected from isophthalic acid, terephthalic acid, and derivatives thereof.
35 mol%, 2 to 4 mol% of an aromatic tricarboxylic acid component selected from trimellitic acid and derivatives thereof, 12 to 18 mol% of a dicarboxylic acid component selected from dodecenyl succinic acid, octyl succinic acid and anhydride thereof, and propoxy Contains a polyester resin produced from a monomer composition comprising 45 to 60 mol% of an etherified diphenol component which has been converted and / or ethoxylated, wherein the polyester resin has a hydroxyl value of 10 to 20, and a weight average molecular weight (Mw). Is 13,000 to 20,000, the number average molecular weight (Mn) is 5,000 to 8,000, and Mw / Mn is 2 to 2.
3.5, a full-color toner. 2. A mold release agent having a melting onset temperature of 40 ° C. or higher and at least 2 to 50 to 250 ° C. as measured by DSC.
A release agent obtained by mixing one or more kinds having two or more melting points or two or more kinds having different melting points in the range,
2. The full-color toner according to claim 1, wherein the amount is 0.1 to 20 parts by weight per 100 parts by weight of the binder resin. 3. A yellow toner, a magenta toner and a cyan toner as an external additive having a weight average diameter of 0.01 to 3.
3. The full-color toner according to claim 1, wherein 0.2 μm titanium oxide fine particles are externally added to a black toner as a fluidity improver, silica fine powder having a weight average diameter of 0.001 to 2 μm. 4. A full-color toner for forming a color image by appropriately selecting at least one of a yellow toner, a magenta toner, a cyan toner, and a black toner, wherein the yellow toner, the magenta toner, and the cyan toner The binder resin used for the diol component 45 to 55 mol% selected from bisphenol derivatives or substituted products,
55 to 45 mol of a carboxylic acid component selected from dicarboxylic acids, acid anhydrides and lower alkyl esters thereof
%, A hydroxyl value of the polyester resin is 50 or less, a weight average molecular weight (Mw) is 6,000 to 100,000, and a number average molecular weight (Mn) is 1,500 to 50. 000, Mw / Mn is 4
Wherein the binder resin used in the black toner is 25 to 35 mol% of an aromatic dicarboxylic acid component selected from isophthalic acid, terephthalic acid, and derivatives thereof, and is selected from trimellitic acid and derivatives thereof. 2 to 4 mol% of an aromatic tricarboxylic acid component, 12 to 18 mol% of a dicarboxylic acid component selected from dodecenyl succinic acid, octyl succinic acid, and anhydride thereof, and 45 to 45 propoxylated and / or ethoxylated etherified diphenol components 60m
% of a polyester resin produced from a monomer composition comprising a polyester resin having a hydroxyl value of 10%.
-20, weight average molecular weight (Mw) of 13,000-2
000, the number average molecular weight (Mn) is 5,000-8,
000, Mw / Mn of 2 to 3.5. 5. A yellow toner, a magenta toner and a cyan toner as an external additive having a weight average diameter of 0.01 to
5. The full-color toner according to claim 4, wherein titanium oxide fine particles of 0.2 [mu] m are externally added. 6. A full-color toner according to claim 1, wherein the toner is a yellow toner, a magenta toner,
A toner image is formed by developing an electrostatic image on the electrostatic image carrier using at least one of cyan toner and black toner as appropriate, and sequentially transferring the toner image onto a transfer material. An image forming method comprising: 7. The image forming method according to claim 6, wherein a black toner is developed on the first layer on the transfer material to control image formation. 8. The electrostatic image bearing member according to claim 4, wherein at least one of a yellow toner, a magenta toner, a cyan toner and a black toner is selectively used as appropriate. An image forming method comprising: developing a charge image to form a toner image; and sequentially forming the toner image on a transfer material to form an image. 9. The image forming method according to claim 8, wherein a black toner is developed on the first layer on the transfer material to control image formation.