JP6824671B2 - toner - Google Patents

Description

The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method, a toner jet recording method, or the like.

In recent years, printers and copiers have been required to be downsized in consideration of energy saving and space saving. Further, as one method of reducing the size of the main body, there is a simplification of the fixing device. Examples of the simplification of the fixing device include film fixing that facilitates simplification of the heat source and the device configuration. Film fixing facilitates simplification of the heat source and device configuration, and the use of film as the fixing member improves thermal conductivity, so that the first printout time can be shortened. However, since the film is pressed against the roller at a relatively high pressure for use, problems such as wear of the film during long-term use are likely to occur.
In order to suppress these problems, toner that exhibits good low-temperature fixability even at light pressure is required. For example, if the fixing nip is light pressure and an image with a high print rate is output at high speed, it is given to the toner. There is a problem that the amount of heat is small and the deformation of the toner is insufficient, so that the toner is easily peeled off from the paper (cold offset).
As one method for improving the cold offset resistance of the toner, a method for adjusting the interfacial adhesion force and the internal cohesive force under appropriate conditions, which is measured by a specific measuring method, has been proposed (Patent Documents 1 and 2). reference).
In Patent Document 1, the interfacial adhesive force (Fr) between the toner and polytetrafluoroethylene, which is measured by using a specific measuring method, is 1.0 N or more and 3.5 N or less, and is similarly a specific measuring method. A toner having an internal cohesive force (Ft) of 10 N or more and 18 N or less measured using the above has been proposed. Further, Patent Document 2 proposes a toner having an internal cohesive force (F) of 5N or more and 10N or less and an interfacial adhesion force (f) of 0.5N or more and 1N or less, which is measured by using a specific measuring method. Has been done.

Japanese Unexamined Patent Publication No. 2006-330706 Japanese Unexamined Patent Publication No. 2014-071332

The toner described in Patent Document 1 has excellent cold offset resistance in a normal fixing machine configuration. However, when an image with a high printing rate is output at high speed in addition to further reducing the pressure of the fixing nip, the meltability with a small amount of pressure and heat is poor, and the cold offset resistance is still insufficient.
Further, in the measurement of Patent Document 2, there is a step of pressurizing and heating the toner, but in addition to heating the stage on which the toner is placed, the time for pressurizing and heating is 30 seconds, which is the actual fixing. It deviates from the momentary amount of heat given by. Therefore, even with the toner satisfying the above physical characteristics, the cold offset resistance when outputting an image with a high printing rate at high speed with the fixing nip under light pressure is still insufficient.
The present invention provides a toner that solves the above problems. More specifically, even in a light pressure type fuser, a toner having excellent cold offset resistance and hot offset resistance is provided when an image having a high printing rate is output at high speed.

As a result of diligent studies, the present inventors adjusted the instantaneous melting characteristics of the toner to a certain value or more under the condition of instantaneously applying heat using a tacking tester, and also adjusted the average circularity and softening point of the toner. The present invention has been completed by finding that the above-mentioned problems can be solved by adjusting the above to a certain range.
That is, the present invention is a toner having toner particles containing a binder resin, a wax, and a colorant.
The colorant is a magnetic material and
The softening point of the toner is 80 ° C. or higher and 140 ° C. or lower.
The average circularity of the toner is 0.940 or more, and the toner has an average circularity of 0.940 or more.
When the toner pellet obtained by compressing the toner is measured using a tacking tester, the integrated value of the stress of the toner at 150 ° C. is 78 g · m / sec or more.

The present invention provides a toner having excellent cold offset resistance and hot offset resistance even in a light pressure type fuser when an image having a high printing rate is output at high speed.

Schematic diagram of a tacking tester for measuring the integrated value of stress

The toner of the present invention is a toner having toner particles containing a binder resin, a wax, and a colorant. Further, the softening point of the toner is within a certain range, and when the toner pellet obtained by compressing the toner is measured using an average circularity and a tacking tester, the integrated value of the stress of the toner is equal to or more than a certain value. It is characterized by that.
The present inventors consider the reason why the present invention has solved the above problems as follows. In order to obtain excellent cold offset resistance, it is important that the toner is properly deformed by receiving heat and pressure, and that the toner surfaces are melted and bonded to each other by the heat. In particular, under a light pressure fixing nip, the toner is less likely to be thermally deformed, so that the importance of surface binding of the toner at the time of melting is considered to increase. Regarding the binding force between the toners at the time of melting, the toner itself is instantly plasticized and deformed to increase the contact area between the toners, thereby increasing the binding force and the surface of the toners at the time of melting. I presume that gender is also related.

Therefore, in order to improve the cold offset resistance under light pressure, it is essential to increase the binding force between the toners with respect to the instantaneous amount of heat. Therefore, by measuring the integrated value of the stress of the toner using a tacking tester and controlling this value, it is possible to increase the binding force between the toners against instantaneous heat.
It is important to measure under the following conditions as specific measurement conditions for the tacking tester.
Pressing temperature: 150 ° C
Pressing and holding time: 1s

That is, it has been found that the integrated value of the stress having a strong correlation with the cold offset resistance can be obtained by measuring under the above-mentioned conditions. Regarding this detail, the inventors speculate as follows.
First, regarding the pressing temperature, heat is taken away by continuously passing the media through the paper, so it is estimated that the amount of heat given to the toner is lower than the actual fixing set temperature. That is, 150 ° C. is appropriate as the pressing temperature, and if it is too high or too low than 150 ° C., the correlation with the cold offset resistance in the light pressure system image forming apparatus tends to be low. In addition, assuming a situation in which the media actually passes through the fixing nip, the pressing and holding time is preferably as short as 1 s.

Regarding the softening point of the toner, it is important to adjust the softening point within a certain range in order to improve the cold offset resistance. If the softening point is too low, the toner tends to peel off when the image is output at a high temperature (hot offset), and if the softening point is too high, thermal deformation is difficult with a small amount of heat and the toner tends to peel off. There is.
Further, increasing the average circularity is also essential for obtaining excellent cold offset resistance. If the average circularity is high, the toner on the media when output with high printing can be filled more densely, so that voids are less likely to occur between the toners, so that heat loss is reduced and heat is transferred to the toner firmly. Because it is done.
For the above reasons, the present invention has been completed by finding that a toner having excellent cold offset resistance can be obtained even under a light pressure if the above conditions can be satisfied. In the present invention, as a specific numerical value of light pressure, for example, a range of 69 kg · m / sec or less can be mentioned.
Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

In the present invention, when the toner pellet obtained by compressing the toner is measured by using a tacking tester, it is essential that the integrated value of stress at 150 ° C. is 78 g · m / sec or more. If it is less than 78 g · m / sec, the binding force of the toner at the time of melting is poor, and excellent cold offset resistance under light pressure cannot be obtained. Further, if the integrated value of the stress at 150 ° C. is preferably 78 g · m / sec or more, the desired effect can be obtained, but the toner can be applied while controlling the softening point within the desired range. When it is adjusted to such a range, it is preferably 200 g · m / sec or less. More preferably, it is 80 g · m / sec or more and 130 g · m / sec or less.
Examples of the method for controlling the integrated value of the stress of the toner at 150 ° C. include adjusting the thermal conductivity of the toner in addition to adjusting the amount and type of the binder resin, crystalline polyester, and wax. ..

Further, in order to obtain the above-mentioned cold offset resistance, it is essential that the softening point of the toner is 80 ° C. or higher and 140 ° C. or lower, and the average circularity of the toner is 0.940 or higher. When the softening point is lower than 80 ° C., even if the fixing nip is under light pressure, the pressure is high at the nip end, so that when an image is output at a high temperature, hot offset tends to occur around the end. Further, when the softening point is 140 ° C. or higher, the deformation at the nip portion is insufficient, so that the toner tends to be easily peeled off from the media and the cold offset resistance tends to be low, so that the desired effect under light pressure can be obtained. I can't. The softening point is preferably 90 ° C. or higher and 120 ° C. or lower.
Further, when the average circularity of the toner is less than 0.940, many voids are generated between the toner particles on the media, and heat tends to be easily released, so that the cold offset resistance under high-speed output tends to decrease. is there. The upper limit is not particularly limited, but is usually 1.00 or less, and the lower limit is more preferably 0.950 or more because it becomes easier to suppress heat loss due to the voids between the toners described above.

The softening point of the toner can be controlled by the type and amount of the cross-linking agent. Further, in the case of production by the suspension polymerization method described later, the type and amount of the initiator, the reaction temperature and the like can also be adjusted.
Further, the average circularity can be set to a desired range by a method for producing toner, for example, a method of pulverizing and then performing a thermal spheroidizing treatment, a suspension polymerization method or an emulsion polymerization method. From the viewpoint of improving the dispersibility of materials such as crystalline polyester and ester wax preferably used in the present invention in addition to the average circularity, a method for producing a toner suspended in an aqueous medium is preferable, and a suspension weight is more preferable. To use legality.

The material used for the toner of the present invention will be specifically described below.
The toner particles used in the present invention preferably contain crystalline polyester from the viewpoint of controlling the integrated value of stress to a desired value.
Here, the structure of crystalline polyester will be described. The crystalline polyester that can be used in the present invention preferably has a partial structure having a somewhat long hydrocarbon chain as a main chain. The crystalline polyester preferably has a partial structure represented by the following formula (1).

The length of the main chain is determined by the values of m and n in the partial structure, but from the viewpoint of encapsulating the crystalline polyester in an aqueous medium and improving storage stability, m is 4 or more and n is 6 or more. It is preferable to have. Further, specifically, from the viewpoint of increasing the solubility of the crystalline polyester itself, it is preferable that m is 14 or less and n is 16 or less. Regarding the partial structure, from the viewpoint of controlling the integrated value of stress within a range of a desired value, it is preferable that the partial structure has 50% by mass or more with respect to the entire crystalline polyester.

Next, as the crystalline polyester, known ones can be used, but it is preferably a polycondensate of an aliphatic dicarboxylic acid and an aliphatic diol. Further, saturated polyester is more preferable. Hereinafter, usable monomers will be illustrated.
Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid and the like.
Specific examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, trimethylene glycol, neopentyl glycol, and 1, 4-butanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12 -Dodecanediol and the like can be mentioned.

The crystalline polyester used in the present invention can be produced by a usual polyester synthesis method. For example, it can be obtained by subjecting a dicarboxylic acid component and a dialcohol component to an esterification reaction or a transesterification reaction, and then performing a polycondensation reaction under reduced pressure or by introducing nitrogen gas according to a conventional method.
At the time of esterification or transesterification reaction, a usual esterification catalyst such as sulfuric acid, tertiary butyl titanium butoxide, dibutyltin oxide, manganese acetate, magnesium acetate or the like or a transesterification catalyst can be used, if necessary. For polymerization, ordinary polymerization catalysts such as tertiary butyl titanium butoxide, dibutyl tin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide and the like can be used. it can. The polymerization temperature and the amount of catalyst are not particularly limited, and may be arbitrarily selected as needed.
A titanium catalyst is preferably used as the catalyst, and a chelate type titanium catalyst is more preferable. This is because the reactivity of the titanium catalyst is appropriate and the polyester having the desired molecular weight distribution in the present invention can be obtained.

The crystalline polyester preferably has a weight average molecular weight (Mw) of 10,000 or more and 40,000 or less, and more preferably 10,000 or more and 30,000 or less. This is because when the weight average molecular weight is in this range, the crystallinity of the crystalline polyester can be kept high, and the plasticizing effect of the crystalline polyester can be quickly obtained in the fixing step.
The weight average molecular weight (Mw) of the crystalline polyester can be controlled by various production conditions of the crystalline polyester.
Further, the acid value of the crystalline polyester is preferably controlled to be low when considering the dispersibility in the toner, and specifically, it is 8.0 mgKOH / g or less. More preferably, it is 5.0 mgKOH / g or less, and even more preferably 3.5 mgKOH / g or less.
The content of the crystalline polyester is preferably 1.0 part by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

Next, wax will be described.
First, the wax preferably contains an ester wax in order to control the integrated value of stress to a desired value. Regarding this, the inventor and the like describe that by containing the ester wax in the toner, in addition to improving the dispersibility of the crystalline polyester in the toner, the low molecular weight of the ester wax when heated. This is because it is considered that the components dissolve first and assist the exposure of the crystalline polyester to the surface.

In addition, known ester waxes can be used in the present invention. For example, waxes containing fatty acid esters such as carnauba wax and montanic acid ester wax as main components; and deoxidized fatty acid esters such as carnauba wax with some or all of the acid components deoxidized; vegetable fats and oils. Methyl ester compounds having a hydroxyl group obtained by hydrogenation of the above; saturated fatty acid monoesters such as stearyl stearate and behenyl behenyl; saturated fats such as dibehenyl sebacate, distearyl dodecane and distearyl octadecane Diesterates of group dicarboxylic acids and saturated aliphatic alcohols; examples thereof include diesterates of saturated aliphatic diols such as nonanediol dibehenate and dodecanediol distearate and saturated aliphatic monocarboxylic acids.
Among these waxes, a bifunctional ester wax (diester) having two ester bonds in the molecular structure is contained from the viewpoint of improving the dispersibility of the crystalline material and controlling the integrated value of stress to a more preferable value. It is preferable to do so.

The bifunctional ester wax is an ester compound of a divalent alcohol and an aliphatic monocarboxylic acid, or an ester compound of a divalent carboxylic acid and an aliphatic monoalcohol.
Specific examples of the above aliphatic monocarboxylic acid include myristic acid, palmitic acid, stearic acid, arachidic acid, behic acid, lignoceric acid, cerotic acid, montanic acid, melissic acid, oleic acid, vaccenic acid, and linoleic acid. Examples include linolenic acid.
Specific examples of the aliphatic monoalcohol include myristyl alcohol, cetanol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, tetracosanol, hexacosanol, octacosanol, triacontanol and the like.
Specific examples of the divalent carboxylic acid include butanedioic acid (succinic acid), pentanedioic acid (glutaric acid), hexanedioic acid (adipic acid), heptanedioic acid (pimelic acid), and octanedioic acid (sveric acid). , Nonanedioic acid (azelaic acid), decanedioic acid (sevacinic acid), dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosandioic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. Can be mentioned.
Specific examples of the divalent alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol. , 1,12-Dodecanediol, 1,14-Tetradecanediol, 1,16-Hexadecandiol, 1,18-Octadecanediol, 1,20-Eicosandiol, 1,30-Triacontanediol, Diethylene glycol, Di Examples include propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, spiroglycol, 1,4-phenylene glycol, bisphenol A, hydrogenated bisphenol A, etc. Be done.

In the present invention, waxes other than ester wax can be used in combination as long as the effects of the present invention are not impaired.
A known wax can be used as another wax to be combined with the ester wax, but an aliphatic hydrocarbon wax such as Fishertropshoe wax is preferably used from the viewpoint of releasability of the fixing roller and the toner. Can be done.
The mass ratio of the ester wax (A) to the aliphatic hydrocarbon wax (B) in the toner is preferably (A) / (B) of 0.25 or more and 4.0 or less, more preferably. It is 0.40 or more and 2.3 or less.
The wax content is preferably 5.0 parts by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin. The content of the ester wax is preferably 1.0 part by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

The binder resin used in the toner of the present invention is a monopolymer of styrene such as polystyrene and polyvinyltoluene and its substitution product; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer weight. Combined, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene -Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinylmethyl ether copolymer, styrene Styrene such as −vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer System copolymers; polymethylmethacrylate, polybutylmethacrylate, polyvinylacetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin can be used, and these can be used alone. Alternatively, a plurality of types can be used in combination. Of these, a styrene-based copolymer typified by styrene-butyl acrylate is particularly preferable in controlling the integrated value of stress within a desired range.
More preferably, it is a styrene-acrylic resin, for example, a styrene-methyl acrylate copolymer, a styrene-ethyl acrylate copolymer, a styrene-butyl acrylate copolymer, a styrene-octyl acrylate copolymer, styrene. -Dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylic acid copolymer, styrene-dimethylaminoethyl methacrylate copolymer And so on.

Next, examples of the colorant used in the present invention include the following organic pigments, organic dyes, and inorganic pigments.
Examples of the cyan-based colorant include a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound. Specifically, the following can be mentioned. C. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, and 66.
Examples of the magenta colorant include the following. Condensed azo compound, diketopyrrolopyrrole compound, anthraquinone compound, quinacridone compound, base dye lake compound, naphthol compound, benzimidazolone compound, thioindigo compound, and perylene compound. Specifically, the following can be mentioned. C. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 1
46, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254, and C.I. I. Pigment Violet 19.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following can be mentioned. C. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, 191 and 194.

Examples of the black colorant include carbon black and those colored black by using the above-mentioned yellow colorant, magenta colorant, cyan colorant, and magnetic material.
These colorants can be used alone or in the form of a solid solution. The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner particles.
Among the above, the colorant is preferably a magnetic material from the viewpoint of adjusting the thermal conductivity of the toner to a desired range. Further, in controlling the thermal conductivity, the toner of the present invention is preferably produced in an aqueous medium.
The amount of the colorant added is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the binder resin. When a magnetic material is used, it is preferably 20.0 parts by mass or more and 200.0 parts by mass or less, and more preferably 40.0 parts by mass or more and 150.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

The value of the thermal conductivity of the toner of the present invention is preferably 0.190 W / mK or more and 0.300 W / mK or less, and more preferably 0.230 W / mK or more and 0.270 W / mK or less. When it is 0.190 W / mK or more, heat between the toners is easily transferred, the binding property at the time of melting the toner becomes good, and the toner is hard to be peeled off from the media even if the fixed image is rubbed. Further, when it is 0.300 W / mK or less, the hot offset resistance at the end of the fixing nip having a high pressure becomes good at the time of fixing at a high temperature.
The thermal conductivity of the toner can be controlled by the content of the magnetic material, the particle size of the magnetic material, and the surface treatment of the magnetic material.

When a magnetic material is used for the toner of the present invention, the magnetic material preferably contains magnetic iron oxide such as triiron tetraoxide or γ-iron oxide as the main component, and phosphorus, cobalt, nickel, copper, magnesium, etc. It may contain elements such as manganese, aluminum and silicon. These magnetic materials preferably have a BET specific surface area of ² to 30 m ² / g by the nitrogen adsorption method, and more preferably 3 to 28 m ² / g. Further, those having a Mohs hardness of 5 to 7 are preferable. The shape of the magnetic material includes a polyhedron, an octahedron, a hexahedron, a sphere, a needle, and a scale, but a polyhedron, an octahedron, a hexahedron, a sphere, and the like with less anisotropy increase the image density. Preferred above.
The magnetic material preferably has a number average particle size of 0.10 to 0.40 μm. Generally, the smaller the particle size of the magnetic material, the higher the coloring power, but the above range is preferable from the viewpoint of preventing aggregation of the magnetic material and uniformly dispersing the magnetic material in the toner. Further, when the number average particle size is 0.10 μm or more, the magnetic material itself is less likely to become reddish black, and especially in a halftone image, the redness is less noticeable, and a high-quality image can be obtained. On the other hand, when the number average particle size is 0.40 μm or less, the coloring power of the toner becomes good and uniform dispersion becomes easy in the suspension polymerization method.

The number average particle diameter of the magnetic material can be measured using a transmission electron microscope. Specifically, after the toner particles to be observed are sufficiently dispersed in the epoxy resin, the cured product is obtained by curing in an atmosphere at a temperature of 40 ° C. for 2 days. The obtained cured product is used as a flaky sample by a microtome, and the diameters of 100 magnetic particles in the field of view are measured with a transmission electron microscope (TEM) at a magnification of 10,000 to 40,000 times. Then, the number average particle diameter is calculated based on the equivalent diameter of the circle equal to the projected area of the magnetic material. It is also possible to measure the particle size with an image analyzer.

The magnetic material used for the toner of the present invention can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide to the ferrous salt aqueous solution in an equivalent amount or equal to or more than the iron component. Air is blown while maintaining the pH of the prepared aqueous solution at pH 7 or higher, and the ferrous hydroxide oxidation reaction is carried out while heating the aqueous solution to 70 ° C. or higher to first generate seed crystals that form the core of magnetic iron oxide. ..
Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the liquid at 5 to 10, the reaction of ferrous hydroxide is promoted while blowing air to grow magnetic iron oxide powder around the seed crystal. At this time, it is possible to control the shape and magnetic characteristics of the magnetic material by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction progresses, the pH of the liquid shifts to the acidic side, but it is preferable that the pH of the liquid is not less than 5. The magnetic material thus obtained can be obtained by filtering, washing and drying the magnetic material by a conventional method.

Further, in the case of producing toner in an aqueous medium in the present invention, it is very preferable to hydrophobize the surface of the magnetic material. When surface treatment is performed by a dry method, a coupling agent treatment is performed on the washed, filtered, and dried magnetic material. When the surface treatment is performed in a wet manner, the dried iron oxide is redispersed after the oxidation reaction is completed, or the iron oxide obtained by washing and filtering after the oxidation reaction is completed in another aqueous medium without drying. Redisperse and perform coupling processing. In the present invention, both the dry method and the wet method can be appropriately selected.
Examples of the coupling agent that can be used in the surface treatment of the magnetic material in the present invention include a silane coupling agent, a silane compound, and a titanium coupling agent. More preferably used are silane coupling agents and silane compounds, which are represented by the general formula (I).
R _m SiY _n (I)
[In the formula, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a functional group such as an alkyl group, a phenyl group, a vinyl group, an epoxy group, and a (meth) acrylic group, and n is 1. Indicates an integer of ~ 3. However, m + n = 4. ]

Examples of the silane coupling agent or silane compound represented by the general formula (I) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and β- (3,4 epoxycyclohexyl) ethyltri. Methoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltri Methoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-propyltri Methoxysilane, isopropyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, trimethylmethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxy Examples thereof include silane, hydroxypropyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane. In the present invention, those in which Y of the general formula (I) is an alkyl group can be preferably used. Among them, from the viewpoint of setting the thermal conductivity to a desired value, Y is preferably an alkyl group having 3 or more carbon atoms and 6 or less carbon atoms, and particularly preferably an alkyl group having 3 or 4 carbon atoms.

When the above silane coupling agent is used, it can be treated alone or in combination of a plurality of types. When a plurality of types are used in combination, they may be treated individually with each coupling agent or may be treated at the same time.
The total amount of the coupling agent used is preferably 0.9 to 3.0 parts by mass with respect to 100 parts by mass of the magnetic material. The amount of the treatment agent can be adjusted according to the surface area of the magnetic material, the reactivity of the coupling agent, and the like.

In the present invention, other colorants may be used in combination with the magnetic material. Examples of the colorant that can be used in combination include the above-mentioned known dyes and pigments, as well as magnetic or non-magnetic inorganic compounds. Specifically, ferromagnetic metal particles such as cobalt and nickel, or alloys obtained by adding chromium, manganese, copper, zinc, aluminum, rare earth elements, etc. to these. Particles such as hematite, titanium black, niglosin dye / pigment, carbon black, phthalocyanine and the like can be mentioned. These are also preferably used after surface treatment.
The content of the magnetic substance in the toner can be measured by using a thermal analyzer TGA7 manufactured by PerkinElmer. The measurement method is as follows. The toner is heated from room temperature to 900 ° C. at a heating rate of 25 ° C./min in a nitrogen atmosphere. The weight loss mass% between 100 ° C. and 750 ° C. is defined as the amount of binder resin, and the residual mass is approximately defined as the amount of magnetic material.

Next, the weight average particle size (D4) of the toner produced by the present invention is preferably 3.0 μm or more and 12.0 μm or less, and more preferably 4.0 μm or more and 10.0 μm or less. When the weight average particle size (D4) is 3.0 μm or more and 12.0 μm or less, good fluidity can be obtained, and the latent image can be faithfully developed.

The toner of the present invention can be produced by thermosphere-forming the toner particles obtained by the pulverization method, but it is also possible to control the existence state of a material such as crystalline polyester or ester wax in an aqueous medium. It is preferable to produce toner. In particular, the suspension polymerization method is preferable because it is easy to control the fine dispersion of the crystalline polyester and the promotion of crystallization.

The suspension polymerization method will be described below.
The method for producing a toner using the suspension polymerization method includes a polymerizable monomer, a wax and a colorant (further, if necessary, a crystalline polyester, a polymerization initiator, a cross-linking agent, a charge control agent, etc.) constituting the binder resin. Other additives) are uniformly dissolved or dispersed to obtain a polymerizable monomer composition. Then, the polymerizable monomer composition is dispersed in a continuous phase (for example, an aqueous phase) containing a dispersant using an appropriate stirrer, and the polymerizable monomer composition is dispersed in the aqueous medium. It includes a step of forming particles and a step of polymerizing the polymerizable monomer contained in the particles of the polymerizable monomer composition. Since the toners obtained by this suspension polymerization method (hereinafter, also referred to as "polymerized toners") have almost spherical shapes of individual toner particles, the distribution of the amount of charge is relatively uniform, so that the image quality is improved. You can expect it. Further, in the step of polymerizing the above-mentioned polymerizable monomer, the polymerization temperature may be set to 40 ° C. or higher, generally 50 ° C. or higher and 90 ° C. or lower.

Examples of the polymerizable monomer constituting the polymerizable monomer composition include the following.
As the polymerizable monomer, styrene-based monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methylacrylic acid, ethylacrylic acid, etc. Acrylic acids such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate and the like. Kind, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid esters such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; other monomers such as acrylonitrile, methacrylonitrile and acrylamide can be mentioned. These monomers can be used alone or in admixture. Among the above-mentioned monomers, it is preferable to use styrene alone or in combination with other monomers from the viewpoint of toner development characteristics and durability.

The polymerization initiator used in the production of the toner by the polymerization method of the present invention preferably has a half-life of 0.5 to 30 hours during the polymerization reaction. Further, when the polymerization reaction is carried out by using an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, a polymer having a maximum molecular weight between 5,000 and 50,000 is obtained. It is possible to give the toner the desired strength and suitable melting properties.
Specific examples of polymerization initiators include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, and 1,1'-azobis (cyclohexane-1-). Carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropylper Oxycarbonate, cumenehydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy2-ethylhexanoate, t-butylperoxypivalate, di (2-ethylhexyl) peroxydi Peroxide-based polymerization initiators such as carbonate and di (secondary butyl) peroxydicarbonate can be mentioned.

When the toner of the present invention is produced by the polymerization method, a cross-linking agent may be added, and the preferable amount of addition is 0.001 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. is there.
Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used, and for example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate and ethylene glycol di. A carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate; a divinyl compound such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and having three or more vinyl groups. Compound; is used alone or as a mixture of two or more.

When the medium used for the polymerization of the polymerizable monomer is an aqueous medium, a dispersion stabilizer is used to stabilize the particles of the polymerizable monomer composition. The following can be used as the dispersion stabilizer.
As an inorganic dispersion stabilizer, tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like.
Examples of the organic dispersion stabilizer include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch.

Furthermore, commercially available nonionic, anionic and cationic surfactants can also be used. Examples of such a surfactant include the following. Sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate.
In the present invention, when a poorly water-soluble inorganic dispersion stabilizer is used to prepare an aqueous medium, the amount of these dispersion stabilizers added is 0.2 to 2 with respect to 100.0 parts by mass of the polymerizable monomer. It is preferably 9.0 parts by mass. Further, 300 to 3,0 with respect to 100 parts by mass of the polymerizable monomer composition.
It is preferable to prepare an aqueous medium using 00 parts by mass of water.
In the present invention, when preparing an aqueous medium in which the above-mentioned poorly water-soluble inorganic dispersant is dispersed, a commercially available dispersion stabilizer may be used as it is. Further, in order to obtain a dispersion stabilizer having a fine and uniform particle size, a poorly water-soluble inorganic dispersant may be produced in a liquid medium such as water under high-speed stirring. Specifically, when tricalcium phosphate is used as a dispersion stabilizer, a preferable dispersion stabilizer is formed by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring to form fine particles of tricalcium phosphate. Can be obtained.

In the present invention, in order to control the integrated value of the stress of the toner, it becomes easy to control within the above range by using the method described below.
For example, after polymerizing the above polymerizable monomer to obtain resin particles, the temperature of the dispersion in which the resin particles are dispersed in an aqueous medium is raised to a temperature exceeding the melting points of the crystalline polyester and wax. However, this operation is not necessary when the polymerization temperature exceeds the melting point.
Regarding the cooling rate in the subsequent cooling step, not only the polymerization method but also the toner manufacturing method in general will be described as a preferable range in the present invention.
Focus on the method for producing toner for the purpose of crystallizing crystalline substances, especially crystalline polyester.
For example, when toner is produced by a pulverization method, suspension polymerization, or emulsion polymerization, it is preferable to include a step of raising the temperature to a temperature at which the crystalline polyester or wax melts and then cooling to room temperature. Considering the cooling process, the molecular motion of the crystalline polyester liquefied by the temperature rise becomes slower as the temperature decreases, and crystallization starts when the temperature reaches the vicinity of the crystallization temperature. Further cooling promotes crystallization and completely solidifies at room temperature. According to the study by the present inventors, it was found that the crystallinity of the crystalline substance differs depending on the cooling rate.
Specifically, when the crystalline polyester or wax is cooled at a rate of 5.0 ° C./min or more from a sufficiently high temperature (for example, 100 ° C.) at which the crystalline polyester or wax melts to a temperature below the glass transition temperature of the toner, the crystalline substance contained therein The crystallinity tended to increase. By setting the cooling conditions as described above, it becomes easy to control the integrated value of the stress of the toner within the above range.
More specifically, the state in which the cooling rate is sufficiently high is the case where the cooling is performed at a rate sufficiently faster than 5.0 ° C./min as described above. This cooling rate is preferably 10.0 ° C./min or higher, more preferably 30.0 ° C./min or higher, and even more preferably 50.0 ° C./min or higher. The upper limit of the cooling rate is about 3000 ° C./min at which the effect is saturated.
Further, after cooling the dispersion to a temperature equal to or lower than the glass transition temperature of the toner at a sufficiently high cooling rate, the dispersion is held at a temperature equal to or lower than the glass transition temperature of the toner for 30 minutes or more, and then the cooling rate is 1.0 ° C./. It is preferable to cool at a relatively slow cooling rate of minutes or less.
By holding the toner at a temperature equal to or lower than the glass transition temperature of the toner for 30 minutes or more, the annealing treatment can be performed and the crystallinity of the crystalline polyester can be improved. The holding time is preferably 100 minutes or more, and more preferably 180 minutes or more. The upper limit of the holding time is about 1440 minutes when the effect is saturated.
In the present invention, cooling at a cooling rate of 1.0 ° C./min or less is referred to as gradual cooling. As a result, the same effect as the annealing treatment can be obtained, the crystallinity of the crystalline polyester can be further increased, and the integrated value of the stress of the toner can be easily controlled within the above range. The cooling rate is preferably 0.50 ° C./min or less, more preferably 0.01 ° C./min or less. The dispersion containing the toner particles obtained by performing the above-mentioned gentle cooling is filtered, washed, and dried by a known method to obtain toner particles.

In the present invention, the toner particles may contain a polar resin. As the polar resin, a saturated or unsaturated polyester resin can be preferably exemplified. The polar resin is preferably an amorphous resin.
As the polyester resin, one obtained by condensation polymerization of the carboxylic acid component and the alcohol component listed below can be used.
Examples of the carboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid.
Examples of the alcohol component include bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.
Further, the polyester resin may be a polyester resin containing a urea group. In the present invention, the weight average molecular weight of the polar resin is preferably 4,000 or more and less than 100,000. The content of the polar resin is preferably 3.0 parts by mass or more and 70.0 parts by mass or less, and more preferably 3.0 parts by mass or more and 50.0 parts by mass with respect to 100 parts by mass of the binder resin. It is less than or equal to, more preferably 5.0 parts by mass or more and 30.0 parts by mass or less.

In the present invention, the toner particles may contain a charge control agent. As the charge control agent, known ones can be used. In particular, a charge control agent having a high charge speed and capable of stably maintaining a constant charge amount is preferable. Further, when the toner particles are produced by the direct polymerization method, a charge control agent having low polymerization inhibitory property and substantially no solubilized product in an aqueous medium is particularly preferable.
Examples of the charge control agent that controls the toner particles to be charge-electric are as follows. Examples of the organic metal compound and chelate compound include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids and dicarboxylic acid-based metal compounds. Others include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, phenol derivatives such as bisphenol, and the like. Further, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, calixarene and the like can be mentioned.

On the other hand, examples of the charge control agent for controlling the toner particles to be positively charged include the following. Nigrosin modifications with niglosin and fatty acid metal salts; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and analogs thereof. Onium salts such as phosphonium salts and their lake pigments; triphenylmethane dyes and their lake pigments (as lake agents include phosphotung acid, phosphomolybdic acid, phosphotungene molybdic acid, tannic acid, lauric acid, Caric acid, ferricyanide, ferrocyanide, etc.); Metal salts of higher fatty acids; Resin-based charge control agents.
These charge control agents can be contained alone or in combination of two or more. Among these charge control agents, metal-containing salicylic acid-based compounds are preferable, and the metal thereof is particularly preferably aluminum or zirconium. A more preferred charge control agent is a 3,5-di-tert-butylsalicylate aluminum compound.

Further, as the resin-based charge control agent, a polymer having a sulfonic acid-based functional group is preferable. The polymer having a sulfonic acid-based functional group is a polymer or a copolymer having a sulfonic acid group, a sulfonic acid base or a sulfonic acid ester group.
Examples of the polymer or copolymer having a sulfonic acid group, a sulfonic acid base or a sulfonic acid ester group include a high molecular weight compound having a sulfonic acid group in the side chain. In particular, styrene and / or styrene (meth) containing a sulfonic acid group-containing (meth) acrylamide-based monomer in a copolymerization ratio of 2% by mass or more, preferably 5% by mass or more, and having a glass transition temperature (Tg) of 40 to 90 ° C. ) A polymer compound which is an acrylic ester copolymer is preferable. Improves charge stability under high humidity.
The above-mentioned sulfonic acid group-containing (meth) acrylamide-based monomer has the following general formula (X).
) Is preferable, and specific examples thereof include 2-acrylamide-2-methylpropanesulfonic acid and 2-methacrylamide-2-methylpropanesulfonic acid.

(In the above general formula (X), R ₁ represents a hydrogen atom or a methyl group, and R ₁ and R ₃ are hydrogen atoms, alkyl groups having 1 to 10 carbon atoms, alkenyl groups, aryl groups or alkoxy groups, respectively. Indicated, n indicates an integer of 1 to 10.)
The polymer having a sulfonic acid group contains 0.1 part by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner particles to further improve the charged state of the toner particles. Can be.
The amount of these charge control agents added is preferably 0.01 parts by mass or more and 10.00 parts by mass or less with respect to 100.00 parts by mass of the binder resin.

In the toner of the present invention, various organic fine powders or inorganic fine powders may be externally added to the toner particles for the purpose of imparting various characteristics.
Organic fine powder or inorganic fine powder affects the surface properties and thermal meltability of toner particles, but by controlling the addition amount within an appropriate range, the effect on the integrated value of stress can be grasped for the time being. That is, from the viewpoint of facilitating the adjustment of the integrated value of stress to a desired range, the amount of these organic fine powders or inorganic fine powders added is 0.01 part by mass or more and 10.00 parts by mass with respect to 100.00 parts by mass of the toner particles. It is preferably 0.02 parts by mass or more, more preferably 0.02 parts by mass or more and 5.00 parts by mass or less, and further preferably 0.03 parts by mass or more and 1.00 parts by mass or less.

The following are used as the organic fine powder or the inorganic fine powder.
(1) Fluidity imparting agent: silica, alumina, titanium oxide, carbon black and carbon fluoride.
(2) Abrasives: Strontium titanate, cerium oxide, alumina, magnesium oxide, metal oxides such as chromium oxide, nitrides such as silicon nitride, carbides such as silicon carbide, calcium sulfate, barium sulfate, calcium carbonate Metal salt like.
(3) Lubricants: Fluorine-based resin powders such as vinylidene fluoride and polytetrafluoroethylene, fatty acid metal salts such as zinc stearate and calcium stearate.
(4) Charge control particles: metal oxides such as tin oxide, titanium oxide, zinc oxide, silica, and alumina, and carbon black.

The organic or inorganic fine powder treats the surface of the toner particles in order to improve the fluidity of the toner and homogenize the charge of the toner. By hydrophobizing the organic fine powder or the inorganic fine powder, it is possible to adjust the chargeability of the toner and improve the charging characteristics in a high humidity environment. Therefore, the hydrophobized organic fine powder or the inorganic fine powder can be treated. It is preferable to use fine powder. Examples of the treatment agent for hydrophobizing organic fine powder or inorganic fine powder include unmodified silicone varnish, various modified silicone varnish, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, and other organosilicon. Examples include compounds and organosilicon compounds. These treatment agents may be used alone or in combination.
Among them, inorganic fine powder treated with silicone oil is preferable. More preferably, the inorganic fine powder is treated with silicone oil at the same time as or after being hydrophobized with a coupling agent. Hydrophobicized inorganic fine powder treated with silicone oil is preferable for maintaining a high charge amount of toner even in a high humidity environment and reducing selective developability. These organic fine powders or inorganic fine powders may be used alone or in combination of two or more.

In the present invention, the BET specific surface area of the organic fine powder or the inorganic fine powder is preferably 10 m ² / g or more and 450 m ² / g or less.
The specific surface area BET of the organic fine powder or the inorganic fine powder can be determined by a low temperature gas adsorption method by a dynamic constant pressure method according to the BET method (preferably the BET multipoint method). For example, by adsorbing nitrogen gas on the sample surface using the specific surface area measuring device "Gemini 2375 Ver.5.0" (manufactured by Shimadzu Corporation) and measuring using the BET multipoint method, the BET specific surface area ( m ² / g) can be calculated.
The organic fine powder or the inorganic fine powder may be firmly adhered or adhered to the surface of the toner particles. Henschel mixer, mechanofusion, cyclomix, turbulizer, flexomix, hybridization, mechanohybrid, and novirta are used as external mixers for firmly adhering or adhering organic fine powder or inorganic fine powder to the surface of toner particles. Can be mentioned. Further, the organic fine powder or the inorganic fine powder can be strongly adhered or adhered by increasing the rotation peripheral speed or lengthening the processing time.

The content of the tetrahydrofuran insoluble component (excluding the colorant and the inorganic fine powder) of the toner of the present invention is less than 50.0% by mass with respect to the toner component other than the colorant and the inorganic fine powder of the toner. It is preferable, more preferably 0.0% by mass or more and less than 45.0% by mass, and further preferably 5.0% by mass or more and less than 40.0% by mass. By setting the content of the tetrahydrofuran insoluble content to less than 50.0% by mass, the low temperature fixability can be improved.
The content of the tetrahydrofuran insoluble component of the toner means the mass ratio of the ultrapolymer polymer component (substantially crosslinked polymer) insoluble in the tetrahydrofuran solvent. The content of the tetrahydrofuran insoluble component of the toner can be adjusted by the degree of polymerization and the degree of cross-linking of the binder resin.

<Measurement method of integrated toner stress>
(1) Preparation of Toner Pellet Approximately 3 g of toner (variable depending on the specific gravity of the sample) is placed in a vinyl chloride ring for measuring an inner diameter of 27 mm, and for example, a sample press molding machine "MAEKAWA Testing Machine" (MFG Co, LTD) Toner pellets are prepared by pressing at 200 kN for 60 seconds and molding a sample.
(2) Measurement of integrated value of stress The integrated value of toner stress was measured using a tacking tester "TAC-1000" (manufactured by Reska) according to the operation manual of the device. A schematic diagram of the tacking tester is shown in FIG.
As a specific measurement method, the toner pellet is placed on the sample holding plate 205, and the probe tip 203 is set to 150 ° C. using the probe unit 202.
Next, by adjusting the head portion 200, the probe tip is lowered until the probe tip can pressurize the toner pellet 204.
Next, the toner pellet is pressurized under the following conditions, and the stress value when the probe tip is pulled up is detected by the load sensor 201.
・ Pressing speed 5 mm / sec
・ Pressing load 19.7 kg ・ m / sec
・ Pressing and holding time 1 sec
・ Pulling speed 15mm / sec
The integrated value of stress is calculated by integrating the stress value detected by the load sensor.
Specifically, the stress value required for the time from the moment when the sensor pulls away from the pellet (the point where the stress value becomes 0 g ・ m / sec ² ) to the point where the sensor is completely separated from the pellet is integrated. Can be calculated with.

<Measuring method of average circularity of toner>
The average circularity of the toner is measured by the flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex) under the measurement and analysis conditions at the time of calibration work (the same applies to magnetic toner).
The specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids and the like have been removed in advance is placed in a glass container. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a precision measuring instrument at pH 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted about 3 times by mass with ion-exchanged water, and about 0.2 ml of the diluted solution is added. Further, about 0.02 g of the measurement sample is added, and the dispersion treatment is performed for 2 minutes using an ultrasonic disperser to prepare a dispersion liquid for measurement. At that time, the dispersion is appropriately cooled so that the temperature of the dispersion is 10 ° C. or higher and 40 ° C. or lower. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser (for example, "VS-150" (manufactured by Vervocrea)) having an oscillation frequency of 50 kHz and an electrical output of 150 W is used, and a predetermined amount is contained in the water tank. Ion-exchanged water is added, and about 2 ml of the contaminanton N is added into the water tank.
For the measurement, the flow type particle image analyzer equipped with "UPlanApro" (magnification 10 times, numerical aperture 0.40) was used as the objective lens, and the particle sheath "PSE-900A" (manufactured by Sysmex) was used as the sheath liquid. It was used. The dispersion liquid adjusted according to the above procedure is introduced into the flow type particle image analyzer, and 3000 toners are measured in the total count mode in the HPF measurement mode. Then, the binarization threshold value at the time of particle analysis is set to 85%, the diameter of the analyzed particle is limited to 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner is obtained.

In the measurement, automatic focus adjustment is performed using standard latex particles (for example, "RESAARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A" manufactured by Duke Scientific Co., Ltd. diluted with ion-exchanged water) before the start of the measurement. After that, it is preferable to perform focus adjustment every 2 hours from the start of measurement.
In the present invention, a flow-type particle image measuring device that has been calibrated by Sysmex and has been issued with a calibration certificate issued by Sysmex is used. The measurement is performed under the measurement and analysis conditions at the time of receiving the calibration certificate, except that the diameter of the analysis particle is limited to 1.985 μm or more and less than 39.69 μm in equivalent circle diameter.
The measurement principle of the flow-type particle image measuring device "FPIA-3000" (manufactured by Sysmex Corporation) is that the flowing particles are imaged as a still image and image analysis is performed. The sample added to the sample chamber is sent to the flat sheath flow cell by the sample suction syringe. The sample sent into the flat sheath flow is sandwiched between the sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Moreover, since the flow is flat, the image is taken in a focused state. The particle image is captured by a CCD camera, the captured image is image-processed at an image processing resolution of 512 × 512 pixels (0.37 × 0.37 μm per pixel), the outline of each particle image is extracted, and the particle image is obtained. The projected area S, the peripheral length L, and the like are measured.
Next, the equivalent circle diameter and circularity are obtained using the area S and the peripheral length L. The circle-equivalent diameter is the diameter of a circle that has the same area as the projected area of the particle image, and the circularity is the value obtained by dividing the circumference of the circle obtained from the circle-equivalent diameter by the circumference of the particle projection image. It is defined and calculated by the following formula.
Circularity = 2 × (π × S) ^1/2 / L
When the particle image is circular, the circularity is 1.000, and the greater the degree of unevenness on the outer circumference of the particle image, the smaller the circularity. After calculating the circularity of each particle, the range of circularity 0.200 to 1.000 is divided into 800, the arithmetic mean value of the obtained circularity is calculated, and the value is taken as the average circularity.

<Method of thermal conductivity>
(1) Preparation of measurement sample The measurement sample is made by compressing about 5 g of toner (variable depending on the specific gravity of the sample) in an environment of 25 ° C. using a tablet molding compressor at about 20 MPa for 60 seconds. , Two cylindrical ones with a diameter of 25 mm and a height of 6 mm are produced.
(2) Thermal conductivity measuring device: Hot disk method Thermal property measuring device TPS2500S
Sample holder: Room temperature sample holder Sensor: Standard accessory (RTK) Sensor software: Hot disk analysis 7
Place the measurement sample on the mounting table stand of the room temperature sample holder, and adjust the height of the table so that the surface of the measurement sample is at the same height as the sensor.
On the sensor every two eyes of the measurement sample, yet still puts the metal piece that comes in, using the screw at the top of the sensor applies pressure. Adjust the pressure to 30 cN ・ m with a torque wrench. Make sure that the center of the measurement sample and sensor is directly below the screw.
Start Hot disk analysis and select the experiment type as Bulk (Type I).
Enter the following in the input items.
Available Proving Depth: 6mm
Measurement time: 40s
Heating Power: 60mW
Simple Temple: 23 ° C
TCR: 0.004679K ^-1
Sensor Type: Disk
Sensor Material Type: Kapton
Sensor Design: 5465
Sensor Radius: 3.189 mm
After the above input, measurement is started. After the measurement is completed, the Calculate button is selected, Start Point: 10 and End Point: 200 are input, and the Standard Analysis button is selected to calculate Thermal Conducivity [W / mK].

<Measurement method of toner softening point>
The softening point of the toner by the flow tester heating method was measured using a flow tester CFT-500D (manufactured by Shimadzu Corporation) under the following conditions according to the operation manual of the apparatus.
In this device, while applying a constant load from the top of the measurement sample with a piston, the measurement sample filled in the cylinder is heated and melted, and the melted measurement sample is pushed out from the die at the bottom of the cylinder, and the amount of piston drop at this time. A flow curve showing the relationship between and temperature can be obtained.
In the present invention, the "melting temperature in the 1/2 method" described in the manual attached to the device is used as the softening point. The melting temperature in the 1/2 method is calculated as follows.
First, 1/2 of the difference between the piston descent amount Smax at the time when the outflow ends and the piston descent amount Smin at the time when the outflow starts is obtained (this is defined as X. X = (Smax-Smin) / 2). Then, the temperature of the flow curve when the amount of descent of the piston becomes X in the flow curve is the melting temperature in the 1/2 method.
Sample: 1.0 g of toner is weighed and molded by a pressure molder having a diameter of 1 cm under a load of 20 kN for 1 minute to obtain a sample.
Die hole diameter: 1.0 mm
Die length: 1.0 mm
Cylinder pressure: 9.807 × ¹⁰ 5 (Pa)
Measurement mode: Temperature rise method Temperature rise rate: 4.0 ° C / min
Draw a plunger drop (flow value) -temperature curve obtained by the above method, and when the height of the S-shaped curve is h, the temperature corresponding to h / 2 (the temperature at which half of the resin flows out) Measure the softening point.

Hereinafter, the present invention will be specifically described with reference to Production Examples and Examples, but this does not limit the present invention in any way. The number of copies in the following formulations is based on mass.

<Manufacturing of magnetic iron oxide 1>
A ferrous salt aqueous solution containing a ferrous hydroxide colloid was mixed and stirred with 50 liters of an iron sulfate aqueous solution containing 2.0 mol / L of Fe ²⁺ and 55 liters of a 4.0 mol / L sodium hydroxide aqueous solution. Obtained. This aqueous solution was kept at 85 ° C. and an oxidation reaction was carried out while blowing air at 20 L / min to obtain a slurry containing core particles.
The obtained slurry was filtered and washed with a filter press, and then the core particles were redispersed in water and reslurryed. To this slurry liquid, sodium silicate having a silicon equivalent of 0.20 mass% per 100 parts of core particles is added, the pH of the slurry liquid is adjusted to 6.0, and the mixture is stirred to have a magnetism having a silicon-rich surface. Iron oxide particles were obtained. The obtained slurry was filtered and washed with a filter press, and further reslurryed with ion-exchanged water. 500 g (10% by mass with respect to magnetic iron oxide) of an ion exchange resin SK110 (manufactured by Mitsubishi Chemical) was added to this reslurry solution (solid content 50 g / L), and the mixture was stirred for 2 hours to perform ion exchange. Then, the ion exchange resin was filtered through a mesh to remove it, filtered and washed with a filter press, dried and crushed to obtain magnetic iron oxide 1 having an average number of primary particles of 190 nm.

<Manufacturing of magnetic iron oxides 2 and 3>
Magnetic iron oxides 2 and 3 were obtained in the same manner as in the production of magnetic iron oxide 1 except that the number average particle size of magnetic iron oxide was adjusted in the production of magnetic iron oxide 1. Table 2 shows the physical properties of the obtained magnetic iron oxides 2 and 3.

<Manufacturing of Silane Compound 1>
30 parts of iso-butyltrimethoxysilane was added dropwise to 70 parts of ion-exchanged water with stirring. Then, this aqueous solution was maintained at pH 5.5 and a temperature of 55 ° C., and hydrolyzed by dispersing at a peripheral speed of 0.46 m / sec for 120 minutes using a disper blade. Then, the pH of the aqueous solution was adjusted to 7.0, and the solution was cooled to 10 ° C. to stop the hydrolysis reaction. In this way, silane compound 1 which is an aqueous solution containing a hydrolyzate was obtained.

<Production of Silane Compounds 2 and 3>
In the production of the silane compound 1, the silane compounds 2 and 3 were obtained in the same manner as the silane compound 1 except that the type of the silane compound was changed as shown in Table 1. Table 1 shows the production conditions of the obtained silane compounds 2 and 3.

<Manufacturing of magnetic material 1>
Magnetic iron oxide 1 (100 parts) was placed in a high-speed mixer (LFS-2 type manufactured by Fukae Powtech Co., Ltd.), and silane compound 1 (8.0 parts) was added dropwise over 2 minutes while stirring at a rotation speed of 2000 rpm. Then, it was mixed and stirred for 5 minutes. Then, in order to enhance the adhesiveness of the silane compound 1, the mixture was dried at 40 ° C. for 1 hour to reduce the water content, and then the mixture was dried at 110 ° C. for 3 hours to allow the condensation reaction of the silane compound 1 to proceed. Then, it was crushed and passed through a sieve having an opening of 100 μm to obtain a magnetic substance 1.

<Manufacturing of magnetic materials 2 to 6>
In the production of the magnetic material 1, the magnetic materials 2 to 6 were produced in the same manner except that the magnetic iron oxide and the silane compound were changed to the magnetic iron oxide and the silane compound shown in Table 2.

表面珪素量は、磁性酸化鉄１００質量部あたりの珪素量（質量％）を示す。

The amount of surface silicon indicates the amount of silicon (mass%) per 100 parts by mass of magnetic iron oxide.

<Manufacturing of crystalline polyester 1>
230.0 parts of sebacic acid as a carboxylic acid monomer and 242.1 parts of 1,10-decanediol as an alcohol monomer were charged into a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple. The temperature was raised to 140 ° C. with stirring, heated to 140 ° C. under a nitrogen atmosphere, and reacted for 8 hours while distilling off water under normal pressure. Then, 1 part of tin dioctylate was added to 100 parts by mass of the total amount of the monomers, and then the reaction was carried out while raising the temperature to 200 ° C. at 10 ° C./hour. Further, after the reaction was carried out for 2 hours after reaching 200 ° C., the inside of the reaction vessel was reduced to 5 kPa or less and reacted at 200 ° C. for 3 hours to obtain a crystalline polyester 1. The weight average molecular weight (Mw) of the obtained crystalline polyester 1 was 20100, and the acid value was 2.2 mgKOH / g.

<Manufacturing of crystalline polyesters 2-8>
In the production of the crystalline polyester 1, the crystalline polyesters 2 to 8 were obtained in the same manner except that the alcohol monomer and the acid monomer were changed as shown in Table 3. Table 3 shows the physical characteristics and structure of the obtained crystalline polyester.

<Manufacturing of toner particles 1>
450 parts of 0.1 mol / L-Na ₃ PO ₄ aqueous solution was added to 720 parts of ion-exchanged water and heated to 60 ° C., and then 67.7 parts of 1.0 mol / L-CaCl ₂ aqueous solution was added. , An aqueous medium containing a dispersion stabilizer was obtained.
・ Styrene 79.0 parts ・ n-butyl acrylate 21.0 parts ・ Divinylbenzene 0.5 parts ・ Monoazo dye iron complex (T-77: manufactured by Hodogaya Chemical Co., Ltd.) 1.5 parts ・ Magnetic material 1 90.0 parts 5.0 parts of amorphous saturated polyester resin (Acrystalline saturated polyester resin obtained by condensation reaction of ethylene oxide (2 mol) and propylene oxide (2 mol) adduct of bisphenol A with terephthalic acid; Mw = 9500 , Acid value = 2.2 mgKOH / g, glass transition temperature = 68 ° C.)
The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Machinery Co., Ltd.) to obtain a monomer composition. This monomer composition is heated to 63 ° C., and 10.0 parts of crystalline polyester 1 shown in Table 3 and 10.0 parts of behenyl sebacate (melting point Tm: 73.0 ° C.) are added and mixed therein. , Dissolved.
The aqueous medium of the above monomer composition was charged in, 60 ° C., and stirred at 12000 rpm 10 min at T.K. homomixer (Tokushu Kika Kogyo Co., Ltd.) under _{N 2} atmosphere and granulated. Then, 9.0 parts of the polymerization initiator t-butylperoxypivalate was added while stirring with a paddle stirring blade, the temperature was raised to 70 ° C., and the reaction was carried out for 4 hours. After completion of the reaction, the suspension is heated to 100 ° C. and held for 120 minutes. Then, water at 5 ° C. is added to the aqueous medium, and the mixture is cooled from 100 ° C. to 50 ° C. at a cooling rate of 50.0 ° C./min. Subsequently, the aqueous medium was held at 50 ° C. for 120 minutes, and then naturally cooled to 25 ° C. at room temperature to cool it. The cooling rate at that time was 1.0 ° C./min. Then, it was cooled, filtered and dried to obtain toner particles 1. The formulations are shown in Table 4.

<Manufacturing of toner particles 2 to 24>
In the production of the toner particles 1, except that the type and number of magnetic materials, the type and number of crystalline polyesters, the type and number of ester waxes, the number of parts of the cross-linking agent and the cooling conditions were changed as shown in Tables 4 and 5. Toner particles 2 to 24 were produced in the same manner. The formulations are shown in Table 4.

ＨＮＰ−９は、パラフィンワックス（日本精蝋株式会社製）である。

HNP-9 is a paraffin wax (manufactured by Nippon Seiro Co., Ltd.).

<Manufacturing of toner 1>
The specific surface area by the BET method is 200 m ² / g with respect to 1 (100 parts) of toner particles, and the surface is hydrophobized with 3.0% by mass of hexamethyldisilazane and 3% by mass of silicone oil of 100 cps. Toner 1 is a toner obtained by mixing 0.3 part of silica and 0.1 part of aluminum oxide having a specific surface area of 50 m ² / g by the BET method with an FM mixer (Nippon Coke Industries Co., Ltd.). The physical characteristics of the toner 1 are shown in Table 6.

<Manufacturing of toners 2 to 24>
In the production of the toner 1, the toners 2 to 24 were produced in the same manner except that the toner particles were changed as shown in Table 6. The physical characteristics are shown in Table 6.

<Manufacturing of comparative toner particles 1>
・ Acrylic resin (V / S-1057 manufactured by Seiko PMC) 100.0 parts ・ Iron complex of monoazo dye (T-77: manufactured by Hodogaya Chemical Co., Ltd.) 1.5 parts ・ Magnetic material 6 90.0 parts ・ Dibehenyl sebacate (Melting point Tm: 73.0 ° C) 2.0 parts, HNP-9 (manufactured by Nippon Seiwa Co., Ltd.) 5.0 parts, crystalline polyester 1 5.0 parts Mitsui Henchel Mixer (Mitsui Miike Machinery Co., Ltd.) After pre-mixing with (manufactured by the company), the mixture was kneaded with a twin-screw kneading extruder set at 130 ° C. and 200 rpm. The resulting kneaded product was rapidly cooled to room temperature. After coarse pulverization with a cutter mill, the obtained coarse pulverized product is finely pulverized by adjusting the air temperature so that the exhaust temperature becomes 50 ° C. using a turbo mill T-250 (manufactured by Turbo Industries, Ltd.), and the Coanda effect is obtained. The comparison toner particles 1 were obtained by classifying using a multi-division classifier using the above.

<Manufacturing of comparative toner particles 2 to 6>
In the production of the toner particles 1, the same applies except that the type and number of magnetic materials, the type and number of crystalline polyesters, the type and number of ester waxes, the number of parts of the cross-linking agent and the cooling conditions are changed as shown in Table 7. The comparative toner particles 2 to 6 were produced.

<Manufacturing of comparative toners 1 to 6>
In the production of the toner 1, the comparative toners 1 to 6 were produced in the same manner except that the toner particles were changed as shown in Table 8. The physical characteristics are shown in Table 8.

<Manufacturing of comparative toner 7>
(Preparation of resin particles A) Preparation of three-layer structure resin particles 8 g of sodium dodecyl sulfate was charged into 3000 g of ion-exchanged water in a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device, and 230 rpm under a nitrogen stream. The internal temperature was raised to 80 ° C. while stirring at the stirring speed. After raising the temperature, a solution prepared by dissolving 10 g of potassium persulfate in 200 g of ion-exchanged water was added, the liquid temperature was adjusted to 80 ° C. again, the following monomer mixed solution was added dropwise over 1 hour, and then heated at 80 ° C. for 2 hours. Polymerization was carried out by stirring to prepare resin particles. This is referred to as "resin particles (1H)".
・ Styrene 480.0g
・ N-Butyl acrylate 250.0 g
・ Methacrylic acid 68.0g
・ N-octyl-3-mercaptopropionate 16.0 g
Next, in a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device, a solution prepared by dissolving 7 g of polyoxyethylene (2) dodecyl ether sodium sulfate in 800 g of ion-exchanged water was charged and heated to 98 ° C. After that, 260 g of the resin particles (1H) and a solution prepared by dissolving the following monomer solution at 90 ° C. were added, and a mechanical disperser "CLEARMIX" (M Technique Co., Ltd.) having a circulation path was added. A dispersion containing emulsified particles (oil droplets) was prepared by mixing and dispersing for 1 hour.
・ Styrene 245.0g
120.0 g of n-butyl acrylate
・ N-octyl-3-mercaptopropionate 1.5g
-Polyethylene wax (melting point 80 ° C) 190.0 g

Next, an initiator solution prepared by dissolving 6 g of potassium persulfate in 200 g of ion-exchanged water was added to this dispersion, and the system was heated and stirred at 82 ° C. for 1 hour to carry out polymerization to obtain resin particles. It was. This is referred to as "resin particles (1HM)".
Further, a solution prepared by dissolving 11 g of potassium persulfate in 400 g of ion-exchanged water was added, and the temperature condition was 82 ° C.
・ Styrene 435.0g
・ N-Butyl acrylate 130.0 g
・ Methacrylic acid 33.0g
-N-octyl-3-mercaptopropionate 8.0 g
A monomer mixed solution consisting of the above was added dropwise over 1 hour. After completion of the dropping, polymerization was carried out by heating and stirring for 2 hours, and then the mixture was cooled to 28 ° C. to obtain resin particles. This is referred to as "resin particle A". The Tg of the resin particles A was 48 ° C., and the softening point was 88 ° C.

(Preparation of resin particles B)
In a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device, 2.3 g of sodium dodecyl sulfate was charged into 3000 g of ion-exchanged water, and the internal temperature was raised to 80 ° C. while stirring at a stirring rate of 230 rpm under a nitrogen stream. The temperature was raised to. After raising the temperature, 10 g of potassium persulfate dissolved in 200 g of ion-exchanged water was added, the liquid temperature was adjusted to 80 ° C. again, the following monomer mixed solution was added dropwise over 1 hour, and then heated at 80 ° C. for 2 hours. , Polymerization was carried out by stirring to prepare resin particles. This is referred to as "resin particle B".
・ Styrene 520.0g
210.0 g of n-butyl acrylate
・ Methacrylic acid 68.0g
・ N-octyl-3-mercaptopropionate 16.0 g

(Preparation of colorant dispersion)
90 g of sodium dodecyl sulfate was stirred and dissolved in 1600 g of ion-exchanged water. While stirring this solution, 420 g of carbon black was gradually added, and then dispersion treatment was performed using a stirrer "Clearmix" (manufactured by M-Technique) to prepare a dispersion of colorant particles. This is referred to as a "colorant dispersion".

(Agglomeration / fusion process)
In a reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introduction device, 300 g of resin particles A in terms of solid content, 1400 g of ion-exchanged water, 120 g of "colorant dispersion", and polyoxyethylene (2). ) A solution prepared by dissolving 3 g of dodecyl ether sodium sulfate in 120 g of ion-exchanged water was prepared, the liquid temperature was adjusted to 30 ° C., and then a 5N aqueous sodium hydroxide solution was added to adjust the pH to 10. Then, an aqueous solution prepared by dissolving 35 g of magnesium chloride in 35 g of ion-exchanged water was added at 30 ° C. for 10 minutes with stirring. After holding for 3 minutes, the temperature rise was started, the temperature of this system was raised to 90 ° C. over 60 minutes, and the particle growth reaction was continued while maintaining 90 ° C.
In this state, the particle size of the associated particles was measured with "Coulter Multisizer III" (manufactured by Beckman Coulter), and when the median particle size (D50) on a volume basis reached 3.1 μm, the resin particles B 260 g was added, and the particle growth reaction was further continued. When the desired particle size is reached, an aqueous solution prepared by dissolving 150 g of sodium chloride in 600 g of ion-exchanged water is added to stop particle growth, and further, as a fusion step, the mixture is heated and stirred at a solution temperature of 98 ° C. Fusion between the particles was allowed to proceed until the circularity was 0.96 as measured by "FPIA-3000" (manufactured by Sysmex). Then, the liquid temperature was cooled to 30 ° C., hydrochloric acid was added to adjust the pH to 4.0, and stirring was stopped.

(Washing / drying process)
The particles produced in the agglomeration / fusion step were solid-liquid separated by a basket-type centrifuge "MARK III model number 60 × 40" (manufactured by Matsumoto Machinery Co., Ltd.) to form a wet cake of the toner base. The wet cake is washed with water using the basket-type centrifuge until the electrical conductivity of the filtrate reaches 5 μS / cm, and then transferred to a “flash jet dryer” (manufactured by Seishin Enterprise Co., Ltd.) to have a water content of 0.5 mass. It was dried to%, and a toner base having a median particle size (D50) of 6.2 μm on a volume basis was prepared.

(External agent mixing process)
In the toner base obtained above, 1% by mass of hydrophobic silicon oxide (number average primary particle diameter = 12 nm, degree of hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter = 20 nm, degree of hydrophobicity =). 63) was added in an amount of 0.3% by mass and mixed with a Mitsui Henschel mixer (manufactured by Mitsui Miike Machinery Co., Ltd.) to prepare a comparative toner 7. Table 8 shows the physical characteristics of the comparative toner 7.

<Example 1>
The printer LBP3100 manufactured by Canon Inc. is modified and used for image output evaluation. As a modification point, the process speed was set to 200 mm / sec, which was faster than before, and the contact pressure between the fixing film and the pressure roller was modified to 69 kg / m / sec so as to be light. In addition, the modified LBP3100 was modified so that the fixing temperature of the fixing unit could be adjusted.

<Fixation evaluation>
In the image forming apparatus described above, the cold offset resistance was evaluated under a normal temperature and pressure environment (temperature 25.0 ° C., humidity 50% RH). As the fixing medium, FOXRIVER BOND paper (110 g / m ² ) was used. By using a medium that has a relatively large surface unevenness and is thick paper, the fixability can be severely evaluated by making the media easy to peel off and rub.

(Cold offset resistance)
First, the amount of toner loaded was adjusted so that the amount of toner loaded on the fixing medium was 0.90 mg / cm ² . Next, the fuser is cooled to room temperature (15 ° C.), 20 solid images are printed continuously, and the heater temperature of the fuser is arbitrarily set in the range of 190 ° C. or higher and 250 ° C. or lower (hereinafter referred to as fixing temperature). , Established. In the 20 sheets of paper sheets, the cold offset was visually judged and evaluated according to the following judgment criteria.
A: Cold offset does not occur up to 200 ° C B: Cold offset occurs at 200 ° C or higher and lower than 210 ° C C: Cold offset occurs at 210 ° C or higher and lower than 220 ° C D: Cold offset occurs at 220 ° C or higher

(Rubbing test)
Adjust the halftone image density so that the image density (measured using a Macbeth reflection densitometer (manufactured by Macbeth)) on the fixing medium is 0.75 or more and 0.80 or less, and image at a fixing temperature of 150 ° C. Do the work.
Then, the halftone fixed image was rubbed 10 times with Sylbon paper loaded with 55 g / cm ² . From the halftone image density before and after rubbing, the density reduction rate at 150 ° C. was calculated using the following formula.
Density reduction rate (%) = (Image density before rubbing-Image density after rubbing) / Image density before rubbing x 100
Similarly, the fixing temperature was increased by 5 ° C., and the concentration decrease rate was calculated in the same manner up to 200 ° C. From the evaluation results of the fixing temperature and the concentration decrease rate obtained by a series of operations, the temperature at which the concentration decrease rate was 15% was calculated, and the temperature was set as the lower limit temperature for fixing indicating the threshold value at which the low temperature fixability was good. .. A: Lower limit temperature for fixing is less than 160 ° C B: Lower limit temperature for fixing is 160 ° C or higher and lower than 170 ° C C: Lower limit temperature for fixing is 170 ° C or higher and lower than 180 ° C D: Lower limit temperature for fixing is 180 ° C or higher

(Hot offset resistance)
The evaluation of hot offset resistance is performed by displaying a halftone image of 2.0 cm in length and 15.0 cm in width on 90 g / m ² paper of A4 under normal temperature and humidity (25 ° C., 50% RH) in the paper passing direction. On the other hand, it was formed in a portion 2.0 cm from the upper end portion and a portion 2.0 cm from the lower end portion. The image density measured by a Macbeth reflection densitometer (manufactured by Macbeth) was adjusted to be 0.75 or more and 0.80 or less, and image was projected. The set temperature of the fuser was raised from 170 ° C. by 5 ° C. to perform image extraction. The evaluation was performed visually according to the following criteria.
A: No hot offset occurs up to 200 ° C B: Hot offset occurs at 190 ° C or higher and lower than 200 ° C C: Hot offset occurs at 180 ° C or higher and lower than 190 ° C D: Hot offset occurs at lower than 180 ° C

<Evaluation of storage stability>
(Evaluation of long-term storage stability)
10 g of toner 1 was placed in a 100 ml glass bottle, left at a temperature of 45 ° C. and a humidity of 95% for 3 months, and then visually judged.
A: No change B: There are aggregates, but they loosen immediately C: Aggregates that are difficult to loosen are generated D: No fluidity E: Clear caking occurs

<Examples 2 to 24>
Evaluation was carried out in the same manner except that toners 2 to 24 were used in Example 1. The evaluation results are shown in Table 9.

<Comparative Examples 1 to 7>
The evaluation was performed in the same manner except that the comparative toners 1 to 7 were used in Example 1. The evaluation results are shown in Table 9.

200: Head, 201: Load sensor, 202 probe unit, 203: Probe tip, 204: Toner pellet, 205: Sample holding plate

Claims (9)

A toner having toner particles containing a binder resin, a wax, and a colorant.
The colorant is a magnetic material and
The softening point of the toner is 80 ° C. or higher and 140 ° C. or lower.
The average circularity of the toner is 0.940 or more, and the toner has an average circularity of 0.940 or more.
When the toner pellet obtained by compressing the toner is measured using a tacking tester, the integrated value of the stress of the toner at 150 ° C. is 78 g · m / sec or more. The toner according to claim 1, wherein the wax contains an ester wax. The toner according to claim 2, wherein the ester wax is an ester compound of a divalent alcohol and an aliphatic monocarboxylic acid, or an ester compound of a divalent carboxylic acid and an aliphatic monoalcohol. The toner according to the toner particles is further claim 1 containing a crystalline polyester. The toner according to claim 4, wherein the crystalline polyester has a partial structure represented by the following formula (1).

The binder resin is a styrene - toner according to claim 1 is an acrylic resin. Thermal conductivity of the toner, the toner according to any one of claims 1 to 6 or less 0.190W / mK or more 0.300W / mK. The average circularity of the toner is the toner according to any one of claims 1 to 7 0.950 or more. When measured toner pellets obtained by compressing the toner by using a tacking tester, the integral value of the toner of the stress at 0.99 ° C. is claim 1-8 is 80 g · m / sec or more 1 The toner described in the section.

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