JP2020181034A - toner - Google Patents

Abstract

To provide a toner which is capable of clearly reproducing fine lines, providing good images with little transfer unevenness even when the toner particle size is small, and minimizing density reduction even after outputting a number of solid images.SOLUTION: A toner provided herein comprises toner particles and inorganic fine particles on surfaces of the toner particles, and satisfies a condition expressed as: 1.10≤Xs/Xl, where Xs represents a degree of hydrophobization of the inorganic fine particles belonging to the toner with diameters less than a number median diameter (D50) as measured by the methanol titration method, and Xl represents a degree of hydrophobization of the inorganic fine particles belonging to the toner with diameters equal to or greater than the number median diameter (D50) as measured by the methanol titration method.SELECTED DRAWING: None

Description

The present invention relates to toners used in electrophotographic methods, electrostatic recording methods, electrostatic printing methods, and toner jet methods.

As copiers and printers become more widespread, the performance required of toner is becoming more sophisticated. In recent years, in addition to energy saving, a digital printing technology called print on demand (POD), which prints directly without going through a plate making process, has attracted attention. This print-on-demand (POD) has an advantage over the conventional offset printing because it can support small lot printing, printing in which the content is changed for each sheet (variable printing), and distributed printing. Considering the application of the image forming method using toner to the POD market, it is required to stably obtain high quality print products with high quality even when a large amount of images are output at high speed for a long time. Be done.
As a print product of high quality image quality, improvement of micro image quality such as clarity of fine lines is further required. In toner, the particle size is smaller than before, for example, 50% cumulative particle size of the average number (50% cumulative particle size). There is a growing demand for toners having a D50) of less than 6 um.
Since the specific surface area of toner particles is inversely proportional to the particle size and the number of particles per mass is inversely proportional to the cube of the particle size, if the effect of the adhesive force between toner particles increases due to the smaller particle size of the toner, the cohesive force of the toner Increases. As a result, a blurred image is generated due to non-uniform transfer, and when a large number of solid images are output due to a decrease in the amount discharged from the toner container, the toner supply cannot catch up and the density decreases. There is a problem that it often ends up.
In Patent Document 1, the powder fluidity and chargeability of the toner are maintained high by devising the methanol wettability of three types of external additives having different particle sizes used for the toner, and the transfer stability and charge environment over time are maintained. Toners for electrostatic latent image development have been proposed, which can improve stability and stably obtain high-quality images. However, the current situation is that there are still problems in terms of achieving both fine line reproducibility and chargeability / transferability.

JP-A-2007-303394

An object of the present invention is to solve the above problems. That is, it is to provide a toner that can clearly reproduce fine lines, provide a good image with less transfer blur, and can suppress a decrease in density even when a large number of solid images are output.

The above problem can be solved by a toner having the following configuration.
That is, the present invention is a toner having toner particles and inorganic fine particles on the surface of the toner particles.
Among the toners, the degree of hydrophobization of the inorganic fine particles contained in the toner having a central particle size of less than D50 by the methanol titration method is Xs.
When the degree of hydrophobization of the inorganic fine particles contained in the toner having a central particle size of D50 or more by the methanol titration method is Xl.
The toner is characterized by satisfying the following formula (1).
1.10 ≤ Xs / Xl (1)

According to the toner of the present invention, fine lines can be clearly reproduced, a good image with less transfer blur can be provided even with a toner having a small particle size, and a decrease in density can be suppressed even when a large number of solid images are output. Toner can be provided.

Hereinafter, embodiments for carrying out the present invention will be described in detail.

The toner of the present invention is a toner having toner particles and inorganic fine particles on the surface of the toner particles.
Among the toners, the degree of hydrophobization of the inorganic fine particles contained in the toner having a central particle size of less than D50 by the methanol titration method is Xs.
When the degree of hydrophobization of the inorganic fine particles contained in the toner having a central particle size of D50 or more by the methanol titration method is Xl.
The toner is characterized by satisfying the following formula (1).
1.10 ≤ Xs / Xl (1)

The toner of the present invention can clearly reproduce fine lines, provides a good image with less transfer blur even with a toner having a small particle size, and suppresses a decrease in density even when a large number of solid images are output. it can.

Although the reason for solving the above problems in the present invention is not always clear, the present inventors speculate as follows.

The adhesive force between toner particles can be divided into electrostatic and non-electrostatic. When the diameter of the toner particles is reduced, if the charge amount per mass is constant, the charge amount per toner particle decreases, so that the influence of the adhesive force due to the non-electrostatic factor becomes relatively high. Therefore, it is more important to reduce the non-electrostatic adhesive force.

The main factors of non-electrostatic adhesive force are the van der Waals force acting between particles and the liquid cross-linking force due to the cross-linking of water existing in the environment between particles. Of these, when the particle size of the toner is reduced, the influence of the liquid cross-linking force becomes larger. Therefore, it is considered that reducing the liquid cross-linking force of the toner leads to a solution to the problem, and diligent studies have been carried out to reach the present invention.

It is known that the liquid cross-linking force Fb of the toner can be expressed by the formula Fb = 2πσDcosθ, where D is the particle size of the toner, σ is the surface tension of water, and θ is the contact angle of water on the surface of the toner. When the particle size D of the toner becomes smaller, the absolute value of the liquid cross-linking force becomes smaller, but the number of particles increases in inverse proportion to the cube of the particle size, so that the aggregation of the toner becomes stronger. Therefore, it was thought that increasing the contact angle with water would lead to a reduction in the liquid cross-linking force. The contact angle with water can be achieved by making the surface of the toner particles hydrophobic. However, it has been clarified by the present inventors that if the surface of the toner particles is made excessively hydrophobic, the aggregation of the toner increases, probably because of the hydrophobic interaction in a high temperature and high humidity environment. That control is needed. The present inventors have found that these problems can be solved by making the hydrophobicity of the toner particles having a small particle size higher than that of the toner particles having a large particle size.

The composition of the toner preferable for achieving the object in the present invention will be described in detail below.

The toner of the present invention has a degree of hydrophobicity of the inorganic fine particles contained in the toner having a central particle size of less than D50 by the methanol titration method of Xs, and methanol of the inorganic fine particles contained in the toner having a central particle size of D50 or more. When the degree of hydrophobicity by the titration method is Xl, Xs / Xl is 1.10 or more.

When Xs and Xl satisfy the above relationship, the liquid cross-linking force of the toner on the small particle size side can be lowered, so that transfer blurring can be suppressed, and the density decreases even when a large number of solid images are output. High-quality images can be obtained without doing so. More preferably, it is 1.20 or more.

As a method of controlling Xs / Xl, for example, toner particles having a small particle size using an external agent having a high degree of hydrophobicity and toner particles having a large particle size using an external agent having a low degree of hydrophobicity are separately used. It can be created and mixed.

Further, the toner of the present invention has a surface tension index of the toner with respect to a 40 mass% methanol aqueous solution measured by the capillary suction time method and calculated by the following formula (A) of a toner having a central particle size of less than D50. Of the toners, when the surface tension index of the toner with respect to the 40 mass% methanol aqueous solution measured by the capillary suction time method and calculated by the following formula (A) is Sl, the following formula is used. It is more preferable to satisfy (3).
1.5 ≤ Ss / Sl (3)
Toner surface tension index = Pα / (A × B × 10 ⁶ ) (N / m) ・ ・ ・ (A)
Capillary pressure of toner against Pα: 40 mass% methanol aqueous solution (N / m ² )
A: Specific surface area of toner (m ² / g)
B: Toner true density (g / cm ³ )

When the toner satisfies the formula (3), it is shown that there is a difference in hydrophobicity depending on the particle size not only on the external additive but also on the surface of the toner not coated with the external additive. As a result, the toner fluidity in a high temperature and high humidity environment can be maintained high. Therefore, the density fluctuation can be suppressed even when a large number of images having a high image ratio are printed. It is more preferable that Ss / Sl is 2.0 or more.

Ss and Sl are preferably in the range of 0.01 or more and 0.5 or less after satisfying the formula (3).

The values of Ss and Sl can be controlled by the degree of hydrophobicity and the amount of the external additive added, the acid value of the binder resin in the toner particles, the amount of the wax added, and the like.

Further, when the coverage of the inorganic fine particles contained in the toner having a central particle size D50 or less is Ys and the coverage rate of the inorganic fine particles contained in the toner having a central particle size D50 or more is Yl, both Ys and Yl are 25 or more. It is preferable to have. This range is preferable because the transferability in a high-temperature and high-humidity environment is improved and a high-quality image with less blur is easily obtained.

Ys and Yl can be controlled by the amount and particle size of the inorganic fine particles added, the external addition conditions, and the like.

[External agent]
As the external additive used for the toner of the present invention, it is preferable to use inorganic fine particles such as silica, titanium oxide, aluminum oxide, and strontium titanate. It is particularly preferable that these inorganic fine particles are hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil or a mixture thereof.

Examples of the method for hydrophobizing the inorganic fine particles include a method of chemically treating the inorganic fine particles with an organosilicon compound that reacts with the inorganic fine particles or an organosilicon compound that physically adsorbs silica fine powder. A preferred method is a method of treating inorganic fine particles produced by vapor phase oxidation of a silicon halogen compound with an organosilicon compound. Examples of the organosilicon compound include the following. Hexamethyldisilazane, trimethylsilane, trimethylchlorsilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorsilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, brommethyldimethylchlorsilane, α- Chlorethyl trichlorosilane, β-chloroethyl trichlorosilane, chlormethyldimethylchlorsilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, 1 -Hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane. These are used in one or a mixture of two or more.

The inorganic fine particles may be treated with silicone oil, or may be treated with the silicone oil and the above-mentioned organosilicon compound in combination. The silicone oil preferably has a viscosity at 25 ° C. of 30 mm ² / s or more and 1000 mm ² / s or less. For example, dimethyl silicone oil, methyl phenyl silicone oil, α-methylstyrene modified silicone oil, chlorphenyl silicone oil, and fluorine modified silicone oil can be mentioned.

Examples of the method for hydrophobizing the inorganic fine particles with silicone oil include the following methods. A method of directly mixing inorganic fine particles treated with a silane coupling agent and silicone oil using a mixer such as a Henschel mixer; a method of spraying silicone oil on a base silica fine powder. Alternatively, a method in which silicone oil is dissolved or dispersed in an appropriate solvent, and then silica fine powder is added and mixed to remove the solvent. The silicone oil-treated silica is more preferably one in which the silica is heated in an inert gas at a temperature of 200 ° C. or higher (more preferably 250 ° C. or higher) after the treatment with the silicone oil to stabilize the surface coating.

The degree of hydrophobization Xs of the inorganic fine particles contained in the toner having a central particle size of less than D50 by the methanol titration method is preferably 60 or more and 90 or less, and more preferably 68 or more and 84 or less.

The degree of hydrophobization Xl of the inorganic fine particles contained in the toner having a central particle size D50 or more by the methanol titration method is preferably 40 or more and 80 or less, and more preferably 45 or more and 70 or less.

When Xs and Xl are in the above range, the affinity of the toner with water is lowered, so that the non-electrostatic adhesive force is lowered and the transfer batter can be reduced, which is preferable.

When the number average diameter of the primary particles of the inorganic fine particles is 20 nm or more and 75 nm or less, it is preferable that a high-quality image can be output without impairing the transferability even with a small particle size toner. In particular, when the number average diameter of the primary particles of the inorganic fine particles contained in the toner having a central particle size of less than D50 satisfies the above range, a high-quality image with less transfer blur can be obtained, which is preferable. More preferably, it is 35 nm or more and 75 nm or less. On the other hand, when the number average diameter of the primary particles of the inorganic fine particles is less than 20 nm, the adhesive force between the toner and the transfer member or the toner tends to increase in the transfer step, and the suppression of transfer blur tends to decrease.

As the external additive for improving the fluidity, inorganic fine particles having a specific surface area of 50 m ² / g or more and 400 m ² / g or less are preferable, and for stabilizing durability, the specific surface area is 10 m ² / g or more and 50 m ² It is preferably inorganic fine particles of / g or less. Inorganic fine particles having a specific surface area in the above range may be used in combination in order to achieve both improvement in fluidity and stabilization of durability.

The external additive is preferably used in an amount of 0.1 part by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the toner particles. A known mixer such as a Henschel mixer can be used for mixing the toner particles and the external additive.

It is more preferable that the toner of the present invention has a median diameter (D50) of 3.0 μm or more and 6.0 μm or less on a number basis. When D50 is in the above range, the dot reproducibility is improved and excellent image quality can be obtained. On the other hand, when D50 is less than 3.0 μm, the amount of fine powder is excessively large, so that toner spots are generated on the magnetic carriers in long-term image output, and the fluidity of the developer cannot be lowered or stable charging cannot be applied. Excellent image quality cannot be obtained. Further, when D50 is larger than 6.0 μm, scattering may occur during development or transfer, and excellent image quality may not be obtained.

Further, the toner of the present invention preferably has a span value obtained by the following formula (2) of 0.2 or more and 0.7 or less.
Span value = (D90-D10) / D50 (2)

The span value indicates variation in particle size, and it is preferable that the span value of the toner is in this range because the variation in characteristics due to particle size is small.

[Bundling resin]
The following polymers can be used as the binder resin used in the toner of the present invention.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and its substitutions; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer. , Styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl Styrene-based copolymers such as ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-acrylonitrile-inden copolymer; polyvinyl chloride, phenol resin, naturally modified phenol resin, natural resin modified maleic acid resin, Acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, kumaron-inden resin, petroleum resin and the like can be used. These binder resins may be used alone, but a plurality of different resins may be used.

Among these, it is preferable to use a polyester resin or a styrene-based copolymer from the viewpoint of achieving both low-temperature fixability and chargeability. From the viewpoint of concentration stability after durability stabilization, the content of the polyester resin in the total binder resin is more preferably 50% by mass or more and 100% by mass or less, and preferably 70% by mass or more and 100% by mass or less. ..

When a polyester resin is used as the binding resin, the polyester resin is a resin having a "polyester unit" in the binding resin chain, and as a component constituting the polyester unit, the constituent component is Specific examples thereof include a divalent or higher valent alcohol monomer component and an acid monomer component such as a divalent or higher carboxylic acid, a divalent or higher carboxylic acid anhydride, and a divalent or higher carboxylic acid ester.

For example, as the divalent or higher valent alcohol monomer component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4) -Hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2- Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2 -Propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol , Dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbit, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2 , 4-Butantriol, 1,2,5-Pentaerythritol, Glycerin, 2-Methylpropantriol, 2-Methyl-1,2,4-Butanetriol, Trimethylolethane, Trimethylolpropane, 1,3,5- Examples thereof include trihydroxymethylbenzene.

Among these, the alcohol monomer component preferably used is an aromatic diol, and the alcohol monomer component constituting the polyester resin preferably contains the aromatic diol in a proportion of 80 mol% or more and 100 mol% or less. ..

On the other hand, as the acid monomer component such as the divalent or higher carboxylic acid, the divalent or higher carboxylic acid anhydride and the divalent or higher carboxylic acid ester, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or The anhydride; an alkyldicarboxylic acid such as succinic acid, adipic acid, sebacic acid and azelaic acid or an anhydride thereof; a succinic acid or an anhydride thereof substituted with an alkyl group or an alkenyl group having 6 to 18 carbon atoms; Unsaturated dicarboxylic acids such as acids, maleic acids and citraconic acids or anhydrides thereof;

Among these, the acid monomer component preferably used is a polyvalent carboxylic acid such as terephthalic acid, succinic acid, adipic acid, fumaric acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid and its anhydride.

The acid value of the amorphous polyester is preferably 0 mgKOH / g or more and 50 mgKOH / g or less from the viewpoint of charge stability, and more preferably 1 mgKOH / g or more and 20 mgKOH / g or less.

The acid value can be set in the above range by adjusting the type and blending amount of the monomer used in the resin. Specifically, it can be controlled by adjusting the alcohol monomer component ratio / acid monomer component ratio and the molecular weight at the time of resin production. Further, it can be controlled by reacting the terminal alcohol with a polyhydric acid monomer (for example, trimellitic acid) after ester polycondensation.

When a plurality of resins are used in combination, the average acid value is calculated according to the molar ratio.

The softening point of these binder resins is preferably 70 ° C. or higher and 180 ° C. or lower from the viewpoint of achieving both low-temperature fixability and hot offset resistance. More preferably, it is 80 ° C. or higher and 160 ° C. or lower.

Further, if it contains a vinyl resin having a structure in which a styrene acrylic resin and a hydrocarbon compound are bonded, such as polystyrene, a copolymer of styrene and an acrylic acid ester, and / or a copolymer of a styrene methacrylate ester, When a hydrocarbon wax is used as the wax, the wax dispersibility in the toner is improved, and the wax dispersibility between the small particle size side particles and the large particle size side particles tends to be the same, which is preferable. The content of the vinyl resin is preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polyester resin.

[wax]
The toner of the present invention may contain a wax, and examples of the wax used in the toner of the present invention include the following. Hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystallin wax, paraffin wax, Fishertropch wax; oxides of hydrocarbon waxes such as polyethylene oxide wax or block copolymers thereof; Waxes containing fatty acid esters such as carnauba wax as the main component; deoxidized waxes obtained by deoxidizing some or all of fatty acid esters such as carnauba wax. Among these waxes, hydrocarbon waxes such as paraffin wax and Fishertroph wax, and fatty acid ester waxes such as carnauba wax are preferable from the viewpoint of improving low temperature fixability and hot offset resistance.

In the present invention, a hydrocarbon-based wax or an ester-based wax is more preferable in that it has low-temperature fixability and further improves hot offset resistance. The content of the wax 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 the wax content is in this range, it is easy to exhibit the effect of maintaining hot offset resistance at high temperatures.

Further, from the viewpoint of achieving both toner storage stability and high temperature offset resistance, the maximum endothermic curve at the time of temperature rise measured by a differential scanning calorimetry device (DSC) is the maximum existing in the temperature range of 30 ° C. or higher and 200 ° C. or lower. The peak temperature of the endothermic peak is preferably 50 ° C. or higher and 140 ° C. or lower. More preferably, it is 60 ° C. or higher and 105 ° C. or lower.

[Colorant]
Examples of the colorant that can be contained in the toner of the present invention include the following.

Examples of the black colorant include carbon black; a color toned black using a yellow colorant, a magenta colorant, and a cyan colorant. A pigment may be used alone as the colorant, but it is more preferable to use a dye and a pigment in combination to improve the sharpness from the viewpoint of the image quality of a full-color image.

Examples of the magenta toner pigment include the following. C. I. Pigment Red 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,21,22,23,30,31, 32, 37, 38, 39, 40, 41, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; I. Pigment Violet 19; C.I. I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

Examples of the magenta toner dye include the following. C. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; C.I. I. Disperse thread 9; C.I. I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. Basic Red 1,2,9,12,13,14,15,17,18,22,23,24,27,29,32,34,35,36,37,38,39,40; I. Basic dyes such as Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Examples of the cyan toner pigment include the following. C. I. Pigment Blue 2, 3, 15: 2, 15: 3, 15: 4, 16, 17; C.I. I. Bat Blue 6; C.I. I. Acid blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalocyanine groups are substituted in the phthalocyanine skeleton.

Examples of dyes for cyan toner include C.I. I. There is Solvent Blue 70.

Examples of the pigment for yellow toner include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; C.I. I. Bat Yellow 1, 3, 20.

Examples of the dye for yellow toner include C.I. I. There is Solvent Yellow 162.

[Charge control agent]
The toner of the present invention may also contain a charge control agent, if necessary. Examples of the charge control agent include a metal salicylate compound, a metal naphthoate compound, a metal dicarboxylic acid compound, a polymer compound having a sulfonic acid or a carboxylic acid as a side chain, a sulfonate or a sulfone, as a negative charge control agent. Examples thereof include a polymer compound having an acid esterified product on the side chain, a carboxylate or a polymer compound having a carboxylic acid esterified product on the side chain, a boron compound, a urea compound, a silicon compound, and calix array. The charge control agent may be added internally or externally to the toner particles. The amount of the charge control agent added is preferably 0.2 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

[Career]
The toner of the present invention can also be used as a one-component developer, but in order to further improve dot reproducibility, a two-component developer mixed with a magnetic carrier can be obtained in a stable image for a long period of time. It is more preferable to use as.

Examples of the magnetic carrier include iron powder whose surface has been oxidized, unoxidized iron powder, metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, and rare earth, and alloys thereof. Generally known materials such as magnetic materials such as particles, oxide particles, and ferrite, and magnetic material dispersed resin carriers (so-called resin carriers) containing a magnetic material and a binder resin that holds the magnetic material in a dispersed state are used. Can be used.

When the toner of the present invention is mixed with a magnetic carrier and used as a two-component developer, the carrier mixing ratio at that time is preferably 2% by mass or more and 15% by mass or less as the toner concentration in the two-component developer. , More preferably, it is 4% by mass or more and 13% by mass or less, and usually good results are obtained.

[Production method]
The toner particles of the present invention can be produced by conventionally known toner production methods such as an emulsion aggregation method, a melt-kneading method, and a dissolution-suspension method, and are not particularly limited.

Hereinafter, an example of the toner manufacturing procedure by the pulverization method will be described.

In the raw material mixing step, a predetermined amount of other components such as a binder resin containing an amorphous polyester resin, a wax, a colorant, and a charge control agent, if necessary, are weighed as materials constituting the toner particles. Mix and mix. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.) and the like.

Next, the mixed materials are melt-kneaded to disperse wax and the like in the binder resin. In the melt-kneading process, a batch-type kneader such as a pressure kneader or a Bambary mixer or a continuous-type kneader can be used, and a single-screw or twin-screw extruder has become the mainstream because of the advantage of continuous production. ing. For example, KTK type twin-screw extruder (manufactured by Kobe Steel), TEM type twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), PCM kneader (manufactured by Ikegai Iron Works), twin-screw extruder (Ktk Inc.) , Co-kneader (manufactured by Bus), Kneedex (manufactured by Nippon Coke Industries Co., Ltd.), etc. Further, the resin composition obtained by melt-kneading may be rolled with two rolls or the like and cooled with water or the like in the cooling step.

Then, the cooled product of the resin composition is pulverized to a desired particle size in the pulverization step. In the crushing process, for example, after coarse crushing with a crusher such as a crusher, a hammer mill, or a feather mill, further, for example, a Cryptron system (manufactured by Kawasaki Heavy Industries), a super rotor (manufactured by Nisshin Engineering Co., Ltd.), and a turbo mill (Made by Turbo Industries) or a fine crusher using the air jet method.

After that, if necessary, classification of inertial classification type elbow jet (manufactured by Nittetsu Mining Co., Ltd.), centrifugal force classification method turboplex (manufactured by Hosokawa Micron), TSP separator (manufactured by Hosokawa Micron), faculty (manufactured by Hosokawa Micron), etc. Classify using a machine or a sieving machine to obtain a classified product (toner particles). Among them, Faculti (manufactured by Hosokawa Micron Co., Ltd.) is preferable in that the toner particles can be sphericalized at the same time as the classification, and the transfer efficiency is improved.

If necessary, after crushing, use a hybridization system (manufactured by Nara Machinery Co., Ltd.), mechanofusion system (manufactured by Hosokawa Micron), faculty (manufactured by Hosokawa Micron), and Meteole Invo MR Type (manufactured by Nippon Pneumatic). It is also possible to perform surface treatment of toner particles such as spherical treatment.

Then, it is divided into a fine powder side and a coarse powder side. For example, it is divided into two using an inertial classification type elbow jet (manufactured by Nittetsu Mining Co., Ltd.). Inorganic fine particles having different degrees of hydrophobicity are externally added to the surface of each of the divided toner particles.

As a method of external addition treatment, toner particles and various known external additives are mixed in a predetermined amount, and a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, and a mechano hybrid (Nippon Coke Industries Co., Ltd.) Examples thereof include a method of stirring and mixing using a mixing device such as Nobilta (manufactured by Hosokawa Micron Co., Ltd.).

Next, a method for measuring each physical property related to the present invention will be described.

<Hydrophobicity of inorganic fine particles>
The degree of hydrophobization of the inorganic fine particles in the present invention is determined from the methanol dropping transmittance curve obtained as follows.

First, 70 ml of a hydrous methanol solution having a known methanol concentration (% by volume) is placed in a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm, and ultrasonically dispersed in order to remove air bubbles and the like in the measurement sample. Disperse in a vessel for 5 minutes.

Next, 0.1 g of the inorganic fine particles is precisely weighed and added to the container containing the hydrous methanol solution to prepare a sample solution for measurement.

Then, the sample liquid for measurement is set in the powder wettability tester "WET-100P" (manufactured by Reska). This measurement sample solution is stirred at a speed of 6.7 s-1 (400 rpm) using a magnetic stirrer. As the rotor of the magnetic stirrer, a spindle-shaped rotor coated with a fluororesin and having a length of 25 mm and a maximum body diameter of 8 mm is used.

Next, the transmittance was measured with light having a wavelength of 780 nm while continuously adding methanol at a dropping rate of 1.5 ml / min into the sample solution for measurement through the above apparatus, and a methanol dropping transmittance curve was created. To do.

The degree of hydrophobization of the inorganic fine particles in the present invention is calculated by setting the intermediate value of the methanol concentration between the lowering start point and the lowering end point of the light transmittance as the degree of hydrophobicity.

<Calculation of coverage of inorganic fine particles on the surface of toner particles>
In the present invention, the coverage of inorganic fine particles on the surface of toner particles is determined by using image analysis software Image-, which is a toner surface image taken by Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (Hitachi High Technologies America, Ltd.). Pro Plus ver. Calculated by analysis according to 5.0 (Nippon Roper Co., Ltd.).

In the toner particles, the inorganic fine particles on the toner surface are observed with the above SEM device. When observing, select a place where the surface of the toner particles is as flat as possible. The obtained image is binarized and the following analysis is performed. It is calculated from the obtained image as the ratio of the area occupied by the inorganic fine particles to the area of the surface of the toner particles. The same operation is performed on 10 toner particles, and the average value thereof is calculated.

<Measurement of median diameter (D50) based on the number of toners>
<Calculation of coverage Ys and Yl of inorganic fine particles on the surface of toner particles>
The median diameter (D50), average coverage Ss, and average coverage Sl based on the number of toners of the present invention can be determined by observing a secondary electron image with a scanning electron microscope and subsequent image processing.

The median diameter (D50), average coverage Ss, and average coverage Sl based on the number of toners of the present invention were measured using a scanning electron microscope (SEM) and S-4800 (manufactured by Hitachi, Ltd.). The area ratio of the portion derived from the inorganic fine particles is calculated mainly from the image processing of the portion having high brightness when the acceleration voltage is 2.0 kV.

Specifically, the toner was fixed on a sample table for electron microscope observation with carbon tape so as to form a single layer, and vapor deposition was performed with platinum. Under the following conditions, the scanning electron microscope S-4800 (manufactured by Hitachi, Ltd.) ) Was observed. Observe after performing the flushing operation.
SignalName = SE (U, LA80)
Acceleratorating Voltage = 2000 Volt
Emissioncurent = 10000nA
WorkingDistance = 6000um
LensMode = High
Condencer1 = 5
ScanSpeed = Slow4 (40 seconds)
Magnification = 50,000
DataSize = 1280 x 960
ColorModel = Grayscale

The brightness of the secondary electron image is adjusted to'contrast 5 and brightness -5'on the control software of the scanning electron microscope S-4800, and the capture speed / integrated number of sheets'Slow4 is 40 seconds' and the image size is 1280 x 960pixels. A projected image of the toner was obtained as an 8-bit 256-gradation grayscale image. From the scale on the image, the length of 1 pixel is 0.02 μm and the area of 1 pixel is 0.0004 μm ² .

Subsequently, using the obtained projected image of secondary electrons, the area ratio (area%) of the projected area circle-equivalent diameter and the portion derived from the inorganic fine particles was calculated for 100 toner particles. Details of the method for selecting 100 toners to be analyzed will be described later. Image processing software Image-Pro Plus 5.1J (manufactured by Media Cybernetics) was used for the area% of the portion derived from the inorganic fine particles.

Next, a portion of the toner particle group was extracted, and the size of one extracted toner particle was counted. Specifically, first, in order to extract the toner particle group to be analyzed, the toner particle group and the background portion are separated. Select "Measurement"-"Count / Size" of Image-Pro Plus 5.1J. In "Brightness range selection" of "Count / Size", the brightness range was set to the range of 50 to 255, the low-brightness carbon tape part reflected as the background was excluded, and the toner particle group was extracted. .. When the toner particle group is fixed by a method other than carbon tape, there is a possibility that the background does not necessarily have a low brightness region or the brightness partially becomes the same as that of the toner particle group. However, the boundary between the toner particle group and the background can be easily distinguished from the secondary electron observation image. When extracting, select 4 concatenation in the extraction option of "Count / Size", enter smoothness 5, check fill in the holes, toner particles located on all boundaries (outer circumference) of the image, etc. Toner particles that overlap with the toner particles of No. 1 are excluded from the calculation. Next, the area and the ferret diameter (average) were selected in the measurement items of "count / size", the selection range of the area was set to a minimum of 100 pixels and a maximum of 10000 pixels, and each toner grain to be image-analyzed was extracted. One toner particle was selected from the extracted toner particle group, and the size (pixel number) of the portion derived from the particle was determined as (ja). From the obtained ja, the diameter d1 corresponding to the projected area circle was obtained by using the following formula.
d1 = {(4 x ja x 0.3088) /3.14} ^(1/2)

Next, the brightness range was set to the range of 140 to 255 in the "brightness range selection" of "count / size" of Image-Pro Plus 5.1J, and the high-brightness portion on one toner grain was extracted. .. By setting the area selection range to a minimum of 3 pixels and a maximum of 200 pixels, it is possible to extract a highly bright portion derived from the silica fine particles A.

Then, for the toner particles selected when determining ja, the size (pixel number) (ma) of the portion derived from the inorganic fine particles on the toner surface was determined. In each toner grain, the extracted portions derived from the inorganic fine particles are scattered with a certain size, and ma is the total area thereof. From the obtained ma, the coverage s1 of the silica fine particles A was obtained using the following formula.
s1 = (ma / ja) x 100

Then, each particle of the extracted particle group was subjected to the same treatment until the number of selected toner particles reached 100. When the number of toner particles in one field of view was less than 100, the same operation was repeated for the toner projection image in another field of view.

The 100 toner particles obtained were arranged in ascending order in diameter equivalent to the projected area circle, and the diameter equivalent to the projected area circle of the 50th toner particle was defined as the median diameter (D50) based on the number of toners of the present invention.

Further, the average value of the coverage s of the first to 50th toner particles whose projected area circle-equivalent diameters are arranged in ascending order is an image of a toner scanning electron microscope having a particle size smaller than D50 of the toner of the present invention. The average coverage of the inorganic fine particles Ys determined by the analysis was used. Similarly, the average value of the coverage l of the 51st to 100th toner particles whose projected area circle-equivalent diameters are arranged in ascending order is the average value of the coating ratio l of the toner scanning electron microscope having a particle size larger than D50 of the toner of the present invention. The average coverage of the inorganic fine particles obtained by image analysis was Yl.

<Measurement method of toner surface tension index>
Approximately 5.5 g of toner was gently poured into the measuring cell, and a tapping operation was performed for 1 minute at a tapping speed of 30 times / min using a tapping machine PTM-1 type (manufactured by Sankyo Piotech Co., Ltd.). This was set in a measuring device (manufactured by Sankyo Piotech Co., Ltd .: WTMY-232A type wet tester) and measured. The capillary suction time method was used to measure the capillary pressure Pα (kN / m ² ). The conditions for each measurement are as follows.
Solvent: 45% by volume methanol aqueous solution Measurement mode: Constant flow method (A2 mode)
Liquid flow rate: 2.4 ml / min
Cell: Y-type measurement cell

The surface tension index (N / m) of the toner is Pα (N / m ² ) for the capillary pressure measured by the capillary suction time method of the toner, A (m ² / g) for the specific surface area of the toner, and the true density of the toner. Was calculated as B (g / cm ³ ) from the following formula (A). The specific surface area and true density of the toner were measured by the method described later.
Formula (A): Toner surface tension index = Pα / (A × B × 10 ⁶ )

<Measurement method of softening point Tm of binder resin>
The softening point of the binder resin is measured by using a constant load extrusion type thin tube rheometer "Flow Tester CFT-500D" (manufactured by Shimadzu Corporation) and following the manual attached to the device. In this device, while applying a constant load from the top of the measurement sample with a piston, the temperature of the measurement sample filled in the cylinder is raised 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.

Further, the softening point is the "melting temperature in the 1/2 method" described in the manual attached to the "flow characteristic evaluation device flow tester CFT-500D". 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.

As a measurement sample, about 1.0 g of resin was compression-molded in an environment of 25 ° C. using a tablet molding compressor (for example, NT-100H, manufactured by NPA System Co., Ltd.) at about 10 MPa for about 60 seconds. Use a columnar one with a diameter of about 8 mm.

The measurement conditions for the CFT-500D are as follows.
Test mode: Hot compress start temperature: 50 ° C
Achieved temperature: 200 ° C
Measurement interval: 1.0 ° C
Temperature rise rate: 4.0 ° C / min
Piston cross-sectional area: 1.000 cm ²
Test load (piston load): 10.0 kgf (0.9807 MPa)
Preheating time: 300 seconds Die hole diameter: 1.0 mm
Die length: 1.0 mm

<Measurement of maximum endothermic peak of wax>
The peak temperature of the maximum endothermic peak of wax is measured according to ASTM D3418-82 using a differential scanning calorimetry device "Q1000" (manufactured by TA Instruments). The melting points of indium and zinc are used for temperature correction of the device detector, and the heat of fusion of indium is used for the correction of calorific value.

Specifically, about 10 mg of wax is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature is raised in the measurement temperature range of 30 ° C. or higher and 200 ° C. or lower. The measurement is performed at a speed of 10 ° C./min. In the measurement, the temperature is once raised to 200 ° C., then lowered to 30 ° C., and then raised again. The temperature showing the maximum endothermic peak of the DSC curve in the temperature range of 30 ° C. or higher and 200 ° C. or lower in the second temperature raising process is defined as the peak temperature of the maximum endothermic peak of the wax.

<Measurement of specific surface area (BET specific surface area) of toner and inorganic fine particles>
The BET specific surface area of the toner and the inorganic fine particles is measured according to JIS Z8830 (2001). The specific measurement method is as follows.

As the measuring device, an "automatic specific surface area / pore distribution measuring device TriStar3000 (manufactured by Shimadzu Corporation)" that employs a gas adsorption method based on a constant volume method is used. The measurement conditions are set and the measurement data is analyzed by using the dedicated software "TriStar3000 Version 4.00" attached to this device. A vacuum pump, nitrogen gas piping, and helium gas piping are connected to this device. Nitrogen gas is used as an adsorption gas, and the value calculated by the BET multipoint method is used as the BET specific surface area of the inorganic fine particles in the present invention.

The BET specific surface area is calculated as follows.

First, nitrogen gas is adsorbed on the toner or the inorganic fine particles, and the equilibrium pressure P (Pa) in the sample cell at that time and the nitrogen adsorption amount Va (mol / g) of the toner or the inorganic fine particles are measured. Then, the horizontal axis is the relative pressure Pr, which is the value obtained by dividing the equilibrium pressure P (Pa) in the sample cell by the saturated vapor pressure Po (Pa) of nitrogen, and the vertical axis is the nitrogen adsorption amount Va (mol / g). Obtain an adsorption isotherm. Next, the adsorption amount Vm (mol / g) of the monolayer, which is the adsorption amount required to form the monolayer on the surface of the external additive, is determined by applying the following BET formula.
Pr / Va (1-Pr) = 1 / (Vm × C) + (C-1) × Pr / (Vm × C)

Here, C is a BET parameter, which is a variable that varies depending on the measurement sample type, the adsorbed gas type, and the adsorption temperature.

The BET formula is interpreted as a straight line with a slope of (C-1) / (Vm × C) and an intercept of 1 / (Vm × C), where Pr is the X-axis and Pr / Va (1-Pr) is the Y-axis. it can. This straight line is called a BET plot.
Slope of a line = (C-1) / (Vm × C)
Straight line intercept = 1 / (Vm × C)

When the measured value of Pr and the measured value of Pr / Va (1-Pr) are plotted on a graph and a straight line is drawn by the least squares method, the slope value of the straight line and the intercept value can be calculated. By substituting these values into the above equations and solving the obtained simultaneous equations, Vm and C can be calculated.

Further, the BET specific surface area S (m ² / g) of the toner or the inorganic fine particles is calculated from the Vm and the molecular occupied cross-sectional area of the nitrogen molecule (0.162 nm ² ) calculated here based on the following formula.
S = Vm x N x 0.162 x 10 ^-18

Here, N is Avogadro's number (mol- ¹ ).

The measurement using this device follows the "TriStar 3000 Instruction Manual V4.0" attached to the device, but specifically, the measurement is performed by the following procedure.

Weigh the tare of a special glass sample cell (stem diameter 3/8 inch, volume about 5 ml) that has been thoroughly washed and dried. Then, using a funnel, about 1.0 g of toner and about 0.1 g of inorganic fine particles are put into this sample cell.

Set the sample cell containing toner or inorganic fine particles in the "pretreatment device Vacuprep 061 (manufactured by Shimadzu Corporation)" connected to the vacuum pump and nitrogen gas piping, and continue vacuum degassing at 23 ° C for about 10 hours. To do. At the time of vacuum degassing, the valve is gradually degassed so that toner or inorganic fine particles are not sucked into the vacuum pump. The pressure in the sample cell gradually decreases with degassing, and finally reaches about 0.4 Pa (about 3 mitol). After the vacuum deaeration is completed, nitrogen gas is gradually injected into the sample cell to return the inside of the sample cell to atmospheric pressure, and the sample cell is removed from the pretreatment device. Then, the mass of this sample cell is precisely weighed, and the accurate mass of the external additive is calculated from the difference from the mass of the tare. At this time, the sample cell is covered with a rubber stopper during weighing so that the toner or inorganic fine particles in the sample cell are not contaminated by moisture in the atmosphere.

Next, a dedicated "isothermal jacket" is attached to the stem of the sample cell containing toner or inorganic fine particles. Then, a dedicated filler rod is inserted into the sample cell, and the sample cell is set in the analysis port of the apparatus. The isothermal jacket is a tubular member having a porous material on the inner surface and an impermeable material on the outer surface, which can suck up liquid nitrogen to a certain level by capillarity.

Subsequently, the free space of the sample cell including the connecting device is measured. In the free space, the volume of the sample cell was measured using helium gas at 23 ° C., and then the volume of the sample cell after cooling the sample cell with liquid nitrogen was also measured using helium gas. It is calculated by converting from the difference in volume of. Further, the saturated vapor pressure Po (Pa) of nitrogen is automatically measured separately by using the Po tube built in the present apparatus.

Next, after performing vacuum degassing in the sample cell, the sample cell is cooled with liquid nitrogen while continuing the vacuum degassing. Then, nitrogen gas is introduced stepwise into the sample cell to adsorb nitrogen molecules on the toner or inorganic fine particles. At this time, since the adsorption isotherm is obtained by measuring the equilibrium pressure P (Pa) at any time, the adsorption isotherm is converted into a BET plot. The points of the relative pressure Pr for collecting data are set to a total of 6 points of 0.05, 0.10, 0.15, 0.25, 0.25, and 0.30. A straight line is drawn from the obtained measurement data by the method of least squares, and Vm is calculated from the slope and intercept of the straight line. Further, using this value of Vm, the BET specific surface area of the toner or the inorganic fine particles is calculated as described above.

<Measurement of true toner density>
The true density of the toner was measured using a dry automatic density meter Accupic 1330 (manufactured by Shimadzu Corporation).

First, 1 g of a sample left in an environment of 23 ° C./50% RH for 24 hours was precisely weighed, placed in a measurement cell (10 cm ³ ), and inserted into the main body sample chamber. The measurement can be automatically performed by inputting the mass (weight) of the sample into the main body and starting the measurement. As the measurement condition of the automatic measurement, helium gas adjusted at 20.000 psig (2.392 × 10 ² kPa) was used. After 10 purges the sample chamber, and a state in which the pressure change in the sample chamber is 0.005Psig / min (3.447 × 10 ^-2 kPa / min) equilibrium, purged repeatedly helium gas until an equilibrium state did. The pressure in the main body sample chamber in the equilibrium state was measured. The sample volume was calculated from the pressure change when the equilibrium state was reached.

The sample volume was calculated, and the true density of the sample was calculated by the following formula.
True density of sample (g / cm ³ ) = sample mass (g) / sample volume (cm ³ )

The average value of the values obtained by repeating this automatic measurement 5 times was taken as the true density of the toner (g / cm ³ ).

<Measurement of acid value of resin>
The acid value is the number of mg of potassium hydroxide required to neutralize the acid contained in 1 g of the sample. The acid value of the binder resin is measured according to JIS K 0070-1992, but specifically, it is measured according to the following procedure.

(1) Preparation of Reagents 1.0 g of phenolphthalein is dissolved in 90 ml of ethyl alcohol (95% by volume), and ion-exchanged water is added to make 100 ml to obtain a phenolphthalein solution.

Dissolve 7 g of special grade potassium hydroxide in 5 ml of water and add ethyl alcohol (95% by volume) to make 1 L. Put it in an alkali-resistant container so as not to come into contact with carbon dioxide, leave it for 3 days, and then filter it to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution is stored in an alkali-resistant container. As for the factor of the potassium hydroxide solution, take 25 ml of 0.1 mol / l hydrochloric acid in a triangular flask, add a few drops of the phenolphthaline solution, titrate with the potassium hydroxide solution, and carry out the hydroxylation required for neutralization. Obtained from the amount of potassium solution. As the 0.1 mol / l hydrochloric acid, one prepared and prepared according to JIS K 8001-1998 is used.

(2) Operation (A) Main test 2.0 g of the sample is precisely weighed in a 200 ml Erlenmeyer flask, 100 ml of a mixed solution of toluene / ethanol (2: 1) is added, and the mixture is dissolved over 5 hours. Then, a few drops of the phenolphthalein solution are added as an indicator, and titration is performed using the potassium hydroxide solution. The end point of the titration is when the light red color of the indicator continues for about 30 seconds.

(B) Blank test Titration is performed in the same manner as above except that no sample is used (that is, only a mixed solution of toluene / ethanol (2: 1) is used).

(3) Substitute the obtained result into the following formula to calculate the acid value.
A = [(CB) x f x 5.61] / S

Here, A: acid value (mgKOH / g), B: addition amount of potassium hydroxide solution in blank test (ml), C: addition amount of potassium hydroxide solution in this test (ml), f: potassium hydroxide Solution factor, S: sample (g).

Hereinafter, the present invention will be described with reference to Production Examples and Examples. ..

<Production example 1 of silica fine particles>
In producing the silica fine particles 1, a hydrocarbon-oxygen mixed burner having a double-tube structure capable of forming an internal flame and an external flame was used as a combustion furnace. In this burner, a two-fluid nozzle for slurry injection is installed in the center of the burner, and a silicon compound as a raw material is introduced. Further, a flammable gas of hydrocarbon-oxygen is injected from the periphery of the two-fluid nozzle to form an inner flame and an outer flame which are reducing atmospheres. By controlling the amount and flow rate of flammable gas and oxygen, the atmosphere, temperature, flame length, etc. can be adjusted. Further, in a flame, silica fine particles are generated from the raw material silicon compound, and the silica fine particles can be fused until they have a desired particle size. After that, it is cooled and the generated silica fine particles are collected by a bag filter or the like to obtain silica fine particles having a desired particle size.

Hexamethylcyclotrisiloxane was used as a raw material silicon compound to produce silica fine particles. Next, 100 parts by mass of the obtained silica fine particles were surface-treated with 25 parts by mass (that is, 25% by mass) of hexamethyldisilazane (HMDS) to obtain silica fine particles 1.

The physical properties are shown in Table 1.

<Production Examples 2 to 13 of Silica Fine Particles>
Silica fine particles 2 to 13 were obtained in the same manner as in Silica fine particle production example 1 except that the number average diameter of the primary particles and the amount of the surface treatment agent were changed as shown in Table 1.

<Production example of binder resin>
(Production Example 1 of Polyester Resin L)
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 59.0 parts by mass (0.15 mol; 80.0 mol% based on the total number of moles of polyhydric alcohol)
-Polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane:
13.6 parts by mass (0.04 mol; 20.0 mol% with respect to the total number of moles of polyhydric alcohol)
-Terephthalic acid: 20.8 parts by mass (0.13 mol; 80.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
Trimellitic anhydride: 6.6 parts by mass (0.03 mol; 20.0 mol% based on the total number of moles of polyvalent carboxylic acid)
The above materials were put into a cooling pipe, a stirrer, a nitrogen introduction pipe, and a reaction vessel equipped with a thermocouple. Then, 1.5 parts by mass of tin 2-ethylhexanoate (esterification catalyst) was added as a catalyst to 100 parts by mass of the total amount of the monomers. Next, the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 2.5 hours while stirring at a temperature of 200 ° C.

Further, the pressure in the reaction vessel was lowered to 8.3 kPa, maintained for 1 hour, cooled to 180 ° C., reacted as it was, and after confirming that the softening point measured according to ASTM D36-86 reached 90 ° C. The temperature was lowered to stop the reaction. The softening point (Tm) of the obtained polyester resin L1 was 95 ° C., and the acid value was 8 mgKOH / g.

(Production Examples 2 to 4 of Polyester Resin L)
In Production Example 1 of the polyester resin, the production was carried out in the same manner except that the amount of trimellitic acid was changed to obtain polyester resins L2 to L4. The physical properties are shown in Table 2.

(Production Example 1 of Amorphous Polyester Resin H)
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 73.4 parts by mass (0.19 mol; 100.0 mol% based on the total number of moles of polyhydric alcohol)
-Terephthalic acid: 11.6 parts by mass (0.07 mol; 82.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Adipic acid: 6.8 parts by mass (0.05 mol; 14.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Di (2-ethylhexylate) tin: 0.8 parts by mass The above materials were weighed and charged into a cooling tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. Next, the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 3 hours while stirring at a temperature of 200 ° C.

Further, the pressure in the reaction vessel was lowered to 8.3 kPa, maintained for 1 hour, cooled to 180 ° C., and returned to atmospheric pressure (first reaction step).
Trimellitic anhydride: 8.2 parts by mass (0.04 mol; 6.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Then, the above material is added, the pressure in the reaction vessel is lowered to 8.3 kPa, and the reaction is carried out for 10 hours while maintaining the temperature at 150 ° C. to lower the temperature. As a result, the reaction was stopped (second reaction step) to obtain an amorphous polyester resin H. The obtained amorphous polyester resin H had a softening point of 145 ° C. and an acid value of 10 mgKOH / g. The physical properties are shown in Table 2.

<Manufacturing example of vinyl resin>
Low molecular weight polypropylene (Viscol 660P manufactured by Sanyo Chemical Industries, Ltd.): 15.0 parts by mass (0.03 mol; 3.0 mol% with respect to the total number of moles of constituent monomers)
-Xylene: 25.0 parts by mass The above materials were weighed in a cooling tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. Next, the inside of the flask was replaced with nitrogen gas, and then the temperature was gradually raised to 175 ° C. with stirring.
-Styrene: 64.5 parts by mass (0.62 mol; 76.0 mol% with respect to the total number of moles of constituent monomers)
-Cyclohexyl methacrylate: 9.6 parts by mass (0.06 mol; 7.0 mol% based on the total number of moles of constituent monomers)
Butyl acrylate: 11.5 parts by mass (0.09 mol; 11.0 mol% with respect to the total number of moles of constituent monomers)
-Methyl methacrylate: 2.4 parts by mass (0.02 mol; 3.0 mol% with respect to the total number of moles of constituent monomers)
-Xylene: 10.0 parts by mass-Di-t-butylperoxyhexahydroterephthalate: 0.5 parts by mass Then, the above material was added dropwise over 2.5 hours and stirred for another 40 minutes. Then, the solvent was distilled off to obtain a vinyl resin in which a styrene acrylic polymer was grafted on polypropylene. The obtained vinyl resin had a peak molecular weight of Mp7000 and a softening point of 120 ° C.

<Toner manufacturing example 1>
-Polyester resin L1 80.0 parts by mass-Polyester resin H 20.0 parts by mass-Vinyl resin 5.0 parts by mass-Aluminum 3,5-di-t-butylsalicylate compound 0.1 parts by mass-Fishertropsh wax ( Peak temperature of maximum heat absorption peak 90 ° C.) 5.0 parts by mass ・ C.I. I. Pigment Blue 15: 3 5.0 parts by mass After mixing the raw materials shown in the above formulation with a Henschel mixer (FM75J type, manufactured by Mitsui Miike Machinery Co., Ltd.) at a rotation speed of 20 s ^-1 and a rotation time of 5 min. The mixture was kneaded with a twin-screw kneader (PCM-30 type, manufactured by Ikegai Corp.) set at a temperature of 130 ° C. and a barrel rotation speed of 200 rpm. The obtained kneaded product was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely crushed product. The obtained coarse crushed product was finely pulverized with a mechanical crusher (T-250, manufactured by Turbo Industries, Ltd.) to obtain finely pulverized toner particles 1. The operating conditions of the mechanical crusher (T-250, manufactured by Turbo Industries, Ltd.) were that the crushing rotor rotation speed was 200 s ^-1 .

The finely pulverized particles were divided into a large particle size side and a small particle size side using an inertial classification type elbow jet (manufactured by Nittetsu Mining Co., Ltd.). The operating conditions are feed amount = 5 kg / hr, the F classification edge (fine powder classification edge) is 10 to 15 mm, the G classification edge (coarse powder classification edge) is maximized and closed, and the finely pulverized toner particles are evenly distributed between F and M. The particles were adjusted so as to be divided into two, and the particles on the small diameter side were designated as toner particles F1 and the particles on the large diameter side were designated as toner particles M1.
-Toner particles F1 100 parts by mass-Silica fine particles 1 3.5 parts by mass The above materials are mixed with a Henshell mixer (FM-75 type, manufactured by Mitsui Miike Machinery Co., Ltd.) at a rotation speed of 1900 rpm and a rotation time of 10 min, and the toner F1 Got
-Toner particles M1 100 parts by mass-Silica fine particles 1 3.5 parts by mass The above materials are mixed with a Henshell mixer (FM-75 type, manufactured by Mitsui Miike Machinery Co., Ltd.) at a rotation speed of 1900 rpm and a rotation time of 10 min, and the toner M1 Got

The obtained toner F1 and toner M1 were mixed by a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Machinery Co., Ltd.) and passed through an ultrasonic vibrating sieve having a mesh size of 54 μm to obtain toner 1. Table 3 shows the physical properties of the toner 1.

<Toner manufacturing examples 2-5>
In Toner Production Example 1, the silica fine particles 1 externally attached together with the toner particles F1 were changed to those shown in Table 3, but the same production was carried out to obtain toners 2 to 5.

<Toner manufacturing examples 6 and 7>
In Toner Production Example 1, toners 6 and 7 were obtained in the same manner except that the number of copies of silica fine particles 1 externally added together with the toner particles F1 was changed to those shown in Table 3.

<Toner manufacturing examples 8 to 10>
In the toner production example 7, the polyester resin L1 was changed to the polyester resins L2 to L4 shown in Table 3, and the toner particles F2 to F4 were obtained as the toner particles on the small diameter side. I got 10.

<Toner manufacturing examples 11 to 15>
In Toner Production Example 6, the silica fine particles 1 externally attached together with the toner particles F1 were changed to those shown in Table 3, and the same was produced to obtain toners 11 to 15.

<Toner manufacturing examples 16 and 17>
In Toner Production Example 15, toners 16 and 17 were obtained in the same manner except that the silica fine particles 12 externally attached together with the toner particles M1 were changed to those shown in Table 3.

<Toner manufacturing example 18>
In Toner Production Example 10, the toner 18 was produced in the same manner except that the operating conditions of the mechanical crusher (T-250, manufactured by Turbo Industries, Ltd.) were set to 150 s ^-1 for the crushing rotor rotation speed. Obtained.

<Toner manufacturing example 19>
In Toner Production Example 1, the toner 19 was obtained in the same manner except that the silica fine particles externally added together with the toner particles F1 and the toner particles M1 and the number of copies thereof were changed to those shown in Table 3.

<Production example of magnetic core particle 1>
・ Process 1 (weighing / mixing process):
Fe ₂ O ₃ 62.7 parts by mass MnCO ₃ 29.5 parts by mass Mg (OH) ₂ 6.8 parts by mass SrCO ₃ 1.0 part by mass The ferrite raw material was weighed so as to have the above composition ratio. Then, it was pulverized and mixed for 5 hours with a dry vibration mill using stainless beads having a diameter of 1/8 inch.

-Step 2 (temporary firing step):
The obtained pulverized product was made into pellets of about 1 mm square by a roller compactor. Coarse powder is removed from the pellets with a vibrating sieve having a mesh opening of 3 mm, and then fine powder is removed with a vibrating sieve having a mesh opening of 0.5 mm. It was calcined at a temperature of 1000 ° C. for 4 hours at 01% by volume) to prepare calcined ferrite. The composition of the obtained calcined ferrite is as follows.
(MnO) a (MgO) b (SrO) c (Fe ₂ O ₃ ) d
In the above formula, a = 0.257, b = 0.117, c = 0.007, d = 0.393

-Step 3 (crushing step):
After crushing to about 0.3 mm with a crusher, 30 parts by mass of water was added to 100 parts by mass of calcined ferrite using zirconia beads having a diameter of 1/8 inch, and the mixture was crushed with a wet ball mill for 1 hour. The slurry was pulverized with a wet ball mill using alumina beads having a diameter of 1/16 inch for 4 hours to obtain a ferrite slurry (a finely pulverized product of calcined ferrite).

・ Process 4 (granulation process):
To 100 parts by mass of calcined ferrite, 1.0 part by mass of ammonium polycarboxylic acid as a dispersant and 2.0 parts by mass of polyvinyl alcohol as a binder were added to the ferrite slurry, and a spray dryer (manufacturer: Okawara Kakoki) was used. It was granulated into spherical particles. After adjusting the particle size of the obtained particles, the particles were heated at 650 ° C. for 2 hours using a rotary kiln to remove organic components of the dispersant and the binder.

-Step 5 (firing step):
In order to control the firing atmosphere, the temperature was raised from room temperature to a temperature of 1300 ° C. in 2 hours under a nitrogen atmosphere (oxygen concentration 1.00% by volume) in an electric furnace, and then firing was performed at a temperature of 1150 ° C. for 4 hours. Then, over 4 hours, the temperature was lowered to 60 ° C., the nitrogen atmosphere was returned to the atmosphere, and the mixture was taken out at a temperature of 40 ° C. or lower.

・ Process 6 (sorting process):
After crushing the agglomerated particles, the low magnetic force product is cut by magnetic beneficiation, sieved with a sieve having a mesh size of 250 μm to remove coarse particles, and 50% particle size (D50) 37.0 μm based on the volume distribution. Magnetic core particles 1 were obtained.

<Preparation of coating resin 1>
Cyclohexyl methacrylate monomer 26.8% by mass
Methyl methacrylate monomer 0.2% by mass
Methyl methacrylate macromonomer 8.4% by mass
(Macromonomer having a methacryloyl group at one end and having a weight average molecular weight of 5000)
Toluene 31.3% by mass
Methyl ethyl ketone 31.3% by mass
Azobisisobutyronitrile 2.0% by mass
Of the above materials, cyclohexyl methacrylate, methyl methacrylate, methyl methacrylate macromonomer, toluene, and methyl ethyl ketone are added to a four-port separable flask equipped with a reflux condenser, a thermometer, a nitrogen introduction tube, and a stirrer, and nitrogen gas is added. Was introduced to give a sufficient nitrogen atmosphere, the mixture was heated to 80 ° C., azobisisobutyronitrile was added, and the mixture was refluxed for 5 hours for polymerization. Hexane was injected into the obtained reaction product to precipitate a copolymer, and the precipitate was separated by filtration and vacuum dried to obtain a coating resin 1. The obtained coating resin 1:30 parts by mass was dissolved in 40 parts by mass of toluene and 30 parts by mass of methyl ethyl ketone to obtain a polymer solution 1 (solid content 30% by mass).

<Preparation of coating resin solution 1>
Polymer solution 1 (resin solid content concentration 30%) 33.3% by mass
Toluene 66.4% by mass
Carbon black (Regal330; manufactured by Cabot) 0.3% by mass
(Primary particle size 25 nm, nitrogen adsorption specific surface area 94 m ² / g, DBP oil absorption 75 ml / 100 g)
These were dispersed in a paint shaker for 1 hour using zirconia beads having a diameter of 0.5 mm. The obtained dispersion was filtered through a 5.0 μm membrane filter to obtain a coating resin solution 1.

<Manufacturing example of magnetic carrier 1>
(Resin coating process):
The coating resin solution 1 was added to a vacuum degassing type kneader maintained at room temperature so as to be 2.5 parts by mass as a resin component with respect to 100 parts by mass of the packed core particles 1. After charging, the mixture was stirred at a rotation speed of 30 rpm for 15 minutes, the solvent was volatilized above a certain level (80% by mass), the temperature was raised to 80 ° C. while mixing under reduced pressure, toluene was distilled off over 2 hours, and then the mixture was cooled. The obtained magnetic carrier is separated into low magnetic force products by magnetic beneficiation, passed through a sieve having an opening of 70 μm, and then classified by a wind power classifier. A magnetic carrier having a volume distribution standard of 50% particle size (D50) of 38.2 μm. I got 1.

<Production example 1 of a two-component developer>
8.0 parts by mass of toner 1 was added to 1: 92.0 parts by mass of the magnetic carrier and mixed with a V-type mixer (V-20, manufactured by Seishin Enterprise Co., Ltd.) to obtain a two-component developer 1.

<Production Examples 2 to 19 of Two-Component Developer>
In Production Example 1 of the two-component developer, the same production was carried out except that the toner was changed as shown in Table 4, to obtain two-component developers 2 to 19.

[Example 1]
[Evaluation]
As an image forming apparatus to be evaluated, a Canon full-color copying machine imageRUNNER ADVANCE C5560 modified machine was used. This image forming apparatus has a photoconductor that forms an electrostatic latent image as an image carrier, and has a developing step of developing the electrostatic latent image of the photoconductor as a toner image by a two-component developer. Further, it has a transfer step of transferring the developed toner image to an intermediate transfer body and then transferring the toner image of the intermediate transfer body to paper, and has a fixing step of fixing the toner image on paper by heat. The two-component developer 1 was put into the developer of the cyan station of this image forming apparatus and evaluated.

<Evaluation 1> Evaluation of fine line reproducibility A thin line reproducibility test was conducted on the two-component developer 1. As the evaluation paper, copy paper GF-C081 (A4, basis weight 81.4 g / m ² , sold by Canon Marketing Japan Inc.) was used.
Vcontlast: 300V
(Adjusted by DC voltage VDC of developer carrier, charging voltage VD of electrostatic latent image carrier, and laser power)
Evaluation image: 1 dot, 1 space vertical line image is placed on the above A4 paper Test environment: Room temperature and humidity (NN) Environment: Temperature 23 ° C, humidity 50% RH
Fixing temperature: 170 ° C
Process speed: 377 mm / sec

The above evaluation image was output and the image quality was evaluated. The value of Blur (a numerical value indicating how the line is blurred defined by ISO13660) was used as an evaluation index of image quality. The measurement was performed using a personal IAS (image analysis system) (manufactured by QEA). The obtained Blur value was evaluated according to the following evaluation criteria. C or higher was judged to have the effect of the present invention.

(Evaluation criteria)
A: Blur value less than 35 μm (very good)
B: Blur value 35 μm or more and less than 38 μm (excellent)
C: Blur value 38 μm or more and less than 44 μm (no problem level)
D: Blur value 44 μm or more (not acceptable)

<Evaluation 2> Evaluation of transfer uniformity Using a Canon full-color copying machine imageRUNNER ADVANCE C5560 remodeling machine as an image forming apparatus, the above two-component developer 1 is placed in a cyan developing device of the image forming apparatus, and a cyan toner bottle is used. 1 was filled with toner 1 and evaluated later. The modification point is that the mechanism for discharging the excess magnetic carrier inside the developing device from the developing device has been removed.

The amount of toner on the paper in the FFh image (solid image) was adjusted to 0.45 mg / cm ² . FFh is a value obtained by displaying 256 gradations in hexadecimal, 00h is the first gradation of 256 gradations (white background portion), and FF is the 256th gradation of 256 gradations (solid portion). ..

In the endurance image output test, an endurance image output test of 10,000 images was performed with an image ratio of 1%. The test environment was a normal temperature and humidity (NN) environment (temperature 23 ° C., humidity 50% RH or more and 60% RH or less) and a high temperature and high humidity (HH) environment (temperature 32 ° C., humidity 80% RH). .. During the continuous passing of 10,000 sheets, it was decided to pass the sheets under the same development conditions and transfer conditions (without calibration) as the first sheet. As the evaluation paper, copy plain paper GF-C081 (A4, basis weight 81.4 g / m ² , sold by Canon Marketing Japan Inc.) was used.

The items and evaluation criteria for the image output evaluation at the initial stage (first sheet) and when 10,000 sheets are continuously passed are shown below. The evaluation results are shown in Table 5.

(Evaluation of image uniformity)
After the endurance output of 10,000 sheets, a solid image is output, a 2 cm square image is captured by a digital microscope, the captured image is subjected to 8-bit grayscale conversion with Image-J, and then a density histogram is measured. The standard deviation was calculated. Ranking was performed according to the value of the standard deviation according to the following evaluation criteria.
A: Standard deviation less than 2.0 (very good, non-uniformity is not visible to the naked eye)
B: Standard deviation 2.0 or more and less than 4.0 (quite excellent)
C: Standard deviation of 4.0 or more and less than 6.0 (the effect of the present invention is obtained)
D: Standard deviation of 6.0 or more (the effect of the present invention is not obtained, non-uniformity is felt at a distance)

[Solid image followability evaluation]
Solid image (FFh printing rate) under normal temperature and humidity (NN) environment (23 ° C, 50% RH) and high temperature and high humidity (HH) environment (30 ° C, 80% RH) using a C5560 remodeling machine as in the case of developability evaluation. Durability test was performed at 100%). The amount of toner on the photoconductor was set to about 0.35 mg / cm ² , the initial image density was set to 1.45, durability was started, and the change in image density was evaluated.

GFC-081 (81.0 g / m ² ) (sold by Canon Marketing Japan Inc.) was used as the evaluation paper.

The number of durable sheets was A4 chart, and 1000 sheets were continuously passed. An X-Rite color reflection densitometer (500 series: manufactured by X-Rite) was used for the density measurement.

The density measurement was carried out by arranging an image of 2 cm × 5 cm in the center as in the evaluation of developability.

(Evaluation criteria)
A: The difference in image density is less than 0.05 (very excellent)
B: Difference in image density is 0.05 or more and less than 0.10 (good)
C: Difference in image density is 0.10 or more and less than 0.15 (allowable level in the present invention)
D: Difference in image density is 0.15 or more (unacceptable level in the present invention)

[Examples 2 to 18, Comparative Example 1]
The two-component developer 2 to 26 were also evaluated in the same manner as the two-component developer 1. The results are shown in Table 5.

Claims (4)

A toner having toner particles and inorganic fine particles on the surface of the toner particles.
Among the toners, the degree of hydrophobization of the inorganic fine particles contained in the toner having a central particle size of less than D50 by the methanol titration method is defined as Xs.
When the degree of hydrophobization of the inorganic fine particles contained in the toner having a central particle size of D50 or more by the methanol titration method is Xl.
A toner characterized by satisfying the following formula (1).
1.10 ≤ Xs / Xl (1) The median diameter (D50) based on the number of toners is 3.0 μm or more and 6.0 μm or less.
The toner according to claim 1, wherein the span value obtained by the following formula (2) of the toner is 0.2 or more and 0.7 or less.
Span value = (D90-D10) / D50 (2) Among the toners, the surface tension index of the toner having a central particle size of less than D50 with respect to a 40 mass% methanol aqueous solution measured by the capillary suction time method and calculated by the following formula (A) is defined as Ss.
When the surface tension index of the toner with respect to a 40 mass% methanol aqueous solution measured by the capillary suction time method and calculated by the following formula (A) of the toner having a center particle size of D50 or more is Sl. The toner according to claim 1 or 2, which satisfies the following formula (3).
1.5 ≤ Ss / Sl (3)
Toner surface tension index = Pα / (A × B × 10 ⁶ ) (N / m) ・ ・ ・ (A)
Capillary pressure of toner against Pα: 40 mass% methanol aqueous solution (N / m ² )
A: Specific surface area of toner (m ² / g)
B: Toner true density (g / cm ³ ) The coverage of the inorganic fine particles contained in the toner having a central particle size of less than D50 of the toner is Ys.
When the coverage of the inorganic fine particles contained in the toner having a central particle size of D50 or more of the toner is Yl,
The toner according to any one of claims 1 to 3, which satisfies the following relational expression.
25 ≤ Ys
25 ≤ Yl