JP2012123196A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner capable of stably obtaining a high-definition and high-quality image over a long period of time, which is excellent in fluidity, charge stability, developability and transferability, regardless of environment.SOLUTION: In toner containing toner particles and silica/alumina composite particles which are subjected to hydrophobic treatment with a hydrophobic treatment agent and have a hydrophobicity degree of 60% or more, silica/alumina composite particles before hydrophobic treatment have a zeta potential of -42.0 mV or more and -28.0 mV or less and silica/alumina composite particles before the hydrophobic treatment have a silica content of 55.0 mass% or more and 95.0 mass% or less. The degree of crystallinity of alumina in silica/alumina composite particles subjected to the hydrophobic treatment is 10.0% or more and 60.0% or less.

Description

  The present invention relates to an electrostatic charge image developing toner used for electrophotographic image formation represented by copying machines and printers.

  An electrostatic image developing toner that can be used for electrophotographic image formation (hereinafter simply referred to as toner) includes particles made of an inorganic compound or resin called an external additive on its surface (hereinafter external additive). In many cases, the composition is also added.

  The presence of such an external additive improves the performance of the toner, such as chargeability and fluidity, and the use of the external additive is regarded as one of the effective means for realizing good image formation.

  On the other hand, in recent years, there has been an increasing demand for high definition and high image quality in printers and the like, and in this technical field, attempts have been made to achieve high image quality by reducing the particle diameter of toner. Especially in the case of color toners, the toner particle size is reduced due to the appearance of toners produced not only by dry methods but also by wet methods such as suspension polymerization methods, agglomeration particle methods and dissolution suspension polymerization methods. It is further accelerated. When the toner particle diameter is small (hereinafter also referred to as small-diameter toner), the charge amount per unit weight tends to be large, and the image density tends to be low. One of the causes is a decrease in the toner development amount with respect to the latent image on the photoreceptor. This can be determined by how much toner amount the potential well is filled with. However, as described above, since the charge amount per unit weight increases as the toner particle size decreases, the development amount decreases with small-diameter toner. Cheap. Further, there is a problem that the efficiency (hereinafter also referred to as transferability) of transferring the toner image on the photosensitive member to the transfer material or the intermediate transfer member is lowered. In general, the toner is electrically transferred from the photosensitive member to the transfer material or the intermediate transfer member. However, when the particle diameter of the toner is reduced, the non-electrostatic adhesion force is relatively increased. This is due to a decrease in efficiency. Further, since the surface area per unit weight of the toner is increased, the fluidity of the toner is easily expected to be greatly deteriorated. For example, the toner is likely to deteriorate during long-term use. For this reason, it is important to configure the toner so that the problems of chargeability and fluidity are compatible when reducing the particle size of the toner. For the purpose of improving these, silica particles and alumina particles are required. In many cases, external additives such as titania particles are used.

  For example, it is known to use hydrophobized silica particles, hydrophobized alumina particles, hydrophobized titania particles, or the like as external additives.

  The external additive of silica particles can improve the charge imparting ability and fluidity of the toner. On the other hand, toner with externally added silica particles has a higher negative chargeability than alumina particles, titania particles, etc., and has a high initial charge level especially under low humidity, and is charged up during continuous use. Cheap. Furthermore, there is a problem that the amount of change in charge amount between high temperature and high humidity and low temperature and low humidity environment is large. For example, fogging, transferability and image density stability are deteriorated in a high temperature and high humidity environment, and the image density tends to be low in a low temperature and low humidity environment.

  When the alumina particles are externally added to the toner particles, a low friction charging site is formed on the surface of the toner particles, and excessive friction charging (charge up) of the toner is prevented (hereinafter also referred to as low friction charging property). In addition, because of the low frictional charging property, the influence of electrostatic aggregation is small, and the function as a spacer can be exhibited to the maximum. Therefore, it is possible to prevent a decrease in toner fluidity even in an environment that receives a large share in the developing device such as a high-speed developing system, and it is possible to maintain stable performance over a long period of time.

  On the other hand, under high temperature and high humidity, the chargeability of the toner is liable to decrease, and fog, transferability and image density stability tend to deteriorate.

  In order to eliminate the harmful effects of silica particles and alumina particles, a method of using hydrophobic silica particles and hydrophobized alumina particles in combination has been proposed (see Patent Document 1). However, Patent Document 1 makes no mention of the surface activity and crystal structure of alumina particles, and there is a point that should be improved in terms of stabilization of charging.

  As described above, in order to provide sufficient fluidity, chargeability, environmental stability, and durability to the toner, there are still no satisfactory silica particles and alumina particles.

  Against this background, composite particles containing silica and alumina (hereinafter referred to as “silica particles” and “alumina particles”), which have the objection to further improve the performance of silica particles and alumina particles, have no adverse effects on both silica particles and alumina particles, And may be abbreviated as silica-alumina composite particles).

  For example, a toner using silica-alumina composite particles as an external additive has been proposed (see Patent Documents 2 to 7).

  However, the ratio and the crystal structure of silica and alumina in the silica-alumina composite particles have not been sufficiently studied, and there has been a point to be improved in terms of stabilization of charging.

  That is, the silica-alumina composite particles that have been conventionally proposed still have room for improvement.

JP-A-4-345169 Japanese Patent Laid-Open No. 2002-244341 JP 2005-84295 A JP 2001-83738 A Japanese Patent No. 3587671 JP 2003-192940 A Japanese Patent No. 4255233

  An object of the present invention is to provide a toner that is excellent in fluidity, charging stability, developability, and transferability regardless of the environment, and that can stably obtain high definition and high image quality over a long period of time.

  As a result of intensive studies, the present inventors have used specific silica-alumina composite particles in which the content of silica, the crystallinity of alumina, the surface exposure state of silica and alumina, and the degree of hydrophobicity are controlled as external toner additives. As a result, the inventors have found that the above problems can be solved, and have reached the present invention.

That is, the present invention is a toner containing toner particles containing at least a binder resin and a colorant, and silica alumina composite particles hydrophobized with a hydrophobizing agent,
The hydrophobized silica-alumina composite particles have a hydrophobization degree of 60% or more,
The zeta potential of the silica-alumina composite particles before being hydrophobized is from −42.0 mV to −28.0 mV,
The silica content in the silica-alumina composite particles before being hydrophobized is 55.0 mass% or more and 95.0 mass% or less,
The present invention relates to a toner characterized in that the hydrophobized silica-alumina composite particles have an alumina crystallinity of 10.0% to 60.0%.

  According to the present invention, it is possible to provide a toner that is excellent in fluidity, charging stability, developability, and transferability regardless of the environment, and that can provide a stable, high-definition and high-quality image over a long period of time.

It is a schematic explanatory drawing of the measuring apparatus of the volume resistivity of a silica alumina composite particle.

  In the present invention, in the toner to which silica-alumina composite particles are externally added, the silica-alumina composite particles that have both the good characteristics synergistically without the adverse effects of the silica particles and the alumina particles have been earnestly studied. As a result, it has been found that a toner capable of solving the above-mentioned problems can be obtained by specifying the structure and physical properties of the externally added silica-alumina composite particles, and the present invention has been completed.

  In order to obtain good charge stability, developability, and transferability, it is important to control the crystallinity of alumina in the silica-alumina composite particles.

  The degree of crystallinity of alumina in the silica-alumina composite particles used in the present invention is 10.0% or more and 60.0% or less, preferably 15.0% or more and 48.0% or less. When the crystallinity of alumina is lower than 10.0%, that is, when the proportion of amorphous material is large, the electrical resistance becomes low and the surface activity of the silica-alumina composite particles becomes weak. For this reason, the fog and image uniformity and image density stability are deteriorated particularly in a high temperature and high humidity environment. When the crystallinity of alumina is higher than 60.0%, the surface activity of the silica-alumina composite particles is strong and the electrical resistance is high. Therefore, when the toner is used continuously in a low-temperature and low-humidity environment, Will come up. As a result, image density and image uniformity are reduced, and fogging is observed. In addition, in the vapor phase method, which is a preferable method for producing the silica-alumina composite particles used in the present invention, which will be described later, the particles must be heated at a high temperature for a long time in order to increase the crystallinity to more than 60.0%. Therefore, aggregation of silica-alumina composite particles tends to occur. When the aggregation occurs, the fluidity imparting ability to the toner is lowered and the spacer function is lowered.

  The silica content before the hydrophobization treatment of the silica-alumina composite particles used in the present invention is 55.0 mass% or more and 95.0 mass% or less, preferably 60.0 mass% or more and 85.0 mass% or less. is there.

  If the silica content is less than 55.0% by mass, the alumina content in the silica-alumina composite particles is too high even if the crystallinity of alumina and the zeta potential described later are satisfied. Is strongly expressed. That is, the characteristics of low triboelectric chargeability become too strong, and it becomes difficult to maintain the charge (large loss of charge), especially when the toner is left for a long time under high humidity, and image density stability and image uniformity. To become fogged.

  When the content of silica is more than 95.0% by mass, the characteristics of silica are easily expressed, and the toner is easily charged up when continuously used at low temperature and low humidity. As a result, the image density is lowered and the image uniformity is also lowered. Furthermore, the variation in charge amount between environments such as a high temperature and high humidity environment and a low temperature and low humidity environment increases, and image density stability decreases. Further, the silica-alumina composite particles having a silica content of more than 95.0% by mass are likely to aggregate together, and the fluidity imparting ability to the toner is lowered.

  In the silica-alumina composite particles used in the present invention, it is important to control the respective surface exposure ratios together with the contents of silica and alumina and the crystallinity of alumina. That is, the silica-alumina composite particles used in the present invention have a zeta potential measured in the base state before being hydrophobized, of −42.0 mV to −28.0 mV, preferably −40.0 mV or more. -30.0 mV or less.

  The zeta potential measured in the state before the hydrophobization treatment is a parameter indicating the abundance ratio of silica and alumina on the surface of the silica-alumina composite particles. When the zeta potential is small, the surface exposure ratio of silica is large, and when the zeta potential is large, the surface exposure ratio of alumina is large.

  Therefore, if the zeta potential of the silica-alumina composite particles measured in an untreated state is within the above range, the silica and alumina exposed ratios are moderate, and the silica-alumina composite particles having both good characteristics. It becomes.

  In the silica-alumina composite particles, in order to control the zeta potential within the above range, for example, in the case of producing by a gas phase method, the amount of inflow of gas supplied into the system, temperature, etc. may be adjusted. Details will be described later.

  In the present invention, the silica-alumina composite particles are required to have a high degree of hydrophobicity for the purpose of obtaining desired characteristics, that is, long-term environmental stability. Therefore, the hydrophobization treatment with the hydrophobization agent, the hydrophobization degree of the silica-alumina composite particles measured in the hydrophobized state (methanol hydrophobization degree) needs to be 60% or more, and 70% More preferably.

In the silica-alumina composite particles used in the present invention, the addition amount of the hydrophobizing agent and the BET specific surface area of the silica-alumina composite particles before being hydrophobized using the hydrophobizing agent satisfy the following relationship: It is preferable.
(Addition amount of hydrophobizing agent to 1 g of silica-alumina composite particles before being hydrophobized (g / g) / (BET specific surface area of silica-alumina composite particles before being hydrophobized using a hydrophobizing agent) (M ² /g))≦1.7×10 ⁻³ (g / m ² )
More preferably, in the above formula, it is 1.6 × 10 ⁻³ (g / m ² ) or less.

  If the amount of the hydrophobizing agent added is within the above-specified range, the amount of the hydrophobizing agent per unit surface area of the silica-alumina composite particles is moderate, and while increasing the degree of hydrophobicity, The characteristics based on the matrix can be expressed well.

  As the hydrophobization treatment of the silica-alumina composite particles of the present invention, known treatment agents and methods can be used without particular limitation.

  Hydrophobization treatment is a method in which silica-alumina composite particles are treated with a hydrophobizing agent in a dry process (including a method in which silica-alumina composite particles are sprayed with a hydrophobizing agent vapor under stirring or flow), water or an organic compound. The treatment method is not particularly limited, such as a method in which the silica-alumina composite particles are immersed in a solvent and the like, and the hydrophobization treatment agent is wet-treated, and any known method can be used without any problem.

  Among them, the dry method is preferable in that it has moderate low chargeability and excellent charge rising properties, weak cohesiveness, and excellent fluidity imparting properties. Examples of the dry method include a method in which silica alumina composite particles are treated by spraying a hydrophobizing agent with stirring, and a method in which hydrophobizing agent vapor is introduced into a fluidized bed or silica alumina composite particles under stirring.

  As the hydrophobic treatment agent, a known treatment agent can be used without any limitation. Specifically, as a silylating agent, chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, t-butyldimethylchlorosilane, vinyltrichlorosilane, tetramethoxysilane, methyl Trimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, hexyltrimethoxy Silane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyl Diethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, i-butyltriethoxysilane, decyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) Alkoxysilanes such as aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, hex Buchirujishirazan, hexa pliers distearate disilazane, hexa hexyl disilazane, hexa cyclohexyl disilazane, there hexaphenyl disilazane, divinyl tetramethyl disilazane, silazanes such as dimethyl tetra-vinyl disilazane and the like. Also, dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, alkyl modified silicone oil, chloroalkyl modified silicone oil, chlorophenyl modified silicone oil, fatty acid modified silicone oil, polyether modified silicone oil, alkoxy modified silicone oil, Silicone oils such as diol-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, and terminal-reactive silicone oil, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane Siloxanes such as octamethyltrisiloxane are also preferred as the hydrophobizing agent. In addition, fatty acids and their metal salts include undecyl acid, lauric acid, tridecylic acid, dodecylic acid, myristic acid, palmitic acid, pentadecylic acid, stearic acid, heptadecylic acid, arachidic acid, montanic acid, oleic acid, linoleic acid, arachidonic acid Long chain fatty acids such as zinc salts, salts with metals such as zinc, iron, magnesium, aluminum, calcium, sodium and lithium are also effective as hydrophobizing agents. Among these, alkoxysilanes, silazanes, and straight silicone oil are preferable because they are easy to carry out. In the present invention, one type of such a hydrophobizing agent is used alone, or in the case of two or more types, they are mixed, or the surface treatment is sequentially carried out step by step, and the hydrophobicity required according to the application. Can be achieved.

Moreover, the silica alumina composite particles used in the present invention have a volume resistivity of 1.0 × 10 ⁷ Ω · m or more and 5.0 × 10 ¹¹ measured in a state where the silica alumina composite particles are not subjected to a hydrophobic treatment. It is preferably Ω · m or less. By setting the volume resistivity of the silica-alumina composite particles in the above range, a stable image can be continuously produced over a longer period.

Silica-alumina composite particles of the present invention, the state BET specific surface area measured by the before hydrophobic treatment is preferably, ^{20 m} 2 / g or more 350 meters ² / g or less, more preferably, ^{45 m} 2 / g or more 330 m ² / g or less. When the BET specific surface area measured in the state before the hydrophobization treatment is within the above range, embedding of the silica-alumina composite particles in the toner particles is suppressed, so that a good effect can be easily obtained over a longer period. .

  Hereinafter, a method for producing silica-alumina composite particles will be described.

  Examples of the production method include a method in which silica or alumina is deposited on the surface of alumina particles or silica particles in an aqueous medium, a method of doping, a gas phase method, and the like. Among these, a production method in which heat treatment is performed as a subsequent step after producing particles by a vapor phase method is preferable.

  As an example, a case of manufacturing by a vapor phase method using silicon tetrachloride gas and aluminum trichloride gas will be described. First, silicon tetrachloride gas, inert gas, hydrogen, and air are mixed to prepare a mixed gas of a predetermined ratio. Similarly, a mixed gas is prepared by mixing aluminum trichloride gas, inert gas, hydrogen, and air. These two kinds of mixed gases are mixed or introduced separately into the reaction chamber and burned at a temperature of 1000 ° C. or higher and 2500 ° C. or lower to produce silica-alumina composite particles, which are cooled and collected by a filter. . At this time, in order to obtain silica alumina composite particles having desired alumina crystallinity and zeta potential, and to suppress generation of uncomplexed particles such as silica particles and alumina particles, silica tetrachloride gas to silica, It is necessary to consider the difference in the reaction rate for producing alumina from the aluminum trichloride gas (the reaction rate for the silica production reaction is faster than that for the alumina production reaction). Specifically, the combustion time, temperature, and combustion atmosphere may be adjusted together with the concentration, flow rate ratio, and inflow method of silicon tetrachloride gas and aluminum trichloride gas introduced into the combustion burner.

  The silica-alumina composite particles obtained by the vapor phase method generally have an alumina crystallinity of about 5%.

  Therefore, in order to obtain silica-alumina composite particles having a desired alumina crystallinity and zeta potential, a post-process for heating at a temperature of 800 ° C. or higher and lower than the melting point of silica may be performed. Further, by heating, silica tends to be exposed on the surface, the zeta potential can be lowered, and a desired zeta potential can be achieved. Although this reason is not certain, it is thought that crystallization of alumina occurs and silica is pushed out to the particle surface.

  The silica-alumina composite particles of the present invention may be slightly agglomerated by a treatment for increasing the crystallinity. Therefore, if necessary, the crushing treatment may be performed before or after the hydrophobic treatment. As a crushing method, a known crusher can be used. For example, there is a method of crushing surface-treated silica alumina composite particles with a high-speed impact type fine crusher pulverizer (manufactured by Hosokawa Micron).

  The addition amount (external addition amount) of the silica-alumina composite particles used in the present invention is preferably 0.01 parts by weight or more and 2.50 parts by weight or less, more preferably 0.10 with respect to 100 parts by weight of the toner particles. It is not less than 2.00 parts by mass.

  Next, toner particles will be described.

  Any toner particles that contain a binder resin and a colorant can be used without particular limitation.

  Examples of the binder resin that can be used include the following resins. Polystyrene; Homopolymers of styrene-substituted products such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene 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 ethyl ether copolymer Styrene copolymers such as polymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers; acrylic resins; methacrylic resins; polyvinyl acetate ;Silicone resin; Riesuteru resin; polyamide resin; furan resins, epoxy resins, xylene resins. These resins are used alone or in combination.

  As the main component of the binder resin, a polyester resin and a styrene copolymer are preferable in terms of developability and fixability.

  As a comonomer for the styrene monomer of the styrenic copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, Monocarboxylic acid having a double bond such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, or a substituted product thereof; maleic acid, butyl maleate, methyl maleate , Dicarboxylic acids having a double bond such as dimethyl maleate, or substituted products thereof; vinyl esters such as vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; Ketones, such as vinyl vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl propionate ether. These vinyl monomers are used alone or in combination of two or more. The styrenic copolymer is preferably crosslinked with a crosslinking agent such as divinylbenzene because the fixing temperature range as a toner can be widened and offset resistance can be improved.

  In the present invention, the toner particles preferably contain 30 ppm or more and 1000 ppm or less of titanium element.

  When the titanium element is contained in the toner particles within the above range, the toner particles and the silica-alumina composite particles added externally interact with each other, so that the toners can be appropriately exchanged with each other. . For this reason, the charge amount can be relaxed to suppress the charge-up, and the saturation charge amount can be increased in a state where the charge rising property (charging speed) and charge distribution of the toner are good. Further, when the titanium particles are contained in the toner particles, the externally added silica-alumina composite particles are difficult to be released, and stable and good image quality can be obtained over a long period of time.

  The method for incorporating the titanium element into the toner particles is not particularly limited, and a known method can be used. For example, the toner particles may contain a resin having a polyester unit synthesized using a titanium chelate compound as a catalyst.

  In particular, it is preferable to produce toner particles by a suspension polymerization method or an agglomerated particle method using a polar resin having a polyester unit synthesized using a titanium chelate compound as a catalyst. In this case, a large amount of polar resin is unevenly distributed on the toner particle surface, and a titanium chelate compound is also unevenly distributed on the toner particle surface. The titanium compound finely dispersed on the surface of the toner particles functions as a site for injecting or leaking electric charge, and can stably maintain a high charge amount even when left for a long time under high temperature and high humidity. Even under low temperature and low humidity, toner overcharge (charge-up) can be suppressed. Furthermore, it is presumed that the presence of the sites makes it possible to transfer charges between toners, and the charge amount distribution becomes sharper.

  The addition effect is further enhanced by adding silica-alumina composite particles to such toner particles. That is, after a long period of continuous use or after standing, the charge amount can be maintained well even in a high temperature and high humidity environment, and an increase in charge in a low temperature and low humidity environment can be suppressed. Further, since the affinity between the toner particles and the silica-alumina composite particles is increased, the silica-alumina composite particles are more stably held on the toner surface over a long period of time.

  In the titanium chelate compound, the ligand is preferably any of diol, dicarboxylic acid, and oxycarboxylic acid. Among these, the ligand is particularly preferably an aliphatic diol, dicarboxylic acid, or oxycarboxylic acid. Aliphatic ligands are preferable because they have higher catalytic activity than aromatic ligands, are preferable in terms of shortening the reaction time and controlling the temperature, and the resin physical properties tend to be sharp in molecular weight distribution.

  For example, the following are exemplified. Examples of the diol include 1,2-ethanediol, 1,2-propanediol, and 1,3-propanediol. Dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and oxycarboxylic acid, such as glycolic acid, lactic acid, hydroxyacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid, malic acid , Tartaric acid, citric acid.

  Further, when polymerizing a polar resin having a polyester unit, the addition amount of the titanium chelate compound is 0.01% by mass or more and 2.00% by mass or less, preferably 0.05% by mass with respect to the total amount of the polyester unit component. % Or more and 1.00% by mass or less, and more preferably 0.10% by mass or more and 0.70% by mass or less.

  The acid value of the polar resin having a polyester unit is preferably 3 mgKOH / g or more and 35 mgKOH / g or less, more preferably 5 mgKOH / g or more and 30 mgKOH / g or less, and further preferably 7 mgKOH / g or more and 20 mgKOH / g or less. The hydroxyl value of the polar resin is preferably 5 mgKOH / g or more and 40 mgKOH / g or less, more preferably 10 mgKOH / g or more and 35 mgKOH / g or less, and further preferably 15 mgKOH / g or more and 30 mgKOH / g or less.

  In particular, when toner particles are produced by suspension polymerization, the surface layer (shell portion) can be neatly coated with a polar resin if the acid value and hydroxyl value are within the above ranges. Thereby, the interaction between the titanium element contained in the toner particles in a preferable range and the silica-alumina composite particles becomes more remarkable.

  The “polyester unit” used in the present invention means a portion derived from polyester, and may be a single polyester or a hybrid resin in which a polyester and a vinyl polymer are chemically bonded.

  Any polyester resin that can be used as a toner resin can be used without particular limitation. Particularly preferably, a bisphenol derivative represented by the following general formula (1) is a dihydric alcohol monomer component, and a divalent or higher carboxylic acid or an acid anhydride thereof, or a lower alkyl ester thereof (for example, fumaric acid, maleic acid, A resin obtained by condensation polymerization using maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid monomer component.

(In the formula, R represents an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 or more and 10 or less.)

  Examples of the release agent used in the toner of the present invention include polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax, and Fischer Tropish wax, amide wax, higher fatty acid, long chain alcohol, ketone wax, ester wax, and the like. Derivatives such as these graft compounds and block compounds can be mentioned. As the molecular weight of the release agent, the weight average molecular weight (Mw) is preferably from 300 to 1,500, and more preferably from 400 to 1,250. Moreover, it is preferable that ratio (Mw / Mn) of the weight average molecular weight / number average molecular weight of the release agent is 1.5 or less.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complex methine compounds, and allylamide compounds are used as pigments. Specifically, C.I. I. Pigment Yellow 3, 7, 10, 12, 13, 14, 15, 17, 23, 24, 60, 62, 74, 75, 83, 93, 94, 95, 99, 100, 101, 104, 108, 109, 110 111, 117, 123, 128, 129, 138, 139, 147, 148, 150, 155, 166, 168, 169, 177, 179, 180, 181, 183, 185, 191: 1, 191, 192, 193 199 or the like is preferably used. Examples of the dye system include C.I. I. Solvent Yellow 33, 56, 79, 82, 93, 112, 162, 163, C.I. I. Disperse Yellow 42, 64, 201, 211 etc. are mentioned.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. Pigment Bio Red 19 is particularly preferable.

  As the cyan colorant, phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like are particularly preferably used.

  As the black colorant, carbon black or a magnetic material can be used as the main colorant.

  The toner of the present invention may contain a charge control agent. For example, the following compounds are exemplified. These can be used alone or in combination of two or more.

  Organic metal compounds and chelate compounds are effective for controlling the toner to be negatively charged. Examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Other examples include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, and phenol derivatives such as bisphenol. Furthermore, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, resin charge control agents, and the like can be given. Of these, metal-containing salicylic acid compounds are preferable, and the metal is particularly preferably aluminum or zirconium. Most preferred is an aluminum salicylate compound.

  Examples of compounds that control the toner to be positively charged include the following compounds. Nigrosine-modified products of nigrosine and fatty acid metal salts, etc .; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like Phosphonium salts and other onium salts and their lake pigments; triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid Acid, ferricyanide, ferrocyanide, etc.); metal salt of higher fatty acid; diorganotin oxide such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; DOO, dioctyl tin borate, such as diorganotin tin borate such dicyclohexyl tin borate; resin charge control agent and the like.

  The toner of the present invention preferably has a weight average particle diameter (D4) of 4.0 μm or more and 9.0 μm or less. More preferably, it is 5.0 μm or more and 7.5 μm or less.

  The toner of the present invention preferably contains a release agent. The release agent preferably has a peak temperature of the maximum endothermic peak in the range of 50 to 120 ° C. in the endothermic curve obtained by differential scanning calorimetry (DSC) measurement. Furthermore, it is more preferably in the range of 55 to 100 ° C, and particularly preferably in the range of 60 to 75 ° C. Moreover, it is preferable that the half value width of the maximum endothermic peak of a mold release agent is 15 degrees C or less, and it is more preferable that it is 7 degrees C or less.

  The total amount of the release agent contained in the toner is preferably 2.5 parts by mass or more and 25.0 parts by mass or less, and more preferably 4.0 parts by mass with respect to 100 parts by mass of the binder resin. The amount is 20 parts by mass or less, and particularly preferably 6.0 parts by mass or more and 18.0 parts by mass or less.

  The toner of the present invention preferably has a number average molecular weight (Mn) of 2,000 or more and 50,000 or less, more preferably 5,000 or more and 40,000 or less with respect to the THF soluble content. Further, the weight average molecular weight (Mw) is preferably 10,000 or more and 1,500,000 or less, more preferably 50,000 or more and 1,000,000 or less, and further preferably 100,000 or more and 750,000 or less.

  The glass transition temperature (Tg) of the toner of the present invention is preferably 50 ° C. or higher and 75 ° C. or lower, and preferably 52 ° C. or higher and 70 ° C. or lower, from the viewpoint of achieving both good storage stability and low temperature fixability. More preferably, the temperature is 54 ° C. or higher and 65 ° C. or lower.

  To the toner of the present invention, inorganic fine particles and resin particles are externally added as necessary in addition to the silica alumina composite particles in order to further improve charging stability, developability, fluidity, member adhesion suppression, and durability. May be.

  Examples of the charge controllable particles include metal oxides (tin oxide, titania, zinc oxide, silica, alumina, etc.), carbon black, and the like.

  Examples of cleaning aids include fatty acid metal salts (such as zinc stearate).

  As polishing agents, metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, barium sulfate, etc.) , Calcium carbonate, etc.). Of these, strontium titanate is preferably used as the abrasive.

  Examples of the lubricant include fluorine-based resin powder (polyvinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.) and the like. Of the above, polyvinylidene fluoride is preferably used.

  Examples of the fluidity-imparting agent include metal oxides (such as silica, alumina, titania), fatty acid metal salts (such as zinc stearate), and carbon fluoride. The metal oxide is more preferably subjected to a hydrophobic treatment.

  The total amount of the inorganic fine powder and silica-alumina composite particles added to the toner in the present invention is preferably 0.5 parts by mass or more and 4.5 parts by mass or less with respect to 100 parts by mass of the toner particles. More preferred is at least 3.5 parts by weight.

The titania, silica, and alumina that are preferably added as the inorganic fine particles preferably have a BET specific surface area of 20 m ² / g or more and 400 m ² / g or less by nitrogen adsorption measured by the BET method. More preferably, not more than ^35m 2 / g or more 300 meters ² / g, still more preferably not more than ^{50 m} 2 / g or more 230 m ² / g.

  The inorganic fine particles as the fluidity-imparting agent are silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane coupling agents, and others for the purpose of improving hydrophobicity, chargeability, and transferability. The treatment is preferably performed using a treating agent such as an organosilicon compound alone or in combination.

  Other inorganic fine particles include an anti-caking agent; a conductivity imparting agent such as zinc oxide, antimony oxide, tin oxide; and a developability improver.

  The toner of the present invention can be used in a known image forming method. For example, a known one-component developing method or two-component developing method such as a toner for a high-speed system, a toner for an oilless fixing, a toner for a cleanerless system is used. It can be applied to the conventional image forming method. In particular, since the toner of the present invention has very good transferability and can obtain a stable image over a long period of time, it is suitable for an image forming method having an intermediate transfer member and an image forming method having a cleaner-less system. Can be used.

  Next, a carrier when the toner of the present invention is used as a two-component developer will be described.

  When the toner of the present invention is used for a two-component developer, the toner is used by mixing with a magnetic carrier. As the magnetic carrier, known magnetic carriers such as the magnetic particles themselves, a coated carrier obtained by coating the magnetic particles with a resin, and a magnetic material-dispersed resin carrier in which the magnetic particles are dispersed in the resin particles can be used. Examples of magnetic particles include surface oxidized or unoxidized iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, rare earth metal particles, alloy particles thereof, oxide particles, ferrite, etc. Can be used.

  Hereafter, the measuring method of each physical property is shown.

[Measurement method of crystallinity of alumina in silica-alumina composite particles]
The degree of crystallinity of alumina of the silica-alumina composite particles is measured using a powder X-ray diffractometer, using CuKα rays (λ = 0.15418 nm) as an X-ray source under the following conditions.

  The powder X-ray diffractometer is used using a sample horizontal strong X-ray diffractometer “RINT.TTR2” manufactured by Rigaku Corporation.

The measurement sample is placed on a non-reflective sample plate (manufactured by Rigaku) that does not have a diffraction peak within the measurement range while being lightly pressed so that it remains flat. When flat, set the sample plate together with the device.
"Measurement condition"
・ Tube: Cu
・ Parallel beam optical system ・ Voltage: 50 kV
・ Current: 300mA
・ Starting angle: 10 °
・ End angle: 40 °
・ Sampling width: 0.02 °
・ Scanning speed: 4.00 ° / min
・ Divergent slit: Open ・ Divergent longitudinal slit: 10 mm
・ Scattering slit: Open ・ Reception slit: Open

  Based on the peak obtained by the measurement, the degree of crystallinity is calculated as follows using “JADE6” of analysis software attached to the apparatus.

  (1) AEROSIL (registered trademark) 130 (Nippon Aerosil Co., Ltd. fumed silica particles) and MT-150W (Taika Co., Ltd. titania particles) are mixed (in this application, the mass ratio of AEROSIL130 and MT-150W is 100.0: 0.0, 80.0: 20.0, 60.0: 40.0, 40.0: 60.0, 20.0: 80.0, 0.0: 100.0) and the silica content Make a modified sample. X-ray diffraction measurement was performed on these samples, and the obtained diffraction angle (2θ ± 0.5 °) was a broad peak derived from an amorphous silica having a peak top from 21.0 ° to 25.0 °. Create a calibration curve of area and silica content.

  Here, the reason why MT-150W (Titanic particles manufactured by Teica) was used is as follows. Since MT-150W has a rutile crystal and has a crystalline peak at a diffraction angle (2θ ± 0.5 °) of 27.4 °, it does not overlap with an amorphous peak of silica. Therefore, it is suitable for preparing a calibration curve between a broad peak area derived from an amorphous silica and the silica content.

  (2) X-ray diffraction measurement of silica-alumina composite particles is performed. The peak area A of the broad peak derived from the amorphous of silica and alumina having a peak top at a diffraction angle (2θ ± 0.5 °) obtained by X-ray diffraction of 21.0 ° to 25.0 °. Is calculated.

  Also, the peak derived from the γ crystal of alumina having a diffraction angle (2θ ± 0.5 °) having a peak top at 46.0 ° and the diffraction angle (2θ ± 0.5 °) having a peak top at 26.1 ° The sum B of peak areas of peaks derived from mullite crystals made of alumina and silica is calculated.

(3) The crystallinity is calculated by the following formula.
Crystallinity (%) = B / {(AC) + B} × 100
C in the above formula has a diffraction angle (2θ ± 0.5 °) calculated from the silica content of the silica-alumina composite particles based on the calibration curve obtained from (1) from 21.0 ° to 25. This is the peak area of a silica-derived peak having a peak top at 0 °.

[Measurement method of zeta potential]
The zeta potential of the silica-alumina composite particles was measured using Zeta Sizer Nano-Zs (manufactured by Sysmex Corporation). The details are as follows.

  Under an environment of 25 ° C., 7 mg of silica-alumina composite particles was added to the dispersion (methanol 100 mg), and dispersed for 3 minutes with an ultrasonic disperser (manufactured by Nihon Riken Kikai Co., Ltd.) to obtain a dispersion. However, when white dispersion and suspended matters of the silica-alumina composite particles are present in the dispersion, the amount of the silica-alumina composite particles added to methanol is appropriately adjusted. This dispersion liquid is put into a measuring cell (DTS1060C-Clear Disposable Zeta Cell) using a dropper so that bubbles do not enter. This cell is attached to a measuring instrument, and the zeta potential is measured at 25 ° C. This measurement is performed 5 times, and the average value is set as the zeta potential of the present invention.

[Measurement method of degree of hydrophobicity]
70 ml of a hydrated methanol solution composed of 50% by volume of methanol and 50% by volume of water is placed in a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm. Next, in order to remove bubbles and the like in the mixed solution, dispersion is performed for 5 minutes with an ultrasonic disperser to prepare a measurement sample solution.

  Into a container in which the sample liquid for measurement is placed, 0.1 g of silica-alumina composite particles are precisely weighed and added.

Then, the measurement sample solution is set in a powder wettability tester “WET-100P” (manufactured by Reska). The sample liquid for measurement 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 type rotor having a length of 25 mm and a maximum barrel diameter of 8 mm coated with a fluororesin is used.

  Next, through this device, methanol is continuously added at a drop rate of 1.3 ml / min, and the transmittance is measured with light having a wavelength of 780 nm to create a methanol drop transmittance curve. To do. In the methanol dropping transmittance curve, the methanol concentration at the end point at which the transmittance is minimized is defined as the degree of hydrophobicity.

[Method of measuring silica (SiO ₂ ) content in silica-alumina composite particles]
The silica content in the silica-alumina composite particles is measured by performing fluorescent X-ray analysis using a fluorescent X-ray analyzer SYSTEM3080 (manufactured by Rigaku Denki Kogyo Co., Ltd.) according to JIS K0119 “General rules for fluorescent X-ray analysis”. In addition, as a measurement sample, silica alumina composite particles before hydrophobization treatment are used.

[Measurement of the Abundance Ratio of Silica Single Particles and Alumina Single Particles]
The abundance ratio of silica single particles and alumina single particles can be measured by observation with a transmission electron microscope (TEM-EDX). Specifically, in observation with a transmission electron microscope (TEM-EDX), for example, observation and element mapping are performed in a continuous field of view under a magnification of 100,000 times or more and 200,000 times or less. When the elements of Al and Al are mapped, those in which both Si and Al elements are observed in the same particle are defined as composite particles, and those in which only one of the elements is observed are defined as single particles. By this observation, the number of uncomplexed particles per 1000 particles is defined as the existence ratio of single particles.

[Measurement method of volume resistivity]
FIG. 1 shows an apparatus for measuring the volume resistivity of silica-alumina composite particles used in the present invention. The measuring device is filled with silica alumina composite particles, electrodes 1 and 2 are arranged so as to be in contact with the silica alumina composite particles, voltage is applied between the electrodes, current flowing at that time is measured, and specific volume is determined by specific resistance. A method for obtaining resistance was used. In the above measurement method, since the silica-alumina composite particles are powder, the filling rate is changed, and the volume resistivity may be changed accordingly. The measurement conditions of the volume resistivity in the present invention are as follows: the contact area S between the silica-alumina composite particles and the electrode is about 2.3 cm ² , the sample thickness d is 1.0 mm to 1.5 mm, and the load of the upper electrode 22 is 180 g. And The applied voltage was increased by 200 V at 30 second intervals, and the specific resistance measured at an applied voltage of 1000 V was defined as the volume resistivity of the present invention.

[Method for measuring BET specific surface area of silica-alumina composite particles]
The BET specific surface area is measured according to JIS Z8830 (2001). A specific measurement method is as follows.

  As the measuring device, an “automatic BET specific surface area / pore distribution measuring device TriStar 3000 (manufactured by Shimadzu Corporation)” which employs a gas adsorption method by a constant volume method as a measuring method is used. Setting of measurement conditions and analysis of measurement data are performed using dedicated software “TriStar3000 Version 4.00” attached to the apparatus, and a vacuum pump, a nitrogen gas pipe, and a helium gas pipe are connected to the apparatus. The value calculated by the BET multipoint method using nitrogen gas as the adsorption gas is defined as the BET specific surface area in the present invention.

  The BET specific surface area is calculated as follows.

First, nitrogen gas is adsorbed on silica particles, and the equilibrium pressure P (Pa) in the sample cell and the nitrogen adsorption amount Va (mol · g ⁻¹ ) of the silica particles are measured. The relative pressure Pr, which is a value obtained by dividing the equilibrium pressure P (Pa) in the sample cell by the saturated vapor pressure Po (Pa) of nitrogen, is plotted on the horizontal axis, and the nitrogen adsorption amount Va (mol · g ⁻¹ ) is plotted on the vertical axis. The adsorption isotherm is obtained. Next, a monomolecular layer adsorption amount Vm (mol · g ⁻¹ ), which is an adsorption amount necessary for forming a monomolecular layer on the surface of the toner, is obtained by applying the following BET equation.
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, adsorbed gas type, and adsorption temperature.)
The BET equation is interpreted as a straight line with an inclination of (C-1) / (Vm × C) and an intercept of 1 / (Vm × C), where Pr is X axis and Pr / Va (1-Pr) is Y axis. Yes (this line is called a BET plot).
Straight line slope = (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 square method, the slope and intercept value of the straight line can be calculated. Vm and C can be calculated by solving the above slope and intercept simultaneous equations using these values.

Further, the BET specific surface area S (m ² · g ⁻¹ ) of the toner is calculated from the calculated Vm and the molecular occupation cross-sectional area of the nitrogen molecule (0.162 nm ² ) based on the following formula.
S = Vm × N × 0.162 × 10 ⁻¹⁸
(N is Avogadro's number (mol- ¹ ).)

  The measurement using this apparatus follows the “TriStar 3000 Instruction Manual V4.0” attached to the apparatus, and specifically, the measurement is performed according to the following procedure.

  Thoroughly weigh the tare of a dedicated glass sample cell (stem diameter 3/8 inch, volume about 5 ml) that has been thoroughly cleaned and dried. Then, about 0.5 g of silica-alumina composite particles are put into this sample cell using a funnel.

  The sample cell containing the silica-alumina composite particles is set in a “pretreatment device Bacuprep 061 (manufactured by Shimadzu Corporation)” connected with a vacuum pump and a nitrogen gas pipe, and vacuum degassing is continued at 23 ° C. for about 10 hours. To do. In the vacuum deaeration, the gas is gradually deaerated while adjusting the valve so that the silica particles are not sucked into the vacuum pump. The pressure in the cell gradually decreases with deaeration and finally becomes about 0.4 Pa (about 3 mTorr). After completion of vacuum degassing, nitrogen gas is gradually injected 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 the sample cell is precisely weighed, and the exact mass of the silica particles is calculated from the difference from the tare. At this time, the sample cell is covered with a rubber stopper during weighing so that the silica particles in the sample cell are not contaminated by moisture in the atmosphere.

  Next, a dedicated “isothermal jacket” is attached to the stem portion of the sample cell containing the silica-alumina composite 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 cylindrical member having an inner surface made of a porous material and an outer surface made of an impermeable material capable of sucking liquid nitrogen to a certain level by capillary action.

  Subsequently, the free space of the sample cell including the connection tool is measured. Free space is measured by measuring the volume of the sample cell with helium gas at 23 ° C., and then measuring the volume of the sample cell after cooling the sample cell with liquid nitrogen in the same manner using helium gas. Calculated from the difference in volume. Further, the saturated vapor pressure Po (Pa) of nitrogen is automatically measured separately using a Po tube built in the apparatus.

  Next, after performing vacuum deaeration in the sample cell, the sample cell is cooled with liquid nitrogen while continuing the vacuum deaeration. Thereafter, nitrogen gas is gradually introduced into the sample cell to adsorb nitrogen molecules on the silica particles. At this time, the adsorption isotherm is obtained by measuring the equilibrium pressure P (Pa) as needed, and the adsorption isotherm is converted into a BET plot. Note that 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, 0.20, 0.25, and 0.30. A straight line is drawn from the obtained measurement data by the least square method, and Vm is calculated from the slope and intercept of the straight line. Further, using the value of Vm, the BET specific surface area of the silica-alumina composite particles is calculated as described above.

[Measurement of Titanium Element Content in Toner Particles]
The measurement of the fluorescent X-ray of each element is in accordance with JIS K 0119-1969, and is specifically as follows.

  As a measuring device, a wavelength dispersion type fluorescent X-ray analyzer “Axios” (manufactured by PANalytical) and attached dedicated software “SuperQ ver. 4.0F” (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data ) Is used. Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 27 mm, and the measurement time is 10 seconds. Further, when measuring a light element, it is detected by a proportional counter (PC), and when measuring a heavy element, it is detected by a scintillation counter (SC).

  As a measurement sample, about 4 g of toner particles are put in a dedicated aluminum ring for press and flattened, and using a tablet molding compressor “BRE-32” (manufactured by Maekawa Test Co., Ltd.) at 20 MPa, Pellets formed by pressing for 60 seconds and having a thickness of about 2 mm and a diameter of about 39 mm are used.

  The measurement is performed under the above conditions, the element is identified based on the obtained X-ray peak position, and the concentration is calculated from the count rate (unit: cps) which is the number of X-ray photons per unit time.

  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.

(Production Example 1 of Polyester Resin)
Bisphenol A propylene oxide 2.2 mol adduct 2.75 mol%
Bisphenol A ethylene oxide 2.2 mol adduct 1.00 mol%
Isophthalic acid 6.10 mol%
Trimet anhydride 0.15 mol%
100 parts by mass of the above acid component and alcohol component and 0.30 parts by mass of potassium titanyl oxalate were placed in a 4-liter four-necked flask made of glass. A thermometer, a stirring rod, a condenser, and a nitrogen introducing tube were attached thereto and placed in a mantle heater. Reaction was performed at 220 ° C. in a nitrogen atmosphere, and when the acid value reached 13 mg KOH / g, heating was stopped and the mixture was gradually cooled to obtain polyester resin 1. This resin had a hydroxyl value of 20 mgKOH / g, Mw of 10,000, Mn4400, and Tg of 67.1 ° C.

(Production Example 2 of Polyester Resin)
Put 65.3 parts by mass of terephthalic acid and 18 parts by mass of ethylene glycol into a 4 liter glass flask, and attach a thermometer, stir bar, condenser and nitrogen inlet tube, place in a mantle heater, It heated to 100 degreeC, performing dehydration. After cooling to 50 ° C., 17.2 parts by mass of titanium tetramethoxide was added under a nitrogen atmosphere. Thereafter, the pressure was reduced, and methanol as a reaction product was distilled off to obtain an aromatic carboxylic acid titanium compound A.

  In Polyester Resin Production Example 1, polyester resin 2 was obtained in the same manner except that 3.00 parts by mass of aromatic carboxylate titanium compound A was used instead of potassium titanyl oxalate. This resin had a hydroxyl value of 20 mgKOH / g, Mw of 7,650, Mn of 3,500, and Tg of 68.5 ° C.

(Production Example 1 of Toner Particles)
Styrene monomer 100.0 parts by mass C.I. I. Pigment Blue 15: 3 16.5 parts by mass Di-tert-butylsalicylic acid aluminum compound 3.0 parts by mass [Bontron E88 (manufactured by Orient Chemical Co., Ltd.)]
These were introduced into an attritor (manufactured by Mitsui Mining Co., Ltd.), and stirred at 200 rpm at 25 ° C. for 180 minutes using zirconia beads (140 parts by mass) with a radius of 1.25 mm. Prepared.

On the other hand, 710 parts by mass of ion-exchanged water and 450 parts by mass of a 0.1 mol / liter Na ₃ PO ₄ aqueous solution were added to a 2-liter four-necked flask equipped with a high-speed stirring device TK-homomixer. Was adjusted to 14,000 and heated to 60 ° C. To this, 67.7 parts by mass of a 1.0 mol / liter CaCl ₂ aqueous solution was gradually added to prepare an aqueous medium containing a minute sparingly water-soluble dispersant Ca ₃ (PO ₄ ) ₂ .
Master batch dispersion 1 40 parts by mass styrene monomer 50 parts by mass n-butyl acrylate monomer 21 parts by mass Low molecular weight polystyrene 15 parts by mass (Mw = 3,000, Mn = 1,050, Tg = 55 ° C.)
Hydrocarbon wax 9 parts by mass (Fischer-Tropsch wax, maximum endothermic peak = 78 ° C., Mw = 750)
12 parts by mass of polyester resin 1 Add the above materials to a 0.5 liter beaker, heat to 63 ° C., and uniformly dissolve and disperse at 5,000 rpm using a TK homomixer (manufactured by Special Machine Industries). did. In this, 7.0 parts by mass of a 70% toluene solution of a polymerization initiator 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate was dissolved to prepare a polymerizable monomer composition.

  The polymerizable monomer composition was put into the aqueous medium, and granulated by stirring at 12,000 rpm for 10 minutes with a TK homomixer in a nitrogen atmosphere at a temperature of 65 ° C. Thereafter, the temperature was raised to 67 ° C. while stirring with a paddle stirring blade, and when the polymerization conversion of the polymerizable vinyl monomer reached 90%, a 0.1 mol / l sodium hydroxide aqueous solution was added. The pH of the aqueous dispersion medium was adjusted to 9. Furthermore, it heated up at 85 degreeC with the temperature increase rate of 40 degreeC / h, and was made to react for 4 hours. After completion of the polymerization reaction, the residual monomer in the toner particles was distilled off under reduced pressure. After cooling the aqueous medium, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 6 hours to dissolve the calcium phosphate compound. The toner particles were separated by filtration and washed with water, and then dried at a temperature of 40 ° C. for 48 hours to obtain cyan toner particles 1. The toner element 1 had a Ti element content of 121 ppm. The weight average particle diameter (D4) was 6.1 μm.

(Toner particle production example 2)
Toner particles 2 were obtained in the same manner as in Toner Particle Production Example 1 except that the amount of polyester resin 1 added was changed to 3 parts by mass. The toner element 2 had a Ti element content of 30 ppm. Moreover, the weight average particle diameter (D4) was 6.2 μm.

(Toner particle production example 3)
Toner particles 3 were obtained in the same manner as in Toner Particle Production Example 1 except that the amount of polyester resin 1 added was changed to 1.5 parts by mass. The toner element 3 had a Ti element content of 15 ppm. The weight average particle diameter (D4) was 6.1 μm.

(Production Examples 4 and 5 of toner particles)
Except that the polyester resin 1 was changed to the polyester resin 2 and the addition amounts thereof were changed to 10.5 parts by mass and 12.6 parts by mass, respectively, the same procedure as in the toner particle production example 1 was carried out. Obtained. The Ti element contents of the toner particles 4 and 5 were 1000 ppm and 1160 ppm, respectively. The weight average particle diameter (D4) was 6.2 μm and 6.3 μm, respectively.

<Example of production of silica-alumina composite particles>
<< Production Example 1 of Silica-Alumina Composite Particles >>
Aluminium trichloride aqueous solution (flow rate 0.135 kg / h) sprayed with ultrasonic waves into an aerosol, silicon tetrachloride vaporized at 200 ° C. (flow rate 0.410 kg / h), and nitrogen are uniformly mixed to form a flame. It sprayed in the oxygen-hydrogen flame of 2100 degreeC temperature, and hydrolyzed at high temperature. After cooling, it was collected with a filter to obtain silica-alumina composite particles. Further, the obtained powder was heated to about 500 ° C. to remove the adhering chloride.

  Further, the obtained silica-alumina composite particles were put in an electric furnace and heated at 1000 ° C. for 25 minutes to increase the crystallinity of the composite particles.

  Further, 100 parts by mass of the composite particles having increased crystallinity were put into a stirrer, and 20.2 parts by mass of dimethyl silicone oil (trade name: KF96-50cs: manufactured by Shin-Etsu Chemical Co., Ltd.) was added while stirring. It sprayed using the fluid nozzle, it was made to adhere to a silica alumina composite particle, the stirring process was continued for 60 minutes, and the silica alumina composite particle 1 hydrophobized with silicone oil was obtained. Table 3 shows the physical properties of the obtained silica-alumina composite particles 1.

<< Production Examples 2 to 7 of Silica Alumina Composite Particle >>
In Production Example 1 of silica-alumina composite particles, the gas flow rate ratio of silicon tetrachloride gas and aluminum trichloride was adjusted. Further, the addition amount of dimethyl silicone oil was adjusted so that the ratio (addition amount of hydrophobizing agent / BET specific surface area of silica-alumina composite particles before being hydrophobized) was 0.155. Other conditions were the same as in Production Example 1 of silica-alumina composite particles, and silica-alumina composite particles 2 to 7 were obtained. Table 3 shows the physical properties of the obtained silica-alumina composite particles 2 to 7.

<< Production Examples 8 to 12 of Silica Alumina Composite Particles >>
In the production example 1 of silica-alumina composite particles, for the purpose of changing the crystallinity of alumina, the heating conditions which were 25 minutes at 1000 ° C. were changed to 1150 ° C., 1280 ° C., 1360 ° C., 870 ° C. and 820 ° C., respectively. For 25 minutes. Further, the addition amount of dimethyl silicone oil was adjusted so that the ratio (addition amount of hydrophobizing agent / BET specific surface area of silica-alumina composite particles before being hydrophobized) was 0.155. Other conditions were the same as in Production Example 1 of silica-alumina composite particles, and silica-alumina composite particles 8 to 12 were obtained. Table 3 shows the physical properties of the obtained silica-alumina composite particles 8 to 12.

<< Production Example 13 of Silica-Alumina Composite Particles >>
In silica alumina composite particle production example 1, silica alumina composite particles 13 were obtained in the same manner as silica alumina composite particle production example 1 except that the heating step for increasing the crystallinity was not performed. Table 3 shows the physical properties of the obtained silica-alumina composite particles.

<< Production Examples 14 to 16 of Silica Alumina Composite Particles >>
In Production Example 1 of silica-alumina composite particles, dimethyl silicone oil was changed to hexamethylene disilazane (HMDS). Hydrophobization treatment with HMDS was performed so that 100 parts by mass of untreated silica-alumina composite particles were introduced into a mixer, and the temperature in the mixer was adjusted to 250 ° C. while stirring and nitrogen substitution. Thereafter, water vapor was introduced into the mixer so that the partial pressure was 60 kPa, and 30 parts by mass of hexamethyldisilazane was introduced. After maintaining for 1 hour and replacing with nitrogen, hydrophobized silica-alumina composite particles were extracted. In the hydrophobization treatment of the silica-alumina composite particles with HMDS, the addition amounts of HMDS were 13.3 parts by mass, 9.0 parts by mass, and 5.5 parts by mass, respectively, to obtain silica-alumina composite particles 14 to 16. Table 3 shows the physical properties of the obtained silica-alumina composite particles.

<< Production Examples 17 and 18 of Silica Alumina Composite Particles >>
In Production Example 1 of silica-alumina composite particles, the addition amount of dimethyl silicone oil was changed to 2.08 parts by mass and 22.1 parts by mass, respectively, to obtain silica-alumina composite particles 17 and 18. Table 3 shows the physical properties of the obtained silica-alumina composite particles.

<< Production Examples 19 to 28 of silica-alumina composite particles >>
In Production Example 1 of silica-alumina composite particles, the flame temperature, gas flow rate ratio, and heating temperature were changed as shown in Table 2 so that the physical properties described in Table 3 were obtained. Other conditions were the same as in Production Example 1 of silica-alumina composite particles, and silica-alumina composite particles 19 to 28 were obtained. Table 3 shows the physical properties of the obtained silica-alumina composite particles 19 to 28.

[Example 1]
A Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) was prepared by adding 100 parts by weight of toner particles, 1: 1.5 parts by weight of silica-alumina composite particles, and 0.15 parts by weight of zinc stearate having a primary particle number average particle size of 0.4 μm. ) For 5 minutes to obtain toner 1.

  The obtained toner 1 was used for the following evaluation. The evaluation results are shown in Table 4.

Image evaluation
A Canon printer 7200C was remodeled so that a blade bias of −180 V with respect to the developing bias could be applied, and used for image evaluation. In the evaluation, a toner filled with the above toner 1:70 g as a toner was mounted on the cyan station, and a dummy cartridge was mounted on the other, and each image evaluation was performed. As an evaluation paper, Canon GF-R200 was used.

  Image evaluation in each environment was performed after the printer (including the cartridge) and the evaluation paper were left in each evaluation environment for 48 hours.

i) Evaluation of fog in a high temperature and high humidity (32.5 ° C / 80% Rh) environment 200 images with a printing rate of 5% in a high temperature and high humidity (32.5 ° C / 80% Rh) environment And then output a solid white image.

Thereafter, the following (1) to (3) were repeated until the remaining amount of toner in the cartridge reached 20 g.
(1) Leave for 36 hours (2) Output one solid white image (3) Output 200 images with 5% printing rate and output continuously

For the solid image thus obtained, the reflectance Ds (%) was measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd.). An amberlite filter was used as the filter. The difference (Dr−Ds) (%) between the average reflectance Dr (%) and the reflectance Ds (%) of the unused transfer paper was calculated and evaluated based on the following criteria. For the evaluation, the worst value in each environment was used.
A: Less than 0.5% B: 0.5% or more and less than 1.0% C: 1.0% or more and less than 1.5% D: 1.5% or more

ii) Evaluation of fog in a low-temperature and low-humidity (15 ° C / 10% Rh) environment In a low-temperature and low-humidity (15 ° C / 10% Rh) environment, 400 images with a printing rate of 1% are output continuously, A solid white image was output. Thereafter, the output of 400 sheets of an image with a printing rate of 1% and the output of one sheet having a white background portion were repeated until the remaining amount of toner in the cartridge reached 20 g.

  The solid white image thus obtained was evaluated for fog in the same manner as in the evaluation under a high temperature and high humidity environment.

iii) Image uniformity and image quality in an environment of 32.5 ° C / 80% Rh A photographic image, a monochrome solid image, and a halftone image were output one by one in an environment of 32.5 ° C / 80% Rh. Thereafter, 200 images with a printing rate of 5% were output continuously. After 200 sheets were output, a photographic image, a single color solid image, and a halftone image were output one by one.

Thereafter, the following (1) to (3) were repeated until the remaining amount of toner in the cartridge reached 20 g.
(1) Leave for 36 hours (2) Output photographic image, single color solid image and halftone image one by one (3) Output 200 images with 5% printing rate Obtained photographic image, single color solid image and halftone The images were visually observed for image uniformity and image quality.
A: Very good (uniform image cannot be confirmed)
B: Good (Slight image unevenness can be confirmed)
C: Average (image unevenness can be confirmed)
D: Inferior (image unevenness is remarkable)

iv) Image uniformity and image quality in an environment of 15 ° C / 10% Rh In a 15 ° C / 10% Rh environment, a photographic image, a monochrome solid image, and a halftone image are output one by one, and the printing rate is 400 images of 1% were output continuously. After outputting 400 sheets, a photographic image, a single color solid image, and a halftone image were output one by one. Thereafter, until the remaining amount of toner in the cartridge reached 20 g, the output of 400 sheets of an image with a printing rate of 1% and the output of each of a photographic image, a monochrome solid image, and a halftone image were repeated.

  The photographic image, single color solid image and halftone image thus obtained were evaluated in the same manner as the evaluation at 32.5 ° C./80% Rh.

v) Image density stability (1) In a 32.5 ° C./80% Rh environment, one single-color solid image was output, and then 200 images with a printing rate of 5% were output continuously. Immediately after output, one single-color solid image was output.
Thereafter, it was allowed to stand for 36 hours, and after that, a photographic image, a single-color solid image, and a halftone image were output one by one, and then 200 images with a printing rate of 5% were continuously output. Immediately after output, one single-color solid image was output. Thereafter, this operation was repeated until the remaining amount of toner in the cartridge reached 20 g.

  (2) One single-color solid image was output in an environment of 15 ° C./10% Rh, and then 400 images with a printing rate of 1% were output continuously. Immediately after output, one single-color solid image was output. Thereafter, this operation was repeated until the remaining amount of toner in the cartridge reached 20 g.

The image density of all the single-color solid images obtained in (1) and (2) was measured using a color reflection densitometer (X-RITE 404A manufactured by X-Rite Co.). Throughout the durability, the density difference between the highest and lowest image density was shown based on the following evaluation criteria.
A: Less than 0.2 B: 0.2 or more and less than 0.3 C: 0.3 or more and less than 0.4 D: 0.4 or more

[Examples 2 to 21, Comparative Examples 1 to 7]
Toners 2 to 28 were obtained in the same manner as in Example 1 except that the silica alumina composite particles 1 were changed to the silica alumina composite particles shown in Table 4. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 4.

[Examples 22 to 25]
In Example 1, the same procedure was performed except that the toner particles 1 were changed to toner particles 2 to 5, and toners 29 to 32 were obtained. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 4.

  In Comparative Example 1 using the toner 4, the image uniformity, image quality, and image density stability in a low temperature and low humidity environment were inferior. This is because the silica content of the silica-alumina composite particles is large, so that charge-up occurs, resulting in a decrease in transferability. Further, the fog and image density stability in a high-temperature and high-humidity environment were also inferior. This is because the silica content of the silica-alumina composite particles was large and the fluidity of the toner was lowered.

  In Comparative Example 2 using the toner 7, the results were inferior in image density stability, image uniformity, and image quality in a high temperature and high humidity environment. This is because the silica-alumina composite particles have a high alumina content, so that the low frictional charging property of the silica-alumina composite particles is too strong, making it difficult to maintain the charge of the toner (a large loss of charge).

  In Comparative Example 3 using the toner 10, the image uniformity, image quality, and image density stability in a low temperature and low humidity environment were inferior. This is because charge-up occurs due to the high crystallinity of the silica-alumina composite particles, resulting in a decrease in transferability. In addition, the image quality deteriorated in both low temperature and low humidity and high temperature and high humidity environments. This is because the silica alumina particles are aggregated in the heating process, and as a result, they are separated from the toner particles and adhere to the regulating blade, resulting in streaky image density (development streaks).

  In Comparative Example 4 using the toner 13, fogging, image uniformity, image quality, and image density stability in a high temperature and high humidity environment decreased. This is due to the low crystallinity of the silica-alumina composite particles, resulting in low electrical resistance and low surface activity.

  In Comparative Example 5 using the toner 16, fog and image uniformity in a high temperature and high humidity environment were deteriorated. This is because the silica-alumina composite particles have a low degree of hydrophobicity, so that the hygroscopicity is increased and the chargeability of the toner is lowered.

  In Comparative Example 6 using the toner 21, image density stability and image uniformity in a high temperature and high humidity environment were lowered. This is because the zeta potential in the untreated state of the silica-alumina composite particles 22 is high, that is, because alumina is present on the particle surface, the characteristics of alumina are strongly expressed. That is, the low frictional charging property becomes too strong, and it becomes difficult to maintain charging under high humidity.

  In Comparative Example 7 using the toner 24, the image uniformity and the image density stability were lowered in a low temperature and low humidity environment. In addition, fogging decreased in a high temperature and high humidity environment. This is because the silica-alumina composite particles have a high zeta potential in an untreated state, that is, because the silica surface exposure ratio is large, the characteristics of silica are strongly expressed. In a low-temperature and low-humidity environment, charge-up occurs during continuous use, and in a high-temperature and high-humidity environment, silica alumina particles become slightly agglomerated and the fluidity of the toner is reduced. As a result.

  In Example 23 using the toner 30, all items and image density stability under a low temperature and low humidity environment were slightly lowered. This is because the toner element 3 has a small titanium element content, so that it is difficult to reduce the charge between the toners, the charge distribution becomes slightly wider, and the charge is slightly increased.

  In Example 25 using the toner 32, all items and image density stability under a high temperature and high humidity environment were slightly decreased. This is because the toner element has a high titanium element content, so that when it is left for a long period of time, the loss of charge from the toner is slightly increased, fogging is observed, and transferability is slightly lowered.

1 Main electrode 2 Upper electrode 3 Insulator 4 Ammeter 5 Voltmeter 6 Constant voltage device 7 Measurement sample 8 Guide ring

Claims (4)

A toner containing toner particles containing at least a binder resin and a colorant, and silica alumina composite particles hydrophobized with a hydrophobizing agent,
The hydrophobized silica-alumina composite particles have a hydrophobization degree of 60% or more,
The zeta potential of the silica-alumina composite particles before being hydrophobized is from −42.0 mV to −28.0 mV,
The silica content in the silica-alumina composite particles before being hydrophobized is 55.0 mass% or more and 95.0 mass% or less,
The toner according to claim 1, wherein the hydrophobized silica-alumina composite particles have an alumina crystallinity of 10.0% to 60.0%. Ratio A / B of the addition amount A (g / g) of the hydrophobizing agent to the BET specific surface area B (g / m ² ) of the silica-alumina composite particles before being hydrophobized using the hydrophobizing agent The toner according to claim 1, wherein (m ² / g) is 1.70 × 10 ⁻³ or less. The volume specific resistance of the silica-alumina composite particles before being hydrophobized is 1.0 × 10 ⁷ Ω · m or more and 5.0 × 10 ¹¹ Ω · m or less. The toner described in 1.   The toner according to claim 1, wherein the toner particles contain 30 ppm or more and 1000 ppm or less of a titanium element.

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