JP7066473B2 - toner - Google Patents

Description

The present invention relates to toners used for image formation such as electrophotographic and electrostatic printing.

In recent years, copiers and printers are required to be able to obtain stable images in all environments in addition to miniaturization, high speed, and long life (stable images can be obtained for a long period of time).
In order to meet such demands, toners using a titanium oxide external additive having an effect of reducing the difference in charging environment have been proposed.
For example, for the purpose of further improving the chargeability under high temperature and high humidity, a toner using an external additive containing titanium oxide surface-treated with a fluorine atom-containing silane compound has been proposed (Patent Document 1). According to this, it is disclosed that the rising property of charging is improved by using an external additive containing titanium oxide surface-treated with a silane compound containing a fluorine atom.
Further, in Patent Document 2, in a toner containing toner particles having a core-shell structure and an external additive, the shell of the toner particles contains a polyester resin having specific physical properties and is surface-treated with a silane compound containing a fluorine atom. Toners containing an external additive containing titanium oxide are disclosed. According to this, it is disclosed that the rising property of charging is excellent from the initial stage and that an excessive increase in the amount of charging can be suppressed even in a low temperature and low humidity environment.

Japanese Patent No. 4310146 Japanese Unexamined Patent Publication No. 2017-44982

Certainly, the toners described in Patent Document 1 and Patent Document 2 have improved charging rising properties, and stable images can be obtained. However, as a result of diligent studies by the present inventors, any of the disclosed techniques is used in the in-flight contamination of the image forming apparatus caused by the wax contained in the toner when the speed is increased and the life is extended. It turned out that there was room for improvement.
An object of the present invention is to provide a toner that has less internal contamination of an image forming apparatus, has excellent durability, and can maintain high image quality.

The present invention comprises toner particles having a core containing a binder resin and a shell existing on the surface of the core .
Titanate metal fine particles and
Toner with
The toner particles contain a hydrocarbon wax and
The shell contains polyester resin A and contains
The polyester resin A has a unit derived from an alcohol having an isosorbide structure or a carboxylic acid having an isosorbide structure, and the alcohol having the isosorbide structure and the carboxylic acid having the isosorbide structure with respect to the total number of units constituting the polyester resin A. The ratio of the number of units derived from acid is 0.10% or more and 20.00% or less.
The metal titanate fine particles are
( I) Number of primary particles The average particle size is 10 nm or more and 100 nm or less .
( Ii) Perovskite crystal structure ,
( Iii) In the methanol wettability test, the methanol concentration was 30.0% or more and 60.0% or less when the transmittance of light having a wavelength of 780 nm was 50% .
(Iv) Fine particles treated with a compound having a structure represented by the formula (2) described later .
It relates to a toner characterized by that.

According to the present invention, it is possible to provide a toner that has less internal contamination and can maintain high image quality in long-term use regardless of the environment.

Hereinafter, the present invention will be described in detail.

Generally, in electrophotographic methods, in-flight contamination occurs near the fuser. The reason is that the wax contained in the toner excessively adheres to the fixing roller, and when it is heated, it becomes ultrafine particles and adheres to the inside of the machine. The present inventors have diligently studied the suppression of in-flight contamination while maintaining excellent durability and high image quality.

As a result, it was found that the above object can be achieved by adopting the configuration of the present invention.

The details of the mechanism of expression of the effect of the present invention are unknown, but it is expected as follows.

In order to suppress an excessive increase in the amount of charge even in a low-temperature and low-humidity environment with excellent charge rise from the initial stage, a polyester resin having a specific structure is contained, and the surface is made of a silane compound containing a fluorine atom. It is disclosed that the toner contains an external additive containing treated titanium oxide (Patent Document 2).

On the other hand, the present inventors, in addition to the above-mentioned performance, in order to further suppress the in-flight pollution,
(1) It is assumed that the external additive is difficult to be embedded in the surface of the toner particles at the time of fixing (2) the external additive itself has a high affinity for wax (hydrophobicity) (1) and (2). Therefore, it was considered that the excess amount of wax existing on the surface of the toner could be captured by the external additive on the surface of the toner particles at the time of fixing, and the adhesion of the wax to the fuser could be suppressed. As a result, with respect to (1) and (2), an alicyclic polyester resin was used as the shell of the toner particles having a core-shell structure, and titanium acid metal fine particles having a perovskite crystal structure were used as an external additive. It was found that the effect of the present invention is produced by controlling the number average particle size and the degree of hydrophobicity of the primary particles.

The reason for this is that by using an alicyclic polyester resin as the shell of the toner particles, the cyclic structure has an appropriate rigidity, so that it becomes difficult for the external additive to be embedded even at the time of fixing. The metal titanate fine particles used for the toner particles have a perovskite-type crystal structure. Further, the metal titanate fine particles have a cubic / rectangular parallelepiped shape. It is believed that this creates a spacer effect on other external additives such as silica fine particles and suppresses the embedding of the external additive. Due to the synergistic effect of the physical characteristics of the toner particle surface and the shape of the external additive, it is considered that the external additive increases the surface area of the fixed surface at the time of fixing, and the wax wets and spreads from these as the starting point.

Furthermore, the metal titanate fine particles have a methanol concentration of 30.0% or more and 60.0% or less when the transmittance of light having a wavelength of 780 nm is 50% in the methanol wettability test. , The affinity is high. It is believed that this produces the effect of the wax spreading by the affinity at the time of fixing. Based on the above, it is considered that the excess amount of wax existing on the surface of the toner can be captured by the external additive on the surface of the toner particles at the time of fixing, and the adhesion of the wax to the fuser can be suppressed.

Toner particles, which are one of the constituent elements in the present invention, will be described.

In the present invention, the toner particles have a core containing a binder resin and a shell existing on the surface of the core.

The shell contains a polyester resin A and has a unit derived from an alcohol having an alicyclic structure or a carboxylic acid having an alicyclic structure, and has an alicyclic structure for the total number of units constituting the polyester resin A. It is essential that the ratio of the number of units derived from the alcohol and the carboxylic acid to have is 0.10% or more and 20.00% or less.

When the number of units of the polyester resin A is smaller than 0.10% in the alicyclic structure, the effect of suppressing the embedding of the external additive at the time of fixing becomes small. In the alicyclic structure of the polyester resin A, if the number of units is larger than 20.00%, the rigidity of the toner particles is excessively increased, the adhesiveness of the external additive is deteriorated, and the adhesion is poor.

The polyester resin A has a unit derived from an alcohol having an alicyclic structure or a carboxylic acid having an alicyclic structure as a unit constituting the polymer chain. In the polyester resin A, a polymer chain is formed by polycondensation of an acid component and an alcohol component. The polymer chain has a repeating unit containing a structure in which a unit obtained from an acid component and a unit obtained from an alcohol component are bonded by an ester bond. In the polyester resin A, at least one of the unit obtained from the acid component constituting the repeating unit and the unit obtained from the alcohol component has an alicyclic structure.

This alicyclic structure is incorporated into the polymer chain as a unit as a structural unit of the polymer chain itself, that is, a unit in which the alicyclic structure is directly adjacent to the unit and is incorporated into the polymer chain, and a group that binds to the polymer chain. For example, it is not arranged on a side group or a pendant group that does not have a repeating unit structure as a polymer.

The polyester resin A may have only a linear main chain or a branched chain having a main chain and a side chain as the polymer chain. In the case of a branched chain, an alicyclic structure can be incorporated as a constituent unit of the main chain and / or the side chain.

The alicyclic compound refers to a compound having a cyclic structure that does not have aromaticity. According to the classification based on the constituent elements, the alicyclic structure includes an alicyclic hydrocarbon structure in which the non-aromatic cyclic structure is composed of only carbon and hydrogen, and a non-aromatic cyclic structure. There is an alicyclic heterocyclic structure containing carbon, hydrogen and other elements, and any of these alicyclic structures can be used.

Examples of the monomer (acid monomer) as an acid component and the monomer (alcohol monomer) as an alcohol component containing an alicyclic hydrocarbon structure include the following various monomers.

Examples of the acid monomer include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, and cis-4-cyclohexene-1,2. -Dicarboxylic acid, cis-1-cyclohexene-1,2-dicarboxylic acid, norbornandicarboxylic acid, norbornendicarboxylic acid, 1,3-adamantandicarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, 1,2,4-cyclohexane Examples thereof include tricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid and methylcyclohexcentricarboxylic acid.

Examples of the alcohol monomer include 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, 1,4-cyclohexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, and 4- (2-hydroxyethyl). ) Cyclohexanol, 4- (hydroxymethyl) cyclohexanol, 4,4'-bicyclohexanol, 1,3-adamantandiol and the like can be mentioned. Examples of the monomer having an alicyclic heterocyclic structure include isosorbide, spiroglycol and the like as alcohol monomers.

In particular, by using isosorbide as the alcohol monomer, it is more preferable that the main chain and / or the side chain of the polyester resin has an isosorbide structure as a constituent unit of the polymer chain.

In addition to the alcohol or carboxylic acid having an alicyclic structure, the polyester resin A contains the following dibasic acids and derivatives thereof (carboxylic acid halides, esters, acid anhydrides) and divalent alcohols, and if necessary, trifunctional. It can be prepared by a method of dehydrating and condensing the above polybasic acid, its derivative (carboxylic acid halide, ester, acid anhydride), monobasic acid, trifunctional or higher alcohol, monovalent alcohol and the like.

Examples of the dibasic acid include maleic acid, fumaric acid, itaconic acid, oxalic acid, malonic acid, succinic acid, dodecyl succinic acid, dodecenyl succinic acid, adipic acid, azelaic acid, sebacic acid, decane-1,10-dicarbonate. Fat group dibasic acids such as acids; phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrabromphthalic acid, tetrachlorphthalic acid, het acid, hymic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid Examples thereof include aromatic dibasic acids such as. Examples of the derivative of the dibasic acid include the above-mentioned aliphatic dibasic acid, a carboxylic acid halide of the aromatic dibasic acid, an esterified product, and an acid anhydride.

Examples of the divalent alcohol include ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and diethyleneglyco. -Lilipene glycols, triethylene glycols, neopentyl glycols and other aliphatic diols; bisphenol A, bisphenol F and other bisphenols; bisphenol A Examples thereof include bisphenol A alkylene oxide adducts such as ethylene oxide adducts and propylene oxide adducts of bisphenol A; and aralkylene glycols such as xylylene diglycol.

Examples of the trifunctional or higher polybasic acid and its anhydride include trimellitic acid, trimellitic anhydride, 1,3,5-cyclohexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2, Examples thereof include 4,5-cyclohexanetetracarboxylic acid, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, methylcyclohexcentricarboxylic acid, methylcyclohexcentricarboxylic acid anhydride, pyromellitic acid, pyromellitic anhydride and the like. ..

The acid value of the polyester resin A is preferably 0.5 mgKOH / g or more and 25.0 mgKOH / g or less. When the acid value is 0.5 mgKOH / g or more, the generation of a large domain of the polyester resin A in the toner mother particles is more effectively suppressed, and the charge amount distribution of the toner can be sharpened. Further, when the acid value is 25.0 mgKOH / g or less, excessive charging can be more effectively suppressed under low temperature and low humidity. Further, when the acid value of the polyester resin A contained in the shell layer of the toner particles satisfies the above range, the polymerizable monomer and the aqueous medium forming the binder resin of the toner particles in the suspension polymerization method or the like described later will be used. The added polyester resin A tends to form a shell layer on the surface of the toner particles according to the balance of the polarities exhibited by the toner particles.

When the weight average molecular weight of the polyester resin A is 5,000 or more and 50,000 or less, the durability is good, which is preferable. When the number average molecular weight of the polyester resin A is 1000 or more and 20000 or less, the durability is good, which is preferable.

As a method for adjusting the weight average molecular weight of the polyester resin A, a known method can be used. For example, in order to keep the weight average molecular weight in the above range, the weight average molecular weight can be controlled by changing the conditions such as the amount of the raw material, the reaction temperature, and the solvent concentration when producing the polyester resin A.

Further, the alicyclic structure of the polyester resin A is preferably an isosorbide structural formula represented by the following structural formula (1). Since the ether-bonded portion in the isosorbide structure has polarity, it interacts with the hydrophilic portion of the external additive, the external additive does not easily come off from the surface of the mother body, and the external additive has an effect of suppressing charge-up. As a result, it becomes possible to produce an effect on poor regulation and in-flight pollution during long-term durability.

It is more preferable that the polyester resin A is contained in an amount of 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin of the toner particles. Within this range, the formation of the shell and the adhered state of the external additive are improved. Therefore, the embedding of the external additive during durability is further suppressed. In addition, the embedding of the external additive at the time of fixing is suppressed. Further, since the surface area of the external additive can be increased at the time of fixing, the adhesion of wax to the fixing device can be further suppressed.

[About binding resin]
In the present invention, it has a binder resin together with the polyester resin A. For example, the following can be exemplified. Styline resin, acrylic resin, methacrylic resin, styrene-acrylic resin, styrene-methacrylic resin, polyethylene resin, polyethylene-vinyl acetate resin, vinyl acetate resin, polybutadiene resin, phenol resin, polyurethane resin, polybutyral resin, Polyester resin, or a hybrid resin in which these resins are arbitrarily bonded.

Among them, the following are preferably used in terms of toner characteristics. Styrene-based resin, acrylic-based resin, methacrylic-based resin, styrene-acrylic resin, styrene-methacryl-based resin.

As the polymerizable monomer that can be used in the above case, styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and 2,4-dimethylstyrene; Acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, ethyl. Methacrylate-based polymerizable monomers such as methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, and tert-butyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl acetate, propion. Suitable examples include vinyl esters such as vinyl oxyate, vinyl benzoate, vinyl butylate, vinyl benzoate and vinyl acrylate.

[About colorants]
The toner particles of the present invention contain a colorant. As the black colorant, carbon black, a magnetic material, and a black colorant using the following yellow / magenta / cyan colorants are used.

Examples of the yellow colorant include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 128, 129, 138, 147, 150, 151, 154, 155, 168, 180, 185, 214 can be mentioned.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, the following C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221 238, 254, 269, C.I. I. Pigment Bio Red 19.

Examples of the cyan colorant include a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

These colorants can be used alone or in a mixed state or in a solid solution state. The colorant is selected in terms of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner. The amount of the colorant added is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer or the binder resin that produces the binder resin.

Further, the toner of the present invention can be made into a magnetic toner by containing a magnetic substance as a colorant. Magnetic materials include iron oxides such as magnetite, hematite, and ferrite, metals such as iron, cobalt, and nickel, or these metals and aluminum, copper, magnesium, tin, zinc, beryllium, calcium, manganese, selenium, and titanium. Examples include alloys with metals such as tungsten and vanadium and mixtures thereof.

The magnetic material is more preferably a surface-modified magnetic material. When the magnetic toner is prepared by a polymerization method, it is preferably hydrophobized with a surface modifier which is a substance that does not inhibit polymerization. Examples of such a surface modifier include a silane coupling agent and a titanium coupling agent. The average particle size of these magnetic materials is preferably 2.0 μm or less, and more preferably 0.1 μm or more and 0.5 μm or less. The amount contained in the toner particles is preferably 20 parts by mass or more and 200 parts by mass or less, and more preferably 40 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer or the binder resin.

[About wax]
The toner particles of the present invention contain wax.

Wax components include paraffin wax, microcrystalline wax, petroleum wax such as petrolatum and its derivatives, Montan wax and its derivatives, hydrocarbon wax and its derivatives by the Fisher Tropsch method, polyethylene, polyolefin wax such as polypropylene and its derivatives. Derivatives, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and the derivatives include oxides, block copolymers with vinyl-based monomers, and graft modified products. Further, fatty acids such as higher fatty alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes and ester waxes can also be used.

[About charge control agent]
For the toner of the present invention, a known charge control agent may be used in order to keep the chargeability of the toner stable regardless of the environment.

[About the method for producing toner particles of the present invention]
The method for producing the toner particles is not particularly limited. For example, a method for directly producing toner in a hydrophilic medium (hereinafter, also referred to as a polymerization method) such as a suspension polymerization method, an interfacial polymerization method, and a dispersion polymerization method can be mentioned. Further, a pulverization method may be used, or the toner obtained by the pulverization method may be formed into a thermal sphere.

Among them, a toner produced by a suspension polymerization method is preferable because the individual particles are substantially spherical and the distribution of the amount of charge is relatively uniform, so that the toner has high transferability.

In the suspension polymerization method, a polymerizable monomer composition having an additive such as a polymerizable monomer, a colorant, and a wax that produces a binder resin is dispersed in an aqueous medium to form a polymerizable monomer composition. It is a method of producing toner particles by going through a granulation step of producing droplets of an object and a polymerization step of polymerizing the polymerizable monomer in the droplets.

[About metal fine particles of titanium acid]
The metal titanate fine particles, which are one of the constituent elements in the present invention, will be described.

In the present invention, it is a metal titanate fine particle having a perovskite crystal structure, the number average particle size of the primary particles is 10 nm or more and 100 nm or less, and the transmittance of light having a wavelength of 780 nm is 50% in the methanol wettability test. It is essential to contain an external additive having a methanol concentration of 30.0% or more and 60.0% or less.

By containing the titanium acid metal fine particles in the above-mentioned specific range with respect to the toner particles having an appropriately rigid surface layer as described above, there is an effect of improving in-flight contamination and poor regulation in a low temperature and low humidity environment, and it is long. It has become possible to obtain stable image quality over a period of time.

Further, by taking the shape of the cube / rectangular parallelepiped of the external additive, the embedding of the external additive can be suppressed at the time of fixing, and at the same time, the surface area can be increased.

Further, in the methanol wettability test, the external additive has a methanol concentration of 30.0% or more and 60.0% or less when the transmittance of light having a wavelength of 780 nm is 50%. Affinity can be enhanced. Therefore, it is considered that the wax has a wet-spreading effect at the time of fixing.

It is important that the number average particle size of the primary particles of the metal titanate fine particles is 10 nm or more and 100 nm or less, preferably 10 nm or more and 80 nm or less. If the average particle size of the number of primary particles of the metal titanate fine particles is smaller than 10 nm, the shape characteristics become small, embedding at the time of fixing is not suppressed, and in-flight contamination does not improve. If it is larger than 100 nm, the metal titanate fine particles tend to come off from the toner surface, and the effect of the metal titanate fine particles cannot be obtained for a long period of time.

The metal titanate fine particles have a methanol concentration of 30.0% or more and 60.0% or less when the transmittance of light having a wavelength of 780 nm is 50% in a wettability test with a mixed solvent of methanol / water. Hereinafter, the methanol concentration when the transmittance of light having a wavelength of 780 nm is 50% in the wettability test with a mixed solvent of methanol / water is referred to as “hydrophobicity”.

When the degree of hydrophobicity is 30.0% or more, the affinity with the wax is enhanced, so that the ease of wetting and spreading of the wax is improved. In addition, environmental fluctuations in the amount of water adsorbed can be suppressed, and changes in developability depending on the environment can be suppressed. When the degree of hydrophobization is lower than 30.0%, the rising property of charging is particularly lowered in a high temperature and high humidity environment. However, it was found that if the hydrophobicity becomes too high, the rising property of charging cannot be ensured even in a low temperature and low humidity environment. It was found that this is because the adsorbed water cannot penetrate the surface layer, the effect of increasing the negative chargeability cannot be obtained, and the chargeability becomes low. The wettability required to obtain the effect of increasing the chargeability by invading the adsorbed water from the surface layer was when the degree of hydrophobicity was 60.0% or less. The degree of hydrophobicity of the metal titanate fine particles can be controlled by adjusting the surface treatment conditions of the metal titanate fine particles.

The metal titanate fine particles are preferably added in an amount of 0.01 parts by mass or more and 2.00 parts by mass or less, more preferably 0.05 parts by mass or more and 1.50 parts by mass with respect to 100 parts by mass of the toner particles. It is as follows.

It is preferable that the metal titanate fine particles are treated fine particles with any compound having a structure represented by the general formula (1) or (2). Since the external additive containing fluorine has a structure having a high negative charge, it has a high charge rising property from the initial stage of durability, and the fog suppression is improved in a high temperature and high humidity environment.

（式（１）中、Ｒａ～Ｒｆは水素原子、炭素数１以上１０以下のアルキル基又は炭素数１以上１０以下のフッ化アルキル基を表す。Ｒａ～Ｒｆの少なくとも一つは炭素数１以上１０以下のフッ化アルキル基を表す。）

(In the formula (1), Ra to Rf represent a hydrogen atom, an alkyl group having 1 or more and 10 or less carbon atoms or an alkyl fluoride group having 1 or more and 10 or less carbon atoms. At least one of Ra to Rf has 1 or more carbon atoms. Represents an alkyl fluoride group of 10 or less.)

（式（２）中、Ｒｇは炭素数１以上１０以下のフッ化アルキル基を表し、Ｒｈは水素原子又は炭素数１以上３以下のアルコキシ基を表す。）

(In the formula (2), Rg represents an alkyl fluoride group having 1 or more and 10 or less carbon atoms, and Rh represents a hydrogen atom or an alkoxy group having 1 or more and 3 or less carbon atoms.)

Examples of the metal titanate fine particles include alkali metal titanate fine particles such as strontium titanate fine particles, calcium titanate fine particles, and magnesium titanate fine particles; and alkali metal titanate fine particles such as potassium titanate fine particles. Above all, strontium titanate fine particles are more preferable.

When the strontium titanate fine particles are strontium titanate fine particles, the X-ray diffraction spectrum of CuKα obtained in the range of 2θ of 10 ° or more and 90 ° or less, where θ is the Bragg angle of the strontium titanate fine particles, is described above. It has peaks derived from strontium titanate particles at 39.700 ° ± 0.150 ° and 46.200 ° ± 0.150 °. Strontium titanate, which has a peak at this position, adopts a perovskite structure belonging to the cubic system. The peaks of 39.700 ° ± 0.150 ° and 46.200 ° ± 0.150 ° are diffraction peaks derived from the Miller index (111) and (200) lattice planes, respectively. Generally, particles belonging to the cubic system tend to adopt a hexahedral shape as the external shape of the particles.

The strontium titanate fine particles grow while having the (100) plane and the (200) plane corresponding to the plane direction of the hexahedron shape in the manufacturing process.

Above all, as a result of studies by the present inventors, it was found that good characteristics are exhibited when strontium titanate fine particles having a hexahedral shape having a (200) plane corresponding to the plane direction and a (111) plane corresponding to the apex direction are used. I found it.

As a result of detailed examination, when the peak area of 39.700 ° ± 0.150 ° is Sa and the peak area of 46.200 ° ± 0.150 ° is Sb, Sb / Sa is 1.80 or more. When it was 2.30 or less, it was found that the embedding of the external additive in the toner particles was further suppressed during the durability.

Further, although the mechanism is not clear, the strontium titanate fine particles can be attached to the toner particles in a more uniformly dispersed state by taking the above range.

It was found that having the above shape further suppresses in-flight pollution. The reason for this is that the embedding of the external additive in the toner particles is further suppressed, and the external additive can be adhered in a uniformly dispersed state, so that the ease of wetting and spreading of the wax is increased. is expected.

The metal titanate fine particles may be surface-coated with a separate treatment agent in addition to the above-mentioned treatment agent in order to adjust the charge and improve the environmental stability.

As a treatment agent
Titanium coupling agent;
Silane coupling agent;
Silicone oil;
Fatty acid metal salts such as zinc stearate, sodium stearate, calcium stearate, zinc laurate, aluminum stearate, magnesium stearate;
Fatty acids such as stearic acid;
Can be exemplified.

Treatment methods include a wet method in which a surface treatment agent is dissolved / dispersed in a solvent, fine particles of titanate are added thereto, and the solvent is removed while stirring, a coupling agent, a fatty acid metal salt and titanium. Examples thereof include a dry method in which fine particles of the acid salt are directly mixed and treated while stirring.

The metal titanate fine particles can be produced, for example, by a normal pressure heating reaction method. At this time, it is preferable to use a mineral acid deflated product of a hydrolyzate of a titanium compound as a titanium oxide source and a water-soluble acidic metal compound as a metal source other than titanium. Then, it can be produced by a method of reacting the mixed solution of the raw materials while adding an alkaline aqueous solution at 60 ° C. or higher, and then treating with an acid. Further, as a method of controlling the shape of the metal titanate particles, there is also a method of performing a dry mechanical treatment.

Hereinafter, the normal pressure heating reaction method will be described.

As the titanium oxide source, a mineral acid defoliated product of a hydrolyzate of a titanium compound is used. Preferably, the pH of metatitanic acid obtained by the sulfuric acid method having an SO ₃ content of 1.0% by mass or less, more preferably 0.5% by mass or less is adjusted to 0.8 or more and 1.5% or less with hydrochloric acid. Use the one that has been deflated. On the other hand, as a metal source other than titanium, metal nitrate or hydrochloride can be used.

As the nitrate, for example, strontium nitrate, magnesium nitrate, calcium nitrate and the like can be used. As the hydrochloride salt, for example, strontium chloride, magnesium chloride, calcium chloride and the like can be used. When manufactured using nitrates or hydrochlorides of strontium, calcium, and magnesium, the obtained metal titanate particles have a perovskite crystal structure, which is preferable in that the environmental stability of charging is further improved.

As the alkaline aqueous solution, caustic alkali can be used, but the sodium hydroxide aqueous solution is particularly preferable.

Factors that affect the particle size of the obtained metal titanate particles in the production method include the pH when thawing metatitanium acid with hydrochloric acid, the mixing ratio of the titanium oxide source and the metal source other than titanium, and the initial stage of the reaction. Examples include the titanium oxide source concentration, the temperature at which the alkaline aqueous solution is added, the addition rate, the reaction time, and the stirring conditions.

These factors can be appropriately adjusted to obtain metal titanate particles having a desired particle size and particle size distribution. In addition, it is preferable to prevent the mixing of carbon dioxide gas by reacting in a nitrogen gas atmosphere in order to prevent the formation of carbon dioxide in the reaction process.

The mixing ratio of the titanium oxide source and the metal source other than titanium at the time of the reaction is preferably 0.70 or more and 1.40 or less in terms of the molar ratio of M / Ti when the metal other than titanium is represented by M. It is more preferably 0.75 or more and 1.20 or less. When the M / Ti (molar ratio) is in the above range, the ratio of Ti that is close to negative charge in terms of charge increases, so that the charge distribution tends to be sharp and the charge distribution on the toner surface becomes uniform. , Electrostatic aggregation is suppressed.

The concentration of the titanium oxide source at the initial stage of the reaction is preferably 0.050 mol / L or more and 1.300 mol / L or less, and 0.080 mol / L or more and 1.200 mol / L or less as TiO ₂ . Is more preferable. By increasing the concentration of the titanium oxide source at the initial stage of the reaction, the number average particle size of the primary particles of the metal titanate particles can be reduced.

When the temperature at which the alkaline aqueous solution is added is 100 ° C. or higher, a pressure vessel such as an autoclave is required, and a practical range of 60 ° C. or higher and 100 ° C. or lower is appropriate.

As for the addition rate of the alkaline aqueous solution, the slower the addition rate, the larger the particle size of metal titanate particles can be obtained, and the faster the addition rate, the smaller the metal titanate particle size can be obtained. The addition rate of the alkaline aqueous solution is preferably 0.001 equivalent / h or more and 1.2 equivalent / h or less, and more preferably 0.002 equivalent / h or more and 1.1 equivalent / h or less with respect to the charged raw material. .. These can be appropriately adjusted according to the particle size to be obtained.

In the production method, it is preferable to further acid-treat the metal titanate particles obtained by the atmospheric heating reaction. When the titanium oxide source and the metal source other than titanium are mixed in the M / Ti (molar ratio) in excess of 1.40 when the titanium acid metal particles are produced by performing the atmospheric heating reaction, after the reaction is completed. The remaining unreacted metal source other than titanium reacts with carbon dioxide in the air to easily generate impurities such as metal carbonate. Further, if impurities such as metal carbonate remain on the surface, it becomes difficult to uniformly coat the surface treatment agent due to the influence of the impurities when performing the surface treatment for imparting hydrophobicity. Therefore, after adding the alkaline aqueous solution, it is advisable to carry out acid treatment in order to remove the unreacted metal source.

In the acid treatment, it is preferable to adjust the pH to 2.5 or more and 7.0 or less using hydrochloric acid, and more preferably to adjust the pH to 4.5 or more and 6.0 or less. As the acid, nitric acid, acetic acid and the like can be used for the acid treatment in addition to hydrochloric acid. When sulfuric acid is used, metal sulfate having low solubility in water is likely to be generated.

Next, shape control will be described. As a method for obtaining the shape of the metal titanate fine particles used in the present invention, dry mechanical treatment can be mentioned.

For example, a hybridizer (manufactured by Nara Machinery Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.), Mechanofusion (manufactured by Hosokawa Micron Co., Ltd.), Hiflex Gural (manufactured by EarthTechnica Co., Ltd.) and the like can be used. By treating the metal titanate fine particles with these devices, the surface treatability of the metal titanate can be improved. When the shape of the metal titanate fine particles is controlled by mechanical treatment, fine particles of the metal titanate fine particles may be generated. In order to remove fine powder, it is preferable to carry out acid treatment. In the acid treatment, it is preferable to adjust the pH to 0.1 or more and 5.0 or less using hydrochloric acid. As the acid, nitric acid, acetic acid and the like can be used for the acid treatment in addition to hydrochloric acid. It is preferable that the mechanical treatment for controlling the shape of the metal titanate fine particles is performed before the surface treatment of the metal titanate fine particles is applied.

[About external additives]
The toner of the present invention may contain an external additive other than the titanium acid metal fine particles. In particular, in order to improve the fluidity and chargeability of the toner, a fluidity improver may be added. The following can be used as the fluidity improver. Examples thereof include silica fine powders such as wet-processed silica and dry-processed silica, and treated silica obtained by surface-treating them with a silane compound or silicone oil.

When the number average particle size of the primary particles is 5 nm or more and 30 nm or less, the fluidity improver is preferable because it can have high chargeability and fluidity. Further, as the fluidity improver, treated silica fine powder obtained by hydrophobizing silica fine powder with silicone oil or / and a silane coupling agent is more preferable.

The fluidity improver preferably has a specific surface area of 30 m ² / g or more and 300 m ² / g or less due to nitrogen adsorption measured by the BET method. It is preferable to use 0.01 parts by mass or more and 3 parts by mass or less of the fluidity improver in total with respect to 100 parts by mass of the toner particles.

Examples of the mixer externally attached to the toner particles include FM mixer (manufactured by Nippon Coke Industries Co., Ltd.), super mixer (manufactured by Kawata Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.), and hybridizer (manufactured by Nara Machinery Co., Ltd.).

In addition, examples of the sieving device used for sieving the coarse particles after external addition include the following. Ultrasonic (manufactured by Koei Sangyo Co., Ltd.); Resona Sheave, Gyroshifter (manufactured by Tokuju Kosakusho); Vibrasonic System (manufactured by Dalton); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Turbo Cleaner (manufactured by Freund Turbo Industries) ); Micro shifter (manufactured by Makino Sangyo Co., Ltd.).

[Toner particle size]
The weight average particle size (D4) of the toner of the present invention is preferably 4.0 μm or more and 12.0 μm or less, and more preferably 4.0 μm or more and 9.0 μm or less. This is because if the weight average particle size is less than 4.0 μm, the specific surface area of the toner is large, so problems are likely to occur in durability and heat resistance during long-term use. It is not desirable because it is inferior in terms of coloring power and image resolution. The weight average particle size of the toner of the present invention can be adjusted by the production conditions and classification at the time of toner production.

The method for measuring various physical properties of the toner of the present invention will be described below.

<Method of isolating metal fine particles of titanium acid>
When measuring the physical properties of the metal titanate fine particles and the toner particles from the toner to which the metal titanate fine particles are externally attached, the metal titanate fine particles and other external additives can be separated from the toner and measured. The toner is ultrasonically dispersed in methanol to remove metal titanate fine particles and other external additives, and the mixture is allowed to stand for 24 hours. Toner particles can be isolated by separating and recovering the precipitated toner particles from the metal titanate fine particles and other external additives dispersed in the supernatant liquid and sufficiently drying them. Further, the metal titanate fine particles can be isolated by treating the supernatant liquid by centrifugation.

<Number average particle size of primary particles of metal titanate fine particles>
The number average particle size of the primary particles of the metal titanate fine particles is measured using a transmission electron microscope "JEM-2800" (JEOL Ltd.). By observing the toner to which the metal titanate fine particles are externally attached, the major axis of 100 primary particles of the metal titanate fine particles is randomly measured in a field magnified up to 200,000 times to obtain the number average particle size. The observation magnification is appropriately adjusted according to the size of the metal titanate fine particles. Confirmation that the external additive is metal titanate fine particles is carried out by STEM-EDS measurement.

The measurement conditions are as follows.
JEM2800 type transmission electron microscope: Acceleration voltage 200kV
EDS detector: JED-2300T (JEOL, element area 100mm ² ) is used. EDS analyzer: Noran System7 (Thermo Fisher Scientific) is used.
X-ray storage rate: 10,000 to 15,000 cps
Dead time: Adjust the electron dose to 20 to 30%, and perform EDS analysis (total number of times 100 times or measurement time 5 minutes).

<Identification of partial structure on the surface of metal titanate fine particles>
The identification of the partial structure on the surface of the metal titanate fine particles is performed by a time-of-flight secondary ion mass spectrometer (TOF-SIMS). The following device is used under the following conditions to identify the partial structure from the fragment peak of the surface layer of the metal titanate fine particles.
-Measuring device: TRIFT-IV (trade name, manufactured by ULVACFY Co., Ltd.)
・ Primary ion: Au3
-Raster size: 100 μm x 100 μm
・ Neutralizing electron gun: used

<Mole ratio of M / Ti of metal fine particles of titanium acid>
The M and Ti contents of the metal titanate fine particles used in the present invention can be measured by a fluorescent X-ray analyzer. For example, using a wavelength-dispersed X-ray fluorescence analyzer Axios advanced (manufactured by PANalytical), 1 g of a sample is weighed on a cup dedicated to powder measurement recommended by PANalytical with a special film attached, and the sample is weighed under an atmospheric pressure He atmosphere. In, the elements from Na to U in the metal titanate fine particles are measured by the FP method. At that time, assuming that all the detected elements are oxides, the total mass of them is 100%, and the content of MXO and TiO ₂ with respect to the total mass by software SpectraEvolution (version 5.0L) (mass%). ) Is calculated as an oxide conversion value. After that, M / Ti (mass ratio) obtained by removing oxygen from the quantification result is obtained, and then converted into M / Ti (molar ratio) from the atomic weight of each element.

<Measurement of diffraction peak of strontium titanate particles>
A powder X-ray diffractometer "SmartLab" (manufactured by Rigaku Co., Ltd., sample horizontal strong X-ray diffractometer) is used to measure the position of the diffraction peak of the strontium titanate particles.

Further, the calculation of Sb / Sa from the obtained peak uses "PDXL2 (version 2.2.2.0)" of the analysis software attached to the above apparatus.

As the measurement sample, toner or strontium titanate particles isolated from the toner are used, and the measurement is performed by the following procedure. In the following examples, the produced strontium titanate particles are also measured.

～ (Preparation of sample) ～
The measurement sample is measured after being uniformly placed in a 0.5 mm diameter Boro-Silicate capillary (manufactured by W. Muller).

~ (Measurement conditions) ~
・ Tube: Cu
-Optical system: CBO-E
・ Sample table: Capillary sample table ・ Detector: D / tex Ultra250 detector ・ Voltage: 45kV
・ Current: 200mA
・ Starting angle: 10 °
・ End angle: 60 °
・ Sampling width: 0.02 °
・ Speed measurement time setting value: 10
・ IS: 1mm
・ RS1: 20mm
・ RS2: 20mm
・ Attenuator: Open
・ Capillary rotation speed setting value: 100

For other conditions, the default values of the device are used.

~ (Analysis) ~
First, the obtained peak is subjected to peak separation processing using the software "PDXL2" attached to the apparatus. The peak separation is obtained by performing optimization using the "divided Voigt function" that can be selected by PDXL, and the obtained integrated intensity value is used.

This determines the 2θ value of the diffraction peak top and its area. Sb / Sa is calculated from the peak area of a predetermined 2θ value. At this time, if the calculation result of the peak separation and the measured spectrum are significantly different from each other, processing such as manually setting the baseline is performed to adjust so that the calculated result and the actually measured spectrum match.

<Degree of hydrophobicity of metal titanate fine particles>
The degree of hydrophobicity of the metal titanate fine particles was measured by a powder wettability tester "WET-100P" (manufactured by Reska).

A fluororesin-coated spindle-shaped rotor with a length of 25 mm and a maximum body diameter of 8 mm was placed in a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm. After putting 70 ml of a hydrous methanol solution consisting of 50% by volume of methanol and 50% by volume of water in the cylindrical glass container, 0.5 g of metal titanate fine particles were added and set in a powder wettability tester. Methanol was added to the liquid at a rate of 0.8 mL / min through the above powder wettability tester while stirring at a rotation speed of 3.3 times / sec using a magnetic stirrer. The transmittance was measured with light having a wavelength of 780 nm, and the value represented by the volume percentage of methanol when the transmittance reached 50% (= (volume of methanol / volume of mixture) × 100) was defined as the degree of hydrophobicity. .. The volume ratio of initial methanol to water is adjusted as appropriate according to the degree of hydrophobization of the sample.

<Measuring method of weight average particle size (D4) of toner particles>
The weight average particle size (D4) of the toner particles is calculated as follows. As the measuring device, a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter) equipped with a 100 μm aperture tube by the pore electric resistance method is used. For the setting of measurement conditions and the analysis of measurement data, the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) is used. The measurement is performed with 25,000 effective measurement channels. As the electrolytic aqueous solution used for the measurement, a special grade sodium chloride dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter) can be used.

Before performing the measurement and analysis, the dedicated software was set as follows. On the "Change standard measurement method (SOM)" screen of the dedicated software, set the total count number of the control mode to 50,000 particles, measure once, and set the Kd value to "standard particles 10.0 μm" (Beckman Coulter). Set the value obtained using (manufactured by the company). By pressing the "threshold / noise level measurement button", the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTON II, and check "Flash of aperture tube after measurement". On the "Pulse to particle size conversion setting" screen of the dedicated software, the bin spacing is set to logarithmic particle size, the particle size bin is set to 256 particle size bins, and the particle size range is set from 2 μm to 60 μm.

The specific measurement method is as follows.
(1) Put about 200 ml of the electrolytic aqueous solution in a 250 ml round bottom beaker made of glass dedicated to Multisizer 3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "aperture flash" function of the dedicated software.
(2) Put about 30 ml of the electrolytic aqueous solution in a 100 ml flat bottom beaker made of glass. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a pH 7 precision measuring instrument consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted about 3 times by mass with ion-exchanged water, and about 0.3 ml of the diluted solution is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with their phases shifted by 180 degrees, and an ultrasonic disperser "Ultrasonic Dispension System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W is prepared. About 3.3 liters of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of contaminantinone N is added into this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic solution in the beaker is maximized.
(5) With the electrolytic aqueous solution in the beaker of (4) being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. For ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.
(6) Using a pipette, drop the aqueous electrolyte solution of (5) in which toner is dispersed into the round-bottomed beaker of (1) installed in the sample stand, and adjust the measured concentration to about 5%. .. Then, the measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed by the dedicated software attached to the device, and the weight average particle size (D4) is calculated. The "average diameter" of the "analysis / volume statistical value (arithmetic mean)" screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Weight average molecular weight of polyester resin A>
The weight average molecular weight of the polyester resin A in the present invention can be obtained by the following operation.

After dissolving 0.03 g of polyester resin in 10 ml of o-dichlorobenzene, shaking at 135 ° C. for 24 hours with a shaker, filtering with a 0.2 μm filter, and using the filtrate as a sample, the following conditions Analyze at.

[Analysis conditions]
Separation column: Shodex (TSK GMHR-HHT20) x 2
Column temperature: 135 ° C
Mobile phase solvent: o-dichlorobenzene Mobile phase flow rate: 1.0 ml / min.
Sample concentration: Approximately 0.3%
Injection amount: 300 μl
Detector: Differential refractometer detector Shodex RI-71

In addition, in calculating the molecular weight of the sample, standard polystyrene resin (TSK standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- of Tosoh Corporation) 10. The molecular weight calibration curve created by F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500) is used.

<Acid value>
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 in the present invention is measured according to JIS K 0070-1992, but specifically, it is measured according to the following procedure.

Titration is performed using a 0.1 mol / l potassium hydroxide ethyl alcohol solution (manufactured by Kishida Chemical Co., Ltd.). The factor of the potassium hydroxide ethyl alcohol solution can be determined by using a potentiometric titration device (potentiometric titration measuring device AT-510 manufactured by Kyoto Electronics Manufacturing Co., Ltd.). Take 100 ml of 0.100 mol / l hydrochloric acid in a 250 ml tall beaker, titrate with the potassium hydroxide ethyl alcohol solution, and determine from the amount of the potassium hydroxide ethyl alcohol solution required for neutralization. As the above 0.100 mol / l hydrochloric acid, those prepared according to JIS K 8001-1998 are used.

The measurement conditions for acid value measurement are shown below.
Titration device: Potentiometric titration device AT-510 (manufactured by Kyoto Electronics Manufacturing Co., Ltd.)
Electrode: Composite glass electrode Double junction type (manufactured by Kyoto Electronics Manufacturing Co., Ltd.)
Control software for titrator: AT-WIN
Titration analysis software: Tview
The titration parameters and control parameters at the time of titration are as follows.
Titration parameters Titration mode: Blank Titration Titration style: Total titration Maximum titration quantification: 20 ml
Waiting time before titration: 30 seconds Titration direction: Automatic control Paramailer End point judgment potential: 30dE
End point judgment potential value: 50dE / dmL
End point detection judgment: Not set Control speed mode: Standard gain: 1
Data collection potential: 4 mV
Data collection Titration: 0.1 ml

main exam;
Weigh 0.100 g of the measurement sample into a 250 ml tall beaker, add 150 ml of a mixed solution of toluene / ethanol (3: 1), and dissolve over 1 hour. Titration is performed using the potassium hydroxide ethyl alcohol solution using the potentiometric titrator.

Blank test;
The same titration as the above operation is performed except that no sample is used (that is, only a mixed solution of toluene / ethanol (3: 1) is used).

Substitute the obtained result into the following formula to calculate the acid value.
A = [(CB) x f x 5.611] / S
(In the formula, A: acid value (mgKOH / g), B: addition amount of potassium hydroxide ethyl alcohol solution in blank test (ml), C: addition amount of potassium hydroxide ethyl alcohol solution in this test (ml), f: Factor of potassium hydroxide solution, S: Sample (g).)

<Method of calculating the content ratio of polyester resin A and styrene acrylic resin to the resin in the toner particles, and the method of calculating the content ratio of the unit derived from alcohol or carboxylic acid having an alicyclic structure in polyester resin A>
A pyrolysis gas chromatography-mass spectrometer (hereinafter referred to as thermal decomposition GC / MS) and NMR are used to analyze the content ratio of the resin and the content ratio of the unit derived from alcohol or carboxylic acid having an alicyclic structure. .. In the present invention, a component having a molecular weight of 1500 or more is targeted for measurement. This is because the region having a molecular weight of less than 1500 is considered to be a region in which the proportion of the release agent is high and the resin is hardly contained.

In pyrolysis GC / MS, it is possible to determine the constituent monomers of the total amount of resin in the toner particles and determine the peak area of each monomer. Is required. On the other hand, in NMR, it is possible to determine and quantify the constituent monomers without using a sample having a known concentration. Therefore, depending on the situation, the constituent monomers are determined by comparing the spectra of both NMR and pyrolysis GC / MS.

Specifically, when the amount of the resin component insoluble in deuterated chloroform, which is the extraction solvent at the time of NMR measurement, is less than 5.0% by mass, quantification is performed by NMR measurement.

On the other hand, when 5.0% by mass or more of a resin component insoluble in deuterated chloroform, which is an extraction solvent at the time of NMR measurement, is present, NMR and thermal decomposition GC / are obtained with respect to the deuterated chloroform-soluble component. Both measurements of MS are performed, and thermal decomposition GC / MS is measured for deuterated chloroform insoluble matter. In this case, first, NMR measurement of the deuterated chloroform-soluble component is performed, and the constituent monomers are determined and quantified (quantification result 1). Next, pyrolysis GC / MS measurement is performed on the deuterated chloroform-soluble content, and the peak area of the peak attributed to each constituent monomer is determined. Using the quantitative result 1 obtained by NMR measurement, the relationship between the amount of each constituent monomer and the peak area of pyrolysis GC / MS is determined. Next, pyrolysis GC / MS measurement of deuterated chloroform insoluble matter is performed, and the peak area of the peak attributed to each constituent monomer is determined. Based on the relationship between the amount of each constituent monomer obtained by measuring the deuterated chloroform soluble content and the peak area of pyrolysis GC / MS, the constituent monomers in the deuterated chloroform insoluble content are quantified (quantitative result 2). .. Then, the quantification result 1 and the quantification result 2 are combined to obtain the final quantification result of each constituent monomer. Specifically, the following operations are performed.

(1) 500 mg of toner particles are precisely weighed in a 30 mL glass sample bottle, 10 mL of deuterated chloroform is added, the lid is closed, and the mixture is dispersed and dissolved by an ultrasonic disperser for 1 hour. Then, the filtrate is collected by filtering with a membrane filter having a diameter of 0.4 μm. At this time, the deuterated chloroform insoluble matter remains on the membrane filter.

(2) Collect 3 mL of the filtrate using high efficiency liquid chromatography (HPLC) to collect the resin solution from which the components having a molecular weight of less than 1500 have been removed by a fraction collector and the components having a molecular weight of less than 1500 have been removed. Chloroform is removed from the recovered solution using a rotary evaporator to obtain a resin. If the molecular weight is less than 1500, it is determined by measuring the polystyrene resin having a known molecular weight in advance and obtaining the elution time.

(3) 20 mg of the obtained resin is dissolved in 1 mL of deuterated chloroform, 1H-NMR measurement is performed, spectra are assigned to each constituent monomer in the resin, and quantitative values are obtained.

(4) If deuterated chloroform insoluble content needs to be analyzed, it is analyzed by thermal decomposition GC / MS. If necessary, derivatization treatment such as methylation is performed.

<Measurement conditions for NMR>
Bruker AVANCE 500 manufactured by Bruker Biospin Co., Ltd.
Measurement nucleus: 1H
Measurement frequency: 500.1MHz
Number of integrations: 16 times Measurement temperature: Room temperature

<Measurement conditions for pyrolysis GC / MS>
Pyrolysis device: TPS-700 manufactured by Nippon Analytical Industry Co., Ltd.
Pyrolysis temperature: Appropriate value at 400 ° C to 600 ° C, 590 ° C in this case
GC / MS device: ISQ manufactured by Thermo Fisher Scientific Co., Ltd.
Column: "HP5-MS" (Agilent / 19091S-433), length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm
GC / MS condition Injection port condition:
InletTemp: 250 ° C,
SpiritFlow: 50mL / min
GC temperature rise condition: 40 ° C (5 min) → 10 ° C / min (300 ° C) → 300 ° C (20 min)

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

An example of manufacturing the polyester resin A in the present invention is described below.

<Manufacturing of polyester resin 1>
A nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple are equipped with 100 parts by mass of a mixture in which raw material monomers are mixed at the charging ratio shown in Table 1 and 0.55 parts by mass of di (2-ethylhexanoic acid) tin as a catalyst. The mixture was placed in a 6-liter four-necked flask and reacted at 200 ° C. for 6 hours under a nitrogen atmosphere. Further, trimellitic anhydride was added at 210 ° C., and the reaction was carried out under a reduced pressure of 40 kPa, and the reaction was continued until the weight average molecular weight (Mw) reached 12000. The obtained polyester resin A is referred to as polyester resin 1.

The composition of the polyester resin 1 was analyzed, and the ratio of the units derived from the isosorbide monomer was determined. Table 1 shows the ratio and acid value of the isosorbide unit in the polyester resin 1.

The composition analysis of the polyester resin 1 was performed by 1H-NMR. The specific measurement method is as follows.
Measuring device: FT NMR device JNM-EX400 (manufactured by JEOL Ltd.)
Measurement frequency: 400MHz
Pulse condition: 5.0 μs
Frequency range: 10500Hz
Number of integrations: 64 times Measurement temperature: 30 ° C

50 mg of the sample is placed in a sample tube having an inner diameter of 5 mm, deuterated chloroform (CDCl ₃ ) is added as a solvent, and this is dissolved in a constant temperature bath at 40 ° C. to prepare a measurement sample. The measurement was performed under the above conditions using the measurement sample.

<Manufacturing of polyester resins 2 to 6>
The polyester resins 2 to 6 were produced in the same manner as the polyester resin 1 except that the amounts of the acid component and the alcohol component charged were changed as shown in Table 1. Table 1 shows the physical characteristics of the polyester resins 2 to 6.

ＴＰＡ：テレフタル酸
ＴＭＡ：トリメリット酸
ＢＰＡ（ＰＯ２）：ビスフェノールＡのプロピレンオキサイド２ｍｏｌ付加物
ＥＧ：エチレングリコール
ＣＨＤＭ：１，４－シクロヘキサンジメタノール

TPA: Terephthalic acid TMA: Trimellitic acid BPA (PO2): 2 mol propylene oxide adduct of bisphenol A EG: Ethylene glycol CHDM: 1,4-Cyclohexanedimethanol

An example of producing the metal titanate fine particles in the present invention is described below.

<Production example of metal titanium acid fine particles 1>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanium acid slurry in an amount of 2.16 mol so that the Sr / Ti molar ratio was 1.15, and then the TiO ₂ concentration was adjusted to 1.039 mol / L. Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 N mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., and hydrochloric acid was added to adjust the pH to 2.5. Next, 4.6% by mass of isobutyltrimethoxysilane and 4.6% by mass of trifluoropropyltrimethoxysilane were added by stirring and mixing for 1 hour with respect to the solid content, and the stirring and holding was continued for 10 hours. After adding a 5N sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours. The obtained metal titanate fine particles are referred to as metal titanate fine particles 1. Table 2 shows the physical characteristics of the obtained metal titanate fine particles.

<Production example of metal titanium acid fine particles 2>
For Production Example 1 of strontium titanate particles, the TiO ₂ concentration to be adjusted after adding 2.16 mol of an aqueous solution of strontium chloride to a deflated metatitanium acid slurry so as to have an Sr / Ti molar ratio of 1.15 is 1. The same operation was performed except that the concentration was adjusted to 0.083 mol / L to obtain metal titanate fine particles 2.

<Production example of metal titanium acid fine particles 3>
With respect to Production Example 1 of strontium titanate particles, 2.54 mol of an aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry so that the Sr / Ti molar ratio was 0.941, 10 mol / L. The same operation was carried out except that 440 mL of the sodium hydroxide aqueous solution was added over "45 minutes" over "50 minutes" to obtain metal titanate fine particles 3.

<Production example of metal titanium acid fine particles 4>
With respect to Production Example 1 of strontium titanate particles, 2.54 mol of an aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry so that the Sr / Ti molar ratio was 0.933, 10 mol / L. The same operation was carried out except that 440 mL of the sodium hydroxide aqueous solution was added over "45 minutes" over "60 minutes" to obtain metal titanate fine particles 4.

<Production example of metal titanium acid fine particles 7>
With respect to Production Example 1 of strontium titanate particles, 2.54 mol of an aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry so that the Sr / Ti molar ratio was 0.927, 10 mol / L. The same operation was carried out except that 440 mL of the sodium hydroxide aqueous solution was added over "45 minutes" and then over "70 minutes" to obtain strontium titanate fine particles 7.

<Production example of metal titanium acid fine particles 8>
With respect to Production Example 1 of strontium titanate particles, 2.01 mol of an aqueous solution of strontium chloride was added to the glycated metatitanic acid slurry so that the Sr / Ti molar ratio was 1.07, with respect to the solid content. From 4.6% by mass of isobutyltrimethoxysilane and 4.6% by mass of trifluoropropyltrimethoxysilane to 1.0% by mass of isobutyltrimethoxysilane and 3.0% by mass of trifluoropropyltrimethoxysilane. The same operation was carried out except that the strontium acid metal fine particles 8 were obtained.

<Production example of metal titanium acid fine particles 9>
With respect to Production Example 1 of strontium titanate particles, 2.54 mol of an aqueous solution of strontium chloride was added to the glycated metatitanic acid slurry so that the Sr / Ti molar ratio was 1.35, with respect to the solid content. From 4.6% by mass of isobutyltrimethoxysilane and 4.6% by mass of trifluoropropyltrimethoxysilane to 7.5% by mass of isobutyltrimethoxysilane and 6.9% by mass of trifluoropropyltrimethoxysilane. The same operation was performed except for making silane, to obtain metal titanate fine particles 9.

<Production example of metal titanium acid fine particles 10>
The same operation was carried out for Production Example 1 of strontium titanate particles except that the place where the strontium chloride aqueous solution was added to the deflated metatitanic acid slurry was changed to magnesium chloride to obtain metal titanate fine particles 10.

<Production example of metal titanium acid fine particles 11>
In the production example of the strontium titanate particles 1, 2.03 mol of the strontium chloride aqueous solution was added to the deflated metatitanium acid slurry so as to have an Sr / Ti molar ratio of 1.08, and the metal titanate fine particles 11 were similarly added. Got

<Production example of metal titanium acid fine particles 12>
In the production example of the strontium titanate particles 1, the metal titanate fine particles 12 were obtained in the same manner except that the TiO ₂ concentration was adjusted to 1.039 mol / L after adding the strontium chloride aqueous solution to the deflated metatitanic acid slurry. ..

<Production Example of Metal Titanate Fine Particles 13>
Hydrolyzed titanium hydroxide obtained by adding aqueous ammonia to the titanium tetrachloride aqueous solution was washed with pure water, and 0.25% sulfuric acid was added as SO ₃ to the titanium hydroxide slurry to the titanium hydroxide slurry. bottom.

Next, hydrochloric acid was added to the hydroxide-containing titanium slurry to adjust the pH to 0.65 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 4.7, and washing was repeated until the electrical conductivity of the supernatant reached 50 μS / cm.

A 0.95 times molar amount of strontium hydroxide octahydrate was added to the titanium hydroxide-containing titanium, and the mixture was placed in a SUS stainless steel reaction vessel and replaced with nitrogen gas. Further, distilled water was added so as to be 0.6 mol mol / liter L in terms of SrTiO ₃ .

The slurry was heated to 65 ° C. at 10 ° C./hour in a nitrogen atmosphere, and the reaction was carried out for 8 hours after reaching 65 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and then washing with pure water was repeated.

Further, under a nitrogen atmosphere, the above slurry was placed in an aqueous solution in which 2% by mass of sodium stearate was dissolved with respect to the solid content of the slurry, and a magnesium sulfate aqueous solution was added dropwise with stirring to add stearic acid to the surface of the perovskite-type crystal. Magnesium was precipitated.

The slurry was repeatedly washed with pure water and then filtered through Nutche, and the obtained cake was dried to obtain metal titanate fine particles 13 surface-treated with magnesium stearate.

<Manufacturing example of titanium oxide 1>
As a starting material, ilmenite ore containing 50% by mass of TiO ₂ equivalent was used. After drying this raw material at 150 ° C. for 2 hours, sulfuric acid was added and dissolved to obtain an aqueous solution of TiOSO ₄ . This was concentrated, 4.5 parts by mass was added using titania sol having rutile crystals as a seed, and then hydrolysis was carried out at 110 ° C. to obtain a slurry of TiO (OH) ₂ containing impurities. This slurry was repeatedly washed with water at pH 5 to 6 to sufficiently remove sulfuric acid, FeSO ₄ , and impurities. Then, a slurry of high-purity metatitanic acid [TiO (OH) ₂ ] was obtained. This slurry was filtered and fired at 180 ° C. for 2 hours, and then repeatedly crushed by a jet mill until the aggregates of fine particles disappeared. This titanium oxide is dispersed in ethanol, and 4.6% by mass of isobutyltrimethoxysilane and 4.6% by mass of trifluoropropyltrimethoxysilane are combined with respect to 100 parts by mass of the solid content of titanium oxide. The mixture was dropped and mixed with sufficient stirring so as not to cause the above-mentioned reaction. Further, the pH of the slurry was adjusted to 6.5 with sufficient stirring.

This was filtered and dried, and then heat-treated at 170 ° C. for 2 hours, and then repeatedly crushed by a jet mill until the agglomerates of titanium oxide disappeared to obtain titanium oxide particles 1.

Table 2 shows the physical properties of the obtained metal titanate fine particles 1 to 4, 7 to 13, and titanium oxide 1.

An example of manufacturing toner particles in the present invention is described below.

<Manufacturing example of toner particles 1>
With respect to 100 parts by mass of the styrene monomer, C.I. I. Pigment Blue 15: 3 was prepared in an amount of 16.5 parts by mass, and an aluminum compound of the tertiary butyl salicylic acid [Bontron E88 (manufactured by Orient Chemical Industry Co., Ltd.)] was prepared in an amount of 3.0 parts by mass. 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) having a radius of 1.25 mm to prepare a masterbatch dispersion liquid 1. ..

On the other hand, 450 parts by mass of 0.1 M-Na _{3PO 4 aqueous} solution was added to 710 parts by mass of ion-exchanged water and heated to 60 ° C., and then 67.7 parts by mass of 1.0 M-CaCl ₂ aqueous solution was gradually added. An aqueous medium containing a calcium phosphate compound was obtained.

・ Masterbatch dispersion 1 40 parts by mass ・ Styrene monomer 49.5 parts by mass ・ n-butyl acrylate monomer 16.5 parts by mass ・ Hydrocarbon wax 9 parts by mass (Fishertropsh wax, peak of maximum heat absorption peak Temperature = 78 ° C, Mw = 750)
1 5.0 parts by mass of polyester resin The above material was heated to 65 ° C. and uniformly dissolved and dispersed at 5,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). A polymerizable monomer composition was prepared by dissolving 7.1 parts by mass of a 70% toluene solution of the polymerization initiator 1,1,3,3-tetramethylbutylperoxy2-ethylhexanoate.

The polymerizable monomer composition is put into the aqueous medium and stirred at 12,000 rpm for 10 minutes with a TK homomixer in an N ₂ atmosphere at a temperature of 65 ° C. to obtain the polymerizable monomer composition. Granulated. Then, the temperature was raised to 67 ° C. while stirring with a paddle stirring blade, and when the polymerization conversion rate of the polymerizable vinyl-based monomer reached 90%, a 0.1 mol / liter sodium hydroxide aqueous solution was added. The pH of the aqueous dispersion medium was adjusted to 9. Further, the temperature was raised to 80 ° C. at a heating rate of 40 ° C./h, and the reaction was carried out 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 salt. The toner particles were separated by filtration, washed with water, and then dried at a temperature of 40 ° C. for 48 hours. The obtained dried product is rigorously classified and removed at the same time with an elbow jet classifier manufactured by Nittetsu Mining Co., Ltd., and has a cyan color with a weight average particle size (D4) of 6.3 μm. Toner particles 1 were obtained.

<Manufacturing example of toner particles 2 to 10>
Toner particles 2 to 10 were obtained in the same manner as in the production example of toner particles 1, except that the type of polyester resin A used and the amount of polyester resin A added were changed as shown in Table 3. Table 3 shows the weight average particle diameter D4 of the obtained toner particles.

An example of manufacturing the toner of the present invention will be described below.

<Manufacturing example of toner 1>
An example of manufacturing the toner of the present invention is described below.

In the toner particles 1, as shown in Table 4, 1.0 part by mass of RX300 (manufactured by Nippon Aerodil Co., Ltd.), which is silica fine particles, and 0.2 parts by mass of titanium acid metal fine particles 1 with respect to 100 parts by mass of toner particles. , Henshell mixer FM10C (manufactured by Mitsui Mining Co., Ltd.) and dry-mixed for 12 minutes under the condition of 3600 rpm to obtain toner 1.

<Manufacturing examples of toners 2 to 6, 9 to 27>
In the production example of the toner 1, the external addition was performed in the same manner except that the type of the toner particles, the type of the external additive, and the addition amount were changed by the combinations shown in Table 4. The toners produced in this manner were designated as toners 2 to 6 and 9 to 27.

[Example 1]
Toner 1 was evaluated for the following items. The evaluation results are shown in Table 5.

<Evaluation machine>
At the time of evaluation, a modified machine of LBP712Ci (manufactured by Canon Inc.) was used as an evaluation machine. The process speed of the main body was modified to 280 mm / sec. Then, necessary adjustments were made so that image formation was possible under these conditions. In addition, the toner was filled in a predetermined cartridge. As the evaluation paper, CS-680 sold by Canon Marketing Japan was used.

<In-flight pollution>
The contamination around the fuser was visually evaluated.

The durability evaluation chart uses an original chart with a printing rate of 5% for each color (full color printing rate of 20%). Cartridges refilled with toner 1 are attached to all stations of yellow, magenta, cyan, and black, and each time the toner runs out. The cartridge was replaced and printing was continued.

The conditions for the durability test are plain paper under high temperature and high humidity environment (30 ° C, 80% RH), normal temperature and humidity environment (23 ° C, 50% RH), and low temperature and low humidity environment (15 ° C, 10% RH). A total of 500,000 print tests were performed in the mode.

The state of contamination around the fuser after durability was visually evaluated according to the following criteria.
A: No noticeable contamination is found around the fuser.
B: A small amount of contamination is observed around the fuser.
C: The spread of contamination is clearly observed in the fixing guide portion for guiding the paper to the nip between the fixing member and the pressure member.
D: A considerable amount of contamination is conspicuous around the fuser, and image omission occurs.

<Poor regulation>
The evaluation of poor regulation was carried out in a low temperature and low humidity environment (temperature 15 ° C., relative humidity 10%), which is strict for charge-up. Assuming a long-term durability test, the horizontal line pattern with a print rate of 1% was set as 2 sheets / job, and the machine was temporarily stopped between jobs before the next job started. In the above mode, a total of 17,000 images were subjected to an image ejection test, and images were visually confirmed by the 15,000th image every 500 images. The evaluation was made as follows according to the number of sheets until the image became uneven due to the toner that could not be regulated on the toner carrier due to poor regulation of the toner regulating member and the toner carrier.
A: No occurrence.
B: Occurs from 16001 to 17000th sheet.
C: Occurs from 15001 to 16000th.
D: Occurs up to the 15000th sheet.

<Left fog>
The evaluation of the abandoned fog was carried out in a high-temperature and high-humidity environment (temperature 30 ° C., relative humidity 80%) in which the rising property of charging was disadvantageous. First, an all-white image was printed on a piece of paper with Post-it around the bottom center, and the density difference between the part hidden by Post-it and the part not covered by Post-it was used as the initial fog value. Assuming a long-term durability test, the horizontal line pattern with a print rate of 1% was set as 2 sheets / job, and the machine was temporarily stopped between jobs before the next job started. In this mode, a total of 15,000 image extraction tests were performed, the machine was turned off for 72 hours immediately after the 15,000 image output was completed, and the developer was left in the machine. After leaving the machine, the power of the machine was turned on again, an image similar to the initial fog was printed, and the density difference was used as the value of the left fog. A reflection densitometer (reflect meter model TC-6DS manufactured by Tokyo Denshi Co., Ltd.) was used, and an amber light filter was used as the filter. The evaluation criteria were set as follows.
A: Less than 2.0 B: 2.0 or more and less than 3.0 C: 3.0 or more and less than 4.0 D: 4.0 or more

[Examples 2 to 6, 9 to 21, Comparative Examples 1 to 6]
Toners 2 to 6 and 9 to 27 were evaluated by the above evaluation method. The evaluation results are shown in Table 5.

Claims (6)

Toner particles having a core containing a binder resin and a shell existing on the surface of the core , and
Titanate metal fine particles and
Toner with
The toner particles contain a hydrocarbon wax and
The shell contains polyester resin A and contains
The polyester resin A has a unit derived from an alcohol having an isosorbide structure or a carboxylic acid having an isosorbide structure, and the alcohol having the isosorbide structure and the carboxylic acid having the isosorbide structure with respect to the total number of units constituting the polyester resin A. The ratio of the number of units derived from acid is 0.10% or more and 20.00% or less.
The metal titanate fine particles are
(I) Number of primary particles The average particle size is 10 nm or more and 100 nm or less .
( Ii) Perovskite crystal structure ,
( Iii) In the methanol wettability test, the methanol concentration was 30.0% or more and 60.0% or less when the transmittance of light having a wavelength of 780 nm was 50% .
(Iv) Fine particles treated with a compound having a structure represented by the following formula (2) .
Toner characterized by that.

(In the formula (2), Rg represents an alkyl fluoride group having 1 or more and 10 or less carbon atoms, and Rh represents a hydrogen atom or an alkoxy group having 1 or more and 3 or less carbon atoms.) The toner makes the metal titanate fine particles 0. With respect to 100 parts by mass of the toner particles. The toner according to claim 1, which contains 01 part by mass or more and 2.00 parts by mass or less . The toner particles add the polyester resin A to 100.0 parts by mass of the binder resin. The toner according to claim 1 or 2, which contains 0 parts by mass or more and 20.0 parts by mass or less. The toner according to any one of claims 1 to 3 , wherein the metal titanate fine particles have an average number of primary particles of 10 nm or more and 80 nm or less. The toner according to any one of claims 1 to 4 , wherein the metal titanate fine particles are strontium titanate fine particles. The strontium titanate fine particles have a peak derived from the strontium titanate particles of 39.700 ° in the X-ray diffraction spectrum of CuKα obtained in the range where 2θ is 10 ° or more and 90 ° or less when the Bragg angle is θ. It has ± 0.150 ° and 46.200 ° ± 0.150 °, the peak area of 39.700 ° ± 0.150 ° is Sa, and the peak area of 46.200 ° ± 0.150 ° is Sb. The toner according to claim 5 , wherein Sb / Sa is 1.80 or more and 2.30 or less.