JP2014063000A - Toner for electrostatic charge image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development capable of ensuring low-temperature fixability, and forming images with low glossiness.SOLUTION: A toner for electrostatic charge image development comprises toner particle including core particles and shell layers formed on the core particles. The shell layers contain a chelate compound.

Description

  The present invention relates to an electrostatic charge image developing toner used for electrophotographic image formation.

  In recent years, in consideration of the global environment, reduction of power consumption of an image forming apparatus has been studied, and in particular, a technique for reducing power consumption of a fixing device has been studied. As one of the technologies for realizing energy saving of such a fixing device, there is a so-called low-temperature fixing technology in which toner is melted at a lower heating temperature than in the past. By reducing the warm-up time from the standby state by low-temperature fixing, it is possible to save energy in the fixing device. From this point of view, low-temperature fixing compatible toners in which the glass transition temperature and molecular weight of the toner resin are set to be low have been studied.

  However, a toner whose glass transition temperature and molecular weight of the toner resin are set to be low tends to deteriorate the heat-resistant storage property, and easily causes a phenomenon of blocking in which the toners in the storage state are fixed and aggregated. Therefore, a toner having a core-shell structure in which a shell layer made of a resin having a high glass transition temperature is formed on the core particle surface made of a resin having a low glass transition temperature has been proposed (for example, a patent). Reference 1).

  On the other hand, a toner having a low temperature fixing has a problem that a low gloss image cannot be obtained because the softening point of the toner resin is lowered.

JP 2002-116574 A

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a toner for developing an electrostatic image capable of ensuring low-temperature fixability and forming a low gloss image. There is.

The electrostatic image developing toner of the present invention comprises toner particles in which a shell layer is formed on core particles,
The shell layer contains a chelate compound represented by the following general formula (1).

[In the general formula (1), M represents a divalent metal ion, and R ¹ , R ^2, and R ³ represent a hydrogen atom, an electron-withdrawing group, or a straight-chain or branched carbon, respectively. An alkyl group, an alkenyl group, an alkoxy group or an alkenyloxy group represented by formulas 12 to 22 is shown. However, at least one of R ¹ , R ² and R ³ is an electron withdrawing group, and the sum of the substituent constants (σp value) of the electron withdrawing group is 0.4 to 4.0. And at least one of R ¹ , R ² and R ³ is a linear or branched alkyl group having 12 to 22 carbon atoms, an alkenyl group, an alkoxy group or an alkenyloxy group. ]

In the electrostatic image developing toner of the present invention, M in the general formula (1) is preferably Cu ²⁺ , Ni ²⁺ or Zn ²⁺ .

In the electrostatic image developing toner of the present invention, at least one of R ¹ , R ² and R ³ in the general formula (1) is a cyano group, a nitro group, a dichloromethyl group, a dibromomethyl group, an alkoxy group. An electron withdrawing group selected from an acyl group, an acyl group, and an aromatic ring having these substituents is preferable.

  In the toner for developing an electrostatic charge image of the present invention, the chelate compound represented by the general formula (1) is preferably contained in the toner particles in a proportion of 1 to 8% by mass.

In the electrostatic image developing toner of the present invention, at least one of R ¹ , R ² and R ³ in the general formula (1) is a linear or branched alkyl group having 15 to 20 carbon atoms, alkenyl. It is preferably a group, an alkoxy group or an alkenyloxy group.

In the electrostatic image developing toner of the present invention, the resin constituting the core particles is a styrene-acrylic copolymer resin,
The resin constituting the shell layer is preferably a polyester resin.

  In the electrostatic image developing toner of the present invention, the polyester resin constituting the shell layer is one in which a styrene-acrylic copolymer segment is bonded to the end of the polyester segment, and the styrene-acrylic modified polyester resin It is preferable that the content rate of the styrene-acrylic copolymer segment in is 5 mass% or more and 30 mass% or less.

  According to the electrostatic image developing toner of the present invention, the shell layer having the core-shell structure contains the chelate compound represented by the general formula (1) (hereinafter also referred to as “specific chelate compound”). While ensuring low temperature fixability, a low gloss image can be formed.

  Hereinafter, the present invention will be described in detail.

[Toner for electrostatic image development]
The toner of the present invention comprises toner particles having a core-shell structure in which a shell layer is formed on core particles, and the shell layer contains a chelate compound represented by the above general formula (1).

[Core particles]
The core particles constituting the toner particles according to the present invention contain at least a resin (hereinafter also referred to as “core resin”), and contain internal additives such as a colorant, a release agent, and a charge control agent. It may be.

  The core resin is not particularly limited, and for example, acrylic resins made of polymers such as styrene resins, alkyl acrylates, and alkyl methacrylates, styrene-acrylic copolymer resins, and the like can be used. Among these, styrene-acrylic copolymer resins are preferable from the viewpoint of ease of precision synthesis and cost.

  Examples of the polymerizable monomer used for forming the styrene resin include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, and p-ethyl. Styrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene And styrene and derivatives thereof. Examples of the polymerizable monomer used to form the acrylic resin include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, Methacrylic acid esters such as n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, and derivatives thereof; methyl acrylate, acrylic acid Ethyl, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylic acid Uril and acrylic acid esters and their derivatives, such as phenyl acrylate. Examples of the polymerizable monomer for forming the styrene-acrylic copolymer resin include styrene and derivatives thereof, methacrylic acid esters and derivatives thereof, acrylic acid esters and derivatives thereof, and the like. These can be used alone or in combination of two or more.

  The core particle may have a structure of two or more layers made of resins having different compositions.

The glass transition point of the core resin is preferably 30 to 70 ° C, more preferably 40 to 60 ° C.
In the present invention, the glass transition point of the core resin is measured using a differential scanning calorimeter “Diamond DSC” (manufactured by Perkin Elmer).
Specifically, 4.5 mg of the sample (core resin) is precisely weighed to two digits after the decimal point, sealed in an aluminum pan, and set in a DSC-7 sample holder. For the reference, an empty aluminum pan was used, and heat-cool-heat temperature control was performed at a measurement temperature of 0 to 200 ° C., a temperature increase rate of 10 ° C./min, and a temperature decrease rate of 10 ° C./min. Analysis is performed based on the data in Heat. The glass transition point is the value of the intersection of the baseline extension before the first endothermic peak rises and the tangent line that shows the maximum slope between the first endothermic peak rising portion and the peak apex.

The softening point of the core resin is preferably 80 to 140 ° C, more preferably 100 to 120 ° C.
In the present invention, the softening point of the core resin is measured as follows.
First, in an environment of 20 ° C. ± 1 ° C. and 50% ± 5% RH, 1.1 g of a sample (core resin) is placed in a petri dish and flattened and left to stand for 12 hours or more. Then, a molding machine “SSP-10A” (Shimadzu Corporation) pressurizes with a force of 3820 kg / cm ² for 30 seconds to make a cylindrical molded sample with a diameter of 1 cm, and then this molded sample is 24 ° C. ± 5 ° C., 50% ± 20% RH Under the environment, the hole of the cylindrical die was measured with a flow tester “CFT-500D” (manufactured by Shimadzu Corporation) under the conditions of a load of 196 N (20 kgf), a starting temperature of 60 ° C., a preheating time of 300 seconds, and a heating rate of 6 ° C./min. (1 mm diameter × 1 mm) from the end of preheating using a piston with a diameter of 1 cm, and the offset method temperature T _offset measured at the offset temperature setting of 5 mm in the temperature rise method melting temperature measurement method is The softening point of a resin.

The weight average molecular weight of the core resin is preferably 20000 to 35000, more preferably 25000 to 30000.
In the present invention, the weight average molecular weight of the core resin is measured by gel permeation chromatography (GPC). Specifically, using an apparatus “HLC-8220” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZM-M3 series” (manufactured by Tosoh Corporation), while maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) was used as a carrier solvent. The sample was poured at a flow rate of 0.2 mL / min, and the sample (core resin) was dissolved in THF to a concentration of 1 mg / mL under a dissolution condition in which treatment was performed for 5 minutes using an ultrasonic disperser at room temperature. A sample solution is obtained by processing with a 2 μm membrane filter, 10 μL of this sample solution is injected into the apparatus together with the carrier solvent, and detected using a refractive index detector (RI detector), and the molecular weight distribution of the sample is determined. It is calculated using a calibration curve measured using monodisperse polystyrene standard particles. Ten polystyrenes are used for calibration curve measurement.

  As the colorant in the case where the core particle is configured to contain a colorant, a pigment is preferably used from the viewpoint of incorporation of the colorant into the toner resin. For example, carbon black, C.I. I. Pigment Red 5, 48: 1, 48: 3, 53: 1, 57: 1, 81: 4, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31 and 43, C.I. Pigment Yellow 14, 17, 17, 74, 93, 94, 138, 139, 155, 180, 185, C.I. I. Pigment green 7, C.I. Pigment Blue 15: 3, 15: 4, 60, and the like can be used. These can be used alone or in combination of two or more. Among these, from the viewpoint of color gamut, carbon black, C.I. Pigment Yellow 74, C.I. Pigment Red 122, C.I. I. Pigment Blue 15: 3 is preferably used.

  The content of the colorant is preferably 4 to 10% by mass in the toner particles, and more preferably 5 to 9% by mass.

[Shell layer]
The shell layer constituting the toner particles according to the present invention is formed on the core particles, and is at least a resin (hereinafter also referred to as “shell resin”) and a chelate compound represented by the above general formula (1). May be contained, and internal additives such as a colorant, a release agent, and a charge control agent may be contained. Examples of the colorant include the same colorants as those contained in the above core particles.

The shell resin is not particularly limited, but it is preferable to use a polyester resin from the viewpoint of ensuring low-temperature fixability. Particularly, a resin having a styrene-acrylic copolymer segment bonded to the end of the polyester segment (hereinafter referred to as “shell resin”). , Also referred to as “styrene-acryl-modified polyester resin”).
By using a styrene-acryl-modified polyester resin as the shell resin, the following effects can be obtained.
That is, in general, the advantage of using a polyester resin as a binder resin in the design of toner particles is that the polyester resin maintains a high glass transition point (Tg) as compared with the styrene-acrylic copolymer resin. This is because it is easy to design. That is, the polyester resin is a suitable resin for satisfying both low-temperature fixability and heat-resistant storage stability. Then, by introducing a styrene-acrylic copolymer segment into the polyester resin used for the shell layer, the affinity of the core particle with the styrene-acrylic resin of the core particle is maintained while maintaining the high glass transition point and low softening point of the polyester resin. Thus, it is possible to form a shell layer having a more uniform film thickness and a smooth surface while being a thin layer. Therefore, according to the toner of the present invention, both low-temperature fixability and heat-resistant storage stability are satisfied, and excellent chargeability is obtained. Further, since the shell layer is hardly peeled off, the toner is stirred in the developing device. Thus, sufficient resistance to crushing can be obtained without being crushed even when stressed.

In the present invention, the content ratio of the styrene-acrylic copolymer segment in the styrene-acrylic modified polyester resin (hereinafter, also referred to as “styrene-acrylic modification amount”) is 5% by mass or more and 30% by mass or less. In particular, the content is preferably 5% by mass or more and 20% by mass or less.
Specifically, the amount of styrene-acryl modification is the total mass of the resin material used to synthesize the styrene-acryl modification polyester resin, that is, the unmodified polyester resin that becomes the polyester segment, and the styrene-acrylic copolymer weight. Aromatic vinyl monomer and (meth) acrylic acid ester monomer serving as a coalesced segment, and the total mass of both reactive monomers for bonding these aromatic vinyl monomer and ( It refers to the mass ratio of the (meth) acrylic acid ester monomer.

  When the amount of styrene-acrylic modification is in the above range, the affinity between the styrene-acrylic modified polyester resin and the core particles is properly controlled, and a thin shell layer with a more uniform thickness and a smooth layer can be obtained. Can be formed. On the other hand, when the amount of styrene-acryl modification is too small, a shell layer with a uniform film thickness cannot be formed, and the core particles are partially exposed. As a result, sufficient heat storage stability and chargeability are obtained. I can't get it. If the amount of styrene-acrylic modification is excessive, the styrene-acrylic modified polyester resin has a high softening point, so that sufficient low-temperature fixability cannot be obtained for the entire toner particles.

In the toner of the present invention, an aliphatic unsaturated dicarboxylic acid is used as a polyvalent carboxylic acid monomer to form a polyester segment of a styrene-acryl-modified polyester resin, and the aliphatic unsaturated dicarboxylic acid is added to the polyester segment. It is preferable that a structural unit derived from an acid is contained.
The aliphatic unsaturated dicarboxylic acid refers to a chain dicarboxylic acid having a vinylene group in the molecule.
According to the styrene-acryl-modified polyester resin having a structural unit derived from an aliphatic unsaturated dicarboxylic acid, it is possible to reliably form a smooth shell layer having a more uniform film thickness while being a thin layer.

The proportion of structural units derived from aliphatic unsaturated dicarboxylic acids in the structural units derived from polyvalent carboxylic acid monomers constituting the polyester segment of the styrene-acrylic modified polyester resin (hereinafter referred to as “specific unsaturated dicarboxylic acid-containing” The ratio is also preferably 25 mol% or more and 75 mol% or less, and more preferably 30 mol% or more and 60 mol% or less.
When the content ratio of the specific unsaturated dicarboxylic acid is within the above range, a smooth shell layer having a more uniform film thickness can be more reliably formed while being a thin layer. On the other hand, if the specific unsaturated dicarboxylic acid content is too small, sufficient heat-resistant storage stability and chargeability may not be obtained, and if the specific unsaturated dicarboxylic acid content is excessive, Sufficient chargeability may not be obtained.

The structural unit derived from the aliphatic unsaturated dicarboxylic acid is preferably a structural unit derived from one represented by the following general formula (A).
Formula ^{(A): HOOC- (CR 4} = CR 5) n -COOH
[Wherein, R ⁴ and R ⁵ are a hydrogen atom, a methyl group or an ethyl group, and may be the same or different from each other. n is an integer of 1 or 2. ]
By containing the structural unit derived from such an aliphatic unsaturated dicarboxylic acid, it is possible to more reliably form a smooth shell layer with a more uniform film thickness while being a thin layer.
This was emulsified by using a styrene-acryl-modified polyester resin having a structural unit derived from an aliphatic unsaturated dicarboxylic acid having a vinylene group, for example, when producing toner particles by an emulsion polymerization aggregation method described later. It is inferred that the aggregation of fine particles with the styrene-acryl-modified polyester resin at the time is improved, and the aggregation of the core particles to the surface proceeds uniformly. In addition, since the styrene-acryl-modified polyester resin having a structural unit derived from an aliphatic unsaturated dicarboxylic acid having a vinylene group has a high polarity, the toner particles are used, for example, by an emulsion polymerization aggregation method described later. This is also presumed that the polyester segment portion of the fine particles of the styrene-acrylic modified polyester resin to form the shell layer is easily oriented to the surface side in the aggregated particles.

  The shell resin preferably has a glass transition point of 50 to 70 ° C. from the viewpoint of surely obtaining fixing properties such as low-temperature fixing property and fixing separation property, and heat resistance such as heat-resistant storage property and blocking resistance, More preferably, it is 50-65 degreeC, and it is preferable that a softening point is 80-110 degreeC.

The glass transition point of the shell resin is a value measured by a method (DSC method) defined in ASTM (American Society for Testing and Materials) D3418-82.
The softening point of the shell resin is measured as follows.
First, in an environment of 20 ° C. ± 1 ° C. and 50% ± 5% RH, 1.1 g of shell resin is placed in a petri dish and left flat for 12 hours or more. Then, a molding machine “SSP-10A” (Shimadzu Corporation) Pressure) with a force of 3820 kg / cm ² for 30 seconds to produce a cylindrical molded sample having a diameter of 1 cm. Then, the molded sample is subjected to an environment of 24 ° C. ± 5 ° C. and 50% ± 20% RH. Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), a cylindrical die hole (1 mm diameter) under the conditions of a load of 196 N (20 kgf), a starting temperature of 60 ° C., a preheating time of 300 seconds, and a heating rate of 6 ° C./min. The offset method temperature T _offset measured from the end of preheating using a piston with a diameter of 1 cm from the end of preheating and measured at a setting of an offset value of 5 mm by the melting temperature measurement method of the temperature rising method is the shell tree. The softening point of fat.

The content ratio of the shell resin is preferably 15 to 30% by mass and more preferably 20 to 25% by mass with respect to the total amount of the resin constituting the toner particles.
When the content ratio of the shell resin is within the above range, good heat storage stability and low temperature fixability can be obtained.
When the content ratio of the shell resin is excessively low, sufficient heat storage stability may not be obtained. When the content ratio of the shell resin is excessively high, sufficient low-temperature fixability may not be obtained. is there.

[Production Method of Styrene-Acrylic Modified Polyester Resin]
As a method for producing the styrene-acrylic modified polyester resin contained in the shell resin as described above, an existing general scheme can be used. Typical methods include the following three methods.
(A-1) A polyester segment is polymerized in advance, the polyester segment is allowed to react with both reactive monomers, and an aromatic vinyl monomer for forming a styrene-acrylic copolymer segment and ( A method of forming a styrene-acrylic copolymer segment by reacting a (meth) acrylic acid ester monomer.
(A-2) A polyvalent carboxylic acid for polymerizing a styrene-acrylic copolymer segment in advance, reacting the styrene-acrylic copolymer segment with both reactive monomers, and further forming a polyester segment. A method of forming a polyester segment by reacting an acid monomer and a polyhydric alcohol monomer.
(B) A method in which a polyester segment and a styrene-acrylic copolymer segment are respectively polymerized in advance, and both are reacted with each other to react them.
In this specification, the both reactive monomers are a group capable of reacting with a polyvalent carboxylic acid monomer and / or a polyhydric alcohol monomer for forming a polyester segment of a styrene-acryl-modified polyester resin, and a polymerizable unsaturated group. And a monomer having

The method (A-1) will be specifically described.
(1) a mixing step of mixing an unmodified polyester resin, an aromatic vinyl monomer and a (meth) acrylic acid ester monomer, and both reactive monomers; and
(2) A styrene-acrylic polymer segment can be formed at the end of the polyester segment by passing through a polymerization step of polymerizing the aromatic vinyl monomer and the (meth) acrylic acid ester monomer.

  Among unmodified polyester resin, aromatic vinyl monomer, (meth) acrylic acid ester monomer and both reactive monomers, aromatic vinyl monomer and (meth) acrylic acid ester monomer The total proportion of the resin material used, that is, the total amount of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer when the total mass of the four members is 100% by mass. The ratio is 5% by mass or more and 30% by mass or less, and particularly preferably 5% by mass or more and 20% by mass or less.

  When the total ratio of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer to the total mass of the resin material used is within the above range, the styrene-acrylic modified polyester resin and the core particle The affinity is appropriately controlled, and a smooth shell layer can be formed with a more uniform film thickness while being a thin layer. On the other hand, when the ratio is too small, the resulting styrene-acryl-modified polyester resin cannot form a shell layer with a uniform film thickness, resulting in partial exposure of the core particles. Therefore, sufficient heat storage stability and chargeability cannot be obtained for the obtained toner. If the ratio is excessive, the resulting styrene-acryl-modified polyester resin has a high softening point, so that the resulting toner cannot obtain sufficient low-temperature fixability as a whole.

The relative proportion of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer is such that the glass transition point (Tg) calculated by the FOX formula represented by the following formula (A) is 35. It is preferable that the ratio is in the range of -80 ° C, preferably 40-60 ° C.
Formula (A): 1 / Tg = Σ (Wx / Tgx)
[In Formula (A), Wx is the weight fraction of monomer x, and Tgx is the glass transition point of the homopolymer of monomer x. ]
In the present specification, both reactive monomers are not used for calculation of the glass transition point.

  Among unmodified polyester resin, aromatic vinyl monomer, (meth) acrylic acid ester monomer, and both reactive monomers, the proportion of both reactive monomers used is the total mass of the resin material used, that is, The ratio of the two reactive monomers when the total mass of the four components is 100% by mass is 0.1% by mass or more and 5.0% by mass or less, and particularly 0.5% by mass or more and 3.0% by mass. The following is preferable.

[Aromatic vinyl monomers and (meth) acrylic acid ester monomers]
The aromatic vinyl monomer and (meth) acrylic acid ester monomer for forming the styrene-acrylic copolymer segment have an ethylenically unsaturated bond capable of radical polymerization. .
Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples include 4-dimethylstyrene, 3,4-dichlorostyrene, and derivatives thereof.
These aromatic vinyl monomers can be used alone or in combination of two or more.
Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Examples include butyl, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.
These (meth) acrylic acid ester monomers can be used alone or in combination of two or more.

  As the aromatic vinyl monomer and (meth) acrylic acid ester monomer for forming the styrene-acrylic copolymer segment, styrene or its monomer is used from the viewpoint of obtaining excellent chargeability and image quality characteristics. It is preferable to use many derivatives. Specifically, the amount of styrene or a derivative thereof used is such that all monomers (aromatic vinyl monomers and (meth) acrylic acid ester units) used to form a styrene-acrylic copolymer segment are used. It is preferable that it is 50 mass% or more in (mer).

[Amotropic monomer]
As the both reactive monomers for forming the styrene-acrylic copolymer segment, a group capable of reacting with the polyvalent carboxylic acid monomer and / or the polyhydric alcohol monomer for forming the polyester segment and a polymerizable unsaturated group Specifically, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride and the like can be used.

[Polyester resin]
The unmodified polyester resin used for preparing the styrene-acrylic modified polyester resin according to the present invention is a heavy polymer in the presence of an appropriate catalyst using a polyvalent carboxylic acid monomer (derivative) and a polyhydric alcohol monomer (derivative) as raw materials. It is produced by a condensation reaction.

  As polyvalent carboxylic acid monomer derivatives, alkyl esters, acid anhydrides and acid chlorides of polyvalent carboxylic acid monomers can be used. As polyhydric alcohol monomer derivatives, ester compounds of polyhydric alcohol monomers and hydroxycarboxylic acids are used. Can be used.

  Examples of the polyvalent carboxylic acid monomer include oxalic acid, succinic acid, maleic acid, mesaconic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, and dodecanedicarboxylic acid. Acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid, tartaric acid, mucoic acid, Phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycol Glycolic acid, diphenylacetic acid, diphenyl divalent carboxylic acids such as p, p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, dodecenyl succinic acid; Examples thereof include divalent or higher carboxylic acids such as merit acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid.

As the polyvalent carboxylic acid monomer, an aliphatic unsaturated dicarboxylic acid such as fumaric acid, maleic acid or mesaconic acid is preferably used, and in particular, an aliphatic unsaturated dicarboxylic acid represented by the above general formula (A) is used. It is preferable.
By using the aliphatic unsaturated dicarboxylic acid, the obtained styrene-acryl-modified polyester resin can surely form a smooth shell layer with a more uniform film thickness while being a thin layer. . In particular, by using the aliphatic unsaturated dicarboxylic acid represented by the general formula (A), the obtained styrene-acryl-modified polyester resin is more surely a thin layer with a more uniform film thickness and A smooth shell layer can be formed.

The ratio of the aliphatic unsaturated dicarboxylic acid in the total polyvalent carboxylic acid monomer to be used is preferably 25 mol% or more and 75 mol% or less, and more preferably 30 mol% or more and 60 mol% or less.
When the ratio of the aliphatic unsaturated dicarboxylic acid used is in the above range, the obtained styrene-acryl-modified polyester resin is more surely a thin shell with a more uniform film thickness and a smooth shell layer. Can be formed. On the other hand, if the proportion of the aliphatic unsaturated dicarboxylic acid used is too small, sufficient heat-resistant storage stability and chargeability may not be obtained in the obtained toner, and the proportion of the aliphatic unsaturated dicarboxylic acid used is If it is excessive, sufficient chargeability may not be obtained for the obtained toner.

  Examples of the polyhydric alcohol monomer include ethylene glycol, propylene glycol, butanediol, diethylene glycol, hexanediol, cyclohexanediol, octanediol, decanediol, dodecanediol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, and the like. And trivalent or higher polyols such as glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, and tetraethylol benzoguanamine.

  The ratio of the polyhydric carboxylic acid monomer to the polyhydric alcohol monomer is preferably an equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] of the polyhydric alcohol monomer and the carboxyl group [COOH] of the polyhydric carboxylic acid. Is 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2.

  Various conventionally known catalysts can be used as a catalyst for synthesizing the unmodified polyester resin.

  The unmodified polyester resin for obtaining the styrene-acrylic modified polyester resin preferably has a glass transition point of 40 ° C. or higher and 70 ° C. or lower, more preferably 50 ° C. or higher and 65 ° C. or lower. When the glass transition point of the unmodified polyester resin is 40 ° C. or higher, the cohesive force in the high temperature region becomes appropriate for the polyester resin, and the occurrence of hot offset phenomenon during fixing is suppressed. Further, since the glass transition point of the unmodified polyester resin is 70 ° C. or less, sufficient melting can be obtained at the time of fixing, and a sufficient minimum fixing temperature can be ensured.

The unmodified polyester resin preferably has a weight average molecular weight (Mw) of 1,500 to 60,000, more preferably 3,000 to 40,000.
When the weight average molecular weight is 1,500 or more, a cohesive force suitable for the entire resin is obtained, and the occurrence of a hot offset phenomenon during fixing is suppressed. Further, when the weight average molecular weight is 60,000 or less, it is possible to obtain a sufficient melting and secure a minimum fixing temperature, while suppressing occurrence of a hot offset phenomenon during fixing. The

  The unmodified polyester resin has a partially branched structure or a crosslinked structure formed by selecting a carboxylic acid valence or an alcohol valence as a polyvalent carboxylic acid monomer and / or a polyhydric alcohol monomer to be used. May be.

(Polymerization initiator)
In the polymerization of the styrene-acrylic copolymer segment, the polymerization is preferably performed in the presence of a radical polymerization initiator, and the timing of addition of the radical polymerization initiator is not particularly limited, but the control of the radical polymerization is easy. Therefore, it is preferable to add after mixing the aromatic vinyl monomer and the (meth) acrylic acid ester monomer for forming the polymerization of the styrene-acrylic copolymer segment.

  Various known polymerization initiators are preferably used as the polymerization initiator. Specifically, for example, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, Lauroyl oxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-butyl hydroperoxide, performic acid- tert-butyl, peracetic acid-tert-butyl, perbenzoic acid-tert-butyl, perphenylacetic acid-tert-butyl, permethoxyacetic acid-tert-butyl, per-N- (3-toluyl) palmitic acid-tert-butyl, etc. Peroxide 2,2'-azobis (2-aminodipropane) hydrochloride, 2,2'-azobis- (2-aminodipropane) nitrate, 1,1'-azobis (1-methylbutyronitrile-3-sulfone) Acid salt), 4,4'-azobis-4-cyanovaleric acid, poly (tetraethylene glycol-2,2'-azobisisobutyrate) and other azo compounds.

[Chain transfer agent]
In the polymerization of the styrene-acrylic copolymer segment, a generally used chain transfer agent can be used for the purpose of adjusting the molecular weight of the styrene-acrylic copolymer segment. The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans and mercapto fatty acid esters.
The chain transfer agent is mixed with the resin material in the mixing step of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer to form the polymerization of the styrene-acrylic copolymer segment. It is preferable.

  The addition amount of the chain transfer agent varies depending on the molecular weight and molecular weight distribution of the desired styrene-acrylic copolymer segment. Specifically, the aromatic vinyl monomer and the (meth) acrylic acid ester monomer, Moreover, it is preferable to add in the range of 0.1-5 mass% with respect to the total amount of both reactive monomers.

  The polymerization temperature in the polymerization of the styrene-acrylic copolymer segment is not particularly limited, and the polymerization between the aromatic vinyl monomer and the (meth) acrylic acid ester monomer and the unmodified polyester resin is performed. It can select suitably in the range which a coupling | bonding advances. For example, the polymerization temperature is preferably 85 ° C. or higher and 125 ° C. or lower, more preferably 90 ° C. or higher and 120 ° C. or lower, and further preferably 95 ° C. or higher and 115 ° C. or lower.

  In the production of a styrene-acrylic modified polyester resin, it is practically preferable that the volatile organic substances from the emulsion such as the amount of residual monomer after polymerization are suppressed to 1,000 ppm or less, more preferably 500 ppm or less, and still more preferably. Is 200 ppm or less.

[Chelate compound represented by general formula (1) (specific chelate compound)]
The shell layer contains a specific chelate compound. When the specific chelate compound is contained in the shell layer, that is, unevenly distributed on the surface side of the toner particles, plasticization of the resin occurs due to the specific chelate compound, and the softening point of the resin is lowered. In addition, since the plasticized resin has high adhesiveness, a high adhesive force is generated locally with the fixing roller during fixing, and fine irregularities are locally formed on the image surface. Therefore, it is estimated that a low gloss image can be formed.

In the general formula (1), M represents a divalent metal ion, and examples thereof include Cu ²⁺ , Ni ²⁺ and Zn ²⁺ .

In the general formula (1), R ¹ , R ² and R ³ are each a hydrogen atom, an electron withdrawing group, or a linear or branched alkyl group having 12 to 22 carbon atoms, an alkenyl group, an alkoxy group. A group or an alkenyloxy group;
However, at least one of R ¹ , R ² and R ³ is an electron withdrawing group, and the sum of substituent constants (σp value) of the electron withdrawing group is 0.4 to 4.0. Is done.
A molecule | numerator is stabilized because the sum total of the substituent constant ((sigma) p value) of an electron withdrawing group is the said range. The sum of substituent constants means the sum of substituent constants of each electron-withdrawing group. For example, when R ¹ and R ² are electron-withdrawing groups, two R ¹ and two R The sum of the substituent constants of ² .

Here, the electron-withdrawing group means a substituent whose Hammett's substituent constant (σp value) can take a positive value. Hammett's substituent constant (σp value) is established when the reaction rate constants of a compound having no substituent and a compound having a substituent in the meta- or para-substituted product of the aromatic compound are k0 and k, respectively. It is defined as σ in the Hammett equation shown in FIG. In the Hammett's formula shown below, the dissociation reaction of benzoic acid and its derivatives in an aqueous solution at 25 ° C. is p = 1.
[Hammett formula]
log (k / k0) = σp

  Examples of the electron withdrawing group include a cyano group, a nitro group, a dichloromethyl group, a dibromomethyl group, an alkoxyacyl group, an acyl group, an aromatic ring having these substituents, and a trifluoro group, Alkylsulfonyl groups (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group), arylsulfonyl groups (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridyl group) Sulfonyl group) aryloxycarbonyl group (for example, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminos group) Phonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethyl group) Carbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy) Group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group ), Amide groups (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecyl) Carbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, Octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthyla Minocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2 -Pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group) Group) and the like.

  Among the above, the electron withdrawing group is preferably a cyano group, a nitro group, a dichloromethyl group, a dibromomethyl group, an alkoxyacyl group, an acyl group, or an aromatic ring having these substituents.

In the general formula (1), at least one of R ¹ , R ² and R ³ is a linear or branched alkyl group having 12 to 22 carbon atoms, a linear or branched carbon number of 12 Or a linear or branched alkoxy group having 12 to 22 carbon atoms, or a linear or branched alkenyloxy group having 12 to 22 carbon atoms.
In the general formula (1), when at least one of R ¹ , R ² and R ³ has less than 12 carbon atoms, the specific chelate compound and the resin are not compatible with each other, and low temperature fixing is performed. Sex cannot be obtained. On the other hand, in the general formula (1), when at least one of R ¹ , R ² and R ³ has more than 22 carbon atoms, steric hindrance of a specific chelate compound occurs, Compatibility does not occur and chelation reaction does not easily occur.
Among these, at least one of R ¹ , R ² and R ³ is a linear or branched alkyl group having 15 to 20 carbon atoms or a linear or branched alkenyl group having 15 to 20 carbon atoms. A linear or branched alkoxy group having 15 to 20 carbon atoms or a linear or branched alkenyloxy group having 15 to 20 carbon atoms is preferable.

The content of the specific chelate compound is preferably 1 to 8% by mass in the toner particles, and more preferably 2 to 7% by mass.
When the content ratio of the specific chelate compound is in the above range, a low gloss image can be formed.
When the content ratio of the specific chelate compound is too small, it is difficult to achieve low-temperature fixing, and it may not be possible to form a low-gloss image. On the other hand, when the content of the specific chelate compound is excessive, there is a risk of sticking to the fixing roller.

[Toner Production Method]
The toner of the present invention can be produced by various known methods. However, since the shell layer can be uniformly formed on the surface of the core particles, the core resin fine particles and the colorant dispersed in the aqueous medium can be used. It is preferable to produce by the emulsion polymerization aggregation method in which toner particles are obtained by agglomerating and fusing fine particles to form core particles and aggregating and fusing fine particles of the shell resin on the surface of the core particles.

Specific examples of production when the toner of the present invention is produced by an emulsion polymerization aggregation method are as follows:
(1-1) Preparation of a shell resin fine particle dispersion in which fine particles of a shell resin (hereinafter also referred to as “shell resin fine particles”) are formed in an aqueous medium to prepare a dispersion in which the shell resin fine particles are dispersed. Process,
(1-2) Core resin polymerization step in which a core resin fine particle (hereinafter, also referred to as “core resin fine particle”) is formed by polymerization in an aqueous medium to prepare a dispersion in which the core resin fine particle is dispersed. ,
(1-3) Colorant fine particle dispersion preparation step of preparing a dispersion in which fine particles of colorant (hereinafter also referred to as “colorant fine particles”) are dispersed in an aqueous medium.
(1-4) A chelate compound fine particle dispersion preparing step of preparing a dispersion in which fine particles of a specific chelate compound (hereinafter also referred to as “chelate fine particles”) are dispersed in an aqueous medium.
(2) a core particle forming step of aggregating the core resin fine particles and the colorant fine particles in an aqueous medium to form core particles;
(3) Toner having a core-shell structure by adding shell resin fine particles and chelate compound fine particles to an aqueous medium in which core particles are dispersed, and aggregating and fusing the shell resin fine particles and chelate compound fine particles on the surface of the core particles Shelling process to form particles,
(4) An aging step of adjusting the shape of the toner particles by aging with heat energy;
(5) a cleaning step of separating the toner particles from the toner particle dispersion (aqueous medium) and removing the surfactant from the toner particles;
(6) a drying step of drying the washed toner particles;
Consisting of, if necessary,
(7) An external additive adding step of adding an external additive to the dried toner particles can be added.

(1-1) Shell resin fine particle dispersion preparation step In this shell resin fine particle dispersion preparation step, the dispersion of shell resin fine particles is an aqueous system to which a surfactant is added by, for example, an ultrasonic dispersion method or a bead mill dispersion method. It can be obtained by a direct dispersion method.

The average particle diameter of the shell resin fine particles obtained in the shell resin fine particle dispersion preparing step is preferably in the range of, for example, 50 to 500 nm in terms of volume-based median diameter.
The volume-based median diameter of the shell resin fine particles is measured using “UPA-150” (manufactured by Microtrack).

  In the present invention, the “aqueous medium” refers to a medium comprising 50 to 100% by mass of water and 0 to 50% by mass of a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, and alcohol-based organic solvents that do not dissolve the resulting resin are preferable.

[Surfactant]
A dispersion stabilizer is preferably added to the aqueous medium in order to prevent aggregation of dispersed fine particles.
As the dispersion stabilizer, various known surfactants such as a cationic surfactant, an anionic surfactant, and a nonionic surfactant can be used.
Specific examples of the cationic surfactant include dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl anonium bromide and the like.
Specific examples of nonionic surfactants include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, norylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, styrylphenyl poly Examples thereof include oxyethylene ether and monodecanoyl sucrose.
Specific examples of the anionic surfactant include aliphatic soaps such as sodium stearate and sodium laurate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene (2) sodium lauryl ether sulfate and the like. it can.
The above surfactants can be used singly or in combination of two or more as desired.

(1-2) Core resin polymerization step In this core resin polymerization step, resin fine particles related to the core resin are formed, and this is used for the core particle formation step.
Specifically, the resin fine particles related to the core resin are separated from the polymerizable monomer for forming the core resin in an aqueous medium containing a surfactant having a critical micelle concentration (CMC) or less as necessary. Add a monomer solution in which toner constituents such as molds and charge control agents are dissolved or dispersed, add mechanical energy to form droplets, and then add a water-soluble radical polymerization initiator. The polymerization reaction is allowed to proceed in the droplet. Note that an oil-soluble polymerization initiator may be contained in the droplet. In such a core resin polymerization process, mechanical energy is imparted and forcedly emulsified (droplet formation) treatment is essential. Examples of the means for applying mechanical energy include means for applying strong stirring or ultrasonic vibration energy such as homomixer, ultrasonic wave, and manton gorin.

  The core resin fine particles formed in this core resin polymerization step can also have a structure of two or more layers made of resins having different compositions. In this case, by emulsion polymerization treatment (first stage polymerization) according to a conventional method. A method in which a polymerization initiator and a polymerizable monomer are added to the prepared dispersion of the first resin particles, and this system is polymerized (second stage polymerization) can be employed.

  When using a surfactant in the core resin polymerization step, it is possible to use, for example, the same surfactants as those listed as the surfactant that can be used in the above-mentioned shell resin fine particle dispersion preparation step. it can.

The toner particles according to the present invention may contain an internal additive such as a release agent, a charge control agent, and magnetic powder as necessary. Such an internal additive may be, for example, the core resin. In the polymerization step, it can be introduced into the toner particles by dissolving or dispersing in advance in a monomer solution for forming the core resin.
In addition, such an internal additive is prepared by separately preparing a dispersion of internal additive fine particles consisting only of the internal additive, and aggregating the internal additive fine particles together with the core resin fine particles and the colorant fine particles in the core particle forming step. Can be introduced into the toner particles, but it is preferable to adopt a method that is introduced in advance in the core resin polymerization step.

〔Release agent〕
Examples of the release agent include hydrocarbon waxes such as low molecular weight polyethylene wax, low molecular weight polypropylene wax, Fischer-Tropsch wax, microcrystalline wax, and paraffin wax, carnauba wax, pentaerythritol behenate, and behenyl behenate. And ester waxes such as behenyl citrate. These can be used individually by 1 type or in combination of 2 or more types.
As the releasing agent, it is preferable to use a releasing agent having a melting point of 50 to 95 ° C. from the viewpoint of reliably obtaining low-temperature fixability and releasing property of the toner.

  The content of the release agent is preferably 2 to 20% by mass in the toner particles, more preferably 3 to 18% by mass, and still more preferably 4 to 15% by mass.

[Charge control agent]
As the charge control agent, various known compounds that can be dispersed in an aqueous medium can be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, fourth compounds. Examples include quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

  The content ratio of the charge control agent is preferably 0.1 to 10% by mass in the toner particles, and more preferably 0.5 to 5% by mass.

(Polymerization initiator)
As the polymerization initiator used in the core resin polymerization step, the same ones as described above can be used.

[Chain transfer agent]
In the core resin polymerization step, a generally used chain transfer agent can be used for the purpose of adjusting the molecular weight of the core resin. As the chain transfer agent, the same ones as described above can be used.

The average particle diameter of the core resin fine particles obtained in this core resin polymerization step is preferably in the range of, for example, 50 to 500 nm in terms of volume-based median diameter.
The volume-based median diameter of the core resin fine particles was measured using “UPA-150” (manufactured by Microtrack).

(1-3) Colorant fine particle dispersion preparation step The colorant fine particle dispersion can be prepared by dispersing a colorant in an aqueous medium. The colorant dispersion treatment is preferably performed in a state where the surfactant concentration in the aqueous medium is not less than the critical micelle concentration (CMC) since the colorant is uniformly dispersed. Various known dispersers can be used as a disperser used for the dispersion treatment of the colorant.

The dispersion diameter of the colorant fine particles in the colorant fine particle dispersion prepared in the colorant fine particle dispersion preparing step is preferably 10 to 300 nm in terms of volume-based median diameter.
The volume-based median diameter of the colorant fine particles is measured by an electrophoretic light scattering photometer “ELS-800 (manufactured by Otsuka Electronics Co., Ltd.)”.

  When a surfactant is used in this colorant fine particle dispersion preparation step, the same surfactant as the surfactant that can be used in the above-mentioned shell resin fine particle dispersion preparation step, for example, is used. Can be used.

(1-4) Chelate Compound Fine Particle Dispersion Preparation Step In this chelate compound fine particle dispersion preparation step, the chelate compound fine particle dispersion is an aqueous system to which a surfactant is added by, for example, an ultrasonic dispersion method or a bead mill dispersion method. It can be obtained by a direct dispersion method.

The average particle size of the chelate compound fine particles obtained in this chelate compound fine particle dispersion preparation step is preferably in the range of, for example, 50 to 300 nm in terms of volume-based median diameter.
The volume-based median diameter of the chelate compound fine particles is measured using “UPA-150” (manufactured by Microtrac).

  As the surfactant to be used in the chelate compound fine particle dispersion preparation step, for example, the same ones as mentioned as the surfactant that can be used in the above-mentioned shell resin fine particle dispersion preparation step can be used.

(2) Core particle forming step In this core particle forming step, fine particles of other toner constituent components such as a release agent and a charge control agent may be aggregated together with the core resin fine particles and the colorant fine particles, if necessary. it can.

  As a specific method for agglomerating and fusing the core resin fine particles and the colorant fine particles, a flocculant is added to an aqueous medium so as to have a critical aggregation concentration or higher, and then the glass transition point of the core resin fine particles or higher. Further, by heating the mixture to a temperature equal to or higher than the melting peak temperature (° C.) of the mixture, the salting out of the fine particles such as the core resin fine particles and the colorant fine particles proceeds, and at the same time, the fusion is proceeded in parallel to obtain desired particles In this method, the particle growth is stopped by adding a coagulation terminator when it has grown to the diameter, and further, heating is continued to control the particle shape as necessary.

  In this method, the time allowed to stand after adding the flocculant is as short as possible, and the temperature is not less than the glass transition point of the resin fine particles relating to the core resin and not less than the melting peak temperature (° C.) of the mixture. It is preferable to heat it. The reason for this is not clear, but depending on the standing time after salting out, the aggregation state of the particles may fluctuate and the particle size distribution may become unstable, and the surface properties of the fused particles may vary. This is because there is concern about the occurrence. The time until this temperature rise is usually preferably within 30 minutes, and more preferably within 10 minutes. Moreover, it is preferable that it is 1 degree-C / min or more as a temperature increase rate. The upper limit of the heating rate is not particularly specified, but is preferably 15 ° C./min or less from the viewpoint of suppressing the generation of coarse particles due to rapid progress of fusion. Furthermore, after the reaction system reaches a temperature equal to or higher than the glass transition point, it is important to continue the fusion by maintaining the temperature of the reaction system for a certain time. Thereby, the growth and fusion of the core particles can be effectively advanced, and the durability of the toner particles finally obtained can be improved.

[Flocculant]
The flocculant used in the core particle forming step is not particularly limited, but a material selected from metal salts is preferably used. Examples of the metal salt include monovalent metal salts such as alkali metal salts such as sodium, potassium and lithium; divalent metal salts such as calcium, magnesium, manganese and copper; and trivalent metal salts such as iron and aluminum. Etc. Specific metal salts can include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. It is particularly preferable to use a divalent metal salt. These can be used individually by 1 type or in combination of 2 or more types.

  When using a surfactant in the core particle forming step, it is possible to use, for example, the same surfactant as the surfactant that can be used in the above-mentioned shell resin fine particle dispersion preparation step. it can.

As for the particle size of the core particles obtained in this core particle forming step, for example, the volume-based median diameter (D ₅₀ ) is preferably 2 to 9 μm, more preferably 4 to 7 μm.
The volume-based median diameter of the core particles is measured by “Coulter Multisizer 3” (manufactured by Coulter Beckman).

(3) Shelling step In this shelling step, the shell resin fine particles and the chelate compound fine particles are added to the core particle dispersion to agglomerate and fuse the shell resin fine particles and the chelate compound fine particles on the surface of the core particles. Toner particles are formed by coating the surface of the core particles with a shell layer.
Specifically, the dispersion of the core particles is added to the dispersion of the shell resin fine particles while maintaining the temperature in the core particle formation step, and the shell resin fine particles are slowly removed over several hours while continuing the heating and stirring. The toner particles are formed by aggregating and fusing the surfaces of the core particles with a shell layer having a thickness of 100 to 300 nm on the surface of the core particles. The heating and stirring time is preferably 1 to 7 hours, particularly preferably 3 to 5 hours.

  In this shelling step, the chelate compound fine particles may be added to the core particle dispersion together with the shell resin fine particle dispersion. From the viewpoint of incorporation into the toner particles, the chelate compound fine particles are previously added to the shell resin fine particle dispersion. After being added to and mixed, it is preferable to add the dispersion to the core particle dispersion.

(4) Ripening step The shape of the toner particles in the toner can be made uniform to some extent by controlling the heating temperature in the core particle forming step and the shelling step, but in order to further make the shape uniform, the ripening step Go through.
This aging step is controlled by controlling the heating temperature and time so that the surface of the toner particles formed with a constant particle size and a narrow distribution has a smooth but uniform shape. Specifically, the heating temperature is lowered in the core particle forming step and the shelling step to suppress the progress of fusion between the resin fine particles to promote leveling, and in this aging step, the heating temperature is lowered. In addition, the toner particles are controlled so as to have a desired average circularity, that is, a surface having a uniform shape by extending the time.

(5) Washing step to (6) Drying step The washing step and the drying step can be performed by employing various known methods.

(7) External additive addition step This external additive addition step is a step of preparing toner particles by adding and mixing external additives as necessary to the dried toner particles.
The toner particles produced through the steps up to the drying step can be used as toner particles as they are, but from the viewpoint of improving the charging performance, fluidity, and cleaning properties of the toner, the surface thereof is known. It is preferable to add particles such as inorganic fine particles and organic fine particles, and a lubricant as external additives.
Various external additives may be used in combination.

Examples of the inorganic fine particles include inorganic oxide fine particles such as silica fine particles, alumina fine particles, and titanium oxide fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, or strontium titanate and zinc titanate. An inorganic titanic acid compound fine particle etc. are mentioned.
These inorganic fine particles are preferably those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, or the like from the viewpoint of heat-resistant storage stability and environmental stability.

The amount of these external additives added is 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner particles.
Examples of the method of adding the external additive include a dry method in which the external additive is added in powder form to the dried toner base particles. Examples of the mixing device include mechanical mixing devices such as a Henschel mixer and a coffee mill. It is done.

[Average toner particle size]
The average particle diameter of the toner of the present invention is preferably, for example, 3 to 10 μm in volume-based median diameter (D ₅₀ ). This particle size can be controlled by the concentration of the coagulant used, the amount of organic solvent added, the fusing time, and the composition of the polymer, for example, when the emulsion polymerization aggregation method described later is employed.
When the volume-based median diameter is in the above range, for example, a very minute dot image at a level of 1200 dpi (dpi; number of dots per inch (2.54 cm)) can be faithfully reproduced.

  The volume-based median diameter of the toner particles is measured and calculated using a measuring device in which “Multisizer 3” (manufactured by Beckman Coulter) is connected to a computer system equipped with data processing software “Software V3.51”. Is. Specifically, 0.02 g of toner is added to 20 mL of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). Then, ultrasonic dispersion was performed for 1 minute to prepare a toner particle dispersion, and this toner particle dispersion was placed in a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand. Inject with a pipette until the displayed concentration of the measuring device is 8%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the frequency value is calculated by setting the number of measured particle counts to 25000 and the aperture diameter to 100 μm, and the particle diameter of 50% from the larger volume integrated fraction is the volume-based median diameter.

[Average circularity of toner particles]
In the toner of the present invention, the arithmetic average value of the circularity represented by the following formula (T) is 0.850 to 0.990 from the viewpoint of improving the transfer efficiency of the individual toner particles constituting the toner. Is preferred.
Formula (T): Circularity = perimeter of perfect circle having projection area equivalent to particle projection image / perimeter of particle projection image

Here, the average circularity of the toner particles is a value measured using “FPIA-2100” (manufactured by Sysmex).
Specifically, the toner particles are moistened with an aqueous surfactant solution, and ultrasonic dispersion is performed for 1 minute. After dispersion, HPFP detection is performed in the measurement condition HPF (high magnification imaging) mode using “FPIA-2100”. Measurement is performed at appropriate concentrations of several thousand to 10,000. Within this range, reproducible measurement values can be obtained.

(Developer)
The toner of the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.
As the carrier, for example, magnetic particles made of conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Among these, ferrite particles Is preferably used. As the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a resin-dispersed carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used.
The carrier preferably has a volume average particle diameter of 15 to 100 μm, more preferably 25 to 80 μm.

[Image forming apparatus]
The toner of the present invention can be used in a general electrophotographic image forming method. As an image forming apparatus in which such an image forming method is performed, for example, a photosensitive member that is an electrostatic latent image carrier, A charging means for applying a uniform potential to the surface of the photoconductor by corona discharge having the same polarity as that of the toner, and an electrostatic latent image by performing image exposure on the surface of the uniformly charged photoconductor based on image data. An exposure means for forming an image; a developing means for conveying the toner to the surface of the photoreceptor to visualize the electrostatic latent image to form a toner image; and passing the toner image through an intermediate transfer member as necessary. For example, a transfer unit that transfers to a transfer material and a fixing unit that fixes a toner image on the transfer material can be used. Among image forming apparatuses having such a configuration, a color image forming apparatus having a configuration in which image forming units related to a plurality of photoconductors are provided along the intermediate transfer body, in particular, the photoconductors are arranged in series on the intermediate transfer body. It can be suitably used for the tandem type color image forming apparatus.

The toner of the present invention can be suitably used at a relatively low temperature where the fixing temperature (the surface temperature of the fixing member) is 100 to 200 ° C.
Furthermore, the toner of the present invention can be suitably used for a high-speed machine in which the linear velocity of the electrostatic latent image carrier is 100 to 500 mm / sec.

  According to the above toner, since the specific chelate compound is contained in the shell layer having the core-shell structure, the plasticization of the resin occurs due to the chelate and the softening point of the resin is lowered, so that the low temperature fixability is ensured. Can do. In addition, since the resin containing the specific chelate compound is high in viscosity, a high adhesive force is locally generated with the fixing roller during fixing, and fine irregularities are locally formed on the image surface. A low-gloss image can be formed.

  As mentioned above, although embodiment of this invention was described concretely, embodiment of this invention is not limited to said example, A various change can be added.

[Toner Production Example 1: Example 1]
(1) Preparation Step of Core Resin Fine Particle Dispersion (1-1) First Stage Polymerization An anionic surfactant “lauryl” is previously prepared in a reaction vessel equipped with a stirrer, a temperature sensor, a temperature controller, a cooling pipe and a nitrogen introducing device. An anionic surfactant solution in which 2.0 parts by mass of “sodium sulfate” was dissolved in 2900 parts by mass of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. .
After adding 9.0 parts by mass of a polymerization initiator “potassium persulfate (KPS)” to this anionic surfactant solution and adjusting the internal temperature to 78 ° C.,
Styrene 540 parts by mass n-butyl acrylate 154 parts by mass Methacrylic acid 77 parts by mass n-Octyl mercaptan 17 parts by mass A monomer solution [1] was added dropwise over 3 hours. After completion of the dropping, polymerization (first stage polymerization) was carried out by heating and stirring at 78 ° C. for 1 hour to prepare a dispersion of “resin fine particles [a1]”.

(1-2) Second-stage polymerization: formation of intermediate layer In a flask equipped with a stirrer,
Styrene 94 parts by mass n-butyl acrylate 27 parts by mass Methacrylic acid 6 parts by mass n-octyl mercaptan 1.7 parts by mass Paraffin wax (melting point: 73 ° C.) 51 parts by mass is added as an anti-offset agent, and 85 The monomer solution [2] was prepared by heating to ° C and dissolving.
On the other hand, a surfactant solution in which 2 parts by mass of the anionic surfactant “sodium lauryl sulfate” was dissolved in 1100 parts by mass of ion-exchanged water was heated to 90 ° C., and the above-mentioned “resin fine particles [ a1] ”in the amount of solids of the resin fine particles [a1] is added in an amount of 28 parts by mass, and then the monomer is dispersed by a mechanical disperser“ CLEAMIX ”(manufactured by M Technique Co., Ltd.) having a circulation path. Solution [2] is mixed and dispersed for 4 hours to prepare a dispersion containing emulsified particles having a dispersed particle diameter of 350 nm, and 2.5 parts by mass of a polymerization initiator “KPS” is added to 110 parts by mass of ion-exchanged water. A dispersion of “resin fine particles [a11]” is prepared by performing polymerization (second stage polymerization) by adding an initiator aqueous solution dissolved in the solution and heating and stirring the system at 90 ° C. for 2 hours. It was.

(1-3) Third-stage polymerization: formation of outer layer Start of dissolving 2.5 parts by mass of polymerization initiator “KPS” in 110 parts by mass of ion-exchanged water in the dispersion of “resin fine particles [a11]” Aqueous agent aqueous solution is added and under the temperature condition of 80 ° C.
Styrene 230 mass parts n-butyl acrylate 78 mass parts Methacrylic acid 16 mass parts n-octyl mercaptan 4.2 mass parts monomer solution [3] was dripped over 1 hour. After completion of the dropwise addition, polymerization (third stage polymerization) was carried out by heating and stirring for 3 hours. Then, it cooled to 28 degreeC and produced "the dispersion liquid of core resin microparticles | fine-particles [A]" by which core resin microparticles | fine-particles [A] were disperse | distributed in the anionic surfactant solution.
The glass transition point of the core resin fine particles [A] was 45 ° C., and the softening point was 100 ° C.

(2) Preparation Step of Shell Resin Fine Particle Dispersion (2-1) Synthesis of Shell Resin (Styrene-Acrylic Modified Polyester Resin) Four-neck with a capacity of 10 liters equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple Into the flask,
Bisphenol A propylene oxide 2-mole adduct 500 parts by mass Terephthalic acid 117 parts by mass Fumaric acid 82 parts by mass Esterification catalyst (tin octylate) 2 parts by mass were added and subjected to a polycondensation reaction at 230 ° C. for 8 hours. After reacting for hours and cooling to 160 ° C,
Acrylic acid 10 parts by mass Styrene 30 parts by mass Butyl acrylate 7 parts by mass Polymerization initiator (di-t-butyl peroxide) 10 parts by mass of the mixture was added dropwise with a dropping funnel over 1 hour, and then maintained at 160 ° C. After continuing the addition polymerization reaction for 1 hour, the temperature was raised to 200 ° C. and maintained at 10 kPa for 1 hour, and then the acrylic acid, styrene, and butyl acrylate were removed to remove the styrene-acryl modified polyester resin [1]. Got.
This styrene-acryl-modified polyester resin [1] had a glass transition point of 60 ° C. and a softening point of 105 ° C.

(2-2) Preparation of Shell Resin Fine Particle Dispersion The obtained styrene-acrylic modified polyester resin [1] 100 parts by mass was pulverized with “Landel mill type: RM” (manufactured by Tokuju Kogakusha Co., Ltd.), and 0 prepared in advance. Mixing with 638 parts by mass of sodium lauryl sulfate solution with a concentration of 26 mass%, and ultrasonically dispersing with stirring using an ultrasonic homogenizer “US-150T” (manufactured by Nippon Seiki Seisakusho) at V-LEVEL, 300 μA for 30 minutes, A “dispersion of shell resin fine particles [B]” in which shell resin fine particles [B] having a volume-based median diameter (D ₅₀ ) of 250 nm were dispersed was produced.

(3) Preparation Step of Colorant Fine Particle Dispersion Solution 90 parts by mass of sodium dodecyl sulfate is dissolved in 1600 parts by mass of ion-exchanged water, and 420 parts by mass of carbon black “Mogal L” (Cabot Corporation) while stirring this solution. Is added, and then dispersed using a stirrer “CLEARMIX” (manufactured by M Technique Co., Ltd.) to thereby disperse “colorant fine particles [C] in which colorant fine particles [C] are dispersed”. Was prepared. The particle diameter of the colorant fine particles [C] in this dispersion was measured using a Microtrac particle size distribution measuring device “UPA-150” (manufactured by Nikkiso Co., Ltd.), and was 117 nm.

(4) Preparation Step of Chelate Compound Fine Particle Dispersion 90 parts by mass of “sodium dodecyl sulfate” was stirred and dissolved in 1600 parts by mass of ion-exchanged water. While stirring this solution, 200 parts by mass of chelate compound [1] shown in Table 1 was gradually added, and then dispersed using a dispersion apparatus “SC Mill” (manufactured by Nippon Coke Co., Ltd.). A “dispersion liquid (D) of chelate compound fine particles” in which the fine particles (D) were dispersed was prepared.

(5) Aggregation, fusion-maturation-washing-drying-addition of external additives In a reaction vessel equipped with a stirrer, temperature sensor, and cooling tube, "dispersion of core resin fine particles [A]" is converted to solid content. 288 parts by mass and 2,000 parts by mass of ion-exchanged water were added, and a 5 mol / liter aqueous sodium hydroxide solution was added to adjust the pH to 10.
Thereafter, 25.2 parts by mass of “dispersion of colorant fine particles [C]” in terms of solid content was added, and then an aqueous solution in which 60 parts by mass of magnesium chloride was dissolved in 60 parts by mass of ion-exchanged water was stirred for 30 Added at 10 ° C. over 10 minutes. Thereafter, the temperature was raised after being allowed to stand for 3 minutes, and the temperature of the system was raised to 80 ° C. over 60 minutes, and the particle growth reaction was continued while maintaining 80 ° C. In this state, the particle diameter of the core particles was measured with “Coulter Multisizer 3” (manufactured by Coulter Beckman). When the volume-based median diameter (D ₅₀ ) reached 6.0 μm, “shell resin fine particles 72 parts by mass of [dispersion of [B] ”in terms of solids and 12.8 parts by mass of“ dispersion of chelate compound fine particles (D) ”in terms of solids were mixed in advance over 30 minutes. When the supernatant of the reaction solution became transparent, an aqueous solution in which 190 parts by mass of sodium chloride was dissolved in 760 parts by mass of ion-exchanged water was added to stop particle growth. Further, the temperature is raised and the mixture is heated and stirred in a state of 90 ° C. to advance the fusing of the particles, and the average circularity measurement apparatus “FPIA-2100” (manufactured by Sysmex) is used (HPF detection). When the average circularity reached 0.945, the mixture was cooled to 30 ° C. to obtain a “dispersion of toner particles [1]”.
This “dispersion of toner particles [1]” is solid-liquid separated with a centrifuge to form a wet cake of toner particles, and this is used until the electric conductivity of the filtrate reaches 5 μS / cm using the centrifuge. After washing with ion exchange water at 35 ° C., it was transferred to “flash jet dryer” (manufactured by Seishin Enterprise Co., Ltd.) and dried until the water content became 0.5 mass%.
To the dried toner particles [1], 1% by mass of hydrophobic silica (number average primary particle size = 12 nm) and 0.3% by mass of hydrophobic titania (number average primary particle size = 20 nm) are added, and a Henschel mixer is used. By mixing, Toner [1] was produced.

[Toner Production Examples 2 to 27: Examples 2 to 21, Comparative Examples 1 to 4 and Reference Examples 1 and 2]
In the toner production example 1, (5) aggregation, fusion-ripening-washing-drying-external additive addition step, instead of “dispersion of colorant fine particles [C]”, types of colorants shown in Table 2 And the colorant fine particle dispersion prepared according to the addition amount, and the type of chelate compound shown in Table 1 instead of 12.8 parts by mass (in terms of solid content) of “dispersion of chelate compound fine particles (D)” Toners [2] to [27] were prepared in the same manner except that the dispersions of the chelate compound fine particles prepared according to Table 2 were changed to the addition amounts shown in Table 2, respectively.

[Developer Production Examples 1 to 27]
(1) Production of carrier 100 parts by mass of ferrite core and 5 parts by mass of copolymer resin particles of cyclohexyl methacrylate / methyl methacrylate (copolymerization ratio 5/5) were put into a high-speed mixer equipped with stirring blades at 120 ° C. A carrier having a volume-based median diameter of 50 μm was obtained by stirring and mixing for 30 minutes to form a resin coat layer on the surface of the ferrite core by the action of mechanical impact force.
The volume-based median diameter of the carrier was measured with a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by Sympathic) equipped with a wet disperser.

(2) Mixing of toner and carrier To each of the toners [1] to [27], the above carrier is added so that the toner concentration becomes 6%. The developer [1] to [27] was produced by mixing at a rotational speed of 45 rpm for 30 minutes.

[Evaluation]
(1) Low-temperature fixability In a commercially available color multifunction peripheral “bizhub PRO C6500” (manufactured by Konica Minolta Business Technologies), the surface of the lower fixing roller is set to a surface temperature of the fixing upper belt in the range of 140 to 170 ° C. Developers [1] to [27] were mounted using the ones modified so that the temperature could be changed within the range of 120 to 150 ° C. A fixing experiment in which a solid image with a toner adhesion amount of 11.3 g / m ² is fixed at a fixing speed of 300 mm / sec on an evaluation paper “NPi fine paper 128 g / m ² ” (manufactured by Nippon Paper Industries Co., Ltd.) is fixed by cold offset. Until a defect was observed, the fixing temperature (surface temperature of the fixing upper belt) was repeatedly changed while being changed in steps of 5 ° C. at 170 ° C., 165 ° C., and so on. The lower fixing roller was always set to a surface temperature 20 ° C. lower than the surface temperature of the upper fixing belt. Then, the lowest fixing temperature in the fixing experiment in which fixing failure due to cold offset was not observed was evaluated as the lower limit fixing temperature. In addition, it means that it is excellent in low temperature fixability, so that this fixing minimum temperature is low, and if it is 160 degrees C or less, it will be judged that there is no problem practically and it is a pass. The results are shown in Table 3.

(2) Glossiness Commercially available color multifunction peripherals “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies, Inc.) were used, and developers [1] to [27] were mounted, respectively. Evaluation paper “POD 128 g gloss coat (128 g / m ² )” (Oji) under the environment of normal temperature and normal humidity (temperature 20 ° C., humidity 50% RH) with the surface temperature of the heating member (fixing belt) of the fixing device being 180 ° C. A solid image having a toner adhesion amount of 3.4 g / m ² on the evaluation paper was formed. The glossiness of the obtained image was measured with “micro-gloss” (manufactured by BYK) at an incident angle of 75 °. If the glossiness is 58 or less, it is determined to be acceptable. The results are shown in Table 3.

(3) Toner Scattering A developer was put in a Monet developing machine, and the number of scattered toner was counted with a particle counter while stirring with a single unit motive. If the count is 5000 or less, it is determined to be acceptable. The results are shown in Table 3.

  From the above results, it was confirmed that the toners [1] to [21] according to Examples 1 to 21 can form a low-gloss image while ensuring low-temperature fixability. Moreover, in Examples 1-21, the result which becomes favorable also about toner scattering was obtained.

Claims (7)

Consisting of toner particles in which a shell layer is formed on the core particles,
A toner for developing an electrostatic charge image, wherein the shell layer contains a chelate compound represented by the following general formula (1).

[In the general formula (1), M represents a divalent metal ion, and R ¹ , R ^2, and R ³ represent a hydrogen atom, an electron-withdrawing group, or a straight-chain or branched carbon, respectively. An alkyl group, an alkenyl group, an alkoxy group or an alkenyloxy group represented by formulas 12 to 22 is shown. However, at least one of R ¹ , R ² and R ³ is an electron withdrawing group, and the sum of the substituent constants (σp value) of the electron withdrawing group is 0.4 to 4.0. And at least one of R ¹ , R ² and R ³ is a linear or branched alkyl group having 12 to 22 carbon atoms, an alkenyl group, an alkoxy group or an alkenyloxy group. ] The electrostatic charge image developing toner according to claim 1, wherein M in the general formula (1) is Cu ²⁺ , Ni ^2+, or Zn ²⁺ . At least one of R ¹ , R ² and R ³ in the general formula (1) is a cyano group, a nitro group, a dichloromethyl group, a dibromomethyl group, an alkoxyacyl group, an acyl group, and a substituent thereof. The toner for developing an electrostatic charge image according to claim 1, wherein the toner is an electron withdrawing group selected from aromatic rings having the above.   4. The electrostatic charge image developing device according to claim 1, wherein the chelate compound represented by the general formula (1) is contained in the toner particles at a ratio of 1 to 8% by mass. 5. toner. That at least one of R ¹ , R ² and R ³ in the general formula (1) is a linear or branched alkyl group having 15 to 20 carbon atoms, an alkenyl group, an alkoxy group or an alkenyloxy group. The electrostatic charge image developing toner according to claim 1, wherein the toner is for electrostatic image development. The resin constituting the core particle is a styrene-acrylic copolymer resin,
6. The electrostatic image developing toner according to claim 1, wherein the resin constituting the shell layer is a polyester resin.   The polyester resin constituting the shell layer is one in which a styrene-acrylic copolymer segment is bonded to the terminal of the polyester segment, and the content ratio of the styrene-acrylic copolymer segment in the styrene-acrylic modified polyester resin. The toner for developing an electrostatic charge image according to claim 6, wherein the toner is 5% by mass or more and 30% by mass or less.