Toner for electrostatic image development, electrostatic image developer and toner cartridge

Abstract

The present invention provides a toner for electrostatic image development, an electrostatic image developer and a toner box that have excellent gloss unevenness suppression properties even when forming an image with a large amount of toner per unit area. The electrostatic image development toner has a toner masterbatch containing at least a binding resin and a release agent, the binding resin containing a mixed resin having a polyester resin segment and a styrene-acrylic copolymer segment, and the molecular weight distribution curve of the mixed resin satisfies formula (1). a represents the width of the low molecular weight side at 15% of the height of the maximum peak when a perpendicular line is drawn from the baseline of the molecular weight distribution curve to the maximum peak; b represents the width of the high molecular weight side at 15% of the height of the maximum peak when a perpendicular line is drawn from the baseline of the molecular weight distribution curve to the maximum peak. 1.3≦b / a≦2.5 Formula (1).

Description

Technical Field

[0001] The present invention relates to a toner for developing electrostatic charge images, an electrostatic charge image developer and a toner box. Background Art

[0002] Methods such as electrophotography that visualize image information via electrostatic charge images are currently used in various fields.

[0003] In the past, in electronic photography, a method generally used to make it visible is to use the following multiple steps: various components are used to form an electrostatic latent image on a photoreceptor or an electrostatic recording body, and charge-detecting particles called toner are attached to the electrostatic latent image to develop the electrostatic latent image (toner image), transfer it to the surface of the transfer body, and fix it by heating or the like.

[0004] In addition, as a conventional method for producing toner, the method described in Patent Document 1 is known.

[0005] Patent document 1 discloses a method for producing a toner for electrostatic image development, comprising the steps of agglomerating and fusing particles containing resin particles and colorant particles in an aqueous medium. In the method for producing a toner for electrostatic image development, the resin particles contain a mixed resin having an addition polymerized resin segment which is an addition polymer of a raw material monomer containing a polyester segment and a styrene-based compound and a unit derived from a bireactive monomer, and the colorant particles are obtained by mixing a colorant with a compound represented by the following formula (1).

[0006] [Chemistry 1]

[0007]

[0008] 〔In the formula, R 1 is an alkanediyl group having 1 to 12 carbon atoms, m represents an average number of substitutions, and the value of m is 1 to 4, R 2 A is a hydrogen atom or a methyl group. 1 O represents an oxyalkylene group, A 1 is ethylene or propylene, n is the average number of added moles of alkylene oxide, and the value of n is 5 or more and 100 or less]

[0009] Furthermore, as a conventional toner, the one described in Patent Document 2 is known.

[0010] Patent document 2 discloses a toner having toner particles containing a binder resin and a release agent, wherein the toner is characterized in that: the binder resin contains a binder resin A and a binder resin B, the binder resin A is a mixed resin in which a vinyl polymer unit and a polyester unit are chemically bonded, the mass ratio of the vinyl polymer unit to the polyester unit (vinyl polymer unit / polyester unit) is 10 / 90 to 50 / 50, and the vinyl polymer unit is a polymer obtained by polymerizing at least styrene and a compound represented by formula (1),

[0011] CH2=CR 1 COOR 2 Formula (1)

[0012] (R 1 : indicates H or methyl, R 2 : represents an alkyl group or a hydroxyalkyl group with a carbon number of 12 or less)

[0013] The ratio of the compound represented by formula (1) relative to the total molar number of the vinyl monomers used in the polymerization of the vinyl polymer units is greater than or equal to 20 mol% and less than or equal to 90 mol%, and the binder resin B is a polyester resin formed by condensing at the terminal at least one aliphatic compound selected from the group consisting of an aliphatic monocarboxylic acid having a carbon number of greater than or equal to 102 and an aliphatic monoalcohol having a carbon number of greater than or equal to 25 and less than 102.

[0014] Prior art literature

[0015] Patent Literature

[0016] Patent Document 1: Japanese Patent Application Publication No. 2018-97153

[0017] Patent Document 2: Japanese Patent Application Publication No. 2018-13600 Summary of the invention

[0018] Problems to be solved by the invention

[0019] The problem to be solved by the present invention is to provide a toner for electrostatic charge image development that has excellent gloss unevenness suppression properties even when forming an image with a large toner load per unit area, compared to a case where the binder resin contains only a styrene-acrylic acid copolymer or the b / a of the molecular weight distribution curve of the toner is less than 1.3 or exceeds 2.5.

[0020] Technical means of solving problems

[0021] Specific means for solving the above-mentioned problems include the following embodiments.

[0022] <1> A toner for electrostatic image development, comprising a toner base particle containing at least a binder resin and a release agent, wherein the binder resin comprises a mixed resin having a polyester resin segment and a styrene-acrylic copolymer segment, wherein the molecular weight distribution curve of the toner satisfies the following formula (1).

[0023] 1.3≦b / a≦2.5Formula (1)

[0024] In formula (1), a represents the width of the lower molecular weight side at a height of 15% of the maximum peak height when a perpendicular line is drawn from the baseline of the molecular weight distribution curve to the maximum peak; b represents the width of the higher molecular weight side at a height of 15% of the maximum peak height when a perpendicular line is drawn from the baseline of the molecular weight distribution curve to the maximum peak.

[0025] <2> The electrostatic image developing toner according to <1>, wherein a molecular weight distribution curve of the toner satisfies the following formula (2).

[0026] 2.5≦b / c Formula (2)

[0027] c represents the width of the high molecular weight side closer to the vertical line at a height of 40% of the maximum peak height when a vertical line is drawn from the base line to the maximum peak of the molecular weight distribution curve.

[0028] <3> The electrostatic image developing toner according to <1> or <2>, wherein a ratio of a width d at 15% of the maximum peak height to a width e at 40% of the maximum peak height of the toner molecular weight distribution curve satisfies d / e≧2.0.

[0029] <4> The electrostatic charge image developing toner according to any one of <1> to <3>, wherein a weight average molecular weight Mw of the binder resin is 50,000 or more and 120,000 or less.

[0030] <5> The electrostatic charge image developing toner according to any one of <1> to <4>, wherein a z average molecular weight Mz of the binder resin is 200,000 or more and 1,300,000 or less.

[0031] <6> The electrostatic charge image developing toner according to any one of <1> to <5>, wherein the mixed resin has a gel fraction of 3% by mass or more and 15% by mass or less.

[0032] <7> The electrostatic charge image developing toner according to any one of <1> to <6>, wherein the toner base particles further contain a colorant.

[0033] <8> The electrostatic charge image developing toner according to <7>, wherein the colorant contains CI Pigment Yellow 74.

[0034] <9> The electrostatic charge image developing toner according to any one of <1> to <8>, wherein a content of the structural unit derived from styrene in the mixed resin is 5% by mass or more and 20% by mass or less based on the total mass of the mixed resin.

[0035] <10> The electrostatic charge image developing toner according to any one of <1> to <9>, wherein the domain diameter of the release agent in the toner base particles is 400 nm or more and 1,500 nm or less.

[0036] <11> The electrostatic image developing toner according to any one of <1> to <10>, wherein the toner base particles further contain 1-amino-2-methoxybenzene.

[0037] <12> The electrostatic image developing toner according to <11>, wherein a content of the 1-amino-2-methoxybenzene is 1 ppm or more and 100 ppm or less based on the total mass of the toner.

[0038] <13> An electrostatic image developer comprising the electrostatic image developing toner according to any one of <1> to <12>.

[0039] <14> A toner cartridge that houses the electrostatic image developing toner according to any one of <1> to <12> and is detachably mountable in an image forming apparatus.

[0040] <15> A processing box that can be detachably installed in an image forming device, the processing box including a developing component that accommodates the electrostatic charge image developer according to <13>, and uses the electrostatic charge image developer to develop the electrostatic charge image formed on the surface of the image retaining body into a toner image.

[0041] <16> An image forming device, comprising: an image retaining body; a charging component for charging the surface of the image retaining body; an electrostatic charge image forming component for forming an electrostatic charge image on the charged surface of the image retaining body; a developing component for storing the electrostatic charge image developer according to <13> and developing the electrostatic charge image formed on the surface of the image retaining body into a toner image using the electrostatic charge image developer; a transferring component for transferring the toner image formed on the surface of the image retaining body to the surface of a recording medium; and a fixing component for fixing the toner image transferred to the surface of the recording medium.

[0042] <17> An image forming method, comprising: a charging step of charging the surface of an image retaining body; an electrostatic charge image forming step of forming an electrostatic charge image on the charged surface of the image retaining body; a developing step of developing the electrostatic charge image formed on the surface of the image retaining body into a toner image using the electrostatic charge image developer according to <13>; a transferring step of transferring the toner image formed on the surface of the image retaining body to the surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0043] Effects of the Invention

[0044] According to the invention of <1> or <7>, the following electrostatic charge image developing toner can be provided: compared with the case where the binding resin only contains styrene-acrylic resin, or the b / a of the molecular weight distribution curve of the toner is less than 1.3 or exceeds 2.5, even when an image with a large toner carrying amount per unit area is formed, the gloss unevenness suppression property is excellent.

[0045] According to the invention of <2>, there is provided an electrostatic image developing toner having better gloss unevenness suppression performance than when the b / c in the molecular weight distribution curve of the toner is less than 2.5 even when an image having a large toner load per unit area is formed.

[0046] According to the invention of <3>, the following electrostatic charge image developing toner can be provided: compared with the case where the ratio d / e of the width d at 15% of the maximum peak height to the width e at 40% of the maximum peak height of the molecular weight distribution curve of the binder resin is less than 2.0, the gloss unevenness suppression property is better even when an image with a large toner carrying amount per unit area is formed.

[0047] According to the invention of <4>, a toner for electrostatic image development can be provided which has better gloss unevenness suppression performance even when forming an image with a large toner load per unit area, compared with a case where the weight average molecular weight Mw of the binder resin is less than 50,000 or exceeds 120,000.

[0048] According to the invention of <5>, there is provided an electrostatic image developing toner having a better gloss unevenness suppression property than when the toner has a z average molecular weight Mz of less than 200,000 or more than 1,300,000 even when forming an image with a large toner load per unit area.

[0049] According to the invention of <6>, a toner for electrostatic image development can be provided that has better gloss unevenness suppression performance even when forming an image with a large toner load per unit area, compared with a case where the gel fraction of the mixed resin is less than 3% by mass or exceeds 15% by mass.

[0050] According to the invention of <8>, the following electrostatic charge image developing toner can be provided: compared with the case where the colorant is used alone as CI Pigment Yellow 75, CI Pigment Yellow 81, CI Pigment Yellow 93, or CI Pigment Yellow 95, even when an image with a large toner load per unit area is formed, the gloss unevenness suppression property is better.

[0051] According to the invention of <9>, the following electrostatic charge image developing toner can be provided: compared with the case where the content of the structural units derived from styrene in the mixed resin is less than 5% by mass or exceeds 20% by mass relative to the total mass of the mixed resin, even when an image with a large toner carrying amount per unit area is formed, the gloss unevenness suppression property is better.

[0052] According to the invention of <10>, a toner for electrostatic image development can be provided that has better gloss unevenness suppression properties even when forming an image with a large toner load per unit area, compared with the case where the domain diameter of the release agent in the toner base particles is less than 400 nm or exceeds 1,500 nm.

[0053] According to the invention of <11>, it is possible to provide an electrostatic image developing toner having better gloss unevenness suppression performance than when the toner base particles do not contain 1-amino-2-methoxybenzene even when forming an image with a large toner load per unit area.

[0054] According to the invention of <12>, the following electrostatic charge image developing toner can be provided: compared with the case where the content of the 1-amino-2-methoxybenzene relative to the total mass of the toner is less than 1 ppm or exceeds 100 ppm, even when an image with a large toner load per unit area is formed, the gloss unevenness suppression property is better.

[0055] According to the inventions of <13> to <17>, the following electrostatic charge image developer, toner box, processing box, image forming device or image forming method can be provided: compared with the case where the binding resin in the toner contains only styrene-acrylic resin, or the b / a of the molecular weight distribution curve of the mixed resin is less than 1.3 or exceeds 2.5, even when an image with a large toner carrying amount per unit area is formed, the gloss unevenness suppression property is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a schematic diagram showing an example of a molecular weight distribution curve of the mixed resin used in the present embodiment.

[0057] Figure 2 It is a diagram schematically showing the configuration of the image forming apparatus according to the present embodiment.

[0058] Figure 3 It is a diagram schematically showing the configuration of a process cartridge according to the present embodiment.

[0059] Explanation of symbols

[0060] R: Molecular weight distribution curve

[0061] PL: A vertical line drawn from the baseline to the maximum peak of the molecular weight distribution curve

[0062] PT: Maximum peak value of molecular weight distribution curve

[0063] P1: 15% height of the maximum peak height

[0064] P2: 40% of the maximum peak height

[0065] a: When a vertical line is drawn from the baseline of the molecular weight distribution curve to the maximum peak, the width of the lower molecular weight side at a height 15% of the maximum peak height.

[0066] b: When a vertical line is drawn from the baseline of the molecular weight distribution curve to the maximum peak, the width of the high molecular weight side at a height 15% of the maximum peak height is closer to the vertical line.

[0067] c: When a vertical line is drawn from the baseline of the molecular weight distribution curve to the maximum peak, the width of the high molecular weight side at a height of 40% of the maximum peak height is

[0068] d: The width of the molecular weight distribution curve at 15% of the maximum peak height

[0069] e: The width of the molecular weight distribution curve at 40% of the maximum peak height

[0070] 1Y, 1M, 1C, 1K: Photoreceptor (an example of an image holding body)

[0071] 2Y, 2M, 2C, 2K: Charging roller (an example of a charging member)

[0072] 3: Exposure device (an example of electrostatic charge image forming member)

[0073] 3Y, 3M, 3C, 3K: Laser light

[0074] 4Y, 4M, 4C, 4K: Development device (an example of a development unit)

[0075] 5Y, 5M, 5C, 5K: primary transfer rollers (an example of primary transfer members)

[0076] 6Y, 6M, 6C, 6K: Photosensitive body cleaning device (an example of an image holding body cleaning member)

[0077] 8Y, 8M, 8C, 8K: Toner cartridge

[0078] 10Y, 10M, 10C, 10K: Image forming unit

[0079] 20: Intermediate transfer belt (an example of an intermediate transfer body)

[0080] 22: Driving roller

[0081] 24: Support roller

[0082] 26: Secondary transfer roller (an example of a secondary transfer member)

[0083] 28: Fixing device (an example of a fixing part)

[0084] 30: Intermediate transfer belt cleaning device (an example of an intermediate transfer body cleaning component)

[0085] P: Recording paper (an example of recording medium)

[0086] 107: Photoreceptor (an example of an image holding member)

[0087] 108: Charging roller (an example of a charging component)

[0088] 109: Exposure device (an example of electrostatic charge image forming member)

[0089] 111: Development device (an example of a development unit)

[0090] 112: Transfer device (an example of a transfer member)

[0091] 113: Photosensitive body cleaning device (an example of a photosensitive body cleaning member)

[0092] 115: Fixing device (an example of a fixing member)

[0093] 116: Install the rails

[0094] 117: Frame

[0095] 118: Opening for exposure

[0096] 200: Processing box

[0097] 300: Recording paper (an example of recording medium) DETAILED DESCRIPTION

[0098] When the amount of each component in the composition is mentioned in the present specification, when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified, the amount refers to the total amount of the plurality of substances present in the composition.

[0099] In this specification, “toner for developing electrostatic charge image” is also simply referred to as “toner”, and “electrostatic charge image developer” is also simply referred to as “developer”.

[0100] Hereinafter, an embodiment as an example of the present invention will be described.

[0101] <Toner for electrostatic image development>

[0102] The electrostatic charge image developing toner of this embodiment has a toner base particle containing at least a binder resin and a release agent, wherein the binder resin contains a mixed resin having a polyester resin segment and a styrene-acrylic copolymer segment, and the molecular weight distribution curve of the toner satisfies the following formula (1).

[0103] 1.3≦b / a≦2.5Formula (1)

[0104] a represents the width of the lower molecular weight side at 15% of the height of the maximum peak when a vertical line is drawn from the baseline of the molecular weight distribution curve to the maximum peak; b represents the width of the higher molecular weight side at 15% of the height of the maximum peak when a vertical line is drawn from the baseline of the molecular weight distribution curve to the maximum peak.

[0105] Conventional binder resins used for toners have insufficient elasticity of toners and therefore are not sufficiently releasable from recording media. When an image having a large amount of toner per unit area is formed, gloss unevenness is likely to occur.

[0106] The electrostatic charge image developing toner of the present embodiment has excellent gloss unevenness suppression (hereinafter also referred to as “gloss unevenness suppression”) due to the above-mentioned structure even when forming an image with a large toner carrying amount per unit area. The reason for this is not certain, but it is presumed to be due to the following reasons.

[0107] The binder resin comprises a mixed resin having a polyester resin chain segment and a styrene-acrylic copolymer chain segment, wherein the molecular weight distribution curve of the mixed resin satisfies the formula (1). Thus, the binder resin contains a large number of high molecular weight components, and both the elasticity of the toner and the exudation of the release agent are taken into consideration. Therefore, even when an image having a large toner carrying amount per unit area is formed, the gloss unevenness suppression property (hereinafter also referred to as "gloss unevenness suppression property") is excellent.

[0108] Since the mixed resin having the polyester resin segment and the styrene-acrylic copolymer segment as the binder resin has two resin species in one molecule, the two resin species are uniformly dispersed. Therefore, by having the mixed resin having the resin species uniformly dispersed, unevenness during fixing is reduced.

[0109] Hereinafter, the electrostatic image developing toner according to the present embodiment will be described in detail.

[0110] The toner of the present embodiment includes toner base particles (also referred to as "toner particles") and, if necessary, external additives.

[0111] In addition, from the viewpoint of suppressing uneven gloss, the toner of the present embodiment is preferably a yellow toner.

[0112] (Toner Masterbatch)

[0113] The toner base particles contain, for example, a binder resin, a release agent, a colorant as needed, and other additives, and preferably contain a binder resin, a colorant, and a release agent.

[0114] -Bonding resin-

[0115] The electrostatic image developing toner of this embodiment has a toner base particle containing at least a binder resin, wherein the binder resin contains a mixed resin having a polyester resin segment and a styrene-acrylic copolymer segment, and the molecular weight distribution curve of the toner satisfies the formula (1).

[0116] <<Mixed resin having polyester resin segment and styrene-acrylic acid copolymer segment>>

[0117] The binder resin includes a mixed resin (also referred to as a “mixed resin”) having a polyester resin segment and a styrene-acrylic acid copolymer segment.

[0118] In addition, the mixed resin satisfies the formula (1).

[0119] 〔Molecular weight distribution curve〕

[0120] A schematic diagram showing an example of a molecular weight distribution curve of the toner used in this embodiment is shown in FIG. Figure 1 .

[0121] Figure 1 The horizontal axis represents the molecular weight, and the vertical axis represents the weight fraction.

[0122] Figure 1 The molecular weight distribution curve R in has a maximum peak PT.

[0123] In addition, a is the width of the lower molecular weight side at a height P1 that is 15% of the maximum peak height when a perpendicular line PL is drawn from the baseline of the molecular weight distribution curve R to the maximum peak PT; b is the width of the higher molecular weight side at a height P1 that is 15% of the maximum peak height when a perpendicular line PL is drawn from the baseline of the molecular weight distribution curve R to the maximum peak PT.

[0124] In addition, c is the width of the high molecular weight side at a height P2 that is 40% of the maximum peak height when a vertical line PL is drawn from the baseline of the molecular weight distribution curve R to the maximum peak PT; d is the width at a height P1 that is 15% of the maximum peak height of the molecular weight distribution curve R; and e is the width at a height P2 that is 40% of the maximum peak height of the molecular weight distribution curve R.

[0125] From the viewpoint of gloss unevenness suppression, the molecular weight distribution curve of the toner preferably satisfies the following formula (1-1), and more preferably satisfies the following formula (1-2).

[0126] 1.5≦b / a≦2.4Formula (1-1)

[0127] 1.8≦b / a≦2.3Formula (1-2)

[0128] From the viewpoint of gloss unevenness suppression, the molecular weight distribution curve of the toner preferably satisfies the following formula (2), more preferably satisfies the following formula (2-1), and particularly preferably satisfies the following formula (2-2).

[0129] 2.5≦b / c Formula (2)

[0130] 3.0≦b / c Formula (2-1)

[0131] 3.5≦b / c≦5.0Formula (2-2)

[0132] c represents the width of the high molecular weight side closer to the vertical line at a height of 40% of the maximum peak height when a vertical line is drawn from the base line to the maximum peak of the molecular weight distribution curve.

[0133] In addition, from the perspective of suppressing gloss unevenness, the ratio of the width d at 15% of the maximum peak height of the molecular weight distribution curve of the color powder to the width e at 40% of the maximum peak height preferably satisfies d / e≧2.0, more preferably satisfies d / e≧2.5, and particularly preferably satisfies 5.0≧d / e≧3.0.

[0134] 〔Average molecular weight of binder resin〕

[0135] From the viewpoint of suppressing gloss unevenness, the weight average molecular weight Mw of the binder resin is preferably 10,000 or more and 200,000 or less, more preferably 50,000 or more and 120,000 or less, and particularly preferably 60,000 or more and 110,000 or less.

[0136] From the viewpoint of suppressing gloss unevenness, the z average molecular weight Mz of the binder resin is preferably 100,000 to 2,000,000, more preferably 200,000 to 1,300,000, and particularly preferably 400,000 to 1,000,000.

[0137] The average molecular weight of the binder resin is determined by gel permeation chromatography (GPC). The molecular weight determination using GPC is carried out using GPC HLC-8120GPC manufactured by Tosoh (stock) as a measuring device, and using a column TSKgel SuperHM-M (15cm) manufactured by Tosoh (stock) under a tetrahydrofuran (THF) solvent. According to the measurement results, a molecular weight distribution curve (molecular weight calibration curve) is prepared using a monodisperse polystyrene standard sample. Then, the weight average molecular weight Mw and the z average molecular weight Mz are calculated based on the obtained molecular weight distribution curve.

[0138] 〔Gel fraction of mixed resin〕

[0139] From the viewpoint of suppressing gloss unevenness, the gel fraction of the mixed resin is preferably 1 mass % to 20 mass %, more preferably 3 mass % to 15 mass %, particularly preferably 4 mass % to 10 mass %.

[0140] The determination of the gel fraction is based on Japanese Industrial Standards (JIS) K6796 (1998). The mixed resin to be measured is taken from the toner and the mass is measured. This is set as the mass of the mixed resin before solvent extraction. After that, after immersion in tetrahydrofuran at 45°C for 24 hours, the residue is filtered and separated and recovered, and the residue is dried and the mass is measured. The mass is set as the dry mass of the residue after extraction. The gel fraction is calculated according to the following formula.

[0141] Gel fraction (%) = ((dry mass of the residue after extraction) / (mass of the mixed resin before solvent extraction)) × 100

[0142] The gel fraction of the mixed resin can be adjusted by using a trivalent or higher polycarboxylic acid or a trivalent or higher polyol in the polyester resin segment.

[0143] However, the details of the mechanism for improving the "gloss unevenness suppression property" in an image having a large toner load per unit area are not clear, but are considered as follows.

[0144] It is necessary to utilize the close fine dispersion in the toner by the π-π interaction between aromatic groups such as styrene and aromatic groups in the pigment.

[0145] Furthermore, the three-dimensional structure of styrene is effective for fine dispersion of styrene, and therefore gelation in the styrene-acrylic acid copolymer is considered to be necessary.

[0146] For the three-dimensional structure of the styrene-acrylic acid copolymer segment, an acrylic acid monomer having an unsaturated bond site of divalent or higher valence is effective, and a di(meth)acrylate compound or a polyfunctional (meth)acrylate compound is preferred.

[0147] Examples of the di(meth)acrylate compound include polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, and 1,10-decanediol diacrylate. Examples of the polyfunctional (meth)acrylate compound include pentaerythritol triacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate.

[0148] 〔Polyester resin segment〕

[0149] The polyester resin segment of the mixed resin is preferably a polycondensate of an alcohol component (a-a1) and a carboxylic acid component (a-ac). The mixed resin having the polyester resin segment can provide a toner having excellent low-temperature fixability.

[0150] The alcohol component (a-a1) may include linear or branched aliphatic diols, aromatic diols, alicyclic diols, trivalent or higher polyols, etc. Among these, aromatic diols are preferred, and alkylene oxide adducts of bisphenol A are more preferred from the viewpoint of improving low-temperature fixability and image density of printed materials.

[0151] The alkylene oxide adduct of bisphenol A is preferably at least one selected from the group consisting of an ethylene oxide adduct of bisphenol A (2,2-bis(4-hydroxyphenyl)propane) and a propylene oxide adduct of bisphenol A, and more preferably a propylene oxide adduct of bisphenol A.

[0152] The average number of moles of alkylene oxide added in the alkylene oxide adduct of bisphenol A is preferably 1 or more, more preferably 1.2 or more, further preferably 1.5 or more, and is preferably 16 or less, more preferably 12 or less, further preferably 8 or less, particularly preferably 4 or less.

[0153] The amount of the alkylene oxide adduct of bisphenol A in the alcohol component (a-a1) is preferably 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, particularly preferably 98 mol% or more and 100 mol% or less, and most preferably 100 mol%.

[0154] The alcohol component (a-a1) may contain other alcohol components different from the alkylene oxide adduct of bisphenol A. Examples of other alcohol components include linear or branched aliphatic diols, other aromatic diols, alicyclic diols, trivalent or higher polyols, and the like.

[0155] Examples of the linear or branched aliphatic diol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,3-butylene glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol.

[0156] Examples of the alicyclic diol include hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane) and an alkylene oxide (average addition mole number of 2 to 12) adduct of hydrogenated bisphenol A having 2 to 4 carbon atoms.

[0157] Examples of the trivalent or higher polyhydric alcohol include glycerin, pentaerythritol, trimethylolpropane, and sorbitol.

[0158] These alcohol components can be used alone or in combination of two or more.

[0159] Examples of the carboxylic acid component (a-ac) include dicarboxylic acids and trivalent or higher-valent polycarboxylic acids.

[0160] Examples of the dicarboxylic acid include aromatic dicarboxylic acids, linear or branched aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Among these, at least one compound selected from the group consisting of aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferred.

[0161] Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, etc. Among these, at least one compound selected from the group consisting of isophthalic acid and terephthalic acid is preferred, and terephthalic acid is more preferred.

[0162] The amount of the aromatic dicarboxylic acid in the carboxylic acid component (a-ac) is preferably 20 mol% or more, more preferably 25 mol% or more, and further preferably 30 mol% or more, and is preferably 90 mol% or less, more preferably 70 mol% or less, and further preferably 50 mol% or less.

[0163] The carbon number of the linear or branched aliphatic dicarboxylic acid is preferably 2 or more, more preferably 3 or more, and is preferably 30 or less, more preferably 20 or less.

[0164] Examples of the linear or branched aliphatic dicarboxylic acid having 2 to 30 carbon atoms include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, and succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms.

[0165] Examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, octenylsuccinic acid, and the like.

[0166] Among these, at least one compound selected from the group consisting of terephthalic acid, sebacic acid, and fumaric acid is preferred, and a combination of two or more of these is more preferred.

[0167] As the trivalent or higher polyvalent carboxylic acid, a trivalent carboxylic acid is preferred, and an example thereof is trimellitic acid.

[0168] When a trivalent or higher polycarboxylic acid is included, the amount of the trivalent or higher polycarboxylic acid in the carboxylic acid component (a-ac) is preferably 3 mol% or more, more preferably 5 mol% or more, and is preferably 20 mol% or less, more preferably 15 mol% or less, and further preferably 12 mol% or less.

[0169] These carboxylic acid components can be used alone or in combination of two or more.

[0170] The ratio of the carboxyl group of the carboxylic acid component (a-ac) to the hydroxyl group of the alcohol component (a-al) [COOH group / OH group] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0171] 〔Styrene-acrylic acid copolymer segment〕

[0172] Examples of the styrene compound used to form the styrene-acrylic copolymer segment include substituted or unsubstituted styrene, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group or a salt thereof.

[0173] Examples of the styrene-based compound include styrenes such as styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, and styrenesulfonic acid or salts thereof.

[0174] Among these, styrene is preferred.

[0175] From the viewpoint of suppressing uneven gloss, the amount of the styrene compound, preferably styrene, in the raw material monomers of the styrene-acrylic copolymer segment is preferably 50 mass % or more and 95 mass % or less, more preferably 55 mass % or more and 90 mass % or less, and particularly preferably 60 mass % or more and 85 mass % or less.

[0176] From the viewpoint of suppressing uneven gloss, the content of the monomer unit derived from a styrene-based compound, preferably derived from styrene (also referred to as "monomer unit formed from styrene"), relative to the total mass of the styrene-acrylic copolymer segment is preferably 50% by mass or more and 95% by mass or less, more preferably 55% by mass or more and 90% by mass or less, and particularly preferably 60% by mass or more and 85% by mass or less.

[0177] Furthermore, from the viewpoint of suppressing uneven gloss, the content of the constituent units derived from styrene in the mixed resin is preferably from 1 mass % to 50 mass %, more preferably from 3 mass % to 40 mass %, further preferably from 5 mass % to 35 mass %, and particularly preferably from 8 mass % to 30 mass %, relative to the total mass of the mixed resin.

[0178] Preferred examples of the (meth)acrylic acid compound used to form the styrene-acrylic acid copolymer segment include (meth)acrylic acid ester compounds, (meth)acrylamide compounds, (meth)acrylic acid, and (meth)acrylonitrile. More preferred examples include (meth)acrylic acid ester compounds, and particularly preferred examples include alkyl esters of (meth)acrylic acid. In the case of alkyl esters of (meth)acrylic acid, the hydrocarbon group is an alcohol side residue of the ester.

[0179] Examples of the alkyl ester of (meth)acrylic acid include (iso)propyl (meth)acrylate, (iso)butyl (meth)acrylate, (iso)hexyl (meth)acrylate, cyclohexyl (meth)acrylate, (iso)octyl (meth)acrylate (hereinafter also referred to as 2-ethylhexyl (meth)acrylate), (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate (hereinafter also referred to as (iso)lauryl (meth)acrylate), (iso)palmityl (meth)acrylate, (iso)stearyl (meth)acrylate, and (iso)behenyl (meth)acrylate.

[0180] Among these, 2-ethylhexyl (meth)acrylate, (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate, (iso)stearyl (meth)acrylate, and (iso)behenyl (meth)acrylate are preferred; 2-ethylhexyl (meth)acrylate, (iso)dodecyl (meth)acrylate, and (iso)stearyl (meth)acrylate are more preferred; (iso)dodecyl (meth)acrylate and (iso)stearyl (meth)acrylate are further preferred; and (iso)stearyl (meth)acrylate is further preferred.

[0181] Here, "alkyl (meth)acrylate" means alkyl acrylate or alkyl methacrylate. In addition, regarding the alkyl part, "(iso)" means normal alkyl or isoalkyl.

[0182] From the viewpoint of suppressing uneven gloss, the amount of the (meth)acrylic compound in the raw material monomers of the styrene-acrylic copolymer segment is preferably 5 mass % or more and 50 mass % or less, more preferably 10 mass % or more and 45 mass % or less, particularly preferably 15 mass % or more and 40 mass % or less.

[0183] From the viewpoint of suppressing uneven gloss, the content of the monomer unit derived from the (meth)acrylic compound is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, particularly preferably 15% by mass or more and 40% by mass or less, relative to the total mass of the styrene-acrylic copolymer segment.

[0184] As other raw material monomers, for example, there can be listed: ethylene unsaturated monoolefins such as ethylene and propylene; conjugated dienes such as butadiene; vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; (meth)acrylic acid aminoalkyl esters such as dimethylaminoethyl (meth)acrylate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinyl pyrrolidone.

[0185] [Units derived from direactive monomers]

[0186] From the viewpoint of image density in printed matter, the mixed resin preferably has units derived from a bireactive monomer. If a bireactive monomer is used as a raw material monomer of the mixed resin, the bireactive monomer reacts with the polyester resin segment, the styrene-acrylic copolymer segment, or these raw material monomers respectively to become a bonding point between the polyester resin segment and the styrene-acrylic copolymer segment.

[0187] The "unit derived from a bireactive monomer" refers to a unit in which a functional group or a vinyl site of a bireactive monomer reacts.

[0188] As the bireactive monomer, for example, there can be mentioned a vinyl monomer having at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group and a secondary amino group in the molecule. Among these, from the viewpoint of reactivity, a vinyl monomer having a hydroxyl group or a carboxyl group is preferred, and a vinyl monomer having a carboxyl group is more preferred.

[0189] Examples of the bireactive monomer include acrylic acid, methacrylic acid, fumaric acid, maleic acid, etc. Among these, acrylic acid and methacrylic acid are preferred from the viewpoint of reactivity in both polycondensation reaction and addition polymerization reaction, and acrylic acid is more preferred.

[0190] From the viewpoint of further improving the image density of printed materials, the content of the unit derived from the amphireactive monomer is preferably 1 mol part or more, more preferably 5 mol parts or more, and further preferably 8 mol parts or more, and is preferably 30 mol parts or less, more preferably 25 mol parts or less, and further preferably 20 mol parts or less, relative to 100 mol parts of the alcohol component of the polyester resin segment of the mixed resin. In addition, when using an amphireactive monomer, when calculating the amount of each segment in the mixed resin, the structural unit derived from the amphireactive monomer is calculated as the structural unit contained in the polyester resin segment.

[0191] From the viewpoint of suppressing uneven gloss, the amount of the polyester resin segment in the mixed resin is preferably 40% by mass or more, more preferably 50% by mass or more, and further preferably 55% by mass or more, and is preferably 95% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass or less, relative to the total mass of the mixed resin.

[0192] From the viewpoint of suppressing uneven gloss, the amount of the styrene-acrylic copolymer segment in the mixed resin is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, and further preferably 45% by mass or less, relative to the total mass of the mixed resin.

[0193] From the viewpoint of suppressing uneven gloss, the total amount of the polyester resin segment and the styrene-acrylic copolymer segment in the mixed resin is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, further preferably 93% by mass or more and 100% by mass or less, particularly preferably 95% by mass or more and 100% by mass or less, relative to the total mass of the mixed resin.

[0194] From the viewpoint of suppressing density unevenness of the obtained image, the softening temperature Tm of the mixed resin is preferably 70°C or higher, more preferably 90°C or higher, and further preferably 100°C or higher, and is preferably 140°C or lower, more preferably 130°C or lower, and further preferably 125°C or lower.

[0195] The softening temperature Tm of the resin is the temperature (1 / 2 outflow temperature) measured using a flow tester (manufactured by Shimadzu Corporation: CFT-500C) at a load of 10 kgf / cm 2 , nozzle diameter 1mm, nozzle length 1mm, preheating 80℃ and 5 minutes, heating rate 6℃ / min, measure and record the temperature of 1 / 2 of the height of the S-shaped curve in the plunger descent-temperature curve of the flow tester when the sample weight is 1g (1 / 2 outflow temperature).

[0196] From the viewpoint of suppressing density unevenness of the obtained image, the glass transition temperature of the mixed resin is preferably 30°C or higher, more preferably 35°C or higher, and further preferably 40°C or higher, and is preferably 70°C or lower, more preferably 60°C or lower, and further preferably 55°C or lower.

[0197] In addition, the glass transition temperature Tg of the resin is measured by the method described later.

[0198] From the viewpoint of suppressing uneven concentration of the obtained image, the acid value of the mixed resin is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and further preferably 15 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less, and further preferably 30 mgKOH / g or less.

[0199] The acid value refers to the number of mg of potassium hydroxide required to neutralize the acid groups (eg, carboxyl groups) in 1 g of the sample. The acid value in the present embodiment is measured according to the method (potentiometric titration method) specified in JIS K0070-1992.

[0200] Furthermore, the neutralized state is measured by removing the neutralizing agent by decompression (and further heating), or by acid treatment to restore to the state of acid groups (such as carboxyl groups). In addition, when the sample is not dissolved, a solvent such as dioxane or tetrahydrofuran (THF) is used as a solvent.

[0201] The softening point, glass transition temperature, and acid value of the mixed resin can be appropriately adjusted according to the types and amounts of raw monomers used, and production conditions such as reaction temperature, reaction time, and cooling rate, and these values ​​can be obtained by the methods described in the Examples.

[0202] When two or more kinds of mixed resins are used in combination, it is preferred that the softening point, glass transition temperature, and acid value obtained as a mixture of these resins fall within the above ranges.

[0203] The method for preparing the mixed resin includes, for example, condensation polymerization using the alcohol component (a-al) and the carboxylic acid component (a-ac), addition polymerization using the raw material monomers of the styrene-acrylic copolymer segment and the bireactive monomers, and more specifically, the following methods (i) to (iii) are listed.

[0204] (i) A method of performing a polycondensation reaction using an alcohol component (a-al) and a carboxylic acid component (a-ac), and then performing an addition polymerization reaction using a raw material monomer of a styrene-acrylic acid copolymer segment and a bireactive monomer

[0205] In addition, from the viewpoint of reactivity, it is preferred to supply the raw material monomers of the styrene-acrylic acid copolymer segment and the two reactive monomers to the reaction system together. From the viewpoint of reactivity, catalysts such as esterification catalysts and esterification co-catalysts can be used, and free radical polymerization initiators and free radical polymerization inhibitors can also be used.

[0206] From the viewpoint of further advancing the polycondensation reaction and the reaction with the bireactive monomer as necessary, it is preferred that a portion of the carboxylic acid component is subjected to the polycondensation reaction, the reaction temperature is raised again after the addition polymerization reaction, and the remainder is added to the reaction system.

[0207] Alternatively, the present invention can also be produced by the following method (ii) or (iii).

[0208] (ii) A method of performing a polycondensation reaction using the raw material monomers of the styrene-acrylic acid copolymer segment and the bireactive monomers, followed by a polycondensation reaction using the raw material monomers of the polyester resin segment

[0209] (iii) A method of simultaneously carrying out a polycondensation reaction using an alcohol component and a carboxylic acid component and an addition polymerization reaction using a raw material monomer and a dual-reactive monomer of a styrene-acrylic acid copolymer segment

[0210] The polycondensation reaction and the polyaddition reaction in the methods (i) to (iii) are preferably carried out in the same container.

[0211] The mixed resin is preferably produced by the method (i) or (ii) above, and the method (i) above is more preferred, because the degree of freedom of the reaction temperature of the polycondensation reaction is high.

[0212] Regarding the polycondensation reaction, the alcohol component (a-a1) and the carboxylic acid component (a-ac) are polycondensed. In addition, if necessary, an esterification catalyst such as 0.01 mass part or more and 5 mass parts of di(2-ethylhexanoate)tin(II), dibutyltin oxide, bistriethanolamine diisopropyl titanate, etc. may be used relative to 100 mass parts of the total amount of the alcohol component and the carboxylic acid component; an esterification co-catalyst such as 0.001 mass part or more and 0.5 mass parts of gallic acid (same as 3,4,5-trihydroxybenzoic acid) may be used relative to 100 mass parts of the total amount of the alcohol component and the carboxylic acid component; and if necessary, a free radical polymerization inhibitor such as 0.001 mass part or more and 0.5 mass parts of 4-tert-butylcatechol may be used relative to 100 mass parts of the total amount of the alcohol component and the carboxylic acid component to carry out the polycondensation.

[0213] The temperature of the polycondensation reaction is preferably 120°C or higher, more preferably 160°C or higher, further preferably 180°C or higher, and is preferably 250°C or lower, more preferably 230°C or lower.

[0214] Furthermore, the polycondensation can also be carried out in an inert gas environment.

[0215] In the addition polymerization reaction, the raw material monomers of the styrene-acrylic acid copolymer segment and the bireactive monomers are subjected to addition polymerization.

[0216] The temperature of the addition polymerization reaction is preferably 110° C. or higher, more preferably 130° C. or higher, and preferably 220° C. or lower, more preferably 200° C. or lower. In addition, the reaction is preferably accelerated by reducing the pressure of the reaction system in the second half of the polymerization.

[0217] As the polymerization initiator for the addition polymerization reaction, for example, a known radical polymerization initiator may be used, such as a peroxide such as dibutyl peroxide, a persulfate such as sodium persulfate, or an azo compound such as 2,2′-azobis(2,4-dimethylvaleronitrile).

[0218] The amount of the radical polymerization initiator used is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less, based on 100 parts by mass of the raw material monomers of the styrene-acrylic copolymer segment.

[0219] <<Other adhesive resins>>

[0220] As the binder resin, other binder resins other than the mixed resin may be contained.

[0221] As other binder resins, for example, there can be mentioned vinyl resins which are homopolymers of monomers such as styrenes (for example, styrene, p-chlorostyrene, α-methylstyrene, etc.), (meth)acrylates (for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (for example, acrylonitrile, methacrylonitrile, etc.), vinyl ethers (for example, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (for example, ethylene, propylene, butadiene, etc.), or copolymers formed by combining two or more of these monomers.

[0222] As other binder resins, for example, non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or graft polymers obtained by polymerizing vinyl monomers in the coexistence of these, etc.

[0223] Among them, at least one resin selected from the group consisting of polyester resins and styrene-acrylic acid copolymers is preferred, and polyester resins are more preferred.

[0224] The other binder resins may be used alone or in combination of two or more.

[0225] As other binder resins, non-crystalline (also referred to as "non-crystalline") resins and crystalline resins can be mentioned. In addition, the mixed resin is preferably a non-crystalline resin.

[0226] From the viewpoint of suppressing uneven gloss, the binder resin preferably contains a crystalline resin.

[0227] The content of the crystalline resin is preferably 2% by mass or more and 40% by mass or less, and more preferably 2% by mass or more and 20% by mass or less, relative to the total mass of the binder resin.

[0228] The "crystallinity" of a resin refers to a clear endothermic peak in differential scanning calorimetry (DSC) rather than a step-by-step change in endothermic value. Specifically, it refers to a half-width of the endothermic peak being within 10°C when measured at a heating rate of 10 (°C / min).

[0229] On the other hand, the "amorphous" nature of a resin means that the half width exceeds 10°C, the endothermic value shows a step-wise change, or a clear endothermic peak is not confirmed.

[0230] Examples of the polyester resin include known polyester resins.

[0231] Amorphous polyester resin

[0232] Examples of the non-crystalline polyester resin include polycondensates of polycarboxylic acids and polyols. As the non-crystalline polyester resin, a commercially available product or a synthetic resin may be used.

[0233] Examples of the polycarboxylic acid include aliphatic dicarboxylic acids (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., carbon number 1 or more and 5 or less) alkyl esters thereof. Among these, the polycarboxylic acid is preferably, for example, an aromatic dicarboxylic acid.

[0234] The polycarboxylic acid may be used together with the dicarboxylic acid to obtain a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, or lower (e.g., carbon number 1 to 5) alkyl esters thereof.

[0235] The polyvalent carboxylic acid may be used alone or in combination of two or more.

[0236] Examples of the polyol include aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.), and aromatic diols (e.g., ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, the polyol is preferably an aromatic diol or an alicyclic diol, and more preferably an aromatic diol.

[0237] As the polyol, a trivalent or higher polyol that can obtain a crosslinked structure or a branched structure may be used together with a diol. Examples of the trivalent or higher polyol include glycerin, trimethylolpropane, and pentaerythritol.

[0238] The polyols may be used alone or in combination of two or more.

[0239] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50° C. or higher and 80° C. or lower, and more preferably 50° C. or higher and 65° C. or lower.

[0240] The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, is determined according to the “extrapolated glass transition initiation temperature” described in the method for determining the glass transition temperature in JIS K 7121-1987 “Methods for determining transition temperatures of plastics”.

[0241] The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.

[0242] The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less.

[0243] The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.

[0244] Furthermore, the weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a GPC HLC-8120GPC manufactured by Tosoh Corporation as a measuring device and a column TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation in a THF solvent. The weight average molecular weight and the number average molecular weight are calculated based on the measurement results and using a molecular weight calibration curve made from a monodisperse polystyrene standard sample.

[0245] The amorphous polyester resin can be obtained by a known production method. Specifically, for example, the amorphous polyester resin can be obtained by a method in which the polymerization temperature is set to 180° C. to 230° C., the pressure in the reaction system is reduced as necessary, and the water or alcohol generated during condensation is removed while the reaction is carried out.

[0246] Furthermore, when the monomer of the raw material is insoluble or incompatible at the reaction temperature, a high boiling point solvent may be added as a dissolving aid to dissolve it. In such a case, the dissolving aid is distilled off and the polycondensation reaction is carried out. In the case of the presence of monomers with poor compatibility, the monomers with poor compatibility may be condensed in advance with the acid or alcohol to be polycondensed with the monomers and then polycondensed with the main component.

[0247] Crystalline polyester resin

[0248] Examples of the crystalline polyester resin include polycondensates of polycarboxylic acids and polyols. As the crystalline polyester resin, a commercially available product may be used, and a synthetic resin may also be used.

[0249] Here, in order to easily form a crystalline structure, the crystalline polyester resin is preferably a polycondensate of a polymerizable monomer having a linear aliphatic group rather than a polymerizable monomer having an aromatic group.

[0250] Examples of the polycarboxylic acid include aliphatic dicarboxylic acids (e.g., oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalene-2,6-dicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., carbon number of 1 to 5) alkyl esters thereof.

[0251] The polycarboxylic acid may be used together with the dicarboxylic acid to obtain a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (e.g., 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.), anhydrides thereof, or lower (e.g., carbon number 1 or more and 5 or less) alkyl esters thereof.

[0252] As the polycarboxylic acid, a dicarboxylic acid having a sulfonic acid group or a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.

[0253] The polyvalent carboxylic acid may be used alone or in combination of two or more.

[0254] Examples of the polyol include aliphatic diols (e.g., linear aliphatic diols having a main chain carbon number of 7 or more and 20 or less). Examples of the aliphatic diols include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,14-eicosane decanediol. Among these, preferred aliphatic diols are 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol.

[0255] A trivalent or higher alcohol may be used together with a diol to obtain a cross-linked structure or a branched structure. Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.

[0256] The polyols may be used alone or in combination of two or more.

[0257] Here, the polyol preferably contains an aliphatic diol in an amount of 80 mol % or more, preferably 90 mol % or more.

[0258] The melting temperature of the crystalline polyester resin is preferably 50° C. or higher and 100° C. or lower, more preferably 55° C. or higher and 90° C. or lower, and still more preferably 60° C. or higher and 85° C. or lower.

[0259] The melting temperature is determined based on a DSC curve obtained by differential scanning calorimetry (DSC) according to the “melting peak temperature” described in the method for determining the melting temperature in JIS K7121-1987 “Methods for determining transition temperatures of plastics”.

[0260] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0261] The crystalline polyester resin can be obtained, for example, by a well-known production method, similar to the amorphous polyester resin.

[0262] From the viewpoint of scratch resistance of the image, the weight average molecular weight (Mw) of the other binder resin is preferably 5,000 or more and 1,000,000 or less, more preferably 7,000 or more and 500,000 or less, and particularly preferably 25,000 or more and 60,000 or less. The number average molecular weight (Mn) of the binder resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the binder resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.

[0263] The weight average molecular weight and number average molecular weight of other binder resins are measured by gel permeation chromatography (GPC). The molecular weight determination by GPC is carried out using GPC HLC-8120GPC manufactured by Tosoh Corporation as a measuring device and TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation in a tetrahydrofuran (THF) solvent. The weight average molecular weight and number average molecular weight are calculated based on the measurement results and using a molecular weight calibration curve made from a monodisperse polystyrene standard sample.

[0264] The content of the binder resin is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and still more preferably 60% by mass or more and 85% by mass or less, based on the entire toner base particles.

[0265] The content of the binder resin when the toner mother particles are white toner mother particles is preferably 30 mass % or more and 85 mass % or less, and more preferably 40 mass % or more and 60 mass % or less, relative to the entire white toner mother particles.

[0266] Furthermore, from the viewpoint of suppressing gloss unevenness, the content of the mixed resin in the binding resin is preferably 50% by mass or more and 100% by mass or less, more preferably 65% ​​by mass or more and 100% by mass or less, further preferably 80% by mass or more and 100% by mass or less, and particularly preferably 90% by mass or more and 100% by mass or less, relative to the total mass of the binding resin.

[0267] -Release agent-

[0268] Examples of the release agent include hydrocarbon waxes, natural waxes such as carnauba wax, rice wax, and candelilla wax, synthetic or mineral / petroleum waxes such as montan wax, and ester waxes such as fatty acid esters and montanic acid esters. The release agent is not limited thereto.

[0269] The melting temperature of the release agent is preferably 50°C or higher and 110°C or lower, and more preferably 60°C or higher and 100°C or lower.

[0270] The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) according to the “melting peak temperature” described in the method for determining the melting temperature in JIS K7121-1987 “Methods for determining transition temperatures of plastics”.

[0271] From the viewpoint of suppressing gloss unevenness, the domain diameter of the release agent in the toner base particles is preferably 200 nm to 2,000 nm, more preferably 400 nm to 1,500 nm, further preferably 500 nm to 1,300 nm, particularly preferably 600 nm to 1,200 nm.

[0272] The domain diameter (average diameter of the domains) of the release agent is a value measured by the following method.

[0273] The toner particles (or toner) are mixed and embedded in an epoxy resin and the epoxy resin is cured. The obtained cured product is cut using an ultrathin microtome device (Ultracut UCT manufactured by Leica) to produce a thin slice sample with a thickness of more than 80nm and less than 130nm. Secondly, the obtained thin slice sample is stained with ruthenium tetroxide in a desiccator at 30°C for 3 hours. Then, an ultra-high resolution field emission scanning electron microscope (FE-SEM (field emission-scanning electron microscope), S-4800 manufactured by Hitachi High-technologies (Hitachi High-technologies) (Co., Ltd.)) is used to obtain a SEM image of the stained thin slice sample.

[0274] Furthermore, in the cross section of the toner particle, the colorant region is smaller than the release agent region, so the regions can be distinguished based on their size. In addition, the colorant region can also be distinguished based on the depth of coloring of the release agent region.

[0275] In the SEM image, 30 toner particle cross sections whose maximum length is 85% or more of the volume average particle diameter of the toner particles are selected, and a total of 100 regions of the dyed release agent are observed. The maximum length of each region is measured, and the maximum length is set as the major diameter of the region, and the arithmetic mean thereof is set as the average diameter (region diameter) of the °C surface.

[0276] The content of the release agent is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less, based on the entire toner base particles.

[0277] -1-amino-2-methoxybenzene-

[0278] From the viewpoint of suppressing uneven gloss, the toner base particles preferably contain 1-amino-2-methoxybenzene.

[0279] From the viewpoint of suppressing uneven gloss, the content of 1-amino-2-methoxybenzene in the electrostatic charge image developing toner of the present embodiment is preferably 0.1 ppm to 300 ppm, more preferably 0.5 ppm to 200 ppm, further preferably 1 ppm to 100 ppm, and particularly preferably 10 ppm to 70 ppm, based on mass, relative to the total mass of the toner.

[0280] By using aromatic PY74, the π-π electron interaction between the π electrons of PY74 and the π electrons of St in the resin is more likely to occur. Since St in the toner is finely dispersed, the mixed resin of StAc is also easy to finely disperse PY74 and is easily dispersed evenly in the toner.

[0281] Since PY74 is easily dispersed in the toner, the elasticity of the toner increases, and the peeling property is good even at high TMA. In particular, when yellow exists in the outermost layer of the fixed image, the peeling property is good, and there is no uneven glossiness compared to the case where PY74 is not used, resulting in a high-quality image.

[0282] The content of 1-amino-2-methoxybenzene in this embodiment is measured using a gas chromatograph (manufactured by Shimadzu Corporation, model: GC-2010) and a column Rtx-1 (manufactured by Restek, P / N: 10157). The specific measurement method is as follows.

[0283] 100 mg of toner was weighed in a glass bottle for HS-GCMS analysis and sealed to prepare a sample for measurement. The column temperature was maintained at 40°C for 5 minutes and then raised to 250°C at a rate of 15°C / min. 1-amino-2-methoxybenzene was quantified based on the area of ​​the peak corresponding to 1-amino-2-methoxybenzene and the standard curve, and the content of 1-amino-2-methoxybenzene relative to the total amount of toner (ppm) was calculated.

[0284] -Colorants-

[0285] Examples of the colorant include carbon black, chrome yellow, Hansa yellow, benzidine yellow, threne yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watchung red, permanent red, brilliant carmine 3B, brilliant carmine 6B, Dupont Oil Red, pyrazolone red, lithotripter red, rhodamine B lake, lake red C, pigment red, rose bengal, aniline blue, ultramarine blue, calco oil blue, and chromatin. oilblue), methylene blue chloride, phthalocyanine blue, pigment blue, phthalocyanine green, malachite green oxalate and other pigments, or acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindigo, dioxazine, thiazine, azomethine, indigo, phthalocyanine, nigrosine, polymethine, triphenylmethane, diphenylmethane, thiazole and other dyes.

[0286] The coloring agent may be used alone or in combination of two or more.

[0287] The colorant may be a surface-treated colorant as required, or may be used in combination with a dispersant. In addition, a plurality of colorants may be used in combination.

[0288] The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less, based on the entire toner base particles.

[0289] As the colorant, from the viewpoint of suppressing uneven gloss, a yellow colorant is preferred, and CI Pigment Yellow 74 is particularly preferred.

[0290] Examples of yellow pigments include CI Pigment Yellow 1, CI Pigment Yellow 2, CI Pigment Yellow 3, CI Pigment Yellow 6, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 15, CI Pigment Yellow 16, CI Pigment Yellow 17, CI Pigment Yellow 55, CI Pigment Yellow 62, CI Pigment Yellow 65, CI Pigment Yellow 73, CI Pigment Yellow 74, CI Pigment Yellow 81, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 94, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 100, CI Pigment Yellow 104, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 111, CI Pigment Yellow 112, CI Pigment Yellow 113, CI Pigment Yellow 114, CI Pigment Yellow 115, CI Pigment Yellow 116, CI Pigment Yellow 117, CI Pigment Yellow 118, CI Pigment Yellow 119, CI Pigment Yellow 120, CI Pigment Yellow 121, CI Pigment Yellow 122, CI Pigment Yellow 123, CI Pigment Yellow 124, CI Pigment Yellow 125 CI Pigment Yellow 120, CI Pigment Yellow 127, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 138, CI Pigment Yellow 139, CI Pigment Yellow 151, CI Pigment Yellow 152, CI Pigment Yellow 154, CI Pigment Yellow 155, CI Pigment Yellow 166, CI Pigment Yellow 167, CI Pigment Yellow 168, CI Pigment Yellow 174, CI Pigment Yellow 175, CI Pigment Yellow 176, CI Pigment Yellow 180, CI Pigment Yellow 181, CI Pigment Yellow 185, CI Pigment Yellow 191, CI Pigment Yellow 191:1, CI Pigment Yellow 194, CI Pigment Yellow 213, CI Pigment Yellow 214, CI Pigment Yellow 219;

[0291] CI Bat Yellow 1, CI Bat Yellow 3, CI Bat Yellow 20;

[0292] Mineral Fast Yellow, Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG;

[0293] CI Solvent Yellow 9, CI Solvent Yellow 17, CI Solvent Yellow 19, CI Solvent Yellow 24, CI Solvent Yellow 31, CI Solvent Yellow 35, CI Solvent Yellow 44, CI Solvent Yellow 58, CI Solvent Yellow 77, CI Solvent Yellow 79, CI Solvent Yellow 81, CI Solvent Yellow 82, CI Solvent Yellow 93, CI Solvent Yellow 98, CI Solvent Yellow 100, CI Solvent Yellow 102, CI Solvent Yellow 103, CI Solvent Yellow 104, CI Solvent Yellow 105, CI Solvent Yellow 112, CI Solvent Yellow 162, CI Solvent Yellow 163, etc.

[0294] Note that 1-amino-2-methoxybenzene is similar in part to CI Pigment Yellow 74 in chemical structure. When CI Pigment Yellow 74 is used as a colorant, 1-amino-2-methoxybenzene mixed into CI Pigment Yellow 74 may be carried into the toner.

[0295] In the present embodiment, when CI Pigment Yellow 74 is used, the content of CI Pigment Yellow 74 is preferably 1 mass % to 30 mass % inclusive, more preferably 2 mass % to 20 mass % inclusive, and particularly preferably 3 mass % to 15 mass % inclusive, relative to the entire toner base particles.

[0296] In the present embodiment, when the toner particles are yellow toner particles, as a colorant, for example, CI Pigment Yellow 74 may be used alone, or CI Pigment Yellow 74 and other colorants may be used in combination. The proportion of CI Pigment Yellow 74 in the total amount of the colorant is, for example, preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, further preferably 90% by mass or more and 100% by mass or less, and particularly preferably 100% by mass.

[0297] -Other additives-

[0298] Examples of other additives include known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner base particles as internal additives.

[0299] -Characteristics of toner masterbatch particles, etc.-

[0300] The toner master particles may be monolayer structured toner master particles or so-called core-shell structured toner master particles (core-shell type particles) including a core (core particle) and a coating layer (shell layer) coating the core. The core-shell structured toner master particles may include, for example, a core containing a binder resin and, if necessary, a colorant and a release agent, etc., and a coating layer containing a binder resin.

[0301] Among them, from the viewpoint of suppressing uneven gloss, the toner base particles are preferably core-shell type particles.

[0302] The volume average particle size (D 50v ), preferably from 2 μm to 10 μm, more preferably from 4 μm to 8 μm.

[0303] The volume average particle size of the toner was measured using a Coulter Multisizer II (manufactured by Beckman-Coulter) and the electrolyte was measured using an ISOTON-II (manufactured by Beckman-Coulter).

[0304] During measurement, 0.5 mg to 50 mg of a measurement sample is added to 2 mL of a 5% by mass aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant, and then added to 100 mL to 150 mL of an electrolyte.

[0305] The electrolyte in which the sample was suspended was dispersed by an ultrasonic disperser for 1 minute, and the particle size of each particle in the range of 2 μm to 60 μm was measured by a Coulter Counter II using an aperture of 100 μm. The number of particles sampled was 50,000.

[0306] The measured particle sizes were cumulatively distributed based on volume from the smaller diameter side, and the particle size at which the cumulative distribution reached 50% was defined as the volume average particle size D. 50v .

[0307] In this embodiment, the average circularity of the toner base particles is not particularly limited, but is preferably 0.91 to 0.98, more preferably 0.94 to 0.98, and even more preferably 0.95 to 0.97 from the viewpoint of optimizing the cleanliness of the toner of the image holder.

[0308] In this embodiment, the circularity of the toner master particles is (the circumference of a circle having the same area as the particle projection image) ÷ (the circumference of the particle projection image), and the average circularity of the toner master particles is the circularity that reaches 50% from the smallest side in the distribution of circularity. The average circularity of the toner master particles is obtained by analyzing at least 3,000 toner master particles using a flow-type particle image analyzer.

[0309] For example, when the toner base particles are produced by the agglomeration method, the average circularity of the toner base particles can be controlled by adjusting the stirring speed of the dispersion, the temperature of the dispersion or the holding time in the agglomeration step.

[0310] [External additives]

[0311] The electrostatic image developing toner of the present embodiment preferably contains an external additive.

[0312] Examples of the external additive include inorganic particles.

[0313] Examples of the inorganic particles include SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, K2O·(TiO2) n , Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, MgSO4, etc.

[0314] The surface of the inorganic particles as an external additive may be subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobic treatment agent is not particularly limited, and examples thereof include: a silane coupling agent, silicone oil, a titanate coupling agent, an aluminum coupling agent, etc. These may be used alone or in combination of two or more.

[0315] The amount of the hydrophobizing agent is preferably 1 part by mass or more and 10 parts by mass or less relative to 100 parts by mass of the inorganic particles.

[0316] Examples of external additives include resin particles (polystyrene, polymethylmethacrylate (PMMA), melamine resin, etc.), cleaning activators (for example, metal salts of higher fatty acids represented by zinc stearate, and particles of fluorine-based high molecular weight bodies), and the like.

[0317] The amount of the external additive added is, for example, preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2.0% by mass or less, based on the total mass of the toner base particles.

[0318] [Method for producing toner]

[0319] Next, a method for producing toner according to the present embodiment will be described.

[0320] The toner of the present embodiment is obtained by manufacturing toner base particles and then adding external additives to the toner base particles.

[0321] The toner masterbatch particles can also be produced by any method of a dry method (e.g., a kneading and pulverizing method, etc.) or a wet method (e.g., an agglomeration method, a suspension polymerization method, a dissolution suspension method, etc.). These methods are not particularly limited, and known methods can be used. Among these, the toner masterbatch particles can be obtained by an agglomeration method.

[0322] In the kneading and pulverizing method, toner particles can be preferably prepared by kneading toner forming materials including a binder resin and a release agent, and optionally including a colorant and 1-amino-2-methoxybenzene to obtain a kneaded product, and then pulverizing the kneaded product.

[0323] In addition, specifically, for example, when the color powder master particles are manufactured by utilizing the coagulation and unification method, the color powder master particles are manufactured through the following steps: a step of preparing a resin particle dispersion in which resin particles serving as a binding resin are dispersed (resin particle dispersion preparation step); a step of agglomerating resin particles (and other particles as necessary) in the resin particle dispersion (a dispersion obtained by mixing other particle dispersions as necessary) to form agglomerated particles (agglomerated particle formation step); and a step of heating the agglomerated particle dispersion in which the agglomerated particles are dispersed to fuse and unify the agglomerated particles to form the color powder master particles (fusion and unification step).

[0324] 1-Amino-2-methoxybenzene may also be added to the dispersion in the step of forming aggregated particles.

[0325] The following describes the details of each step.

[0326] In the following description, a method for obtaining a toner base particle containing a colorant and a release agent is described, but the colorant and the release agent are used as needed. Of course, other additives besides the colorant and the release agent may also be used.

[0327] - Resin particle dispersion preparation step -

[0328] A resin particle dispersion in which resin particles serving as a binder resin are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle dispersion in which release agent particles are dispersed are prepared.

[0329] The resin particle dispersion is prepared by dispersing the resin particles in a dispersion medium using a surfactant, for example.

[0330] Examples of the dispersion medium used in the resin particle dispersion include aqueous media.

[0331] Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols, etc. These may be used alone or in combination of two or more.

[0332] Examples of surfactants include anionic surfactants such as sulfate ester salts, sulfonates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyols. Among these, anionic surfactants and cationic surfactants are particularly useful. Nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants.

[0333] The surfactant may be used alone or in combination of two or more.

[0334] In the resin particle dispersion, as a method for dispersing the resin particles in the dispersion medium, for example, general dispersion methods such as a rotary shearing homogenizer, or a ball mill, a sand mill, and a dyno mill with a medium can be cited. In addition, depending on the type of resin particles, the resin particles can also be dispersed in the dispersion medium by using a phase inversion emulsification method. The so-called phase inversion emulsification method is the following method: the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, an alkali is added to the organic continuous phase (O phase) and neutralized, and then an aqueous medium (W phase) is added, thereby performing a phase inversion from W / O to O / W, thereby dispersing the resin in the aqueous medium in the form of particles.

[0335] The volume average particle size of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and still more preferably 0.1 μm or more and 0.6 μm or less.

[0336] The volume average particle size of the resin particles is a particle size distribution obtained by measurement using a laser diffraction particle size distribution measuring device (e.g., LA-700 manufactured by Horiba, Ltd.), and a cumulative distribution is drawn from the small particle size side for the volume relative to the divided particle size range (channel), and the particle size that accumulates to 50% relative to the total particles is measured as the volume average particle size D50v. The volume average particle size of particles in other dispersions is also measured in the same manner.

[0337] The content of the resin particles contained in the resin particle dispersion is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0338] Similar to the resin particle dispersion, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared. That is, the volume average particle size of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles are the same for the colorant particles dispersed in the colorant particle dispersion and the release agent particles dispersed in the release agent particle dispersion.

[0339] - Agglomerated Particle Formation Steps -

[0340] Next, the resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion are mixed. At this time, 1-amino-2-methoxybenzene may also be mixed.

[0341] Then, the resin particles, the colorant particles, and the release agent particles are heterogeneously aggregated in the mixed dispersion to form aggregated particles having a diameter close to the target diameter of the toner mother particles and including the resin particles, the colorant particles, and the release agent particles.

[0342] Specifically, for example, a coagulant is added to the mixed dispersion, and the pH value of the mixed dispersion is adjusted to be acidic (for example, a pH value of not less than 2 and not more than 5), and after a dispersion stabilizer is added as needed, it is heated at a temperature close to the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles is not less than -30°C and not more than -10°C), so that the particles dispersed in the mixed dispersion are agglomerated to form agglomerated particles.

[0343] In the step of forming aggregated particles, for example, a coagulant may be added to the mixed dispersion using a rotary shearing homogenizer under stirring at room temperature (e.g., 25° C.), the pH of the mixed dispersion may be adjusted to an acidic state (e.g., a pH of 2 or more and 5 or less), a dispersion stabilizer may be added as needed, and then the mixture may be heated.

[0344] Examples of the coagulant include a surfactant having a polarity opposite to that of the surfactant contained in the mixed dispersion, an inorganic metal salt, and a divalent or higher metal complex. When a metal complex is used as the coagulant, the amount of the surfactant used can be reduced, and the charging characteristics are improved.

[0345] If necessary, an additive that forms a complex with the metal ion of the coagulant or a similar bond may be used together with the coagulant. As the additive, a chelating agent can be preferably used.

[0346] Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; and inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide.

[0347] As the chelating agent, a water-soluble chelating agent may also be used. Examples of the chelating agent include hydroxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; and aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylene diamine tetraacetic acid (EDTA).

[0348] The amount of the coagulant added is preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass, relative to 100 parts by mass of the resin particles.

[0349] -Fusion and unification steps-

[0350] Secondly, the agglomerated particle dispersion containing the agglomerated particles is heated to a temperature, for example, above the glass transition temperature of the resin particles (for example, a temperature 30°C to 50°C higher than the glass transition temperature of the resin particles) and above the melting temperature of the release agent to allow the agglomerated particles to fuse and merge, thereby forming color powder masterbatch particles.

[0351] In the fusion and unification step, the resin and the release agent are in a fused state at a temperature above the glass transition temperature of the resin particles and above the melting temperature of the release agent. Thereafter, the mixture is cooled to obtain toner mother particles.

[0352] As a method for adjusting the aspect ratio of the release agent in the color powder, the aspect ratio can be adjusted by maintaining the temperature around the solidification point of the release agent for a certain period of time during cooling to allow crystal growth. By using two or more release agents with different melting points to promote crystal growth during cooling, the aspect ratio can be adjusted.

[0353] The toner masterbatch particles are obtained through the above steps.

[0354] The color powder master particles can also be manufactured through the following steps: after obtaining a coagulated particle dispersion in which coagulated particles are dispersed, the coagulated particle dispersion is further mixed with a resin particle dispersion in which resin particles are dispersed, so as to coagulate the resin particles by attaching them to the surface of the coagulated particles to form a second coagulated particle; and the second coagulated particle dispersion in which the second coagulated particles are dispersed is heated to fuse and unify the second coagulated particles to form a color powder master particle with a core-shell structure.

[0355] After the fusion and unification step is completed, the toner master particles formed in the solution are subjected to a known washing step, a solid-liquid separation step, and a drying step to obtain the toner master particles in a dry state. From the perspective of chargeability, the washing step can be fully carried out by replacement washing using ion exchange water. From the perspective of productivity, the solid-liquid separation step can be carried out by suction filtration, pressure filtration, etc. From the perspective of productivity, the drying step can be carried out by freeze drying, air flow drying, fluidized drying, vibration-type fluidized drying, etc.

[0356] The toner of the present embodiment can be produced, for example, by adding an external additive to the obtained dry toner master particles and mixing them. The mixing can be performed, for example, using a V-type blender, a Henschel mixer, a Loedige mixer, etc. Furthermore, if necessary, a vibration sieving machine, a wind sieving machine, etc. can be used to remove coarse particles of the toner.

[0357] <Electrostatic image developer>

[0358] The electrostatic charge image developer of this embodiment includes at least the toner of this embodiment. The electrostatic charge image developer of this embodiment may be a single-component developer including only the toner of this embodiment, or a two-component developer including the toner and a carrier.

[0359] The carrier is not particularly limited, and known carriers can be cited. Examples of the carrier include: a coated carrier in which a core material containing magnetic powder is coated with a resin; a magnetic powder dispersion carrier in which magnetic powder is dispersed in a matrix resin and formulated; a resin impregnated carrier in which a porous magnetic powder is impregnated with a resin, etc. The magnetic powder dispersion carrier and the resin impregnated carrier can also be a carrier in which the constituent particles of the carrier are set as a core material and the surface thereof is coated with a resin.

[0360] Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt; and magnetic oxides such as ferrite and magnetite.

[0361] Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylate copolymer, pure silicone resin or modified products thereof containing organic siloxane bonds, fluororesins, polyesters, polycarbonates, phenol resins, epoxy resins, etc. The coating resin and matrix resin may also contain additives such as conductive particles. Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0362] When the surface of the core material is coated with a resin, a coating layer forming solution prepared by dissolving a coating resin and various additives (used as needed) in an appropriate solvent can be used for coating. The solvent is not particularly limited, and can be selected by considering the type of resin used or coating adaptability. Specific resin coating methods include: an immersion method in which the core material is immersed in a coating layer forming solution; a spray method in which the coating layer forming solution is sprayed on the surface of the core material; a fluidized bed method in which the coating layer forming solution is sprayed while the core material is suspended by flowing air; a kneading coater method in which the core material of the carrier is mixed with the coating layer forming solution in a kneading coater and then the solvent is removed.

[0363] The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner:carrier=1:100 to 30:100, more preferably 3:100 to 20:100.

[0364] <Image forming apparatus, image forming method>

[0365] The image forming apparatus and image forming method according to the present embodiment will be described.

[0366] The image forming device of the present embodiment includes: an image holder; a charging member for charging the surface of the image holder; an electrostatic charge image forming member for forming an electrostatic charge image on the surface of the charged image holder; a developing member for storing an electrostatic charge image developer and developing the electrostatic charge image formed on the surface of the image holder into a toner image using the electrostatic charge image developer; a transfer member for transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and a fixing member for fixing the toner image transferred to the surface of the recording medium. Furthermore, as the electrostatic charge image developer, the electrostatic charge image developer of the present embodiment can be applied.

[0367] In the image forming device of the present embodiment, an image forming method (the image forming method of the present embodiment) is implemented, and the image forming method includes: a charging step of charging the surface of an image retaining body; an electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image retaining body; a developing step of developing the electrostatic charge image formed on the surface of the image retaining body into a toner image using the electrostatic charge image developer of the present embodiment; a transfer step of transferring the toner image formed on the surface of the image retaining body to the surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0368] The image forming device of this embodiment can apply the following well-known image forming devices: a device using a direct transfer method for directly transferring a toner image formed on the surface of an image retaining body to a recording medium; a device using an intermediate transfer method for transferring a toner image formed on the surface of an image retaining body to the surface of an intermediate transfer body for the first time, and for a second time transferring the toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium; a device including a cleaning component for cleaning the surface of the image retaining body before charging after the transfer of the toner image; a device including a static eliminating component for eliminating static by irradiating the surface of the image retaining body with static eliminating light after the transfer of the toner image and before charging, etc.

[0369] In the case where the image forming device of the present embodiment is an intermediate transfer type device, the transfer component can, for example, be applied with the following structure, which comprises an intermediate transfer body for transferring the toner image to the surface, a primary transfer component for transferring the toner image formed on the surface of the image retaining body to the surface of the intermediate transfer body for the first time, and a secondary transfer component for secondarily transferring the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium.

[0370] In the image forming apparatus of this embodiment, for example, the part including the developing component may also be a box structure (processing box) detachably mounted on the image forming apparatus. As the processing box, for example, a processing box including a developing component that accommodates the electrostatic charge image developer of this embodiment can be preferably used.

[0371] Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the description of other parts will be omitted.

[0372] Figure 2 It is a diagram schematically showing the configuration of the image forming apparatus according to the present embodiment.

[0373] Figure 2 The image forming apparatus shown includes first to fourth image forming units 10Y, 10M, 10C, 10K (image forming means) of an electronic photographic method for outputting images of yellow (Y), magenta (M), cyan (C), and black (K) colors based on color-decomposed image data. These image forming units (hereinafter, also referred to as "units") 10Y, 10M, 10C, 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. These units 10Y, 10M, 10C, 10K may also be process cartridges detachably mounted on the image forming apparatus.

[0374] An intermediate transfer belt (an example of an intermediate transfer body) 20 is extended above each unit 10Y, 10M, 10C, and 10K through each unit. The intermediate transfer belt 20 is wound around a driving roller 22 and a supporting roller 24 that are in contact with the inner surface of the intermediate transfer belt 20, and moves in the direction from the first unit 10Y to the fourth unit 10K. A force is applied to the supporting roller 24 in a direction away from the driving roller 22 by a spring (not shown), so that tension is applied to the intermediate transfer belt 20 wound around the two. An intermediate transfer belt cleaning device 30 is provided on the image holding surface side of the intermediate transfer belt 20 facing the driving roller 22.

[0375] The developing devices (an example of developing means) 4Y, 4M, 4C, 4K of the respective units 10Y, 10M, 10C, 10K are supplied with yellow, magenta, cyan, and black toners contained in toner boxes 8Y, 8M, 8C, 8K.

[0376] The first to fourth units 10Y, 10M, 10C, and 10K have the same configuration and operation, and therefore the first unit 10Y disposed on the upstream side in the intermediate transfer belt moving direction and forming a yellow image will be representatively described here.

[0377] The first unit 10Y has a photosensitive body 1Y that functions as an image holder. The following are arranged in order around the photosensitive body 1Y: a charging roller (an example of a charging member) 2Y that charges the surface of the photosensitive body 1Y to a predetermined potential; an exposure device (an example of an electrostatic charge image forming member) 3 that forms an electrostatic charge image by exposing the charged surface to a laser beam 3Y based on a color-decomposed image signal; a developing device (an example of a developing member) 4Y that supplies charged toner to the electrostatic charge image and develops the electrostatic charge image; a primary transfer roller (an example of a primary transfer member) 5Y that transfers the developed toner image to the intermediate transfer belt 20; and a photosensitive body cleaning device (an example of an image holder cleaning member) 6Y that removes the toner remaining on the surface of the photosensitive body 1Y after the primary transfer.

[0378] The primary transfer roller 5Y is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoreceptor 1Y. A bias power supply (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K of each unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roller by control of a control unit (not shown).

[0379] Next, the operation of forming a yellow image in the first unit 10Y will be described.

[0380] First, before the operation, the surface of the photoreceptor 1Y is charged to a potential of -600 V to -800 V by the charging roller 2Y.

[0381] The photoreceptor 1Y is conductive (for example, the volume resistivity at 20° C. is 1×10 -6 The photosensitive layer is formed by laminating a photosensitive layer on a substrate with a resistance of 100 Ωcm or less. The photosensitive layer is usually high in resistance (resistance of a general resin), and has a property that the resistivity of the portion irradiated with the laser light changes when irradiated with laser light. Therefore, according to the image data for yellow sent from the control unit (not shown), the surface of the charged photoreceptor 1Y is irradiated with laser light 3Y from the exposure device 3. As a result, an electrostatic charge image of a yellow image pattern is formed on the surface of the photoreceptor 1Y.

[0382] The so-called electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and is a so-called negative latent image formed by utilizing the laser light 3Y to reduce the resistivity of the irradiated portion of the photosensitive layer, causing the charged charge on the surface of the photoreceptor 1Y to flow, while the charge on the portion not irradiated by the laser light 3Y remains.

[0383] The electrostatic charge image formed on the photoreceptor 1Y rotates to a predetermined development position as the photoreceptor 1Y moves. Then, at the development position, the electrostatic charge image on the photoreceptor 1Y is developed into a toner image by the developing device 4Y and made visible.

[0384] The developing device 4Y contains, for example, an electrostatic charge image developer containing at least yellow toner and a carrier. The yellow toner is stirred and frictionally charged inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charge on the photoreceptor 1Y, and is retained on a developer roller (an example of a developer retainer). Then, the surface of the photoreceptor 1Y is difficult to pass through the developing device 4Y, so that the yellow toner is electrostatically attached to the de-charged latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed using the yellow toner. The photoreceptor 1Y formed with the yellow toner image then moves at a predetermined speed, and the toner image developed on the photoreceptor 1Y is transported to a predetermined primary transfer position.

[0385] When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5Y, and the electrostatic force from the photoreceptor 1Y to the primary transfer roller 5Y acts on the toner image, thereby transferring the toner image on the photoreceptor 1Y to the intermediate transfer belt 20. The transfer bias applied at this time is a polarity (+) opposite to the polarity (-) of the toner, and is controlled to, for example, +10 μA by a control unit (not shown) in the first unit 10Y. The toner remaining on the photoreceptor 1Y is removed and recovered by the photoreceptor cleaning device 6Y.

[0386] The primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second unit 10M is also controlled by the first unit.

[0387] In this way, the intermediate transfer belt 20 to which the yellow toner image has been transferred in the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and toner images of respective colors are superimposed to perform multi-transfer.

[0388] The intermediate transfer belt 20 to which the toner images of four colors are multi-transferred through the first to fourth units arrives at a secondary transfer section including the intermediate transfer belt 20, a support roller 24 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roller (an example of a secondary transfer member) 26 disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, a recording paper (an example of a recording medium) P is supplied to the gap between the secondary transfer roller 26 and the intermediate transfer belt 20 at a predetermined time point via a supply mechanism, and a secondary transfer bias is applied to the support roller 24. The transfer bias applied at this time has the same polarity (-) as the polarity (-) of the toner, and the electrostatic force from the intermediate transfer belt 20 to the recording paper P acts on the toner image, thereby transferring the toner image on the intermediate transfer belt 20 to the recording paper P. The secondary transfer bias at this time is determined based on the resistance detected by the resistance detection member (not shown) that detects the resistance of the secondary transfer section, and the voltage is controlled.

[0389] The recording paper P to which the toner image is transferred is fed into the pressure contact portion (nip portion) of a pair of fixing rollers in the fixing device (an example of a fixing member) 28, and the toner image is fixed on the recording paper P, thereby forming a fixed image. The recording paper P to which the color image has been fixed is discharged toward the discharge portion, and a series of color image forming operations are completed.

[0390] As the recording paper P to transfer the toner image, for example, ordinary paper used in electrophotographic copiers, printers, etc. can be cited. As the recording medium, in addition to the recording paper P, OHP sheets can also be cited. In order to further improve the smoothness of the image surface after fixing, it is preferred that the surface of the recording paper P is also smooth, for example, coated paper obtained by coating the surface of ordinary paper with a resin or the like, coated paper for printing, etc. can be preferably used.

[0391] <Process cartridge, toner cartridge>

[0392] The processing box of this embodiment is a processing box that can be detachably installed in an image forming device: it includes a developing component that accommodates the electrostatic charge image developer of this embodiment and uses the electrostatic charge image developer to develop the electrostatic charge image formed on the surface of the image retaining body into a toner image.

[0393] The process cartridge of this embodiment may be configured to include a developing member and, if necessary, at least one member selected from other members such as an image holding member, a charging member, an electrostatic charge image forming member, and a transfer member.

[0394] An example of the process cartridge of the present embodiment is shown below, but the present invention is not limited thereto. In the following description, the main parts shown in the drawings are described, and the description of other parts is omitted.

[0395] Figure 3 It is a schematic structural diagram showing an example of the process cartridge according to the present embodiment.

[0396] Figure 3 The processing box 200 shown, for example, utilizes a frame 117 including a mounting guide 116 and an opening 118 for exposure, and combines and holds a photosensitive body 107 (an example of an image retaining body), a charging roller 108 (an example of a charging component) disposed around the photosensitive body 107, a developing device 111 (an example of a developing component), and a photosensitive body cleaning device 113 (an example of a cleaning component) in an integral manner, thereby being boxed.

[0397] Figure 3 109 denotes an exposure device (an example of an electrostatic charge image forming member), 112 denotes a transfer device (an example of a transfer member), 115 denotes a fixing device (an example of a fixing member), and 300 denotes recording paper (an example of a recording medium).

[0398] Next, the toner cartridge according to the present embodiment will be described.

[0399] The toner cartridge of the present embodiment is a toner cartridge that stores the toner of the present embodiment and is detachably mounted in an image forming apparatus. The toner cartridge stores replenishment toner to be supplied to a developing unit provided in the image forming apparatus.

[0400] Figure 2 The image forming apparatus shown is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K are detachably mounted, and the developing devices 4Y, 4M, 4C, and 4K are connected to toner cartridges corresponding to the respective colors by toner supply pipes (not shown). When the toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

[0401] [Example]

[0402] Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples. In the following description, "parts" and "%" are based on mass unless otherwise specified.

[0403] The arithmetic mean particle size and free amount of the specific external additive and the content of 5'-chloro-3-hydroxy-2'-methoxy-2-naphthylaniline were measured by the above-described method.

[0404] <Manufacture of styrene (meth) acrylic acid-modified polyester resin>

[0405] [Preparation of styrene acrylic acid modified polyester resin particle dispersion (SPE1)]

[0406] The interior of a four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 5,670 parts of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, 585 parts of polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, 2,450 parts of terephthalic acid, and 44 parts of di(2-ethylhexanoate)tin(II) were added, stirred under a nitrogen atmosphere, and heated to 235°C. After maintaining for 5 hours, the pressure in the flask was further reduced and maintained at 8.0 kPa for 1 hour. After returning to atmospheric pressure, the flask was cooled to 190°C, 42 parts of fumaric acid and 207 parts of trimellitic acid were added, and the temperature was maintained at 190°C for 2 hours, and then the temperature was raised to 210°C over 2 hours. The pressure in the flask was further reduced and maintained at 8.0 kPa for 4 hours to obtain a non-crystalline polyester resin A (polyester segment).

[0407] Next, 800 parts of amorphous polyester resin A were added to a four-necked flask equipped with a cooling tube, a stirring device and a thermocouple, and stirred at a stirring speed of 200 rpm in a nitrogen atmosphere. Then, as addition polymerizable monomers, 100 parts of styrene, 82 parts of ethyl acrylate, 16 parts of acrylic acid, 2 parts of 1,10-decanediol diacrylate and 1,00 parts of toluene were added, and mixed for 30 minutes.

[0408] Furthermore, 6 parts of polyoxyethylene alkyl ether (nonionic surfactant, trade name: emalgen 430, manufactured by Kao Corporation), 40 parts of 15% sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, trade name: neoplex G-15, manufactured by Kao Corporation) and 233 parts of 5% potassium hydroxide were added, stirred and heated to 95°C to melt, and mixed at 95°C for 2 hours to obtain a resin mixture solution.

[0409] Next, the resin mixture solution was stirred, and 1,145 parts of deionized water was added dropwise at a rate of 6 parts / min to obtain an emulsion. Next, the obtained emulsion was cooled to 25° C., passed through a 200-mesh metal mesh, and deionized water was added to adjust the solid content to 30%, thereby obtaining a styrene-acrylic acid modified polyester resin particle dispersion (SPE1).

[0410] The mass ratio of the styrene-acrylic acid copolymer segment to the polyester resin segment (styrene-acrylic acid copolymer segment / polyester resin segment) of the synthesized styrene-acrylic acid modified polyester resin was 10 / 90.

[0411] <Preparation of amorphous polyester resin B (polyester segment)>

[0412] When preparing the amorphous polyester resin A, the temperature was raised to 235° C. and maintained for 2 hours instead of being raised to 235° C. and maintained for 5 hours. Amorphous polyester resin B (polyester segment) was obtained in the same manner as the amorphous polyester resin A except for this.

[0413] <Preparation of amorphous polyester resin C (polyester segment)>

[0414] When preparing the amorphous polyester resin A, the temperature was raised to 235° C. and maintained for 3 hours instead of being raised to 235° C. and maintained for 5 hours. Amorphous polyester resin C (polyester segment) was obtained in the same manner as the amorphous polyester resin A except for this.

[0415] <Preparation of amorphous polyester resin D (polyester segment)>

[0416] When preparing the amorphous polyester resin A, the temperature was raised to 235° C. and maintained for 6 hours instead of being raised to 235° C. and maintained for 5 hours. Amorphous polyester resin D (polyester segment) was obtained in the same manner as the amorphous polyester resin A except for this.

[0417] <Preparation of amorphous polyester resin E (polyester segment)>

[0418] When preparing the amorphous polyester resin A, the temperature was raised to 235° C. and maintained for 7 hours instead of being raised to 235° C. and maintained for 5 hours. Amorphous polyester resin E (polyester segment) was obtained in the same manner as the amorphous polyester resin A except for this.

[0419] <Preparation of amorphous polyester resin F (polyester segment)>

[0420] When preparing the amorphous polyester resin A, 42 parts of fumaric acid and 207 parts of trimellitic acid were added, but 145 parts of fumaric acid and 104 parts of trimellitic acid were added. Otherwise, the amorphous polyester resin F (polyester segment) was obtained in the same manner as the amorphous polyester resin A.

[0421] <Preparation of amorphous polyester resin G (polyester segment)>

[0422] When preparing the amorphous polyester resin A, 42 parts of fumaric acid and 207 parts of trimellitic acid were added, but 12 parts of fumaric acid and 237 parts of trimellitic acid were added. Otherwise, the amorphous polyester resin G (polyester segment) was obtained in the same manner as the amorphous polyester resin A.

[0423] <Preparation of styrene acrylic acid modified polyester resin particle dispersion (SPE2 to SPE17)>

[0424] According to the composition ratios in Table 1, SPE2 to SPE17 were prepared under the same conditions as SPE1.

[0425] <Preparation of polyester-modified styrene acrylic resin particle dispersion (SPE18)>

[0426] 1000 parts of butyl acetate were added to a four-necked flask equipped with a cooling tube, a stirring device and a thermocouple, and the mixture was stirred and heated to 110°C. Next, a mixed solution of 200 parts of styrene, 730 parts of butyl acrylate, 10 parts of 1,10-decanediol diacrylate, 60 parts of acrylic acid and 6 parts of azobisisobutyronitrile was added dropwise to the stirred four-necked flask over 2 hours, and the mixture was stirred for 4 hours while maintaining at 110°C. The mixture was then cooled to room temperature to obtain styrene acrylic resin A (styrene acrylic segment).

[0427] Next, the interior of a four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 138 parts of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, 32 parts of polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, 88 parts of terephthalic acid, and 1 part of di(2-ethylhexanoate)tin(II) were added, stirred under a nitrogen environment, and the temperature was raised to 235° C. and maintained for 5 hours, and then the pressure in the flask was reduced and maintained at 8.0 kPa for 5 hours.

[0428] Furthermore, 3 parts of polyoxyethylene alkyl ether (nonionic surfactant, trade name: emalgen 430, manufactured by Kao Corporation), 20 parts of 15% sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, trade name: neoplex G-15, manufactured by Kao Corporation) and 116 parts of 5% potassium hydroxide were added, stirred and heated to 95°C to melt, and mixed at 95°C for 2 hours to obtain a resin mixture solution.

[0429] Next, the resin mixture solution was stirred and 1,000 parts of deionized water was added dropwise at a rate of 6 parts / min to obtain an emulsion. Next, the obtained emulsion was cooled to 25° C., passed through a 200-mesh metal mesh, and deionized water was added to adjust the solid content to 30%, thereby obtaining a polyester-modified styrene acrylic resin particle dispersion (SPE18).

[0430] <Preparation of polyester-modified styrene acrylic resin particle dispersion (SPE19)>

[0431] When preparing the polyester-modified styrene acrylic resin particle dispersion (SPE18), 730 parts of butyl acrylate and 10 parts of 1,10-decanediol diacrylate were replaced with 720 parts of butyl acrylate and 20 parts of 1,10-decanediol diacrylate. A polyester-modified styrene acrylic resin particle dispersion (SPE19) was obtained in the same manner as the polyester-modified styrene acrylic resin particle dispersion (SPE18) except for the above.

[0432] <Preparation of polyester-modified styrene acrylic resin particle dispersion (SPE20)>

[0433] When preparing the polyester-modified styrene acrylic resin particle dispersion (SPE18), 730 parts of butyl acrylate and 10 parts of 1,10-decanediol diacrylate were replaced with 700 parts of butyl acrylate and 40 parts of 1,10-decanediol diacrylate. A polyester-modified styrene acrylic resin particle dispersion (SPE20) was obtained in the same manner as the polyester-modified styrene acrylic resin particle dispersion (SPE18) except for the above.

[0434] [Preparation of styrene acrylic acid modified polyester resin]

[0435] The interior of a four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 5,670 parts of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, 585 parts of polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, 2,450 parts of terephthalic acid, and 44 parts of di(2-ethylhexanoate)tin(II) were added, stirred under a nitrogen atmosphere, and heated to 235°C. After maintaining for 5 hours, the pressure in the flask was further reduced and maintained at 8.0 kPa for 1 hour. After returning to atmospheric pressure, the flask was cooled to 190°C, 42 parts of fumaric acid and 207 parts of trimellitic acid were added, and the temperature was maintained at 190°C for 2 hours, and then the temperature was raised to 210°C over 2 hours. The pressure in the flask was further reduced and maintained at 8.0 kPa for 4 hours to obtain a non-crystalline polyester resin A (polyester segment).

[0436] Next, 800 parts of amorphous polyester resin A were added to a four-necked flask equipped with a cooling tube, a stirring device and a thermocouple, and stirred at a stirring speed of 200 rpm in a nitrogen atmosphere. Then, as addition polymerizable monomers, 100 parts of styrene, 79 parts of ethyl acrylate, 16 parts of acrylic acid, 5 parts of 1,10-decanediol diacrylate, 6 parts of azobisisobutyronitrile and 1,000 parts of toluene were added, and mixed for 30 minutes.

[0437] Thereafter, the temperature was raised to 105° C. and maintained at 105° C. for 4 hours. Next, the pressure was reduced while the temperature was maintained to remove toluene, thereby obtaining a styrene acrylic acid-modified polyester resin (SPE21).

[0438] [Preparation of comparative resin particle dispersion (P1)]

[0439] ·Bisphenol A ethylene oxide 2 mole adduct: 3 moles

[0440] Ethylene glycol: 7.5 mol parts

[0441] Terephthalic acid: 8 mol parts

[0442] · Dodecenylsuccinic acid: 1 mol

[0443] The above components were placed in a flask equipped with a stirring device, a nitrogen inlet pipe, a temperature sensor, and a distillation tower. The temperature was raised to 240° C. in 1 hour. After stirring in the reaction system, 3.0 parts of dibutyltin oxide were added to 100 parts of the total amount of the monomers. Furthermore, the generated water was distilled off and the mixture was kept for 6 hours. Thereafter, the pressure in the flask was reduced and kept at 8.0 kPa for 1 hour.

[0444] Next, the pressure in the flask was returned to atmospheric pressure, and then cooled to 190° C., 2 mol parts of succinic acid and 0.4 mol parts of trimellitic acid were added, and the temperature was maintained at 190° C. for 2 hours, and then the temperature was raised to 210° C. over 2 hours. The pressure in the flask was further reduced, and after maintaining at 8.0 kPa for 4 hours, the alcohol was distilled off to obtain an amorphous polyester resin.

[0445] Next, 6 parts of polyoxyethylene alkyl ether (nonionic surfactant, emalgen 430: manufactured by Kao Corporation), 40 parts of 15% sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, neoplex G-15: manufactured by Kao Corporation), 233 parts of 5% potassium hydroxide, and 1,145 parts of ion exchange water were added dropwise at a rate of 6 parts / min to 1,000 parts of the obtained amorphous polyester resin, thereby obtaining an emulsion. Next, the emulsion was cooled to 25° C., passed through a 200-mesh metal mesh, and deionized water was added to adjust the solid content concentration to 30%, thereby obtaining a resin particle dispersion (P1) in which polyester resin particles were dispersed.

[0446] [Preparation of comparative styrene acrylic resin particle dispersion (S1)]

[0447] -Preparation of styrene acrylic resin dispersion-

[0448] Styrene: 308 parts

[0449] Butyl acrylate: 100 parts

[0450] Acrylic acid: 4 parts

[0451] · Dodecanethiol: 3 parts

[0452] Propylene glycol diacrylate: 1.5 parts

[0453] The mixture in which the above components were mixed and dissolved was added to an aqueous solution in which 4 parts of anionic surfactant (produced by Daiichi Kogyo Seiyaku Co., Ltd., Neogen SC) was dissolved in 550 parts of ion exchange water, and after emulsification in a flask, it was mixed for 10 minutes and an aqueous solution in which 6 parts of ammonium persulfate were dissolved in 350 parts of ion exchange water was added thereto, and after nitrogen substitution, it was stirred in the flask and heated in an oil bath until the content reached 75°C, and emulsion polymerization was continued for 5 hours in the above state. In this way, a styrene acrylic resin particle dispersion (S1) (resin particle concentration: 30%) in which resin particles having an average particle diameter of 195 nm and a weight average molecular weight (Mw) of 41,000 were dispersed was obtained.

[0454] <Preparation of Colorant Particle Dispersion (1)>

[0455] 70 parts by mass of CI Pigment Yellow 74 (commercially available), 1 part by mass of anionic surfactant (manufactured by Daiichi Kogyo Seiyaku (stock), Neogen RK), and 200 parts by mass of ion exchange water were mixed and dispersed for 10 minutes using a homogenizer (manufactured by IKA, Ultraturrax T50). Ion exchange water was added in such a way that the solid content in the dispersion became 20% by mass, thereby obtaining a colorant particle dispersion. The volume average particle size of the colorant particles in the colorant particle dispersion was 190 nm.

[0456] <Preparation of Colorant Particle Dispersion (2)>

[0457] A colorant particle dispersion (2) was prepared in the same manner as in the preparation of the colorant particle dispersion (1) except that the colorant was changed to CI Pigment Yellow 75 (commercially available product).

[0458] <Preparation of Colorant Particle Dispersion (3)>

[0459] A colorant particle dispersion (3) was prepared in the same manner as in the preparation of the colorant particle dispersion (1), except that the colorant was changed to CI Pigment Yellow 83 (commercially available product).

[0460] <Preparation of Release Agent Particle Dispersion (1)>

[0461] 50 parts by mass of paraffin wax (HNP-9, manufactured by Nippon Seiwa Co., Ltd.), 5 parts by mass of anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) and 200 parts by mass of ion exchange water were mixed and heated to 110°C, dispersed using a homogenizer (manufactured by IKA, Ultraturrax T50), and then dispersed using a Manton Gaulin high pressure homogenizer (Gaulin Co., Ltd.) to obtain a release agent particle dispersion. The solid content of the release agent particle dispersion was 26% by mass, and the volume average particle size of the release agent particles was 150 nm.

[0462] <Preparation of Release Agent Particle Dispersion (2)>

[0463] A release agent particle dispersion (2) was prepared in the same manner as in the preparation of the release agent particle dispersion (1), except that polyethylene wax (PW600, manufactured by TOYO ADL Co., Ltd.) was used.

[0464] <Preparation of Release Agent Particle Dispersion (3)>

[0465] A release agent particle dispersion (3) was prepared in the same manner as in the preparation of the release agent particle dispersion (1), except that Fischer-Tropsch wax (FT-105, manufactured by Nippon Seiro Co., Ltd.) was used.

[0466] (Example 1)

[0467] <Production of Toner (1)>

[0468] Ion exchange water: 215 parts

[0469] Styrene-acrylic acid modified polyester resin particle dispersion (SPE1): 230 parts

[0470] Colorant particle dispersion (1): 20 parts (solid content 20%)

[0471] Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.: Neogen RK, 20%): 2.8 parts

[0472] The components were placed in a 3-liter reaction vessel equipped with a thermometer, a pH meter, and a stirrer, and the temperature was controlled from the outside using a mantle heater, and the temperature was maintained at 30° C. and a stirring speed of 150 rpm for 30 minutes. Then, a 0.3 N (= mol / L) nitric acid aqueous solution was added to adjust the pH in the coagulation step to 3.0.

[0473] A homogenizer (Ultraturrax T50 manufactured by IKA Japan) was used for dispersion, and a PAC aqueous solution was added in which 0.7 parts of PAC (30% powder manufactured by Prince Paper Co., Ltd.) was dissolved in 7 parts of ion exchange water. Afterwards, the mixture was stirred and heated to 50°C, and the particle size was measured using a Coulter particle counter II (aperture: 50 μm, manufactured by Coulter), and the volume average particle size was set to 5.0 μm. Afterwards, a preparation liquid of 30 parts of a styrene-acrylic acid modified polyester resin particle dispersion (SPE1) and 15 parts of a release agent particle dispersion was added. After 30 minutes, 47 parts of a styrene-acrylic acid modified polyester resin particle dispersion (SPE1) was further added to allow the release agent dispersion and the resin particles to adhere to the surface of the agglomerated particles (shell structure).

[0474] Next, 20 parts of a 10% aqueous solution of nitrilotriacetic acid (NTA) metal salt (Chelest 70: manufactured by Chelist Co., Ltd.) were added, and the pH was adjusted to 9.0 using a 1N (mol / L) aqueous sodium hydroxide solution. Thereafter, the temperature was raised to 90°C at a rate of 0.05°C / min, maintained at 90°C for 3 hours, and then cooled to 30°C. Thereafter, the temperature was raised to 87°C, which is higher than the melting point of the release agent, at a rate of 0.05°C / min, maintained for 30 minutes, and then slowly cooled to 30°C at a rate of 1°C / min, and then filtered to obtain coarse toner particles. This was further redispersed in ion exchange water and filtered, and the above operation was repeated, and the filtrate was washed until the conductivity of the filtrate became 20μS / cm or less, and then vacuum dried in an oven at 40°C for 5 hours to obtain toner particles (1).

[0475] 1.5 parts of hydrophobic silica (RY50 manufactured by Aerosil Co., Ltd.) and 1.0 part of hydrophobic titanium oxide (T805 manufactured by Aerosil Co., Ltd.) were mixed with 100 parts of the obtained toner particles (1) using a sample mill at 10,000 rpm (revolutions per minute) for 30 seconds. Thereafter, the mixture was sieved using a vibrating sieve with a mesh size of 45 μm to prepare a toner (1). The volume average particle size of the obtained toner (1) was 6.1 μm.

[0476] <Production of electrostatic image developer>

[0477] 8 parts by mass of the obtained electrostatic image developing toner (1) was mixed with 100 parts by mass of a resin-coated ferrite carrier (average particle size 35 μm) to prepare a two-component developer to obtain a developer (electrostatic image developer). The obtained developers were respectively filled into a developer of a document printer (DocuPrint) C2220 (manufactured by Fuji Xerox Co., Ltd.) and aged (seasoning) for 24 hours in a low temperature and low humidity environment (10°C / 15%RH).

[0478] (Examples 2 to 23, and Comparative Examples 1 and 2)

[0479] For Examples 2 to 23 and Comparative Examples 1 and 2, the resin particle dispersion, pigment particle dispersion, and release agent particle dispersion described in Table 2 were used to prepare toners 2 to 23 and toners of Comparative Examples 1 and 2 in the same manner as in Example 1. Thereafter, each toner was subjected to the same procedure as in Example 1 to obtain an electrostatic charge image developer.

[0480] (Example 24)

[0481] In Example 1, 0.01 parts of o-anisidine (1-amino-2-methoxybenzene, manufactured by Fuji Film & Wako Pure Chemical Industries, Ltd.) was added together with 20 parts of the colorant particle dispersion (1), and toner was prepared in the same manner as in Example 1 to obtain toner (24) and toner for electrostatic charge image development.

[0482] (Example 25)

[0483] In Example 1, 0.02 parts of o-anisidine (manufactured by Fuji Film & Wako Pure Chemical Industries, Ltd.) was added together with 20 parts of the colorant particle dispersion (1), and toner was prepared in the same manner as in Example 1 to obtain toner (25) and toner for electrostatic image development.

[0484] (Example 26)

[0485] In Example 1, 0.03 parts of o-anisidine (manufactured by Fuji Film & Wako Pure Chemical Industries, Ltd.) was added together with 20 parts of the colorant particle dispersion (1), and toner was prepared in the same manner as in Example 1 to obtain toner (26) and toner for electrostatic image development.

[0486] (Example 27)

[0487] In Example 1, the mixture is heated to 87°C, maintained for 30 minutes, and then cooled to 30°C at a rate of 1°C / min. The cooling rate is changed to 3°C / min, and toner is prepared in the same manner as in Example 1 to obtain toner (27) and toner for electrostatic charge image development.

[0488] (Example 28)

[0489] In Example 1, the mixture is heated to 87°C, maintained for 30 minutes, and then cooled to 30°C at a rate of 1°C / min. The cooling rate is changed to 2°C / min, and toner is prepared in the same manner as in Example 1 to obtain toner (28) and toner for electrostatic charge image development.

[0490] (Example 29)

[0491] In Example 1, the mixture was heated to 87°C, maintained for 30 minutes, and then cooled to 30°C at a rate of 1°C / min. The cooling rate was changed to 0.7°C / min, and toner was prepared in the same manner as in Example 1 to obtain toner (29) and toner for electrostatic charge image development.

[0492] (Example 30)

[0493] In Example 1, the mixture is heated to 87°C, maintained for 30 minutes, and then cooled to 30°C at a rate of 1°C / min. The cooling rate is changed to 0.5°C / min, and toner is prepared in the same manner as in Example 1 to obtain toner (30) and toner for electrostatic charge image development.

[0494] (Example 31)

[0495] 92.1 parts of styrene acrylic modified polyester resin (SPE21), 4 parts of CI Pigment Yellow 74 (commercially available product), and 3.9 parts of paraffin wax (HNP-9, manufactured by Nippon Seira Co., Ltd.) were fully premixed using a Henschel mixer, melt-kneaded using a double-shaft roll mill, and after cooling, finely pulverized using a jet mill. The mixture was then classified twice using a pneumatic classifier to obtain toner particles (31).

[0496] 1.5 parts of hydrophobic silica (RY50 manufactured by Aerosil Co., Ltd., Japan) and 1.0 part of hydrophobic titanium oxide (T805 manufactured by Aerosil Co., Ltd., Japan) were mixed with 100 parts of the obtained toner particles (31) using a sample mill at 10,000 rpm (revolutions per minute) for 30 seconds. Thereafter, the mixture was sieved using a vibrating sieve with a mesh size of 45 μm to prepare a toner (31). The volume average particle size of the obtained toner (31) was 7.0 μm.

[0497] (Comparative Example 3)

[0498] In Example 1, instead of the styrene-acrylic modified polyester resin particle dispersion, a 4:1 mixed dispersion of the comparative resin particle dispersion (P1) and the comparative styrene acrylic resin particle dispersion (S1) was used to obtain a toner and an electrostatic image developing toner in the same manner as in Example 1.

[0499] (Comparative Example 4)

[0500] In Example 1, a toner and an electrostatic image developing toner were obtained in the same manner as in Example 1 except that a comparative styrene acrylic resin particle dispersion (S1) was used instead of the styrene acrylic modified polyester resin particle dispersion.

[0501] <Evaluation of gloss unevenness suppression performance>

[0502] The developer obtained in each of the examples and comparative examples was filled in a developer of an image forming apparatus "Document Center Color 400 manufactured by Fuji Xerox Co., Ltd.". Using the image forming apparatus, 1,000 sheets of solid images with an image density of 100% (toner loading (TMA) 3.8 g / m 2 ) were output on OS coated paper (manufactured by Oji Paper Co., Ltd., trade name: ) at a processing speed of 228 mm / s for the Electrophotographic Society Test Chart No. 5-1. 2 Then, 1,000 sheets of solid images with an image density of 100% (toner loading (TMA) 14.4 g / m) were output on OS coated paper at a fixing temperature of 190°C and a processing speed of 60 m / s. 2 ).

[0503] Regarding the Electrophotographic Society Test Chart No. 5-1 when the first sheet of OS coated paper was output and the Electrophotographic Society Test Chart No. 5-1 after 1,000 sheets were output, the glossiness of the green portion was measured by the following method.

[0504] The glossiness was measured using a portable gloss meter (BYK Gardner micro-tri-gross, manufactured by Toyo Seiki Seisaku-sho, Ltd.) and the glossiness was measured at 60 degrees at five locations.

[0505] The difference was calculated from the measured value of glossiness, and the evaluation was performed according to the following evaluation criteria.

[0506] A: The glossiness difference between the maximum and minimum glossiness values ​​of 1,001 output images is less than 5°

[0507] B: The glossiness difference between the maximum and minimum glossiness values ​​of 1,001 output images is 5° or more and less than 7°

[0508] C: The glossiness difference between the maximum and minimum glossiness values ​​of 1,001 output images is 7° or more and less than 10°

[0509] D: The glossiness difference between the maximum and minimum glossiness values ​​of 1,001 output images is 10° or more

[0510] The evaluation results are summarized in Table 2.

[0511]

[0512]

[0513] In addition, Mz and Mw in Table 2 represent Mz and Mw of the binder resin in the toner, the gel fraction in Table 2 represents the gel fraction of the mixed resin, and the amount of 1-amino-2-methoxybenzene in Table 2 represents the amount of 1-amino-2-methoxybenzene in the toner.

[0514] As can be seen from the results shown in Table 2, the electrostatic image developing toner of this example is superior in gloss unevenness suppression performance compared to the electrostatic image developing toner of the comparative example even when an image having a large toner load per unit area is formed.

Claims

1. A toner for developing electrostatic charge images, comprising: A toner masterbatch particle comprising at least a binder resin and a release agent, The bonding resin comprises a mixed resin having a polyester resin segment and a styrene-acrylic acid copolymer segment, The molecular weight distribution curve of the toner satisfies the following formula (1) and formula (2): 1.3≦b / a≦2.5Formula (1) 2.5≦b / c Formula (2) In formula (1) and formula (2), a represents the width of the lower molecular weight side at 15% of the height of the maximum peak when a perpendicular line is drawn from the baseline of the molecular weight distribution curve to the maximum peak; b represents the width of the higher molecular weight side at 15% of the height of the maximum peak when a perpendicular line is drawn from the baseline of the molecular weight distribution curve to the maximum peak; c represents the width of the higher molecular weight side at 40% of the height of the maximum peak when a perpendicular line is drawn from the baseline of the molecular weight distribution curve to the maximum peak.

2. The electrostatic image developing toner according to claim 1, wherein a ratio of a width d at 15% of the maximum peak height to a width e at 40% of the maximum peak height of the toner molecular weight distribution curve satisfies d / e≧2.

0. 3 . The electrostatic charge image developing toner according to claim 1 , wherein a Z average molecular weight Mz of the binder resin is 200,000 or more and 1,300,000 or less. 4 . The electrostatic image developing toner according to claim 1 , wherein the mixed resin has a gel fraction of 3% by mass or more and 15% by mass or less. 5 . The electrostatic image developing toner according to claim 1 , comprising a linear aliphatic diol di(meth)acrylate compound as a monomer component constituting the styrene-acrylic acid copolymer segment. 6 . The electrostatic charge image developing toner according to claim 5 , wherein the linear aliphatic diol di(meth)acrylate compound is 1,10-decanediol diacrylate.

7. The electrostatic image developing toner according to claim 1, wherein the toner mother particles further comprise a colorant. 8 . The electrostatic charge image developing toner according to claim 7 , wherein the colorant comprises Color Index Pigment Yellow 74. 9 . The electrostatic charge image developing toner according to claim 1 , wherein a content of the structural unit derived from styrene in the mixed resin is 5% by mass or more and 20% by mass or less based on the total mass of the mixed resin. 10 . The electrostatic charge image developing toner according to claim 1 , wherein the amount of the polyester resin segment in the mixed resin is 40% by mass or more and 95% by mass or less relative to the total mass of the mixed resin. 11 . The electrostatic charge image developing toner according to claim 1 , wherein the domain diameter of the release agent in the toner base particles is 400 nm or more and 1,500 nm or less.

12. The electrostatic image developing toner according to claim 1, wherein the toner mother particles further comprise 1-amino-2-methoxybenzene. 13 . The electrostatic charge image developing toner according to claim 12 , wherein the content of the 1-amino-2-methoxybenzene is 1 ppm or more and 100 ppm or less based on the total mass of the toner.

14. An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.

15. A toner cartridge, containing the electrostatic charge image developing toner according to claim 1, and detachably mounted in an image forming apparatus.

Images