JP2018128511A - Toner for electrostatic latent image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means that sufficiently reduces glossiness memory in a toner for electrostatic latent image development containing a polyester resin and a mold release agent.SOLUTION: The present invention relates to a toner for electrostatic latent image development including a toner base particle containing a binder resin and a mold release agent, where the mold release agent has a hydroxyl value of 2 or less; the binder resin contains an amorphous polyester resin and a crystalline polyester resin; the amorphous polyester resin has a hydroxyl value higher than the hydroxyl value of the mold release agent; Mw/Mn of the amorphous polyester resin is 5 or less; Mw/Mn of the crystalline polyester resin is 4 or less.SELECTED DRAWING: None

Description

  The present invention relates to a toner for developing an electrostatic latent image.

  In recent years, from the viewpoint of speeding up and energy saving, development of a toner having excellent low-temperature fixability has been demanded in order to thermally fix a toner image with less energy than in the past.

  In order to lower the fixing temperature of the toner, it is necessary to lower the melting temperature and the viscosity of the binder resin contained in the toner base particles constituting the toner. For this reason, in order to lower the melting temperature and melt viscosity of the binder resin, a method of reducing the glass transition temperature and melt viscosity of the binder resin by adding a crystalline polyester resin having sharp melt properties is known.

  It is known that when toner containing a polyester resin is used, the melted toner particles and the fixing roller may be fused at the time of fixing. In this case, the occurrence of an offset particularly during high temperature printing becomes a problem.

  In addition, it is known that when a toner containing a polyester resin is used, the interaction between the polyester resin and the release agent is increased, and the release agent may not easily leak onto the image surface during fixing. Yes. In this case, the problem is that the low-temperature fixability is particularly insufficient.

  In a toner containing a polyester resin, various studies have been made to improve these problems.

  Patent Document 1 discloses a toner manufacturing method in which a crystalline polyester resin, two types of amorphous polyester resins, a wax (release agent), and a colorant are melt-kneaded, which includes crystalline polyester resin and Weight average molecular weight of two types of amorphous polyester resins, ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) of crystalline polyester resin and relatively higher molecular weight amorphous polyester resin (Mw / Mn) and a method for setting the melting point, acid value, and hydroxyl value of the release agent within a predetermined range are disclosed.

  Patent Document 2 discloses a toner manufacturing method in which two types of polyester resins, a wax (release agent), and a colorant are melt-kneaded, and the weight average molecular weight and relative molecular weight of the two types of polyester resins. Discloses a method in which the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) having a larger value is within a predetermined range, and the melting point, acid value and hydroxyl value of the release agent.

  Patent Document 3 includes a binder resin containing a crystalline polyester resin and an amorphous polyester resin, a release agent, a core-shell structure, and a shell portion including a thermosetting component and a thermoplastic component. An electrostatic latent image developing toner containing toner particles having the following is disclosed. In this document, the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the amorphous polyester resin (Mw / Mn) is in the range of 8 to 50, whereby the strength of the core and the fixing of the toner are determined. It is disclosed to improve the performance. Further, it is disclosed that when the hydroxyl value of the amorphous polyester resin is in the range of 15 mgKOH / g or more and 80 mgKOH / g or less, sufficient anionicity is imparted to the toner core and the shell layer can be easily formed. Yes.

JP 2012-155103 A JP 2012-155104 A JP 2006-095457 A

  If the releasability between the toner and the image is insufficient at the time of fixing, a part of the toner of the image sticks on the fixing roller, and a latent image is formed on the fixing roller. When fixing is performed with the fixing roller in this state, the image becomes rough due to the toner latent image on the fixing roller, the image portion fixed on the portion where the latent image on the fixing roller is fixed, and the fixing roller There arises a problem that a difference in gloss occurs between an image portion fixed at a portion where no latent image is present. This image defect due to the difference in gloss is called gloss memory.

  In the technologies according to Patent Documents 1 to 3, although a certain improvement effect is recognized with respect to the low-temperature fixability and the offset resistance, the effect of suppressing the occurrence of gloss memory is insufficient.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a means capable of sufficiently suppressing gloss memory in an electrostatic latent image developing toner containing a polyester resin and a release agent. .

  The above-described problems of the present invention are solved by the following means.

An electrostatic latent image developing toner comprising toner base particles containing a binder resin and a release agent,
The release agent has a hydroxyl value of 2 or less,
The binder resin includes an amorphous polyester resin and a crystalline polyester resin,
The hydroxyl value of the amorphous polyester resin is higher than the hydroxyl value of the release agent,
The amorphous polyester resin has Mw / Mn of 5 or less,
The crystalline polyester resin has an Mw / Mn of 4 or less.
Toner for electrostatic latent image development.

  According to the present invention, a means capable of sufficiently suppressing gloss memory is provided in an electrostatic latent image developing toner containing a polyester resin and a release agent.

  Embodiments of the present invention will be described below. In addition, this invention is not limited only to the following embodiment.

  The present invention is not limited only to the following embodiments. In this specification, “X to Y” indicating a range means “X or more and Y or less”. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50% RH.

  In this specification, “(meth) acrylic acid ester monomer” is a general term for “acrylic acid ester monomer” and “methacrylic acid ester monomer”. For example, “(meth) acrylic acid monomer” “Methyl” is a general term for “methyl acrylate (methyl acrylate)” and “methyl methacrylate (methyl methacrylate)”.

  In the present specification, the “electrostatic image developing toner” may be simply referred to as “toner”. Further, in the present specification, the “hybrid crystalline polyester resin” may be simply referred to as “hybrid crystalline resin”. In the present specification, the “hybrid amorphous polyester resin” may be simply referred to as “hybrid amorphous resin”.

<< Electrostatic image developing toner >>
One aspect of the present invention is an electrostatic latent image developing toner including toner base particles containing a binder resin and a release agent, and the release agent has a hydroxyl value of 2 or less, The binder resin includes an amorphous polyester resin and a crystalline polyester resin, the hydroxyl value of the amorphous polyester resin is higher than the hydroxyl value of a release agent, and the amorphous polyester resin is Mw / Mn is 5 or less, and the crystalline polyester resin is a toner for developing an electrostatic latent image, wherein Mw / Mn is 4 or less.

  As a result of investigation, the inventors have determined that the value of the hydroxyl value of the release agent is 2 mgKOH / g or less, and that the hydroxyl value of the amorphous polyester resin is higher than the hydroxyl value of the release agent. It has been found that the generation of memory can be suppressed. Then, the inventors have determined that the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the amorphous polyester resin and the weight average with respect to the number average molecular weight (Mn) of the crystalline polyester resin. The present invention has been completed by finding that the occurrence of gloss memory can be further suppressed by setting the ratio (Mw / Mn) of the molecular weight (Mw) to a lower value.

  The present inventors presume the mechanism by which the above-described problems can be solved by adopting the configuration of the present invention as follows.

  First, when determining the compatibility between the release agent and the polyester resin, it is optimal to use the hydroxyl value as an indicator of polarity. The hydroxyl value is a polar indicator and a hydrophilic indicator. In the polyester resin, when the hydroxyl value of the release agent is low, the release agent is more uniformly dispersed and retained in the polyester resin in the toner base particles in a microphase separated state. As a result, the mold release agent can be more uniformly exuded to the surface of the image, so that a more stable mold release property can be obtained, and the occurrence of gloss memory is further suppressed.

  Further, in the toner base particles, the release agent is dispersed and held mainly in the amorphous polyester resin. Accordingly, the compatibility between the release agent and the amorphous polyester resin is reduced by setting the hydroxyl value of the release agent to a lower value and increasing the difference between the hydroxyl value of the amorphous polyester resin. . When the toner is melted at the time of fixing, the exudation of the wax on the image surface is promoted. As a result, the releasability between the fixing roller and the image surface is improved, and the occurrence of gloss memory is suppressed.

  Here, when the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the amorphous polyester resin is large, the content of the low molecular component in the amorphous polyester resin increases. . In this case, since the low molecular weight component of the amorphous polyester resin is easily compatible with the release agent, the release agent is more amorphous than the state dispersed in the amorphous polyester resin in a microphase-separated state. It tends to be compatible with the low-molecular component of the polyester resin. In this state, when the toner is melted at the time of fixing, it is difficult for the release agent to ooze out to the image surface. Thus, by setting Mw / Mn to a certain value or less, the content of the low molecular weight component of the amorphous polyester resin is sufficiently small, and the compatibility between the release agent and the amorphous polyester resin is sufficiently low. Thus, when the toner is melted at the time of fixing, the amount of the release agent oozing out to the image surface becomes sufficient.

  Moreover, when the ratio (Mw / Mn) of the weight average molecular weight (Mw) with respect to the number average molecular weight (Mn) of a crystalline polyester resin is large, content of the low molecular component in a crystalline polyester resin becomes large. In this case, since the low-molecular component of the crystalline polyester resin is more compatible with the release agent, the release agent is more crystalline polyester than the dispersed state in the amorphous polyester resin in a microphase-separated state. It tends to be compatible with the low-molecular components of the resin. In this state, when the toner is melted at the time of fixing, the release agent hardly oozes out on the image surface. From this, by setting Mw / Mn to a value below a certain value, the content of the low molecular weight component of the crystalline polyester resin is sufficiently small, and the amount of the release agent compatible with this is sufficiently small. When the toner is melted at the time of fixing, the amount of the release agent that exudes to the image surface is sufficient.

  Note that the above mechanism is based on speculation, and its correctness does not affect the technical scope of the present invention.

<Toner base particles>
The toner according to the present invention includes toner base particles. The toner base particles are particles containing a binder resin and a release agent and, if necessary, particles containing other additives (internal additives). Generally, a toner is prepared by adding an external additive to toner base particles.

  The content of the binder resin in the toner base particles is preferably 80% by mass or more based on the total mass of the toner base particles. When the content of the binder resin is within this range, the function as the binder resin is more effectively exhibited. From the same viewpoint, the content of the binder resin is more preferably 82% by mass or more, and further preferably 84% by mass or more. Further, the content of the binder resin in the toner base particles is preferably 95% by mass or less based on the total mass of the toner base particles. When the content of the binder resin is within this range, the release agent can be contained in an appropriate amount, the releasability can be further improved, and the occurrence of gloss memory can be further reduced. From the same viewpoint, the content of the binder resin is more preferably 94% by mass or less, and further preferably 90% by mass or less.

[Binder resin]
The binder resin includes an amorphous polyester resin and a crystalline polyester resin.

  The content of the amorphous polyester resin with respect to the total mass of the amorphous polyester resin and the crystalline polyester resin is preferably 10% by mass or more. When the content of the amorphous polyester resin is within this range, the peelability is further improved and the occurrence of glossy memory is further reduced. This is because the release agent is considered to be mainly dispersed in the amorphous polyester resin, so that the higher the content of the amorphous polyester resin, the better the effect of the present invention can be obtained. I guess from. From the same viewpoint, the content of the amorphous polyester resin relative to the total mass of the amorphous polyester resin and the crystalline polyester resin is preferably 20% by mass or more, and more preferably 30% by mass or more. Moreover, it is preferable that content of the amorphous polyester resin with respect to the total mass of an amorphous polyester resin and a crystalline polyester resin is 90 mass% or less. When the content of the amorphous polyester resin is within this range, the low-temperature fixability is further improved. From the same viewpoint, the content of the amorphous polyester resin with respect to the total mass of the amorphous polyester resin and the crystalline polyester resin is more preferably 80% by mass or less, and further preferably 70% by mass or less. .

  Each component that can be included as the binder resin will be described in detail below.

[Amorphous polyester resin]
The toner base particles according to the present invention include an amorphous polyester resin as a binder resin.

  In the present invention, the amorphous polyester resin refers to a resin that shows a stepwise endothermic change and has no clear endothermic peak in differential scanning calorimetry (DSC). Hereinafter, preferred examples of the amorphous polyester will be shown, but the invention is not limited thereto.

  The amorphous polyester resin used in this embodiment is a copolymer of a polyvalent carboxylic acid component and a polyhydric alcohol component.

  In the present specification, the “acid component” and the “alcohol component” represent not only an acid and an alcohol, but also an acid or a derivative thereof capable of synthesizing a polyester resin, and an alcohol or a derivative thereof. Examples of the acid component include acids, salts thereof, lower alkyl esters, acid anhydrides, and the like. It should be noted that terms such as “diol component” are handled in the same manner.

  The amorphous polyester resin may be one kind of amorphous polyester resin, but may be a mixture of two or more kinds of amorphous polyester resins.

  A known polyester resin can be used as the amorphous polyester resin. The amorphous polyester resin is synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In addition, as an amorphous polyester resin, a commercial item may be used and what was synthesize | combined may be used.

  Examples of the polyhydric alcohol component include ethylene glycol, propylene glycol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane as the diol component. Diol, neopentyl glycol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, bisphenol A, hydrogenated bisphenol A, BPA-PO (propylene oxide n mol adduct of bisphenol A), BPA- EO (ethylene oxide nmole adduct of bisphenol A) or the like can be used. Moreover, as a trivalent or more alcohol component, glycerol, sorbitol, 1, 4- sorbitan, a trimethylol propane etc. can be used, for example. Among these, bisphenol A, hydrogenated bisphenol A, BPA-PO or BPA-EO is preferable, BPA-PO or BPA-EO is more preferable, and propylene oxide 2-mol adduct or bisphenol of bisphenol A More preferably, it is an ethylene oxide 2-mole adduct of A. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Examples of the polyvalent carboxylic acid component include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, trimellitic acid, pyromellitic acid, and naphthalenedicarboxylic acid; Fats such as 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 Saturated aliphatic carboxylic acids; aliphatic unsaturated dicarboxylic acids such as maleic acid, maleic acid, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic acid, and mesaconic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid; Salts, lower alkyl esters and acid anhydrides. Among these, aromatic carboxylic acids, salts thereof, lower alkyl esters or acid anhydrides are preferable, and terephthalic acid or trimellitic acid, salts thereof, lower alkyl esters or acid anhydrides are more preferable. . These polyvalent carboxylic acid components are preferably in the form of an acid or an acid anhydride. These may be used individually by 1 type and may be used in combination of 2 or more type.

  By containing a trivalent or higher carboxylic acid component as the polyvalent carboxylic acid component, the polymer chain can take a cross-linked structure, and once the cross-linked structure is taken, it is once compatible with the amorphous polyester resin. The effect of fixing the crystalline polyester resin and making it difficult to separate can be further obtained.

  Examples of the trivalent or higher carboxylic acid component include trimellitic acid such as 1,2,4-benzenetricarboxylic acid and 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and hemimeritic acid. , Trimesic acid, melophanoic acid, planitic acid, pyromellitic acid, meritic acid, 1,2,3,4-butanetetracarboxylic acid, salts thereof, lower alkyl esters and acid anhydrides, etc. , Its salts, lower alkyl esters or acid anhydrides are particularly preferred.

  When the dicarboxylic acid component and the trivalent or higher carboxylic acid component are contained as the polyvalent carboxylic acid component, the addition amount of the trivalent or higher carboxylic acid component is 1 with respect to the total number of moles of the polyvalent carboxylic acid component. It is preferably from mol% to 30 mol%, more preferably from 5 mol% to 20 mol%, and preferably from 10 mol% to 15 mol%.

  Moreover, as a polyvalent carboxylic acid component, the dicarboxylic acid component which has a sulfonic acid group other than the above-mentioned aliphatic dicarboxylic acid component and aromatic dicarboxylic acid component may be contained.

  For the above reason, it is particularly preferable that the amorphous polyester resin contains a structural unit derived from an aromatic dicarboxylic acid or its anhydride and a structural unit derived from trimellitic acid or its anhydride.

  The production of the amorphous polyester resin is not particularly limited, but the polymerization temperature is set to 180 to 230 ° C. by a polycondensation reaction between a polyvalent carboxylic acid component and a polyhydric alcohol component, and the pressure in the reaction system is reduced as necessary. It is preferable to carry out the reaction while removing water and alcohol generated during the condensation. The polymerization time is not particularly limited, but is preferably 1 to 10 hours, and more preferably 2 to 6 hours.

  In addition, when synthesizing the hybrid amorphous polyester resin described later, the reaction temperature for carrying out addition polymerization of the graft chain is not particularly limited, but is preferably 100 to 230 ° C, and preferably 160 to 200 ° C. Is more preferable. The reaction time for carrying out addition polymerization of the graft chain is not particularly limited, but is preferably 10 minutes to 6 hours, and more preferably 30 minutes to 2 hours.

  When the polymerizable monomer (polyhydric carboxylic acid component, polyhydric alcohol component) is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution aid is distilled off. If there is a polymerizable monomer having poor compatibility in the copolymerization reaction, the polymerizable monomer having poor compatibility and the polymerizable monomer and the acid or alcohol to be polycondensed are condensed in advance. And then polycondensation with the main component.

Examples of catalysts that can be used in the production of the amorphous polyester resin include alkali metal compounds such as sodium and lithium; Group 2 metal compounds such as magnesium and calcium; zinc, manganese, antimony, titanium, zirconium, and germanium. Metal compounds such as: phosphorous acid compounds; phosphoric acid compounds; and amine compounds. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these, from the viewpoint of making Mw / Mn smaller, it is preferably a metal compound such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium, and is a metal compound of titanium (titanium catalyst). Is more preferable. Although it does not restrict | limit especially as a titanium system catalyst, For example, Ti (OBu) ₄ , Ti (O-Pr) ₄ etc. are mentioned.

  The addition amount of the catalyst is not particularly limited, but is preferably 0.00001 mol% or more and 10 mol% or less with respect to the total number of moles of acid and alcohol. When the amount of the catalyst added increases, the reaction can proceed more reliably, and when the amount of the catalyst added decreases, the economy is more excellent. From the same viewpoint, it is more preferably 0.1 mol% or more and 5 mol% or less, and further preferably 1 mol% or more and 5 mol% or less.

Hybrid Amorphous Polyester Resin In the toner according to an embodiment of the present invention, the amorphous polyester resin includes an amorphous polyester polymer segment and an amorphous resin that is different from the amorphous polyester resin. It is preferable to contain a hybrid amorphous polyester resin chemically bonded to a polymerizable polymer segment (also referred to simply as an amorphous polymer segment in this specification). More specifically, an amorphous polyester resin is an amorphous polyester resin having a graft copolymer structure in which an amorphous polymer segment and an amorphous polyester polymer segment are chemically bonded (in this specification, Is also referred to as “hybrid amorphous polyester resin”).

  The inclusion of the amorphous polymerized segment in the hybrid amorphous polyester resin can be confirmed by specifying the chemical structure using, for example, NMR measurement or methylation reaction P-GC / MS measurement.

  The amorphous polymer segment does not have a melting point and has a relatively high glass transition temperature (Tg) when differential scanning calorimetry (DSC) is performed on a resin having the same chemical structure and molecular weight as the segment. It is a polymerization segment.

  In the present specification, the amorphous polyester polymerized segment represents a partial structure (main chain or graft chain) made of an amorphous polyester resin, and the amorphous polymerized segment refers to an amorphous polyester described later. This represents a partial structure (main chain or graft chain) made of an amorphous resin other than resin.

  By hybridizing the amorphous polyester resin, the affinity between the amorphous polyester resin and the crystalline polyester resin or an amorphous resin that can be optionally used in the binder resin can be further increased. Thereby, the dispersibility of the amorphous polyester resin or the crystalline polyester resin in the toner base particles is further improved. Further, by suppressing the localization of the amorphous polyester resin or the crystalline polyester resin in the toner base particles, the localization of the amorphous polyester resin or the crystalline polyester resin in the image to be fixed can be reduced. It becomes. At this time, the interaction generated between the fixing roller during fixing and the amorphous polyester resin or crystalline polyester resin in the image is further reduced. As a result, generation of an optical memory due to latent image formation on the fixing roller can be further suppressed.

  The amorphous polymer segment of the hybrid amorphous polyester resin is an amorphous polymer segment of the hybrid crystal polyester resin that can optionally be included in the binder resin, or the same type of resin as the amorphous resin that can be optionally used. Preferably configured. By hybridizing in such a form, the affinity with the crystalline polyester resin or amorphous resin in the binder resin is further improved, and the effect of suppressing the occurrence of optical memory due to the formation of a latent image on the fixing roller is achieved. It can be improved further.

  Here, “the same kind of resin” means that a characteristic chemical bond is commonly contained in the repeating unit. “Characteristic chemical bond” is described in the National Institute for Materials Science (NIMS) Substance / Material Database (http://polymer.nims.go.jp/PoLyInfo/guide/jp/term_polymer.html). Follow “Polymer classification”. That is, polyacryl, polyamide, polyanhydride, polycarbonate, polydiene, polyester, polyhaloolefin, polyimide, polyimine, polyketone, polyolefin, polyether, polyphenylene, polyphosphazene, polysiloxane, polystyrene, polysulfide, polysulfone, polyurethane, polyurea Chemical bonds constituting polymers classified by a total of 22 types of polyvinyl and other polymers are referred to as “characteristic chemical bonds”.

  The amorphous polymer segment is preferably composed of a vinyl resin, and more preferably composed of a styrene acrylic resin.

  The amorphous polymer segment and the amorphous polyester polymer segment constituting the hybrid amorphous polyester resin are respectively composed of an amorphous resin described later and the above-described amorphous polyester resin. In addition, when the content (mass ratio) of the amorphous polymer segment in the hybrid amorphous polyester resin is defined as a hybridization rate (HB rate), the HB rate may be in the range of 5 to 30% by mass. Preferably, it is in the range of 5 to 15% by mass, more preferably 5 to 10% by mass.

  As the polymerization method and conditions for the amorphous polyester polymer segment, the above-described polymerization method and conditions for the amorphous polyester resin can be preferably used. As the polymerization method and conditions for the amorphous polymerization segment, the polymerization method and conditions for the amorphous resin described later can be preferably used.

  As a method for producing the hybrid amorphous polyester resin, an existing general scheme can be used. The following three methods are listed as typical methods.

  (1) A method for producing a hybrid amorphous polyester resin by polymerizing an amorphous polymer segment in advance and performing a polymerization reaction to form an amorphous polyester polymer segment in the presence of the amorphous polymer segment.

  (2) A method of producing a hybrid amorphous polyester resin by forming an amorphous polyester polymer segment and an amorphous polymer segment, respectively, and combining them.

  (3) A method for producing a hybrid amorphous polyester resin by polymerizing an amorphous polyester polymer segment in advance and performing a polymerization reaction to form the amorphous polymer segment in the presence of the amorphous polyester polymer segment .

  The number average molecular weight (Mn) of the amorphous polyester resin is not particularly limited, but is preferably 1,000 to 30,000, and more preferably 5,000 to 25,000.

  The weight average molecular weight (Mw) of the amorphous polyester resin is not particularly limited, but is preferably 2,000 to 150,000, and more preferably 10,000 to 100,000.

  When the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the amorphous polyester resin is more than 5, the occurrence of gloss memory becomes remarkable. Therefore, the amorphous polyester resin according to the present invention has Mw / Mn of 5 or less. On the other hand, when Mw / Mn is 2 or more, the synthesis of the amorphous polyester resin becomes easier and the productivity is further improved. Therefore, the amorphous polyester resin according to the present invention preferably has Mw / Mn of 2 or more. Thus, in the amorphous polyester resin according to the present invention, Mw / Mn is more preferably 2 or more and 5 or less, further preferably 2.5 or more and 4.5 or less, and more preferably 3 or more and 4 or less. More preferably, it is 3.5 or more and 4 or less.

  The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the amorphous polyester resin can be measured by gel permeation chromatography measurement.

  Here, the gel permeation chromatography measurement can be performed as follows.

First, the object to be measured is subjected to ultrasonic dispersion for 15 minutes with an ultrasonic disperser at 40 ° C., dissolved in tetrahydrofuran to a concentration of 1 mg / mL, and then filtered with a membrane filter having a pore size of 0.2 μm. To obtain a measurement sample. Next, using the apparatus “HLC-8220” (manufactured by Tosoh Corporation) and the column “TSKguardcolumn + TSKgelSuperHZM-M3 series” (manufactured by Tosoh Corporation), while maintaining the column temperature at 40 ° C., with tetrahydrofuran (THF) as a carrier solvent 10 μL of the measurement sample is flowed at a flow rate of 0.2 mL / min. By detecting this using a refractive index detector (RI detector), an elution curve can be obtained. Further, based on this elution curve, the molecular weight distribution of the measurement sample can be calculated by a calibration curve created using monodisperse polystyrene standard particles. As a standard polystyrene sample for preparing a calibration curve, molecular weights manufactured by Pressure Chemical are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1 .1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ To do. A refractive index detector is used as the detector.

  Examples of the method for controlling the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the amorphous polyester resin mainly include selection of a catalyst used for the synthesis of the amorphous polyester resin. For example, it is possible to use a titanium-based catalyst.

  The hydroxyl value of the amorphous polyester resin according to the present invention is higher than the hydroxyl value of the release agent. When the hydroxyl value of the amorphous polyester resin is higher than the hydroxyl value of the release agent, the releasability between the fixing roller and the image surface is improved, and the occurrence of gloss memory is suppressed.

  The hydroxyl value of the amorphous polyester resin according to an embodiment of the present invention is not particularly limited as long as it has a value higher than the hydroxyl value of the release agent, but is preferably 20.1 mgKOH / g or more. When the hydroxyl value of the amorphous polyester resin is within this range, the releasability between the fixing roller and the image surface is further improved, and the occurrence of gloss memory can be further suppressed. From the same viewpoint, the hydroxyl value is more preferably 25 mgKOH / g or more, further preferably 30 mgKOH / g or more, and particularly preferably 40 mgKOH / g or more. The hydroxyl value of the amorphous polyester resin according to one embodiment of the present invention is preferably 100 mgKOH / g or less. When the hydroxyl value of the amorphous polyester resin is within this range, the occurrence of gloss memory is further reduced. The reason is presumed to be as follows. The hydroxyl value is an index of polarity and also an index of hydrophilicity. By setting the value of the hydroxyl value of the amorphous polyester resin to a certain value or less, the release agent can be more uniformly dispersed and held in the amorphous polyester resin in the toner base particles in a microphase separated state. As a result, the release agent can obtain more stable releasability by causing the seepage to the image surface more uniformly, and the generation of gloss memory can be further suppressed. From the same viewpoint, the hydroxyl value is more preferably 70 mgKOH / g or less, further preferably 50 mgKOH / g or less, and particularly preferably 45 mgKOH / g or less.

  Here, from the viewpoint of further promoting bleeding of the release agent at the time of fixing, the difference between the hydroxyl value of the amorphous polyester resin and the hydroxyl value of the release agent is preferably 20 mgKOH / g or more. 25 mgKOH / g or more is more preferable, 30 mgKOH / g or more is more preferable, and 40 mgKOH / g or more is particularly preferable. In particular, from the viewpoint of more reliably including a release agent in the amorphous polyester resin as described above, the difference between the hydroxyl value of the amorphous polyester resin and the hydroxyl value of the release agent is 99. It is preferably 9.9 mgKOH / g or less, more preferably 69.9 mgKOH / g or less, further preferably 49.9 mgKOH / g or less, and particularly preferably 44.9 mgKOH / g or less.

  The hydroxyl value of the amorphous polyester resin is the same as JIS K0070-1992 except that the measurement solvent is changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1). It can be obtained by measuring.

  Examples of the method for controlling the hydroxyl value of the amorphous polyester resin mainly include selection of the monomer ratio of the polyvalent carboxylic acid component and the polyhydric alcohol component in the synthesis of the amorphous polyester resin, the reaction temperature, or the reaction time. It is done. For example, an amorphous polyester resin having a lower hydroxyl value can be obtained by increasing the reaction temperature or increasing the reaction time.

  The acid value of the amorphous polyester resin according to one embodiment of the present invention is preferably 20 mgKOH / g or more. When the acid value of the amorphous polyester resin is within this range, the occurrence of gloss memory is further reduced. This is because the compatibility between the amorphous polyester resin and the release agent is further lowered, and the compatibility between the amorphous polyester resin and the crystalline polyester resin is further improved, so that a more uniform toner base can be obtained. It is assumed that the particles are obtained. From the same viewpoint, the acid value is more preferably 25 mgKOH / g or more, further preferably 28 mgKOH / g or more, and particularly preferably 30 mgKOH / g or more. The acid value of the amorphous polyester resin according to one embodiment of the present invention is preferably 100 mgKOH / g or less. When the acid value of the amorphous polyester resin is within this range, the occurrence of gloss memory is further reduced. The reason for this is presumed to be that the compatibility between the amorphous polyester resin, the crystalline polyester resin and the release agent is further improved, and more uniform toner base particles can be obtained. From the same viewpoint, the acid value is more preferably 50 mgKOH / g or less, further preferably 40 mgKOH / g or less, and particularly preferably 35 mgKOH / g or less.

  The acid value of the amorphous polyester resin is the same as JIS K0070-1992 except that the measurement solvent is changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1). It can be obtained by measuring.

  The method for controlling the acid value of the amorphous polyester resin mainly includes selection of the monomer ratio of the polyvalent carboxylic acid component and the polyhydric alcohol component in the synthesis of the amorphous polyester resin, the reaction temperature, or the reaction time. It is done. For example, an amorphous polyester resin having a lower acid value can be obtained by increasing the reaction temperature or increasing the reaction time.

  The glass transition temperature (Tg) of the amorphous polyester resin is not particularly limited, but is preferably 25 to 70 ° C, and more preferably 35 to 65 ° C. The softening temperature is not particularly limited, but is preferably 75 to 130 ° C, more preferably 85 to 115 ° C.

The presence / absence of the amorphous polyester resin contained in the toner and the amount of components can be calculated by the following method. That is, under the same conditions as in the gel permeation chromatography measurement, the measurement target is run using tetrahydrofuran (THF) as the mobile phase, the eluate is fractionated with a fraction collector, etc., and the desired molecular weight portion of the entire integral of the elution curve. Summarize the corresponding fractions. After concentrating and drying the collected eluate with an evaporator or the like, the solid content is dissolved in a heavy solvent such as deuterated chloroform or deuterated THF, and ¹ H-NMR measurement is performed. Is calculated.

[Crystalline polyester resin]
The toner base particles of the present invention contain a crystalline polyester resin as a binder resin. The crystalline polyester resin has a function of improving low-temperature fixability. The low temperature fixing means fixing the toner by heating at about 120 ° C. or less.

  In the present invention, the crystalline polyester resin refers to a resin having a clear endothermic peak rather than a stepwise change in endothermic amount in differential scanning calorimetry (DSC). Any resin having the endothermic peak may be used, and in the case of a polymer obtained by copolymerizing other components with respect to the crystalline polyester main chain, the other components are 50 mol% or less of the total raw material monomers in terms of raw material monomers If so, this copolymer is also a crystalline polyester resin. That is, a crystalline polyester resin is obtained by showing an endothermic peak. Hereinafter, although the preferable example of crystalline polyester is shown, it is not limited to this.

  The crystalline polyester resin is a copolymer of a polyvalent carboxylic acid component and a polyhydric alcohol component.

  In the present specification, “acid component” and “alcohol component” represent not only an acid and an alcohol, but also an acid or a derivative thereof, an alcohol or a derivative thereof capable of synthesizing a polyester resin. Examples of the acid component include acids, salts thereof, lower alkyl esters, acid anhydrides, and the like. It should be noted that terms such as “diol component” are handled in the same manner.

  The crystalline polyester resin may be one kind of crystalline polyester resin, but may be a mixture of two or more kinds of crystalline polyester resins.

  The polyvalent carboxylic acid component is preferably an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid is particularly preferably a linear carboxylic acid component. Moreover, the acid component may have a sulfonic acid group from the viewpoint of improving the emulsifying property in the emulsion aggregation method.

  Examples of the aliphatic dicarboxylic acid component which is a polyvalent carboxylic acid component include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid. Acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid 1,18-octadecanedicarboxylic acid and the like, and lower alkyl esters and acid anhydrides thereof are not limited thereto. Among these, considering availability, adipic acid, sebacic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, salts thereof, lower alkyl esters or acid anhydrides are preferable, and sebacic acid, The lower alkyl ester or acid anhydride is more preferred. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The polyvalent carboxylic acid component may include an aromatic dicarboxylic acid component. Examples of the aromatic dicarboxylic acid component include terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, salts thereof, and lower alkyl esters. And acid anhydrides. Among these, terephthalic acid, isophthalic acid, t-butylisophthalic acid, salts thereof, lower alkyl esters, acid anhydrides, and the like are preferable from the viewpoint of availability and easy emulsification. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The addition amount of these aliphatic dicarboxylic acid components is preferably 80 mol% or more, more preferably 90 mol% or more, more preferably 95 mol% or more of the polyvalent carboxylic acid component constituting the crystalline polyester resin. It is particularly preferred that When the added amount of the aliphatic dicarboxylic acid is 80 mol% or more, emulsification becomes easier, image gloss peculiar to the crystalline polyester resin can be obtained, and furthermore, storage stability of the image is suppressed by suppressing the melting point drop. Can be improved. From the same viewpoint, it is more preferable that the total acid-derived constituent component constituting the crystalline polyester resin is only an aliphatic dicarboxylic acid component.

  In the crystalline polyester resin, a polyvalent aliphatic diol component and an aromatic diol component are desirable. In particular, the aliphatic diol component is preferably a linear diol component.

  Specific examples of the aliphatic diol component include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptane. Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecane Examples include, but are not limited to, diol, 1,18-octadecanediol, and 1,20-eicosanediol. Among these, considering availability, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol are preferable, and 1,6-hexanediol is preferable. 1,9-nonanediol is more preferable. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The content of the aliphatic diol component in the crystalline polyester resin is preferably 80 mol% or more of the polyhydric alcohol component constituting the crystalline polyester resin, more preferably 90 mol% or more, and necessary. Other ingredients may be included accordingly. When the content of the aliphatic diol component is 80 mol% or more, the crystallinity of the polyester resin is improved and the melting point is increased, so that toner blocking resistance, image storage stability and low-temperature fixability can be improved. From the same viewpoint, it is more preferable that all alcohol components constituting the crystalline polyester resin are only aliphatic diols.

  Examples of other components included as necessary include diol components having a double bond and diol components having a sulfonic acid group. Examples of the diol component having a double bond include 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type. As content in the polyhydric alcohol component of the diol component which has these double bonds, 20 mol% or less is preferable. When the content of the diol component having a double bond is 20 mol% or less, the crystallinity of the polyester resin is improved, the melting point is increased, and the image storage stability is improved.

  The crystalline polyester resin in the present embodiment is preferably an aliphatic crystalline polyester resin.

  In this case, an aliphatic crystalline polyester resin obtained by reacting a C10-12 dicarboxylic acid and a C4-9 diol is preferable. By setting the carbon number within this range, it is easy to obtain a crystalline polyester resin having a melting temperature suitable for the toner, and because it is aliphatic, the linearity of the resin structure is increased and it has a higher affinity with the amorphous polyester resin. It becomes easy to do.

  More preferably, the carbon number of the dicarboxylic acid is in the range of 10 to 12, and the carbon number of the diol is in the range of 6 to 9.

  Although the production of the crystalline polyester resin is not particularly limited, the polymerization temperature is 180 to 230 ° C., and the polycondensation reaction between the polyvalent carboxylic acid component and the polyhydric alcohol component is performed. The reaction is preferably carried out while removing water and alcohol generated during the condensation. The polymerization temperature is more preferably 180 to 210 ° C, further preferably 180 to 200 ° C, and particularly preferably 180 to 190 ° C. The polymerization time is not particularly limited, but is preferably 1 to 12 hours, and more preferably 6 to 12 hours.

  In addition, when synthesizing the hybrid crystalline polyester resin described later, the reaction temperature for carrying out addition polymerization of the graft chain is not particularly limited, but is preferably 100 to 230 ° C, and preferably 160 to 200 ° C. More preferred. The reaction time for carrying out addition polymerization of the graft chain is not particularly limited, but is preferably 1 to 12 hours, and more preferably 6 to 12 hours.

  When the polymerizable monomer (polyhydric carboxylic acid component, polyhydric alcohol component) is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution aid is distilled off. If there is a polymerizable monomer having poor compatibility in the copolymerization reaction, the polymerizable monomer having poor compatibility and the polymerizable monomer and the acid or alcohol to be polycondensed are condensed in advance. And then polycondensation with the main component.

Examples of the catalyst that can be used in the production of the crystalline polyester resin include alkali metal compounds such as sodium and lithium; group 2 metal compounds such as magnesium and calcium; zinc, manganese, antimony, titanium, tin, zirconium, Examples thereof include metal compounds such as germanium; phosphorous acid compounds; phosphoric acid compounds; and amine compounds. Among these, from the viewpoint of making Mw / Mn smaller, metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium are preferable, and titanium metal compounds (titanium-based catalysts) or tin A metal compound (tin-based catalyst) is more preferable, and a tin-based catalyst is more preferable. Although it does not restrict | limit especially as a tin-type catalyst, For example, octyl acid tin, dibutyltin oxide, dibutyltin laurate, monobutyltin hydroxybutyl oxide, stannous chloride, stannic chloride etc. are mentioned. The titanium-based catalyst is not particularly limited, and examples thereof include Ti (OBu) ₄ and Ti (O—Pr) ₄ . Among these, dibutyltin oxide is particularly preferable. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The addition amount of the catalyst is not particularly limited, but is preferably 0.00001 mol% or more and 10 mol% or less with respect to the total number of moles of acid and alcohol. When the amount of the catalyst added increases, the reaction can proceed more reliably, and when the amount of the catalyst added decreases, the economy is more excellent. From the same viewpoint, it is more preferably 0.0001 mol% or more and 1 mol% or less, and further preferably 0.002 mol% or more and 0.05 mol% or less.

Hybrid Crystalline Polyester Resin In the toner according to one embodiment of the present invention, the crystalline polyester resin comprises a crystalline polyester polymer segment and an amorphous polymer segment comprising an amorphous resin different from the amorphous polyester resin. It is preferable to contain a hybrid crystalline polyester resin that is chemically bonded to (in this specification, also simply referred to as an amorphous polymer segment). More specifically, the crystalline polyester resin is a crystalline polyester resin having a graft copolymer structure in which an amorphous polymer segment and a crystalline polyester polymer segment are chemically bonded (in this specification, , Also referred to as “hybrid crystalline polyester resin”).

  The inclusion of an amorphous polymer segment in the hybrid crystalline polyester resin can be confirmed by specifying the chemical structure using, for example, NMR measurement or methylation reaction P-GC / MS measurement.

  The amorphous polymer segment does not have a melting point and has a relatively high glass transition temperature (Tg) when differential scanning calorimetry (DSC) is performed on a resin having the same chemical structure and molecular weight as the segment. It is a polymerization segment.

  In the present specification, the crystalline polyester polymerization segment represents a partial structure (main chain or graft chain) made of a crystalline polyester resin, and the amorphous polymerization segment is other than the amorphous polyester resin described later. Represents a partial structure (main chain or graft chain) made of an amorphous resin.

  By hybridizing the crystalline polyester resin, the affinity between the crystalline polyester resin and the amorphous polyester resin or an amorphous resin that can be optionally used in the binder resin can be further increased. Thereby, the dispersibility of the amorphous polyester resin or the crystalline polyester resin in the toner base particles is further improved. Further, by suppressing the localization of the amorphous polyester resin or the crystalline polyester resin in the toner base particles, the localization of the amorphous polyester resin or the crystalline polyester resin in the image to be fixed can be reduced. It becomes. At this time, the interaction generated between the fixing roller during fixing and the amorphous polyester resin or crystalline polyester resin in the image is further reduced. As a result, generation of an optical memory due to latent image formation on the fixing roller can be further suppressed.

  The amorphous polymer segment of the hybrid crystalline polyester resin is the same as the amorphous polyester resin contained in the binder resin or a partial structure thereof (for example, an amorphous polymer segment), or an amorphous resin that can be optionally used. It is preferable that it is comprised with resin of. By hybridizing in this way, the affinity between the crystalline polyester resin and the amorphous polyester resin or amorphous resin in the binder resin is further increased, and the optical memory of the latent image formed on the fixing roller is improved. The effect of suppressing generation can be further improved.

  Here, “the same kind of resin” means that a characteristic chemical bond is commonly contained in the repeating unit. “Characteristic chemical bond” is described in the National Institute for Materials Science (NIMS) Substance / Material Database (http://polymer.nims.go.jp/PoLyInfo/guide/jp/term_polymer.html). Follow “Polymer classification”. That is, polyacryl, polyamide, polyanhydride, polycarbonate, polydiene, polyester, polyhaloolefin, polyimide, polyimine, polyketone, polyolefin, polyether, polyphenylene, polyphosphazene, polysiloxane, polystyrene, polysulfide, polysulfone, polyurethane, polyurea Chemical bonds constituting polymers classified by a total of 22 types of polyvinyl and other polymers are referred to as “characteristic chemical bonds”.

  The amorphous polymer segment is preferably composed of a vinyl resin, and more preferably composed of a styrene acrylic resin.

  The amorphous polymerized segment and the crystalline polyester polymerized segment constituting the hybrid crystalline polyester resin are respectively composed of an amorphous resin described later and the above-described crystalline polyester resin. When the content (mass ratio) of the amorphous polymer segment in the hybrid crystalline polyester resin is defined as the hybridization rate (HB rate), the HB rate is preferably in the range of 5 to 30% by mass. More preferably, it is in the range of 5 to 15% by mass, and further preferably 5 to 10% by mass.

  As the polymerization method and conditions for the crystalline polyester polymer segment, the above-described polymerization method and conditions for the crystalline polyester resin can be preferably used. As the polymerization method and conditions for the amorphous polymerization segment, the polymerization method and conditions for the amorphous resin described later can be preferably used.

  As a method for producing the hybrid crystalline polyester resin, an existing general scheme can be used. The following three methods are listed as typical methods.

  (1) A method for producing a hybrid crystalline polyester resin by polymerizing an amorphous polymer segment in advance and performing a polymerization reaction to form a crystalline polyester polymer segment in the presence of the amorphous polymer segment.

  (2) A method of producing a hybrid crystalline polyester resin by forming a crystalline polyester polymer segment and an amorphous polymer segment, respectively, and combining them.

  (3) A method of producing a hybrid crystalline polyester resin by polymerizing a crystalline polyester polymerization segment in advance and performing a polymerization reaction to form an amorphous polymerization segment in the presence of the crystalline polyester polymerization segment.

  The number average molecular weight (Mn) of the crystalline polyester resin is not particularly limited, but is preferably 1,000 to 50,000, and more preferably 1,500 to 20,000.

  The weight average molecular weight (Mw) of the crystalline polyester resin is not particularly limited, but is preferably 2,000 to 200,000, more preferably 3,000 to 80,000, and 15,000 to 70. More preferably, it is 1,000.

  When the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the crystalline polyester resin is more than 4, the occurrence of gloss memory becomes remarkable. Therefore, the crystalline polyester resin according to the present invention has Mw / Mn of 4 or less. On the other hand, when Mw / Mn is 2 or more, the synthesis of the amorphous polyester resin becomes easier and the productivity is further improved. Therefore, it is preferable that Mw / Mn is 2 or more in the crystalline polyester resin according to the present invention. Accordingly, in the crystalline polyester resin in the present invention, Mw / Mn is preferably 2 or more and 4 or less, more preferably 2.5 or more and 4 or less, and even more preferably 3 or more and 4 or less. 3.5 or more and 4 or less is particularly preferable.

  The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the crystalline polyester resin can be measured by gel permeation chromatography measurement. The details of the gel permeation chromatography measurement are the same as those described for the amorphous polyester resin.

  Examples of a method for controlling the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the crystalline polyester resin include selection of a catalyst used for the synthesis of the crystalline polyester resin. For example, it is possible to use a titanium-based catalyst or a tin-based catalyst.

  The hydroxyl value of the crystalline polyester resin according to one embodiment of the present invention is preferably 15 mgKOH / g or more. When the hydroxyl value of the crystalline polyester resin is within this range, the occurrence of gloss memory is further reduced. The reason is presumed as follows. In the toner base particles, the release agent is mainly present in the amorphous polyester, but a part is also present in the crystalline polyester resin. By increasing the difference between the release agent and the value of the hydroxyl value of the crystalline polyester resin, the compatibility between the release agent and the crystalline polyester resin is lowered. When the toner is melted at the time of fixing, the exudation of the wax on the image surface is promoted. As a result, the releasability between the fixing roller and the image surface is improved, and the occurrence of gloss memory can be suppressed. From the same viewpoint, the hydroxyl value is more preferably 18 mgKOH / g or more, further preferably 20 mgKOH / g or more, and particularly preferably 22 mgKOH / g or more. In addition, the hydroxyl value of the crystalline polyester resin according to one embodiment of the present invention is preferably 100 mgKOH / g or less. When the hydroxyl value of the crystalline polyester resin is within this range, the occurrence of gloss memory is further reduced. The reason is presumed as follows. In the toner base particles, the release agent is mainly present in the amorphous polyester, but a part is also present in the crystalline polyester resin. By setting the value of the hydroxyl value of the crystalline polyester resin to a certain value or less, the release agent can be more uniformly dispersed and held in the crystalline polyester resin in the toner base particles in a microphase separated state. As a result, the release agent can obtain more stable releasability by causing the seepage to the image surface more uniformly, and the generation of gloss memory can be further suppressed. From the same viewpoint, the hydroxyl value is more preferably 30 mgKOH / g or less, further preferably 25 mgKOH / g or less, and particularly preferably 24 mgKOH / g or less.

  The hydroxyl value of the crystalline polyester resin is the same as JIS K0070-1992 except that the measurement solvent is changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1). It can be obtained by measuring.

  Examples of the method for controlling the hydroxyl value of the crystalline polyester resin mainly include selection of the monomer ratio of the polyvalent carboxylic acid component and the polyhydric alcohol component, the reaction temperature or the reaction time in the synthesis of the crystalline polyester resin. For example, a crystalline polyester resin having a lower hydroxyl value can be obtained by increasing the reaction temperature or increasing the reaction time.

  The acid value of the crystalline polyester resin according to one embodiment of the present invention is preferably 10 mgKOH / g or more. When the acid value of the crystalline polyester resin is within this range, the occurrence of gloss memory is further reduced. This is because the compatibility between the crystalline polyester resin and the release agent is further lowered, and the compatibility between the crystalline polyester resin and the amorphous polyester resin is further improved, so that more uniform toner base particles can be obtained. Is presumed to be obtained. From the same viewpoint, the acid value is more preferably 12 mgKOH / g or more, further preferably 20 mgKOH / g or more, and particularly preferably 22 mgKOH / g or more. The acid value of the crystalline polyester resin according to one embodiment of the present invention is preferably 100 mgKOH / g or less. When the acid value of the crystalline polyester resin is within this range, the occurrence of gloss memory is further reduced. This is presumed to be because the compatibility between the crystalline polyester resin, the amorphous polyester resin and the release agent is further improved, and more uniform toner base particles can be obtained. From the same viewpoint, the acid value is more preferably 30 mgKOH / g or less, further preferably 24 mgKOH / g or less, and particularly preferably 23 mgKOH / g or less.

  The acid value of the crystalline polyester resin is the same as JIS K0070-1992 except that the measurement solvent is changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1). It can be obtained by measuring.

  Examples of the method for controlling the acid value of the crystalline polyester resin mainly include selection of the monomer ratio of the polyvalent carboxylic acid component and the polyhydric alcohol component, the reaction temperature or the reaction time in the synthesis of the crystalline polyester resin. For example, a crystalline polyester resin having a lower acid value can be obtained by increasing the reaction temperature or increasing the reaction time.

  The melting point of the crystalline polyester resin is preferably 55 ° C. or higher and 90 ° C. or lower, more preferably 70 ° C. or higher and 85 ° C. or lower.

  The presence / absence of the crystalline polyester resin contained in the toner and the amount of components can be calculated by the same method as that described for the amorphous polyester resin.

[Amorphous resin different from amorphous polyester resin]
The toner base particles of the present invention preferably further include an amorphous resin (also simply referred to as “amorphous resin” in the present specification) different from the above-described amorphous polyester resin as a binder resin. . The amorphous resin has a function of improving the dispersibility of the crystalline polyester resin, the amorphous polyester resin, and the release agent in the toner base particles.

  When the crystalline polyester resin is a hybrid crystalline polyester resin, or when the amorphous polyester resin is a hybrid amorphous polyester resin, the amorphous resin is the same type of resin as the amorphous polymer segment. Preferably configured. Here, “consisting of the same kind of resin” may be a form consisting of only the same kind of resin, or a form including not only the same kind of resin but also other amorphous resins. Also good. However, in the case of a form containing the same type of resin and another amorphous resin, the content of the same type of resin is preferably 15% by mass or more, and 20% by mass or more with respect to the total amount of the amorphous resin. More preferably, it is more preferably 50% by mass or more, particularly preferably 70% by mass or more, and most preferably 100% by mass.

  As the amorphous resin, particularly when the amorphous polymer segment of the hybrid crystal polyester resin or the hybrid amorphous polyester resin is a vinyl polymer segment, the compatibility with these resins can be easily controlled. A vinyl resin is preferred.

Vinyl resin The vinyl resin is not particularly limited as long as a vinyl compound is polymerized. For example, an acrylic ester resin, a styrene acrylic copolymer (also referred to as a styrene acrylic resin in this specification), ethylene- Examples thereof include vinyl acetate resin. These may be used individually by 1 type and may be used in combination of 2 or more type. Among the vinyl resins mentioned above, considering the manufacturability in the emulsion aggregation method (that is, a toner having a sharp particle size distribution can be obtained by making a latex having uniform aggregation properties) and the plasticity at the time of heat fixing Styrene acrylic copolymers are preferred. In addition, when the amorphous resin is a styrene acrylic copolymer, the dispersibility of the crystalline polyester resin, the amorphous polyester resin, and the release agent in the toner base particles can be greatly improved. Memory generation can be significantly reduced.

・ Styrene acrylic resin (styrene acrylic copolymer)
In this specification, a styrene acrylic copolymer (also referred to as a styrene acrylic copolymer in this specification) is a polymerization using at least a styrene monomer and a (meth) acrylate monomer. It represents what is formed by performing. Here, the styrene monomer includes not only styrene represented by the structural formula of CH ₂ ═CH—C ₆ H ₅ but also those having a structure having a known side chain or functional group in the styrene structure. And

The (meth) acrylic acid ester monomer has a functional group having an ester bond in the side chain. _{Specifically,} CH 2 = CHCOOR (R is an alkyl group) other acrylic acid ester monomer represented _by, methacrylic acid ester represented by _{CH 2 = C (CH 3)} COOR (R is an alkyl group) Vinyl-based ester compounds such as monomers are included.

  Specific examples of the styrene monomer and (meth) acrylic acid ester monomer that can form a styrene acrylic copolymer are shown below, but are not limited to those shown below.

  Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p- Examples thereof include tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, and pn-dodecyl styrene. Among these, styrene is preferable. These may be used individually by 1 type and may be used in combination of 2 or more type. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The (meth) acrylic acid ester monomer is typically the following acrylic acid ester monomer and methacrylic acid ester monomer. Examples of the acrylic acid ester monomer include methyl acrylate, Examples include ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, and phenyl acrylate phenyl. Examples of the methacrylic acid ester monomer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate. Lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate and the like. Among these, n-butyl acrylate or 2-ethylhexyl acrylate is preferable. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The styrene acrylic copolymer is formed by polymerization using a styrene monomer, a (meth) acrylic acid ester monomer, and a vinyl monomer having an ionic dissociation group in the side chain. It is preferable that it is a thing. Specific examples of the ionic dissociation group include a carboxy group, a sulfonic acid group, and a phosphoric acid group. Specific examples of these vinyl monomers having an ionic dissociation group are shown below.

  Specific examples of the vinyl monomer having a carboxy group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, and the like. . Among these, acrylic acid or methacrylic acid is preferable. These may be used individually by 1 type and may be used in combination of 2 or more type.

  These styrene monomers, acrylate monomers, methacrylate monomers, and vinyl monomers having an ionic dissociation group in the side chain may be used alone or in combination of two A combination of the above may also be used.

  In addition, the styrene acrylic copolymer includes a copolymer formed only of the styrene monomer and the (meth) acrylate monomer described above, a styrene monomer, and a (meth) acrylate monomer. In addition to the copolymer formed from a vinyl monomer having an ionic dissociation group in the side chain, it may be formed by further using a general vinyl monomer. Although the vinyl monomer which can be used together is illustrated below, the vinyl monomer which can be used together is not limited to what is shown below.

(1) Olefins Ethylene, propylene, isobutylene, etc. (2) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc. (3) Vinyl ethers Vinyl methyl ether, vinyl ethyl ether, etc. (4) Vinyl ketones Vinyl methyl ketone, Vinyl ethyl ketone, vinyl hexyl ketone, etc. (5) N-vinyl compounds N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, etc. (6) Other vinyl compounds such as vinyl naphthalene, vinyl pyridine, acrylonitrile, methacrylo Acrylic acid or methacrylic acid derivatives such as nitrile and acrylamide.

  It is also possible to produce a crosslinked resin using a polyfunctional vinyl monomer.

  The method for forming the styrene acrylic copolymer is not particularly limited, and examples thereof include a method of polymerizing a monomer using a known oil-soluble or water-soluble polymerization initiator. Specific examples of the oil-soluble polymerization initiator or the water-soluble polymerization initiator are the same as those described above, and thus the description thereof is omitted here.

  When forming the styrene acrylic copolymer used in the present invention, the content of the styrene monomer and the acrylate monomer is not particularly limited, and the softening temperature and glass transition temperature of the binder resin are not limited. It is possible to adjust appropriately from the viewpoint of adjustment. Specifically, the content of the styrene monomer is preferably 40 to 95% by mass and more preferably 50 to 80% by mass with respect to the whole monomer. Moreover, 5-60 mass% is preferable with respect to the whole monomer, and, as for content of an acrylic ester monomer, 10-50 mass% is more preferable.

  The toner of the present invention may have a single layer structure or a core-shell structure, but preferably has a core-shell structure. Conventionally known knowledge is appropriately applied to the manufacturing method of the core-shell structure.

  The number average molecular weight (Mn) of the amorphous resin is preferably 1,000 to 100,000.

  The weight average molecular weight (Mw) of the amorphous resin is preferably 2,000 to 1,000,000.

  The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the amorphous resin is preferably 1.5 to 100, and more preferably 1.8 to 70.

  The glass transition temperature of the styrene acrylic copolymer is preferably 30 to 70 ° C, and the softening temperature is preferably 80 to 170 ° C.

  The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the amorphous resin can be measured by gel permeation chromatography measurement. The details of the gel permeation chromatography measurement are the same as those described for the amorphous polyester resin.

  The presence or amount of the amorphous resin contained in the toner and the amount of components can be calculated by the same method as described for the amorphous polyester resin.

  An amorphous resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  When the toner base particles include an amorphous resin, the content of the amorphous resin with respect to the total mass of the amorphous polyester resin, the crystalline polyester resin, and the amorphous resin is 50% by mass or more and 99% by mass or less. It is preferable. As the amorphous resin content increases, the dispersibility of the crystalline polyester resin, amorphous polyester resin, and release agent in the toner base particles is further improved, thereby reducing the occurrence of gloss memory. The In addition, as the content of the amorphous resin decreases, an appropriate amount of an amorphous polyester resin that can disperse the release agent in the interior can be contained in an appropriate amount, thereby further improving the dispersibility of the release agent. Thus, the occurrence of gloss memory is further reduced. From the same viewpoint, the content of the amorphous resin with respect to the total mass of the amorphous polyester resin, the crystalline polyester resin and the amorphous resin is more preferably 55% by mass or more and 95% by mass or less, and 60% by mass. % To 90% by mass is more preferable.

<Release agent>
The toner base particles according to an embodiment of the present invention contain a release agent. The release agent has a function of improving the releasability between the fixing roller and the image surface by exuding the wax onto the image surface during fixing.

  Examples of the mold release agent include paraffin waxes, ester waxes, natural product waxes, and amide waxes.

  Paraffin waxes are not particularly limited, and examples thereof include low molecular weight polyethylene wax and polypropylene wax, microcrystalline wax, Fischer-Tropsch wax, and paraffin wax. Among these, paraffin wax is preferable.

  Examples of ester waxes include, but are not limited to, for example, behenyl behenate, ethylene glycol stearate, ethylene glycol behenate, neopentyl glycol stearate, neopentyl glycol behenate, 1,6-hexanediol. Stearic acid ester, 1,6-hexanediol behenic acid ester, glycerin stearic acid ester, glycerin behenic acid ester, pentaerythritol tetrastearic acid ester, pentaerythritol tetrabehenic acid ester, stearyl citrate, behenyl citrate, stearyl ring acid, Examples thereof include ester waxes such as esters of higher fatty acids such as behenyl ring acid and higher alcohols.

  Among these, from the viewpoint of improving peelability, that is, reducing gloss memory, ester waxes or paraffin waxes are preferable, ester waxes or paraffin waxes are more preferable, and ester waxes are preferable. Further preferred.

  The melting point of the release agent is not particularly limited, but is preferably 40 to 160 ° C, and more preferably 60 to 100 ° C.

  If the hydroxyl value of the release agent is more than 2 mgKOH / g, the release agent will not bleed out onto the image surface, and the releasability between the fixing roller and the image surface will be insufficient, resulting in a gloss memory. It occurs remarkably. Thus, the release agent according to the present invention has a hydroxyl value of 2 mgKOH / g or less. When the hydroxyl value of the release agent is within this range, the releasability between the fixing roller and the image surface is sufficient, and the occurrence of gloss memory is sufficiently suppressed. On the other hand, the hydroxyl value of the release agent is preferably 0.01 mgKOH / g or more. When the hydroxyl value of the release agent is within this range, synthesis of the release agent becomes easier and productivity is further improved. From the same viewpoint, the hydroxyl value is more preferably 0.1 mgKOH / g or more, further preferably 1.0 mgKOH / g or more, and particularly preferably 1.5 mgKOH / g or more.

  The preferred range of the difference between the hydroxyl value of the release agent, the hydroxyl value of the amorphous polyester resin, and the hydroxyl value of the release agent in the toner according to an embodiment of the present invention is the above-described amorphous polyester resin. It is described in the explanation.

  The hydroxyl value of the release agent was measured in the same manner as in JIS K0070-1992 except that the measurement solvent was changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1). You can ask for it.

  The method for controlling the hydroxyl value of the release agent mainly includes adjustment of the monomer ratio and reaction conditions in the synthesis of the release agent. For example, when the release agent is an ester wax, the monomer of acid and alcohol Examples include selection of ratio, reaction temperature or reaction time. For example, a release agent having a lower hydroxyl value can be obtained by increasing the reaction temperature or extending the reaction time.

  The acid value of the release agent according to one embodiment of the present invention is preferably 3 mgKOH / g or less. When the acid value of the release agent is within this range, the occurrence of gloss memory is further reduced. The reason for this is that the compatibility of the release agent with the amorphous polyester and the crystalline polyester is further lowered, so that the release agent is more uniformly dispersed and retained in the toner base particles. This is presumed to be because more uniform toner base particles can be obtained. On the other hand, the acid value of the release agent is preferably 0.01 mgKOH / g or more. When the acid value of the release agent is within this range, the synthesis of the release agent becomes easier and the productivity is further improved. From the same viewpoint, the acid value is more preferably 0.01 mgKOH / g or more and 1 mgKOH / g or less, further preferably 0.01 mgKOH / g or more and 0.5 mgKOH / g or less, and 0.01 mgKOH / g or more. It is especially preferable that it is 0.1 mgKOH / g or less.

  The acid value of the release agent was measured in the same manner as in JIS K0070-1992 except that the measurement solvent was changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1). You can ask for it.

  The method for controlling the acid value of the release agent mainly includes adjustment of the monomer ratio and reaction conditions in the synthesis of the release agent. For example, when the release agent is an ester wax, the acid and alcohol monomers are used. Examples include selection of ratio, reaction temperature or reaction time. For example, a release agent having a lower acid value can be obtained by increasing the reaction temperature or extending the reaction time.

  A commercial product may be used as the release agent. Examples of commercially available ester wax include WEP-1, WEP-3, WEP-6, and WEP-8 manufactured by NOF Corporation. Examples of commercially available paraffin wax include WBM-1 manufactured by Nippon Oil & Fats Co., Ltd., FNP0090 manufactured by Nippon Seiwa Co., Ltd., and the like.

  These release agents can be used alone or in combination of two or more.

  In addition, there is no particular limitation on the method of incorporating the release agent into the toner base particles, and the release agent particle dispersion solution is separately prepared and contained by mixing with the dispersion liquid of other constituents of the toner base particles. It may be allowed to be included, or may be included together when the raw material component of the binder resin is polymerized. The former method has a technical effect for improving the fixing property, and the latter method has a technical effect for improving the charging property.

  The content of the release agent in the toner base particles is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass with respect to the total mass of the toner base particles.

<Colorant>
The toner base particles according to an embodiment of the present invention may further contain a colorant.

  The colorant may be a dye or a pigment, but a pigment is desirable from the viewpoint of light resistance and water resistance.

  Preferred colorants include, for example, carbon black, aniline black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, Rose Bengal, Quinacridone, Benzicine Yellow, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 185, C.I. I. Pigment red 238, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 74, C.I. I. Pigment blue 15: 1, C.I. I. A known pigment such as CI Pigment Blue 15: 3 can be used.

  It is also effective to use a surface-treated colorant or a pigment dispersant as necessary. By selecting the type of colorant, for example, yellow toner, magenta toner, cyan toner, black toner and the like can be obtained. Moreover, a clear toner etc. are obtained by not containing a coloring agent.

  These colorants can be used alone or in combination of two or more.

  The content of the colorant in the toner base particles is preferably 1 to 30% by weight and more preferably 5 to 20% by weight with respect to the total weight of the toner base particles.

<Other additives (internal additives)>
The toner base particles according to an embodiment of the present invention may be used as an internal additive in various known toners such as a magnetic material, a charge control agent, inorganic powder (inorganic particles), and organic particles, if necessary. An additive may be further contained.

  As the magnetic material, for example, various known magnetic materials such as metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, or compounds containing these metals can be used.

  As the charge control agent, various known compounds such as nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, and salicylic acid metal salts can be used. .

  The inorganic particles are added for various purposes, but may be added for adjusting the viscoelasticity of the toner. By adjusting the viscoelasticity, it is possible to adjust the image glossiness and the penetration into the paper. As the inorganic particles, for example, known inorganic particles such as silica particles, titanium oxide particles, alumina particles, cerium oxide particles, or those obtained by hydrophobizing the surface thereof may be used alone or in combination of two or more. it can. Among these, silica particles having a refractive index smaller than that of the binder resin are preferably used from the viewpoint of not impairing transparency such as color developability and OHP permeability. Further, the silica particles may be subjected to various surface treatments, and for example, those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, silicone oil or the like are preferably used.

  As the organic particles, various known organic particles such as homopolymers such as styrene and methyl methacrylate, and organic particles of these copolymers can be used.

<Average circularity of toner base particles>
The average circularity represented by the following mathematical formula 1 of the toner base particles according to an embodiment of the present invention is preferably 0.91 or more. From the viewpoint of improving transfer efficiency and charging stability, it is more preferably 0.920 to 0.995, and further preferably 0.930 to 0.975.

  The average circularity can be measured using, for example, an average circularity measuring device “FPIA-2100” (manufactured by Sysmex Corporation).

<External additive>
From the viewpoint of improving the charging performance, fluidity, and cleaning properties of the toner, it is preferable to add particles such as known inorganic particles and organic particles and a lubricant as external additives to the surface of the toner base particles.

  As the inorganic particles, for example, silica, titania, alumina, strontium titanate and the like can be mentioned as preferable examples. If necessary, these inorganic particles may be hydrophobized.

  As the organic particles, for example, organic particles such as homopolymers such as styrene and methyl methacrylate, copolymers thereof, and the like can be used.

  As a lubricant, for example, a salt of zinc stearate, aluminum, copper, magnesium, calcium, etc., a salt of zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. And salts of higher fatty acids such as zinc of linoleic acid, salts of zinc, calcium, etc., zinc of ricinoleic acid, salts of calcium, etc.

  Among these, as the external additive, for example, sol-gel silica particles, silica particles whose surfaces have been subjected to a hydrophobic treatment (hydrophobic silica particles) or titanium oxide particles (hydrophobic titanium oxide particles) are preferable. It is more preferable to use two or more kinds of external additives.

  The average primary particle diameter of the external additive is preferably in the range of 1 to 200 nm, more preferably 10 to 180 nm. At this time, at least one of the external additives is particularly preferably 30 nm or more and 180 nm or less.

  These external additives can be used alone or in combination of two or more.

  The hydrophobicity of the external additive is preferably 50 or more and 80 or less.

  The content of the external additive is preferably 0.1 to 10.0% by mass with respect to 100% by mass of the toner base particles.

<Method for producing toner for developing electrostatic image>
The method for producing the toner for developing an electrostatic charge image according to the present invention is not particularly limited. An amorphous polyester resin having a hydroxyl value higher than that of the release agent and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 5 or less, and a hydroxyl value of 2 mgKOH / g or less. It is preferable to have a step of mixing with a certain release agent. For example, in the emulsion aggregation method described below, the step of mixing the crystalline polyester resin, the amorphous polyester resin, and the release agent corresponds to the aggregation step.

  As a method for producing the toner for developing an electrostatic charge image according to one embodiment of the present invention, any production method such as a dry production method or a wet production method may be used, but an emulsion aggregation method is preferably used.

  The emulsion aggregation method includes an emulsification step in which a raw material constituting the toner is emulsified to form resin particles (emulsion particles), an aggregation step in which aggregates of the resin particles are formed, and a fusion step in which the aggregates are fused. And having. When the emulsion aggregation method is used, the composition and structure from the inside to the surface of the toner particles are easily controlled using a plurality of types of particles.

[Emulsification process]
In the emulsification step, crystalline polyester resin particles and amorphous polyester resin particles are formed to prepare a release agent dispersion (hereinafter also referred to as release agent dispersion). If necessary, particles may be formed for components that may be optionally included, and dispersions may be prepared. For example, amorphous resin particles (amorphous resin particles) may be formed to disperse the colorant. A liquid (hereinafter also referred to as a colorant dispersion) may be further prepared.

  For example, the crystalline polyester resin particles can be formed by applying a shearing force to a solution obtained by mixing an aqueous solvent and a crystalline polyester resin with a disperser. At that time, particles can be formed by heating to lower the viscosity of the resin component. A dispersant may be used for stabilizing the dispersed resin particles.

  In addition, if the crystalline polyester resin particles are oily and dissolve in a solvent having a relatively low solubility in water, they are sheared by a disperser into a solution in which this solvent and the crystalline polyester resin are mixed. Dispersion is performed by applying force, followed by further dispersion while adding an aqueous solvent, and then heating or decompressing to evaporate a solvent that is oily and has a relatively low solubility in water. At that time, particles can be formed by heating to lower the viscosity of the resin component. Further, a polymer electrolyte or a dispersant may be used for stabilizing the dispersed resin particles.

  An aqueous solvent refers to a solvent containing at least 50% by mass of water, and examples of components other than water include organic solvents that dissolve in water, such as alcohols such as methanol and ethanol. Examples of water include distilled water and ion exchange water. Among these, it is preferable that it is only water.

  As the solvent which is oily and has a relatively low solubility in water, for example, a solvent having a low boiling point is preferable from the viewpoint of easy removal treatment. Specifically, for example, methyl acetate, ethyl acetate, methyl ethyl ketone, isopropanol, methyl Examples include isobutyl ketone, toluene, xylene and the like.

  Examples of the dispersant used in the emulsification step include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate; sodium dodecylbenzenesulfonate. Anionic surfactants such as sodium octadecyl sulfate, sodium oleate, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, lauryldimethylamine oxide, etc. Zwitterionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene Nonionic surfactants such as polyalkylamine, polyoxyethylene (2) sodium dodecyl ether sulfate, etc .; inorganic salts such as tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, barium carbonate, etc. Can be mentioned.

  In order to stably emulsify the resin particles in the aqueous phase and smoothly proceed with the emulsification, ammonia, sodium hydroxide or the like may be added.

  Also in the case of amorphous polyester resin particles, a dispersion of amorphous polyester resin particles is prepared in accordance with the formation of the crystalline polyester resin particles.

  For amorphous resins that can be used arbitrarily, the polymerization of monomers is carried out in a plurality of stages, so that a plurality of layers composed of two or more layers made of resins having different compositions (or resins having the same composition) can be used. It is also preferable to adopt a form. By using a multi-layer form in this way, a toner having a sharper particle size distribution can be obtained when the toner is produced by the emulsion aggregation method. From this, for amorphous resin particles, after performing one-stage polymerization to form the innermost layer in an aqueous solvent or organic solvent, the raw material of the polymerization reaction for forming the outermost layer is dropped. It is preferable to prepare a dispersion of amorphous resin particles by applying a shearing force to the resulting solution with a disperser to form emulsified particles, and further performing polymerization to form a further layer as necessary. As this preparation method, for example, a one-stage polymerization for forming the innermost layer in an aqueous solvent or an organic solvent is performed, and then a shearing force is applied to a solution in which a raw material of a polymerization reaction for the two-stage polymerization is dropped A method of preparing a dispersion of amorphous resin particles by forming emulsion particles to give three-stage polymerization.

  The content of the resin particles contained in the emulsion in the emulsification step is preferably in the range of 10 to 50% by mass. When the content is 10% by mass or more, the particle size distribution can be narrowed and the toner characteristics can be improved. Further, when the amount is 50% by mass or less, stirring without more variation can be performed, and a toner having a narrow particle size distribution and uniform characteristics can be obtained.

  Examples of the dispersion method of the emulsion include, but are not limited to, dispersion using a disperser such as a stirrer, a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser. .

  The size of the resin particles is not particularly limited, but the average particle diameter (volume average particle diameter) is preferably in the range of 0.01 to 1.0 μm, more preferably in the range of 0.03 to 0.6 μm. The range of 0.03 to 0.4 μm is more preferable.

  If necessary, an aqueous dispersion or an organic solvent dispersion of a release agent and a colorant can also be prepared. These dispersions may contain a dispersant that can be used for dispersion. For example, a dispersion according to a dispersant that can be used when dispersing a crystalline polyester resin or the like can be used.

  As the solvent for the release agent dispersion, an aqueous solvent is preferably used, and water is preferable. As the dispersant, an anionic surfactant is preferable, and sodium dodecylbenzenesulfonate is more preferable. Here, the content of the release agent in the release agent dispersion is not particularly limited, but is preferably 1 to 50% by mass, and more preferably 10 to 50% by mass. Further, the content of the dispersant in the release agent dispersion is not particularly limited, but is preferably 0.1 to 10% by mass, and more preferably 1 to 5% by mass.

  As a solvent for the colorant dispersion, an aqueous solvent is preferably used, and water is preferable. An anionic surfactant is preferable, and sodium lauryl sulfate is more preferable. Here, the content of the colorant in the colorant dispersion is not particularly limited, but is preferably 1 to 50% by mass, and more preferably 10 to 50% by mass. Further, the content of the dispersant in the colorant dispersion is not particularly limited, but is preferably 0.1 to 10% by mass, and more preferably 1 to 5% by mass.

  As a dispersion method of the release agent and the colorant, for example, a general dispersion method such as a rotary shear type homogenizer, a stirrer, a ball mill having a medium, a sand mill, a dyno mill, or the like can be used, but is not limited thereto. It is not something.

  Note that a release agent or a colorant may be mixed in the emulsification step. In this case, a release agent or a colorant or a dispersion thereof is added to the dispersion of the amorphous polyester resin or the crystalline polyester resin. What is necessary is just to mix.

[Aggregation and fusion process]
In the agglomeration and fusion process, first, a dispersion of the obtained crystalline polyester resin particles, a dispersion of the amorphous polyester resin, a release agent dispersion, and, if necessary, a dispersion of the amorphous resin and A dispersion liquid of other components such as a colorant dispersion liquid is mixed to obtain a mixed liquid (aggregation dispersion liquid). Next, the liquid mixture is heated to aggregate each component to form aggregated particles. The heating temperature at the time of aggregation is preferably a temperature not higher than the glass transition temperature of the amorphous polyester resin.

  When forming aggregated particles, it is preferable to adjust the pH of the mixed solution. The pH is preferably 9 to 11 at a liquid temperature of 25 ° C. At this time, it is also effective to use a flocculant.

  The pH can be adjusted with a known pH adjusting agent, and the pH adjusting agent is preferably an alkali, more preferably sodium hydroxide. The method for adding the pH adjuster is not particularly limited, but it is preferably added as an aqueous solution.

  These pH adjusters can be used alone or in combination of two or more.

  As the flocculant to be used, a surfactant having a polarity opposite to that of the surfactant used for the dispersant, an inorganic metal salt, and a metal complex having a valence of 2 or more can be preferably used. In particular, the use of a metal complex is particularly preferable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

  Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic substances such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, it is more suitable that the valence of the inorganic metal salt is bivalent rather than monovalent, trivalent than bivalent, and tetravalent than trivalent.

  These flocculants can be used alone or in combination of two or more.

  The flocculant is a dispersion of crystalline polyester resin particles, a dispersion of an amorphous polyester resin, a release agent dispersion, and other components such as an amorphous resin dispersion and a colorant dispersion as required. When the total solid content of the dispersion is 100 parts by mass, 5 to 20 parts by mass is appropriate.

  In one embodiment of the present invention, when preparing the toner base particles, first, only the resin particle dispersion is introduced into the agglomeration system, and only the resin particles are aggregated, and then the colorant and the release agent. It is preferable to add the dispersion liquid. Thereby, the inhibition of the aggregation of the resin particles due to the presence of the release agent particles or the like can be avoided, and the toner base particles are efficiently formed.

  In one embodiment of the present invention, when the aggregated particles have a desired particle size, a toner having a structure in which the surface of the core aggregated particles is coated with the amorphous polyester resin by additionally adding amorphous polyester resin particles. Is preferably prepared. At this time, the volume-based median diameter of the aggregated particles is preferably 3 to 8 μm. This particle size can be controlled by the concentration of the flocculant, the amount of organic solvent added, the fusing time, and the composition of the polymer itself. When the median diameter is within the above range, reproducibility of fine lines and high image quality of photographic images can be achieved, and toner consumption can be reduced as compared with the case of using a large particle size toner. it can. The volume-based median diameter can be measured by, for example, “Multisizer 3” (manufactured by Beckman Coulter, Inc.). Moreover, when adding an amorphous polyester resin particle additionally, a flocculant may be added before additional addition and pH adjustment may be performed.

  The heating conditions for the agglomeration and fusion processes are as follows. The aggregation dispersion after addition of the aggregating agent is allowed to stand at 30 ° C. or lower for 1 to 15 minutes (more preferably 1 to 6 minutes), and then 75 to 30 to 90 minutes. Increase the temperature to ˜95 ° C., and grow the particles by adjusting the stirring speed so that the growth rate of the particle diameter is from 0.01 μm / min to 0.03 μm / min at 75 to 95 ° C. Is preferred.

  In the agglomeration and fusion process, as described above, the agglomeration dispersion is heated to advance agglomeration, and when the toner base particle size reaches the target size, an aggregation terminator is added to agglomerate. Stop.

  As the aggregation terminator, a salt that alleviates the aggregation action can be used. Examples of the aggregation terminator include sodium chloride, polyvalent organic acid or a salt thereof, amino acid, polyphosphonic acid or a salt thereof. These aggregation terminators can be used alone or in combination of two or more.

  Moreover, the method of relieving the aggregation action by changing the pH in the system can also be used.

  Aggregation terminators include crystalline polyester resin particle dispersions, amorphous polyester resin dispersions, release agent dispersions, and other amorphous resin dispersions and colorant dispersions as required. When the total solid content of the component dispersion is 100 parts by mass, 20 to 50 parts by mass is appropriate.

  After the aggregation is stopped, the temperature is raised to 75 to 95 ° C., and stirring is performed at this temperature to advance the fusion of the particles. At this time, it is preferable that the particles are fused until the average circularity reaches a desired value, preferably the value within a preferable range described in the above-mentioned average circularity of the toner base particles. The method for measuring and calculating the average circularity is described in the above-mentioned average circularity of the toner base particles.

  Cooling is performed after fusing to obtain fused particles. Further, crystallization may be promoted by so-called slow cooling in the cooling step.

  As described above, it is preferable to effectively advance the growth of toner base particles (aggregation of binder resin fine particles and colorant fine particles) and fusion (disappearance of the interface between particles).

[Washing process]
The fused particles obtained by fusing become toner base particles through a solid-liquid separation process such as filtration and, if necessary, a washing process and a drying process.

[External additive treatment process]
The toner according to an embodiment of the present invention is preferably added as an external additive to the surface of the toner base particles. Thus, this step is provided as necessary, and by adding and mixing external additives as necessary to the surface of the toner base particles dried in the drying step, toner particles are produced. This is a process for producing a toner. By adding the external additive, the fluidity and chargeability of the toner can be further improved, and further improvement of the cleaning property can be realized.

  Examples of the method of adding the external additive include a method of adding using various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer.

<Developer>
The above toner may be used as a one-component magnetic toner containing a magnetic material, mixed with a so-called carrier and used as a two-component developer, or a non-magnetic toner may be used alone. Any of these can be suitably used.

  As the carrier constituting the two-component developer, for example, magnetic particles made of conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. In particular, it is preferable to use ferrite particles.

  The carrier preferably has a volume average particle size in the range of 15 to 100 μm, more preferably in the range of 25 to 60 μm.

  As the carrier, it is preferable to use a carrier further coated with a resin or a so-called resin dispersion type carrier in which magnetic particles are dispersed in the resin. The resin composition for coating is not particularly limited, and for example, olefin resin, cyclohexyl methacrylate-methyl methacrylate copolymer, styrene resin, styrene acrylic resin, silicone resin, ester resin, fluorine resin, or the like is used. The resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, acrylic resin, styrene acrylic resin, polyester resin, fluorine resin, phenol resin, etc. are used. be able to.

  The concentration of the toner contained in the two-component developer is preferably 4.0% by mass or more and 8.0% by mass or less.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the following examples, the operation was performed at room temperature (25 ° C.) unless otherwise specified. Unless otherwise specified, “%” and “part” mean “% by mass” and “part by mass”, respectively.

1. Production of dispersion of each component <Preparation of release agent dispersion>
(Preparation of release agent dispersion (W1))
The following components were heated to 95 ° C. and dispersed using a homogenizer (IKA, Ultra Tarrax T50), and then dispersed with a pressure discharge type gorin homogenizer (Gorin), with a volume average particle size of 210 nm. A release agent dispersion (W1) (release agent concentration: 18% by mass) obtained by dispersing a release agent was prepared.

Wax: Ester wax WEP-3 (manufactured by NOF Corporation) 45 parts by mass,
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen (registered trademark) RK)
5 parts by mass,
-200 parts by mass of ion exchange water.

(Preparation of release agent dispersion (W2))
In the preparation of the release agent dispersion (W1), a release agent dispersion (W2) was obtained in the same manner except that the wax was changed to ester wax WEP-4 (manufactured by NOF Corporation).

(Preparation of release agent dispersion (W3))
In the preparation of the release agent dispersion (W1), a release agent dispersion (W3) was obtained in the same manner except that the wax was changed to ester wax WEP-6 (manufactured by NOF Corporation).

(Preparation of release agent dispersion (W4))
In the preparation of the release agent dispersion (W1), a release agent dispersion (W4) was obtained in the same manner except that the wax was changed to ester wax WEP-8 (manufactured by NOF Corporation).

(Preparation of release agent dispersion (W5))
In the preparation of the release agent dispersion (W1), a release agent dispersion (W5) was obtained in the same manner except that the wax was changed to paraffin wax WBM-1 (manufactured by NOF Corporation).

(Preparation of release agent dispersion (W6))
In the preparation of the release agent dispersion (W1), a release agent dispersion (W6) was obtained in the same manner except that the wax was changed to ester wax WEP-5 (manufactured by NOF Corporation).

(Preparation of release agent dispersion (W7))
In the preparation of the release agent dispersion (W1), a release agent dispersion (W7) was obtained in the same manner except that the wax was changed to paraffin wax FNP0090 (manufactured by Nippon Seiwa Co., Ltd.).

(Preparation of release agent dispersion (W8))
A 3-liter four-necked flask equipped with a thermometer, a nitrogen inlet tube, a stirrer and a condenser tube was charged with 1050.0 g (3.22 mol) of behenyl alcohol, 1240.7 g (3.65 mol) of behenic acid and 2.2 g of paratoluenesulfonic acid. The reaction was carried out at 220 ° C. under a nitrogen stream for 15 hours at atmospheric pressure while distilling off the water produced by the reaction. The obtained esterified crude product was 2107.2 g, and the acid value was 10.0 mgKOH / g. To 1000.0 g of this esterified crude product, 65 g of toluene, 30 g of xylene, 15 g of isopropanol and 120 g of ethanol are added, and 10% by weight of water in an amount corresponding to 1.5 times the acid value of the esterified crude product. An aqueous potassium oxide solution was added, and the mixture was stirred at 75 ° C. for 30 minutes. It left still for 30 minutes, the water layer part was removed, and the deoxidation process was complete | finished. Next, 20 parts by mass of ion-exchanged water was added to 100 parts by mass of the esterified product used, and the mixture was stirred at 70 ° C. for 30 minutes, and then allowed to stand for 30 minutes to discharge the aqueous layer part. Washing with water was repeated 4 times until the pH of the wastewater became neutral. The ester layer was depressurized under conditions of 180 ° C. and 1.0 kPa, the solvent was distilled off, filtration was performed, and an ester having a melting point of 73.0 ° C., an acid value of 2.9 mgKOH / g, and a hydroxyl value of 1.5 mgKOH / g. 954.4 g of wax Wax1 was obtained.

  Then, in the preparation of the release agent dispersion (W1), a release agent dispersion (W8) was obtained in the same manner except that the wax was changed to the ester wax Wax1 obtained above.

<Preparation of colorant dispersion>
(Preparation of aqueous dispersion (Bk) of colorant particles)
90 parts by mass of sodium lauryl sulfate was added to 1600 parts by mass of ion-exchanged water. While stirring this solution, 420 parts by mass of carbon black (Regal 330R: manufactured by Cabot) was gradually added. Next, an aqueous dispersion (Bk) of colorant particles was prepared by performing a dispersion treatment using a stirrer CLEARMIX (M Technique Co., Ltd.).

  The volume-based median diameter (d50) of the colorant particles in the aqueous dispersion (Bk) was 110 nm.

<Preparation of dispersion of crystalline polyester resin particles>
(Preparation of Crystalline Polyester Resin Particle Dispersion (C1))
Put 300 parts by weight of sebacic acid, 160 parts by weight of 1,9-nonanediol, 60 parts by weight of 1,6-hexanediol and 0.08 parts by weight of dibutyltin oxide into a flask purged with nitrogen, and further reduce the pressure at 180 ° C. for 4 hours. The reaction was carried out at 190 ° C. for 5 hours to obtain a crystalline polyester resin C1. The crystalline polyester resin C1 had a weight average molecular weight Mw of 47000, a number average molecular weight Mn of 15000, and a melting temperature of 76 ° C.

  The crystalline polyester resin C1: 200 parts by mass is weighed into a flask together with 64 parts by mass of ethyl acetate and 64 parts by mass of 2-propanol, heated to 60 ° C. in a water bath (IWB.100, manufactured by ASONE), and stirred with a stirrer ( BL600 (manufactured by HEIDON) was melted while stirring at a rotation speed of 20 rpm. After completion of melting, 11 parts by mass of a 10% by mass aqueous ammonia solution was gradually added dropwise with a dropper, and then 1800 parts by mass of ion-exchanged water was used with a quantitative liquid feed pump (MP-3N, manufactured by EYELA). Then, the solution was gradually dropped while maintaining the dropping speed of 7 to 8 g / min, and at the same time, the stirring speed was changed to 100 rpm and stirring was performed.

  After 2 hours, when dropping of 700 parts by mass of ion-exchanged water was completed, nitrogen flow was performed to remove ethyl acetate in the resin dispersion. After 1 hour, when the removal of ethyl acetate was completed, the flask was removed from the water bath and cooled at room temperature. When the resin dispersion is cooled to room temperature, it is transferred to an eggplant flask and heated to 40 ° C. with a water bath (B-480, manufactured by SHIBATA), while an evaporator (Rotavapor R-114, manufactured by SHIBATA), a vacuum controller (NVC). -1100, manufactured by EYELA), 2-propanol was removed to obtain a dispersion (C1) of crystalline polyester resin particles having an average particle diameter of 110 nm and a solid content concentration of 15% by mass.

(Preparation of Crystalline Polyester Resin Particle Dispersion (C2))
In the preparation of the dispersion (C1) of the crystalline polyester resin particles, the polymerization conditions for synthesizing the crystalline polyester resin C1 are changed to the conditions of “reacting at 180 ° C. for 5 hours and further under reduced pressure at 190 ° C. for 6 hours”. A crystalline polyester resin C2 was obtained in the same manner except for the change. The crystalline polyester resin C2 had a weight average molecular weight Mw of 65,000, a number average molecular weight Mn of 16000, and a melting temperature of 80 ° C.

  Next, using the crystalline polyester resin C2 obtained above, a dispersion (C2) of crystalline polyester resin particles having a solid content concentration of 15% by mass was prepared according to the preparation of the dispersion (C1) of crystalline polyester resin particles. Obtained.

(Preparation of Crystalline Polyester Resin Particle Dispersion (C3))
In the preparation of the dispersion (C1) of the crystalline polyester resin particles, the polymerization conditions for synthesizing the crystalline polyester resin C1 were changed to the conditions of “reacting at 180 ° C. for 3 hours and further under reduced pressure at 190 ° C. for 4 hours”. A crystalline polyester resin C3 was obtained in the same manner except that it was changed. The crystalline polyester resin C3 had a weight average molecular weight Mw of 57000, a number average molecular weight Mn of 14,000, and a melting temperature of 75 ° C.

  Further, using the obtained crystalline polyester resin C3, a dispersion (C3) of crystalline polyester resin particles having a solid content concentration of 15% by mass was prepared in accordance with the preparation of the dispersion (C1) of crystalline polyester resin particles. Obtained.

(Preparation of Crystalline Polyester Resin Particle Dispersion (C4))
In the preparation of the dispersion (C1) of the crystalline polyester resin particles, the polymerization conditions for synthesizing the crystalline polyester resin C1 were changed to the conditions of “reacting at 180 ° C. for 6 hours and further under reduced pressure at 190 ° C. for 7 hours”. A crystalline polyester resin C4-1 was obtained in the same manner except for the change.

  Next, 80 parts by mass of the crystalline polyester resin C3 obtained by preparing the dispersion liquid (C3) of crystalline polyester resin particles and the obtained crystalline polyester resin C4-1: 110 parts by mass were pulverized. The mixture was heated to about 150 ° C. and melted, and the cooled one was further pulverized and mixed to obtain a crystalline polyester resin C4. The crystalline polyester resin C4 had a weight average molecular weight Mw of 66000, a number average molecular weight Mn of 4100, and a melting temperature of 75 ° C.

  Subsequently, using the obtained crystalline polyester resin C4, a dispersion (C4) of crystalline polyester resin particles having a solid content concentration of 15% by mass in accordance with the preparation of the dispersion (C1) of crystalline polyester resin particles. Got.

(Preparation of Hybrid Crystalline Polyester Resin Particle Dispersion (C5))
The following composition containing an amphoteric monomer, a vinyl monomer that is a raw material of styrene acrylic resin (StAc), and a radical polymerization initiator was placed in a dropping funnel.

38 parts by mass of styrene,
9 parts by mass of n-butyl acrylate,
5 parts by mass of acrylic acid,
Polymerization initiator (di-t-butyl peroxide) 6 parts by mass.

  300 parts by weight of sebacic acid, 160 parts by weight of 1,9-nonanediol, 60 parts by weight of 1,6-hexanediol and 0.08 parts by weight of dibutyltin oxide were put into a nitrogen-substituted four-necked flask and heated to 180 ° C. Dissolved.

  Under stirring, a raw material such as styrene acrylic resin (StAc) is dropped into a four-necked flask from a dropping funnel over 90 minutes, and reacted at 180 ° C. for 4 hours and further under reduced pressure at 190 ° C. for 5 hours to produce crystalline polyester polymerization. A hybrid crystalline polyester resin C5 obtained by bonding a segment and an amorphous polymer segment (styrene acrylic resin polymer segment) was obtained. This crystalline polyester resin C5 had a weight average molecular weight Mw of 46000, a number average molecular weight Mn of 12000, and a melting temperature of 77 ° C.

  The hybrid crystalline polyester resin C5: 200 parts by mass was weighed into a flask together with 64 parts by mass of ethyl acetate and 64 parts by mass of 2-propanol, and heated to 60 ° C. in a water bath (IWB.100, manufactured by ASONE), and stirred. (BL600, manufactured by HEIDON) was melted while stirring at a rotation speed of 20 rpm. After completion of melting, 11 parts by mass of a 10% by mass aqueous ammonia solution was gradually added dropwise with a dropper, and then 1800 parts by mass of ion-exchanged water was used with a quantitative liquid feed pump (MP-3N, manufactured by EYELA). Then, the solution was gradually dropped while maintaining the dropping speed of 7 to 8 g / min, and at the same time, the stirring speed was changed to 100 rpm and stirring was performed.

  After 2 hours, when dropping of 700 parts by mass of ion-exchanged water was completed, nitrogen flow was performed to remove ethyl acetate in the resin dispersion. After 1 hour, when the removal of ethyl acetate was completed, the flask was removed from the water bath and cooled at room temperature. When the resin dispersion is cooled to room temperature, it is transferred to an eggplant flask and heated to 40 ° C. with a water bath (B-480, manufactured by SHIBATA), while an evaporator (Rotavapor R-114, manufactured by SHIBATA), a vacuum controller (NVC). -1100, manufactured by EYELA), 2-propanol was removed to obtain a dispersion (C5) of crystalline polyester resin particles having an average particle diameter of 110 nm and a solid content concentration of 15% by mass.

<Preparation of Amorphous Polyester Resin Particle Dispersion>
(Preparation of Amorphous Polyester Resin Particle Dispersion (A1))
75 parts by mass of BPA-PO (2 mol adduct of bisphenol A with propylene oxide), 25 parts by mass of BPA-EO (2 mol adduct of bisphenol A with ethylene oxide), 85 parts by mass of terephthalic acid, 15 masses of trimellitic anhydride And 8 parts by mass of a titanium-based catalyst (tetrabutoxytitanium) were placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and reacted at 230 ° C. for 3 hours. Then, it cooled to 180 degreeC. The temperature was increased from 180 ° C. to 210 ° C. at a rate of 15 ° C./hour, reacted for 2 hours, and then reacted under reduced pressure at 210 ° C. and 8.3 kPa until a predetermined softening point was reached. Resin A1 was obtained. The amorphous polyester resin A1 had a weight average molecular weight Mw of 55,000 and a number average molecular weight Mn of 18,000.

  The amorphous polyester resin A1: 200 parts by mass was weighed into a flask together with 64 parts by mass of ethyl acetate and 64 parts by mass of 2-propanol, and heated to 60 ° C. in a water bath (IWB.100, manufactured by ASONE), and stirred. (BL600, manufactured by HEIDON) was melted while stirring at a rotation speed of 20 rpm. After completion of melting, 11 parts by mass of a 10% by mass aqueous ammonia solution was gradually added dropwise with a dropper, and then 1800 parts by mass of ion-exchanged water was used with a quantitative liquid feed pump (MP-3N, manufactured by EYELA). Then, the solution was gradually dropped while maintaining the dropping speed of 7 to 8 g / min, and at the same time, the stirring speed was changed to 100 rpm and stirring was performed.

  After 2 hours, when dropping of 700 parts by mass of ion-exchanged water was completed, nitrogen flow was performed to remove ethyl acetate in the resin dispersion. After 1 hour, when the removal of ethyl acetate was completed, the flask was removed from the water bath and cooled at room temperature. When the resin dispersion is cooled to room temperature, it is transferred to an eggplant flask and heated to 40 ° C. with a water bath (B-480, manufactured by SHIBATA), while an evaporator (Rotavapor R-114, manufactured by SHIBATA), a vacuum controller (NVC). -1100, manufactured by EYELA), 2-propanol was removed to obtain a dispersion (A1) of an amorphous polyester resin having an average particle size of 110 nm and a solid content concentration of 15%.

(Preparation of Amorphous Polyester Resin Particle Dispersion (A2))
In the preparation of the dispersion (A1) of the amorphous polyester resin particles, the polymerization reaction conditions for synthesizing the amorphous polyester resin A1 were “reaction at 230 ° C. for 3 hours” and “at 230 ° C. Amorphous polyester resin A2 was obtained in the same manner except that the reaction conditions were changed to “react for 2.5 hours”. The amorphous polyester resin A2 had a weight average molecular weight Mw of 69000 and a number average molecular weight Mn of 17,000.

  Next, using the obtained amorphous polyester resin A2, a dispersion of crystalline polyester resin particles having a solid content concentration of 15% by mass (A2) according to the preparation of the dispersion of amorphous polyester resin particles (A1). )

(Preparation of Hybrid Amorphous Polyester Resin Particle Dispersion (A3))
150 parts by mass of BPA-PO (2 mol adduct of propylene oxide of bisphenol A), 50 parts by mass of BPA-EO (2 mol adduct of ethylene oxide of bisphenol A), 170 parts by mass of terephthalic acid, 30 masses of trimellitic anhydride And 8 parts by mass of a titanium-based catalyst (tetrabutoxytitanium) were placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and reacted at 230 ° C. for 3 hours. After cooling to 180 ° C., 5 parts by mass of acrylic acid, 20 parts by mass of styrene, 14 parts by mass of n-butyl acrylate (BA), and 5 parts by mass of a polymerization initiator (di-t-butyl peroxide) are added dropwise. The solution was added dropwise with a funnel over 1 hour. After the addition, the addition polymerization reaction was continued for 1 hour while maintaining the temperature at 160 ° C. After holding at kPa for 1 hour, acrylic acid, styrene and butyl acrylate are removed to combine a non-crystalline polyester polymer segment and an amorphous polymer segment (styrene acrylic resin polymer segment). Conductive polyester resin A3 was obtained. The amorphous polyester resin A3 had a weight average molecular weight Mw of 49000 and a number average molecular weight Mn of 12,000.

  Next, using the obtained hybrid amorphous polyester resin A3, the dispersion of the hybrid amorphous polyester resin particles having a solid content concentration of 15% by mass in accordance with the preparation of the dispersion liquid (A1) of the amorphous polyester resin particles. A liquid (A3) was obtained.

(Preparation of Amorphous Polyester Resin Particle Dispersion (A4))
2310 parts by mass of BPA-PO (2 mol adduct of bisphenol A propylene oxide), 715 parts by mass of BPA-EO (2 mol adduct of bisphenol A ethylene oxide), 1129 parts by mass of terephthalic acid and 12 parts by mass of dibutyltin oxide catalyst Was placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, reacted at 220 ° C. for 5 hours, and then reacted at 8.3 kPa for 1 hour. . Furthermore, it cooled to 210 degreeC, 230 mass parts of trimellitic anhydride was added, it was made to react until it reached a desired softening point, and amorphous polyester resin A4 was obtained. The amorphous polyester resin A4 had a weight average molecular weight Mw of 58,000 and a number average molecular weight Mn of 5900.

  Then, using the obtained amorphous polyester resin A4, a dispersion of crystalline polyester resin particles having a solid content concentration of 15% by mass (A4) according to the preparation of the dispersion of amorphous polyester resin particles (A1). )

(Preparation of Hybrid Amorphous Polyester Resin Particle Dispersion (A5))
In the preparation of the dispersion (A3) of the amorphous polyester resin particles, the polymerization reaction conditions for synthesizing the amorphous polyester resin A3 were “reaction for 3 hours at 230 ° C.” A hybrid amorphous polyester resin A5 formed by bonding an amorphous polyester polymer segment and an amorphous polymer segment (styrene acrylic resin polymer segment) in the same manner except that the condition is changed to “2 hours reaction”. Got. The amorphous polyester resin A5 had a weight average molecular weight Mw of 45,000 and a number average molecular weight Mn of 11,000.

  Next, using the obtained hybrid amorphous polyester resin A5, a dispersion (A5) of hybrid crystalline polyester resin particles was obtained according to the preparation of the dispersion (A1) of amorphous polyester resin particles.

(Preparation of Amorphous Polyester Resin Particle Dispersion (A6))
In the preparation of the dispersion (A1) of the amorphous polyester resin particles, the polymerization reaction conditions for synthesizing the amorphous polyester resin A1 were “reaction at 230 ° C. for 3 hours” and “at 230 ° C. An amorphous polyester resin A6 was obtained in the same manner except that the conditions were changed to “4 hours reaction”. The amorphous polyester resin A6 had a weight average molecular weight Mw of 57000 and a number average molecular weight Mn of 14,000.

  Subsequently, using the obtained amorphous polyester resin A6, a dispersion (A6) of crystalline polyester resin particles was obtained according to the preparation of the dispersion (A1) of amorphous polyester resin particles.

<Preparation of Amorphous Resin Dispersion>
(Amorphous resin particle dispersion (A))
(First stage polymerization)
A 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introducing device was charged with 8 parts by weight of sodium dodecyl sulfate and 3000 parts by weight of ion-exchanged water, while stirring at a stirring speed of 230 rpm under a nitrogen stream. The temperature was raised to 80 ° C. After the temperature increase, a solution in which 10 parts by mass of potassium persulfate was dissolved in 200 parts by mass of ion-exchanged water was added, the liquid temperature was again set to 80 ° C., and a mixture of the following monomers was added dropwise over 1 hour.

480.0 parts by mass of styrene (St),
250.0 parts by mass of n-butyl acrylate (BA),
Methacrylic acid (MA) 68.0 parts by mass.

  After the dropping, polymerization was carried out by heating and stirring at 80 ° C. for 2 hours to prepare a dispersion of vinyl resin particles.

(Second stage polymerization)
A 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introducing device was charged with a solution prepared by dissolving 7 parts by mass of polyoxyethylene (2) sodium dodecyl ether sulfate in 3000 parts by mass of ion-exchanged water, Heated to ° C. After heating, 80 parts by mass in terms of solid content of the dispersion of vinyl resin particles prepared by the first stage polymerization, and a mixed solution in which the following monomers, chain transfer agent and release agent are dissolved at 90 ° C. , Was added.

285.0 parts by mass of styrene (St),
95.0 parts by mass of n-butyl acrylate (BA),
20.0 parts by weight of methacrylic acid (MAA),
n-octyl-3-mercaptopropionate (chain transfer agent) 1.5 parts by mass,
Behenyl behenate (release agent, melting point 73 ° C.) 190.0 parts by mass.

    A mechanical dispersion machine CLEARMIX (manufactured by M Technique Co., Ltd.) having a circulation path was used for 1 hour of mixing and dispersing treatment to prepare a dispersion containing emulsified particles (oil droplets). A polymerization initiator solution in which 6 parts by mass of potassium persulfate was dissolved in 200 parts by mass of ion-exchanged water was added to this dispersion, and this system was heated and stirred at 84 ° C. for 1 hour to perform polymerization. A dispersion of vinyl resin particles was prepared.

(3rd stage polymerization)
After adding 400 parts by mass of ion exchange water to the dispersion of vinyl resin particles obtained by the second stage polymerization and mixing well, a solution in which 11 parts by mass of potassium persulfate was dissolved in 400 parts by mass of ion exchange water was prepared. Added. Furthermore, the liquid mixture of the following monomer and chain transfer agent was dripped over 1 hour on 82 degreeC temperature conditions.

454.8 parts by mass of styrene (St),
143.2 parts by mass of 2-ethylhexyl acrylate (2EHA),
52.0 parts by weight of methacrylic acid (MAA),
n-octyl-3-mercaptopropionate 8.0 parts by weight.

  After completion of the dropwise addition, polymerization was carried out by heating and stirring for 2 hours, followed by cooling to 28 ° C. to prepare a dispersion (A) of amorphous resin (styrene acrylic resin) particles. The amorphous resin (styrene acrylic resin) had a weight average molecular weight Mw of 40,000 and a number average molecular weight Mn of 10,000.

2. Evaluation of each component <Measurement of hydroxyl value>
For the hydroxyl value of the release agent, crystalline polyester resin and amorphous polyester resin, the measurement solvent was changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1), respectively. The measurement was performed in the same manner as in JIS K0070-1992. The measurement was performed in a resin state before preparing the resin particle dispersion.

<Measurement of acid value>
The acid value of the release agent, crystalline polyester resin and amorphous polyester resin was changed from a mixed solvent of ethanol and ether to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1), respectively. The measurement was performed in the same manner as in JIS K0070-1992. The measurement was performed in a resin state before preparing the resin particle dispersion.

<Measurement of number average molecular weight and weight average molecular weight>
The number average molecular weight and weight average molecular weight of the crystalline polyester resin, the amorphous polyester resin, and the amorphous resin were determined by gel permeation chromatography measurement according to the following conditions and procedures. The measurement was performed in a resin state before preparing the resin particle dispersion.

  First, it is a carrier solvent so as to have a concentration of 1 mg / mL under a dissolution condition in which a crystalline polyester resin, an amorphous polyester resin, and an amorphous resin are treated at 40 ° C. for 15 minutes using an ultrasonic disperser. Dissolved in tetrahydrofuran. Subsequently, it processed with the membrane filter with the pore size of 0.2 micrometer, and obtained the sample solution.

  Next, using the apparatus “HLC-8220” (manufactured by Tosoh Corporation) and the column “TSKguardcolumn + TSKgelSuperHZM-M3 series” (manufactured by Tosoh Corporation), the sample solution obtained above was 10 μL while maintaining the column temperature at 40 ° C. Was flown at a flow rate of 0.2 mL / min with tetrahydrofuran (THF) as a carrier solvent, and an elution curve was obtained by performing detection using a refractive index detector (RI detector).

Based on the obtained elution curve, the molecular weight distribution of the measurement sample was calculated using a calibration curve measured using monodisperse polystyrene standard particles. As a standard polystyrene sample for calibration curve measurement, the molecular weights manufactured by Pressure Chemical are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1 .1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ did. A refractive index detector was used as the detector.

  Tables 1 to 3 below show the measurement results for the toner forming components of toners (1) to (15), respectively.

3. Toner manufacturing <Toner manufacturing>
(Manufacture of toner (1))
In a reaction vessel equipped with a stirrer, a temperature sensor and a cooling tube, 350 parts by mass of vinyl resin particle dispersion (A) (converted to solid content), 50 parts by mass of crystalline polyester resin particle dispersion (C1) (solid content) Conversion), 35 parts by mass (in terms of solid content) of release agent dispersion (W1) and 2000 parts by mass of ion-exchanged water were added. Under room temperature (25 ° C.), 5 mol / L sodium hydroxide aqueous solution was added to adjust the pH to 10.

  Furthermore, 50 parts by mass (in terms of solid content) of an aqueous dispersion (Bk) of colorant particles was added, and a solution in which 60 parts by mass of magnesium chloride was dissolved in 60 parts by mass of ion-exchanged water was stirred at 30 ° C. for 10 Added over a minute. After standing for 3 minutes, the temperature was raised to 80 ° C. over 60 minutes, and when reaching 80 ° C., the stirring speed was adjusted so that the growth rate of the particle diameter was 0.01 μm / min, and the Coulter Multisizer 3 ( The product was grown until the volume-based median diameter measured by Coulter-Beckman was 6.0 μm.

  Further, 50 parts by mass (in terms of solid content) of the dispersion liquid (A1) of amorphous polyester resin particles was added, and when the supernatant of the liquid became transparent, 190 parts by mass of sodium chloride was changed to 760 parts by mass of ion-exchanged water. The dissolved aqueous solution was added to stop particle size growth. The mixture was further heated and stirred at 80 ° C., and particle fusion proceeded until the average circularity of the toner particles reached 0.970, followed by cooling to 30 ° C.

  Next, the toner cake obtained by solid-liquid separation and dehydration was redispersed in ion-exchanged water, and solid-liquid separation and dehydration were repeated three times for washing. After washing, the toner particles were obtained by drying at 40 ° C. for 24 hours.

  To 100 parts by mass of the obtained toner particles, 0.6 parts by mass of hydrophobic silica particles (number average primary particle size: 12 nm, degree of hydrophobicity: 68), hydrophobic titanium oxide particles (number average primary particle size: 20 nm, hydrophobic) Degree of conversion: 63) 1.0 part by mass and 1.0 part by mass of sol-gel silica (number average primary particle size = 110 nm) were added, and the peripheral speed of the rotary blade was 35 mm / sec using a Henschel mixer (manufactured by Mitsui Miike Chemical Co., Ltd.) Mix at 32 ° C. for 20 minutes. After mixing, coarse particles were removed using a sieve having an opening of 45 μm to obtain toner (1).

(Production of toners (2) to (15))
In the production of the toner (1), the combination of the dispersion of the crystalline polyester resin particles, the dispersion of the amorphous polyester resin particles, and the dispersion of the release agent was changed to the combinations shown in Table 4 below. Other than that, toners (2) to (15) were prepared in the same manner.

4). Evaluation of toner <Manufacture of developer>
For each toner obtained, a ferrite carrier having a volume average particle diameter of 30 μm coated with a copolymer resin of cyclohexyl methacrylate and methyl methacrylate (monomer mass ratio = 1: 1) is used, and the toner concentration becomes 6% by mass. Thus, a developer] was obtained by mixing.

<Glossy memory evaluation>
Copying machine bizhub PRO (registered trademark) C6501 (manufactured by Konica Minolta Co., Ltd.), changing the pressure in the nip region of the fixing device and the surface temperature of the fixing heat roller (fixing roller) within a range of 100 to 210 ° C. In addition, the developer was modified so that the process speed (nip time) could be changed, and a developer manufactured from each toner was loaded.

For each developer produced from toner, in an environment of normal temperature and humidity (temperature 20 ° C., humidity 50% RH), on A3 size coated paper Esprit C 209 g / m ² (manufactured by Nippon Paper Industries Co., Ltd.), Fixing temperature to set a fixing experiment for outputting a gloss memory evaluation image with a toner adhesion amount of 8 g / m ^{2 under} the conditions that the nip pressure of the fixing device is 238 kPa and the nip time is 25 milliseconds (process speed 480 mm / s). Was repeated while changing the temperature from 160 ° C to 200 ° C by 10 ° C.

  Five images with different gloss memory levels were prepared, and compared with these images, the rank was evaluated (the higher the number, the better). In addition, it was set as the pass when the average value of the rank in all temperature ranges was 4 or more. The evaluation criteria are shown below. Here, the glossiness was measured in accordance with JIS Z 8741 using a gloss meter “GMX-203” (manufactured by Murakami Color Research Laboratory Co., Ltd.) with a 75 ° measuring square shape selected.

  5: The difference in glossiness at the location where the gloss memory is generated is less than 2.

  4: The difference in glossiness at the gloss memory occurrence location is 2 or more and less than 4.

  3: The difference in glossiness at the gloss memory occurrence location is 4 or more and less than 6.

  2: The difference in glossiness at the gloss memory occurrence location is 6 or more and less than 8.

  1: The difference in glossiness at the location where gloss memory is generated is 8 or more.

  The results of gloss memory evaluation are shown in Table 4 below.

  From the results shown in Table 2, it was confirmed that the toner according to the present invention has a good gloss memory evaluation. Since the gloss memory is a problem that occurs when the releasability between the image and the fixing roller is not sufficient, this result indicates that good releasability is realized by the toner according to the present invention. Is.

  Further, in the above results, the gloss memory evaluation of the toners according to Examples 6 to 8 and Example 11 is very good, so that the toner according to the present invention is a crystalline polyester resin or amorphous resin that is a binder resin. It was confirmed that particularly excellent releasability was realized by using at least one of the conductive polyester resins as a hybrid resin.

  Although the gloss memory evaluations of the toners according to Examples 6 to 8 and Example 11 are within the same rank, the toner of Example 11 in which both the crystalline polyester resin and the amorphous polyester resin are hybrid resins is used. The best results were obtained.

Claims (12)

An electrostatic latent image developing toner comprising toner base particles containing a binder resin and a release agent,
The release agent has a hydroxyl value of 2 mgKOH / g or less,
The binder resin includes an amorphous polyester resin and a crystalline polyester resin,
The hydroxyl value of the amorphous polyester resin is higher than the hydroxyl value of the release agent,
The amorphous polyester resin has Mw / Mn of 5 or less,
The crystalline polyester resin has an Mw / Mn of 4 or less.
Toner for electrostatic latent image development.   The electrostatic latent image developing toner according to claim 1, wherein the binder resin further contains an amorphous resin different from the amorphous polyester resin.   The crystalline polyester resin contains a hybrid crystalline polyester resin in which a crystalline polyester polymer segment and an amorphous polymer segment made of an amorphous resin different from the amorphous polyester resin are chemically bonded. The toner for developing an electrostatic latent image according to claim 1.   The amorphous polyester resin is a hybrid amorphous polyester resin in which an amorphous polyester polymer segment and an amorphous polymer segment made of an amorphous resin different from the amorphous polyester resin are chemically bonded. The electrostatic latent image developing toner according to claim 1, which is contained.   The electrostatic latent image developing toner according to claim 1, wherein the acid value of the amorphous polyester resin is 25 mgKOH / g or more.   6. The electrostatic latent image developing toner according to claim 1, wherein the crystalline polyester resin has a hydroxyl value of 20 mgKOH / g or more.   The toner for developing electrostatic latent images according to claim 1, wherein the crystalline polyester resin has an acid value of 20 mgKOH / g or more.   The electrostatic latent image developing toner according to claim 1, wherein the release agent has an acid value of 1 mg KOH / g or less.   The electrostatic latent image developing toner according to claim 1, wherein the release agent includes ester wax or paraffin wax.   10. The electrostatic latent image developing toner according to claim 1, wherein the difference between the hydroxyl value of the release agent and the hydroxyl value of the amorphous polyester resin is 20 mgKOH / g or more.   The electrostatic latent image developing toner according to claim 1, further comprising a colorant.   The electrostatic latent image developing toner according to claim 1, wherein the amorphous polyester resin has a hydroxyl group of 40 mgKOH / g or more.