Image forming method

Abstract

To provide a method for forming an image on a film label having a film with a melting point of 200°C or less, the image forming method preventing a curl of a print to be obtained and excellent in dot reproducibility.SOLUTION: Provided is a method for forming an image, by using toner for electrostatic charge image development, on a film surface of a film label having a release paper, an adhesive layer, and a film laminated in this order. The toner for electrostatic charge image development contains toner particles each having a core-shell structure having a core and a shell present on a surface of the core. A content of a resin in the shell based on 100 pts.mass of a binder resin in the toner for electrostatic charge image development is 5 pts.mass or more and 30 pts.mass or less. The toner for electrostatic charge image development contains a crystalline resin in an amount of 10 pts.mass or more in 100 pts.mass of the binder resin. A basis weight of the release paper is 65 g / m2 or more. A melting point of the film is 200°C or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an image forming method. [Background technology]

[0002] The diversification of print media has led to a growing demand for electrophotographic printing on print media other than paper. One of the main media is polypropylene film (hereinafter referred to as "PP film") and polyethylene film (hereinafter referred to as "PE film"), which are used for PET bottle labels and various packages. On the other hand, paper, polypropylene, and polyethylene have very different properties as printing media, such as the polarity and surface condition of the material. Patent Document 1 describes a heat absorption coefficient (H) of a heat absorption material containing a polyester resin and a polypropylene wax, which has an endothermic ratio ΔH expressed by the following formula (1): CW / W is 0.10 or more and 0.80 or less. Heat absorption ratio ΔH CW / W =ΔH CW / ΔH W (1) ΔH CW : The endothermic amount of the melting endothermic peak per 1 g of polypropylene wax when measured as the binder resin composition ΔH W : Endothermic heat of melting endothermic peak per 1g of polypropylene wax when polypropylene wax is measured alone It is described that the binder resin composition can provide a toner that has excellent fixability to a PP (polypropylene) film. Patent Document 2 describes a toner for developing electrostatic images containing an amorphous polyester resin A and a crystalline polyester resin C, wherein the amorphous polyester resin A has a constituent moiety derived from a polyester resin and a constituent moiety derived from a modified polyolefin polymer A having a reactive functional group, the constituent moiety derived from the polyester resin and the constituent moiety derived from the modified polyolefin polymer A are linked via a covalent bond, and the amount of the constituent moiety derived from the modified polyolefin polymer A is 5% by mass or more and 30% by mass or less of the total amount of resin components in the toner. It is also described that this toner has excellent fixability to polypropylene film and excellent abrasion resistance of printed images. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-218448 [Patent Document 2] Japanese Patent Application Publication No. 2020-86459 Summary of the Invention [Problem to be solved by the invention]

[0004] In existing copying systems, the toner fixing temperature is higher than the heat resistance temperature of the film, and when toner is fixed to a film label with a release paper, the film itself tends to shrink. As a result, for example, previously developed toners have the problem of not being able to fix to PP or PE film. Another problem is that the film label tends to curl. Furthermore, even with the toners disclosed in Patent Documents 1 and 2, there are problems such as curling of film labels and poor dot reproducibility. Therefore, taking into consideration the manner of use of labels on PET bottles and the like, there is a need for a printing method that suppresses curling of printed matter after printing on film labels having PP or PE films and also has excellent dot reproducibility. The present invention relates to a method for forming an image on a film label having a film with a melting point of 200°C or less, which method suppresses curling of the resulting printed matter and provides an image forming method with excellent dot reproducibility. [Means for solving the problem]

[0005] The present inventors have found that the above problem can be solved by using a toner for developing electrostatic images having toner particles with a core-shell structure, the toner having a specific shell content and containing a specific amount or more of crystalline resin, to form an image on a film label having a release paper with a specific basis weight adhered thereto, the film having a melting point of 200°C or less.

[0006] That is, the present invention relates to the following [1]. [1] A method for forming an image on the film surface of a film label having a release paper, an adhesive layer, and a film laminated in this order using a toner for developing an electrostatic image, The toner for developing electrostatic images contains toner particles having a core-shell structure having a core and a shell present on the surface of the core, the content of the shell resin in 100 parts by mass of the binder resin of the electrostatic image developing toner is 5 parts by mass or more and 30 parts by mass or less, The toner for developing electrostatic images contains 10 parts by mass or more of a crystalline resin in 100 parts by mass of a binder resin, The release paper has a basis weight of 65 g / m 2 That's all, The melting point of the film is 200°C or less. Image forming method. [Effects of the Invention]

[0007] According to the present invention, there can be provided a method for forming an image on a film label having a film with a melting point of 200°C or less, which suppresses curling of the resulting printed matter and further provides an image forming method with excellent dot reproducibility. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Image forming method] The image forming method of the present invention is a method of forming an image on the film surface of a film label having a release paper, a pressure-sensitive adhesive layer, and a film laminated in this order, using a toner for developing electrostatic images, wherein the toner for developing electrostatic images contains toner particles having a core-shell structure having a core and a shell present on the surface of the core, the content of the shell resin in 100 parts by mass of the binder resin in the toner for developing electrostatic images is 5 parts by mass or more and 30 parts by mass or less, the toner for developing electrostatic images contains 10 parts by mass or more of a crystalline resin in 100 parts by mass of the binder resin, and the basis weight of the release paper is 65 g / m 2 or more, and the melting point of the film is 200°C or less. According to the image forming method of the present invention, curling of the obtained printed matter is suppressed and the obtained printed image has excellent dot reproducibility. Note that the "image forming method having excellent dot reproducibility" means that the image obtained by the image forming method has excellent dot reproducibility.

[0009] The detailed reasons why the above effects are obtained are unknown, but some of the reasons are thought to be as follows. In the process of thermally fixing toner onto film labels made of films with a melting point of 200°C or less, the film tends to shrink, causing the printed matter to curl. 2 By combining the above release paper, shrinkage of the film due to heat during fixing is suppressed, which is thought to prevent curling of the printed label. However, at the same time, a new problem has arisen in that the image quality is likely to deteriorate. In the case of film labels, the outermost surface of which is made of film, the outermost surface of the label is easily charged, and highly charged toner is easily electrostatically repelled by the label surface, which tends to deteriorate the image quality. 2 When a label made of the release paper described above is used, the electrostatic attraction to the transfer belt is weakened by the label being interposed between the film and the transfer belt, which makes electrostatic repulsion more likely to occur on the label surface, making it difficult to sufficiently fix the toner transferred to the label and making the toner more likely to move, which is thought to result in poor dot reproducibility. In contrast, in the present invention, if the content of the shell resin in 100 parts by mass of the binder resin of the toner for developing electrostatic images is 5 parts by mass or more and 30 parts by mass or less, and the toner contains 10 parts by mass or more of a crystalline resin relative to 100 parts by mass of the binder resin in the toner, the toner has a basis weight of 65 g / m 2 It has been found that label prints with excellent dot reproducibility can be obtained even for labels having the above release paper. This is because the toner particles contain 10 parts by mass or more of crystalline resin in 100 parts by mass of the binder resin of the toner, and the content of the shell resin in 100 parts by mass of the binder resin of the toner is 5 parts by mass or more and 30 parts by mass or less, and by using toner particles in which the core is covered with a shell, it is possible to improve the charging uniformity of the toner while appropriately reducing the charging property, and the basis weight is 65 g / m 2 It is presumed that this is because, even in situations where the electrostatic attraction that fixes the toner is weak, such as in the case of a film label made of release paper, the electrostatic repulsion that occurs between the film and the toner can be kept small, thereby suppressing the movement of the toner. The above-mentioned mechanism regarding the effects of the present invention is only a supposition, and the present invention is not limited to this.

[0010] The definitions of various terms used in this specification are shown below. Whether a resin is crystalline or amorphous is determined by its crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the endothermic maximum peak temperature (softening point (°C) / endothermic maximum peak temperature (°C)) measured by the method described in the Examples below. A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one in which no endothermic peak is observed, or, if an endothermic peak is observed, one with a crystallinity index of less than 0.6 or more than 1.4. The crystallinity index can be adjusted appropriately by adjusting the types and ratios of raw material monomers, as well as production conditions such as reaction temperature, reaction time, and cooling rate. In the specification, the carboxylic acid component of the polyester resin includes not only the compound itself, but also anhydrides that decompose during the reaction to produce an acid, and alkyl esters of each carboxylic acid (alkyl groups having 1 to 3 carbon atoms). Volume median particle size (D50 )" is the particle size at which the cumulative volume frequency calculated by volume fraction is 50% calculated from the smallest particle size. The coefficient of variation of particle size distribution (hereinafter also simply referred to as "CV value") is a value expressed by the following formula: The volume average particle size in the formula is the particle size obtained by multiplying the particle size of all measured particles by the volume of that particle, and then dividing the sum by the total volume of the measured particles. CV value (%) = [Standard deviation of particle size distribution (μm) / Volume average particle size (μm)] x 100

[0011] <Image forming method> The image forming method of the present invention is, similar to a conventional image forming method using a toner (toner for developing electrostatic images), an example of an image forming method including an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, a transfer step of transferring the toner image formed on the electrostatic latent image carrier to the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium. In the present invention, a film label to which a release agent is adhered is used as the recording medium, and the film label is made of a film having a melting point of 200°C or less. Furthermore, the basis weight of the release paper is 65 g / m 2 That's all.

[0012] The melting point of polypropylene film varies depending on whether it is stretched or not, but is approximately 135° C. to 170° C. On the other hand, the melting point of polyethylene film varies depending on the density, but is approximately 105 to 150° C. The melting points of the polypropylene film and the polyethylene film are measured by the method described in the Examples. In the present invention, the fixing temperature is preferably 120°C or lower, more preferably 115°C or lower, even more preferably 110°C or lower, and is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 85°C or higher.

[0013] <Film label> The image forming method of the present invention uses a toner for developing electrostatic images to form an image on the film surface of a film label having a release paper, an adhesive layer, and a film laminated in this order. That is, the film label is used as a printing medium (recording medium), and the release paper is adhered to the film label. 〔film〕 The film of the film label (hereinafter simply referred to as "film") has a melting point of 200° C. or less. Films with a higher melting point are less likely to cause the problem of curling of printed matter due to heat fixation. The melting point of the film is not particularly limited as long as it is 200°C or lower, but from the viewpoint of the heat resistance of the film, it is preferably 90°C or higher, more preferably 100°C or higher, and even more preferably 110°C or higher. The melting point of the film is measured by the method described in the Examples.

[0014] Examples of films include polypropylene film, polyethylene film, polyvinyl chloride film, polyethylene terephthalate film, polystyrene film, polyester film, and polylactic acid film. Among these, polypropylene film or polyethylene film is preferred from the viewpoint of versatility, etc. Polypropylene and polyethylene films are used for various labels, packaging, etc.

[0015] The polypropylene film and polyethylene film may be subjected to a surface treatment as appropriate in order to improve printability. Furthermore, the polypropylene film and polyethylene film may be transparent films, or may contain pigments or the like and have any color such as white, and may have a toner-receiving layer formed on the surface.

[0016] [Release paper] In the present invention, a release paper is adhered to the film label, and the release paper has a basis weight of 65 g / m 2 That's all. The basis weight of the release paper is 65 g / m 2This prevents the printed matter from curling. The basis weight of the release paper is 65 g / m 2 or more, preferably 70 g / m 2 More preferably, 75 g / m 2 From the viewpoint of dot reproducibility, it is preferably 200 g / m 2 or less, more preferably 180 g / m 2 More preferably 150 g / m or less 2 The following is the result. The basis weight of the release paper is measured by the method described in the examples.

[0017] The thickness of the release paper is not particularly limited as long as the above-mentioned basis weight is obtained, but from the viewpoint of suppressing curling of the printed matter and improving dot reproducibility, it is preferably 50 μm or more, more preferably 55 μm or more, even more preferably 60 μm or more, even more preferably 65 μm or more, and preferably 240 μm or less, more preferably 200 μm or less, even more preferably 180 μm or less, even more preferably 160 μm or less. The thickness of the release paper is measured by the method described in the Examples.

[0018] The release paper preferably has a release agent layer formed on a release paper base material. The release paper base material may be any paper such as glassine paper, kraft paper, or wood-free paper, and may also be, for example, a polyester film. However, from the viewpoint of reducing the environmental load, the release paper is preferably made primarily from pulp. The release paper is preferably provided with a release agent layer containing a release agent such as a silicone resin or a fluororesin to impart releasability. A filling layer may be provided between the release paper and the release agent layer. The filling layer is a layer formed by using a natural or synthetic resin alone or in combination with an inorganic pigment such as kaolin, calcium carbonate, calcined clay, titanium oxide, or silica, or an organic pigment such as a plastic pigment. Furthermore, as the release paper, polylaminated paper may be used, which is a release paper base material such as glassine paper, kraft paper, or high-quality paper laminated with a synthetic resin such as polyethylene. However, from the viewpoint of suppressing curling of the printed matter, a release paper having a release paper base material, if necessary a sealing layer, and a release agent layer in this order is preferred.

[0019] [Adhesive] The adhesive may be appropriately selected from known adhesives, for example, acrylic, rubber, silicone, and other adhesives.

[0020] <Toner for developing electrostatic images> The toner for developing electrostatic images (hereinafter also referred to simply as "toner" or "toner of the present invention") used in the image forming method of the present invention contains toner particles having a core-shell structure having a core and a shell present on the surface of the core, and the content of the shell resin in 100 parts by mass of the binder resin of the toner for developing electrostatic images is 5 parts by mass or more and 30 parts by mass or less, and 10 parts by mass or more of a crystalline resin (hereinafter also referred to as "crystalline resin C") is contained in 100 parts by mass of the binder resin. The toner of the present invention may be a toner obtained by any known method such as a melt-kneading method, an emulsion phase inversion method, a polymerization method, or an aggregation fusion method. However, from the viewpoint of producing toner particles having a core-shell structure, a chemical toner obtained by an aggregation fusion method is preferred.

[0021] [Core-shell structure] The toner of the present invention preferably has a core-shell structure, and the core portion preferably contains the crystalline resin C. Furthermore, the core portion preferably contains an amorphous polyester resin A in addition to the crystalline resin C. Furthermore, the core portion preferably contains a colorant and a release agent in addition to the crystalline resin C and the amorphous polyester resin A. The shell preferably contains an amorphous polyester resin B.

[0022] In the present invention, from the viewpoint of dot reproducibility, the content of the shell in the toner particles is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, even more preferably 10 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, relative to 100 parts by mass of the toner. The shell in the toner preferably contains an amorphous polyester resin B described below, and more preferably the shell is made of an amorphous polyester resin B. From the viewpoint of dot reproducibility, the amount of the shell binder resin in 100 parts by mass of the toner binder resin is 5 parts by mass or more, preferably 7 parts by mass or more, more preferably 10 parts by mass or more, and is 30 parts by mass or less, preferably 25 parts by mass or less, more preferably 20 parts by mass or less.

[0023] [Binder resin] <Crystalline Resin C> The toner of the present invention contains 10 parts by mass or more of crystalline resin C per 100 parts by mass of binder resin. From the viewpoints of low-temperature fixability, suppression of curling of printed matter, and dot reproducibility, the content of crystalline resin C per 100 parts by mass of binder resin is 10 parts by mass or more, preferably 12 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, still more preferably 23 parts by mass or more, and preferably 60 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 30 parts by mass or less, and still more preferably 27 parts by mass or less. Furthermore, the toner of the present invention preferably has a core-shell structure and contains the crystalline resin C in the core portion, and more preferably contains the crystalline resin C only in the core portion.

[0024] The crystalline resin C is preferably a crystalline polyester resin C. The crystalline polyester resin C is, for example, a crystalline polyester resin that is a polycondensation product of an alcohol component and a carboxylic acid component. The crystalline polyester resin is a polycondensation product of an alcohol component and a carboxylic acid component. The alcohol component is preferably an α,ω-aliphatic diol. The α,ω-aliphatic diol preferably has 2 or more carbon atoms, more preferably 4 or more carbon atoms, and even more preferably 6 or more carbon atoms, and preferably has 16 or less carbon atoms, more preferably 14 or less carbon atoms, and even more preferably 12 or less carbon atoms. Examples of α,ω-aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol. Among these, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol are preferred, and 1,10-decanediol is more preferred.

[0025] The amount of α,ω-aliphatic diol in the alcohol component is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[0026] The alcohol component may contain other alcohol components different from the α,ω-aliphatic diol. Examples of other alcohol components include aliphatic diols other than α,ω-aliphatic diols, such as 1,2-propanediol and neopentyl glycol; aromatic diols, such as alkylene oxide adducts of bisphenol A; and trihydric or higher alcohols, such as glycerin, pentaerythritol, and trimethylolpropane. These alcohol components may be used alone or in combination.

[0027] The carboxylic acid component is preferably an aliphatic dicarboxylic acid, more preferably a straight-chain aliphatic dicarboxylic acid. The aliphatic dicarboxylic acid preferably has 4 or more carbon atoms, more preferably 8 or more carbon atoms, and even more preferably 10 or more carbon atoms, and preferably has 14 or less carbon atoms, more preferably 12 or less carbon atoms. Examples of aliphatic dicarboxylic acids include fumaric acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid. Among these, sebacic acid and tetradecanedioic acid are preferred, and sebacic acid is more preferred. These carboxylic acid components may be used alone or in combination.

[0028] The amount of aliphatic dicarboxylic acid in the carboxylic acid component is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[0029] The carboxylic acid component may contain other carboxylic acid components different from the aliphatic dicarboxylic acid. Examples of other carboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and polycarboxylic acids having three or more carboxylic acids. These carboxylic acid components may be used alone or in combination.

[0030] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component [COOH groups / OH groups] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0031] The crystalline polyester resin C is produced, for example, by a method of polycondensing an alcohol component and a carboxylic acid component. During polycondensation, if necessary, an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropoxybis(triethanolaminate) may be used in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component; or an esterification promoter such as gallic acid (equivalent to 3,4,5-trihydroxybenzoic acid) may be used in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. When a monomer having an unsaturated bond such as fumaric acid is used in polycondensation, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The temperature of the polycondensation reaction is preferably 120° C. or higher, more preferably 160° C. or higher, and even more preferably 180° C. or higher, and is preferably 250° C. or lower, and more preferably 240° C. or lower. The polycondensation may be carried out in an inert gas atmosphere.

[0032] (Physical properties of crystalline polyester resin C) The softening point of the crystalline polyester resin C is preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher, from the viewpoint of the storage stability of the toner, and is preferably 150°C or lower, more preferably 120°C or lower, even more preferably 100°C or lower, and even more preferably 95°C or lower, from the viewpoint of further improving the low-temperature fixability. The melting point of the crystalline polyester resin C is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher, from the viewpoint of the storage stability of the toner, and is preferably 100°C or lower, more preferably 90°C or lower, even more preferably 85°C or lower, and even more preferably 80°C or lower, from the viewpoint of further improving the low-temperature fixability.

[0033] The acid value of the crystalline polyester resin C is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and is preferably 35 mgKOH / g or less, more preferably 25 mgKOH / g or less, even more preferably 20 mgKOH / g or less.

[0034] The softening point, melting point, and acid value of the crystalline polyester resin C can be appropriately adjusted by the types and amounts of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and are determined by the method described in the Examples below. When two or more crystalline polyester resins C are used in combination, it is preferable that the softening point, melting point, and acid value of the mixture thereof each fall within the above-mentioned ranges.

[0035] The mass ratio of the amorphous polyester resin A to the crystalline resin C (preferably the crystalline polyester resin C) [amorphous polyester resin A / crystalline resin C] is preferably 40 / 60 or more, more preferably 50 / 50 or more, even more preferably 60 / 40 or more, even more preferably 65 / 35 or more, and is preferably 95 / 5 or less, more preferably 90 / 10 or less, even more preferably 85 / 15 or less, even more preferably 75 / 25 or less.

[0036] <Amorphous polyester resin A> In the present invention, the toner preferably contains, as a binder resin, an amorphous polyester resin A in addition to the crystalline polyester resin C, and more preferably, the core contains the amorphous polyester resin A. The amorphous polyester resin A is, for example, an amorphous polyester resin containing a polycondensate of an alcohol component and a carboxylic acid component. Examples of amorphous polyester resins include polyester resins and modified polyester resins. Examples of modified polyester resins include urethane-modified polyester resins, epoxy-modified polyester resins, and composite resins containing polyester resin segments and addition-polymerized resin segments. Among these, amorphous composite resins containing polyester resin segments that are polycondensates of alcohol components and carboxylic acid components and addition-polymerized resin segments that are addition-polymerized products of raw material monomers containing styrene-based compounds are preferred.

[0037] Examples of the alcohol component include alkylene oxide adducts of aromatic diols, linear or branched aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols. Among these, alkylene oxide adducts of aromatic diols are preferred from the viewpoint of obtaining a toner with excellent low-temperature fixability. The alkylene oxide adduct of an aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably an alkylene oxide adduct of formula (I):

[0038] [ka] (In the formula, OR 1 and R 2 O is an oxyalkylene group, and R 1 and R 2 are each independently an ethylene group or a propylene group, x and y are each a positive number that indicates the average number of moles of alkylene oxide added, and the sum of x and y is 1 or more, preferably 1.5 or more, and more preferably 1.8 or more, and is 16 or less, preferably 8 or less, more preferably 4 or less, even more preferably 3 or less, and even more preferably 2.5 or less.

[0039] Examples of alkylene oxide adducts of bisphenol A include a propylene oxide adduct of bisphenol A [2,2-bis(4-hydroxyphenyl)propane] and an ethylene oxide adduct of bisphenol A. These may be used alone or in combination. Among these, the propylene oxide adduct of bisphenol A is preferred. The content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 70 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and is 100 mol % or less, even more preferably 100 mol %.

[0040] Examples of linear or branched aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol. Examples of alicyclic diols include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and alkylene oxide adducts of hydrogenated bisphenol A having 2 to 4 carbon atoms (average number of moles added: 2 to 12). Examples of trihydric or higher polyhydric alcohols include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used alone or in combination of two or more.

[0041] Examples of the carboxylic acid component include dicarboxylic acids and trivalent or higher polycarboxylic acids. Examples of dicarboxylic acids include aromatic dicarboxylic acids, linear or branched aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Among these, at least one selected from aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferred. Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred. The amount of aromatic dicarboxylic acid in the carboxylic acid component is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, even more preferably 50 mol% or more, and is preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less.

[0042] The linear or branched aliphatic dicarboxylic acid preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms, and preferably 30 or less, more preferably 20 or less carbon atoms. Examples of linear or branched aliphatic dicarboxylic acids include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, and succinic acids substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms. Examples of succinic acids substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, fumaric acid, sebacic acid, and succinic acids substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms are preferred, with fumaric acid and sebacic acid being more preferred. The amount of linear or branched aliphatic dicarboxylic acid in the carboxylic acid component is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 10 mol% or more, and is preferably 80 mol% or less, more preferably 50 mol% or less, even more preferably 30 mol% or less.

[0043] The trivalent or higher polyvalent carboxylic acid is preferably a trivalent carboxylic acid, for example, trimellitic acid, and preferably trimellitic acid or its anhydride. When a trivalent or higher polycarboxylic acid is contained, the amount of the trivalent or higher polycarboxylic acid in the carboxylic acid component is preferably 3 mol% or more, more preferably 5 mol% or more, even more preferably 8 mol% or more, and is preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less. These carboxylic acid components may be used alone or in combination of two or more.

[0044] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component [COOH groups / OH groups] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0045] The addition polymerized resin segment is, for example, an addition polymer of raw material monomers containing a styrene-based compound. Examples of styrene compounds include unsubstituted or substituted styrene. Examples of the substituent substituted on styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group, or a salt thereof. Examples of styrene compounds include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid, and salts thereof. Among these, styrene is preferred. The content of styrene-based compounds in the raw material monomers of the addition polymerization resin segment is preferably 50% by mass or more, more preferably 65% ​​by mass or more, even more preferably 75% by mass or more, and is 100% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less.

[0046] Examples of raw material monomers other than styrene-based compounds include (meth)acrylic acid esters such as alkyl (meth)acrylate, benzyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; olefins such as ethylene, propylene, and butadiene; halovinyl compounds such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, (meth)acrylic acid esters are preferred, and alkyl (meth)acrylates are more preferred. The number of carbon atoms in the alkyl group in the alkyl (meth)acrylate is preferably 1 or more, more preferably 4 or more, even more preferably 6 or more, and is preferably 24 or less, more preferably 22 or less, even more preferably 20 or less. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, (iso)propyl (meth)acrylate, (iso- or tertiary)butyl (meth)acrylate, (iso)amyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate, (iso)palmityl (meth)acrylate, (iso)stearyl (meth)acrylate, and (iso)behenyl (meth)acrylate. Preferred are 2-ethylhexyl (meth)acrylate or stearyl (meth)acrylate, more preferred are 2-ethylhexyl acrylate and stearyl methacrylate, and even more preferred are stearyl methacrylate. In addition, "(iso or tertiary)" and "(iso)" refer to both the presence and absence of these prefixes, and the absence of these prefixes indicates normal. In addition, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid.

[0047] The content of (meth)acrylic acid ester in the raw material monomers of the addition polymerization resin segment is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 35% by mass or less, even more preferably 25% by mass or less. The total amount of the styrene compound and (meth)acrylic acid ester in the raw material monomers of the addition polymerization resin segment is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and still more preferably 100% by mass.

[0048] The amorphous polyester resin A preferably has a constitutional unit derived from a bireactive monomer bonded to a polyester resin segment and an addition polymerization resin segment via a covalent bond. The term "structural unit derived from a bireactive monomer" refers to a unit formed by reaction of a functional group and an addition polymerizable group of a bireactive monomer. An example of the addition polymerizable group is a carbon-carbon unsaturated bond (ethylenically unsaturated bond). Examples of the bireactive monomer include addition-polymerizable monomers having at least one functional group selected from a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, and a secondary amino group in the molecule. Among these, from the viewpoint of reactivity, addition-polymerizable monomers having at least one functional group selected from a hydroxyl group and a carboxyl group are preferred, and addition-polymerizable monomers having a carboxyl group are more preferred. Examples of addition-polymerizable monomers having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, from the viewpoint of reactivity in both polycondensation reactions and addition polymerization reactions, acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred. When the bireactive monomer is an addition-polymerizable monomer having a carboxy group, the amount of the constitutional units derived from the bireactive monomer is preferably 1 mol part or more, more preferably 5 mol parts or more, even more preferably 8 mol parts or more, and preferably 30 mol parts or less, more preferably 25 mol parts or less, even more preferably 20 mol parts or less, relative to 100 mol parts of the alcohol component of the polyester resin segment of the amorphous polyester resin A.

[0049] The amorphous polyester resin A may further contain, in addition to the polyester resin segment and the addition polymerization resin segment, a structural unit derived from a hydrocarbon wax having at least one of a carboxy group and a hydroxyl group (structural unit derived from hydrocarbon wax).

[0050] The content of the polyester resin segment in the amorphous polyester resin A is preferably 35% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more, and is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 75% by mass or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment. The structural unit derived from a bireactive monomer is referred to as a polyester resin segment.

[0051] The content of the addition polymerization resin segment in the amorphous polyester resin A is preferably 5% by mass or more, more preferably 15% by mass or more, and even more preferably 25% by mass or more, and is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 45% by mass or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment. The bireactive monomer-derived structural unit is referred to as the polyester resin segment.

[0052] The amount of the bireactive monomer-derived structural units in the amorphous polyester resin A is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, and is preferably 10% by mass or less, more preferably 7% by mass or less, even more preferably 4% by mass or less, based on the total amount of the polyester resin segment, the addition polymerization resin segment, and the bireactive monomer-derived structural units.

[0053] The amount of the hydrocarbon wax-derived structural units in the amorphous polyester resin A is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 6 parts by mass or less, relative to 100 parts by mass of the total amount of the polyester resin segment, the addition polymerization resin segment, and the structural units derived from the bireactive monomer.

[0054] The above amount is calculated based on the ratio of the amounts of the polyester resin segment, raw material monomer for the addition polymerization resin segment, bireactive monomer, and radical polymerization initiator, and is based on the mass excluding the amount of dehydration due to polycondensation in the polyester resin segment, etc. When a radical polymerization initiator is used, the mass of the radical polymerization initiator is calculated by including it in the addition polymerization resin segment.

[0055] The amorphous polyester resin A may be produced, for example, by a method including a step A of polycondensing an alcohol component and a carboxylic acid component, and a step B of addition-polymerizing raw material monomers of the addition-polymerized resin segment and a bireactive monomer. When the amorphous polyester resin A further contains a structural unit derived from a hydrocarbon wax, in the above-mentioned step A, for example, a polycondensation reaction of an alcohol component and a carboxylic acid component is carried out in the presence of a hydrocarbon wax having at least one of a hydroxyl group and a carboxyl group. Step B may be carried out after step A, step B may be carried out after step A, or step A and step B may be carried out simultaneously. A preferred method is to subject a part of the carboxylic acid component to a polycondensation reaction in step A, then carry out step B, and then add the remainder of the carboxylic acid component to the polymerization system to further promote the polycondensation reaction of step A and the polycondensation reaction with the carboxy group of the bireactive monomer or the constituent moiety derived from the bireactive monomer.

[0056] In step A, if necessary, polycondensation may be carried out using an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropoxybis(triethanolaminate) in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component; or an esterification promoter such as gallic acid (equivalent to 3,4,5-trihydroxybenzoic acid) in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. When a monomer having an unsaturated bond such as fumaric acid is used in polycondensation, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The temperature of the polycondensation reaction is preferably 120° C. or higher, more preferably 160° C. or higher, and even more preferably 180° C. or higher, and is preferably 250° C. or lower, and more preferably 240° C. or lower. The polycondensation may be carried out in an inert gas atmosphere.

[0057] Examples of the radical polymerization initiator for the addition polymerization in step B include peroxides such as dibutyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of the radical polymerization initiator used is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the raw material monomer of the addition polymerization resin segment. The temperature of the addition polymerization is preferably 110°C or higher, more preferably 130°C or higher, and preferably 230°C or lower, more preferably 220°C or lower, and even more preferably 210°C or lower.

[0058] (Physical properties of amorphous polyester resin A) The softening point of the amorphous polyester resin A is preferably 70°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, and from the viewpoint of further improving low-temperature fixability, it is preferably 150°C or lower, more preferably 140°C or lower, and even more preferably 125°C or lower. The glass transition temperature of the amorphous polyester resin A is preferably 30°C or higher, more preferably 35°C or higher, and even more preferably 40°C or higher, and from the viewpoint of further improving low-temperature fixability, is preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 60°C or lower.

[0059] The acid value of the amorphous polyester resin A is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less, even more preferably 30 mgKOH / g or less. The softening point, glass transition temperature, and acid value of the amorphous polyester resin A can be appropriately adjusted by adjusting the types and amounts of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and these values ​​can be determined by the methods described in the examples. When two or more kinds of amorphous polyester resins A are used in combination, the softening point, glass transition temperature and acid value of the mixture thereof preferably fall within the above-mentioned ranges.

[0060] The content of the amorphous polyester resin A relative to the total amount of the resin components of the resin particles X is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 87% by mass or less.

[0061] <Amorphous polyester resin B> In the present invention, the toner preferably contains, as a binder resin, an amorphous polyester resin B in addition to the crystalline polyester resin C and the amorphous polyester resin A, and it is more preferable that the shell contains the amorphous polyester resin B. The amorphous polyester resin B is preferably an amorphous polyester resin containing, for example, a polycondensate of an alcohol component and a carboxylic acid component. Examples of polyester-based resins include polyester resins and modified polyester resins. Examples of modified polyester resins include urethane-modified polyester resins, epoxy-modified polyester resins, and composite resins containing polyester resin segments and addition-polymerized resin segments. Among these, amorphous polyester resins, which are polycondensates of alcohol components and carboxylic acid components, are preferred.

[0062] Examples of the alcohol component include alkylene oxide adducts of aromatic diols from the viewpoint of obtaining a desired aromatic ring concentration. Among these, alkylene oxide adducts of aromatic diols are preferred from the viewpoint of obtaining a toner having excellent low-temperature fixability. The alkylene oxide adduct of an aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably an alkylene oxide adduct of formula (I):

[0063] [ka] (In the formula, OR 1 and R 2 O is an oxyalkylene group, and R 1 and R 2 are each independently an ethylene group or a propylene group, x and y are each a positive number that indicates the average number of moles of alkylene oxide added, and the sum of x and y is 1 or more, preferably 1.5 or more, more preferably 1.8 or more, and is 16 or less, preferably 8 or less, more preferably 4 or less, even more preferably 3 or less, and even more preferably 2.5 or less.

[0064] Examples of alkylene oxide adducts of bisphenol A include a propylene oxide adduct of bisphenol A [2,2-bis(4-hydroxyphenyl)propane] and an ethylene oxide adduct of bisphenol A. These may be used alone or in combination. Of these, the ethylene oxide adduct of bisphenol A is more preferred. The content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 70 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and is 100 mol % or less, even more preferably 100 mol %.

[0065] In addition to the alkylene oxide adduct of bisphenol A, the amorphous polyester resin A may contain the linear or branched aliphatic diol, alicyclic diol, trihydric or higher polyhydric alcohol, and the like. These alcohol components may be used alone or in combination of two or more.

[0066] Examples of the carboxylic acid component include dicarboxylic acids and trivalent or higher polycarboxylic acids. Examples of dicarboxylic acids include aromatic dicarboxylic acids, linear or branched aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Among these, at least one selected from aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferred. Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred. The amount of aromatic dicarboxylic acid in the carboxylic acid component is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, even more preferably 70 mol% or more, and is preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 85 mol% or less.

[0067] The linear or branched aliphatic dicarboxylic acid preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms, and preferably 30 or less, more preferably 20 or less carbon atoms. Examples of linear or branched aliphatic dicarboxylic acids include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, and succinic acid substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms. Examples of succinic acid substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, adipic acid and succinic acid substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms are preferred. The amount of linear or branched aliphatic dicarboxylic acid in the carboxylic acid component is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and is preferably 60 mol% or less, more preferably 30 mol% or less, even more preferably 20 mol% or less, even more preferably 15 mol% or less.

[0068] The trivalent or higher polyvalent carboxylic acid is preferably a trivalent carboxylic acid, for example, trimellitic acid, and preferably trimellitic acid or its anhydride. When a trivalent or higher polycarboxylic acid is contained, the amount of the trivalent or higher polycarboxylic acid in the carboxylic acid component is preferably 3 mol% or more, more preferably 5 mol% or more, even more preferably 8 mol% or more, and is preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less. These carboxylic acid components may be used alone or in combination of two or more.

[0069] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component [COOH groups / OH groups] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0070] The polyester resin B may be produced, for example, by the step A of polycondensing an alcohol component and a carboxylic acid component. Step A is the same as step A described in the method for producing amorphous polyester resin A, and the preferred ranges are also the same. In step A, if necessary, polycondensation may be carried out using an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropoxybis(triethanolaminate) in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component; or an esterification promoter such as gallic acid (equivalent to 3,4,5-trihydroxybenzoic acid) in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. When a monomer having an unsaturated bond such as fumaric acid is used in polycondensation, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The temperature of the polycondensation reaction is preferably 120° C. or higher, more preferably 160° C. or higher, and even more preferably 180° C. or higher, and is preferably 250° C. or lower, and more preferably 240° C. or lower. The polycondensation may be carried out in an inert gas atmosphere.

[0071] (Physical properties of amorphous polyester resin B) The softening point of the amorphous polyester resin B is preferably 70°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, and from the viewpoint of further improving low-temperature fixability, it is preferably 150°C or lower, more preferably 140°C or lower, and even more preferably 125°C or lower. The glass transition temperature of the amorphous polyester resin B is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher, and from the viewpoint of further improving low-temperature fixability, is preferably 90°C or lower, more preferably 80°C or lower, and even more preferably 70°C or lower.

[0072] The acid value of the amorphous polyester resin B is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, even more preferably 25 mgKOH / g or less. The softening point, glass transition temperature, and acid value of the amorphous polyester resin B can be appropriately adjusted by adjusting the types and amounts of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and these values ​​can be determined by the methods described in the examples. When two or more kinds of amorphous polyester resins B are used in combination, the softening point, glass transition temperature and acid value of the mixture thereof preferably fall within the above-mentioned ranges.

[0073] The content of the amorphous polyester resin B is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and is 100% by mass or less, even more preferably 100% by mass, relative to the total amount of the resin components of the resin particles Y.

[0074] [Coloring Agent] The toner of the present invention preferably contains a colorant, and the core preferably contains a colorant. As the colorant, any dye, pigment, etc. that is used as a colorant for toner can be used. Examples of colorants include carbon black, phthalocyanine blue (e.g., pigment blue 15:3), permanent brown FG, brilliant fast scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, and disazo yellow. The toner may be either black toner or a color toner other than black.

[0075] When the toner of the present invention is a white toner, it preferably contains a white pigment as a colorant, and the white pigment is preferably titanium oxide. As the titanium oxide, rutile type titanium oxide or anatase type titanium oxide can be used, but from the viewpoints of stability and availability, rutile type titanium oxide is preferred. From the viewpoint of obtaining good dispersibility in the toner, titanium oxide is preferably surface-treated. The surface treatment of titanium oxide is not particularly limited, and titanium oxide may be surface-treated with either an organic substance or an inorganic substance. From the viewpoint of avoiding the influence of photocatalysis, titanium oxide surface-treated with an inorganic substance is preferred, titanium oxide surface-treated with at least one of silica and alumina is more preferred, and titanium oxide surface-treated with silica and alumina is even more preferred. By firing the surface-treated titanium oxide powder at a temperature of 800°C or higher and 1000°C or lower, sintering between particles can be suppressed, and the fluidity and dispersibility of the titanium oxide can be improved. The particle shape of titanium oxide is exemplified by granular and needle-like shapes, but is not particularly limited.

[0076] The average primary particle size of titanium oxide is preferably 100 nm or more, more preferably 150 nm or more, even more preferably 200 nm or more, and even more preferably 220 nm or more, from the viewpoint of obtaining high whiteness, and is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 350 nm or less, from the viewpoint of dispersibility. The average primary particle size of titanium oxide can be measured using a transmission electron microscope. Specifically, 500 primary particles of titanium oxide are extracted using a transmission electron microscope and their particle sizes are measured by image analysis, and the average is calculated to be the number-average particle size. If titanium oxide has a major axis and a minor axis, the major axis is used for calculation. Examples of commercially available titanium oxides that can be used in the present invention include trade names JR, JR-300, JR-605, and JR-701 manufactured by Teika Corporation, and trade names Typepaque CR-93, CR-90, and CR-80 manufactured by Ishihara Sangyo Kaisha, Ltd.

[0077] When the colorant is other than a white pigment, the content of the colorant in the toner particles is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, and preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less. When the colorant is a white pigment, the content of the colorant (white pigment) in the toner particles is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, from the viewpoint of increasing whiteness, and is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less.

[0078] [Release agent] The toner of the present invention preferably contains a release agent, and more preferably contains a release agent in the core portion. Examples of release agents include polypropylene wax, polyethylene wax, polypropylene-polyethylene copolymer wax; hydrocarbon waxes such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and Sasol wax, or oxides thereof; ester waxes such as carnauba wax, montan wax, or deacidified waxes thereof, and fatty acid ester wax; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts. These may be used alone or in combination.

[0079] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, and preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 100°C or lower. The content of the release agent in the toner particles is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 3% by mass or more, and even more preferably 5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less.

[0080] <Toner manufacturing method> The toner having the above-mentioned core-shell structure is preferably obtained by a method including the following steps 1 to 3. Step 1: A step of aggregating resin particles X containing a crystalline resin C and an amorphous polyester-based resin A in the same or different particles in an aqueous medium to obtain aggregated particles 1; Step 2: A step of aggregating resin particles Y containing an amorphous polyester resin B to the aggregated particles 1 obtained in Step 1 to obtain aggregated particles 2; Step 3: A step of heating and fusing the aggregated particles 2 obtained in Step 2 to obtain fused particles. In step 1, resin particles X are aggregated in an aqueous medium to obtain aggregated particles 1. Here, it is preferable that the resin particles X contain a crystalline resin C and an amorphous polyester resin A. It is also preferable to aggregate colorant particles and release agent particles in addition to the resin particles X, and it is more preferable to mix a resin particle dispersion containing resin particles X, a colorant particle dispersion containing colorant particles, and a release agent particle dispersion containing release agent particles to aggregate these particles. Each step will be described below.

[0081] [Process 1] Step 1 is a step of obtaining aggregated particles 1 by aggregating resin particles X, which contain a crystalline resin C and an amorphous polyester resin A in the same or different particles, in an aqueous medium. In step 1, the aggregated particles 1 are preferably obtained by aggregating colorant particles containing a colorant together with the resin particles X. Furthermore, in step 1, it is preferable to aggregate release agent particles containing a release agent together with the resin particles X and the colorant particles. The resin particles X, colorant particles, and release agent particles used in step 1, as well as their manufacturing methods, will be described in detail below.

[0082] <Resin Particles X> The resin particle dispersion used in step 1 contains resin particles X. In order to obtain excellent low-temperature fixability, the resin particles X preferably contain an amorphous polyester resin A and a crystalline resin C in the same or different resin particles, and from the viewpoints of further improving the low-temperature fixability of the resulting toner and further widening the non-offset temperature range, the resin particles X preferably contain the amorphous polyester resin A and the crystalline resin C in the same resin particles.

[0083] (Preparation of Resin Particle Dispersion) A resin particle dispersion containing resin particles X, preferably a resin particle dispersion containing an amorphous polyester resin A and a crystalline resin C in the same or different resin particles, can be prepared using a known method, but is preferably dispersed by a phase inversion emulsification method, such as a method in which an aqueous medium is added to an organic solvent solution of a resin or a molten resin to perform phase inversion emulsification.

[0084] The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the resin, but from the viewpoint of facilitating phase inversion, examples include alcohol-based solvents such as ethanol, isopropanol, isobutanol, etc.; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, etc.; ether-based solvents such as dibutyl ether, tetrahydrofuran, dioxane, etc.; and acetate-based solvents such as ethyl acetate, isopropyl acetate, etc. Among these, from the viewpoint of ease of removal from the mixed solution after addition of the aqueous medium, ketone-based solvents and acetate-based solvents are preferred, and methyl ethyl ketone, ethyl acetate, and isopropyl acetate are more preferred. It is preferable to add a neutralizing agent to the organic solvent solution. Examples of the neutralizing agent include basic substances. Examples of the basic substance include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. The equivalent amount (mol%) of the neutralizing agent used relative to the acid groups of the resin contained in the resin particles X is preferably 10 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, from the viewpoint of obtaining fine resin particles and improving dispersion stability, and is preferably 90 mol% or less, more preferably 70 mol% or less. The equivalent amount (mol %) of the neutralizing agent used can be calculated by the following formula: When the equivalent amount of the neutralizing agent used is 100 mol % or less, it is synonymous with the degree of neutralization. Equivalent amount of neutralizing agent used (mol%) = [{mass of neutralizing agent added (g) / equivalent amount of neutralizing agent} / [{weighted average acid value of resin constituting resin particle X (mg KOH / g) × mass of resin constituting resin particle X (g)} / (56 × 1000)]] × 100

[0085] While stirring the organic solvent solution or the molten resin, the aqueous medium is gradually added to cause phase inversion. From the viewpoint of improving the dispersion stability of the resin particles X, the temperature of the organic solvent solution when the aqueous medium is added is preferably equal to or higher than the glass transition temperature of the resin constituting the resin particles X, more preferably equal to or higher than 50°C, even more preferably equal to or higher than 60°C, and is preferably equal to or lower than 85°C, more preferably equal to or lower than 80°C. The contents of the amorphous polyester resin A and the crystalline resin C are as described above.

[0086] After the phase inversion emulsification, if necessary, the organic solvent may be removed from the obtained dispersion by distillation, etc. In this case, the amount of the remaining organic solvent in the dispersion is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably substantially 0% by mass.

[0087] The volume median particle size (D 50 ) is preferably 0.05 μm or more, more preferably 0.08 μm or more, even more preferably 0.12 μm or more, and is preferably 0.8 μm or less, more preferably 0.4 μm or less, even more preferably 0.3 μm or less, from the viewpoint of obtaining a toner that can produce high-quality images. From the viewpoint of obtaining a toner that can produce high-quality images, the CV value of the resin particles X in the dispersion is preferably 10% or more, more preferably 20% or more, and is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. The volume median particle size of resin particle X (D 50 ) and the CV value can be determined by the method described in the Examples below.

[0088] When resin particles Xa containing amorphous polyester resin A and resin particles Xc containing crystalline resin C are used in combination, resin particles Xa and Xc can be obtained by the same method as described above. The amount of resin particles Xa and resin particles Xc added is preferably an amount that corresponds to the content of the amorphous polyester resin A and the crystalline resin C described above.

[0089] (aqueous medium) In the present invention, the aqueous medium is a medium containing water as a main component, and the water content in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and 100% by mass or less. The water is preferably deionized water, ion-exchanged water, or distilled water. Examples of components other than water that can constitute the aqueous medium together with water include water-soluble organic solvents such as alkyl alcohols having 1 to 5 carbon atoms, dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone, and cyclic ethers such as tetrahydrofuran. Among these, alkyl alcohols having 1 to 5 carbon atoms are preferred, and methanol or ethanol is more preferred.

[0090] <Colorant particles> The colorant is preferably mixed with resin particles as a dispersion of colorant particles, and then aggregated to be contained in the aggregated particles. The colorant particle dispersion is preferably obtained by dispersing the colorant and an aqueous medium using a disperser such as a homogenizer, an ultrasonic disperser, etc. From the viewpoint of improving the dispersion stability of the colorant, the dispersion is preferably carried out in the presence of an addition polymer (hereinafter, the addition polymer used to disperse the colorant is also referred to as "addition polymer E") or a surfactant. Examples of the surfactant include nonionic surfactants, anionic surfactants, and cationic surfactants. From the viewpoint of improving the dispersion stability of the colorant particles, anionic surfactants are preferred. Examples of the anionic surfactant include dodecylbenzenesulfonate, dodecyl sulfate, lauryl ether sulfate, and alkenyl succinate. Among these, dodecylbenzenesulfonate is preferred. From the viewpoint of improving the dispersion stability of the colorant, the content of the surfactant in the colorant particle dispersion liquid is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, relative to 100 parts by mass of the colorant, and is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less.

[0091] When the colorant is a colorant other than a white pigment, the addition polymer E (hereinafter, the addition polymer E when the colorant is a colorant other than a white pigment is also referred to as "addition polymer E1") is preferably an addition polymer of raw material monomers including an addition-polymerizable monomer a having an aromatic group (hereinafter, simply referred to as "monomer a"). More preferably, the addition polymer E1 contains a structural unit derived from the addition-polymerizable monomer a having an aromatic group in its main chain. The raw material monomers for the addition polymer E1 contain an addition polymerizable monomer a having an aromatic group, and more preferably an addition polymerizable monomer b having an ionic group (hereinafter also simply referred to as "monomer b"). Furthermore, in addition to monomer b, the raw material monomers of the addition polymer E1 preferably further contain at least one selected from addition-polymerizable monomer c (hereinafter also simply referred to as "monomer c") or macromonomer d (hereinafter also simply referred to as "monomer d") having a polyalkylene oxide group.

[0092] The addition-polymerizable monomer a having an aromatic group is preferably nonionic. Examples of the addition-polymerizable monomer a having an aromatic group include a styrene-based compound a-1 and an aromatic group-containing (meth)acrylate a-2. Examples of the styrene-based compound a-1 include substituted or unsubstituted styrene. Examples of the substituent substituted on styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfo group, or a salt thereof. The molecular weight of the styrene-based compound a-1 is preferably 1,000 or less, more preferably 800 or less, even more preferably 500 or less, even more preferably 300 or less, and preferably 80 or more, more preferably 90 or more, even more preferably 100 or more. Examples of the styrene-based compound a-1 include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid, and salts thereof. Among these, styrene is preferred. From the viewpoint of further improving image quality, the amount of the styrene-based compound a-1 in the raw material monomers of the addition polymer E1 is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 35% by mass or more, and is preferably 98% by mass or less, more preferably 80% by mass or less, even more preferably 65% ​​by mass or less, even more preferably 50% by mass or less.

[0093] Examples of the aromatic group-containing (meth)acrylate a-2 include benzyl (meth)acrylate and phenoxyethyl (meth)acrylate. The molecular weight of the aromatic group-containing (meth)acrylate a-2 is preferably 1,000 or less, more preferably 800 or less, even more preferably 500 or less, still more preferably 300 or less, and preferably 160 or more. When an aromatic group-containing (meth)acrylate a-2 is used, from the viewpoint of further improving image quality, the content of the aromatic group-containing (meth)acrylate a-2 in the raw material monomers of the addition polymer E1 is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less.

[0094] From the viewpoint of further improving image density, the amount of the addition polymerizable monomer a having an aromatic group in the raw material monomers of the addition polymer E1 is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 35% by mass or more, and is preferably 98% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less, even more preferably 80% by mass or less, even more preferably 65% ​​by mass or less, even more preferably 50% by mass or less.

[0095] The ionic group in the monomer b means a group that undergoes ionic dissociation in water. Examples of the ionic group include a carboxy group, a sulfo group, a phosphate group, an amino group, or salts thereof. The ionic group is preferably an anionic group from the viewpoint of improving the dispersion stability of the colorant particles. The anionic group is preferably an acidic group or a salt thereof, more preferably a carboxy group, a sulfo group, or a salt thereof, and even more preferably a carboxy group or a salt thereof. Examples of addition polymerizable monomers having a carboxy group include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, and 2-methacryloyloxymethylsuccinic acid. Among these, addition polymerizable monomers having an anionic group are preferred, (meth)acrylic acid is more preferred, and methacrylic acid is even more preferred. When monomer b is contained, the amount of monomer b in the raw material monomers of the addition polymer E1 is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less.

[0096] The average number of moles of alkylene oxide added in the polyalkylene oxide group of monomer c is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and preferably 30 or less, more preferably 20 or less, even more preferably 10 or less. Monomer c is preferably non-ionic. Examples of monomer c include polyalkylene glycol (meth)acrylates such as polyethylene glycol (meth)acrylate and polypropylene glycol (meth)acrylate; alkoxypolyalkylene glycol (meth)acrylates such as methoxypolyethylene glycol (meth)acrylate; and aryloxypolyalkylene glycol (meth)acrylates such as phenoxy(ethylene glycol-propylene glycol copolymer) (meth)acrylate. When monomer c is contained, the amount of monomer c in the raw material monomers of the addition polymer E1 is preferably 3% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less.

[0097] Examples of the monomer d include a styrene compound polymer having an addition polymerizable functional group at one end (hereinafter also referred to as a "styrene macromonomer"). Examples of the addition polymerizable functional group include a vinyl group, an allyl group, and a (meth)acryloyl group. Among these, a (meth)acryloyl group is preferred. In the monomer d, the styrene-based compound is preferably styrene. The number average molecular weight of the monomer d is preferably 1,000 or more and 10,000 or less. The number average molecular weight is measured by gel permeation chromatography using chloroform containing 1 mmol / L dodecyldimethylamine as a solvent and polystyrene as a standard substance. Commercially available styrene macromonomers include, for example, "AS-6," "AS-6S," "AN-6," "AN-6S," "HS-6," and "HS-6S" (all manufactured by Toagosei Co., Ltd.). When monomer d is contained, the amount of monomer d in the raw material monomers of the addition polymer E1 is preferably 3% by mass or more, more preferably 6% by mass or more, even more preferably 10% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less.

[0098] Furthermore, the raw material monomers of the addition polymer E1 may contain addition polymerizable monomers (other monomers) other than the monomers a to d. Examples of other monomers include alkyl (meth)acrylates having an alkyl group with 1 to 22 carbon atoms (preferably 6 to 18 carbon atoms). When other monomers are contained, the amount of the other monomers in the raw material monomers of the addition polymer E1 is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0099] From the viewpoint of further improving image density, the weight-average molecular weight of the addition polymer E1 is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 20,000 or more, even more preferably 40,000 or more, even more preferably 48,000 or more, and is preferably 200,000 or less, more preferably 90,000 or less, even more preferably 60,000 or less, even more preferably 53,000 or less. The weight-average molecular weight can be measured by the method described in the Examples.

[0100] When the colorant is a white pigment, preferably titanium oxide, the addition polymer E (hereinafter, the addition polymer E when the colorant is a white pigment will also be referred to as "addition polymer E2") is preferably an addition polymer of raw material monomers including an addition polymerizable monomer having an ionic group and an addition polymerizable monomer having a polyalkylene oxide group, from the viewpoint of obtaining an image with excellent dispersibility of titanium oxide and excellent whiteness. Examples of the addition polymerizable monomer having an ionic group in the addition polymer E2 include the same monomers as the monomer b in the addition polymer E1 described above, and preferred embodiments are also the same. Examples of the addition polymerizable monomer having a polyalkylene oxide group in the addition polymer E2 include the same monomers as the monomer c in the addition polymer E1 described above, and preferred embodiments are also the same. The average number of moles of alkylene oxide added in the polyalkylene oxide group of the addition-polymerizable monomer having a polyalkylene oxide group in the addition polymer E2 is preferably 1 or more, more preferably 5 or more, even more preferably 10 or more, and is preferably 60 or less, more preferably 40 or less, even more preferably 30 or less.

[0101] As the ionic group-containing monomer, from the viewpoint of improving the dispersibility of the white pigment in the dispersion liquid and the dispersibility of the white pigment in the toner, a carboxy group-containing monomer is preferred, more preferably at least one selected from acrylic acid and methacrylic acid, and even more preferably methacrylic acid. The ionic group-containing monomer may form a salt, and examples of the salt include sodium salt and potassium salt.

[0102] The content of the ionic group-containing monomer in the raw material monomers of the addition polymer E2 is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, from the viewpoints of excellent dispersibility of the white pigment and improved whiteness, and low-temperature fixability, and is preferably 50% by mass or less, more preferably 35% by mass or less, even more preferably 20% by mass or less.

[0103] From the viewpoints of improving whiteness and low-temperature fixability, the content of the polyalkylene oxide group-containing monomer in the raw material monomers of the addition polymer E2 is preferably 50% by mass or more, more preferably 65% ​​by mass or more, even more preferably 80% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less.

[0104] The mass ratio of the ionic group-containing monomer to the polyalkylene oxide group-containing monomer (ionic group-containing monomer / alkylene oxide group-containing monomer) among the raw material monomers of the addition polymer E2 is, from the viewpoint of improving whiteness and low-temperature fixability, preferably 5 / 95 or more, more preferably 10 / 90 or more, even more preferably 15 / 85 or more, and is preferably 50 / 50 or less, more preferably 35 / 65 or less, even more preferably 20 / 80 or less.

[0105] In the present invention, the raw material monomers for the addition polymer E2 may further contain, in addition to the ionic group-containing monomer and the polyalkylene oxide group-containing monomer, addition-polymerizable monomers (other monomers) other than the monomer a, monomer d, and monomers a to d described above in the addition polymer E1, within a range that does not impair the effects of the present invention. When the raw material monomers contain monomers other than the ionic group-containing monomer and the polyalkylene oxide group-containing monomer, the content of the monomers other than the ionic group-containing monomer and the polyalkylene oxide group-containing monomer in the raw material monomers is preferably 0.1% by mass or more and preferably 5% by mass or less.

[0106] From the viewpoints of excellent dispersibility of white pigments, further improving whiteness, and low-temperature fixability, the weight-average molecular weight of the addition polymer E2 is preferably 3,000 or more, more preferably 20,000 or more, even more preferably 40,000 or more, and even more preferably 48,000 or more, and is preferably 200,000 or less, more preferably 80,000 or less, and even more preferably 70,000 or less. The weight-average molecular weight can be measured by the method described in the examples.

[0107] The addition polymer E can be produced, for example, by copolymerizing raw material monomers by a known polymerization method, preferably a solution polymerization method in which raw material monomers are polymerized by heating in a solvent together with a polymerization initiator, a polymerization chain transfer agent, etc. Examples of the polymerization initiator include peroxides such as dibutyl peroxide, persulfates such as ammonium persulfate and sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of the polymerization initiator added is preferably 0.5 parts by mass or more and preferably 30 parts by mass or less based on 100 parts by mass of the raw material monomer. Examples of the polymerization chain transfer agent (also simply referred to as "chain transfer agent") include mercaptans such as 2-mercaptoethanol and 3-mercaptopropionic acid. The amount of the polymerization chain transfer agent added is preferably 0.01 parts by mass or more and preferably 10 parts by mass or less, based on 100 parts by mass of the raw material monomer. After the polymerization reaction is complete, the produced polymer may be isolated and purified from the reaction solution by known methods such as reprecipitation, solvent distillation, etc. Alternatively, the reaction solution after the reaction may be used as it is as a dispersion of the addition polymer.

[0108] In the colorant particles, the mass ratio of the colorant other than the white pigment to the addition polymer E1 (colorant / addition polymer E1) is preferably 50 / 50 or more, more preferably 60 / 40 or more, even more preferably 70 / 30 or more, even more preferably 75 / 25 or more, from the viewpoint of further improving hiding power and low-temperature fixability, and is preferably 95 / 5 or less, more preferably 90 / 10 or less, even more preferably 85 / 15 or less. Furthermore, in the colorant particles, the mass ratio of the white pigment (preferably titanium oxide) to the addition polymer E2 (white pigment / addition polymer E2) is preferably 50 / 50 or more, more preferably 70 / 30 or more, even more preferably 85 / 15 or more, even more preferably 90 / 10 or more, and even more preferably 95 / 5 or more, from the viewpoints of excellent dispersibility of the white pigment, further improvement in whiteness, and low-temperature fixability, and is preferably 99.5 / 0.5 or less, more preferably 99.2 / 0.8 or less.

[0109] (Method of producing colorant particles and colorant particle dispersion) The colorant particles are obtained by mixing the colorant and the addition polymer E, for example. There is no particular limitation on the method for producing the colorant particle dispersion. 50 It is sufficient if the colorant particles can be controlled to obtain the colorant particles of the above formula, but the colorant and the dispersion of addition polymer E are preferably mixed using a bead mill or a homogenizer.

[0110] The method for producing a colorant particle dispersion preferably includes the steps of: Step a: obtaining a dispersion of addition polymer E; and Step b: A step of dispersing the dispersion obtained in step a and a colorant to obtain a dispersion of colorant particles (colorant particle dispersion 2). It is a method having the following. When the colorant is a colorant other than a white pigment, step a is preferably a step of mixing the addition polymer E1 with an organic solvent, then adding a neutralizing agent as needed, and then adding an aqueous medium to obtain a dispersion of the addition polymer E1 (hereinafter also referred to as step a1). The inclusion of an organic solvent allows the addition polymer E1 to dissolve in the organic solvent, making it easier for the addition polymer E to be adsorbed onto the colorant, thereby further improving the dispersibility of the colorant. Furthermore, when the colorant is a white pigment, step a is preferably a step of obtaining an aqueous dispersion of a neutralized addition polymer E2 (hereinafter also referred to as step a2). When the reaction solution after completion of the reaction can be used as is as a dispersion of the addition polymer, step a may be omitted. Furthermore, the step b is preferably a step of dispersing the dispersion liquid obtained in the step a and the colorant using a bead mill or a homogenizer.

[0111] When the colorant is a colorant other than a white pigment, it is preferable that in step a1, the addition polymer E1 is first mixed with an organic solvent to dissolve the addition polymer E1. Examples of the organic solvent used here include alkyl alcohols having 1 to 3 carbon atoms, dialkyl ketones having a total of 3 to 5 carbon atoms, and cyclic ethers. Among these, dialkyl ketones having a total of 3 to 5 carbon atoms are preferred, and methyl ethyl ketone is more preferred. When the addition polymer E1 is synthesized by solution polymerization, the solvent used in the polymerization may be used as is.

[0112] Examples of the neutralizing agent include basic substances, such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. When the addition polymer E is addition polymer E1, the degree of neutralization of addition polymer E1 is preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 40 mol% or more, even more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, and preferably 100 mol% or less, more preferably 95 mol% or less. Furthermore, when the addition polymer E is addition polymer E2, the degree of neutralization of addition polymer E2 is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and preferably 100 mol% or less, more preferably 80 mol% or less, even more preferably 60 mol% or less, even more preferably 50 mol% or less. The degree of neutralization of the addition polymer E can be determined by the following formula. Degree of neutralization (mol%) = [{weight (g) of neutralizing agent added / equivalent weight of neutralizing agent} / {weight ratio of addition polymerizable monomer having an acidic group constituting addition polymer E × weight (g) of addition polymer E / molecular weight of addition polymerizable monomer having an acidic group}] × 100 When the calculated degree of neutralization exceeds 100, the degree of neutralization is taken to be 100 mol %. In step a1, the device used for mixing may be, for example, a mixer / stirrer equipped with an anchor blade, a disperser blade, or the like. The temperature during mixing in step a1 is preferably 0°C or higher, more preferably 10°C or higher, and preferably 40°C or lower, more preferably 30°C or lower, and even more preferably 25°C or lower. The mixing time in step a1 is preferably 1 minute or more, more preferably 3 minutes or more, even more preferably 5 minutes or more, and preferably 30 hours or less, more preferably 10 hours or less, even more preferably 5 hours or less, even more preferably 3 hours or less, even more preferably 1 hour or less.

[0113] In step b, the mass ratio of the colorant to the addition polymer E [colorant / addition polymer E] is as described above. In step b, the dispersion liquid obtained in step a and a colorant may be mixed and then subjected to a dispersion treatment. Examples of the device used for mixing in step b include the same device as the device used for mixing in step a. The temperature during mixing in step b is preferably 0°C or higher, more preferably 10°C or higher, and preferably 40°C or lower, more preferably 30°C or lower, and even more preferably 25°C or lower. The mixing time in step b is preferably 1 minute or longer, more preferably 10 minutes or longer, even more preferably 30 minutes or longer, and is preferably 30 hours or shorter, more preferably 10 hours or shorter, even more preferably 5 hours or shorter, even more preferably 3 hours or shorter.

[0114] Examples of devices used in the dispersion treatment in step b include kneaders such as roll mills and kneaders, homogenizers such as Microfluidizer (manufactured by Microfluidic Corp.) and Starburst (manufactured by Sugino Machine Co., Ltd.), and media-type dispersers such as paint shakers and bead mills. One or more of these devices may be used. Among these, homogenizers and media-type dispersers are preferred from the viewpoint of reducing the particle size of the pigment. When a homogenizer is used, the processing pressure is preferably 60 MPa or more, more preferably 100 MPa or more, even more preferably 130 MPa or more, and preferably 270 MPa or less, more preferably 200 MPa or less, even more preferably 180 MPa or less. The number of passes is preferably 5 or more, more preferably 8 or more, and even more preferably 12 or more, and is preferably 30 or less, and more preferably 20 or less. When a media-type disperser is used, the material of the media is preferably ceramics such as zirconia or titania, polymeric materials such as polyethylene or polyamide, or metal, with zirconia being preferred from the viewpoint of wear, etc. The shape of the media is not particularly limited, but is preferably bead-like (spherical). When a media-type disperser is used, the dispersion time is preferably 0.3 hours or more, more preferably 1 hour or more, from the viewpoint of sufficiently pulverizing the colorant, and is preferably 100 hours or less, more preferably 50 hours or less, and even more preferably 20 hours or less, from the viewpoint of production efficiency of the colorant dispersion.

[0115] It is preferable to remove the organic solvent from the obtained colorant particle dispersion liquid, if necessary. The colorant particle dispersion is preferably filtered through a wire mesh or the like to remove coarse particles, etc. From the viewpoint of improving the productivity and storage stability of the dispersion, the addition polymer E of the colorant particles may be crosslinked. In addition, various additives such as organic solvents, preservatives, and antifungal agents may be added to the colorant particle dispersion liquid.

[0116] When the colorant is a colorant other than a white pigment, the content of the colorant in the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 25% by mass or less. In the above case, the solid content concentration of the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less.

[0117] When the colorant is a white pigment, the content of the white pigment in the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 25% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less. In the above case, the solid content concentration of the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and is preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 35% by mass or less.

[0118] When the colorant is a colorant other than a white pigment, the volume median particle diameter D of the colorant particles in the colorant particle dispersion liquid 50 From the viewpoint of improving image density, the thickness is preferably 0.05 μm or more, more preferably 0.07 μm or more, even more preferably 0.08 μm or more, and is preferably 0.4 μm or less, more preferably 0.3 μm or less, even more preferably 0.2 μm or less. In the above case, the CV value of the colorant particles in the colorant particle dispersion is preferably 10% or more, more preferably 15% or more, and is preferably 45% or less, more preferably 40% or less, and even more preferably 35% or less, from the viewpoint of improving image density. Volume median particle size D of colorant particles 50 The CV value is measured by the method described in the Examples.

[0119] If the colorant is a white pigment, the volume median particle size D of the colorant 50 From the viewpoint of obtaining a toner having excellent whiteness, the particle size is preferably 0.10 μm or more, more preferably 0.15 μm or more, even more preferably 0.20 μm or more, and is preferably 0.55 μm or less, more preferably 0.45 μm or less, even more preferably 0.35 μm or less. In the above case, the volume median particle diameter D 50 From the viewpoint of improving the whiteness, the CV value is preferably 10% or more, more preferably 20% or more, and is preferably 45% or less, more preferably 35% or less. Volume median particle size D of colorant 50 and CV values ​​are measured by the methods in the Examples.

[0120] When the colorant is a colorant other than a white pigment, the amount of colorant particles is, relative to 100 parts by mass of resin particles, preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, from the viewpoint of further improving image density, and is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less. When the colorant is a white pigment, the amount of colorant particles is, relative to 100 parts by mass of resin particles, preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, and is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, from the viewpoint of further improving image density.

[0121] <Release agent particles> The release agent is preferably contained in the aggregated particles 1 by mixing the resin particle dispersion and the colorant particle dispersion as a dispersion of release agent particles and aggregating them. A dispersion of release agent particles can be obtained using a surfactant, but is preferably obtained by mixing the release agent with resin particles Z, which will be described later. By preparing release agent particles using a release agent and resin particles Z, the release agent particles are stabilized by the resin particles Z, making it possible to disperse the release agent in an aqueous medium without using a surfactant. It is believed that the dispersion of release agent particles has a structure in which a large number of resin particles Z adhere to the surfaces of the release agent particles.

[0122] The resin constituting the resin particles Z in which the release agent is dispersed is preferably a polyester resin, and it is more preferable to use a composite resin D having a polyester resin segment and an addition polymerization resin segment.

[0123] The softening point of composite resin D is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 85°C or higher, and preferably 140°C or lower, more preferably 120°C or lower, even more preferably 100°C or lower. From the viewpoint of obtaining fine resin particles and a fine release agent particle dispersion, the acid value of the composite resin D is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and even more preferably 20 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less, and even more preferably 30 mgKOH / g or less.

[0124] The preferred ranges of other resin properties of the composite resin D and the preferred examples of the raw material monomers constituting the resin are the same as those shown for the amorphous polyester resin A. The dispersion of the resin particles Z can be obtained, for example, by the phase inversion emulsification method described above. The volume median particle size (D 50 ) is preferably 0.01 μm or more, more preferably 0.03 μm or more, and is preferably 0.3 μm or less, more preferably 0.2 μm or less, from the viewpoint of dispersion stability of the release agent particles. From the viewpoint of dispersion stability of the release agent particles, the CV value of the resin particles Z is preferably 10% or more, more preferably 15% or more, and is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. The volume median particle size (D 50 ) and CV values ​​are measured by the method described in the Examples.

[0125] The release agent particle dispersion liquid can be obtained, for example, by dispersing a dispersion liquid of the release agent and the resin particles Z, and optionally an aqueous medium, at a temperature equal to or higher than the melting point of the release agent using a disperser such as a homogenizer, a high-pressure disperser, or an ultrasonic disperser. The heating temperature during dispersion is preferably above the melting point of the release agent and 80°C or higher, more preferably 85°C or higher, and even more preferably 90°C or higher, and is preferably below a temperature 10°C higher than the softening point of the resin contained in the resin particles Z and 100°C or lower, more preferably 98°C or lower, and even more preferably 95°C or lower.

[0126] The amount of resin particles Z is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, relative to 100 parts by mass of the release agent, and is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, even more preferably 50 parts by mass or less.

[0127] The volume median particle size of the release agent particles (D 50) is preferably 0.05 μm or more, more preferably 0.2 μm or more, even more preferably 0.4 μm or more, and is preferably 1 μm or less, more preferably 0.8 μm or less, even more preferably 0.6 μm or less, from the viewpoint of obtaining uniform aggregated particles by aggregation. The CV value of the release agent particles is preferably 10% or more, more preferably 20% or more, and is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. The volume median particle size of the release agent particles (D 50 ) and CV values ​​are measured by the method described in the Examples.

[0128] Aggregated particles 1 may also contain additives such as charge control agents, magnetic powders, flowability improvers, conductivity adjusters, reinforcing fillers such as fibrous substances, antioxidants, antiaging agents, and cleaning property improvers.

[0129] ≪Mixing conditions≫ In step 1, it is preferable to mix resin particles X and colorant particles in an aqueous medium and aggregate the resin particles X and colorant particles to obtain aggregated particles. The mixing of resin particles X and colorant particles is preferably carried out by mixing a resin particle dispersion containing resin particles X with a colorant particle dispersion containing colorant particles. Furthermore, it is preferable that the resin particle dispersion is an aqueous dispersion of resin particles, and the colorant particle dispersion is an aqueous dispersion of colorant particles. In step 1, it is preferable to aggregate the release agent particles together with the resin particles X and the colorant particles.

[0130] (surfactant) In step 1, it is preferable to prepare a mixed dispersion by mixing a resin particle dispersion with, as needed, a colorant particle dispersion and a release agent particle dispersion, and then aggregate the resin particles X, colorant particles, and release agent particles. The mixed dispersion may be prepared in the presence of a surfactant in order to improve the dispersion stability of the resin particles X and optional components, such as colorant particles and release agent particles, which are added as needed. Examples of the surfactant include anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; and nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers. When a surfactant is used, the amount of surfactant used is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, relative to 100 parts by mass of resin particles X, as the total amount of surfactant.

[0131] The dispersion of the resin particles X and the optional components are mixed by a conventional method. From the viewpoint of efficiently carrying out aggregation, it is preferable to add an aggregating agent to the mixed dispersion obtained by the mixing.

[0132] (flocculant) Examples of the flocculant include organic flocculants such as quaternary salt cationic surfactants and polyethyleneimine; inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate; and inorganic flocculants such as divalent or higher metal complexes. From the viewpoint of improving flocculation properties and obtaining uniform flocculated particles, inorganic flocculants having a valence of 1 to 5 are preferred, inorganic metal salts having a valence of 1 to 2 and inorganic ammonium salts are more preferred, and ammonium sulfate is even more preferred. The flocculant may be added as is, but is preferably dissolved in an aqueous medium and added as an aqueous solution. When the flocculant is added as an aqueous solution, the pH of the aqueous flocculant solution may be adjusted.

[0133] For example, a flocculant is added to a mixed dispersion containing resin particles X, and, if necessary, colorant particles and release agent particles, at a temperature of 0° C. or higher and 40° C. or lower, in an amount of preferably 5 parts by mass or higher and 50 parts by mass or lower relative to 100 parts by mass of resin particles X, to aggregate the resin particles X and colorant particles in an aqueous medium to obtain aggregated particles 1. Furthermore, from the viewpoint of promoting aggregation, it is preferable to increase the temperature of the dispersion after adding the flocculant.

[0134] Volume median particle size D of aggregated particles 1 obtained in step 1 50 is preferably 3 μm or more, more preferably 4 μm or more, even more preferably 5 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6.5 μm or less. It is preferred to continue the agglomeration process until the desired volume median particle size is achieved.

[0135] [Process 2] Step 2 is a step of aggregating resin particles Y containing amorphous polyester resin B with aggregated particles 1 obtained in step 1 to obtain aggregated particles 2. In step 2, it is preferable to add a dispersion of resin particles Y to the dispersion of aggregated particles 1 described above, thereby causing resin particles Y to further adhere to aggregated particles 1, thereby obtaining a dispersion of aggregated particles 2.

[0136] <Resin Particle Y> The resin particle dispersion used in step 2 contains resin particles Y. The resin particles Y preferably contain an amorphous polyester resin B in order to obtain excellent low-temperature fixability. (Preparation of Resin Particle Dispersion) The resin particles Y are preferably produced by a method in which a resin component containing the amorphous polyester resin B and, if necessary, optional components such as a surfactant are dispersed in an aqueous medium to obtain a resin particle Y dispersion. The method for obtaining the resin particle Y dispersion can be exemplified by the same methods as those for the resin particle dispersion of resin particle X. Among these, it is preferable to obtain the resin particle Y dispersion by a phase inversion emulsification method, from the viewpoint of improving the low-temperature fixability of the resulting toner. As in the case of resin particles X, the phase inversion emulsification method is preferably a method in which an aqueous medium is added to a solution obtained by dissolving a resin and optional components such as a surfactant in an organic solvent, and then phase inversion emulsification is carried out. Preferred embodiments of the aqueous medium and organic solvent that can be used are the same as those of the aqueous medium and organic solvent used in the production of resin particles X. In addition, in the phase inversion emulsification method, preferred ranges for the mass ratio of amorphous polyester resin B to organic solvent, the degree of neutralization of amorphous polyester resin B, the amount of aqueous medium added, the mixing temperature, and the like are the same as those in the production of resin particles X.

[0137] The solid content concentration of the resulting dispersion of resin particles Y is preferably 7% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of improving toner productivity and dispersion stability of resin particles Y, and is preferably 50% by mass or less, more preferably 35% by mass or less, and even more preferably 25% by mass or less. The solid content is the total amount of nonvolatile components such as resin and surfactant.

[0138] The volume median particle diameter (D 50 ) is preferably 0.04 μm or more, more preferably 0.06 μm or more, even more preferably 0.08 μm or more, and is preferably 0.5 μm or less, more preferably 0.3 μm or less, even more preferably 0.2 μm or less, even more preferably 0.15 μm or less, from the viewpoint of obtaining a toner that can produce high-quality images.

[0139] Furthermore, the coefficient of variation (CV value) (%) of the particle size distribution of the resin particles Y is preferably 5% or more, more preferably 10% or more, and even more preferably 15% or more, from the viewpoint of improving the productivity of the resin particle Y dispersion, and is preferably 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 25% or less, from the viewpoint of obtaining a toner that can produce high-quality images. The volume median particle size of resin particle Y (D 50 ) and coefficient of variation (CV value) are measured by the method described in the Examples.

[0140] Before adding the dispersion of resin particles Y to the dispersion of aggregated particles 1, the dispersion of aggregated particles 1 may be diluted by adding an aqueous medium. When the dispersion of resin particles Y is added to the dispersion of aggregated particles 1, the aggregating agent may be used in this step to efficiently attach the resin particles Y to the aggregated particles 1. The temperature when adding the resin particle Y dispersion is preferably 40°C or higher, more preferably 45°C or higher, even more preferably 50°C or higher, from the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability of the toner, and is preferably 80°C or lower, more preferably 70°C or lower, even more preferably 65°C or lower.

[0141] The resin particle Y dispersion may be added continuously over a certain period of time, all at once, or in multiple divided portions. However, it is preferable to add the resin particle Y continuously over a certain period of time or in multiple divided portions. By adding the resin particle Y in this manner, the resin particle Y is more likely to selectively adhere to the aggregated particles 1. From the viewpoints of promoting selective adhesion and improving toner productivity, it is particularly preferable to add the resin particle Y continuously over a certain period of time. When the resin particle Y is added continuously, the time is preferably 1 hour or more, more preferably 1.2 hours or more, and is preferably 10 hours or less, more preferably 7 hours or less, and even more preferably 3 hours or less, from the viewpoints of obtaining uniform aggregated particles 2 and improving toner productivity.

[0142] From the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability of the toner, the amount of resin particles Y added is an amount such that the mass ratio of resin particles Y to resin particles X (resin particles Y / resin particles X) is preferably 0.05 or more, more preferably 0.08 or more, even more preferably 0.10 or more, even more preferably 0.12 or more, and is preferably 0.9 or less, more preferably 0.5 or less, even more preferably 0.3 or less, even more preferably 0.2 or less.

[0143] The volume median particle size (D 50) is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6.5 μm or less, from the viewpoint of obtaining a toner that can produce high-quality images and from the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability of the toner.

[0144] [Step 3] Step 3 is a step of raising the temperature of the aggregated particles 2 obtained in step 2 to fuse them together, thereby obtaining fused particles. In step 3, the particles in the aggregated particles, which were primarily physically attached to each other, are fused together to form toner particles with a core-shell structure. In this step, the temperature is maintained at or above the glass transition temperature of the amorphous polyester resin B from the viewpoint of improving the fusion property of the aggregated particles and achieving both low-temperature fixability and dot reproducibility of the toner. From the viewpoint of improving the fusion properties of the aggregated particles and improving the productivity of the toner, the holding temperature in the fusion step is preferably at least 2°C higher, more preferably at least 3°C ​​higher, and even more preferably at least 5°C higher than the glass transition temperature of the amorphous polyester resin B, and is preferably not higher than 30°C higher, more preferably not higher than 25°C higher, and even more preferably not higher than 20°C higher than the glass transition temperature of the amorphous polyester resin B. In this case, the time for which the toner is maintained at a temperature equal to or higher than the glass transition temperature of the amorphous polyester resin B is, from the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability of the toner, preferably 1 minute or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, and is preferably 240 minutes or less, more preferably 180 minutes or less, even more preferably 120 minutes or less, even more preferably 90 minutes or less. It is preferable to maintain the temperature at the above temperature until the desired circularity is achieved.

[0145] The volume median particle size (D 50) is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less, from the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability of the toner. The volume median particle diameter of the core-shell particles obtained in step 3 is preferably equal to or less than the volume median particle diameter of aggregated particles 2. In other words, in step 3, it is preferable that aggregation and fusion of aggregated particles 2 do not occur.

[0146] [Post-processing process] In the present invention, a post-treatment step may be carried out after step 3, and it is preferable to obtain toner particles by isolation. Since the core-shell particles obtained in step 3 exist in an aqueous medium, it is preferable to first carry out solid-liquid separation. For solid-liquid separation, a suction filtration method or the like is preferably used. It is preferable to wash the solid-liquid separation product. At this time, it is preferable to remove the added surfactant and the like. Therefore, if the surfactant has a cloud point, washing with an aqueous medium at a temperature below the cloud point of the surfactant is preferable. It is preferable to wash the solid-liquid separation product multiple times.

[0147] Next, it is preferable to carry out drying. The temperature during drying is preferably set so that the temperature of the core-shell particles themselves is lower than the glass transition temperature of the amorphous polyester resin A, more preferably 10°C or more lower. As the drying method, it is preferable to use a vacuum low-temperature drying method, a vibration fluidized bed drying method, a spray drying method, a freeze drying method, a flash jet method, or the like.

[0148] [Toner particles] The toner particles obtained by drying or the like can be used as they are as a toner for developing electrostatic images, but it is preferable to use toner particles whose surfaces have been treated as described below as a toner for developing electrostatic images. The volume median particle size of the toner particles (D 50) is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less, from the viewpoint of improving the productivity of the toner and achieving both low-temperature fixability and heat-resistant storage stability of the toner. The CV value of the toner particles is preferably 12% or more, more preferably 14% or more, and even more preferably 16% or more from the viewpoint of improving toner productivity, and is preferably 32% or less, more preferably 30% or less, and even more preferably 29% or less from the viewpoint of obtaining high-quality images. From the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability of the toner, the circularity of the toner particles is preferably 0.955 or more, more preferably 0.960 or more, even more preferably 0.965 or more, and is preferably 0.990 or less, more preferably 0.985 or less, even more preferably 0.980 or less.

[0149] <External additives> The toner particles can be used as they are as a toner for developing electrostatic images, but it is preferable to use the toner particles after adding a fluidizing agent or the like as an external additive to the surface of the toner particles. Examples of external additives include inorganic fine particles such as hydrophobic silica, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin, and among these, hydrophobic silica is preferred. The external additives may be used alone or in combination of two or more. Also, external additives of the same type but different particle diameters may be used in combination. When the surface treatment of the toner particles is performed using an external additive, the amount of the external additive added is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, even more preferably 4 parts by mass or less, relative to 100 parts by mass of the toner particles.

[0150] <<Toner for developing electrostatic images>> The toner for developing electrostatic images obtained as described above can be used as a one-component developer, or mixed with a carrier to form a two-component developer.

[0151] [Printed material] The printed matter of the present invention is a printed matter obtained by the image forming method of the present invention described above, and has an image formed on the film surface of a film label having a release paper, an adhesive layer, and a film laminated in this order, using a specific toner for developing electrostatic images, and the basis weight of the release paper is 65 g / m 2 or more, and the melting point of the film is 200°C or less. The printed matter of the present invention is a printed matter in which curling is suppressed and an image with excellent dot reproducibility is formed. The printed matter of the present invention can be applied to various film labels, and is expected to be applied to, for example, various packaging, indoor and outdoor displays, and the like. [Example]

[0152] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Each property value was measured and evaluated by the following methods. In expressions such as "alkylene oxide (X)", the number X in parentheses means the average number of moles of alkylene oxide added.

[0153] [measurement] [Acid value of resin] Measurement was performed in accordance with JIS K0070: 1992, except that the measurement solvent was a mixed solvent of acetone and toluene (acetone:toluene=1:1 (volume ratio)).

[0154] [Resin softening point, crystallinity index, melting point, glass transition temperature] (1) Softening point Using a flow tester "CFT-500D" (Shimadzu Corporation), 1 g of sample was heated at a temperature increase rate of 6°C / min, while a load of 1.96 MPa was applied by the plunger, and the sample was extruded from a nozzle 1 mm in diameter and 1 mm in length. The plunger depression distance of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.

[0155] (2) Crystallinity index Using a differential scanning calorimeter "Q100" (TA Instruments Japan), 0.02 g of sample was weighed into an aluminum pan and cooled to 0°C at a rate of 10°C / min. The sample was then left to stand for 1 minute, after which it was heated to 180°C at a rate of 10°C / min and the calorific value was measured. The temperature of the endothermic peak with the largest area was defined as the endothermic maximum peak temperature (1), and the crystallinity index was calculated by (softening point (°C)) / (endothermic maximum peak temperature (1) (°C)).

[0156] (3) Melting point and glass transition temperature Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the calorific value was measured. The temperature of the peak with the largest peak area among the observed endothermic peaks was taken as the maximum endothermic peak temperature (2). For crystalline resins, this peak temperature was taken as the melting point. In the case of an amorphous resin, when a peak is observed, the temperature of the peak is taken as the glass transition temperature. When a step is observed instead of a peak, the temperature at the intersection of the tangent line showing the maximum slope of the curve at the step and an extension of the baseline on the low-temperature side of the step is taken as the glass transition temperature.

[0157] [Weight-average molecular weight of addition polymer E1] The measurements were performed by gel permeation chromatography (GPC) using a Tosoh HLC-8320GPC gel permeation chromatography system with Tosoh TSKgel SuperAWM-H, Tosoh SuperAW3000, and Tosoh TSKgel guardcolumn Super AW-H columns at a flow rate of 0.5 mL / min. The eluent was a solution of 60 mmol / L phosphoric acid and 50 mmol / L lithium bromide dissolved in N,N-dimethylformamide. The standard samples were monodisperse polystyrene kits with known molecular weights (PStQuick B (F-550, F-80, F-10, F-1, A-1000), PStQuick C (F-288, F-40, F-4, A-5000, A-500), Tosoh PStQuick C).

[0158] [Weight-average molecular weight of addition polymer E2] Using a solution of 0.2 M phosphate buffer / acetonitrile = 9 / 1 (volume ratio) as the eluent, measurements were performed by gel permeation chromatography (GPC apparatus (HLC-8320GPC) manufactured by Tosoh Corporation, columns (PW+G4000PW+G2500PW) manufactured by Tosoh Corporation, flow rate: 1.0 mL / min, temperature: 40°C) using polyethylene glycol, the weight-average molecular weight of which had been previously determined to be monodisperse, as the standard substance.

[0159] [Melting point of release agent] Using a differential scanning calorimeter "Q100" (TA Instruments Japan Co., Ltd.), 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, the calorific value was measured, and the maximum endothermic peak temperature was taken as the melting point.

[0160] [Volume median particle diameter D of resin particles, release agent particles, and colorant particles 50 and CV value) (1) Measuring device: Laser diffraction particle size measuring instrument "LA-920" (manufactured by Horiba Ltd.) (2) Measurement conditions: Add distilled water to the measurement cell and measure the volume median particle size D at a concentration that brings the absorbance into the appropriate range.50 The volume average particle size was measured, and the CV value (particle size distribution) was calculated according to the following formula. CV value (%) = (standard deviation of particle size distribution / volume average particle size) x 100

[0161] [Solid Content Concentration of Resin Particle Dispersion, Release Agent Particle Dispersion, and Colorant Particle Dispersion] Using an infrared moisture meter "FD-230" (Kett Electric Laboratory Co., Ltd.), the moisture content (mass%) of 5 g of the measurement sample was measured at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 min / fluctuation range 0.05%). The solid content concentration was calculated according to the following formula. Solid content concentration (mass%) = 100-moisture (mass%)

[0162] [Volume median particle size of agglomerated particles D 50 and CV value) Volume median particle size of agglomerated particles D 50 was measured as follows: Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) Aperture diameter: 50 μm Analysis software: "Multisizer (registered trademark) III version 3.51" (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (Beckman Coulter, Inc.) Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, 30,000 particles are measured, and the volume median particle size D is calculated from the particle size distribution. 50 The volume average particle size was calculated. The CV value (particle size distribution) was calculated according to the following formula. CV value (%) = (standard deviation of particle size distribution / volume average particle size) x 100

[0163] [Circularity of fused particles] The circularity of the fused particles was measured under the following conditions. Measurement equipment: Flow particle image analyzer "FPIA-3000" (Sysmex Corporation) Preparation of dispersion: The dispersion of fused particles was prepared by diluting with deionized water so that the solid content concentration was 0.001% by mass or more and 0.05% by mass or less. Measurement mode: HPF measurement mode

[0164] [Volume median particle size D of toner particles 50 and CV value) Volume median particle size D of toner particles 50 was measured as follows: The measuring instrument, aperture diameter, analysis software, and electrolyte are all set to the volume median particle diameter D of the agglomerated particles. 50 The same was used. Dispersion: Polyoxyethylene lauryl ether "EMULGEN (registered trademark) 109P" (manufactured by Kao Corporation, HLB: 13.6) was dissolved in the electrolyte solution to obtain a dispersion with a concentration of 5% by mass. Dispersion conditions: 10 mg of the toner measurement sample was added to 5 mL of the dispersion liquid, and dispersed for 1 minute using an ultrasonic disperser. Thereafter, 25 mL of electrolyte was added, and the mixture was further dispersed for 1 minute using an ultrasonic disperser to prepare a sample dispersion liquid. Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, 30,000 particles are measured and the volume median particle size D is calculated from the particle size distribution. 50 and the volume average particle size were determined. The CV value (%) was calculated according to the following formula. CV value (%) = (standard deviation of particle size distribution / volume average particle size) x 100

[0165] [Toner Charge Amount] At a temperature of 25°C and a relative humidity of 50%, 2.1 g of toner and 27.9 g of silicone ferrite carrier (Kanto Denka Kogyo Co., Ltd., average particle size: 40 μm) were placed in a 50 mL cylindrical polypropylene bottle (Nikko Hansen Co., Ltd.) and pre-mixed by shaking 10 times vertically and horizontally. The mixture was then mixed for 1 hour at a speed of 90 r / min using a Turbula Mixer "T2F" (Shinmaru Enterprises Co., Ltd.), and the charge amount was measured using a "q / m-meter" (Epping Co.) under the following conditions. Mesh size: 635 mesh (opening: 24 μm, stainless steel) Soft blow: Blow pressure (1000V) ·Suction time: 90 seconds The charge amount can be calculated using the following formula: Charge amount (μC / g) = Total amount of electricity after 90 seconds (μC) / Amount of toner absorbed (g)

[0166] [Basis weight of release paper] The release paper portion of the label was cut into a size of 10 cm length x 10 cm width, and the weight was measured using a laboratory electronic balance "QUINTIX" (manufactured by Sartorius) to determine the basis weight. Release paper basis weight (g / cm 2 ) can be calculated using the following formula: Release paper basis weight (g / cm 2 ) = Weight of release paper cut to a size of 10 cm length x 10 cm width (g) / 0.01(m 2 ) Here, the weight of the release paper was determined as the average weight of the release paper cut at any five points.

[0167] [Release paper thickness] The thickness of the release paper of the label was measured at any five points on the release paper using a micrometer "Coolant Proof Micrometer" (manufactured by Mitutoyo Corporation), and the average value was taken as the thickness of the release paper.

[0168] [Film melting point] The film portion was peeled off from the release paper and used as a sample. 0.015 g of the sample was weighed into an aluminum pan, heated to 200°C, and cooled to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min and the calorific value was measured. The temperature of the peak with the largest area among the endothermic peaks observed was taken as the melting point of the film.

[0169] [evaluation] [Label curl suppression rate] A label cut to A4 size was printed using a commercially available printer, Microline (registered trademark) 5400 (manufactured by OKI Data Corporation), with the toner adhesion amount on the label being 0.29 to 0.31 mg / cm 2 A solid image of the above was printed without fixing, leaving a 5mm margin from the top edge of an A4 label and a length of 50mm. Next, the same printer was prepared with a temperature-adjustable fixing unit, and the fixing unit temperature was set to 90°C. The toner was fixed at a speed of 4 seconds per sheet in portrait A4 format, resulting in a printout (equivalent to 15 sheets per minute in portrait A4 format). The label curl suppression rate is calculated using the following formula, and the larger the absolute value of the value, the less likely the label is to curl. Label curl suppression rate (%) = A4 length of printed label (cm) / A4 length of label before passing through fixing unit (cm) × 100

[0170] [Dot reproducibility of printed labels] A commercially available printer, "Microline® 5400" (manufactured by OKI Data Corporation), was used to print a 2-dot, 2-space halftone image at a resolution of 1200 dpi onto an A4-sized label, without fixing. Next, an external fuser with variable temperature and rotation speed was used. The temperature of the external fuser was set to 90°C, and the toner was fixed at a speed of 4 seconds per sheet in portrait orientation, resulting in a label print (equivalent to 15 sheets per minute in portrait orientation). Labels printed with color toner were visually evaluated on a 5-point scale. Labels printed with white toner were peeled off and attached to colored wood-free paper, "Super Heavy Black" manufactured by Hokuetsu Kishu Paper Co., Ltd., and visually evaluated on a 5-point scale. A higher number indicates less toner scattering around the dots and less voids within the dots, resulting in clearer dots. 5: Almost no scattered toner was observed around the dots, the dots were very clear, and there were no missing dots. 4: Although a small amount of scattered toner is observed around the dots, the dots are clear and there are no missing dots. 3: Scattered toner was observed around the dots, making the dots somewhat unclear, but no missing toner was observed within the dots. 2: Scattered toner was observed around the dots, making the dots somewhat unclear, and missing parts within the dots were also observed. 1: There is noticeable scattered toner around the dots, making the dots unclear and also noticeable voids within the dots.

[0171] [Resin manufacturing] [Production of amorphous resin] Production Example A1 (Production of Resin A-1) The inside of a 10 L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 3253 g of a propylene oxide (2.2) adduct of bisphenol A, 1003 g of terephthalic acid, 24 g of tin(II) di(2-ethylhexanoate), and 2.4 g of 3,4,5-trihydroxybenzoic acid were added. The mixture was heated to 235°C under a nitrogen atmosphere with stirring and maintained at 235°C for 5 hours. The pressure inside the flask was then reduced and maintained at 8 kPa for 1 hour. The pressure was then returned to atmospheric pressure, cooled to 160°C, and a mixture of 2139 g of styrene, 535 g of stearyl methacrylate, 107 g of acrylic acid, and 321 g of dibutyl peroxide was added dropwise over 1 hour while maintaining the temperature at 160°C. After that, the temperature was maintained at 160°C for 30 minutes, then increased to 200°C, and the pressure inside the flask was further reduced and maintained at 8 kPa for 1 hour. After that, the pressure was returned to atmospheric pressure, and the mixture was cooled to 190°C. 129 g of fumaric acid, 94 g of sebacic acid, 214 g of trimellitic anhydride, and 2.4 g of 4-tert-butylcatechol were added, and the temperature was increased to 210°C at 10°C / hr. Then, the mixture was reacted at 4 kPa until the desired softening point was reached, yielding Resin A-1. The physical properties are shown in Table 1.

[0172] Manufacturing Example B1 (Manufacturing of Resin B-1) A four-neck flask equipped with a nitrogen inlet, dehydration tube, stirrer, and thermocouple was purged with nitrogen. 3265 g of ethylene oxide (2.2) adduct of bisphenol A, 1334 g of terephthalic acid, 25 g of tin(II) di(2-ethylhexanoate), and 2.5 g of 3,4,5-trihydroxybenzoic acid were added. Under a nitrogen atmosphere, the mixture was heated to 235°C with stirring. After maintaining this temperature for 6 hours, the pressure in the flask was further reduced to 8.3 kPa and maintained for 1 hour. After returning to atmospheric pressure, the mixture was cooled to 180°C. 73 g of adipic acid, 135 g of dodecenylsuccinic anhydride, and 193 g of trimellitic anhydride were added. The temperature was increased at 10°C / hr to 220°C. The pressure in the flask was then reduced and the reaction was continued at 10 kPa until the desired softening point was reached, yielding Resin B-1. The physical properties are shown in Table 1.

[0173] Manufacturing Example D1 (Manufacturing of Resin D-1) Resin D-1 was obtained in the same manner as in Production Example A1, except that the raw material composition was changed as shown in Table 1. The physical properties are shown in Table 1.

[0174] [Table 1]

[0175] [Production of crystalline resin] Manufacturing Example C1 (Manufacturing of Resin C-1) A 10 L four-neck flask equipped with a nitrogen inlet, dehydration tube, stirrer, and thermocouple was purged with nitrogen. 3,416 g of 1,10-decanediol and 4,084 g of sebacic acid were added and heated to 135°C with stirring. The mixture was then held at 135°C for 3 hours, and then heated from 135°C to 200°C over 10 hours. 23 g of tin(II) di(2-ethylhexanoate) was then added and the mixture was held at 200°C for another hour. The pressure inside the flask was then reduced and the mixture was held under a reduced pressure of 8.3 kPa for 1 hour, yielding Resin C-1. The physical properties are shown in Table 2.

[0176] [Table 2]

[0177] [Production of resin particle dispersion] Production Example X1 (Production of Resin Particle Dispersion X-1) 210 g of Resin A-1, 90 g of Resin C-1, and 360 g of methyl ethyl ketone were placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resins were dissolved over 2 hours at 73° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization relative to the acid value of the resin was 60 mol%, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 600 g of deionized water was added over 60 minutes while stirring at 280 r / min (circumferential speed 88 m / min), resulting in phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while continuing to stir at 280 r / min (circumferential speed 88 m / min), the aqueous dispersion was cooled to 30°C, and deionized water was added to obtain a solids concentration of 20 mass%, thereby obtaining resin particle dispersion X-1. The volume median particle diameter D of the resulting resin particles was 50 and CV values ​​are shown in Table 3.

[0178] Production Examples X2 to X4 (Production of Resin Particle Dispersions X-2 to X-4) Resin particle dispersions X-2 to X-4 were obtained in the same manner as in Production Example X1, except that the ratio of the resins used was changed as shown in Table 3. The volume median particle diameter D of the obtained resin particles was 50 and CV values ​​are shown in Table 3.

[0179] Production Example Y1 (Production of Resin Particle Dispersion Y-1) 300 g of Resin B-1 and 360 g of methyl ethyl ketone were placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resin was dissolved over 2 hours at 40° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization relative to the acid value of the resin was 60 mol %, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 40°C, 600 g of deionized water was added over 60 minutes while stirring at 280 r / min (circumferential speed 88 m / min), resulting in phase inversion emulsification. The temperature was raised to 73°C, and methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, the aqueous dispersion was cooled to 30°C while stirring at 280 r / min (circumferential speed 88 m / min), and deionized water was added to obtain a solids concentration of 20 mass%, thereby obtaining resin particle dispersion Y-1. The volume median particle diameter D of the obtained resin particles was 50 and CV values ​​are shown in Table 3.

[0180] [Table 3]

[0181] Production Example Z1 (Production of Resin Particle Dispersion Z-1) 200 g of Resin D-1 and 200 g of methyl ethyl ketone were placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resin was dissolved over 2 hours at 73° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization relative to the acid value of Resin D-1 was 60 mol %, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 700 g of deionized water was added over 50 minutes while stirring at 280 r / min (circumferential speed 88 m / min), resulting in phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while stirring at 280 r / min (circumferential speed 88 m / min), the aqueous dispersion was cooled to 30°C, and deionized water was added to obtain a solids concentration of 20 mass%, thereby obtaining resin particle dispersion Z-1. The volume median particle diameter D of the resulting resin particles was 50 The particle size was 0.09 μm and the CV value was 23%.

[0182] [Production of release agent particle dispersion] Production Example W1 (Production of Release Agent Particle Dispersion W-1) 120 g of deionized water, 86 g of resin particle dispersion liquid Z-1, and 40 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) were added to a 1 L beaker, and the mixture was melted by maintaining the temperature at 90 to 95°C and stirred to obtain a molten mixture. The obtained molten mixture was further dispersed for 20 minutes using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) while maintaining the temperature at 90 to 95°C, and then cooled to room temperature (20°C). Deionized water was added to adjust the solid content to 20% by mass, thereby obtaining release agent particle dispersion W-1. The volume median particle diameter D of the release agent particles in the dispersion was 50 The particle size was 0.47 μm and the CV value was 27%.

[0183] Production Example W2 (Production of Release Agent Particle Dispersion W-2) A release agent particle dispersion W-2 was obtained in the same manner as in Production Example W1, except that the type of release agent used was changed to Fischer-Tropsch wax "FNP-0090" (manufactured by Nippon Seiro Co., Ltd., melting point 90°C). 50 The particle size was 0.45 μm and the CV value was 28%.

[0184] [Production of addition polymers] Production Example E1 (Synthesis of Addition Polymer E-1) 16 g of methacrylic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 44 g of styrene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 30 g (15 g as solids) of styrene macromonomer "AS-6S" (manufactured by Toagosei Co., Ltd., number average molecular weight 6,000, solids content 50%), and 25 g of methoxypolyethylene glycol methacrylate "Blenmer PME-200" (NOF Corporation) were mixed to prepare 115 g of a monomer mixture. 18 g of methyl ethyl ketone, 0.03 g of 2-mercaptoethanol as a chain transfer agent, and 10% (11.5 g) of the monomer mixture were placed in a reaction vessel and mixed, and the atmosphere was thoroughly purged with nitrogen gas. Separately, a mixture of the remaining 90% (103.5 g) of the monomer mixture with 0.27 g of the chain transfer agent, 42 g of methyl ethyl ketone, and 3 g of the polymerization initiator 2,2'-azobis(2,4-dimethylvaleronitrile) "V-65" (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was placed in a dropping funnel. The mixture in the reaction vessel was heated to 75°C under a nitrogen atmosphere while stirring, and the mixture in the dropping funnel was added dropwise over 3 hours. After 2 hours at 75°C after the completion of the dropping, a solution of 3 g of the polymerization initiator in 5 g of methyl ethyl ketone was added, and the mixture was further aged at 75°C for 2 hours and then at 80°C for 2 hours. The methyl ethyl ketone was then distilled off under reduced pressure to obtain addition polymer E-1. The weight-average molecular weight of the resulting addition polymer is shown in Table 4.

[0185] Production Example E2 (Synthesis of Addition Polymer E-2) 233 g of water was placed in a 2 L glass reaction vessel equipped with a dropping funnel and heated to 80 ° C under a nitrogen atmosphere. Next, under a nitrogen gas atmosphere, a monomer solution of 166 g of methoxypolyethylene glycol methacrylate (average ethylene oxide (EO) addition mole number n = 23, manufactured by Shin-Nakamura Chemical Co., Ltd., product name "NK Ester M-230G") and 34 g of methacrylic acid was added as dropping solution 1, and 27 g of a 7% 2-mercaptoethanol aqueous solution was added as dropping solution 2, and 32 g of a 6% ammonium persulfate aqueous solution was added as dropping solution 3. These three solutions were each gradually added dropwise into the reaction vessel over 90 minutes. Next, 11 g of a 6% ammonium persulfate aqueous solution was gradually added dropwise into the reaction vessel over 30 minutes, and after the completion of the dropwise addition, the mixture was aged at 80 ° C for 1 hour. The mixture was then cooled to 40°C, neutralized with 13 g of a 48% aqueous solution of sodium hydroxide (neutralization degree 40 mol%), and water was added to adjust the solids concentration to 40%, yielding an aqueous solution of addition polymer E-2. The weight-average molecular weight of the resulting addition polymer is shown in Table 4.

[0186] [Table 4]

[0187] [Production of colorant particle dispersion] Production Example F1 (Production of Colorant Particle Dispersion F-1) In a 5L vessel equipped with a stirrer equipped with a disperser blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 75g of addition polymer E-1 was dissolved in 620g of methyl ethyl ketone. Then, 96g of a 5% by weight aqueous solution of sodium hydroxide as a neutralizing agent and 942g of deionized water were added, and the mixture was stirred with a disperser blade at 20°C for 10 minutes. Next, 300g of copper phthalocyanine pigment "ECB-301" (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was added, and the mixture was stirred with a disperser blade at 6400 rpm at 20°C for 2 hours. The mixture was then passed through a 200-mesh filter and subjected to 15 passes at 150MPa using a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics). While stirring the resulting dispersion, the methyl ethyl ketone and some of the water were removed under reduced pressure at 70°C. The mixture was then passed through a 200 mesh filter, and deionized water was added to the mixture so that the solid content was 20% by mass, thereby obtaining a colorant particle dispersion F-1. 50 The particle size was 0.12 μm and the CV value was 21%.

[0188] Production Example F2 (Production of Colorant Particle Dispersion F-2) To a 250 mL polyethylene bottle, 0.765 g (active content: 0.306 g) of the aqueous solution of addition polymer E-2 obtained in Production Example E2 (solids concentration: 40%), 15 g of titanium oxide (CR-80, manufactured by Ishihara Sangyo Kaisha, Ltd., rutile type, Al and Si treated, average primary particle size: 250 nm), 15.3 g of water, and 369 g of zirconia beads (diameter: 2 mm) were added, and the mixture was dispersed at 25°C for 8 hours using a benchtop pot mill stand (manufactured by AS ONE Corporation). The zirconia beads were removed using a mesh, and the solids concentration was adjusted with water to obtain colorant dispersion F-2 (solids concentration: 30% by mass). Volume median particle size D 50 The particle size was 0.26 μm and the CV value was 26%.

[0189] [Toner manufacturing] Production Example 1 (Production of Toner 1) In a 3 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of resin particle dispersion X-1, 35 g of release agent particle dispersion W-1, 35 g of release agent particle dispersion W-2, 63 g of colorant particle dispersion F-1, 10 g of a 10 mass% aqueous solution of polyoxyethylene (50) lauryl ether "EMULGEN 150" (Kao Corporation, nonionic surfactant), and 10 g of a 15 mass% aqueous solution of sodium dodecylbenzenesulfonate "NEOPELEX G-15" (Kao Corporation, anionic surfactant) were mixed at 25°C. Next, while stirring the mixture, a solution prepared by dissolving 35 g of ammonium sulfate in 519 g of deionized water and adding 26 g of 4.8 mass% aqueous potassium hydroxide solution was added dropwise at 25°C over 10 minutes, and the mixture was then heated to 65°C over 2 hours to measure the volume median particle diameter D of the aggregated particles. 50 The temperature was maintained at 65° C. until the particle size reached 5.9 μm, thereby obtaining a dispersion of aggregated particles 1. Subsequently, the dispersion of aggregated particles 1 was cooled to 59°C, and while maintaining the temperature at 59°C, 75 g of resin particle dispersion Y-1 was added over 90 minutes to obtain a dispersion of aggregated particles 2 in which resin particles were aggregated to aggregated particles 1. To the resulting dispersion of aggregated particles 2, an aqueous solution containing 41 g of polyoxyethylene lauryl ether sodium sulfate "EMAL E-27C" (Kao Corporation, anionic surfactant, effective concentration 27% by mass), 1,396 g of deionized water, and 26 g of 0.1 mol / L aqueous sulfuric acid solution was added. The mixture was then heated to 75°C over 1 hour and maintained at 75°C for 30 minutes. After that, 75 g of 0.1 mol / L aqueous sulfuric acid solution was added, and the mixture was further maintained at 75°C for 15 minutes. Another 25 g of 0.1 mol / L aqueous sulfuric acid solution was then added, and the mixture was maintained at 75°C until the circularity reached 0.975, thereby obtaining a dispersion of fused particles in which the aggregated particles were fused. The obtained dispersion of fused particles was cooled to 30°C, and the solid matter was separated by suction filtration, washed with deionized water at 25°C, and then vacuum dried at 30°C for 48 hours to obtain toner particles. The physical properties of the obtained toner particles are shown in Table 5. 100 parts by weight of the toner particles, 2.5 parts by weight of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., number average particle size: 0.04 μm), and 1.0 part by weight of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Japan Co., Ltd., number average particle size: 0.012 μm) were placed in a Henschel mixer and stirred, and the mixture was passed through a 150 mesh sieve to obtain toner 1.

[0190] Production Examples 2 to 4 (Production of Toners 2 to 4) A toner was produced in the same manner as in Production Example 1, except that the type of resin particle dispersion used was changed as shown in Table 5. Table 5 shows the physical properties of the obtained toner particles.

[0191] Production Examples 5 to 8 (Production of Toners 5 to 8) A toner was produced in the same manner as in Production Example 1, except that the amount of shell resin particle dispersion used was changed as shown in Table 5. Table 5 shows the physical properties of the obtained toner particles.

[0192] Production Example 9 (Production of Toner 9) In a 3 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of resin particle dispersion X-1, 35 g of release agent particle dispersion W-1, 35 g of release agent particle dispersion W-2, 126 g of colorant particle dispersion F-2, 10 g of a 10 mass% aqueous solution of polyoxyethylene (50) lauryl ether "EMULGEN 150" (Kao Corporation, nonionic surfactant), and 8 g of a 15 mass% aqueous solution of sodium dodecylbenzenesulfonate "NEOPELEX G-15" (Kao Corporation, anionic surfactant) were mixed at 25°C. Next, while stirring the mixture, a solution prepared by dissolving 35 g of ammonium sulfate in 519 g of deionized water and adding 26 g of a 4.8 mass% aqueous solution of potassium hydroxide was added dropwise at 25°C over 10 minutes, and the mixture was then heated to 58°C over 2 hours to measure the volume median particle diameter D of the aggregated particles. 50 The temperature was maintained at 58° C. until the particle size reached 5.9 μm, thereby obtaining a dispersion of aggregated particles 1. Thereafter, Toner 9 was produced in the same manner as in Production Example 1. Table 5 shows the physical properties of the obtained toner particles.

[0193] Example 1 Polyethylene label "CLPE85TC / S692N / G80" manufactured by Avery Dennison Japan Co., Ltd. Polyethylene film (CLPE85TC), acrylic adhesive (S692N), release paper (G80) (basis weight: 81 g / m 2 )" and the results are shown in Table 5.

[0194] Examples 2 to 9, Comparative Examples 1 and 2 Toner 1 was evaluated in the same manner as in Example 1, except that the type of label was changed as shown in Table 5. The results are shown in Table 5.

[0195] Examples 10 to 14, Comparative Examples 3 to 5 The evaluation was carried out in the same manner as in Example 1, except that the type of toner was changed as shown in Table 5, and the results are shown in Table 5.

[0196] Example 15, Comparative Example 6 The evaluation was carried out in the same manner as in Example 14, except that the type of label was changed as shown in Table 5, and the results are shown in Table 5.

[0197] [Table 5-1]

[0198] [Table 5-2]

[0199] [Table 5-3]

[0200] From the results of the Examples and Comparative Examples, it is clear that the present invention makes it possible to obtain label prints that are less prone to curling and have excellent dot reproducibility.

Claims

1. A method for forming an image on the film surface of a film label having a release paper, an adhesive layer, and a film laminated in this order, using a toner for developing an electrostatic image, The toner for developing electrostatic images contains toner particles having a core-shell structure having a core and a shell present on the surface of the core, the content of the shell resin in 100 parts by mass of the binder resin of the electrostatic image developing toner is 5 parts by mass or more and 30 parts by mass or less, The toner for developing electrostatic images contains 10 parts by mass or more of a crystalline resin in 100 parts by mass of a binder resin, The release paper has a basis weight of 65 g / m ２ That's all, The melting point of the film is 200°C or less. Image forming method.

2. 2. The image forming method according to claim 1, wherein the film of the film label is a polypropylene film or a polyethylene film.

3. 3. The image forming method according to claim 1, wherein the release paper has a thickness of 60 [mu]m or more.

4. 4. The image forming method according to claim 1, wherein the core contains a crystalline resin.

5. 5. The image forming method according to claim 1, wherein the core contains an amorphous polyester resin A as a binder resin.

6. 6. The image forming method according to claim 5, wherein the amorphous polyester resin A comprises a polyester resin segment which is a polycondensate of an alcohol component and a carboxylic acid component, and an addition polymerization resin segment which is an addition polymerization product of raw material monomers including a styrene-based compound.

7. 7. The image forming method according to claim 1, wherein the shell contains an amorphous polyester resin B.

8. A printed matter obtained by the image forming method of any one of claims 1 to 7.

Images