JP2020201305A - toner - Google Patents

Abstract

To provide a toner that is excellent in metal glossiness and can form an image with a clear color.SOLUTION: A toner includes toner particles 10. The toner particles 10 each include a composite core 11 and a shell layer 12 covering the surface of the composite core 11. The composite core 11 is a complex of a toner core 13 containing a binder resin and a metal layer 14 arranged on the surface of the toner core 13. The shell layer 12 contains a resin for a shell layer and a coloring agent. The metal layer 14 preferably has a thickness of 3 nm or more and 1000 nm or less. The shell layer 12 preferably has a thickness of 1 nm or more and 30 nm or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to toner.

In recent years, in the field of commercial printing, there is an increasing demand for printed matter having excellent metallic luster.

For example, Patent Document 1 proposes using a toner in which a metal pigment and an insulating surface additive are arranged in this order on the surface of the toner particles in order to form an image having excellent metallic luster. ..

Japanese Unexamined Patent Publication No. 2017-161901

However, it is difficult to obtain a toner having excellent metallic luster and capable of forming a clear color image only by the technique disclosed in Patent Document 1.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a toner having excellent metallic luster and capable of forming a clear color image.

The toner according to the present invention contains toner particles. The toner particles include a composite core and a shell layer that covers the surface of the composite core. The composite core is a composite of a toner core containing a binder resin and a metal layer arranged on the surface of the toner core. The shell layer contains a resin for the shell layer and a colorant.

According to the present invention, it is possible to provide a toner having excellent metallic luster and capable of forming a clear color image.

It is a figure which shows an example of the cross-sectional structure of the toner particle contained in the toner which concerns on embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described. First, terms used in the present specification will be described. Toner is an aggregate of toner particles (for example, powder). The external additive is an aggregate of external additive particles (for example, powder). Unless otherwise specified, the evaluation results (values indicating the shape, physical properties, etc.) of the powder (more specifically, the powder of the toner particles, the powder of the external additive particles, etc.) are obtained from the powder. It is the number average of the values measured for each of the particles selected in a considerable number.

Unless otherwise specified, the measured value of the median volume diameter (D ₅₀ ) of the powder was measured using a laser diffraction / scattering type particle size distribution measuring device (“LA-950” manufactured by HORIBA, Ltd.). The median diameter. Unless otherwise specified, the average primary particle diameter of the number of powders is the circle-equivalent diameter (Haywood diameter: primary particle) of the primary particle measured using a scanning electron microscope (“JSM-7401F” manufactured by JEOL Ltd.). It is the number average value of the diameter of a circle having the same area as the projected area of. The number average primary particle diameter of the powder is, for example, the average number of circle-equivalent diameters of 100 primary particles. The number average primary particle diameter of the particles refers to the number average primary particle diameter of the particles in the powder (the number average primary particle diameter of the powder) unless otherwise specified.

The strength of chargeability is the ease of triboelectric charging unless otherwise specified. For example, a standard carrier provided by the Japan Imaging Society (standard carrier for negatively charged polar toner: N-01, standard carrier for positively charged polar toner: P-01) and a measurement target (for example, toner) are mixed and stirred. Then, the measurement target is triboelectrically charged. Before and after triboelectric charging, for example, a suction-type compact charge amount measuring device (“MODEL 212HS” manufactured by Trek Corporation) measures the charge amount to be measured. The larger the change in the amount of charge before and after triboelectric charging, the stronger the chargeability.

Unless otherwise specified, the measured value of the softening point (Tm) is a value measured using a heightened flow tester (“CFT-500D” manufactured by Shimadzu Corporation). In the S-curve (horizontal axis: temperature, vertical axis: stroke) measured by the heightened flow tester, the temperature that becomes "(baseline stroke value + maximum stroke value) / 2" becomes Tm (softening point). Equivalent to. Unless otherwise specified, the measured value of the glass transition point (Tg) shall be in accordance with "JIS (Japanese Industrial Standards) K7121-2012" using a differential scanning calorimeter ("DSC-6220" manufactured by Seiko Instruments Inc.). It is a measured value. In the heat absorption curve (vertical axis: heat flow (DSC signal), horizontal axis: temperature) measured by the differential scanning calorimeter, the temperature of the turning point due to the glass transition (specifically, the baseline extrapolation and falling). The temperature at the intersection of the line with the extra line) corresponds to Tg (glass transition point).

The "alkyl group having 1 or more and 6 or less carbon atoms" is linear or branched and unsubstituted. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, n-pentyl group and isopentyl. Groups include groups, neopentyl groups, and n-hexyl groups.

The "alkylene group having 1 or more and 6 or less carbon atoms" is linear or branched and unsubstituted. Examples of the alkylene group having 1 or more and 6 or less carbon atoms include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, an n-pentylene group, and an n-hexylene group.

Hereinafter, the compound and its derivative may be collectively referred to by adding "system" after the compound name. When the polymer name is represented by adding "system" after the compound name, it means that the repeating unit of the polymer is derived from the compound or its derivative.

<Toner>
The toner according to this embodiment can be suitably used for developing an electrostatic latent image, for example, as a positively charged toner. The toner according to the present embodiment is an aggregate (for example, powder) of toner particles (particles having a constitution described later). The toner may be used as a one-component developer. Further, the toner and the carrier may be mixed using a mixing device (for example, a ball mill) to prepare a two-component developer.

The toner particles contained in the toner according to the present embodiment include a composite core and a shell layer covering the surface of the composite core. The composite core is a composite of a toner core containing a binder resin and a metal layer arranged on the surface of the toner core. The shell layer contains a resin for the shell layer and a colorant.

By providing the toner according to the present embodiment with the above-mentioned structure, it is possible to form an image having excellent metallic luster and a clear color. The reason is presumed as follows.

The toner particles contained in the toner according to the present embodiment include a composite core which is a composite of a toner core and a metal layer arranged on the surface of the toner core. As described above, in the toner according to the present embodiment, the metal layer is arranged on the outside of the toner core. Therefore, according to the toner according to the present embodiment, an image having excellent metallic luster can be formed.

Further, in the toner according to the present embodiment, the composite core is covered with a shell layer. Further, the shell layer covering the composite core contains a resin for the shell layer and a colorant. As described above, in the toner according to the present embodiment, the shell layer containing the colorant is arranged on the outside of the metal layer (for example, the outermost layer of the toner particles). Therefore, according to the toner according to the present embodiment, a clear color image can be formed.

In the present embodiment, in order to form an image having a better metallic luster, the area ratio of the region covered by the metal layer (hereinafter, may be referred to as metal coverage) in the surface region of the toner core is determined. It is preferably 90% or more, and particularly preferably 100%. The method for measuring the metal coverage is the same as or similar to that of Examples described later.

In the present embodiment, in order to form a clearer color image, the area ratio of the region covered by the shell layer in the surface region of the composite core (hereinafter, may be referred to as shell coverage) is determined. , 80% or more and 100% or less is preferable. The method for measuring the shell coverage is the same as or similar to that in the examples described later.

In the present embodiment, in order to form a clearer color image, the amount of the colorant in the shell layer is preferably 1.00 parts by mass or more with respect to 100 parts by mass of the resin for the shell layer. , 3.00 parts by mass or more is more preferable. Further, in the present embodiment, in order to suppress the occurrence of color unevenness (color unevenness in the same image), the amount of the colorant in the shell layer is 10. With respect to 100 parts by mass of the resin for the shell layer. It is preferably 00 parts by mass or less, and more preferably 5.00 parts by mass or less.

In the present embodiment, in order to form a clearer color image, the amount of the colorant is preferably 0.01 part by mass or more with respect to 100 parts by mass of the binder resin in the toner core. More preferably, it is .00 parts by mass or more. Further, in the present embodiment, in order to suppress the occurrence of color unevenness, the amount of the colorant is preferably 5.00 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner core. More preferably, it is 3.00 parts by mass or less.

In the present embodiment, the toner core may contain an internal additive (for example, at least one of a colorant, a mold release agent, a charge control agent, and a magnetic powder) in addition to the binder resin, if necessary.

The toner particles contained in the toner according to the present embodiment may include an external additive. When the toner particles include an external additive, the toner particles include a toner mother particle having a composite core and a shell layer, and an external additive. The external additive adheres to the surface of the toner matrix particles. If it is not necessary, the external additive may be omitted. When the external additive is omitted, the toner mother particles correspond to the toner particles.

Hereinafter, the details of the toner according to the present embodiment will be described with reference to the drawings as appropriate. The drawings to be referred to are schematically shown mainly for each component for easy understanding, and the size, number, shape, etc. of each component shown are shown for convenience of drawing creation. It may differ from the actual one.

[Structure of toner particles]
Hereinafter, the configuration of the toner particles contained in the toner according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an example of a cross-sectional structure of toner particles contained in the toner according to the present embodiment. For ease of explanation, a case where the toner particles 10 shown in FIG. 1 are toner particles without an external additive will be described.

The toner particles 10 shown in FIG. 1 include a composite core 11 and a shell layer 12 that covers the surface of the composite core 11. The composite core 11 is a composite of a toner core 13 containing a binder resin and a metal layer 14 arranged on the surface of the toner core 13. The shell layer 12 contains a resin for the shell layer and a colorant.

In order to form an image having a better metallic luster, the thickness of the metal layer 14 is preferably 3 nm or more. Further, in order to obtain a toner having excellent fixability while suppressing the occurrence of color unevenness, the thickness of the metal layer 14 is preferably 1000 nm or less. The method for measuring the thickness of the metal layer 14 is the same as or similar to that of the examples described later.

In order to form a clearer color image, the thickness of the shell layer 12 is preferably 1 nm or more. Further, in order to suppress the occurrence of color unevenness, the thickness of the shell layer 12 is preferably 30 nm or less. The method for measuring the thickness of the shell layer 12 is the same method as in Examples described later or a method similar thereto.

In order to obtain a toner suitable for image formation, the volume median diameter (D ₅₀ ) of the toner core 13 is preferably 4 μm or more and 9 μm or less.

Although an example of toner particles contained in the toner according to the present embodiment has been described above with reference to FIG. 1, the present invention is not limited thereto. For example, the toner particles contained in the toner according to the present invention may include an external additive (not shown). For example, the toner particles 10 shown in FIG. 1 may be used as the toner mother particles, and the toner particles having an external additive attached to the surface of the toner mother particles may be used as the toner particles contained in the toner according to the present invention.

[Elements of toner particles]
Next, the elements of the toner particles contained in the toner according to the present embodiment will be described.

{Composite core}
The composite core is a composite of a toner core and a metal layer arranged on the surface of the toner core. Hereinafter, the components contained in the toner core will be described.

(Bundling resin)
In the toner core, for example, the binder resin occupies 85% by mass or more of all the components. Therefore, it is considered that the properties of the binder resin have a great influence on the properties of the entire toner core. By using a plurality of types of resins in combination as the binder resin, the properties of the binder resin (more specifically, the glass transition point, etc.) can be adjusted.

In order to obtain a toner having excellent low-temperature fixability, the toner core preferably contains a thermoplastic resin as the binder resin, and more preferably contains the thermoplastic resin in a proportion of 85% by mass or more of the entire binder resin. preferable. Examples of the thermoplastic resin include styrene resin, acrylic acid ester resin, olefin resin (more specifically, polyethylene resin, polypropylene resin, etc.), vinyl resin (more specifically, vinyl chloride resin, polyvinyl chloride, etc.). (Alcohol, vinyl ether resin, N-vinyl resin, etc.), polyester resin, polyamide resin, and urethane resin can be mentioned. Further, a copolymer of each of these resins, that is, a copolymer in which an arbitrary repeating unit is introduced into the above resin (more specifically, a styrene-acrylic acid ester resin, a styrene-butadiene resin, etc.) is also available. Can be used as a binder resin.

The thermoplastic resin is obtained by addition polymerization, copolymerization, or polycondensation of one or more kinds of thermoplastic monomers. The thermoplastic monomer is a monomer that becomes a thermoplastic resin by homopolymerization (more specifically, an acrylic acid ester-based monomer, a styrene-based monomer, etc.) or a monomer that becomes a thermoplastic resin by polycondensation (for example, polycondensation). A combination of a polyhydric alcohol and a polyvalent carboxylic acid that becomes a polyester resin).

In order to obtain a toner having excellent low-temperature fixability, a polyester resin is preferable as the binder resin. The polyester resin is obtained by polycondensing one or more polyhydric alcohols and one or more polyvalent carboxylic acids. Examples of the alcohol for synthesizing the polyester resin include divalent alcohols (more specifically, aliphatic diols, bisphenols, etc.) as shown below, and trihydric or higher alcohols. Examples of the carboxylic acid for synthesizing the polyester resin include a divalent carboxylic acid and a trivalent or higher carboxylic acid as shown below. In addition, instead of the polyvalent carboxylic acid, a polyvalent carboxylic acid derivative capable of forming an ester bond by polycondensation of an anhydride of the polyvalent carboxylic acid, polyvalent carboxylic acid halide or the like may be used.

Preferable examples of aliphatic diols include diethylene glycol, triethylene glycol, neopentyl glycol, 1,2-propanediol, α, ω-alkanediol (more specifically, ethylene glycol, 1,3-propanediol, etc.). 1,4-Butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,12-dodecanediol, etc.) , 2-Buten-1,4-diol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

Preferable examples of bisphenol include bisphenol A, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct.

Preferable examples of trihydric or higher alcohols are sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolethane, and 1,3,5- Examples include trihydroxymethylbenzene.

Preferable examples of divalent carboxylic acids include maleic acid, fumaric acid, succinic acid, succinic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, azeline acid, malonic acid , 1,10-decandicarboxylic acid, succinic acid, alkyl succinic acid (more specifically, n-butyl succinic acid, isobutyl succinic acid, n-octyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, etc.), And alkenyl succinic acid (more specifically, n-butenyl succinic acid, isobutenyl succinic acid, n-octenyl succinic acid, n-dodecenyl succinic acid, isododecenyl succinic acid and the like).

Preferable examples of trivalent or higher valent carboxylic acids are 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1, 2,4-Butantricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) Examples include methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, and empole trimeric acid.

(Colorant)
The toner core may contain a colorant. As the colorant, a pigment or dye known according to the color of the toner can be used. In the present embodiment, since the shell layer containing the colorant is arranged outside the composite core, a clear color image can be formed even if the toner core does not contain the colorant.

The toner core may contain a black colorant. An example of a black colorant is carbon black. Further, the black colorant may be a colorant that has been toned to black using a yellow colorant, a magenta colorant, and a cyan colorant.

The toner core may contain a color colorant. Examples of the color colorant include a yellow colorant, a magenta colorant, and a cyan colorant.

As the yellow colorant, for example, one or more compounds selected from the group consisting of condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and arylamide compounds can be used. Examples of the yellow colorant include C.I. I. Pigment Yellow (3,12,13,14,15,17,62,74,83,93,94,95,97,109,110,111,120,127,128,129,147,151,154,155 168, 174, 175, 176, 180, 181, 191 and 194), Naphthol Yellow S, Hansa Yellow G, and C.I. I. Bat yellow can be mentioned.

The magenta colorant is selected from the group consisting of, for example, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. More than one compound can be used. Examples of the magenta colorant include C.I. I. Pigment Red (2, 3, 5, 6, 7, 19, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 150, 166, 169, 177 , 184, 185, 202, 206, 220, 221 and 254).

As the cyan colorant, for example, one or more compounds selected from the group consisting of copper phthalocyanine compounds, anthraquinone compounds, and base dye lake compounds can be used. Examples of the cyan colorant include C.I. I. Pigment Blue (1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, and 66), Phthalocyanine Blue, C.I. I. Bat Blue, as well as C.I. I. Acid blue can be mentioned.

(Release agent)
The toner core may contain a release agent. The release agent is used, for example, to obtain a toner having excellent offset resistance. In order to obtain a toner having excellent offset resistance, the amount of the release agent is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

Examples of the release agent include ester wax, polyolefin wax (more specifically, polyethylene wax, polypropylene wax, etc.), microcrystalline wax, fluororesin wax, Fishertroph wax, paraffin wax, candelilla wax, and Montan wax. And Custer wax. Examples of the ester wax include natural ester wax (more specifically, carnauba wax, rice wax, etc.) and synthetic ester wax. In the present embodiment, one type of release agent may be used alone, or a plurality of types of release agents may be used in combination.

A compatibilizer may be added to the toner core in order to improve the compatibility between the binder resin and the release agent.

(Charge control agent)
The toner core may contain a charge control agent. The charge control agent is used, for example, to obtain a toner having excellent charge stability or charge rise characteristics. The charge rising characteristic of the toner is an index of whether or not the toner can be charged to a predetermined charge level in a short time.

By incorporating a positively charged charge control agent into the toner core, the cationicity (positively charged) of the toner core can be strengthened. Further, by incorporating a negative charge control agent into the toner core, the anionic property (negative charge property) of the toner core can be strengthened.

Examples of positively charged charge control agents include pyridazine, pyrimidine, pyrazine, 1,2-oxazine, 1,3-oxazine, 1,4-oxazine, 1,2-thiazine, 1,3-thiazine, 1, 4-thiadine, 1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, 1,2,4-oxadiazine, 1,3,4-oxadiazine, 1,2,6- Oxaziazine, 1,3,4-triazine, 1,3,5-triazine, 1,2,3,4-tetrazine, 1,2,4,5-tetrazine, 1,2,3,5-tetrazine, 1, Adin compounds such as 2,4,6-oxatriazine, 1,3,4,5-oxatriazine, phthalazine, quinazoline, quinoxalin; Adinfast Red FC, Adinfast Red 12BK, Adin Violet BO, Adin Brown 3G, Adinlite Direct dyes such as Brown GR, Azine Dark Green BH / C, Azin Deep Black EW, Azin Deep Black 3RL; Acidic dyes such as Niglosin BK, Niglosin NB, Niglosin Z; Alkalkylated amines; Alkylamides; Quaternary ammonium salts such as ammonium chloride, decyltrimethylammonium chloride, 2- (methacryloyloxy) ethyltrimethylammonium chloride, dimethylaminopropylacrylamide methyl chloride quaternary salt; resins containing a quaternary ammonium cation group can be mentioned. Only one of these charge control agents may be used, or two or more types of charge control agents may be used in combination.

An example of a negatively charged charge control agent is an organometallic complex which is a chelate compound. As the organometallic complex, one or more selected from the group consisting of an acetylacetone metal complex, a salicylic acid-based metal complex, and salts thereof is preferable.

In order to obtain a toner having excellent charge stability, the content of the charge control agent is preferably 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

(Magnetic powder)
The toner core may contain magnetic powder. Examples of the material of the magnetic powder include ferromagnetic metals (more specifically, iron, cobalt, nickel, etc.) and their alloys, ferromagnetic metal oxides (more specifically, ferrite, magnetite, chromium dioxide, etc.). , And a material that has been subjected to a ferromagnetism treatment (more specifically, a carbon material to which ferromagnetism has been imparted by heat treatment, etc.). In the present embodiment, one kind of magnetic powder may be used alone, or a plurality of kinds of magnetic powder may be used in combination.

(Metal layer)
Next, the metal layer will be described. The metal constituting the metal layer is not particularly limited as long as it can impart metallic luster to the formed image. In order to form an image with better metal gloss, the metal constituting the metal layer is one selected from the group consisting of aluminum, nickel, titanium, chromium, zinc, copper, silver, gold, platinum and stainless steel. The above metals are preferable, and aluminum is more preferable.

The metal layer may contain components other than metal. However, in order to form an image having more excellent metallic luster, the content of the metal in the metal layer is preferably 90% by mass or more, and 99% by mass or more and 100% by mass with respect to the total mass of the metal layer. More preferably, it is less than%. When the metal layer contains a component other than metal (other component), examples of the other component include metal oxides and resins.

Further, the surface layer of the metal layer may be, for example, a metal oxide layer. For example, when an aluminum layer is provided as a metal layer covering the toner core, the surface layer of the aluminum layer may be an alumina layer oxidized (naturally oxidized) by oxygen in the air.

{Shell layer}
Next, the shell layer will be described. The shell layer contains a resin for the shell layer and a colorant. Further, the shell layer may contain other components (more specifically, a charge control agent, etc.) in addition to the resin for the shell layer and the colorant. However, in order to form a clearer color image, the total content of the shell layer resin and the colorant in the shell layer is preferably 90% by mass or more with respect to the total mass of the shell layer. , 100% by mass is particularly preferable.

(Resin for shell layer)
The resin for the shell layer is not particularly limited, and for example, one or more resins selected from known thermosetting resins and thermoplastic resins can be used.

When a thermosetting resin is used as the resin for the shell layer, examples of the thermosetting resin that can be used include melamine resin, urea resin, glioxal resin, and guanamine resin.

When a thermoplastic resin is used as the resin for the shell layer, examples of the thermoplastic resin that can be used include styrene resin, acrylic acid ester resin, olefin resin (more specifically, polyethylene resin, polypropylene resin, etc. ), Vinyl resin (more specifically, vinyl chloride resin, polyvinyl alcohol, vinyl ether resin, N-vinyl resin, etc.), polyester resin, polyamide resin, and urethane resin. Further, a copolymer of each of these resins, that is, a copolymer in which an arbitrary repeating unit is introduced into the above resin (more specifically, a styrene-acrylic acid-based resin, a styrene-butadiene-based resin, etc.) is also a shell. Can be used as a layer resin.

In order to easily form a shell layer on the surface of the composite core, a styrene-acrylic acid-based resin is preferable as the resin for the shell layer. The styrene-acrylic acid-based resin is a resin obtained by polymerizing one or more styrene-based monomers and one or more types of acrylic acid-based monomers. Therefore, the styrene-acrylic acid-based resin contains one or more repeating units derived from a styrene-based monomer and one or more repeating units derived from an acrylic acid-based monomer.

In order to suppress the occurrence of color unevenness, the resin for the shell layer includes a repeating unit represented by the following general formula (1) (hereinafter, may be referred to as a repeating unit (1)). The repetition unit represented by the general formula (2) shown below (hereinafter, may be referred to as the repetition unit (2)) and the repetition unit represented by the general formula (3) shown below (hereinafter, the repetition unit). A resin containing (may be described as (3)) is preferable (hereinafter, may be described as a specific resin). The repeating unit (1) and the repeating unit (2) are repeating units derived from an acrylic acid-based monomer. The repeating unit (3) is a repeating unit derived from a styrene-based monomer. Therefore, the specific resin is a kind of styrene-acrylic acid-based resin.

In the formula (1), R ¹¹ and R ¹² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms. R ² represents an alkylene group having 1 or more and 6 or less carbon atoms. As R ¹¹ and R ¹² , hydrogen atoms or methyl groups are preferable independently of each other. As R ² , an ethylene group is preferable. In order to further suppress the occurrence of color unevenness, the repeating unit (1) is preferably a repeating unit derived from 2-hydroxyethyl methacrylate.

In the formula (2), R ³¹ and R ³² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms. R ³³ represents an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms. As R ³¹ and R ³² , hydrogen atoms or methyl groups are preferable independently of each other. As R ³³ , an n-butyl group is preferable. In order to further suppress the occurrence of color unevenness, the repeating unit (2) is preferably a repeating unit derived from n-butyl acrylate.

In formula (3), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ and R ⁴⁵ each independently represent a hydrogen atom, a halogen atom, a hydroxy group, or an alkyl group having 1 or more and 6 or less carbon atoms. R ⁴⁶ and R ⁴⁷ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 or more and 6 or less carbon atoms. As R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ and R ⁴⁵ , hydrogen atoms or halogen atoms are preferable, and hydrogen atoms are more preferable, respectively. As R ⁴⁶ and R ⁴⁷ , a hydrogen atom or a methyl group is preferable, and a hydrogen atom is more preferable, respectively. In order to further suppress the occurrence of color unevenness, the repeating unit (3) is preferably a repeating unit derived from styrene.

In order to particularly suppress the occurrence of color unevenness, the resin for the shell layer includes a repeating unit derived from 2-hydroxyethyl methacrylate, a repeating unit derived from n-butyl acrylate, and a repeating unit derived from styrene. A resin containing (specific resin) is preferable, and as the repeating unit, a resin containing only a repeating unit derived from 2-hydroxyethyl methacrylate, a repeating unit derived from n-butyl acrylate, and a repeating unit derived from styrene (specific). Resin) is more preferable.

(Colorant)
Examples of the colorant contained in the shell layer include the same colorants as those exemplified as the optional components of the toner core described above.

{Preferable combination of materials}
In order to form an image having better metallic luster while particularly suppressing the occurrence of color unevenness, the resin for the shell layer is derived from n-butyl acrylate, a repeating unit derived from 2-hydroxyethyl methacrylate. It is preferable that the resin (specific resin) contains the repeating unit and the repeating unit derived from styrene, and the metal constituting the metal layer is aluminum.

{External agent}
The toner particles may further include an external additive. As a method of externalizing the external additive, for example, the toner particles 10 shown in FIG. 1 described above are used as the toner mother particles, and the toner mother particles (powder) and the external additive particles (powder) are stirred together. By doing so, a method of adhering the external additive particles to the surface of the toner mother particles can be mentioned.

Inorganic particles are preferable as the external additive particles, and silica particles and particles of metal oxides (more specifically, alumina, titanium oxide, magnesium oxide, zinc oxide, strontium titanate, barium titanate, etc.) are particularly preferable. preferable. In the present embodiment, one kind of external additive particles may be used alone, or a plurality of kinds of external additive particles may be used in combination.

In order to fully exert the function of the external additive while suppressing the detachment of the external agent particles from the toner mother particles, the amount of the external additive (when using a plurality of types of external agent particles, when using multiple types of external agent particles, The total amount of the external additive particles) is preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the toner mother particles.

The external additive particles may be surface-treated. For example, when silica particles are used as the external additive particles, the surface of the silica particles may be imparted with hydrophobicity and / or positive chargeability by a surface treatment agent. Examples of the surface treatment agent include a coupling agent (more specifically, a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, etc.), a silazane compound (more specifically, a chain silazane compound, etc.). Cyclic silane compounds and the like) and silicone oils (more specifically, dimethyl silicone oils and the like) can be mentioned. As the surface treatment agent, one or more selected from a silane coupling agent and a silazane compound is particularly preferable. Preferable examples of the silane coupling agent include silane compounds (more specifically, methyltrimethoxysilane, aminosilane, etc.). Preferable examples of the silazane compound include HMDS (hexamethyldisilazane). When the surface of the silica substrate (untreated silica particles) is treated with a surface treatment agent, a large number of hydroxy groups (-OH) present on the surface of the silica substrate are partially or wholly derived from the surface treatment agent. Substituted with a functional group. As a result, silica particles having a functional group derived from the surface treatment agent (specifically, a functional group having a stronger hydrophobicity and / or positive charge than the hydroxy group) on the surface can be obtained.

<Toner manufacturing method>
Next, a preferred method for producing the toner according to the above-described embodiment will be described. Hereinafter, the description of the components overlapping with the toner according to the above-described embodiment will be omitted.

[Toner core preparation process]
First, a toner core is prepared by an agglutination method or a pulverization method.

The agglutination method includes, for example, an agglutination step and a coalescence step. In the agglomeration step, fine particles containing components constituting the toner core are agglomerated in an aqueous medium to form agglomerated particles. In the coalescence step, the components contained in the agglomerated particles are coalesced in an aqueous medium to form a toner core.

Next, the pulverization method will be described. According to the pulverization method, the toner core can be prepared relatively easily and the manufacturing cost can be reduced. When the toner core is prepared by the pulverization method, the toner core preparation step includes, for example, a melt-kneading step and a pulverization step. The toner core preparation step may further include a mixing step before the melt kneading step. Further, the toner core preparation step may further include at least one of a fine pulverization step and a classification step after the pulverization step.

In the mixing step, for example, the binder resin and the internal additive added as needed are mixed to obtain a mixture. In the melt-kneading step, the toner material is melted and kneaded to obtain a melt-kneaded product. As the toner material, for example, a mixture obtained in a mixing step is used. In the pulverization step, the obtained melt-kneaded product is cooled to, for example, room temperature (25 ° C.) and then pulverized to obtain a pulverized product. When it is necessary to reduce the diameter of the pulverized product obtained in the pulverization step, a step of further pulverizing the pulverized product (fine pulverization step) may be carried out. Further, when the particle size of the pulverized product is made uniform, a step of classifying the obtained pulverized product (classification step) may be carried out. By the above steps, a pulverized toner core is obtained.

(Composite core preparation process)
Subsequently, a metal layer is formed on the surface of the obtained toner core by using, for example, a known metal layer forming method (more specifically, a sputtering method, an electroless plating method, a vapor deposition method, etc.) to form a composite core. obtain.

(Shell layer forming process)
Subsequently, the obtained composite core, a raw material for forming the shell layer (shell raw material), and a solvent (for example, ion-exchanged water) are put into the reaction vessel, and then the container is stirred while stirring the contents of the vessel. The internal temperature is raised to a set temperature (for example, a temperature of 60 ° C. or higher and 80 ° C. or lower). Examples of the shell raw material include a suspension containing resin particles composed of a resin for a shell layer and a colorant. After the temperature inside the container reaches the set temperature, the shell layer (shell layer) that covers the surface of the composite core by stirring the contents of the container while maintaining the set temperature for a predetermined time (for example, 30 minutes or more and 180 minutes or less). A shell layer containing a resin for use and a colorant) is formed, and a dispersion liquid containing toner matrix particles is obtained. The thickness and shell coverage of the shell layer vary from each other, for example, to at least one of the content of the shell layer resin and colorant in the shell material and the amount of the shell material used relative to the mass of the composite core. By doing so, it can be adjusted.

[Washing process and drying process]
Subsequently, the toner matrix particles in the obtained dispersion are washed with ion-exchanged water, and then the toner matrix particles are dried using, for example, a continuous surface modifier. As a result, a powder of toner mother particles can be obtained.

[External process]
Then, if necessary, the obtained toner mother particles and the external additive are mixed using a mixer (for example, FM mixer manufactured by Nippon Coke Industries Co., Ltd.) and externally added to the surface of the toner mother particles. The agent may be attached. The toner mother particles may be used as the toner particles without adhering the external additive to the toner mother particles. In this way, the toner (powder of toner particles) according to the above-described embodiment can be obtained.

Hereinafter, examples of the present invention will be described. The present invention is not limited to the scope of the examples.

<Making toner>
First, a method for producing the toners TA-1 to TA-4, TB-1 and TB-2 will be described.

[Preparation of toner TA-1]
(Toner core preparation process)
Using an FM mixer (“FM-20B” manufactured by Nippon Coke Industries Co., Ltd.), 750 g of low Tg polyester resin (Tg: 38 ° C, Tm: 65 ° C) and 100 g of medium Tg polyester under the condition of rotation speed of 2400 rpm. Resin (Tg: 53 ° C, Tm: 84 ° C), 150 g of high Tg polyester resin (Tg: 71 ° C, Tm: 120 ° C), and 55 g of mold release agent (Carnauba wax: Hiroyuki Kato Co., Ltd. "Carnauba" Wax No. 1 ") was mixed for 3 minutes. Subsequently, the obtained mixture was melt-kneaded using a twin-screw extruder (“PCM-30” manufactured by Ikegai Corp.) under the conditions of a material supply speed of 5 kg / hour, a shaft rotation speed of 160 rpm, and a cylinder temperature of 120 ° C. .. Then, the obtained melt-kneaded product was cooled. Subsequently, the cooled melt-kneaded product was coarsely pulverized using a pulverizer (“Rotoplex®” manufactured by Hosokawa Micron Corporation). Subsequently, the obtained coarsely pulverized product was finely pulverized using a jet mill (“ultrasonic jet mill type I” manufactured by Nippon Pneumatic Industries Co., Ltd.). Subsequently, the obtained finely pulverized product was classified using a classifier (“Elbow Jet EJ-LABO type” manufactured by Nittetsu Mining Co., Ltd.) to obtain a toner core having a medium volume diameter (D ₅₀ ) of 6.0 μm. It was.

(Composite core preparation process)
A metal layer (aluminum layer) was formed on the surface of the toner core obtained as described above by using a sputtering device (“JEC-3000FC” manufactured by JEOL Ltd.). Specifically, 30 g of toner core powder (sample) is placed on the sample table of the above sputtering apparatus, aluminum is used as a target, and the pressure is reduced (pressure: 3 × 10 ^-4 Pa), and the applied current is 20 mA. Sputtering was performed for 30 seconds. Next, the sample that had been sputtered for 30 seconds was once taken out from the sputtering apparatus and placed on the sample table of the sputtering apparatus again. Next, using aluminum as a target, sputtering was performed for 30 seconds under a reduced pressure (pressure: 3 × 10 ^-4 Pa) under the condition of an applied current of 20 mA. As a result, a composite core (hereinafter referred to as composite core CA-1) which is a composite of the toner core and a metal layer (aluminum layer) arranged on the surface of the toner core was obtained.

(Preparation process of shell raw material)
A 2 L capacity three-necked flask equipped with a thermometer and a stirring blade was set in a water bath, and 875 mL of ion-exchanged water was placed in the flask. Then, the temperature inside the flask was maintained at 30 ° C. using a water bath. Next, 75 mL of an anionic surfactant (“Latemuru (registered trademark) WX” manufactured by Kao Corporation, component: sodium polyoxyethylene alkyl ether sulfate, solid content concentration: 26% by mass) was placed in a flask. Then, after raising the internal temperature of the flask to 80 ° C. using a water bath, two kinds of liquids (first liquid and second liquid) were added dropwise into the flask over 5 hours, respectively. The first solution was a mixed solution of 17 mL of styrene, 1 mL of 2-hydroxyethyl methacrylate and 2 mL of n-butyl acrylate. The second solution was a solution in which 0.5 g of potassium persulfate was dissolved in 30 mL of ion-exchanged water. Subsequently, the flask contents were polymerized by stirring the flask contents at a rotation speed of 250 rpm for 2 hours while keeping the temperature inside the flask at 80 ° C. Next, 10 g of a colorant (“KET Blue111” manufactured by DIC Corporation, component: phthalocyanine blue) was placed in the flask, and then the contents of the flask were rotated at a rotation speed of 150 rpm for 2 hours while maintaining the temperature inside the flask at 80 ° C. Stirred. As a result, a suspension containing resin particles composed of a copolymer (resin for shell layer) of styrene, 2-hydroxyethyl methacrylate and n-butyl acrylate, and a colorant was obtained. The resin particles in the obtained suspension had an average primary particle diameter of 33 nm.

(Shell layer forming process)
A 3-necked flask having a capacity of 2 L equipped with a thermometer and a stirring blade was set in a water bath, and 300 mL of ion-exchanged water was placed in the flask. Then, the temperature inside the flask was maintained at 30 ° C. using a water bath. Subsequently, dilute hydrochloric acid was added to the flask to adjust the pH of the flask contents to 4. Subsequently, 150 mL of the suspension obtained in the above-mentioned shell raw material preparation step was placed in the flask. Subsequently, 300 g of the composite core CA-1 was placed in the flask, and the contents of the flask were stirred at a rotation speed of 200 rpm for 1 hour while keeping the temperature inside the flask at 30 ° C. Then, 300 mL of ion-exchanged water was placed in the flask. Subsequently, the temperature inside the flask was raised to 70 ° C. at a rate of 1 ° C./min while stirring the contents of the flask at a rotation speed of 100 rpm. Subsequently, the contents of the flask were stirred for 2 hours at a rotation speed of 100 rpm while maintaining the temperature inside the flask at 70 ° C. While the temperature inside the flask was kept at 70 ° C., a shell layer (a shell layer containing a resin for a shell layer and a colorant) was formed to cover the surface of the composite core CA-1. Next, sodium hydroxide was added into the flask to adjust the pH of the flask contents to 7, and then the flask contents were cooled until the temperature reached 25 ° C. to obtain a dispersion liquid containing toner matrix particles. ..

(Washing process)
Next, the obtained dispersion of toner matrix particles was filtered (solid-liquid separation) using a Büchner funnel to obtain wet cake-shaped toner matrix particles. Then, the obtained wet cake-like toner matrix particles were redispersed in ion-exchanged water and then filtered using a Büchner funnel. Further, redispersion and filtration were repeated 5 times to wash the toner matrix particles.

(Drying process)
Next, the washed toner matrix particles were dispersed in an aqueous ethanol solution having a concentration of 50% by mass. As a result, a slurry of toner mother particles was obtained. Subsequently, using a continuous surface modifier (“Coatmizer (registered trademark)” manufactured by Freund Sangyo Co., Ltd.), the toner matrix particles in the slurry were removed under the conditions of a hot air temperature of 45 ° C. and a blower air volume of 2 m ³ / min. It was dried. As a result, a powder of toner mother particles was obtained.

(External process)
100 parts by mass of the obtained toner mother particles and 1.0 part by mass of silica particles (“AEROSIL® REA90” manufactured by Nippon Aerosil Co., Ltd., silica particles imparted with positive charge by a surface treatment agent). Using an FM mixer (“FM-10B” manufactured by Nippon Coke Industries Co., Ltd.), mixing was performed under the conditions of a rotation speed of 3000 rpm and a jacket temperature of 20 ° C. for 5 minutes. As a result, the entire amount of the external additive (silica particle powder) was adhered to the surface of the toner mother particles.

Subsequently, the obtained powder was sieved using a 200 mesh (opening 75 μm) sieve. As a result, toner TA-1, which is a positively charged toner, was obtained. The composition ratio of the components constituting the toner did not change before and after sieving. In the obtained toner TA-1, the amount of the colorant was 5.00 parts by mass with respect to 100 parts by mass of the resin for the shell layer. Further, in the obtained toner TA-1, the amount of the colorant was 2.00 parts by mass with respect to 100 parts by mass of the binder resin (polyester resin) of the toner core.

[Preparation of toner TA-2]
Toner TA-2, which is a positively charged toner, was obtained by the same method as that for producing toner TA-1, except that the process for preparing the composite core and the process for preparing the shell raw material were changed as shown below. .. In the obtained toner TA-2, the amount of the colorant was 1.00 parts by mass with respect to 100 parts by mass of the resin for the shell layer. Further, in the obtained toner TA-2, the amount of the colorant was 0.03 parts by mass with respect to 100 parts by mass of the binder resin (polyester resin) of the toner core.

(Preparation step of composite core when producing toner TA-2)
30 g of toner core powder (sample) is placed on the sample table of a sputtering device (“JEC-3000FC” manufactured by JEOL Ltd.), and aluminum is used as a target under reduced pressure (pressure: 3 × 10 ^-4 Pa). ), Sputtering was performed for 450 seconds under the condition of an applied current of 60 mA. Then, the sample that had been sputtered for 450 seconds was once taken out from the sputtering apparatus and placed on the sample table of the sputtering apparatus again. Next, using aluminum as a target, sputtering was carried out under reduced pressure (pressure: 3 × 10 ^-4 Pa) under the condition of an applied current of 60 mA for 450 seconds. As a result, a composite core which is a composite of the toner core and a metal layer (aluminum layer) arranged on the surface of the toner core was obtained.

(Preparation process of shell raw material when producing toner TA-2)
A 2 L capacity three-necked flask equipped with a thermometer and a stirring blade was set in a water bath, and 875 mL of ion-exchanged water was placed in the flask. Then, the temperature inside the flask was maintained at 30 ° C. using a water bath. Next, 450 mL of an anionic surfactant (“Latemuru (registered trademark) WX” manufactured by Kao Corporation, component: sodium polyoxyethylene alkyl ether sulfate, solid content concentration: 26% by mass) was placed in a flask. Then, after raising the internal temperature of the flask to 80 ° C. using a water bath, two kinds of liquids (first liquid and second liquid) were added dropwise into the flask over 5 hours, respectively. The first solution was a mixed solution of 102 mL of styrene, 6 mL of 2-hydroxyethyl methacrylate and 12 mL of n-butyl acrylate. The second solution was a solution in which 3.0 g of potassium persulfate was dissolved in 180 mL of ion-exchanged water. Subsequently, the flask contents were polymerized by stirring the flask contents at a rotation speed of 250 rpm for 2 hours while keeping the temperature inside the flask at 80 ° C. Next, 10 g of a colorant (“KET Blue111” manufactured by DIC Corporation, component: phthalocyanine blue) was placed in the flask, and then the contents of the flask were rotated at a rotation speed of 250 rpm for 2 hours while maintaining the temperature inside the flask at 70 ° C. Stirred. As a result, a suspension containing resin particles composed of a copolymer (resin for shell layer) of styrene, 2-hydroxyethyl methacrylate and n-butyl acrylate, and a colorant was obtained. The resin particles in the obtained suspension had an average primary particle diameter of 150 nm.

[Manufacturing of toner TA-3]
Preparation of toner TA-1 except that the amount of colorant (“KET Blue111” manufactured by DIC Corporation, component: phthalocyanine blue) used (the amount placed in the flask) was changed to 1 g in the process of preparing the shell raw material. Toner TA-3, which is a positively charged toner, was obtained in the same manner as above. In the obtained toner TA-3, the amount of the colorant was 1.00 parts by mass with respect to 100 parts by mass of the resin for the shell layer. Further, in the obtained toner TA-3, the amount of the colorant was 0.20 parts by mass with respect to 100 parts by mass of the binder resin (polyester resin) of the toner core.

[Manufacturing of toner TA-4]
Preparation of toner TA-1 except that the amount of colorant (“KET Blue111” manufactured by DIC Corporation, component: phthalocyanine blue) used (the amount placed in the flask) was changed to 20 g in the process of preparing the shell raw material. Toner TA-4, which is a positively charged toner, was obtained in the same manner as above. In the obtained toner TA-4, the amount of the colorant was 10.00 parts by mass with respect to 100 parts by mass of the resin for the shell layer. Further, in the obtained toner TA-4, the amount of the colorant was 5.00 parts by mass with respect to 100 parts by mass of the binder resin (polyester resin) of the toner core.

[Preparation of toner TB-1]
Toner that is a positively charged toner by the same method as the preparation of toner TA-1, except that the toner core preparation process was changed as follows and no colorant was used in the shell raw material preparation process. TB-1 was obtained. In the obtained toner TB-1, the amount of the colorant was 2.00 parts by mass with respect to 100 parts by mass of the binder resin (polyester resin) of the toner core.

(Toner core preparation process when producing toner TB-1)
Using an FM mixer (“FM-20B” manufactured by Nippon Coke Industries Co., Ltd.), 750 g of low Tg polyester resin (Tg: 38 ° C, Tm: 65 ° C) and 100 g of medium Tg polyester under the condition of rotation speed of 2400 rpm. Resin (Tg: 53 ° C, Tm: 84 ° C), 150 g of high Tg polyester resin (Tg: 71 ° C, Tm: 120 ° C), and 55 g of mold release agent (Carnauba wax: Hiroyuki Kato Co., Ltd. "Carnauba" Wax No. 1 ") and 20 g of a colorant ("KET Blue111 "manufactured by DIC Corporation, component: phthalocyanine blue) were mixed for 3 minutes. Subsequently, the obtained mixture was melt-kneaded using a twin-screw extruder (“PCM-30” manufactured by Ikegai Corp.) under the conditions of a material supply speed of 5 kg / hour, a shaft rotation speed of 160 rpm, and a cylinder temperature of 120 ° C. .. Then, the obtained melt-kneaded product was cooled. Subsequently, the cooled melt-kneaded product was coarsely pulverized using a pulverizer (“Rotoplex®” manufactured by Hosokawa Micron Corporation). Subsequently, the obtained coarsely pulverized product was finely pulverized using a jet mill (“ultrasonic jet mill type I” manufactured by Nippon Pneumatic Industries Co., Ltd.). Subsequently, the obtained finely pulverized product was classified using a classifier (“Elbow Jet EJ-LABO type” manufactured by Nittetsu Mining Co., Ltd.) to obtain a toner core having a medium volume diameter (D ₅₀ ) of 6.0 μm. It was.

[Preparation of toner TB-2]
(Shell layer forming process)
A 3-necked flask having a capacity of 2 L equipped with a thermometer and a stirring blade was set in a water bath, and 300 mL of ion-exchanged water was placed in the flask. Then, the temperature inside the flask was maintained at 30 ° C. using a water bath. Subsequently, dilute hydrochloric acid was added to the flask to adjust the pH of the flask contents to 4. Subsequently, 150 mL of suspension was placed in the flask. The suspension placed in the flask was a suspension obtained under the same conditions as in the process of preparing the shell raw material when producing the toner TA-1. Subsequently, 300 g of a toner core was placed in the flask, and the contents of the flask were stirred at a rotation speed of 200 rpm for 1 hour while maintaining the temperature inside the flask at 30 ° C. The toner core placed in the flask was a toner core obtained under the same conditions as in the process of preparing the toner core when producing the toner TA-1. Then, 300 mL of ion-exchanged water was placed in the flask. Subsequently, the temperature inside the flask was raised to 70 ° C. at a rate of 1 ° C./min while stirring the contents of the flask at a rotation speed of 100 rpm. Subsequently, the contents of the flask were stirred for 2 hours at a rotation speed of 100 rpm while maintaining the temperature inside the flask at 70 ° C. While the temperature inside the flask was kept at 70 ° C., a shell layer (a shell layer containing a resin for a shell layer and a colorant) was formed to cover the surface of the toner core. Next, sodium hydroxide was added into the flask to adjust the pH of the flask contents to 7, and then the flask contents were cooled until the temperature reached 25 ° C., and a toner core covered with a shell layer (hereinafter referred to as “shell layer”) was cooled. A dispersion containing (described as a shell-coated toner core) was obtained.

(Washing process)
Next, the obtained dispersion of the shell-coated toner core was filtered (solid-liquid separation) using a Büchner funnel to obtain a wet cake-shaped shell-coated toner core. Then, the obtained wet cake-like shell-coated toner core was redispersed in ion-exchanged water and then filtered using a Büchner funnel. Further, redispersion and filtration were repeated 5 times to wash the shell-coated toner core.

(Drying process)
Next, the washed shell-coated toner core was dispersed in an aqueous ethanol solution having a concentration of 50% by mass. As a result, a slurry of shell-coated toner core was obtained. Subsequently, using a continuous surface modifier (“Coatmizer (registered trademark)” manufactured by Freund Sangyo Co., Ltd.), the shell-coated toner core in the slurry was subjected to the conditions of hot air temperature of 45 ° C. and blower air volume of 2 m ³ / min. It was dried. As a result, a powder of a shell-coated toner core was obtained.

(Metal layer forming process)
A metal layer (aluminum layer) was formed on the surface of the shell-coated toner core obtained as described above by using a sputtering device (“JEC-3000FC” manufactured by JEOL Ltd.). Specifically, 30 g of shell-coated toner core powder (sample) is placed on the sample table of the above sputtering apparatus, and aluminum is used as a target under reduced pressure (pressure: 3 × 10 ^-4 Pa), and the applied current is 20 mA. Sputtering was performed for 30 seconds under the conditions. Next, the sample that had been sputtered for 30 seconds was once taken out from the sputtering apparatus and placed on the sample table of the sputtering apparatus again. Next, using aluminum as a target, sputtering was performed for 30 seconds under a reduced pressure (pressure: 3 × 10 ^-4 Pa) under the condition of an applied current of 20 mA. As a result, a powder of toner matrix particles containing a shell-coated toner core and a metal layer (aluminum layer) arranged on the surface of the shell-coated toner core was obtained.

(External process)
100 parts by mass of the obtained toner mother particles and 1.0 part by mass of silica particles (“AEROSIL® REA90” manufactured by Nippon Aerosil Co., Ltd., silica particles imparted with positive charge by a surface treatment agent). Using an FM mixer (“FM-10B” manufactured by Nippon Coke Industries Co., Ltd.), mixing was performed under the conditions of a rotation speed of 3000 rpm and a jacket temperature of 20 ° C. for 5 minutes. As a result, the entire amount of the external additive (silica particle powder) was adhered to the surface of the toner mother particles.

Subsequently, the obtained powder was sieved using a 200 mesh (opening 75 μm) sieve. As a result, toner TB-2, which is a positively charged toner, was obtained. The composition ratio of the components constituting the toner did not change before and after sieving. In the obtained toner TB-2, the amount of the colorant was 5.00 parts by mass with respect to 100 parts by mass of the resin for the shell layer. Further, in the obtained toner TB-2, the amount of the colorant was 2.00 parts by mass with respect to 100 parts by mass of the binder resin (polyester resin) of the toner core.

<Measurement of metal layer thickness and shell layer thickness>
The toner to be measured (one of toners TA-1 to TA-4 and TB-1) was dispersed in a visible light curable resin ("Aronix (registered trademark) LCR D-800" manufactured by Toa Synthetic Co., Ltd.). After that, the resin was cured by irradiation with visible light to obtain a cured product. Subsequently, a cured product was cut out using an ultramicrotome equipped with a diamond knife (“EM UC6” manufactured by Leica Microsystems, Inc.) to obtain a flaky sample having a thickness of 150 nm. Subsequently, the cross section (cross section of the toner particles) of the obtained flaky sample was photographed at a magnification of 100,000 using a transmission electron microscope (TEM) (“H-7100FA” manufactured by Hitachi High-Technologies Corporation). Then, the thickness of the metal layer and the thickness of the shell layer were measured by analyzing the TEM photographed image using image analysis software (“WinROOF” manufactured by Mitani Corporation).

Regarding the measurement procedure, first, 10 toner particles contained in the measurement target (toner) were randomly selected from the obtained TEM image. Then, the thickness of the metal layer and the thickness of the shell layer were measured for each of the 10 selected toner particles, and the evaluation values (thickness of the metal layer and the thickness of the shell layer) of the toner to be measured were obtained. .. More specifically, for one toner particle (cross section), two straight lines orthogonal to each other at the substantially center of the cross section are drawn, and the thickness of the metal layer is determined at each of the four points where the two straight lines intersect the metal layer. It was measured. The arithmetic mean value of the measured thicknesses at the four points was taken as the thickness of the metal layer of the toner particles. The thickness of the metal layer was measured for each of the 10 selected toner particles, and the average number of the measured thicknesses was used as the evaluation value (thickness of the metal layer) of the toner to be measured. Similarly, for one toner particle (cross section), draw two straight lines orthogonal to each other at the substantially center of the cross section, and measure the thickness of the shell layer at each of the four points where the two straight lines intersect the shell layer. did. The arithmetic mean value of the measured thicknesses at the four points was taken as the thickness of the shell layer of the toner particles. The thickness of the shell layer was measured for each of the 10 selected toner particles, and the average number of the measured thicknesses was used as the evaluation value (thickness of the shell layer) of the toner to be measured.

<Measurement of metal coverage and shell coverage>
The toner to be measured (one of toners TA-1 to TA-4 and TB-1) was dispersed in a visible light curable resin ("Aronix (registered trademark) LCR D-800" manufactured by Toa Synthetic Co., Ltd.). After that, the resin was cured by irradiation with visible light to obtain a cured product. Subsequently, a cured product was cut out using an ultramicrotome equipped with a diamond knife (“EM UC6” manufactured by Leica Microsystems, Inc.) to obtain a flaky sample having a thickness of 150 nm. Subsequently, the cross section (cross section of the toner particles) of the obtained flaky sample was photographed at a magnification of 100,000 using a transmission electron microscope (TEM) (“H-7100FA” manufactured by Hitachi High-Technologies Corporation). Then, the metal coverage and the shell coverage were measured by analyzing the TEM photographed image using image analysis software (“WinROOF” manufactured by Mitani Corporation).

Regarding the measurement procedure, first, 10 toner particles contained in the measurement target (toner) were randomly selected from the obtained TEM image. Then, the metal coverage and the shell coverage were measured for each of the 10 selected toner particles, and the evaluation values (metal coverage and shell coverage) of the toner to be measured were obtained. More specifically, for one toner particle (cross section), the ratio of the region covered with the metal layer (metal coverage) to the surface region (contour line showing the outer edge) of the toner core was measured. The metal coverage was calculated based on the formula "metal coverage = 100 x (total length of the area covered by the metal layer in the surface region of the toner core) / (perimeter of the toner core)". The metal coverage of each of the 10 selected toner particles was measured, and the average number of measured metal coverages was used as the evaluation value (metal coverage) of the toner to be measured. Similarly, for one toner particle (cross section), the ratio of the region covered with the shell layer (shell coverage) to the surface region (contour line indicating the outer edge) of the composite core was measured. The shell coverage was calculated based on the formula "shell coverage = 100 x (total length of the area covered by the shell layer in the surface region of the composite core) / (perimeter of the composite core)". The shell coverage was measured for each of the 10 selected toner particles, and the average number of measured shell coverage was used as the evaluation value (shell coverage) of the toner to be measured.

Table 1 shows the thickness of the metal layer, the thickness of the shell layer, the metal coating ratio, and the shell coating ratio for each of the toners TA-1 to TA-4 and TB-1.

<Evaluation method>
Hereinafter, the evaluation method of the toners TA-1 to TA-4, TB-1 and TB-2 will be described.

[Preparation of two-component developer]
A shaker mixer contains 100 parts by mass of a carrier for "TASKalfa5550ci" manufactured by Kyocera Document Solutions Co., Ltd. and 8 parts by mass of toner (toner TA-1 to TA-4, TB-1 or TB-2) used for evaluation. ("Tubler (registered trademark) mixer T2F" manufactured by Willy et Bacoffen (WAB)) was mixed for 30 minutes to prepare a two-component developer to be used for evaluation.

[Printing of evaluation image]
An evaluation image was printed using a color multifunction device (“TASKalfa5550ci” manufactured by Kyocera Document Solutions Co., Ltd.). Specifically, the two-component developer prepared as described above is put into the cyan developing apparatus of the color multifunction device, and the replenishing toner (evaluation target: toners TA-1 to TA-4, TB-1 and TB-) is charged. Any one of 2) was put into the cyan toner container of the above color multifunction device. Next, in an environment of a temperature of 23 ° C. and a humidity of 50% RH, using the above-mentioned color multifunction device, one evaluation sheet (Mondy's "ColorCopy (registered trademark)", A4 size, basis weight 90 g / m ² ) was used. A solid image having a size of 5 cm × 5 cm and a pattern image having a length of 5 cm and a line width of 0.35 mm were printed to obtain an evaluation image.

[Judgment of evaluation image]
The obtained evaluation image was visually observed, and the white spots and uneven color, metallic luster, vividness of color, and printability of fine lines were judged according to the criteria shown below.

(White spots and uneven color)
White spots and uneven color were judged according to the following criteria. When the judgment was A, B or C, it was evaluated as "good", and when the judgment was D, it was evaluated as "not good".
A: In the solid image, the total of the white spots and the color unevenness was 4 or less.
B: In the solid image, the total of the white spots and the uneven color was 5 or more and 9 or less.
C: In the solid image, the total of the white spots and the color unevenness was 10 or more and 19 or less.
D: In the solid image, the total of the white spots and the color unevenness was 20 or more.

(Metallic luster)
The metallic luster was judged according to the following criteria. When the judgment was A, it was evaluated that "an image having excellent metallic luster could be formed", and when the judgment was B, it was evaluated as "an image having excellent metallic luster could not be formed".
A: The image had a metallic luster.
B: The image had no metallic luster.

(Color vividness)
The vividness of the color was judged according to the following criteria. When the judgment was A or B, it was evaluated as "a clear color image could be formed", and when the judgment was C, it was evaluated as "a clear color image could not be formed".
A: It was an image in which the vividness of colors was strongly felt.
B: It was an image in which the vividness of color was felt.
C: It was an image in which the vividness of color was not felt.

(Printability of thin lines)
The printability of thin lines was judged according to the following criteria. When the judgment was A, B or C, it was evaluated as "good", and when the judgment was D, it was evaluated as "not good".
A: The thin lines were printed with the same thickness.
B: The thin lines were printed, but the width of the printed thin lines was non-uniform.
C: The printed thin line had breaks, and the number of breaks was 4 or less.
D: The printed thin line had breaks, and the number of breaks was 5 or more.

For each of the toners TA-1 to TA-4, TB-1 and TB-2, the judgment result of white spots and color unevenness, the judgment result of metallic luster, the judgment result of color vividness, and the printability of fine lines The determination result of is shown in Table 2.

In the toners TA-1 to TA-4, the toner particles provided a composite core and a shell layer covering the surface of the composite core. In the toners TA-1 to TA-4, the composite core was a composite of a toner core containing a binder resin and a metal layer arranged on the surface of the toner core. In the toners TA-1 to TA-4, the shell layer contained a resin for the shell layer and a colorant.

As shown in Table 2, for the toners TA-1 to TA-4, the determination result of metallic luster was A. For the toners TA-1 to TA-4, the determination result of color vividness was A or B.

In toner TB-1, the shell layer did not contain a colorant. In the toner TB-2, the shell layer contained a colorant, but the shell layer was covered with a metal layer.

As shown in Table 2, for the toners TB-1 and TB-2, the color vividness determination result was C.

From the above results, it was shown that according to the present invention, an image having excellent metallic luster and a clear color can be formed.

The toner according to the present invention can be used for forming an image in, for example, a multifunction device or a printer.

10: Toner particles 11: Composite core 12: Shell layer 13: Toner core 14: Metal layer

Claims (7)

Toner containing toner particles
The toner particles include a composite core and a shell layer covering the surface of the composite core.
The composite core is a composite of a toner core containing a binder resin and a metal layer arranged on the surface of the toner core.
The shell layer is a toner containing a resin for the shell layer and a colorant. The toner according to claim 1, wherein the thickness of the metal layer is 3 nm or more and 1000 nm or less. The toner according to claim 1 or 2, wherein the thickness of the shell layer is 1 nm or more and 30 nm or less. The toner according to any one of claims 1 to 3, wherein the area ratio of the region covered by the shell layer in the surface region of the composite core is 80% or more and 100% or less. The toner according to any one of claims 1 to 4, wherein the amount of the colorant is 1.00 parts by mass or more and 10.00 parts by mass or less with respect to 100 parts by mass of the resin for the shell layer. The toner according to any one of claims 1 to 5, wherein the amount of the colorant is 0.01 part by mass or more and 5.00 parts by mass or less with respect to 100 parts by mass of the binder resin. The metal layer according to any one of claims 1 to 6, wherein the metal layer contains one or more metals selected from the group consisting of aluminum, nickel, titanium, chromium, zinc, copper, silver, gold, platinum and stainless steel. The described toner.

Images