JP2013020174A - Positively chargeable toner, electrostatic charge image developer, toner cartridge, image forming method and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positively chargeable toner excellent in uniformity of image density.SOLUTION: The positively chargeable toner comprises toner base particles containing a binder resin, a colorant and a release agent, and an external additive. The binder resin includes a crystalline polyester resin and a non-crystalline polyester resin. The external additive includes two or more types of silica particles; the two or more types of silica particles include silica particles A, which are surface-treated with a silane coupling agent containing an amino group and which have a number average primary particle diameter of 5 nm or more and 15 nm or less, and silica particles B, which are surface-treated with silicone oil and which have a number average primary particle diameter of 5 nm or more and 15 nm or less. When the contents of the crystalline polyester resin, the silica particles A and the silica particles B are denoted by wp, wA and wB, respectively, wA/wB is 0.5 or more and 8.0 or less and wB/wp is 0.005 or more and 0.100 or less.

Description

  The present invention relates to a positively chargeable toner, an electrostatic charge image developer, a toner cartridge, an image forming method, and an image forming apparatus.

As an image forming apparatus using an electrophotographic method, the use in an on-demand printing area is expanding from the use in a conventional office, and a high-speed color machine with high image quality and high reliability is demanded. From the viewpoint of low energy fixing, a toner using a crystalline resin has been proposed, but the externally added structure changes due to the partial compatibility of the crystalline resin and the amorphous resin and plasticization. Cheap.
As an external addition design, it has been proposed to use a positively charged external additive and a negatively charged external additive. For example, Patent Document 1 selects an aminosilane coupling agent and an aminosilicone oil as the external additive. The first inorganic fine particles having a number average particle size in the range of 0.1 to 3 μm surface-treated with at least one kind of surface treatment agent, and the average primary particle size subjected to the hydrophobization treatment is 0.005 to 0.005. A toner containing second inorganic fine particles in the range of 02 μm is disclosed.
Further, Patent Document 2 discloses silica A having a specific surface area of 30 to 70 m ² / g and surface treated with aminosilane, silica B and silicone having a specific surface area of 100 m ² / g or more and surface treated with silicone oil. A non-magnetic one-component toner is disclosed which is characterized by having oil attached thereto.
Patent Document 3 discloses a non-magnetic one-component full-color toner characterized in that the external additive contains inorganic fine particles that are positively charged when frictionally charged with iron powder and inorganic fine particles that are negatively charged. Has been.
Patent Document 4 discloses a toner comprising a toner base containing a specific crystalline polyester and an inorganic fine powder having a specific particle size, loss on ignition, and loss on drying.

Japanese Patent Laid-Open No. 10-48888 JP 2002-148851 A Japanese Patent Laid-Open No. 10-171155 JP 2005-10454 A

  An object of the present invention is to provide a positively chargeable toner excellent in image density uniformity.

The above-mentioned problems of the present invention have been solved by means described in the following <1>, <2>, <4>, <5> and <8>. The preferred embodiments are shown below together with <3>, <6>, <7>, <9>, and <10>.
<1> A toner base particle containing a binder resin, a colorant, and a release agent, and an external additive, wherein the binder resin includes a crystalline polyester resin and an amorphous polyester resin. The external additive includes two or more types of silica particles, and the two or more types of silica particles have a number average primary particle size of 5 nm or more and 15 nm or less that is surface-treated with a silane coupling agent having an amino group. Including silica particles A and silica particles B having a number average primary particle size of 5 nm or more and 15 nm or less that are surface-treated with silicone oil, the content of the crystalline polyester resin is wp, and the content of the silica particles A is wA, where the content of the silica particles B is wB, wA / wB is 0.5 or more and 8.0 or less, and wB / wp is 0.005 or more and 0.100 or less. Chargeable toner,
<2> an electrostatic charge image developer comprising the positively chargeable toner according to the above <1> and a carrier,
<3> The electrostatic charge image developer according to the above <2>, wherein the carrier is a resin-coated carrier having a core material and a coating resin layer containing a conductive material and a crosslinkable resin on the surface of the core material.
<4> The positive charge according to <1> described above, which is detachable from an image forming apparatus including at least a developing unit that develops an electrostatic charge image to form a toner image, and serves as toner to be supplied to the developing unit. Toner cartridges that contain functional toner,
<5> A latent image forming step of forming an electrostatic latent image on the surface of the image holding member, and the electrostatic latent image formed on the surface of the image holding member with the developer containing the positively chargeable toner according to <1>. An image forming method comprising at least a developing step of developing and forming a toner image, a transferring step of transferring the toner image to the surface of the transfer target, and a fixing step of fixing the toner image transferred to the surface of the transfer target ,
<6> The image forming method according to <5>, wherein the surface of the image carrier is amorphous silicon,
<7> In the developing step, the developer image having a peripheral speed of 1,000 mm / s or more is rubbed against the surface of the image carrier to develop the electrostatic image with the positively charged toner < Image forming method according to 5> or <6>,
<8> An image carrier, an electrostatic image forming means for forming an electrostatic image on the surface of the image carrier, and developing the electrostatic image with a developer containing the positively chargeable toner according to <1>. An image forming apparatus including at least a developing unit that forms a toner image, a transfer unit that transfers the toner image to the surface of the transfer target, and a fixing unit that fixes the toner image transferred to the surface of the transfer target. ,
<9> The image forming apparatus according to <8>, wherein the surface of the image carrier is amorphous silicon.
<10> The developing unit includes a developer holding body having a peripheral speed of 1,000 mm / s or more, and the developer holding body is rubbed against the surface of the image holding body to display the electrostatic image. The image forming apparatus according to <8> or <9>, wherein development is performed with the positively chargeable toner.

According to the invention described in <1> above, it is possible to provide a positively chargeable toner that is superior in image density uniformity as compared with the case where this configuration is not provided.
According to the invention described in the above <2>, it is possible to provide an electrostatic charge image developer that is excellent in image density uniformity as compared with the case where this configuration is not provided.
According to the invention described in <3> above, the carrier is not a resin-coated carrier having a core material and a coating resin layer containing a conductive material and a crosslinkable resin on the surface of the core material. An electrostatic charge image developer that is superior in image density uniformity can be provided.
According to the invention described in <4> above, it is possible to provide a toner cartridge having excellent image density uniformity as compared with the case where the present configuration is not provided.
According to the invention described in <5>, it is possible to provide an image forming method that is superior in image density uniformity as compared with the case where the present configuration is not provided.
According to the invention described in <6>, it is possible to provide an image forming method that is excellent in image density uniformity even when the surface of the image carrier is amorphous silicon that is difficult to maintain image density uniformity. it can.
According to the invention described in <7> above, development is performed by rubbing a developer holding body having a peripheral speed of 1,000 mm / s or more against the surface of the image holding body, which makes it difficult to maintain uniform image density. Even when it is performed, an image forming method having excellent image density uniformity can be provided.
According to the invention described in <8> above, it is possible to provide an image forming apparatus that is excellent in image density uniformity as compared with the case where the present configuration is not provided.
According to the invention described in <9>, it is possible to provide an image forming method excellent in image density uniformity even when the surface of the image carrier is amorphous silicon which is difficult to maintain image density uniformity. it can.
According to the invention described in <10> above, development is performed by rubbing a developer holder having a peripheral speed of 1,000 mm / s or more against the surface of the image holder, which makes it difficult to maintain uniform image density. Even when it is performed, an image forming method having excellent image density uniformity can be provided.

Hereinafter, this embodiment will be described in detail.
In the present embodiment, the description “A to B” represents not only a range between A and B but also a range including A and B at both ends thereof. For example, if “A to B” is a numerical value range, “A or more and B or less” or “B or more and A or less” is represented according to the magnitude of the numerical value.

(Positively chargeable toner)
The positively chargeable toner (hereinafter, also simply referred to as “toner”) of the present embodiment includes toner base particles containing a binder resin, a colorant, and a release agent, and an external additive. The binder resin includes a crystalline polyester resin and an amorphous polyester resin, the external additive includes two or more types of silica particles, and the two or more types of silica particles include an amino group. The number average primary particle size surface-treated with the agent is 5 nm or more and 15 nm or less, and the number average primary particle size surface-treated with silicone oil is 5 nm or more and 15 nm or less silica particles B, When the content of the crystalline polyester resin is wp, the content of the silica particles A is wA, and the content of the silica particles B is wB, wA / wB is 0.5 or more and 8.0 or less, wB wp is characterized in that from 0.005 to 0.100.

Conventionally, from the viewpoint of low-temperature fixing, a toner containing a crystalline polyester resin as a part of a binder resin has been proposed. However, it has been found that when a crystalline polyester resin-containing toner is combined with an amorphous silicon photoreceptor as a positively charged toner, a phenomenon occurs in which the image density becomes nonuniform in the print surface. In particular, it has been found that this phenomenon in which the image density becomes non-uniform is likely to occur remarkably after continuously printing a large number of images with a low printing rate.
As a result of diligent studies on the subject, the present inventors changed the uniformity of image density by adding two types of silica particles and considering the content of the crystalline polyester resin in the toner base particles. As a result, the present invention has been found. Although the mechanism is not necessarily clear, it is assumed that the following mechanism is acting.

  First, in a toner surface-treated with a silane coupling agent having an amino group for imparting positive charge and externally added with silica particles, the silica particles are almost uniform in the toner particles when there is no toner deterioration. It is attached with. However, the crystalline polyester resin and the amorphous polyester resin are partially compatible and plasticized due to stress caused by agitation in the developing machine, so that the silica surface is easily embedded in the toner surface, and is difficult to be embedded. Due to the presence of the place, the embedded state of the external additive becomes non-uniform. When the unevenly deteriorated toner is developed as described above, the adhesion between the toner particles and the photoreceptor tends to vary. For this reason, when the photosensitive member is cleaned with a cleaning blade, the drum surface wear tends to become non-uniform according to the non-uniformity of the adhesion force of the toner, and the difference in the surface of the photosensitive member can be made to a minute surface roughness. Therefore, the toner / photoreceptor adhesion non-uniformity due to the non-uniformity of the external additive structure of the toner and the non-uniformity of the toner / photoreceptor adherence due to the non-uniformity of the drum surface property are combined to improve the toner transferability. The present inventors have found that the image density becomes non-uniform as a result and the image density uniformity in the print surface deteriorates.

  On the other hand, when at least two types of silica particles, silica particles A surface-treated with an amino group-containing silane coupling agent and silica particles B surface-treated with silicone oil, are contained, It is considered that the silica particles B are present in a state of being attached to a part of the secondary aggregate. When stress is applied to the toner particles, the silicone oil-treated silica particles B first move to the carrier surface. On the other hand, among the silica particles A, particles present in the vicinity of the crystalline polyester resin are easily embedded in the toner, and the presence state of the silica particles A on the toner surface becomes non-uniform. However, when the carrier to which the silica particles B adhere and the toner come into contact, the silicone oil component on the surface of the silica particles B adheres to the toner again, and the toner is developed. At this time, the adhesion force between the toner and the photosensitive member (image holding member) is dominated by silicone oil as compared to the externally added state of the toner, and as a result, the adhesion force between the photosensitive member and the toner becomes substantially uniform. Furthermore, when the silica particles B are excessively attached to the carrier surface, the silica particles A and the silica particles B that are not buried are electrostatically attached, so that the excessive silica particles B are again attached to the toner. Thus, since the amount of silica particles B adhering to the carrier is kept below a certain level, the silicone oil can be stably applied to the toner without affecting the chargeability. For this reason, it is considered that the adhesive force between the toner and the photoreceptor is kept uniform regardless of the deterioration state of the toner, and stable image density uniformity can be obtained.

<External additive>
The positively chargeable toner according to the exemplary embodiment includes toner base particles and an external additive, and the external additive includes two or more types of silica particles.
In addition, the two or more types of silica particles are the number of surface-treated silica particles A having a number average primary particle size of 5 to 15 nm and surface-treated with a silane coupling agent containing an amino group and silicone oil. Silica particles B having an average primary particle diameter of 5 nm to 15 nm, the content of the crystalline polyester resin in the toner base particles is wp, the content of the silica particles A is wA, and the content of the silica particles B Is wB / wB is 0.5 or more and 8.0 or less, and wB / wp is 0.005 or more and 0.100 or less.

The positively chargeable toner of the present embodiment includes the silica particles A and the silica particles B as external additives, and when the content of the silica particles A in the toner is wA and the content of the silica particles B is wB, It is 0.5 <= wA / wB <= 8.0, it is preferable that it is 0.7 <= wA / wB <= 7.0, and it is more preferable that it is 1.0 <= wA / wB <= 6.0.
When the amount is within the above range, the amount of silica particles B attached to the carrier is moderate, the chargeability is stable, the occurrence of image defects such as density unevenness is suppressed, and the adhesive force change due to embedding of silica particles A Is sufficiently obtained, and the image density uniformity is excellent.

Further, the positively chargeable toner of the present embodiment includes the silica particles B as external additives, the toner base particles include a crystalline polyester resin, the content of the silica particles B in the toner is wB, When the content of the polyester resin is wp, 0.005 ≦ wB / wp ≦ 0.100, preferably 0.010 ≦ wB / wp ≦ 0.080, and 0.015 ≦ wB / wp ≦ More preferably, it is 0.070.
Within the above range, the adhesion of the silicone oil derived from the silica particles B to the carrier is more dominant than the embedding of the external additive in the portion where the crystalline polyester resin is present on the surface of the toner base particles, and the toner adhesion is reduced. Uniformity is maintained, stable image density uniformity is obtained, the adhesion between the silica particles B and the toner base particles is sufficient, the amount of the silica particles B adhering to the carrier is moderate, and the chargeability is stable. The occurrence of image defects such as density unevenness is suppressed.

[Silica particle A]
The silica particle A in this embodiment is a silica particle surface-treated with a silane coupling agent having an amino group. Since the silica particles A have an amino group and are positively charged, it is presumed that the toner of this embodiment contributes to the positive chargeability.
The silane coupling agent having an amino group in the silica particle A may be physically attached to the surface of the silica particle A or chemically bonded thereto, but may be chemically bonded to the surface of the silica particle A. Bonding is preferred.
As the silane coupling agent having an amino group, known ones are used. Specifically, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyl Examples include trimethoxysilane.
In addition, in the silica particle A, in addition to the surface treatment with a silane coupling agent having an amino group, a silane coupling agent having no amino group may be used in combination.
Examples of silane coupling agents having no amino group include methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, ethyltrimethoxysilane, and propyl. Trimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, butyltrimethoxy Silane, butyltriethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimeth Sisilane, decyltrimethoxysilane, hexadecyltrimethoxysilane, trimethyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N-bis (trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyl Trichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxy Silane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane Trifluoropropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, hepadecafluorodecyltrimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, Decafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, heptadecafluoro-1,1,2,2-tetrahydrodecyltriethoxysilane, 3- Fluorine silane compounds such as heptafluoroisopropoxypropyltriethoxysilane can be used.
The number average primary particle size of the silica particles A is 5 nm to 15 nm, preferably 7 nm to 14 nm, and more preferably 10 nm to 13 nm. Within the above range, there is little embedding in the toner mother particles, and adhesion force control between the photoconductor / toner is easy.
Further, the content wA of the silica particles A is preferably 0.1 to 3.0 parts by weight, more preferably 0.2 to 2.5 parts by weight, and more preferably 0.3 to 3.0 parts by weight with respect to 100 parts by weight of the toner base particles. 2.0 parts by weight is more preferable. Within the above range, the adhesion force between the toner and the photoconductor is kept uniform, the transferability is excellent, the occurrence of density unevenness is suppressed, and the image density uniformity is excellent.

[Silica particle B]
Silica particles B in the present embodiment are silica particles that have been surface-treated with silicone oil.
The silicone oil in the silica particles B may be physically attached to the surface of the silica particles B or may be chemically bonded.
Known silicone oils are used, and specific examples include dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, cyclic dimethyl silicone oil, epoxy modified silicone oil, carboxyl modified silicone oil, Examples include diol-modified silicone oil, methacryl-modified silicone oil, mercapto-modified silicone oil, polyether-modified silicone oil, methylstyryl-modified silicone oil, alkyl-modified silicone oil, amino-modified silicone oil, and fluorine-modified silicone oil.
The number average primary particle size of the silica particles B is 5 nm to 15 nm, preferably 7 nm to 14 nm, and more preferably 10 nm to 13 nm. Within the above range, the silica particles B can be easily transferred to the carrier, and since the silicone oil is stably applied to the toner, the toner adhesion can be easily controlled and the image quality is excellent.
Further, the heat loss when the silica particles B are heated to 600 ° C. is preferably 4% by weight to 20% by weight, more preferably 5% by weight to 18% by weight, and more preferably 6% by weight or more. More preferably, it is 15% by weight or less. Within the above range, an appropriate amount of silicone oil adheres to the toner surface, and the adhesion force between the toner and the photoreceptor can be easily controlled.
The thermal loss can be determined as a decrease in weight when the temperature is raised from room temperature to 1,000 ° C. at 30 ° C./min with a thermogravimetric measuring device (TGA).
The content wB of the silica particles B is preferably 0.02 to 2.0 parts by weight, more preferably 0.04 to 1.5 parts by weight, and more preferably 0.06 to 1.5 parts by weight with respect to 100 parts by weight of the toner base particles. 1.0 part by weight is more preferable. Within the above range, the effect of suppressing the adhesive force change is sufficiently obtained, the image density uniformity is excellent, the carrier adhesion amount of the silica particles B is moderate, the charging property is stable, and the density unevenness image or the like. The occurrence of defects is suppressed.

In the toner of the exemplary embodiment, known inorganic particles or organic particles may be used in combination with the silica particles A and the silica particles B as an external additive.
Examples of inorganic particles include silica powder, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide. Cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like.
Examples of organic particles include vinyl polymers such as styrene polymers, (meth) acrylic polymers, and ethylene polymers, and various types of heavy polymers such as ester, melamine, amide, and allyl phthalate. Examples thereof include fluorine-based polymers such as polymers, vinylidene fluoride, metal salts of higher fatty acids represented by zinc stearate, and organic particles composed of higher alcohols.
The external additive can be further externally added by mixing it with a desired additive as required, using a mixer such as a Henschel mixer.

<Toner base particles>
The positively chargeable toner according to the exemplary embodiment includes toner base particles containing at least a binder resin, a colorant, and a release agent, and an external additive, and the binder resin includes a crystalline polyester resin. And an amorphous polyester resin.
Hereinafter, each component in the toner base particles will be described in detail.

(Crystalline polyester)
The positively chargeable toner of this embodiment includes a crystalline polyester resin as a binder resin on the toner base particles.
The “crystalline polyester resin” refers to a resin having a clear endothermic peak in differential scanning calorimetry (DSC). “Crystallinity” in the resin used in the present embodiment refers to having a clear endothermic peak in differential scanning calorimetry (DSC), specifically, when measured at a heating rate of 10 ° C./min. This means that the half-value width of the endothermic peak is within 6 ° C. On the other hand, a resin in which the half-value width of the endothermic peak exceeds 6 ° C. or a resin in which no clear endothermic peak is observed means that it is amorphous.
The crystalline polyester resin is preferably synthesized from an acid (preferably dicarboxylic acid) component and an alcohol (preferably diol) component. In the present embodiment, a copolymer obtained by copolymerizing other components at a ratio of 50% by weight or less with respect to the main chain of the crystalline polyester resin is also referred to as a crystalline polyester resin.

  The acid (dicarboxylic acid) component preferably contains an aliphatic dicarboxylic acid. For example, succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,10-undecanedicarboxylic acid Acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc. 1-8) alkyl esters and acid anhydrides. Further, it may contain a dicarboxylic acid component having a heavy bond such as fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid.

  On the other hand, the alcohol (diol) component preferably contains an aliphatic diol. For example, 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, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20 -Eicosanediol and the like may be mentioned, but not limited thereto.

  The content wp of the crystalline polyester resin with respect to the toner base particles is preferably 2% by weight to 40% by weight, more preferably 3% by weight to 30% by weight, and further preferably 4% by weight to 25% by weight. If it is in the above range, sufficient low-temperature fixability is obtained, plasticization due to the compatibility of the crystalline polyester resin with the amorphous polyester resin is suppressed, the externally added structure is easily maintained, and the image density Excellent uniformity.

[Amorphous polyester resin]
As the amorphous (also referred to as “amorphous” or “amorphous”) polyester resin, a known amorphous polyester resin can be used. The amorphous polyester resin is also preferably synthesized from an acid component and an alcohol component, similarly to the crystalline polyester resin.
As the acid component, various known polycarboxylic acids used for the synthesis of an amorphous polyester resin can be used. For example, various dicarboxylic acids mentioned for the crystalline polyester resin as the divalent carboxylic acid can be used in the same manner, and in addition, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, etc., dodecenyl succinate Succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, such as acid and octyl succinic acid, anhydrides of these acids, and alkyls of these acids (1 to 8 carbon atoms) Esters are preferably used.
Trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5-hexanetricarboxylic acid, 1,2,7,8-octanetetracarboxylic acid or acid anhydrides or lower alkyl esters thereof may be used. These may be used individually by 1 type and may use 2 or more types together.
As the alcohol component, various known polyols used for the synthesis of an amorphous polyester resin can be used. For example, in addition to the aliphatic diols mentioned for the crystalline polyester resin, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2 -Bisphenol A alkylene (carbon number 2 or 3) oxide (average addition mole number 1-10) adduct, hydrogenated bisphenol A, etc., such as bis (4-hydroxyphenyl) propane, can be used. Further, as trihydric or higher alcohols, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1 , 2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and other aliphatic polyhydric alcohols having 3 to 20 carbon atoms, Examples include aromatic polyhydric alcohols having 6 to 20 carbon atoms such as 1,3,5-trihydroxylmethylbenzene, and alkylene oxide adducts thereof. These may be used individually by 1 type and may use 2 or more types together.

The endothermic peak temperature of the crystalline polyester resin is preferably 50 to 120 ° C, and more preferably 55 to 100 ° C. When the endothermic peak temperature is 50 ° C. or higher, the cohesive force of the binder resin itself is good even in a high temperature range, the peelability during fixing is excellent, and hot offset can be suppressed. Further, when the endothermic peak temperature is 120 ° C. or lower, sufficient melting can be obtained and the minimum fixing temperature can be lowered.
The glass transition temperature Tg of the amorphous polyester resin is preferably 40 to 80 ° C, and more preferably 50 to 65 ° C. When Tg is 40 ° C. or higher, the cohesive force of the binder resin itself is maintained even in a high temperature range, and hot offset can be suppressed during fixing. Further, when Tg is 80 ° C. or lower, sufficient melting can be obtained, and the minimum fixing temperature can be lowered.

Here, for measuring the endothermic peak temperature of the crystalline resin, a differential scanning calorimeter (DSC) was used to measure JIS when measured from room temperature (20 ° C.) to 150 ° C. at a rate of temperature increase of 10 ° C. per minute. It can be determined as the melting peak temperature of the input compensation differential scanning calorimetry shown in K-7121. Although the crystalline resin may show a plurality of melting peaks, in the present invention, the maximum peak is regarded as the melting point.
Moreover, the glass transition temperature of an amorphous resin means the value measured by the method (DSC method) prescribed | regulated to ASTMD3418-82.

  Moreover, it is preferable that the weight average molecular weights of the polyester resin used for this invention are 4,000-100,000, and it is more preferable that it is 6,000-80,000. When the weight average molecular weight is 4,000 or more, a good cohesive force can be obtained as a binder resin, and the hot offset property is excellent. Further, when the weight average molecular weight is 100,000 or less, good hot offset property and a suitable minimum fixing temperature can be obtained.

  In addition to polyester resins, binder resins include copolymers of styrene and acrylic acid or methacrylic acid, polyvinyl chloride resins, phenol resins, acrylic resins, methacrylic resins, polyvinyl acetate, silicone resins, polyurethane resins, polyamides Resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone indene resins, petroleum resins, polyether polyol resins, and the like can be used in combination.

  Further, the content of the binder resin in the toner base particles in the toner of the exemplary embodiment is not particularly limited, but is preferably 30 to 99% by weight with respect to the total weight of the toner base particles, and 40 to 40%. It is more preferably 98% by weight, and still more preferably 50 to 96% by weight. Within the above range, the fixing property, storage property, powder property, charging property and the like are excellent.

[Colorant]
The positively chargeable toner of the present embodiment contains a colorant in the toner base particles.
As the colorant, known ones can be used, and may be arbitrarily selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner.
For example, in a cyan toner, as the colorant, for example, C.I. I. Pigment Blue 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 13, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 17, 23, 60, 65, 73, 83, 180, C.I. I. Vat cyan 1, 3 and 20, etc., bitumen, cobalt blue, alkali blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, first sky blue, indanthrene blue BC cyan pigment, C.I. I. Cyan dyes such as solvent cyan 79 and 162 are used.
In the magenta toner, as the colorant, for example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 70, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90 112, 114, 122, 123, 163, 184, 185, 202, 206, 207, 209, 238, etc., pigment violet 19 magenta pigments, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 30, 49, 81, 82, 83, 84, 100, 109, 121, C . I. Disper thread 9, C.I. I. Basic Red 1, 2, 9, 9, 13, 14, 15, 17, 17, 18, 22, 23, 24, 27, 29, 32, 34, the same 35, 36, 37, 38, 39, 40, etc. Magenta dyes, etc., Bengala, Cadmium Red, Lead Tan, Mercury Sulfide, Cadmium, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red, Calcium Salt, lake red D, brilliant carmine 6B, eosin lake, rotamin lake B, alizarin lake, brilliant carmine 3B and the like are used.
In the yellow toner, as the colorant, for example, C.I. I. Pigment Yellow 2, 3, 15, 15, 17, 74, 93, 97, 128, 155, 180, 185, 139, and the like are used.
In the black toner, as the colorant, for example, carbon black, activated carbon, titanium black, magnetic powder, Mn-containing nonmagnetic powder, or the like is used. Further, black toner may be obtained by mixing yellow, magenta, cyan, red, green, and blue pigments.

  The amount of the colorant used is preferably 0.1 to 20 parts by weight and more preferably 0.5 to 15 parts by weight with respect to 100 parts by weight of the toner base particles. Moreover, as a coloring agent, these pigments, dyes, etc. can be used individually by 1 type, or 2 or more types can be used together.

〔Release agent〕
The positively chargeable toner of the present embodiment contains a release agent in the toner base particles.
Specific examples of the release agent include, for example, ester wax, polyethylene, polypropylene or a copolymer of polyethylene and polypropylene, polyglycerin wax, microcrystalline wax, paraffin wax, carnauba wax, sazol wax, montanic acid ester wax, Acid carnauba wax, palmitic acid, stearic acid, montanic acid, blandic acid, eleostearic acid, valinalic acid and other unsaturated fatty acids, stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, ceryl alcohol, melyl alcohol, Alternatively, saturated alcohols such as long-chain alkyl alcohols having a long-chain alkyl group; polyhydric alcohols such as sorbitol; linoleic acid amide, oleic acid alcohol Fatty acid amides such as methylenebisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide, ethylene bisoleic acid amide, hexamethylene Unsaturated fatty acid amides such as bisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, N′-distearyl Aromatic bisamides such as isophthalamide; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (generally called metal soaps); aliphatic hydrocarbon waxes with styrene and acrylic Acid Waxes grafted with vinyl monomers of the above; partial esterified products of fatty acids such as behenic monoglyceride and polyhydric alcohols; methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable oils and the like .
The release agent is preferably contained in the range of 1 to 20% by weight and more preferably in the range of 3 to 15% by weight with respect to 100% by weight of the binder resin. Within the above range, both good fixing and image quality characteristics can be achieved.

(Charge control agent)
The positively chargeable toner of the present exemplary embodiment may contain a charge control agent as necessary.
There is no restriction | limiting in particular as said charge control agent, According to the objective, a well-known thing can be used. For example, nigrosine dyes, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts that are analogs thereof, and these Lake pigments; triphenylmethane dyes; higher fatty acid metal salts; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate; guanidine compounds, imidazole compounds, aminoacrylic compounds Resin etc. are mentioned.
These charge control agents may be used alone or in combination of two or more.

[Infrared absorber]
The toner base particles in the toner of the present embodiment preferably contain an infrared absorber when used in an image forming method or apparatus using a photofixing method.
As the infrared absorber used in the present embodiment, a known infrared absorber can be used. For example, a cyanine compound, a merocyanine compound, a benzenethiol metal complex, a mercaptophenol metal complex, an aromatic diamine metal complex, Diimonium compounds, aminium compounds, nickel complex compounds, phthalocyanine compounds, anthraquinone compounds, naphthalocyanine compounds, and the like can be used.
Among the colorants described above, those having absorption in the infrared region such as carbon black are also used as infrared absorbers.

  Specific infrared absorbers include nickel metal complex infrared absorbers (Mitsui Chemical Co., Ltd .: SIR-130, SIR-132), bis (dithiobenzyl) nickel (Midori Chemical Co., Ltd .: MIR-101). ), Bis [1,2-bis (p-methoxyphenyl) -1,2-ethylenedithiolate] nickel (manufactured by Midori Chemical Co., Ltd .: MIR-102), tetra-n-butylammonium bis (cis-1, 2-diphenyl-1,2-ethylenedithiolate) nickel (manufactured by Midori Chemical Co., Ltd .: MIR-1011), tetra-n-butylammonium bis [1,2-bis (p-methoxyphenyl) -1,2- Ethylene dithiolate] nickel (manufactured by Midori Chemical Co., Ltd .: MIR-1021), bis (4-tert-1,2-butyl-1,2-dithiophenolate) Neckel-tetra-n-butylammonium (manufactured by Sumitomo Seika Co., Ltd .: BBDT-NI), cyanine infrared absorber (manufactured by Fuji Film Co., Ltd .: IRF-106, IRF-107), cyanine infrared absorber ( Yamamoto Kasei Co., Ltd., YKR2900), aminium, diimonium-based infrared absorbers (Nagase Chemtex Co., Ltd .: NIR-AM1, IM1), imonium compounds (Nippon Carlit Co., Ltd .: CIR-1080, CIR-1081) ), Aminium compounds (Nippon Carlit Co., Ltd .: CIR-960, CIR-961), anthraquinone compounds (Nippon Kayaku Co., Ltd .: IR-750), aminium compounds (Nippon Kayaku Co., Ltd .: IRG-002, IRG-003, IRG-003K), polymethine compound (manufactured by Nippon Kayaku Co., Ltd .: IR-820) ), Diimonium compounds (Nippon Kayaku Co., Ltd .: IRG-022, IRG-023), dianine compounds (Nippon Kayaku Co., Ltd .: CY-2, CY-4, CY-9), soluble phthalocyanine ( Nippon Shokubai Co., Ltd .: TX-305A), Naphthalocyanine (Yamamoto Kasei Co., Ltd .: YKR5010, Sanyo Dye Co., Ltd .: Sample 1), Inorganic Materials (Shin-Etsu Chemical Co., Ltd .: Ytterbium UU-) HP, manufactured by Sumitomo Metal Industries, Ltd .: Injumetin oxide) and the like.

The volume average particle diameter (D _50v ) of the positively chargeable toner of this embodiment is preferably 2 μm or more and 10 μm or less, more preferably 3 μm or more and 9 μm or less, and further preferably 4 μm or more and 8 μm or less.
Further, the volume average particle diameter (D _50v ) of the toner base particles in the positively chargeable toner of this embodiment is preferably 2 μm or more and 10 μm or less, more preferably 3 μm or more and 9 μm or less, and further preferably 4 μm or more and 8 μm or less.
The toner preferably has a narrow particle size distribution, and more specifically, the ratio of the 16% diameter (D _16p ) and the 84% diameter (D _84p ) in _terms of the square root in terms of the smaller number particle size of the toner. (GSDp), that is, GSDp represented by the following formula is preferably 1.40 or less, more preferably 1.31 or less, and particularly preferably 1.27 or less.
_{GSDp = {(D 84p) /} (D 16p)} 0.5
If the volume average particle size and GSDp are both in the above ranges, extremely small particles do not exist, and therefore, it is possible to suppress a decrease in developability due to an excessive charge amount of the small particle size toner.

  A Coulter Multisizer II type (manufactured by Beckman Coulter, Inc.) can be used to measure the average particle size of particles such as toner and toner base particles. In this case, measurement can be performed using an optimum aperture depending on the particle size level of the particles. The particle diameter of the measured particle is expressed by a volume average particle diameter.

<Method for producing positively chargeable toner>
The method for producing the positively chargeable toner of this embodiment is not particularly limited, and may be produced by a known method.
For example, after blending a binder resin, a colorant, a release agent, and components such as a charge control agent and an infrared absorber as necessary, the above materials are melt-kneaded using a kneader, an extruder, or the like. . Thereafter, the obtained melt-kneaded material is coarsely pulverized, then finely pulverized with a jet mill or the like, and obtained by a kneading pulverization method or a kneading pulverization method to obtain toner particles having a target particle diameter with an air classifier. A method of changing the shape of the particles by mechanical impact force or thermal energy, emulsifying the binder resin, and forming a dispersion and a dispersion of a colorant, a release agent, and a charge control agent as necessary Emulsion, agglomeration method to obtain toner particles, a monomer for obtaining a binder resin, a colorant, a release agent, and a charge control agent, if necessary. Suspension polymerization in which the solution is suspended in an aqueous solvent for polymerization, a binder resin, a colorant, a release agent, and, if necessary, a solution such as a charge control agent suspended in an aqueous solvent for granulation The dissolution suspension method is used. Further, a production method may be performed in which the toner particles obtained by the above method are used as a core, and further, aggregated particles are attached and heat-fused to give a core-shell structure.
Among these, it is preferable to produce the toner of this embodiment using a kneading and pulverizing method or an emulsion aggregation method.

  The method for externally adding the external additive to the toner is not particularly limited, and a known method can be used. Specifically, for example, a method of adhering to the surface of the toner base particles by a dry method using a blender such as a V blender or a Henschel mixer, a surface after dispersing external additives in a liquid, adding to a toner in a slurry state, and drying the surface Examples of the method of adhering to the toner or the wet method include a method of drying while spraying a slurry on a dry toner.

(Electrostatic image developer)
The electrostatic image developer of the present embodiment (hereinafter also simply referred to as “developer”) includes the positively chargeable toner of the present embodiment and a carrier.

A known carrier can be used as the carrier, and a resin-coated carrier having a coating resin layer containing a conductive material on the surface of the core material can be used.
A carrier having a coating resin layer containing a conductive material on the core material surface is obtained by coating the core material with a resin by a spray drying method, a rotary drying method, an immersion drying method using a universal stirrer, or the like.
Further, the coating resin layer is not limited to a single layer, and may be composed of two or more layers.

Examples of the coating resin used for coating the core surface include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene. -An acrylic acid copolymer, a fluororesin, polyester, a polycarbonate, a phenol resin, etc. are mentioned.
In particular, the outermost surface of the coating resin layer is preferably a crosslinkable resin. By using the crosslinkable resin, it is possible to suppress the external additive from being embedded in the carrier surface and changing the external additive structure.
Examples of the crosslinkable resin include polyurethane resin, phenol resin, urea resin, melamine resin, guanamine resin, melamine-urea cocondensation resin, crosslinkable fluororesin, epoxy resin, and crosslinkable silicone resin.
Among these, an epoxy resin and a crosslinkable silicone resin are preferable, and as the crosslinkable silicone resin, a crosslinkable straight silicone resin and a fluorine-modified silicone resin are preferable.
Specific examples of conductive materials include metals such as gold, silver and copper; carbon black; conductive metal oxides such as titanium oxide and zinc oxide; titanium oxide, zinc oxide, aluminum borate and titanic acid. And a composite system in which the surface of fine particles of potassium, tin oxide, indium tin oxide or the like is coated with a conductive metal oxide.
Moreover, you may add additives, such as a charge control agent, in coating resin as needed.

  The total content of the coating resin layer in the carrier is preferably in the range of 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight, and more preferably 1 part by weight with respect to 100 parts by weight of the core material. More preferred is 3 parts by weight or less. When the content of the coating resin layer is 0.5 parts by weight or more, the surface exposure of the core particles is small, and injection of the development electric field can be suppressed. Further, when the content of the coating resin layer is 10 parts by weight or less, the resin powder released from the coating resin layer is small, and the resin powder peeled off in the developer can be suppressed from the initial stage.

  The average film thickness of each coating resin layer is preferably 0.1 μm or more and 10 μm or less, more preferably 0.1 μm or more and 3.0 μm or less, and further preferably 0.1 μm or more and 1.0 μm or less. preferable. When the average film thickness of the coating resin layer is 0.1 μm or more, resistance reduction due to peeling of the coating resin layer does not occur during long-time use, and carrier pulverization can be easily controlled. On the other hand, when the average film thickness of the coating resin layer is 10 μm or less, the time until the saturation charge amount is reached is short.

The average film thickness (μm) of the coating resin layer is such that the true specific gravity of the core material is ρ (dimensionless), the volume average particle diameter of the core material is d (μm), the average specific gravity of the coating resin layer is ρ _C , and the core material 100 When the total content of the coating resin layer with respect to parts by weight is W _C (parts by weight), it can be determined as in the following formula (11).
Formula (11): Average film thickness (μm) = {[amount of coating resin per carrier (including all additives such as conductive powder) / surface area per carrier]} / average specific gravity of coating resin layer
= {[4 / 3π · (d / 2) ³ · ρ · W _C ] / [4π · (d / 2) ² ]} / ρ _C
= (1/6) · (d · ρ · W _C / ρ _C )

  The content of the conductive material is preferably 0.5 to 20 parts by weight and more preferably 2 to 18 parts by weight with respect to 100 parts by weight of the coating resin. If it is in the range of 0.5 to 20 parts by weight, the resistance of the carrier can be controlled well.

The average particle size of the carrier is preferably 20 to 100 μm, and more preferably 30 to 80 μm.
The toner content in the electrostatic image developer of the exemplary embodiment is preferably 2.0 parts by weight or more and 20 parts by weight or less, and more preferably 2.5 parts by weight or more and 16 parts by weight or less with respect to 100 parts by weight of the developer. Preferably, it is 3.0 parts by weight or more and 14 parts by weight or less.

(Image forming method and image forming apparatus)
The positively chargeable toner of the present embodiment and the electrostatic charge image developer of the present embodiment are not particularly limited, and are used in an image forming method and apparatus of an electrostatic charge image developing method (electrophotographic method).
Among these, the image forming method can be suitably used for an image forming method and apparatus using an image holding member whose surface is composed of amorphous silicon.
The positively chargeable toner of the present embodiment and the electrostatic charge image developer of the present embodiment can also be suitably used in an image forming method and apparatus in which the peripheral speed of the developer carrying member is 1,000 mm / s or more. .

The image forming method of this embodiment includes a latent image forming step of forming an electrostatic latent image on the surface of the image carrier, and the electrostatic latent image formed on the surface of the image carrier includes the positively chargeable toner of this embodiment. At least a developing step for forming a toner image by developing with a developer, a transferring step for transferring the toner image to the surface of the transfer member, and a fixing step for fixing the toner image transferred to the surface of the transfer member. It is preferable. In the transfer step, the transfer may be performed twice or more using an intermediate transfer member. In addition, a cleaning process or the like may be included as necessary.
The image forming apparatus according to the present embodiment includes an image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the image carrier, and the positively chargeable toner according to the present embodiment. A developing means for developing a toner image by developing with a developer, a transfer means for transferring the toner image to the surface of the transfer body, and a fixing means for fixing the toner image transferred to the surface of the transfer body. It is preferable to provide at least. In the transfer unit, the transfer may be performed twice or more using an intermediate transfer member. Further, it may have a cleaning means for removing toner remaining on the image carrier.

Photoreceptors that are image carriers include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors using polysilane, phthalocyanine, etc. as charge generation materials and charge transport materials. Is preferred.
Amorphous silicon photoconductors are particularly durable and have a long service life due to their high surface hardness. On the other hand, wear on the photoconductor surface tends to be non-uniform, and the surface roughness on the photoconductor surface becomes non-uniform. Although the image density uniformity tends to decrease, the use of the toner of the present embodiment provides excellent image density uniformity even in an image forming apparatus using an amorphous silicon photoreceptor.

The developing step is a step of developing the electrostatic charge image with the positively chargeable toner by rubbing a developer holding member having a peripheral speed of 1,000 mm / s or more against the surface of the image holding member. preferable.
The developing unit includes a developer holding body having a peripheral speed of 1,000 mm / s or more, and the developer holding body is rubbed against the surface of the image holding body to display the electrostatic image. A means for developing with a positively chargeable toner is preferred.
When the positively chargeable toner of the present embodiment is used as a developer, an image on a printed matter can be obtained even when high-speed development is applied on the peripheral side of the developer holding body of 1,000 mm / s or more, which applies excessive stress to the developer. Excellent density uniformity.
The peripheral speed of the developer holder is preferably 1,000 to 3,000 mm / s, and more preferably 1,000 to 2,000 mm / s.

Further, each step in the image forming method is described in, for example, Japanese Patent Laid-Open Nos. 56-40868 and 49-91231. Note that the image forming method of the present embodiment is carried out by using a known image forming apparatus such as a copying machine or a facsimile machine.
The latent image forming step is a step of forming an electrostatic latent image on the surface of the image carrier.
The developing step is a step of developing the electrostatic latent image with a developer layer on a developer holder to form a toner image. The developer layer is not particularly limited as long as it contains the electrostatic image developer of this embodiment containing the electrostatic image developer of the present embodiment.
The transfer step is a step of transferring the toner image onto a transfer target.
The fixing step is a step of forming a copy image by fixing the toner image transferred onto a recording medium such as recording paper by an optical fixing device or a thermal fixing device.
The cleaning step is a step of removing the electrostatic charge image developer remaining on the image carrier. In the image forming method of the present embodiment, an aspect that further includes a recycling step is preferable.
The recycling step is a step of transferring the electrostatic charge image developing toner collected in the cleaning step to a developer layer. The image forming method including the recycling process is performed using an image forming apparatus such as a toner recycling system type copying machine or facsimile machine. The present invention is also applicable to a recycling system in which the cleaning step is omitted and toner is collected simultaneously with development.
Through such a series of processing steps, a desired duplicate product (printed matter or the like) can be obtained.

Further, as each unit in the image forming apparatus, the configuration described in each step of the image forming method is preferably used.
As each of the above-described means, a known means is used in the image forming apparatus. Further, the image forming apparatus used in the present embodiment may include means and devices other than the above-described configuration. Further, the image forming apparatus used in the present embodiment may simultaneously perform a plurality of the above-described means.

(Toner cartridge and process cartridge)
The toner cartridge according to the present exemplary embodiment is detachable from an image forming apparatus including at least a developing unit that develops an electrostatic charge image to form a toner image. The toner cartridge according to the present exemplary embodiment is used as a toner to be supplied to the developing unit. Toner cartridge containing positively chargeable toner.
In addition, the process cartridge according to the present embodiment is detachable from an image forming apparatus including at least a developing unit that develops an electrostatic charge image to form a toner image, and develops the electrostatic charge image to form a toner image. At least one selected from the group consisting of a developing means, a charging means for charging the surface of the image carrier, and a cleaning means for removing the toner remaining on the surface of the image carrier. And a process cartridge containing at least the positively chargeable toner of the present embodiment or the electrostatic charge image developer of the present embodiment.

  As the toner cartridge and the process cartridge, known configurations may be employed. For example, Japanese Patent Application Laid-Open Nos. 2008-209489 and 2008-203736 are referred to.

  Hereinafter, although this embodiment is described in detail with examples, this embodiment is not limited in any way. In the following description, “parts” means “parts by weight” unless otherwise specified.

〔Measuring method〕
<Number average primary particle size of silica particles>
The particle diameter of 500 or more silica particles was measured from an image observed at a magnification of 100,000 on a scanning electron microscope image, and the average primary particle diameter was determined by number average.

<Method of measuring endothermic peak temperature and glass transition temperature of resin>
The glass transition temperature (Tg) of the resin can be obtained using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60A) in accordance with ASTM D3418. For the sample, an aluminum pan was used, an empty pan was set for control, the temperature was raised at a rate of temperature increase of 10 ° C / min, held at 200 ° C for 5 minutes, and liquid nitrogen was used from 200 ° C to 0 ° C The temperature is lowered at 10 ° C./min, held at 0 ° C. for 5 minutes, and again heated from 0 ° C. to 200 ° C. at 10 ° C./min. Analysis is performed from the endothermic curve during the second temperature increase, and the onset temperature is set to Tg for the amorphous polyester resin, and the endothermic peak temperature is set from the maximum peak for the crystalline polyester resin.

<Method for measuring weight average molecular weight and molecular weight distribution of resin>
In the present invention, the molecular weight of the binder resin or the like is determined under the following conditions. GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corp.)”, column uses “TSKgel, SuperHM-H (Tosoh Corp. 6.0 mmID × 15 cm)”, two eluents THF (tetrahydrofuran) was used. As experimental conditions, an experiment was performed using a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. In addition, the calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A” -2500 "," F-4 "," F-40 "," F-128 ", and" F-700 ".

<Measurement method of volume average particle diameter of toner>
The volume average particle size of the toner was measured using a Coulter Multisizer II (manufactured by Beckman-Coulter). As the electrolytic solution, ISOTON-II (manufactured by Beckman-Coulter) was used.
As a measuring method, first, 0.5 mg to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this is added to 100 ml to 150 ml of the electrolytic solution. Added. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute. Using the Coulter Multisizer II type, an aperture having an aperture diameter of 100 μm is used. The particle size distribution of the following range of particles was measured. The number of particles to be measured was 50,000.
In the measured particle size distribution, a cumulative distribution is drawn from the smaller diameter side with respect to the divided particle size range (channel), and the particle size at which 50% is accumulated is defined as the volume average particle size.

<Measurement method of volume average particle diameter of carrier>
The volume average particle diameter of the carrier was measured using a laser diffraction / scattering particle size distribution analyzer (LS Particle Size Analyzer: LS13 320, manufactured by Beckman Coulter, Inc.). For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution was subtracted from the small particle size side, and the particle size at 50% cumulative was taken as the volume average particle size.

<Preparation of silica particle A-1>
While stirring gas phase method silica having a number average particle diameter of 12 nm (product name: Aerosil 200, manufactured by Nippon Aerosil Co., Ltd.) under a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane ( Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, and the mixture was heated and mixed and stirred at 150 ° C. for 90 minutes to remove volatile components, followed by cooling to obtain aminosilane surface-treated silica particles A-1.

<Preparation of silica particle A-2>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 5 nm. While stirring the obtained silica in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, 150 The mixture was stirred and heated at 90 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles A-2.

<Preparation of silica particle A-3>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 15 nm. While stirring the obtained silica in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, 150 The mixture was stirred and heated at 90 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles A-3.

<Preparation of silica particle A-4>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 7 nm. While stirring the obtained silica in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, 150 The mixture was heated and mixed at 90 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles A-4.

<Preparation of silica particle A-5>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 14 nm. While stirring the obtained silica in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, 150 The mixture was heated and mixed at 90 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles A-5.

<Preparation of silica particle A-6>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 4 nm. While stirring the obtained silica in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, 150 The mixture was heated and mixed at 90 ° C. for 90 minutes to remove volatile components, and then cooled to obtain aminosilane surface-treated silica particles A-6.

<Preparation of silica particle A-7>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 20 nm. While stirring the obtained silica in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, 150 The mixture was stirred and heated at 90 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles A-7.

<Preparation of silica particle B-1>
Dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-96-100cs) is sprayed on gas phase method silica having a volume average particle size of 12 nm (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 200). After stirring for 30 minutes, the temperature was raised to 300 ° C. with stirring, and the mixture was further stirred for 2 hours to obtain silicone oil surface-treated silica particles B-1.
At this time, the heat loss was 9% by weight. In addition, the heat loss was calculated | required as a reduction | decrease of a weight when it heated up from room temperature to 1,000 degreeC at 30 degree-C / min by DTG-60 by Shimadzu Corporation.

<Preparation of silica particle B-2>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 5 nm. The obtained silica is sprayed with dimethyl silicone oil (trade name: KF-96-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.), and stirred for 30 minutes. By stirring for a period of time, silicone oil surface-treated silica particles B-2 were obtained. At this time, the heat loss was 15% by weight.

<Preparation of silica particle B-3>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 15 nm. The obtained silica is sprayed with dimethyl silicone oil (trade name: KF-96-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.), and stirred for 30 minutes. The mixture was stirred for a time to obtain silicone oil surface-treated silica particles B-3. At this time, the heat loss was 8% by weight.

<Preparation of silica particle B-4>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 7 nm. The obtained silica is sprayed with dimethyl silicone oil (trade name: KF-96-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.), and stirred for 30 minutes. The mixture was stirred for a time to obtain silicone oil surface-treated silica particles B-4. At this time, the heat loss was 12% by weight.

<Preparation of silica particle B-5>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 14 nm. The obtained silica is sprayed with dimethyl silicone oil (trade name: KF-96-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.), and stirred for 30 minutes. By stirring for a period of time, silicone oil surface-treated silica particles B-5 were obtained. At this time, the heat loss was 8% by weight.

<Preparation of silica particle B-6>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 4 nm. The obtained silica is sprayed with dimethyl silicone oil (trade name: KF-96-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.), and stirred for 30 minutes. By stirring for a period of time, silicone oil surface-treated silica particles B-6 were obtained. At this time, the heat loss was 16% by weight.

<Preparation of silica particle B-7>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 20 nm. The obtained silica is sprayed with dimethyl silicone oil (trade name: KF-96-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.), and stirred for 30 minutes. By stirring for a period of time, silicone oil surface-treated silica particles B-7 were obtained. At this time, the heat loss was 6% by weight.

<Preparation of Amorphous Polyester Resin A>
Bisphenol A ethylene oxide 2 mol adduct: 15 mol%
Bisphenol A propylene oxide 2 mol adduct: 35 mol%
Terephthalic acid: 50 mol%
A monomer equipped with the above composition ratio is charged into a flask equipped with a stirrer, nitrogen introduction tube, temperature sensor, and rectifying column, and the temperature is raised to 190 ° C. over 1 hour, and the reaction system is stirred uniformly. After confirming the above, 1.0% by weight of dibutyltin oxide was added. Further, while distilling off the generated water, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 2.5 hours, with a glass transition temperature of 62 ° C. and a weight average molecular weight. An amorphous polyester resin A (Mw) of 16,000 was obtained.

<Preparation of crystalline polyester resin A>
679.4 parts of succinic acid, 450.5 parts of 1,4-butanediol, 40.6 parts of fumaric acid, and 2.5 parts of dibutyltin oxide were mixed in a flask and heated to 240 ° C. under reduced pressure for 6 hours. Dehydration condensation was performed to obtain a crystalline polyester resin A. It was 14,000 when the weight average molecular weight (Mw) of the obtained crystalline polyester resin A was measured by the above-mentioned method. The endothermic peak temperature Tm of the obtained crystalline polyester resin A was 91 ° C. when measured by a differential scanning calorimeter (DSC) by the above-described measuring method.

<Preparation of crystalline polyester resin B>
293 parts of 1,4-butanediol, 750 parts of dodecanedicarboxylic acid, and 0.3 part of dibutyltin oxide are mixed in a flask, heated to 240 ° C. under reduced pressure and dehydrated for 6 hours to form a crystalline polyester. Resin B was obtained. The obtained crystalline polyester resin B had a weight average molecular weight of 18,000 and an endothermic peak temperature Tm of 70 ° C.

Example 1
<Preparation of toner mother particle 1>
Amorphous polyester resin A 76 parts by weight Crystalline polyester resin A 10 parts by weight Carbon black (trade name Regal 330, manufactured by Cabot Corporation) 7 parts by weight Paraffin wax (manufactured by Nippon Seisaku Co., Ltd., trade name HNP9) 7 parts by weight The composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D ₅₀ of 7.4 μm 1 was obtained.

<Preparation of Toner 1>
Black toner 1 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer.
The black toner 1 had a wA / wB of 2.3 and a wB / wp of 0.040.

<Preparation of carrier 1>
Appropriate amounts of each raw material are blended so that it is 30 mol% in terms of MnO, 9.5 mol% in terms of MgO, 60 mol% in terms of Fe ₂ O ₃ , and 0.5 mol% in terms of SrO, water is added, and the wet ball mill is used for 10 hours Crushing, mixing, drying, holding at 900 ° C. for 4 hours, granulating and drying the slurry after grinding for 24 hours with a wet ball mill, holding at 1250 ° C. in an atmosphere of 2% oxygen concentration for 6 hours, Crushing and particle size adjustment were performed to obtain manganese-magnesium-strontium ferrite particles 1.
A dimethyl silicone resin containing trifluoropropyl group (SR-2410, manufactured by Toray Dow Corning) was weighed in 200 parts by weight in terms of solid content, dissolved in 867 parts by weight of a toluene solvent, and conductive carbon black (Cabot Corporation). Vulcan XC72), 15% by weight of resin solids and 2 parts by weight of an organic aluminum curing catalyst (aluminum-di-n-butoxide monoethylacetoacetate), and dispersed in a pearl mill to prepare a carrier coating solution Got.
After applying the carrier coating solution to 100 parts by weight of manganese-magnesium-strontium ferrite particles 1 using a fluidized bed (spray dry) coating device so that the silicone resin is 2.0 parts by weight in solid content, 100 ° C. After drying at 270 ° C., baking was performed at 270 ° C. for 1 hour, followed by crushing treatment and 30 minutes of post-treatment using a vibration type mill to obtain a carrier 1 coated with a crosslinkable resin.
The volume average particle diameter of the carrier 1 was 40 μm.

<Preparation of Developer 1>
Developer 1 was obtained by mixing 6 parts by weight of toner 1 and 94 parts by weight of carrier 1 with a V blender.

<Evaluation method>
Evaluation was performed using a remodeled machine obtained by modifying the 650J Continuous Feeding System manufactured by Fuji Xerox Co., Ltd. so that the peripheral speed of the developer carrier was variable. The peripheral speed of the developing roll was set to 1,100 mm / s.
With the above-mentioned remodeling machine, after supplying the developer, an image with an image density of 30% is printed in the form of 10,000 sheets of A4 equivalent, and further, an image density of 0.6% is output equivalent to 10,000 sheets in A4 equivalent, 3cm x 3cm A pattern in which ten solid images were arranged was output. The image density of 10 solid images at this time was measured, the difference between the maximum value and the minimum value of the density was determined, and the determination was made according to the following criteria.
A: The difference between the maximum value and the minimum value of the density is 0.05 or less, and the image density uniformity is very good.
A: The difference between the maximum value and the minimum value of the density is more than 0.05 and 0.10 or less, and the image density uniformity is good.
Δ: The difference between the maximum value and the minimum value of the density exceeds 0.10 and is 0.15 or less, and the image density uniformity is at an acceptable level.
X: The difference between the maximum value and the minimum value of density is larger than 0.15, and there is a problem in image density uniformity.
Further, after printing the solid image, a halftone image (image adjusted to have an image density of 0.4 to 0.6) was printed, and the presence or absence of image unevenness was visually observed.
○: Unevenness cannot be confirmed visually.
(Triangle | delta): It is an acceptable level although a nonuniformity can be confirmed visually.
X: Unevenness is noticeable visually and is not acceptable.
The evaluation results are shown in Table 1.

(Example 2)
<Preparation of Toner 2>
Black toner 2 was obtained by mixing 100 parts by weight of toner mother particles 1 with 0.35 parts by weight of silica particles A-1 and 0.7 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 2 had a wA / wB of 0.5 and a wB / wp of 0.070.
Further, developer 2 was obtained by mixing 6 parts by weight of toner 2 and 194 parts by weight of carrier 1 with a V blender. The evaluation results are shown in Table 1.

(Example 3)
<Preparation of Toner 3>
Black toner 3 was obtained by mixing 100 parts by weight of toner base particles 1 with 1.6 parts by weight of silica particles A-1 and 0.2 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 3 had wA / wB of 8.0 and wB / wp of 0.020.
Further, developer 3 was obtained by mixing 6 parts by weight of toner 3 and 194 parts by weight of carrier 1 with a V blender. The evaluation results are shown in Table 1.

Example 4
<Preparation of toner mother particles 2>
Amorphous polyester resin A 66 parts by weight Crystalline polyester resin A 20 parts by weight Carbon black (trade name Regal 330, manufactured by Cabot) 7 parts by weight Paraffin wax (trade name HNP9, manufactured by Nippon Seiki Co., Ltd.) 7 parts by weight The composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D ₅₀ of 7.4 μm 2 was obtained.

<Preparation of Toner 4>
Black toner 4 was obtained by mixing 100 parts by weight of toner base particles 2 with 1.4 parts by weight of silica particles A-1 and 0.2 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 4 had a wA / wB of 6.0 and a wB / wp of 0.005.
Further, developer 4 was obtained by mixing 6 parts by weight of toner 4 and 194 parts by weight of carrier 1 with a V blender. The evaluation results are shown in Table 1.

(Example 5)
<Preparation of Toner 5>
Black toner 5 was obtained by mixing 100 parts by weight of toner base particles 1 with 1.1 parts by weight of silica particles A-1 and 1.0 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 5 had a wA / wB of 1.1 and a wB / wp of 0.100.
Further, developer 5 was obtained by mixing 6 parts by weight of toner 5 and 194 parts by weight of carrier 1 with a V blender. The evaluation results are shown in Table 1.

(Example 6)
<Preparation of Toner 6>
Black toner 6 was obtained by mixing 100 parts by weight of toner base particles 1 0.35 parts by weight of silica particles A-1 and 0.5 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 6 had a wA / wB of 0.7 and a wB / wp of 0.050.
Further, developer 6 was obtained by mixing 6 parts by weight of toner 6 and 194 parts by weight of carrier 1 with a V blender. The evaluation results are shown in Table 1.

(Example 7)
<Preparation of Toner 7>
Black toner 7 was obtained by mixing 100 parts by weight of toner base particles 1 with 1.4 parts by weight of silica particles A-1 and 0.2 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 7 had wA / wB of 7.0 and wB / wp of 0.020.
Further, developer 7 was obtained by mixing 6 parts by weight of toner 7 and 194 parts by weight of carrier 1 with a V blender. The evaluation results are shown in Table 1.

(Example 8)
<Preparation of toner mother particle 3>
Amorphous polyester resin A 71 parts by weight Crystalline polyester resin A 15 parts by weight Carbon black (trade name Regal 330, manufactured by Cabot Corporation) 7 parts by weight Paraffin wax (trade name HNP9, manufactured by Nippon Seiki Co., Ltd.) 7 parts by weight The composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D ₅₀ of 7.4 μm 3 was obtained.

<Preparation of Toner 8>
Black toner 8 was obtained by mixing 100 parts by weight of toner base particles 3 with 0.6 parts by weight of silica particles A-1 and 0.15 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 8 had a wA / wB of 4.0 and a wB / wp of 0.010.
Further, 6 parts by weight of toner 8 and 194 parts by weight of carrier 1 were mixed with a V blender to obtain developer 8. The evaluation results are shown in Table 1.

Example 9
<Preparation of toner mother particles 4>
Amorphous polyester resin A 81 parts by weight Crystalline polyester resin A 5 parts by weight Carbon black (trade name Regal 330, manufactured by Cabot Corporation) 7 parts by weight Paraffin wax (trade name HNP9, manufactured by Nippon Seiki Co., Ltd.) 7 parts by weight The composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D ₅₀ of 7.4 μm 4 was obtained.

<Preparation of Toner 9>
Black toner 9 was obtained by mixing 100 parts by weight of toner base particles 4 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 9 had a wA / wB of 2.3 and a wB / wp of 0.080.
Further, 6 parts by weight of toner 9 and 194 parts by weight of carrier 1 were mixed with a V blender to obtain developer 9. The evaluation results are shown in Table 1.

(Example 10)
<Preparation of Toner 10>
Black toner 10 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-2 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 10 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, 6 parts by weight of toner 10 and 194 parts by weight of carrier 1 were mixed with a V blender to obtain developer 10. The evaluation results are shown in Table 1.

(Example 11)
<Preparation of Toner 11>
Black toner 11 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-3 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 11 had a wA / wB of 2.3 and a wB / Wp of 0.040.
Further, developer 11 was obtained by mixing 6 parts by weight of toner 11 and 194 weight of carrier 1 with a V blender. The evaluation results are shown in Table 1.

(Example 12)
<Preparation of Toner 12>
Black toner 12 was obtained by mixing 100 parts by weight of toner mother particles 1 with 0.9 parts by weight of silica particles A-4 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 12 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, 6 parts by weight of toner 12 and 194 parts by weight of carrier 1 were mixed with a V blender to obtain developer 12. The evaluation results are shown in Table 1.

(Example 13)
<Preparation of Toner 13>
Black toner 13 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-5 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 13 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, developer 13 was obtained by mixing 6 6 parts by weight of toner 13 and 194 weight of carrier by a V blender. The evaluation results are shown in Table 1.

(Example 14)
<Preparation of Toner 14>
Black toner 14 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-2 with a Henschel mixer. The black toner 14 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, developer 14 was obtained by mixing 6 6 parts by weight of toner 14 and 194 weight of carrier with a V blender. The evaluation results are shown in Table 1.

(Example 15)
<Preparation of Toner 15>
Black toner 15 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-3 with a Henschel mixer. The black toner 15 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, developer 15 was obtained by mixing 6 6 parts by weight of toner 15 and 194 weight of carrier by a V blender. The evaluation results are shown in Table 1.

(Example 16)
<Preparation of Toner 16>
Black toner 16 was obtained by mixing 100 parts by weight of toner mother particles 1 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-4 with a Henschel mixer. The black toner 16 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, developer 16 was obtained by mixing 66 parts by weight of toner 16 and 194 parts by weight of carrier with a V blender. The evaluation results are shown in Table 1.

(Example 17)
<Preparation of Toner 17>
Black toner 17 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-5 with a Henschel mixer. The black toner 17 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, 76 parts by weight of toner 17 and 194 parts by weight of carrier were mixed with a V blender to obtain developer 17. The evaluation results are shown in Table 1.

(Example 18)
<Preparation of toner mother particles 5>
Amorphous polyester resin A 74 parts by weight Crystalline polyester resin B 12 parts by weight Carbon black (trade name Regal 330, manufactured by Cabot Corporation) 7 parts by weight Paraffin wax (manufactured by Nippon Seisaku Co., Ltd., trade name HNP9) 7 parts by weight The composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D ₅₀ of 7.4 μm 5 was obtained.

<Preparation of Toner 18>
Black toner 18 was obtained by mixing 100 parts by weight of toner base particles 5 with 1.2 parts by weight of silica particles A-1 and 0.2 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 18 had a wA / wB of 6.0 and a wB / wp of 0.017.
Further, developer 18 was obtained by mixing 86 parts by weight of toner 18 and 194 parts by weight of carrier with a V blender. The evaluation results are shown in Table 1.

(Example 19)
<Preparation of Toner 19>
Black toner 19 was obtained by mixing 100 parts by weight of toner base particles 5 with 0.8 parts by weight of silica particles A-1 and 0.8 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 19 had a wA / wB of 1.0 and a wB / wp of 0.067.
Further, 19 parts by weight of toner 194 and 194 parts by weight of carrier were mixed with a V blender to obtain developer 19. The evaluation results are shown in Table 1.

(Example 20)
<Production of Carrier 2>
Manganese-magnesium-strontium ferrite particles 1 were obtained in the same manner as the production of the carrier 1.
A solution prepared by dissolving 2.0 parts by weight of a styrene / methyl methacrylate copolymer and 0.3 parts by weight of conductive carbon black (Vulcan XC72, manufactured by Cabot Corporation) in 10 parts by weight of toluene, and manganese-magnesium-strontium ferrite particles 1 100 parts by weight were put into a kneader, heated to 70 ° C. at normal pressure and stirred for 30 minutes, and then the solvent was distilled off under reduced pressure. The obtained coated carrier was sieved with a 75 μm mesh to prepare Carrier 2 coated with a non-crosslinkable resin. The volume average particle diameter of the carrier 2 was 40 μm.
Further, 16 parts by weight of toner 1 and 294 parts by weight of carrier 2 were mixed with a V blender to obtain a developer 20. The evaluation results are shown in Table 1.

(Comparative Example 1)
<Preparation of Toner 20>
Black toner 20 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-1 and 0.1 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 20 had a wA / wB of 9.0 and a wB / wp of 0.010.
Further, 60 parts by weight of toner and 194 parts by weight of carrier were mixed with a V blender to obtain developer 21. The evaluation results are shown in Table 1.

(Comparative Example 2)
<Preparation of toner mother particles 6>
Amorphous polyester resin A 61 parts by weight Crystalline polyester resin A 25 parts by weight Carbon black (trade name Regal 330, manufactured by Cabot Corporation) 7 parts by weight Paraffin wax (trade name HNP9, manufactured by Nippon Seiki Co., Ltd.) 7 parts by weight The composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D ₅₀ of 7.4 μm 6 obtained.

<Preparation of Toner 21>
Black toner 21 was obtained by mixing 100 parts by weight of toner mother particles 6 with 0.7 parts by weight of silica particles A-1 and 0.1 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 21 had a wA / wB of 7.0 and a wB / wp of 0.004.
Further, 16 parts by weight of toner 21 and 194 parts by weight of carrier 1 were mixed with a V blender to obtain developer 22. The evaluation results are shown in Table 1.

(Comparative Example 3)
<Preparation of Toner 22>
Black toner 22 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.4 parts by weight of silica particles A-1 and 0.9 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 22 had a wA / wB of 0.4 and a wB / wp of 0.090.
Further, 26 parts by weight of toner 22 and 194 weights of carrier were mixed with a V blender to obtain developer 23. The evaluation results are shown in Table 1.

(Comparative Example 4)
<Preparation of Toner 23>
Black toner 23 was obtained by mixing 100 parts by weight of toner base particles 1 and 1.1 parts by weight of silica particles A-1 and 1.2 parts by weight of silica particles B-1 using a Henschel mixer. The black toner 23 had a wA / wB of 0.9 and a wB / wp of 0.120.
Furthermore, 36 parts by weight of toner 23 and 194 parts by weight of carrier were mixed with a V blender to obtain developer 24. The evaluation results are shown in Table 1.

(Comparative Example 5)
<Preparation of Toner 24>
Black toner 24 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-6 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 24 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, 46 parts by weight of toner 24 and 194 parts by weight of carrier were mixed with a V blender to obtain developer 25. The evaluation results are shown in Table 1.

(Comparative Example 6)
<Preparation of Toner 25>
Black toner 25 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-7 and 0.4 parts by weight of silica particles B-1 with a Henschel mixer. The black toner 25 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, 26 parts by weight of toner 256 and 194 parts by weight of carrier were mixed with a V blender to obtain developer 26. The evaluation results are shown in Table 1.

(Comparative Example 7)
<Preparation of Toner 26>
Black toner 26 was obtained by mixing 100 parts by weight of toner mother particles 1 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-6 with a Henschel mixer. The black toner 26 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, developer 27 was obtained by mixing 66 parts by weight of toner 26 and 194 parts by weight of carrier with a V blender. The evaluation results are shown in Table 1.

(Comparative Example 8)
<Preparation of Toner 27>
Black toner 27 was obtained by mixing 100 parts by weight of toner base particles 1 with 0.9 parts by weight of silica particles A-1 and 0.4 parts by weight of silica particles B-7 with a Henschel mixer. The black toner 27 had a wA / wB of 2.3 and a wB / wp of 0.040.
Further, 276 parts by weight of toner and 194 parts by weight of carrier were mixed with a V blender to obtain developer 28. The evaluation results are shown in Table 1.

Claims (10)

Toner base particles containing a binder resin, a colorant, and a release agent;
An external additive,
The binder resin includes a crystalline polyester resin and an amorphous polyester resin,
The external additive contains two or more kinds of silica particles,
The two or more types of silica particles include silica particles A having a number average primary particle size of 5 nm or more and 15 nm or less surface-treated with a silane coupling agent having an amino group, and number average primary particles surface-treated with silicone oil. Silica particles B having a diameter of 5 nm or more and 15 nm or less,
When the content of the crystalline polyester resin is wp, the content of the silica particles A is wA, and the content of the silica particles B is wB, wA / wB is 0.5 or more and 8.0 or less, wB A positively chargeable toner, wherein / wp is 0.005 or more and 0.100 or less.   An electrostatic charge image developer comprising the positively chargeable toner according to claim 1 and a carrier.   The electrostatic charge image developer according to claim 2, wherein the carrier is a resin-coated carrier having a core material and a coating resin layer containing a conductive material and a crosslinkable resin on the surface of the core material. It is detachable from an image forming apparatus having at least developing means for developing an electrostatic charge image to form a toner image,
A toner cartridge containing the positively chargeable toner according to claim 1 as toner to be supplied to the developing means. A latent image forming step for forming an electrostatic latent image on the surface of the image carrier;
A developing step of developing the electrostatic latent image formed on the surface of the image carrier with a developer containing the positively chargeable toner according to claim 1 to form a toner image;
A transfer step of transferring the toner image onto the surface of the transfer target; and
An image forming method comprising at least a fixing step of fixing the toner image transferred to the surface of the transfer target.   The image forming method according to claim 5, wherein a surface of the image carrier is amorphous silicon.   7. The developing step develops the electrostatic image with the positively chargeable toner by rubbing a developer holding member having a peripheral speed of 1,000 mm / s or more against the surface of the image holding member. The image forming method described in 1. An image carrier,
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the image carrier;
Developing means for developing the electrostatic charge image with a developer containing the positively chargeable toner according to claim 1 to form a toner image;
Transfer means for transferring the toner image onto the surface of the transfer target;
An image forming apparatus comprising at least fixing means for fixing the toner image transferred onto the surface of the transfer target.   The image forming apparatus according to claim 8, wherein a surface of the image carrier is amorphous silicon.   The developing means includes a developer holding body having a peripheral speed of 1,000 mm / s or more, and the developer holding body is rubbed against the surface of the image holding body to positively charge the electrostatic image. The image forming apparatus according to claim 8, wherein the image forming apparatus is developed with a conductive toner.