JP2010169910A - Black toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a black toner, wherein stable image density is ensured to obtain an image of high quality without density unevenness while preventing generation of fog even in long-term use regardless to the use environment. <P>SOLUTION: The black toner contains at least a binder resin, carbon black, a plurality of colorants except for carbon black, and wax, wherein the toner satisfies relational expressions (1):0.00<Wf(P1)-Wf(CB)≤0.50 and (2):0.00<Wf(W)-Wf(P2)≤0.50. In the expressions, Wf represents a work function, Wf(CB) and Wf(W) represent work functions Wf of the carbon black and the wax, respectively. Of the plurality of colorants, a colorant minimum in the work function Wf which is between Wf(CB) and Wf(W) is denoted as P1 and a colorant maximum in the work function Wf is denoted as P2, and Wf(P1) and Wf(P2) represent work functions of the colorant P1 and the colorant P2, respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a black toner used in an electrophotographic system, an electrostatic recording system, and an electrostatic printing system.

Until now, when carbon black was used as a colorant for a toner, it had many problems.
First, since carbon black has a smaller primary particle size compared to other organic pigments, it is very difficult to disperse, and it is likely to be unevenly distributed on the surface of toner particles or to generate free carbon black. In addition, since carbon black is a fine powder with high adhesiveness, the presence of free carbon black leads to a decrease in toner fluidity and adhesion to the surface of a charging member such as a carrier, preventing good frictional charging, In some cases, the image has uneven density (decrease in image uniformity). Further, when the carbon black is not sufficiently dispersed, there are cases where sufficient image density cannot be obtained.
Secondly, since carbon black is more conductive than binder resins and other organic pigments, electric charges are likely to leak, and fogging or transfer loss may occur.

  Therefore, many proposals for improving the dispersibility of carbon black have been made. Techniques have been proposed in which carbon black having specific physical properties and an azo-based iron compound having a specific structure are used in combination to improve the dispersibility of carbon black and the chargeability of toner (Patent Documents 1 and 2). reference). However, with these technologies, a toner having high coloring power and stable chargeability can be obtained. However, after standing for a long time in a high-temperature and high-humidity environment, the density change or fog may deteriorate due to a decrease in chargeability, and there is room for improvement. was there.

  Further, a black toner in which carbon black and a plurality of organic pigments are mixed and a dispersion effect is enhanced by a metal compound of an aromatic oxycarboxylic acid has been proposed (see Patent Document 3). However, when the carbon black content exceeds 5 parts by mass with respect to 100 parts by mass of the binder resin, there is room for improvement because the charge relaxation property in a high-temperature and high-humidity environment becomes strong. Further, when the toner contains a release agent, the study on the charging property has not been sufficiently confirmed.

  Accordingly, proposals have been made regarding toners containing both carbon black and a release agent. There has been proposed a toner in which the dispersibility of carbon black in the toner is improved by containing a hydrocarbon wax having a styrene unit (see Patent Document 4). However, when the carbon black content exceeds 10 parts by mass with respect to 100 parts by mass of the binder resin, or when the average circularity of the toner is greater than 0.960, the triboelectric chargeability of the toner tends to be insufficient. As a result, fog is likely to occur and there is room for improvement.

In recent years, in particular, for the purpose of reducing energy consumption, there has been a demand for a toner that is more highly colored than in the past, with which a sufficient image density can be obtained even with low consumption. However, there has been a proposal regarding a black toner that solves the above problems. Not.
JP 7-64337 A Japanese Patent Laid-Open No. 10-186713 JP 2000-131879 A JP 2004-78206 A

  An object of the present invention is to provide a black toner that solves the above-described problems, and can stably form a high-quality image. Specifically, it is an object of the present invention to provide a black toner that does not cause fogging even in long-term use regardless of the use environment, provides a stable image density, and provides a high-quality image without density unevenness.

The present inventors have solved the various problems described above, and have reached the following invention in the course of earnestly studying to develop a black toner that meets the object of the present invention. By using the black toner of the present invention, it is possible to provide a black toner capable of producing a stable image density and a high-quality image without density unevenness even in long-term use regardless of the use environment. I found out.
The present invention relates to a black toner containing at least a binder resin, carbon black, a plurality of colorants other than carbon black, and wax, wherein the following relational expressions (1) and (2) are satisfied: About.
0.00 <Wf (P1) −Wf (CB) ≦ 0.50 (1)
0.00 <Wf (W) −Wf (P2) ≦ 0.50 (2)
(Wf represents a work function, and Wf (CB) and Wf (W) represent the work function Wf of carbon black and wax, respectively. Among a plurality of colorants, the work function Wf is between Wf (CB) and Wf (W). The colorant P1 is the minimum colorant and the colorant P2 is the maximum colorant, and Wf (P1) and Wf (P2) denote the work functions Wf of the colorant P1 and the colorant P2, respectively. .)

  By using the black toner of the present invention, a high-quality image can be stably formed. Specifically, regardless of the use environment, fogging does not occur even in long-term use, a stable image density is obtained, and a high-quality image without density unevenness is obtained.

The black toner of the present invention is characterized by containing at least a binder resin, carbon black, a plurality of colorants other than carbon black, and wax, and satisfying the following relational expressions (1) and (2).
0.00 <Wf (P1) −Wf (CB) ≦ 0.50 (1)
0.00 <Wf (W) −Wf (P2) ≦ 0.50 (2)

  In the above formula, Wf represents the work function, and Wf (CB) and Wf (W) represent the work function Wf of carbon black and wax, respectively. Further, among the plurality of colorants, the work function Wf exists between Wf (CB) to Wf (W), the minimum colorant is the colorant P1, the maximum colorant is the colorant P2, and Wf (P1 ) And Wf (P2) represent work functions Wf of the colorant P1 and the colorant P2, respectively.

By setting the relationship of the work function Wf within the above range, the toner can be charged stably, and a stable image density can be obtained without fogging even during long-term use, and a high-quality image without density unevenness can be obtained.
Here, the work function is an energy level of electrons unique to a substance. Specifically, the energy for extracting electrons from the surface of the material is shown. The smaller the work function, the easier the electron is emitted, and the larger the electron, the harder the electron is emitted. In other words, it is considered that the relationship between the work functions unique to each substance contained in the toner greatly affects the charging characteristics of the toner.

In general, when the work functions of carbon black and wax are compared, the value of carbon black is smaller and there is a large difference between the value of wax. As a result, there are local differences in charging characteristics on the toner surface, charging stability is reduced, and image density may fluctuate during long-term use. That is, it is important to reduce the difference in the work function values between the carbon black and the wax.

  Therefore, in the present invention, a plurality of colorants other than carbon black having a work function value between the work function value of carbon black and the work function value of wax are added. As a result, even if there is a difference between the work function value of carbon black and the work function of wax, due to the presence of multiple colorants having intermediate work function values, the charging characteristics of the toner surface are substantially uniform. To solve the above problems.

  The work function Wf of a plurality of colorants other than carbon black contained in the black toner of the present invention is between the work function value of carbon black and the work function value of wax (Wf (CB) to Wf (W )). That is, the relationship between the work function Wf (CB) of carbon black and the work function Wf (P1) of the colorant P1 is 0.00 <Wf (P1) −Wf (CB) ≦ 0.50, and 0.10 ≦ It is more preferable that Wf (P1) −Wf (CB) ≦ 0.50. Further, the relationship between the work function Wf (P2) of the colorant P2 and the work function Wf (W) of the wax is 0.00 <Wf (W) −Wf (P2) ≦ 0.50, and 0.10 ≦ Wf. It is more preferable that (W) −Wf (P2) ≦ 0.50.

  When Wf (P1) -Wf (CB) or Wf (W) -Wf (P2) is 0.00 or less, the values of work functions Wf of a plurality of colorants other than carbon black are as described above. In addition, it does not exist between the work function value of carbon black and the work function value of wax, and the charging characteristics of the toner surface cannot be made substantially uniform. On the other hand, when Wf (P1) -Wf (CB) or Wf (W) -Wf (P2) is greater than 0.50, the work between carbon black, a plurality of colorants other than carbon black, and wax The difference in function value is large, and the charging characteristics of the toner surface cannot be made uniform, charging stability is lowered, and the image density may fluctuate during long-term use.

  Further, in the present invention, a plurality of colorants other than carbon black are contained, but when only one colorant other than carbon black is used, the difference in work function values between carbon black and wax is also large. Therefore, the charging characteristics of the toner surface cannot be made uniform. The number of colorants other than carbon black is not particularly limited as long as the performance required for normal black toner is satisfied, but it is preferable to contain two to three kinds of colorants. Also, a plurality of similar colorants may be contained.

In the black toner of the present invention, the proximity maximum difference in work function Wf of the colorant other than carbon black is preferably 0.50 or less, and more preferably 0.10 or more and 0.40 or less.
Here, the proximity maximum difference of the work function Wf indicates a maximum difference when a difference between a substance having a certain work function value and another substance having an adjacent value is compared.
When the proximity maximum difference in the work function Wf of the colorant other than carbon black is 0.50 or less, the difference in work function of the colorant other than carbon black to be added is small, so that the charging characteristics of the toner surface are small. More uniform. As a result, the charging stability of the toner is further improved, and it is easy to further suppress the occurrence of density unevenness even during long-term use.

In the black toner of the present invention, the proximity maximum difference between the work functions Wf of carbon black, colorants other than carbon black, and wax is preferably 0.40 or less, and preferably 0.10 or more and 0.35 or less. More preferred.
When the maximum difference in proximity of the work function Wf of carbon black, a colorant other than carbon black, and wax is 0.40 or less, the dispersibility of carbon black in the toner is further improved. As a result, even when left in a high-temperature and high-humidity environment, a decrease in charge is further suppressed, and a higher-quality image with less fog is easily obtained.

  The reason why the dispersibility of carbon black in the toner is improved by reducing the difference in work function is not clear, but is presumed as follows.

In general, carbon black has a small primary particle size and strong cohesion, and therefore forms a structure. Therefore, it is difficult to disperse the toner in the primary particle size state in the toner, and the structure tends to exist in the toner. When carbon black is present in a large structure in the toner, the large structure becomes a conductive path, which may cause charge leakage and fogging due to a decrease in chargeability. Furthermore, since it is difficult to finely disperse carbon black, the coloring power of carbon black cannot be obtained effectively, and the image density may be insufficient.
On the other hand, the wax is relatively easy to enter the gap formed between the carbon black structure structures. However, when carbon black is finely dispersed, the electrical affinity is low, and it has been insufficient so far to achieve both carbon black and wax dispersibility.

  Therefore, first, by reducing the work function difference between the carbon black and the colorant other than carbon black in the toner, the electrical affinity between the carbon black and the wax is increased. By applying shearing force in the mixing and stirring processes during toner production, part of the structure collapses, and at the same time, colorants other than carbon black collect on the surface of carbon black, thereby preventing carbon black from re-aggregating. . Furthermore, since the colorant other than carbon black has a higher resistance than carbon black, the effect of blocking the conductive path was also obtained, so that charge leakage could be suppressed. In addition, due to the presence of a colorant having a small work function difference from the wax (high electrical affinity) on the carbon black surface, the familiarity with the wax was improved. As a result, the presence of wax in the vicinity of the carbon black surface enabled fine dispersion with uniform charging characteristics. As a result, even when left in a high-temperature and high-humidity environment, it is presumed that a reduction in charge is suppressed, and a higher quality image with less fog is obtained.

  In the black toner of the present invention, the addition amount M (CB) (parts by mass) of carbon black with respect to 100 parts by mass of the binder resin and the total addition amount M (P) (parts by mass) of colorants other than carbon black are 0. 10 ≦ M (P) / M (CB) ≦ 5.00 is preferable, and 0.50 ≦ M (P) / M (CB) ≦ 3.00 is more preferable.

  When M (P) / M (CB) is in the above range, the ratio between the low-resistance carbon black and the colorant other than the high-resistance carbon black is optimal. As a result, even during long-term use, the change in chargeability becomes smaller, and it is preferable because a high-quality image free from fluctuations in image density can be easily obtained.

  The carbon black used in the present invention is not particularly limited, but the average primary particle size is preferably 10 nm or more and 60 nm or less, and more preferably 10 nm or more and 45 nm or less. The carbon black content is preferably 1.0 part by mass or more and 12.0 parts by mass or less, and more preferably 3.0 parts by mass or more and 10.0 parts by mass with respect to 100 parts by mass of the binder resin in the toner. The following is more preferable. When the average primary particle size and the content of carbon black are in the above ranges, the dispersibility of carbon black becomes better and sufficient coloring power is easily obtained.

Further, the carbon black used in the present invention preferably has a DBP oil absorption of 20 ml / 100 g or more and 150 ml / 100 g or less, and more preferably 30 ml / 100 g or more and 120 ml / 100 g or less. When the DBP oil absorption of carbon black is in the above range, the familiarity of the wax is good, and a stable image is easily obtained regardless of the use environment.

  The black toner of the present invention preferably has a weight average particle diameter (D4) of 4.0 μm or more and 10.0 μm or less, and more preferably 4.0 μm or more and 9.0 μm or less. When the weight average particle diameter (D4) of the toner is in the above range, the fluidity of the toner is good, it is easy to obtain a sufficient charge amount, and the occurrence of fog is easily suppressed.

  The black toner of the present invention preferably has an average circularity of 0.940 or more and 1.000 or less. When the average circularity of the toner is within the above range, the adhesion force of the toner is reduced and the transferability is improved. The average circularity is a circularity measured by a flow type particle image measuring apparatus having a field of view of 512 pixels × 512 pixels (0.37 μm × 0.37 μm per pixel) of 0.200 to 1.000. This is based on the circularity distribution in the range of the circle equivalent diameter of 1.985 or more and less than 39.69 μm. When the average circularity is in the above range, the fluidity as a developer can be appropriately controlled when used in a two-component developer using the toner of the present invention and a magnetic carrier in combination. As a result, the transportability of the two-component developer on the developer carrying member is improved, the toner is separated from the magnetic carrier, and the toner is more easily developed.

  Examples of the binder resin contained in the black toner of the present invention include the following. Polyester, polystyrene; polymer of styrene derivatives such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic Acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, Styrene copolymers such as styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenol resin, modified phenol resin, maleic resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin; Polyester resin having as a structural unit a monomer selected from aliphatic polyhydric alcohol, aliphatic dicarboxylic acid, aromatic dicarboxylic acid, aromatic dialcohol and diphenol; polyurethane resin, polyamide resin, polyvinyl butyral, terpene resin, A hybrid resin having coumarone indene resin, petroleum resin, polyester unit and vinyl polymer unit.

  The polyester resin used in the present invention is obtained by condensation polymerization of an alcohol monomer and a carboxylic acid monomer.

The following are mentioned as an alcohol monomer component. Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2. 0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) alkylene oxide adducts of bisphenol A such as -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1 , 4-butanediol, neopentyl glycol, 1,4-butenediol 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, sorbitol, 1,2 , 3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropane Triol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene.

  Examples of the carboxylic acid monomer component include the following. Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or their anhydrides; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or their anhydrides; alkyl group or alkenyl having 6 to 18 carbon atoms Succinic acid substituted with a group or anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydride thereof; In particular, isophthalic acid is preferably used because of its high reactivity.

  Other monomers include glycerin, sorbit, sorbitan, and polyhydric alcohols such as oxyalkylene ethers of novolak-type phenolic resins; trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, and anhydrides thereof. And polyvalent carboxylic acids. Among these, in particular, a bisphenol derivative represented by the following general formula (4) is a dihydric alcohol monomer component, and a carboxylic acid component comprising a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof ( For example, fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) are used as acid monomer components, and resins obtained by condensation polymerization with these polyester unit components have good charging characteristics. Therefore, it is preferable.

（式中、Ｒはエチレン又はプロピレン基を示し、ｘ、ｙはそれぞれ１以上の整数であり、かつｘ＋ｙの平均値は２〜１０である。）

(In the formula, R represents an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10.)

  Examples of monomers used for vinyl resins such as polystyrene and styrene derivatives include the following.

Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-crawler styrene, 3, Styrene and its derivatives such as 4-dicroller styrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; styrene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated such as butadiene and isoprene Polyenes; vinyl chloride, vinylidene chloride, vinyl bromide Vinyl halides such as vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacryl Α-methylene aliphatic monocarboxylic acid esters such as n-octyl acid, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate; Ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylic Acid 2-crawler ethyl, acrylic esters such as phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N -N-vinyl compounds such as vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide.

  The hybrid resin means a resin in which a vinyl polymer unit and a polyester unit are chemically bonded. Specifically, a polyester unit and a vinyl polymer unit obtained by polymerizing a monomer having a carboxylic acid ester group such as (meth) acrylic acid ester may be formed by a transesterification reaction. In addition, both reactive monomers capable of reacting with at least either a condensation polymerization monomer or an addition polymerization monomer (for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, alkenyl succinic acid, mesacone) An unsaturated dibasic acid such as an acid; an unsaturated dibasic acid anhydride such as maleic anhydride, citraconic anhydride, itaconic anhydride, and alkenyl succinic anhydride). A product obtained by addition polymerization of a system polymerization monomer may also be used.

  The binder resin used in the black toner of the present invention has a peak molecular weight (Mp) of 2 in the molecular weight distribution measured by gel permeation chromatography (GPC) in order to achieve both the storage stability and low-temperature fixability of the toner. 1,000 to 50,000, number average molecular weight (Mn) is 1,500 to 30,000, weight average molecular weight (Mw) is 2,000 to 1,000,000, and glass transition point (Tg) is 40. It is preferable that it is 80 degreeC or more.

  The wax contained in the black toner of the present invention is preferably used at a content of 0.5 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the binder resin. The peak temperature of the maximum endothermic peak of the wax is preferably 45 ° C. or higher and 140 ° C. or lower. Such a peak temperature is preferable because both the storage stability of the toner and the hot offset property can be achieved.

  Examples of the wax include the following. Low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymer, hydrocarbon wax such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax; oxide of hydrocarbon wax such as oxidized polyethylene wax or block copolymer thereof; Waxes composed mainly of fatty acid esters such as carnauba wax, behenic acid behenate wax, and montanic acid ester wax; fatty acid esters such as deoxidized carnauba wax that have been partially or fully deoxidized.

Furthermore, the following are mentioned. Saturated linear fatty acids such as palmitic acid, stearic acid and montanic acid; unsaturated fatty acids such as brandic acid, eleostearic acid and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, seryl alcohol, Saturated alcohols such as sil alcohols; polyhydric alcohols such as sorbitol; fatty acids such as palmitic acid, stearic acid, behenic acid, montanic acid, and stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, seryl alcohol, Esters with alcohols such as sil alcohols; Fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; Methylene bis stearic acid amide, ethylene biscapric acid Saturated fatty acid bisamides such as amide, ethylene bis lauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N 'dioleyl adipic acid amide, N, N' dioleyl Unsaturated fatty acid amides such as sebacic acid amides; aromatic bisamides such as m-xylene bis-stearic acid amide, N, N ′ distearyl isophthalic acid amide; calcium stearate, calcium laurate, zinc stearate, magnesium stearate Aliphatic metal salts such as those commonly referred to as metal soaps; waxes grafted to aliphatic hydrocarbon waxes using vinylic monomers such as styrene and acrylic acid; fatty acids such as behenic acid monoglycerides Alcohol Partial ester; methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable fats and oils.

  In the toner of the present invention, it is preferable to use hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax from the viewpoint of adhesion to the fixing member.

  The black toner of the present invention preferably further contains a graft polymer having a structure in which a polyolefin is grafted on a vinyl resin or a graft polymer in which a vinyl monomer is graft-polymerized on a polyolefin.

  The graft polymer having a structure in which a polyolefin is grafted to the vinyl resin or the graft polymer in which a vinyl monomer is graft-polymerized to a polyolefin functions as a surfactant of a binder resin and a wax. Therefore, the dispersibility of the wax in the toner and the carbon black existing in the vicinity thereof can be further improved. The graft polymer is preferably contained in an amount of 0.2 to 20 parts by mass in 100 parts by mass of the binder resin.

  Regarding a graft polymer having a structure in which a polyolefin is grafted to a vinyl resin or a graft polymer in which a vinyl monomer is graft-polymerized to a polyolefin, the polyolefin is a polymer or copolymer of an unsaturated hydrocarbon having one double bond. There is no particular limitation as long as it is, and various polyolefins can be used. In particular, polyethylene and polypropylene are preferably used.

Examples of the monomer having a vinyl group include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene. , P-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, p- Styrenic units such as styrene and derivatives thereof such as n-decylstyrene and pn-dodecylstyrene. Amino group-containing α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; vinyl-based units containing N atoms such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide. Unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; unsaturated such as maleic acid anhydride, citraconic acid anhydride, itaconic acid anhydride, alkenyl succinic acid anhydride Dibasic acid anhydride: maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, alkenyl succinic acid Half-esters of unsaturated dibasic acids such as acid methyl half ester, fumaric acid methyl half ester and mesaconic acid methyl half ester; Unsaturated dibasic acid esters such as dimethylmaleic acid and dimethylfumaric acid; Acrylic acid, Methacrylic acid Α, β-unsaturated acids such as crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, and anhydrous α and β-unsaturated acids and lower fatty acids. A vinyl-based unit containing a carboxyl group such as alkenyl malonic acid, alkenyl glutaric acid, alkenyl adipic acid, acid anhydrides thereof, and monoesters thereof. Acrylic acid or methacrylic acid ester such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1-methyl) (Hexyl) Vinyl-based units containing hydroxyl groups such as styrene. Methyl acrylate, ethyl acrylate, acrylate-n-butyl, acrylate isobutyl, propyl acrylate, acrylate-n-octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylate-2- An ester unit comprising an acrylic ester such as chloroethyl and acrylic ester such as phenyl acrylate. Methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylate-n-butyl, isobutyl methacrylate, methacrylate-n-octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacryl Examples include ester units composed of methacrylic acid esters such as α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl acid and diethylaminoethyl methacrylate.

  A graft polymer having a structure in which a polyolefin is grafted to a vinyl resin used in the present invention or a graft polymer in which a vinyl monomer is graft polymerized to a polyolefin is the reaction between these polymers described above, It can be obtained by a known method such as a reaction between a monomer and the other polymer.

  Moreover, it is preferable that a styrene-type unit and also acrylonitrile or methacrylonitrile are included as a structural unit of the vinyl resin of the said graft polymer. The weight ratio of polyolefin to vinyl resin in the polymer is preferably 1/99 to 25/75.

  The black toner of the present invention contains a plurality of colorants other than carbon black. Examples of the colorant other than carbon black contained include magenta pigments, magenta dyes, cyan pigments, cyan dyes, yellow pigments, and yellow dyes. Specific examples include the following.

  Examples of the magenta pigment include the following. C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 81: 2, 81: 3, 81: 4, 81: 5, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 185, 202, 206, 207, 209, 238, 269; C.I. I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35.

  Examples of magenta dyes include the following. C. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; I. Disper thread 9; I. Solvent violet 8, 13, 14, 21, 27; C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. B. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; I. Basic dyes such as Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Examples of cyan pigments include the following. C. I. Pigment blue 2, 3, 15: 3, 15: 4, 16, 17; I. Bat Blue 6; C.I. I. Acid Blue 4
5. A copper phthalocyanine pigment having 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton.

  Examples of cyan dyes include C.I. I. There is Solvent Blue 70.

  Examples of yellow pigments include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; I. Bat yellow 1, 3, 20

  Examples of yellow dyes include C.I. I. There is Solvent Yellow 162.

  The content of a plurality of colorants other than these carbon blacks is preferably 1.0 part by weight or more and 15.0 parts by weight or less in total with respect to 100 parts by weight of the binder resin, 1.1 parts by weight. More preferably, it is 9.0 parts by mass or less.

  The black toner of the present invention may contain a charge control agent as necessary. As the charge control agent contained in the toner, known ones can be used. In particular, a metal compound of an aromatic carboxylic acid that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable.

  Negative charge control agents include salicylic acid metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, sulfonic acid or polymer compounds having carboxylic acid in the side chain, sulfonates or sulfonated products in the side chain. Examples thereof include a polymer compound having a carboxylate or a carboxylate ester compound in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene. Examples of the positive charge control agent include quaternary ammonium salts, polymer compounds having the quaternary ammonium salt in the side chain, guanidine compounds, and imidazole compounds. The charge control agent may be added internally or externally to the toner particles. The addition amount of the charge control agent is preferably 0.2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

  It is preferable that an external additive is added to the black toner of the present invention in order to improve fluidity. As the external additive, inorganic fine powders such as silica, titanium oxide and aluminum oxide are preferable. The inorganic fine powder is preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil or a mixture thereof. The external additive is preferably used in an amount of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the toner particles. For mixing the toner particles and the external additive, a known mixer such as a Henschel mixer can be used.

  Examples of the method for producing toner particles include a pulverization method in which a binder resin and a colorant are melt-kneaded, the kneaded product is cooled, and then pulverized and classified; the binder resin and the colorant are dissolved or dispersed in a solvent. Suspension granulation method in which toner particles are obtained by introducing the solution into an aqueous medium, suspending granulation, and removing the solvent; dispersing and stabilizing a monomer composition in which a colorant is uniformly dissolved or dispersed in the monomer Suspension polymerization method in which toner particles are produced by dispersing in a continuous layer containing an agent (for example, an aqueous phase) and carrying out a polymerization reaction; monomers and aqueous systems that are soluble in monomers but become insoluble when a polymer is formed Direct dispersion in the presence of a water-soluble polar polymerization initiator using a water-based organic solvent that is soluble in the monomer that directly produces toner particles using an organic solvent and insoluble in the resulting polymer; Toner particles An emulsion polymerization method to be produced; an emulsion aggregation method obtained through a step of aggregating at least polymer fine particles and colorant fine particles to form a fine particle aggregate and a ripening step of causing fusion between the fine particles in the fine particle aggregate; and so on.

Hereinafter, a toner manufacturing procedure using the pulverization method will be described. In the raw material mixing step, as a material constituting the toner particles, for example, a binder resin, carbon black, a colorant other than carbon black and a wax, and other components such as a charge control agent as required are weighed and blended. And mix. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, and a mechano hybrid (manufactured by Mitsui Mining Co., Ltd.).
Next, the mixed material is melt-kneaded to disperse the colorant and the like in the binder resin. In the melt-kneading process, a batch kneader such as a pressure kneader or a Banbury mixer or a continuous kneader can be used, and a single-screw or twin-screw extruder has become the mainstream because of the advantage of continuous production. ing. For example, KTK type twin screw extruder (manufactured by Kobe Steel Co., Ltd.), TEM type twin screw extruder (manufactured by Toshiba Machine Co., Ltd.), PCM kneader (manufactured by Ikekai Tekko), twin screw extruder (manufactured by K.C.K. ), Ko Kneader (Bus), Needex (Mitsui Mining).
Furthermore, the colored resin composition obtained by melt-kneading may be rolled with two rolls or the like and cooled with water or the like in the cooling step. Next, the cooled product of the resin composition is pulverized to a desired particle size in the pulverization step. In the pulverization step, for example, after coarse pulverization with a pulverizer such as a crusher, a hammer mill, or a feather mill, for example, a kryptron system (manufactured by Kawasaki Heavy Industries), a super rotor (manufactured by Nisshin Engineering), a turbo mill Finely pulverize with a turbomill (made by Turbo Industries) or air jet type fine pulverizer.
Then, if necessary, classification such as inertial class elbow jet (manufactured by Nippon Steel & Mining Co., Ltd.), centrifugal classifier turboplex (manufactured by Hosokawa Micron), TSP separator (manufactured by Hosokawa Micron), Faculty (manufactured by Hosokawa Micron) The toner particles are obtained by classification using a machine or a sieving machine.
In addition, if necessary, after pulverization, a hybridization system (manufactured by Nara Machinery Co., Ltd.), a mechano-fusion system (manufactured by Hosokawa Micron), a faculty (manufactured by Hosokawa Micron), or Meteole Inbo MR Type (manufactured by Nippon Pneumatic Co., Ltd.) is used. Thus, the surface modification treatment of the toner particles such as spheroidization treatment can also be performed.

  FIG. 1 is a schematic cross-sectional view showing an example of an apparatus capable of performing surface modification. The surface modification apparatus in FIG. 1 is composed of the following members. Casing 30. A jacket 31 through which cooling water or antifreeze can be passed. A distributed rotor 32 as a surface modifying means, which is a disk-shaped rotating body which is attached to a central rotating shaft in a casing 30 and has a plurality of rectangular disks or cylindrical pins 33 on its upper surface and which rotates at high speed. A liner 34 disposed on the outer periphery of the dispersion rotor 32 at regular intervals and provided with a large number of grooves on the surface (there is no need to have grooves on the liner surface). A classification rotor 35 which is a means for classifying the surface-modified raw material into a predetermined particle size. A cold air inlet 46 for introducing cold air. A raw material supply port 39 for introducing the raw material to be processed. A discharge valve 41 installed to be openable and closable so that the surface modification time can be freely adjusted. A powder discharge port 40 for discharging the processed powder. A first space 47 before the space between the classification rotor 35 and the dispersion rotor 32-liner 34 is introduced into the classification rotor 35. A cylindrical guide ring 36 which is a guide means for partitioning the particles, from which fine powder has been classified and removed by the classification means, into a second space 48 for introducing the particles into the surface treatment means. A gap portion between the dispersion rotor 32 and the liner 34 is a surface modification zone, and the classification rotor 35 and its peripheral portion are classification zones.

  In the surface reforming apparatus, when a finely pulverized product is introduced from the raw material supply port 39 with the discharge valve 41 closed, the charged finely pulverized product is first sucked by a blower (not shown), and is classified by the classification rotor 35. Classified. At that time, the classified fine powder having a predetermined particle size or less is continuously discharged and removed out of the apparatus, and the coarse powder having a predetermined particle size or more passes along the inner periphery (second space 48) of the guide ring 36 by centrifugal force. The circulating flow generated by the dispersion rotor 32 is guided to the surface modification zone.

  The raw material guided to the surface modification zone receives a mechanical impact force between the dispersion rotor 32 and the liner 34 and is subjected to surface modification treatment. The surface-modified particles whose surface has been modified are guided to the classification zone along the outer periphery (first space 47) of the guide ring 36 by the cold air passing through the machine. The fine powder generated at this time is again discharged out of the machine by the classification rotor 35, and the coarse powder is returned to the surface reforming zone again through the circulating flow and repeatedly undergoes the surface modifying action. After a certain period of time, the discharge valve 41 is opened and the surface modified particles are recovered from the discharge port 40.

  As a result of investigations by the present inventors, in the surface modification step using the surface modification apparatus, the time (cycle time) from the introduction of the finely pulverized product through the raw material supply port 39 to the release valve opening and the rotation of the dispersion rotor The number is important in controlling the sphericity of the toner. To increase the sphericity, it is effective to increase the cycle time or increase the peripheral speed of the dispersion rotor.

  The black toner of the present invention is mainly classified into a one-component contact developing method that does not require a carrier and a two-component developing method that includes a toner and a magnetic carrier, but can be used in any developing method.

  When the black toner of the present invention is mixed with a magnetic carrier and used as a two-component developer, examples of the magnetic carrier include an oxidized or unoxidized iron powder on the surface; iron, lithium, calcium, magnesium, nickel, Contains metal particles such as copper, zinc, cobalt, manganese, chromium, rare earth, alloy particles or oxide particles thereof; magnetic material such as ferrite; magnetic material and binder resin that holds the magnetic material in a dispersed state Magnetic material-dispersed resin carriers (so-called resin carriers); generally known ones can be used.

  When the black toner of the present invention is used as a two-component developer, the mixing ratio is preferably 2 to 20 parts by mass with respect to 100 parts by mass of the magnetic carrier, and preferably 4 to 15 parts by mass. The following is more preferable. By setting the amount within the above range, toner scattering can be reduced.

  The two-component developer containing the black toner and the magnetic carrier of the present invention is replenished to the developing device, and at least used for the two-component developing method for discharging the excess magnetic carrier inside the developing device from the developing device. It can also be used as a developer. When used as a replenishing developer, the mixing ratio is preferably 2 parts by mass or more and 50 parts by mass or less of toner with respect to 1 part by mass of the magnetic carrier from the viewpoint of enhancing the durability of the developer.

  The methods for measuring various physical properties in the present invention will be described below.

<Measurement of work function>
For the work function, a surface analyzer (AC-2, low energy electronic counting method manufactured by Riken Keiki Co., Ltd.) was used. In the present invention, a deuterium lamp is used in the apparatus, the setting value of the irradiation light amount is 500 nW, monochromatic light is selected by a spectroscope, and the spot size is 4 mm square. The energy scanning range is set to 4.20 to 6.20 eV, the interval is set to 0.05 eV, and the sample is irradiated at a measurement time of 10 sec / 1 point to detect photoelectrons emitted from the sample surface. The work function is measured with a repeatability (standard deviation) of 0.02 eV. When measuring powder, a cell for powder measurement was used.

FIG. 2 is a schematic view of a cell for powder measurement. (A) is a top view of the cell 10, (b) is a side view partly cut away, and (c) is a perspective view. The cell 10 has a sample accommodating recess 10a having a diameter of 15 mm and a depth of 3 mm at the center of a stainless steel disk having a diameter of 30 mm and a height of 5 mm. After the sample is placed in the recess 10a without being squeezed using a weighing sledge, the measurement cell is fixed on the specified position of the sample stage with the knife edge being used to level the surface and leveling. I do.

  And as shown in FIG.3 (b), the measurement cell (a) is fixed on the prescription | regulation position of the sample stand 11 so that an irradiation surface may become smooth with respect to the direction where the measurement light L is irradiated. Thereby, the emitted photoelectrons 12 are efficiently detected by the detector (photoelectron tube) 13. In this surface analysis, when the excitation energy of monochromatic light is scanned from low to high, photon emission starts from a certain energy value (eV), and this energy value is called a work function (eV). FIG. 4 shows an example of a chart obtained for carbon black. FIG. 4 shows the excitation energy (eV) as the horizontal axis and the normalized photon yield (photon yield per unit photon as the nth power) as the vertical axis, and a constant slope (Y / eV) is obtained. . In the case of FIG. 4, the work function is indicated by an excitation energy value (eV) at the inflection point (A). A specific inflection point (A) is obtained by the following regression curve: the value at which the normalized photon yield increases continuously between the excitation energy 4.20 eV to 6.20 eV of irradiation light. A regression curve is selected from the first to fourth points selected from four or more points. The first point is the fulcrum. Ground line: A ground line is selected from the excitation energy 4.20 eV of irradiation light to a point not including a fulcrum. The excitation energy value at the intersection of the ground line and the regression curve is defined as a work function. In addition, in order to ensure data reproducibility, the samples left for 24 hours under the conditions of temperature 23 ° C./humidity 60 RH% were used as measurement samples.

<DBP oil absorption>
Measurement is performed in accordance with JIS K 6211 oil absorption amount A method using an abstract meter using dibutyl phthalate as oil.

<Weight average particle diameter of toner (D4)>
The weight average particle diameter (D4) of the toner is a precision particle size distribution measuring apparatus “Coulter Counter Multisizer by pore electrical resistance method equipped with an aperture tube of 100 μm.
3 ”(registered trademark, manufactured by Beckman Coulter) and attached dedicated software“ Beckman Coulter Multisizer 3 Version 3.51 ”(manufactured by Beckman Coulter, Inc.) for measurement condition setting and measurement data analysis, Measurement was performed with 25,000 effective measurement channels, and the measurement data was analyzed and calculated.
As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.
Prior to measurement and analysis, the dedicated software was set as follows.
In the “Standard measurement method (SOM) change screen” of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman・ Set the value obtained using Coulter). The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. Also, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the aperture tube flash after measurement is checked.
In the “pulse to particle size conversion setting screen” of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic aqueous solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rotations / second. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.
(2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder pH 7 precision measurement is used as a dispersant therein. About 0.3 ml of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel (made by Wako Pure Chemical Industries, Ltd.) 3 times with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and placed in a water tank of an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikkiki Bios Co., Ltd.) having an electrical output of 120 W. A predetermined amount of ion-exchanged water is put, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the analysis / volume statistics (arithmetic average) screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Average circularity of toner>
The average circularity of the toner was measured with a flow type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during calibration.
The measurement principle of the flow-type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation) is to take a flowing particle as a still image and perform image analysis. The sample added to the sample chamber is fed into the flat sheath flow cell by a sample suction syringe. The sample fed into the flat sheath flow is sandwiched between sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Further, since the flow is flat, the image is taken in a focused state. The particle images are picked up by a CCD camera, and the picked-up image is 512 pixels × 512 pixels in one field of view, and image processing is performed at an image processing resolution of 0.37 × 0.37 μm per pixel, and the contour of each particle image Extraction is performed, and the projected area and perimeter of the particle image are measured.
Next, the projected area S and the perimeter L of each particle image are obtained. Using the area S and the perimeter L, the equivalent circle diameter and the circularity are obtained. The circular equivalent diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity is a value obtained by dividing the circumference of the circle obtained from the circular diameter by the circumference of the projected particle image. Defined and calculated by the following formula.
Circularity C = 2 × (π × S) ^1/2 / L
When the particle image is a perfect circle, the circularity becomes 1.000, and the circularity becomes smaller as the degree of irregularities on the outer periphery of the particle image increases.
After calculating the circularity of each particle, the range of the circularity of 0.200 or more and 1.000 or less is assigned to 800 divided channels, and the average value is calculated using the center value of each channel as a representative value to calculate the average circularity. .

As a specific measurement method, 0.02 g of a surfactant as a dispersant, preferably sodium dodecylbenzenesulfonate, is added to 20 ml of ion-exchanged water, 0.02 g of a measurement sample is added, an oscillation frequency of 50 kHz, electrical Dispersion treatment was performed for 2 minutes using a desktop ultrasonic cleaner / disperser with an output of 150 W (for example, “VS-150” (manufactured by Velvo Crea Co., Ltd.)) to obtain a dispersion for measurement. Is suitably cooled so that the temperature becomes 10 ° C. or higher and 40 ° C. or lower.
The flow type particle image analyzer equipped with a standard objective lens (10 ×) was used for the measurement, and a particle sheath “PSE-900A” (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, 3000 toner particles are measured in the total count mode in the HPF measurement mode, and the binarization threshold at the time of particle analysis is 85%. The analysis particle diameter was limited to a circle equivalent diameter of 2.00 μm to 200.00 μm, and the average circularity of the toner was determined.
In the measurement, automatic focus adjustment is performed using standard latex particles (for example, Duke Scientific 5200A diluted with ion-exchanged water) before the measurement is started. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.
In the examples of the present application, a flow type particle image analyzer that has been issued a calibration certificate issued by Sysmex Corporation is used, and the analysis particle diameter is limited to a circle equivalent diameter of 2.00 μm or more and 200.00 μm or less. Measured under the measurement and analysis conditions when the calibration certificate was received.

<Measurement method of peak molecular weight (Mp), number average molecular weight (Mn), and weight average molecular weight (Mw) of resin or toner>
The peak molecular weight (Mp), number average molecular weight (Mn), and weight average molecular weight (Mw) are measured by gel permeation chromatography (GPC) as follows.
First, a sample is dissolved in tetrahydrofuran (THF) at room temperature over 24 hours. As the sample, resin or toner is used. The obtained solution is filtered through a solvent-resistant membrane filter “Maescho Disc” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of the component soluble in THF is about 0.8% by mass. Using this sample solution, measurement is performed under the following conditions.
Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml
In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F— 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) are used.

<Peak temperature of maximum endothermic peak of wax, glass transition temperature Tg of binder resin>
The peak temperature of the maximum endothermic peak of the wax is measured according to ASTM D3418-82 using a differential scanning calorimeter “Q1000” (manufactured by TA Instruments). The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.
Specifically, about 10 mg of wax is precisely weighed, put in an aluminum pan, and an empty aluminum pan is used as a reference. Measurement is performed at 10 ° C./min. In the measurement, the temperature is once raised to 200 ° C., subsequently lowered to 30 ° C., and then the temperature is raised again. The maximum endothermic peak of the DSC curve in the temperature range of 30 ° C. to 200 ° C. in the second temperature raising process is defined as the maximum endothermic peak of the wax of the present invention.
Further, the glass transition temperature (Tg) of the binder resin is measured by precisely weighing about 10 mg of the binder resin in the same manner as the peak temperature measurement of the maximum endothermic peak of the wax. Then, a specific heat change is obtained in the temperature range of 40 ° C to 100 ° C. At this time, the intersection of the intermediate point line of the baseline before the specific heat change and after the specific heat change and the differential heat curve is defined as the glass transition temperature Tg of the binder resin.

<Measurement Method of Volume Distribution Standard 50% Particle Size (D50) of Magnetic Carrier>
For measuring the 50% particle size (D50) of the magnetic carrier based on the volume distribution, the sample distribution machine for dry measurement “One Shot Dry” is used in the laser diffraction / scattering particle size distribution measuring device “Microtrack MT3300EX” (manufactured by Nikkiso Co., Ltd.). A type sample conditioner “Turbotrac” (manufactured by Nikkiso Co., Ltd.) was attached. As the supply conditions of Turbotrac, a dust collector was used as a vacuum source, the air volume was about 33 liters / sec, and the pressure was about 17 kPa. Control is automatically performed on software. For the particle size, a 50% particle size (D50), which is a cumulative value based on volume, is obtained. Control and analysis are performed using attached software (version 10.3.3-202D).
The measurement conditions are as follows.
SetZero time: 10 seconds Measurement time: 10 seconds Number of measurements: 1 time Particle refractive index: 1.81
Particle shape: Non-spherical measurement upper limit: 1408 μm
Measurement lower limit: 0.243 μm
Measurement environment: Approx. 23 ° C / 50% RH

  Specific examples of the present invention will be described below, but the present invention is not limited to these examples.

<Example of toner production>
(Production example of toner 1)
The following materials were weighed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube.
-290 parts by mass of terephthalic acid-800 parts by mass of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane-1 part by mass of titanium dihydroxybis (triethanolaminate) Then heated to 200 ° C Then, the reaction was carried out for 9 hours while removing water produced while introducing nitrogen. Furthermore, 58 parts by mass of trimellitic anhydride was added, heated to 170 ° C., and reacted for 3 hours to synthesize Resin 1. The molecular weight of resin 1 determined by GPC was weight average molecular weight (Mw) 60,000, number average molecular weight (Mn) 5,400, peak molecular weight (Mp) 9,800, and glass transition point (Tg) 60 ° C. .

Also,
・ 20 parts by mass of low density polyethylene (Mw1,600, Mn900, endothermic peak 100 ° C.)
Styrene 64 parts by mass n-butyl acrylate 13.5 parts by mass Acrylonitrile 2.5 parts by mass were charged into an autoclave and the system was replaced with N ₂ , and then maintained at 180 ° C. while stirring at elevated temperature. A graft polymer in which 50 parts by mass of a 2% by mass t-butyl hydroperoxide xylene solution was continuously dropped into the system for 4.5 hours, the solvent was separated and removed after cooling, and the copolymer was grafted onto polyethylene. A was obtained. When the molecular weight of the graft polymer was measured, they were Mw 7,300 and Mn 3,100.

-Resin 1 100.0 parts by mass-Paraffin wax 5.0 parts by mass (DSC maximum endothermic peak: 65 ° C work function: 5.76 eV)
Graft polymer A 5.0 parts by mass Carbon black 6.0 parts by mass (average primary particle size: 31 nm, DPB oil absorption: 40 ml / 100 g, work function: 4.71e
V)
・ C. I. Pigment Blue 15: 3 (work function: 5.06 eV) 1.7 parts by mass I. Pigment Yellow 74 (work function: 5.65 eV) 0.9 parts by mass I. Pigment Red 57: 1 (work function: 5.39 eV) 1.4 parts by mass The above materials were thoroughly mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) and then set to a temperature of 100 ° C. The mixture was melt-kneaded in a biaxial kneader (PCM-30 type, manufactured by Ikekai Tekko Co., Ltd.). The obtained kneaded product was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized product 1. Next, the obtained coarsely pulverized product 1 was produced using a turbo mill (T-250: RSS rotor / SNB liner) manufactured by Turbo Industry Co., Ltd. to produce a finely pulverized product 1 having a size of about 5 μm.

Next, the obtained finely pulverized product was charged into the surface modifying apparatus by 1.3 kg at a time using the surface modifying apparatus shown in FIG. The surface treatment was performed for 60 seconds at a rotational speed of the dispersion rotor 32 of 5,300 rpm (rotational peripheral speed: 119 m / sec) while removing fine particles with the rotational speed of the classification rotor 35 of 7,400 rpm. Finely pulverized material was introduced from the raw material supply port 39, and after processing for 70 seconds, the product discharge valve 41 was opened to take out the toner particles 1 as a processed product.
At this time, in this embodiment, ten square disks 33 are installed on the upper part of the dispersion rotor 32, the distance between the guide ring 36 and the square disk 33 on the dispersion rotor 32 is 30 mm, and the dispersion rotor 32 and the liner 34 are arranged. Was set at 5 mm. The blower air volume was 14 m ³ / min, the temperature of the refrigerant passed through the jacket and the cold air temperature T1 were −20 ° C. As a result of repeated operation for 20 minutes in this state, the temperature T2 behind the classification rotor 35 was stabilized at 25 ° C.

The obtained toner particles 1 had a weight average particle diameter (D4) of 5.9 μm and an average circularity of 0.955. To 100.0 parts by mass of toner particles 1 thus obtained, 0.8 part by mass of STT-30A (manufactured by Titanium Industry Co., Ltd.) and 1.0 part by mass of AEROSIL R972 (manufactured by Nippon Aerosil Co., Ltd.) were externally added and mixed, and toner 1 Got.

(Production example of toner 2)
As shown in Table 1, except that the raw material formulation and the mixing ratio were changed, the rotational speed of the dispersion rotor of the surface reformer was changed to 5,800 rpm (rotational peripheral speed: 130 m / sec), and the processing time was changed to 75 seconds. In the same manner as in the toner 1 production example, toner 2 was obtained.

(Production example of toners 3 to 12)
As shown in Table 1, toners 2 to 12 were obtained in the same manner as in the production example of toner 1 except that the raw material formulation and the blending ratio were changed. Table 2 shows the physical properties of Toners 1 to 12.

Next, an example of manufacturing a magnetic carrier will be described.
<Example of manufacturing magnetic carrier>
4.0% by mass of a coupling agent (3- (2-aminoethylaminopropyl) trimethoxysilane) is added to each of magnetite powder and hematite powder having a number average particle size of 0.30 μm, and 100 in a container. Each fine particle was processed by high-speed mixing and stirring at a temperature of 0 ° C. or higher.
・ Phenol 10 parts by mass ・ Formaldehyde solution 15 parts by mass (formaldehyde 40%, methanol 10%, water 50%)
-Treated magnetite 80 parts by weight-Treated hematite 4 parts by weight The above materials, 5 parts by weight of 28% ammonia water, and 20 parts by weight of water are placed in a flask, and heated to 85 ° C in 30 minutes while stirring and mixing. The resulting phenol resin was cured by a polymerization reaction for 3 hours. Thereafter, the cured phenol resin was cooled to 30 ° C., water was further added, the supernatant was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 mmHg or less) at a temperature of 60 ° C. to obtain a spherical magnetic substance-containing resin carrier core in which the magnetic substance was dispersed.

  As the coating material, a copolymer of methyl methacrylate and styrene (copolymerization ratio (mass% ratio) 8: 2, weight average molecular weight 44,000) was used. A carrier coat solution containing 10% by mass of the copolymer of methyl methacrylate and styrene was prepared using toluene so that the amount would be 1 part by mass with respect to 100 parts by mass of the magnetic material-dispersed resin core. In addition, 0.4 parts by mass of a crosslinked melamine resin (number average particle size 200 nm) and 0.6 parts by mass of carbon black (number average particle size 30 nm, DBP oil absorption 50 ml / 100 g) were mixed with this carrier coat solution by a homogenizer. . Next, the magnetic material-dispersed resin core was put into a universal stirrer, and while stirring at 70 ° C., the carrier coat solution was dropped, the solvent was removed, and coating was performed. Further, the mixture was stirred at 100 ° C. for 2 hours, cooled and crushed after heat treatment. Thereafter, it was classified with a 200-mesh sieve to obtain a magnetic carrier having a volume distribution standard 50% particle size (D50) of 38 μm.

<Example 1>
A two-component developer was prepared using the toner 1 thus prepared and a magnetic carrier. The two-component developer was blended in a proportion of 10.0% by weight of toner and 90.0% by weight of magnetic carrier and mixed for 5 minutes with a V-type mixer.

As an image forming apparatus, a digital commercial printing printer imagePRESSSC1 modified by Canon was used, and the developer was put in a developing device at a black position to form an image for evaluation. As a modification, the mechanism for discharging the excess magnetic carrier inside the developing device from the developing device was removed. The amount of the FFh image (solid image) on the paper was adjusted to 0.45 mg / cm ² . The FFh image is a value in which 256 gradations are displayed in hexadecimal notation, where 00h is the first gradation (white background portion) of 256 gradations and FFh is the 256th gradation (solid portion) of 256 gradations. Under the above conditions, a 50,000-sheet durability test was performed using the original document (A4) of the FFh image, and the following evaluation was performed.
Printing environment Normal temperature and humidity environment: Temperature 23 ° C / Humidity 60% RH (hereinafter “N / N”)
High-temperature and high-humidity environment: Temperature 30 ° C / Humidity 80% RH (hereinafter “H / H”)
Normal temperature and low humidity environment: Temperature 23 ° C / Humidity 5% RH (hereinafter "N / L")
Durable image ratio Normal temperature and humidity environment: 5%
High temperature and high humidity environment: 20%
Room temperature and low humidity: 2%
Paper Color laser copier paper (81.4 g / m ² )
(Sold from Canon Marketing Japan Inc.)

Evaluation is based on the following evaluation methods, and the results are shown in Table 3.
[Evaluation methods and standards]
1) Change in image density by endurance test Before and after the endurance test in each environment, three FFh images each having a size of 5 cm × 5 cm were output, and the image density of the third sheet was measured. The image density was measured, and the density difference before and after durability was evaluated. The image density was measured with an X-Rite color reflection densitometer (Color reflection densitometer X-Rite 404A).
A: 0.00 or more and less than 0.07 (very good)
B: 0.07 or more and less than 0.15 (good)
C: 0.15 or more and less than 0.25 (practical level)
D: 0.25 or more (practical difficulty level)

2) Change in image density due to standing After endurance at N / N and H / H, the evaluation machine itself was left in each environment for 3 days, and then one FFh image with a size of 5 cm × 5 cm was output. The image density was measured, and the density difference before and after being left was evaluated. The density was measured using the aforementioned X-Rite color reflection densitometer.
A: 0.00 or more and less than 0.05 (very good)
B: 0.05 or more and less than 0.10 (good)
C: 0.10 or more and less than 0.20 (practical level)
D: 0.20 or more (practical level)

3) Image uniformity (density unevenness)
The image uniformity before and after endurance in each environment was evaluated. Three 90h images were output on the entire surface of A3 paper, and the third image was used for evaluation. The image uniformity was evaluated by measuring the image density at five locations and determining the difference between the maximum value and the minimum value. The density was measured using the aforementioned X-Rite color reflection densitometer.
A: Less than 0.04 (very good)
B: 0.04 or more and less than 0.08 (good)
C: 0.08 or more and less than 0.12 (Acceptable level in the present invention)
D: 0.12 or more (not acceptable in the present invention)

4) Fog The fog before and after endurance in each environment was evaluated. Ten 00h images were output in each environment, and the average reflectance Dr (%) on the tenth sheet of paper was measured with a reflectometer (“REFLECTOMETER MODEL TC-6DS” manufactured by Tokyo Denshoku Co., Ltd.). On the other hand, the reflectance Ds (%) on paper on which no image was output was measured, and the fog (%) was calculated from the following equation.
Fog (%) = Dr (%) − Ds (%)
A: Less than 0.5% (very good)
B: 0.5% or more and less than 1.0% (good)
C: 1.0% or more and less than 2.0% (practical level)
D: 2.0% or more (practical level)

<Examples 2 to 9 and Comparative Examples 1 to 3>
In the same manner as in Example 1, for the prepared toners 2 to 12, a two-component developer was prepared using each toner and carrier, and evaluation was performed in the same manner as in Example 1. The evaluation results are shown in Table 3.

It is a schematic diagram of the surface modification apparatus applicable to this invention. It is the schematic of the cell for powder measurement. It is the schematic of the surface analyzer measuring method used by this invention. It is an example of the chart obtained about carbon black measured with the surface analyzer.

10 Cell 10a Sample Containing Recess 11 Sample Base 12 Photoelectron 13 Detector 30 Casing 31 Jacket 32 Dispersion Rotor 33 Disc or Pin 34 Liner 35 Classification Roller 36 Guide Ring 37 Material Input Port 38 Material Supply Valve 39 Material Supply Port 40 Powder Drainage Outlet 41 Discharge valve 42 Product extraction port 43 Top plate 44 Powder discharge part 45 Powder discharge port 46 Cold air introduction port 47 First space 48 Second space 49 Surface modification zone 50 Classification zone

Claims (4)

A black toner containing at least a binder resin, carbon black, a plurality of colorants other than carbon black, and a wax, wherein the following relational expressions (1) and (2) are satisfied:
0.00 <Wf (P1) −Wf (CB) ≦ 0.50 (1)
0.00 <Wf (W) −Wf (P2) ≦ 0.50 (2)
(Wf represents a work function, and Wf (CB) and Wf (W) represent the work function Wf of carbon black and wax, respectively. Among a plurality of colorants, the work function Wf is between Wf (CB) and Wf (W). The colorant P1 is the minimum colorant and the colorant P2 is the maximum colorant, and Wf (P1) and Wf (P2) denote the work functions Wf of the colorant P1 and the colorant P2, respectively. .)   The black toner according to claim 1, wherein the black toner has a maximum proximity difference in work function Wf of a colorant other than carbon black of 0.50 or less.   3. The black toner according to claim 1, wherein the black toner has a maximum proximity difference in work function Wf between carbon black, a colorant other than carbon black, and a wax, of 0.40 or less. 4. In the black toner, the addition amount M (CB) (parts by mass) of carbon black to 100 parts by mass of the binder resin and the total addition amount M (P) (parts by mass) of colorants other than carbon black have the following relationship: The black toner according to claim 1, wherein the formula (3) is satisfied.
0.10 ≦ M (P) / M (CB) ≦ 5.00 (3)

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