JP2012002977A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner, which does not induce fixing tailing even on a rough paper that is left to stand under high temperature and high humidity conditions, which favorably suppresses thinning on a rough surface, and which prevents development stripes in long-term use.SOLUTION: A toner comprises toner particles containing a binder resin and a colorant. The toner particles are produced by a suspension polymerization method; and the binder resin is styrene acrylic resin. A THF soluble content S(p) derived from the styrene acrylic resin component when the toner is extracted using a Soxhlet extractor with THF is 50 mass% or more and 85 mass% or less based on the styrene acrylic resin. The THF soluble content S(p) shows a peak molecular weight Mp(p) of 12000 or more and 16000 or less. When the styrene acrylic resin is dissolved from the surface up to 30 mass% by using an acetone/water mixed solvent in a proportion of 95:5, the peak molecular weight Mp(q) of the styrene acrylic resin satisfies a formula of 0.60≤Mp(q)/Mp(p)≤0.95.

Description

  The present invention relates to a toner used in a recording method using electrophotography or the like.

  In recent years, printers and copiers have become more energy-saving to reduce the power required for fixing, and there is a strong demand for consistently high image quality even in various environments.

  Here, paying attention to various environments, it has been found that specific problems occur in specific environments and conditions. Specifically, when printing on so-called rough paper having many irregularities left in a high-temperature and high-humidity environment, there is a problem that toner is scattered on the rear end side of the image.

  This problem is caused by a sudden flow of water vapor from the media such as paper due to the heat in the fixing unit, and the toner is blown away. In the line image such as a horizontal line, the height of the toner on the line is high. It is easy to happen when it is developed with. This problem is hereinafter referred to as “fixing tailing”.

  From the viewpoint of toner, there has been proposed a toner that improves the low-temperature fixability of the toner in order to prevent fixing tailing and that can be easily fixed before water vapor generated from the media is generated (Patent Document 1). In addition, to improve the fixability, we proposed a method that uses a chain transfer agent and a polyfunctional monomer to lower the molecular weight of the binder resin to achieve sufficient low-temperature fixing performance and ensure high-temperature offset resistance. (Patent Document 2). Further, a toner having a more precise low-temperature fixability by controlling the amount of the low molecular weight component has also been proposed (Reference Document 3).

  However, even when these toners are used, the improvement of fixing tailing is insufficient on rough paper with many irregularities left in a high temperature and high humidity environment, and there is room for improvement. Further, in the case of a toner with improved low-temperature fixability, the toner is likely to be fused on the toner carrier, and as a result, development streaks are likely to occur, and there is room for improvement. At the same time, in the case of toner with improved low-temperature fixability, the toner on the convex portion of the paper flows out into the concave portion, so that “glossiness” in which the background of the paper can be seen easily occurs and there is room for improvement. In other words, there is a trade-off relationship between fixing tailing and rustling, and there is room for improvement in the breakthrough technology for solving both problems simultaneously.

JP 2008-102390 A JP 2005-173479 A JP 2006-349898 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and is to provide a toner that does not cause a fixing tail even on rough paper left under high temperature and high humidity. It is another object of the present invention to provide a toner having excellent durability and stability that does not cause roughness and does not occur over a long period of time during development and fogging.

The present invention relates to a toner having toner particles containing at least a binder resin and a colorant and an inorganic fine powder.
The toner particles are produced by a suspension polymerization method, the binder resin is a styrene acrylic resin,
A THF-soluble component S (p) derived from a component of the styrene acrylic resin when the toner is subjected to Soxhlet extraction with tetrahydrofuran (THF) in an amount of 50% by mass to 85% by mass with respect to the styrene acrylic resin;
The THF-soluble component S (p) has a peak molecular weight Mp (p) in gel permeation chromatography (GPC) of 12000 or more and 16000 or less,
When 30% by mass of the styrene acrylic resin was dissolved from the surface using a 95: 5 mixed solvent (acetone solution) of acetone / water, the peak molecular weight Mp (q) at GPC of the styrene acrylic resin was expressed by the following formula (1 It is related with the toner characterized by satisfy | filling.
Formula (1) 0.60 <= Mp (q) / Mp (p) <= 0.95

  It is possible to obtain a toner that does not cause a fixing tail even on rough paper left under high temperature and high humidity. Further, no roughness occurs, development streaks and fog do not occur over a long period of use, and an excellent image can be obtained.

FIG. 2 is a schematic cross-sectional view illustrating an example of an image forming apparatus that can suitably use the toner of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of an image forming apparatus that can suitably use the toner of the present invention.

  The present inventors have found that by using the present invention, fixing tailing and roughness can be improved at the same time. The reason why both problems can be solved at the same time will be explained in order.

First, regarding fixing tailing, as described above, fixing tailing is considered to occur by the following mechanism.
(1-1) The medium is heated in the fixing unit.
(1-2) A water vapor flow is suddenly generated from the media.
(1-3) The water vapor stream blows away the unfixed toner on the medium.

In contrast, the present inventors (1-4) promptly anchor the toner and paper in the fixing unit.
(1-5) The surface state of the toner is controlled, and a network of toners is quickly formed during fixing.

  The inventors have found that fixing tailing can be improved by controlling the above two points, and have reached the present invention.

  According to the study by the present inventors, for the anchoring of (1-4), the viscosity of the toner in the fixing portion can be controlled by controlling the peak molecular weight of the binder resin and the THF soluble content. It turns out to be effective. Furthermore, it was found that for the formation of the network of (1-5), it is effective to reduce the molecular weight of the binder resin existing in the vicinity of the toner surface and to quickly soften the toner surface. At this time, the inventors have found that about 30% by mass of the binder resin from the surface of the binder resin contained in the toner is effectively used for forming a network between the toners. 30% by mass of the binder resin corresponds to about 10% of the radius of the toner. When about 10% of the binder resin is softened, this component stays on the remaining about 90% of the component and entrains adjacent toner particles, thereby forming a bond between the toners. For this reason, controlling the molecular weight of the binder resin present at about 30% by mass from the surface of the binder resin is particularly effective for forming a toner network.

Next, the roughness is considered to occur by the following mechanism.
(2-1) In the fixing step, the toner receives heat from the fixing device.
(2-2) The toner positioned on the convex portion of the medium receives more heat and pressure than the toner positioned on the concave portion.
(2-3) The toner located on the convex portion of the medium flows out into the concave portion of the medium.
(2-4) Density of density occurs depending on the unevenness of the media.

On the other hand, the present inventors consider that the following points are particularly effective for improving the roughness.
(2-5) The amount of the crosslinked structure of the binder resin is controlled to suppress a decrease in melt viscosity.
(2-6) Suppressing the decrease in melt viscosity without excessively decreasing the molecular weight of the binder resin.
In particular, with regard to (2-6), according to the study by the present inventors, the molecular weight of the binder resin present in about 70% by mass from the center of the binder resin contained in the toner is not reduced excessively, It was found that a significant decrease in viscosity can be suppressed and is effective in improving roughness. This about 70% by mass is a value corresponding to about 90% of the radius of the toner particles. By controlling the melt viscosity of this amount of the binder resin, the toner particles are likely to behave as an elastic body, and are difficult to flow out from the convex portion of the medium to the concave portion.

  As described above, the present invention solves both the problem of fixing tailing and rustiness, which were in a conventional trade-off relationship, by controlling the molecular weight of the toner binder resin near the toner surface and near the toner center. I can do it.

  Considering the fixing tail, first, regarding the anchoring of the toner (1-4) and paper, the toner of the present invention is capable of THF derived from a binder resin when subjected to Soxhlet extraction with tetrahydrofuran (THF). The dissolved component S (p) is 50% by mass or more and 85% by mass or less. Furthermore, the peak molecular weight Mp (p) by GPC measurement of the THF-soluble matter is 12000 or more and 16000 or less.

  Considering the concave portion of rough paper having large irregularities, by controlling the above Mp (p) to 12000 or more and 16000 or less, the toner is likely to be deformed even in the concave portion that is hardly subjected to heat at the fixing portion. For this reason, the toner is easily anchored to the paper even in the concave portion. On the other hand, when considering the convex portion, the convex portion receives a large amount of heat in the fixing portion. For this reason, the viscosity of the toner is excessively lowered and flows out into the surrounding concave portions, and as a result, the so-called “glossy” in which the paper is washed out becomes a problem. On the other hand, by adjusting the THF soluble content S (p) to 50% by mass or more and 85% by mass or less, even if the toner receives a large amount of heat, the toner retains elasticity and suppresses the outflow to the recess. It becomes easy to do.

Next, regarding the formation of a network between toners of (1-5), the toner of the present invention uses 30% by mass of the styrene acrylic resin from the surface using a 95: 5 mixed solvent (acetone solution) of acetone / water. When the styrene acrylic resin is dissolved, the peak molecular weight Mp (q) in GPC of the styrene acrylic resin satisfies the following formula (1).
Formula (1) 0.60 <= Mp (q) / Mp (p) <= 0.95
[Mp (p) represents the peak molecular weight of the binder resin, and Mp (q) represents the peak molecular weight of the binder resin present near the surface of the toner. ]

  Compared with THF, the acetone solution is a relatively poor solvent and can be gradually dissolved from the toner particle surface depending on the impregnation time. In order to dissolve 30% by mass of the styrene acrylic resin from the surface, the impregnation time of the toner in the acetone solution is appropriately determined in view of the influence of the molecular weight of the styrene acrylic resin, other materials, and further the insoluble content of tetrahydrofuran (THF). It is necessary to adjust. The toner of the present invention may be a core / shell toner having a shell layer. In this case, when analyzing from the toner, it is necessary to appropriately adjust the impregnation time of the acetone solution in consideration of the influence of the shell layer. When there is a possibility that Mp (q) is affected by the molecular weight of the material of the shell layer, Mp (q) can be obtained by analysis of the acetone-soluble component and the cyclohexane-soluble component. In the present invention, when a toner having a core / shell structure is formed by a suspension polymerization method, a styrene acrylic resin and a shell layer are formed by using a nonpolar solvent to impart polarity to the resin for the shell and form a shell layer. It is possible to separate the materials. In some cases, Mp (q) can also be obtained by producing and analyzing toner particles consisting of only the core layer not including the shell layer.

  When Mp (q) / Mp (p) is 0.60 or more and 0.95 or less, the peak molecular weight Mp (q) of the binder resin in the vicinity of the surface of the toner is greater than the peak molecular weight Mp (p) of the binder resin. Means low. That is, it means that a low molecular weight substance exists in the vicinity of the toner surface.

  When the molecular weight of the low molecular weight material is satisfied, since the low molecular weight material has a lower molecular weight than the peak molecular weight Mp (p) of the toner, it can be softened faster than the entire binder resin is softened. For this reason, before the toner is fixed on the paper in the fixing unit, the toner surfaces are bonded to each other to form a network between the toners, and even on rough paper with many irregularities, the toner is not easily blown off by water vapor. Further, when Mp (q) / Mp (p) is 0.60 or more and 0.95 or less, the toner is not fused on the toner carrying member, and development streaks can be suppressed.

  When Mp (q) / Mp (p) is less than 0.60, the molecular weight of the low molecular weight substance existing near the toner surface becomes too small. For this reason, good developability cannot be obtained and development streaks tend to occur, which is not preferable. On the other hand, when Mp (q) / Mp (p) is higher than 0.95, the toner surfaces cannot be softened, and the toner surfaces cannot be bound to each other. For this reason, the toner tends to be blown off on the rough paper, which is not preferable.

  Therefore, in the present invention, it is important that Mp (q) / Mp (p) is 0.60 or more and 0.95 or less. More preferably, the range of Mp (q) / Mp (p) is 0.60 or more and 0.85 or less.

  In this way, by controlling S (p), Mp (p), M (q) / M (p) within the above ranges, the effect of suppressing the fixing tailing is greatly enhanced, and under severe conditions. Improve fixing tailing can be achieved.

  As described above, by using the present invention, it is possible to improve fixing tailing and roughness at the same time. In addition, it is possible to obtain an excellent image free from development streaks and fog over a long period of use.

In order to control Mp (q) / Mp (p) from 0.60 to 0.95, it is important to produce toner particles by suspension polymerization. In addition, in the reaction step of the suspension polymerization method, it is possible to control by suppressing the following points.
(3-1) The polymerization near the center is completed at an early stage, and the polymerizable monomer remains in the vicinity of the droplet surface.
(3-2) A polymerization initiator is newly added to react the remaining polymerizable monomer.

  In order for the polymerizable monomer to remain in the vicinity of the droplet surface, it is important to temporarily lower the polymerization reaction temperature with a relatively small cross-linked structure formed in the binder resin. Yes. Although the detailed mechanism is unknown, the shrinkage of the cross-linked structure occurs due to the temperature decrease, the relatively small cross-linked structure moves into the toner (droplet) particles, and the polymerizable monomer is formed on the toner (droplet) particle surface. I think it will be easy to survive. In addition, it is a method of forming a relatively small cross-linked structure. However, if the molecular weight of the binder resin is low, the cross-linked structure formed in the binder resin is small because the molecular chain before cross-linking is short. We are using. On the other hand, when the molecular weight of the binder resin is relatively high, the cross-linked structure to be formed becomes too large, so that the movement of the cross-linked structure is limited, and the polymerizable monomer remains in the droplets evenly. It is difficult to leave the polymerizable monomer on the toner particle surface.

  Means for lowering the peak molecular weight Mp (p) include a method of proceeding the polymerization reaction at a relatively high temperature relative to the 10-hour half-life temperature of the polymerization initiator, and increasing the amount of the polymerization initiator used. Can be mentioned. When adjusting the polymerization temperature, in order to effectively adjust the peak molecular weight Mp (p), it is preferable to proceed the polymerization reaction at a temperature higher by 25 ° C. or more than the 10-hour half-life temperature using toluene.

  Furthermore, the temporary polymerization reaction temperature decrease is preferably 10 ° C. or more and 25 ° C. or less. When the temperature is 10 ° C. or higher, the formed crosslinked structure shrinks, which is a suitable condition for the present invention. Further, when the temperature is 25 ° C. or lower, the influence on the dispersibility of the material is reduced, and it is easy to achieve a balance with various toner performances. Conversely, if the temporary polymerization reaction temperature drop is less than 10 ° C., the crosslinked structure is distributed throughout the droplet, which is not preferable. When the temperature is 25 ° C. or higher, the dispersibility of each material included in the toner particles tends to be uneven, which is not preferable.

In addition, the molecular weight of 30% by mass of the binder resin can be controlled from the toner particle surface by adding the polymerization initiator again.

  In order to initiate the polymerization reaction of the polymerizable monomer remaining in the vicinity of the surface, it is preferable to newly add a polymerization initiator when the conversion rate is 70% or more and 95% or less. When added at this timing, a cross-linked structure is formed to some extent and a sufficient amount of polymerizable monomer remains in the vicinity of the droplet surface, so that 30% by mass of the binder resin from the toner particle surface. It becomes easy to control the peak molecular weight of the binder resin to a value different from the peak molecular weight in the vicinity of the droplet center. When the conversion rate is less than 70%, the crosslinked structure is not sufficiently formed, and it becomes difficult to control the molecular weight in the vicinity of the toner particle surface. On the other hand, when the conversion rate is higher than 95%, since the remaining monomer is small, it is difficult to lower the peak molecular weight in the vicinity of the surface. Further, the amount added is the polymerization initiator added at the second time, but it is necessary to appropriately select it in consideration of the half-life temperature of the polymerization initiator, the polymerization temperature, the ease of deactivation with respect to water, and the like.

  As described above, the low molecular weight component in the vicinity of the toner surface can be controlled.

  The toner particles of the present invention must be produced by a suspension polymerization method. The reason is that, in addition to the technology essential for controlling the molecular weight described above, the integral production method in the suspension polymerization method has almost no boundary between the two layers in the binder resin. This is because the toner does not easily deform or partially peel off. On the other hand, when the binder resin has a boundary between two layers, partial peeling occurs during long-term use, and fogging and the like deteriorate, which is not preferable.

The toner of the present invention preferably satisfies the following formula (3), where S (q) is an acetone-soluble component with respect to the binder resin derived from the binder resin component when subjected to Soxhlet extraction with acetone.
Formula (3) 5.0 mass% ≦ S (p) −S (q) ≦ 25.0 mass%

  Although it is an acetone-soluble component S (q), acetone has a lower solubility of the binder resin than THF, and further has a low penetrating ability to the crosslinked structure. For this reason, the fact that S (p) -S (q) has a positive value indicates that a crosslinked structure having a coarse crosslinking density exists in the binder resin. Therefore, when S (p) -S (q) is 5.0% or more and 25.0% or less, the durability can be improved without inhibiting the anchoring of the toner particles to the paper. Is preferable.

  In order to control the S (p) -S (q) within the above range, a method of controlling the length of the molecular chain at the crosslinking site of the crosslinking agent to be added can be mentioned. By making the cross-linking site longer, the distance between cross-linking points of the cross-linked structure becomes longer, and as a result, the value of S (p) -S (q) can be controlled to be higher.

  Specific examples of the crosslinking agent that can be used in the present invention include compounds having two or more polymerizable double bonds, such as aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, and polyethylene glycol diacrylate. 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, 1,7-heptanediol diacrylate, 1,8-octanediol diacrylate, 1,9- Double such as nonanediol diacrylate, 1,10-decanediol diacrylate, 1,11-undecanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate etc. Carboxylic acid esters having two cases, divinyl aniline, divinyl ether, divinyl sulfide, divinyl compounds such as divinyl sulfone, alone is a compound having three or more vinyl groups, or used as a mixture of two or more thereof. In particular, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, 1,7-heptanediol diacrylate, 1,8-octanediol diacrylate represented by the following formula 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, and 1,11-undecanediol diacrylate have a sufficient size and flexibility in structure, and therefore, the above S (p) -S ( It is easy to control the value of q) to 5.0% or more and 25.0% or less, which is preferable. Further, the preferable addition amount of the crosslinking agent used in the toner of the present invention is 0.01 parts by mass or more and 10.00 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. A more preferable addition amount is 0.05 parts by mass or more and 2.00 parts by mass or less.

Here, R ₁ represents a hydrogen atom or a carbon group, and R ₂ represents a linear alkylene group having 3 to 12 carbon atoms.

  The toner of the present invention may have a core-shell structure, in which case the shell layer preferably contains at least a polyester resin. By including a polyester resin in the shell layer, the density is stabilized over a long period of use, and development streaks can be suppressed. The reason for this is that the core-shell structure prevents the core colorant from being exposed and suppresses the release of the release agent in the vicinity of the toner surface.

  The toner of the present invention preferably contains 1.0 to 7.0 parts by mass of the polyester resin with respect to 100 parts by mass of the binder resin. By containing 1.0 part by mass or more, the strength of the shell layer can be sufficiently secured, the density can be stabilized over a long period of use, and development streaks can be suppressed. By containing 7.0 parts by mass or less, it is less likely that the binder resin in the vicinity of the toner surface melts in the fixing unit and prevents the toners from forming a network, thereby effectively improving the fixing tail. Is possible.

  As the polyester resin used in the toner of the present invention, a saturated polyester resin, an unsaturated polyester resin, or both can be appropriately selected and used.

  As the polyester resin used in the present invention, a normal resin composed of an alcohol component and an acid component can be used, and both components are exemplified below.

  As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, and bisphenol derivatives represented by formula (I);

［式中、Ｒはエチレンまたはプロピレン基であり、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から１０である。］
あるいは式（Ｉ）の化合物の水添物、また、式（ＩＩ）で示されるジオール；

[Wherein, R is 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. ]
Or hydrogenated compound of formula (I), or diol of formula (II);

あるいは式（ＩＩ）の化合物の水添物のジオールが挙げられる。

Or the diol of the hydrogenated compound of the compound of a formula (II) is mentioned.

  In particular, the polyester resin in the present invention is preferably a polyester obtained by condensation polymerization of an alcohol component containing a propylene oxide adduct of bisphenol A and a carboxylic acid component.

  In the toner of the present invention, in the monomer component constituting the polyester, 80 mol% or more of the alcohol component is a propylene oxide adduct of bisphenol A, and the average addition mole number of the propylene oxide adduct is 1.5 or more. It is particularly preferred that it is 1 or less. 80 mol% or more of the alcohol monomer units are propylene oxide adducts of bisphenol A, and the average addition mole number of propylene oxide satisfies the above range, so that the polyester resin covers the toner surface as a more uniform shell layer. . Further, when the toner is subjected to heat and pressure in the fixing unit, the binder resin near the toner surface is less likely to quickly melt and ooze out, and fixing tailing can be highly suppressed. Although the details of this reason are not known, the above-mentioned polyester can achieve uniform coating of the shell layer, and the propylene group may keep the molecular chain spacing of the polyester moderately and hardly hinder the melting of the binder resin. The present inventors have inferred. In addition, since a uniform surface property of the toner can be secured, it is possible to obtain a good image with a high density and a stable fog over a long period of use.

  Divalent carboxylic acids include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or anhydrides thereof; Further, succinic acid substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid or the anhydride thereof may be used.

  In addition, polyhydric alcohols such as glycerin, pentaerythritol, sorbit, sorbitan, and oxyalkylene ethers of novolac type phenol resins can be cited as the alcohol component, and trimellitic acid, pyromellitic acid, 1,2,3,4- Examples thereof include polyvalent carboxylic acids such as butanetetracarboxylic acid, benzophenonetetracarboxylic acid and anhydrides thereof.

  In the polyester resin of the present invention, it is preferable that 45 mol% to 55 mol% of all components are alcohol components, and 55 mol% to 45 mol% are acid components.

The polyester resin in the present invention preferably has a peak top molecular weight of 2.5 × 10 ³ or more and 2.5 × 10 ⁴ or less, more preferably 2.5 × 10 ³ or more and 1. 5 × 10 ⁴ or less.

When the peak top molecular weight is 2.5 × 10 ³ or more, developability, blocking resistance and durability are improved. A peak top molecular weight of 2.5 × 10 ⁴ or less is preferable because the low-temperature fixability is improved.

  The polyester resin in the present invention preferably has an acid value of 1 mgKOH / g or more and 15 mgKOH / g or less from the viewpoint of charging stability. When it is 15 mgKOH / g or less, the chargeability of the toner is easily stabilized, so that the developability particularly in a high temperature and high humidity environment is easily improved. Moreover, it is easy to form a uniform shell layer by being 1 mgKOH / g or more.

  In the present invention, the content of the polyester resin with respect to 100 parts by mass of the binder resin is preferably 1.0 part by mass to 7.0 parts by mass.

  When the content of the polyester resin is 1.0 part by mass or more and 7.0 parts by mass or less, high dispersibility of materials such as a wax component and a colorant component in the toner is easily achieved, and further at a light pressure. It is easy to achieve both fixing properties.

  The weight average particle diameter (D4) of the toner of the present invention is preferably 3.0 μm or more and 12.0 μm or less, and more preferably 4.0 μm or more and 10.0 μm or less. When the weight average particle diameter (D4) is 3.0 μm or more and 12.0 μm or less, good fluidity can be obtained and development can be performed faithfully to the latent image. For this reason, a good image excellent in dot reproducibility can be obtained.

  In the toner of the present invention, a charge control agent may be blended as necessary to improve charging characteristics. As the charge control agent, a known one can be used, but a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable. Among the charge control agents, specific examples of negative charge control agents include metal compounds of aromatic carboxylic acids such as salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, dicarboxylic acid, azo dyes or metal salts of azo pigments or Examples thereof include a metal complex, a polymer compound having a sulfonic acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene.

  As a method for incorporating a charge control agent into the toner, in the present invention in which the toner is produced by suspension polymerization, a method of adding the charge control agent to the polymerizable monomer composition before granulation is generally used. is there. In the case where an organometallic compound is used as the charge control agent, it is also possible to introduce the compound by adding these compounds to the toner particles, and applying a shear and mixing and stirring.

  The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. However, when added internally to the toner particles, it is preferably 0.1 parts by weight or more and 10.0 parts by weight or less, more preferably 0.1 parts by weight or more and 5.0 parts by weight or less with respect to 100 parts by weight of the binder resin. Used in a range. In addition, when externally added to the toner particles, the amount is preferably 0.005 parts by mass or more and 1.000 parts by mass or less, more preferably 0.01 parts by mass or more and 0.30 parts by mass or less with respect to 100 parts by mass of the toner particles. .

  In the toner of the present invention, a release agent may be blended as necessary for improving the fixing property. Any known release agent can be used as the release agent. Specifically, petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof by Fischer-Tropsch method, polyolefin waxes and derivatives thereof typified by polyethylene Natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and ester waxes. As the ester wax, monofunctional ester wax, bifunctional ester wax, and other polyfunctional ester waxes such as tetrafunctional and hexafunctional can be used.

  The endothermic peak top temperature of the release agent used in the present invention is preferably 50 ° C. or higher and 90 ° C. or lower. When the endothermic peak top temperature is 50 ° C. or higher and 90 ° C. or lower, the toner is easily plasticized at the time of fixing, and the fixing property is improved. Moreover, even when left in a high-temperature and high-humidity environment, wax bleeding and the like are unlikely to occur.

  When a release agent is used in the toner of the present invention, it is preferable to use 2 to 30 parts by weight of the release agent with respect to 100 parts by weight of the binder resin. The content of 2 parts by mass or more and 30 parts by mass or less is preferable because the fixability is improved and the storage stability of the toner is easily improved.

  The toner particles produced according to the present invention contain a colorant that matches the target color. As the colorant that can be used in the present invention, any of known organic pigments or dyes, carbon black, magnetic materials, and the like can be used.

  Specifically, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used as cyan colorants.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used.

  These colorants can be used singly or in combination of two or more, and also in a solid solution state. The colorant used in the toner particles produced according to the present invention is appropriately selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in toner particles. Further, the addition amount of the colorant is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

  Further, as the black colorant, carbon black, a magnetic material, and a color toned to black using the yellow / magenta / cyan colorant are used. When carbon black is used as the black colorant, the amount added is preferably 1.0 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

  Further, when the toner particles produced according to the present invention are used as a magnetic toner, a magnetic material can be used as a colorant. When a magnetic material is used as the black colorant, the magnetic material is preferably 20.0 parts by mass or more and 150.0 parts by mass or less with respect to 100 parts by mass of the binder resin. When the added amount of the magnetic material is less than 20.0 parts by mass, the fixability is improved, but the coloring power of the toner is poor and fogging is difficult to suppress. On the other hand, if the amount exceeds 150.0 parts by mass, the fixability is deteriorated and the holding force by the magnetic force of the toner carrier is increased, so that the developability may be deteriorated.

  Note that the content of the magnetic substance in the toner can be measured using a thermal analyzer, TGA7, manufactured by PerkinElmer. In the measurement method, the toner is heated from room temperature to 900 ° C. at a temperature rising rate of 25 ° C./min in a nitrogen atmosphere, and the weight loss from 100 ° C. to 750 ° C. is defined as the binder resin amount, and the remaining weight is approximated. The amount of magnetic material.

  The magnetic material that can be used in the toner of the present invention is composed mainly of triiron tetroxide or γ-iron oxide, and contains elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, and aluminum. But you can.

  Examples of the shape of the magnetic material that can be used in the toner of the present invention include polyhedron, octahedron, hexahedron, spherical shape, needle shape, and scale shape, but anisotropy such as polyhedron, octahedron, hexahedron, and spherical shape. Those having a small amount are preferable for increasing the image density.

  The magnetic material that can be used in the toner of the present invention preferably has a volume average particle diameter (Dv) of 0.10 μm or more and 0.40 μm or less. It is preferable that the volume average particle diameter (Dv) of the magnetic material is 0.10 μm or more and 0.40 μm or less because sufficient coloring power can be obtained and the dispersibility of the magnetic material can be improved and fogging can be reduced.

  The volume average particle diameter (Dv) of the magnetic material can be measured using a transmission electron microscope. Specifically, after sufficiently dispersing the toner particles to be observed in the epoxy resin, a cured product obtained by curing in an atmosphere at a temperature of 40 ° C. for 2 days is obtained. The obtained cured product is used as a flaky sample by a microtome, and the particle diameters of 100 magnetic bodies in the field of view are measured with a transmission electron microscope (TEM) with a photograph with a magnification of 10,000 to 40,000 times. Then, the volume average particle diameter (Dv) is calculated based on the equivalent diameter of a circle equal to the projected area of the magnetic material. It is also possible to measure the particle size with an image analyzer.

  The magnetic material that can be used in the toner of the present invention can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equivalent to or greater than the iron component to the ferrous salt aqueous solution. Air was blown in while maintaining the pH of the prepared aqueous solution at 7.0 or higher, and ferrous hydroxide was oxidized while heating the aqueous solution to 70 ° C. or higher, and seed crystals serving as the core of the magnetic iron oxide particles were formed. First generate.

  Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. The pH of the liquid is maintained at 5.0 or higher and 10.0 or lower, and the reaction of ferrous hydroxide proceeds while blowing air, and magnetic iron oxide particles are grown with the seed crystal as a core. At this time, it is possible to control the shape and magnetic characteristics of the magnetic material by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction proceeds, the pH of the liquid shifts to the acidic side, but the pH of the liquid is preferably not less than 5.0. A magnetic material can be obtained by filtering, washing, and drying the magnetic material thus obtained by a conventional method.

  The magnetic material that can be used in the present invention is very preferably subjected to a hydrophobic treatment on the surface of the magnetic material. When the hydrophobizing treatment is performed by a dry method, the hydrophobizing treatment is performed on the washed, filtered and dried magnetic material using a coupling agent. When the hydrophobization treatment is performed in a wet manner, after the oxidation reaction is completed, the dried material is redispersed, or after the oxidation reaction is completed, the iron oxide body obtained by washing and filtering is not dried and another aqueous medium is used. It is redispersed in and hydrophobized. Specifically, the hydrophobizing treatment is performed by adding a coupling agent while sufficiently stirring the re-dispersed liquid to increase the temperature after hydrolysis, or adjusting the pH of the dispersion to an alkaline region after hydrolysis. Among these, from the viewpoint of carrying out a uniform hydrophobization treatment, it is preferable to carry out the hydrophobization treatment after completion of the oxidation reaction, by reslurry as it is without drying after filtration and washing.

  To hydrophobize a magnetic material, that is, in order to treat the magnetic material with a coupling agent in an aqueous medium, first, sufficiently disperse the magnetic substance in the aqueous medium so as to have a primary particle size, and do not settle or aggregate. Stir with a stirring blade or the like. Next, an arbitrary amount of coupling agent is added to the above dispersion, and the coupling agent is hydrophobized while hydrolyzing, but at this time it is sufficient to avoid aggregation while using a device such as a pin mill or a line mill while stirring. It is more preferable to perform the hydrophobizing treatment while dispersing.

  Here, the aqueous medium is a medium containing water as a main component. Specific examples include water itself, water added with a small amount of surfactant, water added with a pH adjuster, and water added with an organic solvent. As the surfactant, nonionic surfactants such as polyvinyl alcohol are preferable. The addition amount of the surfactant is preferably 0.1% by mass or more and 5.0% by mass or less with respect to 100 parts by mass of water. Examples of the pH adjuster include inorganic acids such as hydrochloric acid. Examples of the organic solvent include alcohols.

Examples of the silane compound that can be used for the surface treatment of magnetic iron oxide include those represented by the general formula (3).
R _m SiY _n (3)
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a functional group such as an alkyl group, a vinyl group, an epoxy group, or a (meth) acryl group, and n represents 1 to 3] Indicates an integer. However, m + n = 4. ]

  When the silane compound is used, it can be treated alone or in combination of a plurality of types. When using several types together, you may process separately with each silane compound, and may process simultaneously.

  The amount of the silane compound to be used is preferably 0.5 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the magnetic iron oxide, and the treatment agent depending on the surface area of the magnetic iron oxide, the reactivity of the silane compound, etc. It is important to adjust the amount.

  It is important that the toner particles of the present invention are produced by a suspension polymerization method.

  The suspension polymerization method is a method in which a polymerizable monomer and a colorant or a magnetic substance (further, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives) are uniformly dissolved or dispersed. A functional monomer composition is obtained. Thereafter, the polymerizable monomer composition is dispersed in a continuous layer (for example, an aqueous phase) containing a dispersion stabilizer by using a suitable stirrer, and a polymerization reaction is simultaneously performed to obtain a toner having a desired particle size. To get. The toner obtained by this suspension polymerization method is preferable because the shape of individual toner particles is almost spherical, and the charge amount distribution is relatively uniform.

  In the production of the toner according to the present invention, examples of the polymerizable monomer constituting the polymerizable monomer composition include the following.

  Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene, methyl acrylate, ethyl acrylate, Acrylate esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate , Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination. Among the above-mentioned monomers, styrene or a styrene derivative is preferably used alone or mixed with other monomers from the viewpoint of developing characteristics and durability of the toner.

  In the method for producing the toner of the present invention, it is important to add the polymerization initiator a plurality of times.

  As the polymerization initiator added at the first time used in the production by the toner production method of the present invention, those having a half-life at a polymerization reaction temperature of 0.5 hours or more and 30.0 hours or less are preferable. Moreover, although the addition amount of the polymerization initiator added for the first time needs to be adjusted with respect to the target Mp (p), specifically, 0.5 mass part with respect to 100 mass parts of polymerizable monomers. The amount is preferably 20.0 parts by mass or less.

  Specific examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1- Carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or isoazo polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxide Peroxide polymerization initiators such as oxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, t-butylperoxypivalate, etc. Can be mentioned.

  In the method for producing the toner of the present invention, as the polymerization initiator added for the second time, a water-soluble polymerization initiator can be used in addition to the above-described peroxide polymerization initiator and the like. Specifically, ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloride, Azobis (isobutylamidine) hydrochloride, 2,2′-azobisisobutyronitrile sodium sulfonate, ferrous sulfate or hydrogen peroxide. Further, the amount of the polymerization initiator added for the second time needs to be selected based on the target Mp (q), and specifically, 0.1 parts by mass with respect to 100 parts by mass of the polymerizable monomer. The amount is preferably 5.0 parts by mass or less.

  In the production of the toner of the present invention, a polymerizable monomer composition, which is generally dissolved or dispersed uniformly by a dispersing machine such as a homogenizer, a ball mill, an ultrasonic dispersing machine, or the like, is appropriately added to the above-described toner composition. Suspend in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size all at once. The timing of addition of the polymerization initiator added for the first time may be added simultaneously with the addition of other additives in the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and particle floating and sedimentation are prevented.

  When the toner of the present invention is produced, known surfactants, organic dispersants and inorganic dispersants can be used as the dispersion stabilizer. In particular, inorganic dispersants are less likely to produce harmful ultrafine powders, and because of their steric hindrance, dispersion stability is obtained, so even if the reaction temperature is changed, stability is not easily lost, and washing is easy and does not adversely affect the toner. Therefore, it can be preferably used. Examples of such inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, phosphate polyvalent metal salts such as hydroxyapatite, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate, Examples thereof include inorganic salts such as barium sulfate and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.

  These inorganic dispersants are preferably used in an amount of 0.20 parts by mass or more and 20.00 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. Moreover, the said dispersion stabilizer may be used independently and may use multiple types together. Furthermore, you may use together 0.0001 mass part or more and 0.1000 mass part or less surfactant with respect to 100 mass parts of polymerizable monomers.

  In the step of polymerizing the polymerizable monomer, the polymerization temperature is set to 40 ° C or higher, and generally 50 ° C to 90 ° C.

  After the polymerization of the polymerizable monomer is completed, the obtained polymer particles are filtered, washed and dried by a known method to obtain toner particles. The toner of the present invention can be obtained by mixing the toner particles with inorganic fine powder as will be described later as necessary and adhering them to the surface of the toner particles. It is also possible to insert a classification step in the manufacturing process (before mixing the inorganic fine powder) to cut coarse powder and fine powder contained in the toner particles.

  The toner of the present invention preferably has an inorganic fine powder, and the inorganic fine powder preferably has a number average primary particle size (D1) of 4 nm to 80 nm, more preferably 6 nm to 40 nm.

  When the number average primary particle size (D1) of the inorganic fine powder is 4 nm or more and 80 nm or less, the fluidity of the toner is excellent, and uniform chargeability can be obtained, and a uniform image can be obtained even in long-term use. I can get it.

  In the present invention, the number average primary particle size (D1) of the inorganic fine powder is measured using a photograph of the toner magnified by a scanning electron microscope.

  Silica, titanium oxide, alumina, etc. can be used as the inorganic fine powder used in the present invention. As the fine silica powder, for example, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. is there.

  In the present invention, the addition amount of the inorganic fine powder is preferably 0.1 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles. The addition amount of the inorganic fine powder is preferably in the above range since the toner can be given good fluidity and the fixing property is not hindered.

  The content of the inorganic fine powder can be quantified using a calibration curve prepared from a standard sample using fluorescent X-ray analysis.

  Next, an example of an image forming apparatus that can suitably use the toner of the present invention will be described in detail with reference to FIGS. Reference numeral 100 denotes an electrostatic latent image carrier (hereinafter also referred to as a photoconductor), which includes a charging roller 117, a toner carrier 102, a developing device 140 having an elastic blade 103, a transfer charging roller 114, a cleaner 116, and a register roller. 124 etc. are provided. The electrostatic latent image carrier 100 is charged to, for example, −600 V by the charging roller 117 (applied voltages are, for example, an AC voltage of 1.85 kVpp and a DC voltage of −620 Vdc). Then, exposure is performed by irradiating the electrostatic latent image carrier 100 with the laser beam 123 by the laser generator 121, and an electrostatic latent image corresponding to the target image is formed. The electrostatic latent image on the electrostatic latent image carrier 100 is developed with a one-component toner by the developing device 140 to obtain a toner image, and the toner image is transferred in contact with the electrostatic latent image carrier via a transfer material. The image is transferred onto the transfer material by the roller 114. The transfer material on which the toner image is placed is conveyed to the fixing device 126 by the conveying belt 125 or the like and fixed on the transfer material. In addition, the toner remaining on the electrostatic latent image carrier is partially cleaned by the cleaner 116.

  Next, a method for measuring each physical property related to the toner of the present invention will be described.

(1) Average Particle Size of Toner The weight average particle size (D4) of the toner of the present invention is a precision particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark) using a pore electrical resistance method equipped with a 100 μm aperture tube. Using Beckman Coulter Multisizer 3 Version 3.51 (manufactured by Beckman Coulter, Inc.) and the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.). Measurements were taken with 55,000 channels, and the measurement data was analyzed and calculated.

  As the electrolytic aqueous solution used for the measurement, a solution obtained by dissolving special grade sodium chloride in ion-exchanged water so as to have a concentration of 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, dedicated software was set up as follows.

  In the “Standard Measurement Method (SOM) Change Screen” of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using 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.

  1-1) Put 200 ml of the electrolytic aqueous solution in a glass 250 ml round bottom beaker for exclusive use of Multisizer 3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.

  1-2) 30 ml of the electrolytic aqueous solution is placed in a glass 100 ml flat-bottom beaker, and “Contaminone N” (nonionic surfactant, anionic surfactant, organic builder consisting of an organic builder) is accurately measured as a dispersant. 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 exchange water is added.

  1-3) 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 Nikka Ki Bios) with an electrical output of 120 W. A predetermined amount of ion-exchanged water is added, and 2 ml of the above-mentioned Contaminone N is added to this water tank.

  1-4) The beaker of 1-2) 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.

  1-5) In a state where the electrolytic aqueous solution in the beaker of 1-4) is irradiated with ultrasonic waves, 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.

  1-6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte aqueous solution of 1-5) in which toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to 5%. To do. The measurement is performed until the number of measured particles reaches 50,000.

  1-7) Analyze the measurement data with the dedicated software attached to the device and calculate the weight average particle diameter (D4. Note that the analysis / volume statistics (when graph / volume% is set with the dedicated software) The “average diameter” on the (arithmetic average) screen is the weight average particle diameter (D4).

(2) Measurement of THF soluble content of toner binder resin The THF soluble content of the binder resin in the toner is measured as follows.

  1.0 g of toner is weighed (W1 g), placed in a pre-weighed cylindrical filter paper (for example, trade name No. 86R (size 28 × 100 mm), manufactured by Advantech Toyo Co., Ltd.), and set in a Soxhlet extractor. Then, extraction is performed for 16 hours using 200 ml of tetrahydrofuran (THF) as a solvent. At this time, extraction is performed at a reflux rate such that the solvent extraction cycle is once every 5 minutes.

  After the extraction is completed, the cylindrical filter paper is taken out and air-dried, and then vacuum-dried at 40 ° C. for 8 hours. The mass of the cylindrical filter paper including the extraction residue is weighed, and the mass of the extraction residue ( W2g) is calculated.

And THF soluble content can be calculated | required by subtracting content (W3g) of components other than a resin component like following formula (3).
Formula (3) THF soluble part (mass%) = 100-{(W2-W3) / (W1-W3)} * 100

  Content of components other than a resin component can be measured by a well-known analysis means. When analysis is difficult, the content of components other than the resin component (incineration residual ash content (W3′g)) in the toner is estimated and the THF soluble content is subtracted by subtracting the content as follows. Can be sought.

The incineration residual ash content in the toner is obtained by the following procedure. 2 g of toner is weighed (Wag) into a 30 ml magnetic crucible weighed in advance. Place the crucible in an electric furnace, heat at 900 ° C. for 3 hours, cool in the electric furnace, cool in a desiccator for 1 hour at room temperature, weigh the mass of the crucible containing the incineration residual ash, and mass of the crucible Incineration residual ash content (Wbg) is calculated by subtracting. And the mass (W3'g) of the incineration residual ash content in sample W1g is computed by following formula (4).
Formula (4) W3 ′ = W1 × (Wb / Wa)

In this case, the THF soluble content is determined by the following formula (5).
Formula (5) THF soluble content (mass%) = 100 − {(W2−W3 ′) / (W1−W3 ′)} × 100

(3) Measurement of molecular weight of THF soluble part of toner The molecular weight distribution of the THF soluble part of the toner is measured by gel permeation chromatography (GPC) as follows.

First, the toner is dissolved in tetrahydrofuran (THF) at room temperature over 24 hours. 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 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.

(4) Measurement of peak molecular weight Mp (q) of styrene acrylic resin when 30% by mass of styrene acrylic resin is dissolved from the surface Peak molecular weight Mp of styrene acrylic resin when 30% by mass of styrene acrylic resin is dissolved from the surface (Q) is measured as follows. The following measurement method is applied when the toner is applied to the core / shell structure, and can be applied when the polar resin is used as the shell layer.

1.0 g (W4 g) of toner is weighed and added to 10 ml of a mixed solvent of acetone / water = 95: 5 (acetone solution) and left to stand for 1 minute. At this time, components near the surface of the toner particles are eluted in the acetone solution. When the toner contains a magnetic material, the toner is magnetically separated using a magnet, and the supernatant is collected. On the other hand, when the toner does not contain a magnetic substance, the insoluble matter of the toner and the supernatant are separated by a method such as centrifugation, and the supernatant is collected. The separated supernatant is air-dried and then vacuum-dried at 40 ° C. for 8 hours to obtain an extract. This extract is added to 10 ml of cyclohexane and the extract is redissolved at room temperature for 24 hours. Thereafter, 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 an extract solution in which cyclohexane-soluble components are dissolved. This extract is again vacuum dried at 40 ° C. for 8 hours, and then a mass W5 g of the extract (styrene acrylic resin near the toner surface) is obtained. Then, by calculating the ratio to the total amount (W6 g) of styrene acrylic resin contained in the toner, which will be described later, the acetone solution soluble content (% by mass) of the styrene acrylic resin can be obtained from equation (6).
Formula (6) Acetone solution soluble content of styrene acrylic resin (mass%) = {(W5) / (W6)} × 100

  Subsequently, for example, impregnation of the toner in an acetone solution is performed for 3 minutes and 5 minutes, and a graph of “impregnation time in acetone solution” and “acetone solution soluble part” is prepared. (If necessary, impregnation time other than 3 minutes and 5 minutes may also be performed.) By reading this graph, 30% by mass was soluble in acetone solution with respect to 100 parts by mass of styrene acrylic resin. The impregnation time t1 in the acetone solution is determined. Next, the toner that is not used in the impregnation experiment is impregnated in the acetone solution, and when the time t1 has elapsed, the toner and the supernatant liquid are quickly separated. Similar to the measurement in (4), a cyclohexane-soluble component is obtained. By doing in this way, the styrene acrylic resin when 30 mass% of styrene acrylic resins are melt | dissolved from the surface can be obtained. The peak molecular weight Mp (q) of the obtained styrene acrylic resin extract can be calculated in the same manner as the measurement of the molecular weight of the THF soluble matter of the toner.

(5) Measurement of acetone soluble part of toner binder resin The measurement of the acetone soluble part of the toner is performed by using acetone in place of THF in the above measurement of the THF soluble part of the toner binder resin. Can be calculated in the same manner.

(6) Measurement of polymerization conversion The polymerization conversion in the suspension polymerization method is calculated by quantifying the residual styrene monomer. That is, the polymerization addition rate is 0% when the total amount of the added styrene monomer is detected in the following measurement, and the polymerization conversion rate is 100% when the styrene monomer is no longer detected in the toner as the polymerization reaction proceeds. And

(7) Measurement of amount of styrene acrylic resin in toner The total amount (W6g) of styrene acrylic resin in the toner can be obtained by the following formula (7). Here, the calculation method of W7 and W8 will be described later.
Formula (7) Total amount of styrene acrylic resin = W7 + W8

(7-1) Measurement of the amount of styrene acrylic resin (W7g) in the THF soluble part of the toner First, (2) In the measurement of the THF soluble part of the binder resin of the toner, after the Soxhlet extraction, the extraction is performed. The used THF is recovered. Next, the whole amount is air-dried and then vacuum-dried at 40 ° C. for 8 hours to obtain an extract. The extract is added to 10 ml of cyclohexane and the extract is redissolved for 24 hours at room temperature. Thereafter, 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 an extract solution in which cyclohexane-soluble components are dissolved. This extract is again vacuum-dried at 40 ° C. for 8 hours, and then a mass W7 g of the extract (the amount of styrene acrylic resin in the THF-soluble matter of the toner) is obtained. Here, when this extract contains components other than the styrene acrylic resin, the mass W7 g can be obtained by measuring by a known analysis means and subtracting the mass.

(7-2) Measurement of the amount of styrene acrylic resin (W8g) in the THF-insoluble matter of the toner First, (2) In the measurement of the THF-soluble matter of the binder resin of the toner, after the Soxhlet extraction, Collect insoluble matter. Next, the whole amount is air-dried and then vacuum-dried at 40 ° C. for 8 hours to obtain 9 g of extract W. By incinerating the extract according to the following procedure, the amount of styrene acrylic resin (W8 g) in the THF-insoluble matter of the toner can be calculated.

The above-mentioned extract W9g is put into a 30 ml magnetic crucible weighed in advance, the mass including the magnetic crucible is measured, and this is defined as W10 g. In a nitrogen atmosphere, place the crucible in an electric furnace, heat at 900 ° C. for 3 hours, allow to cool in the electric furnace, allow to cool in a desiccator for 1 hour or more at room temperature, and weigh the mass of the crucible containing the incineration residual ash. Then, the incineration residual ash content (W11 g) is calculated by subtracting the mass of the crucible. The amount of styrene acrylic resin (W8 g) in the THF-insoluble matter of the toner can be calculated from the following formula (8).
Formula (8) W8 = (W11-W9) / (W10-W9)

  The amount of residual styrene monomer in the toner is measured by gas chromatography (GC) as follows.

  Weigh accurately 500 mg of toner into a sample bottle. A well-balanced 10 g of acetone is added to this and the lid is capped, followed by thorough mixing. A tabletop ultrasonic cleaner with an oscillation frequency of 42 kHz and an electrical output of 125 W (for example, “B2510J-MTH”, manufactured by Branson) Irradiate with ultrasonic waves for 30 minutes. Thereafter, filtration is performed using a solvent-resistant membrane filter “Maesori Disc” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm, and 2 μl of the filtrate is analyzed by gas chromatography. And the residual amount of a residual styrene monomer is computed with the analytical curve created beforehand using styrene.

The measurement apparatus and measurement conditions are as follows.
GC: HP 6890GC
Column: HP INNOWax (200 μm × 0.40 μm × 25 m)
Carrier gas: He (constant pressure mode: 20 psi)
Oven: (1) Hold at 50 ° C. for 10 minutes, (2) Temperature rise to 200 ° C. at 10 ° C./minute, (3) Hold at 200 ° C. for 5 minutes Inlet: 200 ° C., pulsed splitless mode (20 → 40 psi, until 0.5 min)
Split ratio: 5.0: 1.0
Detector: 250 ° C. (FID)

  Hereinafter, the present invention will be described more specifically with reference to production examples and examples, but these do not limit the present invention in any way. In addition, all the parts in the following mixing | blending show a mass part.

<Manufacture of magnetic body 1>
During an aqueous ferrous sulfate solution, 1.10 eq of sodium hydroxide solution from 1.00 relative to iron element, the amount of P ₂ O ₅ to an iron element to be 0.15% by mass in terms of phosphorus, the iron element On the other hand, SiO ₂ in an amount of 0.50% by mass in terms of silicon element was mixed to prepare an aqueous solution containing ferrous hydroxide. The pH of the aqueous solution was 8.0, and an oxidation reaction was performed at 85 ° C. while blowing air to prepare a slurry liquid having seed crystals.

  Subsequently, after adding ferrous sulfate aqueous solution so that it may become 0.90 to 1.20 equivalent with respect to the original alkali amount (sodium component of caustic soda) to this slurry liquid, the slurry liquid is maintained at pH 7.6, The oxidation reaction was promoted while blowing air to obtain a slurry liquid containing magnetic iron oxide. After filtration and washing, the water-containing slurry was once taken out. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample is put into another aqueous medium without being dried, stirred and redispersed with a pin mill while circulating the slurry, and the pH of the redispersed liquid is adjusted to 4.8. Then, 1.6 parts of n-hexyltrimethoxysilane coupling agent was added to 100 parts of magnetic iron oxide with stirring (the amount of magnetic iron oxide was calculated as a value obtained by subtracting the water content from the water-containing sample), and water was added. Decomposition was performed. Thereafter, the mixture was sufficiently stirred, and the dispersion was subjected to surface treatment at a pH of 8.6. The produced hydrophobic magnetic material is filtered with a filter press, washed with a large amount of water, dried at 100 ° C. for 15 minutes, and then at 90 ° C. for 30 minutes. 0.21 μm magnetic body 1 was obtained.

<Synthesis of polyester resin 1>
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, monomer components other than trimellitic anhydride shown in Table 1 are added in the molar ratio shown in the table, the following components are added, and nitrogen is added at 230 ° C. It was made to react for 10 hours, distilling off the water produced | generated under air flow. At this time, as a catalyst, 0.25 parts of titanium-based catalyst (titanium dihydroxybis (triethanolaminate)) was added to 100 parts of the total amount of acid / alcohol monomers.

  Next, the reaction is carried out under a reduced pressure of 20 mmHg. When the acid value becomes 2 or less, it is cooled to 180 ° C., trimellitic anhydride is added, taken out after reaction for 2 hours under normal pressure sealing, cooled to room temperature, and then pulverized. Thus, a polyester resin 1 was obtained. Obtained polyester resin 1 was Mp = 10500.

<Synthesis of polyester resins 2 and 3>
Polyester resins 2 and 3 were obtained in the same manner as in the synthesis of polyester resin 1 except that the monomer composition was changed as shown in Table 1. Table 1 shows the physical properties of the obtained polyester resin.

  In the above table, BPA-PO (2): propylene oxide 2 mol adduct of bisphenol A, BPA-PO (3): propylene oxide 3 mol adduct of bisphenol A, BPA-EO (2): ethylene oxide of bisphenol A 2 mol adduct, TPA: terephthalic acid, TMA: trimellitic anhydride are shown respectively.

<Manufacture of toner 1>
450 parts of 0.1M Na ₃ PO ₄ aqueous solution is added to 720 parts of ion-exchanged water and heated to 60 ° C., and then 67.7 parts of 1.0M CaCl ₂ aqueous solution is added to contain a dispersion stabilizer. An aqueous medium was obtained.
・ Styrene 78.0 parts ・ N-butyl acrylate 22.0 parts ・ Decandiol diacrylate (crosslinking agent) 1.0 part ・ Iron complex of monoazo dye (T-77: manufactured by Hodogaya Chemical Co., Ltd.) 3.0 parts ・ Magnetic Body 1 90.0 parts / Polyester resin 1 3.0 parts The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.) to obtain a monomer composition. This monomer composition was heated to 60 ° C., and 15.0 parts of Fischer-Tropsch wax was added and mixed there. After dissolution, 7.0 parts of t-butylperoxyneoheptanoate (10-hour half-life temperature of toluene 41 ° C.) as a polymerization initiator was dissolved.

The monomer composition was charged into the aqueous medium, and granulated by stirring at 12,000 rpm for 10 minutes in a TK homomixer (Special Machine Industries Co., Ltd.) in an N ₂ atmosphere at 60 ° C. Thereafter, the reaction was started at 77 ° C. while stirring with a paddle stirring blade. When the polymerization conversion rate reached 80%, the temperature was lowered to 62 ° C. over 2 minutes, held for 5 minutes, and then 1.5 parts of potassium persulfate as a water-soluble polymerization initiator was added over 5 minutes. The reaction temperature was raised to 77 ° C., and the polymerization reaction was continued for an additional 4 hours to complete the polymerization reaction.

  After completion of the reaction, the suspension was cooled, washed with hydrochloric acid, filtered and dried to obtain magnetic toner particles 1.

  100.00 parts of this magnetic toner particle 1 and 1.00 parts of hydrophobic silica fine powder having a number average primary particle size of 12 nm were charged into a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Then, the peripheral speed of the stirring blade was set to 40 m / sec, and the mixture was stirred and mixed for 4 minutes to obtain a magnetic toner 1 having a weight average particle diameter (D4) of 6.5 μm. When the obtained magnetic toner 1 was analyzed, it contained 100 parts of a binder resin. Table 2 shows the physical properties of the magnetic toner 1.

<Manufacture of toner 2>
In the production of toner 1, 1.5 parts of potassium persulfate was changed to 1.0 part of t-butylperoxyneoheptanoate, and polyester resin 1 was changed to polyester resin 2. Further, a magnetic toner 2 was obtained by the same method except that the temperature drop when the polymerization conversion rate reached 80% was changed to 67 ° C. When the obtained magnetic toner 2 was analyzed, it contained 100 parts of a binder resin. Table 2 shows the physical properties of the magnetic toner 2.

<Manufacture of toner 3>
Magnetic toner 3 was obtained by the same method except that polyester resin 1 was changed to polyester resin 3 in the production of toner 1. When the obtained magnetic toner 3 was analyzed, it contained 100 parts of a binder resin. Table 2 shows the physical properties of the magnetic toner 3.

<Manufacture of toner 4>
In the production of toner 1, a magnetic toner is produced in the same manner as in the production of toner 1 except that polyester resin 1 is changed to styrene-acrylic resin (peak molecular weight = 10000, glass transition point: 74 ° C., acid value = 10 mg / KOH). 4 was obtained. Table 2 shows the physical properties of the magnetic toner 4.

<Production of toners 5 to 16>
In the production of toner 1, magnetic toners 5 to 16 were obtained in the same manner as in the production of toner 1 except that the production conditions and the like were changed as shown in Table 2. Table 2 shows the physical properties of the magnetic toners 5 to 16.

<Production of Toners 17 to 28>
In the production of the toner 1, the magnetic toner 17 is produced in the same manner as in the production of the toner 1 except that the temperature is not lowered when the polymerization conversion rate reaches 80% and the production conditions are changed as shown in Table 3. 28 was obtained. Table 3 shows the physical properties of the magnetic toners 17 to 28.

<Manufacture of toner 29>
・ 5 parts of crystalline polyester (melting point 80 ° C., number average molecular weight Mn3600) ・ Polyester resin (peak molecular weight 7700)
・ Hybrid resin (styrene acrylic copolymer and polyester resin, peak molecular weight 7050) 100 parts ・ 95 parts of magnetic substance 1 ・ monoazo dye iron complex (T-77: manufactured by Hodogaya Chemical Co., Ltd.) 3.0 parts ・ paraffin wax (melting point) 75 ° C., peak molecular weight 500) 2 parts The above raw materials were premixed with a Henschel mixer, and then kneaded by a twin-screw kneading extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) set at 130 ° C. and 200 rpm. The obtained kneaded product is cooled and coarsely pulverized with a cutter mill, and then the obtained coarsely pulverized product is finely pulverized using a turbo mill T-250 (manufactured by Turbo Kogyo Co., Ltd.), and a multi-division classifier utilizing the Coanda effect. Was used to obtain negatively charged toner particles 29.

  100.00 parts of this magnetic toner particle 29 and 1.00 parts of hydrophobic silica fine powder having a number average primary particle size of 12 nm were charged into a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Then, the peripheral speed of the stirring blade was set to 40 m / sec, and the mixture was stirred and mixed for 4 minutes to obtain a magnetic toner 29. When the obtained magnetic toner 29 was analyzed, it contained 100 parts of a binder resin. Table 3 shows the physical properties of the magnetic toner 29.

<Manufacture of toner 30>
450 parts of 0.1M Na ₃ PO ₄ aqueous solution is added to 720 parts of ion-exchanged water and heated to 60 ° C., and then 67.7 parts of 1.0M CaCl ₂ aqueous solution is added to contain a dispersion stabilizer. An aqueous medium was obtained.

  Next, the following prescription was uniformly dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Industries) to prepare a monomer composition.

Styrene: 80 parts n-Butyl acrylate: 20 parts Divinylbenzene: 1.0 part Dodecanethiol: 2.0 parts Saturated polyester resin (etherified bisphenol-aromatic polycarboxylic acid polycondensate, Mw: 20,000, Tg : 60 ° C., acid value: 10 mg KOH / g): 6.0 parts Charge control agent (BONTRON (registered trademark), E-84 (Orient Chemical Co., Ltd.)): 1.0 part Magnetic material 1: 80 parts The above monomer The composition was heated to 60 ° C., 10 parts of styrene-modified paraffin wax (maximum value of endothermic peak in DSC: 74 ° C.) was added, mixed and dissolved, and dilauroyl peroxide as a polymerization initiator. 0 parts and 2.0 parts of t-butylperoxyisobutyrate were dissolved to obtain a polymerizable monomer composition.

  The polymerizable monomer composition is charged into the aqueous medium, and stirred at 10,000 rpm for 15 minutes in a nitrogen atmosphere at 60 ° C. using a TK homomixer (manufactured by Tokushu Kika Kogyo). Granulation was performed.

  Then, polymerization was performed at 90 ° C. for 8 hours while stirring the obtained suspension with a paddle stirring blade. After completion of the reaction, the suspension was cooled and hydrochloric acid was added to dissolve the dispersion stabilizer, followed by filtration, washing with water and drying to obtain toner particles 30.

  100.00 parts of the magnetic toner particles 30 and 1.00 parts of hydrophobic silica fine powder having a number average primary particle size of 12 nm were charged into a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Then, the peripheral speed of the stirring blade was set to 40 m / sec, and the mixture was stirred and mixed for 4 minutes to obtain a magnetic toner 30. When the obtained magnetic toner 30 was analyzed, it contained 100 parts of a binder resin. Table 3 shows the physical properties of the magnetic toner 30.

<Toner Production 31>
3 parts of tricalcium phosphate was added to 900 parts of ion-exchanged water heated to 65 ° C., and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain an aqueous medium.

Styrene 75 parts 2-ethylhexyl acrylate 25 parts divinylbenzene 0.01 part saturated polyester resin 2 parts (polycondensation product of propylene oxide modified bisphenol A and isophthalic acid, Tg = 65 ° C., Mn = 17000, Mw / Mn = 2. 4)
2 parts of saturated polyester resin (polycondensation product of propylene oxide modified bisphenol A and terephthalic acid, Tg = 55 ° C., Mn = 2500, Mw / Mn = 1.9)
Carbon black (trade name: MA-100, manufactured by Mitsubishi Chemical Corporation) 10 parts Methylcalixarene (manufactured by Orient Chemical Industry Co., Ltd.) 2 parts The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). . This monomer composition is heated to 65 ° C.
10 parts of paraffin wax (maximum endothermic peak in DSC measurement: 77 ° C.), Mn = 900, Mw / Mn = 1.5 were added, mixed and dissolved, and 5 parts of the polymerization initiator dilauroyl peroxide was dissolved therein.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring at 10,000 rpm for 7 minutes with a TK homomixer in an N ₂ atmosphere at 70 ° C. As a first reaction, the mixture was then reacted at 70 ° C. for 4 hours while stirring with a paddle stirring blade.

Thereafter, 10 parts of styrene was gradually dropped again over 30 minutes, and then 1.0 part of a polymerization initiator (dilauroyl peroxide) was gradually added dropwise over 30 minutes. Further, 0.2 parts of isopropanol was dropped as a chain transfer agent. As a second reaction, the reaction was carried out at 70 ° C. for 4 hours. Finally, the liquid temperature was raised to 85 ° C. and stirring was continued for 3 hours.

  Hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  Next, the particles were dried at 40 ° C. for 12 hours to obtain toner particles 31 as black colored particles.

  100.00 parts of the toner particles 31 and 1.00 parts of hydrophobic silica fine powder having a number average primary particle size of 12 nm were charged into a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Then, the peripheral speed of the stirring blade was set to 40 m / sec, and the mixture was stirred and mixed for 4 minutes to obtain toner 31. The obtained toner 31 was analyzed and found to contain 100 parts of a binder resin. Table 3 shows the physical properties of Toner 31.

<Manufacture of Toner 32>
3 parts of tricalcium phosphate was added to 900 parts of ion-exchanged water heated to 65 ° C., and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain an aqueous medium.

  On the other hand, the following formulation was uniformly dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Industries) to prepare a monomer composition.

Styrene: 80 parts n-butyl acrylate: 20 parts Saturated polyester resin (terephthalic acid-propylene oxide modified bisphenol A polycondensate, Mw: 20,000, Tg: 60 ° C., acid value: 10 mg KOH / g): 8 parts Charge control agent (BONTRON (registered trademark), E-84 (Orient Chemical Co., Ltd.): 1 part Magnetic material 1: 80 parts The above monomer composition was heated to 60 ° C., and styrene-modified paraffin wax (endothermic peak in DSC). (Maximum value: 74 ° C.) 10 parts were added and mixed and dissolved.

  Next, as a polymerization initiator, 3.0 parts of di (2-ethylhexyl) peroxydicarbonate and 2 parts of diisononanoyl peroxide were mixed and further added to the monomer composition and dissolved.

  This was put into the aqueous medium, and granulated by stirring for 15 minutes at 10,000 rpm in a nitrogen atmosphere at 60 ° C. using CLEARMIX (M Technique Co., Ltd.).

  Further, polymerization was performed at 70 ° C. for 10 hours while stirring the obtained suspension with a paddle stirring blade. After completion of the reaction, the suspension was cooled and hydrochloric acid was added to dissolve the dispersion stabilizer, followed by filtration, washing with water and drying to obtain magnetic toner particles 32.

  100.00 parts of the toner particles 32 and 1.00 parts of hydrophobic silica fine powder having a number average primary particle size of 12 nm were charged into a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Then, the peripheral speed of the stirring blade was set to 40 m / sec, and the mixture was stirred and mixed for 4 minutes to obtain a magnetic toner 32. When the obtained magnetic toner 32 was analyzed, it contained 100 parts of a binder resin. Table 3 shows the physical properties of the magnetic toner 32.

<Manufacture of Toner 33>
In the production of the toner particles 1, t-butyl peroxyneodecanoate, potassium persulfate, the kind and amount of the crosslinking agent, no temperature decrease at a polymerization conversion rate of 80%, and as shown in Table 3 A magnetic toner 33 was obtained in the same manner as in the manufacture of the toner 1 except that the change was made. Table 3 shows the physical properties of the magnetic toner 33.

[Example 1]
(Image forming device)
LBP3100 (manufactured by Canon Inc.) was used as the image forming apparatus, and the image formation test was performed with the diode of the fixing device removed. By removing the diode, the potential of the fixing member cannot be controlled, and the fixing tail can be evaluated more strictly. Using toner 1, horizontal line with a printing rate of 4% in one-sheet intermittent mode in a normal temperature and humidity environment (23 ° C./60% RH) and a high temperature and high humidity environment (32.5 ° C./80% RH). A 2000-sheet printing test was conducted.

  As a result, images with high density were obtained before and after the durability test in each environment. In addition, fixing tailing and development streaks did not occur throughout the durability, and good images could be obtained.

  Table 4 shows the evaluation results in each environment.

  The evaluation methods for each evaluation performed in the examples and comparative examples of the present invention and the judgment criteria thereof will be described below.

<Image density>
The image density formed a solid image portion, and the density of the solid image was measured with a Macbeth reflection densitometer (manufactured by Macbeth).

<Fog>
A white image was output and the fog on paper was measured and judged according to the following criteria. In addition, the measurement of fog was performed using a REFECTMETER MODEL TC-6DS manufactured by Tokyo Denshoku Co., Ltd. The filter used was a green filter, and fog was calculated from the following equation.
Fog (%) = reflectance of standard paper (%)-reflectance of sample outputting white image (%)

<Gastsuki>
A solid image portion was formed using FOX RIVER BOND 90g paper as a medium, and the level of roughness was visually judged based on the following criteria.
Rank A: No rusting occurred Rank B: Slight galling occurred, but there was no practical problem.
Rank C: Roughness is generated, and this is an undesirable level for practical use.

<Development stripe>
A4 75 g / m ² paper was used as the medium. After printing 2000 sheets, solid black was printed on the entire surface, and the level of development streaks was visually determined based on the following criteria.
Rank A: No white streak-like image defect occurred.
Rank B: A white streak-like image defect rarely occurred, but there was no practical problem.
Rank C: A white streak-like image defect occurred, but it was not practically desirable.
Rank D: A white streak-like image defect is generated in a large amount, which is not preferable for practical use.

<Fixing trail>
Using FOX RIBER BOND 75g paper left in each environment for 24 hours as a medium, the evaluation of fixing tailing that occurred when 2000 horizontal lines were printed was visually judged according to the following criteria.
Rank A: No fixing tail occurs Rank B: A very slight amount of toner is scattered at the rear end of the horizontal line.
Rank C: A level where there is no problem in practical use although a slight scattering of toner is seen at the rear end of the horizontal line.
Rank D: Toner scattering frequently occurs at the rear end of the horizontal line, which is an undesirable level for practical use.

<Examples 2 to 16>
An image formation test was conducted in the same manner as in Example 1 except that toners 2 to 16 were used. As a result, an image with a level that is practically satisfactory before and after the endurance test was obtained for each toner. Table 4 shows the evaluation results.

<Comparative Examples 1 to 17>
The image output test was performed in the same manner as in Example 1 except that the toners 17 to 33 were used. As a result, an image that is not preferable for practical use with any toner was confirmed. The evaluation results are shown in Table 5.

  DESCRIPTION OF SYMBOLS 100 Photoconductor, 102 Developing sleeve (toner carrier), 103 Developing blade, 104 Magnet roller, 114 Transfer charging roller, 116 Cleaner, 117 Primary charging roller, 121 Laser generator, 123 Laser light, 124 Register roller, 125 Conveyor belt 126 fixing device 140 developing device 141 stirring member

Claims (5)

In a toner having toner particles and inorganic fine powder containing at least a binder resin and a colorant,
The toner particles are produced by a suspension polymerization method, and the binder resin is a styrene acrylic resin,
A THF-soluble component S (p) derived from a component of the styrene acrylic resin when the toner is subjected to Soxhlet extraction with tetrahydrofuran (THF) in an amount of 50% by mass to 85% by mass with respect to the styrene acrylic resin;
The THF-soluble component S (p) has a peak molecular weight Mp (p) in gel permeation chromatography (GPC) of 12000 or more and 16000 or less,
When 30% by mass of the styrene acrylic resin was dissolved from the surface using a 95: 5 mixed solvent (acetone solution) of acetone / water, the peak molecular weight Mp (q) at GPC of the styrene acrylic resin was expressed by the following formula (1 A toner characterized by satisfying
Formula (1) 0.60 <= Mp (q) / Mp (p) <= 0.95 The following formula (2) is satisfied, where S (q) is an acetone-soluble component derived from the binder resin component when the toner is subjected to Soxhlet extraction with acetone. The toner according to 1.
Formula (2) 5.0 mass% ≦ S (p) −S (q) ≦ 25.0 mass%   The toner according to claim 1, wherein the toner has a core-shell structure, and the shell layer contains at least a polyester resin.   The toner according to claim 1, wherein the toner contains 1.0 to 7.0 parts by mass of the polyester resin with respect to 100 parts by mass of the binder resin.   In the monomer component constituting the polyester resin, 80 mol% or more of the alcohol component is a propylene oxide adduct of bisphenol A, and the average addition mole number of the propylene oxide adduct is 1.5 or more and 2.1 or less. The toner according to claim 4.

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