JP5338290B2 - Magenta toner and colorant used for magenta toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magenta toner for forming a full-color image that enlarges color reproduction region of RGB and achieves color reproduction close to the region of AdobeRGB in order to accurately reproduce document data. <P>SOLUTION: The magenta toner contains at least binding resin and the coloring agent. This magenta toner contains, as the coloring agent, composition produced by mixing rhodamine-based dyestuff and rosin denatured maleic acid resin. Preferably, the softening point by a ring and ball method of the rosin denatured maleic acid resin is 80-170&deg;C. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a dry magenta toner used for developing an electrostatic latent image in an electronic copying machine, a laser beam printer or the like in which an image is formed using an electrophotographic method, an electrostatic recording method, etc., and the dry magenta The present invention relates to a colorant used for toner.

Rhodamine dye is known as a magenta color material and is a high color rendering color material capable of expanding the color reproduction region. The applicant has also studied full-color toners using rhodamine lake pigments while paying attention to the excellent color reproducibility, and has found a preferable combination of full-color toners. (For example, see Patent Documents 1, 2, and 3)
However, although initial and initial full-color images and magenta images can be obtained, there are problems with printing durability, and there are problems with long-term use. The output of 1000 sheets or more causes a decrease in image density, and there is a problem in environmental stability. In particular, in the case of a negatively chargeable magenta toner using a rhodamine lake pigment, since the positive chargeability of the rhodamine lake pigment itself is extremely strong, it becomes impossible to hold a negatively charged charge as the number of printed sheets passes. The problem of scattering inside the machine due to the decrease in density and charge decay has occurred.

  Rhodamine dyes and rhodamine lake pigments (collectively rhodamine coloring materials) have two amino groups in the skeleton of the rhodamine moiety, so they are very positively charged materials, and can be used as toner colorants as they are. The current situation is difficult.

  Although it has high positive chargeability, it is difficult to use it as a positively chargeable toner due to its unstable environmental stability. Furthermore, due to its excessively strong positive chargeability, it is negatively chargeable. It is also difficult to use as a toner. In order to maintain negative chargeability, silica, titanium oxide, etc. that were hydrophobized were added and fixed as external additives, and they were used by adjusting the development process conditions (development bias, surface potential). Currently.

As an effort to use a rhodamine color material as a negatively chargeable toner, it has been proposed to make a negatively chargeable toner by thermally kneading a rhodamine dye and a styrene acrylate ester copolymer. (For example, see Patent Document 4)
However, there is a disadvantage that the rhodamine dye is eluted after the toner is formed, and the fixing device and the photoreceptor are contaminated. Moreover, sufficient negative chargeability is not obtained. Furthermore, the amount of rhodamine dye that has contaminated the fixing device also causes contamination of the printed matter and causes image smearing, so it cannot be said that it can be practically used.
JP 2008-203798 A JP 2008-216510 A JP 2008-225127 A Japanese Patent Laid-Open No. 11-119472

  As described above, the rhodamine colorant is a colorant having excellent color developability, but has a great drawback that the positive chargeability is too strong. Magenta toner that solves this defect, can be easily used for magenta toners with neutral charge and positive or negative polarity, and has good dispersion and blending of pigment components in binder resin and toner materials Colorants and magenta toners are in demand.

 There is also a need for a magenta toner colorant using a rhodamine color material that allows easy charge control when designing a toner formulation, and a magenta toner having charge stability.

  An object of the present invention is to provide a magenta toner having excellent characteristics that solves the above problems, and a colorant for magenta toner.

  Another object of the present invention is to provide a magenta toner in which the triboelectric charge amount is stable even when the number of copies increases, and no fog is generated and toner is not scattered in the machine.

  Another object of the present invention is to provide a magenta image that contains a rhodamine dye and a rosin-modified maleic resin as a colorant and can form a clear image in which the rhodamine dye is uniformly dispersed in the toner without causing fogging. To provide toner.

  Another object of the present invention is to provide a colorant used for producing a magenta toner having the above-mentioned excellent characteristics.

  As a result of intensive studies, the present inventors have found that the above object can be achieved by using a composition obtained by mixing a rhodamine-based dye and a rosin-modified maleic resin as a colorant, leading to the present invention. It is a thing.

That is, the present invention relates to the following inventions (1) to (16).
(1) A magenta toner comprising a magenta toner containing at least a binder resin and a colorant, wherein the colorant is a composition obtained by mixing a rhodamine dye and a rosin-modified maleic resin.
(2) The magenta toner according to (1), wherein the softening point of the rosin-modified maleic resin by the ring and ball method is 80 to 170 ° C.
(3) The magenta toner according to (1), wherein the rosin-modified maleic resin has a softening point of 120 to 160 ° C. according to the ring and ball method.
(4) The magenta toner according to any one of (1) to (3), wherein the acid value of the rosin-modified maleic resin is 20 to 320.
(5) The magenta toner according to any one of (1) to (3), wherein the acid value of the rosin-modified maleic resin is 20 to 200.
(6) The magenta toner according to any one of (1) to (5), wherein the weight mixing ratio of the rhodamine dye and the rosin-modified maleic resin (rhodamine lake dye: rosin-modified maleic resin) is 60:40 to 95: 5. .
(7) Rhodamine type dye is C.I. I. Basic Red 1 and / or C.I. I. The magenta toner according to any one of (1) to (6), which is basic violet 10.
(8) The magenta toner according to any one of (1) to (7), wherein the binder resin is a polyester resin.
(9) The magenta toner according to (8), wherein the softening temperature Ts of the polyester resin by a flow tester is 60 to 90 ° C.
(10) A colorant used for a magenta toner containing a rhodamine dye and a rosin-modified maleic resin.
(11) A colorant used for the magenta toner according to (10), wherein the softening point of the rosin-modified maleic resin by the ring and ball method is 80 to 170 ° C.
(12) A colorant used for the magenta toner according to (10), wherein the rosin-modified maleic resin has a softening point of 120 to 160 ° C. according to the ring and ball method.
(13) The colorant used for the magenta toner according to any one of (10) to (12), wherein the acid value of the rosin-modified maleic resin is 20 to 320.
(14) The colorant used for the magenta toner according to any one of (10) to (12), wherein the acid value of the rosin-modified maleic resin is 20 to 200.
(15) The magenta toner according to any one of (10) to (14), wherein a weight mixing ratio of the rhodamine dye and the rosin-modified maleic resin (rhodamine dye: rosin-modified maleic resin) is 60:40 to 95: 5. Colorant used in
(16) Rhodamine type dye is C.I. I. Basic Red 1 and / or C.I. I. The colorant used for the magenta toner according to any one of (10) to (15), which is Basic Violet 10.

  As described above, by using a composition obtained by mixing a rhodamine dye and a rosin-modified maleic resin as a colorant for the magenta toner, the positive chargeability of the rhodamine dye is mixed with the rosin-modified maleic resin. As a result, the positive charging property is canceled and a magenta colorant having a neutral charging polarity can be obtained.

 Since this magenta colorant does not have a positive charging property derived from a rhodamine colorant and has a neutral polarity, a magenta toner using this colorant can be produced by using a material such as a charge control agent. The amount of charge can be controlled, and a copy image having good image density and no fog can be obtained from the beginning. Particularly, it is suitable as a negatively chargeable magenta toner.

 In addition, since the magenta colorant of the present invention has good dispersibility, compoundability, and compatibility in the binder resin, it not only excels in image quality and color reproducibility, but also facilitates reuse of classified fine powder. Therefore, it contributes greatly to resource saving and cost reduction during toner production.

  Hereinafter, the present invention will be described in more detail.

  The magenta toner of the present invention is excellent in the following points by adding, as a colorant, a composition obtained by mixing a rhodamine dye and a rosin-modified maleic acid resin in a toner containing at least a binder resin and a colorant. It was confirmed that the effect was obtained. The colorant used in the magenta toner of the present invention can be obtained by mixing a rhodamine dye and a rosin-modified maleic resin.

(A) By mixing a rhodamine dye and a rosin-modified maleic resin, the amino group (—NHC ₂ H ₅ ) portion in the rhodamine dye and the carboxyl group (—COOH) in the rosin-modified maleic resin are mixed. The positive chargeability derived from rhodamine is counteracted by binding to the moiety, and the effect of charge neutrality and attenuation of the positive charge polarity can be obtained. As a result, the colorant for magenta toner of the present invention can be used regardless of the polarity of the toner.

(B) The rhodamine dye is coated with rosin-modified maleic resin, which greatly improves the compatibility, dispersibility, and compoundability (mixing of pigment particles into uniform toner particles) in the binder resin. Improved. As a result, the magenta toner has excellent color developability, charging stability, and image stability. Also, the mixing of rhodamine dyes in the toner becomes uniform, the content of rhodamine dyes in the classified product (toner base particles) and the classified fine powder becomes uniform, and as a result, the classified fine powder generated in the classification process is recycled as a raw material. It becomes possible to do.

(C) Since the rhodamine dye is uniformly dispersed and blended in the binder resin, more rhodamine colorant (magenta colorant) can be added to the toner than before.

 The reason why the addition of this rosin-modified maleic resin significantly reduces the positive charge of rhodamine dyes, the dispersibility in the binder resin, and the compounding properties has not been fully clarified. It is thought that it is in the structure of the modified maleic acid resin. The rosin-modified maleic resin has an acid-containing polar group portion and a non-polar rosin skeleton portion. The part of the polar group having this acid is a part of the carboxyl group derived from unreacted abietic acid and the carboxyl group of maleic acid, which not only binds and reacts with the amino group derived from rhodamine but also the polarity of the binder resin. Reacts with and is compatible with the group. Further, the nonpolar rosin skeleton portion is compatible with the nonpolar portion of the binder resin and the release agent.

  Specific examples of the rhodamine dye include rhodamine dyes such as rhodamine B, rhodamine 3G, rhodamine 6G, rhodamine 6GCP, and rhodamine B base.

 Among the rhodamine dyes, rhodamine 6G (CI Basic Red 1), C.I. I. Basic Red 1: 1, rhodamine B (CI Basic Violet 10), rhodamine B based (CI Solvent Red 49) dyes are preferred.

  Particularly preferably, as the dye component, C.I. I. Basic Red 1 and C.I. I. It is preferable to use Basic Violet 10 in combination. C. I. Basic Red 1 (Rhodamine 6G) and C.I. I. When using Basic Violet 10 (Rhodamine B) in combination, the 6G: B relationship is preferably in the range of 80:20 to 99.5: 0.5. If rhodamine B is smaller than 0.5, purple color reproduction may be deteriorated, and if rhodamine B is larger than 20, purple color becomes strong, and red reproduction tends to be poor. . More preferably, it is the range of 85: 15-98: 2.

  The rosin-modified maleic resin that can be used in the magenta toner of the present invention is a maleic rosin polyhydric alcohol ester, and may contain an unesterified maleated rosin. The rosin-modified maleic acid resin is preferable in that it has an effect of imparting gloss to the pigment and can produce a glossy magenta color as a magenta toner.

  Levopimaric acid is obtained by heating abietic acid, the main component of rosin, and maleopimaric acid is obtained by adding maleic anhydride and fumaric acid by Diels-Alder reaction. Maleinized rosin contains a maleopimaric acid skeleton as a main component.

  The acid value and softening point of the rosin-modified maleic resin can be adjusted by changing the amount of maleic acid and fumaric acid relative to rosin, the type and amount of polyhydric alcohol, and the end point of the reaction. The softening point is controlled by the amount of maleic acid and fumaric acid relative to rosin.

 The rosin-modified maleic acid resin defined in the present invention includes rosin-modified fumaric acid resin as the same meaning. Maleic anhydride and fumaric acid can be used in the same manner. The polyhydric alcohol represents a dihydric or higher alcohol.

  Examples of the rosin component of the rosin-modified maleic resin include tall oil rosin, gum rosin, and wood rosin mainly composed of abietic acid, dehydroabietic acid, neoabietic acid, parastrinic acid, pimaric acid, and isopimaric acid.

  Examples of the polyhydric alcohol to be reacted with an adduct of rosin and maleic acid include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane, glycerin, pentaerythritol, sorbitol and the like.

  Of these, ethylene glycol, pentaerythritol, and glycerin are preferable as the alcohol component.

  From the viewpoint of the composition of the rosin-modified maleic resin, a partial ester of rosin / maleic resin, in which the alcohol component is pentaerythritol, is particularly preferable in terms of the compatibility with the binder resin.

The following three methods are used for producing the rosin-modified maleic resin.
A) A method in which rosin is reacted with maleic anhydride and fumaric acid, and the resulting product is esterified with a polyhydric alcohol.
B) A method in which maleic anhydride and fumaric acid are reacted with a polyhydric alcohol, and the resulting polyester is reacted with rosin.
C) A method in which rosin, maleic anhydride or fumaric acid, and a polyhydric alcohol are reacted simultaneously.

 The acid value of the rosin-modified maleic resin that can be preferably used in the present invention is preferably 20 to 320 (mgKOH / g), more preferably 20 to 200 (mgKOH / g). If the acid value is less than 20 (mgKOH / g), the positive chargeability of the rhodamine dye may not be suppressed. On the other hand, if the acid value is larger than 320 (mgKOH / g), the —COOH group is excessively present, so that it is easily affected by moisture and the environmental stability is lowered, and the charge amount under high temperature and high humidity. In some cases, problems such as in-flight scattering, increased fogging, and excessive increase in charge amount under low temperature and low humidity may occur due to the decrease in temperature.

  The rosin-modified maleic resin preferably used in the magenta colorant and magenta toner of the present invention preferably has a softening point in the range of 80 to 170 ° C. by the ring and ball method. This is related to compatibility with the binder resin and compounding properties. By using a rosin-modified maleic resin having a softening point in this range, the colorant can be uniformly dispersed and blended in the binder resin. is there. Here, if the softening point is lower than 80 ° C., the dispersibility and compoundability of the rhodamine dye in the binder resin may be deteriorated. The reason is not clear, but it is assumed that at a softening point lower than 80 ° C., the rosin-modified maleic resin rapidly melts during kneading and becomes incompatible with rhodamine dyes and binder resins. On the other hand, if the temperature is lower than 80 ° C., hot offset tends to occur as toner, and satisfactory fixing performance may not be obtained.

  On the other hand, when the temperature exceeds 170 ° C., it becomes difficult to melt during kneading, and the dispersion and blending in the binder resin become worse. Also, the fixing performance (which tends to peel off) may be deteriorated. The range of a more preferable softening point is in the range of 120 to 160 ° C, and the range of 130 to 150 ° C is particularly preferable.

  The measurement of the softening point by the ring-and-ball method is a method widely used in the standard test method, and JIS K 2046 can be mentioned. Specifically, a brass ring filled with a sample is held horizontally in a water bath, a steel ball of a constant weight is placed on the center of the sample, the bath temperature is increased at a constant speed, the sample gradually softens, and the steel ball is The softening point is determined by the reading of the thermometer when it descends and finally reaches the bottom plate at a thickness of 25 mm.

 Specific examples of rosin-modified maleic resin that can be used include Marquide No. manufactured by Arakawa Chemical Industries. 1, 2, 5, 6, 8, 31, 32, 33, 34, 3002, etc., Harima Chemical Co., Ltd. Harimac R-80, T-80, R-100, M-453, M-130A, 135GN, 145P, Examples thereof include rosin-modified maleic resin such as R-120AH.

  The true density of the rosin-modified maleic resin used in the present invention is preferably in the range of 1.08 to 1.25 (g / cc). This figure is an approximate figure because the true density of the polyester resin that is the binder resin is about 1.20 to 1.35 (g / cc), and is effective in achieving compatibilization, good dispersion, and blending. The numerical range.

  The true density of the rhodamine dye is in the range of 1.29 to 1.32 (g / cc), and since it approximates the true density of the polyester resin, the function of the rosin-modified maleic resin makes the magenta of the present invention. It is effective for the colorant to be uniformly dispersed in the polyester resin.

  In the present invention, the acid value of rosin can be measured according to the method of JIS K-0070. The acid value is expressed in mg of potassium hydroxide necessary to neutralize 1 g of rosin.

  The colorant for magenta toner (magenta coloring composition) of the present invention can be obtained by mixing these rhodamine dyes and rosin-modified maleic resin.

 As a method of mixing these, (1) a method in which a rhodamine dye is added after being dissolved in a solvent soluble in rosin-modified maleic resin, and mixing in the solution is performed. (2) a kneader or the like is used. For example, there is a method in which a rhodamine dye is added and mixed while the rosin-modified maleic resin is melted. Specifically:

(1) A rosin-modified maleic resin is dissolved in an alkaline aqueous solution or solvent and stirred, and then a rhodamine dye is added and mixed while stirring. Next, a rosin-modified maleic acid resin is insolubilized by adding a mineral acid such as hydrochloric acid or sulfuric acid to make it acidic, or by adding a poor solvent, followed by filtration, washing and drying to obtain a composition. Here, the amino group (—NHC ₂ H ₅ ) portion in the rhodamine dye reacts with the carboxyl group (—COOH) in the rosin-modified maleic resin. Further, if necessary, the composition may be made into a magenta colorant through a pulverization step to a desired particle size.

(2) The rhodamine dye and the rosin-modified maleic resin are put into a kneader such as a heating kneader, a Banbury mixer, a three roll mill, a two roll mill, a vibration mill, a ball mill, an attritor, and an extruder and mixed thoroughly. Melt kneading is performed at a temperature equal to or higher than the softening point of the rosin-modified maleic resin. As a result, the rhodamine dye is dispersed in the rosin-modified maleic resin. At this time, the positive chargeability of rhodamine is suppressed by binding and reacting the amino group portion in the rhodamine dye and the acid component in the rosin-modified maleic resin. The composition obtained here is in a state where a rosin-modified maleic resin is coated on a rhodamine dye. Furthermore, the composition may be used as a magenta colorant by roughly crushing and pulverizing the composition to adjust to a desired particle size.

  A good magenta colorant can be obtained if the weight mixing ratio of the rhodamine dye and the rosin-modified maleic resin (rhodamine dye: rosin-modified maleic resin) is in the range of 60:40 to 95: 5. If the ratio of the rhodamine dye is smaller than 60%, the color developability deteriorates, that is, the color defect derived from the rosin-modified maleic resin occurs, and the function as a colorant becomes difficult to work. If it exceeds 95%, the positive chargeability of rhodamine is not sufficiently suppressed, and it becomes difficult to use it for negatively chargeable toners.

  More preferably, the weight mixing ratio of the rhodamine dye and the rosin-modified maleic resin (rhodamine dye: rosin-modified maleic resin) is in the range of 65:35 to 85:15.

  The amount of the magenta colorant used in the magenta toner of the present invention varies depending on the type of binder resin used, but is usually 1 to 20 parts by weight, preferably 2 to 15 parts per 100 parts by weight of toner base particles (classification). Part by weight, more preferably 3 to 12 parts by weight.

  As a constituent component of the magenta toner of the present invention, a binder resin, which is a known material constituting the toner, is used in addition to the colorant of the present invention. In the magenta toner of the present invention, a release agent and a charge control agent are further used as necessary, and as external additives, a lubricant, a fluidity improver, an abrasive, a conductivity imparting agent, an image peeling prevention agent, and the like are used. Used.

 As the binder resin used in the magenta toner of the present invention, a resin exhibiting colorless, transparent, white, or light color is preferable so as not to disturb the hue of each color pigment.

 Examples of binder resins that can be used include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substituted products thereof; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer Polymer, styrene-vinyl naphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl Styrenes such as methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Copolymer or cross-linked Tylene copolymer; polyvinyl chloride, phenol resin, natural modified phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy Examples thereof include resins, xylene resins, polyvinyl butyral, terpene resins, coumarone indene resins, and petroleum resins. Of these, polyester resins and styrene copolymers are preferably used.

 In the magenta toner of the present invention, a polyester resin is the most preferable binder resin. Examples of the alcohol component constituting the polyester resin include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1, 4-butenediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, bisphenol A, hydrogenated bisphenol A, 1, Diols such as 4-bis (hydroxymethyl) cyclohexane, bisphenol derivatives represented by the following general formula (1), glycerol, diglycerol, sorbit, sorbitan, butanetriol, trimethylolethane, trimethylolpropane, pentae Suritoru, dipentaerythritol, tripentaerythritol, polyhydric alcohols and the like can be mentioned, which are used alone or in combination of two or more.

（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２〜１０である。）

(In the formula, 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.)

 As the acid component, divalent carboxylic acids such as 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 succinic acid substituted with an alkyl group having 16 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid, glutaconic acid or the anhydride thereof; Cyclohexanedicarboxylic acid; naphthalenedicarboxylic acid; diphenoxyethane-2,6-dicarboxylic acid and the like. Trivalent or higher carboxylic acids that function as crosslinking components include trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, and butanetricarboxylic acid. Acid, hexanetricarboxylic acid Tetra (methylene carboxyl) methane, octane tetracarboxylic acid, and benzophenone tetracarboxylic acid anhydride and the like, which are used alone or in combination of two or more.

 A preferred alcohol component is a bisphenol derivative represented by the general formula 1, and a preferred acid component is phthalic acid, terephthalic acid, isophthalic acid or its anhydride, succinic acid, n-dodecenyl succinic acid or its anhydride, fumaric acid, Dicarboxylic acids such as maleic acid and maleic anhydride, and tricarboxylic acids such as trimellitic acid or its anhydride.

 In the present invention, the acid value of the binder resin can be measured according to the method of JIS K-0070. The acid value is represented by the number of mg of potassium hydroxide required to neutralize 1 g of toner.

 Further, in the styrene copolymer included in the styrene polymer, examples of the comonomer for the styrene monomer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, and acrylic acid. Monocarboxylic acid having a double bond such as 2-ethylhexyl, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, or a substituted product thereof; For example, dicarboxylic acids having a double bond such as maleic acid, methyl maleate, butyl maleate, and dimethyl maleate, and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate, and vinyl benzoate For example, ethylene monomers such as ethylene, propylene and butylene; vinyl monomers such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; can give. These may be used alone or in combination of two or more.

 As a crosslinking agent used when producing a crosslinked styrene-based copolymer, a compound having two or more polymerizable double bonds is mainly used. For example, aromatic divinyl such as divinylbenzene and divinylnaphthalene. Compound; carboxylic acid ester having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinyl compound such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; And compounds having three or more vinyl groups are used alone or as a mixture. The styrenic polymer is a styrenic polymer having at least one peak in the region of 3 × 10 3 to 5 × 10 4 in the molecular weight distribution measured by GPC, and at least one other peak or shoulder in the region of 10 5 or more. A copolymer is preferred from the standpoint of fixability.

 In producing the vinyl polymer, a polymerization initiator is used. Any conventionally known polymerization initiator can be used. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, tertiary butyl hydroperoxide, tertiary butyl peroxybenzoate, ditertiary butyl peroxide, cumene hydroperoxide, dicumyl peroxide, azo Isobutyronitrile, azobisvaleronitrile, and the like are preferably used conventionally. The use ratio of the polymerization initiator to the vinyl monomer is generally 0.2 to 5% by mass. The polymerization temperature is appropriately selected according to the type of monomer and initiator used.

 In the present invention, a hybrid resin in which a vinyl polymer unit and a polyester unit are chemically bonded, such as a graft copolymer using a vinyl polymer as a trunk polymer and a polyester unit as a branch polymer, is also used. be able to. As the vinyl resin, a monomer having a carboxyl group or a hydroxyl group is preferably contained as a polymerization unit. As other polymerization units, the monomers exemplified in the vinyl polymer are used as appropriate. Furthermore, as a monomer component which forms a polyester unit, the said alcohol component, acid component, etc. which are used in order to manufacture a polyester resin are used.

 The glass transition temperature (Tg) of the binder resin is preferably in the range of 50 to 70 ° C. In the present invention, the glass transition temperature (Tg) is an extension of the baseline below Tg when measured with a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation) at a heating rate of 10 ° C./min. The value of the intersection with the tangent of the endothermic curve near Tg was determined and measured.

 In the magenta toner of the present invention, the binder resin preferably has an acid value in the range of 5 to 40 mgKOH / g. When the acid value of the binder resin is less than 5 mgKOH / g, the compatibility with the rosin-modified maleic resin is lowered, and as a result, the dispersion of the rhodamine dye may be deteriorated. When the acid value of the binder resin exceeds 40 mgKOH / g, there may be a problem that storage stability and image characteristics of the obtained toner at high temperature and high humidity are deteriorated.

 When the binder resin of the magenta toner of the present invention is a polyester resin, it may be a homopolyester or a copolyester alone or a blend of two or more of these. The polyester resin preferably has a weight average molecular weight (Mw) of 5,000 or more in terms of molecular weight measured by gel permeation chromatography (GPC) from the viewpoint of offset resistance and low-temperature fixability. The thing of 000-1,000,000 is more preferable. When the weight average molecular weight of the polyester resin decreases, the offset resistance of the toner tends to decrease, and when the weight average molecular weight increases, the fixability tends to decrease. In addition, the polyester resin used has a type having a molecular weight distribution curve of two peaks composed of a specific low molecular weight condensation polymer component and a specific high molecular weight condensation polymer component, or has a single molecular weight distribution curve. Any type.

When a styrene resin is used as the binder resin, the molecular weight distribution measured by GPC has at least one peak in the region of 3 × 10 ^{3 to} 5 × 10 ⁴ and at least one in the region of 10 ⁵ or more. Those having two peaks or shoulders are preferred from the standpoint of fixability.

  A binder resin having such a molecular weight distribution can be produced by mixing two or more resins having different average molecular weights, or can be produced by using a crosslinking agent as a crosslinked resin.

  The molecular weight distribution by GPC is measured, for example, under the following conditions.

  The column is stabilized in a 40 ° C. heat chamber, and tetrahydrofuran (THF) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml / min, and about 100 μl of a sample solution dissolved in THF is injected for measurement. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts.

As a standard polystyrene sample for preparing a calibration curve, for example, a standard polystyrene sample having a molecular weight of about 10 ² to 10 ⁷ manufactured by Tosoh Corporation or Showa Denko is used, and it is appropriate to use at least about 10 standard polystyrene samples. . An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, combinations of shodex GPC KF-801, 802, 803, 804, 805, 806, 807, 800P manufactured by Showa Denko KK, TSKgel G1000H (HXL), G2000H (HXL), G3000H (HXL) manufactured by Tosoh Corporation, A combination of G4000H (HXL), G5000H (HXL), G6000H (HXL), G7000H (HXL), and TSKguardcolumn can be given.

  The measurement sample is prepared as follows. That is, after putting a sample in THF and leaving it to stand for several hours, the sample is sufficiently shaken, mixed well with THF until the sample is no longer united, and further allowed to stand for 12 hours or more. At this time, the standing time in THF is set to be 24 hours or longer. Then, GPC measurement was performed on a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-5 manufactured by Tosoh Corp., Excro Disc 25CR manufactured by Gelman Science Japan Ltd., etc.). Sample for use. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

  The binder resin used in the magenta toner of the present invention preferably has a softening temperature Ts by a flow tester of 60 to 90 ° C. This is an effective numerical value for increasing the compatibility with the colorant. When the softening temperature Ts is lower than 60 ° C., the binder resin is excessively softened during kneading, and the dispersion of the colorant is deteriorated. On the other hand, if the softening temperature Ts is higher than 90 ° C., the binder resin is not sufficiently melted at the time of kneading, and it becomes difficult to disperse the colorant.

  In the present invention, the softening temperature Ts is measured using a flow tester CFT-500D manufactured by Shimadzu Corporation with a starting temperature of 40 ° C. and a temperature increase rate of 6.0 ° C./min. The test load was 20 kg, the preheating time was 300 seconds, the die hole diameter was 0.5 mm, and the die length was 1.0 mm.

  In addition, an additive such as a release agent that has been used in the production of conventional toners can be added to the magenta toner of the present invention as long as it does not have a substantial adverse effect. Examples of the release agent include aliphatic hydrocarbons, fatty acid metal salts, higher fatty acids, fatty acid esters or partially saponified products thereof, silicone oils, various oils that improve release properties (offset prevention properties) at the time of heat roll fixing. A wax is mentioned. Among these, waxes such as ethylene homopolymer having a weight average molecular weight Mw of about 500 to 8000, low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, sazol wax and paraffin wax are preferable. These are usually added at a ratio of about 0.5 to 10% by weight based on 100 parts by weight of the toner base particles.

  The presence of the rosin maleic acid-modified resin constituting the colorant of the present invention is also an effective material for dispersing and compatibilizing the release agent in the binder resin. In particular, as a release agent, ethylene homopolymer, low molecular weight polyethylene or low molecular weight polypropylene having a weight average molecular weight Mw of 500 to 8000, a molecular weight distribution (Mw / Mn) of 1.0 to 5.0, and a melting point of about 100 to 145 ° C. Is effective in dispersing and compatibilizing the release agent in the binder resin. Especially, it is preferable that molecular weight distribution (Mw / Mn) is 1.5-4.0. The melting point of the release agent was calculated as the temperature of the endothermic peak value measured by DSC.

 The magenta toner of the present invention may contain a colorless or light-color charge control agent as long as it does not interfere with the hue as necessary. As the charge control agent, a positive charge control agent or a negative charge control agent is used according to the polarity of the electrostatic image on the electrostatic latent image carrier to be developed.

 As the positive charge control agent, quaternary ammonium salt compounds (for example, tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylbenzylammonium tetrafluoroborate), quaternary ammonium salt organic tin oxide (for example, dibutyltin) Oxide, dioctyltin oxide, dicyclohexyltin oxide), diorganotin borate (dibutyltin borate, dioctyltin borate, dicyclohexyltin borate), electron donating substances such as polymers having amino groups, etc. are used alone or in combination of two or more. be able to.

 On the other hand, as negative charge control agents, aromatic hydroxycarboxylic acid zinc salt, calcium salt, chromium salt, aryloxycarboxylic acid divalent or trivalent metal salt or metal chelate (complex) such as salicylic acid or salicylic acid derivative, etc. , Fatty acid soaps, naphthenic acid metal salts and the like. These charge control agents are usually used at a ratio of 0.1 to 10 parts by mass, preferably 0.5 to 8 parts by mass, with respect to 100 parts by mass of the binder resin.

 As the external additive used in the magenta toner of the present invention, those such as a fluidizing agent, an abrasive, a conductivity imparting agent, and a lubricant can be used. As the base material of the fluidizing agent used in the present invention, for example, fine powders such as silica, alumina, titania, magnesia, amorphous silicon-aluminum co-oxide, amorphous silicon-titanium co-oxide are used. Can do. The fluidizing agent as an external additive has not only the purpose of imparting fluidity to the toner but also the role of imparting and controlling toner chargeability. That is, the external additive adheres to the outermost part of the toner, thereby greatly affecting the chargeability of the toner.

 The particles used for the fluidizing agent can be used as they are without surface treatment, but the environmental stability is impaired by the hygroscopicity, and the fluidizing agent adheres to the surface of the photosensitive drum. There may be a problem that filming occurs and an image defect is caused. Regarding the problem that the environmental stability due to hygroscopicity is impaired, the fluidizing agent is affected by moisture in a high humidity environment, causing toner charge decay, causing fog on the image, and causing toner scattering in the machine End up. Therefore, it is preferable to carry out surface treatment of the particles used for the fluidizing agent so as to impart hydrophobicity. Further, by selecting the treatment agent used for the surface treatment, it is possible to adjust, control, and stabilize the chargeability of the toner by imparting desired positive and negative polarities. It is necessary to select the surface treatment agent to be used.

 Examples of the surface treatment agent for the fluidizing agent used in the magenta toner of the present invention include organoalkoxysilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane, dimethyldichlorosilane, trimethylchlorosilane, octadecyltrichlorosilane, and t-butyldimethylchlorosilane. Organochlorosilanes, silazanes such as hexamethyldisilazane, organoaminosilanes such as bis (dimethylamino) dimethylsilane, and silicone oil compounds can be used.

 As the silicone oil-based compound, straight silicone oil such as dimethyl silicone oil, methylphenyl silicone oil, and methylhydrogen silicone oil, or modified silicone oil can be used. Examples of the modifying group used in the modified silicone oil include methylstyrene group, long chain alkyl group, polyether group, carbinol group, amino group, epoxy group, carboxyl group, higher fatty acid group, mercapto group, methacryl group and the like. . Silicone oil has an effect of preventing adhesion of toner components to the surface of the photosensitive drum and filming by having excellent release properties and slipping properties.

 As the external additives other than the fluidizing agent used in the magenta toner of the present invention, the following known additives such as a lubricant, an abrasive, and a conductivity imparting agent can be used. Examples of the lubricant include polytetrafluoroethylene and zinc stearate, and examples of the abrasive include strontium titanate, calcium titanate, barium titanate, calcium carbonate, chromium oxide, silicon carbide, tungsten carbide, and silicon nitride. The body is mentioned. These abrasives have an effect of removing adhering toner components and filming substances on the surface of the photosensitive drum by polishing and scraping, and are used in combination with the above-mentioned fluidizing agent that has been surface-treated with silicone oil. A great effect can be found. As the conductivity imparting agent, a metal oxide such as tin oxide can be added. However, these examples are merely examples, and what is added and mixed in the magenta toner of the present invention is not limited to those specifically exemplified above.

  In the magenta toner of the present invention, in addition to the magenta colorant of the present invention, a colorant known to be used in the production of conventional toners can be used for the purpose of complementary color. Examples of these colorants include naphthol, quinacridone, xanthene, monoazo, and azo dyes. These can be used alone or in admixture of two or more.

 The magenta toner of the present invention can also be used with a carrier as a two-component developer. As the carrier, any carrier conventionally used in a two-component dry developer can be used. Examples of such carriers include ferromagnetic powder such as iron powder or alloy powder of ferromagnetic metal, metal oxide such as iron oxide, ferrite powder composed of elements such as nickel, copper, zinc, magnesium, barium, Magnetic powder carrier made of magnetic powder such as magnetite powder, magnetic powder resin coated carrier coated with these magnetic powder with resin, binder carrier made of magnetic powder and binder resin, glass beads with or without resin coating, etc. Can be mentioned. These carriers usually have a particle size of about 15 to 100 μm, preferably about 20 to 80 μm.

 Examples of the coating resin for the magnetic powder resin-coated carrier include silicon-containing resins such as polyethylene and silicone resin, fluorine-containing resins, styrene resins, acrylic resins, styrene-acrylic resins, polyvinyl acetate, cellulose derivatives, Maleic acid resin, epoxy resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl bromide, polyvinylidene bromide, polycarbonate, polyester, polypropylene, phenol resin, polyvinyl alcohol, fumarate ester resin, polyacrylonitrile, polyvinyl ether, chloroprene rubber , Acetal resin, ketone resin, xylene resin, butadiene rubber, styrene-butadiene copolymer, polyurethane, polyamide resin, ionomer resin, polyphenylene sulfide resin, etc. That. Among these, fluorine-containing resins and silicon-containing resins are particularly preferable because the formation of spent toner is small. This magnetic powder resin coated carrier includes conductive fine particles (carbon black, conductive metal oxide, metal powder), inorganic fillers (silica, silicon nitride, boron nitride, alumina, zirconia, silicon carbide, boron carbide, oxidized (Titanium, clay, talc, glass fiber), the charge control agent exemplified above, and the like may be contained as necessary. The resin coating thickness on the carrier core material is preferably about 0.1 to 5 μm.

  Further, as the carrier coating state, a state such as so-called “small particle size Kintaro” in which every particle is uniformly coated, such as Kintaro, is preferable.

 It is also possible to use a trickle development method in which the carrier is filled with the toner in the toner container and a new carrier is supplied to the developing device at the same time as the supply of the toner. Thus, by collecting a part of the developer (toner and carrier) in the developing machine, the developer does not deteriorate and replacement of the developer can be made unnecessary. The trickle developer has a long history and was used around 1984.

 The magenta toner according to the present invention can be manufactured using a conventionally known toner manufacturing method. The toner production methods are roughly classified into two types: a pulverization method obtained through kneading and pulverization steps, and a polymerization method obtained by chemical polymerization. In the case of the pulverization method, for example, the toner constituent materials as described above are sufficiently mixed by a mixer such as a ball mill or a Henschel mixer, and then kneaded well using a thermal kneader such as a hot roll kneader, a uniaxial or biaxial extruder. Then, after cooling and solidification, a method of manufacturing by a method of coarsely pulverizing mechanically using a pulverizer such as a hammer mill, then finely pulverizing with a jet mill, a mechanical pulverizer, etc., and then classifying.

  In addition, for the purpose of uniformly dispersing and blending the pigment component in the binder resin, a colorant dispersion in which the colorant component and the binder resin are mixed in advance and the colorant component is dispersed in the binder resin (concrete). It is preferable to add a material constituting the remaining toner and then melt and knead. The colorant dispersion (conc) comprises at least the magenta colorant of the present invention and a binder resin.

 On the other hand, in the case of the polymerization method, a method for producing toner by the so-called microcapsule method in which other toner constituent materials are dispersed in a binder resin solution and then spray-dried, and a predetermined material as a monomer for forming the binder resin And a method of obtaining a toner by emulsion or suspension polymerization. In the emulsion polymerization method, resin particles having a particle size of submicron are associated with an internal additive such as a pigment component and wax previously emulsified in water in a coagulation step to obtain a particle size of a desired toner size. In the suspension polymerization method, polymerization is performed by dispersing and heating necessary materials such as a polymerization initiator, a pigment component, a wax, and a charge control agent in a monomer.

 The magenta toner mother particles thus obtained are preferably mixed with an external additive using a mixer such as a Henschel mixer.

 The magenta toner used in the present invention preferably has a weight average particle diameter of 3 to 15 μm, and more preferably 5 to 12 μm. In addition, toner particles having a particle size of 5 μm or less are contained in 12 to 60% by number, toner particles having a particle size of 8 to 12.7 μm are contained in 1 to 33% by number, and toner particles having a particle size of 16 μm or more are contained. From the viewpoint of development characteristics, it is more preferable that the content is 2.0% by weight or less and the weight average particle diameter of the toner is 4 to 12 μm. The particle size distribution of the toner can be measured using, for example, a Coulter counter (Multisizer 3).

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the embodiment of the present invention is not limited to these examples.
[Magenta Colorant Production Example 1]
To 6000 g of water, 80 g of sodium hydroxide and 400 g of rosin-modified maleic acid resin (softening point 135 ° C., acid value 130, partial ester of rosin / maleic anhydride resin with pentaerythritol) were added and mixed and dissolved sufficiently. To this, 2000 g of rhodamine dyes (CI Basic Red 1 Rhodamine 6G 1900 g and CI Basic Violet 10 Rhodamine B 100 g) were added, followed by stirring and mixing at room temperature for 1 hour. Further, 230 g of 35% hydrochloric acid was added to make the pH acidic. The pH at this time was 1.77. Further, it was washed with water and dried, and then pulverized with a hammer mill to obtain 2150 g of a composition. This is magenta colorant 1.

[Production Example 2 of Magenta Colorant]
In 6000 g of water, 105 g of sodium hydroxide and 800 g of rosin-modified maleic acid resin (softening point 135 ° C., acid value 130, partial ester of rosin / maleic anhydride resin by pentaerythritol) were added and mixed and dissolved sufficiently. To this, 2000 g of rhodamine dyes (CI Basic Red 1 Rhodamine 6G 1900 g and CI Basic Violet 10 Rhodamine B 100 g) were added, followed by stirring and mixing at room temperature for 1 hour. Further, 280 g of 35% hydrochloric acid was added to make the pH acidic. The pH at this time was 5.86. Furthermore, after washing | cleaning with water and drying, it grind | pulverized with the hammer mill and obtained 2450g of compositions. This is magenta colorant 2.

[Magenta Colorant Production Example 3]
800 g of rosin-modified maleic resin (softening point 145 ° C., acid value 180, partial ester of rosin / fumaric acid resin with ethylene glycol), rhodamine dye (CI basic red 1 1520 g rhodamine 6G and CI basic violet) 10 Rhodamine B 80g) 1600g was mixed and kneaded at 150 ° C for 30 minutes using a pressure kneader. After taking out and cooling, the mixture was pulverized with a hammer mill and a jet mill to obtain 2060 g of a composition. (Volume average particle diameter 4 μm) This is designated as magenta colorant 3.

[Production Example 4 of Magenta Colorant]
800 g of rosin-modified maleic resin (softening point 145 ° C., acid value 180, partial ester of rosin / fumaric acid resin with ethylene glycol), rhodamine dye (CI Basic Red 1 1392 g Rhodamine 6G and CI Basic Violet) 10 Rhodamine B (208 g) and 1600 g were mixed and kneaded at 150 ° C. for 30 minutes using a pressure kneader. After taking out and cooling, it was pulverized with a hammer mill and a jet mill to obtain 2040 g of a composition. (Volume average particle diameter 4 μm) This is designated as magenta colorant 4.

[Production Example 5 of Magenta Colorant]
800 g of rosin-modified maleic resin (softening point 135 ° C., acid value 30, ester of rosin / maleic anhydride resin with glycerin), rhodamine dye (CI Basic Red 1 Rhodamine 6G 1520 g and CI Basic Violet 10 1600 g of rhodamine B (80 g) was mixed and kneaded at 140 ° C. for 45 minutes using a pressure kneader. After taking out and cooling, the mixture was pulverized with a hammer mill and a jet mill to obtain 2020 g of a composition. (Volume average particle diameter: 4 μm) This is designated as magenta colorant 5.

[Production Example 6 of Magenta Colorant]
Using a pressure kneader, 800 g of rosin-modified maleic resin (softening point 145 ° C., acid value 180, partial ester of rosin and fumaric acid resin with ethylene glycol) and 1600 g of rhodamine dye (CI Basic Red 1 Rhodamine 6G) Were mixed and kneaded at 150 ° C. for 30 minutes. After taking out and cooling, it was pulverized by a hammer mill and a jet mill to obtain 2070 g of a composition. (Volume average particle diameter 4 μm) This is designated as magenta colorant 6.

  Table 1 below shows a list of compositions and physical properties of magenta colorants 1 to 6.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the embodiments of the present invention are not limited to these examples. In the following, all parts represent parts by weight. Detailed conditions and results of the following examples and comparative examples are shown in Tables 2 and 3 below. Further, the content of the dye in the toner was adjusted to be about 5% of the whole toner classified product.

  The binder resins used in the following examples and comparative examples are as follows.

(Binder resin)
Thermoplastic polyester resin 1
Polyester resin composed of terephthalic acid, isophthalic acid, trimellitic acid, propylene oxide-added bisphenol A, and ethylene glycol.
Acid value: 10 mg KOH / g OH value: 43 mg KOH / g Tg 58 ° C. Softening temperature Ts 65 ° C. True density 1.32 g / cc Molecular weight Mw: 28200 Mn: 2500

Thermoplastic polyester resin 2
Polyester resin composed of terephthalic acid, isophthalic acid, trimellitic acid, propylene oxide-added bisphenol A, and ethylene glycol.
Acid value: 18 mg KOH / g OH value: 36 mg KOH / g Tg 59 ° C. Softening temperature Ts 66 ° C. True density 1.32 g / cc Molecular weight Mw: 32000 Mn: 2600

[Example 1]
Thermoplastic polyester resin 1 60.0 parts by weight Magenta colorant 1 (rhodamine dye content 83.3%) 40.0 parts by weight The above materials (5 kg in total) were set in a pressure kneader at a set temperature of 150 ° C. for 10 minutes. And kneading and taking out. Further, the mixture was kneaded with three rolls at a roll temperature of 95 ° C., cooled and roughly crushed to 10 mm or less to obtain magenta concrete 1 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 1 82.0 parts by weight Magenta concrete 1 15.0 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene Weight Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.7 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 1.

 The actual image test was performed using a commercially available color printer (N6100 manufactured by Casio Computer Co., Ltd.) under an environmental condition of 23 ° C./50% RH. At this time, output was performed in magenta monochromatic image production conditions. The image densities at the initial and 10,000 copies were 1.36 and 1.35, respectively. Further, fog at the initial stage and at the time of copying 10,000 sheets was 0.5 and 0.5, respectively. Furthermore, there was no scattering of the toner particles in the machine after copying 10,000 sheets, and there was no stain on the obtained image. The charge amounts of the classified product and the toner were −41.3 μC / g and −49.1 μC / g, respectively.

  The image density is determined using a Macbeth photometer and may be a density of 1.3 or more. The fog was measured by measuring the reflectance with a photovolt. 1.0% or less is a good value. The toner was scattered in the machine by checking whether or not the scattered toner was present around the developing unit and the photosensitive drum. When toner scattering is observed, image stains accompanying this occur.

  The charge amount of the classified product and the toner was measured as follows. 19.0 g of powder-tech iron powder carrier (product name: MF-70), 1.0 g of dried product or toner is weighed into a 50 cc plastic bottle, shaken 5 times, and then ball mill (manufactured by Shinei Koki Sangyo Co., Ltd.) (PLASTIC PLANT SKS type) was mixed for 30 minutes under the condition that the rotation number was 230 rotations (120 rotations for the main body of the poly bottle). The obtained sample after mixing was subjected to charge amount measurement using a blow-off charge amount measuring device manufactured by Toshiba Chemical Corporation. At this time, the blow pressure was 1 kgf / cm 2, the maximum value was read at a measurement time of 20 seconds, and the mesh was 400 mesh. The measurement environment was 23 ° C./50% RH.

[Example 2]
Thermoplastic polyester resin 1 60.0 parts by weight Magenta colorant 2 (rhodamine lake content 71.4%) 40.0 parts by weight The above materials (5 kg in total) were set in a pressure kneader at a set temperature of 150 ° C. for 10 minutes. And kneading and taking out. Furthermore, kneading was carried out with a three roll having a roll temperature of 95 ° C., and after cooling, the mixture was roughly crushed to 10 mm or less to obtain magenta concrete 2 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 1 79.5 parts by weight Magenta concrete 2 17.5 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene Weight Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.7 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 2.

 Using this toner, a live-action test was conducted in the same manner as in Example 1. As a result, the image densities at the initial stage and when copying 10,000 sheets were 1.34 and 1.36, respectively. Further, the fog at the initial stage and at the time of copying 10,000 sheets was 0.7 and 0.5, respectively. Furthermore, there was no scattering of the toner particles in the machine after copying 10,000 sheets, and there was no stain on the obtained image. The charge amounts of the classified product and the toner were −40.2 μC / g and −52.1 μC / g, respectively.

[Example 3]
Thermoplastic polyester resin 1 60.0 parts by weight Magenta colorant 3 (rhodamine lake content 66.7%) 40.0 parts by weight The above materials (5 kg in total) were set in a pressure kneader at a set temperature of 150 ° C. for 10 minutes. And kneading and taking out. Further, kneading was carried out with a three roll having a roll temperature of 95 ° C., and after cooling, the mixture was roughly crushed to 10 mm or less to obtain magenta concrete 3 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 1 78.4 parts by weight Magenta concrete 3 18.6 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene Weight Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.7 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 3.

 Using this toner, a live-action test was conducted in the same manner as in Example 1. As a result, the image densities at the initial stage and when copying 10,000 sheets were 1.36 and 1.35, respectively. Further, the fog at the initial stage and at the time of copying 10,000 sheets was 0.4 and 0.6, respectively. Furthermore, there was no scattering of the toner particles in the machine after copying 10,000 sheets, and there was no stain on the obtained image. The charge amounts of the classified product and the toner were −45.6 μC / g and −53.4 μC / g, respectively.

[Example 4]
Thermoplastic polyester resin 1 60.0 parts by weight Magenta colorant 4 (rhodamine lake content 66.7%) 40.0 parts by weight The above materials (5 kg in total) were set in a pressure kneader at a set temperature of 150 ° C. for 10 minutes. And kneading and taking out. Further, the mixture was kneaded with a three roll having a roll temperature of 95 ° C., and after cooling, coarsely crushed to 10 mm or less to obtain magenta concrete 4 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 1 78.4 parts by weight Magenta concrete 4 18.6 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene) Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.7 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 4.

 Using this toner, a real image test was conducted in the same manner as in Example 1. As a result, the image densities at the initial stage and when 10,000 sheets were copied were 1.35 and 1.36, respectively. Further, fog at the initial stage and when 10,000 sheets were copied was 0.6 and 0.8, respectively. Furthermore, there was no scattering of the toner particles in the machine after copying 10,000 sheets, and there was no stain on the obtained image. The charge amounts of the classified product and the toner were −44.8 μC / g and −53.5 μC / g, respectively.

[Example 5]
Thermoplastic polyester resin 2 60.0 parts by weight Magenta colorant 5 (rhodamine lake content 66.7%) 40.0 parts by weight The above materials (5 kg in total) were set in a pressure kneader at a set temperature of 150 ° C. for 10 minutes. And kneading and taking out. Further, the mixture was kneaded with a three roll having a roll temperature of 95 ° C., and after cooling, coarsely crushed to 10 mm or less to obtain magenta concrete 5 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 2 78.4 parts by weight Magenta concrete 5 18.6 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene) Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.7 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 5.

 Using this toner, a live-action test was conducted in the same manner as in Example 1. As a result, the image densities at the initial stage and when 10,000 sheets were copied were 1.35 and 1.34, respectively. Further, fog at the initial stage and at the time of copying 10,000 sheets was 0.8 and 0.7, respectively. Furthermore, there was no scattering of the toner particles in the machine after copying 10,000 sheets, and there was no stain on the obtained image. The charge amounts of the classified product and the toner were −40.5 μC / g and −46.7 μC / g, respectively.

[Example 6]
Thermoplastic polyester resin 2 60.0 parts by weight Magenta colorant 6 (rhodamine lake content 66.7%) 40.0 parts by weight The above materials (total 5 kg) were set in a pressure kneader at a set temperature of 150 ° C. for 10 minutes. And kneading and taking out. Further, kneading was carried out with a three roll having a roll temperature of 95 ° C., and after cooling, the mixture was coarsely crushed to 10 mm or less to obtain magenta concrete 6 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 2 78.4 parts by weight Magenta concrete 6 18.6 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene) Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.5 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 6.

 Using this toner, a live-action test was conducted in the same manner as in Example 1. As a result, the image densities at the initial stage and when copying 10,000 sheets were 1.35 and 1.35, respectively. Further, fog at the initial stage and when 10,000 sheets were copied was 0.6 and 0.5, respectively. Furthermore, there was no scattering of the toner particles in the machine after copying 10,000 sheets, and there was no stain on the obtained image. The charge amounts of the classified product and the toner were −41.1 μC / g and −49.4 μC / g, respectively.

[Comparative Example 1]
Thermoplastic polyester resin 1 60.0 parts by weight Rhodamine dye (CI Pigment Red 81) 40.0 parts by weight The above materials (5 kg in total) were set in a pressure kneader at a set temperature of 150 ° C. for 20 minutes. Mixing and kneading were carried out. Further, the mixture was kneaded with three rolls at a roll temperature of 95 ° C., cooled and roughly crushed to 10 mm or less to obtain magenta concrete 7 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 1 84.5 parts by weight Magenta concrete 7 12.5 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene Weight Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.7 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 7.

 Using this toner, a live-action test was performed in the same manner as in Example 1. As a result, the initial image density was 1.25 and fog was 1.6, which did not reach the target value. After copying 1,000 sheets, the live-action test was stopped because the image was very dirty. Further, in-machine scattering due to toner particles occurred around the photosensitive drum. The charge amounts of the classified product and the toner were −1.2 μC / g and −33.1 μC / g, respectively.

[Comparative Example 2]
Thermoplastic polyester resin 1 60.0 parts by weight Rhodamine lake pigment (CI Pigment Red 81: 3) 40.0 parts by weight The above materials (total of 5 kg) were set in a pressure kneader at a set temperature of 150 ° C. for 20 minutes. And kneading and taking out. Furthermore, kneading was carried out with a three roll having a roll temperature of 95 ° C., and after cooling, the mixture was roughly crushed to 10 mm or less to obtain magenta concrete 8 as a magenta colorant dispersion.
further,
Thermoplastic polyester resin 1 84.5 parts by weight Magenta concrete 8 12.5 parts by weight Charge control agent (zinc salt compound of 3,5-di-tert-butylsalicylic acid) 1.0 part by weight Release agent (low molecular weight polypropylene Weight Average molecular weight (Mw) 7000, Mw / Mn 2.5, melting point 128 ° C.) 2.0 parts by weight The above materials (total 5 kg) were mixed with a Henschel mixer having a volume of 20 L (3000 rpm, 3 minutes), and then biaxial It is melt-kneaded with a kneading extruder (PCM30) at a supply rate of 6 kg / hr and a discharge temperature of 145 ° C., cooled and solidified, coarsely pulverized with a hammer mill, and then finely pulverized with an I-type jet mill (IDS-2 type). Then, classification (DS-2 type) was performed to obtain a classified product (toner mother particles) having a weight average particle diameter of about 8.5 μm.

 Next, 100 parts by weight of the classified product obtained above, 1.0 part by weight of hydrophobic silica (NY-50 manufactured by Nippon Aerosil Co., Ltd.) and 0.7 part by weight of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.) Were mixed with a Henschel mixer (3000 rpm, 3 minutes) and passed through a sieving step (150 mesh) to obtain magenta toner 8.

 Using this toner, a real image test was conducted in the same manner as in Example 1. As a result, the initial image density was 1.23 and fog was 1.7, which did not reach the target value. After copying 1,000 sheets, the live-action test was stopped because the image was very dirty. Further, in-machine scattering due to toner particles occurred around the photosensitive drum. The charge amounts of the classified product and the toner were +0.5 μC / g and −29.3 μC / g, respectively.

 The magenta toner of the present invention has a wide color reproduction area and is used for developing an electrostatic latent image in an electrophotographic copying machine, a laser beam printer, or the like in which an image is formed using an electrophotographic method, an electrostatic recording method, or the like. It can be preferably used as a magenta toner to be used.

Claims (12)

In a magenta toner containing at least a binder resin and a colorant, the colorant is a composition obtained by mixing a rhodamine dye and a rosin-modified maleic resin, and further, the rhodamine dye and the rosin-modified maleic resin. A magenta toner having a mixing ratio (rhodamine lake dye: rosin-modified maleic resin) of 60:40 to 95: 5 . The magenta toner according to claim 1, wherein the rosin-modified maleic resin has a softening point of 80 to 170 ° C. according to the ring and ball method. The magenta toner according to claim 1, wherein the rosin-modified maleic resin has a softening point of 120 to 160 ° C. according to the ring and ball method. 4. The magenta toner according to claim 1, wherein the rosin-modified maleic resin has an acid value of 20 to 320. 4. The magenta toner according to claim 1, wherein the rosin-modified maleic resin has an acid value of 20 to 200. Rhodamine dyes are C.I. I. Basic Red 1 and / or C.I. I. Magenta toner according to claim 1, 5 or which is a basic violet 10. Magenta toner according to claim 1 to 6, the binder resin is characterized in that it is a polyester resin. The magenta toner according to claim 7, wherein the softening temperature Ts of the polyester resin by a flow tester is 60 to 90 ° C. A rhodamine-based dye and a rosin-modified maleic resin are contained , and the weight mixing ratio of the rhodamine-based dye and the rosin-modified maleic resin (rhodamine lake dye: rosin-modified maleic resin) is 60:40 to 95: 5. A colorant for use in a magenta toner characterized by The colorant used for a magenta toner according to claim 9 , wherein the rosin-modified maleic resin has a softening point of 80 to 170 ° C. according to the ring and ball method. The colorant used for a magenta toner according to claim 9 , wherein the rosin-modified maleic resin has a softening point of 120 to 160 ° C. according to the ring and ball method. The colorant used for a magenta toner according to any one of claims 9 to 11 , wherein the acid value of the rosin-modified maleic resin is 20 to 320.