JP4646318B2 - Magenta toner - Google Patents

Description

  The present invention relates to a toner used as a developer in an electrophotographic copying machine, a laser printer, a facsimile, and the like, and relates to a magenta electrophotographic dry toner suitable for use in forming a color image.

  In the electrophotographic system in which a visible image is formed by developing an electric latent image with a developer, an electric latent image is formed on a photoconductor made of a photoconductive substance, and then the latent image is developed with a toner. The toner image is developed into a toner image, and if necessary, the toner image is transferred onto paper or the like, and then fixed by heating, pressurizing or the like to obtain a fixed image. In order to obtain a full-color image by electrophotography, for example, light from an original is exposed on a photoconductor through a color separation filter, or an image read by a scanner is written and exposed with a laser. A yellow toner image formed by forming an electrical latent image of the yellow image portion on the body and developing the electrical latent image with yellow toner is transferred to a transfer material such as paper, and then the magenta toner is obtained by the same process. A magenta toner image and a cyan toner image obtained by using cyan toner may be sequentially superimposed on the yellow toner image.

  Conventionally, a toner obtained by kneading and pulverizing a pigment as a colorant and a charge control agent together with a thermoplastic resin is generally used in the electrophotographic system. In this case, particularly in the magenta toner, since the pigment as the colorant is difficult to be dispersed, it is easy to cause a problem that the dispersed particles scatter light and reduce the transparency of the toner. For this reason, the color reproducibility of a multi-color image formed by superimposing a plurality of color toners is inferior, and the projected image formed by transferring and fixing to a transparent sheet for an overhead projector (OHP) is dark and colored. It had the disadvantage that the degree was low. Further, the magenta toner has drawbacks such as a low degree of coloring or an ideal magenta color tone.

  For these problems, improvement of pigments and dyes mainly used for magenta toners and improvement by combined use of pigments and dyes have been proposed. For example, Patent Document 1 discloses that by using a quinacridone pigment and a xanthene dye in combination, a clear magenta toner is obtained, light resistance is improved, and there is no dyeing on a silicon rubber roller. Patent Document 2 discloses that a clear color image can be obtained without contaminating a copying machine by using a quinacridone pigment and a methine pigment in combination.

  In order to solve the above-mentioned problem, Patent Document 3 discloses an attempt to increase the coloring power by increasing the pigment dispersion by using a polyurethane pigment dispersant in combination with a so-called chemical toner production method.

  However, these proposals also provide excellent spectral reflection characteristics for color reproduction, a clear magenta color, good dispersibility of the colorant in the resin and high coloration, and stable triboelectric charging characteristics in the environment. No magenta toner for electrophotography that sufficiently satisfies all the required characteristics such as having a good transparency and good transparency has not been obtained.

JP-A-1-224777 Japanese Patent Laid-Open No. 2-013968 JP 2005-181839 A Japanese Patent Publication No. 2-01844 JP-A-4-227774 Japanese Patent Application No. 7-250953

  Accordingly, an object of the present invention is to solve such problems and to provide a magenta toner for electrophotography satisfying color tone, coloring degree, triboelectric charging characteristics, transparency and the like.

  As a result of intensive studies to solve the above problems, the present inventors have found that C.I. I. Pigment RED184 (hereinafter also referred to as PR184), and by using a modified polyurethane dispersant having an acid value of 0 to 10 mgKOH / g and an amine value of 1 to 10 mgKOH / g as a pigment dispersant, colorant particles Since most of the dispersant polymer is adsorbed on the surface of the toner and the amount of the dispersant polymer having an amine value that tends to be positively charged is reduced on the toner surface, the negatively chargeable toner is inhibited particularly in negatively charged toners. We found that there is no such thing and came to create the present invention. That is, the present invention adopts the following configuration.

(1) The present invention provides at least a magenta pigment C.I. I. Pigment RED184, a modified polyurethane dispersant having an acid value of 0 to 10 mgKOH / g and an amine value of 1 to 10 mgKOH / g, and a binder resin, and magenta that is granulated in an aqueous medium The toner has an image density of 1.4 to 2.0 when the adhesion amount of the magenta toner is 0.3 mg / cm ² , and a charge amount after stirring for 15 seconds using the magenta toner as a developer is 20 It is a negatively chargeable magenta toner characterized by being (−μC / g) or more .
If the amount of charge is less than 20 (-μC / g), the electrostatic attraction force with the developing roller may decrease, leading to a decrease in image density.

(2) The magenta toner according to (1), wherein the modified polyurethane dispersant has compatibility with the binder resin.
(3) The magenta toner according to (1) or (2), wherein the modified polyurethane-based dispersant has a weight average molecular weight of 2,000 to 100,000.
(4) In the present invention, the addition amount of the modified polyurethane dispersant is 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the magenta pigment. The magenta toner according to any one of the above.
(5) In the present invention, any one of the above (1) to (4) is characterized in that the modified polyurethane-based dispersant is contained in the toner at a ratio of 0.1 wt% to 10 wt%. The magenta toner described in the above.

(6) The magenta toner according to any one of (1) to (5), wherein the magenta toner has a volume average particle diameter (Dv) of 2.5 to 5.5 μm. It is.
(7) In the present invention, the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the magenta toner is 1.00 to 1.20. The magenta toner according to any one of (1) to (6).

( 8 ) The present invention dissolves or disperses a binder resin composed of a polymer having at least a site capable of reacting with a compound having an active hydrogen group, a magenta pigment, and a modified polyurethane-based dispersant in an organic solvent. Alternatively, the dispersion is obtained by subjecting the dispersion to a crosslinking reaction and / or elongation reaction in an aqueous medium and removing the solvent from the obtained dispersion liquid, according to any one of the above (1) to (9), Magenta toner.
( 9 ) The magenta toner according to (10), wherein the polymer having the reactive site is a modified polyester (i) having a reactive substituent.
( 10 ) The magenta toner according to (11), wherein the reactive substituent of the modified polyester (i) is an isocyanate group.
( 11 ) In the present invention, the binder resin contains unmodified polyester (ii) together with the modified polyester (i), and the weight ratio of (i) / (ii) is 5/95 to 30 /. The magenta toner according to (12), which is 70.

The present invention has the following effects.
An electrophotographic dry magenta toner satisfying all of the color tone, coloring degree, transparency and the like can be obtained, and an electrophotographic dry magenta toner having stable triboelectric charging characteristics in various environments can be obtained.

  In the present invention, a pigment dispersion is prepared by using PR184 and a modified polyurethane dispersant in combination as a magenta pigment, and this is used. As PR184, Toner Magenta F8B LV3162 manufactured by Clariant Japan is optimal.

In the present invention, the pigment dispersant is a modified polyurethane dispersant having an acid value of 0 to 10 mgKOH / g and an amine value of 1 to 10 mgKOH / g. In the present invention, when a modified polyurethane-based dispersant is used when preparing a pigment dispersion, and PR184 is used for the colorant particles, most of the dispersant polymer is adsorbed to the colorant particles and becomes positively charged. Since the amount of the dispersant polymer having an easy amine value on the toner surface is reduced, the negative chargeability is not particularly disturbed in the negatively chargeable toner.
For example, when a pigment other than PR184 is used, properties such as the main color tone, coloring degree, and transparency can be satisfied. However, the pigment dispersion must be negatively charged as a toner. Depending on the amine value of the agent, even if the toner has a positive chargeability or a negative chargeability, the toner has very weak charge characteristics.
On the other hand, when PR184 is used as a pigment, there is no problem in charging characteristics due to the above reasons, and a magenta toner satisfying all of the color tone, coloring degree, triboelectric charging characteristics, and transparency can be obtained. .

In the present invention, the colorant is preferably used by dispersing it with a modified polyurethane dispersant having an acid value of 10 mgKOH / g or less and an amine value of 1 to 10 mgKOH / g. When the acid value exceeds 10 mgKOH / g, the chargeability under high humidity is lowered and the pigment dispersibility is also insufficient. Also, when the amine value is less than 1 and when the amine value exceeds 10 mgKOH / g, the pigment dispersibility becomes insufficient, or the negative charge characteristic is caused by the amine value. The acid value can be measured by the method described in JIS K0070, and the amine value can be measured by the method described in JIS K7237.
The modified polyurethane dispersant is preferably highly compatible with the binder resin in terms of pigment dispersibility, and is preferably a silane coupling agent having an amino group or a polyurethane derivative such as polyurethane modified with diisocyanate.

  The particle size of the colorant in the dispersion after dispersing the colorant is desirably 1 μm or less. When the particle size is larger than 1 μm, the particle size of the colorant is increased when the toner is formed, and the image quality is likely to be deteriorated. In particular, the light transmittance of OHP is likely to be decreased. The particle size of the colorant can be determined with a laser diffraction / scattering particle size distribution measuring device “LA-920” (manufactured by Horiba, Ltd.).

The polymer type dispersant will be specifically described as follows.
1) One part of the isocyanate group of the polyisocyanate compound is reacted with a compound having one hydroxyl group, and further a part of the unreacted isocyanate group is reacted with a compound having active hydrogen at both ends, and then the above reaction A dispersant obtained by reacting an unreacted isocyanate group with a substituent having active hydrogen and a compound having a tertiary amino group or heterocyclic group.

2) Polyepoxy having a hydroxyl group at the molecular end obtained by reacting a monocarboxylic acid compound with a monoepoxy compound, an acid anhydride and a lactone, or a compound having a monohydric alcohol, a monoepoxy compound and a lactone, and in some cases Further, a polyester having a hydroxyl group at the molecular end obtained by reacting with an acid anhydride is reacted with a diisocyanate compound, and further a hydroxyl group-containing copolymerizable monomer is reacted to obtain a polyester macromer. It is obtained by reacting an acid anhydride with any one and reacting with glycidyl (meth) acrylate to obtain a polyester macromer, and further copolymerizing a tertiary amino group-containing copolymer monomer with any of the above polyester macromers. Dispersant.

3) Reaction product of monocarboxylic acid compound and lactone, reaction product of monocarboxylic acid compound and acid anhydride and monoepoxy compound, reaction product of monohydric alcohol and acid anhydride and monoepoxy compound, monohydric alcohol and lactone Having a carboxyl group at one end obtained by polymerizing a compound obtained by reacting an acid anhydride with the above reaction product, or a polymerizable vinyl group-containing monomer using a radical chain transfer agent having a carboxyl group and a mercapto group A dispersant obtained by reacting any of the compounds with a polyepoxy compound and then reacting an organic amino compound having one secondary amino group in the molecule.
These three types of dispersants are described in 1) in Patent Document 4, 2) in Patent Document 5, and 3) in Patent Document 6, respectively.

  Specific examples of the modified polyurethane dispersant having such requirements include “EFKA-4060”, “EFKA-4080”, “EFKA-7462”, “EFKA-4015”, “EFKA-4046”, “EFKA-4047”, “EFKA-4055”, “EFKA-4050” (manufactured by EFKA CHEMICALS) and the like can be mentioned.

The modified polyurethane dispersant is preferably blended in the toner at a ratio of 0.1 wt% or more and 10 wt% or less. If the amount is less than 0.1% by weight, the pigment dispersibility is insufficient. If the amount is more than 10% by weight, the chargeability under high humidity may be lowered.
The weight average molecular weight of the modified polyurethane dispersant is the maximum molecular weight of the main peak in terms of styrene conversion weight in gel permeation chromatography, preferably 2000 or more, and more preferably 3000 or more in pigment dispersibility. In particular, about 5000 to 50000 is preferable, and 5000 to 30000 is more preferable. If the molecular weight is less than 500, the polarity becomes high, and the dispersibility of the colorant tends to decrease. If the molecular weight exceeds 100,000, the affinity with the solvent increases, and the dispersibility of the colorant tends to decrease. Is preferably 1 part by weight or more and 50 parts by weight or less, and more preferably 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the colorant. This is because if the amount is less than 1 part by weight, the dispersibility is lowered, and if it exceeds 50 parts by weight, the chargeability tends to decrease.

  These modified polyurethane-based dispersants may be used alone or in combination with other dispersants. Examples of other dispersants that can be used include polyester dispersants, acrylic acid, methacrylic acid and / or ester polymers thereof, and colorant derivatives.

The colorant used in the present invention is used as a dispersion obtained by previously dispersing a colorant and a modified polyurethane dispersant in an organic solvent, and is further bound to apply an appropriate shearing force when dispersing the pigment. A resin may be added and dispersed in an organic solvent.
The blending ratio of the colorant and the organic solvent in the colorant dispersion is preferably in the range of 5:95 to 50:50. If the blending ratio of the colorant is less than this, the amount of the dispersion is increased at the time of toner preparation, and the efficiency of toner preparation tends to be reduced. If the blending ratio of the colorant is larger than this, the dispersion of the pigment tends to be insufficient.

In the present invention, any known binder resin can be used. Specifically, thermoplastic resins, for example, styrenes such as styrene, parachlorostyrene, α-methylstyrene, methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, Esters having unsaturated bonds such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, nitriles having unsaturated bonds such as acrylonitrile and methacrylonitrile, vinylmethyl Polymer or copolymer using monomers such as ethers, vinyl ethers such as vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone, and olefins such as ethylene, propylene and butadiene Or a mixture thereof, and further, non-vinyl condensation resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, and polyether resins, and the vinyl resins are mixed with these condensation resins. A graft polymer obtained by polymerizing a vinyl monomer in the presence of these polymers can be used.
Among these, it is preferable to use a polyester resin in terms of excellent low-temperature fixability and color reproducibility. As the polyester resin, modified polyester (i) or unmodified polyester (ii) can be used. These may be used alone, but it is preferable to use (i) and (ii) in combination because they improve low-temperature fixability and gloss when used in a full-color apparatus. Details of (i) and (ii) will be described below.

  In the present invention, the modified polyester means that the polyester resin has a functional group contained in the acid or alcohol monomer unit and a bonding group other than the ester bond, and the polyester resin shares a different resin component. It is in a state of being bonded by bonding, ionic bonding or the like.

For example, the polyester terminal is reacted with something other than an ester bond, specifically, a functional group such as an isocyanate group that reacts with an acid group or a hydroxyl group is introduced at the terminal, and further reacted with an active hydrogen compound, and the terminal is terminated. Those that have been modified or extended are also included.
Furthermore, if it is a compound in which a plurality of active hydrogen groups are present, those in which the polyester ends are bonded together (urea-modified polyester, urethane-modified polyester, etc.) are included. In addition, a reactive group such as a double bond is introduced into the polyester main chain, and radical polymerization is caused therefrom to introduce a carbon-carbon bond graft component into the side chain, or a double bond is bridged. (Styrene-modified, acrylic-modified polyester, etc.).

  In addition, a resin component having a different structure is copolymerized in the main chain of the polyester, or reacted with a carboxyl group or a hydroxyl group at the terminal, for example, a silicone having a terminal modified with a carboxyl group, a hydroxyl group, an epoxy group, or a mercapto group Also included are those copolymerized with resins (silicone-modified polyesters, etc.). This will be specifically described below.

Examples of the polyester (i) modified with a urea bond include a reaction product of a modified polyester (A) having an isocyanate group and amines (B). Examples of the modified polyester (A) having an isocyanate group include a polycondensate of a polyol (1) and a polycarboxylic acid (2) and a polyester having an active hydrogen group further reacted with a polyisocyanate (3). Can be mentioned. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

  Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2), and (1-1) alone or a mixture of (1-1) and a small amount of (1-2). Is preferred. Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) and a small amount of (2) -2) is preferred. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid) , Naphthalenedicarboxylic acid, etc.). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of said thing.

  The ratio of the polyol (1) to the polycarboxylic acid (2) is usually 2/1 to 1/1, preferably 1 as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 0.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyisocyanate (3) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; And a combination of two or more of these.

The ratio of the polyisocyanate (3) is usually 5/1 to 1 as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group.
/ 1, preferably 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, the low-temperature fixability is deteriorated. When the molar ratio of [NCO] is less than 1, the urea content in the modified polyester is lowered and the hot offset resistance is deteriorated. The content of the polyisocyanate (3) component in the modified polyester (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. %. If it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. If it exceeds 40% by weight, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the modified polyester (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is a piece. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1 to B5 blocked (B6) etc. are mentioned. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of B1 to B5 blocked amino groups (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  Furthermore, if necessary, the molecular weight of the urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.) and those blocked (ketimine compounds).

  The ratio of the amines (B) is the equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] in the modified polyester (A) having an isocyanate group and the amino group [NHx] in the amine (B). Usually, it is 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, and more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] exceeds 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low, and the hot offset resistance deteriorates.

  In the present invention, the modified polyester (i) may contain a urethane bond as well as a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The modified polyester (i) of the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the modified polyester is not particularly limited when the unmodified polyester (ii) described below is used, and may be a number average molecular weight that can be easily obtained to obtain the above weight average molecular weight. (I) In the case of being independent, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

  In the present invention, not only the above-mentioned modified polyester (i) is used alone, but also the polyester (ii) not modified can be contained as a toner binder component together with this (i). By using (ii) in combination, the low-temperature fixability and glossiness when used in a full-color apparatus are improved, which is preferable to single use. Examples of (ii) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component (i) above, and preferred ones are also the same as (i). Further, (ii) is not limited to unmodified polyester, but may be modified with, for example, a urea bond or a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 30/70, preferably 5/95 to 25/75, particularly preferably 7/93 to 20/80. It is. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The peak molecular weight of the toner is usually 1000 to 30000, preferably 1500 to 10000, and more preferably 2000 to 8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 30000, low-temperature fixability will deteriorate.
Here, the peak molecular weight of the toner in the present invention is specifically determined by the following procedure.

(Measurement of peak molecular weight of toner)
Gel permeation chromatography (GPC) measuring device: GPC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel SuperHZM-H 15cm triple (made by Tosoh Corporation)
Temperature: 40 ° C
Solvent: THF
Flow rate: 0.35 ml / min
Sample: 0.4 ml of 0.15% sample was injected Sample pretreatment: The toner was dissolved in tetrahydrofuran THF (made by Wako Pure Chemical Industries, Ltd.) at 0.15 wt% and filtered through a 0.2 μm filter. Used as a sample. 100 μl of the THF sample solution is injected and measured. 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, Showd STANDARD Std. No S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, S-0.580, and toluene were used. An RI (refractive index) detector was used as the detector.

The hydroxyl value of the toner is preferably 5 mgKOH / g or more, more preferably 10 to 120 mgKOH / g, and particularly preferably 20 to 80 mgKOH / g. If it is less than 5 mgKOH / g, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of the toner is usually 1 to 40 mgKOH / g, preferably 5 to 30 mgKOH / g, and more preferably 15 to
28 mg KOH / g. By giving an acid value, it tends to be negatively charged, and the affinity with paper at the time of fixing is increased, and the fixing power is increased.

Here, the acid value (AV) and the hydroxyl value (OHV) in the present invention are specifically determined by the following procedure.
Measuring apparatus: Automatic potentiometric titrator DL-53 Titoror (Metler Toledo)
Electrode used: DG113-SC (Metler Toledo)
Analysis software: LabX Light Version 1.00.000
Calibration of the apparatus: Use a mixed solvent of 120 ml of toluene and 30 ml of ethanol.
Measurement temperature: 23 ° C

The measurement conditions are as follows.
Stir
Speed [%] 25
Time [s] 15
EQP titration
Titrant / Sensor
Titrant CH3ONa
Concentration [mol / L] 0.1
Sensor DG115
Unit of measurement mV
Predispensing to volume
Volume [mL] 1.0
Wait time [s] 0
Titrant addition Dynamic
dE (set) [mV] 8.0
dV (min) [mL] 0.03
dV (max) [mL] 0.5
Measurement mode Equilibrium controlled
dE [mV] 0.5
dt [s] 1.0
t (min) [s] 2.0
t (max) [s] 20.0
Recognition
Threshold 100.0
Steppes jump only No
Range No
Tendency None
Termination
at maximum volume [mL] 10.0
at potential No
at slope No
after number EQPs Yes
n = 1
comb. termination conditions No
Evaluation
Procedure Standard
Potential 1 No
Potentialial 2 No
Stop for revaluation No

(Measurement method of acid value)
Measurement is performed under the following conditions in accordance with the measurement method described in JIS K0070-1992.
Sample preparation: 0.5 g of toner (0.3 g for ethyl acetate soluble component) is added to 120 ml of toluene and dissolved by stirring at room temperature (23 ° C.) for about 10 hours. Further, 30 ml of ethanol is added to prepare a sample solution.
The measurement can be calculated by the apparatus described above, but specifically, the calculation is performed as follows.
Titrate with a pre-standardized N / 10 caustic potash to alcohol solution, and obtain the acid value from the consumption of the alcohol potash solution by the following calculation.
Acid value = KOH (ml) x N x 56.1 / sample weight (where N is a factor of N / 10 KOH)

(Measurement method of hydroxyl value)
Weigh accurately 0.5 g of sample into a 100 ml volumetric flask and add 5 ml of acetylating reagent correctly. Then, it is immersed in a bath at 100 ° C. ± 5 ° C. and heated. After 1-2 hours, the flask is removed from the bath, allowed to cool, water is added and shaken to decompose acetic anhydride. Further, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. This solution is subjected to potentiometric titration with an N / 2 potassium hydroxide ethyl alcohol solution using the electrode to determine the OH value (according to JISK0070-1966).

In the present invention, the glass transition point (Tg) of the toner is usually 40 to 70 ° C., preferably 45 to 60 ° C. If it is less than 40 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with known polyester toners.
Here, the glass transition point (Tg) in the present invention is specifically determined by the following procedure. Using Shimadzu TA-60WS and DSC-60 as measuring devices, the measurement was performed under the following measurement conditions.

Measurement conditions Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50 ml / min)
Temperature conditions Starting temperature: 20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
Holding time: None Temperature drop: 10 ° C / min
End temperature: 20 ° C
Holding time: None Temperature increase rate: 10 ° C / min
End temperature: 150 ° C

The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. The analysis method specifies a range of ± 5 ° C around the point showing the maximum peak on the lowest temperature side of the DrDSC curve which is the DSC differential curve of the second temperature rise, and the peak temperature is determined using the peak analysis function of the analysis software. Ask. Next, in the DSC curve, the peak temperature +5
The maximum endothermic temperature of the DSC curve is obtained using the peak analysis function of the analysis software in the range of ℃ and -5 ℃. The temperature shown here corresponds to the Tg of the toner.

  Further, the toner of the present invention may contain a release agent together with the binder resin and the colorant. As the release agent of the present invention, known ones can be used, and examples thereof include polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sazol wax, etc.); carbonyl group-containing wax. Of these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.); polyalkanol esters (trimellitic acid tristearyl, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.

The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature.
Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability.
The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

  The toner of the present invention may contain a charge control agent as necessary. As the charge control agent, all known ones can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts ( Fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E of salicylic acid metal complex -84, phenolic condensate E-89 (above, Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary Copy charge PSY VP2038 of ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR- which is a boron complex 147 (Nippon Carlit), copper phthalocyanine, perylene, quinacrid And azo pigments, and other polymer compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

The amount of charge control agent used in the present invention is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method. However, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density Cause a decline. These charge control agents and release agents can be melt-kneaded together with the masterbatch and resin, and may be added when dissolved and dispersed in an organic solvent.

As the external additive used for assisting the fluidity, developability and chargeability of the colored particles obtained in the present invention, inorganic fine particles can be preferably used. The primary particle size of the inorganic fine particles is preferably 5 μm to 2 μm, and particularly preferably 5 μm to 500 μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, Examples thereof include diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
In addition, polymer fine particles, for example, polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, dispersion polymerization, methacrylic acid ester or acrylate copolymer, polycondensation system such as silicone, benzoguanamine, nylon, thermosetting Polymer particles made of functional resin

  Such a fluidizing agent increases the hydrophobicity by performing a surface treatment, and can prevent the deterioration of the flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferred surface treatment agents. It is done.

  Examples of the cleaning improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium include, for example, zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, for example, polymethyl methacrylate fine particles, polystyrene fine particles And polymer fine particles produced by soap-free emulsion polymerization and the like. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

The production method of the dry toner of the present invention is exemplified.
For example, when urea-modified polyester is used, the toner binder can be produced by the following method. The polyol (1) and the polycarboxylic acid (2) are heated to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and the generated water is distilled off while reducing the pressure as necessary. Thus, a polyester having a hydroxyl group is obtained. Subsequently, this is made to react with polyisocyanate (3) at 40-140 degreeC, and the modified polyester (A) which has an isocyanate group is obtained. Further, (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When reacting (3) and reacting (A) and (B), a solvent may be used as necessary.

  Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to the isocyanate (3), such as tetrahydrofuran (such as tetrahydrofuran). When polyester (ii) not modified with urea bond is used in combination, (ii) is produced in the same manner as polyester having a hydroxyl group, and this is dissolved in the solution after completion of the reaction of (i) and mixed. To do. The dry toner can be produced by the following method, but is not limited thereto.

  The aqueous medium used in the present invention may be water alone, or a solvent miscible with water may be used in combination. Examples of the solvent miscible with water include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.

  The toner particles may be formed by reacting a dispersion composed of a modified polyester (A) having a substituent capable of reacting in an aqueous medium with (B), or using a modified polyester (i) produced in advance. Good. As a method for stably forming a dispersion composed of the modified polyester (i) and the modified polyester (A) having a reactive substituent in the aqueous medium, the modified polyester (i) and the reactive substitution can be performed in the aqueous medium. Examples thereof include a method of adding a toner raw material composition composed of a modified polyester (A) having a group and dispersing the composition by shearing force. Colorant, colorant masterbatch, release agent, charge control agent, unmodified polyester resin, etc., which are a modified polyester (A) having a reactive substituent and other toner composition (hereinafter referred to as toner raw material), Mixing may be performed when the dispersion is formed in the aqueous medium, but it is more preferable to mix the toner raw material in advance and then add and disperse the mixture in the aqueous medium.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear type, a high-speed shear type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. A high-speed shearing method is preferred in order to make the particle size of the pigment and the release agent in the dispersion such as the pigment dispersion and the release agent dispersion 0.1 to 20 μm. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. As the temperature during dispersion, a higher temperature is preferable in that the dispersion of the modified polyester (i) or the modified polyester (A) having a reactive substituent has a low viscosity and is easily dispersed.

  The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts of the toner composition containing the modified polyester (i) and the modified polyester (A) having a reactive substituent. . If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. The use of a dispersant is preferable in that the particle size distribution becomes sharp and the dispersion is stable.

  Dispersants used to emulsify and disperse the oily phase in which the toner material is dispersed in a liquid containing water include anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters, Amine salt types such as alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N -Archi -N, amphoteric surfactants of tines such as downy N- dimethyl ammonium.

In addition, by using a surfactant having a fluoroalkyl group, the effect can be increased in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate,
3- [Omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carboxylic acid and metal salt, perfluoroalkyl carboxylic acid (C7-C13) and Its metal salt, perfluoroalkyl (C4-C12) sulfonic acid and its metal salt, perfluorooctane sulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perfluorooctane sulfonamide, perfluoroalkyl (C6 -C10) sulfonamidopropyl trimethyl ammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, and the like.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (Daikin Kogyo Co., Ltd.), MegaFuck F-110, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF-102 , 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Examples of cationic surfactants include aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts, and benzas. Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Megafac F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos).

Further, as the inorganic compound dispersant that is hardly soluble in water, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, and the like can be used.
Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and other acids, or (meth) acrylic simple substances containing hydroxyl groups Mer, for example, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, acrylic acid 3-chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N- Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as , Pinyl acetate, vinyl propionate, vinyl butyrate, etc., acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, pinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, etc. Homopolymers or copolymers such as those having a nitrogen atom or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, polyoxyethylene alkyl Such as amine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester Celluloses such as polyoxyethylene, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and the like can be used.

  In addition, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water. To do. In addition, it can be removed by an operation such as enzymatic degradation. When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, it is preferable from the charged surface of the toner that the dispersant is washed and removed after the elongation and / or crosslinking reaction.

  Furthermore, in order to lower the viscosity of the toner raw material, a solvent in which the modified polyester (i) or (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. This solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of such solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, acetic acid. Ethyl, methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred. The usage-amount of the solvent with respect to 100 parts of modified polyester (A) which has a reactive substituent is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after the elongation and / or crosslinking reaction.

  In the case of a urea-modified polyester, the elongation and / or crosslinking reaction time is selected depending on the reactivity of the isocyanate group structure of the modified polyester (A) having a reactive substituent and the amines (B). 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed, Specifically, a dibutyltin laurate, a dioctyltin laurate, etc. are mentioned.

  In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. It is also possible to spray the emulsified dispersion in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and to evaporate and remove the aqueous dispersant together. As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. A spray dryer, belt dryer, rotary kiln, etc. can provide the desired quality in a short time.

  When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution. In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Although classification operation may be performed after obtaining as powder after drying, it is preferable in terms of efficiency to be performed in a liquid. The obtained unnecessary fine particles or coarse particles can be returned to the kneading step and used for forming particles. At that time, fine particles or coarse particles may be wet. The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the above classification operation.

By mixing the obtained toner powder after drying together with different kinds of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or applying mechanical impact force to the mixed powder. By immobilizing and fusing on the surface, it is possible to prevent detachment of the foreign particles from the surface of the resulting composite particle.

  Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture into a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron system (Manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar and the like.

  According to such a production method, it is possible to obtain a toner that is excellent in powder flowability and transferability, and provides a high-quality image with a small particle diameter. Furthermore, it is excellent in low-temperature fixability and hot offset resistance and does not cause filming spent. Thus, toners that satisfy various required characteristics, including pulverized toners, have not been obtained conventionally.

The volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner of the present invention are measured using a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.) and an aperture diameter of 100 μm.
And analyzed with analysis software (Beckman Coulter Multisizer 3 Version 3.51). Specifically, 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; Daiichi Kogyo Seiyaku) is added to a glass 100 ml beaker, 0.5 g of each toner is added, and the mixture is stirred with a micropartel. 80 ml of ion exchange water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter) as the measurement solution.
In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

The volume average particle size of the toner of the present invention is preferably 2.5 to 5.5 μm. When it is larger than 5.5 μm, it becomes difficult to obtain a high-quality image when the adhesion amount is 0.3 mg / cm ² , and when it is smaller than 2.5 μm, transferability and cleaning properties are deteriorated, filming and carrier It will be easy to generate spent.

  In the present invention, the ratio Dv / Dn of the volume average particle diameter Dv to the number average particle diameter Dn of the toner is preferably 1.00 to 1.20. With such a toner, it is excellent in all of heat-resistant storage stability, low-temperature fixability, and hot offset resistance, particularly excellent in image glossiness when used in a full-color copying machine, etc. Even if the toner balance is extended over a wide range, fluctuations in the toner particle size in the developer are reduced, and good and stable developability can be obtained even with long-term stirring in the developing device. Even when used as a one-component developer, even if the balance of the toner is performed, the fluctuation of the toner particle size is reduced, and the toner is filmed on the developing roller and the toner is thinned. The toner was not fused to a member such as a blade, and good and stable developability and images were obtained even when the developing device was used (stirred) for a long time.

When the toner of the present invention is used for a two-component developer, it may be used by mixing with a magnetic carrier. The content ratio of the carrier and the toner in the developer is 1 to 10 toners per 100 parts by weight of the carrier. Part by weight is preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins, for example, acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and polystyrene resins such as styrene acrylic copolymer resins, Halogenated olefin resins such as polyvinyl chloride, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, poly Hexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Fluoro terpolymers and silicone resins such terpolymers, etc. of the non-fluoric monomers including can be used. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle size of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control the electric resistance.
The toner of the present invention can also be used as a one-component magnetic toner or non-magnetic toner that does not use a carrier.

The toner of the present invention is characterized in that the toner layer after fixing is made thinner than before, the colorant in the toner is highly dispersed, and the image density (ID) is high in order to obtain high image quality equivalent to offset printing. . Therefore, the toner of the present invention is characterized in that the ID is 1.4 or more when the adhesion amount is 0.3 mg / cm ² .

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
Example 1
--Preparation of fine particle dispersion 1--
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. The volume average particle diameter of [fine particle dispersion 1] measured by LA-920 was 105 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The resin content had a Tg of 59 ° C. and a weight average molecular weight of 150,000.

--Synthesis of polyester resin (1)-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 229 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 529 parts by mass of bisphenol A propylene oxide 3 mol adduct, 208 parts by mass of terephthalic acid, 46 adipic acid 46 2 parts by weight of dibutyltin oxide and 2 parts by weight of dibutyltin oxide were reacted at normal pressure and 230 ° C. for 8 hours, and further reacted at 10 to 15 mmHg for 5 hours, and then 30 parts by weight of trimellitic anhydride was added to the reaction vessel. The polyester resin (1) was obtained by reacting at 180 ° C. and normal pressure for 2 hours. The polyester resin (1) had a weight average molecular weight (Mw) of 6,700, a glass transition temperature (Tg) of 43 ° C., and an acid value of 20 mgKOH / g.

-Preparation of aqueous phase-
990 parts by weight of water, 183 parts by weight of the fine particle dispersion, 37 parts by weight of an aqueous solution of 48.5% by weight of sodium dodecyl diphenyl ether disulfonate (“Eleminol MON-7”; manufactured by Sanyo Chemical Industries), and 90 parts by weight of ethyl acetate The mixture was stirred to obtain a milky white liquid (aqueous phase).

--Synthesis of low molecular weight polyester--
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 81 parts by mass of bisphenol A propylene oxide 2 mol adduct, 283 parts by mass of terephthalic acid, trimellitic anhydride A low molecular weight polyester was synthesized by charging 22 parts by mass of an acid and 2 parts by mass of dibutyltin oxide and reacting at 230 ° C. for 5 hours under normal pressure.
The obtained low molecular weight polyester has a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 9,500, a glass transition temperature (Tg) of 55 ° C., and an acid value of 0.5 mgKOH / g. The hydroxyl value was 51.

--Synthesis of modified polyester having a reactive substituent--
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 410 parts by mass of the low molecular weight polyester, 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate were charged and reacted at 100 ° C. for 5 hours. A modified polyester having a reactive substituent (polymer capable of reacting with the active hydrogen group-containing compound) was synthesized.
The free isocyanate content of the obtained modified polyester having a reactive substituent was 1.53% by mass.

-Preparation of master batch-
1200 parts by weight of water, PR184 as a colorant (Toner Magenta F8B LV3162 manufactured by Clariant Japan) 540 parts by weight, “EFKA-4080” as a polymer dispersant (modified polyurethane amine value: 3.6 to 4.1, EFKA Chemicals) 108 parts) and 1200 parts by mass of the polyester resin (1) were mixed with a Henschel mixer (Mitsui Mining Co., Ltd.). The mixture was kneaded with a two-roller at 150 ° C. for 30 minutes, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron) to prepare a pigment dispersion.

-Preparation of organic solvent phase-
In a reaction vessel in which a stir bar and a thermometer are set, 378 parts by mass of the polyester resin (1), 110 parts by mass of carnauba wax, and 947 parts by mass of ethyl acetate are charged, and the temperature is raised to 80 ° C. with stirring. After being kept for 30 hours, it was cooled to 30 ° C. over 1 hour to obtain a raw material solution.
1324 parts by mass of the obtained raw material solution was transferred to a reaction vessel, and using a bead mill (“Ultra Visco Mill”; manufactured by Imex Co., Ltd.), the liquid feeding speed was 1 kg / hr, the disk peripheral speed was 6 m / sec, and 0.5 mm zirconia. The carnauba wax was dispersed by dispersing for 9 hours under the condition of 80% by volume of beads.
Next, 1324 parts by mass of a 65% by mass ethyl acetate solution of the low molecular weight polyester was added to the dispersion, and 500 parts by mass of the master batch and 500 parts by mass of ethyl acetate were charged and mixed for 1 hour. Next, the mixed solution was kept at 25 ° C. and passed 4 times with an Ebara milder (combination of G, M, and S from the inlet side) at a flow rate of 1 kg / min to prepare an organic solvent phase (pigment / wax dispersion).
The solid content concentration of the obtained organic solvent phase (130 ° C., 30 minutes) was 50% by mass.

--Emulsification / Dispersion--
Into a reaction vessel, 749 parts by mass of the organic solvent phase, 115 parts by mass of the modified polyester having a reactive substituent, and 2.9 parts by mass of isophoronediamine (manufactured by Wako Pure Chemical Industries) compound were charged. TK homomixer MKII) for 1 minute at 5,000 rpm, 1200 parts by mass of the aqueous phase is added to the reaction vessel, and the homomixer is mixed at 9,000 rpm for 3 minutes. did. Thereafter, the mixture was stirred with a stirrer for 20 minutes to prepare an emulsified slurry. Next, the emulsified slurry was charged into a reaction vessel equipped with a stirrer and a thermometer, and the solvent was removed at 25 ° C. After removing the organic solvent, aging was performed at 45 ° C. for 15 hours to obtain a dispersed slurry.

-Washing process-
After 100 parts by mass of the dispersion slurry was filtered under reduced pressure, 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a homomixer (rotation speed: 8,000 rpm for 10 minutes), and then filtered. 100 parts by mass of ion-exchanged water was added to the obtained filter cake, mixed with a homomixer (10 minutes at a rotation speed of 8,000 rpm), and then filtered under reduced pressure. 100 mass parts of 10 mass% sodium hydroxide aqueous solution was added to the filter cake obtained here, it mixed with the homomixer (10 minutes at the rotation speed of 8,000 rpm), and then filtered. 100 mass parts of 10 mass% hydrochloric acid was added to the filter cake obtained here, it mixed with the homomixer (10 minutes at the rotation speed of 8,000 rpm), and then filtered. 300 parts by mass of ion-exchanged water was added to the obtained filter cake, mixed with a homomixer (10 minutes at a rotation speed of 8,000 rpm), and then filtered twice to obtain a final filter cake. The final filter cake obtained here was dried at 45 ° C. for 48 hours with a circulating drier and sieved with a mesh having a mesh size of 75 μm, whereby toner base particles of Example 1 were obtained.

-External additive treatment-
2.5 parts by mass of the toner base particles obtained in Example 1 and 97.5 parts by mass of a silicone ferrite carrier (core particle size: 45 μm) as an external additive were mixed with a tumbler mixer (manufactured by Shinmaru Enterprises). The toner 1 of Example 1 was produced by stirring.

(Example 2)
A toner 2 was obtained in the same manner as in Example 1 except that the pigment dispersant in Example 1 was changed to EFKA-4060 (amine value 1 to 6).

(Comparative Example 1)
Toner 3 was obtained in the same manner as in Example 1 except that the pigment of Example 1 was changed to PR57: 1 (Dainippon Ink and Chemicals).

(Comparative Example 2)
Toner 4 was obtained in the same manner as in Example 1 except that the polymer dispersant “EFKA-4080” (modified polyurethane amine value: 3.6 to 4.1, manufactured by EFKA Chemicals) was not added.

(Evaluation of toner)
10 g of each toner thus obtained and 100 g of ferrite carrier were mixed in an environment having a temperature of 28 ° C. and a humidity of 80%, and the charge amount of the toner was measured by a blow-off method. In addition, the charge distribution at this time was sharp. The particle size of the toner was measured with Multisizer III (manufactured by Beckman Coulter).

The image density (ID) is 0.3 ± 0.00% on a solid image on a transfer paper (Ricoh type 6200 and NBS Ricoh copy printing paper <135>) using a Ricoh image Neo Neo 450. Adjust so that the toner of 02 mg / cm ² is developed, adjust the temperature of the fixing belt to be variable, output a solid image, and then measure the image density with X-Rite (manufactured by X-Rite). did. This was measured at five points to determine the average of the magenta image density.

Next, 1 part by weight of “Silica R972” (manufactured by Nippon Aerosil Co., Ltd.) as an external additive is added to 100 parts by weight of this toner, and the silica externally added toner mixed for 1 minute in a sample mill is added to an electrophotographic full-color copying machine “imageio” With a modified machine of Neo 450 "(manufactured by Ricoh), fixing was performed without fixing fuser oil, and an OHP fixed image was created.
Turbidity was measured by fixing a solid color image on a transparent sheet for OHP and using a turbidity measuring apparatus.

  From the above results, according to the present invention, a magenta toner having high coloring power and excellent negative chargeability can be obtained.

Claims (11)

At least magenta pigment C.I. I. Pigment RED184, a modified polyurethane dispersant having an acid value of 0 to 10 mgKOH / g and an amine value of 1 to 10 mgKOH / g, and a binder resin, and magenta that is granulated in an aqueous medium The toner has an image density of 1.4 to 2.0 when the adhesion amount of the magenta toner is 0.3 mg / cm ² , and a charge amount after stirring for 15 seconds using the magenta toner as a developer is 20 A negatively chargeable magenta toner, which is (−μC / g) or more .   The magenta toner according to claim 1, wherein the modified polyurethane-based dispersant is compatible with the binder resin.   3. The magenta toner according to claim 1, wherein the modified polyurethane-based dispersant has a weight average molecular weight of 2,000 or more and 100,000 or less.   The magenta toner according to any one of claims 1 to 3, wherein the amount of the modified polyurethane dispersant added is 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the magenta pigment.   5. The magenta toner according to claim 1, wherein the modified polyurethane-based dispersant is contained in the toner at a ratio of 0.1 wt% or more and 10 wt% or less.   6. The magenta toner according to claim 1, wherein the magenta toner has a volume average particle size (Dv) of 2.5 to 5.5 μm.   The ratio (Dv / Dn) of the volume average particle diameter (Dv) and the number average particle diameter (Dn) of the magenta toner is 1.00 to 1.20. The magenta toner described in 1. A binder resin composed of a polymer having at least a site capable of reacting with a compound having an active hydrogen group, a magenta pigment, and a modified polyurethane-based dispersant are dissolved or dispersed in an organic solvent, and the dissolved or dispersed solution is dissolved in an aqueous medium. magenta toner according to any one of claims 1 to 7, the crosslinking reaction and / or elongation is reacted, characterized in that it is obtained by removing the solvent from the resulting dispersion in. The magenta toner according to claim 8 , wherein the polymer having a reactive site is a modified polyester (i) having a reactive substituent. The magenta toner according to claim 9 , wherein the reactive substituent of the modified polyester (i) is an isocyanate group. Said binder resin, wherein with modified polyester (i), and contains a polyester (ii) which is not denatured, in claim 10 which is a weight ratio of 5/95 to 30/70 (i) / (ii) The magenta toner described.