JP2011116997A - Hyper-branched polymer, pigment masterbatch, and toner using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hyper-branched polymer based pigment masterbatch excellent in strength, handling properties, and further having a little dependency to environment. <P>SOLUTION: The invention relates to a pigment masterbatch containing at least a pigment, and a hyper-branched polymer, to the described pigment masterbatch wherein the hyper-branched polymer has an ester bond at a core part, and is further modified by a kind of rosin, or to the described pigment masterbatch wherein the hyper-branched polymer has an ester bond at the core part, and is further modified by abietic acid and/or hydrogenated abietic acid. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a hyperbranched polymer, a hyperbranched polymer pigment masterbatch, and a toner using the same.

  Pigment masterbatch is used to color resin such as polyester resin, polyurethane resin, polyamide resin, polycarbonate resin, phenol resin, acrylic resin, styrene-acrylic resin, styrene-butadiene copolymer, polystyrene. And dispersed in resin. The pigment master batch is used to obtain a target product by blending with a resin containing no pigment or a master batch of another component. Masterbatches are used in a wide range of applications such as molding, coating, adhesion, and toner in order to improve versatility, cost, handleability, dispersibility, and the like.

  For example, Patent Document 1 reports a pigment master batch used for toner. In Patent Document 1, a saturated polyester having a wide molecular weight distribution composed of a tri- or higher functional crosslinking component is used as a main binder resin, and the resin used for the pigment masterbatch has the same composition as the binder resin, and more It is stated that those mainly composed of low molecular weight saturated polyesters are preferred.

  However, the pigment masterbatch using the technology of Patent Document 1 is only characterized by using a resin having the same composition as the binder resin and having a low molecular weight, and has drastically improved pigment dispersibility. It's hard to say. In addition, when a resin different from the resin used for the pigment masterbatch is used as the binder resin, particularly when an aliphatic polyester resin, polycaprolactone resin, polylactic acid resin, or the like is used, color unevenness or poor gloss occurs. Was also scattered. That is, in the technique of Patent Document 1, since the resin used for the pigment masterbatch is limited to the same composition as the binder resin, the versatility is poor and a dramatic improvement in pigment dispersibility cannot be realized. For this reason, a resin excellent in pigment dispersibility is desired regardless of the composition of the binder resin.

Hyperbranched polymer is a polymer that grows as a highly branched polymer with repeated branching during polymerization. Linear polymers that have been widely used in the past (including polymers with polyfunctional components copolymerized at low concentrations) Including, the same shall apply hereinafter). This hyperbranched polymer has terminal groups at a high concentration on the outside of the resin, but does not cause gelation and exhibits thermoplasticity. It is known that hyperbranched polymers can be synthesized by polymerization of AB _x (x is an integer of 2 or more) type molecules (Non-patent Documents 1 and 2). Here, A and B are organic groups having different functional groups a and b, and the functional groups a and b are capable of chemically condensing and adding to each other. It is also known that an AB type molecule (a compound having one each of A and B organic groups in one molecule) is copolymerized during the polymerization of AB _x .

  It is known that the hyperbranched polymer has a weak interaction between molecules and a low viscosity as compared with the linear polymer. The hyperbranched polymer has a characteristic that the pigment dispersibility is very good due to its specific structure (Patent Document 2). That is, since the hyperbranched polymer has a low viscosity and good pigment dispersibility, the use of the hyperbranched polymer as a pigment masterbatch resin can greatly increase the pigment concentration and significantly improve the production efficiency. Be expected. However, the hyperbranched polymer used in Patent Document 2 and the hyperbranched polymer as shown in Patent Documents 3 and 4 are low in molecular weight and have a concern about strength, and have a low glass transition temperature and handling properties. There is a problem. Furthermore, since it has many hydroxyl groups at the terminal, the physical properties of the resin itself may change under high humidity. For this reason, it must be said that the hyperbranched polymer as shown in Patent Documents 2 to 4 is not suitable as a resin for the pigment master batch.

  On the other hand, rosins are a general term for low-volatility resin acids obtained from trees, and the main components are substances derived from natural products including abietic acid, which is a kind of tricyclic diterpenes, and isomers thereof. Since it is derived from natural products and is relatively inexpensive, it is widely used industrially, such as paper surface treatment agents, inks, paints, and pigment dispersant resins (Patent Document 5). In recent years, attention has been paid to pigment dispersibility, and examples of use as a toner application (Patent Documents 6 and 7) are also seen, but the addition amount is limited due to problems of durability and fluidity.

P. J. et al. Flori (Co-authored by Oka Koten and Kanamaru Ko), “Polymer Chemistry”, Chapter 9, Maruzen Co., Ltd. (1956) Koji Ishizu, “Nanotechnology of Branched Polymers”, Chapter 6, IPC Corporation (2000)

Japanese Patent Laid-Open No. 10-268573 JP 2005-276401 A U.S. Pat. No. 3,669,939 Japanese Patent No. 2574201 JP-A-10-307419 JP 2003-322997 A JP 2006-292820 A

  An object of the present invention is to provide a hyperbranched polymer pigment masterbatch that is good in strength and handling properties and that is less dependent on the environment.

  As a result of diligent research and investigations to solve the above problems, the present inventors have found that the use of hyperbranched polymer as a component of the pigment masterbatch has extremely good pigment dispersibility, and further less environmental dependency. In this way, a pigment master batch having excellent resin strength and handling properties has been produced. That is, the present invention relates to a pigment master batch containing at least a pigment and a hyperbranched polymer, and a toner manufactured using the same.

  The pigment master batch of the present invention is extremely excellent in pigment dispersibility by using a hyperbranched polymer as a resin. Furthermore, due to the features derived from the hyperbranched polymer skeleton such as low intermolecular interaction, the viscosity is low, the pigment concentration can be increased, the kneading in a short share and in a short time is possible, and the production efficiency is greatly improved. Can be made. Further, since kneading can be performed in a low share and in a short time, the concern that the molecular chain of the resin is broken during kneading can be reduced. In addition, as a hyperbranched polymer, when the terminal functional group is modified with rosin or abietic acid, etc., it is excellent in resin strength and handling property, and has less environmental dependency since the functional group is reduced. Useful for toner applications.

Hyperbranched polymer used in the present invention preferably is not particularly limited in its structure to the polycondensation reaction or main skeletons those obtained by polyaddition reaction of AB _X type compound. Here, A and B represent organic groups having different functional groups, and the AB _X type compound means a compound having two different functional groups a and b in one molecule. These compounds do not undergo intramolecular condensation or intramolecular addition, but the functional group a and the functional group b are functional groups capable of causing a condensation reaction and an addition reaction chemically. In the present invention, those having an ester bond in the core portion are particularly preferred, and the functional group a and functional group b are preferably a carboxyl group or a derivative thereof and a combination of a hydroxyl group or a derivative thereof.

Specific examples of AB _x- type compounds include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, diphenolic acid, 5- (2-hydroxyethoxy) isophthalic acid, 5-acetoxyisophthalic acid, 3,5-bis (2-hydroxyethoxy) benzoic acid, 3,5-bis (2-hydroxyethoxy) benzoic acid methyl ester, 4,4- (4′-hydroxyphenyl) pentanoic acid, 5-hydroxycyclohexane-1 , 3-dicarboxylic acid, 1,3-dihydroxy-5-carboxycyclohexane, 5- (2-hydroxyethoxy) cyclohexane-1,3-dicarboxylic acid, 1,3- (2-hydroxyethoxy) -5-carboxycyclohexane, etc. From the versatility of these raw material compounds and the simplicity of the polymerization reaction process, 2,2 Dimethylol propionic acid, 2,2-dimethylol butanoic acid are preferred.

  Among these, a type in which an ester bond is generated by reaction is particularly preferable from the viewpoint of heat resistance of the obtained hyperbranched polymer and compatibility with other resin components and additive components.

In the above reaction, an AB _X- type compound may be reacted alone in the presence of a condensation reaction catalyst, or a polyhydric hydroxy compound, a polyvalent carboxylic acid compound, or a compound having both of them is branched into a hyperbranched polymer molecule. It may be used as a point. Examples of the polyvalent hydroxy compound include various general-purpose glycol compounds as a polyester resin raw material and trifunctional or higher functional hydroxyl group-containing compounds such as trimethylolpropane, pentaerythritol, and dipentaerythritol. In addition, examples of the polyvalent carboxylic acid compound include trifunctional or higher functional carboxylic acid compounds such as various dibasic acids, trimellitic acid, pyromellitic acid, and benzophenone tetracarboxylic acid which are generally used as polyester resin raw materials. Furthermore, examples of the compound having both a hydroxyl group and a carboxylic acid group include glycolic acid, hydroxypivalic acid, 3-hydroxy-2-methylpropionic acid, lactic acid, glyceric acid, malic acid, and citric acid.

  In addition to the above as a branching point of the hyperbranched polymer molecule of the present invention, a linear polyester oligomer obtained by a condensation reaction of a dibasic acid component and a glycol component, or a trifunctional or higher polyvalent carboxylic acid or polyvalent hydroxy compound is added thereto. A copolymerized branched polyester oligomer may be used.

  As a constituent material of the linear or branched polyester oligomer that can be a branching point, general-purpose various dibasic acids and glycol compounds, or tri- or higher functional polycarboxylic acids and polyhydric alcohol compounds can be used. Dibasic acid compounds include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid and other aliphatic dibasic acids, terephthalic acid, isophthalic acid, orthophthalic acid, 1,2-naphthalenecarboxylic acid, 1,6 -An aromatic dibasic acid such as naphthalenedicarboxylic acid, or an alicyclic dibasic acid such as 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid In view of heat resistance, terephthalic acid, isophthalic acid, orthophthalic acid, 1,2-naphthalene carboxylic acid, and 1,6-naphthalenedicarboxylic acid are preferable, and terephthalic acid and 1,2-naphthalene carboxylic acid are particularly preferable. 1,6-naphthalenedicarboxylic acid.

As glycol components, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol 2-methyl-1,3-propylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,4-diethyl-1, 5-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-dimethyl-3-hydroxypropyl-2 ′, 2′-dimethyl-3-hydroxypropanoate, 2-nbutyl-2-ethyl- 1,3-propanediol, 3-ethyl-1,5-pentanediol, 3-propyl-1,5-pentane Aliphatic diols such as ol, 2,2-diethyl-1,3-propanediol, 3-octyl-1,5-pentanediol, 1,3-bis (hydroxymethyl) cyclohexane, 1,4-bis ( Hydroxymethyl) cyclohexane, 1,4-bis (hydroxyethyl) cyclohexane, 1,4-bis (hydroxypropyl) cyclohexane, 1,4-bis (hydroxymethoxy) cyclohexane, 1,4-bis (hydroxyethoxy) cyclohexane, 2 , 2bis (4-hydroxymethoxycyclohexyl) propane, 2,2-bis (4hydroxyethoxycyclohexyl) propane, bis (4-hydroxycyclohexyl) methane, 2,2-bis (4-hydroxycyclohexyl) propane, 3 (4 ), 8 (9) -Tricyclo [5.2. 1.0 ^2,6 ] alicyclic glycols such as decanedimethanol, or aromatic glycols such as ethylene oxide and propylene oxide adducts of bisphenol A. Among these, 2,2-dimethyl -3-hydroxypropyl-2 ', 2'-dimethyl-3-hydroxypropanate, 2,2-bis (4-hydroxycyclohexyl) propane, 3 (4), 8 (9) -tricyclo [5.2.1 .0 ^2,6] decane dimethanol, and ethylene oxide or propylene oxide adduct of bisphenol a are preferred due to its flexibility as a heat resistance and a raw material of the polyester resin obtained.

  Further, examples of the trifunctional or higher polyhydric carboxylic acid and polyhydric alcohol compound include trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, glycerin, trimethylolpropane, pentaerythritol and the like.

  In the above reaction, the condensation water produced by the condensation reaction is azeotropically dehydrated with toluene or xylene, the inert gas is blown into the reaction system, and the water or monoalcohol produced by the condensation reaction is blown out of the reaction system together with the inert gas. It proceeds by a method or a method of distilling under reduced pressure. As a catalyst used for the reaction, it is possible to use various metal compounds such as titanium-based, tin-based, antimony-based, zinc-based, germanium-based, and strong acid compounds such as p-toluenesulfonic acid and sulfuric acid as in the case of a normal polyester resin polymerization catalyst. I can do it.

The hyperbranched polymer used in the pigment masterbatch of the present invention has a number average molecular weight of 1000 to 60000 and a glass transition temperature of 30 ° C. or higher. In the present invention, it is desirable to react the hyperbranched polymer with rosins in order to increase the molecular weight and glass transition temperature of the hyperbranched polymer. A method as a method of reacting the rosin is reacted with a functional group and rosin core portion end of the hyperbranched structure formed by condensation of AB _X type compound is desired, the rosin condensation process of AB _X type compound There is no problem even if you let the reaction.

  Specific components of the rosins used for the modification of the hyperbranched polymer include abietic acid, levopimaric acid, pultrinic acid, neoabietic acid, dehydroabietic acid, dihydroabietic acid, etc., and one or more of these are included. It is preferable to use one. The rosin used in the present invention may be a mixture thereof, a purified product thereof, or a modified product thereof. Of course, there is no problem even if rosin constituents abietic acid, levopimaric acid, pulstrated acid, neoabietic acid, dehydroabietic acid, dihydroabietic acid, etc. themselves or their hydrogenated products are used. In particular, those using abietic acid or hydrogenated abietic acid are also preferred. Rosin belongs to a monocarboxylic acid as a chemical structure, and a carboxyl group is a typical reactive group. As the rosin used in the present invention, it is preferable to use an ultra-light rosin for the purpose of reducing coloring.

  The hydroxyl value of the hyperbranched polymer used in the pigment master batch of the present invention is preferably 1 to 510 mgKOH / g. When the hydroxyl value is less than 1 mg KOH / g, it is difficult to perform an acid addition modification reaction described later, and pigment dispersibility may not be ensured. On the other hand, when the hydroxyl value exceeds 510 mgKOH / g, the hygroscopicity becomes high and the environmental dependency may be extremely high. The hydroxyl value is more preferably 2 to 350 mgKOH / g, still more preferably 3 to 250 mgKOH / g.

  The hyperbranched polymer used in the pigment master batch of the present invention may have a carboxyl group at the molecular end as necessary. By appropriately introducing the carboxyl group into the molecule, the pigment dispersibility can be further improved, and the affinity with other materials is improved. The method for introducing a carboxyl group into the resin is not limited, and a generally known method can be used, but a method in which an acid anhydride compound is added to a hydroxyl group at the end of the hyperbranched polymer is particularly desirable. Acid anhydrides include maleic anhydride, itaconic anhydride, malonic anhydride, succinic anhydride, propionic anhydride, methyl hymic anhydride, hymic anhydride, octenyl succinic anhydride, pentadodecenyl succinic anhydride, dodecenyl succinic anhydride Aliphatic acid anhydrides such as phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, tri Alkyltetrahydrophthalic anhydride, Stillylstyrene styrenetetrahydrophthalic anhydride, Endomethylenetetrahydrophthalic anhydride, Methylendomethylenetetrahydrophthalic anhydride, Stillenstyrene styrenetetrahydrophthalic anhydride, Tetrabromophthalic anhydride, Naphtha Down-2,3-dicarboxylic anhydride, alicyclic or aromatic dibasic acid anhydrides such as trimellitic anhydride. Trimellitic anhydride and tetrahydrophthalic anhydride are preferable. Polyfunctional anhydrides such as benzophenone tetracarboxylic acid dianhydride, biphenyl tetracarboxylic acid dianhydride, and cyclohexane tetracarboxylic acid dianhydride can also be used. These acid anhydrides can be used alone or in combination of two or more.

  The acid value of the hyperbranched polymer used in the pigment master batch of the present invention is preferably 1 to 70 mgKOH / g, and more preferably 1 to 50 mgKOH / g. When the acid value is less than 1 mgKOH / g, the pigment dispersibility may be lowered. On the other hand, when the acid value exceeds 70 mgKOH / g, the resin physical properties under high temperature and high humidity are affected, and the aggregation of the resins becomes remarkable, and the pigment dispersibility may be lowered.

  In the hyperbranched polymer used in the pigment master batch of the present invention, pigment dispersibility can be dramatically improved by introducing a sulfonic acid metal base into the molecule. In this case, the amount of sulfonic acid metal base is preferably 500 eq / ton or less, and more preferably 400 eq / ton or less. The lower limit is not particularly limited. However, if the amount of the sulfonic acid metal base exceeds 500 eq / ton, the resin melt viscosity increases and the properties of the hyperbranched polymer are impaired, which is not preferable.

  As a method of introducing the sulfonic acid metal salt into the hyperbranched polymer used in the pigment master batch of the present invention, a method of copolymerizing a compound having a sulfonic acid metal base copolymerizable with the hyperbranched terminal functional group is preferable. Compounds having a sulfonic acid metal base copolymerizable with a hyperbranched terminal functional group include 2-sodium sulfo-1,4-butanediol, 2-sodium sulfo-1,6-hexanediol, and 5-sodium sulfoisophthalic acid. Ethylene glycol diester, 5-sodium isophthalic acid dimethyl ester, and the like.

  In preparing the hyperbranched polymer used in the pigment masterbatch of the present invention, a catalyst may be used for the reaction with rosins and acid anhydrides, and the reaction with compounds having a sulfonic acid metal base. Examples of the catalyst include various metal compounds such as titanium, tin, antimony, zinc, and germanium, and organic sulfonic acid compounds such as p-toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, and xylenesulfonic acid. Can be used. You may use the said polymerization catalyst 1 type (s) or 2 or more types.

  The reaction temperature is preferably 100 to 300 ° C, more preferably 150 to 250 ° C. If it is lower than 100 ° C., the reaction takes time, which is not economical. Moreover, when it exceeds 300 degreeC, the decomposition | disassembly of the hyperbranched polymer and the compound which has a reactive group may occur.

  The hyperbranched polymer used in the pigment master batch of the present invention preferably has a number average molecular weight of 1000 or more. If the number average molecular weight is lower than 1000, the resin may become brittle. On the other hand, if the number average molecular weight exceeds 60,000, the compatibility with other resins may be deteriorated, and further, the melt flow characteristics may be deteriorated, and as a result, characteristics as a hyperbranched polymer may be lost. A preferred range for the number average molecular weight is 1000 to 60000, more preferably 1500 to 40000.

  The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the hyperbranched polymer used in the pigment master batch of the present invention is preferably 2-15. If this ratio exceeds 15, the melt flow characteristics inherent to the hyperbranched polymer may deteriorate. Moreover, there exists a possibility of gelatinizing during manufacture and there exists a possibility that it cannot produce stably. On the other hand, if Mw / Mn is smaller than 2, brittleness as a polymer may become remarkable. A preferred range for Mw / Mn is 4-12.

  The glass transition temperature of the hyperbranched polymer used in the pigment master batch of the present invention is preferably 30 ° C. or higher. More preferably, the glass transition temperature is 40 ° C. or higher. When the temperature is lower than 30 ° C., the handling property is poor, and there is a possibility that the polymers are fused with each other when the polymer is stored. The upper limit is not particularly limited, but considering the flow characteristics of the hyperbranched polymer, the temperature is preferably less than 120 ° C. from the viewpoint of fixability when used as a toner.

  The pigment masterbatch of the present invention contains a hyperbranched polymer and a pigment as essential components, but there is no problem even if blended with other linear polymers or other hyperbranched polymers to such an extent that the properties of the hyperbranched polymer are not impaired. . Examples of other linear polymers include polyester resins, polyamide resins, polycarbonate resins, polyurethane resins, phenol resins, acrylic resins, styrene-acrylic resins, styrene-butadiene copolymers, and polystyrene. When the hyperbranched polymer is used by blending with another linear polymer, the linear polymer is desirably contained in the total resin in an amount of 70% by weight or less, preferably 50% by weight or less, more preferably 40% by weight or less. If the linear polymer is contained in an amount of more than 70% by weight, the properties of the hyperbranched polymer may not be exhibited.

  The pigment master batch of the present invention can be used, for example, as a toner. Particularly for color toners, color development is particularly important. Although this color developability depends on the type of color pigment, it is greatly influenced by the pigment dispersion state in the toner. That is, a toner image in which the pigment is well dispersed has a good color developability and a bright color tone, whereas an image with a toner having a poor pigment dispersion has a poor color developability and a dark color tone. Further, since the color pigment itself also has triboelectric charging properties, in the case of toner with poor pigment dispersion, the charging properties of individual toners become non-uniform and image defects such as background fog are likely to occur. Since the pigment master batch of the present invention includes a hyperbranched polymer having extremely excellent pigment dispersibility, a toner having extremely good pigment dispersion and uniform chargeability can be produced by using the pigment master batch of the present invention. .

  Since the toner produced using the pigment master batch of the present invention contains a hyperbranched polymer in which the resin easily flows when the glass transition temperature is exceeded, it can also contribute to an improvement in low-temperature fixability of the toner.

  The pigment master batch of the present invention contains a hyperbranched polymer and a pigment as essential components, and may contain other inorganic particles, organic particles, waxes, and a solvent as necessary. The pigment concentration in this case is usually 10 to 60% by mass in the pigment master batch, although it varies depending on the type of pigment.

  Known organic pigments are used. For example, aniline blue, calco oil blue, phthalocyanine blue, ultramarine blue, bitumen, cobalt blue, phthalocyanine blue, fast sky blue, alkali blue lake, Victoria blue lake, quinacridone, chrome yellow, quinoline yellow, methylene blue chloride, malachite green oxa Rate, Rose Bengal, Dupont Oil Red, Permanent Red 4R, Lake Red, Watching Red Calcium Salt, Brilliant Carmine 3B, First Violet B, Methyl Violet Lake, Alkaline Blue Lake, Victoria Blue Lake, Quinacridone, Rhodamine B, Rhodamine Lake, Pigment Green B, Malachite Green Lake, Final Yellow Green G, etc. It is. These organic pigments can be used alone or in combination.

  Organic particles include polymethyl methacrylate resin, polystyrene resin, nylon resin, melamine resin, benzoguanamine resin, phenol resin, urea resin, silicone resin, methacrylate resin, acrylate resin, terpene resin and other polymer particles, or cellulose powder. Nitrocellulose powder, wood powder, waste paper powder, rice husk powder, starch and the like. The polymer particles may be dispersed using organic particles obtained by a polymerization method such as emulsion polymerization, suspension polymerization, dispersion polymerization, soap-free polymerization, or microsuspension polymerization. The shape of the particles may be any shape such as powder, granule, granule, flat plate, and needle, and is not limited. These organic particles can be used alone or in combination.

  Examples of inorganic pigments include inorganic oxides such as magnesium, calcium, barium, zinc, iron, zirconium, molybdenum, silicon, antimony, titanium, and other metal oxides, hydroxides, sulfates, carbonates, and silicates. System particles, carbon black and the like. These inorganic pigments can be used alone or in combination.

  Specific examples of waxes include liquid wax, natural paraffin, micro wax, synthetic paraffin, hydrocarbon waxes such as polyethylene wax, fatty acid waxes such as stearic acid, stearic acid amide, palmitic acid amide, and methylene bisstearo. Fatty acid amide waxes such as amide, ethylenebisstearoamide, oleic acid amide, esylic acid amide, lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, etc. waxes, cetyl alcohol, stearyl alcohol And other natural waxes such as alcohol waxes, olefin waxes, caster waxes and carnauba waxes, and metal soaps derived from fatty acids having 12 to 30 carbon atoms. These waxes can be used alone or in combination.

  Examples of the organic solvent include aromatic hydrocarbon solvents such as toluene, xylene, and solvesso, ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate, and ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone. Alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, glycol ether solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, Further examples include glycol ether ester solvents obtained by acetylating these, and lactic acid ester solvents such as ethyl lactate and methyl lactate. It is. The solvent can be used alone or in combination of two or more.

  In the pigment master batch of the present invention, an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, a tackifier, a plasticizer, a cross-linking agent, a viscosity modifier, an antistatic agent, a fragrance, an antibacterial agent, and a dispersion, as necessary. Various additives such as an agent and a polymerization inhibitor can be added as long as the effects of the present invention are not impaired.

  As a method for producing the pigment master batch of the present invention, a hyperbranched polymer, an inorganic pigment, an organic pigment, and the like are used in an ordinary dispersing machine such as a paint shaker, a pressure kneader, a Banbury mixer, a two-roll kneader, and a three-roll kneader. , Roll mill dispersers, sand grind mill dispersers, planetary mixers, high speed disperser dispersers, uniaxial kneaders, biaxial kneaders, etc., can be mixed and dispersed by setting temperature conditions according to the resin characteristics it can.

  As a method for producing a toner using the pigment master batch of the present invention, there is a so-called pulverization method in which a master batch is mixed with a main resin and various additives, melt kneaded and pulverized and classified to form a toner. On the other hand, since the pigment master batch of the present invention can efficiently disperse a very high concentration of pigment, it can be expected to be applied to coloring of solvent-soluble or water-dispersed polyester resins. For this reason, the toner may be produced by a so-called polymerization method. Examples of polymerization methods include a method in which initiators and colorants are mixed in vinyl monomers and the particles are grown by the so-called radical polymerization method, “fine particle resin” dispersed in water, and the resin is dissolved in an organic solvent. Using the “resin solution” as a starting material, create particles by agglomeration and mixing with a pigment masterbatch or wax dispersion, etc., then remove the solvent if necessary, and then heat to fuse the particles. , And the method of uniting. When a toner is prepared using the pigment master batch of the present invention, either a pulverization method or a polymerization method may be used.

  As an external additive used when externally treating the toner particles produced in the above-described steps, known inorganic fine particles used as a fluidity adjusting agent in the field of electrostatic image developing toners are used. For example, silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, diamond carbon lactam, etc. Various nitrides such as carbide, boron nitride, titanium nitride, zirconium nitride, various borides such as zirconium boride, titanium oxide (titania), calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, silica, colloidal silica Various oxides such as calcium titanate, magnesium titanate Various titanate compounds such as strontium, strontium titanate, sulfides such as molybdenum disulfide, various fluorides such as magnesium fluoride and carbon fluoride, various types such as aluminum stearate, calcium stearate, zinc stearate, magnesium stearate Various nonmagnetic inorganic fine particles such as metal soap, talc and bentonite can be used alone or in combination. Inorganic fine particles, especially silica, titanium oxide, alumina, zinc oxide, etc. are conventionally used hydrophobizing agents such as silane coupling agents, titanate coupling agents, silicone oils, silicone varnishes, and fluorine-based silanes. It is preferable that the surface treatment is carried out by a known method using a coupling agent or a fluorine-based silicone oil, a coupling agent having an amino group or a quaternary ammonium base, or a modified silicone oil.

  The average primary particle size of the inorganic fine particles used as the external additive is 5 to 100 nm, preferably 10 to 50 nm, and more preferably 20 to 40 nm.

  The toner using the hyperbranched polymer pigment master batch can be used as it is as a one-component developer or as a toner in a two-component developer comprising a carrier and a toner. Examples of the carrier that can be used for the two-component developer include a resin-coated carrier having a coating layer made of a resin such as polyethylene or polypropylene on the surface of the core material. Further, a resin-dispersed carrier in which a metal such as gold or copper or carbon black is dispersed in a matrix resin may be used. Examples of the carrier core material include magnetic metals such as iron and nickel, magnetic oxides such as ferrite and magnetite, and glass beads.

  The toner produced using the hyperbranched polymer pigment masterbatch of the present invention may be used as a full color toner used in a full color image forming apparatus, or may be used as a monochrome toner used in a monochrome image forming apparatus. .

The toner produced using the hyperbranched polymer pigment masterbatch of the present invention may be used in an image forming apparatus having any type of fixing device, but the release oil applied to a fixing member such as a roller may be used. The amount of the fixing device is reduced, that is, the fixing device having a release oil application amount of 4 mg / m ² or less, in particular, an image forming apparatus having a fixing device that does not apply the release oil. Is preferred.

  By preparing the toner using the hyperbranched polymer pigment master batch of the present invention, it is possible to prepare a toner with extremely good pigment dispersion and uniform chargeability. In addition, since the hyperbranched polymer with less intermolecular interaction is used as the dispersion resin, it can contribute to the low-temperature fixability of the toner.

  Next, the present invention will be specifically described using the following examples and comparative examples, but the present invention is not limited thereto. In the examples, the characteristics of the resin, the resin particle dispersion, the pigment dispersion, and the wax dispersion were measured as follows. In the examples and comparative examples, the term “parts” means parts by mass.

(1) Number average molecular weight, weight average molecular weight: From the results of GPC measurement at a column temperature of 30 ° C. and a flow rate of 1 ml / min using Waters Gel Permeation Chromatography (GPC) 150c using tetrahydrofuran as an eluent. Calculation was performed to obtain a measurement value in terms of polystyrene. However, Showa Denko Co., Ltd. shodex KF-802, 804, 806 was used for the column.

(2) Acid value: 0.2 g of a sample was precisely weighed and dissolved in 20 ml of chloroform. Subsequently, it titrated with 0.01N potassium hydroxide (ethanol solution). Phenolphthalein was used as an indicator.

(3) Hydroxyl value: esterified with pyridine solution of acetic anhydride, and excess acetic anhydride was titrated with potassium hydroxide solution and phenolphthalein as indicator.

(4) Sulfonic acid metal base concentration: determined from Na concentration as a metal component. After 0.1 g of Na concentration sample was carbonized and dissolved in acid, it was determined by atomic absorption analysis, and the value was converted as the content of sulfonic acid metal salt. The unit was expressed as eq / ton.

(5) Glass transition temperature: 5 mg of sample was put in an aluminum sample pan and sealed, and a differential scanning calorimeter (DSC) DSC-220 manufactured by Seiko Instruments Inc. was used. Measured at / min, it was determined at the temperature of the intersection of the base line extension below the glass transition temperature and the tangent indicating the maximum slope at the transition.

Example of resin production (1)
Synthesis of Hyperbranched Polymer A1 A reaction kettle equipped with a partial condenser, a thermometer, and a stirring bar was charged with 136 parts of pentaerythritol, 1776 parts of dimethylolbutanoic acid and 21 parts of paratoluenesulfonic acid (hereinafter abbreviated as PTS) at 100 ° C. Stir to a uniform liquid mixed melt. Subsequently, 100 parts of toluene was injected, the temperature was raised to 140 ° C., and water generated while refluxing toluene was distilled out of the system by azeotropic distillation. After continuing the reaction for 5 hours under the same conditions, toluene was distilled out of the system to obtain a hyperbranched polymer A1 (which becomes a core). The number average molecular weight of the obtained polycondensate was 1500, the weight average molecular weight was 2,100, the hydroxyl value was 502.0 mgKOH / g, the acid value was 0.6 mgKOH / g, and the glass transition temperature was 32 ° C.

  Next, 1450 parts of Pine Crystal KR-85 (produced by Arakawa Chemical Industry Co., Ltd., ultralight rosin) and 30 parts of PTS are added to 1000 parts of this hyperbranched polymer (A1), and a nitrogen atmosphere is distilled off at 230 ° C. Under reaction for 24 hours, hyperbranched polymer B1 was obtained. The resulting hyperbranched polymer B1 had a number average molecular weight of 2,200, a weight average molecular weight of 18,200, a hydroxyl value of 48.0 mgKOH / g, an acid value of 1.8 mgKOH / g, and a glass transition temperature of 58 ° C.

Example of resin production (2)
To 1000 parts of the hyperbranched polymer (A1), 2010 parts of abietic acid and 30 parts of PTS were added and reacted at 230 ° C. in a nitrogen atmosphere for 24 hours to obtain a hyperbranched polymer B2. The obtained hyperbranched polymer B2 had a number average molecular weight of 2,800, a weight average molecular weight of 10,100, a hydroxyl value of 25.0 mgKOH / g, an acid value of 1.4 mgKOH / g, and a glass transition temperature of 65 ° C.

Example of resin production (3)
To 102 parts of hyperbranched polymer (A1), 2102 parts of pine crystal KR-85 and 30 parts of PTS were added and reacted at 230 ° C. in a nitrogen atmosphere for 24 hours. Then, it cooled to 220 degreeC under nitrogen stream, 90 parts of trimellitic anhydride was thrown in, and it reacted for 30 minutes, and obtained hyperbranched polymer B3. The obtained hyperbranched polymer B3 had a number average molecular weight of 3,100, a weight average molecular weight of 14,300, a hydroxyl value of 21.0 mgKOH / g, an acid value of 11.2 mgKOH / g, and a glass transition temperature of 64 ° C.

Example of resin production (4)
Synthesis of hyperbranched polymer A2 In a reaction kettle equipped with a partial condenser, a thermometer, and a stirring rod, 136 parts of pentaerythritol, 4144 parts of dimethylolbutanoic acid, and 21 parts of PTS were charged and stirred at 100 ° C. to obtain a uniform liquid mixed melt. did. Subsequently, 100 parts of toluene was injected, the temperature was raised to 140 ° C., and water generated while refluxing toluene was distilled out of the system by azeotropic distillation. After the reaction was continued for 5 hours under the same conditions, toluene was distilled out of the system to obtain a hyperbranched polymer A2 (to be a core). The number average molecular weight of the obtained polycondensate was 2,300, the weight average molecular weight was 3,500, the hydroxyl value was 494.0 mgKOH / g, the acid value was 0.7 mgKOH / g, and the glass transition temperature was 40 ° C.

  Next, 1390 parts of Shiroiku rosin (manufactured by Arakawa Chemical Industries) and 30 parts of paratoluenesulfonic acid were added to 1000 parts of this hyperbranched polymer (A2), and the water was distilled off at 230 ° C. for 24 hours under a nitrogen atmosphere. Reacted. Then, it cooled to 170 degreeC, 100 parts of 5-sodium isophthalic acid dimethyl ester was injected | thrown-in, and it reacted at 220 degreeC for 6 hours, and obtained hyperbranched polymer B4. The obtained hyperbranched polymer B4 has a number average molecular weight of 4200, a weight average molecular weight of 59000, a hydroxyl value of 25.0 mgKOH / g, an acid value of 1.7 mgKOH / g, a sulfonic acid metal base concentration of 140 eq / ton, and a glass transition. The temperature was 66 ° C.

Example of resin production (5)
Synthesis of Hyperbranched Polymer A3 A reaction kettle equipped with a partial condenser, a thermometer, and a stirring rod was charged with 136 parts of pentaerythritol, 8880 parts of dimethylolbutanoic acid and 21 parts of PTS, and stirred at 100 ° C. to obtain a uniform liquid mixed melt. did. Subsequently, 100 parts of toluene was injected, the temperature was raised to 140 ° C., and water generated while refluxing toluene was distilled out of the system by azeotropic distillation. After continuing the reaction for 5 hours under the same conditions, toluene was distilled out of the system to obtain a hyperbranched polymer A3 (which becomes a core). The number average molecular weight of the obtained polycondensate was 2,800, the weight average molecular weight was 5,100, the hydroxyl value was 484.0 mgKOH / g, the acid value was 0.7 mgKOH / g, and the glass transition temperature was 43 ° C.

  Next, 2300 parts of abietic acid and 30 parts of paratoluenesulfonic acid were added to 1000 parts of the hyperbranched polymer (A3), and reacted at 230 ° C. in a nitrogen atmosphere for 24 hours to obtain a hyperbranched polymer B5. The obtained hyperbranched polymer B5 had a number average molecular weight of 2500, a weight average molecular weight of 8,600, a hydroxyl value of 15.2 mgKOH / g, an acid value of 1.1 mgKOH / g, and a glass transition temperature of 78 ° C.

Example of resin production (6)
A reaction vessel equipped with a stirrer, condenser and thermometer is charged with 318 parts of terephthalic acid, 318 parts of isophthalic acid, 7.7 parts of trimellitic anhydride, 447 parts of ethylene glycol, 70 parts of 2-methyl-1,3-propanediol. Then, an esterification reaction was carried out from 160 ° C. to 230 ° C. over 3 hours under a nitrogen atmosphere. After releasing the pressure, 0.42 part of tetrabutyl titanate was charged, and then the pressure inside the system was gradually reduced to 5 mmHg over 20 minutes, and then the pressure was reduced to 260 ° C. for 40 minutes under a vacuum of 0.3 mmHg or less. A condensation reaction was performed. The mixture was cooled to 220 ° C. under a nitrogen stream, 4 parts of trimellitic anhydride was added, and the reaction was performed for 30 minutes. Polyester resin B6 obtained had a number average molecular weight of 9000, a weight average molecular weight of 21,000, a hydroxyl value of 10.5 mgKOH / g, an acid value of 18.0 mgKOH / g, and a glass transition temperature of 55 ° C.

Example of resin production (7)
In a reaction vessel equipped with a stirrer, condenser and thermometer, 330 parts of terephthalic acid, 330 parts of isophthalic acid, 7.7 parts of trimellitic anhydride, 322 parts of ethylene glycol, 1300 parts of propylene oxide adduct of bisphenol A, and nitrogen The esterification reaction was carried out from 160 ° C. to 230 ° C. over 3 hours under an atmosphere. After releasing the pressure, 0.42 part of tetrabutyl titanate was charged, and then the pressure inside the system was gradually reduced to 5 mmHg over 20 minutes, and then the pressure was reduced to 260 ° C. for 40 minutes under a vacuum of 0.3 mmHg or less. A condensation reaction was performed. Polyester resin B7 obtained had a number average molecular weight of 3,100, a weight average molecular weight of 9,900, a hydroxyl value of 18.5 mgKOH / g, an acid value of 12.0 mgKOH / g, and a glass transition temperature of 56 ° C.

Example of resin production (8)
Into a reaction vessel equipped with a stirrer, condenser and thermometer, 325 parts of terephthalic acid, 325 parts of isophthalic acid, 15.4 parts of trimellitic anhydride, 322 parts of ethylene glycol, 1300 parts of propylene oxide adduct of bisphenol A and nitrogen The esterification reaction was carried out from 160 ° C. to 230 ° C. over 3 hours under an atmosphere. After releasing the pressure, 0.2 part of tetrabutyl titanate was charged, and then the pressure inside the system was gradually reduced to 5 mmHg over 20 minutes, and then the pressure was reduced to 260 ° C. for 40 minutes under a vacuum of 0.3 mmHg or less. A condensation reaction was performed. The obtained polyester resin C1 had a number average molecular weight of 4,400, a weight average molecular weight of 14,900, a hydroxyl value of 17.5 mgKOH / g, an acid value of 15.0 mgKOH / g, and a glass transition temperature of 58 ° C.

[Example 1]
After adding 20 parts by weight of a pigment TonerMagenta 6B (Clariant) as a colorant to 100 parts by weight of the resin B1, the mixture is thoroughly mixed with a Henschel mixer, and then a continuous two-roll kneader (Mitsui Mine Co., Ltd.). Kneaded. This kneaded product was roughly pulverized to a diameter of about 2 mm with a pulverizer (manufactured by Hosokawa Micron Corporation) to obtain a master batch BM1. 30 parts by weight of the obtained master batch, 76 parts by weight of the above-described polyester resin C1, 1 part by weight of Bontron E-81 (manufactured by Orient Chemical Co., Ltd.) as CCA, and carnauba wax (Japan) as a release agent 1 part by weight of Wax Co.) was added, mixed thoroughly with a Henschel mixer, melt-kneaded with a twin screw extruder (manufactured by Toshiba Machine Co., Ltd.), cooled to room temperature (25 ° C), pulverized and classified This was pulverized and classified by a machine (manufactured by Hosokawa Micron Co., Ltd.) to produce mother particles having a weight D50 of 8 μm. To 100 parts by weight of the base particles, 1.0 part by weight of silica RX200 (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed with a Henschel mixer to obtain toner BMT1 of Example 1.

[Examples 2 to 5]
In Example 1, instead of using hyperbranched polymer B1, hyperbranched polymers B2 to B5 were used, respectively, and pigment master batches BM2 to BM5 and toner particles BMT2 to BMT5 were obtained in the same manner.

  A solution containing 22 parts by weight of hyperbranched polymer B1 and 160 parts by weight of methyl ethyl ketone was sufficiently dissolved, 28 parts by weight of carbon black and 300 parts by weight of zirconia beads were added thereto, and a paint shaker was shaken for 12 hours. The zirconia beads were removed with a mesh to obtain a pigment master batch BM6. Next, in a polymerization vessel equipped with a mechanical stirrer and an introduction tube for nitrogen bubbling, 94 parts by weight of polymethyl vinyl ether, 800 parts by weight of ethanol, 90 parts by weight of styrene, 20 parts by weight of n-butyl acrylate, 2, A mixture of 6 parts by weight of 2′-azobisisobutyronitrile was sufficiently dissolved. While stirring this, 70 parts by weight of pigment master batch BM6 was gradually added to form a polymerization reaction system. While maintaining the polymerization reaction system at 20 ° C., nitrogen was bubbled into the liquid until the amount of dissolved oxygen in the polymerization reaction system reached 0.1 mg / liter. This was heated to 75 ° C. and polymerized with stirring for 12 hours. Nitrogen bubbling was continued during the polymerization. After completion of the reaction, the mixture was cooled to 20 ° C. while stirring, and the toner particle dispersion was recovered by decantation. While maintaining the temperature at 20 ° C. to 22 ° C., the toner particle dispersion was washed with methanol and solid-liquid separation was repeated five times. And dried to obtain black toner particles BMT6.

[Comparative Example 1]
After adding 20 parts by weight of a pigment TonerMagenta 6B (manufactured by Clariant) as a colorant to 100 parts by weight of the above-described polyester resin B6, the mixture is thoroughly mixed with a Henschel mixer, and then a continuous two-roll kneader (manufactured by Mitsui Mining Co., Ltd.) ). This kneaded product was coarsely pulverized to a diameter of about 2 mm with a pulverizer (manufactured by Hosokawa Micron Corporation) to obtain a master batch BM7. 30 parts by weight of the obtained master batch, 76 parts by weight of the above-described polyester resin C1, 1 part by weight of Bontron E-81 (manufactured by Orient Chemical Co., Ltd.) as CCA, and carnauba wax (Japan) as a release agent 1 part by weight of Wax Co., Ltd. was added, mixed thoroughly with a Henschel mixer, melt kneaded with a twin screw extruder (Toshiba Machine Co., Ltd.), cooled to room temperature (25 ° C), and then pulverized -Crushing and classification with a classifier (manufactured by Hosokawa Micron Corporation) to produce mother particles with a weight D50 of 14.8 μm. To 100 parts by weight of the mother particles, 1.0 part by weight of silica RX200 (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed with a Henschel mixer to obtain toner BMT7 of Comparative Example 1.

[Comparative Example 2]
In Comparative Example 1, pigment master batch BM8 and toner particles BMT8 were obtained in the same manner using polyester resin B7 instead of polyester resin B6.

[Comparative Example 3]
A solution containing 22 parts by weight of polyester resin B6 and 160 parts by weight of methyl ethyl ketone was sufficiently dissolved, 28 parts by weight of carbon black and 300 parts by weight of zirconia beads were added thereto, and a paint shaker was shaken for 12 hours. The zirconia beads were removed with a mesh to obtain a pigment master batch BM9. Next, in a polymerization vessel equipped with a mechanical stirrer and an introduction tube for nitrogen bubbling, 94 parts by weight of polymethyl vinyl ether, 800 parts by weight of ethanol, 90 parts by weight of styrene, 20 parts by weight of n-butyl acrylate, 2, A mixture of 6 parts by weight of 2′-azobisisobutyronitrile was sufficiently dissolved. While stirring this, 70 parts by weight of pigment master batch BM9 was gradually added to form a polymerization reaction system. While maintaining the polymerization reaction system at 20 ° C., nitrogen was bubbled into the liquid until the amount of dissolved oxygen in the polymerization reaction system reached 0.1 mg / liter. This was heated to 75 ° C. and polymerized with stirring for 12 hours. Nitrogen bubbling was continued during the polymerization. After completion of the reaction, the mixture was cooled to 20 ° C. while stirring, and the toner particle dispersion was recovered by decantation. While maintaining the temperature at 20 ° C. to 22 ° C., the toner particle dispersion was washed with methanol and solid-liquid separation was repeated 5 times. It was returned and dried to obtain black toner particles BMT9.

(Manufacture of binder type carrier)
In order to use the toners obtained in the above Examples and Comparative Examples as a two-component developer for evaluation, binder type carriers were produced.
100 parts by mass of a polyester resin, 700 parts by mass of magnetic particles (magnetite; EPT-1000: manufactured by Toda Kogyo Co., Ltd.) and 2 parts by mass of carbon black (Mogal L; manufactured by Cabot) are sufficiently mixed with a Henschel mixer and biaxial extrusion kneading. The cylinder part was set at 180 ° C. and the cylinder head part at 170 ° C., and melt kneaded. The kneaded product was cooled, then coarsely pulverized with a hammer mill, finely pulverized with a jet pulverizer, and classified to obtain a binder-type carrier having a volume average particle size of 40 μm.

[Evaluation methods]
In Examples, pigment master batch characteristics and toner characteristics were measured as follows.

(Pigment master batch property evaluation method)
The pigment master batch was dissolved in tetrahydrofuran (THF) at a concentration of 10%, an appropriate amount was dropped onto the preparation, and the pigment master batch was observed and evaluated by a transmission electron microscope image while being covered with a cover glass so that the solvent was not evaporated.
◎: No aggregate ○: There is a little aggregate (no problem in quality)
Δ: Agglomerates (problems in quality)
×: Many aggregates

(Toner characteristics evaluation method)
Volume average particle diameter The volume average particle diameter was measured using a Coulter Counter LS13 320 (manufactured by Beckman).

Heat Resistance 10 g of toner was allowed to stand at a high temperature of 50 ° C. for 24 hours, and then the toner was visually observed and evaluated.
○: No aggregates were observed Δ: Less than 10 aggregates were present ×: 10 or more aggregates were present

  In the following evaluation, a developer obtained by mixing toner and carrier so that the toner concentration becomes 6% by mass was used.

Charging environment stability Blow off the charge amount of the developer stored for 24 hours in a low temperature and low humidity environment (10 ° C, 15%) and the charge amount of the developer stored for 24 hours in a high temperature and high humidity environment (30 ° C, 85%) The charging environment stability was evaluated by the difference between these measured values.
○: Absolute value of difference is 7 μC / g or less ×: Absolute value of difference exceeds 7 μC / g

The degree of coloration was fixed on white paper in the form of a single color image density of 1.0 mg / cm ² and the fixing temperature of 160 ° C., and the degree of coloration was measured with a Macbeth densitometer (RD-514). The greater the value, the greater the degree of coloring.

Fixability Fixability was evaluated comprehensively from the evaluation results of peel resistance and offset resistance.
○: The result of all items was “◎” or “○” △: “△” was included in addition to “◎” or “○” ×: At least one “×” was included The

Peel resistance With a digital copying machine (DIALTA Di350; manufactured by Minolta Co., Ltd.) equipped with an oil-less fixing device while changing the fixing temperature in the range of 80 to 130 ° C. in increments of 2 ° C., 1.5 cm × 1.5 cm A solid image (attachment amount 2.0 mg / cm ² ) was taken, each image was folded in half from the middle, and the peel resistance of the image was visually evaluated. The temperature between the fixing temperature when the image was slightly peeled off and the lower fixing temperature at which the image was not peeled at all was defined as the fixing lower limit temperature.
A: Fixing lower limit temperature was less than 102 ° C. ○: Fixing lower limit temperature was 102 ° C. or more and less than 106 ° C. Δ: Fixing lower limit temperature was 106 ° C. or more and less than 112 ° C. ×: Fixing lower limit temperature was It was 112 ° C or higher.

Offset resistance Offset the digital copier (DIALTA Di350; manufactured by Minolta) by 1/2 and take a halftone image while changing the fixing temperature in the range of 90 ° C to 150 ° C in 5 ° C increments. This state was visually observed to evaluate the temperature at which high temperature offset occurs (offset temperature).
A: Offset temperature was 128 ° C. or higher. ○: Offset temperature was 120 ° C. or higher and lower than 128 ° C. Δ: Offset temperature was 115 ° C. or higher and lower than 120 ° C. ×: Offset temperature was lower than 115 ° C. there were.

Stress Resistance Stress resistance was evaluated by the presence or absence of a phenomenon in which crushed or worn toner particles adhere to the surface of the organic photoconductor in a thin layer due to continuous use of the toner.

  Table 1 shows the physical properties of the toners of Examples 1 to 6 and Comparative Examples 1 to 5.

  From Table 1, it can be seen that the hyperbranched polymer pigment masterbatch of the present invention has very good pigment dispersibility, and that the toner using the hyperbranched polymer pigment masterbatch is particularly excellent in colorability, heat resistance and fixability.

The pigment master batch of the present invention can provide a pigment master batch having extremely excellent pigment dispersibility by using a hyperbranched polymer as a resin. In addition, the hyperbranched polymer has low intermolecular interaction, so the viscosity is low, the pigment concentration can be increased, kneading in a short share and in a short time is possible, and the production efficiency can be greatly improved. . Furthermore, since it uses a hyperbranched polymer that is less dependent on the environment and excellent in resin strength and handling properties, it is extremely useful for toner applications.

Claims (7)

The number average molecular weight is 1000-60000,
The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 15,
The glass transition temperature is 30 ° C. or higher,
The hydroxyl value is from 1 to 510 mg KOH / g,
A hyperbranched polymer having an ester bond in a core portion and further modified with rosins . The number average molecular weight is 1000-60000,
The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 15,
The glass transition temperature is 30 ° C. or higher,
The hydroxyl value is from 1 to 510 mg KOH / g,
A hyperbranched polymer having an ester bond in a core part and further modified with abietic acid and / or hydrogenated abietic acid .   A hyperbranched polymer obtained by adding an acid anhydride to a terminal hydroxyl group of the hyperbranched polymer according to claim 1 or 2.   A hyperbranched polymer obtained by copolymerizing a compound having a sulfonic acid metal base copolymerizable with a terminal functional group of the hyperbranched polymer according to claim 1 or 2.   The hyperbranched polymer according to any one of claims 1 to 4, which has an acid value of 1 to 70 mgKOH / g. A pigment masterbatch comprising at least a pigment and the hyperbranched polymer according to any one of claims 1 to 5 . A toner produced using the pigment master batch according to claim 6 .