JP2008102239A - Toner for electrostatic charge image development - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development which avoids an offset phenomenon and a winding phenomenon in a wide temperature range, that is, excels in fixing properties. <P>SOLUTION: The toner for electrostatic charge image development includes at least a binder resin, a colorant and a butene polymer, wherein the butene polymer is preferably (1) a 1-butene homopolymer and preferably has (2) a melting point Tm(°C) by DSC of 60-80°C and (3) an intrinsic viscosity [η] of 0.3-0.5 dl/g as measured in a tetralin solvent at 135°C. A content of the butene polymer in all the toner is preferably 0.1-30 wt.%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner used in electrophotography, electrostatic recording method and the like.

  In general, an image forming apparatus such as an electrophotographic copying machine or printer forms a latent image on a photoconductive photoconductor, and the latent image forms a carrier or a charging member constituting a part of a developing device. Insulating toner that has obtained triboelectric charge by friction is electrostatically attached and developed, and then the formed toner image is transferred to a transfer medium such as plain paper or film, and then heated, pressurized, solvent vapor, etc. The basic principle is to form a copy image or a print image by fixing by the above method.

In such an image forming apparatus, as a method for fixing toner, a thermal roll fixing method is generally used because of high thermal efficiency and high-speed fixing. This system fixes toner by bringing a transfer sheet into contact with a heating roll in a fixing machine having a heating roller. However, this method has a problem that a part of the toner adheres to the surface of the heating roll at the time of fixing, so that the toner re-transfers onto the transfer paper and stains the subsequent image, so-called offset phenomenon occurs. . Further, this method has a problem that a so-called winding phenomenon occurs in which the transfer paper is wound around the surface of the heating roll and becomes jammed. Such a phenomenon tends to occur when the viscoelasticity of the toner melted by the heating roll is not appropriate and the balance between the viscosity and elasticity of the toner is not appropriate. The viscoelastic properties of the toner are determined by the type of binder resin that is the main component of the toner and the type and content of other components. In particular, in the case of full-color image formation, the toner layer thickness is usually larger than in the case of mono-color image formation because an image is formed by overlapping toners of four colors of yellow, magenta, cyan, and black. The phenomenon and the wrapping phenomenon are more likely to occur, and it is necessary to further improve the toner release property.

  As the binder resin, which is the main component of the toner, styrene-acrylic resins and polyester resins are generally used. Recently, alicyclic olefin resins (cycloolefin resins) have been studied. . Cycloaliphatic olefin resins are colorless and transparent, have good thermal properties (low-temperature fixing and high-speed fixing properties), sharp molecular weight distribution, good grindability (high productivity, sharp particle size distribution), low water absorption, Since it has various excellent properties such as pollution-free, it is expected as a binder resin to replace styrene-acrylic resins and polyester resins. However, since the alicyclic olefin resin generally has a narrow molecular weight distribution, there is a problem that an offset phenomenon and a winding phenomenon are likely to occur at the time of fixing the toner, and the fixing characteristics are not sufficient.

  As a method for preventing the occurrence of an offset phenomenon and a winding phenomenon and improving the fixing characteristics, a method of introducing a release agent such as a low molecular weight wax into the toner has been conventionally used (for example, patents). Reference 1). However, in this method, the toner particles are easily fused to each other or the toner is easily fused to the charging member constituting the developing machine. There is a risk. Further, in this method, it is not easy to uniformly disperse and finely disperse the release agent in the binder resin at the time of toner production, and if this dispersibility is low, the anti-fusing property deteriorates. Cheap. The above problems are more likely to occur as the amount of release agent introduced increases. Therefore, it is difficult to improve the fixing characteristics such as the offset phenomenon and the winding phenomenon without reducing the characteristics such as anti-fusing property only by introducing the release agent.

JP 2003-114546 A

  An object of the present invention is to provide a toner for developing an electrostatic charge image that does not cause an offset phenomenon and a winding phenomenon in a wide temperature range, that is, has excellent fixing characteristics.

  The present invention has solved the above problems by the following technical configuration.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have melt-kneaded a binder resin, a butene polymer, and a colorant, and pulverized and classified the melt-kneaded product. At the time of toner fixing, the inventors have found that the temperature range in which the offset phenomenon and the winding phenomenon do not occur is widened, the toner has improved fusing resistance, and a good toner image can be formed, and the present invention has been completed. That is, the electrostatic image developing toner of the present invention (hereinafter also referred to as toner) contains at least a binder resin, a colorant, and a butene polymer (Claim 1), and the butene polymer (1). ) 1-butene homopolymer, (2) In DSC, melting point Tm (° C.) is 60 ° C. to 80 ° C. (3) Intrinsic viscosity [η] measured in tetralin solvent at 135 ° C. is 0.3 to It is preferably 0.5 dl / g (Claim 2), and the butene polymer content is preferably 0.1% by weight to 30% by weight (Claim 3). In the present invention, the binder resin preferably contains an alicyclic olefin-based resin (Claim 4). In this case, the alicyclic olefin-based resin contains a cyclic olefin and an acyclic unsaturated monomer. It is preferable that the copolymer is a structural unit (Claim 5), and the acyclic unsaturated monomer is preferably an olefin monomer (Claim 6). Further, the toner of the present invention is preferably a non-magnetic one-component developing toner (Claim 7), and is preferably used as a full-color toner (Claim 8).

According to the present invention, it is possible to provide an electrostatic image developing toner that does not cause an offset phenomenon and a winding phenomenon in a wide temperature range, that is, has excellent fixing characteristics.
That is, since it contains a butene-based polymer, viscoelastic characteristics are appropriate when the toner is melted, and an offset phenomenon and a winding phenomenon are unlikely to occur. Further, since this butene polymer has a high melt viscosity for a low melting point, the toner of the present invention has a wide non-offset temperature region in a high temperature region.

  The toner of the present invention is composed of a binder resin, a colorant, and a butene polymer. These will be described in detail below.

<Butene polymer>
The butene homopolymer used in the present invention preferably satisfies the following requirements (a) to (c).
(A) 1-butene homopolymer (b) In DSC, melting point Tm (° C.) is 60 ° C. to 80 ° C.
(C) Intrinsic viscosity [η] measured at 135 ° C. in a tetralin solvent is 0.3 to 0.5 dl / g

  In the case of not being a 1-butene homopolymer, for example, in the case of an olefin polymer obtained by copolymerizing ethylene or propylene with 1-butene, which is known as a polymer having relatively low molecular weight or crystallinity, the molecular weight distribution In addition, since the composition distribution is wide, the uniformity is not preferable.

  The melting point by DSC of the butene polymer Tm (° C.) is preferably 60 ° C. to 80 ° C., more preferably 60 ° C. to 70 ° C. If the melting point is less than 60 ° C, a problem may occur in storage stability and the toner may be hardened. If the melting point exceeds 80 ° C, the low-temperature fixability deteriorates.

  The intrinsic viscosity [η] measured at 135 ° C. in the tetralin solvent of the butene polymer is preferably 0.3 to 0.5 dl / g, more preferably 0.3 to 0.4 dl / g. When the intrinsic viscosity is less than 0.3 dl / g, the strength is lowered and the binding performance is not exhibited. If it exceeds 0.5 dl / g, the fluidity is lowered and the fixing property is deteriorated.

The 1-butene homopolymer can be produced with a magnesium-supported titanium catalyst, but it is preferable to use a metallocene catalyst because it is difficult to control crystallinity. By using a metallocene catalyst, a 1-butene homopolymer having a uniform composition and a relatively low molecular weight can be obtained.
The content of the butene polymer is preferably 0.1% by weight to 30% by weight in the total toner, more preferably 1 to 20% by weight, and still more preferably 1 to 10% by weight.

Hereinafter, the binder resin and the colorant constituting the toner of the present invention will be described.
<Binder resin>
As the binder resin in the present invention, a polyester resin, a styrene- (meth) acrylic acid copolymer resin, a thermoplastic elastomer, a styrene resin, a (meth) acrylic resin, an olefin resin (for example, polyethylene, Α-olefin resins such as polypropylene), vinyl resins (for example, polyvinyl chloride, polyvinylidene chloride, etc.), polyamide resins, polyether resins, urethane resins, epoxy resins, polyphenylene oxide resins, terpene phenols Examples thereof include resins, polylactic acid resins, hydrogenated rosins, cyclized rubbers, and alicyclic olefin resins. These can be used alone or in combination of two or more. Here, (meth) acrylic acid means acrylic acid and / or methacrylic acid.
Among these, binder resins containing any of polyester resins, styrene- (meth) acrylic acid copolymer resins, and alicyclic olefin resins (cycloolefin resins) are preferably used.

  Of these, polyester resins and styrene- (meth) acrylic acid copolymer resins are generally used. Recently, alicyclic olefin resins (cycloolefin resins) have been studied as binder resins. Has been. Cycloaliphatic olefin resins are colorless and transparent, have good thermal properties (low-temperature fixing and high-speed fixing properties), sharp molecular weight distribution, good grindability (high productivity, sharp particle size distribution), low water absorption, Since it has various excellent properties such as pollution-free, it is expected as a binder resin to replace polyester resins and styrene- (meth) acrylic acid copolymer resins.

First, the alicyclic olefin-based resin will be described.
Cycloaliphatic olefin resins are colorless and transparent, have good thermal properties (low-temperature fixing and high-speed fixing properties), sharp molecular weight distribution, good grindability (high productivity, sharp particle size distribution), low water absorption, It has various excellent characteristics such as pollution-free.

The alicyclic olefin-based resin contains at least one kind of cyclic olefin, and the following polymers (a), (b), (c) and the like can be exemplified.
(A) Homopolymer composed of one type of cyclic olefin (b) Copolymer composed of two or more types of cyclic olefin (c) Consists of a cyclic olefin and an acyclic unsaturated monomer Examples of cyclic olefins include, for example, monocyclic olefins such as cyclobutene, cyclopentene, cyclohexene, cycloheptene, and cyclooctene or derivatives thereof, and cyclic such as cyclopentadiene, cyclohexadiene, cycloheptadiene, and cyclooctadiene. Conjugated dienes or derivatives thereof, polycyclic olefins such as norbornene, dicyclopentadiene, tricyclodecene, tetracyclododecene, hexacycloheptadecene, or derivatives thereof, vinyl cyclobutane, vinyl cyclobutene, vinyl cyclopentane, vinyl cyclopent Aromatic rings of vinyl alicyclic hydrocarbons such as styrene, vinylcyclohexane, vinylcyclohexene, vinylcycloheptane, vinylcycloheptene, vinylcyclooctane, vinylcyclooctene or their derivatives, vinyl aromatic monomers such as styrene Examples thereof include cyclic and / or polycyclic olefinic compounds having at least one double bond, such as a partial hydride or a derivative thereof. These cyclic olefins can be used alone or in combination of two or more. Examples of the derivatives include alkyl-substituted products, alkylidene-substituted products, alkoxy-substituted products, acyl-substituted products, halogen-substituted products, and carboxyl-substituted products. The number of carbon atoms constituting the alicyclic structure is usually 4 to 30, preferably 5 to 20, and more preferably about 5 to 15 from the viewpoints of material dispersibility and transparency.

The alicyclic olefin-based resin may be (a) a homopolymer having one type of cyclic olefin as a structural unit, and (b) a copolymer having two or more types of cyclic olefin as a structural unit. (C) A copolymer having a cyclic olefin and an acyclic unsaturated monomer as constituent units is preferable from the viewpoint of grindability, processability, mechanical properties, and the like.
The acyclic unsaturated monomer is not particularly limited as long as it is a non-cyclic unsaturated monomer copolymerizable with a cyclic olefin, but is an olefin monomer; a (meth) acrylic acid monomer; (Meth) acrylic acid ester monomers including (meth) acrylic acid C _1-6 alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate; vinyl acetate, propionic acid Examples thereof include vinylated ester monomers such as vinyl; vinyl cyanide monomers such as (meth) acrylonitrile; diene monomers such as butadiene, 1,4-pentadiene and isoprene. These acyclic unsaturated monomers may be used alone or in combination of two or more. The acyclic unsaturated monomer is preferably an olefin monomer from the viewpoint of imparting flexibility to the toner.
Examples of the olefin monomer include α-C _2-10 olefins (preferably α-C ₂ -2) such as ethylene, propylene, 1-butylene, 1-pentene, 1-hexene, 1-heptene, 1-octene and the like. _6- olefins, more preferably α-C _2-4 olefins), branched olefins such as isobutene and isoprene. These olefinic monomers may be used alone or in combination of two or more. Of these olefinic monomers, ethylene and propylene are particularly preferable.
The amount used in the case of using an acyclic unsaturated monomer can be selected from the range of about 100 mol or less, preferably 90 mol or less, and more preferably about 80 mol or less with respect to 100 mol of the cyclic olefin.

  As the alicyclic olefin resin, specifically, a copolymer of ethylene or butene and norbornene (such as an ethylene-norbornene copolymer or a butene-norbornene copolymer) can be preferably used, and an unsaturated double bond can be used. It is preferably colorless and transparent and has a high light transmittance.

  The alicyclic olefin-based resin has a molecular weight content of 10 to 40% by weight measured by gel permeation chromatography and a molecular weight content of 5 to 40,000 and more, It is preferably 20% by weight. If the content of each molecular weight body is out of the above range, the material dispersibility and transparency may not be sufficient.

  The glass transition temperature of the alicyclic olefin-based resin is determined by the composition ratio of the cyclic olefin and the acyclic unsaturated monomer, and is usually about 50 to 200 ° C., and can be appropriately selected depending on the application and molding temperature. . For toner, it is 50 to 80 ° C., preferably 50 to 70 ° C., more preferably about 50 to 65 ° C. If the glass transition temperature of the alicyclic olefin-based resin is higher than 80 ° C., the fixing characteristics are deteriorated, and the rigidity and impact resistance are increased, so that the material dispersibility of the toner may not be sufficient. In this case, the fixing characteristics may be deteriorated and the anti-fusing property may be deteriorated.

Next, the polyester resin will be described.
Examples of the polyester resin include those obtained by condensation polymerization of alcohol and carboxylic acid.
Examples of the alcohol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butanediol, neopentyl glycol, 1,4 Diols such as butenediol; 1,4-bis (hydroxymethyl) cyclohexane; etherified bisphenols such as bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A; Valent alcohol monomer. These alcohols may be used alone or in combination of two or more.

  Examples of the carboxylic acid include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, Examples thereof include anhydrides of these acids, dimers of lower alkyl esters and linolenic acid, and other divalent organic acid monomers. These carboxylic acids may be used alone or in combination of two or more.

  The polyester resin may be not only a polymer based on only a bifunctional monomer but also a polymer containing a component based on a trifunctional or higher polyfunctional monomer. Examples of trihydric or higher polyhydric alcohol monomers that are polyfunctional monomers include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, Tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, tri Mention may be made of methylolpropane, 1,3,5-trihydroxymethylbenzene and other trihydric or higher polyhydric alcohol monomers.

Examples of the trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Carboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, these acid anhydrides, other trivalent or higher polyvalent carboxylic acid monomers Can do.
The amount of the trifunctional or higher polyfunctional monomer is 10 to 90 mol, preferably 20 to 80 mol, more preferably 30 to 80 mol, based on 100 mol of the total of the alcohol and carboxylic acid components. Can be selected as appropriate.

Next, the styrene- (meth) acrylic acid copolymer resin will be described.
As monomers for constituting the styrene- (meth) acrylic acid copolymer resin, styrene monomers and derivatives thereof, (meth) acrylic monomers, alkoxystyrene (p-methoxy) Styrene, etc.), p-phenylstyrene, halostyrene (o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc.) and derivatives thereof. These monomers can be used alone or in combination of two or more. Examples of the derivatives include alkyl-substituted products, alkylidene-substituted products, alkoxy-substituted products, acyl-substituted products, halogen-substituted products, nitro-substituted products, amino-substituted products, hydroxy-substituted products, and carboxyl-substituted products.

Examples of the (meth) acrylic acid monomer include (meth) acrylic acid, (meth) acrylic acid alkyl ester, (meth) acrylic acid aryl ester, (meth) acrylic acid C _7-12 aralkyl ester, (meth ) hydroxyalkyl acrylate, glycidyl (meth) acrylate, (meth) acrylic acid dialkylaminoalkyl, such as di-C _1-4 alkyl phosphate ethyl (meth) acrylate.
Examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate, (meth) (Meth) acrylic acid C _1-20 alkyl ester such as octyl acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, (meth) _Examples include acrylic acid C _4-10 cycloalkyl ester.
Examples of the hydroxyalkyl (meth) acrylate include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate.
Examples of dialkylaminoalkyl (meth) acrylate include dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate.
These monomers can be used alone or in combination of two or more.

  Other monomers include vinyl monomers (vinyl acetate, vinyl propionate, vinyl benzoate, etc.), unsaturated olefin monomers (ethylene, propylene, etc.), diene monomers (isoprene, butadiene, etc.) ), Unsaturated dicarboxylic acids (fumaric acid, maleic acid, itaconic acid, citraconic acid and their anhydrides), (meth) acrylonitrile monomers, (meth) acrylamide monomers, ketones (vinyl methyl ketone) And vinyl hexyl ketone) and ethers (vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc.). These other monomers are preferably contained in 30 parts by weight or less in 100 parts by weight of the styrene- (meth) acrylic acid copolymer resin. In order to adjust the acid value and charging characteristics, it is preferable to use a monomer containing a carboxyl group or an acid anhydride group such as maleic anhydride and fumaric acid.

As a preferable styrene- (meth) acrylic acid copolymer resin formed by the monomer, a polymer mainly composed of a styrene monomer unit and a (meth) acrylic acid monomer unit, for example, , Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic acid-n-butyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene _Examples thereof include styrene- (meth) acrylic acid C _1-18 alkyl ester copolymers such as methacrylic acid-n-butyl copolymer, and multipolymers such as styrene-acrylic acid ester-methacrylic acid ester.

  The content of the binder resin is preferably 40 to 95 parts by weight in the electrostatic image developing toner (100 parts by weight), and more preferably 80 to 95 parts by weight for the non-magnetic one-component development system. is there.

<Colorant>
As the colorant used in the toner of the present invention, black pigments can be used for black toners, magenta pigments, cyan pigments, yellow pigments and the like for color toners.
As the black pigment, usually carbon black can be used. Carbon black can be used without being limited by the number average particle diameter, oil absorption, PH, etc., and the following are commercially available products. For example, product name: Legal (REGAL) 400, 660, 330, 300, SRF-S, STERLING SO, V, NS, R, manufactured by Columbia Carbon Japan Co., Ltd. Product name: Raven (Raven) H20, MT-P, 410, 420, 430, 450, 500, 760, 780, 1000, 1035, 1060, 1080, manufactured by Mitsubishi Chemical Corporation Product names: # 5B, # 10B, # 40, # 2400B, MA-100 Etc. can be used. These carbon blacks can be used alone or in combination of two or more.
The proportion of carbon black in the toner of the present invention is preferably in the range of 0.1 to 20% by weight, more preferably 1 to 10% by weight, still more preferably 1 to 5% by weight (particularly preferably 1 to 3% by weight). It is. If the ratio of carbon black is too small, the image density is lowered, and if it is too much, the image quality is liable to be lowered and the dispersibility of the toner material is also lowered. As a black pigment, carbon black and black magnetic powder such as iron oxide and ferrite can be used.

Examples of the magenta pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 202, 206, 207, 209; I. Pigment violet 19; C.I. I. Butlet 1, 2, 10, 13, 15, 23, 29, 35, etc. can be used. These magenta pigments can be used alone or in combination of two or more.
Examples of cyan pigments include C.I. I. Pigment Bull-2, 3, 15, 16, 17; I. Bat Bull-6; I. Acid Bull-45 etc. can be used. These cyan pigments can be used alone or in combination of two or more.
Examples of yellow pigments include C.I. I. Pigment Yellow-1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 93, 94, 97, 155 180, etc. can be used. These yellow pigments can be used alone or in combination of two or more.
As a color pigment for full color, magenta pigment is C.I. from the viewpoint of color mixing and color reproducibility. I. Pigment Red 57 and 122 are cyan pigments such as C.I. I. Pigment Blue 15 is yellow pigment, C.I. I. Pigment Yellow 17, 93, 155, and 180 can be preferably used.
The ratio of the color pigment is preferably in the range of 1 to 20% by weight in the toner of the present invention, more preferably 3 to 10% by weight, still more preferably 4 to 9% by weight (particularly 4.5 to 8% by weight). Is preferred). If the ratio of these pigments is too small than the above range, the image density is lowered, and if it is too much, the charging stability is deteriorated and the image quality tends to be lowered. It is also disadvantageous in terms of cost.
Further, the color pigment may be a so-called master batch which is dispersed in a high concentration in a resin that can be a binder resin in advance.

  If necessary, the toner of the present invention may contain a charge control agent and waxes described below.

<Charge control agent>
The charge control agent includes a positive charge control agent and a negative charge control agent.
Examples of positively chargeable charge control agents include modified products of nigrosine and fatty acid metal salts, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, Diorganotin oxide such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide, diorganotin borate such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate, pyridium salt, azine, triphenylmethane compound and cationic functional group And low molecular weight polymers. These positively chargeable charge control agents may be used alone or in combination of two or more. As these positively chargeable charge control agents, nigrosine compounds and quaternary ammonium salts are preferably used.
Examples of negatively chargeable charge control agents include acetylacetone metal complexes, monoazo metal complexes, organometallic compounds such as naphthoic acid or salicylic acid-based metal complexes or salts, chelate compounds, and low molecular weight polymers having an anionic functional group. It is done. These negatively chargeable charge control agents can be used alone or in combination of two or more. As these negatively chargeable charge control agents, salicylic acid metal complexes and monoazo metal complexes are preferably used.
The addition amount of the charge control agent is usually preferably in the range of 0.1 to 5 parts by weight, more preferably 0.5 to 4 parts by weight, and still more preferably 1 to 4 parts by weight with respect to 100 parts by weight of the resin composition. Part. The charge control agent is preferably colorless or light color for color toners.

<Wax>
The toner of the present invention preferably contains a wax as a release agent.
Waxes include polyethylene wax, polybutene wax, polyolefin wax such as modified polyethylene wax, synthetic wax such as Fischer-Tropsch wax, petroleum wax such as paraffin wax and microcrystalline wax, carnauba wax, candelilla wax, rice wax. And hardened castor oil.
These waxes can be used alone or in combination of two or more. The wax content in the toner is preferably in the range of 0.1 to 10% by weight, more preferably 0.5 to 7% by weight, and still more preferably 1 to 5% by weight. If the amount of the wax added is too much above the above range, the fusing resistance and the toner material dispersibility deteriorate, and if it is too small, the releasability is insufficient and the fixing characteristics deteriorate.

  The toner of the present invention further includes magnetic powder, for example, metal such as cobalt, iron, nickel, aluminum, copper, iron, nickel, magnesium, tin, zinc, gold, silver, selenium, titanium, tungsten, if necessary. Zirconium, alloys of other metals, metal oxides such as aluminum oxide, iron oxide, nickel oxide, ferrite, magnetite, etc. can be used. The amount of magnetic powder added is usually preferably 1 to 70 parts by weight, more preferably 5 to 50 parts by weight, and still more preferably 10 to 40 parts by weight with respect to 100 parts by weight of the resin composition. A magnetic powder having an average particle diameter of 0.01 to 3 μm can be suitably used.

  The toner of the present invention further contains various additives as required, for example, stabilizers (for example, ultraviolet absorbers, antioxidants, thermal stabilizers, etc.), flame retardants, antifogging agents, dispersants, nucleating agents. , Plasticizers (phthalate esters, fatty acid plasticizers, phosphate plasticizers, etc.), polymer antistatic agents, low molecular antistatic agents, compatibilizers, conductive agents, fillers, fluidity improvers, etc. May be.

The toner of the present invention preferably has inorganic fine particles attached to the surface from the viewpoint of imparting fluidity. Examples of the inorganic fine particles include silica, alumina, talc, clay, calcium carbonate, magnesium carbonate, titanium oxide, carbon black powder, and magnetic powder. These inorganic fine particles may be used alone or in combination of two or more. Of these inorganic fine particles, silica can be particularly preferably used.
Silica is not particularly limited, such as an average particle diameter, a BET specific surface area, and a surface treatment, and can be appropriately selected according to the use, but the BET specific surface area is preferably in the range of 50 to 400 m ² / g, and the surface-treated hydrophobic Silica is preferred.

  In addition to the inorganic fine particles, a fine resin powder such as polytetrafluoroethylene resin powder, polyvinylidene fluoride resin powder, acrylic resin powder, and styrene-acrylic resin powder may be further adhered to the toner of the present invention. Good. The ratio of adding these inorganic fine particles and resin fine powder to the toner is preferably in the range of 0.01 to 8 parts by weight, more preferably 0.1 to 5 parts by weight, even more preferably 100 parts by weight of the toner. Is 0.1 to 4 parts by weight (particularly 0.3 to 3 parts by weight). When the ratio of addition is out of the above range, the fluidity and charging stability of the toner are lowered, and it is difficult to form a uniform image.

  The toner of the present invention is not particularly limited in use depending on the development method, and can be used in a non-magnetic one-component development method, a magnetic one-component development method, a two-component development method, and other development methods. The magnetic one-component developing system toner is used as a magnetic toner by mixing the magnetic powder in a binder resin, and the two-component developing system toner is used by mixing with a carrier. From the viewpoint of simplicity of the apparatus and cost, it is preferably used as a toner for a non-magnetic one-component development system.

  As the carrier in the two-component development system, for example, nickel, cobalt, iron oxide, ferrite, iron, glass beads and the like can be used. These carriers may be used alone or in combination of two or more. The average particle size of the carrier is preferably 20 to 150 μm. Further, the surface of the carrier may be coated with a coating agent such as a fluorine resin, an acrylic resin, or a silicone resin.

  The toner of the present invention may be a monochrome toner or a full-color toner. In particular, the toner of the present invention may be used as a full-color toner that tends to cause an offset phenomenon or a wrapping phenomenon due to color superposition of four colors. preferable. In the monochrome toner, as the colorant, the non-magnetic toner can be the carbon black, the magnetic toner can be the carbon black, and the magnetic powder can be black. In the full-color toner, the color pigment can be used as a colorant.

Next, a method for producing the toner of the present invention will be described.
First, a butene polymer is prepared.
[Preparation of butene polymer]
For the production of a butene polymer, a method described in WO / 2003/070788 can be used.
For example, butene monomers such as 1-butene, heptane, triisobutylaluminum, methylaluminoxane, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium A butene polymer can be obtained by forming a polymerization catalyst by adding dichloride or the like and allowing the butene monomer to polymerize. The butene monomer is preferably purified by distillation before use.
[Production of toner]
The method for producing the toner of the present invention is not particularly limited. Usually, a binder resin, a colorant, a butene polymer, and other additives as necessary are dry-mixed and hot-melt kneaded to produce a melt-kneaded product. Then, the melt-kneaded product can be pulverized and classified to obtain a toner having a desired particle size and particle shape.
As a dry mixing method, a method using a stirrer such as a Henschel mixer, a super mixer, or a ribbon mixer can be used.
Various methods such as a method using a twin screw extruder, a method using a Banbury mixer, a method using a pressure roller, and a method using a pressure kneader can be used as the method of hot melt kneading. As the hot melt kneading method, a method using a twin screw extruder is preferable from the viewpoint of material dispersibility and versatility. In the method using a twin-screw extruder, a melt-kneaded product can be obtained by melt-kneading a binder resin, a colorant, and other additives dry-mixed with a twin-screw extruder and extruding from the tip. The kneading temperature of the twin screw extruder is 50 to 220 ° C, preferably about 70 to 200 ° C.
As a pulverization method, a pulverization method using a pulverizer such as a hammer mill, a cutter mill or a jet mill can be used.
Moreover, as a classification method, a method using an airflow classifier such as a dry centrifugal classifier can be usually used.
The volume average particle diameter of the toner thus obtained is usually about 5 to 10 μm, preferably 6 to 9 μm. The volume average particle diameter is a 50% volume diameter measured using a particle size distribution measuring apparatus (Multisizer II, manufactured by Beckman Coulter, Inc.).
Further, the above-described inorganic fine particles and resin fine powder may be adhered to the toner surface by stirring using a stirrer such as a turbine stirrer, a Henschel mixer, or a super mixer.
As a method for producing the toner, a method of obtaining a toner having a desired particle size and shape while polymerizing the binder resin can be used.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

<Example 1>
[Preparation of butene polymer]
To a heat-dried 10 liter autoclave, 4 liters of heptane, 4 liters of 1-butene, 4.0 mmol of triisobutylaluminum and 15 mmol of methylaluminoxane were added, and 0.4 MPa of hydrogen was further introduced.
After the temperature was raised to 70 ° C. with stirring, 15 μmol of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium dichloride was added and polymerized for 120 minutes.
After completion of the polymerization reaction, the reaction product was dried under reduced pressure to obtain 1.5 kg of a 1-butene polymer, which is a butene polymer.
The obtained 1-butene polymer had a melting point (Tm) of 70 ° C. and an intrinsic viscosity [η] of 0.39 dl / g.
The melting point (Tm) is determined by DSC measurement. That is, a melting endotherm curve obtained by using a differential scanning calorimeter (Perkin Elmer, DSC-7), holding the sample at 0 ° C. for 3 minutes, and then raising the temperature at 10 ° C./min. The peak top of the highest peak is the melting point (Tm).
The intrinsic viscosity [η] was measured at 135 ° C. in a tetralin solvent using a VMR-053 type automatic viscometer manufactured by Kosei Co., Ltd.
[Production of toner]
Binder resin A (St / Ac): 86% by weight of styrene-acrylic acid copolymer resin
(Mitsui Chemicals, trade name: CPR120)
1-butene polymer 5% by weight
PIG: Cyan pigment for toner C.I. I. Pigment Blue 15 5% by weight
(Clariant Japan Co., Ltd., product name: Hostaperm Blue B2G)
CCA: Zinc salt charge control agent 2% by weight
(Orient Chemical Industry Co., Ltd., trade name: BONTRON E-84)
WAX: Carnauba wax 2% by weight
(Kato Yokosha, trade name: Carnauba wax No. 2 powder)
The above raw materials are dry-mixed for 20 minutes with a super mixer, and using a twin-screw kneading extruder (PCM-30, manufactured by Ikegai Co., Ltd.), the temperature is 120 ° C. to 160 ° C., the discharge rate is 3.5 kg / hr, and the rotational speed. Melt kneading was performed at 250 rpm to obtain a plate-like melt-kneaded product having a thickness of 2 to 3 mm.
Subsequently, the melt-kneaded product was pulverized with a jet mill and then classified with a dry air classifier to obtain toner particles having a volume average particle size of 8.5 μm.
Next, 0.3 parts by weight of hydrophobic silica (RY-50, manufactured by Nippon Aerosil Co., Ltd.) having a volume average particle diameter of 40 nm and hydrophobicity having a volume average particle diameter of 10 nm are obtained with respect to the obtained toner particles. 1.0 part by weight of silica (H2000 / 4M, manufactured by Wacker Chemical Co., Ltd.) was added, and the mixture was stirred and mixed with a Henschel mixer at a peripheral speed of 40 m / sec for 10 minutes to obtain the toner of Example 1.

<Example 2>
Example 2 is the same as Example 1 except that binder resin B (Pes): polyester resin (SK Chemical Company, trade name: ET250) is used instead of binder resin A (St / Ac). A toner was obtained.

<Example 3>
Binder resin C (COC) instead of binder resin A (St / Ac): cycloaliphatic olefin resin (ethylene-norbornene copolymer, manufactured by Ticona Corporation, trade name: TOPAS COC, weight average molecular weight (Mw) : Toner of Example 3 was obtained in the same manner as in Example 1 except that 140,000, number average molecular weight (Mn): 5,000, Mw / Mn: 28) were used.

<Example 4>
A toner of Example 4 was obtained in the same manner as in Example 3 except that the binder resin C (COC) was 81% by weight and the 1-butene polymer was 10% by weight.

<Comparative Example 1>
A toner of Comparative Example 1 was obtained in the same manner as in Example 1 except that the 1-butene polymer was not used and the binder resin A (St / Ac) was 91% by weight.

<Comparative example 2>
A toner of Comparative Example 2 was obtained in the same manner as in Example 2 except that the 1-butene polymer was not used and the binder resin B (Pes) was 91% by weight.

<Comparative Example 3>
A toner of Comparative Example 3 was obtained in the same manner as in Example 3 except that the 1-butene polymer was not used and the binder resin C (COC) was 91% by weight.

<Comparative Example 4>
A toner of Comparative Example 4 was obtained in the same manner as in Example 4 except that 1-butene polymer was not used, binder resin C (COC) was 86% by weight, and WAX was 7% by weight. .

  The composition of the raw materials of Examples 1 to 4 and Comparative Examples 1 to 4 is as shown in the upper part of Tables 1 and 2.

The toners of Examples 1 to 4 and Comparative Examples 1 to 4 thus obtained were evaluated for fixing characteristics, anti-fusing resistance, and material dispersibility.
The specific evaluation method is as follows.

[Fixing characteristics]
4 parts by weight of the obtained toner and 96 parts by weight of a non-coated ferrite carrier (trade name: FL-1020, manufactured by Powdertech Co., Ltd.) were mixed to prepare a two-component developer.
Next, a belt-shaped unfixed image having a length of 3 cm and a width of 6 cm was formed on A4 transfer paper using a commercially available copying machine (SF-9800, manufactured by Sharp Corporation) using this developer. The toner adhesion amount on the transfer paper was adjusted to about 2.0 mg / cm ² depending on the toner concentration, the surface potential of the photoreceptor, the development potential, the exposure amount, the transfer conditions, and the like.
Next, a fixing machine in which a heat fixing roll whose surface layer is made of polytetrafluoroethylene and a pressure fixing roll whose surface layer is made of silicone rubber rotates in a pair, a roll pressure is 1 kgf / cm ² , The roll speed was adjusted to 125 mm / sec, and the surface temperature of the heat fixing roll was increased stepwise between 150-210 ° C. at intervals of 5 ° C., and the above-mentioned unfixed images were held at each surface temperature. The toner image on the transfer paper was fixed.
At the time of fixing, observation was made as to whether or not the transfer paper having an unfixed image was wound around the surface of the heat fixing roll, and the low temperature side winding generation temperature and the high temperature side winding generation temperature were confirmed.
At the same time, it was observed whether or not toner contamination occurred in the blank portion, and a temperature region where the contamination did not occur was defined as a non-offset temperature region.

[Fusion resistance]
The toner was put into a developing machine of a non-magnetic one-component QMS2200 type printer (Minolta QMS), and A4 originals with an image ratio of 5% were copied on A4 transfer paper to 5000 sheets. After copying 5000 sheets, it was visually confirmed whether or not toner fusion was observed on the charging member (charging blade) of the developing machine.
○: No toner fusion, ×: Toner fusion

[Material dispersibility]
In the toner production process, the cross section in the direction perpendicular to the extrusion direction of the plate-like melt-kneaded product extruded by the twin-screw extruder is observed with an optical microscope (400 times magnification), and a butene polymer, a colorant The kneadability (degree of dispersion) of each material such as wax was confirmed.
A: Each material is uniformly dispersed and finely dispersed.
○: Each material is uniformly dispersed and there is no practical problem.
X: The dispersion state of each material is not uniform.
Tables 1 and 2 show the evaluation results of fixing characteristics, fusing resistance, and material dispersibility.

[Evaluation results]
As is apparent from Tables 1 and 2, the toners of Examples 1 to 4 according to the present invention are excellent in various properties such as fixing property, anti-fusing property, and material dispersibility. Specifically, it is as follows.
As for the fixing property, the winding phenomenon can be prevented and it has a wide non-offset temperature region. There is no fusion of toner with respect to anti-fusing property. There is no practical problem with respect to material dispersibility, and in Examples 1 to 3, the dispersion of each material is particularly good.
On the other hand, the toners of Comparative Examples 1 to 3 have a lower lower limit of the non-offset temperature than the examples. Moreover, the high temperature side winding phenomenon occurred in Comparative Examples 1 and 2, and in Comparative Examples 3 and 4, the winding phenomenon occurred on both sides of the low temperature and high temperature. Further, since the toner of Comparative Example 4 had a high wax content, fusion occurred, and the dispersion of each material was not uniform.

Claims (8)

  An electrostatic image developing toner comprising at least a binder resin, a colorant, and a butene polymer. Butene polymer
(1) 1-butene homopolymer,
(2) In DSC, the melting point Tm (° C.) is 60 ° C. to 80 ° C.,
(3) The toner for developing an electrostatic image according to claim 1, wherein the intrinsic viscosity [η] measured in a tetralin solvent at 135 ° C. is 0.3 to 0.5 dl / g.   2. The electrostatic image developing toner according to claim 1, wherein the content of the butene polymer is 0.1% by weight to 30% by weight in the total toner.   The electrostatic image developing toner according to claim 1, wherein the binder resin contains an alicyclic olefin-based resin.   5. The electrostatic image developing toner according to claim 4, wherein the alicyclic olefin-based resin is a copolymer having a cyclic olefin and an acyclic unsaturated monomer as constituent units.   6. The electrostatic image developing toner according to claim 5, wherein the acyclic unsaturated monomer is an olefin monomer.   2. The electrostatic image developing toner according to claim 1, wherein the toner is a non-magnetic one-component developing toner.   2. The electrostatic image developing toner according to claim 1, wherein the toner is a full-color toner.